Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

95 files changed, 76114 insertions, 0 deletions

diff --git a/third_party/rust/naga/src/arena.rs b/third_party/rust/naga/src/arena.rs
new file mode 100644
index 0000000000..c37538667f
--- /dev/null
+++ b/third_party/rust/naga/src/arena.rs
@@ -0,0 +1,772 @@
+use std::{cmp::Ordering, fmt, hash, marker::PhantomData, num::NonZeroU32, ops};
+
+/// An unique index in the arena array that a handle points to.
+/// The "non-zero" part ensures that an `Option<Handle<T>>` has
+/// the same size and representation as `Handle<T>`.
+type Index = NonZeroU32;
+
+use crate::{FastIndexSet, Span};
+
+#[derive(Clone, Copy, Debug, thiserror::Error, PartialEq)]
+#[error("Handle {index} of {kind} is either not present, or inaccessible yet")]
+pub struct BadHandle {
+    pub kind: &'static str,
+    pub index: usize,
+}
+
+impl BadHandle {
+    fn new<T>(handle: Handle<T>) -> Self {
+        Self {
+            kind: std::any::type_name::<T>(),
+            index: handle.index(),
+        }
+    }
+}
+
+/// A strongly typed reference to an arena item.
+///
+/// A `Handle` value can be used as an index into an [`Arena`] or [`UniqueArena`].
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+#[cfg_attr(
+    any(feature = "serialize", feature = "deserialize"),
+    serde(transparent)
+)]
+#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
+pub struct Handle<T> {
+    index: Index,
+    #[cfg_attr(any(feature = "serialize", feature = "deserialize"), serde(skip))]
+    marker: PhantomData<T>,
+}
+
+impl<T> Clone for Handle<T> {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
+
+impl<T> Copy for Handle<T> {}
+
+impl<T> PartialEq for Handle<T> {
+    fn eq(&self, other: &Self) -> bool {
+        self.index == other.index
+    }
+}
+
+impl<T> Eq for Handle<T> {}
+
+impl<T> PartialOrd for Handle<T> {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl<T> Ord for Handle<T> {
+    fn cmp(&self, other: &Self) -> Ordering {
+        self.index.cmp(&other.index)
+    }
+}
+
+impl<T> fmt::Debug for Handle<T> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter, "[{}]", self.index)
+    }
+}
+
+impl<T> hash::Hash for Handle<T> {
+    fn hash<H: hash::Hasher>(&self, hasher: &mut H) {
+        self.index.hash(hasher)
+    }
+}
+
+impl<T> Handle<T> {
+    #[cfg(test)]
+    pub const DUMMY: Self = Handle {
+        index: unsafe { NonZeroU32::new_unchecked(u32::MAX) },
+        marker: PhantomData,
+    };
+
+    pub(crate) const fn new(index: Index) -> Self {
+        Handle {
+            index,
+            marker: PhantomData,
+        }
+    }
+
+    /// Returns the zero-based index of this handle.
+    pub const fn index(self) -> usize {
+        let index = self.index.get() - 1;
+        index as usize
+    }
+
+    /// Convert a `usize` index into a `Handle<T>`.
+    fn from_usize(index: usize) -> Self {
+        let handle_index = u32::try_from(index + 1)
+            .ok()
+            .and_then(Index::new)
+            .expect("Failed to insert into arena. Handle overflows");
+        Handle::new(handle_index)
+    }
+
+    /// Convert a `usize` index into a `Handle<T>`, without range checks.
+    const unsafe fn from_usize_unchecked(index: usize) -> Self {
+        Handle::new(Index::new_unchecked((index + 1) as u32))
+    }
+}
+
+/// A strongly typed range of handles.
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+#[cfg_attr(
+    any(feature = "serialize", feature = "deserialize"),
+    serde(transparent)
+)]
+#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
+pub struct Range<T> {
+    inner: ops::Range<u32>,
+    #[cfg_attr(any(feature = "serialize", feature = "deserialize"), serde(skip))]
+    marker: PhantomData<T>,
+}
+
+impl<T> Range<T> {
+    pub(crate) const fn erase_type(self) -> Range<()> {
+        let Self { inner, marker: _ } = self;
+        Range {
+            inner,
+            marker: PhantomData,
+        }
+    }
+}
+
+// NOTE: Keep this diagnostic in sync with that of [`BadHandle`].
+#[derive(Clone, Debug, thiserror::Error)]
+#[error("Handle range {range:?} of {kind} is either not present, or inaccessible yet")]
+pub struct BadRangeError {
+    // This error is used for many `Handle` types, but there's no point in making this generic, so
+    // we just flatten them all to `Handle<()>` here.
+    kind: &'static str,
+    range: Range<()>,
+}
+
+impl BadRangeError {
+    pub fn new<T>(range: Range<T>) -> Self {
+        Self {
+            kind: std::any::type_name::<T>(),
+            range: range.erase_type(),
+        }
+    }
+}
+
+impl<T> Clone for Range<T> {
+    fn clone(&self) -> Self {
+        Range {
+            inner: self.inner.clone(),
+            marker: self.marker,
+        }
+    }
+}
+
+impl<T> fmt::Debug for Range<T> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter, "[{}..{}]", self.inner.start + 1, self.inner.end)
+    }
+}
+
+impl<T> Iterator for Range<T> {
+    type Item = Handle<T>;
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.inner.start < self.inner.end {
+            self.inner.start += 1;
+            Some(Handle {
+                index: NonZeroU32::new(self.inner.start).unwrap(),
+                marker: self.marker,
+            })
+        } else {
+            None
+        }
+    }
+}
+
+impl<T> Range<T> {
+    /// Return a range enclosing handles `first` through `last`, inclusive.
+    pub fn new_from_bounds(first: Handle<T>, last: Handle<T>) -> Self {
+        Self {
+            inner: (first.index() as u32)..(last.index() as u32 + 1),
+            marker: Default::default(),
+        }
+    }
+
+    /// return the first and last handles included in `self`.
+    ///
+    /// If `self` is an empty range, there are no handles included, so
+    /// return `None`.
+    pub fn first_and_last(&self) -> Option<(Handle<T>, Handle<T>)> {
+        if self.inner.start < self.inner.end {
+            Some((
+                // `Range::new_from_bounds` expects a 1-based, start- and
+                // end-inclusive range, but `self.inner` is a zero-based,
+                // end-exclusive range.
+                Handle::new(Index::new(self.inner.start + 1).unwrap()),
+                Handle::new(Index::new(self.inner.end).unwrap()),
+            ))
+        } else {
+            None
+        }
+    }
+
+    /// Return the zero-based index range covered by `self`.
+    pub fn zero_based_index_range(&self) -> ops::Range<u32> {
+        self.inner.clone()
+    }
+
+    /// Construct a `Range` that covers the zero-based indices in `inner`.
+    pub fn from_zero_based_index_range(inner: ops::Range<u32>, arena: &Arena<T>) -> Self {
+        // Since `inner` is a `Range<u32>`, we only need to check that
+        // the start and end are well-ordered, and that the end fits
+        // within `arena`.
+        assert!(inner.start <= inner.end);
+        assert!(inner.end as usize <= arena.len());
+        Self {
+            inner,
+            marker: Default::default(),
+        }
+    }
+}
+
+/// An arena holding some kind of component (e.g., type, constant,
+/// instruction, etc.) that can be referenced.
+///
+/// Adding new items to the arena produces a strongly-typed [`Handle`].
+/// The arena can be indexed using the given handle to obtain
+/// a reference to the stored item.
+#[cfg_attr(feature = "clone", derive(Clone))]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "serialize", serde(transparent))]
+#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
+#[cfg_attr(test, derive(PartialEq))]
+pub struct Arena<T> {
+    /// Values of this arena.
+    data: Vec<T>,
+    #[cfg_attr(feature = "serialize", serde(skip))]
+    span_info: Vec<Span>,
+}
+
+impl<T> Default for Arena<T> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl<T: fmt::Debug> fmt::Debug for Arena<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_map().entries(self.iter()).finish()
+    }
+}
+
+impl<T> Arena<T> {
+    /// Create a new arena with no initial capacity allocated.
+    pub const fn new() -> Self {
+        Arena {
+            data: Vec::new(),
+            span_info: Vec::new(),
+        }
+    }
+
+    /// Extracts the inner vector.
+    #[allow(clippy::missing_const_for_fn)] // ignore due to requirement of #![feature(const_precise_live_drops)]
+    pub fn into_inner(self) -> Vec<T> {
+        self.data
+    }
+
+    /// Returns the current number of items stored in this arena.
+    pub fn len(&self) -> usize {
+        self.data.len()
+    }
+
+    /// Returns `true` if the arena contains no elements.
+    pub fn is_empty(&self) -> bool {
+        self.data.is_empty()
+    }
+
+    /// Returns an iterator over the items stored in this arena, returning both
+    /// the item's handle and a reference to it.
+    pub fn iter(&self) -> impl DoubleEndedIterator<Item = (Handle<T>, &T)> {
+        self.data
+            .iter()
+            .enumerate()
+            .map(|(i, v)| unsafe { (Handle::from_usize_unchecked(i), v) })
+    }
+
+    /// Returns a iterator over the items stored in this arena,
+    /// returning both the item's handle and a mutable reference to it.
+    pub fn iter_mut(&mut self) -> impl DoubleEndedIterator<Item = (Handle<T>, &mut T)> {
+        self.data
+            .iter_mut()
+            .enumerate()
+            .map(|(i, v)| unsafe { (Handle::from_usize_unchecked(i), v) })
+    }
+
+    /// Adds a new value to the arena, returning a typed handle.
+    pub fn append(&mut self, value: T, span: Span) -> Handle<T> {
+        let index = self.data.len();
+        self.data.push(value);
+        self.span_info.push(span);
+        Handle::from_usize(index)
+    }
+
+    /// Fetch a handle to an existing type.
+    pub fn fetch_if<F: Fn(&T) -> bool>(&self, fun: F) -> Option<Handle<T>> {
+        self.data
+            .iter()
+            .position(fun)
+            .map(|index| unsafe { Handle::from_usize_unchecked(index) })
+    }
+
+    /// Adds a value with a custom check for uniqueness:
+    /// returns a handle pointing to
+    /// an existing element if the check succeeds, or adds a new
+    /// element otherwise.
+    pub fn fetch_if_or_append<F: Fn(&T, &T) -> bool>(
+        &mut self,
+        value: T,
+        span: Span,
+        fun: F,
+    ) -> Handle<T> {
+        if let Some(index) = self.data.iter().position(|d| fun(d, &value)) {
+            unsafe { Handle::from_usize_unchecked(index) }
+        } else {
+            self.append(value, span)
+        }
+    }
+
+    /// Adds a value with a check for uniqueness, where the check is plain comparison.
+    pub fn fetch_or_append(&mut self, value: T, span: Span) -> Handle<T>
+    where
+        T: PartialEq,
+    {
+        self.fetch_if_or_append(value, span, T::eq)
+    }
+
+    pub fn try_get(&self, handle: Handle<T>) -> Result<&T, BadHandle> {
+        self.data
+            .get(handle.index())
+            .ok_or_else(|| BadHandle::new(handle))
+    }
+
+    /// Get a mutable reference to an element in the arena.
+    pub fn get_mut(&mut self, handle: Handle<T>) -> &mut T {
+        self.data.get_mut(handle.index()).unwrap()
+    }
+
+    /// Get the range of handles from a particular number of elements to the end.
+    pub fn range_from(&self, old_length: usize) -> Range<T> {
+        Range {
+            inner: old_length as u32..self.data.len() as u32,
+            marker: PhantomData,
+        }
+    }
+
+    /// Clears the arena keeping all allocations
+    pub fn clear(&mut self) {
+        self.data.clear()
+    }
+
+    pub fn get_span(&self, handle: Handle<T>) -> Span {
+        *self
+            .span_info
+            .get(handle.index())
+            .unwrap_or(&Span::default())
+    }
+
+    /// Assert that `handle` is valid for this arena.
+    pub fn check_contains_handle(&self, handle: Handle<T>) -> Result<(), BadHandle> {
+        if handle.index() < self.data.len() {
+            Ok(())
+        } else {
+            Err(BadHandle::new(handle))
+        }
+    }
+
+    /// Assert that `range` is valid for this arena.
+    pub fn check_contains_range(&self, range: &Range<T>) -> Result<(), BadRangeError> {
+        // Since `range.inner` is a `Range<u32>`, we only need to check that the
+        // start precedes the end, and that the end is in range.
+        if range.inner.start > range.inner.end {
+            return Err(BadRangeError::new(range.clone()));
+        }
+
+        // Empty ranges are tolerated: they can be produced by compaction.
+        if range.inner.start == range.inner.end {
+            return Ok(());
+        }
+
+        // `range.inner` is zero-based, but end-exclusive, so `range.inner.end`
+        // is actually the right one-based index for the last handle within the
+        // range.
+        let last_handle = Handle::new(range.inner.end.try_into().unwrap());
+        if self.check_contains_handle(last_handle).is_err() {
+            return Err(BadRangeError::new(range.clone()));
+        }
+
+        Ok(())
+    }
+
+    #[cfg(feature = "compact")]
+    pub(crate) fn retain_mut<P>(&mut self, mut predicate: P)
+    where
+        P: FnMut(Handle<T>, &mut T) -> bool,
+    {
+        let mut index = 0;
+        let mut retained = 0;
+        self.data.retain_mut(|elt| {
+            let handle = Handle::new(Index::new(index as u32 + 1).unwrap());
+            let keep = predicate(handle, elt);
+
+            // Since `predicate` needs mutable access to each element,
+            // we can't feasibly call it twice, so we have to compact
+            // spans by hand in parallel as part of this iteration.
+            if keep {
+                self.span_info[retained] = self.span_info[index];
+                retained += 1;
+            }
+
+            index += 1;
+            keep
+        });
+
+        self.span_info.truncate(retained);
+    }
+}
+
+#[cfg(feature = "deserialize")]
+impl<'de, T> serde::Deserialize<'de> for Arena<T>
+where
+    T: serde::Deserialize<'de>,
+{
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        let data = Vec::deserialize(deserializer)?;
+        let span_info = std::iter::repeat(Span::default())
+            .take(data.len())
+            .collect();
+
+        Ok(Self { data, span_info })
+    }
+}
+
+impl<T> ops::Index<Handle<T>> for Arena<T> {
+    type Output = T;
+    fn index(&self, handle: Handle<T>) -> &T {
+        &self.data[handle.index()]
+    }
+}
+
+impl<T> ops::IndexMut<Handle<T>> for Arena<T> {
+    fn index_mut(&mut self, handle: Handle<T>) -> &mut T {
+        &mut self.data[handle.index()]
+    }
+}
+
+impl<T> ops::Index<Range<T>> for Arena<T> {
+    type Output = [T];
+    fn index(&self, range: Range<T>) -> &[T] {
+        &self.data[range.inner.start as usize..range.inner.end as usize]
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn append_non_unique() {
+        let mut arena: Arena<u8> = Arena::new();
+        let t1 = arena.append(0, Default::default());
+        let t2 = arena.append(0, Default::default());
+        assert!(t1 != t2);
+        assert!(arena[t1] == arena[t2]);
+    }
+
+    #[test]
+    fn append_unique() {
+        let mut arena: Arena<u8> = Arena::new();
+        let t1 = arena.append(0, Default::default());
+        let t2 = arena.append(1, Default::default());
+        assert!(t1 != t2);
+        assert!(arena[t1] != arena[t2]);
+    }
+
+    #[test]
+    fn fetch_or_append_non_unique() {
+        let mut arena: Arena<u8> = Arena::new();
+        let t1 = arena.fetch_or_append(0, Default::default());
+        let t2 = arena.fetch_or_append(0, Default::default());
+        assert!(t1 == t2);
+        assert!(arena[t1] == arena[t2])
+    }
+
+    #[test]
+    fn fetch_or_append_unique() {
+        let mut arena: Arena<u8> = Arena::new();
+        let t1 = arena.fetch_or_append(0, Default::default());
+        let t2 = arena.fetch_or_append(1, Default::default());
+        assert!(t1 != t2);
+        assert!(arena[t1] != arena[t2]);
+    }
+}
+
+/// An arena whose elements are guaranteed to be unique.
+///
+/// A `UniqueArena` holds a set of unique values of type `T`, each with an
+/// associated [`Span`]. Inserting a value returns a `Handle<T>`, which can be
+/// used to index the `UniqueArena` and obtain shared access to the `T` element.
+/// Access via a `Handle` is an array lookup - no hash lookup is necessary.
+///
+/// The element type must implement `Eq` and `Hash`. Insertions of equivalent
+/// elements, according to `Eq`, all return the same `Handle`.
+///
+/// Once inserted, elements may not be mutated.
+///
+/// `UniqueArena` is similar to [`Arena`]: If `Arena` is vector-like,
+/// `UniqueArena` is `HashSet`-like.
+#[cfg_attr(feature = "clone", derive(Clone))]
+pub struct UniqueArena<T> {
+    set: FastIndexSet<T>,
+
+    /// Spans for the elements, indexed by handle.
+    ///
+    /// The length of this vector is always equal to `set.len()`. `FastIndexSet`
+    /// promises that its elements "are indexed in a compact range, without
+    /// holes in the range 0..set.len()", so we can always use the indices
+    /// returned by insertion as indices into this vector.
+    span_info: Vec<Span>,
+}
+
+impl<T> UniqueArena<T> {
+    /// Create a new arena with no initial capacity allocated.
+    pub fn new() -> Self {
+        UniqueArena {
+            set: FastIndexSet::default(),
+            span_info: Vec::new(),
+        }
+    }
+
+    /// Return the current number of items stored in this arena.
+    pub fn len(&self) -> usize {
+        self.set.len()
+    }
+
+    /// Return `true` if the arena contains no elements.
+    pub fn is_empty(&self) -> bool {
+        self.set.is_empty()
+    }
+
+    /// Clears the arena, keeping all allocations.
+    pub fn clear(&mut self) {
+        self.set.clear();
+        self.span_info.clear();
+    }
+
+    /// Return the span associated with `handle`.
+    ///
+    /// If a value has been inserted multiple times, the span returned is the
+    /// one provided with the first insertion.
+    pub fn get_span(&self, handle: Handle<T>) -> Span {
+        *self
+            .span_info
+            .get(handle.index())
+            .unwrap_or(&Span::default())
+    }
+
+    #[cfg(feature = "compact")]
+    pub(crate) fn drain_all(&mut self) -> UniqueArenaDrain<T> {
+        UniqueArenaDrain {
+            inner_elts: self.set.drain(..),
+            inner_spans: self.span_info.drain(..),
+            index: Index::new(1).unwrap(),
+        }
+    }
+}
+
+#[cfg(feature = "compact")]
+pub(crate) struct UniqueArenaDrain<'a, T> {
+    inner_elts: indexmap::set::Drain<'a, T>,
+    inner_spans: std::vec::Drain<'a, Span>,
+    index: Index,
+}
+
+#[cfg(feature = "compact")]
+impl<'a, T> Iterator for UniqueArenaDrain<'a, T> {
+    type Item = (Handle<T>, T, Span);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        match self.inner_elts.next() {
+            Some(elt) => {
+                let handle = Handle::new(self.index);
+                self.index = self.index.checked_add(1).unwrap();
+                let span = self.inner_spans.next().unwrap();
+                Some((handle, elt, span))
+            }
+            None => None,
+        }
+    }
+}
+
+impl<T: Eq + hash::Hash> UniqueArena<T> {
+    /// Returns an iterator over the items stored in this arena, returning both
+    /// the item's handle and a reference to it.
+    pub fn iter(&self) -> impl DoubleEndedIterator<Item = (Handle<T>, &T)> {
+        self.set.iter().enumerate().map(|(i, v)| {
+            let position = i + 1;
+            let index = unsafe { Index::new_unchecked(position as u32) };
+            (Handle::new(index), v)
+        })
+    }
+
+    /// Insert a new value into the arena.
+    ///
+    /// Return a [`Handle<T>`], which can be used to index this arena to get a
+    /// shared reference to the element.
+    ///
+    /// If this arena already contains an element that is `Eq` to `value`,
+    /// return a `Handle` to the existing element, and drop `value`.
+    ///
+    /// If `value` is inserted into the arena, associate `span` with
+    /// it. An element's span can be retrieved with the [`get_span`]
+    /// method.
+    ///
+    /// [`Handle<T>`]: Handle
+    /// [`get_span`]: UniqueArena::get_span
+    pub fn insert(&mut self, value: T, span: Span) -> Handle<T> {
+        let (index, added) = self.set.insert_full(value);
+
+        if added {
+            debug_assert!(index == self.span_info.len());
+            self.span_info.push(span);
+        }
+
+        debug_assert!(self.set.len() == self.span_info.len());
+
+        Handle::from_usize(index)
+    }
+
+    /// Replace an old value with a new value.
+    ///
+    /// # Panics
+    ///
+    /// - if the old value is not in the arena
+    /// - if the new value already exists in the arena
+    pub fn replace(&mut self, old: Handle<T>, new: T) {
+        let (index, added) = self.set.insert_full(new);
+        assert!(added && index == self.set.len() - 1);
+
+        self.set.swap_remove_index(old.index()).unwrap();
+    }
+
+    /// Return this arena's handle for `value`, if present.
+    ///
+    /// If this arena already contains an element equal to `value`,
+    /// return its handle. Otherwise, return `None`.
+    pub fn get(&self, value: &T) -> Option<Handle<T>> {
+        self.set
+            .get_index_of(value)
+            .map(|index| unsafe { Handle::from_usize_unchecked(index) })
+    }
+
+    /// Return this arena's value at `handle`, if that is a valid handle.
+    pub fn get_handle(&self, handle: Handle<T>) -> Result<&T, BadHandle> {
+        self.set
+            .get_index(handle.index())
+            .ok_or_else(|| BadHandle::new(handle))
+    }
+
+    /// Assert that `handle` is valid for this arena.
+    pub fn check_contains_handle(&self, handle: Handle<T>) -> Result<(), BadHandle> {
+        if handle.index() < self.set.len() {
+            Ok(())
+        } else {
+            Err(BadHandle::new(handle))
+        }
+    }
+}
+
+impl<T> Default for UniqueArena<T> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl<T: fmt::Debug + Eq + hash::Hash> fmt::Debug for UniqueArena<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_map().entries(self.iter()).finish()
+    }
+}
+
+impl<T> ops::Index<Handle<T>> for UniqueArena<T> {
+    type Output = T;
+    fn index(&self, handle: Handle<T>) -> &T {
+        &self.set[handle.index()]
+    }
+}
+
+#[cfg(feature = "serialize")]
+impl<T> serde::Serialize for UniqueArena<T>
+where
+    T: Eq + hash::Hash + serde::Serialize,
+{
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        self.set.serialize(serializer)
+    }
+}
+
+#[cfg(feature = "deserialize")]
+impl<'de, T> serde::Deserialize<'de> for UniqueArena<T>
+where
+    T: Eq + hash::Hash + serde::Deserialize<'de>,
+{
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        let set = FastIndexSet::deserialize(deserializer)?;
+        let span_info = std::iter::repeat(Span::default()).take(set.len()).collect();
+
+        Ok(Self { set, span_info })
+    }
+}
+
+//Note: largely borrowed from `HashSet` implementation
+#[cfg(feature = "arbitrary")]
+impl<'a, T> arbitrary::Arbitrary<'a> for UniqueArena<T>
+where
+    T: Eq + hash::Hash + arbitrary::Arbitrary<'a>,
+{
+    fn arbitrary(u: &mut arbitrary::Unstructured<'a>) -> arbitrary::Result<Self> {
+        let mut arena = Self::default();
+        for elem in u.arbitrary_iter()? {
+            arena.set.insert(elem?);
+            arena.span_info.push(Span::UNDEFINED);
+        }
+        Ok(arena)
+    }
+
+    fn arbitrary_take_rest(u: arbitrary::Unstructured<'a>) -> arbitrary::Result<Self> {
+        let mut arena = Self::default();
+        for elem in u.arbitrary_take_rest_iter()? {
+            arena.set.insert(elem?);
+            arena.span_info.push(Span::UNDEFINED);
+        }
+        Ok(arena)
+    }
+
+    #[inline]
+    fn size_hint(depth: usize) -> (usize, Option<usize>) {
+        let depth_hint = <usize as arbitrary::Arbitrary>::size_hint(depth);
+        arbitrary::size_hint::and(depth_hint, (0, None))
+    }
+}
diff --git a/third_party/rust/naga/src/back/dot/mod.rs b/third_party/rust/naga/src/back/dot/mod.rs
new file mode 100644
index 0000000000..1556371df1
--- /dev/null
+++ b/third_party/rust/naga/src/back/dot/mod.rs
@@ -0,0 +1,703 @@
+/*!
+Backend for [DOT][dot] (Graphviz).
+
+This backend writes a graph in the DOT language, for the ease
+of IR inspection and debugging.
+
+[dot]: https://graphviz.org/doc/info/lang.html
+*/
+
+use crate::{
+    arena::Handle,
+    valid::{FunctionInfo, ModuleInfo},
+};
+
+use std::{
+    borrow::Cow,
+    fmt::{Error as FmtError, Write as _},
+};
+
+/// Configuration options for the dot backend
+#[derive(Clone, Default)]
+pub struct Options {
+    /// Only emit function bodies
+    pub cfg_only: bool,
+}
+
+/// Identifier used to address a graph node
+type NodeId = usize;
+
+/// Stores the target nodes for control flow statements
+#[derive(Default, Clone, Copy)]
+struct Targets {
+    /// The node, if some, where continue operations will land
+    continue_target: Option<usize>,
+    /// The node, if some, where break operations will land
+    break_target: Option<usize>,
+}
+
+/// Stores information about the graph of statements
+#[derive(Default)]
+struct StatementGraph {
+    /// List of node names
+    nodes: Vec<&'static str>,
+    /// List of edges of the control flow, the items are defined as
+    /// (from, to, label)
+    flow: Vec<(NodeId, NodeId, &'static str)>,
+    /// List of implicit edges of the control flow, used for jump
+    /// operations such as continue or break, the items are defined as
+    /// (from, to, label, color_id)
+    jumps: Vec<(NodeId, NodeId, &'static str, usize)>,
+    /// List of dependency relationships between a statement node and
+    /// expressions
+    dependencies: Vec<(NodeId, Handle<crate::Expression>, &'static str)>,
+    /// List of expression emitted by statement node
+    emits: Vec<(NodeId, Handle<crate::Expression>)>,
+    /// List of function call by statement node
+    calls: Vec<(NodeId, Handle<crate::Function>)>,
+}
+
+impl StatementGraph {
+    /// Adds a new block to the statement graph, returning the first and last node, respectively
+    fn add(&mut self, block: &[crate::Statement], targets: Targets) -> (NodeId, NodeId) {
+        use crate::Statement as S;
+
+        // The first node of the block isn't a statement but a virtual node
+        let root = self.nodes.len();
+        self.nodes.push(if root == 0 { "Root" } else { "Node" });
+        // Track the last placed node, this will be returned to the caller and
+        // will also be used to generate the control flow edges
+        let mut last_node = root;
+        for statement in block {
+            // Reserve a new node for the current statement and link it to the
+            // node of the previous statement
+            let id = self.nodes.len();
+            self.flow.push((last_node, id, ""));
+            self.nodes.push(""); // reserve space
+
+            // Track the node identifier for the merge node, the merge node is
+            // the last node of a statement, normally this is the node itself,
+            // but for control flow statements such as `if`s and `switch`s this
+            // is a virtual node where all branches merge back.
+            let mut merge_id = id;
+
+            self.nodes[id] = match *statement {
+                S::Emit(ref range) => {
+                    for handle in range.clone() {
+                        self.emits.push((id, handle));
+                    }
+                    "Emit"
+                }
+                S::Kill => "Kill", //TODO: link to the beginning
+                S::Break => {
+                    // Try to link to the break target, otherwise produce
+                    // a broken connection
+                    if let Some(target) = targets.break_target {
+                        self.jumps.push((id, target, "Break", 5))
+                    } else {
+                        self.jumps.push((id, root, "Broken", 7))
+                    }
+                    "Break"
+                }
+                S::Continue => {
+                    // Try to link to the continue target, otherwise produce
+                    // a broken connection
+                    if let Some(target) = targets.continue_target {
+                        self.jumps.push((id, target, "Continue", 5))
+                    } else {
+                        self.jumps.push((id, root, "Broken", 7))
+                    }
+                    "Continue"
+                }
+                S::Barrier(_flags) => "Barrier",
+                S::Block(ref b) => {
+                    let (other, last) = self.add(b, targets);
+                    self.flow.push((id, other, ""));
+                    // All following nodes should connect to the end of the block
+                    // statement so change the merge id to it.
+                    merge_id = last;
+                    "Block"
+                }
+                S::If {
+                    condition,
+                    ref accept,
+                    ref reject,
+                } => {
+                    self.dependencies.push((id, condition, "condition"));
+                    let (accept_id, accept_last) = self.add(accept, targets);
+                    self.flow.push((id, accept_id, "accept"));
+                    let (reject_id, reject_last) = self.add(reject, targets);
+                    self.flow.push((id, reject_id, "reject"));
+
+                    // Create a merge node, link the branches to it and set it
+                    // as the merge node to make the next statement node link to it
+                    merge_id = self.nodes.len();
+                    self.nodes.push("Merge");
+                    self.flow.push((accept_last, merge_id, ""));
+                    self.flow.push((reject_last, merge_id, ""));
+
+                    "If"
+                }
+                S::Switch {
+                    selector,
+                    ref cases,
+                } => {
+                    self.dependencies.push((id, selector, "selector"));
+
+                    // Create a merge node and set it as the merge node to make
+                    // the next statement node link to it
+                    merge_id = self.nodes.len();
+                    self.nodes.push("Merge");
+
+                    // Create a new targets structure and set the break target
+                    // to the merge node
+                    let mut targets = targets;
+                    targets.break_target = Some(merge_id);
+
+                    for case in cases {
+                        let (case_id, case_last) = self.add(&case.body, targets);
+                        let label = match case.value {
+                            crate::SwitchValue::Default => "default",
+                            _ => "case",
+                        };
+                        self.flow.push((id, case_id, label));
+                        // Link the last node of the branch to the merge node
+                        self.flow.push((case_last, merge_id, ""));
+                    }
+                    "Switch"
+                }
+                S::Loop {
+                    ref body,
+                    ref continuing,
+                    break_if,
+                } => {
+                    // Create a new targets structure and set the break target
+                    // to the merge node, this must happen before generating the
+                    // continuing block since it can break.
+                    let mut targets = targets;
+                    targets.break_target = Some(id);
+
+                    let (continuing_id, continuing_last) = self.add(continuing, targets);
+
+                    // Set the the continue target to the beginning
+                    // of the newly generated continuing block
+                    targets.continue_target = Some(continuing_id);
+
+                    let (body_id, body_last) = self.add(body, targets);
+
+                    self.flow.push((id, body_id, "body"));
+
+                    // Link the last node of the body to the continuing block
+                    self.flow.push((body_last, continuing_id, "continuing"));
+                    // Link the last node of the continuing block back to the
+                    // beginning of the loop body
+                    self.flow.push((continuing_last, body_id, "continuing"));
+
+                    if let Some(expr) = break_if {
+                        self.dependencies.push((continuing_id, expr, "break if"));
+                    }
+
+                    "Loop"
+                }
+                S::Return { value } => {
+                    if let Some(expr) = value {
+                        self.dependencies.push((id, expr, "value"));
+                    }
+                    "Return"
+                }
+                S::Store { pointer, value } => {
+                    self.dependencies.push((id, value, "value"));
+                    self.emits.push((id, pointer));
+                    "Store"
+                }
+                S::ImageStore {
+                    image,
+                    coordinate,
+                    array_index,
+                    value,
+                } => {
+                    self.dependencies.push((id, image, "image"));
+                    self.dependencies.push((id, coordinate, "coordinate"));
+                    if let Some(expr) = array_index {
+                        self.dependencies.push((id, expr, "array_index"));
+                    }
+                    self.dependencies.push((id, value, "value"));
+                    "ImageStore"
+                }
+                S::Call {
+                    function,
+                    ref arguments,
+                    result,
+                } => {
+                    for &arg in arguments {
+                        self.dependencies.push((id, arg, "arg"));
+                    }
+                    if let Some(expr) = result {
+                        self.emits.push((id, expr));
+                    }
+                    self.calls.push((id, function));
+                    "Call"
+                }
+                S::Atomic {
+                    pointer,
+                    ref fun,
+                    value,
+                    result,
+                } => {
+                    self.emits.push((id, result));
+                    self.dependencies.push((id, pointer, "pointer"));
+                    self.dependencies.push((id, value, "value"));
+                    if let crate::AtomicFunction::Exchange { compare: Some(cmp) } = *fun {
+                        self.dependencies.push((id, cmp, "cmp"));
+                    }
+                    "Atomic"
+                }
+                S::WorkGroupUniformLoad { pointer, result } => {
+                    self.emits.push((id, result));
+                    self.dependencies.push((id, pointer, "pointer"));
+                    "WorkGroupUniformLoad"
+                }
+                S::RayQuery { query, ref fun } => {
+                    self.dependencies.push((id, query, "query"));
+                    match *fun {
+                        crate::RayQueryFunction::Initialize {
+                            acceleration_structure,
+                            descriptor,
+                        } => {
+                            self.dependencies.push((
+                                id,
+                                acceleration_structure,
+                                "acceleration_structure",
+                            ));
+                            self.dependencies.push((id, descriptor, "descriptor"));
+                            "RayQueryInitialize"
+                        }
+                        crate::RayQueryFunction::Proceed { result } => {
+                            self.emits.push((id, result));
+                            "RayQueryProceed"
+                        }
+                        crate::RayQueryFunction::Terminate => "RayQueryTerminate",
+                    }
+                }
+            };
+            // Set the last node to the merge node
+            last_node = merge_id;
+        }
+        (root, last_node)
+    }
+}
+
+#[allow(clippy::manual_unwrap_or)]
+fn name(option: &Option<String>) -> &str {
+    match *option {
+        Some(ref name) => name,
+        None => "",
+    }
+}
+
+/// set39 color scheme from <https://graphviz.org/doc/info/colors.html>
+const COLORS: &[&str] = &[
+    "white", // pattern starts at 1
+    "#8dd3c7", "#ffffb3", "#bebada", "#fb8072", "#80b1d3", "#fdb462", "#b3de69", "#fccde5",
+    "#d9d9d9",
+];
+
+fn write_fun(
+    output: &mut String,
+    prefix: String,
+    fun: &crate::Function,
+    info: Option<&FunctionInfo>,
+    options: &Options,
+) -> Result<(), FmtError> {
+    writeln!(output, "\t\tnode [ style=filled ]")?;
+
+    if !options.cfg_only {
+        for (handle, var) in fun.local_variables.iter() {
+            writeln!(
+                output,
+                "\t\t{}_l{} [ shape=hexagon label=\"{:?} '{}'\" ]",
+                prefix,
+                handle.index(),
+                handle,
+                name(&var.name),
+            )?;
+        }
+
+        write_function_expressions(output, &prefix, fun, info)?;
+    }
+
+    let mut sg = StatementGraph::default();
+    sg.add(&fun.body, Targets::default());
+    for (index, label) in sg.nodes.into_iter().enumerate() {
+        writeln!(
+            output,
+            "\t\t{prefix}_s{index} [ shape=square label=\"{label}\" ]",
+        )?;
+    }
+    for (from, to, label) in sg.flow {
+        writeln!(
+            output,
+            "\t\t{prefix}_s{from} -> {prefix}_s{to} [ arrowhead=tee label=\"{label}\" ]",
+        )?;
+    }
+    for (from, to, label, color_id) in sg.jumps {
+        writeln!(
+            output,
+            "\t\t{}_s{} -> {}_s{} [ arrowhead=tee style=dashed color=\"{}\" label=\"{}\" ]",
+            prefix, from, prefix, to, COLORS[color_id], label,
+        )?;
+    }
+
+    if !options.cfg_only {
+        for (to, expr, label) in sg.dependencies {
+            writeln!(
+                output,
+                "\t\t{}_e{} -> {}_s{} [ label=\"{}\" ]",
+                prefix,
+                expr.index(),
+                prefix,
+                to,
+                label,
+            )?;
+        }
+        for (from, to) in sg.emits {
+            writeln!(
+                output,
+                "\t\t{}_s{} -> {}_e{} [ style=dotted ]",
+                prefix,
+                from,
+                prefix,
+                to.index(),
+            )?;
+        }
+    }
+
+    for (from, function) in sg.calls {
+        writeln!(
+            output,
+            "\t\t{}_s{} -> f{}_s0",
+            prefix,
+            from,
+            function.index(),
+        )?;
+    }
+
+    Ok(())
+}
+
+fn write_function_expressions(
+    output: &mut String,
+    prefix: &str,
+    fun: &crate::Function,
+    info: Option<&FunctionInfo>,
+) -> Result<(), FmtError> {
+    enum Payload<'a> {
+        Arguments(&'a [Handle<crate::Expression>]),
+        Local(Handle<crate::LocalVariable>),
+        Global(Handle<crate::GlobalVariable>),
+    }
+
+    let mut edges = crate::FastHashMap::<&str, _>::default();
+    let mut payload = None;
+    for (handle, expression) in fun.expressions.iter() {
+        use crate::Expression as E;
+        let (label, color_id) = match *expression {
+            E::Literal(_) => ("Literal".into(), 2),
+            E::Constant(_) => ("Constant".into(), 2),
+            E::ZeroValue(_) => ("ZeroValue".into(), 2),
+            E::Compose { ref components, .. } => {
+                payload = Some(Payload::Arguments(components));
+                ("Compose".into(), 3)
+            }
+            E::Access { base, index } => {
+                edges.insert("base", base);
+                edges.insert("index", index);
+                ("Access".into(), 1)
+            }
+            E::AccessIndex { base, index } => {
+                edges.insert("base", base);
+                (format!("AccessIndex[{index}]").into(), 1)
+            }
+            E::Splat { size, value } => {
+                edges.insert("value", value);
+                (format!("Splat{size:?}").into(), 3)
+            }
+            E::Swizzle {
+                size,
+                vector,
+                pattern,
+            } => {
+                edges.insert("vector", vector);
+                (format!("Swizzle{:?}", &pattern[..size as usize]).into(), 3)
+            }
+            E::FunctionArgument(index) => (format!("Argument[{index}]").into(), 1),
+            E::GlobalVariable(h) => {
+                payload = Some(Payload::Global(h));
+                ("Global".into(), 2)
+            }
+            E::LocalVariable(h) => {
+                payload = Some(Payload::Local(h));
+                ("Local".into(), 1)
+            }
+            E::Load { pointer } => {
+                edges.insert("pointer", pointer);
+                ("Load".into(), 4)
+            }
+            E::ImageSample {
+                image,
+                sampler,
+                gather,
+                coordinate,
+                array_index,
+                offset: _,
+                level,
+                depth_ref,
+            } => {
+                edges.insert("image", image);
+                edges.insert("sampler", sampler);
+                edges.insert("coordinate", coordinate);
+                if let Some(expr) = array_index {
+                    edges.insert("array_index", expr);
+                }
+                match level {
+                    crate::SampleLevel::Auto => {}
+                    crate::SampleLevel::Zero => {}
+                    crate::SampleLevel::Exact(expr) => {
+                        edges.insert("level", expr);
+                    }
+                    crate::SampleLevel::Bias(expr) => {
+                        edges.insert("bias", expr);
+                    }
+                    crate::SampleLevel::Gradient { x, y } => {
+                        edges.insert("grad_x", x);
+                        edges.insert("grad_y", y);
+                    }
+                }
+                if let Some(expr) = depth_ref {
+                    edges.insert("depth_ref", expr);
+                }
+                let string = match gather {
+                    Some(component) => Cow::Owned(format!("ImageGather{component:?}")),
+                    _ => Cow::Borrowed("ImageSample"),
+                };
+                (string, 5)
+            }
+            E::ImageLoad {
+                image,
+                coordinate,
+                array_index,
+                sample,
+                level,
+            } => {
+                edges.insert("image", image);
+                edges.insert("coordinate", coordinate);
+                if let Some(expr) = array_index {
+                    edges.insert("array_index", expr);
+                }
+                if let Some(sample) = sample {
+                    edges.insert("sample", sample);
+                }
+                if let Some(level) = level {
+                    edges.insert("level", level);
+                }
+                ("ImageLoad".into(), 5)
+            }
+            E::ImageQuery { image, query } => {
+                edges.insert("image", image);
+                let args = match query {
+                    crate::ImageQuery::Size { level } => {
+                        if let Some(expr) = level {
+                            edges.insert("level", expr);
+                        }
+                        Cow::from("ImageSize")
+                    }
+                    _ => Cow::Owned(format!("{query:?}")),
+                };
+                (args, 7)
+            }
+            E::Unary { op, expr } => {
+                edges.insert("expr", expr);
+                (format!("{op:?}").into(), 6)
+            }
+            E::Binary { op, left, right } => {
+                edges.insert("left", left);
+                edges.insert("right", right);
+                (format!("{op:?}").into(), 6)
+            }
+            E::Select {
+                condition,
+                accept,
+                reject,
+            } => {
+                edges.insert("condition", condition);
+                edges.insert("accept", accept);
+                edges.insert("reject", reject);
+                ("Select".into(), 3)
+            }
+            E::Derivative { axis, ctrl, expr } => {
+                edges.insert("", expr);
+                (format!("d{axis:?}{ctrl:?}").into(), 8)
+            }
+            E::Relational { fun, argument } => {
+                edges.insert("arg", argument);
+                (format!("{fun:?}").into(), 6)
+            }
+            E::Math {
+                fun,
+                arg,
+                arg1,
+                arg2,
+                arg3,
+            } => {
+                edges.insert("arg", arg);
+                if let Some(expr) = arg1 {
+                    edges.insert("arg1", expr);
+                }
+                if let Some(expr) = arg2 {
+                    edges.insert("arg2", expr);
+                }
+                if let Some(expr) = arg3 {
+                    edges.insert("arg3", expr);
+                }
+                (format!("{fun:?}").into(), 7)
+            }
+            E::As {
+                kind,
+                expr,
+                convert,
+            } => {
+                edges.insert("", expr);
+                let string = match convert {
+                    Some(width) => format!("Convert<{kind:?},{width}>"),
+                    None => format!("Bitcast<{kind:?}>"),
+                };
+                (string.into(), 3)
+            }
+            E::CallResult(_function) => ("CallResult".into(), 4),
+            E::AtomicResult { .. } => ("AtomicResult".into(), 4),
+            E::WorkGroupUniformLoadResult { .. } => ("WorkGroupUniformLoadResult".into(), 4),
+            E::ArrayLength(expr) => {
+                edges.insert("", expr);
+                ("ArrayLength".into(), 7)
+            }
+            E::RayQueryProceedResult => ("rayQueryProceedResult".into(), 4),
+            E::RayQueryGetIntersection { query, committed } => {
+                edges.insert("", query);
+                let ty = if committed { "Committed" } else { "Candidate" };
+                (format!("rayQueryGet{}Intersection", ty).into(), 4)
+            }
+        };
+
+        // give uniform expressions an outline
+        let color_attr = match info {
+            Some(info) if info[handle].uniformity.non_uniform_result.is_none() => "fillcolor",
+            _ => "color",
+        };
+        writeln!(
+            output,
+            "\t\t{}_e{} [ {}=\"{}\" label=\"{:?} {}\" ]",
+            prefix,
+            handle.index(),
+            color_attr,
+            COLORS[color_id],
+            handle,
+            label,
+        )?;
+
+        for (key, edge) in edges.drain() {
+            writeln!(
+                output,
+                "\t\t{}_e{} -> {}_e{} [ label=\"{}\" ]",
+                prefix,
+                edge.index(),
+                prefix,
+                handle.index(),
+                key,
+            )?;
+        }
+        match payload.take() {
+            Some(Payload::Arguments(list)) => {
+                write!(output, "\t\t{{")?;
+                for &comp in list {
+                    write!(output, " {}_e{}", prefix, comp.index())?;
+                }
+                writeln!(output, " }} -> {}_e{}", prefix, handle.index())?;
+            }
+            Some(Payload::Local(h)) => {
+                writeln!(
+                    output,
+                    "\t\t{}_l{} -> {}_e{}",
+                    prefix,
+                    h.index(),
+                    prefix,
+                    handle.index(),
+                )?;
+            }
+            Some(Payload::Global(h)) => {
+                writeln!(
+                    output,
+                    "\t\tg{} -> {}_e{} [fillcolor=gray]",
+                    h.index(),
+                    prefix,
+                    handle.index(),
+                )?;
+            }
+            None => {}
+        }
+    }
+
+    Ok(())
+}
+
+/// Write shader module to a [`String`].
+pub fn write(
+    module: &crate::Module,
+    mod_info: Option<&ModuleInfo>,
+    options: Options,
+) -> Result<String, FmtError> {
+    use std::fmt::Write as _;
+
+    let mut output = String::new();
+    output += "digraph Module {\n";
+
+    if !options.cfg_only {
+        writeln!(output, "\tsubgraph cluster_globals {{")?;
+        writeln!(output, "\t\tlabel=\"Globals\"")?;
+        for (handle, var) in module.global_variables.iter() {
+            writeln!(
+                output,
+                "\t\tg{} [ shape=hexagon label=\"{:?} {:?}/'{}'\" ]",
+                handle.index(),
+                handle,
+                var.space,
+                name(&var.name),
+            )?;
+        }
+        writeln!(output, "\t}}")?;
+    }
+
+    for (handle, fun) in module.functions.iter() {
+        let prefix = format!("f{}", handle.index());
+        writeln!(output, "\tsubgraph cluster_{prefix} {{")?;
+        writeln!(
+            output,
+            "\t\tlabel=\"Function{:?}/'{}'\"",
+            handle,
+            name(&fun.name)
+        )?;
+        let info = mod_info.map(|a| &a[handle]);
+        write_fun(&mut output, prefix, fun, info, &options)?;
+        writeln!(output, "\t}}")?;
+    }
+    for (ep_index, ep) in module.entry_points.iter().enumerate() {
+        let prefix = format!("ep{ep_index}");
+        writeln!(output, "\tsubgraph cluster_{prefix} {{")?;
+        writeln!(output, "\t\tlabel=\"{:?}/'{}'\"", ep.stage, ep.name)?;
+        let info = mod_info.map(|a| a.get_entry_point(ep_index));
+        write_fun(&mut output, prefix, &ep.function, info, &options)?;
+        writeln!(output, "\t}}")?;
+    }
+
+    output += "}\n";
+    Ok(output)
+}
diff --git a/third_party/rust/naga/src/back/glsl/features.rs b/third_party/rust/naga/src/back/glsl/features.rs
new file mode 100644
index 0000000000..e7de05f695
--- /dev/null
+++ b/third_party/rust/naga/src/back/glsl/features.rs
@@ -0,0 +1,536 @@
+use super::{BackendResult, Error, Version, Writer};
+use crate::{
+    back::glsl::{Options, WriterFlags},
+    AddressSpace, Binding, Expression, Handle, ImageClass, ImageDimension, Interpolation, Sampling,
+    Scalar, ScalarKind, ShaderStage, StorageFormat, Type, TypeInner,
+};
+use std::fmt::Write;
+
+bitflags::bitflags! {
+    /// Structure used to encode additions to GLSL that aren't supported by all versions.
+    #[derive(Clone, Copy, Debug, Eq, PartialEq)]
+    pub struct Features: u32 {
+        /// Buffer address space support.
+        const BUFFER_STORAGE = 1;
+        const ARRAY_OF_ARRAYS = 1 << 1;
+        /// 8 byte floats.
+        const DOUBLE_TYPE = 1 << 2;
+        /// More image formats.
+        const FULL_IMAGE_FORMATS = 1 << 3;
+        const MULTISAMPLED_TEXTURES = 1 << 4;
+        const MULTISAMPLED_TEXTURE_ARRAYS = 1 << 5;
+        const CUBE_TEXTURES_ARRAY = 1 << 6;
+        const COMPUTE_SHADER = 1 << 7;
+        /// Image load and early depth tests.
+        const IMAGE_LOAD_STORE = 1 << 8;
+        const CONSERVATIVE_DEPTH = 1 << 9;
+        /// Interpolation and auxiliary qualifiers.
+        ///
+        /// Perspective, Flat, and Centroid are available in all GLSL versions we support.
+        const NOPERSPECTIVE_QUALIFIER = 1 << 11;
+        const SAMPLE_QUALIFIER = 1 << 12;
+        const CLIP_DISTANCE = 1 << 13;
+        const CULL_DISTANCE = 1 << 14;
+        /// Sample ID.
+        const SAMPLE_VARIABLES = 1 << 15;
+        /// Arrays with a dynamic length.
+        const DYNAMIC_ARRAY_SIZE = 1 << 16;
+        const MULTI_VIEW = 1 << 17;
+        /// Texture samples query
+        const TEXTURE_SAMPLES = 1 << 18;
+        /// Texture levels query
+        const TEXTURE_LEVELS = 1 << 19;
+        /// Image size query
+        const IMAGE_SIZE = 1 << 20;
+        /// Dual source blending
+        const DUAL_SOURCE_BLENDING = 1 << 21;
+        /// Instance index
+        ///
+        /// We can always support this, either through the language or a polyfill
+        const INSTANCE_INDEX = 1 << 22;
+    }
+}
+
+/// Helper structure used to store the required [`Features`] needed to output a
+/// [`Module`](crate::Module)
+///
+/// Provides helper methods to check for availability and writing required extensions
+pub struct FeaturesManager(Features);
+
+impl FeaturesManager {
+    /// Creates a new [`FeaturesManager`] instance
+    pub const fn new() -> Self {
+        Self(Features::empty())
+    }
+
+    /// Adds to the list of required [`Features`]
+    pub fn request(&mut self, features: Features) {
+        self.0 |= features
+    }
+
+    /// Checks if the list of features [`Features`] contains the specified [`Features`]
+    pub fn contains(&mut self, features: Features) -> bool {
+        self.0.contains(features)
+    }
+
+    /// Checks that all required [`Features`] are available for the specified
+    /// [`Version`] otherwise returns an [`Error::MissingFeatures`].
+    pub fn check_availability(&self, version: Version) -> BackendResult {
+        // Will store all the features that are unavailable
+        let mut missing = Features::empty();
+
+        // Helper macro to check for feature availability
+        macro_rules! check_feature {
+            // Used when only core glsl supports the feature
+            ($feature:ident, $core:literal) => {
+                if self.0.contains(Features::$feature)
+                    && (version < Version::Desktop($core) || version.is_es())
+                {
+                    missing |= Features::$feature;
+                }
+            };
+            // Used when both core and es support the feature
+            ($feature:ident, $core:literal, $es:literal) => {
+                if self.0.contains(Features::$feature)
+                    && (version < Version::Desktop($core) || version < Version::new_gles($es))
+                {
+                    missing |= Features::$feature;
+                }
+            };
+        }
+
+        check_feature!(COMPUTE_SHADER, 420, 310);
+        check_feature!(BUFFER_STORAGE, 400, 310);
+        check_feature!(DOUBLE_TYPE, 150);
+        check_feature!(CUBE_TEXTURES_ARRAY, 130, 310);
+        check_feature!(MULTISAMPLED_TEXTURES, 150, 300);
+        check_feature!(MULTISAMPLED_TEXTURE_ARRAYS, 150, 310);
+        check_feature!(ARRAY_OF_ARRAYS, 120, 310);
+        check_feature!(IMAGE_LOAD_STORE, 130, 310);
+        check_feature!(CONSERVATIVE_DEPTH, 130, 300);
+        check_feature!(NOPERSPECTIVE_QUALIFIER, 130);
+        check_feature!(SAMPLE_QUALIFIER, 400, 320);
+        check_feature!(CLIP_DISTANCE, 130, 300 /* with extension */);
+        check_feature!(CULL_DISTANCE, 450, 300 /* with extension */);
+        check_feature!(SAMPLE_VARIABLES, 400, 300);
+        check_feature!(DYNAMIC_ARRAY_SIZE, 430, 310);
+        check_feature!(DUAL_SOURCE_BLENDING, 330, 300 /* with extension */);
+        match version {
+            Version::Embedded { is_webgl: true, .. } => check_feature!(MULTI_VIEW, 140, 300),
+            _ => check_feature!(MULTI_VIEW, 140, 310),
+        };
+        // Only available on glsl core, this means that opengl es can't query the number
+        // of samples nor levels in a image and neither do bound checks on the sample nor
+        // the level argument of texelFecth
+        check_feature!(TEXTURE_SAMPLES, 150);
+        check_feature!(TEXTURE_LEVELS, 130);
+        check_feature!(IMAGE_SIZE, 430, 310);
+
+        // Return an error if there are missing features
+        if missing.is_empty() {
+            Ok(())
+        } else {
+            Err(Error::MissingFeatures(missing))
+        }
+    }
+
+    /// Helper method used to write all needed extensions
+    ///
+    /// # Notes
+    /// This won't check for feature availability so it might output extensions that aren't even
+    /// supported.[`check_availability`](Self::check_availability) will check feature availability
+    pub fn write(&self, options: &Options, mut out: impl Write) -> BackendResult {
+        if self.0.contains(Features::COMPUTE_SHADER) && !options.version.is_es() {
+            // https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_compute_shader.txt
+            writeln!(out, "#extension GL_ARB_compute_shader : require")?;
+        }
+
+        if self.0.contains(Features::BUFFER_STORAGE) && !options.version.is_es() {
+            // https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_shader_storage_buffer_object.txt
+            writeln!(
+                out,
+                "#extension GL_ARB_shader_storage_buffer_object : require"
+            )?;
+        }
+
+        if self.0.contains(Features::DOUBLE_TYPE) && options.version < Version::Desktop(400) {
+            // https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_gpu_shader_fp64.txt
+            writeln!(out, "#extension GL_ARB_gpu_shader_fp64 : require")?;
+        }
+
+        if self.0.contains(Features::CUBE_TEXTURES_ARRAY) {
+            if options.version.is_es() {
+                // https://www.khronos.org/registry/OpenGL/extensions/EXT/EXT_texture_cube_map_array.txt
+                writeln!(out, "#extension GL_EXT_texture_cube_map_array : require")?;
+            } else if options.version < Version::Desktop(400) {
+                // https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_texture_cube_map_array.txt
+                writeln!(out, "#extension GL_ARB_texture_cube_map_array : require")?;
+            }
+        }
+
+        if self.0.contains(Features::MULTISAMPLED_TEXTURE_ARRAYS) && options.version.is_es() {
+            // https://www.khronos.org/registry/OpenGL/extensions/OES/OES_texture_storage_multisample_2d_array.txt
+            writeln!(
+                out,
+                "#extension GL_OES_texture_storage_multisample_2d_array : require"
+            )?;
+        }
+
+        if self.0.contains(Features::ARRAY_OF_ARRAYS) && options.version < Version::Desktop(430) {
+            // https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_arrays_of_arrays.txt
+            writeln!(out, "#extension ARB_arrays_of_arrays : require")?;
+        }
+
+        if self.0.contains(Features::IMAGE_LOAD_STORE) {
+            if self.0.contains(Features::FULL_IMAGE_FORMATS) && options.version.is_es() {
+                // https://www.khronos.org/registry/OpenGL/extensions/NV/NV_image_formats.txt
+                writeln!(out, "#extension GL_NV_image_formats : require")?;
+            }
+
+            if options.version < Version::Desktop(420) {
+                // https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_shader_image_load_store.txt
+                writeln!(out, "#extension GL_ARB_shader_image_load_store : require")?;
+            }
+        }
+
+        if self.0.contains(Features::CONSERVATIVE_DEPTH) {
+            if options.version.is_es() {
+                // https://www.khronos.org/registry/OpenGL/extensions/EXT/EXT_conservative_depth.txt
+                writeln!(out, "#extension GL_EXT_conservative_depth : require")?;
+            }
+
+            if options.version < Version::Desktop(420) {
+                // https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_conservative_depth.txt
+                writeln!(out, "#extension GL_ARB_conservative_depth : require")?;
+            }
+        }
+
+        if (self.0.contains(Features::CLIP_DISTANCE) || self.0.contains(Features::CULL_DISTANCE))
+            && options.version.is_es()
+        {
+            // https://www.khronos.org/registry/OpenGL/extensions/EXT/EXT_clip_cull_distance.txt
+            writeln!(out, "#extension GL_EXT_clip_cull_distance : require")?;
+        }
+
+        if self.0.contains(Features::SAMPLE_VARIABLES) && options.version.is_es() {
+            // https://www.khronos.org/registry/OpenGL/extensions/OES/OES_sample_variables.txt
+            writeln!(out, "#extension GL_OES_sample_variables : require")?;
+        }
+
+        if self.0.contains(Features::MULTI_VIEW) {
+            if let Version::Embedded { is_webgl: true, .. } = options.version {
+                // https://www.khronos.org/registry/OpenGL/extensions/OVR/OVR_multiview2.txt
+                writeln!(out, "#extension GL_OVR_multiview2 : require")?;
+            } else {
+                // https://github.com/KhronosGroup/GLSL/blob/master/extensions/ext/GL_EXT_multiview.txt
+                writeln!(out, "#extension GL_EXT_multiview : require")?;
+            }
+        }
+
+        if self.0.contains(Features::TEXTURE_SAMPLES) {
+            // https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_shader_texture_image_samples.txt
+            writeln!(
+                out,
+                "#extension GL_ARB_shader_texture_image_samples : require"
+            )?;
+        }
+
+        if self.0.contains(Features::TEXTURE_LEVELS) && options.version < Version::Desktop(430) {
+            // https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_texture_query_levels.txt
+            writeln!(out, "#extension GL_ARB_texture_query_levels : require")?;
+        }
+        if self.0.contains(Features::DUAL_SOURCE_BLENDING) && options.version.is_es() {
+            // https://registry.khronos.org/OpenGL/extensions/EXT/EXT_blend_func_extended.txt
+            writeln!(out, "#extension GL_EXT_blend_func_extended : require")?;
+        }
+
+        if self.0.contains(Features::INSTANCE_INDEX) {
+            if options.writer_flags.contains(WriterFlags::DRAW_PARAMETERS) {
+                // https://registry.khronos.org/OpenGL/extensions/ARB/ARB_shader_draw_parameters.txt
+                writeln!(out, "#extension GL_ARB_shader_draw_parameters : require")?;
+            }
+        }
+
+        Ok(())
+    }
+}
+
+impl<'a, W> Writer<'a, W> {
+    /// Helper method that searches the module for all the needed [`Features`]
+    ///
+    /// # Errors
+    /// If the version doesn't support any of the needed [`Features`] a
+    /// [`Error::MissingFeatures`] will be returned
+    pub(super) fn collect_required_features(&mut self) -> BackendResult {
+        let ep_info = self.info.get_entry_point(self.entry_point_idx as usize);
+
+        if let Some(depth_test) = self.entry_point.early_depth_test {
+            // If IMAGE_LOAD_STORE is supported for this version of GLSL
+            if self.options.version.supports_early_depth_test() {
+                self.features.request(Features::IMAGE_LOAD_STORE);
+            }
+
+            if depth_test.conservative.is_some() {
+                self.features.request(Features::CONSERVATIVE_DEPTH);
+            }
+        }
+
+        for arg in self.entry_point.function.arguments.iter() {
+            self.varying_required_features(arg.binding.as_ref(), arg.ty);
+        }
+        if let Some(ref result) = self.entry_point.function.result {
+            self.varying_required_features(result.binding.as_ref(), result.ty);
+        }
+
+        if let ShaderStage::Compute = self.entry_point.stage {
+            self.features.request(Features::COMPUTE_SHADER)
+        }
+
+        if self.multiview.is_some() {
+            self.features.request(Features::MULTI_VIEW);
+        }
+
+        for (ty_handle, ty) in self.module.types.iter() {
+            match ty.inner {
+                TypeInner::Scalar(scalar)
+                | TypeInner::Vector { scalar, .. }
+                | TypeInner::Matrix { scalar, .. } => self.scalar_required_features(scalar),
+                TypeInner::Array { base, size, .. } => {
+                    if let TypeInner::Array { .. } = self.module.types[base].inner {
+                        self.features.request(Features::ARRAY_OF_ARRAYS)
+                    }
+
+                    // If the array is dynamically sized
+                    if size == crate::ArraySize::Dynamic {
+                        let mut is_used = false;
+
+                        // Check if this type is used in a global that is needed by the current entrypoint
+                        for (global_handle, global) in self.module.global_variables.iter() {
+                            // Skip unused globals
+                            if ep_info[global_handle].is_empty() {
+                                continue;
+                            }
+
+                            // If this array is the type of a global, then this array is used
+                            if global.ty == ty_handle {
+                                is_used = true;
+                                break;
+                            }
+
+                            // If the type of this global is a struct
+                            if let crate::TypeInner::Struct { ref members, .. } =
+                                self.module.types[global.ty].inner
+                            {
+                                // Check the last element of the struct to see if it's type uses
+                                // this array
+                                if let Some(last) = members.last() {
+                                    if last.ty == ty_handle {
+                                        is_used = true;
+                                        break;
+                                    }
+                                }
+                            }
+                        }
+
+                        // If this dynamically size array is used, we need dynamic array size support
+                        if is_used {
+                            self.features.request(Features::DYNAMIC_ARRAY_SIZE);
+                        }
+                    }
+                }
+                TypeInner::Image {
+                    dim,
+                    arrayed,
+                    class,
+                } => {
+                    if arrayed && dim == ImageDimension::Cube {
+                        self.features.request(Features::CUBE_TEXTURES_ARRAY)
+                    }
+
+                    match class {
+                        ImageClass::Sampled { multi: true, .. }
+                        | ImageClass::Depth { multi: true } => {
+                            self.features.request(Features::MULTISAMPLED_TEXTURES);
+                            if arrayed {
+                                self.features.request(Features::MULTISAMPLED_TEXTURE_ARRAYS);
+                            }
+                        }
+                        ImageClass::Storage { format, .. } => match format {
+                            StorageFormat::R8Unorm
+                            | StorageFormat::R8Snorm
+                            | StorageFormat::R8Uint
+                            | StorageFormat::R8Sint
+                            | StorageFormat::R16Uint
+                            | StorageFormat::R16Sint
+                            | StorageFormat::R16Float
+                            | StorageFormat::Rg8Unorm
+                            | StorageFormat::Rg8Snorm
+                            | StorageFormat::Rg8Uint
+                            | StorageFormat::Rg8Sint
+                            | StorageFormat::Rg16Uint
+                            | StorageFormat::Rg16Sint
+                            | StorageFormat::Rg16Float
+                            | StorageFormat::Rgb10a2Uint
+                            | StorageFormat::Rgb10a2Unorm
+                            | StorageFormat::Rg11b10Float
+                            | StorageFormat::Rg32Uint
+                            | StorageFormat::Rg32Sint
+                            | StorageFormat::Rg32Float => {
+                                self.features.request(Features::FULL_IMAGE_FORMATS)
+                            }
+                            _ => {}
+                        },
+                        ImageClass::Sampled { multi: false, .. }
+                        | ImageClass::Depth { multi: false } => {}
+                    }
+                }
+                _ => {}
+            }
+        }
+
+        let mut push_constant_used = false;
+
+        for (handle, global) in self.module.global_variables.iter() {
+            if ep_info[handle].is_empty() {
+                continue;
+            }
+            match global.space {
+                AddressSpace::WorkGroup => self.features.request(Features::COMPUTE_SHADER),
+                AddressSpace::Storage { .. } => self.features.request(Features::BUFFER_STORAGE),
+                AddressSpace::PushConstant => {
+                    if push_constant_used {
+                        return Err(Error::MultiplePushConstants);
+                    }
+                    push_constant_used = true;
+                }
+                _ => {}
+            }
+        }
+
+        // We will need to pass some of the members to a closure, so we need
+        // to separate them otherwise the borrow checker will complain, this
+        // shouldn't be needed in rust 2021
+        let &mut Self {
+            module,
+            info,
+            ref mut features,
+            entry_point,
+            entry_point_idx,
+            ref policies,
+            ..
+        } = self;
+
+        // Loop trough all expressions in both functions and the entry point
+        // to check for needed features
+        for (expressions, info) in module
+            .functions
+            .iter()
+            .map(|(h, f)| (&f.expressions, &info[h]))
+            .chain(std::iter::once((
+                &entry_point.function.expressions,
+                info.get_entry_point(entry_point_idx as usize),
+            )))
+        {
+            for (_, expr) in expressions.iter() {
+                match *expr {
+                // Check for queries that need aditonal features
+                Expression::ImageQuery {
+                    image,
+                    query,
+                    ..
+                } => match query {
+                    // Storage images use `imageSize` which is only available
+                    // in glsl > 420
+                    //
+                    // layers queries are also implemented as size queries
+                    crate::ImageQuery::Size { .. } | crate::ImageQuery::NumLayers => {
+                        if let TypeInner::Image {
+                            class: crate::ImageClass::Storage { .. }, ..
+                        } = *info[image].ty.inner_with(&module.types) {
+                            features.request(Features::IMAGE_SIZE)
+                        }
+                    },
+                    crate::ImageQuery::NumLevels => features.request(Features::TEXTURE_LEVELS),
+                    crate::ImageQuery::NumSamples => features.request(Features::TEXTURE_SAMPLES),
+                }
+                ,
+                // Check for image loads that needs bound checking on the sample
+                // or level argument since this requires a feature
+                Expression::ImageLoad {
+                    sample, level, ..
+                } => {
+                    if policies.image_load != crate::proc::BoundsCheckPolicy::Unchecked {
+                        if sample.is_some() {
+                            features.request(Features::TEXTURE_SAMPLES)
+                        }
+
+                        if level.is_some() {
+                            features.request(Features::TEXTURE_LEVELS)
+                        }
+                    }
+                }
+                _ => {}
+            }
+            }
+        }
+
+        self.features.check_availability(self.options.version)
+    }
+
+    /// Helper method that checks the [`Features`] needed by a scalar
+    fn scalar_required_features(&mut self, scalar: Scalar) {
+        if scalar.kind == ScalarKind::Float && scalar.width == 8 {
+            self.features.request(Features::DOUBLE_TYPE);
+        }
+    }
+
+    fn varying_required_features(&mut self, binding: Option<&Binding>, ty: Handle<Type>) {
+        match self.module.types[ty].inner {
+            crate::TypeInner::Struct { ref members, .. } => {
+                for member in members {
+                    self.varying_required_features(member.binding.as_ref(), member.ty);
+                }
+            }
+            _ => {
+                if let Some(binding) = binding {
+                    match *binding {
+                        Binding::BuiltIn(built_in) => match built_in {
+                            crate::BuiltIn::ClipDistance => {
+                                self.features.request(Features::CLIP_DISTANCE)
+                            }
+                            crate::BuiltIn::CullDistance => {
+                                self.features.request(Features::CULL_DISTANCE)
+                            }
+                            crate::BuiltIn::SampleIndex => {
+                                self.features.request(Features::SAMPLE_VARIABLES)
+                            }
+                            crate::BuiltIn::ViewIndex => {
+                                self.features.request(Features::MULTI_VIEW)
+                            }
+                            crate::BuiltIn::InstanceIndex => {
+                                self.features.request(Features::INSTANCE_INDEX)
+                            }
+                            _ => {}
+                        },
+                        Binding::Location {
+                            location: _,
+                            interpolation,
+                            sampling,
+                            second_blend_source,
+                        } => {
+                            if interpolation == Some(Interpolation::Linear) {
+                                self.features.request(Features::NOPERSPECTIVE_QUALIFIER);
+                            }
+                            if sampling == Some(Sampling::Sample) {
+                                self.features.request(Features::SAMPLE_QUALIFIER);
+                            }
+                            if second_blend_source {
+                                self.features.request(Features::DUAL_SOURCE_BLENDING);
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
diff --git a/third_party/rust/naga/src/back/glsl/keywords.rs b/third_party/rust/naga/src/back/glsl/keywords.rs
new file mode 100644
index 0000000000..857c935e68
--- /dev/null
+++ b/third_party/rust/naga/src/back/glsl/keywords.rs
@@ -0,0 +1,484 @@
+pub const RESERVED_KEYWORDS: &[&str] = &[
+    //
+    // GLSL 4.6 keywords, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L2004-L2322
+    // GLSL ES 3.2 keywords, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/es/3.2/GLSL_ES_Specification_3.20.html#L2166-L2478
+    //
+    // Note: The GLSL ES 3.2 keywords are the same as GLSL 4.6 keywords with some residing in the reserved section.
+    // The only exception are the missing Vulkan keywords which I think is an oversight (see https://github.com/KhronosGroup/OpenGL-Registry/issues/585).
+    //
+    "const",
+    "uniform",
+    "buffer",
+    "shared",
+    "attribute",
+    "varying",
+    "coherent",
+    "volatile",
+    "restrict",
+    "readonly",
+    "writeonly",
+    "atomic_uint",
+    "layout",
+    "centroid",
+    "flat",
+    "smooth",
+    "noperspective",
+    "patch",
+    "sample",
+    "invariant",
+    "precise",
+    "break",
+    "continue",
+    "do",
+    "for",
+    "while",
+    "switch",
+    "case",
+    "default",
+    "if",
+    "else",
+    "subroutine",
+    "in",
+    "out",
+    "inout",
+    "int",
+    "void",
+    "bool",
+    "true",
+    "false",
+    "float",
+    "double",
+    "discard",
+    "return",
+    "vec2",
+    "vec3",
+    "vec4",
+    "ivec2",
+    "ivec3",
+    "ivec4",
+    "bvec2",
+    "bvec3",
+    "bvec4",
+    "uint",
+    "uvec2",
+    "uvec3",
+    "uvec4",
+    "dvec2",
+    "dvec3",
+    "dvec4",
+    "mat2",
+    "mat3",
+    "mat4",
+    "mat2x2",
+    "mat2x3",
+    "mat2x4",
+    "mat3x2",
+    "mat3x3",
+    "mat3x4",
+    "mat4x2",
+    "mat4x3",
+    "mat4x4",
+    "dmat2",
+    "dmat3",
+    "dmat4",
+    "dmat2x2",
+    "dmat2x3",
+    "dmat2x4",
+    "dmat3x2",
+    "dmat3x3",
+    "dmat3x4",
+    "dmat4x2",
+    "dmat4x3",
+    "dmat4x4",
+    "lowp",
+    "mediump",
+    "highp",
+    "precision",
+    "sampler1D",
+    "sampler1DShadow",
+    "sampler1DArray",
+    "sampler1DArrayShadow",
+    "isampler1D",
+    "isampler1DArray",
+    "usampler1D",
+    "usampler1DArray",
+    "sampler2D",
+    "sampler2DShadow",
+    "sampler2DArray",
+    "sampler2DArrayShadow",
+    "isampler2D",
+    "isampler2DArray",
+    "usampler2D",
+    "usampler2DArray",
+    "sampler2DRect",
+    "sampler2DRectShadow",
+    "isampler2DRect",
+    "usampler2DRect",
+    "sampler2DMS",
+    "isampler2DMS",
+    "usampler2DMS",
+    "sampler2DMSArray",
+    "isampler2DMSArray",
+    "usampler2DMSArray",
+    "sampler3D",
+    "isampler3D",
+    "usampler3D",
+    "samplerCube",
+    "samplerCubeShadow",
+    "isamplerCube",
+    "usamplerCube",
+    "samplerCubeArray",
+    "samplerCubeArrayShadow",
+    "isamplerCubeArray",
+    "usamplerCubeArray",
+    "samplerBuffer",
+    "isamplerBuffer",
+    "usamplerBuffer",
+    "image1D",
+    "iimage1D",
+    "uimage1D",
+    "image1DArray",
+    "iimage1DArray",
+    "uimage1DArray",
+    "image2D",
+    "iimage2D",
+    "uimage2D",
+    "image2DArray",
+    "iimage2DArray",
+    "uimage2DArray",
+    "image2DRect",
+    "iimage2DRect",
+    "uimage2DRect",
+    "image2DMS",
+    "iimage2DMS",
+    "uimage2DMS",
+    "image2DMSArray",
+    "iimage2DMSArray",
+    "uimage2DMSArray",
+    "image3D",
+    "iimage3D",
+    "uimage3D",
+    "imageCube",
+    "iimageCube",
+    "uimageCube",
+    "imageCubeArray",
+    "iimageCubeArray",
+    "uimageCubeArray",
+    "imageBuffer",
+    "iimageBuffer",
+    "uimageBuffer",
+    "struct",
+    // Vulkan keywords
+    "texture1D",
+    "texture1DArray",
+    "itexture1D",
+    "itexture1DArray",
+    "utexture1D",
+    "utexture1DArray",
+    "texture2D",
+    "texture2DArray",
+    "itexture2D",
+    "itexture2DArray",
+    "utexture2D",
+    "utexture2DArray",
+    "texture2DRect",
+    "itexture2DRect",
+    "utexture2DRect",
+    "texture2DMS",
+    "itexture2DMS",
+    "utexture2DMS",
+    "texture2DMSArray",
+    "itexture2DMSArray",
+    "utexture2DMSArray",
+    "texture3D",
+    "itexture3D",
+    "utexture3D",
+    "textureCube",
+    "itextureCube",
+    "utextureCube",
+    "textureCubeArray",
+    "itextureCubeArray",
+    "utextureCubeArray",
+    "textureBuffer",
+    "itextureBuffer",
+    "utextureBuffer",
+    "sampler",
+    "samplerShadow",
+    "subpassInput",
+    "isubpassInput",
+    "usubpassInput",
+    "subpassInputMS",
+    "isubpassInputMS",
+    "usubpassInputMS",
+    // Reserved keywords
+    "common",
+    "partition",
+    "active",
+    "asm",
+    "class",
+    "union",
+    "enum",
+    "typedef",
+    "template",
+    "this",
+    "resource",
+    "goto",
+    "inline",
+    "noinline",
+    "public",
+    "static",
+    "extern",
+    "external",
+    "interface",
+    "long",
+    "short",
+    "half",
+    "fixed",
+    "unsigned",
+    "superp",
+    "input",
+    "output",
+    "hvec2",
+    "hvec3",
+    "hvec4",
+    "fvec2",
+    "fvec3",
+    "fvec4",
+    "filter",
+    "sizeof",
+    "cast",
+    "namespace",
+    "using",
+    "sampler3DRect",
+    //
+    // GLSL 4.6 Built-In Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L13314
+    //
+    // Angle and Trigonometry Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L13469-L13561C5
+    "radians",
+    "degrees",
+    "sin",
+    "cos",
+    "tan",
+    "asin",
+    "acos",
+    "atan",
+    "sinh",
+    "cosh",
+    "tanh",
+    "asinh",
+    "acosh",
+    "atanh",
+    // Exponential Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L13569-L13620
+    "pow",
+    "exp",
+    "log",
+    "exp2",
+    "log2",
+    "sqrt",
+    "inversesqrt",
+    // Common Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L13628-L13908
+    "abs",
+    "sign",
+    "floor",
+    "trunc",
+    "round",
+    "roundEven",
+    "ceil",
+    "fract",
+    "mod",
+    "modf",
+    "min",
+    "max",
+    "clamp",
+    "mix",
+    "step",
+    "smoothstep",
+    "isnan",
+    "isinf",
+    "floatBitsToInt",
+    "floatBitsToUint",
+    "intBitsToFloat",
+    "uintBitsToFloat",
+    "fma",
+    "frexp",
+    "ldexp",
+    // Floating-Point Pack and Unpack Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L13916-L14007
+    "packUnorm2x16",
+    "packSnorm2x16",
+    "packUnorm4x8",
+    "packSnorm4x8",
+    "unpackUnorm2x16",
+    "unpackSnorm2x16",
+    "unpackUnorm4x8",
+    "unpackSnorm4x8",
+    "packHalf2x16",
+    "unpackHalf2x16",
+    "packDouble2x32",
+    "unpackDouble2x32",
+    // Geometric Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L14014-L14121
+    "length",
+    "distance",
+    "dot",
+    "cross",
+    "normalize",
+    "ftransform",
+    "faceforward",
+    "reflect",
+    "refract",
+    // Matrix Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L14151-L14215
+    "matrixCompMult",
+    "outerProduct",
+    "transpose",
+    "determinant",
+    "inverse",
+    // Vector Relational Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L14259-L14322
+    "lessThan",
+    "lessThanEqual",
+    "greaterThan",
+    "greaterThanEqual",
+    "equal",
+    "notEqual",
+    "any",
+    "all",
+    "not",
+    // Integer Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L14335-L14432
+    "uaddCarry",
+    "usubBorrow",
+    "umulExtended",
+    "imulExtended",
+    "bitfieldExtract",
+    "bitfieldInsert",
+    "bitfieldReverse",
+    "bitCount",
+    "findLSB",
+    "findMSB",
+    // Texture Query Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L14645-L14732
+    "textureSize",
+    "textureQueryLod",
+    "textureQueryLevels",
+    "textureSamples",
+    // Texel Lookup Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L14736-L14997
+    "texture",
+    "textureProj",
+    "textureLod",
+    "textureOffset",
+    "texelFetch",
+    "texelFetchOffset",
+    "textureProjOffset",
+    "textureLodOffset",
+    "textureProjLod",
+    "textureProjLodOffset",
+    "textureGrad",
+    "textureGradOffset",
+    "textureProjGrad",
+    "textureProjGradOffset",
+    // Texture Gather Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L15077-L15154
+    "textureGather",
+    "textureGatherOffset",
+    "textureGatherOffsets",
+    // Compatibility Profile Texture Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L15161-L15220
+    "texture1D",
+    "texture1DProj",
+    "texture1DLod",
+    "texture1DProjLod",
+    "texture2D",
+    "texture2DProj",
+    "texture2DLod",
+    "texture2DProjLod",
+    "texture3D",
+    "texture3DProj",
+    "texture3DLod",
+    "texture3DProjLod",
+    "textureCube",
+    "textureCubeLod",
+    "shadow1D",
+    "shadow2D",
+    "shadow1DProj",
+    "shadow2DProj",
+    "shadow1DLod",
+    "shadow2DLod",
+    "shadow1DProjLod",
+    "shadow2DProjLod",
+    // Atomic Counter Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L15241-L15531
+    "atomicCounterIncrement",
+    "atomicCounterDecrement",
+    "atomicCounter",
+    "atomicCounterAdd",
+    "atomicCounterSubtract",
+    "atomicCounterMin",
+    "atomicCounterMax",
+    "atomicCounterAnd",
+    "atomicCounterOr",
+    "atomicCounterXor",
+    "atomicCounterExchange",
+    "atomicCounterCompSwap",
+    // Atomic Memory Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L15563-L15624
+    "atomicAdd",
+    "atomicMin",
+    "atomicMax",
+    "atomicAnd",
+    "atomicOr",
+    "atomicXor",
+    "atomicExchange",
+    "atomicCompSwap",
+    // Image Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L15763-L15878
+    "imageSize",
+    "imageSamples",
+    "imageLoad",
+    "imageStore",
+    "imageAtomicAdd",
+    "imageAtomicMin",
+    "imageAtomicMax",
+    "imageAtomicAnd",
+    "imageAtomicOr",
+    "imageAtomicXor",
+    "imageAtomicExchange",
+    "imageAtomicCompSwap",
+    // Geometry Shader Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L15886-L15932
+    "EmitStreamVertex",
+    "EndStreamPrimitive",
+    "EmitVertex",
+    "EndPrimitive",
+    // Fragment Processing Functions, Derivative Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L16041-L16114
+    "dFdx",
+    "dFdy",
+    "dFdxFine",
+    "dFdyFine",
+    "dFdxCoarse",
+    "dFdyCoarse",
+    "fwidth",
+    "fwidthFine",
+    "fwidthCoarse",
+    // Fragment Processing Functions, Interpolation Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L16150-L16198
+    "interpolateAtCentroid",
+    "interpolateAtSample",
+    "interpolateAtOffset",
+    // Noise Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L16214-L16243
+    "noise1",
+    "noise2",
+    "noise3",
+    "noise4",
+    // Shader Invocation Control Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L16255-L16276
+    "barrier",
+    // Shader Memory Control Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L16336-L16382
+    "memoryBarrier",
+    "memoryBarrierAtomicCounter",
+    "memoryBarrierBuffer",
+    "memoryBarrierShared",
+    "memoryBarrierImage",
+    "groupMemoryBarrier",
+    // Subpass-Input Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L16451-L16470
+    "subpassLoad",
+    // Shader Invocation Group Functions, from https://github.com/KhronosGroup/OpenGL-Registry/blob/d00e11dc1a1ffba581d633f21f70202051248d5c/specs/gl/GLSLangSpec.4.60.html#L16483-L16511
+    "anyInvocation",
+    "allInvocations",
+    "allInvocationsEqual",
+    //
+    // entry point name (should not be shadowed)
+    //
+    "main",
+    // Naga utilities:
+    super::MODF_FUNCTION,
+    super::FREXP_FUNCTION,
+    super::FIRST_INSTANCE_BINDING,
+];
diff --git a/third_party/rust/naga/src/back/glsl/mod.rs b/third_party/rust/naga/src/back/glsl/mod.rs
new file mode 100644
index 0000000000..e346d43257
--- /dev/null
+++ b/third_party/rust/naga/src/back/glsl/mod.rs
@@ -0,0 +1,4532 @@
+/*!
+Backend for [GLSL][glsl] (OpenGL Shading Language).
+
+The main structure is [`Writer`], it maintains internal state that is used
+to output a [`Module`](crate::Module) into glsl
+
+# Supported versions
+### Core
+- 330
+- 400
+- 410
+- 420
+- 430
+- 450
+
+### ES
+- 300
+- 310
+
+[glsl]: https://www.khronos.org/registry/OpenGL/index_gl.php
+*/
+
+// GLSL is mostly a superset of C but it also removes some parts of it this is a list of relevant
+// aspects for this backend.
+//
+// The most notable change is the introduction of the version preprocessor directive that must
+// always be the first line of a glsl file and is written as
+// `#version number profile`
+// `number` is the version itself (i.e. 300) and `profile` is the
+// shader profile we only support "core" and "es", the former is used in desktop applications and
+// the later is used in embedded contexts, mobile devices and browsers. Each one as it's own
+// versions (at the time of writing this the latest version for "core" is 460 and for "es" is 320)
+//
+// Other important preprocessor addition is the extension directive which is written as
+// `#extension name: behaviour`
+// Extensions provide increased features in a plugin fashion but they aren't required to be
+// supported hence why they are called extensions, that's why `behaviour` is used it specifies
+// whether the extension is strictly required or if it should only be enabled if needed. In our case
+// when we use extensions we set behaviour to `require` always.
+//
+// The only thing that glsl removes that makes a difference are pointers.
+//
+// Additions that are relevant for the backend are the discard keyword, the introduction of
+// vector, matrices, samplers, image types and functions that provide common shader operations
+
+pub use features::Features;
+
+use crate::{
+    back,
+    proc::{self, NameKey},
+    valid, Handle, ShaderStage, TypeInner,
+};
+use features::FeaturesManager;
+use std::{
+    cmp::Ordering,
+    fmt,
+    fmt::{Error as FmtError, Write},
+    mem,
+};
+use thiserror::Error;
+
+/// Contains the features related code and the features querying method
+mod features;
+/// Contains a constant with a slice of all the reserved keywords RESERVED_KEYWORDS
+mod keywords;
+
+/// List of supported `core` GLSL versions.
+pub const SUPPORTED_CORE_VERSIONS: &[u16] = &[140, 150, 330, 400, 410, 420, 430, 440, 450, 460];
+/// List of supported `es` GLSL versions.
+pub const SUPPORTED_ES_VERSIONS: &[u16] = &[300, 310, 320];
+
+/// The suffix of the variable that will hold the calculated clamped level
+/// of detail for bounds checking in `ImageLoad`
+const CLAMPED_LOD_SUFFIX: &str = "_clamped_lod";
+
+pub(crate) const MODF_FUNCTION: &str = "naga_modf";
+pub(crate) const FREXP_FUNCTION: &str = "naga_frexp";
+
+// Must match code in glsl_built_in
+pub const FIRST_INSTANCE_BINDING: &str = "naga_vs_first_instance";
+
+/// Mapping between resources and bindings.
+pub type BindingMap = std::collections::BTreeMap<crate::ResourceBinding, u8>;
+
+impl crate::AtomicFunction {
+    const fn to_glsl(self) -> &'static str {
+        match self {
+            Self::Add | Self::Subtract => "Add",
+            Self::And => "And",
+            Self::InclusiveOr => "Or",
+            Self::ExclusiveOr => "Xor",
+            Self::Min => "Min",
+            Self::Max => "Max",
+            Self::Exchange { compare: None } => "Exchange",
+            Self::Exchange { compare: Some(_) } => "", //TODO
+        }
+    }
+}
+
+impl crate::AddressSpace {
+    const fn is_buffer(&self) -> bool {
+        match *self {
+            crate::AddressSpace::Uniform | crate::AddressSpace::Storage { .. } => true,
+            _ => false,
+        }
+    }
+
+    /// Whether a variable with this address space can be initialized
+    const fn initializable(&self) -> bool {
+        match *self {
+            crate::AddressSpace::Function | crate::AddressSpace::Private => true,
+            crate::AddressSpace::WorkGroup
+            | crate::AddressSpace::Uniform
+            | crate::AddressSpace::Storage { .. }
+            | crate::AddressSpace::Handle
+            | crate::AddressSpace::PushConstant => false,
+        }
+    }
+}
+
+/// A GLSL version.
+#[derive(Debug, Copy, Clone, PartialEq)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub enum Version {
+    /// `core` GLSL.
+    Desktop(u16),
+    /// `es` GLSL.
+    Embedded { version: u16, is_webgl: bool },
+}
+
+impl Version {
+    /// Create a new gles version
+    pub const fn new_gles(version: u16) -> Self {
+        Self::Embedded {
+            version,
+            is_webgl: false,
+        }
+    }
+
+    /// Returns true if self is `Version::Embedded` (i.e. is a es version)
+    const fn is_es(&self) -> bool {
+        match *self {
+            Version::Desktop(_) => false,
+            Version::Embedded { .. } => true,
+        }
+    }
+
+    /// Returns true if targeting WebGL
+    const fn is_webgl(&self) -> bool {
+        match *self {
+            Version::Desktop(_) => false,
+            Version::Embedded { is_webgl, .. } => is_webgl,
+        }
+    }
+
+    /// Checks the list of currently supported versions and returns true if it contains the
+    /// specified version
+    ///
+    /// # Notes
+    /// As an invalid version number will never be added to the supported version list
+    /// so this also checks for version validity
+    fn is_supported(&self) -> bool {
+        match *self {
+            Version::Desktop(v) => SUPPORTED_CORE_VERSIONS.contains(&v),
+            Version::Embedded { version: v, .. } => SUPPORTED_ES_VERSIONS.contains(&v),
+        }
+    }
+
+    fn supports_io_locations(&self) -> bool {
+        *self >= Version::Desktop(330) || *self >= Version::new_gles(300)
+    }
+
+    /// Checks if the version supports all of the explicit layouts:
+    /// - `location=` qualifiers for bindings
+    /// - `binding=` qualifiers for resources
+    ///
+    /// Note: `location=` for vertex inputs and fragment outputs is supported
+    /// unconditionally for GLES 300.
+    fn supports_explicit_locations(&self) -> bool {
+        *self >= Version::Desktop(410) || *self >= Version::new_gles(310)
+    }
+
+    fn supports_early_depth_test(&self) -> bool {
+        *self >= Version::Desktop(130) || *self >= Version::new_gles(310)
+    }
+
+    fn supports_std430_layout(&self) -> bool {
+        *self >= Version::Desktop(430) || *self >= Version::new_gles(310)
+    }
+
+    fn supports_fma_function(&self) -> bool {
+        *self >= Version::Desktop(400) || *self >= Version::new_gles(320)
+    }
+
+    fn supports_integer_functions(&self) -> bool {
+        *self >= Version::Desktop(400) || *self >= Version::new_gles(310)
+    }
+
+    fn supports_frexp_function(&self) -> bool {
+        *self >= Version::Desktop(400) || *self >= Version::new_gles(310)
+    }
+
+    fn supports_derivative_control(&self) -> bool {
+        *self >= Version::Desktop(450)
+    }
+}
+
+impl PartialOrd for Version {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        match (*self, *other) {
+            (Version::Desktop(x), Version::Desktop(y)) => Some(x.cmp(&y)),
+            (Version::Embedded { version: x, .. }, Version::Embedded { version: y, .. }) => {
+                Some(x.cmp(&y))
+            }
+            _ => None,
+        }
+    }
+}
+
+impl fmt::Display for Version {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match *self {
+            Version::Desktop(v) => write!(f, "{v} core"),
+            Version::Embedded { version: v, .. } => write!(f, "{v} es"),
+        }
+    }
+}
+
+bitflags::bitflags! {
+    /// Configuration flags for the [`Writer`].
+    #[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+    #[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+    #[derive(Clone, Copy, Debug, Eq, PartialEq)]
+    pub struct WriterFlags: u32 {
+        /// Flip output Y and extend Z from (0, 1) to (-1, 1).
+        const ADJUST_COORDINATE_SPACE = 0x1;
+        /// Supports GL_EXT_texture_shadow_lod on the host, which provides
+        /// additional functions on shadows and arrays of shadows.
+        const TEXTURE_SHADOW_LOD = 0x2;
+        /// Supports ARB_shader_draw_parameters on the host, which provides
+        /// support for `gl_BaseInstanceARB`, `gl_BaseVertexARB`, and `gl_DrawIDARB`.
+        const DRAW_PARAMETERS = 0x4;
+        /// Include unused global variables, constants and functions. By default the output will exclude
+        /// global variables that are not used in the specified entrypoint (including indirect use),
+        /// all constant declarations, and functions that use excluded global variables.
+        const INCLUDE_UNUSED_ITEMS = 0x10;
+        /// Emit `PointSize` output builtin to vertex shaders, which is
+        /// required for drawing with `PointList` topology.
+        ///
+        /// https://registry.khronos.org/OpenGL/specs/es/3.2/GLSL_ES_Specification_3.20.html#built-in-language-variables
+        /// The variable gl_PointSize is intended for a shader to write the size of the point to be rasterized. It is measured in pixels.
+        /// If gl_PointSize is not written to, its value is undefined in subsequent pipe stages.
+        const FORCE_POINT_SIZE = 0x20;
+    }
+}
+
+/// Configuration used in the [`Writer`].
+#[derive(Debug, Clone)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub struct Options {
+    /// The GLSL version to be used.
+    pub version: Version,
+    /// Configuration flags for the [`Writer`].
+    pub writer_flags: WriterFlags,
+    /// Map of resources association to binding locations.
+    pub binding_map: BindingMap,
+    /// Should workgroup variables be zero initialized (by polyfilling)?
+    pub zero_initialize_workgroup_memory: bool,
+}
+
+impl Default for Options {
+    fn default() -> Self {
+        Options {
+            version: Version::new_gles(310),
+            writer_flags: WriterFlags::ADJUST_COORDINATE_SPACE,
+            binding_map: BindingMap::default(),
+            zero_initialize_workgroup_memory: true,
+        }
+    }
+}
+
+/// A subset of options meant to be changed per pipeline.
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub struct PipelineOptions {
+    /// The stage of the entry point.
+    pub shader_stage: ShaderStage,
+    /// The name of the entry point.
+    ///
+    /// If no entry point that matches is found while creating a [`Writer`], a error will be thrown.
+    pub entry_point: String,
+    /// How many views to render to, if doing multiview rendering.
+    pub multiview: Option<std::num::NonZeroU32>,
+}
+
+#[derive(Debug)]
+pub struct VaryingLocation {
+    /// The location of the global.
+    /// This corresponds to `layout(location = ..)` in GLSL.
+    pub location: u32,
+    /// The index which can be used for dual source blending.
+    /// This corresponds to `layout(index = ..)` in GLSL.
+    pub index: u32,
+}
+
+/// Reflection info for texture mappings and uniforms.
+#[derive(Debug)]
+pub struct ReflectionInfo {
+    /// Mapping between texture names and variables/samplers.
+    pub texture_mapping: crate::FastHashMap<String, TextureMapping>,
+    /// Mapping between uniform variables and names.
+    pub uniforms: crate::FastHashMap<Handle<crate::GlobalVariable>, String>,
+    /// Mapping between names and attribute locations.
+    pub varying: crate::FastHashMap<String, VaryingLocation>,
+    /// List of push constant items in the shader.
+    pub push_constant_items: Vec<PushConstantItem>,
+}
+
+/// Mapping between a texture and its sampler, if it exists.
+///
+/// GLSL pre-Vulkan has no concept of separate textures and samplers. Instead, everything is a
+/// `gsamplerN` where `g` is the scalar type and `N` is the dimension. But naga uses separate textures
+/// and samplers in the IR, so the backend produces a [`FastHashMap`](crate::FastHashMap) with the texture name
+/// as a key and a [`TextureMapping`] as a value. This way, the user knows where to bind.
+///
+/// [`Storage`](crate::ImageClass::Storage) images produce `gimageN` and don't have an associated sampler,
+/// so the [`sampler`](Self::sampler) field will be [`None`].
+#[derive(Debug, Clone)]
+pub struct TextureMapping {
+    /// Handle to the image global variable.
+    pub texture: Handle<crate::GlobalVariable>,
+    /// Handle to the associated sampler global variable, if it exists.
+    pub sampler: Option<Handle<crate::GlobalVariable>>,
+}
+
+/// All information to bind a single uniform value to the shader.
+///
+/// Push constants are emulated using traditional uniforms in OpenGL.
+///
+/// These are composed of a set of primitives (scalar, vector, matrix) that
+/// are given names. Because they are not backed by the concept of a buffer,
+/// we must do the work of calculating the offset of each primitive in the
+/// push constant block.
+#[derive(Debug, Clone)]
+pub struct PushConstantItem {
+    /// GL uniform name for the item. This name is the same as if you were
+    /// to access it directly from a GLSL shader.
+    ///
+    /// The with the following example, the following names will be generated,
+    /// one name per GLSL uniform.
+    ///
+    /// ```glsl
+    /// struct InnerStruct {
+    ///     value: f32,
+    /// }
+    ///
+    /// struct PushConstant {
+    ///     InnerStruct inner;
+    ///     vec4 array[2];
+    /// }
+    ///
+    /// uniform PushConstants _push_constant_binding_cs;
+    /// ```
+    ///
+    /// ```text
+    /// - _push_constant_binding_cs.inner.value
+    /// - _push_constant_binding_cs.array[0]
+    /// - _push_constant_binding_cs.array[1]
+    /// ```
+    ///
+    pub access_path: String,
+    /// Type of the uniform. This will only ever be a scalar, vector, or matrix.
+    pub ty: Handle<crate::Type>,
+    /// The offset in the push constant memory block this uniform maps to.
+    ///
+    /// The size of the uniform can be derived from the type.
+    pub offset: u32,
+}
+
+/// Helper structure that generates a number
+#[derive(Default)]
+struct IdGenerator(u32);
+
+impl IdGenerator {
+    /// Generates a number that's guaranteed to be unique for this `IdGenerator`
+    fn generate(&mut self) -> u32 {
+        // It's just an increasing number but it does the job
+        let ret = self.0;
+        self.0 += 1;
+        ret
+    }
+}
+
+/// Assorted options needed for generating varyings.
+#[derive(Clone, Copy)]
+struct VaryingOptions {
+    output: bool,
+    targeting_webgl: bool,
+    draw_parameters: bool,
+}
+
+impl VaryingOptions {
+    const fn from_writer_options(options: &Options, output: bool) -> Self {
+        Self {
+            output,
+            targeting_webgl: options.version.is_webgl(),
+            draw_parameters: options.writer_flags.contains(WriterFlags::DRAW_PARAMETERS),
+        }
+    }
+}
+
+/// Helper wrapper used to get a name for a varying
+///
+/// Varying have different naming schemes depending on their binding:
+/// - Varyings with builtin bindings get the from [`glsl_built_in`].
+/// - Varyings with location bindings are named `_S_location_X` where `S` is a
+///   prefix identifying which pipeline stage the varying connects, and `X` is
+///   the location.
+struct VaryingName<'a> {
+    binding: &'a crate::Binding,
+    stage: ShaderStage,
+    options: VaryingOptions,
+}
+impl fmt::Display for VaryingName<'_> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match *self.binding {
+            crate::Binding::Location {
+                second_blend_source: true,
+                ..
+            } => {
+                write!(f, "_fs2p_location1",)
+            }
+            crate::Binding::Location { location, .. } => {
+                let prefix = match (self.stage, self.options.output) {
+                    (ShaderStage::Compute, _) => unreachable!(),
+                    // pipeline to vertex
+                    (ShaderStage::Vertex, false) => "p2vs",
+                    // vertex to fragment
+                    (ShaderStage::Vertex, true) | (ShaderStage::Fragment, false) => "vs2fs",
+                    // fragment to pipeline
+                    (ShaderStage::Fragment, true) => "fs2p",
+                };
+                write!(f, "_{prefix}_location{location}",)
+            }
+            crate::Binding::BuiltIn(built_in) => {
+                write!(f, "{}", glsl_built_in(built_in, self.options))
+            }
+        }
+    }
+}
+
+impl ShaderStage {
+    const fn to_str(self) -> &'static str {
+        match self {
+            ShaderStage::Compute => "cs",
+            ShaderStage::Fragment => "fs",
+            ShaderStage::Vertex => "vs",
+        }
+    }
+}
+
+/// Shorthand result used internally by the backend
+type BackendResult<T = ()> = Result<T, Error>;
+
+/// A GLSL compilation error.
+#[derive(Debug, Error)]
+pub enum Error {
+    /// A error occurred while writing to the output.
+    #[error("Format error")]
+    FmtError(#[from] FmtError),
+    /// The specified [`Version`] doesn't have all required [`Features`].
+    ///
+    /// Contains the missing [`Features`].
+    #[error("The selected version doesn't support {0:?}")]
+    MissingFeatures(Features),
+    /// [`AddressSpace::PushConstant`](crate::AddressSpace::PushConstant) was used more than
+    /// once in the entry point, which isn't supported.
+    #[error("Multiple push constants aren't supported")]
+    MultiplePushConstants,
+    /// The specified [`Version`] isn't supported.
+    #[error("The specified version isn't supported")]
+    VersionNotSupported,
+    /// The entry point couldn't be found.
+    #[error("The requested entry point couldn't be found")]
+    EntryPointNotFound,
+    /// A call was made to an unsupported external.
+    #[error("A call was made to an unsupported external: {0}")]
+    UnsupportedExternal(String),
+    /// A scalar with an unsupported width was requested.
+    #[error("A scalar with an unsupported width was requested: {0:?}")]
+    UnsupportedScalar(crate::Scalar),
+    /// A image was used with multiple samplers, which isn't supported.
+    #[error("A image was used with multiple samplers")]
+    ImageMultipleSamplers,
+    #[error("{0}")]
+    Custom(String),
+}
+
+/// Binary operation with a different logic on the GLSL side.
+enum BinaryOperation {
+    /// Vector comparison should use the function like `greaterThan()`, etc.
+    VectorCompare,
+    /// Vector component wise operation; used to polyfill unsupported ops like `|` and `&` for `bvecN`'s
+    VectorComponentWise,
+    /// GLSL `%` is SPIR-V `OpUMod/OpSMod` and `mod()` is `OpFMod`, but [`BinaryOperator::Modulo`](crate::BinaryOperator::Modulo) is `OpFRem`.
+    Modulo,
+    /// Any plain operation. No additional logic required.
+    Other,
+}
+
+/// Writer responsible for all code generation.
+pub struct Writer<'a, W> {
+    // Inputs
+    /// The module being written.
+    module: &'a crate::Module,
+    /// The module analysis.
+    info: &'a valid::ModuleInfo,
+    /// The output writer.
+    out: W,
+    /// User defined configuration to be used.
+    options: &'a Options,
+    /// The bound checking policies to be used
+    policies: proc::BoundsCheckPolicies,
+
+    // Internal State
+    /// Features manager used to store all the needed features and write them.
+    features: FeaturesManager,
+    namer: proc::Namer,
+    /// A map with all the names needed for writing the module
+    /// (generated by a [`Namer`](crate::proc::Namer)).
+    names: crate::FastHashMap<NameKey, String>,
+    /// A map with the names of global variables needed for reflections.
+    reflection_names_globals: crate::FastHashMap<Handle<crate::GlobalVariable>, String>,
+    /// The selected entry point.
+    entry_point: &'a crate::EntryPoint,
+    /// The index of the selected entry point.
+    entry_point_idx: proc::EntryPointIndex,
+    /// A generator for unique block numbers.
+    block_id: IdGenerator,
+    /// Set of expressions that have associated temporary variables.
+    named_expressions: crate::NamedExpressions,
+    /// Set of expressions that need to be baked to avoid unnecessary repetition in output
+    need_bake_expressions: back::NeedBakeExpressions,
+    /// How many views to render to, if doing multiview rendering.
+    multiview: Option<std::num::NonZeroU32>,
+    /// Mapping of varying variables to their location. Needed for reflections.
+    varying: crate::FastHashMap<String, VaryingLocation>,
+}
+
+impl<'a, W: Write> Writer<'a, W> {
+    /// Creates a new [`Writer`] instance.
+    ///
+    /// # Errors
+    /// - If the version specified is invalid or supported.
+    /// - If the entry point couldn't be found in the module.
+    /// - If the version specified doesn't support some used features.
+    pub fn new(
+        out: W,
+        module: &'a crate::Module,
+        info: &'a valid::ModuleInfo,
+        options: &'a Options,
+        pipeline_options: &'a PipelineOptions,
+        policies: proc::BoundsCheckPolicies,
+    ) -> Result<Self, Error> {
+        // Check if the requested version is supported
+        if !options.version.is_supported() {
+            log::error!("Version {}", options.version);
+            return Err(Error::VersionNotSupported);
+        }
+
+        // Try to find the entry point and corresponding index
+        let ep_idx = module
+            .entry_points
+            .iter()
+            .position(|ep| {
+                pipeline_options.shader_stage == ep.stage && pipeline_options.entry_point == ep.name
+            })
+            .ok_or(Error::EntryPointNotFound)?;
+
+        // Generate a map with names required to write the module
+        let mut names = crate::FastHashMap::default();
+        let mut namer = proc::Namer::default();
+        namer.reset(
+            module,
+            keywords::RESERVED_KEYWORDS,
+            &[],
+            &[],
+            &[
+                "gl_",                     // all GL built-in variables
+                "_group",                  // all normal bindings
+                "_push_constant_binding_", // all push constant bindings
+            ],
+            &mut names,
+        );
+
+        // Build the instance
+        let mut this = Self {
+            module,
+            info,
+            out,
+            options,
+            policies,
+
+            namer,
+            features: FeaturesManager::new(),
+            names,
+            reflection_names_globals: crate::FastHashMap::default(),
+            entry_point: &module.entry_points[ep_idx],
+            entry_point_idx: ep_idx as u16,
+            multiview: pipeline_options.multiview,
+            block_id: IdGenerator::default(),
+            named_expressions: Default::default(),
+            need_bake_expressions: Default::default(),
+            varying: Default::default(),
+        };
+
+        // Find all features required to print this module
+        this.collect_required_features()?;
+
+        Ok(this)
+    }
+
+    /// Writes the [`Module`](crate::Module) as glsl to the output
+    ///
+    /// # Notes
+    /// If an error occurs while writing, the output might have been written partially
+    ///
+    /// # Panics
+    /// Might panic if the module is invalid
+    pub fn write(&mut self) -> Result<ReflectionInfo, Error> {
+        // We use `writeln!(self.out)` throughout the write to add newlines
+        // to make the output more readable
+
+        let es = self.options.version.is_es();
+
+        // Write the version (It must be the first thing or it isn't a valid glsl output)
+        writeln!(self.out, "#version {}", self.options.version)?;
+        // Write all the needed extensions
+        //
+        // This used to be the last thing being written as it allowed to search for features while
+        // writing the module saving some loops but some older versions (420 or less) required the
+        // extensions to appear before being used, even though extensions are part of the
+        // preprocessor not the processor ¯\_(ツ)_/¯
+        self.features.write(self.options, &mut self.out)?;
+
+        // Write the additional extensions
+        if self
+            .options
+            .writer_flags
+            .contains(WriterFlags::TEXTURE_SHADOW_LOD)
+        {
+            // https://www.khronos.org/registry/OpenGL/extensions/EXT/EXT_texture_shadow_lod.txt
+            writeln!(self.out, "#extension GL_EXT_texture_shadow_lod : require")?;
+        }
+
+        // glsl es requires a precision to be specified for floats and ints
+        // TODO: Should this be user configurable?
+        if es {
+            writeln!(self.out)?;
+            writeln!(self.out, "precision highp float;")?;
+            writeln!(self.out, "precision highp int;")?;
+            writeln!(self.out)?;
+        }
+
+        if self.entry_point.stage == ShaderStage::Compute {
+            let workgroup_size = self.entry_point.workgroup_size;
+            writeln!(
+                self.out,
+                "layout(local_size_x = {}, local_size_y = {}, local_size_z = {}) in;",
+                workgroup_size[0], workgroup_size[1], workgroup_size[2]
+            )?;
+            writeln!(self.out)?;
+        }
+
+        if self.entry_point.stage == ShaderStage::Vertex
+            && !self
+                .options
+                .writer_flags
+                .contains(WriterFlags::DRAW_PARAMETERS)
+            && self.features.contains(Features::INSTANCE_INDEX)
+        {
+            writeln!(self.out, "uniform uint {FIRST_INSTANCE_BINDING};")?;
+            writeln!(self.out)?;
+        }
+
+        // Enable early depth tests if needed
+        if let Some(depth_test) = self.entry_point.early_depth_test {
+            // If early depth test is supported for this version of GLSL
+            if self.options.version.supports_early_depth_test() {
+                writeln!(self.out, "layout(early_fragment_tests) in;")?;
+
+                if let Some(conservative) = depth_test.conservative {
+                    use crate::ConservativeDepth as Cd;
+
+                    let depth = match conservative {
+                        Cd::GreaterEqual => "greater",
+                        Cd::LessEqual => "less",
+                        Cd::Unchanged => "unchanged",
+                    };
+                    writeln!(self.out, "layout (depth_{depth}) out float gl_FragDepth;")?;
+                }
+                writeln!(self.out)?;
+            } else {
+                log::warn!(
+                    "Early depth testing is not supported for this version of GLSL: {}",
+                    self.options.version
+                );
+            }
+        }
+
+        if self.entry_point.stage == ShaderStage::Vertex && self.options.version.is_webgl() {
+            if let Some(multiview) = self.multiview.as_ref() {
+                writeln!(self.out, "layout(num_views = {multiview}) in;")?;
+                writeln!(self.out)?;
+            }
+        }
+
+        // Write struct types.
+        //
+        // This are always ordered because the IR is structured in a way that
+        // you can't make a struct without adding all of its members first.
+        for (handle, ty) in self.module.types.iter() {
+            if let TypeInner::Struct { ref members, .. } = ty.inner {
+                // Structures ending with runtime-sized arrays can only be
+                // rendered as shader storage blocks in GLSL, not stand-alone
+                // struct types.
+                if !self.module.types[members.last().unwrap().ty]
+                    .inner
+                    .is_dynamically_sized(&self.module.types)
+                {
+                    let name = &self.names[&NameKey::Type(handle)];
+                    write!(self.out, "struct {name} ")?;
+                    self.write_struct_body(handle, members)?;
+                    writeln!(self.out, ";")?;
+                }
+            }
+        }
+
+        // Write functions to create special types.
+        for (type_key, struct_ty) in self.module.special_types.predeclared_types.iter() {
+            match type_key {
+                &crate::PredeclaredType::ModfResult { size, width }
+                | &crate::PredeclaredType::FrexpResult { size, width } => {
+                    let arg_type_name_owner;
+                    let arg_type_name = if let Some(size) = size {
+                        arg_type_name_owner =
+                            format!("{}vec{}", if width == 8 { "d" } else { "" }, size as u8);
+                        &arg_type_name_owner
+                    } else if width == 8 {
+                        "double"
+                    } else {
+                        "float"
+                    };
+
+                    let other_type_name_owner;
+                    let (defined_func_name, called_func_name, other_type_name) =
+                        if matches!(type_key, &crate::PredeclaredType::ModfResult { .. }) {
+                            (MODF_FUNCTION, "modf", arg_type_name)
+                        } else {
+                            let other_type_name = if let Some(size) = size {
+                                other_type_name_owner = format!("ivec{}", size as u8);
+                                &other_type_name_owner
+                            } else {
+                                "int"
+                            };
+                            (FREXP_FUNCTION, "frexp", other_type_name)
+                        };
+
+                    let struct_name = &self.names[&NameKey::Type(*struct_ty)];
+
+                    writeln!(self.out)?;
+                    if !self.options.version.supports_frexp_function()
+                        && matches!(type_key, &crate::PredeclaredType::FrexpResult { .. })
+                    {
+                        writeln!(
+                            self.out,
+                            "{struct_name} {defined_func_name}({arg_type_name} arg) {{
+    {other_type_name} other = arg == {arg_type_name}(0) ? {other_type_name}(0) : {other_type_name}({arg_type_name}(1) + log2(arg));
+    {arg_type_name} fract = arg * exp2({arg_type_name}(-other));
+    return {struct_name}(fract, other);
+}}",
+                        )?;
+                    } else {
+                        writeln!(
+                            self.out,
+                            "{struct_name} {defined_func_name}({arg_type_name} arg) {{
+    {other_type_name} other;
+    {arg_type_name} fract = {called_func_name}(arg, other);
+    return {struct_name}(fract, other);
+}}",
+                        )?;
+                    }
+                }
+                &crate::PredeclaredType::AtomicCompareExchangeWeakResult { .. } => {}
+            }
+        }
+
+        // Write all named constants
+        let mut constants = self
+            .module
+            .constants
+            .iter()
+            .filter(|&(_, c)| c.name.is_some())
+            .peekable();
+        while let Some((handle, _)) = constants.next() {
+            self.write_global_constant(handle)?;
+            // Add extra newline for readability on last iteration
+            if constants.peek().is_none() {
+                writeln!(self.out)?;
+            }
+        }
+
+        let ep_info = self.info.get_entry_point(self.entry_point_idx as usize);
+
+        // Write the globals
+        //
+        // Unless explicitly disabled with WriterFlags::INCLUDE_UNUSED_ITEMS,
+        // we filter all globals that aren't used by the selected entry point as they might be
+        // interfere with each other (i.e. two globals with the same location but different with
+        // different classes)
+        let include_unused = self
+            .options
+            .writer_flags
+            .contains(WriterFlags::INCLUDE_UNUSED_ITEMS);
+        for (handle, global) in self.module.global_variables.iter() {
+            let is_unused = ep_info[handle].is_empty();
+            if !include_unused && is_unused {
+                continue;
+            }
+
+            match self.module.types[global.ty].inner {
+                // We treat images separately because they might require
+                // writing the storage format
+                TypeInner::Image {
+                    mut dim,
+                    arrayed,
+                    class,
+                } => {
+                    // Gather the storage format if needed
+                    let storage_format_access = match self.module.types[global.ty].inner {
+                        TypeInner::Image {
+                            class: crate::ImageClass::Storage { format, access },
+                            ..
+                        } => Some((format, access)),
+                        _ => None,
+                    };
+
+                    if dim == crate::ImageDimension::D1 && es {
+                        dim = crate::ImageDimension::D2
+                    }
+
+                    // Gether the location if needed
+                    let layout_binding = if self.options.version.supports_explicit_locations() {
+                        let br = global.binding.as_ref().unwrap();
+                        self.options.binding_map.get(br).cloned()
+                    } else {
+                        None
+                    };
+
+                    // Write all the layout qualifiers
+                    if layout_binding.is_some() || storage_format_access.is_some() {
+                        write!(self.out, "layout(")?;
+                        if let Some(binding) = layout_binding {
+                            write!(self.out, "binding = {binding}")?;
+                        }
+                        if let Some((format, _)) = storage_format_access {
+                            let format_str = glsl_storage_format(format)?;
+                            let separator = match layout_binding {
+                                Some(_) => ",",
+                                None => "",
+                            };
+                            write!(self.out, "{separator}{format_str}")?;
+                        }
+                        write!(self.out, ") ")?;
+                    }
+
+                    if let Some((_, access)) = storage_format_access {
+                        self.write_storage_access(access)?;
+                    }
+
+                    // All images in glsl are `uniform`
+                    // The trailing space is important
+                    write!(self.out, "uniform ")?;
+
+                    // write the type
+                    //
+                    // This is way we need the leading space because `write_image_type` doesn't add
+                    // any spaces at the beginning or end
+                    self.write_image_type(dim, arrayed, class)?;
+
+                    // Finally write the name and end the global with a `;`
+                    // The leading space is important
+                    let global_name = self.get_global_name(handle, global);
+                    writeln!(self.out, " {global_name};")?;
+                    writeln!(self.out)?;
+
+                    self.reflection_names_globals.insert(handle, global_name);
+                }
+                // glsl has no concept of samplers so we just ignore it
+                TypeInner::Sampler { .. } => continue,
+                // All other globals are written by `write_global`
+                _ => {
+                    self.write_global(handle, global)?;
+                    // Add a newline (only for readability)
+                    writeln!(self.out)?;
+                }
+            }
+        }
+
+        for arg in self.entry_point.function.arguments.iter() {
+            self.write_varying(arg.binding.as_ref(), arg.ty, false)?;
+        }
+        if let Some(ref result) = self.entry_point.function.result {
+            self.write_varying(result.binding.as_ref(), result.ty, true)?;
+        }
+        writeln!(self.out)?;
+
+        // Write all regular functions
+        for (handle, function) in self.module.functions.iter() {
+            // Check that the function doesn't use globals that aren't supported
+            // by the current entry point
+            if !include_unused && !ep_info.dominates_global_use(&self.info[handle]) {
+                continue;
+            }
+
+            let fun_info = &self.info[handle];
+
+            // Skip functions that that are not compatible with this entry point's stage.
+            //
+            // When validation is enabled, it rejects modules whose entry points try to call
+            // incompatible functions, so if we got this far, then any functions incompatible
+            // with our selected entry point must not be used.
+            //
+            // When validation is disabled, `fun_info.available_stages` is always just
+            // `ShaderStages::all()`, so this will write all functions in the module, and
+            // the downstream GLSL compiler will catch any problems.
+            if !fun_info.available_stages.contains(ep_info.available_stages) {
+                continue;
+            }
+
+            // Write the function
+            self.write_function(back::FunctionType::Function(handle), function, fun_info)?;
+
+            writeln!(self.out)?;
+        }
+
+        self.write_function(
+            back::FunctionType::EntryPoint(self.entry_point_idx),
+            &self.entry_point.function,
+            ep_info,
+        )?;
+
+        // Add newline at the end of file
+        writeln!(self.out)?;
+
+        // Collect all reflection info and return it to the user
+        self.collect_reflection_info()
+    }
+
+    fn write_array_size(
+        &mut self,
+        base: Handle<crate::Type>,
+        size: crate::ArraySize,
+    ) -> BackendResult {
+        write!(self.out, "[")?;
+
+        // Write the array size
+        // Writes nothing if `ArraySize::Dynamic`
+        match size {
+            crate::ArraySize::Constant(size) => {
+                write!(self.out, "{size}")?;
+            }
+            crate::ArraySize::Dynamic => (),
+        }
+
+        write!(self.out, "]")?;
+
+        if let TypeInner::Array {
+            base: next_base,
+            size: next_size,
+            ..
+        } = self.module.types[base].inner
+        {
+            self.write_array_size(next_base, next_size)?;
+        }
+
+        Ok(())
+    }
+
+    /// Helper method used to write value types
+    ///
+    /// # Notes
+    /// Adds no trailing or leading whitespace
+    fn write_value_type(&mut self, inner: &TypeInner) -> BackendResult {
+        match *inner {
+            // Scalars are simple we just get the full name from `glsl_scalar`
+            TypeInner::Scalar(scalar)
+            | TypeInner::Atomic(scalar)
+            | TypeInner::ValuePointer {
+                size: None,
+                scalar,
+                space: _,
+            } => write!(self.out, "{}", glsl_scalar(scalar)?.full)?,
+            // Vectors are just `gvecN` where `g` is the scalar prefix and `N` is the vector size
+            TypeInner::Vector { size, scalar }
+            | TypeInner::ValuePointer {
+                size: Some(size),
+                scalar,
+                space: _,
+            } => write!(self.out, "{}vec{}", glsl_scalar(scalar)?.prefix, size as u8)?,
+            // Matrices are written with `gmatMxN` where `g` is the scalar prefix (only floats and
+            // doubles are allowed), `M` is the columns count and `N` is the rows count
+            //
+            // glsl supports a matrix shorthand `gmatN` where `N` = `M` but it doesn't justify the
+            // extra branch to write matrices this way
+            TypeInner::Matrix {
+                columns,
+                rows,
+                scalar,
+            } => write!(
+                self.out,
+                "{}mat{}x{}",
+                glsl_scalar(scalar)?.prefix,
+                columns as u8,
+                rows as u8
+            )?,
+            // GLSL arrays are written as `type name[size]`
+            // Here we only write the size of the array i.e. `[size]`
+            // Base `type` and `name` should be written outside
+            TypeInner::Array { base, size, .. } => self.write_array_size(base, size)?,
+            // Write all variants instead of `_` so that if new variants are added a
+            // no exhaustiveness error is thrown
+            TypeInner::Pointer { .. }
+            | TypeInner::Struct { .. }
+            | TypeInner::Image { .. }
+            | TypeInner::Sampler { .. }
+            | TypeInner::AccelerationStructure
+            | TypeInner::RayQuery
+            | TypeInner::BindingArray { .. } => {
+                return Err(Error::Custom(format!("Unable to write type {inner:?}")))
+            }
+        }
+
+        Ok(())
+    }
+
+    /// Helper method used to write non image/sampler types
+    ///
+    /// # Notes
+    /// Adds no trailing or leading whitespace
+    fn write_type(&mut self, ty: Handle<crate::Type>) -> BackendResult {
+        match self.module.types[ty].inner {
+            // glsl has no pointer types so just write types as normal and loads are skipped
+            TypeInner::Pointer { base, .. } => self.write_type(base),
+            // glsl structs are written as just the struct name
+            TypeInner::Struct { .. } => {
+                // Get the struct name
+                let name = &self.names[&NameKey::Type(ty)];
+                write!(self.out, "{name}")?;
+                Ok(())
+            }
+            // glsl array has the size separated from the base type
+            TypeInner::Array { base, .. } => self.write_type(base),
+            ref other => self.write_value_type(other),
+        }
+    }
+
+    /// Helper method to write a image type
+    ///
+    /// # Notes
+    /// Adds no leading or trailing whitespace
+    fn write_image_type(
+        &mut self,
+        dim: crate::ImageDimension,
+        arrayed: bool,
+        class: crate::ImageClass,
+    ) -> BackendResult {
+        // glsl images consist of four parts the scalar prefix, the image "type", the dimensions
+        // and modifiers
+        //
+        // There exists two image types
+        // - sampler - for sampled images
+        // - image - for storage images
+        //
+        // There are three possible modifiers that can be used together and must be written in
+        // this order to be valid
+        // - MS - used if it's a multisampled image
+        // - Array - used if it's an image array
+        // - Shadow - used if it's a depth image
+        use crate::ImageClass as Ic;
+
+        let (base, kind, ms, comparison) = match class {
+            Ic::Sampled { kind, multi: true } => ("sampler", kind, "MS", ""),
+            Ic::Sampled { kind, multi: false } => ("sampler", kind, "", ""),
+            Ic::Depth { multi: true } => ("sampler", crate::ScalarKind::Float, "MS", ""),
+            Ic::Depth { multi: false } => ("sampler", crate::ScalarKind::Float, "", "Shadow"),
+            Ic::Storage { format, .. } => ("image", format.into(), "", ""),
+        };
+
+        let precision = if self.options.version.is_es() {
+            "highp "
+        } else {
+            ""
+        };
+
+        write!(
+            self.out,
+            "{}{}{}{}{}{}{}",
+            precision,
+            glsl_scalar(crate::Scalar { kind, width: 4 })?.prefix,
+            base,
+            glsl_dimension(dim),
+            ms,
+            if arrayed { "Array" } else { "" },
+            comparison
+        )?;
+
+        Ok(())
+    }
+
+    /// Helper method used to write non images/sampler globals
+    ///
+    /// # Notes
+    /// Adds a newline
+    ///
+    /// # Panics
+    /// If the global has type sampler
+    fn write_global(
+        &mut self,
+        handle: Handle<crate::GlobalVariable>,
+        global: &crate::GlobalVariable,
+    ) -> BackendResult {
+        if self.options.version.supports_explicit_locations() {
+            if let Some(ref br) = global.binding {
+                match self.options.binding_map.get(br) {
+                    Some(binding) => {
+                        let layout = match global.space {
+                            crate::AddressSpace::Storage { .. } => {
+                                if self.options.version.supports_std430_layout() {
+                                    "std430, "
+                                } else {
+                                    "std140, "
+                                }
+                            }
+                            crate::AddressSpace::Uniform => "std140, ",
+                            _ => "",
+                        };
+                        write!(self.out, "layout({layout}binding = {binding}) ")?
+                    }
+                    None => {
+                        log::debug!("unassigned binding for {:?}", global.name);
+                        if let crate::AddressSpace::Storage { .. } = global.space {
+                            if self.options.version.supports_std430_layout() {
+                                write!(self.out, "layout(std430) ")?
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        if let crate::AddressSpace::Storage { access } = global.space {
+            self.write_storage_access(access)?;
+        }
+
+        if let Some(storage_qualifier) = glsl_storage_qualifier(global.space) {
+            write!(self.out, "{storage_qualifier} ")?;
+        }
+
+        match global.space {
+            crate::AddressSpace::Private => {
+                self.write_simple_global(handle, global)?;
+            }
+            crate::AddressSpace::WorkGroup => {
+                self.write_simple_global(handle, global)?;
+            }
+            crate::AddressSpace::PushConstant => {
+                self.write_simple_global(handle, global)?;
+            }
+            crate::AddressSpace::Uniform => {
+                self.write_interface_block(handle, global)?;
+            }
+            crate::AddressSpace::Storage { .. } => {
+                self.write_interface_block(handle, global)?;
+            }
+            // A global variable in the `Function` address space is a
+            // contradiction in terms.
+            crate::AddressSpace::Function => unreachable!(),
+            // Textures and samplers are handled directly in `Writer::write`.
+            crate::AddressSpace::Handle => unreachable!(),
+        }
+
+        Ok(())
+    }
+
+    fn write_simple_global(
+        &mut self,
+        handle: Handle<crate::GlobalVariable>,
+        global: &crate::GlobalVariable,
+    ) -> BackendResult {
+        self.write_type(global.ty)?;
+        write!(self.out, " ")?;
+        self.write_global_name(handle, global)?;
+
+        if let TypeInner::Array { base, size, .. } = self.module.types[global.ty].inner {
+            self.write_array_size(base, size)?;
+        }
+
+        if global.space.initializable() && is_value_init_supported(self.module, global.ty) {
+            write!(self.out, " = ")?;
+            if let Some(init) = global.init {
+                self.write_const_expr(init)?;
+            } else {
+                self.write_zero_init_value(global.ty)?;
+            }
+        }
+
+        writeln!(self.out, ";")?;
+
+        if let crate::AddressSpace::PushConstant = global.space {
+            let global_name = self.get_global_name(handle, global);
+            self.reflection_names_globals.insert(handle, global_name);
+        }
+
+        Ok(())
+    }
+
+    /// Write an interface block for a single Naga global.
+    ///
+    /// Write `block_name { members }`. Since `block_name` must be unique
+    /// between blocks and structs, we add `_block_ID` where `ID` is a
+    /// `IdGenerator` generated number. Write `members` in the same way we write
+    /// a struct's members.
+    fn write_interface_block(
+        &mut self,
+        handle: Handle<crate::GlobalVariable>,
+        global: &crate::GlobalVariable,
+    ) -> BackendResult {
+        // Write the block name, it's just the struct name appended with `_block_ID`
+        let ty_name = &self.names[&NameKey::Type(global.ty)];
+        let block_name = format!(
+            "{}_block_{}{:?}",
+            // avoid double underscores as they are reserved in GLSL
+            ty_name.trim_end_matches('_'),
+            self.block_id.generate(),
+            self.entry_point.stage,
+        );
+        write!(self.out, "{block_name} ")?;
+        self.reflection_names_globals.insert(handle, block_name);
+
+        match self.module.types[global.ty].inner {
+            crate::TypeInner::Struct { ref members, .. }
+                if self.module.types[members.last().unwrap().ty]
+                    .inner
+                    .is_dynamically_sized(&self.module.types) =>
+            {
+                // Structs with dynamically sized arrays must have their
+                // members lifted up as members of the interface block. GLSL
+                // can't write such struct types anyway.
+                self.write_struct_body(global.ty, members)?;
+                write!(self.out, " ")?;
+                self.write_global_name(handle, global)?;
+            }
+            _ => {
+                // A global of any other type is written as the sole member
+                // of the interface block. Since the interface block is
+                // anonymous, this becomes visible in the global scope.
+                write!(self.out, "{{ ")?;
+                self.write_type(global.ty)?;
+                write!(self.out, " ")?;
+                self.write_global_name(handle, global)?;
+                if let TypeInner::Array { base, size, .. } = self.module.types[global.ty].inner {
+                    self.write_array_size(base, size)?;
+                }
+                write!(self.out, "; }}")?;
+            }
+        }
+
+        writeln!(self.out, ";")?;
+
+        Ok(())
+    }
+
+    /// Helper method used to find which expressions of a given function require baking
+    ///
+    /// # Notes
+    /// Clears `need_bake_expressions` set before adding to it
+    fn update_expressions_to_bake(&mut self, func: &crate::Function, info: &valid::FunctionInfo) {
+        use crate::Expression;
+        self.need_bake_expressions.clear();
+        for (fun_handle, expr) in func.expressions.iter() {
+            let expr_info = &info[fun_handle];
+            let min_ref_count = func.expressions[fun_handle].bake_ref_count();
+            if min_ref_count <= expr_info.ref_count {
+                self.need_bake_expressions.insert(fun_handle);
+            }
+
+            let inner = expr_info.ty.inner_with(&self.module.types);
+
+            if let Expression::Math { fun, arg, arg1, .. } = *expr {
+                match fun {
+                    crate::MathFunction::Dot => {
+                        // if the expression is a Dot product with integer arguments,
+                        // then the args needs baking as well
+                        if let TypeInner::Scalar(crate::Scalar { kind, .. }) = *inner {
+                            match kind {
+                                crate::ScalarKind::Sint | crate::ScalarKind::Uint => {
+                                    self.need_bake_expressions.insert(arg);
+                                    self.need_bake_expressions.insert(arg1.unwrap());
+                                }
+                                _ => {}
+                            }
+                        }
+                    }
+                    crate::MathFunction::CountLeadingZeros => {
+                        if let Some(crate::ScalarKind::Sint) = inner.scalar_kind() {
+                            self.need_bake_expressions.insert(arg);
+                        }
+                    }
+                    _ => {}
+                }
+            }
+        }
+    }
+
+    /// Helper method used to get a name for a global
+    ///
+    /// Globals have different naming schemes depending on their binding:
+    /// - Globals without bindings use the name from the [`Namer`](crate::proc::Namer)
+    /// - Globals with resource binding are named `_group_X_binding_Y` where `X`
+    ///   is the group and `Y` is the binding
+    fn get_global_name(
+        &self,
+        handle: Handle<crate::GlobalVariable>,
+        global: &crate::GlobalVariable,
+    ) -> String {
+        match (&global.binding, global.space) {
+            (&Some(ref br), _) => {
+                format!(
+                    "_group_{}_binding_{}_{}",
+                    br.group,
+                    br.binding,
+                    self.entry_point.stage.to_str()
+                )
+            }
+            (&None, crate::AddressSpace::PushConstant) => {
+                format!("_push_constant_binding_{}", self.entry_point.stage.to_str())
+            }
+            (&None, _) => self.names[&NameKey::GlobalVariable(handle)].clone(),
+        }
+    }
+
+    /// Helper method used to write a name for a global without additional heap allocation
+    fn write_global_name(
+        &mut self,
+        handle: Handle<crate::GlobalVariable>,
+        global: &crate::GlobalVariable,
+    ) -> BackendResult {
+        match (&global.binding, global.space) {
+            (&Some(ref br), _) => write!(
+                self.out,
+                "_group_{}_binding_{}_{}",
+                br.group,
+                br.binding,
+                self.entry_point.stage.to_str()
+            )?,
+            (&None, crate::AddressSpace::PushConstant) => write!(
+                self.out,
+                "_push_constant_binding_{}",
+                self.entry_point.stage.to_str()
+            )?,
+            (&None, _) => write!(
+                self.out,
+                "{}",
+                &self.names[&NameKey::GlobalVariable(handle)]
+            )?,
+        }
+
+        Ok(())
+    }
+
+    /// Write a GLSL global that will carry a Naga entry point's argument or return value.
+    ///
+    /// A Naga entry point's arguments and return value are rendered in GLSL as
+    /// variables at global scope with the `in` and `out` storage qualifiers.
+    /// The code we generate for `main` loads from all the `in` globals into
+    /// appropriately named locals. Before it returns, `main` assigns the
+    /// components of its return value into all the `out` globals.
+    ///
+    /// This function writes a declaration for one such GLSL global,
+    /// representing a value passed into or returned from [`self.entry_point`]
+    /// that has a [`Location`] binding. The global's name is generated based on
+    /// the location index and the shader stages being connected; see
+    /// [`VaryingName`]. This means we don't need to know the names of
+    /// arguments, just their types and bindings.
+    ///
+    /// Emit nothing for entry point arguments or return values with [`BuiltIn`]
+    /// bindings; `main` will read from or assign to the appropriate GLSL
+    /// special variable; these are pre-declared. As an exception, we do declare
+    /// `gl_Position` or `gl_FragCoord` with the `invariant` qualifier if
+    /// needed.
+    ///
+    /// Use `output` together with [`self.entry_point.stage`] to determine which
+    /// shader stages are being connected, and choose the `in` or `out` storage
+    /// qualifier.
+    ///
+    /// [`self.entry_point`]: Writer::entry_point
+    /// [`self.entry_point.stage`]: crate::EntryPoint::stage
+    /// [`Location`]: crate::Binding::Location
+    /// [`BuiltIn`]: crate::Binding::BuiltIn
+    fn write_varying(
+        &mut self,
+        binding: Option<&crate::Binding>,
+        ty: Handle<crate::Type>,
+        output: bool,
+    ) -> Result<(), Error> {
+        // For a struct, emit a separate global for each member with a binding.
+        if let crate::TypeInner::Struct { ref members, .. } = self.module.types[ty].inner {
+            for member in members {
+                self.write_varying(member.binding.as_ref(), member.ty, output)?;
+            }
+            return Ok(());
+        }
+
+        let binding = match binding {
+            None => return Ok(()),
+            Some(binding) => binding,
+        };
+
+        let (location, interpolation, sampling, second_blend_source) = match *binding {
+            crate::Binding::Location {
+                location,
+                interpolation,
+                sampling,
+                second_blend_source,
+            } => (location, interpolation, sampling, second_blend_source),
+            crate::Binding::BuiltIn(built_in) => {
+                if let crate::BuiltIn::Position { invariant: true } = built_in {
+                    match (self.options.version, self.entry_point.stage) {
+                        (
+                            Version::Embedded {
+                                version: 300,
+                                is_webgl: true,
+                            },
+                            ShaderStage::Fragment,
+                        ) => {
+                            // `invariant gl_FragCoord` is not allowed in WebGL2 and possibly
+                            // OpenGL ES in general (waiting on confirmation).
+                            //
+                            // See https://github.com/KhronosGroup/WebGL/issues/3518
+                        }
+                        _ => {
+                            writeln!(
+                                self.out,
+                                "invariant {};",
+                                glsl_built_in(
+                                    built_in,
+                                    VaryingOptions::from_writer_options(self.options, output)
+                                )
+                            )?;
+                        }
+                    }
+                }
+                return Ok(());
+            }
+        };
+
+        // Write the interpolation modifier if needed
+        //
+        // We ignore all interpolation and auxiliary modifiers that aren't used in fragment
+        // shaders' input globals or vertex shaders' output globals.
+        let emit_interpolation_and_auxiliary = match self.entry_point.stage {
+            ShaderStage::Vertex => output,
+            ShaderStage::Fragment => !output,
+            ShaderStage::Compute => false,
+        };
+
+        // Write the I/O locations, if allowed
+        let io_location = if self.options.version.supports_explicit_locations()
+            || !emit_interpolation_and_auxiliary
+        {
+            if self.options.version.supports_io_locations() {
+                if second_blend_source {
+                    write!(self.out, "layout(location = {location}, index = 1) ")?;
+                } else {
+                    write!(self.out, "layout(location = {location}) ")?;
+                }
+                None
+            } else {
+                Some(VaryingLocation {
+                    location,
+                    index: second_blend_source as u32,
+                })
+            }
+        } else {
+            None
+        };
+
+        // Write the interpolation qualifier.
+        if let Some(interp) = interpolation {
+            if emit_interpolation_and_auxiliary {
+                write!(self.out, "{} ", glsl_interpolation(interp))?;
+            }
+        }
+
+        // Write the sampling auxiliary qualifier.
+        //
+        // Before GLSL 4.2, the `centroid` and `sample` qualifiers were required to appear
+        // immediately before the `in` / `out` qualifier, so we'll just follow that rule
+        // here, regardless of the version.
+        if let Some(sampling) = sampling {
+            if emit_interpolation_and_auxiliary {
+                if let Some(qualifier) = glsl_sampling(sampling) {
+                    write!(self.out, "{qualifier} ")?;
+                }
+            }
+        }
+
+        // Write the input/output qualifier.
+        write!(self.out, "{} ", if output { "out" } else { "in" })?;
+
+        // Write the type
+        // `write_type` adds no leading or trailing spaces
+        self.write_type(ty)?;
+
+        // Finally write the global name and end the global with a `;` and a newline
+        // Leading space is important
+        let vname = VaryingName {
+            binding: &crate::Binding::Location {
+                location,
+                interpolation: None,
+                sampling: None,
+                second_blend_source,
+            },
+            stage: self.entry_point.stage,
+            options: VaryingOptions::from_writer_options(self.options, output),
+        };
+        writeln!(self.out, " {vname};")?;
+
+        if let Some(location) = io_location {
+            self.varying.insert(vname.to_string(), location);
+        }
+
+        Ok(())
+    }
+
+    /// Helper method used to write functions (both entry points and regular functions)
+    ///
+    /// # Notes
+    /// Adds a newline
+    fn write_function(
+        &mut self,
+        ty: back::FunctionType,
+        func: &crate::Function,
+        info: &valid::FunctionInfo,
+    ) -> BackendResult {
+        // Create a function context for the function being written
+        let ctx = back::FunctionCtx {
+            ty,
+            info,
+            expressions: &func.expressions,
+            named_expressions: &func.named_expressions,
+        };
+
+        self.named_expressions.clear();
+        self.update_expressions_to_bake(func, info);
+
+        // Write the function header
+        //
+        // glsl headers are the same as in c:
+        // `ret_type name(args)`
+        // `ret_type` is the return type
+        // `name` is the function name
+        // `args` is a comma separated list of `type name`
+        //  | - `type` is the argument type
+        //  | - `name` is the argument name
+
+        // Start by writing the return type if any otherwise write void
+        // This is the only place where `void` is a valid type
+        // (though it's more a keyword than a type)
+        if let back::FunctionType::EntryPoint(_) = ctx.ty {
+            write!(self.out, "void")?;
+        } else if let Some(ref result) = func.result {
+            self.write_type(result.ty)?;
+            if let TypeInner::Array { base, size, .. } = self.module.types[result.ty].inner {
+                self.write_array_size(base, size)?
+            }
+        } else {
+            write!(self.out, "void")?;
+        }
+
+        // Write the function name and open parentheses for the argument list
+        let function_name = match ctx.ty {
+            back::FunctionType::Function(handle) => &self.names[&NameKey::Function(handle)],
+            back::FunctionType::EntryPoint(_) => "main",
+        };
+        write!(self.out, " {function_name}(")?;
+
+        // Write the comma separated argument list
+        //
+        // We need access to `Self` here so we use the reference passed to the closure as an
+        // argument instead of capturing as that would cause a borrow checker error
+        let arguments = match ctx.ty {
+            back::FunctionType::EntryPoint(_) => &[][..],
+            back::FunctionType::Function(_) => &func.arguments,
+        };
+        let arguments: Vec<_> = arguments
+            .iter()
+            .enumerate()
+            .filter(|&(_, arg)| match self.module.types[arg.ty].inner {
+                TypeInner::Sampler { .. } => false,
+                _ => true,
+            })
+            .collect();
+        self.write_slice(&arguments, |this, _, &(i, arg)| {
+            // Write the argument type
+            match this.module.types[arg.ty].inner {
+                // We treat images separately because they might require
+                // writing the storage format
+                TypeInner::Image {
+                    dim,
+                    arrayed,
+                    class,
+                } => {
+                    // Write the storage format if needed
+                    if let TypeInner::Image {
+                        class: crate::ImageClass::Storage { format, .. },
+                        ..
+                    } = this.module.types[arg.ty].inner
+                    {
+                        write!(this.out, "layout({}) ", glsl_storage_format(format)?)?;
+                    }
+
+                    // write the type
+                    //
+                    // This is way we need the leading space because `write_image_type` doesn't add
+                    // any spaces at the beginning or end
+                    this.write_image_type(dim, arrayed, class)?;
+                }
+                TypeInner::Pointer { base, .. } => {
+                    // write parameter qualifiers
+                    write!(this.out, "inout ")?;
+                    this.write_type(base)?;
+                }
+                // All other types are written by `write_type`
+                _ => {
+                    this.write_type(arg.ty)?;
+                }
+            }
+
+            // Write the argument name
+            // The leading space is important
+            write!(this.out, " {}", &this.names[&ctx.argument_key(i as u32)])?;
+
+            // Write array size
+            match this.module.types[arg.ty].inner {
+                TypeInner::Array { base, size, .. } => {
+                    this.write_array_size(base, size)?;
+                }
+                TypeInner::Pointer { base, .. } => {
+                    if let TypeInner::Array { base, size, .. } = this.module.types[base].inner {
+                        this.write_array_size(base, size)?;
+                    }
+                }
+                _ => {}
+            }
+
+            Ok(())
+        })?;
+
+        // Close the parentheses and open braces to start the function body
+        writeln!(self.out, ") {{")?;
+
+        if self.options.zero_initialize_workgroup_memory
+            && ctx.ty.is_compute_entry_point(self.module)
+        {
+            self.write_workgroup_variables_initialization(&ctx)?;
+        }
+
+        // Compose the function arguments from globals, in case of an entry point.
+        if let back::FunctionType::EntryPoint(ep_index) = ctx.ty {
+            let stage = self.module.entry_points[ep_index as usize].stage;
+            for (index, arg) in func.arguments.iter().enumerate() {
+                write!(self.out, "{}", back::INDENT)?;
+                self.write_type(arg.ty)?;
+                let name = &self.names[&NameKey::EntryPointArgument(ep_index, index as u32)];
+                write!(self.out, " {name}")?;
+                write!(self.out, " = ")?;
+                match self.module.types[arg.ty].inner {
+                    crate::TypeInner::Struct { ref members, .. } => {
+                        self.write_type(arg.ty)?;
+                        write!(self.out, "(")?;
+                        for (index, member) in members.iter().enumerate() {
+                            let varying_name = VaryingName {
+                                binding: member.binding.as_ref().unwrap(),
+                                stage,
+                                options: VaryingOptions::from_writer_options(self.options, false),
+                            };
+                            if index != 0 {
+                                write!(self.out, ", ")?;
+                            }
+                            write!(self.out, "{varying_name}")?;
+                        }
+                        writeln!(self.out, ");")?;
+                    }
+                    _ => {
+                        let varying_name = VaryingName {
+                            binding: arg.binding.as_ref().unwrap(),
+                            stage,
+                            options: VaryingOptions::from_writer_options(self.options, false),
+                        };
+                        writeln!(self.out, "{varying_name};")?;
+                    }
+                }
+            }
+        }
+
+        // Write all function locals
+        // Locals are `type name (= init)?;` where the init part (including the =) are optional
+        //
+        // Always adds a newline
+        for (handle, local) in func.local_variables.iter() {
+            // Write indentation (only for readability) and the type
+            // `write_type` adds no trailing space
+            write!(self.out, "{}", back::INDENT)?;
+            self.write_type(local.ty)?;
+
+            // Write the local name
+            // The leading space is important
+            write!(self.out, " {}", self.names[&ctx.name_key(handle)])?;
+            // Write size for array type
+            if let TypeInner::Array { base, size, .. } = self.module.types[local.ty].inner {
+                self.write_array_size(base, size)?;
+            }
+            // Write the local initializer if needed
+            if let Some(init) = local.init {
+                // Put the equal signal only if there's a initializer
+                // The leading and trailing spaces aren't needed but help with readability
+                write!(self.out, " = ")?;
+
+                // Write the constant
+                // `write_constant` adds no trailing or leading space/newline
+                self.write_expr(init, &ctx)?;
+            } else if is_value_init_supported(self.module, local.ty) {
+                write!(self.out, " = ")?;
+                self.write_zero_init_value(local.ty)?;
+            }
+
+            // Finish the local with `;` and add a newline (only for readability)
+            writeln!(self.out, ";")?
+        }
+
+        // Write the function body (statement list)
+        for sta in func.body.iter() {
+            // Write a statement, the indentation should always be 1 when writing the function body
+            // `write_stmt` adds a newline
+            self.write_stmt(sta, &ctx, back::Level(1))?;
+        }
+
+        // Close braces and add a newline
+        writeln!(self.out, "}}")?;
+
+        Ok(())
+    }
+
+    fn write_workgroup_variables_initialization(
+        &mut self,
+        ctx: &back::FunctionCtx,
+    ) -> BackendResult {
+        let mut vars = self
+            .module
+            .global_variables
+            .iter()
+            .filter(|&(handle, var)| {
+                !ctx.info[handle].is_empty() && var.space == crate::AddressSpace::WorkGroup
+            })
+            .peekable();
+
+        if vars.peek().is_some() {
+            let level = back::Level(1);
+
+            writeln!(self.out, "{level}if (gl_LocalInvocationID == uvec3(0u)) {{")?;
+
+            for (handle, var) in vars {
+                let name = &self.names[&NameKey::GlobalVariable(handle)];
+                write!(self.out, "{}{} = ", level.next(), name)?;
+                self.write_zero_init_value(var.ty)?;
+                writeln!(self.out, ";")?;
+            }
+
+            writeln!(self.out, "{level}}}")?;
+            self.write_barrier(crate::Barrier::WORK_GROUP, level)?;
+        }
+
+        Ok(())
+    }
+
+    /// Write a list of comma separated `T` values using a writer function `F`.
+    ///
+    /// The writer function `F` receives a mutable reference to `self` that if needed won't cause
+    /// borrow checker issues (using for example a closure with `self` will cause issues), the
+    /// second argument is the 0 based index of the element on the list, and the last element is
+    /// a reference to the element `T` being written
+    ///
+    /// # Notes
+    /// - Adds no newlines or leading/trailing whitespace
+    /// - The last element won't have a trailing `,`
+    fn write_slice<T, F: FnMut(&mut Self, u32, &T) -> BackendResult>(
+        &mut self,
+        data: &[T],
+        mut f: F,
+    ) -> BackendResult {
+        // Loop through `data` invoking `f` for each element
+        for (index, item) in data.iter().enumerate() {
+            if index != 0 {
+                write!(self.out, ", ")?;
+            }
+            f(self, index as u32, item)?;
+        }
+
+        Ok(())
+    }
+
+    /// Helper method used to write global constants
+    fn write_global_constant(&mut self, handle: Handle<crate::Constant>) -> BackendResult {
+        write!(self.out, "const ")?;
+        let constant = &self.module.constants[handle];
+        self.write_type(constant.ty)?;
+        let name = &self.names[&NameKey::Constant(handle)];
+        write!(self.out, " {name}")?;
+        if let TypeInner::Array { base, size, .. } = self.module.types[constant.ty].inner {
+            self.write_array_size(base, size)?;
+        }
+        write!(self.out, " = ")?;
+        self.write_const_expr(constant.init)?;
+        writeln!(self.out, ";")?;
+        Ok(())
+    }
+
+    /// Helper method used to output a dot product as an arithmetic expression
+    ///
+    fn write_dot_product(
+        &mut self,
+        arg: Handle<crate::Expression>,
+        arg1: Handle<crate::Expression>,
+        size: usize,
+        ctx: &back::FunctionCtx,
+    ) -> BackendResult {
+        // Write parentheses around the dot product expression to prevent operators
+        // with different precedences from applying earlier.
+        write!(self.out, "(")?;
+
+        // Cycle trough all the components of the vector
+        for index in 0..size {
+            let component = back::COMPONENTS[index];
+            // Write the addition to the previous product
+            // This will print an extra '+' at the beginning but that is fine in glsl
+            write!(self.out, " + ")?;
+            // Write the first vector expression, this expression is marked to be
+            // cached so unless it can't be cached (for example, it's a Constant)
+            // it shouldn't produce large expressions.
+            self.write_expr(arg, ctx)?;
+            // Access the current component on the first vector
+            write!(self.out, ".{component} * ")?;
+            // Write the second vector expression, this expression is marked to be
+            // cached so unless it can't be cached (for example, it's a Constant)
+            // it shouldn't produce large expressions.
+            self.write_expr(arg1, ctx)?;
+            // Access the current component on the second vector
+            write!(self.out, ".{component}")?;
+        }
+
+        write!(self.out, ")")?;
+        Ok(())
+    }
+
+    /// Helper method used to write structs
+    ///
+    /// # Notes
+    /// Ends in a newline
+    fn write_struct_body(
+        &mut self,
+        handle: Handle<crate::Type>,
+        members: &[crate::StructMember],
+    ) -> BackendResult {
+        // glsl structs are written as in C
+        // `struct name() { members };`
+        //  | `struct` is a keyword
+        //  | `name` is the struct name
+        //  | `members` is a semicolon separated list of `type name`
+        //      | `type` is the member type
+        //      | `name` is the member name
+        writeln!(self.out, "{{")?;
+
+        for (idx, member) in members.iter().enumerate() {
+            // The indentation is only for readability
+            write!(self.out, "{}", back::INDENT)?;
+
+            match self.module.types[member.ty].inner {
+                TypeInner::Array {
+                    base,
+                    size,
+                    stride: _,
+                } => {
+                    self.write_type(base)?;
+                    write!(
+                        self.out,
+                        " {}",
+                        &self.names[&NameKey::StructMember(handle, idx as u32)]
+                    )?;
+                    // Write [size]
+                    self.write_array_size(base, size)?;
+                    // Newline is important
+                    writeln!(self.out, ";")?;
+                }
+                _ => {
+                    // Write the member type
+                    // Adds no trailing space
+                    self.write_type(member.ty)?;
+
+                    // Write the member name and put a semicolon
+                    // The leading space is important
+                    // All members must have a semicolon even the last one
+                    writeln!(
+                        self.out,
+                        " {};",
+                        &self.names[&NameKey::StructMember(handle, idx as u32)]
+                    )?;
+                }
+            }
+        }
+
+        write!(self.out, "}}")?;
+        Ok(())
+    }
+
+    /// Helper method used to write statements
+    ///
+    /// # Notes
+    /// Always adds a newline
+    fn write_stmt(
+        &mut self,
+        sta: &crate::Statement,
+        ctx: &back::FunctionCtx,
+        level: back::Level,
+    ) -> BackendResult {
+        use crate::Statement;
+
+        match *sta {
+            // This is where we can generate intermediate constants for some expression types.
+            Statement::Emit(ref range) => {
+                for handle in range.clone() {
+                    let ptr_class = ctx.resolve_type(handle, &self.module.types).pointer_space();
+                    let expr_name = if ptr_class.is_some() {
+                        // GLSL can't save a pointer-valued expression in a variable,
+                        // but we shouldn't ever need to: they should never be named expressions,
+                        // and none of the expression types flagged by bake_ref_count can be pointer-valued.
+                        None
+                    } else if let Some(name) = ctx.named_expressions.get(&handle) {
+                        // Front end provides names for all variables at the start of writing.
+                        // But we write them to step by step. We need to recache them
+                        // Otherwise, we could accidentally write variable name instead of full expression.
+                        // Also, we use sanitized names! It defense backend from generating variable with name from reserved keywords.
+                        Some(self.namer.call(name))
+                    } else if self.need_bake_expressions.contains(&handle) {
+                        Some(format!("{}{}", back::BAKE_PREFIX, handle.index()))
+                    } else {
+                        None
+                    };
+
+                    // If we are going to write an `ImageLoad` next and the target image
+                    // is sampled and we are using the `Restrict` policy for bounds
+                    // checking images we need to write a local holding the clamped lod.
+                    if let crate::Expression::ImageLoad {
+                        image,
+                        level: Some(level_expr),
+                        ..
+                    } = ctx.expressions[handle]
+                    {
+                        if let TypeInner::Image {
+                            class: crate::ImageClass::Sampled { .. },
+                            ..
+                        } = *ctx.resolve_type(image, &self.module.types)
+                        {
+                            if let proc::BoundsCheckPolicy::Restrict = self.policies.image_load {
+                                write!(self.out, "{level}")?;
+                                self.write_clamped_lod(ctx, handle, image, level_expr)?
+                            }
+                        }
+                    }
+
+                    if let Some(name) = expr_name {
+                        write!(self.out, "{level}")?;
+                        self.write_named_expr(handle, name, handle, ctx)?;
+                    }
+                }
+            }
+            // Blocks are simple we just need to write the block statements between braces
+            // We could also just print the statements but this is more readable and maps more
+            // closely to the IR
+            Statement::Block(ref block) => {
+                write!(self.out, "{level}")?;
+                writeln!(self.out, "{{")?;
+                for sta in block.iter() {
+                    // Increase the indentation to help with readability
+                    self.write_stmt(sta, ctx, level.next())?
+                }
+                writeln!(self.out, "{level}}}")?
+            }
+            // Ifs are written as in C:
+            // ```
+            // if(condition) {
+            //  accept
+            // } else {
+            //  reject
+            // }
+            // ```
+            Statement::If {
+                condition,
+                ref accept,
+                ref reject,
+            } => {
+                write!(self.out, "{level}")?;
+                write!(self.out, "if (")?;
+                self.write_expr(condition, ctx)?;
+                writeln!(self.out, ") {{")?;
+
+                for sta in accept {
+                    // Increase indentation to help with readability
+                    self.write_stmt(sta, ctx, level.next())?;
+                }
+
+                // If there are no statements in the reject block we skip writing it
+                // This is only for readability
+                if !reject.is_empty() {
+                    writeln!(self.out, "{level}}} else {{")?;
+
+                    for sta in reject {
+                        // Increase indentation to help with readability
+                        self.write_stmt(sta, ctx, level.next())?;
+                    }
+                }
+
+                writeln!(self.out, "{level}}}")?
+            }
+            // Switch are written as in C:
+            // ```
+            // switch (selector) {
+            //      // Fallthrough
+            //      case label:
+            //          block
+            //      // Non fallthrough
+            //      case label:
+            //          block
+            //          break;
+            //      default:
+            //          block
+            //  }
+            //  ```
+            //  Where the `default` case happens isn't important but we put it last
+            //  so that we don't need to print a `break` for it
+            Statement::Switch {
+                selector,
+                ref cases,
+            } => {
+                // Start the switch
+                write!(self.out, "{level}")?;
+                write!(self.out, "switch(")?;
+                self.write_expr(selector, ctx)?;
+                writeln!(self.out, ") {{")?;
+
+                // Write all cases
+                let l2 = level.next();
+                for case in cases {
+                    match case.value {
+                        crate::SwitchValue::I32(value) => write!(self.out, "{l2}case {value}:")?,
+                        crate::SwitchValue::U32(value) => write!(self.out, "{l2}case {value}u:")?,
+                        crate::SwitchValue::Default => write!(self.out, "{l2}default:")?,
+                    }
+
+                    let write_block_braces = !(case.fall_through && case.body.is_empty());
+                    if write_block_braces {
+                        writeln!(self.out, " {{")?;
+                    } else {
+                        writeln!(self.out)?;
+                    }
+
+                    for sta in case.body.iter() {
+                        self.write_stmt(sta, ctx, l2.next())?;
+                    }
+
+                    if !case.fall_through && case.body.last().map_or(true, |s| !s.is_terminator()) {
+                        writeln!(self.out, "{}break;", l2.next())?;
+                    }
+
+                    if write_block_braces {
+                        writeln!(self.out, "{l2}}}")?;
+                    }
+                }
+
+                writeln!(self.out, "{level}}}")?
+            }
+            // Loops in naga IR are based on wgsl loops, glsl can emulate the behaviour by using a
+            // while true loop and appending the continuing block to the body resulting on:
+            // ```
+            // bool loop_init = true;
+            // while(true) {
+            //  if (!loop_init) { <continuing> }
+            //  loop_init = false;
+            //  <body>
+            // }
+            // ```
+            Statement::Loop {
+                ref body,
+                ref continuing,
+                break_if,
+            } => {
+                if !continuing.is_empty() || break_if.is_some() {
+                    let gate_name = self.namer.call("loop_init");
+                    writeln!(self.out, "{level}bool {gate_name} = true;")?;
+                    writeln!(self.out, "{level}while(true) {{")?;
+                    let l2 = level.next();
+                    let l3 = l2.next();
+                    writeln!(self.out, "{l2}if (!{gate_name}) {{")?;
+                    for sta in continuing {
+                        self.write_stmt(sta, ctx, l3)?;
+                    }
+                    if let Some(condition) = break_if {
+                        write!(self.out, "{l3}if (")?;
+                        self.write_expr(condition, ctx)?;
+                        writeln!(self.out, ") {{")?;
+                        writeln!(self.out, "{}break;", l3.next())?;
+                        writeln!(self.out, "{l3}}}")?;
+                    }
+                    writeln!(self.out, "{l2}}}")?;
+                    writeln!(self.out, "{}{} = false;", level.next(), gate_name)?;
+                } else {
+                    writeln!(self.out, "{level}while(true) {{")?;
+                }
+                for sta in body {
+                    self.write_stmt(sta, ctx, level.next())?;
+                }
+                writeln!(self.out, "{level}}}")?
+            }
+            // Break, continue and return as written as in C
+            // `break;`
+            Statement::Break => {
+                write!(self.out, "{level}")?;
+                writeln!(self.out, "break;")?
+            }
+            // `continue;`
+            Statement::Continue => {
+                write!(self.out, "{level}")?;
+                writeln!(self.out, "continue;")?
+            }
+            // `return expr;`, `expr` is optional
+            Statement::Return { value } => {
+                write!(self.out, "{level}")?;
+                match ctx.ty {
+                    back::FunctionType::Function(_) => {
+                        write!(self.out, "return")?;
+                        // Write the expression to be returned if needed
+                        if let Some(expr) = value {
+                            write!(self.out, " ")?;
+                            self.write_expr(expr, ctx)?;
+                        }
+                        writeln!(self.out, ";")?;
+                    }
+                    back::FunctionType::EntryPoint(ep_index) => {
+                        let mut has_point_size = false;
+                        let ep = &self.module.entry_points[ep_index as usize];
+                        if let Some(ref result) = ep.function.result {
+                            let value = value.unwrap();
+                            match self.module.types[result.ty].inner {
+                                crate::TypeInner::Struct { ref members, .. } => {
+                                    let temp_struct_name = match ctx.expressions[value] {
+                                        crate::Expression::Compose { .. } => {
+                                            let return_struct = "_tmp_return";
+                                            write!(
+                                                self.out,
+                                                "{} {} = ",
+                                                &self.names[&NameKey::Type(result.ty)],
+                                                return_struct
+                                            )?;
+                                            self.write_expr(value, ctx)?;
+                                            writeln!(self.out, ";")?;
+                                            write!(self.out, "{level}")?;
+                                            Some(return_struct)
+                                        }
+                                        _ => None,
+                                    };
+
+                                    for (index, member) in members.iter().enumerate() {
+                                        if let Some(crate::Binding::BuiltIn(
+                                            crate::BuiltIn::PointSize,
+                                        )) = member.binding
+                                        {
+                                            has_point_size = true;
+                                        }
+
+                                        let varying_name = VaryingName {
+                                            binding: member.binding.as_ref().unwrap(),
+                                            stage: ep.stage,
+                                            options: VaryingOptions::from_writer_options(
+                                                self.options,
+                                                true,
+                                            ),
+                                        };
+                                        write!(self.out, "{varying_name} = ")?;
+
+                                        if let Some(struct_name) = temp_struct_name {
+                                            write!(self.out, "{struct_name}")?;
+                                        } else {
+                                            self.write_expr(value, ctx)?;
+                                        }
+
+                                        // Write field name
+                                        writeln!(
+                                            self.out,
+                                            ".{};",
+                                            &self.names
+                                                [&NameKey::StructMember(result.ty, index as u32)]
+                                        )?;
+                                        write!(self.out, "{level}")?;
+                                    }
+                                }
+                                _ => {
+                                    let name = VaryingName {
+                                        binding: result.binding.as_ref().unwrap(),
+                                        stage: ep.stage,
+                                        options: VaryingOptions::from_writer_options(
+                                            self.options,
+                                            true,
+                                        ),
+                                    };
+                                    write!(self.out, "{name} = ")?;
+                                    self.write_expr(value, ctx)?;
+                                    writeln!(self.out, ";")?;
+                                    write!(self.out, "{level}")?;
+                                }
+                            }
+                        }
+
+                        let is_vertex_stage = self.module.entry_points[ep_index as usize].stage
+                            == ShaderStage::Vertex;
+                        if is_vertex_stage
+                            && self
+                                .options
+                                .writer_flags
+                                .contains(WriterFlags::ADJUST_COORDINATE_SPACE)
+                        {
+                            writeln!(
+                                self.out,
+                                "gl_Position.yz = vec2(-gl_Position.y, gl_Position.z * 2.0 - gl_Position.w);",
+                            )?;
+                            write!(self.out, "{level}")?;
+                        }
+
+                        if is_vertex_stage
+                            && self
+                                .options
+                                .writer_flags
+                                .contains(WriterFlags::FORCE_POINT_SIZE)
+                            && !has_point_size
+                        {
+                            writeln!(self.out, "gl_PointSize = 1.0;")?;
+                            write!(self.out, "{level}")?;
+                        }
+                        writeln!(self.out, "return;")?;
+                    }
+                }
+            }
+            // This is one of the places were glsl adds to the syntax of C in this case the discard
+            // keyword which ceases all further processing in a fragment shader, it's called OpKill
+            // in spir-v that's why it's called `Statement::Kill`
+            Statement::Kill => writeln!(self.out, "{level}discard;")?,
+            Statement::Barrier(flags) => {
+                self.write_barrier(flags, level)?;
+            }
+            // Stores in glsl are just variable assignments written as `pointer = value;`
+            Statement::Store { pointer, value } => {
+                write!(self.out, "{level}")?;
+                self.write_expr(pointer, ctx)?;
+                write!(self.out, " = ")?;
+                self.write_expr(value, ctx)?;
+                writeln!(self.out, ";")?
+            }
+            Statement::WorkGroupUniformLoad { pointer, result } => {
+                // GLSL doesn't have pointers, which means that this backend needs to ensure that
+                // the actual "loading" is happening between the two barriers.
+                // This is done in `Emit` by never emitting a variable name for pointer variables
+                self.write_barrier(crate::Barrier::WORK_GROUP, level)?;
+
+                let result_name = format!("{}{}", back::BAKE_PREFIX, result.index());
+                write!(self.out, "{level}")?;
+                // Expressions cannot have side effects, so just writing the expression here is fine.
+                self.write_named_expr(pointer, result_name, result, ctx)?;
+
+                self.write_barrier(crate::Barrier::WORK_GROUP, level)?;
+            }
+            // Stores a value into an image.
+            Statement::ImageStore {
+                image,
+                coordinate,
+                array_index,
+                value,
+            } => {
+                write!(self.out, "{level}")?;
+                self.write_image_store(ctx, image, coordinate, array_index, value)?
+            }
+            // A `Call` is written `name(arguments)` where `arguments` is a comma separated expressions list
+            Statement::Call {
+                function,
+                ref arguments,
+                result,
+            } => {
+                write!(self.out, "{level}")?;
+                if let Some(expr) = result {
+                    let name = format!("{}{}", back::BAKE_PREFIX, expr.index());
+                    let result = self.module.functions[function].result.as_ref().unwrap();
+                    self.write_type(result.ty)?;
+                    write!(self.out, " {name}")?;
+                    if let TypeInner::Array { base, size, .. } = self.module.types[result.ty].inner
+                    {
+                        self.write_array_size(base, size)?
+                    }
+                    write!(self.out, " = ")?;
+                    self.named_expressions.insert(expr, name);
+                }
+                write!(self.out, "{}(", &self.names[&NameKey::Function(function)])?;
+                let arguments: Vec<_> = arguments
+                    .iter()
+                    .enumerate()
+                    .filter_map(|(i, arg)| {
+                        let arg_ty = self.module.functions[function].arguments[i].ty;
+                        match self.module.types[arg_ty].inner {
+                            TypeInner::Sampler { .. } => None,
+                            _ => Some(*arg),
+                        }
+                    })
+                    .collect();
+                self.write_slice(&arguments, |this, _, arg| this.write_expr(*arg, ctx))?;
+                writeln!(self.out, ");")?
+            }
+            Statement::Atomic {
+                pointer,
+                ref fun,
+                value,
+                result,
+            } => {
+                write!(self.out, "{level}")?;
+                let res_name = format!("{}{}", back::BAKE_PREFIX, result.index());
+                let res_ty = ctx.resolve_type(result, &self.module.types);
+                self.write_value_type(res_ty)?;
+                write!(self.out, " {res_name} = ")?;
+                self.named_expressions.insert(result, res_name);
+
+                let fun_str = fun.to_glsl();
+                write!(self.out, "atomic{fun_str}(")?;
+                self.write_expr(pointer, ctx)?;
+                write!(self.out, ", ")?;
+                // handle the special cases
+                match *fun {
+                    crate::AtomicFunction::Subtract => {
+                        // we just wrote `InterlockedAdd`, so negate the argument
+                        write!(self.out, "-")?;
+                    }
+                    crate::AtomicFunction::Exchange { compare: Some(_) } => {
+                        return Err(Error::Custom(
+                            "atomic CompareExchange is not implemented".to_string(),
+                        ));
+                    }
+                    _ => {}
+                }
+                self.write_expr(value, ctx)?;
+                writeln!(self.out, ");")?;
+            }
+            Statement::RayQuery { .. } => unreachable!(),
+        }
+
+        Ok(())
+    }
+
+    /// Write a const expression.
+    ///
+    /// Write `expr`, a handle to an [`Expression`] in the current [`Module`]'s
+    /// constant expression arena, as GLSL expression.
+    ///
+    /// # Notes
+    /// Adds no newlines or leading/trailing whitespace
+    ///
+    /// [`Expression`]: crate::Expression
+    /// [`Module`]: crate::Module
+    fn write_const_expr(&mut self, expr: Handle<crate::Expression>) -> BackendResult {
+        self.write_possibly_const_expr(
+            expr,
+            &self.module.const_expressions,
+            |expr| &self.info[expr],
+            |writer, expr| writer.write_const_expr(expr),
+        )
+    }
+
+    /// Write [`Expression`] variants that can occur in both runtime and const expressions.
+    ///
+    /// Write `expr`, a handle to an [`Expression`] in the arena `expressions`,
+    /// as as GLSL expression. This must be one of the [`Expression`] variants
+    /// that is allowed to occur in constant expressions.
+    ///
+    /// Use `write_expression` to write subexpressions.
+    ///
+    /// This is the common code for `write_expr`, which handles arbitrary
+    /// runtime expressions, and `write_const_expr`, which only handles
+    /// const-expressions. Each of those callers passes itself (essentially) as
+    /// the `write_expression` callback, so that subexpressions are restricted
+    /// to the appropriate variants.
+    ///
+    /// # Notes
+    /// Adds no newlines or leading/trailing whitespace
+    ///
+    /// [`Expression`]: crate::Expression
+    fn write_possibly_const_expr<'w, I, E>(
+        &'w mut self,
+        expr: Handle<crate::Expression>,
+        expressions: &crate::Arena<crate::Expression>,
+        info: I,
+        write_expression: E,
+    ) -> BackendResult
+    where
+        I: Fn(Handle<crate::Expression>) -> &'w proc::TypeResolution,
+        E: Fn(&mut Self, Handle<crate::Expression>) -> BackendResult,
+    {
+        use crate::Expression;
+
+        match expressions[expr] {
+            Expression::Literal(literal) => {
+                match literal {
+                    // Floats are written using `Debug` instead of `Display` because it always appends the
+                    // decimal part even it's zero which is needed for a valid glsl float constant
+                    crate::Literal::F64(value) => write!(self.out, "{:?}LF", value)?,
+                    crate::Literal::F32(value) => write!(self.out, "{:?}", value)?,
+                    // Unsigned integers need a `u` at the end
+                    //
+                    // While `core` doesn't necessarily need it, it's allowed and since `es` needs it we
+                    // always write it as the extra branch wouldn't have any benefit in readability
+                    crate::Literal::U32(value) => write!(self.out, "{}u", value)?,
+                    crate::Literal::I32(value) => write!(self.out, "{}", value)?,
+                    crate::Literal::Bool(value) => write!(self.out, "{}", value)?,
+                    crate::Literal::I64(_) => {
+                        return Err(Error::Custom("GLSL has no 64-bit integer type".into()));
+                    }
+                    crate::Literal::AbstractInt(_) | crate::Literal::AbstractFloat(_) => {
+                        return Err(Error::Custom(
+                            "Abstract types should not appear in IR presented to backends".into(),
+                        ));
+                    }
+                }
+            }
+            Expression::Constant(handle) => {
+                let constant = &self.module.constants[handle];
+                if constant.name.is_some() {
+                    write!(self.out, "{}", self.names[&NameKey::Constant(handle)])?;
+                } else {
+                    self.write_const_expr(constant.init)?;
+                }
+            }
+            Expression::ZeroValue(ty) => {
+                self.write_zero_init_value(ty)?;
+            }
+            Expression::Compose { ty, ref components } => {
+                self.write_type(ty)?;
+
+                if let TypeInner::Array { base, size, .. } = self.module.types[ty].inner {
+                    self.write_array_size(base, size)?;
+                }
+
+                write!(self.out, "(")?;
+                for (index, component) in components.iter().enumerate() {
+                    if index != 0 {
+                        write!(self.out, ", ")?;
+                    }
+                    write_expression(self, *component)?;
+                }
+                write!(self.out, ")")?
+            }
+            // `Splat` needs to actually write down a vector, it's not always inferred in GLSL.
+            Expression::Splat { size: _, value } => {
+                let resolved = info(expr).inner_with(&self.module.types);
+                self.write_value_type(resolved)?;
+                write!(self.out, "(")?;
+                write_expression(self, value)?;
+                write!(self.out, ")")?
+            }
+            _ => unreachable!(),
+        }
+
+        Ok(())
+    }
+
+    /// Helper method to write expressions
+    ///
+    /// # Notes
+    /// Doesn't add any newlines or leading/trailing spaces
+    fn write_expr(
+        &mut self,
+        expr: Handle<crate::Expression>,
+        ctx: &back::FunctionCtx,
+    ) -> BackendResult {
+        use crate::Expression;
+
+        if let Some(name) = self.named_expressions.get(&expr) {
+            write!(self.out, "{name}")?;
+            return Ok(());
+        }
+
+        match ctx.expressions[expr] {
+            Expression::Literal(_)
+            | Expression::Constant(_)
+            | Expression::ZeroValue(_)
+            | Expression::Compose { .. }
+            | Expression::Splat { .. } => {
+                self.write_possibly_const_expr(
+                    expr,
+                    ctx.expressions,
+                    |expr| &ctx.info[expr].ty,
+                    |writer, expr| writer.write_expr(expr, ctx),
+                )?;
+            }
+            // `Access` is applied to arrays, vectors and matrices and is written as indexing
+            Expression::Access { base, index } => {
+                self.write_expr(base, ctx)?;
+                write!(self.out, "[")?;
+                self.write_expr(index, ctx)?;
+                write!(self.out, "]")?
+            }
+            // `AccessIndex` is the same as `Access` except that the index is a constant and it can
+            // be applied to structs, in this case we need to find the name of the field at that
+            // index and write `base.field_name`
+            Expression::AccessIndex { base, index } => {
+                self.write_expr(base, ctx)?;
+
+                let base_ty_res = &ctx.info[base].ty;
+                let mut resolved = base_ty_res.inner_with(&self.module.types);
+                let base_ty_handle = match *resolved {
+                    TypeInner::Pointer { base, space: _ } => {
+                        resolved = &self.module.types[base].inner;
+                        Some(base)
+                    }
+                    _ => base_ty_res.handle(),
+                };
+
+                match *resolved {
+                    TypeInner::Vector { .. } => {
+                        // Write vector access as a swizzle
+                        write!(self.out, ".{}", back::COMPONENTS[index as usize])?
+                    }
+                    TypeInner::Matrix { .. }
+                    | TypeInner::Array { .. }
+                    | TypeInner::ValuePointer { .. } => write!(self.out, "[{index}]")?,
+                    TypeInner::Struct { .. } => {
+                        // This will never panic in case the type is a `Struct`, this is not true
+                        // for other types so we can only check while inside this match arm
+                        let ty = base_ty_handle.unwrap();
+
+                        write!(
+                            self.out,
+                            ".{}",
+                            &self.names[&NameKey::StructMember(ty, index)]
+                        )?
+                    }
+                    ref other => return Err(Error::Custom(format!("Cannot index {other:?}"))),
+                }
+            }
+            // `Swizzle` adds a few letters behind the dot.
+            Expression::Swizzle {
+                size,
+                vector,
+                pattern,
+            } => {
+                self.write_expr(vector, ctx)?;
+                write!(self.out, ".")?;
+                for &sc in pattern[..size as usize].iter() {
+                    self.out.write_char(back::COMPONENTS[sc as usize])?;
+                }
+            }
+            // Function arguments are written as the argument name
+            Expression::FunctionArgument(pos) => {
+                write!(self.out, "{}", &self.names[&ctx.argument_key(pos)])?
+            }
+            // Global variables need some special work for their name but
+            // `get_global_name` does the work for us
+            Expression::GlobalVariable(handle) => {
+                let global = &self.module.global_variables[handle];
+                self.write_global_name(handle, global)?
+            }
+            // A local is written as it's name
+            Expression::LocalVariable(handle) => {
+                write!(self.out, "{}", self.names[&ctx.name_key(handle)])?
+            }
+            // glsl has no pointers so there's no load operation, just write the pointer expression
+            Expression::Load { pointer } => self.write_expr(pointer, ctx)?,
+            // `ImageSample` is a bit complicated compared to the rest of the IR.
+            //
+            // First there are three variations depending whether the sample level is explicitly set,
+            // if it's automatic or it it's bias:
+            // `texture(image, coordinate)` - Automatic sample level
+            // `texture(image, coordinate, bias)` - Bias sample level
+            // `textureLod(image, coordinate, level)` - Zero or Exact sample level
+            //
+            // Furthermore if `depth_ref` is some we need to append it to the coordinate vector
+            Expression::ImageSample {
+                image,
+                sampler: _, //TODO?
+                gather,
+                coordinate,
+                array_index,
+                offset,
+                level,
+                depth_ref,
+            } => {
+                let dim = match *ctx.resolve_type(image, &self.module.types) {
+                    TypeInner::Image { dim, .. } => dim,
+                    _ => unreachable!(),
+                };
+
+                if dim == crate::ImageDimension::Cube
+                    && array_index.is_some()
+                    && depth_ref.is_some()
+                {
+                    match level {
+                        crate::SampleLevel::Zero
+                        | crate::SampleLevel::Exact(_)
+                        | crate::SampleLevel::Gradient { .. }
+                        | crate::SampleLevel::Bias(_) => {
+                            return Err(Error::Custom(String::from(
+                                "gsamplerCubeArrayShadow isn't supported in textureGrad, \
+                                 textureLod or texture with bias",
+                            )))
+                        }
+                        crate::SampleLevel::Auto => {}
+                    }
+                }
+
+                // textureLod on sampler2DArrayShadow and samplerCubeShadow does not exist in GLSL.
+                // To emulate this, we will have to use textureGrad with a constant gradient of 0.
+                let workaround_lod_array_shadow_as_grad = (array_index.is_some()
+                    || dim == crate::ImageDimension::Cube)
+                    && depth_ref.is_some()
+                    && gather.is_none()
+                    && !self
+                        .options
+                        .writer_flags
+                        .contains(WriterFlags::TEXTURE_SHADOW_LOD);
+
+                //Write the function to be used depending on the sample level
+                let fun_name = match level {
+                    crate::SampleLevel::Zero if gather.is_some() => "textureGather",
+                    crate::SampleLevel::Auto | crate::SampleLevel::Bias(_) => "texture",
+                    crate::SampleLevel::Zero | crate::SampleLevel::Exact(_) => {
+                        if workaround_lod_array_shadow_as_grad {
+                            "textureGrad"
+                        } else {
+                            "textureLod"
+                        }
+                    }
+                    crate::SampleLevel::Gradient { .. } => "textureGrad",
+                };
+                let offset_name = match offset {
+                    Some(_) => "Offset",
+                    None => "",
+                };
+
+                write!(self.out, "{fun_name}{offset_name}(")?;
+
+                // Write the image that will be used
+                self.write_expr(image, ctx)?;
+                // The space here isn't required but it helps with readability
+                write!(self.out, ", ")?;
+
+                // We need to get the coordinates vector size to later build a vector that's `size + 1`
+                // if `depth_ref` is some, if it isn't a vector we panic as that's not a valid expression
+                let mut coord_dim = match *ctx.resolve_type(coordinate, &self.module.types) {
+                    TypeInner::Vector { size, .. } => size as u8,
+                    TypeInner::Scalar { .. } => 1,
+                    _ => unreachable!(),
+                };
+
+                if array_index.is_some() {
+                    coord_dim += 1;
+                }
+                let merge_depth_ref = depth_ref.is_some() && gather.is_none() && coord_dim < 4;
+                if merge_depth_ref {
+                    coord_dim += 1;
+                }
+
+                let tex_1d_hack = dim == crate::ImageDimension::D1 && self.options.version.is_es();
+                let is_vec = tex_1d_hack || coord_dim != 1;
+                // Compose a new texture coordinates vector
+                if is_vec {
+                    write!(self.out, "vec{}(", coord_dim + tex_1d_hack as u8)?;
+                }
+                self.write_expr(coordinate, ctx)?;
+                if tex_1d_hack {
+                    write!(self.out, ", 0.0")?;
+                }
+                if let Some(expr) = array_index {
+                    write!(self.out, ", ")?;
+                    self.write_expr(expr, ctx)?;
+                }
+                if merge_depth_ref {
+                    write!(self.out, ", ")?;
+                    self.write_expr(depth_ref.unwrap(), ctx)?;
+                }
+                if is_vec {
+                    write!(self.out, ")")?;
+                }
+
+                if let (Some(expr), false) = (depth_ref, merge_depth_ref) {
+                    write!(self.out, ", ")?;
+                    self.write_expr(expr, ctx)?;
+                }
+
+                match level {
+                    // Auto needs no more arguments
+                    crate::SampleLevel::Auto => (),
+                    // Zero needs level set to 0
+                    crate::SampleLevel::Zero => {
+                        if workaround_lod_array_shadow_as_grad {
+                            let vec_dim = match dim {
+                                crate::ImageDimension::Cube => 3,
+                                _ => 2,
+                            };
+                            write!(self.out, ", vec{vec_dim}(0.0), vec{vec_dim}(0.0)")?;
+                        } else if gather.is_none() {
+                            write!(self.out, ", 0.0")?;
+                        }
+                    }
+                    // Exact and bias require another argument
+                    crate::SampleLevel::Exact(expr) => {
+                        if workaround_lod_array_shadow_as_grad {
+                            log::warn!("Unable to `textureLod` a shadow array, ignoring the LOD");
+                            write!(self.out, ", vec2(0,0), vec2(0,0)")?;
+                        } else {
+                            write!(self.out, ", ")?;
+                            self.write_expr(expr, ctx)?;
+                        }
+                    }
+                    crate::SampleLevel::Bias(_) => {
+                        // This needs to be done after the offset writing
+                    }
+                    crate::SampleLevel::Gradient { x, y } => {
+                        // If we are using sampler2D to replace sampler1D, we also
+                        // need to make sure to use vec2 gradients
+                        if tex_1d_hack {
+                            write!(self.out, ", vec2(")?;
+                            self.write_expr(x, ctx)?;
+                            write!(self.out, ", 0.0)")?;
+                            write!(self.out, ", vec2(")?;
+                            self.write_expr(y, ctx)?;
+                            write!(self.out, ", 0.0)")?;
+                        } else {
+                            write!(self.out, ", ")?;
+                            self.write_expr(x, ctx)?;
+                            write!(self.out, ", ")?;
+                            self.write_expr(y, ctx)?;
+                        }
+                    }
+                }
+
+                if let Some(constant) = offset {
+                    write!(self.out, ", ")?;
+                    if tex_1d_hack {
+                        write!(self.out, "ivec2(")?;
+                    }
+                    self.write_const_expr(constant)?;
+                    if tex_1d_hack {
+                        write!(self.out, ", 0)")?;
+                    }
+                }
+
+                // Bias is always the last argument
+                if let crate::SampleLevel::Bias(expr) = level {
+                    write!(self.out, ", ")?;
+                    self.write_expr(expr, ctx)?;
+                }
+
+                if let (Some(component), None) = (gather, depth_ref) {
+                    write!(self.out, ", {}", component as usize)?;
+                }
+
+                // End the function
+                write!(self.out, ")")?
+            }
+            Expression::ImageLoad {
+                image,
+                coordinate,
+                array_index,
+                sample,
+                level,
+            } => self.write_image_load(expr, ctx, image, coordinate, array_index, sample, level)?,
+            // Query translates into one of the:
+            // - textureSize/imageSize
+            // - textureQueryLevels
+            // - textureSamples/imageSamples
+            Expression::ImageQuery { image, query } => {
+                use crate::ImageClass;
+
+                // This will only panic if the module is invalid
+                let (dim, class) = match *ctx.resolve_type(image, &self.module.types) {
+                    TypeInner::Image {
+                        dim,
+                        arrayed: _,
+                        class,
+                    } => (dim, class),
+                    _ => unreachable!(),
+                };
+                let components = match dim {
+                    crate::ImageDimension::D1 => 1,
+                    crate::ImageDimension::D2 => 2,
+                    crate::ImageDimension::D3 => 3,
+                    crate::ImageDimension::Cube => 2,
+                };
+
+                if let crate::ImageQuery::Size { .. } = query {
+                    match components {
+                        1 => write!(self.out, "uint(")?,
+                        _ => write!(self.out, "uvec{components}(")?,
+                    }
+                } else {
+                    write!(self.out, "uint(")?;
+                }
+
+                match query {
+                    crate::ImageQuery::Size { level } => {
+                        match class {
+                            ImageClass::Sampled { multi, .. } | ImageClass::Depth { multi } => {
+                                write!(self.out, "textureSize(")?;
+                                self.write_expr(image, ctx)?;
+                                if let Some(expr) = level {
+                                    let cast_to_int = matches!(
+                                        *ctx.resolve_type(expr, &self.module.types),
+                                        crate::TypeInner::Scalar(crate::Scalar {
+                                            kind: crate::ScalarKind::Uint,
+                                            ..
+                                        })
+                                    );
+
+                                    write!(self.out, ", ")?;
+
+                                    if cast_to_int {
+                                        write!(self.out, "int(")?;
+                                    }
+
+                                    self.write_expr(expr, ctx)?;
+
+                                    if cast_to_int {
+                                        write!(self.out, ")")?;
+                                    }
+                                } else if !multi {
+                                    // All textureSize calls requires an lod argument
+                                    // except for multisampled samplers
+                                    write!(self.out, ", 0")?;
+                                }
+                            }
+                            ImageClass::Storage { .. } => {
+                                write!(self.out, "imageSize(")?;
+                                self.write_expr(image, ctx)?;
+                            }
+                        }
+                        write!(self.out, ")")?;
+                        if components != 1 || self.options.version.is_es() {
+                            write!(self.out, ".{}", &"xyz"[..components])?;
+                        }
+                    }
+                    crate::ImageQuery::NumLevels => {
+                        write!(self.out, "textureQueryLevels(",)?;
+                        self.write_expr(image, ctx)?;
+                        write!(self.out, ")",)?;
+                    }
+                    crate::ImageQuery::NumLayers => {
+                        let fun_name = match class {
+                            ImageClass::Sampled { .. } | ImageClass::Depth { .. } => "textureSize",
+                            ImageClass::Storage { .. } => "imageSize",
+                        };
+                        write!(self.out, "{fun_name}(")?;
+                        self.write_expr(image, ctx)?;
+                        // All textureSize calls requires an lod argument
+                        // except for multisampled samplers
+                        if class.is_multisampled() {
+                            write!(self.out, ", 0")?;
+                        }
+                        write!(self.out, ")")?;
+                        if components != 1 || self.options.version.is_es() {
+                            write!(self.out, ".{}", back::COMPONENTS[components])?;
+                        }
+                    }
+                    crate::ImageQuery::NumSamples => {
+                        let fun_name = match class {
+                            ImageClass::Sampled { .. } | ImageClass::Depth { .. } => {
+                                "textureSamples"
+                            }
+                            ImageClass::Storage { .. } => "imageSamples",
+                        };
+                        write!(self.out, "{fun_name}(")?;
+                        self.write_expr(image, ctx)?;
+                        write!(self.out, ")",)?;
+                    }
+                }
+
+                write!(self.out, ")")?;
+            }
+            Expression::Unary { op, expr } => {
+                let operator_or_fn = match op {
+                    crate::UnaryOperator::Negate => "-",
+                    crate::UnaryOperator::LogicalNot => {
+                        match *ctx.resolve_type(expr, &self.module.types) {
+                            TypeInner::Vector { .. } => "not",
+                            _ => "!",
+                        }
+                    }
+                    crate::UnaryOperator::BitwiseNot => "~",
+                };
+                write!(self.out, "{operator_or_fn}(")?;
+
+                self.write_expr(expr, ctx)?;
+
+                write!(self.out, ")")?
+            }
+            // `Binary` we just write `left op right`, except when dealing with
+            // comparison operations on vectors as they are implemented with
+            // builtin functions.
+            // Once again we wrap everything in parentheses to avoid precedence issues
+            Expression::Binary {
+                mut op,
+                left,
+                right,
+            } => {
+                // Holds `Some(function_name)` if the binary operation is
+                // implemented as a function call
+                use crate::{BinaryOperator as Bo, ScalarKind as Sk, TypeInner as Ti};
+
+                let left_inner = ctx.resolve_type(left, &self.module.types);
+                let right_inner = ctx.resolve_type(right, &self.module.types);
+
+                let function = match (left_inner, right_inner) {
+                    (&Ti::Vector { scalar, .. }, &Ti::Vector { .. }) => match op {
+                        Bo::Less
+                        | Bo::LessEqual
+                        | Bo::Greater
+                        | Bo::GreaterEqual
+                        | Bo::Equal
+                        | Bo::NotEqual => BinaryOperation::VectorCompare,
+                        Bo::Modulo if scalar.kind == Sk::Float => BinaryOperation::Modulo,
+                        Bo::And if scalar.kind == Sk::Bool => {
+                            op = crate::BinaryOperator::LogicalAnd;
+                            BinaryOperation::VectorComponentWise
+                        }
+                        Bo::InclusiveOr if scalar.kind == Sk::Bool => {
+                            op = crate::BinaryOperator::LogicalOr;
+                            BinaryOperation::VectorComponentWise
+                        }
+                        _ => BinaryOperation::Other,
+                    },
+                    _ => match (left_inner.scalar_kind(), right_inner.scalar_kind()) {
+                        (Some(Sk::Float), _) | (_, Some(Sk::Float)) => match op {
+                            Bo::Modulo => BinaryOperation::Modulo,
+                            _ => BinaryOperation::Other,
+                        },
+                        (Some(Sk::Bool), Some(Sk::Bool)) => match op {
+                            Bo::InclusiveOr => {
+                                op = crate::BinaryOperator::LogicalOr;
+                                BinaryOperation::Other
+                            }
+                            Bo::And => {
+                                op = crate::BinaryOperator::LogicalAnd;
+                                BinaryOperation::Other
+                            }
+                            _ => BinaryOperation::Other,
+                        },
+                        _ => BinaryOperation::Other,
+                    },
+                };
+
+                match function {
+                    BinaryOperation::VectorCompare => {
+                        let op_str = match op {
+                            Bo::Less => "lessThan(",
+                            Bo::LessEqual => "lessThanEqual(",
+                            Bo::Greater => "greaterThan(",
+                            Bo::GreaterEqual => "greaterThanEqual(",
+                            Bo::Equal => "equal(",
+                            Bo::NotEqual => "notEqual(",
+                            _ => unreachable!(),
+                        };
+                        write!(self.out, "{op_str}")?;
+                        self.write_expr(left, ctx)?;
+                        write!(self.out, ", ")?;
+                        self.write_expr(right, ctx)?;
+                        write!(self.out, ")")?;
+                    }
+                    BinaryOperation::VectorComponentWise => {
+                        self.write_value_type(left_inner)?;
+                        write!(self.out, "(")?;
+
+                        let size = match *left_inner {
+                            Ti::Vector { size, .. } => size,
+                            _ => unreachable!(),
+                        };
+
+                        for i in 0..size as usize {
+                            if i != 0 {
+                                write!(self.out, ", ")?;
+                            }
+
+                            self.write_expr(left, ctx)?;
+                            write!(self.out, ".{}", back::COMPONENTS[i])?;
+
+                            write!(self.out, " {} ", back::binary_operation_str(op))?;
+
+                            self.write_expr(right, ctx)?;
+                            write!(self.out, ".{}", back::COMPONENTS[i])?;
+                        }
+
+                        write!(self.out, ")")?;
+                    }
+                    // TODO: handle undefined behavior of BinaryOperator::Modulo
+                    //
+                    // sint:
+                    // if right == 0 return 0
+                    // if left == min(type_of(left)) && right == -1 return 0
+                    // if sign(left) == -1 || sign(right) == -1 return result as defined by WGSL
+                    //
+                    // uint:
+                    // if right == 0 return 0
+                    //
+                    // float:
+                    // if right == 0 return ? see https://github.com/gpuweb/gpuweb/issues/2798
+                    BinaryOperation::Modulo => {
+                        write!(self.out, "(")?;
+
+                        // write `e1 - e2 * trunc(e1 / e2)`
+                        self.write_expr(left, ctx)?;
+                        write!(self.out, " - ")?;
+                        self.write_expr(right, ctx)?;
+                        write!(self.out, " * ")?;
+                        write!(self.out, "trunc(")?;
+                        self.write_expr(left, ctx)?;
+                        write!(self.out, " / ")?;
+                        self.write_expr(right, ctx)?;
+                        write!(self.out, ")")?;
+
+                        write!(self.out, ")")?;
+                    }
+                    BinaryOperation::Other => {
+                        write!(self.out, "(")?;
+
+                        self.write_expr(left, ctx)?;
+                        write!(self.out, " {} ", back::binary_operation_str(op))?;
+                        self.write_expr(right, ctx)?;
+
+                        write!(self.out, ")")?;
+                    }
+                }
+            }
+            // `Select` is written as `condition ? accept : reject`
+            // We wrap everything in parentheses to avoid precedence issues
+            Expression::Select {
+                condition,
+                accept,
+                reject,
+            } => {
+                let cond_ty = ctx.resolve_type(condition, &self.module.types);
+                let vec_select = if let TypeInner::Vector { .. } = *cond_ty {
+                    true
+                } else {
+                    false
+                };
+
+                // TODO: Boolean mix on desktop required GL_EXT_shader_integer_mix
+                if vec_select {
+                    // Glsl defines that for mix when the condition is a boolean the first element
+                    // is picked if condition is false and the second if condition is true
+                    write!(self.out, "mix(")?;
+                    self.write_expr(reject, ctx)?;
+                    write!(self.out, ", ")?;
+                    self.write_expr(accept, ctx)?;
+                    write!(self.out, ", ")?;
+                    self.write_expr(condition, ctx)?;
+                } else {
+                    write!(self.out, "(")?;
+                    self.write_expr(condition, ctx)?;
+                    write!(self.out, " ? ")?;
+                    self.write_expr(accept, ctx)?;
+                    write!(self.out, " : ")?;
+                    self.write_expr(reject, ctx)?;
+                }
+
+                write!(self.out, ")")?
+            }
+            // `Derivative` is a function call to a glsl provided function
+            Expression::Derivative { axis, ctrl, expr } => {
+                use crate::{DerivativeAxis as Axis, DerivativeControl as Ctrl};
+                let fun_name = if self.options.version.supports_derivative_control() {
+                    match (axis, ctrl) {
+                        (Axis::X, Ctrl::Coarse) => "dFdxCoarse",
+                        (Axis::X, Ctrl::Fine) => "dFdxFine",
+                        (Axis::X, Ctrl::None) => "dFdx",
+                        (Axis::Y, Ctrl::Coarse) => "dFdyCoarse",
+                        (Axis::Y, Ctrl::Fine) => "dFdyFine",
+                        (Axis::Y, Ctrl::None) => "dFdy",
+                        (Axis::Width, Ctrl::Coarse) => "fwidthCoarse",
+                        (Axis::Width, Ctrl::Fine) => "fwidthFine",
+                        (Axis::Width, Ctrl::None) => "fwidth",
+                    }
+                } else {
+                    match axis {
+                        Axis::X => "dFdx",
+                        Axis::Y => "dFdy",
+                        Axis::Width => "fwidth",
+                    }
+                };
+                write!(self.out, "{fun_name}(")?;
+                self.write_expr(expr, ctx)?;
+                write!(self.out, ")")?
+            }
+            // `Relational` is a normal function call to some glsl provided functions
+            Expression::Relational { fun, argument } => {
+                use crate::RelationalFunction as Rf;
+
+                let fun_name = match fun {
+                    Rf::IsInf => "isinf",
+                    Rf::IsNan => "isnan",
+                    Rf::All => "all",
+                    Rf::Any => "any",
+                };
+                write!(self.out, "{fun_name}(")?;
+
+                self.write_expr(argument, ctx)?;
+
+                write!(self.out, ")")?
+            }
+            Expression::Math {
+                fun,
+                arg,
+                arg1,
+                arg2,
+                arg3,
+            } => {
+                use crate::MathFunction as Mf;
+
+                let fun_name = match fun {
+                    // comparison
+                    Mf::Abs => "abs",
+                    Mf::Min => "min",
+                    Mf::Max => "max",
+                    Mf::Clamp => "clamp",
+                    Mf::Saturate => {
+                        write!(self.out, "clamp(")?;
+
+                        self.write_expr(arg, ctx)?;
+
+                        match *ctx.resolve_type(arg, &self.module.types) {
+                            crate::TypeInner::Vector { size, .. } => write!(
+                                self.out,
+                                ", vec{}(0.0), vec{0}(1.0)",
+                                back::vector_size_str(size)
+                            )?,
+                            _ => write!(self.out, ", 0.0, 1.0")?,
+                        }
+
+                        write!(self.out, ")")?;
+
+                        return Ok(());
+                    }
+                    // trigonometry
+                    Mf::Cos => "cos",
+                    Mf::Cosh => "cosh",
+                    Mf::Sin => "sin",
+                    Mf::Sinh => "sinh",
+                    Mf::Tan => "tan",
+                    Mf::Tanh => "tanh",
+                    Mf::Acos => "acos",
+                    Mf::Asin => "asin",
+                    Mf::Atan => "atan",
+                    Mf::Asinh => "asinh",
+                    Mf::Acosh => "acosh",
+                    Mf::Atanh => "atanh",
+                    Mf::Radians => "radians",
+                    Mf::Degrees => "degrees",
+                    // glsl doesn't have atan2 function
+                    // use two-argument variation of the atan function
+                    Mf::Atan2 => "atan",
+                    // decomposition
+                    Mf::Ceil => "ceil",
+                    Mf::Floor => "floor",
+                    Mf::Round => "roundEven",
+                    Mf::Fract => "fract",
+                    Mf::Trunc => "trunc",
+                    Mf::Modf => MODF_FUNCTION,
+                    Mf::Frexp => FREXP_FUNCTION,
+                    Mf::Ldexp => "ldexp",
+                    // exponent
+                    Mf::Exp => "exp",
+                    Mf::Exp2 => "exp2",
+                    Mf::Log => "log",
+                    Mf::Log2 => "log2",
+                    Mf::Pow => "pow",
+                    // geometry
+                    Mf::Dot => match *ctx.resolve_type(arg, &self.module.types) {
+                        crate::TypeInner::Vector {
+                            scalar:
+                                crate::Scalar {
+                                    kind: crate::ScalarKind::Float,
+                                    ..
+                                },
+                            ..
+                        } => "dot",
+                        crate::TypeInner::Vector { size, .. } => {
+                            return self.write_dot_product(arg, arg1.unwrap(), size as usize, ctx)
+                        }
+                        _ => unreachable!(
+                            "Correct TypeInner for dot product should be already validated"
+                        ),
+                    },
+                    Mf::Outer => "outerProduct",
+                    Mf::Cross => "cross",
+                    Mf::Distance => "distance",
+                    Mf::Length => "length",
+                    Mf::Normalize => "normalize",
+                    Mf::FaceForward => "faceforward",
+                    Mf::Reflect => "reflect",
+                    Mf::Refract => "refract",
+                    // computational
+                    Mf::Sign => "sign",
+                    Mf::Fma => {
+                        if self.options.version.supports_fma_function() {
+                            // Use the fma function when available
+                            "fma"
+                        } else {
+                            // No fma support. Transform the function call into an arithmetic expression
+                            write!(self.out, "(")?;
+
+                            self.write_expr(arg, ctx)?;
+                            write!(self.out, " * ")?;
+
+                            let arg1 =
+                                arg1.ok_or_else(|| Error::Custom("Missing fma arg1".to_owned()))?;
+                            self.write_expr(arg1, ctx)?;
+                            write!(self.out, " + ")?;
+
+                            let arg2 =
+                                arg2.ok_or_else(|| Error::Custom("Missing fma arg2".to_owned()))?;
+                            self.write_expr(arg2, ctx)?;
+                            write!(self.out, ")")?;
+
+                            return Ok(());
+                        }
+                    }
+                    Mf::Mix => "mix",
+                    Mf::Step => "step",
+                    Mf::SmoothStep => "smoothstep",
+                    Mf::Sqrt => "sqrt",
+                    Mf::InverseSqrt => "inversesqrt",
+                    Mf::Inverse => "inverse",
+                    Mf::Transpose => "transpose",
+                    Mf::Determinant => "determinant",
+                    // bits
+                    Mf::CountTrailingZeros => {
+                        match *ctx.resolve_type(arg, &self.module.types) {
+                            crate::TypeInner::Vector { size, scalar, .. } => {
+                                let s = back::vector_size_str(size);
+                                if let crate::ScalarKind::Uint = scalar.kind {
+                                    write!(self.out, "min(uvec{s}(findLSB(")?;
+                                    self.write_expr(arg, ctx)?;
+                                    write!(self.out, ")), uvec{s}(32u))")?;
+                                } else {
+                                    write!(self.out, "ivec{s}(min(uvec{s}(findLSB(")?;
+                                    self.write_expr(arg, ctx)?;
+                                    write!(self.out, ")), uvec{s}(32u)))")?;
+                                }
+                            }
+                            crate::TypeInner::Scalar(scalar) => {
+                                if let crate::ScalarKind::Uint = scalar.kind {
+                                    write!(self.out, "min(uint(findLSB(")?;
+                                    self.write_expr(arg, ctx)?;
+                                    write!(self.out, ")), 32u)")?;
+                                } else {
+                                    write!(self.out, "int(min(uint(findLSB(")?;
+                                    self.write_expr(arg, ctx)?;
+                                    write!(self.out, ")), 32u))")?;
+                                }
+                            }
+                            _ => unreachable!(),
+                        };
+                        return Ok(());
+                    }
+                    Mf::CountLeadingZeros => {
+                        if self.options.version.supports_integer_functions() {
+                            match *ctx.resolve_type(arg, &self.module.types) {
+                                crate::TypeInner::Vector { size, scalar } => {
+                                    let s = back::vector_size_str(size);
+
+                                    if let crate::ScalarKind::Uint = scalar.kind {
+                                        write!(self.out, "uvec{s}(ivec{s}(31) - findMSB(")?;
+                                        self.write_expr(arg, ctx)?;
+                                        write!(self.out, "))")?;
+                                    } else {
+                                        write!(self.out, "mix(ivec{s}(31) - findMSB(")?;
+                                        self.write_expr(arg, ctx)?;
+                                        write!(self.out, "), ivec{s}(0), lessThan(")?;
+                                        self.write_expr(arg, ctx)?;
+                                        write!(self.out, ", ivec{s}(0)))")?;
+                                    }
+                                }
+                                crate::TypeInner::Scalar(scalar) => {
+                                    if let crate::ScalarKind::Uint = scalar.kind {
+                                        write!(self.out, "uint(31 - findMSB(")?;
+                                    } else {
+                                        write!(self.out, "(")?;
+                                        self.write_expr(arg, ctx)?;
+                                        write!(self.out, " < 0 ? 0 : 31 - findMSB(")?;
+                                    }
+
+                                    self.write_expr(arg, ctx)?;
+                                    write!(self.out, "))")?;
+                                }
+                                _ => unreachable!(),
+                            };
+                        } else {
+                            match *ctx.resolve_type(arg, &self.module.types) {
+                                crate::TypeInner::Vector { size, scalar } => {
+                                    let s = back::vector_size_str(size);
+
+                                    if let crate::ScalarKind::Uint = scalar.kind {
+                                        write!(self.out, "uvec{s}(")?;
+                                        write!(self.out, "vec{s}(31.0) - floor(log2(vec{s}(")?;
+                                        self.write_expr(arg, ctx)?;
+                                        write!(self.out, ") + 0.5)))")?;
+                                    } else {
+                                        write!(self.out, "ivec{s}(")?;
+                                        write!(self.out, "mix(vec{s}(31.0) - floor(log2(vec{s}(")?;
+                                        self.write_expr(arg, ctx)?;
+                                        write!(self.out, ") + 0.5)), ")?;
+                                        write!(self.out, "vec{s}(0.0), lessThan(")?;
+                                        self.write_expr(arg, ctx)?;
+                                        write!(self.out, ", ivec{s}(0u))))")?;
+                                    }
+                                }
+                                crate::TypeInner::Scalar(scalar) => {
+                                    if let crate::ScalarKind::Uint = scalar.kind {
+                                        write!(self.out, "uint(31.0 - floor(log2(float(")?;
+                                        self.write_expr(arg, ctx)?;
+                                        write!(self.out, ") + 0.5)))")?;
+                                    } else {
+                                        write!(self.out, "(")?;
+                                        self.write_expr(arg, ctx)?;
+                                        write!(self.out, " < 0 ? 0 : int(")?;
+                                        write!(self.out, "31.0 - floor(log2(float(")?;
+                                        self.write_expr(arg, ctx)?;
+                                        write!(self.out, ") + 0.5))))")?;
+                                    }
+                                }
+                                _ => unreachable!(),
+                            };
+                        }
+
+                        return Ok(());
+                    }
+                    Mf::CountOneBits => "bitCount",
+                    Mf::ReverseBits => "bitfieldReverse",
+                    Mf::ExtractBits => "bitfieldExtract",
+                    Mf::InsertBits => "bitfieldInsert",
+                    Mf::FindLsb => "findLSB",
+                    Mf::FindMsb => "findMSB",
+                    // data packing
+                    Mf::Pack4x8snorm => "packSnorm4x8",
+                    Mf::Pack4x8unorm => "packUnorm4x8",
+                    Mf::Pack2x16snorm => "packSnorm2x16",
+                    Mf::Pack2x16unorm => "packUnorm2x16",
+                    Mf::Pack2x16float => "packHalf2x16",
+                    // data unpacking
+                    Mf::Unpack4x8snorm => "unpackSnorm4x8",
+                    Mf::Unpack4x8unorm => "unpackUnorm4x8",
+                    Mf::Unpack2x16snorm => "unpackSnorm2x16",
+                    Mf::Unpack2x16unorm => "unpackUnorm2x16",
+                    Mf::Unpack2x16float => "unpackHalf2x16",
+                };
+
+                let extract_bits = fun == Mf::ExtractBits;
+                let insert_bits = fun == Mf::InsertBits;
+
+                // Some GLSL functions always return signed integers (like findMSB),
+                // so they need to be cast to uint if the argument is also an uint.
+                let ret_might_need_int_to_uint =
+                    matches!(fun, Mf::FindLsb | Mf::FindMsb | Mf::CountOneBits | Mf::Abs);
+
+                // Some GLSL functions only accept signed integers (like abs),
+                // so they need their argument cast from uint to int.
+                let arg_might_need_uint_to_int = matches!(fun, Mf::Abs);
+
+                // Check if the argument is an unsigned integer and return the vector size
+                // in case it's a vector
+                let maybe_uint_size = match *ctx.resolve_type(arg, &self.module.types) {
+                    crate::TypeInner::Scalar(crate::Scalar {
+                        kind: crate::ScalarKind::Uint,
+                        ..
+                    }) => Some(None),
+                    crate::TypeInner::Vector {
+                        scalar:
+                            crate::Scalar {
+                                kind: crate::ScalarKind::Uint,
+                                ..
+                            },
+                        size,
+                    } => Some(Some(size)),
+                    _ => None,
+                };
+
+                // Cast to uint if the function needs it
+                if ret_might_need_int_to_uint {
+                    if let Some(maybe_size) = maybe_uint_size {
+                        match maybe_size {
+                            Some(size) => write!(self.out, "uvec{}(", size as u8)?,
+                            None => write!(self.out, "uint(")?,
+                        }
+                    }
+                }
+
+                write!(self.out, "{fun_name}(")?;
+
+                // Cast to int if the function needs it
+                if arg_might_need_uint_to_int {
+                    if let Some(maybe_size) = maybe_uint_size {
+                        match maybe_size {
+                            Some(size) => write!(self.out, "ivec{}(", size as u8)?,
+                            None => write!(self.out, "int(")?,
+                        }
+                    }
+                }
+
+                self.write_expr(arg, ctx)?;
+
+                // Close the cast from uint to int
+                if arg_might_need_uint_to_int && maybe_uint_size.is_some() {
+                    write!(self.out, ")")?
+                }
+
+                if let Some(arg) = arg1 {
+                    write!(self.out, ", ")?;
+                    if extract_bits {
+                        write!(self.out, "int(")?;
+                        self.write_expr(arg, ctx)?;
+                        write!(self.out, ")")?;
+                    } else {
+                        self.write_expr(arg, ctx)?;
+                    }
+                }
+                if let Some(arg) = arg2 {
+                    write!(self.out, ", ")?;
+                    if extract_bits || insert_bits {
+                        write!(self.out, "int(")?;
+                        self.write_expr(arg, ctx)?;
+                        write!(self.out, ")")?;
+                    } else {
+                        self.write_expr(arg, ctx)?;
+                    }
+                }
+                if let Some(arg) = arg3 {
+                    write!(self.out, ", ")?;
+                    if insert_bits {
+                        write!(self.out, "int(")?;
+                        self.write_expr(arg, ctx)?;
+                        write!(self.out, ")")?;
+                    } else {
+                        self.write_expr(arg, ctx)?;
+                    }
+                }
+                write!(self.out, ")")?;
+
+                // Close the cast from int to uint
+                if ret_might_need_int_to_uint && maybe_uint_size.is_some() {
+                    write!(self.out, ")")?
+                }
+            }
+            // `As` is always a call.
+            // If `convert` is true the function name is the type
+            // Else the function name is one of the glsl provided bitcast functions
+            Expression::As {
+                expr,
+                kind: target_kind,
+                convert,
+            } => {
+                let inner = ctx.resolve_type(expr, &self.module.types);
+                match convert {
+                    Some(width) => {
+                        // this is similar to `write_type`, but with the target kind
+                        let scalar = glsl_scalar(crate::Scalar {
+                            kind: target_kind,
+                            width,
+                        })?;
+                        match *inner {
+                            TypeInner::Matrix { columns, rows, .. } => write!(
+                                self.out,
+                                "{}mat{}x{}",
+                                scalar.prefix, columns as u8, rows as u8
+                            )?,
+                            TypeInner::Vector { size, .. } => {
+                                write!(self.out, "{}vec{}", scalar.prefix, size as u8)?
+                            }
+                            _ => write!(self.out, "{}", scalar.full)?,
+                        }
+
+                        write!(self.out, "(")?;
+                        self.write_expr(expr, ctx)?;
+                        write!(self.out, ")")?
+                    }
+                    None => {
+                        use crate::ScalarKind as Sk;
+
+                        let target_vector_type = match *inner {
+                            TypeInner::Vector { size, scalar } => Some(TypeInner::Vector {
+                                size,
+                                scalar: crate::Scalar {
+                                    kind: target_kind,
+                                    width: scalar.width,
+                                },
+                            }),
+                            _ => None,
+                        };
+
+                        let source_kind = inner.scalar_kind().unwrap();
+
+                        match (source_kind, target_kind, target_vector_type) {
+                            // No conversion needed
+                            (Sk::Sint, Sk::Sint, _)
+                            | (Sk::Uint, Sk::Uint, _)
+                            | (Sk::Float, Sk::Float, _)
+                            | (Sk::Bool, Sk::Bool, _) => {
+                                self.write_expr(expr, ctx)?;
+                                return Ok(());
+                            }
+
+                            // Cast to/from floats
+                            (Sk::Float, Sk::Sint, _) => write!(self.out, "floatBitsToInt")?,
+                            (Sk::Float, Sk::Uint, _) => write!(self.out, "floatBitsToUint")?,
+                            (Sk::Sint, Sk::Float, _) => write!(self.out, "intBitsToFloat")?,
+                            (Sk::Uint, Sk::Float, _) => write!(self.out, "uintBitsToFloat")?,
+
+                            // Cast between vector types
+                            (_, _, Some(vector)) => {
+                                self.write_value_type(&vector)?;
+                            }
+
+                            // There is no way to bitcast between Uint/Sint in glsl. Use constructor conversion
+                            (Sk::Uint | Sk::Bool, Sk::Sint, None) => write!(self.out, "int")?,
+                            (Sk::Sint | Sk::Bool, Sk::Uint, None) => write!(self.out, "uint")?,
+                            (Sk::Bool, Sk::Float, None) => write!(self.out, "float")?,
+                            (Sk::Sint | Sk::Uint | Sk::Float, Sk::Bool, None) => {
+                                write!(self.out, "bool")?
+                            }
+
+                            (Sk::AbstractInt | Sk::AbstractFloat, _, _)
+                            | (_, Sk::AbstractInt | Sk::AbstractFloat, _) => unreachable!(),
+                        };
+
+                        write!(self.out, "(")?;
+                        self.write_expr(expr, ctx)?;
+                        write!(self.out, ")")?;
+                    }
+                }
+            }
+            // These expressions never show up in `Emit`.
+            Expression::CallResult(_)
+            | Expression::AtomicResult { .. }
+            | Expression::RayQueryProceedResult
+            | Expression::WorkGroupUniformLoadResult { .. } => unreachable!(),
+            // `ArrayLength` is written as `expr.length()` and we convert it to a uint
+            Expression::ArrayLength(expr) => {
+                write!(self.out, "uint(")?;
+                self.write_expr(expr, ctx)?;
+                write!(self.out, ".length())")?
+            }
+            // not supported yet
+            Expression::RayQueryGetIntersection { .. } => unreachable!(),
+        }
+
+        Ok(())
+    }
+
+    /// Helper function to write the local holding the clamped lod
+    fn write_clamped_lod(
+        &mut self,
+        ctx: &back::FunctionCtx,
+        expr: Handle<crate::Expression>,
+        image: Handle<crate::Expression>,
+        level_expr: Handle<crate::Expression>,
+    ) -> Result<(), Error> {
+        // Define our local and start a call to `clamp`
+        write!(
+            self.out,
+            "int {}{}{} = clamp(",
+            back::BAKE_PREFIX,
+            expr.index(),
+            CLAMPED_LOD_SUFFIX
+        )?;
+        // Write the lod that will be clamped
+        self.write_expr(level_expr, ctx)?;
+        // Set the min value to 0 and start a call to `textureQueryLevels` to get
+        // the maximum value
+        write!(self.out, ", 0, textureQueryLevels(")?;
+        // Write the target image as an argument to `textureQueryLevels`
+        self.write_expr(image, ctx)?;
+        // Close the call to `textureQueryLevels` subtract 1 from it since
+        // the lod argument is 0 based, close the `clamp` call and end the
+        // local declaration statement.
+        writeln!(self.out, ") - 1);")?;
+
+        Ok(())
+    }
+
+    // Helper method used to retrieve how many elements a coordinate vector
+    // for the images operations need.
+    fn get_coordinate_vector_size(&self, dim: crate::ImageDimension, arrayed: bool) -> u8 {
+        // openGL es doesn't have 1D images so we need workaround it
+        let tex_1d_hack = dim == crate::ImageDimension::D1 && self.options.version.is_es();
+        // Get how many components the coordinate vector needs for the dimensions only
+        let tex_coord_size = match dim {
+            crate::ImageDimension::D1 => 1,
+            crate::ImageDimension::D2 => 2,
+            crate::ImageDimension::D3 => 3,
+            crate::ImageDimension::Cube => 2,
+        };
+        // Calculate the true size of the coordinate vector by adding 1 for arrayed images
+        // and another 1 if we need to workaround 1D images by making them 2D
+        tex_coord_size + tex_1d_hack as u8 + arrayed as u8
+    }
+
+    /// Helper method to write the coordinate vector for image operations
+    fn write_texture_coord(
+        &mut self,
+        ctx: &back::FunctionCtx,
+        vector_size: u8,
+        coordinate: Handle<crate::Expression>,
+        array_index: Option<Handle<crate::Expression>>,
+        // Emulate 1D images as 2D for profiles that don't support it (glsl es)
+        tex_1d_hack: bool,
+    ) -> Result<(), Error> {
+        match array_index {
+            // If the image needs an array indice we need to add it to the end of our
+            // coordinate vector, to do so we will use the `ivec(ivec, scalar)`
+            // constructor notation (NOTE: the inner `ivec` can also be a scalar, this
+            // is important for 1D arrayed images).
+            Some(layer_expr) => {
+                write!(self.out, "ivec{vector_size}(")?;
+                self.write_expr(coordinate, ctx)?;
+                write!(self.out, ", ")?;
+                // If we are replacing sampler1D with sampler2D we also need
+                // to add another zero to the coordinates vector for the y component
+                if tex_1d_hack {
+                    write!(self.out, "0, ")?;
+                }
+                self.write_expr(layer_expr, ctx)?;
+                write!(self.out, ")")?;
+            }
+            // Otherwise write just the expression (and the 1D hack if needed)
+            None => {
+                let uvec_size = match *ctx.resolve_type(coordinate, &self.module.types) {
+                    TypeInner::Scalar(crate::Scalar {
+                        kind: crate::ScalarKind::Uint,
+                        ..
+                    }) => Some(None),
+                    TypeInner::Vector {
+                        size,
+                        scalar:
+                            crate::Scalar {
+                                kind: crate::ScalarKind::Uint,
+                                ..
+                            },
+                    } => Some(Some(size as u32)),
+                    _ => None,
+                };
+                if tex_1d_hack {
+                    write!(self.out, "ivec2(")?;
+                } else if uvec_size.is_some() {
+                    match uvec_size {
+                        Some(None) => write!(self.out, "int(")?,
+                        Some(Some(size)) => write!(self.out, "ivec{size}(")?,
+                        _ => {}
+                    }
+                }
+                self.write_expr(coordinate, ctx)?;
+                if tex_1d_hack {
+                    write!(self.out, ", 0)")?;
+                } else if uvec_size.is_some() {
+                    write!(self.out, ")")?;
+                }
+            }
+        }
+
+        Ok(())
+    }
+
+    /// Helper method to write the `ImageStore` statement
+    fn write_image_store(
+        &mut self,
+        ctx: &back::FunctionCtx,
+        image: Handle<crate::Expression>,
+        coordinate: Handle<crate::Expression>,
+        array_index: Option<Handle<crate::Expression>>,
+        value: Handle<crate::Expression>,
+    ) -> Result<(), Error> {
+        use crate::ImageDimension as IDim;
+
+        // NOTE: openGL requires that `imageStore`s have no effets when the texel is invalid
+        // so we don't need to generate bounds checks (OpenGL 4.2 Core §3.9.20)
+
+        // This will only panic if the module is invalid
+        let dim = match *ctx.resolve_type(image, &self.module.types) {
+            TypeInner::Image { dim, .. } => dim,
+            _ => unreachable!(),
+        };
+
+        // Begin our call to `imageStore`
+        write!(self.out, "imageStore(")?;
+        self.write_expr(image, ctx)?;
+        // Separate the image argument from the coordinates
+        write!(self.out, ", ")?;
+
+        // openGL es doesn't have 1D images so we need workaround it
+        let tex_1d_hack = dim == IDim::D1 && self.options.version.is_es();
+        // Write the coordinate vector
+        self.write_texture_coord(
+            ctx,
+            // Get the size of the coordinate vector
+            self.get_coordinate_vector_size(dim, array_index.is_some()),
+            coordinate,
+            array_index,
+            tex_1d_hack,
+        )?;
+
+        // Separate the coordinate from the value to write and write the expression
+        // of the value to write.
+        write!(self.out, ", ")?;
+        self.write_expr(value, ctx)?;
+        // End the call to `imageStore` and the statement.
+        writeln!(self.out, ");")?;
+
+        Ok(())
+    }
+
+    /// Helper method for writing an `ImageLoad` expression.
+    #[allow(clippy::too_many_arguments)]
+    fn write_image_load(
+        &mut self,
+        handle: Handle<crate::Expression>,
+        ctx: &back::FunctionCtx,
+        image: Handle<crate::Expression>,
+        coordinate: Handle<crate::Expression>,
+        array_index: Option<Handle<crate::Expression>>,
+        sample: Option<Handle<crate::Expression>>,
+        level: Option<Handle<crate::Expression>>,
+    ) -> Result<(), Error> {
+        use crate::ImageDimension as IDim;
+
+        // `ImageLoad` is a bit complicated.
+        // There are two functions one for sampled
+        // images another for storage images, the former uses `texelFetch` and the
+        // latter uses `imageLoad`.
+        //
+        // Furthermore we have `level` which is always `Some` for sampled images
+        // and `None` for storage images, so we end up with two functions:
+        // - `texelFetch(image, coordinate, level)` for sampled images
+        // - `imageLoad(image, coordinate)` for storage images
+        //
+        // Finally we also have to consider bounds checking, for storage images
+        // this is easy since openGL requires that invalid texels always return
+        // 0, for sampled images we need to either verify that all arguments are
+        // in bounds (`ReadZeroSkipWrite`) or make them a valid texel (`Restrict`).
+
+        // This will only panic if the module is invalid
+        let (dim, class) = match *ctx.resolve_type(image, &self.module.types) {
+            TypeInner::Image {
+                dim,
+                arrayed: _,
+                class,
+            } => (dim, class),
+            _ => unreachable!(),
+        };
+
+        // Get the name of the function to be used for the load operation
+        // and the policy to be used with it.
+        let (fun_name, policy) = match class {
+            // Sampled images inherit the policy from the user passed policies
+            crate::ImageClass::Sampled { .. } => ("texelFetch", self.policies.image_load),
+            crate::ImageClass::Storage { .. } => {
+                // OpenGL ES 3.1 mentions in Chapter "8.22 Texture Image Loads and Stores" that:
+                // "Invalid image loads will return a vector where the value of R, G, and B components
+                // is 0 and the value of the A component is undefined."
+                //
+                // OpenGL 4.2 Core mentions in Chapter "3.9.20 Texture Image Loads and Stores" that:
+                // "Invalid image loads will return zero."
+                //
+                // So, we only inject bounds checks for ES
+                let policy = if self.options.version.is_es() {
+                    self.policies.image_load
+                } else {
+                    proc::BoundsCheckPolicy::Unchecked
+                };
+                ("imageLoad", policy)
+            }
+            // TODO: Is there even a function for this?
+            crate::ImageClass::Depth { multi: _ } => {
+                return Err(Error::Custom(
+                    "WGSL `textureLoad` from depth textures is not supported in GLSL".to_string(),
+                ))
+            }
+        };
+
+        // openGL es doesn't have 1D images so we need workaround it
+        let tex_1d_hack = dim == IDim::D1 && self.options.version.is_es();
+        // Get the size of the coordinate vector
+        let vector_size = self.get_coordinate_vector_size(dim, array_index.is_some());
+
+        if let proc::BoundsCheckPolicy::ReadZeroSkipWrite = policy {
+            // To write the bounds checks for `ReadZeroSkipWrite` we will use a
+            // ternary operator since we are in the middle of an expression and
+            // need to return a value.
+            //
+            // NOTE: glsl does short circuit when evaluating logical
+            // expressions so we can be sure that after we test a
+            // condition it will be true for the next ones
+
+            // Write parentheses around the ternary operator to prevent problems with
+            // expressions emitted before or after it having more precedence
+            write!(self.out, "(",)?;
+
+            // The lod check needs to precede the size check since we need
+            // to use the lod to get the size of the image at that level.
+            if let Some(level_expr) = level {
+                self.write_expr(level_expr, ctx)?;
+                write!(self.out, " < textureQueryLevels(",)?;
+                self.write_expr(image, ctx)?;
+                // Chain the next check
+                write!(self.out, ") && ")?;
+            }
+
+            // Check that the sample arguments doesn't exceed the number of samples
+            if let Some(sample_expr) = sample {
+                self.write_expr(sample_expr, ctx)?;
+                write!(self.out, " < textureSamples(",)?;
+                self.write_expr(image, ctx)?;
+                // Chain the next check
+                write!(self.out, ") && ")?;
+            }
+
+            // We now need to write the size checks for the coordinates and array index
+            // first we write the comparison function in case the image is 1D non arrayed
+            // (and no 1D to 2D hack was needed) we are comparing scalars so the less than
+            // operator will suffice, but otherwise we'll be comparing two vectors so we'll
+            // need to use the `lessThan` function but it returns a vector of booleans (one
+            // for each comparison) so we need to fold it all in one scalar boolean, since
+            // we want all comparisons to pass we use the `all` function which will only
+            // return `true` if all the elements of the boolean vector are also `true`.
+            //
+            // So we'll end with one of the following forms
+            // - `coord < textureSize(image, lod)` for 1D images
+            // - `all(lessThan(coord, textureSize(image, lod)))` for normal images
+            // - `all(lessThan(ivec(coord, array_index), textureSize(image, lod)))`
+            //    for arrayed images
+            // - `all(lessThan(coord, textureSize(image)))` for multi sampled images
+
+            if vector_size != 1 {
+                write!(self.out, "all(lessThan(")?;
+            }
+
+            // Write the coordinate vector
+            self.write_texture_coord(ctx, vector_size, coordinate, array_index, tex_1d_hack)?;
+
+            if vector_size != 1 {
+                // If we used the `lessThan` function we need to separate the
+                // coordinates from the image size.
+                write!(self.out, ", ")?;
+            } else {
+                // If we didn't use it (ie. 1D images) we perform the comparison
+                // using the less than operator.
+                write!(self.out, " < ")?;
+            }
+
+            // Call `textureSize` to get our image size
+            write!(self.out, "textureSize(")?;
+            self.write_expr(image, ctx)?;
+            // `textureSize` uses the lod as a second argument for mipmapped images
+            if let Some(level_expr) = level {
+                // Separate the image from the lod
+                write!(self.out, ", ")?;
+                self.write_expr(level_expr, ctx)?;
+            }
+            // Close the `textureSize` call
+            write!(self.out, ")")?;
+
+            if vector_size != 1 {
+                // Close the `all` and `lessThan` calls
+                write!(self.out, "))")?;
+            }
+
+            // Finally end the condition part of the ternary operator
+            write!(self.out, " ? ")?;
+        }
+
+        // Begin the call to the function used to load the texel
+        write!(self.out, "{fun_name}(")?;
+        self.write_expr(image, ctx)?;
+        write!(self.out, ", ")?;
+
+        // If we are using `Restrict` bounds checking we need to pass valid texel
+        // coordinates, to do so we use the `clamp` function to get a value between
+        // 0 and the image size - 1 (indexing begins at 0)
+        if let proc::BoundsCheckPolicy::Restrict = policy {
+            write!(self.out, "clamp(")?;
+        }
+
+        // Write the coordinate vector
+        self.write_texture_coord(ctx, vector_size, coordinate, array_index, tex_1d_hack)?;
+
+        // If we are using `Restrict` bounds checking we need to write the rest of the
+        // clamp we initiated before writing the coordinates.
+        if let proc::BoundsCheckPolicy::Restrict = policy {
+            // Write the min value 0
+            if vector_size == 1 {
+                write!(self.out, ", 0")?;
+            } else {
+                write!(self.out, ", ivec{vector_size}(0)")?;
+            }
+            // Start the `textureSize` call to use as the max value.
+            write!(self.out, ", textureSize(")?;
+            self.write_expr(image, ctx)?;
+            // If the image is mipmapped we need to add the lod argument to the
+            // `textureSize` call, but this needs to be the clamped lod, this should
+            // have been generated earlier and put in a local.
+            if class.is_mipmapped() {
+                write!(
+                    self.out,
+                    ", {}{}{}",
+                    back::BAKE_PREFIX,
+                    handle.index(),
+                    CLAMPED_LOD_SUFFIX
+                )?;
+            }
+            // Close the `textureSize` call
+            write!(self.out, ")")?;
+
+            // Subtract 1 from the `textureSize` call since the coordinates are zero based.
+            if vector_size == 1 {
+                write!(self.out, " - 1")?;
+            } else {
+                write!(self.out, " - ivec{vector_size}(1)")?;
+            }
+
+            // Close the `clamp` call
+            write!(self.out, ")")?;
+
+            // Add the clamped lod (if present) as the second argument to the
+            // image load function.
+            if level.is_some() {
+                write!(
+                    self.out,
+                    ", {}{}{}",
+                    back::BAKE_PREFIX,
+                    handle.index(),
+                    CLAMPED_LOD_SUFFIX
+                )?;
+            }
+
+            // If a sample argument is needed we need to clamp it between 0 and
+            // the number of samples the image has.
+            if let Some(sample_expr) = sample {
+                write!(self.out, ", clamp(")?;
+                self.write_expr(sample_expr, ctx)?;
+                // Set the min value to 0 and start the call to `textureSamples`
+                write!(self.out, ", 0, textureSamples(")?;
+                self.write_expr(image, ctx)?;
+                // Close the `textureSamples` call, subtract 1 from it since the sample
+                // argument is zero based, and close the `clamp` call
+                writeln!(self.out, ") - 1)")?;
+            }
+        } else if let Some(sample_or_level) = sample.or(level) {
+            // If no bounds checking is need just add the sample or level argument
+            // after the coordinates
+            write!(self.out, ", ")?;
+            self.write_expr(sample_or_level, ctx)?;
+        }
+
+        // Close the image load function.
+        write!(self.out, ")")?;
+
+        // If we were using the `ReadZeroSkipWrite` policy we need to end the first branch
+        // (which is taken if the condition is `true`) with a colon (`:`) and write the
+        // second branch which is just a 0 value.
+        if let proc::BoundsCheckPolicy::ReadZeroSkipWrite = policy {
+            // Get the kind of the output value.
+            let kind = match class {
+                // Only sampled images can reach here since storage images
+                // don't need bounds checks and depth images aren't implemented
+                crate::ImageClass::Sampled { kind, .. } => kind,
+                _ => unreachable!(),
+            };
+
+            // End the first branch
+            write!(self.out, " : ")?;
+            // Write the 0 value
+            write!(
+                self.out,
+                "{}vec4(",
+                glsl_scalar(crate::Scalar { kind, width: 4 })?.prefix,
+            )?;
+            self.write_zero_init_scalar(kind)?;
+            // Close the zero value constructor
+            write!(self.out, ")")?;
+            // Close the parentheses surrounding our ternary
+            write!(self.out, ")")?;
+        }
+
+        Ok(())
+    }
+
+    fn write_named_expr(
+        &mut self,
+        handle: Handle<crate::Expression>,
+        name: String,
+        // The expression which is being named.
+        // Generally, this is the same as handle, except in WorkGroupUniformLoad
+        named: Handle<crate::Expression>,
+        ctx: &back::FunctionCtx,
+    ) -> BackendResult {
+        match ctx.info[named].ty {
+            proc::TypeResolution::Handle(ty_handle) => match self.module.types[ty_handle].inner {
+                TypeInner::Struct { .. } => {
+                    let ty_name = &self.names[&NameKey::Type(ty_handle)];
+                    write!(self.out, "{ty_name}")?;
+                }
+                _ => {
+                    self.write_type(ty_handle)?;
+                }
+            },
+            proc::TypeResolution::Value(ref inner) => {
+                self.write_value_type(inner)?;
+            }
+        }
+
+        let resolved = ctx.resolve_type(named, &self.module.types);
+
+        write!(self.out, " {name}")?;
+        if let TypeInner::Array { base, size, .. } = *resolved {
+            self.write_array_size(base, size)?;
+        }
+        write!(self.out, " = ")?;
+        self.write_expr(handle, ctx)?;
+        writeln!(self.out, ";")?;
+        self.named_expressions.insert(named, name);
+
+        Ok(())
+    }
+
+    /// Helper function that write string with default zero initialization for supported types
+    fn write_zero_init_value(&mut self, ty: Handle<crate::Type>) -> BackendResult {
+        let inner = &self.module.types[ty].inner;
+        match *inner {
+            TypeInner::Scalar(scalar) | TypeInner::Atomic(scalar) => {
+                self.write_zero_init_scalar(scalar.kind)?;
+            }
+            TypeInner::Vector { scalar, .. } => {
+                self.write_value_type(inner)?;
+                write!(self.out, "(")?;
+                self.write_zero_init_scalar(scalar.kind)?;
+                write!(self.out, ")")?;
+            }
+            TypeInner::Matrix { .. } => {
+                self.write_value_type(inner)?;
+                write!(self.out, "(")?;
+                self.write_zero_init_scalar(crate::ScalarKind::Float)?;
+                write!(self.out, ")")?;
+            }
+            TypeInner::Array { base, size, .. } => {
+                let count = match size
+                    .to_indexable_length(self.module)
+                    .expect("Bad array size")
+                {
+                    proc::IndexableLength::Known(count) => count,
+                    proc::IndexableLength::Dynamic => return Ok(()),
+                };
+                self.write_type(base)?;
+                self.write_array_size(base, size)?;
+                write!(self.out, "(")?;
+                for _ in 1..count {
+                    self.write_zero_init_value(base)?;
+                    write!(self.out, ", ")?;
+                }
+                // write last parameter without comma and space
+                self.write_zero_init_value(base)?;
+                write!(self.out, ")")?;
+            }
+            TypeInner::Struct { ref members, .. } => {
+                let name = &self.names[&NameKey::Type(ty)];
+                write!(self.out, "{name}(")?;
+                for (index, member) in members.iter().enumerate() {
+                    if index != 0 {
+                        write!(self.out, ", ")?;
+                    }
+                    self.write_zero_init_value(member.ty)?;
+                }
+                write!(self.out, ")")?;
+            }
+            _ => unreachable!(),
+        }
+
+        Ok(())
+    }
+
+    /// Helper function that write string with zero initialization for scalar
+    fn write_zero_init_scalar(&mut self, kind: crate::ScalarKind) -> BackendResult {
+        match kind {
+            crate::ScalarKind::Bool => write!(self.out, "false")?,
+            crate::ScalarKind::Uint => write!(self.out, "0u")?,
+            crate::ScalarKind::Float => write!(self.out, "0.0")?,
+            crate::ScalarKind::Sint => write!(self.out, "0")?,
+            crate::ScalarKind::AbstractInt | crate::ScalarKind::AbstractFloat => {
+                return Err(Error::Custom(
+                    "Abstract types should not appear in IR presented to backends".to_string(),
+                ))
+            }
+        }
+
+        Ok(())
+    }
+
+    /// Issue a memory barrier. Please note that to ensure visibility,
+    /// OpenGL always requires a call to the `barrier()` function after a `memoryBarrier*()`
+    fn write_barrier(&mut self, flags: crate::Barrier, level: back::Level) -> BackendResult {
+        if flags.contains(crate::Barrier::STORAGE) {
+            writeln!(self.out, "{level}memoryBarrierBuffer();")?;
+        }
+        if flags.contains(crate::Barrier::WORK_GROUP) {
+            writeln!(self.out, "{level}memoryBarrierShared();")?;
+        }
+        writeln!(self.out, "{level}barrier();")?;
+        Ok(())
+    }
+
+    /// Helper function that return the glsl storage access string of [`StorageAccess`](crate::StorageAccess)
+    ///
+    /// glsl allows adding both `readonly` and `writeonly` but this means that
+    /// they can only be used to query information about the resource which isn't what
+    /// we want here so when storage access is both `LOAD` and `STORE` add no modifiers
+    fn write_storage_access(&mut self, storage_access: crate::StorageAccess) -> BackendResult {
+        if !storage_access.contains(crate::StorageAccess::STORE) {
+            write!(self.out, "readonly ")?;
+        }
+        if !storage_access.contains(crate::StorageAccess::LOAD) {
+            write!(self.out, "writeonly ")?;
+        }
+        Ok(())
+    }
+
+    /// Helper method used to produce the reflection info that's returned to the user
+    fn collect_reflection_info(&mut self) -> Result<ReflectionInfo, Error> {
+        use std::collections::hash_map::Entry;
+        let info = self.info.get_entry_point(self.entry_point_idx as usize);
+        let mut texture_mapping = crate::FastHashMap::default();
+        let mut uniforms = crate::FastHashMap::default();
+
+        for sampling in info.sampling_set.iter() {
+            let tex_name = self.reflection_names_globals[&sampling.image].clone();
+
+            match texture_mapping.entry(tex_name) {
+                Entry::Vacant(v) => {
+                    v.insert(TextureMapping {
+                        texture: sampling.image,
+                        sampler: Some(sampling.sampler),
+                    });
+                }
+                Entry::Occupied(e) => {
+                    if e.get().sampler != Some(sampling.sampler) {
+                        log::error!("Conflicting samplers for {}", e.key());
+                        return Err(Error::ImageMultipleSamplers);
+                    }
+                }
+            }
+        }
+
+        let mut push_constant_info = None;
+        for (handle, var) in self.module.global_variables.iter() {
+            if info[handle].is_empty() {
+                continue;
+            }
+            match self.module.types[var.ty].inner {
+                crate::TypeInner::Image { .. } => {
+                    let tex_name = self.reflection_names_globals[&handle].clone();
+                    match texture_mapping.entry(tex_name) {
+                        Entry::Vacant(v) => {
+                            v.insert(TextureMapping {
+                                texture: handle,
+                                sampler: None,
+                            });
+                        }
+                        Entry::Occupied(_) => {
+                            // already used with a sampler, do nothing
+                        }
+                    }
+                }
+                _ => match var.space {
+                    crate::AddressSpace::Uniform | crate::AddressSpace::Storage { .. } => {
+                        let name = self.reflection_names_globals[&handle].clone();
+                        uniforms.insert(handle, name);
+                    }
+                    crate::AddressSpace::PushConstant => {
+                        let name = self.reflection_names_globals[&handle].clone();
+                        push_constant_info = Some((name, var.ty));
+                    }
+                    _ => (),
+                },
+            }
+        }
+
+        let mut push_constant_segments = Vec::new();
+        let mut push_constant_items = vec![];
+
+        if let Some((name, ty)) = push_constant_info {
+            // We don't have a layouter available to us, so we need to create one.
+            //
+            // This is potentially a bit wasteful, but the set of types in the program
+            // shouldn't be too large.
+            let mut layouter = crate::proc::Layouter::default();
+            layouter.update(self.module.to_ctx()).unwrap();
+
+            // We start with the name of the binding itself.
+            push_constant_segments.push(name);
+
+            // We then recursively collect all the uniform fields of the push constant.
+            self.collect_push_constant_items(
+                ty,
+                &mut push_constant_segments,
+                &layouter,
+                &mut 0,
+                &mut push_constant_items,
+            );
+        }
+
+        Ok(ReflectionInfo {
+            texture_mapping,
+            uniforms,
+            varying: mem::take(&mut self.varying),
+            push_constant_items,
+        })
+    }
+
+    fn collect_push_constant_items(
+        &mut self,
+        ty: Handle<crate::Type>,
+        segments: &mut Vec<String>,
+        layouter: &crate::proc::Layouter,
+        offset: &mut u32,
+        items: &mut Vec<PushConstantItem>,
+    ) {
+        // At this point in the recursion, `segments` contains the path
+        // needed to access `ty` from the root.
+
+        let layout = &layouter[ty];
+        *offset = layout.alignment.round_up(*offset);
+        match self.module.types[ty].inner {
+            // All these types map directly to GL uniforms.
+            TypeInner::Scalar { .. } | TypeInner::Vector { .. } | TypeInner::Matrix { .. } => {
+                // Build the full name, by combining all current segments.
+                let name: String = segments.iter().map(String::as_str).collect();
+                items.push(PushConstantItem {
+                    access_path: name,
+                    offset: *offset,
+                    ty,
+                });
+                *offset += layout.size;
+            }
+            // Arrays are recursed into.
+            TypeInner::Array { base, size, .. } => {
+                let crate::ArraySize::Constant(count) = size else {
+                    unreachable!("Cannot have dynamic arrays in push constants");
+                };
+
+                for i in 0..count.get() {
+                    // Add the array accessor and recurse.
+                    segments.push(format!("[{}]", i));
+                    self.collect_push_constant_items(base, segments, layouter, offset, items);
+                    segments.pop();
+                }
+
+                // Ensure the stride is kept by rounding up to the alignment.
+                *offset = layout.alignment.round_up(*offset)
+            }
+            TypeInner::Struct { ref members, .. } => {
+                for (index, member) in members.iter().enumerate() {
+                    // Add struct accessor and recurse.
+                    segments.push(format!(
+                        ".{}",
+                        self.names[&NameKey::StructMember(ty, index as u32)]
+                    ));
+                    self.collect_push_constant_items(member.ty, segments, layouter, offset, items);
+                    segments.pop();
+                }
+
+                // Ensure ending padding is kept by rounding up to the alignment.
+                *offset = layout.alignment.round_up(*offset)
+            }
+            _ => unreachable!(),
+        }
+    }
+}
+
+/// Structure returned by [`glsl_scalar`]
+///
+/// It contains both a prefix used in other types and the full type name
+struct ScalarString<'a> {
+    /// The prefix used to compose other types
+    prefix: &'a str,
+    /// The name of the scalar type
+    full: &'a str,
+}
+
+/// Helper function that returns scalar related strings
+///
+/// Check [`ScalarString`] for the information provided
+///
+/// # Errors
+/// If a [`Float`](crate::ScalarKind::Float) with an width that isn't 4 or 8
+const fn glsl_scalar(scalar: crate::Scalar) -> Result<ScalarString<'static>, Error> {
+    use crate::ScalarKind as Sk;
+
+    Ok(match scalar.kind {
+        Sk::Sint => ScalarString {
+            prefix: "i",
+            full: "int",
+        },
+        Sk::Uint => ScalarString {
+            prefix: "u",
+            full: "uint",
+        },
+        Sk::Float => match scalar.width {
+            4 => ScalarString {
+                prefix: "",
+                full: "float",
+            },
+            8 => ScalarString {
+                prefix: "d",
+                full: "double",
+            },
+            _ => return Err(Error::UnsupportedScalar(scalar)),
+        },
+        Sk::Bool => ScalarString {
+            prefix: "b",
+            full: "bool",
+        },
+        Sk::AbstractInt | Sk::AbstractFloat => {
+            return Err(Error::UnsupportedScalar(scalar));
+        }
+    })
+}
+
+/// Helper function that returns the glsl variable name for a builtin
+const fn glsl_built_in(built_in: crate::BuiltIn, options: VaryingOptions) -> &'static str {
+    use crate::BuiltIn as Bi;
+
+    match built_in {
+        Bi::Position { .. } => {
+            if options.output {
+                "gl_Position"
+            } else {
+                "gl_FragCoord"
+            }
+        }
+        Bi::ViewIndex if options.targeting_webgl => "int(gl_ViewID_OVR)",
+        Bi::ViewIndex => "gl_ViewIndex",
+        // vertex
+        Bi::BaseInstance => "uint(gl_BaseInstance)",
+        Bi::BaseVertex => "uint(gl_BaseVertex)",
+        Bi::ClipDistance => "gl_ClipDistance",
+        Bi::CullDistance => "gl_CullDistance",
+        Bi::InstanceIndex => {
+            if options.draw_parameters {
+                "(uint(gl_InstanceID) + uint(gl_BaseInstanceARB))"
+            } else {
+                // Must match FIRST_INSTANCE_BINDING
+                "(uint(gl_InstanceID) + naga_vs_first_instance)"
+            }
+        }
+        Bi::PointSize => "gl_PointSize",
+        Bi::VertexIndex => "uint(gl_VertexID)",
+        // fragment
+        Bi::FragDepth => "gl_FragDepth",
+        Bi::PointCoord => "gl_PointCoord",
+        Bi::FrontFacing => "gl_FrontFacing",
+        Bi::PrimitiveIndex => "uint(gl_PrimitiveID)",
+        Bi::SampleIndex => "gl_SampleID",
+        Bi::SampleMask => {
+            if options.output {
+                "gl_SampleMask"
+            } else {
+                "gl_SampleMaskIn"
+            }
+        }
+        // compute
+        Bi::GlobalInvocationId => "gl_GlobalInvocationID",
+        Bi::LocalInvocationId => "gl_LocalInvocationID",
+        Bi::LocalInvocationIndex => "gl_LocalInvocationIndex",
+        Bi::WorkGroupId => "gl_WorkGroupID",
+        Bi::WorkGroupSize => "gl_WorkGroupSize",
+        Bi::NumWorkGroups => "gl_NumWorkGroups",
+    }
+}
+
+/// Helper function that returns the string corresponding to the address space
+const fn glsl_storage_qualifier(space: crate::AddressSpace) -> Option<&'static str> {
+    use crate::AddressSpace as As;
+
+    match space {
+        As::Function => None,
+        As::Private => None,
+        As::Storage { .. } => Some("buffer"),
+        As::Uniform => Some("uniform"),
+        As::Handle => Some("uniform"),
+        As::WorkGroup => Some("shared"),
+        As::PushConstant => Some("uniform"),
+    }
+}
+
+/// Helper function that returns the string corresponding to the glsl interpolation qualifier
+const fn glsl_interpolation(interpolation: crate::Interpolation) -> &'static str {
+    use crate::Interpolation as I;
+
+    match interpolation {
+        I::Perspective => "smooth",
+        I::Linear => "noperspective",
+        I::Flat => "flat",
+    }
+}
+
+/// Return the GLSL auxiliary qualifier for the given sampling value.
+const fn glsl_sampling(sampling: crate::Sampling) -> Option<&'static str> {
+    use crate::Sampling as S;
+
+    match sampling {
+        S::Center => None,
+        S::Centroid => Some("centroid"),
+        S::Sample => Some("sample"),
+    }
+}
+
+/// Helper function that returns the glsl dimension string of [`ImageDimension`](crate::ImageDimension)
+const fn glsl_dimension(dim: crate::ImageDimension) -> &'static str {
+    use crate::ImageDimension as IDim;
+
+    match dim {
+        IDim::D1 => "1D",
+        IDim::D2 => "2D",
+        IDim::D3 => "3D",
+        IDim::Cube => "Cube",
+    }
+}
+
+/// Helper function that returns the glsl storage format string of [`StorageFormat`](crate::StorageFormat)
+fn glsl_storage_format(format: crate::StorageFormat) -> Result<&'static str, Error> {
+    use crate::StorageFormat as Sf;
+
+    Ok(match format {
+        Sf::R8Unorm => "r8",
+        Sf::R8Snorm => "r8_snorm",
+        Sf::R8Uint => "r8ui",
+        Sf::R8Sint => "r8i",
+        Sf::R16Uint => "r16ui",
+        Sf::R16Sint => "r16i",
+        Sf::R16Float => "r16f",
+        Sf::Rg8Unorm => "rg8",
+        Sf::Rg8Snorm => "rg8_snorm",
+        Sf::Rg8Uint => "rg8ui",
+        Sf::Rg8Sint => "rg8i",
+        Sf::R32Uint => "r32ui",
+        Sf::R32Sint => "r32i",
+        Sf::R32Float => "r32f",
+        Sf::Rg16Uint => "rg16ui",
+        Sf::Rg16Sint => "rg16i",
+        Sf::Rg16Float => "rg16f",
+        Sf::Rgba8Unorm => "rgba8",
+        Sf::Rgba8Snorm => "rgba8_snorm",
+        Sf::Rgba8Uint => "rgba8ui",
+        Sf::Rgba8Sint => "rgba8i",
+        Sf::Rgb10a2Uint => "rgb10_a2ui",
+        Sf::Rgb10a2Unorm => "rgb10_a2",
+        Sf::Rg11b10Float => "r11f_g11f_b10f",
+        Sf::Rg32Uint => "rg32ui",
+        Sf::Rg32Sint => "rg32i",
+        Sf::Rg32Float => "rg32f",
+        Sf::Rgba16Uint => "rgba16ui",
+        Sf::Rgba16Sint => "rgba16i",
+        Sf::Rgba16Float => "rgba16f",
+        Sf::Rgba32Uint => "rgba32ui",
+        Sf::Rgba32Sint => "rgba32i",
+        Sf::Rgba32Float => "rgba32f",
+        Sf::R16Unorm => "r16",
+        Sf::R16Snorm => "r16_snorm",
+        Sf::Rg16Unorm => "rg16",
+        Sf::Rg16Snorm => "rg16_snorm",
+        Sf::Rgba16Unorm => "rgba16",
+        Sf::Rgba16Snorm => "rgba16_snorm",
+
+        Sf::Bgra8Unorm => {
+            return Err(Error::Custom(
+                "Support format BGRA8 is not implemented".into(),
+            ))
+        }
+    })
+}
+
+fn is_value_init_supported(module: &crate::Module, ty: Handle<crate::Type>) -> bool {
+    match module.types[ty].inner {
+        TypeInner::Scalar { .. } | TypeInner::Vector { .. } | TypeInner::Matrix { .. } => true,
+        TypeInner::Array { base, size, .. } => {
+            size != crate::ArraySize::Dynamic && is_value_init_supported(module, base)
+        }
+        TypeInner::Struct { ref members, .. } => members
+            .iter()
+            .all(|member| is_value_init_supported(module, member.ty)),
+        _ => false,
+    }
+}
diff --git a/third_party/rust/naga/src/back/hlsl/conv.rs b/third_party/rust/naga/src/back/hlsl/conv.rs
new file mode 100644
index 0000000000..b6918ddc42
--- /dev/null
+++ b/third_party/rust/naga/src/back/hlsl/conv.rs
@@ -0,0 +1,222 @@
+use std::borrow::Cow;
+
+use crate::proc::Alignment;
+
+use super::Error;
+
+impl crate::ScalarKind {
+    pub(super) fn to_hlsl_cast(self) -> &'static str {
+        match self {
+            Self::Float => "asfloat",
+            Self::Sint => "asint",
+            Self::Uint => "asuint",
+            Self::Bool | Self::AbstractInt | Self::AbstractFloat => unreachable!(),
+        }
+    }
+}
+
+impl crate::Scalar {
+    /// Helper function that returns scalar related strings
+    ///
+    /// <https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-scalar>
+    pub(super) const fn to_hlsl_str(self) -> Result<&'static str, Error> {
+        match self.kind {
+            crate::ScalarKind::Sint => Ok("int"),
+            crate::ScalarKind::Uint => Ok("uint"),
+            crate::ScalarKind::Float => match self.width {
+                2 => Ok("half"),
+                4 => Ok("float"),
+                8 => Ok("double"),
+                _ => Err(Error::UnsupportedScalar(self)),
+            },
+            crate::ScalarKind::Bool => Ok("bool"),
+            crate::ScalarKind::AbstractInt | crate::ScalarKind::AbstractFloat => {
+                Err(Error::UnsupportedScalar(self))
+            }
+        }
+    }
+}
+
+impl crate::TypeInner {
+    pub(super) const fn is_matrix(&self) -> bool {
+        match *self {
+            Self::Matrix { .. } => true,
+            _ => false,
+        }
+    }
+
+    pub(super) fn size_hlsl(&self, gctx: crate::proc::GlobalCtx) -> u32 {
+        match *self {
+            Self::Matrix {
+                columns,
+                rows,
+                scalar,
+            } => {
+                let stride = Alignment::from(rows) * scalar.width as u32;
+                let last_row_size = rows as u32 * scalar.width as u32;
+                ((columns as u32 - 1) * stride) + last_row_size
+            }
+            Self::Array { base, size, stride } => {
+                let count = match size {
+                    crate::ArraySize::Constant(size) => size.get(),
+                    // A dynamically-sized array has to have at least one element
+                    crate::ArraySize::Dynamic => 1,
+                };
+                let last_el_size = gctx.types[base].inner.size_hlsl(gctx);
+                ((count - 1) * stride) + last_el_size
+            }
+            _ => self.size(gctx),
+        }
+    }
+
+    /// Used to generate the name of the wrapped type constructor
+    pub(super) fn hlsl_type_id<'a>(
+        base: crate::Handle<crate::Type>,
+        gctx: crate::proc::GlobalCtx,
+        names: &'a crate::FastHashMap<crate::proc::NameKey, String>,
+    ) -> Result<Cow<'a, str>, Error> {
+        Ok(match gctx.types[base].inner {
+            crate::TypeInner::Scalar(scalar) => Cow::Borrowed(scalar.to_hlsl_str()?),
+            crate::TypeInner::Vector { size, scalar } => Cow::Owned(format!(
+                "{}{}",
+                scalar.to_hlsl_str()?,
+                crate::back::vector_size_str(size)
+            )),
+            crate::TypeInner::Matrix {
+                columns,
+                rows,
+                scalar,
+            } => Cow::Owned(format!(
+                "{}{}x{}",
+                scalar.to_hlsl_str()?,
+                crate::back::vector_size_str(columns),
+                crate::back::vector_size_str(rows),
+            )),
+            crate::TypeInner::Array {
+                base,
+                size: crate::ArraySize::Constant(size),
+                ..
+            } => Cow::Owned(format!(
+                "array{size}_{}_",
+                Self::hlsl_type_id(base, gctx, names)?
+            )),
+            crate::TypeInner::Struct { .. } => {
+                Cow::Borrowed(&names[&crate::proc::NameKey::Type(base)])
+            }
+            _ => unreachable!(),
+        })
+    }
+}
+
+impl crate::StorageFormat {
+    pub(super) const fn to_hlsl_str(self) -> &'static str {
+        match self {
+            Self::R16Float => "float",
+            Self::R8Unorm | Self::R16Unorm => "unorm float",
+            Self::R8Snorm | Self::R16Snorm => "snorm float",
+            Self::R8Uint | Self::R16Uint => "uint",
+            Self::R8Sint | Self::R16Sint => "int",
+
+            Self::Rg16Float => "float2",
+            Self::Rg8Unorm | Self::Rg16Unorm => "unorm float2",
+            Self::Rg8Snorm | Self::Rg16Snorm => "snorm float2",
+
+            Self::Rg8Sint | Self::Rg16Sint => "int2",
+            Self::Rg8Uint | Self::Rg16Uint => "uint2",
+
+            Self::Rg11b10Float => "float3",
+
+            Self::Rgba16Float | Self::R32Float | Self::Rg32Float | Self::Rgba32Float => "float4",
+            Self::Rgba8Unorm | Self::Bgra8Unorm | Self::Rgba16Unorm | Self::Rgb10a2Unorm => {
+                "unorm float4"
+            }
+            Self::Rgba8Snorm | Self::Rgba16Snorm => "snorm float4",
+
+            Self::Rgba8Uint
+            | Self::Rgba16Uint
+            | Self::R32Uint
+            | Self::Rg32Uint
+            | Self::Rgba32Uint
+            | Self::Rgb10a2Uint => "uint4",
+            Self::Rgba8Sint
+            | Self::Rgba16Sint
+            | Self::R32Sint
+            | Self::Rg32Sint
+            | Self::Rgba32Sint => "int4",
+        }
+    }
+}
+
+impl crate::BuiltIn {
+    pub(super) fn to_hlsl_str(self) -> Result<&'static str, Error> {
+        Ok(match self {
+            Self::Position { .. } => "SV_Position",
+            // vertex
+            Self::ClipDistance => "SV_ClipDistance",
+            Self::CullDistance => "SV_CullDistance",
+            Self::InstanceIndex => "SV_InstanceID",
+            Self::VertexIndex => "SV_VertexID",
+            // fragment
+            Self::FragDepth => "SV_Depth",
+            Self::FrontFacing => "SV_IsFrontFace",
+            Self::PrimitiveIndex => "SV_PrimitiveID",
+            Self::SampleIndex => "SV_SampleIndex",
+            Self::SampleMask => "SV_Coverage",
+            // compute
+            Self::GlobalInvocationId => "SV_DispatchThreadID",
+            Self::LocalInvocationId => "SV_GroupThreadID",
+            Self::LocalInvocationIndex => "SV_GroupIndex",
+            Self::WorkGroupId => "SV_GroupID",
+            // The specific semantic we use here doesn't matter, because references
+            // to this field will get replaced with references to `SPECIAL_CBUF_VAR`
+            // in `Writer::write_expr`.
+            Self::NumWorkGroups => "SV_GroupID",
+            Self::BaseInstance | Self::BaseVertex | Self::WorkGroupSize => {
+                return Err(Error::Unimplemented(format!("builtin {self:?}")))
+            }
+            Self::PointSize | Self::ViewIndex | Self::PointCoord => {
+                return Err(Error::Custom(format!("Unsupported builtin {self:?}")))
+            }
+        })
+    }
+}
+
+impl crate::Interpolation {
+    /// Return the string corresponding to the HLSL interpolation qualifier.
+    pub(super) const fn to_hlsl_str(self) -> Option<&'static str> {
+        match self {
+            // Would be "linear", but it's the default interpolation in SM4 and up
+            // https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-struct#interpolation-modifiers-introduced-in-shader-model-4
+            Self::Perspective => None,
+            Self::Linear => Some("noperspective"),
+            Self::Flat => Some("nointerpolation"),
+        }
+    }
+}
+
+impl crate::Sampling {
+    /// Return the HLSL auxiliary qualifier for the given sampling value.
+    pub(super) const fn to_hlsl_str(self) -> Option<&'static str> {
+        match self {
+            Self::Center => None,
+            Self::Centroid => Some("centroid"),
+            Self::Sample => Some("sample"),
+        }
+    }
+}
+
+impl crate::AtomicFunction {
+    /// Return the HLSL suffix for the `InterlockedXxx` method.
+    pub(super) const fn to_hlsl_suffix(self) -> &'static str {
+        match self {
+            Self::Add | Self::Subtract => "Add",
+            Self::And => "And",
+            Self::InclusiveOr => "Or",
+            Self::ExclusiveOr => "Xor",
+            Self::Min => "Min",
+            Self::Max => "Max",
+            Self::Exchange { compare: None } => "Exchange",
+            Self::Exchange { .. } => "", //TODO
+        }
+    }
+}
diff --git a/third_party/rust/naga/src/back/hlsl/help.rs b/third_party/rust/naga/src/back/hlsl/help.rs
new file mode 100644
index 0000000000..fa6062a1ad
--- /dev/null
+++ b/third_party/rust/naga/src/back/hlsl/help.rs
@@ -0,0 +1,1138 @@
+/*!
+Helpers for the hlsl backend
+
+Important note about `Expression::ImageQuery`/`Expression::ArrayLength` and hlsl backend:
+
+Due to implementation of `GetDimensions` function in hlsl (<https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-to-getdimensions>)
+backend can't work with it as an expression.
+Instead, it generates a unique wrapped function per `Expression::ImageQuery`, based on texture info and query function.
+See `WrappedImageQuery` struct that represents a unique function and will be generated before writing all statements and expressions.
+This allowed to works with `Expression::ImageQuery` as expression and write wrapped function.
+
+For example:
+```wgsl
+let dim_1d = textureDimensions(image_1d);
+```
+
+```hlsl
+int NagaDimensions1D(Texture1D<float4>)
+{
+   uint4 ret;
+   image_1d.GetDimensions(ret.x);
+   return ret.x;
+}
+
+int dim_1d = NagaDimensions1D(image_1d);
+```
+*/
+
+use super::{super::FunctionCtx, BackendResult};
+use crate::{arena::Handle, proc::NameKey};
+use std::fmt::Write;
+
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+pub(super) struct WrappedArrayLength {
+    pub(super) writable: bool,
+}
+
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+pub(super) struct WrappedImageQuery {
+    pub(super) dim: crate::ImageDimension,
+    pub(super) arrayed: bool,
+    pub(super) class: crate::ImageClass,
+    pub(super) query: ImageQuery,
+}
+
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+pub(super) struct WrappedConstructor {
+    pub(super) ty: Handle<crate::Type>,
+}
+
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+pub(super) struct WrappedStructMatrixAccess {
+    pub(super) ty: Handle<crate::Type>,
+    pub(super) index: u32,
+}
+
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+pub(super) struct WrappedMatCx2 {
+    pub(super) columns: crate::VectorSize,
+}
+
+/// HLSL backend requires its own `ImageQuery` enum.
+///
+/// It is used inside `WrappedImageQuery` and should be unique per ImageQuery function.
+/// IR version can't be unique per function, because it's store mipmap level as an expression.
+///
+/// For example:
+/// ```wgsl
+/// let dim_cube_array_lod = textureDimensions(image_cube_array, 1);
+/// let dim_cube_array_lod2 = textureDimensions(image_cube_array, 1);
+/// ```
+///
+/// ```ir
+/// ImageQuery {
+///  image: [1],
+///  query: Size {
+///      level: Some(
+///          [1],
+///      ),
+///  },
+/// },
+/// ImageQuery {
+///  image: [1],
+///  query: Size {
+///      level: Some(
+///          [2],
+///      ),
+///  },
+/// },
+/// ```
+///
+/// HLSL should generate only 1 function for this case.
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+pub(super) enum ImageQuery {
+    Size,
+    SizeLevel,
+    NumLevels,
+    NumLayers,
+    NumSamples,
+}
+
+impl From<crate::ImageQuery> for ImageQuery {
+    fn from(q: crate::ImageQuery) -> Self {
+        use crate::ImageQuery as Iq;
+        match q {
+            Iq::Size { level: Some(_) } => ImageQuery::SizeLevel,
+            Iq::Size { level: None } => ImageQuery::Size,
+            Iq::NumLevels => ImageQuery::NumLevels,
+            Iq::NumLayers => ImageQuery::NumLayers,
+            Iq::NumSamples => ImageQuery::NumSamples,
+        }
+    }
+}
+
+impl<'a, W: Write> super::Writer<'a, W> {
+    pub(super) fn write_image_type(
+        &mut self,
+        dim: crate::ImageDimension,
+        arrayed: bool,
+        class: crate::ImageClass,
+    ) -> BackendResult {
+        let access_str = match class {
+            crate::ImageClass::Storage { .. } => "RW",
+            _ => "",
+        };
+        let dim_str = dim.to_hlsl_str();
+        let arrayed_str = if arrayed { "Array" } else { "" };
+        write!(self.out, "{access_str}Texture{dim_str}{arrayed_str}")?;
+        match class {
+            crate::ImageClass::Depth { multi } => {
+                let multi_str = if multi { "MS" } else { "" };
+                write!(self.out, "{multi_str}<float>")?
+            }
+            crate::ImageClass::Sampled { kind, multi } => {
+                let multi_str = if multi { "MS" } else { "" };
+                let scalar_kind_str = crate::Scalar { kind, width: 4 }.to_hlsl_str()?;
+                write!(self.out, "{multi_str}<{scalar_kind_str}4>")?
+            }
+            crate::ImageClass::Storage { format, .. } => {
+                let storage_format_str = format.to_hlsl_str();
+                write!(self.out, "<{storage_format_str}>")?
+            }
+        }
+        Ok(())
+    }
+
+    pub(super) fn write_wrapped_array_length_function_name(
+        &mut self,
+        query: WrappedArrayLength,
+    ) -> BackendResult {
+        let access_str = if query.writable { "RW" } else { "" };
+        write!(self.out, "NagaBufferLength{access_str}",)?;
+
+        Ok(())
+    }
+
+    /// Helper function that write wrapped function for `Expression::ArrayLength`
+    ///
+    /// <https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/sm5-object-rwbyteaddressbuffer-getdimensions>
+    pub(super) fn write_wrapped_array_length_function(
+        &mut self,
+        wal: WrappedArrayLength,
+    ) -> BackendResult {
+        use crate::back::INDENT;
+
+        const ARGUMENT_VARIABLE_NAME: &str = "buffer";
+        const RETURN_VARIABLE_NAME: &str = "ret";
+
+        // Write function return type and name
+        write!(self.out, "uint ")?;
+        self.write_wrapped_array_length_function_name(wal)?;
+
+        // Write function parameters
+        write!(self.out, "(")?;
+        let access_str = if wal.writable { "RW" } else { "" };
+        writeln!(
+            self.out,
+            "{access_str}ByteAddressBuffer {ARGUMENT_VARIABLE_NAME})"
+        )?;
+        // Write function body
+        writeln!(self.out, "{{")?;
+
+        // Write `GetDimensions` function.
+        writeln!(self.out, "{INDENT}uint {RETURN_VARIABLE_NAME};")?;
+        writeln!(
+            self.out,
+            "{INDENT}{ARGUMENT_VARIABLE_NAME}.GetDimensions({RETURN_VARIABLE_NAME});"
+        )?;
+
+        // Write return value
+        writeln!(self.out, "{INDENT}return {RETURN_VARIABLE_NAME};")?;
+
+        // End of function body
+        writeln!(self.out, "}}")?;
+        // Write extra new line
+        writeln!(self.out)?;
+
+        Ok(())
+    }
+
+    pub(super) fn write_wrapped_image_query_function_name(
+        &mut self,
+        query: WrappedImageQuery,
+    ) -> BackendResult {
+        let dim_str = query.dim.to_hlsl_str();
+        let class_str = match query.class {
+            crate::ImageClass::Sampled { multi: true, .. } => "MS",
+            crate::ImageClass::Depth { multi: true } => "DepthMS",
+            crate::ImageClass::Depth { multi: false } => "Depth",
+            crate::ImageClass::Sampled { multi: false, .. } => "",
+            crate::ImageClass::Storage { .. } => "RW",
+        };
+        let arrayed_str = if query.arrayed { "Array" } else { "" };
+        let query_str = match query.query {
+            ImageQuery::Size => "Dimensions",
+            ImageQuery::SizeLevel => "MipDimensions",
+            ImageQuery::NumLevels => "NumLevels",
+            ImageQuery::NumLayers => "NumLayers",
+            ImageQuery::NumSamples => "NumSamples",
+        };
+
+        write!(self.out, "Naga{class_str}{query_str}{dim_str}{arrayed_str}")?;
+
+        Ok(())
+    }
+
+    /// Helper function that write wrapped function for `Expression::ImageQuery`
+    ///
+    /// <https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-to-getdimensions>
+    pub(super) fn write_wrapped_image_query_function(
+        &mut self,
+        module: &crate::Module,
+        wiq: WrappedImageQuery,
+        expr_handle: Handle<crate::Expression>,
+        func_ctx: &FunctionCtx,
+    ) -> BackendResult {
+        use crate::{
+            back::{COMPONENTS, INDENT},
+            ImageDimension as IDim,
+        };
+
+        const ARGUMENT_VARIABLE_NAME: &str = "tex";
+        const RETURN_VARIABLE_NAME: &str = "ret";
+        const MIP_LEVEL_PARAM: &str = "mip_level";
+
+        // Write function return type and name
+        let ret_ty = func_ctx.resolve_type(expr_handle, &module.types);
+        self.write_value_type(module, ret_ty)?;
+        write!(self.out, " ")?;
+        self.write_wrapped_image_query_function_name(wiq)?;
+
+        // Write function parameters
+        write!(self.out, "(")?;
+        // Texture always first parameter
+        self.write_image_type(wiq.dim, wiq.arrayed, wiq.class)?;
+        write!(self.out, " {ARGUMENT_VARIABLE_NAME}")?;
+        // Mipmap is a second parameter if exists
+        if let ImageQuery::SizeLevel = wiq.query {
+            write!(self.out, ", uint {MIP_LEVEL_PARAM}")?;
+        }
+        writeln!(self.out, ")")?;
+
+        // Write function body
+        writeln!(self.out, "{{")?;
+
+        let array_coords = usize::from(wiq.arrayed);
+        // extra parameter is the mip level count or the sample count
+        let extra_coords = match wiq.class {
+            crate::ImageClass::Storage { .. } => 0,
+            crate::ImageClass::Sampled { .. } | crate::ImageClass::Depth { .. } => 1,
+        };
+
+        // GetDimensions Overloaded Methods
+        // https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-to-getdimensions#overloaded-methods
+        let (ret_swizzle, number_of_params) = match wiq.query {
+            ImageQuery::Size | ImageQuery::SizeLevel => {
+                let ret = match wiq.dim {
+                    IDim::D1 => "x",
+                    IDim::D2 => "xy",
+                    IDim::D3 => "xyz",
+                    IDim::Cube => "xy",
+                };
+                (ret, ret.len() + array_coords + extra_coords)
+            }
+            ImageQuery::NumLevels | ImageQuery::NumSamples | ImageQuery::NumLayers => {
+                if wiq.arrayed || wiq.dim == IDim::D3 {
+                    ("w", 4)
+                } else {
+                    ("z", 3)
+                }
+            }
+        };
+
+        // Write `GetDimensions` function.
+        writeln!(self.out, "{INDENT}uint4 {RETURN_VARIABLE_NAME};")?;
+        write!(self.out, "{INDENT}{ARGUMENT_VARIABLE_NAME}.GetDimensions(")?;
+        match wiq.query {
+            ImageQuery::SizeLevel => {
+                write!(self.out, "{MIP_LEVEL_PARAM}, ")?;
+            }
+            _ => match wiq.class {
+                crate::ImageClass::Sampled { multi: true, .. }
+                | crate::ImageClass::Depth { multi: true }
+                | crate::ImageClass::Storage { .. } => {}
+                _ => {
+                    // Write zero mipmap level for supported types
+                    write!(self.out, "0, ")?;
+                }
+            },
+        }
+
+        for component in COMPONENTS[..number_of_params - 1].iter() {
+            write!(self.out, "{RETURN_VARIABLE_NAME}.{component}, ")?;
+        }
+
+        // write last parameter without comma and space for last parameter
+        write!(
+            self.out,
+            "{}.{}",
+            RETURN_VARIABLE_NAME,
+            COMPONENTS[number_of_params - 1]
+        )?;
+
+        writeln!(self.out, ");")?;
+
+        // Write return value
+        writeln!(
+            self.out,
+            "{INDENT}return {RETURN_VARIABLE_NAME}.{ret_swizzle};"
+        )?;
+
+        // End of function body
+        writeln!(self.out, "}}")?;
+        // Write extra new line
+        writeln!(self.out)?;
+
+        Ok(())
+    }
+
+    pub(super) fn write_wrapped_constructor_function_name(
+        &mut self,
+        module: &crate::Module,
+        constructor: WrappedConstructor,
+    ) -> BackendResult {
+        let name = crate::TypeInner::hlsl_type_id(constructor.ty, module.to_ctx(), &self.names)?;
+        write!(self.out, "Construct{name}")?;
+        Ok(())
+    }
+
+    /// Helper function that write wrapped function for `Expression::Compose` for structures.
+    pub(super) fn write_wrapped_constructor_function(
+        &mut self,
+        module: &crate::Module,
+        constructor: WrappedConstructor,
+    ) -> BackendResult {
+        use crate::back::INDENT;
+
+        const ARGUMENT_VARIABLE_NAME: &str = "arg";
+        const RETURN_VARIABLE_NAME: &str = "ret";
+
+        // Write function return type and name
+        if let crate::TypeInner::Array { base, size, .. } = module.types[constructor.ty].inner {
+            write!(self.out, "typedef ")?;
+            self.write_type(module, constructor.ty)?;
+            write!(self.out, " ret_")?;
+            self.write_wrapped_constructor_function_name(module, constructor)?;
+            self.write_array_size(module, base, size)?;
+            writeln!(self.out, ";")?;
+
+            write!(self.out, "ret_")?;
+            self.write_wrapped_constructor_function_name(module, constructor)?;
+        } else {
+            self.write_type(module, constructor.ty)?;
+        }
+        write!(self.out, " ")?;
+        self.write_wrapped_constructor_function_name(module, constructor)?;
+
+        // Write function parameters
+        write!(self.out, "(")?;
+
+        let mut write_arg = |i, ty| -> BackendResult {
+            if i != 0 {
+                write!(self.out, ", ")?;
+            }
+            self.write_type(module, ty)?;
+            write!(self.out, " {ARGUMENT_VARIABLE_NAME}{i}")?;
+            if let crate::TypeInner::Array { base, size, .. } = module.types[ty].inner {
+                self.write_array_size(module, base, size)?;
+            }
+            Ok(())
+        };
+
+        match module.types[constructor.ty].inner {
+            crate::TypeInner::Struct { ref members, .. } => {
+                for (i, member) in members.iter().enumerate() {
+                    write_arg(i, member.ty)?;
+                }
+            }
+            crate::TypeInner::Array {
+                base,
+                size: crate::ArraySize::Constant(size),
+                ..
+            } => {
+                for i in 0..size.get() as usize {
+                    write_arg(i, base)?;
+                }
+            }
+            _ => unreachable!(),
+        };
+
+        write!(self.out, ")")?;
+
+        // Write function body
+        writeln!(self.out, " {{")?;
+
+        match module.types[constructor.ty].inner {
+            crate::TypeInner::Struct { ref members, .. } => {
+                let struct_name = &self.names[&NameKey::Type(constructor.ty)];
+                writeln!(
+                    self.out,
+                    "{INDENT}{struct_name} {RETURN_VARIABLE_NAME} = ({struct_name})0;"
+                )?;
+                for (i, member) in members.iter().enumerate() {
+                    let field_name = &self.names[&NameKey::StructMember(constructor.ty, i as u32)];
+
+                    match module.types[member.ty].inner {
+                        crate::TypeInner::Matrix {
+                            columns,
+                            rows: crate::VectorSize::Bi,
+                            ..
+                        } if member.binding.is_none() => {
+                            for j in 0..columns as u8 {
+                                writeln!(
+                                    self.out,
+                                    "{INDENT}{RETURN_VARIABLE_NAME}.{field_name}_{j} = {ARGUMENT_VARIABLE_NAME}{i}[{j}];"
+                                )?;
+                            }
+                        }
+                        ref other => {
+                            // We cast arrays of native HLSL `floatCx2`s to arrays of `matCx2`s
+                            // (where the inner matrix is represented by a struct with C `float2` members).
+                            // See the module-level block comment in mod.rs for details.
+                            if let Some(super::writer::MatrixType {
+                                columns,
+                                rows: crate::VectorSize::Bi,
+                                width: 4,
+                            }) = super::writer::get_inner_matrix_data(module, member.ty)
+                            {
+                                write!(
+                                    self.out,
+                                    "{}{}.{} = (__mat{}x2",
+                                    INDENT, RETURN_VARIABLE_NAME, field_name, columns as u8
+                                )?;
+                                if let crate::TypeInner::Array { base, size, .. } = *other {
+                                    self.write_array_size(module, base, size)?;
+                                }
+                                writeln!(self.out, "){ARGUMENT_VARIABLE_NAME}{i};",)?;
+                            } else {
+                                writeln!(
+                                    self.out,
+                                    "{INDENT}{RETURN_VARIABLE_NAME}.{field_name} = {ARGUMENT_VARIABLE_NAME}{i};",
+                                )?;
+                            }
+                        }
+                    }
+                }
+            }
+            crate::TypeInner::Array {
+                base,
+                size: crate::ArraySize::Constant(size),
+                ..
+            } => {
+                write!(self.out, "{INDENT}")?;
+                self.write_type(module, base)?;
+                write!(self.out, " {RETURN_VARIABLE_NAME}")?;
+                self.write_array_size(module, base, crate::ArraySize::Constant(size))?;
+                write!(self.out, " = {{ ")?;
+                for i in 0..size.get() {
+                    if i != 0 {
+                        write!(self.out, ", ")?;
+                    }
+                    write!(self.out, "{ARGUMENT_VARIABLE_NAME}{i}")?;
+                }
+                writeln!(self.out, " }};",)?;
+            }
+            _ => unreachable!(),
+        }
+
+        // Write return value
+        writeln!(self.out, "{INDENT}return {RETURN_VARIABLE_NAME};")?;
+
+        // End of function body
+        writeln!(self.out, "}}")?;
+        // Write extra new line
+        writeln!(self.out)?;
+
+        Ok(())
+    }
+
+    pub(super) fn write_wrapped_struct_matrix_get_function_name(
+        &mut self,
+        access: WrappedStructMatrixAccess,
+    ) -> BackendResult {
+        let name = &self.names[&NameKey::Type(access.ty)];
+        let field_name = &self.names[&NameKey::StructMember(access.ty, access.index)];
+        write!(self.out, "GetMat{field_name}On{name}")?;
+        Ok(())
+    }
+
+    /// Writes a function used to get a matCx2 from within a structure.
+    pub(super) fn write_wrapped_struct_matrix_get_function(
+        &mut self,
+        module: &crate::Module,
+        access: WrappedStructMatrixAccess,
+    ) -> BackendResult {
+        use crate::back::INDENT;
+
+        const STRUCT_ARGUMENT_VARIABLE_NAME: &str = "obj";
+
+        // Write function return type and name
+        let member = match module.types[access.ty].inner {
+            crate::TypeInner::Struct { ref members, .. } => &members[access.index as usize],
+            _ => unreachable!(),
+        };
+        let ret_ty = &module.types[member.ty].inner;
+        self.write_value_type(module, ret_ty)?;
+        write!(self.out, " ")?;
+        self.write_wrapped_struct_matrix_get_function_name(access)?;
+
+        // Write function parameters
+        write!(self.out, "(")?;
+        let struct_name = &self.names[&NameKey::Type(access.ty)];
+        write!(self.out, "{struct_name} {STRUCT_ARGUMENT_VARIABLE_NAME}")?;
+
+        // Write function body
+        writeln!(self.out, ") {{")?;
+
+        // Write return value
+        write!(self.out, "{INDENT}return ")?;
+        self.write_value_type(module, ret_ty)?;
+        write!(self.out, "(")?;
+        let field_name = &self.names[&NameKey::StructMember(access.ty, access.index)];
+        match module.types[member.ty].inner {
+            crate::TypeInner::Matrix { columns, .. } => {
+                for i in 0..columns as u8 {
+                    if i != 0 {
+                        write!(self.out, ", ")?;
+                    }
+                    write!(self.out, "{STRUCT_ARGUMENT_VARIABLE_NAME}.{field_name}_{i}")?;
+                }
+            }
+            _ => unreachable!(),
+        }
+        writeln!(self.out, ");")?;
+
+        // End of function body
+        writeln!(self.out, "}}")?;
+        // Write extra new line
+        writeln!(self.out)?;
+
+        Ok(())
+    }
+
+    pub(super) fn write_wrapped_struct_matrix_set_function_name(
+        &mut self,
+        access: WrappedStructMatrixAccess,
+    ) -> BackendResult {
+        let name = &self.names[&NameKey::Type(access.ty)];
+        let field_name = &self.names[&NameKey::StructMember(access.ty, access.index)];
+        write!(self.out, "SetMat{field_name}On{name}")?;
+        Ok(())
+    }
+
+    /// Writes a function used to set a matCx2 from within a structure.
+    pub(super) fn write_wrapped_struct_matrix_set_function(
+        &mut self,
+        module: &crate::Module,
+        access: WrappedStructMatrixAccess,
+    ) -> BackendResult {
+        use crate::back::INDENT;
+
+        const STRUCT_ARGUMENT_VARIABLE_NAME: &str = "obj";
+        const MATRIX_ARGUMENT_VARIABLE_NAME: &str = "mat";
+
+        // Write function return type and name
+        write!(self.out, "void ")?;
+        self.write_wrapped_struct_matrix_set_function_name(access)?;
+
+        // Write function parameters
+        write!(self.out, "(")?;
+        let struct_name = &self.names[&NameKey::Type(access.ty)];
+        write!(self.out, "{struct_name} {STRUCT_ARGUMENT_VARIABLE_NAME}, ")?;
+        let member = match module.types[access.ty].inner {
+            crate::TypeInner::Struct { ref members, .. } => &members[access.index as usize],
+            _ => unreachable!(),
+        };
+        self.write_type(module, member.ty)?;
+        write!(self.out, " {MATRIX_ARGUMENT_VARIABLE_NAME}")?;
+        // Write function body
+        writeln!(self.out, ") {{")?;
+
+        let field_name = &self.names[&NameKey::StructMember(access.ty, access.index)];
+
+        match module.types[member.ty].inner {
+            crate::TypeInner::Matrix { columns, .. } => {
+                for i in 0..columns as u8 {
+                    writeln!(
+                        self.out,
+                        "{INDENT}{STRUCT_ARGUMENT_VARIABLE_NAME}.{field_name}_{i} = {MATRIX_ARGUMENT_VARIABLE_NAME}[{i}];"
+                    )?;
+                }
+            }
+            _ => unreachable!(),
+        }
+
+        // End of function body
+        writeln!(self.out, "}}")?;
+        // Write extra new line
+        writeln!(self.out)?;
+
+        Ok(())
+    }
+
+    pub(super) fn write_wrapped_struct_matrix_set_vec_function_name(
+        &mut self,
+        access: WrappedStructMatrixAccess,
+    ) -> BackendResult {
+        let name = &self.names[&NameKey::Type(access.ty)];
+        let field_name = &self.names[&NameKey::StructMember(access.ty, access.index)];
+        write!(self.out, "SetMatVec{field_name}On{name}")?;
+        Ok(())
+    }
+
+    /// Writes a function used to set a vec2 on a matCx2 from within a structure.
+    pub(super) fn write_wrapped_struct_matrix_set_vec_function(
+        &mut self,
+        module: &crate::Module,
+        access: WrappedStructMatrixAccess,
+    ) -> BackendResult {
+        use crate::back::INDENT;
+
+        const STRUCT_ARGUMENT_VARIABLE_NAME: &str = "obj";
+        const VECTOR_ARGUMENT_VARIABLE_NAME: &str = "vec";
+        const MATRIX_INDEX_ARGUMENT_VARIABLE_NAME: &str = "mat_idx";
+
+        // Write function return type and name
+        write!(self.out, "void ")?;
+        self.write_wrapped_struct_matrix_set_vec_function_name(access)?;
+
+        // Write function parameters
+        write!(self.out, "(")?;
+        let struct_name = &self.names[&NameKey::Type(access.ty)];
+        write!(self.out, "{struct_name} {STRUCT_ARGUMENT_VARIABLE_NAME}, ")?;
+        let member = match module.types[access.ty].inner {
+            crate::TypeInner::Struct { ref members, .. } => &members[access.index as usize],
+            _ => unreachable!(),
+        };
+        let vec_ty = match module.types[member.ty].inner {
+            crate::TypeInner::Matrix { rows, scalar, .. } => {
+                crate::TypeInner::Vector { size: rows, scalar }
+            }
+            _ => unreachable!(),
+        };
+        self.write_value_type(module, &vec_ty)?;
+        write!(
+            self.out,
+            " {VECTOR_ARGUMENT_VARIABLE_NAME}, uint {MATRIX_INDEX_ARGUMENT_VARIABLE_NAME}"
+        )?;
+
+        // Write function body
+        writeln!(self.out, ") {{")?;
+
+        writeln!(
+            self.out,
+            "{INDENT}switch({MATRIX_INDEX_ARGUMENT_VARIABLE_NAME}) {{"
+        )?;
+
+        let field_name = &self.names[&NameKey::StructMember(access.ty, access.index)];
+
+        match module.types[member.ty].inner {
+            crate::TypeInner::Matrix { columns, .. } => {
+                for i in 0..columns as u8 {
+                    writeln!(
+                        self.out,
+                        "{INDENT}case {i}: {{ {STRUCT_ARGUMENT_VARIABLE_NAME}.{field_name}_{i} = {VECTOR_ARGUMENT_VARIABLE_NAME}; break; }}"
+                    )?;
+                }
+            }
+            _ => unreachable!(),
+        }
+
+        writeln!(self.out, "{INDENT}}}")?;
+
+        // End of function body
+        writeln!(self.out, "}}")?;
+        // Write extra new line
+        writeln!(self.out)?;
+
+        Ok(())
+    }
+
+    pub(super) fn write_wrapped_struct_matrix_set_scalar_function_name(
+        &mut self,
+        access: WrappedStructMatrixAccess,
+    ) -> BackendResult {
+        let name = &self.names[&NameKey::Type(access.ty)];
+        let field_name = &self.names[&NameKey::StructMember(access.ty, access.index)];
+        write!(self.out, "SetMatScalar{field_name}On{name}")?;
+        Ok(())
+    }
+
+    /// Writes a function used to set a float on a matCx2 from within a structure.
+    pub(super) fn write_wrapped_struct_matrix_set_scalar_function(
+        &mut self,
+        module: &crate::Module,
+        access: WrappedStructMatrixAccess,
+    ) -> BackendResult {
+        use crate::back::INDENT;
+
+        const STRUCT_ARGUMENT_VARIABLE_NAME: &str = "obj";
+        const SCALAR_ARGUMENT_VARIABLE_NAME: &str = "scalar";
+        const MATRIX_INDEX_ARGUMENT_VARIABLE_NAME: &str = "mat_idx";
+        const VECTOR_INDEX_ARGUMENT_VARIABLE_NAME: &str = "vec_idx";
+
+        // Write function return type and name
+        write!(self.out, "void ")?;
+        self.write_wrapped_struct_matrix_set_scalar_function_name(access)?;
+
+        // Write function parameters
+        write!(self.out, "(")?;
+        let struct_name = &self.names[&NameKey::Type(access.ty)];
+        write!(self.out, "{struct_name} {STRUCT_ARGUMENT_VARIABLE_NAME}, ")?;
+        let member = match module.types[access.ty].inner {
+            crate::TypeInner::Struct { ref members, .. } => &members[access.index as usize],
+            _ => unreachable!(),
+        };
+        let scalar_ty = match module.types[member.ty].inner {
+            crate::TypeInner::Matrix { scalar, .. } => crate::TypeInner::Scalar(scalar),
+            _ => unreachable!(),
+        };
+        self.write_value_type(module, &scalar_ty)?;
+        write!(
+            self.out,
+            " {SCALAR_ARGUMENT_VARIABLE_NAME}, uint {MATRIX_INDEX_ARGUMENT_VARIABLE_NAME}, uint {VECTOR_INDEX_ARGUMENT_VARIABLE_NAME}"
+        )?;
+
+        // Write function body
+        writeln!(self.out, ") {{")?;
+
+        writeln!(
+            self.out,
+            "{INDENT}switch({MATRIX_INDEX_ARGUMENT_VARIABLE_NAME}) {{"
+        )?;
+
+        let field_name = &self.names[&NameKey::StructMember(access.ty, access.index)];
+
+        match module.types[member.ty].inner {
+            crate::TypeInner::Matrix { columns, .. } => {
+                for i in 0..columns as u8 {
+                    writeln!(
+                        self.out,
+                        "{INDENT}case {i}: {{ {STRUCT_ARGUMENT_VARIABLE_NAME}.{field_name}_{i}[{VECTOR_INDEX_ARGUMENT_VARIABLE_NAME}] = {SCALAR_ARGUMENT_VARIABLE_NAME}; break; }}"
+                    )?;
+                }
+            }
+            _ => unreachable!(),
+        }
+
+        writeln!(self.out, "{INDENT}}}")?;
+
+        // End of function body
+        writeln!(self.out, "}}")?;
+        // Write extra new line
+        writeln!(self.out)?;
+
+        Ok(())
+    }
+
+    /// Write functions to create special types.
+    pub(super) fn write_special_functions(&mut self, module: &crate::Module) -> BackendResult {
+        for (type_key, struct_ty) in module.special_types.predeclared_types.iter() {
+            match type_key {
+                &crate::PredeclaredType::ModfResult { size, width }
+                | &crate::PredeclaredType::FrexpResult { size, width } => {
+                    let arg_type_name_owner;
+                    let arg_type_name = if let Some(size) = size {
+                        arg_type_name_owner = format!(
+                            "{}{}",
+                            if width == 8 { "double" } else { "float" },
+                            size as u8
+                        );
+                        &arg_type_name_owner
+                    } else if width == 8 {
+                        "double"
+                    } else {
+                        "float"
+                    };
+
+                    let (defined_func_name, called_func_name, second_field_name, sign_multiplier) =
+                        if matches!(type_key, &crate::PredeclaredType::ModfResult { .. }) {
+                            (super::writer::MODF_FUNCTION, "modf", "whole", "")
+                        } else {
+                            (
+                                super::writer::FREXP_FUNCTION,
+                                "frexp",
+                                "exp_",
+                                "sign(arg) * ",
+                            )
+                        };
+
+                    let struct_name = &self.names[&NameKey::Type(*struct_ty)];
+
+                    writeln!(
+                        self.out,
+                        "{struct_name} {defined_func_name}({arg_type_name} arg) {{
+    {arg_type_name} other;
+    {struct_name} result;
+    result.fract = {sign_multiplier}{called_func_name}(arg, other);
+    result.{second_field_name} = other;
+    return result;
+}}"
+                    )?;
+                    writeln!(self.out)?;
+                }
+                &crate::PredeclaredType::AtomicCompareExchangeWeakResult { .. } => {}
+            }
+        }
+
+        Ok(())
+    }
+
+    /// Helper function that writes compose wrapped functions
+    pub(super) fn write_wrapped_compose_functions(
+        &mut self,
+        module: &crate::Module,
+        expressions: &crate::Arena<crate::Expression>,
+    ) -> BackendResult {
+        for (handle, _) in expressions.iter() {
+            if let crate::Expression::Compose { ty, .. } = expressions[handle] {
+                match module.types[ty].inner {
+                    crate::TypeInner::Struct { .. } | crate::TypeInner::Array { .. } => {
+                        let constructor = WrappedConstructor { ty };
+                        if self.wrapped.constructors.insert(constructor) {
+                            self.write_wrapped_constructor_function(module, constructor)?;
+                        }
+                    }
+                    _ => {}
+                };
+            }
+        }
+        Ok(())
+    }
+
+    /// Helper function that writes various wrapped functions
+    pub(super) fn write_wrapped_functions(
+        &mut self,
+        module: &crate::Module,
+        func_ctx: &FunctionCtx,
+    ) -> BackendResult {
+        self.write_wrapped_compose_functions(module, func_ctx.expressions)?;
+
+        for (handle, _) in func_ctx.expressions.iter() {
+            match func_ctx.expressions[handle] {
+                crate::Expression::ArrayLength(expr) => {
+                    let global_expr = match func_ctx.expressions[expr] {
+                        crate::Expression::GlobalVariable(_) => expr,
+                        crate::Expression::AccessIndex { base, index: _ } => base,
+                        ref other => unreachable!("Array length of {:?}", other),
+                    };
+                    let global_var = match func_ctx.expressions[global_expr] {
+                        crate::Expression::GlobalVariable(var_handle) => {
+                            &module.global_variables[var_handle]
+                        }
+                        ref other => unreachable!("Array length of base {:?}", other),
+                    };
+                    let storage_access = match global_var.space {
+                        crate::AddressSpace::Storage { access } => access,
+                        _ => crate::StorageAccess::default(),
+                    };
+                    let wal = WrappedArrayLength {
+                        writable: storage_access.contains(crate::StorageAccess::STORE),
+                    };
+
+                    if self.wrapped.array_lengths.insert(wal) {
+                        self.write_wrapped_array_length_function(wal)?;
+                    }
+                }
+                crate::Expression::ImageQuery { image, query } => {
+                    let wiq = match *func_ctx.resolve_type(image, &module.types) {
+                        crate::TypeInner::Image {
+                            dim,
+                            arrayed,
+                            class,
+                        } => WrappedImageQuery {
+                            dim,
+                            arrayed,
+                            class,
+                            query: query.into(),
+                        },
+                        _ => unreachable!("we only query images"),
+                    };
+
+                    if self.wrapped.image_queries.insert(wiq) {
+                        self.write_wrapped_image_query_function(module, wiq, handle, func_ctx)?;
+                    }
+                }
+                // Write `WrappedConstructor` for structs that are loaded from `AddressSpace::Storage`
+                // since they will later be used by the fn `write_storage_load`
+                crate::Expression::Load { pointer } => {
+                    let pointer_space = func_ctx
+                        .resolve_type(pointer, &module.types)
+                        .pointer_space();
+
+                    if let Some(crate::AddressSpace::Storage { .. }) = pointer_space {
+                        if let Some(ty) = func_ctx.info[handle].ty.handle() {
+                            write_wrapped_constructor(self, ty, module)?;
+                        }
+                    }
+
+                    fn write_wrapped_constructor<W: Write>(
+                        writer: &mut super::Writer<'_, W>,
+                        ty: Handle<crate::Type>,
+                        module: &crate::Module,
+                    ) -> BackendResult {
+                        match module.types[ty].inner {
+                            crate::TypeInner::Struct { ref members, .. } => {
+                                for member in members {
+                                    write_wrapped_constructor(writer, member.ty, module)?;
+                                }
+
+                                let constructor = WrappedConstructor { ty };
+                                if writer.wrapped.constructors.insert(constructor) {
+                                    writer
+                                        .write_wrapped_constructor_function(module, constructor)?;
+                                }
+                            }
+                            crate::TypeInner::Array { base, .. } => {
+                                write_wrapped_constructor(writer, base, module)?;
+
+                                let constructor = WrappedConstructor { ty };
+                                if writer.wrapped.constructors.insert(constructor) {
+                                    writer
+                                        .write_wrapped_constructor_function(module, constructor)?;
+                                }
+                            }
+                            _ => {}
+                        };
+
+                        Ok(())
+                    }
+                }
+                // We treat matrices of the form `matCx2` as a sequence of C `vec2`s
+                // (see top level module docs for details).
+                //
+                // The functions injected here are required to get the matrix accesses working.
+                crate::Expression::AccessIndex { base, index } => {
+                    let base_ty_res = &func_ctx.info[base].ty;
+                    let mut resolved = base_ty_res.inner_with(&module.types);
+                    let base_ty_handle = match *resolved {
+                        crate::TypeInner::Pointer { base, .. } => {
+                            resolved = &module.types[base].inner;
+                            Some(base)
+                        }
+                        _ => base_ty_res.handle(),
+                    };
+                    if let crate::TypeInner::Struct { ref members, .. } = *resolved {
+                        let member = &members[index as usize];
+
+                        match module.types[member.ty].inner {
+                            crate::TypeInner::Matrix {
+                                rows: crate::VectorSize::Bi,
+                                ..
+                            } if member.binding.is_none() => {
+                                let ty = base_ty_handle.unwrap();
+                                let access = WrappedStructMatrixAccess { ty, index };
+
+                                if self.wrapped.struct_matrix_access.insert(access) {
+                                    self.write_wrapped_struct_matrix_get_function(module, access)?;
+                                    self.write_wrapped_struct_matrix_set_function(module, access)?;
+                                    self.write_wrapped_struct_matrix_set_vec_function(
+                                        module, access,
+                                    )?;
+                                    self.write_wrapped_struct_matrix_set_scalar_function(
+                                        module, access,
+                                    )?;
+                                }
+                            }
+                            _ => {}
+                        }
+                    }
+                }
+                _ => {}
+            };
+        }
+
+        Ok(())
+    }
+
+    pub(super) fn write_texture_coordinates(
+        &mut self,
+        kind: &str,
+        coordinate: Handle<crate::Expression>,
+        array_index: Option<Handle<crate::Expression>>,
+        mip_level: Option<Handle<crate::Expression>>,
+        module: &crate::Module,
+        func_ctx: &FunctionCtx,
+    ) -> BackendResult {
+        // HLSL expects the array index to be merged with the coordinate
+        let extra = array_index.is_some() as usize + (mip_level.is_some()) as usize;
+        if extra == 0 {
+            self.write_expr(module, coordinate, func_ctx)?;
+        } else {
+            let num_coords = match *func_ctx.resolve_type(coordinate, &module.types) {
+                crate::TypeInner::Scalar { .. } => 1,
+                crate::TypeInner::Vector { size, .. } => size as usize,
+                _ => unreachable!(),
+            };
+            write!(self.out, "{}{}(", kind, num_coords + extra)?;
+            self.write_expr(module, coordinate, func_ctx)?;
+            if let Some(expr) = array_index {
+                write!(self.out, ", ")?;
+                self.write_expr(module, expr, func_ctx)?;
+            }
+            if let Some(expr) = mip_level {
+                write!(self.out, ", ")?;
+                self.write_expr(module, expr, func_ctx)?;
+            }
+            write!(self.out, ")")?;
+        }
+        Ok(())
+    }
+
+    pub(super) fn write_mat_cx2_typedef_and_functions(
+        &mut self,
+        WrappedMatCx2 { columns }: WrappedMatCx2,
+    ) -> BackendResult {
+        use crate::back::INDENT;
+
+        // typedef
+        write!(self.out, "typedef struct {{ ")?;
+        for i in 0..columns as u8 {
+            write!(self.out, "float2 _{i}; ")?;
+        }
+        writeln!(self.out, "}} __mat{}x2;", columns as u8)?;
+
+        // __get_col_of_mat
+        writeln!(
+            self.out,
+            "float2 __get_col_of_mat{}x2(__mat{}x2 mat, uint idx) {{",
+            columns as u8, columns as u8
+        )?;
+        writeln!(self.out, "{INDENT}switch(idx) {{")?;
+        for i in 0..columns as u8 {
+            writeln!(self.out, "{INDENT}case {i}: {{ return mat._{i}; }}")?;
+        }
+        writeln!(self.out, "{INDENT}default: {{ return (float2)0; }}")?;
+        writeln!(self.out, "{INDENT}}}")?;
+        writeln!(self.out, "}}")?;
+
+        // __set_col_of_mat
+        writeln!(
+            self.out,
+            "void __set_col_of_mat{}x2(__mat{}x2 mat, uint idx, float2 value) {{",
+            columns as u8, columns as u8
+        )?;
+        writeln!(self.out, "{INDENT}switch(idx) {{")?;
+        for i in 0..columns as u8 {
+            writeln!(self.out, "{INDENT}case {i}: {{ mat._{i} = value; break; }}")?;
+        }
+        writeln!(self.out, "{INDENT}}}")?;
+        writeln!(self.out, "}}")?;
+
+        // __set_el_of_mat
+        writeln!(
+            self.out,
+            "void __set_el_of_mat{}x2(__mat{}x2 mat, uint idx, uint vec_idx, float value) {{",
+            columns as u8, columns as u8
+        )?;
+        writeln!(self.out, "{INDENT}switch(idx) {{")?;
+        for i in 0..columns as u8 {
+            writeln!(
+                self.out,
+                "{INDENT}case {i}: {{ mat._{i}[vec_idx] = value; break; }}"
+            )?;
+        }
+        writeln!(self.out, "{INDENT}}}")?;
+        writeln!(self.out, "}}")?;
+
+        writeln!(self.out)?;
+
+        Ok(())
+    }
+
+    pub(super) fn write_all_mat_cx2_typedefs_and_functions(
+        &mut self,
+        module: &crate::Module,
+    ) -> BackendResult {
+        for (handle, _) in module.global_variables.iter() {
+            let global = &module.global_variables[handle];
+
+            if global.space == crate::AddressSpace::Uniform {
+                if let Some(super::writer::MatrixType {
+                    columns,
+                    rows: crate::VectorSize::Bi,
+                    width: 4,
+                }) = super::writer::get_inner_matrix_data(module, global.ty)
+                {
+                    let entry = WrappedMatCx2 { columns };
+                    if self.wrapped.mat_cx2s.insert(entry) {
+                        self.write_mat_cx2_typedef_and_functions(entry)?;
+                    }
+                }
+            }
+        }
+
+        for (_, ty) in module.types.iter() {
+            if let crate::TypeInner::Struct { ref members, .. } = ty.inner {
+                for member in members.iter() {
+                    if let crate::TypeInner::Array { .. } = module.types[member.ty].inner {
+                        if let Some(super::writer::MatrixType {
+                            columns,
+                            rows: crate::VectorSize::Bi,
+                            width: 4,
+                        }) = super::writer::get_inner_matrix_data(module, member.ty)
+                        {
+                            let entry = WrappedMatCx2 { columns };
+                            if self.wrapped.mat_cx2s.insert(entry) {
+                                self.write_mat_cx2_typedef_and_functions(entry)?;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        Ok(())
+    }
+}
diff --git a/third_party/rust/naga/src/back/hlsl/keywords.rs b/third_party/rust/naga/src/back/hlsl/keywords.rs
new file mode 100644
index 0000000000..059e533ff7
--- /dev/null
+++ b/third_party/rust/naga/src/back/hlsl/keywords.rs
@@ -0,0 +1,904 @@
+// When compiling with FXC without strict mode, these keywords are actually case insensitive.
+// If you compile with strict mode and specify a different casing like "Pass" instead in an identifier, FXC will give this error:
+// "error X3086: alternate cases for 'pass' are deprecated in strict mode"
+// This behavior is not documented anywhere, but as far as I can tell this is the full list.
+pub const RESERVED_CASE_INSENSITIVE: &[&str] = &[
+    "asm",
+    "decl",
+    "pass",
+    "technique",
+    "Texture1D",
+    "Texture2D",
+    "Texture3D",
+    "TextureCube",
+];
+
+pub const RESERVED: &[&str] = &[
+    // FXC keywords, from https://github.com/MicrosoftDocs/win32/blob/c885cb0c63b0e9be80c6a0e6512473ac6f4e771e/desktop-src/direct3dhlsl/dx-graphics-hlsl-appendix-keywords.md?plain=1#L99-L118
+    "AppendStructuredBuffer",
+    "asm",
+    "asm_fragment",
+    "BlendState",
+    "bool",
+    "break",
+    "Buffer",
+    "ByteAddressBuffer",
+    "case",
+    "cbuffer",
+    "centroid",
+    "class",
+    "column_major",
+    "compile",
+    "compile_fragment",
+    "CompileShader",
+    "const",
+    "continue",
+    "ComputeShader",
+    "ConsumeStructuredBuffer",
+    "default",
+    "DepthStencilState",
+    "DepthStencilView",
+    "discard",
+    "do",
+    "double",
+    "DomainShader",
+    "dword",
+    "else",
+    "export",
+    "extern",
+    "false",
+    "float",
+    "for",
+    "fxgroup",
+    "GeometryShader",
+    "groupshared",
+    "half",
+    "Hullshader",
+    "if",
+    "in",
+    "inline",
+    "inout",
+    "InputPatch",
+    "int",
+    "interface",
+    "line",
+    "lineadj",
+    "linear",
+    "LineStream",
+    "matrix",
+    "min16float",
+    "min10float",
+    "min16int",
+    "min12int",
+    "min16uint",
+    "namespace",
+    "nointerpolation",
+    "noperspective",
+    "NULL",
+    "out",
+    "OutputPatch",
+    "packoffset",
+    "pass",
+    "pixelfragment",
+    "PixelShader",
+    "point",
+    "PointStream",
+    "precise",
+    "RasterizerState",
+    "RenderTargetView",
+    "return",
+    "register",
+    "row_major",
+    "RWBuffer",
+    "RWByteAddressBuffer",
+    "RWStructuredBuffer",
+    "RWTexture1D",
+    "RWTexture1DArray",
+    "RWTexture2D",
+    "RWTexture2DArray",
+    "RWTexture3D",
+    "sample",
+    "sampler",
+    "SamplerState",
+    "SamplerComparisonState",
+    "shared",
+    "snorm",
+    "stateblock",
+    "stateblock_state",
+    "static",
+    "string",
+    "struct",
+    "switch",
+    "StructuredBuffer",
+    "tbuffer",
+    "technique",
+    "technique10",
+    "technique11",
+    "texture",
+    "Texture1D",
+    "Texture1DArray",
+    "Texture2D",
+    "Texture2DArray",
+    "Texture2DMS",
+    "Texture2DMSArray",
+    "Texture3D",
+    "TextureCube",
+    "TextureCubeArray",
+    "true",
+    "typedef",
+    "triangle",
+    "triangleadj",
+    "TriangleStream",
+    "uint",
+    "uniform",
+    "unorm",
+    "unsigned",
+    "vector",
+    "vertexfragment",
+    "VertexShader",
+    "void",
+    "volatile",
+    "while",
+    // FXC reserved keywords, from https://github.com/MicrosoftDocs/win32/blob/c885cb0c63b0e9be80c6a0e6512473ac6f4e771e/desktop-src/direct3dhlsl/dx-graphics-hlsl-appendix-reserved-words.md?plain=1#L19-L38
+    "auto",
+    "case",
+    "catch",
+    "char",
+    "class",
+    "const_cast",
+    "default",
+    "delete",
+    "dynamic_cast",
+    "enum",
+    "explicit",
+    "friend",
+    "goto",
+    "long",
+    "mutable",
+    "new",
+    "operator",
+    "private",
+    "protected",
+    "public",
+    "reinterpret_cast",
+    "short",
+    "signed",
+    "sizeof",
+    "static_cast",
+    "template",
+    "this",
+    "throw",
+    "try",
+    "typename",
+    "union",
+    "unsigned",
+    "using",
+    "virtual",
+    // FXC intrinsics, from https://github.com/MicrosoftDocs/win32/blob/1682b99e203708f6f5eda972d966e30f3c1588de/desktop-src/direct3dhlsl/dx-graphics-hlsl-intrinsic-functions.md?plain=1#L26-L165
+    "abort",
+    "abs",
+    "acos",
+    "all",
+    "AllMemoryBarrier",
+    "AllMemoryBarrierWithGroupSync",
+    "any",
+    "asdouble",
+    "asfloat",
+    "asin",
+    "asint",
+    "asuint",
+    "atan",
+    "atan2",
+    "ceil",
+    "CheckAccessFullyMapped",
+    "clamp",
+    "clip",
+    "cos",
+    "cosh",
+    "countbits",
+    "cross",
+    "D3DCOLORtoUBYTE4",
+    "ddx",
+    "ddx_coarse",
+    "ddx_fine",
+    "ddy",
+    "ddy_coarse",
+    "ddy_fine",
+    "degrees",
+    "determinant",
+    "DeviceMemoryBarrier",
+    "DeviceMemoryBarrierWithGroupSync",
+    "distance",
+    "dot",
+    "dst",
+    "errorf",
+    "EvaluateAttributeCentroid",
+    "EvaluateAttributeAtSample",
+    "EvaluateAttributeSnapped",
+    "exp",
+    "exp2",
+    "f16tof32",
+    "f32tof16",
+    "faceforward",
+    "firstbithigh",
+    "firstbitlow",
+    "floor",
+    "fma",
+    "fmod",
+    "frac",
+    "frexp",
+    "fwidth",
+    "GetRenderTargetSampleCount",
+    "GetRenderTargetSamplePosition",
+    "GroupMemoryBarrier",
+    "GroupMemoryBarrierWithGroupSync",
+    "InterlockedAdd",
+    "InterlockedAnd",
+    "InterlockedCompareExchange",
+    "InterlockedCompareStore",
+    "InterlockedExchange",
+    "InterlockedMax",
+    "InterlockedMin",
+    "InterlockedOr",
+    "InterlockedXor",
+    "isfinite",
+    "isinf",
+    "isnan",
+    "ldexp",
+    "length",
+    "lerp",
+    "lit",
+    "log",
+    "log10",
+    "log2",
+    "mad",
+    "max",
+    "min",
+    "modf",
+    "msad4",
+    "mul",
+    "noise",
+    "normalize",
+    "pow",
+    "printf",
+    "Process2DQuadTessFactorsAvg",
+    "Process2DQuadTessFactorsMax",
+    "Process2DQuadTessFactorsMin",
+    "ProcessIsolineTessFactors",
+    "ProcessQuadTessFactorsAvg",
+    "ProcessQuadTessFactorsMax",
+    "ProcessQuadTessFactorsMin",
+    "ProcessTriTessFactorsAvg",
+    "ProcessTriTessFactorsMax",
+    "ProcessTriTessFactorsMin",
+    "radians",
+    "rcp",
+    "reflect",
+    "refract",
+    "reversebits",
+    "round",
+    "rsqrt",
+    "saturate",
+    "sign",
+    "sin",
+    "sincos",
+    "sinh",
+    "smoothstep",
+    "sqrt",
+    "step",
+    "tan",
+    "tanh",
+    "tex1D",
+    "tex1Dbias",
+    "tex1Dgrad",
+    "tex1Dlod",
+    "tex1Dproj",
+    "tex2D",
+    "tex2Dbias",
+    "tex2Dgrad",
+    "tex2Dlod",
+    "tex2Dproj",
+    "tex3D",
+    "tex3Dbias",
+    "tex3Dgrad",
+    "tex3Dlod",
+    "tex3Dproj",
+    "texCUBE",
+    "texCUBEbias",
+    "texCUBEgrad",
+    "texCUBElod",
+    "texCUBEproj",
+    "transpose",
+    "trunc",
+    // DXC (reserved) keywords, from https://github.com/microsoft/DirectXShaderCompiler/blob/d5d478470d3020a438d3cb810b8d3fe0992e6709/tools/clang/include/clang/Basic/TokenKinds.def#L222-L648
+    // with the KEYALL, KEYCXX, BOOLSUPPORT, WCHARSUPPORT, KEYHLSL options enabled (see https://github.com/microsoft/DirectXShaderCompiler/blob/d5d478470d3020a438d3cb810b8d3fe0992e6709/tools/clang/lib/Frontend/CompilerInvocation.cpp#L1199)
+    "auto",
+    "break",
+    "case",
+    "char",
+    "const",
+    "continue",
+    "default",
+    "do",
+    "double",
+    "else",
+    "enum",
+    "extern",
+    "float",
+    "for",
+    "goto",
+    "if",
+    "inline",
+    "int",
+    "long",
+    "register",
+    "return",
+    "short",
+    "signed",
+    "sizeof",
+    "static",
+    "struct",
+    "switch",
+    "typedef",
+    "union",
+    "unsigned",
+    "void",
+    "volatile",
+    "while",
+    "_Alignas",
+    "_Alignof",
+    "_Atomic",
+    "_Complex",
+    "_Generic",
+    "_Imaginary",
+    "_Noreturn",
+    "_Static_assert",
+    "_Thread_local",
+    "__func__",
+    "__objc_yes",
+    "__objc_no",
+    "asm",
+    "bool",
+    "catch",
+    "class",
+    "const_cast",
+    "delete",
+    "dynamic_cast",
+    "explicit",
+    "export",
+    "false",
+    "friend",
+    "mutable",
+    "namespace",
+    "new",
+    "operator",
+    "private",
+    "protected",
+    "public",
+    "reinterpret_cast",
+    "static_cast",
+    "template",
+    "this",
+    "throw",
+    "true",
+    "try",
+    "typename",
+    "typeid",
+    "using",
+    "virtual",
+    "wchar_t",
+    "_Decimal32",
+    "_Decimal64",
+    "_Decimal128",
+    "__null",
+    "__alignof",
+    "__attribute",
+    "__builtin_choose_expr",
+    "__builtin_offsetof",
+    "__builtin_va_arg",
+    "__extension__",
+    "__imag",
+    "__int128",
+    "__label__",
+    "__real",
+    "__thread",
+    "__FUNCTION__",
+    "__PRETTY_FUNCTION__",
+    "__is_nothrow_assignable",
+    "__is_constructible",
+    "__is_nothrow_constructible",
+    "__has_nothrow_assign",
+    "__has_nothrow_move_assign",
+    "__has_nothrow_copy",
+    "__has_nothrow_constructor",
+    "__has_trivial_assign",
+    "__has_trivial_move_assign",
+    "__has_trivial_copy",
+    "__has_trivial_constructor",
+    "__has_trivial_move_constructor",
+    "__has_trivial_destructor",
+    "__has_virtual_destructor",
+    "__is_abstract",
+    "__is_base_of",
+    "__is_class",
+    "__is_convertible_to",
+    "__is_empty",
+    "__is_enum",
+    "__is_final",
+    "__is_literal",
+    "__is_literal_type",
+    "__is_pod",
+    "__is_polymorphic",
+    "__is_trivial",
+    "__is_union",
+    "__is_trivially_constructible",
+    "__is_trivially_copyable",
+    "__is_trivially_assignable",
+    "__underlying_type",
+    "__is_lvalue_expr",
+    "__is_rvalue_expr",
+    "__is_arithmetic",
+    "__is_floating_point",
+    "__is_integral",
+    "__is_complete_type",
+    "__is_void",
+    "__is_array",
+    "__is_function",
+    "__is_reference",
+    "__is_lvalue_reference",
+    "__is_rvalue_reference",
+    "__is_fundamental",
+    "__is_object",
+    "__is_scalar",
+    "__is_compound",
+    "__is_pointer",
+    "__is_member_object_pointer",
+    "__is_member_function_pointer",
+    "__is_member_pointer",
+    "__is_const",
+    "__is_volatile",
+    "__is_standard_layout",
+    "__is_signed",
+    "__is_unsigned",
+    "__is_same",
+    "__is_convertible",
+    "__array_rank",
+    "__array_extent",
+    "__private_extern__",
+    "__module_private__",
+    "__declspec",
+    "__cdecl",
+    "__stdcall",
+    "__fastcall",
+    "__thiscall",
+    "__vectorcall",
+    "cbuffer",
+    "tbuffer",
+    "packoffset",
+    "linear",
+    "centroid",
+    "nointerpolation",
+    "noperspective",
+    "sample",
+    "column_major",
+    "row_major",
+    "in",
+    "out",
+    "inout",
+    "uniform",
+    "precise",
+    "center",
+    "shared",
+    "groupshared",
+    "discard",
+    "snorm",
+    "unorm",
+    "point",
+    "line",
+    "lineadj",
+    "triangle",
+    "triangleadj",
+    "globallycoherent",
+    "interface",
+    "sampler_state",
+    "technique",
+    "indices",
+    "vertices",
+    "primitives",
+    "payload",
+    "Technique",
+    "technique10",
+    "technique11",
+    "__builtin_omp_required_simd_align",
+    "__pascal",
+    "__fp16",
+    "__alignof__",
+    "__asm",
+    "__asm__",
+    "__attribute__",
+    "__complex",
+    "__complex__",
+    "__const",
+    "__const__",
+    "__decltype",
+    "__imag__",
+    "__inline",
+    "__inline__",
+    "__nullptr",
+    "__real__",
+    "__restrict",
+    "__restrict__",
+    "__signed",
+    "__signed__",
+    "__typeof",
+    "__typeof__",
+    "__volatile",
+    "__volatile__",
+    "_Nonnull",
+    "_Nullable",
+    "_Null_unspecified",
+    "__builtin_convertvector",
+    "__char16_t",
+    "__char32_t",
+    // DXC intrinsics, from https://github.com/microsoft/DirectXShaderCompiler/blob/18c9e114f9c314f93e68fbc72ce207d4ed2e65ae/utils/hct/gen_intrin_main.txt#L86-L376
+    "D3DCOLORtoUBYTE4",
+    "GetRenderTargetSampleCount",
+    "GetRenderTargetSamplePosition",
+    "abort",
+    "abs",
+    "acos",
+    "all",
+    "AllMemoryBarrier",
+    "AllMemoryBarrierWithGroupSync",
+    "any",
+    "asdouble",
+    "asfloat",
+    "asfloat16",
+    "asint16",
+    "asin",
+    "asint",
+    "asuint",
+    "asuint16",
+    "atan",
+    "atan2",
+    "ceil",
+    "clamp",
+    "clip",
+    "cos",
+    "cosh",
+    "countbits",
+    "cross",
+    "ddx",
+    "ddx_coarse",
+    "ddx_fine",
+    "ddy",
+    "ddy_coarse",
+    "ddy_fine",
+    "degrees",
+    "determinant",
+    "DeviceMemoryBarrier",
+    "DeviceMemoryBarrierWithGroupSync",
+    "distance",
+    "dot",
+    "dst",
+    "EvaluateAttributeAtSample",
+    "EvaluateAttributeCentroid",
+    "EvaluateAttributeSnapped",
+    "GetAttributeAtVertex",
+    "exp",
+    "exp2",
+    "f16tof32",
+    "f32tof16",
+    "faceforward",
+    "firstbithigh",
+    "firstbitlow",
+    "floor",
+    "fma",
+    "fmod",
+    "frac",
+    "frexp",
+    "fwidth",
+    "GroupMemoryBarrier",
+    "GroupMemoryBarrierWithGroupSync",
+    "InterlockedAdd",
+    "InterlockedMin",
+    "InterlockedMax",
+    "InterlockedAnd",
+    "InterlockedOr",
+    "InterlockedXor",
+    "InterlockedCompareStore",
+    "InterlockedExchange",
+    "InterlockedCompareExchange",
+    "InterlockedCompareStoreFloatBitwise",
+    "InterlockedCompareExchangeFloatBitwise",
+    "isfinite",
+    "isinf",
+    "isnan",
+    "ldexp",
+    "length",
+    "lerp",
+    "lit",
+    "log",
+    "log10",
+    "log2",
+    "mad",
+    "max",
+    "min",
+    "modf",
+    "msad4",
+    "mul",
+    "normalize",
+    "pow",
+    "printf",
+    "Process2DQuadTessFactorsAvg",
+    "Process2DQuadTessFactorsMax",
+    "Process2DQuadTessFactorsMin",
+    "ProcessIsolineTessFactors",
+    "ProcessQuadTessFactorsAvg",
+    "ProcessQuadTessFactorsMax",
+    "ProcessQuadTessFactorsMin",
+    "ProcessTriTessFactorsAvg",
+    "ProcessTriTessFactorsMax",
+    "ProcessTriTessFactorsMin",
+    "radians",
+    "rcp",
+    "reflect",
+    "refract",
+    "reversebits",
+    "round",
+    "rsqrt",
+    "saturate",
+    "sign",
+    "sin",
+    "sincos",
+    "sinh",
+    "smoothstep",
+    "source_mark",
+    "sqrt",
+    "step",
+    "tan",
+    "tanh",
+    "tex1D",
+    "tex1Dbias",
+    "tex1Dgrad",
+    "tex1Dlod",
+    "tex1Dproj",
+    "tex2D",
+    "tex2Dbias",
+    "tex2Dgrad",
+    "tex2Dlod",
+    "tex2Dproj",
+    "tex3D",
+    "tex3Dbias",
+    "tex3Dgrad",
+    "tex3Dlod",
+    "tex3Dproj",
+    "texCUBE",
+    "texCUBEbias",
+    "texCUBEgrad",
+    "texCUBElod",
+    "texCUBEproj",
+    "transpose",
+    "trunc",
+    "CheckAccessFullyMapped",
+    "AddUint64",
+    "NonUniformResourceIndex",
+    "WaveIsFirstLane",
+    "WaveGetLaneIndex",
+    "WaveGetLaneCount",
+    "WaveActiveAnyTrue",
+    "WaveActiveAllTrue",
+    "WaveActiveAllEqual",
+    "WaveActiveBallot",
+    "WaveReadLaneAt",
+    "WaveReadLaneFirst",
+    "WaveActiveCountBits",
+    "WaveActiveSum",
+    "WaveActiveProduct",
+    "WaveActiveBitAnd",
+    "WaveActiveBitOr",
+    "WaveActiveBitXor",
+    "WaveActiveMin",
+    "WaveActiveMax",
+    "WavePrefixCountBits",
+    "WavePrefixSum",
+    "WavePrefixProduct",
+    "WaveMatch",
+    "WaveMultiPrefixBitAnd",
+    "WaveMultiPrefixBitOr",
+    "WaveMultiPrefixBitXor",
+    "WaveMultiPrefixCountBits",
+    "WaveMultiPrefixProduct",
+    "WaveMultiPrefixSum",
+    "QuadReadLaneAt",
+    "QuadReadAcrossX",
+    "QuadReadAcrossY",
+    "QuadReadAcrossDiagonal",
+    "QuadAny",
+    "QuadAll",
+    "TraceRay",
+    "ReportHit",
+    "CallShader",
+    "IgnoreHit",
+    "AcceptHitAndEndSearch",
+    "DispatchRaysIndex",
+    "DispatchRaysDimensions",
+    "WorldRayOrigin",
+    "WorldRayDirection",
+    "ObjectRayOrigin",
+    "ObjectRayDirection",
+    "RayTMin",
+    "RayTCurrent",
+    "PrimitiveIndex",
+    "InstanceID",
+    "InstanceIndex",
+    "GeometryIndex",
+    "HitKind",
+    "RayFlags",
+    "ObjectToWorld",
+    "WorldToObject",
+    "ObjectToWorld3x4",
+    "WorldToObject3x4",
+    "ObjectToWorld4x3",
+    "WorldToObject4x3",
+    "dot4add_u8packed",
+    "dot4add_i8packed",
+    "dot2add",
+    "unpack_s8s16",
+    "unpack_u8u16",
+    "unpack_s8s32",
+    "unpack_u8u32",
+    "pack_s8",
+    "pack_u8",
+    "pack_clamp_s8",
+    "pack_clamp_u8",
+    "SetMeshOutputCounts",
+    "DispatchMesh",
+    "IsHelperLane",
+    "AllocateRayQuery",
+    "CreateResourceFromHeap",
+    "and",
+    "or",
+    "select",
+    // DXC resource and other types, from https://github.com/microsoft/DirectXShaderCompiler/blob/18c9e114f9c314f93e68fbc72ce207d4ed2e65ae/tools/clang/lib/AST/HlslTypes.cpp#L441-#L572
+    "InputPatch",
+    "OutputPatch",
+    "PointStream",
+    "LineStream",
+    "TriangleStream",
+    "Texture1D",
+    "RWTexture1D",
+    "Texture2D",
+    "RWTexture2D",
+    "Texture2DMS",
+    "RWTexture2DMS",
+    "Texture3D",
+    "RWTexture3D",
+    "TextureCube",
+    "RWTextureCube",
+    "Texture1DArray",
+    "RWTexture1DArray",
+    "Texture2DArray",
+    "RWTexture2DArray",
+    "Texture2DMSArray",
+    "RWTexture2DMSArray",
+    "TextureCubeArray",
+    "RWTextureCubeArray",
+    "FeedbackTexture2D",
+    "FeedbackTexture2DArray",
+    "RasterizerOrderedTexture1D",
+    "RasterizerOrderedTexture2D",
+    "RasterizerOrderedTexture3D",
+    "RasterizerOrderedTexture1DArray",
+    "RasterizerOrderedTexture2DArray",
+    "RasterizerOrderedBuffer",
+    "RasterizerOrderedByteAddressBuffer",
+    "RasterizerOrderedStructuredBuffer",
+    "ByteAddressBuffer",
+    "RWByteAddressBuffer",
+    "StructuredBuffer",
+    "RWStructuredBuffer",
+    "AppendStructuredBuffer",
+    "ConsumeStructuredBuffer",
+    "Buffer",
+    "RWBuffer",
+    "SamplerState",
+    "SamplerComparisonState",
+    "ConstantBuffer",
+    "TextureBuffer",
+    "RaytracingAccelerationStructure",
+    // DXC templated types, from https://github.com/microsoft/DirectXShaderCompiler/blob/18c9e114f9c314f93e68fbc72ce207d4ed2e65ae/tools/clang/lib/AST/ASTContextHLSL.cpp
+    // look for `BuiltinTypeDeclBuilder`
+    "matrix",
+    "vector",
+    "TextureBuffer",
+    "ConstantBuffer",
+    "RayQuery",
+    // Naga utilities
+    super::writer::MODF_FUNCTION,
+    super::writer::FREXP_FUNCTION,
+];
+
+// DXC scalar types, from https://github.com/microsoft/DirectXShaderCompiler/blob/18c9e114f9c314f93e68fbc72ce207d4ed2e65ae/tools/clang/lib/AST/ASTContextHLSL.cpp#L48-L254
+// + vector and matrix shorthands
+pub const TYPES: &[&str] = &{
+    const L: usize = 23 * (1 + 4 + 4 * 4);
+    let mut res = [""; L];
+    let mut c = 0;
+
+    /// For each scalar type, it will additionally generate vector and matrix shorthands
+    macro_rules! generate {
+        ([$($roots:literal),*], $x:tt) => {
+            $(
+                generate!(@inner push $roots);
+                generate!(@inner $roots, $x);
+            )*
+        };
+
+        (@inner $root:literal, [$($x:literal),*]) => {
+            generate!(@inner vector $root, $($x)*);
+            generate!(@inner matrix $root, $($x)*);
+        };
+
+        (@inner vector $root:literal, $($x:literal)*) => {
+            $(
+                generate!(@inner push concat!($root, $x));
+            )*
+        };
+
+        (@inner matrix $root:literal, $($x:literal)*) => {
+            // Duplicate the list
+            generate!(@inner matrix $root, $($x)*; $($x)*);
+        };
+
+        // The head/tail recursion: pick the first element of the first list and recursively do it for the tail.
+        (@inner matrix $root:literal, $head:literal $($tail:literal)*; $($x:literal)*) => {
+            $(
+                generate!(@inner push concat!($root, $head, "x", $x));
+            )*
+            generate!(@inner matrix $root, $($tail)*; $($x)*);
+
+        };
+
+        // The end of iteration: we exhausted the list
+        (@inner matrix $root:literal, ; $($x:literal)*) => {};
+
+        (@inner push $v:expr) => {
+            res[c] = $v;
+            c += 1;
+        };
+    }
+
+    generate!(
+        [
+            "bool",
+            "int",
+            "uint",
+            "dword",
+            "half",
+            "float",
+            "double",
+            "min10float",
+            "min16float",
+            "min12int",
+            "min16int",
+            "min16uint",
+            "int16_t",
+            "int32_t",
+            "int64_t",
+            "uint16_t",
+            "uint32_t",
+            "uint64_t",
+            "float16_t",
+            "float32_t",
+            "float64_t",
+            "int8_t4_packed",
+            "uint8_t4_packed"
+        ],
+        ["1", "2", "3", "4"]
+    );
+
+    debug_assert!(c == L);
+
+    res
+};
diff --git a/third_party/rust/naga/src/back/hlsl/mod.rs b/third_party/rust/naga/src/back/hlsl/mod.rs
new file mode 100644
index 0000000000..37ddbd3d67
--- /dev/null
+++ b/third_party/rust/naga/src/back/hlsl/mod.rs
@@ -0,0 +1,302 @@
+/*!
+Backend for [HLSL][hlsl] (High-Level Shading Language).
+
+# Supported shader model versions:
+- 5.0
+- 5.1
+- 6.0
+
+# Layout of values in `uniform` buffers
+
+WGSL's ["Internal Layout of Values"][ilov] rules specify how each WGSL
+type should be stored in `uniform` and `storage` buffers. The HLSL we
+generate must access values in that form, even when it is not what
+HLSL would use normally.
+
+The rules described here only apply to WGSL `uniform` variables. WGSL
+`storage` buffers are translated as HLSL `ByteAddressBuffers`, for
+which we generate `Load` and `Store` method calls with explicit byte
+offsets. WGSL pipeline inputs must be scalars or vectors; they cannot
+be matrices, which is where the interesting problems arise.
+
+## Row- and column-major ordering for matrices
+
+WGSL specifies that matrices in uniform buffers are stored in
+column-major order. This matches HLSL's default, so one might expect
+things to be straightforward. Unfortunately, WGSL and HLSL disagree on
+what indexing a matrix means: in WGSL, `m[i]` retrieves the `i`'th
+*column* of `m`, whereas in HLSL it retrieves the `i`'th *row*. We
+want to avoid translating `m[i]` into some complicated reassembly of a
+vector from individually fetched components, so this is a problem.
+
+However, with a bit of trickery, it is possible to use HLSL's `m[i]`
+as the translation of WGSL's `m[i]`:
+
+- We declare all matrices in uniform buffers in HLSL with the
+  `row_major` qualifier, and transpose the row and column counts: a
+  WGSL `mat3x4<f32>`, say, becomes an HLSL `row_major float3x4`. (Note
+  that WGSL and HLSL type names put the row and column in reverse
+  order.) Since the HLSL type is the transpose of how WebGPU directs
+  the user to store the data, HLSL will load all matrices transposed.
+
+- Since matrices are transposed, an HLSL indexing expression retrieves
+  the "columns" of the intended WGSL value, as desired.
+
+- For vector-matrix multiplication, since `mul(transpose(m), v)` is
+  equivalent to `mul(v, m)` (note the reversal of the arguments), and
+  `mul(v, transpose(m))` is equivalent to `mul(m, v)`, we can
+  translate WGSL `m * v` and `v * m` to HLSL by simply reversing the
+  arguments to `mul`.
+
+## Padding in two-row matrices
+
+An HLSL `row_major floatKx2` matrix has padding between its rows that
+the WGSL `matKx2<f32>` matrix it represents does not. HLSL stores all
+matrix rows [aligned on 16-byte boundaries][16bb], whereas WGSL says
+that the columns of a `matKx2<f32>` need only be [aligned as required
+for `vec2<f32>`][ilov], which is [eight-byte alignment][8bb].
+
+To compensate for this, any time a `matKx2<f32>` appears in a WGSL
+`uniform` variable, whether directly as the variable's type or as part
+of a struct/array, we actually emit `K` separate `float2` members, and
+assemble/disassemble the matrix from its columns (in WGSL; rows in
+HLSL) upon load and store.
+
+For example, the following WGSL struct type:
+
+```ignore
+struct Baz {
+        m: mat3x2<f32>,
+}
+```
+
+is rendered as the HLSL struct type:
+
+```ignore
+struct Baz {
+    float2 m_0; float2 m_1; float2 m_2;
+};
+```
+
+The `wrapped_struct_matrix` functions in `help.rs` generate HLSL
+helper functions to access such members, converting between the stored
+form and the HLSL matrix types appropriately. For example, for reading
+the member `m` of the `Baz` struct above, we emit:
+
+```ignore
+float3x2 GetMatmOnBaz(Baz obj) {
+    return float3x2(obj.m_0, obj.m_1, obj.m_2);
+}
+```
+
+We also emit an analogous `Set` function, as well as functions for
+accessing individual columns by dynamic index.
+
+[hlsl]: https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl
+[ilov]: https://gpuweb.github.io/gpuweb/wgsl/#internal-value-layout
+[16bb]: https://github.com/microsoft/DirectXShaderCompiler/wiki/Buffer-Packing#constant-buffer-packing
+[8bb]: https://gpuweb.github.io/gpuweb/wgsl/#alignment-and-size
+*/
+
+mod conv;
+mod help;
+mod keywords;
+mod storage;
+mod writer;
+
+use std::fmt::Error as FmtError;
+use thiserror::Error;
+
+use crate::{back, proc};
+
+#[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub struct BindTarget {
+    pub space: u8,
+    pub register: u32,
+    /// If the binding is an unsized binding array, this overrides the size.
+    pub binding_array_size: Option<u32>,
+}
+
+// Using `BTreeMap` instead of `HashMap` so that we can hash itself.
+pub type BindingMap = std::collections::BTreeMap<crate::ResourceBinding, BindTarget>;
+
+/// A HLSL shader model version.
+#[allow(non_snake_case, non_camel_case_types)]
+#[derive(Copy, Clone, Debug, Hash, Eq, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub enum ShaderModel {
+    V5_0,
+    V5_1,
+    V6_0,
+}
+
+impl ShaderModel {
+    pub const fn to_str(self) -> &'static str {
+        match self {
+            Self::V5_0 => "5_0",
+            Self::V5_1 => "5_1",
+            Self::V6_0 => "6_0",
+        }
+    }
+}
+
+impl crate::ShaderStage {
+    pub const fn to_hlsl_str(self) -> &'static str {
+        match self {
+            Self::Vertex => "vs",
+            Self::Fragment => "ps",
+            Self::Compute => "cs",
+        }
+    }
+}
+
+impl crate::ImageDimension {
+    const fn to_hlsl_str(self) -> &'static str {
+        match self {
+            Self::D1 => "1D",
+            Self::D2 => "2D",
+            Self::D3 => "3D",
+            Self::Cube => "Cube",
+        }
+    }
+}
+
+/// Shorthand result used internally by the backend
+type BackendResult = Result<(), Error>;
+
+#[derive(Clone, Debug, PartialEq, thiserror::Error)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub enum EntryPointError {
+    #[error("mapping of {0:?} is missing")]
+    MissingBinding(crate::ResourceBinding),
+}
+
+/// Configuration used in the [`Writer`].
+#[derive(Clone, Debug, Hash, PartialEq, Eq)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub struct Options {
+    /// The hlsl shader model to be used
+    pub shader_model: ShaderModel,
+    /// Map of resources association to binding locations.
+    pub binding_map: BindingMap,
+    /// Don't panic on missing bindings, instead generate any HLSL.
+    pub fake_missing_bindings: bool,
+    /// Add special constants to `SV_VertexIndex` and `SV_InstanceIndex`,
+    /// to make them work like in Vulkan/Metal, with help of the host.
+    pub special_constants_binding: Option<BindTarget>,
+    /// Bind target of the push constant buffer
+    pub push_constants_target: Option<BindTarget>,
+    /// Should workgroup variables be zero initialized (by polyfilling)?
+    pub zero_initialize_workgroup_memory: bool,
+}
+
+impl Default for Options {
+    fn default() -> Self {
+        Options {
+            shader_model: ShaderModel::V5_1,
+            binding_map: BindingMap::default(),
+            fake_missing_bindings: true,
+            special_constants_binding: None,
+            push_constants_target: None,
+            zero_initialize_workgroup_memory: true,
+        }
+    }
+}
+
+impl Options {
+    fn resolve_resource_binding(
+        &self,
+        res_binding: &crate::ResourceBinding,
+    ) -> Result<BindTarget, EntryPointError> {
+        match self.binding_map.get(res_binding) {
+            Some(target) => Ok(target.clone()),
+            None if self.fake_missing_bindings => Ok(BindTarget {
+                space: res_binding.group as u8,
+                register: res_binding.binding,
+                binding_array_size: None,
+            }),
+            None => Err(EntryPointError::MissingBinding(res_binding.clone())),
+        }
+    }
+}
+
+/// Reflection info for entry point names.
+#[derive(Default)]
+pub struct ReflectionInfo {
+    /// Mapping of the entry point names.
+    ///
+    /// Each item in the array corresponds to an entry point index. The real entry point name may be different if one of the
+    /// reserved words are used.
+    ///
+    /// Note: Some entry points may fail translation because of missing bindings.
+    pub entry_point_names: Vec<Result<String, EntryPointError>>,
+}
+
+#[derive(Error, Debug)]
+pub enum Error {
+    #[error(transparent)]
+    IoError(#[from] FmtError),
+    #[error("A scalar with an unsupported width was requested: {0:?}")]
+    UnsupportedScalar(crate::Scalar),
+    #[error("{0}")]
+    Unimplemented(String), // TODO: Error used only during development
+    #[error("{0}")]
+    Custom(String),
+}
+
+#[derive(Default)]
+struct Wrapped {
+    array_lengths: crate::FastHashSet<help::WrappedArrayLength>,
+    image_queries: crate::FastHashSet<help::WrappedImageQuery>,
+    constructors: crate::FastHashSet<help::WrappedConstructor>,
+    struct_matrix_access: crate::FastHashSet<help::WrappedStructMatrixAccess>,
+    mat_cx2s: crate::FastHashSet<help::WrappedMatCx2>,
+}
+
+impl Wrapped {
+    fn clear(&mut self) {
+        self.array_lengths.clear();
+        self.image_queries.clear();
+        self.constructors.clear();
+        self.struct_matrix_access.clear();
+        self.mat_cx2s.clear();
+    }
+}
+
+pub struct Writer<'a, W> {
+    out: W,
+    names: crate::FastHashMap<proc::NameKey, String>,
+    namer: proc::Namer,
+    /// HLSL backend options
+    options: &'a Options,
+    /// Information about entry point arguments and result types.
+    entry_point_io: Vec<writer::EntryPointInterface>,
+    /// Set of expressions that have associated temporary variables
+    named_expressions: crate::NamedExpressions,
+    wrapped: Wrapped,
+
+    /// A reference to some part of a global variable, lowered to a series of
+    /// byte offset calculations.
+    ///
+    /// See the [`storage`] module for background on why we need this.
+    ///
+    /// Each [`SubAccess`] in the vector is a lowering of some [`Access`] or
+    /// [`AccessIndex`] expression to the level of byte strides and offsets. See
+    /// [`SubAccess`] for details.
+    ///
+    /// This field is a member of [`Writer`] solely to allow re-use of
+    /// the `Vec`'s dynamic allocation. The value is no longer needed
+    /// once HLSL for the access has been generated.
+    ///
+    /// [`Storage`]: crate::AddressSpace::Storage
+    /// [`SubAccess`]: storage::SubAccess
+    /// [`Access`]: crate::Expression::Access
+    /// [`AccessIndex`]: crate::Expression::AccessIndex
+    temp_access_chain: Vec<storage::SubAccess>,
+    need_bake_expressions: back::NeedBakeExpressions,
+}
diff --git a/third_party/rust/naga/src/back/hlsl/storage.rs b/third_party/rust/naga/src/back/hlsl/storage.rs
new file mode 100644
index 0000000000..1b8a6ec12d
--- /dev/null
+++ b/third_party/rust/naga/src/back/hlsl/storage.rs
@@ -0,0 +1,494 @@
+/*!
+Generating accesses to [`ByteAddressBuffer`] contents.
+
+Naga IR globals in the [`Storage`] address space are rendered as
+[`ByteAddressBuffer`]s or [`RWByteAddressBuffer`]s in HLSL. These
+buffers don't have HLSL types (structs, arrays, etc.); instead, they
+are just raw blocks of bytes, with methods to load and store values of
+specific types at particular byte offsets. This means that Naga must
+translate chains of [`Access`] and [`AccessIndex`] expressions into
+HLSL expressions that compute byte offsets into the buffer.
+
+To generate code for a [`Storage`] access:
+
+- Call [`Writer::fill_access_chain`] on the expression referring to
+  the value. This populates [`Writer::temp_access_chain`] with the
+  appropriate byte offset calculations, as a vector of [`SubAccess`]
+  values.
+
+- Call [`Writer::write_storage_address`] to emit an HLSL expression
+  for a given slice of [`SubAccess`] values.
+
+Naga IR expressions can operate on composite values of any type, but
+[`ByteAddressBuffer`] and [`RWByteAddressBuffer`] have only a fixed
+set of `Load` and `Store` methods, to access one through four
+consecutive 32-bit values. To synthesize a Naga access, you can
+initialize [`temp_access_chain`] to refer to the composite, and then
+temporarily push and pop additional steps on
+[`Writer::temp_access_chain`] to generate accesses to the individual
+elements/members.
+
+The [`temp_access_chain`] field is a member of [`Writer`] solely to
+allow re-use of the `Vec`'s dynamic allocation. Its value is no longer
+needed once HLSL for the access has been generated.
+
+[`Storage`]: crate::AddressSpace::Storage
+[`ByteAddressBuffer`]: https://learn.microsoft.com/en-us/windows/win32/direct3dhlsl/sm5-object-byteaddressbuffer
+[`RWByteAddressBuffer`]: https://learn.microsoft.com/en-us/windows/win32/direct3dhlsl/sm5-object-rwbyteaddressbuffer
+[`Access`]: crate::Expression::Access
+[`AccessIndex`]: crate::Expression::AccessIndex
+[`Writer::fill_access_chain`]: super::Writer::fill_access_chain
+[`Writer::write_storage_address`]: super::Writer::write_storage_address
+[`Writer::temp_access_chain`]: super::Writer::temp_access_chain
+[`temp_access_chain`]: super::Writer::temp_access_chain
+[`Writer`]: super::Writer
+*/
+
+use super::{super::FunctionCtx, BackendResult, Error};
+use crate::{
+    proc::{Alignment, NameKey, TypeResolution},
+    Handle,
+};
+
+use std::{fmt, mem};
+
+const STORE_TEMP_NAME: &str = "_value";
+
+/// One step in accessing a [`Storage`] global's component or element.
+///
+/// [`Writer::temp_access_chain`] holds a series of these structures,
+/// describing how to compute the byte offset of a particular element
+/// or member of some global variable in the [`Storage`] address
+/// space.
+///
+/// [`Writer::temp_access_chain`]: super::Writer::temp_access_chain
+/// [`Storage`]: crate::AddressSpace::Storage
+#[derive(Debug)]
+pub(super) enum SubAccess {
+    /// Add the given byte offset. This is used for struct members, or
+    /// known components of a vector or matrix. In all those cases,
+    /// the byte offset is a compile-time constant.
+    Offset(u32),
+
+    /// Scale `value` by `stride`, and add that to the current byte
+    /// offset. This is used to compute the offset of an array element
+    /// whose index is computed at runtime.
+    Index {
+        value: Handle<crate::Expression>,
+        stride: u32,
+    },
+}
+
+pub(super) enum StoreValue {
+    Expression(Handle<crate::Expression>),
+    TempIndex {
+        depth: usize,
+        index: u32,
+        ty: TypeResolution,
+    },
+    TempAccess {
+        depth: usize,
+        base: Handle<crate::Type>,
+        member_index: u32,
+    },
+}
+
+impl<W: fmt::Write> super::Writer<'_, W> {
+    pub(super) fn write_storage_address(
+        &mut self,
+        module: &crate::Module,
+        chain: &[SubAccess],
+        func_ctx: &FunctionCtx,
+    ) -> BackendResult {
+        if chain.is_empty() {
+            write!(self.out, "0")?;
+        }
+        for (i, access) in chain.iter().enumerate() {
+            if i != 0 {
+                write!(self.out, "+")?;
+            }
+            match *access {
+                SubAccess::Offset(offset) => {
+                    write!(self.out, "{offset}")?;
+                }
+                SubAccess::Index { value, stride } => {
+                    self.write_expr(module, value, func_ctx)?;
+                    write!(self.out, "*{stride}")?;
+                }
+            }
+        }
+        Ok(())
+    }
+
+    fn write_storage_load_sequence<I: Iterator<Item = (TypeResolution, u32)>>(
+        &mut self,
+        module: &crate::Module,
+        var_handle: Handle<crate::GlobalVariable>,
+        sequence: I,
+        func_ctx: &FunctionCtx,
+    ) -> BackendResult {
+        for (i, (ty_resolution, offset)) in sequence.enumerate() {
+            // add the index temporarily
+            self.temp_access_chain.push(SubAccess::Offset(offset));
+            if i != 0 {
+                write!(self.out, ", ")?;
+            };
+            self.write_storage_load(module, var_handle, ty_resolution, func_ctx)?;
+            self.temp_access_chain.pop();
+        }
+        Ok(())
+    }
+
+    /// Emit code to access a [`Storage`] global's component.
+    ///
+    /// Emit HLSL to access the component of `var_handle`, a global
+    /// variable in the [`Storage`] address space, whose type is
+    /// `result_ty` and whose location within the global is given by
+    /// [`self.temp_access_chain`]. See the [`storage`] module's
+    /// documentation for background.
+    ///
+    /// [`Storage`]: crate::AddressSpace::Storage
+    /// [`self.temp_access_chain`]: super::Writer::temp_access_chain
+    pub(super) fn write_storage_load(
+        &mut self,
+        module: &crate::Module,
+        var_handle: Handle<crate::GlobalVariable>,
+        result_ty: TypeResolution,
+        func_ctx: &FunctionCtx,
+    ) -> BackendResult {
+        match *result_ty.inner_with(&module.types) {
+            crate::TypeInner::Scalar(scalar) => {
+                // working around the borrow checker in `self.write_expr`
+                let chain = mem::take(&mut self.temp_access_chain);
+                let var_name = &self.names[&NameKey::GlobalVariable(var_handle)];
+                let cast = scalar.kind.to_hlsl_cast();
+                write!(self.out, "{cast}({var_name}.Load(")?;
+                self.write_storage_address(module, &chain, func_ctx)?;
+                write!(self.out, "))")?;
+                self.temp_access_chain = chain;
+            }
+            crate::TypeInner::Vector { size, scalar } => {
+                // working around the borrow checker in `self.write_expr`
+                let chain = mem::take(&mut self.temp_access_chain);
+                let var_name = &self.names[&NameKey::GlobalVariable(var_handle)];
+                let cast = scalar.kind.to_hlsl_cast();
+                write!(self.out, "{}({}.Load{}(", cast, var_name, size as u8)?;
+                self.write_storage_address(module, &chain, func_ctx)?;
+                write!(self.out, "))")?;
+                self.temp_access_chain = chain;
+            }
+            crate::TypeInner::Matrix {
+                columns,
+                rows,
+                scalar,
+            } => {
+                write!(
+                    self.out,
+                    "{}{}x{}(",
+                    scalar.to_hlsl_str()?,
+                    columns as u8,
+                    rows as u8,
+                )?;
+
+                // Note: Matrices containing vec3s, due to padding, act like they contain vec4s.
+                let row_stride = Alignment::from(rows) * scalar.width as u32;
+                let iter = (0..columns as u32).map(|i| {
+                    let ty_inner = crate::TypeInner::Vector { size: rows, scalar };
+                    (TypeResolution::Value(ty_inner), i * row_stride)
+                });
+                self.write_storage_load_sequence(module, var_handle, iter, func_ctx)?;
+                write!(self.out, ")")?;
+            }
+            crate::TypeInner::Array {
+                base,
+                size: crate::ArraySize::Constant(size),
+                stride,
+            } => {
+                let constructor = super::help::WrappedConstructor {
+                    ty: result_ty.handle().unwrap(),
+                };
+                self.write_wrapped_constructor_function_name(module, constructor)?;
+                write!(self.out, "(")?;
+                let iter = (0..size.get()).map(|i| (TypeResolution::Handle(base), stride * i));
+                self.write_storage_load_sequence(module, var_handle, iter, func_ctx)?;
+                write!(self.out, ")")?;
+            }
+            crate::TypeInner::Struct { ref members, .. } => {
+                let constructor = super::help::WrappedConstructor {
+                    ty: result_ty.handle().unwrap(),
+                };
+                self.write_wrapped_constructor_function_name(module, constructor)?;
+                write!(self.out, "(")?;
+                let iter = members
+                    .iter()
+                    .map(|m| (TypeResolution::Handle(m.ty), m.offset));
+                self.write_storage_load_sequence(module, var_handle, iter, func_ctx)?;
+                write!(self.out, ")")?;
+            }
+            _ => unreachable!(),
+        }
+        Ok(())
+    }
+
+    fn write_store_value(
+        &mut self,
+        module: &crate::Module,
+        value: &StoreValue,
+        func_ctx: &FunctionCtx,
+    ) -> BackendResult {
+        match *value {
+            StoreValue::Expression(expr) => self.write_expr(module, expr, func_ctx)?,
+            StoreValue::TempIndex {
+                depth,
+                index,
+                ty: _,
+            } => write!(self.out, "{STORE_TEMP_NAME}{depth}[{index}]")?,
+            StoreValue::TempAccess {
+                depth,
+                base,
+                member_index,
+            } => {
+                let name = &self.names[&NameKey::StructMember(base, member_index)];
+                write!(self.out, "{STORE_TEMP_NAME}{depth}.{name}")?
+            }
+        }
+        Ok(())
+    }
+
+    /// Helper function to write down the Store operation on a `ByteAddressBuffer`.
+    pub(super) fn write_storage_store(
+        &mut self,
+        module: &crate::Module,
+        var_handle: Handle<crate::GlobalVariable>,
+        value: StoreValue,
+        func_ctx: &FunctionCtx,
+        level: crate::back::Level,
+    ) -> BackendResult {
+        let temp_resolution;
+        let ty_resolution = match value {
+            StoreValue::Expression(expr) => &func_ctx.info[expr].ty,
+            StoreValue::TempIndex {
+                depth: _,
+                index: _,
+                ref ty,
+            } => ty,
+            StoreValue::TempAccess {
+                depth: _,
+                base,
+                member_index,
+            } => {
+                let ty_handle = match module.types[base].inner {
+                    crate::TypeInner::Struct { ref members, .. } => {
+                        members[member_index as usize].ty
+                    }
+                    _ => unreachable!(),
+                };
+                temp_resolution = TypeResolution::Handle(ty_handle);
+                &temp_resolution
+            }
+        };
+        match *ty_resolution.inner_with(&module.types) {
+            crate::TypeInner::Scalar(_) => {
+                // working around the borrow checker in `self.write_expr`
+                let chain = mem::take(&mut self.temp_access_chain);
+                let var_name = &self.names[&NameKey::GlobalVariable(var_handle)];
+                write!(self.out, "{level}{var_name}.Store(")?;
+                self.write_storage_address(module, &chain, func_ctx)?;
+                write!(self.out, ", asuint(")?;
+                self.write_store_value(module, &value, func_ctx)?;
+                writeln!(self.out, "));")?;
+                self.temp_access_chain = chain;
+            }
+            crate::TypeInner::Vector { size, .. } => {
+                // working around the borrow checker in `self.write_expr`
+                let chain = mem::take(&mut self.temp_access_chain);
+                let var_name = &self.names[&NameKey::GlobalVariable(var_handle)];
+                write!(self.out, "{}{}.Store{}(", level, var_name, size as u8)?;
+                self.write_storage_address(module, &chain, func_ctx)?;
+                write!(self.out, ", asuint(")?;
+                self.write_store_value(module, &value, func_ctx)?;
+                writeln!(self.out, "));")?;
+                self.temp_access_chain = chain;
+            }
+            crate::TypeInner::Matrix {
+                columns,
+                rows,
+                scalar,
+            } => {
+                // first, assign the value to a temporary
+                writeln!(self.out, "{level}{{")?;
+                let depth = level.0 + 1;
+                write!(
+                    self.out,
+                    "{}{}{}x{} {}{} = ",
+                    level.next(),
+                    scalar.to_hlsl_str()?,
+                    columns as u8,
+                    rows as u8,
+                    STORE_TEMP_NAME,
+                    depth,
+                )?;
+                self.write_store_value(module, &value, func_ctx)?;
+                writeln!(self.out, ";")?;
+
+                // Note: Matrices containing vec3s, due to padding, act like they contain vec4s.
+                let row_stride = Alignment::from(rows) * scalar.width as u32;
+
+                // then iterate the stores
+                for i in 0..columns as u32 {
+                    self.temp_access_chain
+                        .push(SubAccess::Offset(i * row_stride));
+                    let ty_inner = crate::TypeInner::Vector { size: rows, scalar };
+                    let sv = StoreValue::TempIndex {
+                        depth,
+                        index: i,
+                        ty: TypeResolution::Value(ty_inner),
+                    };
+                    self.write_storage_store(module, var_handle, sv, func_ctx, level.next())?;
+                    self.temp_access_chain.pop();
+                }
+                // done
+                writeln!(self.out, "{level}}}")?;
+            }
+            crate::TypeInner::Array {
+                base,
+                size: crate::ArraySize::Constant(size),
+                stride,
+            } => {
+                // first, assign the value to a temporary
+                writeln!(self.out, "{level}{{")?;
+                write!(self.out, "{}", level.next())?;
+                self.write_value_type(module, &module.types[base].inner)?;
+                let depth = level.next().0;
+                write!(self.out, " {STORE_TEMP_NAME}{depth}")?;
+                self.write_array_size(module, base, crate::ArraySize::Constant(size))?;
+                write!(self.out, " = ")?;
+                self.write_store_value(module, &value, func_ctx)?;
+                writeln!(self.out, ";")?;
+                // then iterate the stores
+                for i in 0..size.get() {
+                    self.temp_access_chain.push(SubAccess::Offset(i * stride));
+                    let sv = StoreValue::TempIndex {
+                        depth,
+                        index: i,
+                        ty: TypeResolution::Handle(base),
+                    };
+                    self.write_storage_store(module, var_handle, sv, func_ctx, level.next())?;
+                    self.temp_access_chain.pop();
+                }
+                // done
+                writeln!(self.out, "{level}}}")?;
+            }
+            crate::TypeInner::Struct { ref members, .. } => {
+                // first, assign the value to a temporary
+                writeln!(self.out, "{level}{{")?;
+                let depth = level.next().0;
+                let struct_ty = ty_resolution.handle().unwrap();
+                let struct_name = &self.names[&NameKey::Type(struct_ty)];
+                write!(
+                    self.out,
+                    "{}{} {}{} = ",
+                    level.next(),
+                    struct_name,
+                    STORE_TEMP_NAME,
+                    depth
+                )?;
+                self.write_store_value(module, &value, func_ctx)?;
+                writeln!(self.out, ";")?;
+                // then iterate the stores
+                for (i, member) in members.iter().enumerate() {
+                    self.temp_access_chain
+                        .push(SubAccess::Offset(member.offset));
+                    let sv = StoreValue::TempAccess {
+                        depth,
+                        base: struct_ty,
+                        member_index: i as u32,
+                    };
+                    self.write_storage_store(module, var_handle, sv, func_ctx, level.next())?;
+                    self.temp_access_chain.pop();
+                }
+                // done
+                writeln!(self.out, "{level}}}")?;
+            }
+            _ => unreachable!(),
+        }
+        Ok(())
+    }
+
+    /// Set [`temp_access_chain`] to compute the byte offset of `cur_expr`.
+    ///
+    /// The `cur_expr` expression must be a reference to a global
+    /// variable in the [`Storage`] address space, or a chain of
+    /// [`Access`] and [`AccessIndex`] expressions referring to some
+    /// component of such a global.
+    ///
+    /// [`temp_access_chain`]: super::Writer::temp_access_chain
+    /// [`Storage`]: crate::AddressSpace::Storage
+    /// [`Access`]: crate::Expression::Access
+    /// [`AccessIndex`]: crate::Expression::AccessIndex
+    pub(super) fn fill_access_chain(
+        &mut self,
+        module: &crate::Module,
+        mut cur_expr: Handle<crate::Expression>,
+        func_ctx: &FunctionCtx,
+    ) -> Result<Handle<crate::GlobalVariable>, Error> {
+        enum AccessIndex {
+            Expression(Handle<crate::Expression>),
+            Constant(u32),
+        }
+        enum Parent<'a> {
+            Array { stride: u32 },
+            Struct(&'a [crate::StructMember]),
+        }
+        self.temp_access_chain.clear();
+
+        loop {
+            let (next_expr, access_index) = match func_ctx.expressions[cur_expr] {
+                crate::Expression::GlobalVariable(handle) => return Ok(handle),
+                crate::Expression::Access { base, index } => (base, AccessIndex::Expression(index)),
+                crate::Expression::AccessIndex { base, index } => {
+                    (base, AccessIndex::Constant(index))
+                }
+                ref other => {
+                    return Err(Error::Unimplemented(format!("Pointer access of {other:?}")))
+                }
+            };
+
+            let parent = match *func_ctx.resolve_type(next_expr, &module.types) {
+                crate::TypeInner::Pointer { base, .. } => match module.types[base].inner {
+                    crate::TypeInner::Struct { ref members, .. } => Parent::Struct(members),
+                    crate::TypeInner::Array { stride, .. } => Parent::Array { stride },
+                    crate::TypeInner::Vector { scalar, .. } => Parent::Array {
+                        stride: scalar.width as u32,
+                    },
+                    crate::TypeInner::Matrix { rows, scalar, .. } => Parent::Array {
+                        // The stride between matrices is the count of rows as this is how
+                        // long each column is.
+                        stride: Alignment::from(rows) * scalar.width as u32,
+                    },
+                    _ => unreachable!(),
+                },
+                crate::TypeInner::ValuePointer { scalar, .. } => Parent::Array {
+                    stride: scalar.width as u32,
+                },
+                _ => unreachable!(),
+            };
+
+            let sub = match (parent, access_index) {
+                (Parent::Array { stride }, AccessIndex::Expression(value)) => {
+                    SubAccess::Index { value, stride }
+                }
+                (Parent::Array { stride }, AccessIndex::Constant(index)) => {
+                    SubAccess::Offset(stride * index)
+                }
+                (Parent::Struct(members), AccessIndex::Constant(index)) => {
+                    SubAccess::Offset(members[index as usize].offset)
+                }
+                (Parent::Struct(_), AccessIndex::Expression(_)) => unreachable!(),
+            };
+
+            self.temp_access_chain.push(sub);
+            cur_expr = next_expr;
+        }
+    }
+}
diff --git a/third_party/rust/naga/src/back/hlsl/writer.rs b/third_party/rust/naga/src/back/hlsl/writer.rs
new file mode 100644
index 0000000000..43f7212837
--- /dev/null
+++ b/third_party/rust/naga/src/back/hlsl/writer.rs
@@ -0,0 +1,3366 @@
+use super::{
+    help::{WrappedArrayLength, WrappedConstructor, WrappedImageQuery, WrappedStructMatrixAccess},
+    storage::StoreValue,
+    BackendResult, Error, Options,
+};
+use crate::{
+    back,
+    proc::{self, NameKey},
+    valid, Handle, Module, ScalarKind, ShaderStage, TypeInner,
+};
+use std::{fmt, mem};
+
+const LOCATION_SEMANTIC: &str = "LOC";
+const SPECIAL_CBUF_TYPE: &str = "NagaConstants";
+const SPECIAL_CBUF_VAR: &str = "_NagaConstants";
+const SPECIAL_FIRST_VERTEX: &str = "first_vertex";
+const SPECIAL_FIRST_INSTANCE: &str = "first_instance";
+const SPECIAL_OTHER: &str = "other";
+
+pub(crate) const MODF_FUNCTION: &str = "naga_modf";
+pub(crate) const FREXP_FUNCTION: &str = "naga_frexp";
+
+struct EpStructMember {
+    name: String,
+    ty: Handle<crate::Type>,
+    // technically, this should always be `Some`
+    binding: Option<crate::Binding>,
+    index: u32,
+}
+
+/// Structure contains information required for generating
+/// wrapped structure of all entry points arguments
+struct EntryPointBinding {
+    /// Name of the fake EP argument that contains the struct
+    /// with all the flattened input data.
+    arg_name: String,
+    /// Generated structure name
+    ty_name: String,
+    /// Members of generated structure
+    members: Vec<EpStructMember>,
+}
+
+pub(super) struct EntryPointInterface {
+    /// If `Some`, the input of an entry point is gathered in a special
+    /// struct with members sorted by binding.
+    /// The `EntryPointBinding::members` array is sorted by index,
+    /// so that we can walk it in `write_ep_arguments_initialization`.
+    input: Option<EntryPointBinding>,
+    /// If `Some`, the output of an entry point is flattened.
+    /// The `EntryPointBinding::members` array is sorted by binding,
+    /// So that we can walk it in `Statement::Return` handler.
+    output: Option<EntryPointBinding>,
+}
+
+#[derive(Clone, Eq, PartialEq, PartialOrd, Ord)]
+enum InterfaceKey {
+    Location(u32),
+    BuiltIn(crate::BuiltIn),
+    Other,
+}
+
+impl InterfaceKey {
+    const fn new(binding: Option<&crate::Binding>) -> Self {
+        match binding {
+            Some(&crate::Binding::Location { location, .. }) => Self::Location(location),
+            Some(&crate::Binding::BuiltIn(built_in)) => Self::BuiltIn(built_in),
+            None => Self::Other,
+        }
+    }
+}
+
+#[derive(Copy, Clone, PartialEq)]
+enum Io {
+    Input,
+    Output,
+}
+
+impl<'a, W: fmt::Write> super::Writer<'a, W> {
+    pub fn new(out: W, options: &'a Options) -> Self {
+        Self {
+            out,
+            names: crate::FastHashMap::default(),
+            namer: proc::Namer::default(),
+            options,
+            entry_point_io: Vec::new(),
+            named_expressions: crate::NamedExpressions::default(),
+            wrapped: super::Wrapped::default(),
+            temp_access_chain: Vec::new(),
+            need_bake_expressions: Default::default(),
+        }
+    }
+
+    fn reset(&mut self, module: &Module) {
+        self.names.clear();
+        self.namer.reset(
+            module,
+            super::keywords::RESERVED,
+            super::keywords::TYPES,
+            super::keywords::RESERVED_CASE_INSENSITIVE,
+            &[],
+            &mut self.names,
+        );
+        self.entry_point_io.clear();
+        self.named_expressions.clear();
+        self.wrapped.clear();
+        self.need_bake_expressions.clear();
+    }
+
+    /// Helper method used to find which expressions of a given function require baking
+    ///
+    /// # Notes
+    /// Clears `need_bake_expressions` set before adding to it
+    fn update_expressions_to_bake(
+        &mut self,
+        module: &Module,
+        func: &crate::Function,
+        info: &valid::FunctionInfo,
+    ) {
+        use crate::Expression;
+        self.need_bake_expressions.clear();
+        for (fun_handle, expr) in func.expressions.iter() {
+            let expr_info = &info[fun_handle];
+            let min_ref_count = func.expressions[fun_handle].bake_ref_count();
+            if min_ref_count <= expr_info.ref_count {
+                self.need_bake_expressions.insert(fun_handle);
+            }
+
+            if let Expression::Math {
+                fun,
+                arg,
+                arg1,
+                arg2,
+                arg3,
+            } = *expr
+            {
+                match fun {
+                    crate::MathFunction::Asinh
+                    | crate::MathFunction::Acosh
+                    | crate::MathFunction::Atanh
+                    | crate::MathFunction::Unpack2x16float
+                    | crate::MathFunction::Unpack2x16snorm
+                    | crate::MathFunction::Unpack2x16unorm
+                    | crate::MathFunction::Unpack4x8snorm
+                    | crate::MathFunction::Unpack4x8unorm
+                    | crate::MathFunction::Pack2x16float
+                    | crate::MathFunction::Pack2x16snorm
+                    | crate::MathFunction::Pack2x16unorm
+                    | crate::MathFunction::Pack4x8snorm
+                    | crate::MathFunction::Pack4x8unorm => {
+                        self.need_bake_expressions.insert(arg);
+                    }
+                    crate::MathFunction::ExtractBits => {
+                        self.need_bake_expressions.insert(arg);
+                        self.need_bake_expressions.insert(arg1.unwrap());
+                        self.need_bake_expressions.insert(arg2.unwrap());
+                    }
+                    crate::MathFunction::InsertBits => {
+                        self.need_bake_expressions.insert(arg);
+                        self.need_bake_expressions.insert(arg1.unwrap());
+                        self.need_bake_expressions.insert(arg2.unwrap());
+                        self.need_bake_expressions.insert(arg3.unwrap());
+                    }
+                    crate::MathFunction::CountLeadingZeros => {
+                        let inner = info[fun_handle].ty.inner_with(&module.types);
+                        if let Some(crate::ScalarKind::Sint) = inner.scalar_kind() {
+                            self.need_bake_expressions.insert(arg);
+                        }
+                    }
+                    _ => {}
+                }
+            }
+
+            if let Expression::Derivative { axis, ctrl, expr } = *expr {
+                use crate::{DerivativeAxis as Axis, DerivativeControl as Ctrl};
+                if axis == Axis::Width && (ctrl == Ctrl::Coarse || ctrl == Ctrl::Fine) {
+                    self.need_bake_expressions.insert(expr);
+                }
+            }
+        }
+    }
+
+    pub fn write(
+        &mut self,
+        module: &Module,
+        module_info: &valid::ModuleInfo,
+    ) -> Result<super::ReflectionInfo, Error> {
+        self.reset(module);
+
+        // Write special constants, if needed
+        if let Some(ref bt) = self.options.special_constants_binding {
+            writeln!(self.out, "struct {SPECIAL_CBUF_TYPE} {{")?;
+            writeln!(self.out, "{}int {};", back::INDENT, SPECIAL_FIRST_VERTEX)?;
+            writeln!(self.out, "{}int {};", back::INDENT, SPECIAL_FIRST_INSTANCE)?;
+            writeln!(self.out, "{}uint {};", back::INDENT, SPECIAL_OTHER)?;
+            writeln!(self.out, "}};")?;
+            write!(
+                self.out,
+                "ConstantBuffer<{}> {}: register(b{}",
+                SPECIAL_CBUF_TYPE, SPECIAL_CBUF_VAR, bt.register
+            )?;
+            if bt.space != 0 {
+                write!(self.out, ", space{}", bt.space)?;
+            }
+            writeln!(self.out, ");")?;
+
+            // Extra newline for readability
+            writeln!(self.out)?;
+        }
+
+        // Save all entry point output types
+        let ep_results = module
+            .entry_points
+            .iter()
+            .map(|ep| (ep.stage, ep.function.result.clone()))
+            .collect::<Vec<(ShaderStage, Option<crate::FunctionResult>)>>();
+
+        self.write_all_mat_cx2_typedefs_and_functions(module)?;
+
+        // Write all structs
+        for (handle, ty) in module.types.iter() {
+            if let TypeInner::Struct { ref members, span } = ty.inner {
+                if module.types[members.last().unwrap().ty]
+                    .inner
+                    .is_dynamically_sized(&module.types)
+                {
+                    // unsized arrays can only be in storage buffers,
+                    // for which we use `ByteAddressBuffer` anyway.
+                    continue;
+                }
+
+                let ep_result = ep_results.iter().find(|e| {
+                    if let Some(ref result) = e.1 {
+                        result.ty == handle
+                    } else {
+                        false
+                    }
+                });
+
+                self.write_struct(
+                    module,
+                    handle,
+                    members,
+                    span,
+                    ep_result.map(|r| (r.0, Io::Output)),
+                )?;
+                writeln!(self.out)?;
+            }
+        }
+
+        self.write_special_functions(module)?;
+
+        self.write_wrapped_compose_functions(module, &module.const_expressions)?;
+
+        // Write all named constants
+        let mut constants = module
+            .constants
+            .iter()
+            .filter(|&(_, c)| c.name.is_some())
+            .peekable();
+        while let Some((handle, _)) = constants.next() {
+            self.write_global_constant(module, handle)?;
+            // Add extra newline for readability on last iteration
+            if constants.peek().is_none() {
+                writeln!(self.out)?;
+            }
+        }
+
+        // Write all globals
+        for (ty, _) in module.global_variables.iter() {
+            self.write_global(module, ty)?;
+        }
+
+        if !module.global_variables.is_empty() {
+            // Add extra newline for readability
+            writeln!(self.out)?;
+        }
+
+        // Write all entry points wrapped structs
+        for (index, ep) in module.entry_points.iter().enumerate() {
+            let ep_name = self.names[&NameKey::EntryPoint(index as u16)].clone();
+            let ep_io = self.write_ep_interface(module, &ep.function, ep.stage, &ep_name)?;
+            self.entry_point_io.push(ep_io);
+        }
+
+        // Write all regular functions
+        for (handle, function) in module.functions.iter() {
+            let info = &module_info[handle];
+
+            // Check if all of the globals are accessible
+            if !self.options.fake_missing_bindings {
+                if let Some((var_handle, _)) =
+                    module
+                        .global_variables
+                        .iter()
+                        .find(|&(var_handle, var)| match var.binding {
+                            Some(ref binding) if !info[var_handle].is_empty() => {
+                                self.options.resolve_resource_binding(binding).is_err()
+                            }
+                            _ => false,
+                        })
+                {
+                    log::info!(
+                        "Skipping function {:?} (name {:?}) because global {:?} is inaccessible",
+                        handle,
+                        function.name,
+                        var_handle
+                    );
+                    continue;
+                }
+            }
+
+            let ctx = back::FunctionCtx {
+                ty: back::FunctionType::Function(handle),
+                info,
+                expressions: &function.expressions,
+                named_expressions: &function.named_expressions,
+            };
+            let name = self.names[&NameKey::Function(handle)].clone();
+
+            self.write_wrapped_functions(module, &ctx)?;
+
+            self.write_function(module, name.as_str(), function, &ctx, info)?;
+
+            writeln!(self.out)?;
+        }
+
+        let mut entry_point_names = Vec::with_capacity(module.entry_points.len());
+
+        // Write all entry points
+        for (index, ep) in module.entry_points.iter().enumerate() {
+            let info = module_info.get_entry_point(index);
+
+            if !self.options.fake_missing_bindings {
+                let mut ep_error = None;
+                for (var_handle, var) in module.global_variables.iter() {
+                    match var.binding {
+                        Some(ref binding) if !info[var_handle].is_empty() => {
+                            if let Err(err) = self.options.resolve_resource_binding(binding) {
+                                ep_error = Some(err);
+                                break;
+                            }
+                        }
+                        _ => {}
+                    }
+                }
+                if let Some(err) = ep_error {
+                    entry_point_names.push(Err(err));
+                    continue;
+                }
+            }
+
+            let ctx = back::FunctionCtx {
+                ty: back::FunctionType::EntryPoint(index as u16),
+                info,
+                expressions: &ep.function.expressions,
+                named_expressions: &ep.function.named_expressions,
+            };
+
+            self.write_wrapped_functions(module, &ctx)?;
+
+            if ep.stage == ShaderStage::Compute {
+                // HLSL is calling workgroup size "num threads"
+                let num_threads = ep.workgroup_size;
+                writeln!(
+                    self.out,
+                    "[numthreads({}, {}, {})]",
+                    num_threads[0], num_threads[1], num_threads[2]
+                )?;
+            }
+
+            let name = self.names[&NameKey::EntryPoint(index as u16)].clone();
+            self.write_function(module, &name, &ep.function, &ctx, info)?;
+
+            if index < module.entry_points.len() - 1 {
+                writeln!(self.out)?;
+            }
+
+            entry_point_names.push(Ok(name));
+        }
+
+        Ok(super::ReflectionInfo { entry_point_names })
+    }
+
+    fn write_modifier(&mut self, binding: &crate::Binding) -> BackendResult {
+        match *binding {
+            crate::Binding::BuiltIn(crate::BuiltIn::Position { invariant: true }) => {
+                write!(self.out, "precise ")?;
+            }
+            crate::Binding::Location {
+                interpolation,
+                sampling,
+                ..
+            } => {
+                if let Some(interpolation) = interpolation {
+                    if let Some(string) = interpolation.to_hlsl_str() {
+                        write!(self.out, "{string} ")?
+                    }
+                }
+
+                if let Some(sampling) = sampling {
+                    if let Some(string) = sampling.to_hlsl_str() {
+                        write!(self.out, "{string} ")?
+                    }
+                }
+            }
+            crate::Binding::BuiltIn(_) => {}
+        }
+
+        Ok(())
+    }
+
+    //TODO: we could force fragment outputs to always go through `entry_point_io.output` path
+    // if they are struct, so that the `stage` argument here could be omitted.
+    fn write_semantic(
+        &mut self,
+        binding: &crate::Binding,
+        stage: Option<(ShaderStage, Io)>,
+    ) -> BackendResult {
+        match *binding {
+            crate::Binding::BuiltIn(builtin) => {
+                let builtin_str = builtin.to_hlsl_str()?;
+                write!(self.out, " : {builtin_str}")?;
+            }
+            crate::Binding::Location {
+                second_blend_source: true,
+                ..
+            } => {
+                write!(self.out, " : SV_Target1")?;
+            }
+            crate::Binding::Location {
+                location,
+                second_blend_source: false,
+                ..
+            } => {
+                if stage == Some((crate::ShaderStage::Fragment, Io::Output)) {
+                    write!(self.out, " : SV_Target{location}")?;
+                } else {
+                    write!(self.out, " : {LOCATION_SEMANTIC}{location}")?;
+                }
+            }
+        }
+
+        Ok(())
+    }
+
+    fn write_interface_struct(
+        &mut self,
+        module: &Module,
+        shader_stage: (ShaderStage, Io),
+        struct_name: String,
+        mut members: Vec<EpStructMember>,
+    ) -> Result<EntryPointBinding, Error> {
+        // Sort the members so that first come the user-defined varyings
+        // in ascending locations, and then built-ins. This allows VS and FS
+        // interfaces to match with regards to order.
+        members.sort_by_key(|m| InterfaceKey::new(m.binding.as_ref()));
+
+        write!(self.out, "struct {struct_name}")?;
+        writeln!(self.out, " {{")?;
+        for m in members.iter() {
+            write!(self.out, "{}", back::INDENT)?;
+            if let Some(ref binding) = m.binding {
+                self.write_modifier(binding)?;
+            }
+            self.write_type(module, m.ty)?;
+            write!(self.out, " {}", &m.name)?;
+            if let Some(ref binding) = m.binding {
+                self.write_semantic(binding, Some(shader_stage))?;
+            }
+            writeln!(self.out, ";")?;
+        }
+        writeln!(self.out, "}};")?;
+        writeln!(self.out)?;
+
+        match shader_stage.1 {
+            Io::Input => {
+                // bring back the original order
+                members.sort_by_key(|m| m.index);
+            }
+            Io::Output => {
+                // keep it sorted by binding
+            }
+        }
+
+        Ok(EntryPointBinding {
+            arg_name: self.namer.call(struct_name.to_lowercase().as_str()),
+            ty_name: struct_name,
+            members,
+        })
+    }
+
+    /// Flatten all entry point arguments into a single struct.
+    /// This is needed since we need to re-order them: first placing user locations,
+    /// then built-ins.
+    fn write_ep_input_struct(
+        &mut self,
+        module: &Module,
+        func: &crate::Function,
+        stage: ShaderStage,
+        entry_point_name: &str,
+    ) -> Result<EntryPointBinding, Error> {
+        let struct_name = format!("{stage:?}Input_{entry_point_name}");
+
+        let mut fake_members = Vec::new();
+        for arg in func.arguments.iter() {
+            match module.types[arg.ty].inner {
+                TypeInner::Struct { ref members, .. } => {
+                    for member in members.iter() {
+                        let name = self.namer.call_or(&member.name, "member");
+                        let index = fake_members.len() as u32;
+                        fake_members.push(EpStructMember {
+                            name,
+                            ty: member.ty,
+                            binding: member.binding.clone(),
+                            index,
+                        });
+                    }
+                }
+                _ => {
+                    let member_name = self.namer.call_or(&arg.name, "member");
+                    let index = fake_members.len() as u32;
+                    fake_members.push(EpStructMember {
+                        name: member_name,
+                        ty: arg.ty,
+                        binding: arg.binding.clone(),
+                        index,
+                    });
+                }
+            }
+        }
+
+        self.write_interface_struct(module, (stage, Io::Input), struct_name, fake_members)
+    }
+
+    /// Flatten all entry point results into a single struct.
+    /// This is needed since we need to re-order them: first placing user locations,
+    /// then built-ins.
+    fn write_ep_output_struct(
+        &mut self,
+        module: &Module,
+        result: &crate::FunctionResult,
+        stage: ShaderStage,
+        entry_point_name: &str,
+    ) -> Result<EntryPointBinding, Error> {
+        let struct_name = format!("{stage:?}Output_{entry_point_name}");
+
+        let mut fake_members = Vec::new();
+        let empty = [];
+        let members = match module.types[result.ty].inner {
+            TypeInner::Struct { ref members, .. } => members,
+            ref other => {
+                log::error!("Unexpected {:?} output type without a binding", other);
+                &empty[..]
+            }
+        };
+
+        for member in members.iter() {
+            let member_name = self.namer.call_or(&member.name, "member");
+            let index = fake_members.len() as u32;
+            fake_members.push(EpStructMember {
+                name: member_name,
+                ty: member.ty,
+                binding: member.binding.clone(),
+                index,
+            });
+        }
+
+        self.write_interface_struct(module, (stage, Io::Output), struct_name, fake_members)
+    }
+
+    /// Writes special interface structures for an entry point. The special structures have
+    /// all the fields flattened into them and sorted by binding. They are only needed for
+    /// VS outputs and FS inputs, so that these interfaces match.
+    fn write_ep_interface(
+        &mut self,
+        module: &Module,
+        func: &crate::Function,
+        stage: ShaderStage,
+        ep_name: &str,
+    ) -> Result<EntryPointInterface, Error> {
+        Ok(EntryPointInterface {
+            input: if !func.arguments.is_empty() && stage == ShaderStage::Fragment {
+                Some(self.write_ep_input_struct(module, func, stage, ep_name)?)
+            } else {
+                None
+            },
+            output: match func.result {
+                Some(ref fr) if fr.binding.is_none() && stage == ShaderStage::Vertex => {
+                    Some(self.write_ep_output_struct(module, fr, stage, ep_name)?)
+                }
+                _ => None,
+            },
+        })
+    }
+
+    /// Write an entry point preface that initializes the arguments as specified in IR.
+    fn write_ep_arguments_initialization(
+        &mut self,
+        module: &Module,
+        func: &crate::Function,
+        ep_index: u16,
+    ) -> BackendResult {
+        let ep_input = match self.entry_point_io[ep_index as usize].input.take() {
+            Some(ep_input) => ep_input,
+            None => return Ok(()),
+        };
+        let mut fake_iter = ep_input.members.iter();
+        for (arg_index, arg) in func.arguments.iter().enumerate() {
+            write!(self.out, "{}", back::INDENT)?;
+            self.write_type(module, arg.ty)?;
+            let arg_name = &self.names[&NameKey::EntryPointArgument(ep_index, arg_index as u32)];
+            write!(self.out, " {arg_name}")?;
+            match module.types[arg.ty].inner {
+                TypeInner::Array { base, size, .. } => {
+                    self.write_array_size(module, base, size)?;
+                    let fake_member = fake_iter.next().unwrap();
+                    writeln!(self.out, " = {}.{};", ep_input.arg_name, fake_member.name)?;
+                }
+                TypeInner::Struct { ref members, .. } => {
+                    write!(self.out, " = {{ ")?;
+                    for index in 0..members.len() {
+                        if index != 0 {
+                            write!(self.out, ", ")?;
+                        }
+                        let fake_member = fake_iter.next().unwrap();
+                        write!(self.out, "{}.{}", ep_input.arg_name, fake_member.name)?;
+                    }
+                    writeln!(self.out, " }};")?;
+                }
+                _ => {
+                    let fake_member = fake_iter.next().unwrap();
+                    writeln!(self.out, " = {}.{};", ep_input.arg_name, fake_member.name)?;
+                }
+            }
+        }
+        assert!(fake_iter.next().is_none());
+        Ok(())
+    }
+
+    /// Helper method used to write global variables
+    /// # Notes
+    /// Always adds a newline
+    fn write_global(
+        &mut self,
+        module: &Module,
+        handle: Handle<crate::GlobalVariable>,
+    ) -> BackendResult {
+        let global = &module.global_variables[handle];
+        let inner = &module.types[global.ty].inner;
+
+        if let Some(ref binding) = global.binding {
+            if let Err(err) = self.options.resolve_resource_binding(binding) {
+                log::info!(
+                    "Skipping global {:?} (name {:?}) for being inaccessible: {}",
+                    handle,
+                    global.name,
+                    err,
+                );
+                return Ok(());
+            }
+        }
+
+        // https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-variable-register
+        let register_ty = match global.space {
+            crate::AddressSpace::Function => unreachable!("Function address space"),
+            crate::AddressSpace::Private => {
+                write!(self.out, "static ")?;
+                self.write_type(module, global.ty)?;
+                ""
+            }
+            crate::AddressSpace::WorkGroup => {
+                write!(self.out, "groupshared ")?;
+                self.write_type(module, global.ty)?;
+                ""
+            }
+            crate::AddressSpace::Uniform => {
+                // constant buffer declarations are expected to be inlined, e.g.
+                // `cbuffer foo: register(b0) { field1: type1; }`
+                write!(self.out, "cbuffer")?;
+                "b"
+            }
+            crate::AddressSpace::Storage { access } => {
+                let (prefix, register) = if access.contains(crate::StorageAccess::STORE) {
+                    ("RW", "u")
+                } else {
+                    ("", "t")
+                };
+                write!(self.out, "{prefix}ByteAddressBuffer")?;
+                register
+            }
+            crate::AddressSpace::Handle => {
+                let handle_ty = match *inner {
+                    TypeInner::BindingArray { ref base, .. } => &module.types[*base].inner,
+                    _ => inner,
+                };
+
+                let register = match *handle_ty {
+                    TypeInner::Sampler { .. } => "s",
+                    // all storage textures are UAV, unconditionally
+                    TypeInner::Image {
+                        class: crate::ImageClass::Storage { .. },
+                        ..
+                    } => "u",
+                    _ => "t",
+                };
+                self.write_type(module, global.ty)?;
+                register
+            }
+            crate::AddressSpace::PushConstant => {
+                // The type of the push constants will be wrapped in `ConstantBuffer`
+                write!(self.out, "ConstantBuffer<")?;
+                "b"
+            }
+        };
+
+        // If the global is a push constant write the type now because it will be a
+        // generic argument to `ConstantBuffer`
+        if global.space == crate::AddressSpace::PushConstant {
+            self.write_global_type(module, global.ty)?;
+
+            // need to write the array size if the type was emitted with `write_type`
+            if let TypeInner::Array { base, size, .. } = module.types[global.ty].inner {
+                self.write_array_size(module, base, size)?;
+            }
+
+            // Close the angled brackets for the generic argument
+            write!(self.out, ">")?;
+        }
+
+        let name = &self.names[&NameKey::GlobalVariable(handle)];
+        write!(self.out, " {name}")?;
+
+        // Push constants need to be assigned a binding explicitly by the consumer
+        // since naga has no way to know the binding from the shader alone
+        if global.space == crate::AddressSpace::PushConstant {
+            let target = self
+                .options
+                .push_constants_target
+                .as_ref()
+                .expect("No bind target was defined for the push constants block");
+            write!(self.out, ": register(b{}", target.register)?;
+            if target.space != 0 {
+                write!(self.out, ", space{}", target.space)?;
+            }
+            write!(self.out, ")")?;
+        }
+
+        if let Some(ref binding) = global.binding {
+            // this was already resolved earlier when we started evaluating an entry point.
+            let bt = self.options.resolve_resource_binding(binding).unwrap();
+
+            // need to write the binding array size if the type was emitted with `write_type`
+            if let TypeInner::BindingArray { base, size, .. } = module.types[global.ty].inner {
+                if let Some(overridden_size) = bt.binding_array_size {
+                    write!(self.out, "[{overridden_size}]")?;
+                } else {
+                    self.write_array_size(module, base, size)?;
+                }
+            }
+
+            write!(self.out, " : register({}{}", register_ty, bt.register)?;
+            if bt.space != 0 {
+                write!(self.out, ", space{}", bt.space)?;
+            }
+            write!(self.out, ")")?;
+        } else {
+            // need to write the array size if the type was emitted with `write_type`
+            if let TypeInner::Array { base, size, .. } = module.types[global.ty].inner {
+                self.write_array_size(module, base, size)?;
+            }
+            if global.space == crate::AddressSpace::Private {
+                write!(self.out, " = ")?;
+                if let Some(init) = global.init {
+                    self.write_const_expression(module, init)?;
+                } else {
+                    self.write_default_init(module, global.ty)?;
+                }
+            }
+        }
+
+        if global.space == crate::AddressSpace::Uniform {
+            write!(self.out, " {{ ")?;
+
+            self.write_global_type(module, global.ty)?;
+
+            write!(
+                self.out,
+                " {}",
+                &self.names[&NameKey::GlobalVariable(handle)]
+            )?;
+
+            // need to write the array size if the type was emitted with `write_type`
+            if let TypeInner::Array { base, size, .. } = module.types[global.ty].inner {
+                self.write_array_size(module, base, size)?;
+            }
+
+            writeln!(self.out, "; }}")?;
+        } else {
+            writeln!(self.out, ";")?;
+        }
+
+        Ok(())
+    }
+
+    /// Helper method used to write global constants
+    ///
+    /// # Notes
+    /// Ends in a newline
+    fn write_global_constant(
+        &mut self,
+        module: &Module,
+        handle: Handle<crate::Constant>,
+    ) -> BackendResult {
+        write!(self.out, "static const ")?;
+        let constant = &module.constants[handle];
+        self.write_type(module, constant.ty)?;
+        let name = &self.names[&NameKey::Constant(handle)];
+        write!(self.out, " {}", name)?;
+        // Write size for array type
+        if let TypeInner::Array { base, size, .. } = module.types[constant.ty].inner {
+            self.write_array_size(module, base, size)?;
+        }
+        write!(self.out, " = ")?;
+        self.write_const_expression(module, constant.init)?;
+        writeln!(self.out, ";")?;
+        Ok(())
+    }
+
+    pub(super) fn write_array_size(
+        &mut self,
+        module: &Module,
+        base: Handle<crate::Type>,
+        size: crate::ArraySize,
+    ) -> BackendResult {
+        write!(self.out, "[")?;
+
+        match size {
+            crate::ArraySize::Constant(size) => {
+                write!(self.out, "{size}")?;
+            }
+            crate::ArraySize::Dynamic => unreachable!(),
+        }
+
+        write!(self.out, "]")?;
+
+        if let TypeInner::Array {
+            base: next_base,
+            size: next_size,
+            ..
+        } = module.types[base].inner
+        {
+            self.write_array_size(module, next_base, next_size)?;
+        }
+
+        Ok(())
+    }
+
+    /// Helper method used to write structs
+    ///
+    /// # Notes
+    /// Ends in a newline
+    fn write_struct(
+        &mut self,
+        module: &Module,
+        handle: Handle<crate::Type>,
+        members: &[crate::StructMember],
+        span: u32,
+        shader_stage: Option<(ShaderStage, Io)>,
+    ) -> BackendResult {
+        // Write struct name
+        let struct_name = &self.names[&NameKey::Type(handle)];
+        writeln!(self.out, "struct {struct_name} {{")?;
+
+        let mut last_offset = 0;
+        for (index, member) in members.iter().enumerate() {
+            if member.binding.is_none() && member.offset > last_offset {
+                // using int as padding should work as long as the backend
+                // doesn't support a type that's less than 4 bytes in size
+                // (Error::UnsupportedScalar catches this)
+                let padding = (member.offset - last_offset) / 4;
+                for i in 0..padding {
+                    writeln!(self.out, "{}int _pad{}_{};", back::INDENT, index, i)?;
+                }
+            }
+            let ty_inner = &module.types[member.ty].inner;
+            last_offset = member.offset + ty_inner.size_hlsl(module.to_ctx());
+
+            // The indentation is only for readability
+            write!(self.out, "{}", back::INDENT)?;
+
+            match module.types[member.ty].inner {
+                TypeInner::Array { base, size, .. } => {
+                    // HLSL arrays are written as `type name[size]`
+
+                    self.write_global_type(module, member.ty)?;
+
+                    // Write `name`
+                    write!(
+                        self.out,
+                        " {}",
+                        &self.names[&NameKey::StructMember(handle, index as u32)]
+                    )?;
+                    // Write [size]
+                    self.write_array_size(module, base, size)?;
+                }
+                // We treat matrices of the form `matCx2` as a sequence of C `vec2`s.
+                // See the module-level block comment in mod.rs for details.
+                TypeInner::Matrix {
+                    rows,
+                    columns,
+                    scalar,
+                } if member.binding.is_none() && rows == crate::VectorSize::Bi => {
+                    let vec_ty = crate::TypeInner::Vector { size: rows, scalar };
+                    let field_name_key = NameKey::StructMember(handle, index as u32);
+
+                    for i in 0..columns as u8 {
+                        if i != 0 {
+                            write!(self.out, "; ")?;
+                        }
+                        self.write_value_type(module, &vec_ty)?;
+                        write!(self.out, " {}_{}", &self.names[&field_name_key], i)?;
+                    }
+                }
+                _ => {
+                    // Write modifier before type
+                    if let Some(ref binding) = member.binding {
+                        self.write_modifier(binding)?;
+                    }
+
+                    // Even though Naga IR matrices are column-major, we must describe
+                    // matrices passed from the CPU as being in row-major order.
+                    // See the module-level block comment in mod.rs for details.
+                    if let TypeInner::Matrix { .. } = module.types[member.ty].inner {
+                        write!(self.out, "row_major ")?;
+                    }
+
+                    // Write the member type and name
+                    self.write_type(module, member.ty)?;
+                    write!(
+                        self.out,
+                        " {}",
+                        &self.names[&NameKey::StructMember(handle, index as u32)]
+                    )?;
+                }
+            }
+
+            if let Some(ref binding) = member.binding {
+                self.write_semantic(binding, shader_stage)?;
+            };
+            writeln!(self.out, ";")?;
+        }
+
+        // add padding at the end since sizes of types don't get rounded up to their alignment in HLSL
+        if members.last().unwrap().binding.is_none() && span > last_offset {
+            let padding = (span - last_offset) / 4;
+            for i in 0..padding {
+                writeln!(self.out, "{}int _end_pad_{};", back::INDENT, i)?;
+            }
+        }
+
+        writeln!(self.out, "}};")?;
+        Ok(())
+    }
+
+    /// Helper method used to write global/structs non image/sampler types
+    ///
+    /// # Notes
+    /// Adds no trailing or leading whitespace
+    pub(super) fn write_global_type(
+        &mut self,
+        module: &Module,
+        ty: Handle<crate::Type>,
+    ) -> BackendResult {
+        let matrix_data = get_inner_matrix_data(module, ty);
+
+        // We treat matrices of the form `matCx2` as a sequence of C `vec2`s.
+        // See the module-level block comment in mod.rs for details.
+        if let Some(MatrixType {
+            columns,
+            rows: crate::VectorSize::Bi,
+            width: 4,
+        }) = matrix_data
+        {
+            write!(self.out, "__mat{}x2", columns as u8)?;
+        } else {
+            // Even though Naga IR matrices are column-major, we must describe
+            // matrices passed from the CPU as being in row-major order.
+            // See the module-level block comment in mod.rs for details.
+            if matrix_data.is_some() {
+                write!(self.out, "row_major ")?;
+            }
+
+            self.write_type(module, ty)?;
+        }
+
+        Ok(())
+    }
+
+    /// Helper method used to write non image/sampler types
+    ///
+    /// # Notes
+    /// Adds no trailing or leading whitespace
+    pub(super) fn write_type(&mut self, module: &Module, ty: Handle<crate::Type>) -> BackendResult {
+        let inner = &module.types[ty].inner;
+        match *inner {
+            TypeInner::Struct { .. } => write!(self.out, "{}", self.names[&NameKey::Type(ty)])?,
+            // hlsl array has the size separated from the base type
+            TypeInner::Array { base, .. } | TypeInner::BindingArray { base, .. } => {
+                self.write_type(module, base)?
+            }
+            ref other => self.write_value_type(module, other)?,
+        }
+
+        Ok(())
+    }
+
+    /// Helper method used to write value types
+    ///
+    /// # Notes
+    /// Adds no trailing or leading whitespace
+    pub(super) fn write_value_type(&mut self, module: &Module, inner: &TypeInner) -> BackendResult {
+        match *inner {
+            TypeInner::Scalar(scalar) | TypeInner::Atomic(scalar) => {
+                write!(self.out, "{}", scalar.to_hlsl_str()?)?;
+            }
+            TypeInner::Vector { size, scalar } => {
+                write!(
+                    self.out,
+                    "{}{}",
+                    scalar.to_hlsl_str()?,
+                    back::vector_size_str(size)
+                )?;
+            }
+            TypeInner::Matrix {
+                columns,
+                rows,
+                scalar,
+            } => {
+                // The IR supports only float matrix
+                // https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-matrix
+
+                // Because of the implicit transpose all matrices have in HLSL, we need to transpose the size as well.
+                write!(
+                    self.out,
+                    "{}{}x{}",
+                    scalar.to_hlsl_str()?,
+                    back::vector_size_str(columns),
+                    back::vector_size_str(rows),
+                )?;
+            }
+            TypeInner::Image {
+                dim,
+                arrayed,
+                class,
+            } => {
+                self.write_image_type(dim, arrayed, class)?;
+            }
+            TypeInner::Sampler { comparison } => {
+                let sampler = if comparison {
+                    "SamplerComparisonState"
+                } else {
+                    "SamplerState"
+                };
+                write!(self.out, "{sampler}")?;
+            }
+            // HLSL arrays are written as `type name[size]`
+            // Current code is written arrays only as `[size]`
+            // Base `type` and `name` should be written outside
+            TypeInner::Array { base, size, .. } | TypeInner::BindingArray { base, size } => {
+                self.write_array_size(module, base, size)?;
+            }
+            _ => return Err(Error::Unimplemented(format!("write_value_type {inner:?}"))),
+        }
+
+        Ok(())
+    }
+
+    /// Helper method used to write functions
+    /// # Notes
+    /// Ends in a newline
+    fn write_function(
+        &mut self,
+        module: &Module,
+        name: &str,
+        func: &crate::Function,
+        func_ctx: &back::FunctionCtx<'_>,
+        info: &valid::FunctionInfo,
+    ) -> BackendResult {
+        // Function Declaration Syntax - https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-function-syntax
+
+        self.update_expressions_to_bake(module, func, info);
+
+        // Write modifier
+        if let Some(crate::FunctionResult {
+            binding:
+                Some(
+                    ref binding @ crate::Binding::BuiltIn(crate::BuiltIn::Position {
+                        invariant: true,
+                    }),
+                ),
+            ..
+        }) = func.result
+        {
+            self.write_modifier(binding)?;
+        }
+
+        // Write return type
+        if let Some(ref result) = func.result {
+            match func_ctx.ty {
+                back::FunctionType::Function(_) => {
+                    self.write_type(module, result.ty)?;
+                }
+                back::FunctionType::EntryPoint(index) => {
+                    if let Some(ref ep_output) = self.entry_point_io[index as usize].output {
+                        write!(self.out, "{}", ep_output.ty_name)?;
+                    } else {
+                        self.write_type(module, result.ty)?;
+                    }
+                }
+            }
+        } else {
+            write!(self.out, "void")?;
+        }
+
+        // Write function name
+        write!(self.out, " {name}(")?;
+
+        let need_workgroup_variables_initialization =
+            self.need_workgroup_variables_initialization(func_ctx, module);
+
+        // Write function arguments for non entry point functions
+        match func_ctx.ty {
+            back::FunctionType::Function(handle) => {
+                for (index, arg) in func.arguments.iter().enumerate() {
+                    if index != 0 {
+                        write!(self.out, ", ")?;
+                    }
+                    // Write argument type
+                    let arg_ty = match module.types[arg.ty].inner {
+                        // pointers in function arguments are expected and resolve to `inout`
+                        TypeInner::Pointer { base, .. } => {
+                            //TODO: can we narrow this down to just `in` when possible?
+                            write!(self.out, "inout ")?;
+                            base
+                        }
+                        _ => arg.ty,
+                    };
+                    self.write_type(module, arg_ty)?;
+
+                    let argument_name =
+                        &self.names[&NameKey::FunctionArgument(handle, index as u32)];
+
+                    // Write argument name. Space is important.
+                    write!(self.out, " {argument_name}")?;
+                    if let TypeInner::Array { base, size, .. } = module.types[arg_ty].inner {
+                        self.write_array_size(module, base, size)?;
+                    }
+                }
+            }
+            back::FunctionType::EntryPoint(ep_index) => {
+                if let Some(ref ep_input) = self.entry_point_io[ep_index as usize].input {
+                    write!(self.out, "{} {}", ep_input.ty_name, ep_input.arg_name,)?;
+                } else {
+                    let stage = module.entry_points[ep_index as usize].stage;
+                    for (index, arg) in func.arguments.iter().enumerate() {
+                        if index != 0 {
+                            write!(self.out, ", ")?;
+                        }
+                        self.write_type(module, arg.ty)?;
+
+                        let argument_name =
+                            &self.names[&NameKey::EntryPointArgument(ep_index, index as u32)];
+
+                        write!(self.out, " {argument_name}")?;
+                        if let TypeInner::Array { base, size, .. } = module.types[arg.ty].inner {
+                            self.write_array_size(module, base, size)?;
+                        }
+
+                        if let Some(ref binding) = arg.binding {
+                            self.write_semantic(binding, Some((stage, Io::Input)))?;
+                        }
+                    }
+
+                    if need_workgroup_variables_initialization {
+                        if !func.arguments.is_empty() {
+                            write!(self.out, ", ")?;
+                        }
+                        write!(self.out, "uint3 __local_invocation_id : SV_GroupThreadID")?;
+                    }
+                }
+            }
+        }
+        // Ends of arguments
+        write!(self.out, ")")?;
+
+        // Write semantic if it present
+        if let back::FunctionType::EntryPoint(index) = func_ctx.ty {
+            let stage = module.entry_points[index as usize].stage;
+            if let Some(crate::FunctionResult {
+                binding: Some(ref binding),
+                ..
+            }) = func.result
+            {
+                self.write_semantic(binding, Some((stage, Io::Output)))?;
+            }
+        }
+
+        // Function body start
+        writeln!(self.out)?;
+        writeln!(self.out, "{{")?;
+
+        if need_workgroup_variables_initialization {
+            self.write_workgroup_variables_initialization(func_ctx, module)?;
+        }
+
+        if let back::FunctionType::EntryPoint(index) = func_ctx.ty {
+            self.write_ep_arguments_initialization(module, func, index)?;
+        }
+
+        // Write function local variables
+        for (handle, local) in func.local_variables.iter() {
+            // Write indentation (only for readability)
+            write!(self.out, "{}", back::INDENT)?;
+
+            // Write the local name
+            // The leading space is important
+            self.write_type(module, local.ty)?;
+            write!(self.out, " {}", self.names[&func_ctx.name_key(handle)])?;
+            // Write size for array type
+            if let TypeInner::Array { base, size, .. } = module.types[local.ty].inner {
+                self.write_array_size(module, base, size)?;
+            }
+
+            write!(self.out, " = ")?;
+            // Write the local initializer if needed
+            if let Some(init) = local.init {
+                self.write_expr(module, init, func_ctx)?;
+            } else {
+                // Zero initialize local variables
+                self.write_default_init(module, local.ty)?;
+            }
+
+            // Finish the local with `;` and add a newline (only for readability)
+            writeln!(self.out, ";")?
+        }
+
+        if !func.local_variables.is_empty() {
+            writeln!(self.out)?;
+        }
+
+        // Write the function body (statement list)
+        for sta in func.body.iter() {
+            // The indentation should always be 1 when writing the function body
+            self.write_stmt(module, sta, func_ctx, back::Level(1))?;
+        }
+
+        writeln!(self.out, "}}")?;
+
+        self.named_expressions.clear();
+
+        Ok(())
+    }
+
+    fn need_workgroup_variables_initialization(
+        &mut self,
+        func_ctx: &back::FunctionCtx,
+        module: &Module,
+    ) -> bool {
+        self.options.zero_initialize_workgroup_memory
+            && func_ctx.ty.is_compute_entry_point(module)
+            && module.global_variables.iter().any(|(handle, var)| {
+                !func_ctx.info[handle].is_empty() && var.space == crate::AddressSpace::WorkGroup
+            })
+    }
+
+    fn write_workgroup_variables_initialization(
+        &mut self,
+        func_ctx: &back::FunctionCtx,
+        module: &Module,
+    ) -> BackendResult {
+        let level = back::Level(1);
+
+        writeln!(
+            self.out,
+            "{level}if (all(__local_invocation_id == uint3(0u, 0u, 0u))) {{"
+        )?;
+
+        let vars = module.global_variables.iter().filter(|&(handle, var)| {
+            !func_ctx.info[handle].is_empty() && var.space == crate::AddressSpace::WorkGroup
+        });
+
+        for (handle, var) in vars {
+            let name = &self.names[&NameKey::GlobalVariable(handle)];
+            write!(self.out, "{}{} = ", level.next(), name)?;
+            self.write_default_init(module, var.ty)?;
+            writeln!(self.out, ";")?;
+        }
+
+        writeln!(self.out, "{level}}}")?;
+        self.write_barrier(crate::Barrier::WORK_GROUP, level)
+    }
+
+    /// Helper method used to write statements
+    ///
+    /// # Notes
+    /// Always adds a newline
+    fn write_stmt(
+        &mut self,
+        module: &Module,
+        stmt: &crate::Statement,
+        func_ctx: &back::FunctionCtx<'_>,
+        level: back::Level,
+    ) -> BackendResult {
+        use crate::Statement;
+
+        match *stmt {
+            Statement::Emit(ref range) => {
+                for handle in range.clone() {
+                    let ptr_class = func_ctx.resolve_type(handle, &module.types).pointer_space();
+                    let expr_name = if ptr_class.is_some() {
+                        // HLSL can't save a pointer-valued expression in a variable,
+                        // but we shouldn't ever need to: they should never be named expressions,
+                        // and none of the expression types flagged by bake_ref_count can be pointer-valued.
+                        None
+                    } else if let Some(name) = func_ctx.named_expressions.get(&handle) {
+                        // Front end provides names for all variables at the start of writing.
+                        // But we write them to step by step. We need to recache them
+                        // Otherwise, we could accidentally write variable name instead of full expression.
+                        // Also, we use sanitized names! It defense backend from generating variable with name from reserved keywords.
+                        Some(self.namer.call(name))
+                    } else if self.need_bake_expressions.contains(&handle) {
+                        Some(format!("_expr{}", handle.index()))
+                    } else {
+                        None
+                    };
+
+                    if let Some(name) = expr_name {
+                        write!(self.out, "{level}")?;
+                        self.write_named_expr(module, handle, name, handle, func_ctx)?;
+                    }
+                }
+            }
+            // TODO: copy-paste from glsl-out
+            Statement::Block(ref block) => {
+                write!(self.out, "{level}")?;
+                writeln!(self.out, "{{")?;
+                for sta in block.iter() {
+                    // Increase the indentation to help with readability
+                    self.write_stmt(module, sta, func_ctx, level.next())?
+                }
+                writeln!(self.out, "{level}}}")?
+            }
+            // TODO: copy-paste from glsl-out
+            Statement::If {
+                condition,
+                ref accept,
+                ref reject,
+            } => {
+                write!(self.out, "{level}")?;
+                write!(self.out, "if (")?;
+                self.write_expr(module, condition, func_ctx)?;
+                writeln!(self.out, ") {{")?;
+
+                let l2 = level.next();
+                for sta in accept {
+                    // Increase indentation to help with readability
+                    self.write_stmt(module, sta, func_ctx, l2)?;
+                }
+
+                // If there are no statements in the reject block we skip writing it
+                // This is only for readability
+                if !reject.is_empty() {
+                    writeln!(self.out, "{level}}} else {{")?;
+
+                    for sta in reject {
+                        // Increase indentation to help with readability
+                        self.write_stmt(module, sta, func_ctx, l2)?;
+                    }
+                }
+
+                writeln!(self.out, "{level}}}")?
+            }
+            // TODO: copy-paste from glsl-out
+            Statement::Kill => writeln!(self.out, "{level}discard;")?,
+            Statement::Return { value: None } => {
+                writeln!(self.out, "{level}return;")?;
+            }
+            Statement::Return { value: Some(expr) } => {
+                let base_ty_res = &func_ctx.info[expr].ty;
+                let mut resolved = base_ty_res.inner_with(&module.types);
+                if let TypeInner::Pointer { base, space: _ } = *resolved {
+                    resolved = &module.types[base].inner;
+                }
+
+                if let TypeInner::Struct { .. } = *resolved {
+                    // We can safely unwrap here, since we now we working with struct
+                    let ty = base_ty_res.handle().unwrap();
+                    let struct_name = &self.names[&NameKey::Type(ty)];
+                    let variable_name = self.namer.call(&struct_name.to_lowercase());
+                    write!(self.out, "{level}const {struct_name} {variable_name} = ",)?;
+                    self.write_expr(module, expr, func_ctx)?;
+                    writeln!(self.out, ";")?;
+
+                    // for entry point returns, we may need to reshuffle the outputs into a different struct
+                    let ep_output = match func_ctx.ty {
+                        back::FunctionType::Function(_) => None,
+                        back::FunctionType::EntryPoint(index) => {
+                            self.entry_point_io[index as usize].output.as_ref()
+                        }
+                    };
+                    let final_name = match ep_output {
+                        Some(ep_output) => {
+                            let final_name = self.namer.call(&variable_name);
+                            write!(
+                                self.out,
+                                "{}const {} {} = {{ ",
+                                level, ep_output.ty_name, final_name,
+                            )?;
+                            for (index, m) in ep_output.members.iter().enumerate() {
+                                if index != 0 {
+                                    write!(self.out, ", ")?;
+                                }
+                                let member_name = &self.names[&NameKey::StructMember(ty, m.index)];
+                                write!(self.out, "{variable_name}.{member_name}")?;
+                            }
+                            writeln!(self.out, " }};")?;
+                            final_name
+                        }
+                        None => variable_name,
+                    };
+                    writeln!(self.out, "{level}return {final_name};")?;
+                } else {
+                    write!(self.out, "{level}return ")?;
+                    self.write_expr(module, expr, func_ctx)?;
+                    writeln!(self.out, ";")?
+                }
+            }
+            Statement::Store { pointer, value } => {
+                let ty_inner = func_ctx.resolve_type(pointer, &module.types);
+                if let Some(crate::AddressSpace::Storage { .. }) = ty_inner.pointer_space() {
+                    let var_handle = self.fill_access_chain(module, pointer, func_ctx)?;
+                    self.write_storage_store(
+                        module,
+                        var_handle,
+                        StoreValue::Expression(value),
+                        func_ctx,
+                        level,
+                    )?;
+                } else {
+                    // We treat matrices of the form `matCx2` as a sequence of C `vec2`s.
+                    // See the module-level block comment in mod.rs for details.
+                    //
+                    // We handle matrix Stores here directly (including sub accesses for Vectors and Scalars).
+                    // Loads are handled by `Expression::AccessIndex` (since sub accesses work fine for Loads).
+                    struct MatrixAccess {
+                        base: Handle<crate::Expression>,
+                        index: u32,
+                    }
+                    enum Index {
+                        Expression(Handle<crate::Expression>),
+                        Static(u32),
+                    }
+
+                    let get_members = |expr: Handle<crate::Expression>| {
+                        let resolved = func_ctx.resolve_type(expr, &module.types);
+                        match *resolved {
+                            TypeInner::Pointer { base, .. } => match module.types[base].inner {
+                                TypeInner::Struct { ref members, .. } => Some(members),
+                                _ => None,
+                            },
+                            _ => None,
+                        }
+                    };
+
+                    let mut matrix = None;
+                    let mut vector = None;
+                    let mut scalar = None;
+
+                    let mut current_expr = pointer;
+                    for _ in 0..3 {
+                        let resolved = func_ctx.resolve_type(current_expr, &module.types);
+
+                        match (resolved, &func_ctx.expressions[current_expr]) {
+                            (
+                                &TypeInner::Pointer { base: ty, .. },
+                                &crate::Expression::AccessIndex { base, index },
+                            ) if matches!(
+                                module.types[ty].inner,
+                                TypeInner::Matrix {
+                                    rows: crate::VectorSize::Bi,
+                                    ..
+                                }
+                            ) && get_members(base)
+                                .map(|members| members[index as usize].binding.is_none())
+                                == Some(true) =>
+                            {
+                                matrix = Some(MatrixAccess { base, index });
+                                break;
+                            }
+                            (
+                                &TypeInner::ValuePointer {
+                                    size: Some(crate::VectorSize::Bi),
+                                    ..
+                                },
+                                &crate::Expression::Access { base, index },
+                            ) => {
+                                vector = Some(Index::Expression(index));
+                                current_expr = base;
+                            }
+                            (
+                                &TypeInner::ValuePointer {
+                                    size: Some(crate::VectorSize::Bi),
+                                    ..
+                                },
+                                &crate::Expression::AccessIndex { base, index },
+                            ) => {
+                                vector = Some(Index::Static(index));
+                                current_expr = base;
+                            }
+                            (
+                                &TypeInner::ValuePointer { size: None, .. },
+                                &crate::Expression::Access { base, index },
+                            ) => {
+                                scalar = Some(Index::Expression(index));
+                                current_expr = base;
+                            }
+                            (
+                                &TypeInner::ValuePointer { size: None, .. },
+                                &crate::Expression::AccessIndex { base, index },
+                            ) => {
+                                scalar = Some(Index::Static(index));
+                                current_expr = base;
+                            }
+                            _ => break,
+                        }
+                    }
+
+                    write!(self.out, "{level}")?;
+
+                    if let Some(MatrixAccess { index, base }) = matrix {
+                        let base_ty_res = &func_ctx.info[base].ty;
+                        let resolved = base_ty_res.inner_with(&module.types);
+                        let ty = match *resolved {
+                            TypeInner::Pointer { base, .. } => base,
+                            _ => base_ty_res.handle().unwrap(),
+                        };
+
+                        if let Some(Index::Static(vec_index)) = vector {
+                            self.write_expr(module, base, func_ctx)?;
+                            write!(
+                                self.out,
+                                ".{}_{}",
+                                &self.names[&NameKey::StructMember(ty, index)],
+                                vec_index
+                            )?;
+
+                            if let Some(scalar_index) = scalar {
+                                write!(self.out, "[")?;
+                                match scalar_index {
+                                    Index::Static(index) => {
+                                        write!(self.out, "{index}")?;
+                                    }
+                                    Index::Expression(index) => {
+                                        self.write_expr(module, index, func_ctx)?;
+                                    }
+                                }
+                                write!(self.out, "]")?;
+                            }
+
+                            write!(self.out, " = ")?;
+                            self.write_expr(module, value, func_ctx)?;
+                            writeln!(self.out, ";")?;
+                        } else {
+                            let access = WrappedStructMatrixAccess { ty, index };
+                            match (&vector, &scalar) {
+                                (&Some(_), &Some(_)) => {
+                                    self.write_wrapped_struct_matrix_set_scalar_function_name(
+                                        access,
+                                    )?;
+                                }
+                                (&Some(_), &None) => {
+                                    self.write_wrapped_struct_matrix_set_vec_function_name(access)?;
+                                }
+                                (&None, _) => {
+                                    self.write_wrapped_struct_matrix_set_function_name(access)?;
+                                }
+                            }
+
+                            write!(self.out, "(")?;
+                            self.write_expr(module, base, func_ctx)?;
+                            write!(self.out, ", ")?;
+                            self.write_expr(module, value, func_ctx)?;
+
+                            if let Some(Index::Expression(vec_index)) = vector {
+                                write!(self.out, ", ")?;
+                                self.write_expr(module, vec_index, func_ctx)?;
+
+                                if let Some(scalar_index) = scalar {
+                                    write!(self.out, ", ")?;
+                                    match scalar_index {
+                                        Index::Static(index) => {
+                                            write!(self.out, "{index}")?;
+                                        }
+                                        Index::Expression(index) => {
+                                            self.write_expr(module, index, func_ctx)?;
+                                        }
+                                    }
+                                }
+                            }
+                            writeln!(self.out, ");")?;
+                        }
+                    } else {
+                        // We handle `Store`s to __matCx2 column vectors and scalar elements via
+                        // the previously injected functions __set_col_of_matCx2 / __set_el_of_matCx2.
+                        struct MatrixData {
+                            columns: crate::VectorSize,
+                            base: Handle<crate::Expression>,
+                        }
+
+                        enum Index {
+                            Expression(Handle<crate::Expression>),
+                            Static(u32),
+                        }
+
+                        let mut matrix = None;
+                        let mut vector = None;
+                        let mut scalar = None;
+
+                        let mut current_expr = pointer;
+                        for _ in 0..3 {
+                            let resolved = func_ctx.resolve_type(current_expr, &module.types);
+                            match (resolved, &func_ctx.expressions[current_expr]) {
+                                (
+                                    &TypeInner::ValuePointer {
+                                        size: Some(crate::VectorSize::Bi),
+                                        ..
+                                    },
+                                    &crate::Expression::Access { base, index },
+                                ) => {
+                                    vector = Some(index);
+                                    current_expr = base;
+                                }
+                                (
+                                    &TypeInner::ValuePointer { size: None, .. },
+                                    &crate::Expression::Access { base, index },
+                                ) => {
+                                    scalar = Some(Index::Expression(index));
+                                    current_expr = base;
+                                }
+                                (
+                                    &TypeInner::ValuePointer { size: None, .. },
+                                    &crate::Expression::AccessIndex { base, index },
+                                ) => {
+                                    scalar = Some(Index::Static(index));
+                                    current_expr = base;
+                                }
+                                _ => {
+                                    if let Some(MatrixType {
+                                        columns,
+                                        rows: crate::VectorSize::Bi,
+                                        width: 4,
+                                    }) = get_inner_matrix_of_struct_array_member(
+                                        module,
+                                        current_expr,
+                                        func_ctx,
+                                        true,
+                                    ) {
+                                        matrix = Some(MatrixData {
+                                            columns,
+                                            base: current_expr,
+                                        });
+                                    }
+
+                                    break;
+                                }
+                            }
+                        }
+
+                        if let (Some(MatrixData { columns, base }), Some(vec_index)) =
+                            (matrix, vector)
+                        {
+                            if scalar.is_some() {
+                                write!(self.out, "__set_el_of_mat{}x2", columns as u8)?;
+                            } else {
+                                write!(self.out, "__set_col_of_mat{}x2", columns as u8)?;
+                            }
+                            write!(self.out, "(")?;
+                            self.write_expr(module, base, func_ctx)?;
+                            write!(self.out, ", ")?;
+                            self.write_expr(module, vec_index, func_ctx)?;
+
+                            if let Some(scalar_index) = scalar {
+                                write!(self.out, ", ")?;
+                                match scalar_index {
+                                    Index::Static(index) => {
+                                        write!(self.out, "{index}")?;
+                                    }
+                                    Index::Expression(index) => {
+                                        self.write_expr(module, index, func_ctx)?;
+                                    }
+                                }
+                            }
+
+                            write!(self.out, ", ")?;
+                            self.write_expr(module, value, func_ctx)?;
+
+                            writeln!(self.out, ");")?;
+                        } else {
+                            self.write_expr(module, pointer, func_ctx)?;
+                            write!(self.out, " = ")?;
+
+                            // We cast the RHS of this store in cases where the LHS
+                            // is a struct member with type:
+                            //  - matCx2 or
+                            //  - a (possibly nested) array of matCx2's
+                            if let Some(MatrixType {
+                                columns,
+                                rows: crate::VectorSize::Bi,
+                                width: 4,
+                            }) = get_inner_matrix_of_struct_array_member(
+                                module, pointer, func_ctx, false,
+                            ) {
+                                let mut resolved = func_ctx.resolve_type(pointer, &module.types);
+                                if let TypeInner::Pointer { base, .. } = *resolved {
+                                    resolved = &module.types[base].inner;
+                                }
+
+                                write!(self.out, "(__mat{}x2", columns as u8)?;
+                                if let TypeInner::Array { base, size, .. } = *resolved {
+                                    self.write_array_size(module, base, size)?;
+                                }
+                                write!(self.out, ")")?;
+                            }
+
+                            self.write_expr(module, value, func_ctx)?;
+                            writeln!(self.out, ";")?
+                        }
+                    }
+                }
+            }
+            Statement::Loop {
+                ref body,
+                ref continuing,
+                break_if,
+            } => {
+                let l2 = level.next();
+                if !continuing.is_empty() || break_if.is_some() {
+                    let gate_name = self.namer.call("loop_init");
+                    writeln!(self.out, "{level}bool {gate_name} = true;")?;
+                    writeln!(self.out, "{level}while(true) {{")?;
+                    writeln!(self.out, "{l2}if (!{gate_name}) {{")?;
+                    let l3 = l2.next();
+                    for sta in continuing.iter() {
+                        self.write_stmt(module, sta, func_ctx, l3)?;
+                    }
+                    if let Some(condition) = break_if {
+                        write!(self.out, "{l3}if (")?;
+                        self.write_expr(module, condition, func_ctx)?;
+                        writeln!(self.out, ") {{")?;
+                        writeln!(self.out, "{}break;", l3.next())?;
+                        writeln!(self.out, "{l3}}}")?;
+                    }
+                    writeln!(self.out, "{l2}}}")?;
+                    writeln!(self.out, "{l2}{gate_name} = false;")?;
+                } else {
+                    writeln!(self.out, "{level}while(true) {{")?;
+                }
+
+                for sta in body.iter() {
+                    self.write_stmt(module, sta, func_ctx, l2)?;
+                }
+                writeln!(self.out, "{level}}}")?
+            }
+            Statement::Break => writeln!(self.out, "{level}break;")?,
+            Statement::Continue => writeln!(self.out, "{level}continue;")?,
+            Statement::Barrier(barrier) => {
+                self.write_barrier(barrier, level)?;
+            }
+            Statement::ImageStore {
+                image,
+                coordinate,
+                array_index,
+                value,
+            } => {
+                write!(self.out, "{level}")?;
+                self.write_expr(module, image, func_ctx)?;
+
+                write!(self.out, "[")?;
+                if let Some(index) = array_index {
+                    // Array index accepted only for texture_storage_2d_array, so we can safety use int3(coordinate, array_index) here
+                    write!(self.out, "int3(")?;
+                    self.write_expr(module, coordinate, func_ctx)?;
+                    write!(self.out, ", ")?;
+                    self.write_expr(module, index, func_ctx)?;
+                    write!(self.out, ")")?;
+                } else {
+                    self.write_expr(module, coordinate, func_ctx)?;
+                }
+                write!(self.out, "]")?;
+
+                write!(self.out, " = ")?;
+                self.write_expr(module, value, func_ctx)?;
+                writeln!(self.out, ";")?;
+            }
+            Statement::Call {
+                function,
+                ref arguments,
+                result,
+            } => {
+                write!(self.out, "{level}")?;
+                if let Some(expr) = result {
+                    write!(self.out, "const ")?;
+                    let name = format!("{}{}", back::BAKE_PREFIX, expr.index());
+                    let expr_ty = &func_ctx.info[expr].ty;
+                    match *expr_ty {
+                        proc::TypeResolution::Handle(handle) => self.write_type(module, handle)?,
+                        proc::TypeResolution::Value(ref value) => {
+                            self.write_value_type(module, value)?
+                        }
+                    };
+                    write!(self.out, " {name} = ")?;
+                    self.named_expressions.insert(expr, name);
+                }
+                let func_name = &self.names[&NameKey::Function(function)];
+                write!(self.out, "{func_name}(")?;
+                for (index, argument) in arguments.iter().enumerate() {
+                    if index != 0 {
+                        write!(self.out, ", ")?;
+                    }
+                    self.write_expr(module, *argument, func_ctx)?;
+                }
+                writeln!(self.out, ");")?
+            }
+            Statement::Atomic {
+                pointer,
+                ref fun,
+                value,
+                result,
+            } => {
+                write!(self.out, "{level}")?;
+                let res_name = format!("{}{}", back::BAKE_PREFIX, result.index());
+                match func_ctx.info[result].ty {
+                    proc::TypeResolution::Handle(handle) => self.write_type(module, handle)?,
+                    proc::TypeResolution::Value(ref value) => {
+                        self.write_value_type(module, value)?
+                    }
+                };
+
+                // Validation ensures that `pointer` has a `Pointer` type.
+                let pointer_space = func_ctx
+                    .resolve_type(pointer, &module.types)
+                    .pointer_space()
+                    .unwrap();
+
+                let fun_str = fun.to_hlsl_suffix();
+                write!(self.out, " {res_name}; ")?;
+                match pointer_space {
+                    crate::AddressSpace::WorkGroup => {
+                        write!(self.out, "Interlocked{fun_str}(")?;
+                        self.write_expr(module, pointer, func_ctx)?;
+                    }
+                    crate::AddressSpace::Storage { .. } => {
+                        let var_handle = self.fill_access_chain(module, pointer, func_ctx)?;
+                        // The call to `self.write_storage_address` wants
+                        // mutable access to all of `self`, so temporarily take
+                        // ownership of our reusable access chain buffer.
+                        let chain = mem::take(&mut self.temp_access_chain);
+                        let var_name = &self.names[&NameKey::GlobalVariable(var_handle)];
+                        write!(self.out, "{var_name}.Interlocked{fun_str}(")?;
+                        self.write_storage_address(module, &chain, func_ctx)?;
+                        self.temp_access_chain = chain;
+                    }
+                    ref other => {
+                        return Err(Error::Custom(format!(
+                            "invalid address space {other:?} for atomic statement"
+                        )))
+                    }
+                }
+                write!(self.out, ", ")?;
+                // handle the special cases
+                match *fun {
+                    crate::AtomicFunction::Subtract => {
+                        // we just wrote `InterlockedAdd`, so negate the argument
+                        write!(self.out, "-")?;
+                    }
+                    crate::AtomicFunction::Exchange { compare: Some(_) } => {
+                        return Err(Error::Unimplemented("atomic CompareExchange".to_string()));
+                    }
+                    _ => {}
+                }
+                self.write_expr(module, value, func_ctx)?;
+                writeln!(self.out, ", {res_name});")?;
+                self.named_expressions.insert(result, res_name);
+            }
+            Statement::WorkGroupUniformLoad { pointer, result } => {
+                self.write_barrier(crate::Barrier::WORK_GROUP, level)?;
+                write!(self.out, "{level}")?;
+                let name = format!("_expr{}", result.index());
+                self.write_named_expr(module, pointer, name, result, func_ctx)?;
+
+                self.write_barrier(crate::Barrier::WORK_GROUP, level)?;
+            }
+            Statement::Switch {
+                selector,
+                ref cases,
+            } => {
+                // Start the switch
+                write!(self.out, "{level}")?;
+                write!(self.out, "switch(")?;
+                self.write_expr(module, selector, func_ctx)?;
+                writeln!(self.out, ") {{")?;
+
+                // Write all cases
+                let indent_level_1 = level.next();
+                let indent_level_2 = indent_level_1.next();
+
+                for (i, case) in cases.iter().enumerate() {
+                    match case.value {
+                        crate::SwitchValue::I32(value) => {
+                            write!(self.out, "{indent_level_1}case {value}:")?
+                        }
+                        crate::SwitchValue::U32(value) => {
+                            write!(self.out, "{indent_level_1}case {value}u:")?
+                        }
+                        crate::SwitchValue::Default => {
+                            write!(self.out, "{indent_level_1}default:")?
+                        }
+                    }
+
+                    // The new block is not only stylistic, it plays a role here:
+                    // We might end up having to write the same case body
+                    // multiple times due to FXC not supporting fallthrough.
+                    // Therefore, some `Expression`s written by `Statement::Emit`
+                    // will end up having the same name (`_expr<handle_index>`).
+                    // So we need to put each case in its own scope.
+                    let write_block_braces = !(case.fall_through && case.body.is_empty());
+                    if write_block_braces {
+                        writeln!(self.out, " {{")?;
+                    } else {
+                        writeln!(self.out)?;
+                    }
+
+                    // Although FXC does support a series of case clauses before
+                    // a block[^yes], it does not support fallthrough from a
+                    // non-empty case block to the next[^no]. If this case has a
+                    // non-empty body with a fallthrough, emulate that by
+                    // duplicating the bodies of all the cases it would fall
+                    // into as extensions of this case's own body. This makes
+                    // the HLSL output potentially quadratic in the size of the
+                    // Naga IR.
+                    //
+                    // [^yes]: ```hlsl
+                    // case 1:
+                    // case 2: do_stuff()
+                    // ```
+                    // [^no]: ```hlsl
+                    // case 1: do_this();
+                    // case 2: do_that();
+                    // ```
+                    if case.fall_through && !case.body.is_empty() {
+                        let curr_len = i + 1;
+                        let end_case_idx = curr_len
+                            + cases
+                                .iter()
+                                .skip(curr_len)
+                                .position(|case| !case.fall_through)
+                                .unwrap();
+                        let indent_level_3 = indent_level_2.next();
+                        for case in &cases[i..=end_case_idx] {
+                            writeln!(self.out, "{indent_level_2}{{")?;
+                            let prev_len = self.named_expressions.len();
+                            for sta in case.body.iter() {
+                                self.write_stmt(module, sta, func_ctx, indent_level_3)?;
+                            }
+                            // Clear all named expressions that were previously inserted by the statements in the block
+                            self.named_expressions.truncate(prev_len);
+                            writeln!(self.out, "{indent_level_2}}}")?;
+                        }
+
+                        let last_case = &cases[end_case_idx];
+                        if last_case.body.last().map_or(true, |s| !s.is_terminator()) {
+                            writeln!(self.out, "{indent_level_2}break;")?;
+                        }
+                    } else {
+                        for sta in case.body.iter() {
+                            self.write_stmt(module, sta, func_ctx, indent_level_2)?;
+                        }
+                        if !case.fall_through
+                            && case.body.last().map_or(true, |s| !s.is_terminator())
+                        {
+                            writeln!(self.out, "{indent_level_2}break;")?;
+                        }
+                    }
+
+                    if write_block_braces {
+                        writeln!(self.out, "{indent_level_1}}}")?;
+                    }
+                }
+
+                writeln!(self.out, "{level}}}")?
+            }
+            Statement::RayQuery { .. } => unreachable!(),
+        }
+
+        Ok(())
+    }
+
+    fn write_const_expression(
+        &mut self,
+        module: &Module,
+        expr: Handle<crate::Expression>,
+    ) -> BackendResult {
+        self.write_possibly_const_expression(
+            module,
+            expr,
+            &module.const_expressions,
+            |writer, expr| writer.write_const_expression(module, expr),
+        )
+    }
+
+    fn write_possibly_const_expression<E>(
+        &mut self,
+        module: &Module,
+        expr: Handle<crate::Expression>,
+        expressions: &crate::Arena<crate::Expression>,
+        write_expression: E,
+    ) -> BackendResult
+    where
+        E: Fn(&mut Self, Handle<crate::Expression>) -> BackendResult,
+    {
+        use crate::Expression;
+
+        match expressions[expr] {
+            Expression::Literal(literal) => match literal {
+                // Floats are written using `Debug` instead of `Display` because it always appends the
+                // decimal part even it's zero
+                crate::Literal::F64(value) => write!(self.out, "{value:?}L")?,
+                crate::Literal::F32(value) => write!(self.out, "{value:?}")?,
+                crate::Literal::U32(value) => write!(self.out, "{}u", value)?,
+                crate::Literal::I32(value) => write!(self.out, "{}", value)?,
+                crate::Literal::I64(value) => write!(self.out, "{}L", value)?,
+                crate::Literal::Bool(value) => write!(self.out, "{}", value)?,
+                crate::Literal::AbstractInt(_) | crate::Literal::AbstractFloat(_) => {
+                    return Err(Error::Custom(
+                        "Abstract types should not appear in IR presented to backends".into(),
+                    ));
+                }
+            },
+            Expression::Constant(handle) => {
+                let constant = &module.constants[handle];
+                if constant.name.is_some() {
+                    write!(self.out, "{}", self.names[&NameKey::Constant(handle)])?;
+                } else {
+                    self.write_const_expression(module, constant.init)?;
+                }
+            }
+            Expression::ZeroValue(ty) => self.write_default_init(module, ty)?,
+            Expression::Compose { ty, ref components } => {
+                match module.types[ty].inner {
+                    TypeInner::Struct { .. } | TypeInner::Array { .. } => {
+                        self.write_wrapped_constructor_function_name(
+                            module,
+                            WrappedConstructor { ty },
+                        )?;
+                    }
+                    _ => {
+                        self.write_type(module, ty)?;
+                    }
+                };
+                write!(self.out, "(")?;
+                for (index, component) in components.iter().enumerate() {
+                    if index != 0 {
+                        write!(self.out, ", ")?;
+                    }
+                    write_expression(self, *component)?;
+                }
+                write!(self.out, ")")?;
+            }
+            Expression::Splat { size, value } => {
+                // hlsl is not supported one value constructor
+                // if we write, for example, int4(0), dxc returns error:
+                // error: too few elements in vector initialization (expected 4 elements, have 1)
+                let number_of_components = match size {
+                    crate::VectorSize::Bi => "xx",
+                    crate::VectorSize::Tri => "xxx",
+                    crate::VectorSize::Quad => "xxxx",
+                };
+                write!(self.out, "(")?;
+                write_expression(self, value)?;
+                write!(self.out, ").{number_of_components}")?
+            }
+            _ => unreachable!(),
+        }
+
+        Ok(())
+    }
+
+    /// Helper method to write expressions
+    ///
+    /// # Notes
+    /// Doesn't add any newlines or leading/trailing spaces
+    pub(super) fn write_expr(
+        &mut self,
+        module: &Module,
+        expr: Handle<crate::Expression>,
+        func_ctx: &back::FunctionCtx<'_>,
+    ) -> BackendResult {
+        use crate::Expression;
+
+        // Handle the special semantics of vertex_index/instance_index
+        let ff_input = if self.options.special_constants_binding.is_some() {
+            func_ctx.is_fixed_function_input(expr, module)
+        } else {
+            None
+        };
+        let closing_bracket = match ff_input {
+            Some(crate::BuiltIn::VertexIndex) => {
+                write!(self.out, "({SPECIAL_CBUF_VAR}.{SPECIAL_FIRST_VERTEX} + ")?;
+                ")"
+            }
+            Some(crate::BuiltIn::InstanceIndex) => {
+                write!(self.out, "({SPECIAL_CBUF_VAR}.{SPECIAL_FIRST_INSTANCE} + ",)?;
+                ")"
+            }
+            Some(crate::BuiltIn::NumWorkGroups) => {
+                // Note: despite their names (`FIRST_VERTEX` and `FIRST_INSTANCE`),
+                // in compute shaders the special constants contain the number
+                // of workgroups, which we are using here.
+                write!(
+                    self.out,
+                    "uint3({SPECIAL_CBUF_VAR}.{SPECIAL_FIRST_VERTEX}, {SPECIAL_CBUF_VAR}.{SPECIAL_FIRST_INSTANCE}, {SPECIAL_CBUF_VAR}.{SPECIAL_OTHER})",
+                )?;
+                return Ok(());
+            }
+            _ => "",
+        };
+
+        if let Some(name) = self.named_expressions.get(&expr) {
+            write!(self.out, "{name}{closing_bracket}")?;
+            return Ok(());
+        }
+
+        let expression = &func_ctx.expressions[expr];
+
+        match *expression {
+            Expression::Literal(_)
+            | Expression::Constant(_)
+            | Expression::ZeroValue(_)
+            | Expression::Compose { .. }
+            | Expression::Splat { .. } => {
+                self.write_possibly_const_expression(
+                    module,
+                    expr,
+                    func_ctx.expressions,
+                    |writer, expr| writer.write_expr(module, expr, func_ctx),
+                )?;
+            }
+            // All of the multiplication can be expressed as `mul`,
+            // except vector * vector, which needs to use the "*" operator.
+            Expression::Binary {
+                op: crate::BinaryOperator::Multiply,
+                left,
+                right,
+            } if func_ctx.resolve_type(left, &module.types).is_matrix()
+                || func_ctx.resolve_type(right, &module.types).is_matrix() =>
+            {
+                // We intentionally flip the order of multiplication as our matrices are implicitly transposed.
+                write!(self.out, "mul(")?;
+                self.write_expr(module, right, func_ctx)?;
+                write!(self.out, ", ")?;
+                self.write_expr(module, left, func_ctx)?;
+                write!(self.out, ")")?;
+            }
+
+            // TODO: handle undefined behavior of BinaryOperator::Modulo
+            //
+            // sint:
+            // if right == 0 return 0
+            // if left == min(type_of(left)) && right == -1 return 0
+            // if sign(left) != sign(right) return result as defined by WGSL
+            //
+            // uint:
+            // if right == 0 return 0
+            //
+            // float:
+            // if right == 0 return ? see https://github.com/gpuweb/gpuweb/issues/2798
+
+            // While HLSL supports float operands with the % operator it is only
+            // defined in cases where both sides are either positive or negative.
+            Expression::Binary {
+                op: crate::BinaryOperator::Modulo,
+                left,
+                right,
+            } if func_ctx.resolve_type(left, &module.types).scalar_kind()
+                == Some(crate::ScalarKind::Float) =>
+            {
+                write!(self.out, "fmod(")?;
+                self.write_expr(module, left, func_ctx)?;
+                write!(self.out, ", ")?;
+                self.write_expr(module, right, func_ctx)?;
+                write!(self.out, ")")?;
+            }
+            Expression::Binary { op, left, right } => {
+                write!(self.out, "(")?;
+                self.write_expr(module, left, func_ctx)?;
+                write!(self.out, " {} ", crate::back::binary_operation_str(op))?;
+                self.write_expr(module, right, func_ctx)?;
+                write!(self.out, ")")?;
+            }
+            Expression::Access { base, index } => {
+                if let Some(crate::AddressSpace::Storage { .. }) =
+                    func_ctx.resolve_type(expr, &module.types).pointer_space()
+                {
+                    // do nothing, the chain is written on `Load`/`Store`
+                } else {
+                    // We use the function __get_col_of_matCx2 here in cases
+                    // where `base`s type resolves to a matCx2 and is part of a
+                    // struct member with type of (possibly nested) array of matCx2's.
+                    //
+                    // Note that this only works for `Load`s and we handle
+                    // `Store`s differently in `Statement::Store`.
+                    if let Some(MatrixType {
+                        columns,
+                        rows: crate::VectorSize::Bi,
+                        width: 4,
+                    }) = get_inner_matrix_of_struct_array_member(module, base, func_ctx, true)
+                    {
+                        write!(self.out, "__get_col_of_mat{}x2(", columns as u8)?;
+                        self.write_expr(module, base, func_ctx)?;
+                        write!(self.out, ", ")?;
+                        self.write_expr(module, index, func_ctx)?;
+                        write!(self.out, ")")?;
+                        return Ok(());
+                    }
+
+                    let resolved = func_ctx.resolve_type(base, &module.types);
+
+                    let non_uniform_qualifier = match *resolved {
+                        TypeInner::BindingArray { .. } => {
+                            let uniformity = &func_ctx.info[index].uniformity;
+
+                            uniformity.non_uniform_result.is_some()
+                        }
+                        _ => false,
+                    };
+
+                    self.write_expr(module, base, func_ctx)?;
+                    write!(self.out, "[")?;
+                    if non_uniform_qualifier {
+                        write!(self.out, "NonUniformResourceIndex(")?;
+                    }
+                    self.write_expr(module, index, func_ctx)?;
+                    if non_uniform_qualifier {
+                        write!(self.out, ")")?;
+                    }
+                    write!(self.out, "]")?;
+                }
+            }
+            Expression::AccessIndex { base, index } => {
+                if let Some(crate::AddressSpace::Storage { .. }) =
+                    func_ctx.resolve_type(expr, &module.types).pointer_space()
+                {
+                    // do nothing, the chain is written on `Load`/`Store`
+                } else {
+                    fn write_access<W: fmt::Write>(
+                        writer: &mut super::Writer<'_, W>,
+                        resolved: &TypeInner,
+                        base_ty_handle: Option<Handle<crate::Type>>,
+                        index: u32,
+                    ) -> BackendResult {
+                        match *resolved {
+                            // We specifically lift the ValuePointer to this case. While `[0]` is valid
+                            // HLSL for any vector behind a value pointer, FXC completely miscompiles
+                            // it and generates completely nonsensical DXBC.
+                            //
+                            // See https://github.com/gfx-rs/naga/issues/2095 for more details.
+                            TypeInner::Vector { .. } | TypeInner::ValuePointer { .. } => {
+                                // Write vector access as a swizzle
+                                write!(writer.out, ".{}", back::COMPONENTS[index as usize])?
+                            }
+                            TypeInner::Matrix { .. }
+                            | TypeInner::Array { .. }
+                            | TypeInner::BindingArray { .. } => write!(writer.out, "[{index}]")?,
+                            TypeInner::Struct { .. } => {
+                                // This will never panic in case the type is a `Struct`, this is not true
+                                // for other types so we can only check while inside this match arm
+                                let ty = base_ty_handle.unwrap();
+
+                                write!(
+                                    writer.out,
+                                    ".{}",
+                                    &writer.names[&NameKey::StructMember(ty, index)]
+                                )?
+                            }
+                            ref other => {
+                                return Err(Error::Custom(format!("Cannot index {other:?}")))
+                            }
+                        }
+                        Ok(())
+                    }
+
+                    // We write the matrix column access in a special way since
+                    // the type of `base` is our special __matCx2 struct.
+                    if let Some(MatrixType {
+                        rows: crate::VectorSize::Bi,
+                        width: 4,
+                        ..
+                    }) = get_inner_matrix_of_struct_array_member(module, base, func_ctx, true)
+                    {
+                        self.write_expr(module, base, func_ctx)?;
+                        write!(self.out, "._{index}")?;
+                        return Ok(());
+                    }
+
+                    let base_ty_res = &func_ctx.info[base].ty;
+                    let mut resolved = base_ty_res.inner_with(&module.types);
+                    let base_ty_handle = match *resolved {
+                        TypeInner::Pointer { base, .. } => {
+                            resolved = &module.types[base].inner;
+                            Some(base)
+                        }
+                        _ => base_ty_res.handle(),
+                    };
+
+                    // We treat matrices of the form `matCx2` as a sequence of C `vec2`s.
+                    // See the module-level block comment in mod.rs for details.
+                    //
+                    // We handle matrix reconstruction here for Loads.
+                    // Stores are handled directly by `Statement::Store`.
+                    if let TypeInner::Struct { ref members, .. } = *resolved {
+                        let member = &members[index as usize];
+
+                        match module.types[member.ty].inner {
+                            TypeInner::Matrix {
+                                rows: crate::VectorSize::Bi,
+                                ..
+                            } if member.binding.is_none() => {
+                                let ty = base_ty_handle.unwrap();
+                                self.write_wrapped_struct_matrix_get_function_name(
+                                    WrappedStructMatrixAccess { ty, index },
+                                )?;
+                                write!(self.out, "(")?;
+                                self.write_expr(module, base, func_ctx)?;
+                                write!(self.out, ")")?;
+                                return Ok(());
+                            }
+                            _ => {}
+                        }
+                    }
+
+                    self.write_expr(module, base, func_ctx)?;
+                    write_access(self, resolved, base_ty_handle, index)?;
+                }
+            }
+            Expression::FunctionArgument(pos) => {
+                let key = func_ctx.argument_key(pos);
+                let name = &self.names[&key];
+                write!(self.out, "{name}")?;
+            }
+            Expression::ImageSample {
+                image,
+                sampler,
+                gather,
+                coordinate,
+                array_index,
+                offset,
+                level,
+                depth_ref,
+            } => {
+                use crate::SampleLevel as Sl;
+                const COMPONENTS: [&str; 4] = ["", "Green", "Blue", "Alpha"];
+
+                let (base_str, component_str) = match gather {
+                    Some(component) => ("Gather", COMPONENTS[component as usize]),
+                    None => ("Sample", ""),
+                };
+                let cmp_str = match depth_ref {
+                    Some(_) => "Cmp",
+                    None => "",
+                };
+                let level_str = match level {
+                    Sl::Zero if gather.is_none() => "LevelZero",
+                    Sl::Auto | Sl::Zero => "",
+                    Sl::Exact(_) => "Level",
+                    Sl::Bias(_) => "Bias",
+                    Sl::Gradient { .. } => "Grad",
+                };
+
+                self.write_expr(module, image, func_ctx)?;
+                write!(self.out, ".{base_str}{cmp_str}{component_str}{level_str}(")?;
+                self.write_expr(module, sampler, func_ctx)?;
+                write!(self.out, ", ")?;
+                self.write_texture_coordinates(
+                    "float",
+                    coordinate,
+                    array_index,
+                    None,
+                    module,
+                    func_ctx,
+                )?;
+
+                if let Some(depth_ref) = depth_ref {
+                    write!(self.out, ", ")?;
+                    self.write_expr(module, depth_ref, func_ctx)?;
+                }
+
+                match level {
+                    Sl::Auto | Sl::Zero => {}
+                    Sl::Exact(expr) => {
+                        write!(self.out, ", ")?;
+                        self.write_expr(module, expr, func_ctx)?;
+                    }
+                    Sl::Bias(expr) => {
+                        write!(self.out, ", ")?;
+                        self.write_expr(module, expr, func_ctx)?;
+                    }
+                    Sl::Gradient { x, y } => {
+                        write!(self.out, ", ")?;
+                        self.write_expr(module, x, func_ctx)?;
+                        write!(self.out, ", ")?;
+                        self.write_expr(module, y, func_ctx)?;
+                    }
+                }
+
+                if let Some(offset) = offset {
+                    write!(self.out, ", ")?;
+                    write!(self.out, "int2(")?; // work around https://github.com/microsoft/DirectXShaderCompiler/issues/5082#issuecomment-1540147807
+                    self.write_const_expression(module, offset)?;
+                    write!(self.out, ")")?;
+                }
+
+                write!(self.out, ")")?;
+            }
+            Expression::ImageQuery { image, query } => {
+                // use wrapped image query function
+                if let TypeInner::Image {
+                    dim,
+                    arrayed,
+                    class,
+                } = *func_ctx.resolve_type(image, &module.types)
+                {
+                    let wrapped_image_query = WrappedImageQuery {
+                        dim,
+                        arrayed,
+                        class,
+                        query: query.into(),
+                    };
+
+                    self.write_wrapped_image_query_function_name(wrapped_image_query)?;
+                    write!(self.out, "(")?;
+                    // Image always first param
+                    self.write_expr(module, image, func_ctx)?;
+                    if let crate::ImageQuery::Size { level: Some(level) } = query {
+                        write!(self.out, ", ")?;
+                        self.write_expr(module, level, func_ctx)?;
+                    }
+                    write!(self.out, ")")?;
+                }
+            }
+            Expression::ImageLoad {
+                image,
+                coordinate,
+                array_index,
+                sample,
+                level,
+            } => {
+                // https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-to-load
+                self.write_expr(module, image, func_ctx)?;
+                write!(self.out, ".Load(")?;
+
+                self.write_texture_coordinates(
+                    "int",
+                    coordinate,
+                    array_index,
+                    level,
+                    module,
+                    func_ctx,
+                )?;
+
+                if let Some(sample) = sample {
+                    write!(self.out, ", ")?;
+                    self.write_expr(module, sample, func_ctx)?;
+                }
+
+                // close bracket for Load function
+                write!(self.out, ")")?;
+
+                // return x component if return type is scalar
+                if let TypeInner::Scalar(_) = *func_ctx.resolve_type(expr, &module.types) {
+                    write!(self.out, ".x")?;
+                }
+            }
+            Expression::GlobalVariable(handle) => match module.global_variables[handle].space {
+                crate::AddressSpace::Storage { .. } => {}
+                _ => {
+                    let name = &self.names[&NameKey::GlobalVariable(handle)];
+                    write!(self.out, "{name}")?;
+                }
+            },
+            Expression::LocalVariable(handle) => {
+                write!(self.out, "{}", self.names[&func_ctx.name_key(handle)])?
+            }
+            Expression::Load { pointer } => {
+                match func_ctx
+                    .resolve_type(pointer, &module.types)
+                    .pointer_space()
+                {
+                    Some(crate::AddressSpace::Storage { .. }) => {
+                        let var_handle = self.fill_access_chain(module, pointer, func_ctx)?;
+                        let result_ty = func_ctx.info[expr].ty.clone();
+                        self.write_storage_load(module, var_handle, result_ty, func_ctx)?;
+                    }
+                    _ => {
+                        let mut close_paren = false;
+
+                        // We cast the value loaded to a native HLSL floatCx2
+                        // in cases where it is of type:
+                        //  - __matCx2 or
+                        //  - a (possibly nested) array of __matCx2's
+                        if let Some(MatrixType {
+                            rows: crate::VectorSize::Bi,
+                            width: 4,
+                            ..
+                        }) = get_inner_matrix_of_struct_array_member(
+                            module, pointer, func_ctx, false,
+                        )
+                        .or_else(|| get_inner_matrix_of_global_uniform(module, pointer, func_ctx))
+                        {
+                            let mut resolved = func_ctx.resolve_type(pointer, &module.types);
+                            if let TypeInner::Pointer { base, .. } = *resolved {
+                                resolved = &module.types[base].inner;
+                            }
+
+                            write!(self.out, "((")?;
+                            if let TypeInner::Array { base, size, .. } = *resolved {
+                                self.write_type(module, base)?;
+                                self.write_array_size(module, base, size)?;
+                            } else {
+                                self.write_value_type(module, resolved)?;
+                            }
+                            write!(self.out, ")")?;
+                            close_paren = true;
+                        }
+
+                        self.write_expr(module, pointer, func_ctx)?;
+
+                        if close_paren {
+                            write!(self.out, ")")?;
+                        }
+                    }
+                }
+            }
+            Expression::Unary { op, expr } => {
+                // https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-operators#unary-operators
+                let op_str = match op {
+                    crate::UnaryOperator::Negate => "-",
+                    crate::UnaryOperator::LogicalNot => "!",
+                    crate::UnaryOperator::BitwiseNot => "~",
+                };
+                write!(self.out, "{op_str}(")?;
+                self.write_expr(module, expr, func_ctx)?;
+                write!(self.out, ")")?;
+            }
+            Expression::As {
+                expr,
+                kind,
+                convert,
+            } => {
+                let inner = func_ctx.resolve_type(expr, &module.types);
+                match convert {
+                    Some(dst_width) => {
+                        let scalar = crate::Scalar {
+                            kind,
+                            width: dst_width,
+                        };
+                        match *inner {
+                            TypeInner::Vector { size, .. } => {
+                                write!(
+                                    self.out,
+                                    "{}{}(",
+                                    scalar.to_hlsl_str()?,
+                                    back::vector_size_str(size)
+                                )?;
+                            }
+                            TypeInner::Scalar(_) => {
+                                write!(self.out, "{}(", scalar.to_hlsl_str()?,)?;
+                            }
+                            TypeInner::Matrix { columns, rows, .. } => {
+                                write!(
+                                    self.out,
+                                    "{}{}x{}(",
+                                    scalar.to_hlsl_str()?,
+                                    back::vector_size_str(columns),
+                                    back::vector_size_str(rows)
+                                )?;
+                            }
+                            _ => {
+                                return Err(Error::Unimplemented(format!(
+                                    "write_expr expression::as {inner:?}"
+                                )));
+                            }
+                        };
+                    }
+                    None => {
+                        write!(self.out, "{}(", kind.to_hlsl_cast(),)?;
+                    }
+                }
+                self.write_expr(module, expr, func_ctx)?;
+                write!(self.out, ")")?;
+            }
+            Expression::Math {
+                fun,
+                arg,
+                arg1,
+                arg2,
+                arg3,
+            } => {
+                use crate::MathFunction as Mf;
+
+                enum Function {
+                    Asincosh { is_sin: bool },
+                    Atanh,
+                    ExtractBits,
+                    InsertBits,
+                    Pack2x16float,
+                    Pack2x16snorm,
+                    Pack2x16unorm,
+                    Pack4x8snorm,
+                    Pack4x8unorm,
+                    Unpack2x16float,
+                    Unpack2x16snorm,
+                    Unpack2x16unorm,
+                    Unpack4x8snorm,
+                    Unpack4x8unorm,
+                    Regular(&'static str),
+                    MissingIntOverload(&'static str),
+                    MissingIntReturnType(&'static str),
+                    CountTrailingZeros,
+                    CountLeadingZeros,
+                }
+
+                let fun = match fun {
+                    // comparison
+                    Mf::Abs => Function::Regular("abs"),
+                    Mf::Min => Function::Regular("min"),
+                    Mf::Max => Function::Regular("max"),
+                    Mf::Clamp => Function::Regular("clamp"),
+                    Mf::Saturate => Function::Regular("saturate"),
+                    // trigonometry
+                    Mf::Cos => Function::Regular("cos"),
+                    Mf::Cosh => Function::Regular("cosh"),
+                    Mf::Sin => Function::Regular("sin"),
+                    Mf::Sinh => Function::Regular("sinh"),
+                    Mf::Tan => Function::Regular("tan"),
+                    Mf::Tanh => Function::Regular("tanh"),
+                    Mf::Acos => Function::Regular("acos"),
+                    Mf::Asin => Function::Regular("asin"),
+                    Mf::Atan => Function::Regular("atan"),
+                    Mf::Atan2 => Function::Regular("atan2"),
+                    Mf::Asinh => Function::Asincosh { is_sin: true },
+                    Mf::Acosh => Function::Asincosh { is_sin: false },
+                    Mf::Atanh => Function::Atanh,
+                    Mf::Radians => Function::Regular("radians"),
+                    Mf::Degrees => Function::Regular("degrees"),
+                    // decomposition
+                    Mf::Ceil => Function::Regular("ceil"),
+                    Mf::Floor => Function::Regular("floor"),
+                    Mf::Round => Function::Regular("round"),
+                    Mf::Fract => Function::Regular("frac"),
+                    Mf::Trunc => Function::Regular("trunc"),
+                    Mf::Modf => Function::Regular(MODF_FUNCTION),
+                    Mf::Frexp => Function::Regular(FREXP_FUNCTION),
+                    Mf::Ldexp => Function::Regular("ldexp"),
+                    // exponent
+                    Mf::Exp => Function::Regular("exp"),
+                    Mf::Exp2 => Function::Regular("exp2"),
+                    Mf::Log => Function::Regular("log"),
+                    Mf::Log2 => Function::Regular("log2"),
+                    Mf::Pow => Function::Regular("pow"),
+                    // geometry
+                    Mf::Dot => Function::Regular("dot"),
+                    //Mf::Outer => ,
+                    Mf::Cross => Function::Regular("cross"),
+                    Mf::Distance => Function::Regular("distance"),
+                    Mf::Length => Function::Regular("length"),
+                    Mf::Normalize => Function::Regular("normalize"),
+                    Mf::FaceForward => Function::Regular("faceforward"),
+                    Mf::Reflect => Function::Regular("reflect"),
+                    Mf::Refract => Function::Regular("refract"),
+                    // computational
+                    Mf::Sign => Function::Regular("sign"),
+                    Mf::Fma => Function::Regular("mad"),
+                    Mf::Mix => Function::Regular("lerp"),
+                    Mf::Step => Function::Regular("step"),
+                    Mf::SmoothStep => Function::Regular("smoothstep"),
+                    Mf::Sqrt => Function::Regular("sqrt"),
+                    Mf::InverseSqrt => Function::Regular("rsqrt"),
+                    //Mf::Inverse =>,
+                    Mf::Transpose => Function::Regular("transpose"),
+                    Mf::Determinant => Function::Regular("determinant"),
+                    // bits
+                    Mf::CountTrailingZeros => Function::CountTrailingZeros,
+                    Mf::CountLeadingZeros => Function::CountLeadingZeros,
+                    Mf::CountOneBits => Function::MissingIntOverload("countbits"),
+                    Mf::ReverseBits => Function::MissingIntOverload("reversebits"),
+                    Mf::FindLsb => Function::MissingIntReturnType("firstbitlow"),
+                    Mf::FindMsb => Function::MissingIntReturnType("firstbithigh"),
+                    Mf::ExtractBits => Function::ExtractBits,
+                    Mf::InsertBits => Function::InsertBits,
+                    // Data Packing
+                    Mf::Pack2x16float => Function::Pack2x16float,
+                    Mf::Pack2x16snorm => Function::Pack2x16snorm,
+                    Mf::Pack2x16unorm => Function::Pack2x16unorm,
+                    Mf::Pack4x8snorm => Function::Pack4x8snorm,
+                    Mf::Pack4x8unorm => Function::Pack4x8unorm,
+                    // Data Unpacking
+                    Mf::Unpack2x16float => Function::Unpack2x16float,
+                    Mf::Unpack2x16snorm => Function::Unpack2x16snorm,
+                    Mf::Unpack2x16unorm => Function::Unpack2x16unorm,
+                    Mf::Unpack4x8snorm => Function::Unpack4x8snorm,
+                    Mf::Unpack4x8unorm => Function::Unpack4x8unorm,
+                    _ => return Err(Error::Unimplemented(format!("write_expr_math {fun:?}"))),
+                };
+
+                match fun {
+                    Function::Asincosh { is_sin } => {
+                        write!(self.out, "log(")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, " + sqrt(")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, " * ")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        match is_sin {
+                            true => write!(self.out, " + 1.0))")?,
+                            false => write!(self.out, " - 1.0))")?,
+                        }
+                    }
+                    Function::Atanh => {
+                        write!(self.out, "0.5 * log((1.0 + ")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, ") / (1.0 - ")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, "))")?;
+                    }
+                    Function::ExtractBits => {
+                        // e: T,
+                        // offset: u32,
+                        // count: u32
+                        // T is u32 or i32 or vecN<u32> or vecN<i32>
+                        if let (Some(offset), Some(count)) = (arg1, arg2) {
+                            let scalar_width: u8 = 32;
+                            // Works for signed and unsigned
+                            // (count == 0 ? 0 : (e << (32 - count - offset)) >> (32 - count))
+                            write!(self.out, "(")?;
+                            self.write_expr(module, count, func_ctx)?;
+                            write!(self.out, " == 0 ? 0 : (")?;
+                            self.write_expr(module, arg, func_ctx)?;
+                            write!(self.out, " << ({scalar_width} - ")?;
+                            self.write_expr(module, count, func_ctx)?;
+                            write!(self.out, " - ")?;
+                            self.write_expr(module, offset, func_ctx)?;
+                            write!(self.out, ")) >> ({scalar_width} - ")?;
+                            self.write_expr(module, count, func_ctx)?;
+                            write!(self.out, "))")?;
+                        }
+                    }
+                    Function::InsertBits => {
+                        // e: T,
+                        // newbits: T,
+                        // offset: u32,
+                        // count: u32
+                        // returns T
+                        // T is i32, u32, vecN<i32>, or vecN<u32>
+                        if let (Some(newbits), Some(offset), Some(count)) = (arg1, arg2, arg3) {
+                            let scalar_width: u8 = 32;
+                            let scalar_max: u32 = 0xFFFFFFFF;
+                            // mask = ((0xFFFFFFFFu >> (32 - count)) << offset)
+                            // (count == 0 ? e : ((e & ~mask) | ((newbits << offset) & mask)))
+                            write!(self.out, "(")?;
+                            self.write_expr(module, count, func_ctx)?;
+                            write!(self.out, " == 0 ? ")?;
+                            self.write_expr(module, arg, func_ctx)?;
+                            write!(self.out, " : ")?;
+                            write!(self.out, "(")?;
+                            self.write_expr(module, arg, func_ctx)?;
+                            write!(self.out, " & ~")?;
+                            // mask
+                            write!(self.out, "(({scalar_max}u >> ({scalar_width}u - ")?;
+                            self.write_expr(module, count, func_ctx)?;
+                            write!(self.out, ")) << ")?;
+                            self.write_expr(module, offset, func_ctx)?;
+                            write!(self.out, ")")?;
+                            // end mask
+                            write!(self.out, ") | ((")?;
+                            self.write_expr(module, newbits, func_ctx)?;
+                            write!(self.out, " << ")?;
+                            self.write_expr(module, offset, func_ctx)?;
+                            write!(self.out, ") & ")?;
+                            // // mask
+                            write!(self.out, "(({scalar_max}u >> ({scalar_width}u - ")?;
+                            self.write_expr(module, count, func_ctx)?;
+                            write!(self.out, ")) << ")?;
+                            self.write_expr(module, offset, func_ctx)?;
+                            write!(self.out, ")")?;
+                            // // end mask
+                            write!(self.out, "))")?;
+                        }
+                    }
+                    Function::Pack2x16float => {
+                        write!(self.out, "(f32tof16(")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, "[0]) | f32tof16(")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, "[1]) << 16)")?;
+                    }
+                    Function::Pack2x16snorm => {
+                        let scale = 32767;
+
+                        write!(self.out, "uint((int(round(clamp(")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(
+                            self.out,
+                            "[0], -1.0, 1.0) * {scale}.0)) & 0xFFFF) | ((int(round(clamp("
+                        )?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, "[1], -1.0, 1.0) * {scale}.0)) & 0xFFFF) << 16))",)?;
+                    }
+                    Function::Pack2x16unorm => {
+                        let scale = 65535;
+
+                        write!(self.out, "(uint(round(clamp(")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, "[0], 0.0, 1.0) * {scale}.0)) | uint(round(clamp(")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, "[1], 0.0, 1.0) * {scale}.0)) << 16)")?;
+                    }
+                    Function::Pack4x8snorm => {
+                        let scale = 127;
+
+                        write!(self.out, "uint((int(round(clamp(")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(
+                            self.out,
+                            "[0], -1.0, 1.0) * {scale}.0)) & 0xFF) | ((int(round(clamp("
+                        )?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(
+                            self.out,
+                            "[1], -1.0, 1.0) * {scale}.0)) & 0xFF) << 8) | ((int(round(clamp("
+                        )?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(
+                            self.out,
+                            "[2], -1.0, 1.0) * {scale}.0)) & 0xFF) << 16) | ((int(round(clamp("
+                        )?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, "[3], -1.0, 1.0) * {scale}.0)) & 0xFF) << 24))",)?;
+                    }
+                    Function::Pack4x8unorm => {
+                        let scale = 255;
+
+                        write!(self.out, "(uint(round(clamp(")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, "[0], 0.0, 1.0) * {scale}.0)) | uint(round(clamp(")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(
+                            self.out,
+                            "[1], 0.0, 1.0) * {scale}.0)) << 8 | uint(round(clamp("
+                        )?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(
+                            self.out,
+                            "[2], 0.0, 1.0) * {scale}.0)) << 16 | uint(round(clamp("
+                        )?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, "[3], 0.0, 1.0) * {scale}.0)) << 24)")?;
+                    }
+
+                    Function::Unpack2x16float => {
+                        write!(self.out, "float2(f16tof32(")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, "), f16tof32((")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, ") >> 16))")?;
+                    }
+                    Function::Unpack2x16snorm => {
+                        let scale = 32767;
+
+                        write!(self.out, "(float2(int2(")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, " << 16, ")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, ") >> 16) / {scale}.0)")?;
+                    }
+                    Function::Unpack2x16unorm => {
+                        let scale = 65535;
+
+                        write!(self.out, "(float2(")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, " & 0xFFFF, ")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, " >> 16) / {scale}.0)")?;
+                    }
+                    Function::Unpack4x8snorm => {
+                        let scale = 127;
+
+                        write!(self.out, "(float4(int4(")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, " << 24, ")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, " << 16, ")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, " << 8, ")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, ") >> 24) / {scale}.0)")?;
+                    }
+                    Function::Unpack4x8unorm => {
+                        let scale = 255;
+
+                        write!(self.out, "(float4(")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, " & 0xFF, ")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, " >> 8 & 0xFF, ")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, " >> 16 & 0xFF, ")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        write!(self.out, " >> 24) / {scale}.0)")?;
+                    }
+                    Function::Regular(fun_name) => {
+                        write!(self.out, "{fun_name}(")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        if let Some(arg) = arg1 {
+                            write!(self.out, ", ")?;
+                            self.write_expr(module, arg, func_ctx)?;
+                        }
+                        if let Some(arg) = arg2 {
+                            write!(self.out, ", ")?;
+                            self.write_expr(module, arg, func_ctx)?;
+                        }
+                        if let Some(arg) = arg3 {
+                            write!(self.out, ", ")?;
+                            self.write_expr(module, arg, func_ctx)?;
+                        }
+                        write!(self.out, ")")?
+                    }
+                    Function::MissingIntOverload(fun_name) => {
+                        let scalar_kind = func_ctx.resolve_type(arg, &module.types).scalar_kind();
+                        if let Some(ScalarKind::Sint) = scalar_kind {
+                            write!(self.out, "asint({fun_name}(asuint(")?;
+                            self.write_expr(module, arg, func_ctx)?;
+                            write!(self.out, ")))")?;
+                        } else {
+                            write!(self.out, "{fun_name}(")?;
+                            self.write_expr(module, arg, func_ctx)?;
+                            write!(self.out, ")")?;
+                        }
+                    }
+                    Function::MissingIntReturnType(fun_name) => {
+                        let scalar_kind = func_ctx.resolve_type(arg, &module.types).scalar_kind();
+                        if let Some(ScalarKind::Sint) = scalar_kind {
+                            write!(self.out, "asint({fun_name}(")?;
+                            self.write_expr(module, arg, func_ctx)?;
+                            write!(self.out, "))")?;
+                        } else {
+                            write!(self.out, "{fun_name}(")?;
+                            self.write_expr(module, arg, func_ctx)?;
+                            write!(self.out, ")")?;
+                        }
+                    }
+                    Function::CountTrailingZeros => {
+                        match *func_ctx.resolve_type(arg, &module.types) {
+                            TypeInner::Vector { size, scalar } => {
+                                let s = match size {
+                                    crate::VectorSize::Bi => ".xx",
+                                    crate::VectorSize::Tri => ".xxx",
+                                    crate::VectorSize::Quad => ".xxxx",
+                                };
+
+                                if let ScalarKind::Uint = scalar.kind {
+                                    write!(self.out, "min((32u){s}, firstbitlow(")?;
+                                    self.write_expr(module, arg, func_ctx)?;
+                                    write!(self.out, "))")?;
+                                } else {
+                                    write!(self.out, "asint(min((32u){s}, firstbitlow(")?;
+                                    self.write_expr(module, arg, func_ctx)?;
+                                    write!(self.out, ")))")?;
+                                }
+                            }
+                            TypeInner::Scalar(scalar) => {
+                                if let ScalarKind::Uint = scalar.kind {
+                                    write!(self.out, "min(32u, firstbitlow(")?;
+                                    self.write_expr(module, arg, func_ctx)?;
+                                    write!(self.out, "))")?;
+                                } else {
+                                    write!(self.out, "asint(min(32u, firstbitlow(")?;
+                                    self.write_expr(module, arg, func_ctx)?;
+                                    write!(self.out, ")))")?;
+                                }
+                            }
+                            _ => unreachable!(),
+                        }
+
+                        return Ok(());
+                    }
+                    Function::CountLeadingZeros => {
+                        match *func_ctx.resolve_type(arg, &module.types) {
+                            TypeInner::Vector { size, scalar } => {
+                                let s = match size {
+                                    crate::VectorSize::Bi => ".xx",
+                                    crate::VectorSize::Tri => ".xxx",
+                                    crate::VectorSize::Quad => ".xxxx",
+                                };
+
+                                if let ScalarKind::Uint = scalar.kind {
+                                    write!(self.out, "((31u){s} - firstbithigh(")?;
+                                    self.write_expr(module, arg, func_ctx)?;
+                                    write!(self.out, "))")?;
+                                } else {
+                                    write!(self.out, "(")?;
+                                    self.write_expr(module, arg, func_ctx)?;
+                                    write!(
+                                        self.out,
+                                        " < (0){s} ? (0){s} : (31){s} - asint(firstbithigh("
+                                    )?;
+                                    self.write_expr(module, arg, func_ctx)?;
+                                    write!(self.out, ")))")?;
+                                }
+                            }
+                            TypeInner::Scalar(scalar) => {
+                                if let ScalarKind::Uint = scalar.kind {
+                                    write!(self.out, "(31u - firstbithigh(")?;
+                                    self.write_expr(module, arg, func_ctx)?;
+                                    write!(self.out, "))")?;
+                                } else {
+                                    write!(self.out, "(")?;
+                                    self.write_expr(module, arg, func_ctx)?;
+                                    write!(self.out, " < 0 ? 0 : 31 - asint(firstbithigh(")?;
+                                    self.write_expr(module, arg, func_ctx)?;
+                                    write!(self.out, ")))")?;
+                                }
+                            }
+                            _ => unreachable!(),
+                        }
+
+                        return Ok(());
+                    }
+                }
+            }
+            Expression::Swizzle {
+                size,
+                vector,
+                pattern,
+            } => {
+                self.write_expr(module, vector, func_ctx)?;
+                write!(self.out, ".")?;
+                for &sc in pattern[..size as usize].iter() {
+                    self.out.write_char(back::COMPONENTS[sc as usize])?;
+                }
+            }
+            Expression::ArrayLength(expr) => {
+                let var_handle = match func_ctx.expressions[expr] {
+                    Expression::AccessIndex { base, index: _ } => {
+                        match func_ctx.expressions[base] {
+                            Expression::GlobalVariable(handle) => handle,
+                            _ => unreachable!(),
+                        }
+                    }
+                    Expression::GlobalVariable(handle) => handle,
+                    _ => unreachable!(),
+                };
+
+                let var = &module.global_variables[var_handle];
+                let (offset, stride) = match module.types[var.ty].inner {
+                    TypeInner::Array { stride, .. } => (0, stride),
+                    TypeInner::Struct { ref members, .. } => {
+                        let last = members.last().unwrap();
+                        let stride = match module.types[last.ty].inner {
+                            TypeInner::Array { stride, .. } => stride,
+                            _ => unreachable!(),
+                        };
+                        (last.offset, stride)
+                    }
+                    _ => unreachable!(),
+                };
+
+                let storage_access = match var.space {
+                    crate::AddressSpace::Storage { access } => access,
+                    _ => crate::StorageAccess::default(),
+                };
+                let wrapped_array_length = WrappedArrayLength {
+                    writable: storage_access.contains(crate::StorageAccess::STORE),
+                };
+
+                write!(self.out, "((")?;
+                self.write_wrapped_array_length_function_name(wrapped_array_length)?;
+                let var_name = &self.names[&NameKey::GlobalVariable(var_handle)];
+                write!(self.out, "({var_name}) - {offset}) / {stride})")?
+            }
+            Expression::Derivative { axis, ctrl, expr } => {
+                use crate::{DerivativeAxis as Axis, DerivativeControl as Ctrl};
+                if axis == Axis::Width && (ctrl == Ctrl::Coarse || ctrl == Ctrl::Fine) {
+                    let tail = match ctrl {
+                        Ctrl::Coarse => "coarse",
+                        Ctrl::Fine => "fine",
+                        Ctrl::None => unreachable!(),
+                    };
+                    write!(self.out, "abs(ddx_{tail}(")?;
+                    self.write_expr(module, expr, func_ctx)?;
+                    write!(self.out, ")) + abs(ddy_{tail}(")?;
+                    self.write_expr(module, expr, func_ctx)?;
+                    write!(self.out, "))")?
+                } else {
+                    let fun_str = match (axis, ctrl) {
+                        (Axis::X, Ctrl::Coarse) => "ddx_coarse",
+                        (Axis::X, Ctrl::Fine) => "ddx_fine",
+                        (Axis::X, Ctrl::None) => "ddx",
+                        (Axis::Y, Ctrl::Coarse) => "ddy_coarse",
+                        (Axis::Y, Ctrl::Fine) => "ddy_fine",
+                        (Axis::Y, Ctrl::None) => "ddy",
+                        (Axis::Width, Ctrl::Coarse | Ctrl::Fine) => unreachable!(),
+                        (Axis::Width, Ctrl::None) => "fwidth",
+                    };
+                    write!(self.out, "{fun_str}(")?;
+                    self.write_expr(module, expr, func_ctx)?;
+                    write!(self.out, ")")?
+                }
+            }
+            Expression::Relational { fun, argument } => {
+                use crate::RelationalFunction as Rf;
+
+                let fun_str = match fun {
+                    Rf::All => "all",
+                    Rf::Any => "any",
+                    Rf::IsNan => "isnan",
+                    Rf::IsInf => "isinf",
+                };
+                write!(self.out, "{fun_str}(")?;
+                self.write_expr(module, argument, func_ctx)?;
+                write!(self.out, ")")?
+            }
+            Expression::Select {
+                condition,
+                accept,
+                reject,
+            } => {
+                write!(self.out, "(")?;
+                self.write_expr(module, condition, func_ctx)?;
+                write!(self.out, " ? ")?;
+                self.write_expr(module, accept, func_ctx)?;
+                write!(self.out, " : ")?;
+                self.write_expr(module, reject, func_ctx)?;
+                write!(self.out, ")")?
+            }
+            // Not supported yet
+            Expression::RayQueryGetIntersection { .. } => unreachable!(),
+            // Nothing to do here, since call expression already cached
+            Expression::CallResult(_)
+            | Expression::AtomicResult { .. }
+            | Expression::WorkGroupUniformLoadResult { .. }
+            | Expression::RayQueryProceedResult => {}
+        }
+
+        if !closing_bracket.is_empty() {
+            write!(self.out, "{closing_bracket}")?;
+        }
+        Ok(())
+    }
+
+    fn write_named_expr(
+        &mut self,
+        module: &Module,
+        handle: Handle<crate::Expression>,
+        name: String,
+        // The expression which is being named.
+        // Generally, this is the same as handle, except in WorkGroupUniformLoad
+        named: Handle<crate::Expression>,
+        ctx: &back::FunctionCtx,
+    ) -> BackendResult {
+        match ctx.info[named].ty {
+            proc::TypeResolution::Handle(ty_handle) => match module.types[ty_handle].inner {
+                TypeInner::Struct { .. } => {
+                    let ty_name = &self.names[&NameKey::Type(ty_handle)];
+                    write!(self.out, "{ty_name}")?;
+                }
+                _ => {
+                    self.write_type(module, ty_handle)?;
+                }
+            },
+            proc::TypeResolution::Value(ref inner) => {
+                self.write_value_type(module, inner)?;
+            }
+        }
+
+        let resolved = ctx.resolve_type(named, &module.types);
+
+        write!(self.out, " {name}")?;
+        // If rhs is a array type, we should write array size
+        if let TypeInner::Array { base, size, .. } = *resolved {
+            self.write_array_size(module, base, size)?;
+        }
+        write!(self.out, " = ")?;
+        self.write_expr(module, handle, ctx)?;
+        writeln!(self.out, ";")?;
+        self.named_expressions.insert(named, name);
+
+        Ok(())
+    }
+
+    /// Helper function that write default zero initialization
+    fn write_default_init(&mut self, module: &Module, ty: Handle<crate::Type>) -> BackendResult {
+        write!(self.out, "(")?;
+        self.write_type(module, ty)?;
+        if let TypeInner::Array { base, size, .. } = module.types[ty].inner {
+            self.write_array_size(module, base, size)?;
+        }
+        write!(self.out, ")0")?;
+        Ok(())
+    }
+
+    fn write_barrier(&mut self, barrier: crate::Barrier, level: back::Level) -> BackendResult {
+        if barrier.contains(crate::Barrier::STORAGE) {
+            writeln!(self.out, "{level}DeviceMemoryBarrierWithGroupSync();")?;
+        }
+        if barrier.contains(crate::Barrier::WORK_GROUP) {
+            writeln!(self.out, "{level}GroupMemoryBarrierWithGroupSync();")?;
+        }
+        Ok(())
+    }
+}
+
+pub(super) struct MatrixType {
+    pub(super) columns: crate::VectorSize,
+    pub(super) rows: crate::VectorSize,
+    pub(super) width: crate::Bytes,
+}
+
+pub(super) fn get_inner_matrix_data(
+    module: &Module,
+    handle: Handle<crate::Type>,
+) -> Option<MatrixType> {
+    match module.types[handle].inner {
+        TypeInner::Matrix {
+            columns,
+            rows,
+            scalar,
+        } => Some(MatrixType {
+            columns,
+            rows,
+            width: scalar.width,
+        }),
+        TypeInner::Array { base, .. } => get_inner_matrix_data(module, base),
+        _ => None,
+    }
+}
+
+/// Returns the matrix data if the access chain starting at `base`:
+/// - starts with an expression with resolved type of [`TypeInner::Matrix`] if `direct = true`
+/// - contains one or more expressions with resolved type of [`TypeInner::Array`] of [`TypeInner::Matrix`]
+/// - ends at an expression with resolved type of [`TypeInner::Struct`]
+pub(super) fn get_inner_matrix_of_struct_array_member(
+    module: &Module,
+    base: Handle<crate::Expression>,
+    func_ctx: &back::FunctionCtx<'_>,
+    direct: bool,
+) -> Option<MatrixType> {
+    let mut mat_data = None;
+    let mut array_base = None;
+
+    let mut current_base = base;
+    loop {
+        let mut resolved = func_ctx.resolve_type(current_base, &module.types);
+        if let TypeInner::Pointer { base, .. } = *resolved {
+            resolved = &module.types[base].inner;
+        };
+
+        match *resolved {
+            TypeInner::Matrix {
+                columns,
+                rows,
+                scalar,
+            } => {
+                mat_data = Some(MatrixType {
+                    columns,
+                    rows,
+                    width: scalar.width,
+                })
+            }
+            TypeInner::Array { base, .. } => {
+                array_base = Some(base);
+            }
+            TypeInner::Struct { .. } => {
+                if let Some(array_base) = array_base {
+                    if direct {
+                        return mat_data;
+                    } else {
+                        return get_inner_matrix_data(module, array_base);
+                    }
+                }
+
+                break;
+            }
+            _ => break,
+        }
+
+        current_base = match func_ctx.expressions[current_base] {
+            crate::Expression::Access { base, .. } => base,
+            crate::Expression::AccessIndex { base, .. } => base,
+            _ => break,
+        };
+    }
+    None
+}
+
+/// Returns the matrix data if the access chain starting at `base`:
+/// - starts with an expression with resolved type of [`TypeInner::Matrix`]
+/// - contains zero or more expressions with resolved type of [`TypeInner::Array`] of [`TypeInner::Matrix`]
+/// - ends with an [`Expression::GlobalVariable`](crate::Expression::GlobalVariable) in [`AddressSpace::Uniform`](crate::AddressSpace::Uniform)
+fn get_inner_matrix_of_global_uniform(
+    module: &Module,
+    base: Handle<crate::Expression>,
+    func_ctx: &back::FunctionCtx<'_>,
+) -> Option<MatrixType> {
+    let mut mat_data = None;
+    let mut array_base = None;
+
+    let mut current_base = base;
+    loop {
+        let mut resolved = func_ctx.resolve_type(current_base, &module.types);
+        if let TypeInner::Pointer { base, .. } = *resolved {
+            resolved = &module.types[base].inner;
+        };
+
+        match *resolved {
+            TypeInner::Matrix {
+                columns,
+                rows,
+                scalar,
+            } => {
+                mat_data = Some(MatrixType {
+                    columns,
+                    rows,
+                    width: scalar.width,
+                })
+            }
+            TypeInner::Array { base, .. } => {
+                array_base = Some(base);
+            }
+            _ => break,
+        }
+
+        current_base = match func_ctx.expressions[current_base] {
+            crate::Expression::Access { base, .. } => base,
+            crate::Expression::AccessIndex { base, .. } => base,
+            crate::Expression::GlobalVariable(handle)
+                if module.global_variables[handle].space == crate::AddressSpace::Uniform =>
+            {
+                return mat_data.or_else(|| {
+                    array_base.and_then(|array_base| get_inner_matrix_data(module, array_base))
+                })
+            }
+            _ => break,
+        };
+    }
+    None
+}
diff --git a/third_party/rust/naga/src/back/mod.rs b/third_party/rust/naga/src/back/mod.rs
new file mode 100644
index 0000000000..8100b930e9
--- /dev/null
+++ b/third_party/rust/naga/src/back/mod.rs
@@ -0,0 +1,273 @@
+/*!
+Backend functions that export shader [`Module`](super::Module)s into binary and text formats.
+*/
+#![allow(dead_code)] // can be dead if none of the enabled backends need it
+
+#[cfg(feature = "dot-out")]
+pub mod dot;
+#[cfg(feature = "glsl-out")]
+pub mod glsl;
+#[cfg(feature = "hlsl-out")]
+pub mod hlsl;
+#[cfg(feature = "msl-out")]
+pub mod msl;
+#[cfg(feature = "spv-out")]
+pub mod spv;
+#[cfg(feature = "wgsl-out")]
+pub mod wgsl;
+
+const COMPONENTS: &[char] = &['x', 'y', 'z', 'w'];
+const INDENT: &str = "    ";
+const BAKE_PREFIX: &str = "_e";
+
+type NeedBakeExpressions = crate::FastHashSet<crate::Handle<crate::Expression>>;
+
+#[derive(Clone, Copy)]
+struct Level(usize);
+
+impl Level {
+    const fn next(&self) -> Self {
+        Level(self.0 + 1)
+    }
+}
+
+impl std::fmt::Display for Level {
+    fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
+        (0..self.0).try_for_each(|_| formatter.write_str(INDENT))
+    }
+}
+
+/// Whether we're generating an entry point or a regular function.
+///
+/// Backend languages often require different code for a [`Function`]
+/// depending on whether it represents an [`EntryPoint`] or not.
+/// Backends can pass common code one of these values to select the
+/// right behavior.
+///
+/// These values also carry enough information to find the `Function`
+/// in the [`Module`]: the `Handle` for a regular function, or the
+/// index into [`Module::entry_points`] for an entry point.
+///
+/// [`Function`]: crate::Function
+/// [`EntryPoint`]: crate::EntryPoint
+/// [`Module`]: crate::Module
+/// [`Module::entry_points`]: crate::Module::entry_points
+enum FunctionType {
+    /// A regular function.
+    Function(crate::Handle<crate::Function>),
+    /// An [`EntryPoint`], and its index in [`Module::entry_points`].
+    ///
+    /// [`EntryPoint`]: crate::EntryPoint
+    /// [`Module::entry_points`]: crate::Module::entry_points
+    EntryPoint(crate::proc::EntryPointIndex),
+}
+
+impl FunctionType {
+    fn is_compute_entry_point(&self, module: &crate::Module) -> bool {
+        match *self {
+            FunctionType::EntryPoint(index) => {
+                module.entry_points[index as usize].stage == crate::ShaderStage::Compute
+            }
+            FunctionType::Function(_) => false,
+        }
+    }
+}
+
+/// Helper structure that stores data needed when writing the function
+struct FunctionCtx<'a> {
+    /// The current function being written
+    ty: FunctionType,
+    /// Analysis about the function
+    info: &'a crate::valid::FunctionInfo,
+    /// The expression arena of the current function being written
+    expressions: &'a crate::Arena<crate::Expression>,
+    /// Map of expressions that have associated variable names
+    named_expressions: &'a crate::NamedExpressions,
+}
+
+impl FunctionCtx<'_> {
+    fn resolve_type<'a>(
+        &'a self,
+        handle: crate::Handle<crate::Expression>,
+        types: &'a crate::UniqueArena<crate::Type>,
+    ) -> &'a crate::TypeInner {
+        self.info[handle].ty.inner_with(types)
+    }
+
+    /// Helper method that generates a [`NameKey`](crate::proc::NameKey) for a local in the current function
+    const fn name_key(&self, local: crate::Handle<crate::LocalVariable>) -> crate::proc::NameKey {
+        match self.ty {
+            FunctionType::Function(handle) => crate::proc::NameKey::FunctionLocal(handle, local),
+            FunctionType::EntryPoint(idx) => crate::proc::NameKey::EntryPointLocal(idx, local),
+        }
+    }
+
+    /// Helper method that generates a [`NameKey`](crate::proc::NameKey) for a function argument.
+    ///
+    /// # Panics
+    /// - If the function arguments are less or equal to `arg`
+    const fn argument_key(&self, arg: u32) -> crate::proc::NameKey {
+        match self.ty {
+            FunctionType::Function(handle) => crate::proc::NameKey::FunctionArgument(handle, arg),
+            FunctionType::EntryPoint(ep_index) => {
+                crate::proc::NameKey::EntryPointArgument(ep_index, arg)
+            }
+        }
+    }
+
+    // Returns true if the given expression points to a fixed-function pipeline input.
+    fn is_fixed_function_input(
+        &self,
+        mut expression: crate::Handle<crate::Expression>,
+        module: &crate::Module,
+    ) -> Option<crate::BuiltIn> {
+        let ep_function = match self.ty {
+            FunctionType::Function(_) => return None,
+            FunctionType::EntryPoint(ep_index) => &module.entry_points[ep_index as usize].function,
+        };
+        let mut built_in = None;
+        loop {
+            match self.expressions[expression] {
+                crate::Expression::FunctionArgument(arg_index) => {
+                    return match ep_function.arguments[arg_index as usize].binding {
+                        Some(crate::Binding::BuiltIn(bi)) => Some(bi),
+                        _ => built_in,
+                    };
+                }
+                crate::Expression::AccessIndex { base, index } => {
+                    match *self.resolve_type(base, &module.types) {
+                        crate::TypeInner::Struct { ref members, .. } => {
+                            if let Some(crate::Binding::BuiltIn(bi)) =
+                                members[index as usize].binding
+                            {
+                                built_in = Some(bi);
+                            }
+                        }
+                        _ => return None,
+                    }
+                    expression = base;
+                }
+                _ => return None,
+            }
+        }
+    }
+}
+
+impl crate::Expression {
+    /// Returns the ref count, upon reaching which this expression
+    /// should be considered for baking.
+    ///
+    /// Note: we have to cache any expressions that depend on the control flow,
+    /// or otherwise they may be moved into a non-uniform control flow, accidentally.
+    /// See the [module-level documentation][emit] for details.
+    ///
+    /// [emit]: index.html#expression-evaluation-time
+    const fn bake_ref_count(&self) -> usize {
+        match *self {
+            // accesses are never cached, only loads are
+            crate::Expression::Access { .. } | crate::Expression::AccessIndex { .. } => usize::MAX,
+            // sampling may use the control flow, and image ops look better by themselves
+            crate::Expression::ImageSample { .. } | crate::Expression::ImageLoad { .. } => 1,
+            // derivatives use the control flow
+            crate::Expression::Derivative { .. } => 1,
+            // TODO: We need a better fix for named `Load` expressions
+            // More info - https://github.com/gfx-rs/naga/pull/914
+            // And https://github.com/gfx-rs/naga/issues/910
+            crate::Expression::Load { .. } => 1,
+            // cache expressions that are referenced multiple times
+            _ => 2,
+        }
+    }
+}
+
+/// Helper function that returns the string corresponding to the [`BinaryOperator`](crate::BinaryOperator)
+/// # Notes
+/// Used by `glsl-out`, `msl-out`, `wgsl-out`, `hlsl-out`.
+const fn binary_operation_str(op: crate::BinaryOperator) -> &'static str {
+    use crate::BinaryOperator as Bo;
+    match op {
+        Bo::Add => "+",
+        Bo::Subtract => "-",
+        Bo::Multiply => "*",
+        Bo::Divide => "/",
+        Bo::Modulo => "%",
+        Bo::Equal => "==",
+        Bo::NotEqual => "!=",
+        Bo::Less => "<",
+        Bo::LessEqual => "<=",
+        Bo::Greater => ">",
+        Bo::GreaterEqual => ">=",
+        Bo::And => "&",
+        Bo::ExclusiveOr => "^",
+        Bo::InclusiveOr => "|",
+        Bo::LogicalAnd => "&&",
+        Bo::LogicalOr => "||",
+        Bo::ShiftLeft => "<<",
+        Bo::ShiftRight => ">>",
+    }
+}
+
+/// Helper function that returns the string corresponding to the [`VectorSize`](crate::VectorSize)
+/// # Notes
+/// Used by `msl-out`, `wgsl-out`, `hlsl-out`.
+const fn vector_size_str(size: crate::VectorSize) -> &'static str {
+    match size {
+        crate::VectorSize::Bi => "2",
+        crate::VectorSize::Tri => "3",
+        crate::VectorSize::Quad => "4",
+    }
+}
+
+impl crate::TypeInner {
+    const fn is_handle(&self) -> bool {
+        match *self {
+            crate::TypeInner::Image { .. } | crate::TypeInner::Sampler { .. } => true,
+            _ => false,
+        }
+    }
+}
+
+impl crate::Statement {
+    /// Returns true if the statement directly terminates the current block.
+    ///
+    /// Used to decide whether case blocks require a explicit `break`.
+    pub const fn is_terminator(&self) -> bool {
+        match *self {
+            crate::Statement::Break
+            | crate::Statement::Continue
+            | crate::Statement::Return { .. }
+            | crate::Statement::Kill => true,
+            _ => false,
+        }
+    }
+}
+
+bitflags::bitflags! {
+    /// Ray flags, for a [`RayDesc`]'s `flags` field.
+    ///
+    /// Note that these exactly correspond to the SPIR-V "Ray Flags" mask, and
+    /// the SPIR-V backend passes them directly through to the
+    /// `OpRayQueryInitializeKHR` instruction. (We have to choose something, so
+    /// we might as well make one back end's life easier.)
+    ///
+    /// [`RayDesc`]: crate::Module::generate_ray_desc_type
+    #[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
+    pub struct RayFlag: u32 {
+        const OPAQUE = 0x01;
+        const NO_OPAQUE = 0x02;
+        const TERMINATE_ON_FIRST_HIT = 0x04;
+        const SKIP_CLOSEST_HIT_SHADER = 0x08;
+        const CULL_BACK_FACING = 0x10;
+        const CULL_FRONT_FACING = 0x20;
+        const CULL_OPAQUE = 0x40;
+        const CULL_NO_OPAQUE = 0x80;
+        const SKIP_TRIANGLES = 0x100;
+        const SKIP_AABBS = 0x200;
+    }
+}
+
+#[repr(u32)]
+enum RayIntersectionType {
+    Triangle = 1,
+    BoundingBox = 4,
+}
diff --git a/third_party/rust/naga/src/back/msl/keywords.rs b/third_party/rust/naga/src/back/msl/keywords.rs
new file mode 100644
index 0000000000..f0025bf239
--- /dev/null
+++ b/third_party/rust/naga/src/back/msl/keywords.rs
@@ -0,0 +1,342 @@
+// MSLS - Metal Shading Language Specification:
+// https://developer.apple.com/metal/Metal-Shading-Language-Specification.pdf
+//
+// C++ - Standard for Programming Language C++ (N4431)
+// https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4431.pdf
+pub const RESERVED: &[&str] = &[
+    // Standard for Programming Language C++ (N4431): 2.5 Alternative tokens
+    "and",
+    "bitor",
+    "or",
+    "xor",
+    "compl",
+    "bitand",
+    "and_eq",
+    "or_eq",
+    "xor_eq",
+    "not",
+    "not_eq",
+    // Standard for Programming Language C++ (N4431): 2.11 Keywords
+    "alignas",
+    "alignof",
+    "asm",
+    "auto",
+    "bool",
+    "break",
+    "case",
+    "catch",
+    "char",
+    "char16_t",
+    "char32_t",
+    "class",
+    "const",
+    "constexpr",
+    "const_cast",
+    "continue",
+    "decltype",
+    "default",
+    "delete",
+    "do",
+    "double",
+    "dynamic_cast",
+    "else",
+    "enum",
+    "explicit",
+    "export",
+    "extern",
+    "false",
+    "float",
+    "for",
+    "friend",
+    "goto",
+    "if",
+    "inline",
+    "int",
+    "long",
+    "mutable",
+    "namespace",
+    "new",
+    "noexcept",
+    "nullptr",
+    "operator",
+    "private",
+    "protected",
+    "public",
+    "register",
+    "reinterpret_cast",
+    "return",
+    "short",
+    "signed",
+    "sizeof",
+    "static",
+    "static_assert",
+    "static_cast",
+    "struct",
+    "switch",
+    "template",
+    "this",
+    "thread_local",
+    "throw",
+    "true",
+    "try",
+    "typedef",
+    "typeid",
+    "typename",
+    "union",
+    "unsigned",
+    "using",
+    "virtual",
+    "void",
+    "volatile",
+    "wchar_t",
+    "while",
+    // Metal Shading Language Specification: 1.4.4 Restrictions
+    "main",
+    // Metal Shading Language Specification: 2.1 Scalar Data Types
+    "int8_t",
+    "uchar",
+    "uint8_t",
+    "int16_t",
+    "ushort",
+    "uint16_t",
+    "int32_t",
+    "uint",
+    "uint32_t",
+    "int64_t",
+    "uint64_t",
+    "half",
+    "bfloat",
+    "size_t",
+    "ptrdiff_t",
+    // Metal Shading Language Specification: 2.2 Vector Data Types
+    "bool2",
+    "bool3",
+    "bool4",
+    "char2",
+    "char3",
+    "char4",
+    "short2",
+    "short3",
+    "short4",
+    "int2",
+    "int3",
+    "int4",
+    "long2",
+    "long3",
+    "long4",
+    "uchar2",
+    "uchar3",
+    "uchar4",
+    "ushort2",
+    "ushort3",
+    "ushort4",
+    "uint2",
+    "uint3",
+    "uint4",
+    "ulong2",
+    "ulong3",
+    "ulong4",
+    "half2",
+    "half3",
+    "half4",
+    "bfloat2",
+    "bfloat3",
+    "bfloat4",
+    "float2",
+    "float3",
+    "float4",
+    "vec",
+    // Metal Shading Language Specification: 2.2.3 Packed Vector Types
+    "packed_bool2",
+    "packed_bool3",
+    "packed_bool4",
+    "packed_char2",
+    "packed_char3",
+    "packed_char4",
+    "packed_short2",
+    "packed_short3",
+    "packed_short4",
+    "packed_int2",
+    "packed_int3",
+    "packed_int4",
+    "packed_uchar2",
+    "packed_uchar3",
+    "packed_uchar4",
+    "packed_ushort2",
+    "packed_ushort3",
+    "packed_ushort4",
+    "packed_uint2",
+    "packed_uint3",
+    "packed_uint4",
+    "packed_half2",
+    "packed_half3",
+    "packed_half4",
+    "packed_bfloat2",
+    "packed_bfloat3",
+    "packed_bfloat4",
+    "packed_float2",
+    "packed_float3",
+    "packed_float4",
+    "packed_long2",
+    "packed_long3",
+    "packed_long4",
+    "packed_vec",
+    // Metal Shading Language Specification: 2.3 Matrix Data Types
+    "half2x2",
+    "half2x3",
+    "half2x4",
+    "half3x2",
+    "half3x3",
+    "half3x4",
+    "half4x2",
+    "half4x3",
+    "half4x4",
+    "float2x2",
+    "float2x3",
+    "float2x4",
+    "float3x2",
+    "float3x3",
+    "float3x4",
+    "float4x2",
+    "float4x3",
+    "float4x4",
+    "matrix",
+    // Metal Shading Language Specification: 2.6 Atomic Data Types
+    "atomic",
+    "atomic_int",
+    "atomic_uint",
+    "atomic_bool",
+    "atomic_ulong",
+    "atomic_float",
+    // Metal Shading Language Specification: 2.20 Type Conversions and Re-interpreting Data
+    "as_type",
+    // Metal Shading Language Specification: 4 Address Spaces
+    "device",
+    "constant",
+    "thread",
+    "threadgroup",
+    "threadgroup_imageblock",
+    "ray_data",
+    "object_data",
+    // Metal Shading Language Specification: 5.1 Functions
+    "vertex",
+    "fragment",
+    "kernel",
+    // Metal Shading Language Specification: 6.1 Namespace and Header Files
+    "metal",
+    // C99 / C++ extension:
+    "restrict",
+    // Metal reserved types in <metal_types>:
+    "llong",
+    "ullong",
+    "quad",
+    "complex",
+    "imaginary",
+    // Constants in <metal_types>:
+    "CHAR_BIT",
+    "SCHAR_MAX",
+    "SCHAR_MIN",
+    "UCHAR_MAX",
+    "CHAR_MAX",
+    "CHAR_MIN",
+    "USHRT_MAX",
+    "SHRT_MAX",
+    "SHRT_MIN",
+    "UINT_MAX",
+    "INT_MAX",
+    "INT_MIN",
+    "ULONG_MAX",
+    "LONG_MAX",
+    "LONG_MIN",
+    "ULLONG_MAX",
+    "LLONG_MAX",
+    "LLONG_MIN",
+    "FLT_DIG",
+    "FLT_MANT_DIG",
+    "FLT_MAX_10_EXP",
+    "FLT_MAX_EXP",
+    "FLT_MIN_10_EXP",
+    "FLT_MIN_EXP",
+    "FLT_RADIX",
+    "FLT_MAX",
+    "FLT_MIN",
+    "FLT_EPSILON",
+    "FLT_DECIMAL_DIG",
+    "FP_ILOGB0",
+    "FP_ILOGB0",
+    "FP_ILOGBNAN",
+    "FP_ILOGBNAN",
+    "MAXFLOAT",
+    "HUGE_VALF",
+    "INFINITY",
+    "NAN",
+    "M_E_F",
+    "M_LOG2E_F",
+    "M_LOG10E_F",
+    "M_LN2_F",
+    "M_LN10_F",
+    "M_PI_F",
+    "M_PI_2_F",
+    "M_PI_4_F",
+    "M_1_PI_F",
+    "M_2_PI_F",
+    "M_2_SQRTPI_F",
+    "M_SQRT2_F",
+    "M_SQRT1_2_F",
+    "HALF_DIG",
+    "HALF_MANT_DIG",
+    "HALF_MAX_10_EXP",
+    "HALF_MAX_EXP",
+    "HALF_MIN_10_EXP",
+    "HALF_MIN_EXP",
+    "HALF_RADIX",
+    "HALF_MAX",
+    "HALF_MIN",
+    "HALF_EPSILON",
+    "HALF_DECIMAL_DIG",
+    "MAXHALF",
+    "HUGE_VALH",
+    "M_E_H",
+    "M_LOG2E_H",
+    "M_LOG10E_H",
+    "M_LN2_H",
+    "M_LN10_H",
+    "M_PI_H",
+    "M_PI_2_H",
+    "M_PI_4_H",
+    "M_1_PI_H",
+    "M_2_PI_H",
+    "M_2_SQRTPI_H",
+    "M_SQRT2_H",
+    "M_SQRT1_2_H",
+    "DBL_DIG",
+    "DBL_MANT_DIG",
+    "DBL_MAX_10_EXP",
+    "DBL_MAX_EXP",
+    "DBL_MIN_10_EXP",
+    "DBL_MIN_EXP",
+    "DBL_RADIX",
+    "DBL_MAX",
+    "DBL_MIN",
+    "DBL_EPSILON",
+    "DBL_DECIMAL_DIG",
+    "MAXDOUBLE",
+    "HUGE_VAL",
+    "M_E",
+    "M_LOG2E",
+    "M_LOG10E",
+    "M_LN2",
+    "M_LN10",
+    "M_PI",
+    "M_PI_2",
+    "M_PI_4",
+    "M_1_PI",
+    "M_2_PI",
+    "M_2_SQRTPI",
+    "M_SQRT2",
+    "M_SQRT1_2",
+    // Naga utilities
+    "DefaultConstructible",
+    super::writer::FREXP_FUNCTION,
+    super::writer::MODF_FUNCTION,
+];
diff --git a/third_party/rust/naga/src/back/msl/mod.rs b/third_party/rust/naga/src/back/msl/mod.rs
new file mode 100644
index 0000000000..5ef18730c9
--- /dev/null
+++ b/third_party/rust/naga/src/back/msl/mod.rs
@@ -0,0 +1,541 @@
+/*!
+Backend for [MSL][msl] (Metal Shading Language).
+
+## Binding model
+
+Metal's bindings are flat per resource. Since there isn't an obvious mapping
+from SPIR-V's descriptor sets, we require a separate mapping provided in the options.
+This mapping may have one or more resource end points for each descriptor set + index
+pair.
+
+## Entry points
+
+Even though MSL and our IR appear to be similar in that the entry points in both can
+accept arguments and return values, the restrictions are different.
+MSL allows the varyings to be either in separate arguments, or inside a single
+`[[stage_in]]` struct. We gather input varyings and form this artificial structure.
+We also add all the (non-Private) globals into the arguments.
+
+At the beginning of the entry point, we assign the local constants and re-compose
+the arguments as they are declared on IR side, so that the rest of the logic can
+pretend that MSL doesn't have all the restrictions it has.
+
+For the result type, if it's a structure, we re-compose it with a temporary value
+holding the result.
+
+[msl]: https://developer.apple.com/metal/Metal-Shading-Language-Specification.pdf
+*/
+
+use crate::{arena::Handle, proc::index, valid::ModuleInfo};
+use std::fmt::{Error as FmtError, Write};
+
+mod keywords;
+pub mod sampler;
+mod writer;
+
+pub use writer::Writer;
+
+pub type Slot = u8;
+pub type InlineSamplerIndex = u8;
+
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub enum BindSamplerTarget {
+    Resource(Slot),
+    Inline(InlineSamplerIndex),
+}
+
+#[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+#[cfg_attr(any(feature = "serialize", feature = "deserialize"), serde(default))]
+pub struct BindTarget {
+    pub buffer: Option<Slot>,
+    pub texture: Option<Slot>,
+    pub sampler: Option<BindSamplerTarget>,
+    /// If the binding is an unsized binding array, this overrides the size.
+    pub binding_array_size: Option<u32>,
+    pub mutable: bool,
+}
+
+// Using `BTreeMap` instead of `HashMap` so that we can hash itself.
+pub type BindingMap = std::collections::BTreeMap<crate::ResourceBinding, BindTarget>;
+
+#[derive(Clone, Debug, Default, Hash, Eq, PartialEq)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+#[cfg_attr(any(feature = "serialize", feature = "deserialize"), serde(default))]
+pub struct EntryPointResources {
+    pub resources: BindingMap,
+
+    pub push_constant_buffer: Option<Slot>,
+
+    /// The slot of a buffer that contains an array of `u32`,
+    /// one for the size of each bound buffer that contains a runtime array,
+    /// in order of [`crate::GlobalVariable`] declarations.
+    pub sizes_buffer: Option<Slot>,
+}
+
+pub type EntryPointResourceMap = std::collections::BTreeMap<String, EntryPointResources>;
+
+enum ResolvedBinding {
+    BuiltIn(crate::BuiltIn),
+    Attribute(u32),
+    Color {
+        location: u32,
+        second_blend_source: bool,
+    },
+    User {
+        prefix: &'static str,
+        index: u32,
+        interpolation: Option<ResolvedInterpolation>,
+    },
+    Resource(BindTarget),
+}
+
+#[derive(Copy, Clone)]
+enum ResolvedInterpolation {
+    CenterPerspective,
+    CenterNoPerspective,
+    CentroidPerspective,
+    CentroidNoPerspective,
+    SamplePerspective,
+    SampleNoPerspective,
+    Flat,
+}
+
+// Note: some of these should be removed in favor of proper IR validation.
+
+#[derive(Debug, thiserror::Error)]
+pub enum Error {
+    #[error(transparent)]
+    Format(#[from] FmtError),
+    #[error("bind target {0:?} is empty")]
+    UnimplementedBindTarget(BindTarget),
+    #[error("composing of {0:?} is not implemented yet")]
+    UnsupportedCompose(Handle<crate::Type>),
+    #[error("operation {0:?} is not implemented yet")]
+    UnsupportedBinaryOp(crate::BinaryOperator),
+    #[error("standard function '{0}' is not implemented yet")]
+    UnsupportedCall(String),
+    #[error("feature '{0}' is not implemented yet")]
+    FeatureNotImplemented(String),
+    #[error("module is not valid")]
+    Validation,
+    #[error("BuiltIn {0:?} is not supported")]
+    UnsupportedBuiltIn(crate::BuiltIn),
+    #[error("capability {0:?} is not supported")]
+    CapabilityNotSupported(crate::valid::Capabilities),
+    #[error("attribute '{0}' is not supported for target MSL version")]
+    UnsupportedAttribute(String),
+    #[error("function '{0}' is not supported for target MSL version")]
+    UnsupportedFunction(String),
+    #[error("can not use writeable storage buffers in fragment stage prior to MSL 1.2")]
+    UnsupportedWriteableStorageBuffer,
+    #[error("can not use writeable storage textures in {0:?} stage prior to MSL 1.2")]
+    UnsupportedWriteableStorageTexture(crate::ShaderStage),
+    #[error("can not use read-write storage textures prior to MSL 1.2")]
+    UnsupportedRWStorageTexture,
+    #[error("array of '{0}' is not supported for target MSL version")]
+    UnsupportedArrayOf(String),
+    #[error("array of type '{0:?}' is not supported")]
+    UnsupportedArrayOfType(Handle<crate::Type>),
+    #[error("ray tracing is not supported prior to MSL 2.3")]
+    UnsupportedRayTracing,
+}
+
+#[derive(Clone, Debug, PartialEq, thiserror::Error)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub enum EntryPointError {
+    #[error("global '{0}' doesn't have a binding")]
+    MissingBinding(String),
+    #[error("mapping of {0:?} is missing")]
+    MissingBindTarget(crate::ResourceBinding),
+    #[error("mapping for push constants is missing")]
+    MissingPushConstants,
+    #[error("mapping for sizes buffer is missing")]
+    MissingSizesBuffer,
+}
+
+/// Points in the MSL code where we might emit a pipeline input or output.
+///
+/// Note that, even though vertex shaders' outputs are always fragment
+/// shaders' inputs, we still need to distinguish `VertexOutput` and
+/// `FragmentInput`, since there are certain differences in the way
+/// [`ResolvedBinding`s] are represented on either side.
+///
+/// [`ResolvedBinding`s]: ResolvedBinding
+#[derive(Clone, Copy, Debug)]
+enum LocationMode {
+    /// Input to the vertex shader.
+    VertexInput,
+
+    /// Output from the vertex shader.
+    VertexOutput,
+
+    /// Input to the fragment shader.
+    FragmentInput,
+
+    /// Output from the fragment shader.
+    FragmentOutput,
+
+    /// Compute shader input or output.
+    Uniform,
+}
+
+#[derive(Clone, Debug, Hash, PartialEq, Eq)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub struct Options {
+    /// (Major, Minor) target version of the Metal Shading Language.
+    pub lang_version: (u8, u8),
+    /// Map of entry-point resources, indexed by entry point function name, to slots.
+    pub per_entry_point_map: EntryPointResourceMap,
+    /// Samplers to be inlined into the code.
+    pub inline_samplers: Vec<sampler::InlineSampler>,
+    /// Make it possible to link different stages via SPIRV-Cross.
+    pub spirv_cross_compatibility: bool,
+    /// Don't panic on missing bindings, instead generate invalid MSL.
+    pub fake_missing_bindings: bool,
+    /// Bounds checking policies.
+    #[cfg_attr(feature = "deserialize", serde(default))]
+    pub bounds_check_policies: index::BoundsCheckPolicies,
+    /// Should workgroup variables be zero initialized (by polyfilling)?
+    pub zero_initialize_workgroup_memory: bool,
+}
+
+impl Default for Options {
+    fn default() -> Self {
+        Options {
+            lang_version: (1, 0),
+            per_entry_point_map: EntryPointResourceMap::default(),
+            inline_samplers: Vec::new(),
+            spirv_cross_compatibility: false,
+            fake_missing_bindings: true,
+            bounds_check_policies: index::BoundsCheckPolicies::default(),
+            zero_initialize_workgroup_memory: true,
+        }
+    }
+}
+
+/// A subset of options that are meant to be changed per pipeline.
+#[derive(Debug, Default, Clone, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub struct PipelineOptions {
+    /// Allow `BuiltIn::PointSize` and inject it if doesn't exist.
+    ///
+    /// Metal doesn't like this for non-point primitive topologies and requires it for
+    /// point primitive topologies.
+    ///
+    /// Enable this for vertex shaders with point primitive topologies.
+    pub allow_and_force_point_size: bool,
+}
+
+impl Options {
+    fn resolve_local_binding(
+        &self,
+        binding: &crate::Binding,
+        mode: LocationMode,
+    ) -> Result<ResolvedBinding, Error> {
+        match *binding {
+            crate::Binding::BuiltIn(mut built_in) => {
+                match built_in {
+                    crate::BuiltIn::Position { ref mut invariant } => {
+                        if *invariant && self.lang_version < (2, 1) {
+                            return Err(Error::UnsupportedAttribute("invariant".to_string()));
+                        }
+
+                        // The 'invariant' attribute may only appear on vertex
+                        // shader outputs, not fragment shader inputs.
+                        if !matches!(mode, LocationMode::VertexOutput) {
+                            *invariant = false;
+                        }
+                    }
+                    crate::BuiltIn::BaseInstance if self.lang_version < (1, 2) => {
+                        return Err(Error::UnsupportedAttribute("base_instance".to_string()));
+                    }
+                    crate::BuiltIn::InstanceIndex if self.lang_version < (1, 2) => {
+                        return Err(Error::UnsupportedAttribute("instance_id".to_string()));
+                    }
+                    // macOS: Since Metal 2.2
+                    // iOS: Since Metal 2.3 (check depends on https://github.com/gfx-rs/naga/issues/2164)
+                    crate::BuiltIn::PrimitiveIndex if self.lang_version < (2, 2) => {
+                        return Err(Error::UnsupportedAttribute("primitive_id".to_string()));
+                    }
+                    _ => {}
+                }
+
+                Ok(ResolvedBinding::BuiltIn(built_in))
+            }
+            crate::Binding::Location {
+                location,
+                interpolation,
+                sampling,
+                second_blend_source,
+            } => match mode {
+                LocationMode::VertexInput => Ok(ResolvedBinding::Attribute(location)),
+                LocationMode::FragmentOutput => {
+                    if second_blend_source && self.lang_version < (1, 2) {
+                        return Err(Error::UnsupportedAttribute(
+                            "second_blend_source".to_string(),
+                        ));
+                    }
+                    Ok(ResolvedBinding::Color {
+                        location,
+                        second_blend_source,
+                    })
+                }
+                LocationMode::VertexOutput | LocationMode::FragmentInput => {
+                    Ok(ResolvedBinding::User {
+                        prefix: if self.spirv_cross_compatibility {
+                            "locn"
+                        } else {
+                            "loc"
+                        },
+                        index: location,
+                        interpolation: {
+                            // unwrap: The verifier ensures that vertex shader outputs and fragment
+                            // shader inputs always have fully specified interpolation, and that
+                            // sampling is `None` only for Flat interpolation.
+                            let interpolation = interpolation.unwrap();
+                            let sampling = sampling.unwrap_or(crate::Sampling::Center);
+                            Some(ResolvedInterpolation::from_binding(interpolation, sampling))
+                        },
+                    })
+                }
+                LocationMode::Uniform => {
+                    log::error!(
+                        "Unexpected Binding::Location({}) for the Uniform mode",
+                        location
+                    );
+                    Err(Error::Validation)
+                }
+            },
+        }
+    }
+
+    fn get_entry_point_resources(&self, ep: &crate::EntryPoint) -> Option<&EntryPointResources> {
+        self.per_entry_point_map.get(&ep.name)
+    }
+
+    fn get_resource_binding_target(
+        &self,
+        ep: &crate::EntryPoint,
+        res_binding: &crate::ResourceBinding,
+    ) -> Option<&BindTarget> {
+        self.get_entry_point_resources(ep)
+            .and_then(|res| res.resources.get(res_binding))
+    }
+
+    fn resolve_resource_binding(
+        &self,
+        ep: &crate::EntryPoint,
+        res_binding: &crate::ResourceBinding,
+    ) -> Result<ResolvedBinding, EntryPointError> {
+        let target = self.get_resource_binding_target(ep, res_binding);
+        match target {
+            Some(target) => Ok(ResolvedBinding::Resource(target.clone())),
+            None if self.fake_missing_bindings => Ok(ResolvedBinding::User {
+                prefix: "fake",
+                index: 0,
+                interpolation: None,
+            }),
+            None => Err(EntryPointError::MissingBindTarget(res_binding.clone())),
+        }
+    }
+
+    fn resolve_push_constants(
+        &self,
+        ep: &crate::EntryPoint,
+    ) -> Result<ResolvedBinding, EntryPointError> {
+        let slot = self
+            .get_entry_point_resources(ep)
+            .and_then(|res| res.push_constant_buffer);
+        match slot {
+            Some(slot) => Ok(ResolvedBinding::Resource(BindTarget {
+                buffer: Some(slot),
+                ..Default::default()
+            })),
+            None if self.fake_missing_bindings => Ok(ResolvedBinding::User {
+                prefix: "fake",
+                index: 0,
+                interpolation: None,
+            }),
+            None => Err(EntryPointError::MissingPushConstants),
+        }
+    }
+
+    fn resolve_sizes_buffer(
+        &self,
+        ep: &crate::EntryPoint,
+    ) -> Result<ResolvedBinding, EntryPointError> {
+        let slot = self
+            .get_entry_point_resources(ep)
+            .and_then(|res| res.sizes_buffer);
+        match slot {
+            Some(slot) => Ok(ResolvedBinding::Resource(BindTarget {
+                buffer: Some(slot),
+                ..Default::default()
+            })),
+            None if self.fake_missing_bindings => Ok(ResolvedBinding::User {
+                prefix: "fake",
+                index: 0,
+                interpolation: None,
+            }),
+            None => Err(EntryPointError::MissingSizesBuffer),
+        }
+    }
+}
+
+impl ResolvedBinding {
+    fn as_inline_sampler<'a>(&self, options: &'a Options) -> Option<&'a sampler::InlineSampler> {
+        match *self {
+            Self::Resource(BindTarget {
+                sampler: Some(BindSamplerTarget::Inline(index)),
+                ..
+            }) => Some(&options.inline_samplers[index as usize]),
+            _ => None,
+        }
+    }
+
+    const fn as_bind_target(&self) -> Option<&BindTarget> {
+        match *self {
+            Self::Resource(ref target) => Some(target),
+            _ => None,
+        }
+    }
+
+    fn try_fmt<W: Write>(&self, out: &mut W) -> Result<(), Error> {
+        write!(out, " [[")?;
+        match *self {
+            Self::BuiltIn(built_in) => {
+                use crate::BuiltIn as Bi;
+                let name = match built_in {
+                    Bi::Position { invariant: false } => "position",
+                    Bi::Position { invariant: true } => "position, invariant",
+                    // vertex
+                    Bi::BaseInstance => "base_instance",
+                    Bi::BaseVertex => "base_vertex",
+                    Bi::ClipDistance => "clip_distance",
+                    Bi::InstanceIndex => "instance_id",
+                    Bi::PointSize => "point_size",
+                    Bi::VertexIndex => "vertex_id",
+                    // fragment
+                    Bi::FragDepth => "depth(any)",
+                    Bi::PointCoord => "point_coord",
+                    Bi::FrontFacing => "front_facing",
+                    Bi::PrimitiveIndex => "primitive_id",
+                    Bi::SampleIndex => "sample_id",
+                    Bi::SampleMask => "sample_mask",
+                    // compute
+                    Bi::GlobalInvocationId => "thread_position_in_grid",
+                    Bi::LocalInvocationId => "thread_position_in_threadgroup",
+                    Bi::LocalInvocationIndex => "thread_index_in_threadgroup",
+                    Bi::WorkGroupId => "threadgroup_position_in_grid",
+                    Bi::WorkGroupSize => "dispatch_threads_per_threadgroup",
+                    Bi::NumWorkGroups => "threadgroups_per_grid",
+                    Bi::CullDistance | Bi::ViewIndex => {
+                        return Err(Error::UnsupportedBuiltIn(built_in))
+                    }
+                };
+                write!(out, "{name}")?;
+            }
+            Self::Attribute(index) => write!(out, "attribute({index})")?,
+            Self::Color {
+                location,
+                second_blend_source,
+            } => {
+                if second_blend_source {
+                    write!(out, "color({location}) index(1)")?
+                } else {
+                    write!(out, "color({location})")?
+                }
+            }
+            Self::User {
+                prefix,
+                index,
+                interpolation,
+            } => {
+                write!(out, "user({prefix}{index})")?;
+                if let Some(interpolation) = interpolation {
+                    write!(out, ", ")?;
+                    interpolation.try_fmt(out)?;
+                }
+            }
+            Self::Resource(ref target) => {
+                if let Some(id) = target.buffer {
+                    write!(out, "buffer({id})")?;
+                } else if let Some(id) = target.texture {
+                    write!(out, "texture({id})")?;
+                } else if let Some(BindSamplerTarget::Resource(id)) = target.sampler {
+                    write!(out, "sampler({id})")?;
+                } else {
+                    return Err(Error::UnimplementedBindTarget(target.clone()));
+                }
+            }
+        }
+        write!(out, "]]")?;
+        Ok(())
+    }
+}
+
+impl ResolvedInterpolation {
+    const fn from_binding(interpolation: crate::Interpolation, sampling: crate::Sampling) -> Self {
+        use crate::Interpolation as I;
+        use crate::Sampling as S;
+
+        match (interpolation, sampling) {
+            (I::Perspective, S::Center) => Self::CenterPerspective,
+            (I::Perspective, S::Centroid) => Self::CentroidPerspective,
+            (I::Perspective, S::Sample) => Self::SamplePerspective,
+            (I::Linear, S::Center) => Self::CenterNoPerspective,
+            (I::Linear, S::Centroid) => Self::CentroidNoPerspective,
+            (I::Linear, S::Sample) => Self::SampleNoPerspective,
+            (I::Flat, _) => Self::Flat,
+        }
+    }
+
+    fn try_fmt<W: Write>(self, out: &mut W) -> Result<(), Error> {
+        let identifier = match self {
+            Self::CenterPerspective => "center_perspective",
+            Self::CenterNoPerspective => "center_no_perspective",
+            Self::CentroidPerspective => "centroid_perspective",
+            Self::CentroidNoPerspective => "centroid_no_perspective",
+            Self::SamplePerspective => "sample_perspective",
+            Self::SampleNoPerspective => "sample_no_perspective",
+            Self::Flat => "flat",
+        };
+        out.write_str(identifier)?;
+        Ok(())
+    }
+}
+
+/// Information about a translated module that is required
+/// for the use of the result.
+pub struct TranslationInfo {
+    /// Mapping of the entry point names. Each item in the array
+    /// corresponds to an entry point index.
+    ///
+    ///Note: Some entry points may fail translation because of missing bindings.
+    pub entry_point_names: Vec<Result<String, EntryPointError>>,
+}
+
+pub fn write_string(
+    module: &crate::Module,
+    info: &ModuleInfo,
+    options: &Options,
+    pipeline_options: &PipelineOptions,
+) -> Result<(String, TranslationInfo), Error> {
+    let mut w = writer::Writer::new(String::new());
+    let info = w.write(module, info, options, pipeline_options)?;
+    Ok((w.finish(), info))
+}
+
+#[test]
+fn test_error_size() {
+    use std::mem::size_of;
+    assert_eq!(size_of::<Error>(), 32);
+}
diff --git a/third_party/rust/naga/src/back/msl/sampler.rs b/third_party/rust/naga/src/back/msl/sampler.rs
new file mode 100644
index 0000000000..0bf987076d
--- /dev/null
+++ b/third_party/rust/naga/src/back/msl/sampler.rs
@@ -0,0 +1,176 @@
+#[cfg(feature = "deserialize")]
+use serde::Deserialize;
+#[cfg(feature = "serialize")]
+use serde::Serialize;
+use std::{num::NonZeroU32, ops::Range};
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+pub enum Coord {
+    Normalized,
+    Pixel,
+}
+
+impl Default for Coord {
+    fn default() -> Self {
+        Self::Normalized
+    }
+}
+
+impl Coord {
+    pub const fn as_str(&self) -> &'static str {
+        match *self {
+            Self::Normalized => "normalized",
+            Self::Pixel => "pixel",
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+pub enum Address {
+    Repeat,
+    MirroredRepeat,
+    ClampToEdge,
+    ClampToZero,
+    ClampToBorder,
+}
+
+impl Default for Address {
+    fn default() -> Self {
+        Self::ClampToEdge
+    }
+}
+
+impl Address {
+    pub const fn as_str(&self) -> &'static str {
+        match *self {
+            Self::Repeat => "repeat",
+            Self::MirroredRepeat => "mirrored_repeat",
+            Self::ClampToEdge => "clamp_to_edge",
+            Self::ClampToZero => "clamp_to_zero",
+            Self::ClampToBorder => "clamp_to_border",
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+pub enum BorderColor {
+    TransparentBlack,
+    OpaqueBlack,
+    OpaqueWhite,
+}
+
+impl Default for BorderColor {
+    fn default() -> Self {
+        Self::TransparentBlack
+    }
+}
+
+impl BorderColor {
+    pub const fn as_str(&self) -> &'static str {
+        match *self {
+            Self::TransparentBlack => "transparent_black",
+            Self::OpaqueBlack => "opaque_black",
+            Self::OpaqueWhite => "opaque_white",
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+pub enum Filter {
+    Nearest,
+    Linear,
+}
+
+impl Filter {
+    pub const fn as_str(&self) -> &'static str {
+        match *self {
+            Self::Nearest => "nearest",
+            Self::Linear => "linear",
+        }
+    }
+}
+
+impl Default for Filter {
+    fn default() -> Self {
+        Self::Nearest
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+pub enum CompareFunc {
+    Never,
+    Less,
+    LessEqual,
+    Greater,
+    GreaterEqual,
+    Equal,
+    NotEqual,
+    Always,
+}
+
+impl Default for CompareFunc {
+    fn default() -> Self {
+        Self::Never
+    }
+}
+
+impl CompareFunc {
+    pub const fn as_str(&self) -> &'static str {
+        match *self {
+            Self::Never => "never",
+            Self::Less => "less",
+            Self::LessEqual => "less_equal",
+            Self::Greater => "greater",
+            Self::GreaterEqual => "greater_equal",
+            Self::Equal => "equal",
+            Self::NotEqual => "not_equal",
+            Self::Always => "always",
+        }
+    }
+}
+
+#[derive(Clone, Debug, Default, PartialEq)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+pub struct InlineSampler {
+    pub coord: Coord,
+    pub address: [Address; 3],
+    pub border_color: BorderColor,
+    pub mag_filter: Filter,
+    pub min_filter: Filter,
+    pub mip_filter: Option<Filter>,
+    pub lod_clamp: Option<Range<f32>>,
+    pub max_anisotropy: Option<NonZeroU32>,
+    pub compare_func: CompareFunc,
+}
+
+impl Eq for InlineSampler {}
+
+#[allow(renamed_and_removed_lints)]
+#[allow(clippy::derive_hash_xor_eq)]
+impl std::hash::Hash for InlineSampler {
+    fn hash<H: std::hash::Hasher>(&self, hasher: &mut H) {
+        self.coord.hash(hasher);
+        self.address.hash(hasher);
+        self.border_color.hash(hasher);
+        self.mag_filter.hash(hasher);
+        self.min_filter.hash(hasher);
+        self.mip_filter.hash(hasher);
+        self.lod_clamp
+            .as_ref()
+            .map(|range| (range.start.to_bits(), range.end.to_bits()))
+            .hash(hasher);
+        self.max_anisotropy.hash(hasher);
+        self.compare_func.hash(hasher);
+    }
+}
diff --git a/third_party/rust/naga/src/back/msl/writer.rs b/third_party/rust/naga/src/back/msl/writer.rs
new file mode 100644
index 0000000000..1e496b5f50
--- /dev/null
+++ b/third_party/rust/naga/src/back/msl/writer.rs
@@ -0,0 +1,4659 @@
+use super::{sampler as sm, Error, LocationMode, Options, PipelineOptions, TranslationInfo};
+use crate::{
+    arena::Handle,
+    back,
+    proc::index,
+    proc::{self, NameKey, TypeResolution},
+    valid, FastHashMap, FastHashSet,
+};
+use bit_set::BitSet;
+use std::{
+    fmt::{Display, Error as FmtError, Formatter, Write},
+    iter,
+};
+
+/// Shorthand result used internally by the backend
+type BackendResult = Result<(), Error>;
+
+const NAMESPACE: &str = "metal";
+// The name of the array member of the Metal struct types we generate to
+// represent Naga `Array` types. See the comments in `Writer::write_type_defs`
+// for details.
+const WRAPPED_ARRAY_FIELD: &str = "inner";
+// This is a hack: we need to pass a pointer to an atomic,
+// but generally the backend isn't putting "&" in front of every pointer.
+// Some more general handling of pointers is needed to be implemented here.
+const ATOMIC_REFERENCE: &str = "&";
+
+const RT_NAMESPACE: &str = "metal::raytracing";
+const RAY_QUERY_TYPE: &str = "_RayQuery";
+const RAY_QUERY_FIELD_INTERSECTOR: &str = "intersector";
+const RAY_QUERY_FIELD_INTERSECTION: &str = "intersection";
+const RAY_QUERY_FIELD_READY: &str = "ready";
+const RAY_QUERY_FUN_MAP_INTERSECTION: &str = "_map_intersection_type";
+
+pub(crate) const MODF_FUNCTION: &str = "naga_modf";
+pub(crate) const FREXP_FUNCTION: &str = "naga_frexp";
+
+/// Write the Metal name for a Naga numeric type: scalar, vector, or matrix.
+///
+/// The `sizes` slice determines whether this function writes a
+/// scalar, vector, or matrix type:
+///
+/// - An empty slice produces a scalar type.
+/// - A one-element slice produces a vector type.
+/// - A two element slice `[ROWS COLUMNS]` produces a matrix of the given size.
+fn put_numeric_type(
+    out: &mut impl Write,
+    scalar: crate::Scalar,
+    sizes: &[crate::VectorSize],
+) -> Result<(), FmtError> {
+    match (scalar, sizes) {
+        (scalar, &[]) => {
+            write!(out, "{}", scalar.to_msl_name())
+        }
+        (scalar, &[rows]) => {
+            write!(
+                out,
+                "{}::{}{}",
+                NAMESPACE,
+                scalar.to_msl_name(),
+                back::vector_size_str(rows)
+            )
+        }
+        (scalar, &[rows, columns]) => {
+            write!(
+                out,
+                "{}::{}{}x{}",
+                NAMESPACE,
+                scalar.to_msl_name(),
+                back::vector_size_str(columns),
+                back::vector_size_str(rows)
+            )
+        }
+        (_, _) => Ok(()), // not meaningful
+    }
+}
+
+/// Prefix for cached clamped level-of-detail values for `ImageLoad` expressions.
+const CLAMPED_LOD_LOAD_PREFIX: &str = "clamped_lod_e";
+
+struct TypeContext<'a> {
+    handle: Handle<crate::Type>,
+    gctx: proc::GlobalCtx<'a>,
+    names: &'a FastHashMap<NameKey, String>,
+    access: crate::StorageAccess,
+    binding: Option<&'a super::ResolvedBinding>,
+    first_time: bool,
+}
+
+impl<'a> Display for TypeContext<'a> {
+    fn fmt(&self, out: &mut Formatter<'_>) -> Result<(), FmtError> {
+        let ty = &self.gctx.types[self.handle];
+        if ty.needs_alias() && !self.first_time {
+            let name = &self.names[&NameKey::Type(self.handle)];
+            return write!(out, "{name}");
+        }
+
+        match ty.inner {
+            crate::TypeInner::Scalar(scalar) => put_numeric_type(out, scalar, &[]),
+            crate::TypeInner::Atomic(scalar) => {
+                write!(out, "{}::atomic_{}", NAMESPACE, scalar.to_msl_name())
+            }
+            crate::TypeInner::Vector { size, scalar } => put_numeric_type(out, scalar, &[size]),
+            crate::TypeInner::Matrix { columns, rows, .. } => {
+                put_numeric_type(out, crate::Scalar::F32, &[rows, columns])
+            }
+            crate::TypeInner::Pointer { base, space } => {
+                let sub = Self {
+                    handle: base,
+                    first_time: false,
+                    ..*self
+                };
+                let space_name = match space.to_msl_name() {
+                    Some(name) => name,
+                    None => return Ok(()),
+                };
+                write!(out, "{space_name} {sub}&")
+            }
+            crate::TypeInner::ValuePointer {
+                size,
+                scalar,
+                space,
+            } => {
+                match space.to_msl_name() {
+                    Some(name) => write!(out, "{name} ")?,
+                    None => return Ok(()),
+                };
+                match size {
+                    Some(rows) => put_numeric_type(out, scalar, &[rows])?,
+                    None => put_numeric_type(out, scalar, &[])?,
+                };
+
+                write!(out, "&")
+            }
+            crate::TypeInner::Array { base, .. } => {
+                let sub = Self {
+                    handle: base,
+                    first_time: false,
+                    ..*self
+                };
+                // Array lengths go at the end of the type definition,
+                // so just print the element type here.
+                write!(out, "{sub}")
+            }
+            crate::TypeInner::Struct { .. } => unreachable!(),
+            crate::TypeInner::Image {
+                dim,
+                arrayed,
+                class,
+            } => {
+                let dim_str = match dim {
+                    crate::ImageDimension::D1 => "1d",
+                    crate::ImageDimension::D2 => "2d",
+                    crate::ImageDimension::D3 => "3d",
+                    crate::ImageDimension::Cube => "cube",
+                };
+                let (texture_str, msaa_str, kind, access) = match class {
+                    crate::ImageClass::Sampled { kind, multi } => {
+                        let (msaa_str, access) = if multi {
+                            ("_ms", "read")
+                        } else {
+                            ("", "sample")
+                        };
+                        ("texture", msaa_str, kind, access)
+                    }
+                    crate::ImageClass::Depth { multi } => {
+                        let (msaa_str, access) = if multi {
+                            ("_ms", "read")
+                        } else {
+                            ("", "sample")
+                        };
+                        ("depth", msaa_str, crate::ScalarKind::Float, access)
+                    }
+                    crate::ImageClass::Storage { format, .. } => {
+                        let access = if self
+                            .access
+                            .contains(crate::StorageAccess::LOAD | crate::StorageAccess::STORE)
+                        {
+                            "read_write"
+                        } else if self.access.contains(crate::StorageAccess::STORE) {
+                            "write"
+                        } else if self.access.contains(crate::StorageAccess::LOAD) {
+                            "read"
+                        } else {
+                            log::warn!(
+                                "Storage access for {:?} (name '{}'): {:?}",
+                                self.handle,
+                                ty.name.as_deref().unwrap_or_default(),
+                                self.access
+                            );
+                            unreachable!("module is not valid");
+                        };
+                        ("texture", "", format.into(), access)
+                    }
+                };
+                let base_name = crate::Scalar { kind, width: 4 }.to_msl_name();
+                let array_str = if arrayed { "_array" } else { "" };
+                write!(
+                    out,
+                    "{NAMESPACE}::{texture_str}{dim_str}{msaa_str}{array_str}<{base_name}, {NAMESPACE}::access::{access}>",
+                )
+            }
+            crate::TypeInner::Sampler { comparison: _ } => {
+                write!(out, "{NAMESPACE}::sampler")
+            }
+            crate::TypeInner::AccelerationStructure => {
+                write!(out, "{RT_NAMESPACE}::instance_acceleration_structure")
+            }
+            crate::TypeInner::RayQuery => {
+                write!(out, "{RAY_QUERY_TYPE}")
+            }
+            crate::TypeInner::BindingArray { base, size } => {
+                let base_tyname = Self {
+                    handle: base,
+                    first_time: false,
+                    ..*self
+                };
+
+                if let Some(&super::ResolvedBinding::Resource(super::BindTarget {
+                    binding_array_size: Some(override_size),
+                    ..
+                })) = self.binding
+                {
+                    write!(out, "{NAMESPACE}::array<{base_tyname}, {override_size}>")
+                } else if let crate::ArraySize::Constant(size) = size {
+                    write!(out, "{NAMESPACE}::array<{base_tyname}, {size}>")
+                } else {
+                    unreachable!("metal requires all arrays be constant sized");
+                }
+            }
+        }
+    }
+}
+
+struct TypedGlobalVariable<'a> {
+    module: &'a crate::Module,
+    names: &'a FastHashMap<NameKey, String>,
+    handle: Handle<crate::GlobalVariable>,
+    usage: valid::GlobalUse,
+    binding: Option<&'a super::ResolvedBinding>,
+    reference: bool,
+}
+
+impl<'a> TypedGlobalVariable<'a> {
+    fn try_fmt<W: Write>(&self, out: &mut W) -> BackendResult {
+        let var = &self.module.global_variables[self.handle];
+        let name = &self.names[&NameKey::GlobalVariable(self.handle)];
+
+        let storage_access = match var.space {
+            crate::AddressSpace::Storage { access } => access,
+            _ => match self.module.types[var.ty].inner {
+                crate::TypeInner::Image {
+                    class: crate::ImageClass::Storage { access, .. },
+                    ..
+                } => access,
+                crate::TypeInner::BindingArray { base, .. } => {
+                    match self.module.types[base].inner {
+                        crate::TypeInner::Image {
+                            class: crate::ImageClass::Storage { access, .. },
+                            ..
+                        } => access,
+                        _ => crate::StorageAccess::default(),
+                    }
+                }
+                _ => crate::StorageAccess::default(),
+            },
+        };
+        let ty_name = TypeContext {
+            handle: var.ty,
+            gctx: self.module.to_ctx(),
+            names: self.names,
+            access: storage_access,
+            binding: self.binding,
+            first_time: false,
+        };
+
+        let (space, access, reference) = match var.space.to_msl_name() {
+            Some(space) if self.reference => {
+                let access = if var.space.needs_access_qualifier()
+                    && !self.usage.contains(valid::GlobalUse::WRITE)
+                {
+                    "const"
+                } else {
+                    ""
+                };
+                (space, access, "&")
+            }
+            _ => ("", "", ""),
+        };
+
+        Ok(write!(
+            out,
+            "{}{}{}{}{}{} {}",
+            space,
+            if space.is_empty() { "" } else { " " },
+            ty_name,
+            if access.is_empty() { "" } else { " " },
+            access,
+            reference,
+            name,
+        )?)
+    }
+}
+
+pub struct Writer<W> {
+    out: W,
+    names: FastHashMap<NameKey, String>,
+    named_expressions: crate::NamedExpressions,
+    /// Set of expressions that need to be baked to avoid unnecessary repetition in output
+    need_bake_expressions: back::NeedBakeExpressions,
+    namer: proc::Namer,
+    #[cfg(test)]
+    put_expression_stack_pointers: FastHashSet<*const ()>,
+    #[cfg(test)]
+    put_block_stack_pointers: FastHashSet<*const ()>,
+    /// Set of (struct type, struct field index) denoting which fields require
+    /// padding inserted **before** them (i.e. between fields at index - 1 and index)
+    struct_member_pads: FastHashSet<(Handle<crate::Type>, u32)>,
+}
+
+impl crate::Scalar {
+    const fn to_msl_name(self) -> &'static str {
+        use crate::ScalarKind as Sk;
+        match self {
+            Self {
+                kind: Sk::Float,
+                width: _,
+            } => "float",
+            Self {
+                kind: Sk::Sint,
+                width: _,
+            } => "int",
+            Self {
+                kind: Sk::Uint,
+                width: _,
+            } => "uint",
+            Self {
+                kind: Sk::Bool,
+                width: _,
+            } => "bool",
+            Self {
+                kind: Sk::AbstractInt | Sk::AbstractFloat,
+                width: _,
+            } => unreachable!(),
+        }
+    }
+}
+
+const fn separate(need_separator: bool) -> &'static str {
+    if need_separator {
+        ","
+    } else {
+        ""
+    }
+}
+
+fn should_pack_struct_member(
+    members: &[crate::StructMember],
+    span: u32,
+    index: usize,
+    module: &crate::Module,
+) -> Option<crate::Scalar> {
+    let member = &members[index];
+
+    let ty_inner = &module.types[member.ty].inner;
+    let last_offset = member.offset + ty_inner.size(module.to_ctx());
+    let next_offset = match members.get(index + 1) {
+        Some(next) => next.offset,
+        None => span,
+    };
+    let is_tight = next_offset == last_offset;
+
+    match *ty_inner {
+        crate::TypeInner::Vector {
+            size: crate::VectorSize::Tri,
+            scalar: scalar @ crate::Scalar { width: 4, .. },
+        } if is_tight => Some(scalar),
+        _ => None,
+    }
+}
+
+fn needs_array_length(ty: Handle<crate::Type>, arena: &crate::UniqueArena<crate::Type>) -> bool {
+    match arena[ty].inner {
+        crate::TypeInner::Struct { ref members, .. } => {
+            if let Some(member) = members.last() {
+                if let crate::TypeInner::Array {
+                    size: crate::ArraySize::Dynamic,
+                    ..
+                } = arena[member.ty].inner
+                {
+                    return true;
+                }
+            }
+            false
+        }
+        crate::TypeInner::Array {
+            size: crate::ArraySize::Dynamic,
+            ..
+        } => true,
+        _ => false,
+    }
+}
+
+impl crate::AddressSpace {
+    /// Returns true if global variables in this address space are
+    /// passed in function arguments. These arguments need to be
+    /// passed through any functions called from the entry point.
+    const fn needs_pass_through(&self) -> bool {
+        match *self {
+            Self::Uniform
+            | Self::Storage { .. }
+            | Self::Private
+            | Self::WorkGroup
+            | Self::PushConstant
+            | Self::Handle => true,
+            Self::Function => false,
+        }
+    }
+
+    /// Returns true if the address space may need a "const" qualifier.
+    const fn needs_access_qualifier(&self) -> bool {
+        match *self {
+            //Note: we are ignoring the storage access here, and instead
+            // rely on the actual use of a global by functions. This means we
+            // may end up with "const" even if the binding is read-write,
+            // and that should be OK.
+            Self::Storage { .. } => true,
+            // These should always be read-write.
+            Self::Private | Self::WorkGroup => false,
+            // These translate to `constant` address space, no need for qualifiers.
+            Self::Uniform | Self::PushConstant => false,
+            // Not applicable.
+            Self::Handle | Self::Function => false,
+        }
+    }
+
+    const fn to_msl_name(self) -> Option<&'static str> {
+        match self {
+            Self::Handle => None,
+            Self::Uniform | Self::PushConstant => Some("constant"),
+            Self::Storage { .. } => Some("device"),
+            Self::Private | Self::Function => Some("thread"),
+            Self::WorkGroup => Some("threadgroup"),
+        }
+    }
+}
+
+impl crate::Type {
+    // Returns `true` if we need to emit an alias for this type.
+    const fn needs_alias(&self) -> bool {
+        use crate::TypeInner as Ti;
+
+        match self.inner {
+            // value types are concise enough, we only alias them if they are named
+            Ti::Scalar(_)
+            | Ti::Vector { .. }
+            | Ti::Matrix { .. }
+            | Ti::Atomic(_)
+            | Ti::Pointer { .. }
+            | Ti::ValuePointer { .. } => self.name.is_some(),
+            // composite types are better to be aliased, regardless of the name
+            Ti::Struct { .. } | Ti::Array { .. } => true,
+            // handle types may be different, depending on the global var access, so we always inline them
+            Ti::Image { .. }
+            | Ti::Sampler { .. }
+            | Ti::AccelerationStructure
+            | Ti::RayQuery
+            | Ti::BindingArray { .. } => false,
+        }
+    }
+}
+
+enum FunctionOrigin {
+    Handle(Handle<crate::Function>),
+    EntryPoint(proc::EntryPointIndex),
+}
+
+/// A level of detail argument.
+///
+/// When [`BoundsCheckPolicy::Restrict`] applies to an [`ImageLoad`] access, we
+/// save the clamped level of detail in a temporary variable whose name is based
+/// on the handle of the `ImageLoad` expression. But for other policies, we just
+/// use the expression directly.
+///
+/// [`BoundsCheckPolicy::Restrict`]: index::BoundsCheckPolicy::Restrict
+/// [`ImageLoad`]: crate::Expression::ImageLoad
+#[derive(Clone, Copy)]
+enum LevelOfDetail {
+    Direct(Handle<crate::Expression>),
+    Restricted(Handle<crate::Expression>),
+}
+
+/// Values needed to select a particular texel for [`ImageLoad`] and [`ImageStore`].
+///
+/// When this is used in code paths unconcerned with the `Restrict` bounds check
+/// policy, the `LevelOfDetail` enum introduces an unneeded match, since `level`
+/// will always be either `None` or `Some(Direct(_))`. But this turns out not to
+/// be too awkward. If that changes, we can revisit.
+///
+/// [`ImageLoad`]: crate::Expression::ImageLoad
+/// [`ImageStore`]: crate::Statement::ImageStore
+struct TexelAddress {
+    coordinate: Handle<crate::Expression>,
+    array_index: Option<Handle<crate::Expression>>,
+    sample: Option<Handle<crate::Expression>>,
+    level: Option<LevelOfDetail>,
+}
+
+struct ExpressionContext<'a> {
+    function: &'a crate::Function,
+    origin: FunctionOrigin,
+    info: &'a valid::FunctionInfo,
+    module: &'a crate::Module,
+    mod_info: &'a valid::ModuleInfo,
+    pipeline_options: &'a PipelineOptions,
+    lang_version: (u8, u8),
+    policies: index::BoundsCheckPolicies,
+
+    /// A bitset containing the `Expression` handle indexes of expressions used
+    /// as indices in `ReadZeroSkipWrite`-policy accesses. These may need to be
+    /// cached in temporary variables. See `index::find_checked_indexes` for
+    /// details.
+    guarded_indices: BitSet,
+}
+
+impl<'a> ExpressionContext<'a> {
+    fn resolve_type(&self, handle: Handle<crate::Expression>) -> &'a crate::TypeInner {
+        self.info[handle].ty.inner_with(&self.module.types)
+    }
+
+    /// Return true if calls to `image`'s `read` and `write` methods should supply a level of detail.
+    ///
+    /// Only mipmapped images need to specify a level of detail. Since 1D
+    /// textures cannot have mipmaps, MSL requires that the level argument to
+    /// texture1d queries and accesses must be a constexpr 0. It's easiest
+    /// just to omit the level entirely for 1D textures.
+    fn image_needs_lod(&self, image: Handle<crate::Expression>) -> bool {
+        let image_ty = self.resolve_type(image);
+        if let crate::TypeInner::Image { dim, class, .. } = *image_ty {
+            class.is_mipmapped() && dim != crate::ImageDimension::D1
+        } else {
+            false
+        }
+    }
+
+    fn choose_bounds_check_policy(
+        &self,
+        pointer: Handle<crate::Expression>,
+    ) -> index::BoundsCheckPolicy {
+        self.policies
+            .choose_policy(pointer, &self.module.types, self.info)
+    }
+
+    fn access_needs_check(
+        &self,
+        base: Handle<crate::Expression>,
+        index: index::GuardedIndex,
+    ) -> Option<index::IndexableLength> {
+        index::access_needs_check(base, index, self.module, self.function, self.info)
+    }
+
+    fn get_packed_vec_kind(&self, expr_handle: Handle<crate::Expression>) -> Option<crate::Scalar> {
+        match self.function.expressions[expr_handle] {
+            crate::Expression::AccessIndex { base, index } => {
+                let ty = match *self.resolve_type(base) {
+                    crate::TypeInner::Pointer { base, .. } => &self.module.types[base].inner,
+                    ref ty => ty,
+                };
+                match *ty {
+                    crate::TypeInner::Struct {
+                        ref members, span, ..
+                    } => should_pack_struct_member(members, span, index as usize, self.module),
+                    _ => None,
+                }
+            }
+            _ => None,
+        }
+    }
+}
+
+struct StatementContext<'a> {
+    expression: ExpressionContext<'a>,
+    result_struct: Option<&'a str>,
+}
+
+impl<W: Write> Writer<W> {
+    /// Creates a new `Writer` instance.
+    pub fn new(out: W) -> Self {
+        Writer {
+            out,
+            names: FastHashMap::default(),
+            named_expressions: Default::default(),
+            need_bake_expressions: Default::default(),
+            namer: proc::Namer::default(),
+            #[cfg(test)]
+            put_expression_stack_pointers: Default::default(),
+            #[cfg(test)]
+            put_block_stack_pointers: Default::default(),
+            struct_member_pads: FastHashSet::default(),
+        }
+    }
+
+    /// Finishes writing and returns the output.
+    // See https://github.com/rust-lang/rust-clippy/issues/4979.
+    #[allow(clippy::missing_const_for_fn)]
+    pub fn finish(self) -> W {
+        self.out
+    }
+
+    fn put_call_parameters(
+        &mut self,
+        parameters: impl Iterator<Item = Handle<crate::Expression>>,
+        context: &ExpressionContext,
+    ) -> BackendResult {
+        self.put_call_parameters_impl(parameters, context, |writer, context, expr| {
+            writer.put_expression(expr, context, true)
+        })
+    }
+
+    fn put_call_parameters_impl<C, E>(
+        &mut self,
+        parameters: impl Iterator<Item = Handle<crate::Expression>>,
+        ctx: &C,
+        put_expression: E,
+    ) -> BackendResult
+    where
+        E: Fn(&mut Self, &C, Handle<crate::Expression>) -> BackendResult,
+    {
+        write!(self.out, "(")?;
+        for (i, handle) in parameters.enumerate() {
+            if i != 0 {
+                write!(self.out, ", ")?;
+            }
+            put_expression(self, ctx, handle)?;
+        }
+        write!(self.out, ")")?;
+        Ok(())
+    }
+
+    fn put_level_of_detail(
+        &mut self,
+        level: LevelOfDetail,
+        context: &ExpressionContext,
+    ) -> BackendResult {
+        match level {
+            LevelOfDetail::Direct(expr) => self.put_expression(expr, context, true)?,
+            LevelOfDetail::Restricted(load) => {
+                write!(self.out, "{}{}", CLAMPED_LOD_LOAD_PREFIX, load.index())?
+            }
+        }
+        Ok(())
+    }
+
+    fn put_image_query(
+        &mut self,
+        image: Handle<crate::Expression>,
+        query: &str,
+        level: Option<LevelOfDetail>,
+        context: &ExpressionContext,
+    ) -> BackendResult {
+        self.put_expression(image, context, false)?;
+        write!(self.out, ".get_{query}(")?;
+        if let Some(level) = level {
+            self.put_level_of_detail(level, context)?;
+        }
+        write!(self.out, ")")?;
+        Ok(())
+    }
+
+    fn put_image_size_query(
+        &mut self,
+        image: Handle<crate::Expression>,
+        level: Option<LevelOfDetail>,
+        kind: crate::ScalarKind,
+        context: &ExpressionContext,
+    ) -> BackendResult {
+        //Note: MSL only has separate width/height/depth queries,
+        // so compose the result of them.
+        let dim = match *context.resolve_type(image) {
+            crate::TypeInner::Image { dim, .. } => dim,
+            ref other => unreachable!("Unexpected type {:?}", other),
+        };
+        let scalar = crate::Scalar { kind, width: 4 };
+        let coordinate_type = scalar.to_msl_name();
+        match dim {
+            crate::ImageDimension::D1 => {
+                // Since 1D textures never have mipmaps, MSL requires that the
+                // `level` argument be a constexpr 0. It's simplest for us just
+                // to pass `None` and omit the level entirely.
+                if kind == crate::ScalarKind::Uint {
+                    // No need to construct a vector. No cast needed.
+                    self.put_image_query(image, "width", None, context)?;
+                } else {
+                    // There's no definition for `int` in the `metal` namespace.
+                    write!(self.out, "int(")?;
+                    self.put_image_query(image, "width", None, context)?;
+                    write!(self.out, ")")?;
+                }
+            }
+            crate::ImageDimension::D2 => {
+                write!(self.out, "{NAMESPACE}::{coordinate_type}2(")?;
+                self.put_image_query(image, "width", level, context)?;
+                write!(self.out, ", ")?;
+                self.put_image_query(image, "height", level, context)?;
+                write!(self.out, ")")?;
+            }
+            crate::ImageDimension::D3 => {
+                write!(self.out, "{NAMESPACE}::{coordinate_type}3(")?;
+                self.put_image_query(image, "width", level, context)?;
+                write!(self.out, ", ")?;
+                self.put_image_query(image, "height", level, context)?;
+                write!(self.out, ", ")?;
+                self.put_image_query(image, "depth", level, context)?;
+                write!(self.out, ")")?;
+            }
+            crate::ImageDimension::Cube => {
+                write!(self.out, "{NAMESPACE}::{coordinate_type}2(")?;
+                self.put_image_query(image, "width", level, context)?;
+                write!(self.out, ")")?;
+            }
+        }
+        Ok(())
+    }
+
+    fn put_cast_to_uint_scalar_or_vector(
+        &mut self,
+        expr: Handle<crate::Expression>,
+        context: &ExpressionContext,
+    ) -> BackendResult {
+        // coordinates in IR are int, but Metal expects uint
+        match *context.resolve_type(expr) {
+            crate::TypeInner::Scalar(_) => {
+                put_numeric_type(&mut self.out, crate::Scalar::U32, &[])?
+            }
+            crate::TypeInner::Vector { size, .. } => {
+                put_numeric_type(&mut self.out, crate::Scalar::U32, &[size])?
+            }
+            _ => return Err(Error::Validation),
+        };
+
+        write!(self.out, "(")?;
+        self.put_expression(expr, context, true)?;
+        write!(self.out, ")")?;
+        Ok(())
+    }
+
+    fn put_image_sample_level(
+        &mut self,
+        image: Handle<crate::Expression>,
+        level: crate::SampleLevel,
+        context: &ExpressionContext,
+    ) -> BackendResult {
+        let has_levels = context.image_needs_lod(image);
+        match level {
+            crate::SampleLevel::Auto => {}
+            crate::SampleLevel::Zero => {
+                //TODO: do we support Zero on `Sampled` image classes?
+            }
+            _ if !has_levels => {
+                log::warn!("1D image can't be sampled with level {:?}", level);
+            }
+            crate::SampleLevel::Exact(h) => {
+                write!(self.out, ", {NAMESPACE}::level(")?;
+                self.put_expression(h, context, true)?;
+                write!(self.out, ")")?;
+            }
+            crate::SampleLevel::Bias(h) => {
+                write!(self.out, ", {NAMESPACE}::bias(")?;
+                self.put_expression(h, context, true)?;
+                write!(self.out, ")")?;
+            }
+            crate::SampleLevel::Gradient { x, y } => {
+                write!(self.out, ", {NAMESPACE}::gradient2d(")?;
+                self.put_expression(x, context, true)?;
+                write!(self.out, ", ")?;
+                self.put_expression(y, context, true)?;
+                write!(self.out, ")")?;
+            }
+        }
+        Ok(())
+    }
+
+    fn put_image_coordinate_limits(
+        &mut self,
+        image: Handle<crate::Expression>,
+        level: Option<LevelOfDetail>,
+        context: &ExpressionContext,
+    ) -> BackendResult {
+        self.put_image_size_query(image, level, crate::ScalarKind::Uint, context)?;
+        write!(self.out, " - 1")?;
+        Ok(())
+    }
+
+    /// General function for writing restricted image indexes.
+    ///
+    /// This is used to produce restricted mip levels, array indices, and sample
+    /// indices for [`ImageLoad`] and [`ImageStore`] accesses under the
+    /// [`Restrict`] bounds check policy.
+    ///
+    /// This function writes an expression of the form:
+    ///
+    /// ```ignore
+    ///
+    ///     metal::min(uint(INDEX), IMAGE.LIMIT_METHOD() - 1)
+    ///
+    /// ```
+    ///
+    /// [`ImageLoad`]: crate::Expression::ImageLoad
+    /// [`ImageStore`]: crate::Statement::ImageStore
+    /// [`Restrict`]: index::BoundsCheckPolicy::Restrict
+    fn put_restricted_scalar_image_index(
+        &mut self,
+        image: Handle<crate::Expression>,
+        index: Handle<crate::Expression>,
+        limit_method: &str,
+        context: &ExpressionContext,
+    ) -> BackendResult {
+        write!(self.out, "{NAMESPACE}::min(uint(")?;
+        self.put_expression(index, context, true)?;
+        write!(self.out, "), ")?;
+        self.put_expression(image, context, false)?;
+        write!(self.out, ".{limit_method}() - 1)")?;
+        Ok(())
+    }
+
+    fn put_restricted_texel_address(
+        &mut self,
+        image: Handle<crate::Expression>,
+        address: &TexelAddress,
+        context: &ExpressionContext,
+    ) -> BackendResult {
+        // Write the coordinate.
+        write!(self.out, "{NAMESPACE}::min(")?;
+        self.put_cast_to_uint_scalar_or_vector(address.coordinate, context)?;
+        write!(self.out, ", ")?;
+        self.put_image_coordinate_limits(image, address.level, context)?;
+        write!(self.out, ")")?;
+
+        // Write the array index, if present.
+        if let Some(array_index) = address.array_index {
+            write!(self.out, ", ")?;
+            self.put_restricted_scalar_image_index(image, array_index, "get_array_size", context)?;
+        }
+
+        // Write the sample index, if present.
+        if let Some(sample) = address.sample {
+            write!(self.out, ", ")?;
+            self.put_restricted_scalar_image_index(image, sample, "get_num_samples", context)?;
+        }
+
+        // The level of detail should be clamped and cached by
+        // `put_cache_restricted_level`, so we don't need to clamp it here.
+        if let Some(level) = address.level {
+            write!(self.out, ", ")?;
+            self.put_level_of_detail(level, context)?;
+        }
+
+        Ok(())
+    }
+
+    /// Write an expression that is true if the given image access is in bounds.
+    fn put_image_access_bounds_check(
+        &mut self,
+        image: Handle<crate::Expression>,
+        address: &TexelAddress,
+        context: &ExpressionContext,
+    ) -> BackendResult {
+        let mut conjunction = "";
+
+        // First, check the level of detail. Only if that is in bounds can we
+        // use it to find the appropriate bounds for the coordinates.
+        let level = if let Some(level) = address.level {
+            write!(self.out, "uint(")?;
+            self.put_level_of_detail(level, context)?;
+            write!(self.out, ") < ")?;
+            self.put_expression(image, context, true)?;
+            write!(self.out, ".get_num_mip_levels()")?;
+            conjunction = " && ";
+            Some(level)
+        } else {
+            None
+        };
+
+        // Check sample index, if present.
+        if let Some(sample) = address.sample {
+            write!(self.out, "uint(")?;
+            self.put_expression(sample, context, true)?;
+            write!(self.out, ") < ")?;
+            self.put_expression(image, context, true)?;
+            write!(self.out, ".get_num_samples()")?;
+            conjunction = " && ";
+        }
+
+        // Check array index, if present.
+        if let Some(array_index) = address.array_index {
+            write!(self.out, "{conjunction}uint(")?;
+            self.put_expression(array_index, context, true)?;
+            write!(self.out, ") < ")?;
+            self.put_expression(image, context, true)?;
+            write!(self.out, ".get_array_size()")?;
+            conjunction = " && ";
+        }
+
+        // Finally, check if the coordinates are within bounds.
+        let coord_is_vector = match *context.resolve_type(address.coordinate) {
+            crate::TypeInner::Vector { .. } => true,
+            _ => false,
+        };
+        write!(self.out, "{conjunction}")?;
+        if coord_is_vector {
+            write!(self.out, "{NAMESPACE}::all(")?;
+        }
+        self.put_cast_to_uint_scalar_or_vector(address.coordinate, context)?;
+        write!(self.out, " < ")?;
+        self.put_image_size_query(image, level, crate::ScalarKind::Uint, context)?;
+        if coord_is_vector {
+            write!(self.out, ")")?;
+        }
+
+        Ok(())
+    }
+
+    fn put_image_load(
+        &mut self,
+        load: Handle<crate::Expression>,
+        image: Handle<crate::Expression>,
+        mut address: TexelAddress,
+        context: &ExpressionContext,
+    ) -> BackendResult {
+        match context.policies.image_load {
+            proc::BoundsCheckPolicy::Restrict => {
+                // Use the cached restricted level of detail, if any. Omit the
+                // level altogether for 1D textures.
+                if address.level.is_some() {
+                    address.level = if context.image_needs_lod(image) {
+                        Some(LevelOfDetail::Restricted(load))
+                    } else {
+                        None
+                    }
+                }
+
+                self.put_expression(image, context, false)?;
+                write!(self.out, ".read(")?;
+                self.put_restricted_texel_address(image, &address, context)?;
+                write!(self.out, ")")?;
+            }
+            proc::BoundsCheckPolicy::ReadZeroSkipWrite => {
+                write!(self.out, "(")?;
+                self.put_image_access_bounds_check(image, &address, context)?;
+                write!(self.out, " ? ")?;
+                self.put_unchecked_image_load(image, &address, context)?;
+                write!(self.out, ": DefaultConstructible())")?;
+            }
+            proc::BoundsCheckPolicy::Unchecked => {
+                self.put_unchecked_image_load(image, &address, context)?;
+            }
+        }
+
+        Ok(())
+    }
+
+    fn put_unchecked_image_load(
+        &mut self,
+        image: Handle<crate::Expression>,
+        address: &TexelAddress,
+        context: &ExpressionContext,
+    ) -> BackendResult {
+        self.put_expression(image, context, false)?;
+        write!(self.out, ".read(")?;
+        // coordinates in IR are int, but Metal expects uint
+        self.put_cast_to_uint_scalar_or_vector(address.coordinate, context)?;
+        if let Some(expr) = address.array_index {
+            write!(self.out, ", ")?;
+            self.put_expression(expr, context, true)?;
+        }
+        if let Some(sample) = address.sample {
+            write!(self.out, ", ")?;
+            self.put_expression(sample, context, true)?;
+        }
+        if let Some(level) = address.level {
+            if context.image_needs_lod(image) {
+                write!(self.out, ", ")?;
+                self.put_level_of_detail(level, context)?;
+            }
+        }
+        write!(self.out, ")")?;
+
+        Ok(())
+    }
+
+    fn put_image_store(
+        &mut self,
+        level: back::Level,
+        image: Handle<crate::Expression>,
+        address: &TexelAddress,
+        value: Handle<crate::Expression>,
+        context: &StatementContext,
+    ) -> BackendResult {
+        match context.expression.policies.image_store {
+            proc::BoundsCheckPolicy::Restrict => {
+                // We don't have a restricted level value, because we don't
+                // support writes to mipmapped textures.
+                debug_assert!(address.level.is_none());
+
+                write!(self.out, "{level}")?;
+                self.put_expression(image, &context.expression, false)?;
+                write!(self.out, ".write(")?;
+                self.put_expression(value, &context.expression, true)?;
+                write!(self.out, ", ")?;
+                self.put_restricted_texel_address(image, address, &context.expression)?;
+                writeln!(self.out, ");")?;
+            }
+            proc::BoundsCheckPolicy::ReadZeroSkipWrite => {
+                write!(self.out, "{level}if (")?;
+                self.put_image_access_bounds_check(image, address, &context.expression)?;
+                writeln!(self.out, ") {{")?;
+                self.put_unchecked_image_store(level.next(), image, address, value, context)?;
+                writeln!(self.out, "{level}}}")?;
+            }
+            proc::BoundsCheckPolicy::Unchecked => {
+                self.put_unchecked_image_store(level, image, address, value, context)?;
+            }
+        }
+
+        Ok(())
+    }
+
+    fn put_unchecked_image_store(
+        &mut self,
+        level: back::Level,
+        image: Handle<crate::Expression>,
+        address: &TexelAddress,
+        value: Handle<crate::Expression>,
+        context: &StatementContext,
+    ) -> BackendResult {
+        write!(self.out, "{level}")?;
+        self.put_expression(image, &context.expression, false)?;
+        write!(self.out, ".write(")?;
+        self.put_expression(value, &context.expression, true)?;
+        write!(self.out, ", ")?;
+        // coordinates in IR are int, but Metal expects uint
+        self.put_cast_to_uint_scalar_or_vector(address.coordinate, &context.expression)?;
+        if let Some(expr) = address.array_index {
+            write!(self.out, ", ")?;
+            self.put_expression(expr, &context.expression, true)?;
+        }
+        writeln!(self.out, ");")?;
+
+        Ok(())
+    }
+
+    /// Write the maximum valid index of the dynamically sized array at the end of `handle`.
+    ///
+    /// The 'maximum valid index' is simply one less than the array's length.
+    ///
+    /// This emits an expression of the form `a / b`, so the caller must
+    /// parenthesize its output if it will be applying operators of higher
+    /// precedence.
+    ///
+    /// `handle` must be the handle of a global variable whose final member is a
+    /// dynamically sized array.
+    fn put_dynamic_array_max_index(
+        &mut self,
+        handle: Handle<crate::GlobalVariable>,
+        context: &ExpressionContext,
+    ) -> BackendResult {
+        let global = &context.module.global_variables[handle];
+        let (offset, array_ty) = match context.module.types[global.ty].inner {
+            crate::TypeInner::Struct { ref members, .. } => match members.last() {
+                Some(&crate::StructMember { offset, ty, .. }) => (offset, ty),
+                None => return Err(Error::Validation),
+            },
+            crate::TypeInner::Array {
+                size: crate::ArraySize::Dynamic,
+                ..
+            } => (0, global.ty),
+            _ => return Err(Error::Validation),
+        };
+
+        let (size, stride) = match context.module.types[array_ty].inner {
+            crate::TypeInner::Array { base, stride, .. } => (
+                context.module.types[base]
+                    .inner
+                    .size(context.module.to_ctx()),
+                stride,
+            ),
+            _ => return Err(Error::Validation),
+        };
+
+        // When the stride length is larger than the size, the final element's stride of
+        // bytes would have padding following the value. But the buffer size in
+        // `buffer_sizes.sizeN` may not include this padding - it only needs to be large
+        // enough to hold the actual values' bytes.
+        //
+        // So subtract off the size to get a byte size that falls at the start or within
+        // the final element. Then divide by the stride size, to get one less than the
+        // length, and then add one. This works even if the buffer size does include the
+        // stride padding, since division rounds towards zero (MSL 2.4 §6.1). It will fail
+        // if there are zero elements in the array, but the WebGPU `validating shader binding`
+        // rules, together with draw-time validation when `minBindingSize` is zero,
+        // prevent that.
+        write!(
+            self.out,
+            "(_buffer_sizes.size{idx} - {offset} - {size}) / {stride}",
+            idx = handle.index(),
+            offset = offset,
+            size = size,
+            stride = stride,
+        )?;
+        Ok(())
+    }
+
+    fn put_atomic_fetch(
+        &mut self,
+        pointer: Handle<crate::Expression>,
+        key: &str,
+        value: Handle<crate::Expression>,
+        context: &ExpressionContext,
+    ) -> BackendResult {
+        self.put_atomic_operation(pointer, "fetch_", key, value, context)
+    }
+
+    fn put_atomic_operation(
+        &mut self,
+        pointer: Handle<crate::Expression>,
+        key1: &str,
+        key2: &str,
+        value: Handle<crate::Expression>,
+        context: &ExpressionContext,
+    ) -> BackendResult {
+        // If the pointer we're passing to the atomic operation needs to be conditional
+        // for `ReadZeroSkipWrite`, the condition needs to *surround* the atomic op, and
+        // the pointer operand should be unchecked.
+        let policy = context.choose_bounds_check_policy(pointer);
+        let checked = policy == index::BoundsCheckPolicy::ReadZeroSkipWrite
+            && self.put_bounds_checks(pointer, context, back::Level(0), "")?;
+
+        // If requested and successfully put bounds checks, continue the ternary expression.
+        if checked {
+            write!(self.out, " ? ")?;
+        }
+
+        write!(
+            self.out,
+            "{NAMESPACE}::atomic_{key1}{key2}_explicit({ATOMIC_REFERENCE}"
+        )?;
+        self.put_access_chain(pointer, policy, context)?;
+        write!(self.out, ", ")?;
+        self.put_expression(value, context, true)?;
+        write!(self.out, ", {NAMESPACE}::memory_order_relaxed)")?;
+
+        // Finish the ternary expression.
+        if checked {
+            write!(self.out, " : DefaultConstructible()")?;
+        }
+
+        Ok(())
+    }
+
+    /// Emit code for the arithmetic expression of the dot product.
+    ///
+    fn put_dot_product(
+        &mut self,
+        arg: Handle<crate::Expression>,
+        arg1: Handle<crate::Expression>,
+        size: usize,
+        context: &ExpressionContext,
+    ) -> BackendResult {
+        // Write parentheses around the dot product expression to prevent operators
+        // with different precedences from applying earlier.
+        write!(self.out, "(")?;
+
+        // Cycle trough all the components of the vector
+        for index in 0..size {
+            let component = back::COMPONENTS[index];
+            // Write the addition to the previous product
+            // This will print an extra '+' at the beginning but that is fine in msl
+            write!(self.out, " + ")?;
+            // Write the first vector expression, this expression is marked to be
+            // cached so unless it can't be cached (for example, it's a Constant)
+            // it shouldn't produce large expressions.
+            self.put_expression(arg, context, true)?;
+            // Access the current component on the first vector
+            write!(self.out, ".{component} * ")?;
+            // Write the second vector expression, this expression is marked to be
+            // cached so unless it can't be cached (for example, it's a Constant)
+            // it shouldn't produce large expressions.
+            self.put_expression(arg1, context, true)?;
+            // Access the current component on the second vector
+            write!(self.out, ".{component}")?;
+        }
+
+        write!(self.out, ")")?;
+        Ok(())
+    }
+
+    /// Emit code for the sign(i32) expression.
+    ///
+    fn put_isign(
+        &mut self,
+        arg: Handle<crate::Expression>,
+        context: &ExpressionContext,
+    ) -> BackendResult {
+        write!(self.out, "{NAMESPACE}::select({NAMESPACE}::select(")?;
+        match context.resolve_type(arg) {
+            &crate::TypeInner::Vector { size, .. } => {
+                let size = back::vector_size_str(size);
+                write!(self.out, "int{size}(-1), int{size}(1)")?;
+            }
+            _ => {
+                write!(self.out, "-1, 1")?;
+            }
+        }
+        write!(self.out, ", (")?;
+        self.put_expression(arg, context, true)?;
+        write!(self.out, " > 0)), 0, (")?;
+        self.put_expression(arg, context, true)?;
+        write!(self.out, " == 0))")?;
+        Ok(())
+    }
+
+    fn put_const_expression(
+        &mut self,
+        expr_handle: Handle<crate::Expression>,
+        module: &crate::Module,
+        mod_info: &valid::ModuleInfo,
+    ) -> BackendResult {
+        self.put_possibly_const_expression(
+            expr_handle,
+            &module.const_expressions,
+            module,
+            mod_info,
+            &(module, mod_info),
+            |&(_, mod_info), expr| &mod_info[expr],
+            |writer, &(module, _), expr| writer.put_const_expression(expr, module, mod_info),
+        )
+    }
+
+    #[allow(clippy::too_many_arguments)]
+    fn put_possibly_const_expression<C, I, E>(
+        &mut self,
+        expr_handle: Handle<crate::Expression>,
+        expressions: &crate::Arena<crate::Expression>,
+        module: &crate::Module,
+        mod_info: &valid::ModuleInfo,
+        ctx: &C,
+        get_expr_ty: I,
+        put_expression: E,
+    ) -> BackendResult
+    where
+        I: Fn(&C, Handle<crate::Expression>) -> &TypeResolution,
+        E: Fn(&mut Self, &C, Handle<crate::Expression>) -> BackendResult,
+    {
+        match expressions[expr_handle] {
+            crate::Expression::Literal(literal) => match literal {
+                crate::Literal::F64(_) => {
+                    return Err(Error::CapabilityNotSupported(valid::Capabilities::FLOAT64))
+                }
+                crate::Literal::F32(value) => {
+                    if value.is_infinite() {
+                        let sign = if value.is_sign_negative() { "-" } else { "" };
+                        write!(self.out, "{sign}INFINITY")?;
+                    } else if value.is_nan() {
+                        write!(self.out, "NAN")?;
+                    } else {
+                        let suffix = if value.fract() == 0.0 { ".0" } else { "" };
+                        write!(self.out, "{value}{suffix}")?;
+                    }
+                }
+                crate::Literal::U32(value) => {
+                    write!(self.out, "{value}u")?;
+                }
+                crate::Literal::I32(value) => {
+                    write!(self.out, "{value}")?;
+                }
+                crate::Literal::I64(value) => {
+                    write!(self.out, "{value}L")?;
+                }
+                crate::Literal::Bool(value) => {
+                    write!(self.out, "{value}")?;
+                }
+                crate::Literal::AbstractInt(_) | crate::Literal::AbstractFloat(_) => {
+                    return Err(Error::Validation);
+                }
+            },
+            crate::Expression::Constant(handle) => {
+                let constant = &module.constants[handle];
+                if constant.name.is_some() {
+                    write!(self.out, "{}", self.names[&NameKey::Constant(handle)])?;
+                } else {
+                    self.put_const_expression(constant.init, module, mod_info)?;
+                }
+            }
+            crate::Expression::ZeroValue(ty) => {
+                let ty_name = TypeContext {
+                    handle: ty,
+                    gctx: module.to_ctx(),
+                    names: &self.names,
+                    access: crate::StorageAccess::empty(),
+                    binding: None,
+                    first_time: false,
+                };
+                write!(self.out, "{ty_name} {{}}")?;
+            }
+            crate::Expression::Compose { ty, ref components } => {
+                let ty_name = TypeContext {
+                    handle: ty,
+                    gctx: module.to_ctx(),
+                    names: &self.names,
+                    access: crate::StorageAccess::empty(),
+                    binding: None,
+                    first_time: false,
+                };
+                write!(self.out, "{ty_name}")?;
+                match module.types[ty].inner {
+                    crate::TypeInner::Scalar(_)
+                    | crate::TypeInner::Vector { .. }
+                    | crate::TypeInner::Matrix { .. } => {
+                        self.put_call_parameters_impl(
+                            components.iter().copied(),
+                            ctx,
+                            put_expression,
+                        )?;
+                    }
+                    crate::TypeInner::Array { .. } | crate::TypeInner::Struct { .. } => {
+                        write!(self.out, " {{")?;
+                        for (index, &component) in components.iter().enumerate() {
+                            if index != 0 {
+                                write!(self.out, ", ")?;
+                            }
+                            // insert padding initialization, if needed
+                            if self.struct_member_pads.contains(&(ty, index as u32)) {
+                                write!(self.out, "{{}}, ")?;
+                            }
+                            put_expression(self, ctx, component)?;
+                        }
+                        write!(self.out, "}}")?;
+                    }
+                    _ => return Err(Error::UnsupportedCompose(ty)),
+                }
+            }
+            crate::Expression::Splat { size, value } => {
+                let scalar = match *get_expr_ty(ctx, value).inner_with(&module.types) {
+                    crate::TypeInner::Scalar(scalar) => scalar,
+                    _ => return Err(Error::Validation),
+                };
+                put_numeric_type(&mut self.out, scalar, &[size])?;
+                write!(self.out, "(")?;
+                put_expression(self, ctx, value)?;
+                write!(self.out, ")")?;
+            }
+            _ => unreachable!(),
+        }
+
+        Ok(())
+    }
+
+    /// Emit code for the expression `expr_handle`.
+    ///
+    /// The `is_scoped` argument is true if the surrounding operators have the
+    /// precedence of the comma operator, or lower. So, for example:
+    ///
+    /// - Pass `true` for `is_scoped` when writing function arguments, an
+    ///   expression statement, an initializer expression, or anything already
+    ///   wrapped in parenthesis.
+    ///
+    /// - Pass `false` if it is an operand of a `?:` operator, a `[]`, or really
+    ///   almost anything else.
+    fn put_expression(
+        &mut self,
+        expr_handle: Handle<crate::Expression>,
+        context: &ExpressionContext,
+        is_scoped: bool,
+    ) -> BackendResult {
+        // Add to the set in order to track the stack size.
+        #[cfg(test)]
+        #[allow(trivial_casts)]
+        self.put_expression_stack_pointers
+            .insert(&expr_handle as *const _ as *const ());
+
+        if let Some(name) = self.named_expressions.get(&expr_handle) {
+            write!(self.out, "{name}")?;
+            return Ok(());
+        }
+
+        let expression = &context.function.expressions[expr_handle];
+        log::trace!("expression {:?} = {:?}", expr_handle, expression);
+        match *expression {
+            crate::Expression::Literal(_)
+            | crate::Expression::Constant(_)
+            | crate::Expression::ZeroValue(_)
+            | crate::Expression::Compose { .. }
+            | crate::Expression::Splat { .. } => {
+                self.put_possibly_const_expression(
+                    expr_handle,
+                    &context.function.expressions,
+                    context.module,
+                    context.mod_info,
+                    context,
+                    |context, expr: Handle<crate::Expression>| &context.info[expr].ty,
+                    |writer, context, expr| writer.put_expression(expr, context, true),
+                )?;
+            }
+            crate::Expression::Access { base, .. }
+            | crate::Expression::AccessIndex { base, .. } => {
+                // This is an acceptable place to generate a `ReadZeroSkipWrite` check.
+                // Since `put_bounds_checks` and `put_access_chain` handle an entire
+                // access chain at a time, recursing back through `put_expression` only
+                // for index expressions and the base object, we will never see intermediate
+                // `Access` or `AccessIndex` expressions here.
+                let policy = context.choose_bounds_check_policy(base);
+                if policy == index::BoundsCheckPolicy::ReadZeroSkipWrite
+                    && self.put_bounds_checks(
+                        expr_handle,
+                        context,
+                        back::Level(0),
+                        if is_scoped { "" } else { "(" },
+                    )?
+                {
+                    write!(self.out, " ? ")?;
+                    self.put_access_chain(expr_handle, policy, context)?;
+                    write!(self.out, " : DefaultConstructible()")?;
+
+                    if !is_scoped {
+                        write!(self.out, ")")?;
+                    }
+                } else {
+                    self.put_access_chain(expr_handle, policy, context)?;
+                }
+            }
+            crate::Expression::Swizzle {
+                size,
+                vector,
+                pattern,
+            } => {
+                self.put_wrapped_expression_for_packed_vec3_access(vector, context, false)?;
+                write!(self.out, ".")?;
+                for &sc in pattern[..size as usize].iter() {
+                    write!(self.out, "{}", back::COMPONENTS[sc as usize])?;
+                }
+            }
+            crate::Expression::FunctionArgument(index) => {
+                let name_key = match context.origin {
+                    FunctionOrigin::Handle(handle) => NameKey::FunctionArgument(handle, index),
+                    FunctionOrigin::EntryPoint(ep_index) => {
+                        NameKey::EntryPointArgument(ep_index, index)
+                    }
+                };
+                let name = &self.names[&name_key];
+                write!(self.out, "{name}")?;
+            }
+            crate::Expression::GlobalVariable(handle) => {
+                let name = &self.names[&NameKey::GlobalVariable(handle)];
+                write!(self.out, "{name}")?;
+            }
+            crate::Expression::LocalVariable(handle) => {
+                let name_key = match context.origin {
+                    FunctionOrigin::Handle(fun_handle) => {
+                        NameKey::FunctionLocal(fun_handle, handle)
+                    }
+                    FunctionOrigin::EntryPoint(ep_index) => {
+                        NameKey::EntryPointLocal(ep_index, handle)
+                    }
+                };
+                let name = &self.names[&name_key];
+                write!(self.out, "{name}")?;
+            }
+            crate::Expression::Load { pointer } => self.put_load(pointer, context, is_scoped)?,
+            crate::Expression::ImageSample {
+                image,
+                sampler,
+                gather,
+                coordinate,
+                array_index,
+                offset,
+                level,
+                depth_ref,
+            } => {
+                let main_op = match gather {
+                    Some(_) => "gather",
+                    None => "sample",
+                };
+                let comparison_op = match depth_ref {
+                    Some(_) => "_compare",
+                    None => "",
+                };
+                self.put_expression(image, context, false)?;
+                write!(self.out, ".{main_op}{comparison_op}(")?;
+                self.put_expression(sampler, context, true)?;
+                write!(self.out, ", ")?;
+                self.put_expression(coordinate, context, true)?;
+                if let Some(expr) = array_index {
+                    write!(self.out, ", ")?;
+                    self.put_expression(expr, context, true)?;
+                }
+                if let Some(dref) = depth_ref {
+                    write!(self.out, ", ")?;
+                    self.put_expression(dref, context, true)?;
+                }
+
+                self.put_image_sample_level(image, level, context)?;
+
+                if let Some(offset) = offset {
+                    write!(self.out, ", ")?;
+                    self.put_const_expression(offset, context.module, context.mod_info)?;
+                }
+
+                match gather {
+                    None | Some(crate::SwizzleComponent::X) => {}
+                    Some(component) => {
+                        let is_cube_map = match *context.resolve_type(image) {
+                            crate::TypeInner::Image {
+                                dim: crate::ImageDimension::Cube,
+                                ..
+                            } => true,
+                            _ => false,
+                        };
+                        // Offset always comes before the gather, except
+                        // in cube maps where it's not applicable
+                        if offset.is_none() && !is_cube_map {
+                            write!(self.out, ", {NAMESPACE}::int2(0)")?;
+                        }
+                        let letter = back::COMPONENTS[component as usize];
+                        write!(self.out, ", {NAMESPACE}::component::{letter}")?;
+                    }
+                }
+                write!(self.out, ")")?;
+            }
+            crate::Expression::ImageLoad {
+                image,
+                coordinate,
+                array_index,
+                sample,
+                level,
+            } => {
+                let address = TexelAddress {
+                    coordinate,
+                    array_index,
+                    sample,
+                    level: level.map(LevelOfDetail::Direct),
+                };
+                self.put_image_load(expr_handle, image, address, context)?;
+            }
+            //Note: for all the queries, the signed integers are expected,
+            // so a conversion is needed.
+            crate::Expression::ImageQuery { image, query } => match query {
+                crate::ImageQuery::Size { level } => {
+                    self.put_image_size_query(
+                        image,
+                        level.map(LevelOfDetail::Direct),
+                        crate::ScalarKind::Uint,
+                        context,
+                    )?;
+                }
+                crate::ImageQuery::NumLevels => {
+                    self.put_expression(image, context, false)?;
+                    write!(self.out, ".get_num_mip_levels()")?;
+                }
+                crate::ImageQuery::NumLayers => {
+                    self.put_expression(image, context, false)?;
+                    write!(self.out, ".get_array_size()")?;
+                }
+                crate::ImageQuery::NumSamples => {
+                    self.put_expression(image, context, false)?;
+                    write!(self.out, ".get_num_samples()")?;
+                }
+            },
+            crate::Expression::Unary { op, expr } => {
+                let op_str = match op {
+                    crate::UnaryOperator::Negate => "-",
+                    crate::UnaryOperator::LogicalNot => "!",
+                    crate::UnaryOperator::BitwiseNot => "~",
+                };
+                write!(self.out, "{op_str}(")?;
+                self.put_expression(expr, context, false)?;
+                write!(self.out, ")")?;
+            }
+            crate::Expression::Binary { op, left, right } => {
+                let op_str = crate::back::binary_operation_str(op);
+                let kind = context
+                    .resolve_type(left)
+                    .scalar_kind()
+                    .ok_or(Error::UnsupportedBinaryOp(op))?;
+
+                // TODO: handle undefined behavior of BinaryOperator::Modulo
+                //
+                // sint:
+                // if right == 0 return 0
+                // if left == min(type_of(left)) && right == -1 return 0
+                // if sign(left) == -1 || sign(right) == -1 return result as defined by WGSL
+                //
+                // uint:
+                // if right == 0 return 0
+                //
+                // float:
+                // if right == 0 return ? see https://github.com/gpuweb/gpuweb/issues/2798
+
+                if op == crate::BinaryOperator::Modulo && kind == crate::ScalarKind::Float {
+                    write!(self.out, "{NAMESPACE}::fmod(")?;
+                    self.put_expression(left, context, true)?;
+                    write!(self.out, ", ")?;
+                    self.put_expression(right, context, true)?;
+                    write!(self.out, ")")?;
+                } else {
+                    if !is_scoped {
+                        write!(self.out, "(")?;
+                    }
+
+                    // Cast packed vector if necessary
+                    // Packed vector - matrix multiplications are not supported in MSL
+                    if op == crate::BinaryOperator::Multiply
+                        && matches!(
+                            context.resolve_type(right),
+                            &crate::TypeInner::Matrix { .. }
+                        )
+                    {
+                        self.put_wrapped_expression_for_packed_vec3_access(left, context, false)?;
+                    } else {
+                        self.put_expression(left, context, false)?;
+                    }
+
+                    write!(self.out, " {op_str} ")?;
+
+                    // See comment above
+                    if op == crate::BinaryOperator::Multiply
+                        && matches!(context.resolve_type(left), &crate::TypeInner::Matrix { .. })
+                    {
+                        self.put_wrapped_expression_for_packed_vec3_access(right, context, false)?;
+                    } else {
+                        self.put_expression(right, context, false)?;
+                    }
+
+                    if !is_scoped {
+                        write!(self.out, ")")?;
+                    }
+                }
+            }
+            crate::Expression::Select {
+                condition,
+                accept,
+                reject,
+            } => match *context.resolve_type(condition) {
+                crate::TypeInner::Scalar(crate::Scalar {
+                    kind: crate::ScalarKind::Bool,
+                    ..
+                }) => {
+                    if !is_scoped {
+                        write!(self.out, "(")?;
+                    }
+                    self.put_expression(condition, context, false)?;
+                    write!(self.out, " ? ")?;
+                    self.put_expression(accept, context, false)?;
+                    write!(self.out, " : ")?;
+                    self.put_expression(reject, context, false)?;
+                    if !is_scoped {
+                        write!(self.out, ")")?;
+                    }
+                }
+                crate::TypeInner::Vector {
+                    scalar:
+                        crate::Scalar {
+                            kind: crate::ScalarKind::Bool,
+                            ..
+                        },
+                    ..
+                } => {
+                    write!(self.out, "{NAMESPACE}::select(")?;
+                    self.put_expression(reject, context, true)?;
+                    write!(self.out, ", ")?;
+                    self.put_expression(accept, context, true)?;
+                    write!(self.out, ", ")?;
+                    self.put_expression(condition, context, true)?;
+                    write!(self.out, ")")?;
+                }
+                _ => return Err(Error::Validation),
+            },
+            crate::Expression::Derivative { axis, expr, .. } => {
+                use crate::DerivativeAxis as Axis;
+                let op = match axis {
+                    Axis::X => "dfdx",
+                    Axis::Y => "dfdy",
+                    Axis::Width => "fwidth",
+                };
+                write!(self.out, "{NAMESPACE}::{op}")?;
+                self.put_call_parameters(iter::once(expr), context)?;
+            }
+            crate::Expression::Relational { fun, argument } => {
+                let op = match fun {
+                    crate::RelationalFunction::Any => "any",
+                    crate::RelationalFunction::All => "all",
+                    crate::RelationalFunction::IsNan => "isnan",
+                    crate::RelationalFunction::IsInf => "isinf",
+                };
+                write!(self.out, "{NAMESPACE}::{op}")?;
+                self.put_call_parameters(iter::once(argument), context)?;
+            }
+            crate::Expression::Math {
+                fun,
+                arg,
+                arg1,
+                arg2,
+                arg3,
+            } => {
+                use crate::MathFunction as Mf;
+
+                let arg_type = context.resolve_type(arg);
+                let scalar_argument = match arg_type {
+                    &crate::TypeInner::Scalar(_) => true,
+                    _ => false,
+                };
+
+                let fun_name = match fun {
+                    // comparison
+                    Mf::Abs => "abs",
+                    Mf::Min => "min",
+                    Mf::Max => "max",
+                    Mf::Clamp => "clamp",
+                    Mf::Saturate => "saturate",
+                    // trigonometry
+                    Mf::Cos => "cos",
+                    Mf::Cosh => "cosh",
+                    Mf::Sin => "sin",
+                    Mf::Sinh => "sinh",
+                    Mf::Tan => "tan",
+                    Mf::Tanh => "tanh",
+                    Mf::Acos => "acos",
+                    Mf::Asin => "asin",
+                    Mf::Atan => "atan",
+                    Mf::Atan2 => "atan2",
+                    Mf::Asinh => "asinh",
+                    Mf::Acosh => "acosh",
+                    Mf::Atanh => "atanh",
+                    Mf::Radians => "",
+                    Mf::Degrees => "",
+                    // decomposition
+                    Mf::Ceil => "ceil",
+                    Mf::Floor => "floor",
+                    Mf::Round => "rint",
+                    Mf::Fract => "fract",
+                    Mf::Trunc => "trunc",
+                    Mf::Modf => MODF_FUNCTION,
+                    Mf::Frexp => FREXP_FUNCTION,
+                    Mf::Ldexp => "ldexp",
+                    // exponent
+                    Mf::Exp => "exp",
+                    Mf::Exp2 => "exp2",
+                    Mf::Log => "log",
+                    Mf::Log2 => "log2",
+                    Mf::Pow => "pow",
+                    // geometry
+                    Mf::Dot => match *context.resolve_type(arg) {
+                        crate::TypeInner::Vector {
+                            scalar:
+                                crate::Scalar {
+                                    kind: crate::ScalarKind::Float,
+                                    ..
+                                },
+                            ..
+                        } => "dot",
+                        crate::TypeInner::Vector { size, .. } => {
+                            return self.put_dot_product(arg, arg1.unwrap(), size as usize, context)
+                        }
+                        _ => unreachable!(
+                            "Correct TypeInner for dot product should be already validated"
+                        ),
+                    },
+                    Mf::Outer => return Err(Error::UnsupportedCall(format!("{fun:?}"))),
+                    Mf::Cross => "cross",
+                    Mf::Distance => "distance",
+                    Mf::Length if scalar_argument => "abs",
+                    Mf::Length => "length",
+                    Mf::Normalize => "normalize",
+                    Mf::FaceForward => "faceforward",
+                    Mf::Reflect => "reflect",
+                    Mf::Refract => "refract",
+                    // computational
+                    Mf::Sign => match arg_type.scalar_kind() {
+                        Some(crate::ScalarKind::Sint) => {
+                            return self.put_isign(arg, context);
+                        }
+                        _ => "sign",
+                    },
+                    Mf::Fma => "fma",
+                    Mf::Mix => "mix",
+                    Mf::Step => "step",
+                    Mf::SmoothStep => "smoothstep",
+                    Mf::Sqrt => "sqrt",
+                    Mf::InverseSqrt => "rsqrt",
+                    Mf::Inverse => return Err(Error::UnsupportedCall(format!("{fun:?}"))),
+                    Mf::Transpose => "transpose",
+                    Mf::Determinant => "determinant",
+                    // bits
+                    Mf::CountTrailingZeros => "ctz",
+                    Mf::CountLeadingZeros => "clz",
+                    Mf::CountOneBits => "popcount",
+                    Mf::ReverseBits => "reverse_bits",
+                    Mf::ExtractBits => "extract_bits",
+                    Mf::InsertBits => "insert_bits",
+                    Mf::FindLsb => "",
+                    Mf::FindMsb => "",
+                    // data packing
+                    Mf::Pack4x8snorm => "pack_float_to_snorm4x8",
+                    Mf::Pack4x8unorm => "pack_float_to_unorm4x8",
+                    Mf::Pack2x16snorm => "pack_float_to_snorm2x16",
+                    Mf::Pack2x16unorm => "pack_float_to_unorm2x16",
+                    Mf::Pack2x16float => "",
+                    // data unpacking
+                    Mf::Unpack4x8snorm => "unpack_snorm4x8_to_float",
+                    Mf::Unpack4x8unorm => "unpack_unorm4x8_to_float",
+                    Mf::Unpack2x16snorm => "unpack_snorm2x16_to_float",
+                    Mf::Unpack2x16unorm => "unpack_unorm2x16_to_float",
+                    Mf::Unpack2x16float => "",
+                };
+
+                match fun {
+                    Mf::ReverseBits | Mf::ExtractBits | Mf::InsertBits => {
+                        // reverse_bits is listed as requiring MSL 2.1 but that
+                        // is a copy/paste error. Looking at previous snapshots
+                        // on web.archive.org it's present in MSL 1.2.
+                        //
+                        // https://developer.apple.com/library/archive/documentation/Miscellaneous/Conceptual/MetalProgrammingGuide/WhatsNewiniOS10tvOS10andOSX1012/WhatsNewiniOS10tvOS10andOSX1012.html
+                        // also talks about MSL 1.2 adding "New integer
+                        // functions to extract, insert, and reverse bits, as
+                        // described in Integer Functions."
+                        if context.lang_version < (1, 2) {
+                            return Err(Error::UnsupportedFunction(fun_name.to_string()));
+                        }
+                    }
+                    _ => {}
+                }
+
+                if fun == Mf::Distance && scalar_argument {
+                    write!(self.out, "{NAMESPACE}::abs(")?;
+                    self.put_expression(arg, context, false)?;
+                    write!(self.out, " - ")?;
+                    self.put_expression(arg1.unwrap(), context, false)?;
+                    write!(self.out, ")")?;
+                } else if fun == Mf::FindLsb {
+                    write!(self.out, "((({NAMESPACE}::ctz(")?;
+                    self.put_expression(arg, context, true)?;
+                    write!(self.out, ") + 1) % 33) - 1)")?;
+                } else if fun == Mf::FindMsb {
+                    let inner = context.resolve_type(arg);
+
+                    write!(self.out, "{NAMESPACE}::select(31 - {NAMESPACE}::clz(")?;
+
+                    if let Some(crate::ScalarKind::Sint) = inner.scalar_kind() {
+                        write!(self.out, "{NAMESPACE}::select(")?;
+                        self.put_expression(arg, context, true)?;
+                        write!(self.out, ", ~")?;
+                        self.put_expression(arg, context, true)?;
+                        write!(self.out, ", ")?;
+                        self.put_expression(arg, context, true)?;
+                        write!(self.out, " < 0)")?;
+                    } else {
+                        self.put_expression(arg, context, true)?;
+                    }
+
+                    write!(self.out, "), ")?;
+
+                    // or metal will complain that select is ambiguous
+                    match *inner {
+                        crate::TypeInner::Vector { size, scalar } => {
+                            let size = back::vector_size_str(size);
+                            if let crate::ScalarKind::Sint = scalar.kind {
+                                write!(self.out, "int{size}")?;
+                            } else {
+                                write!(self.out, "uint{size}")?;
+                            }
+                        }
+                        crate::TypeInner::Scalar(scalar) => {
+                            if let crate::ScalarKind::Sint = scalar.kind {
+                                write!(self.out, "int")?;
+                            } else {
+                                write!(self.out, "uint")?;
+                            }
+                        }
+                        _ => (),
+                    }
+
+                    write!(self.out, "(-1), ")?;
+                    self.put_expression(arg, context, true)?;
+                    write!(self.out, " == 0 || ")?;
+                    self.put_expression(arg, context, true)?;
+                    write!(self.out, " == -1)")?;
+                } else if fun == Mf::Unpack2x16float {
+                    write!(self.out, "float2(as_type<half2>(")?;
+                    self.put_expression(arg, context, false)?;
+                    write!(self.out, "))")?;
+                } else if fun == Mf::Pack2x16float {
+                    write!(self.out, "as_type<uint>(half2(")?;
+                    self.put_expression(arg, context, false)?;
+                    write!(self.out, "))")?;
+                } else if fun == Mf::Radians {
+                    write!(self.out, "((")?;
+                    self.put_expression(arg, context, false)?;
+                    write!(self.out, ") * 0.017453292519943295474)")?;
+                } else if fun == Mf::Degrees {
+                    write!(self.out, "((")?;
+                    self.put_expression(arg, context, false)?;
+                    write!(self.out, ") * 57.295779513082322865)")?;
+                } else if fun == Mf::Modf || fun == Mf::Frexp {
+                    write!(self.out, "{fun_name}")?;
+                    self.put_call_parameters(iter::once(arg), context)?;
+                } else {
+                    write!(self.out, "{NAMESPACE}::{fun_name}")?;
+                    self.put_call_parameters(
+                        iter::once(arg).chain(arg1).chain(arg2).chain(arg3),
+                        context,
+                    )?;
+                }
+            }
+            crate::Expression::As {
+                expr,
+                kind,
+                convert,
+            } => match *context.resolve_type(expr) {
+                crate::TypeInner::Scalar(src) | crate::TypeInner::Vector { scalar: src, .. } => {
+                    let target_scalar = crate::Scalar {
+                        kind,
+                        width: convert.unwrap_or(src.width),
+                    };
+                    let is_bool_cast =
+                        kind == crate::ScalarKind::Bool || src.kind == crate::ScalarKind::Bool;
+                    let op = match convert {
+                        Some(w) if w == src.width || is_bool_cast => "static_cast",
+                        Some(8) if kind == crate::ScalarKind::Float => {
+                            return Err(Error::CapabilityNotSupported(valid::Capabilities::FLOAT64))
+                        }
+                        Some(_) => return Err(Error::Validation),
+                        None => "as_type",
+                    };
+                    write!(self.out, "{op}<")?;
+                    match *context.resolve_type(expr) {
+                        crate::TypeInner::Vector { size, .. } => {
+                            put_numeric_type(&mut self.out, target_scalar, &[size])?
+                        }
+                        _ => put_numeric_type(&mut self.out, target_scalar, &[])?,
+                    };
+                    write!(self.out, ">(")?;
+                    self.put_expression(expr, context, true)?;
+                    write!(self.out, ")")?;
+                }
+                crate::TypeInner::Matrix {
+                    columns,
+                    rows,
+                    scalar,
+                } => {
+                    let target_scalar = crate::Scalar {
+                        kind,
+                        width: convert.unwrap_or(scalar.width),
+                    };
+                    put_numeric_type(&mut self.out, target_scalar, &[rows, columns])?;
+                    write!(self.out, "(")?;
+                    self.put_expression(expr, context, true)?;
+                    write!(self.out, ")")?;
+                }
+                _ => return Err(Error::Validation),
+            },
+            // has to be a named expression
+            crate::Expression::CallResult(_)
+            | crate::Expression::AtomicResult { .. }
+            | crate::Expression::WorkGroupUniformLoadResult { .. }
+            | crate::Expression::RayQueryProceedResult => {
+                unreachable!()
+            }
+            crate::Expression::ArrayLength(expr) => {
+                // Find the global to which the array belongs.
+                let global = match context.function.expressions[expr] {
+                    crate::Expression::AccessIndex { base, .. } => {
+                        match context.function.expressions[base] {
+                            crate::Expression::GlobalVariable(handle) => handle,
+                            _ => return Err(Error::Validation),
+                        }
+                    }
+                    crate::Expression::GlobalVariable(handle) => handle,
+                    _ => return Err(Error::Validation),
+                };
+
+                if !is_scoped {
+                    write!(self.out, "(")?;
+                }
+                write!(self.out, "1 + ")?;
+                self.put_dynamic_array_max_index(global, context)?;
+                if !is_scoped {
+                    write!(self.out, ")")?;
+                }
+            }
+            crate::Expression::RayQueryGetIntersection { query, committed } => {
+                if context.lang_version < (2, 4) {
+                    return Err(Error::UnsupportedRayTracing);
+                }
+
+                if !committed {
+                    unimplemented!()
+                }
+                let ty = context.module.special_types.ray_intersection.unwrap();
+                let type_name = &self.names[&NameKey::Type(ty)];
+                write!(self.out, "{type_name} {{{RAY_QUERY_FUN_MAP_INTERSECTION}(")?;
+                self.put_expression(query, context, true)?;
+                write!(self.out, ".{RAY_QUERY_FIELD_INTERSECTION}.type)")?;
+                let fields = [
+                    "distance",
+                    "user_instance_id", // req Metal 2.4
+                    "instance_id",
+                    "", // SBT offset
+                    "geometry_id",
+                    "primitive_id",
+                    "triangle_barycentric_coord",
+                    "triangle_front_facing",
+                    "",                          // padding
+                    "object_to_world_transform", // req Metal 2.4
+                    "world_to_object_transform", // req Metal 2.4
+                ];
+                for field in fields {
+                    write!(self.out, ", ")?;
+                    if field.is_empty() {
+                        write!(self.out, "{{}}")?;
+                    } else {
+                        self.put_expression(query, context, true)?;
+                        write!(self.out, ".{RAY_QUERY_FIELD_INTERSECTION}.{field}")?;
+                    }
+                }
+                write!(self.out, "}}")?;
+            }
+        }
+        Ok(())
+    }
+
+    /// Used by expressions like Swizzle and Binary since they need packed_vec3's to be casted to a vec3
+    fn put_wrapped_expression_for_packed_vec3_access(
+        &mut self,
+        expr_handle: Handle<crate::Expression>,
+        context: &ExpressionContext,
+        is_scoped: bool,
+    ) -> BackendResult {
+        if let Some(scalar) = context.get_packed_vec_kind(expr_handle) {
+            write!(self.out, "{}::{}3(", NAMESPACE, scalar.to_msl_name())?;
+            self.put_expression(expr_handle, context, is_scoped)?;
+            write!(self.out, ")")?;
+        } else {
+            self.put_expression(expr_handle, context, is_scoped)?;
+        }
+        Ok(())
+    }
+
+    /// Write a `GuardedIndex` as a Metal expression.
+    fn put_index(
+        &mut self,
+        index: index::GuardedIndex,
+        context: &ExpressionContext,
+        is_scoped: bool,
+    ) -> BackendResult {
+        match index {
+            index::GuardedIndex::Expression(expr) => {
+                self.put_expression(expr, context, is_scoped)?
+            }
+            index::GuardedIndex::Known(value) => write!(self.out, "{value}")?,
+        }
+        Ok(())
+    }
+
+    /// Emit an index bounds check condition for `chain`, if required.
+    ///
+    /// `chain` is a subtree of `Access` and `AccessIndex` expressions,
+    /// operating either on a pointer to a value, or on a value directly. If we cannot
+    /// statically determine that all indexing operations in `chain` are within
+    /// bounds, then write a conditional expression to check them dynamically,
+    /// and return true. All accesses in the chain are checked by the generated
+    /// expression.
+    ///
+    /// This assumes that the [`BoundsCheckPolicy`] for `chain` is [`ReadZeroSkipWrite`].
+    ///
+    /// The text written is of the form:
+    ///
+    /// ```ignore
+    /// {level}{prefix}uint(i) < 4 && uint(j) < 10
+    /// ```
+    ///
+    /// where `{level}` and `{prefix}` are the arguments to this function. For [`Store`]
+    /// statements, presumably these arguments start an indented `if` statement; for
+    /// [`Load`] expressions, the caller is probably building up a ternary `?:`
+    /// expression. In either case, what is written is not a complete syntactic structure
+    /// in its own right, and the caller will have to finish it off if we return `true`.
+    ///
+    /// If no expression is written, return false.
+    ///
+    /// [`BoundsCheckPolicy`]: index::BoundsCheckPolicy
+    /// [`ReadZeroSkipWrite`]: index::BoundsCheckPolicy::ReadZeroSkipWrite
+    /// [`Store`]: crate::Statement::Store
+    /// [`Load`]: crate::Expression::Load
+    #[allow(unused_variables)]
+    fn put_bounds_checks(
+        &mut self,
+        mut chain: Handle<crate::Expression>,
+        context: &ExpressionContext,
+        level: back::Level,
+        prefix: &'static str,
+    ) -> Result<bool, Error> {
+        let mut check_written = false;
+
+        // Iterate over the access chain, handling each expression.
+        loop {
+            // Produce a `GuardedIndex`, so we can shared code between the
+            // `Access` and `AccessIndex` cases.
+            let (base, guarded_index) = match context.function.expressions[chain] {
+                crate::Expression::Access { base, index } => {
+                    (base, Some(index::GuardedIndex::Expression(index)))
+                }
+                crate::Expression::AccessIndex { base, index } => {
+                    // Don't try to check indices into structs. Validation already took
+                    // care of them, and index::needs_guard doesn't handle that case.
+                    let mut base_inner = context.resolve_type(base);
+                    if let crate::TypeInner::Pointer { base, .. } = *base_inner {
+                        base_inner = &context.module.types[base].inner;
+                    }
+                    match *base_inner {
+                        crate::TypeInner::Struct { .. } => (base, None),
+                        _ => (base, Some(index::GuardedIndex::Known(index))),
+                    }
+                }
+                _ => break,
+            };
+
+            if let Some(index) = guarded_index {
+                if let Some(length) = context.access_needs_check(base, index) {
+                    if check_written {
+                        write!(self.out, " && ")?;
+                    } else {
+                        write!(self.out, "{level}{prefix}")?;
+                        check_written = true;
+                    }
+
+                    // Check that the index falls within bounds. Do this with a single
+                    // comparison, by casting the index to `uint` first, so that negative
+                    // indices become large positive values.
+                    write!(self.out, "uint(")?;
+                    self.put_index(index, context, true)?;
+                    self.out.write_str(") < ")?;
+                    match length {
+                        index::IndexableLength::Known(value) => write!(self.out, "{value}")?,
+                        index::IndexableLength::Dynamic => {
+                            let global = context
+                                .function
+                                .originating_global(base)
+                                .ok_or(Error::Validation)?;
+                            write!(self.out, "1 + ")?;
+                            self.put_dynamic_array_max_index(global, context)?
+                        }
+                    }
+                }
+            }
+
+            chain = base
+        }
+
+        Ok(check_written)
+    }
+
+    /// Write the access chain `chain`.
+    ///
+    /// `chain` is a subtree of [`Access`] and [`AccessIndex`] expressions,
+    /// operating either on a pointer to a value, or on a value directly.
+    ///
+    /// Generate bounds checks code only if `policy` is [`Restrict`]. The
+    /// [`ReadZeroSkipWrite`] policy requires checks before any accesses take place, so
+    /// that must be handled in the caller.
+    ///
+    /// Handle the entire chain, recursing back into `put_expression` only for index
+    /// expressions and the base expression that originates the pointer or composite value
+    /// being accessed. This allows `put_expression` to assume that any `Access` or
+    /// `AccessIndex` expressions it sees are the top of a chain, so it can emit
+    /// `ReadZeroSkipWrite` checks.
+    ///
+    /// [`Access`]: crate::Expression::Access
+    /// [`AccessIndex`]: crate::Expression::AccessIndex
+    /// [`Restrict`]: crate::proc::index::BoundsCheckPolicy::Restrict
+    /// [`ReadZeroSkipWrite`]: crate::proc::index::BoundsCheckPolicy::ReadZeroSkipWrite
+    fn put_access_chain(
+        &mut self,
+        chain: Handle<crate::Expression>,
+        policy: index::BoundsCheckPolicy,
+        context: &ExpressionContext,
+    ) -> BackendResult {
+        match context.function.expressions[chain] {
+            crate::Expression::Access { base, index } => {
+                let mut base_ty = context.resolve_type(base);
+
+                // Look through any pointers to see what we're really indexing.
+                if let crate::TypeInner::Pointer { base, space: _ } = *base_ty {
+                    base_ty = &context.module.types[base].inner;
+                }
+
+                self.put_subscripted_access_chain(
+                    base,
+                    base_ty,
+                    index::GuardedIndex::Expression(index),
+                    policy,
+                    context,
+                )?;
+            }
+            crate::Expression::AccessIndex { base, index } => {
+                let base_resolution = &context.info[base].ty;
+                let mut base_ty = base_resolution.inner_with(&context.module.types);
+                let mut base_ty_handle = base_resolution.handle();
+
+                // Look through any pointers to see what we're really indexing.
+                if let crate::TypeInner::Pointer { base, space: _ } = *base_ty {
+                    base_ty = &context.module.types[base].inner;
+                    base_ty_handle = Some(base);
+                }
+
+                // Handle structs and anything else that can use `.x` syntax here, so
+                // `put_subscripted_access_chain` won't have to handle the absurd case of
+                // indexing a struct with an expression.
+                match *base_ty {
+                    crate::TypeInner::Struct { .. } => {
+                        let base_ty = base_ty_handle.unwrap();
+                        self.put_access_chain(base, policy, context)?;
+                        let name = &self.names[&NameKey::StructMember(base_ty, index)];
+                        write!(self.out, ".{name}")?;
+                    }
+                    crate::TypeInner::ValuePointer { .. } | crate::TypeInner::Vector { .. } => {
+                        self.put_access_chain(base, policy, context)?;
+                        // Prior to Metal v2.1 component access for packed vectors wasn't available
+                        // however array indexing is
+                        if context.get_packed_vec_kind(base).is_some() {
+                            write!(self.out, "[{index}]")?;
+                        } else {
+                            write!(self.out, ".{}", back::COMPONENTS[index as usize])?;
+                        }
+                    }
+                    _ => {
+                        self.put_subscripted_access_chain(
+                            base,
+                            base_ty,
+                            index::GuardedIndex::Known(index),
+                            policy,
+                            context,
+                        )?;
+                    }
+                }
+            }
+            _ => self.put_expression(chain, context, false)?,
+        }
+
+        Ok(())
+    }
+
+    /// Write a `[]`-style access of `base` by `index`.
+    ///
+    /// If `policy` is [`Restrict`], then generate code as needed to force all index
+    /// values within bounds.
+    ///
+    /// The `base_ty` argument must be the type we are actually indexing, like [`Array`] or
+    /// [`Vector`]. In other words, it's `base`'s type with any surrounding [`Pointer`]
+    /// removed. Our callers often already have this handy.
+    ///
+    /// This only emits `[]` expressions; it doesn't handle struct member accesses or
+    /// referencing vector components by name.
+    ///
+    /// [`Restrict`]: crate::proc::index::BoundsCheckPolicy::Restrict
+    /// [`Array`]: crate::TypeInner::Array
+    /// [`Vector`]: crate::TypeInner::Vector
+    /// [`Pointer`]: crate::TypeInner::Pointer
+    fn put_subscripted_access_chain(
+        &mut self,
+        base: Handle<crate::Expression>,
+        base_ty: &crate::TypeInner,
+        index: index::GuardedIndex,
+        policy: index::BoundsCheckPolicy,
+        context: &ExpressionContext,
+    ) -> BackendResult {
+        let accessing_wrapped_array = match *base_ty {
+            crate::TypeInner::Array {
+                size: crate::ArraySize::Constant(_),
+                ..
+            } => true,
+            _ => false,
+        };
+
+        self.put_access_chain(base, policy, context)?;
+        if accessing_wrapped_array {
+            write!(self.out, ".{WRAPPED_ARRAY_FIELD}")?;
+        }
+        write!(self.out, "[")?;
+
+        // Decide whether this index needs to be clamped to fall within range.
+        let restriction_needed = if policy == index::BoundsCheckPolicy::Restrict {
+            context.access_needs_check(base, index)
+        } else {
+            None
+        };
+        if let Some(limit) = restriction_needed {
+            write!(self.out, "{NAMESPACE}::min(unsigned(")?;
+            self.put_index(index, context, true)?;
+            write!(self.out, "), ")?;
+            match limit {
+                index::IndexableLength::Known(limit) => {
+                    write!(self.out, "{}u", limit - 1)?;
+                }
+                index::IndexableLength::Dynamic => {
+                    let global = context
+                        .function
+                        .originating_global(base)
+                        .ok_or(Error::Validation)?;
+                    self.put_dynamic_array_max_index(global, context)?;
+                }
+            }
+            write!(self.out, ")")?;
+        } else {
+            self.put_index(index, context, true)?;
+        }
+
+        write!(self.out, "]")?;
+
+        Ok(())
+    }
+
+    fn put_load(
+        &mut self,
+        pointer: Handle<crate::Expression>,
+        context: &ExpressionContext,
+        is_scoped: bool,
+    ) -> BackendResult {
+        // Since access chains never cross between address spaces, we can just
+        // check the index bounds check policy once at the top.
+        let policy = context.choose_bounds_check_policy(pointer);
+        if policy == index::BoundsCheckPolicy::ReadZeroSkipWrite
+            && self.put_bounds_checks(
+                pointer,
+                context,
+                back::Level(0),
+                if is_scoped { "" } else { "(" },
+            )?
+        {
+            write!(self.out, " ? ")?;
+            self.put_unchecked_load(pointer, policy, context)?;
+            write!(self.out, " : DefaultConstructible()")?;
+
+            if !is_scoped {
+                write!(self.out, ")")?;
+            }
+        } else {
+            self.put_unchecked_load(pointer, policy, context)?;
+        }
+
+        Ok(())
+    }
+
+    fn put_unchecked_load(
+        &mut self,
+        pointer: Handle<crate::Expression>,
+        policy: index::BoundsCheckPolicy,
+        context: &ExpressionContext,
+    ) -> BackendResult {
+        let is_atomic_pointer = context
+            .resolve_type(pointer)
+            .is_atomic_pointer(&context.module.types);
+
+        if is_atomic_pointer {
+            write!(
+                self.out,
+                "{NAMESPACE}::atomic_load_explicit({ATOMIC_REFERENCE}"
+            )?;
+            self.put_access_chain(pointer, policy, context)?;
+            write!(self.out, ", {NAMESPACE}::memory_order_relaxed)")?;
+        } else {
+            // We don't do any dereferencing with `*` here as pointer arguments to functions
+            // are done by `&` references and not `*` pointers. These do not need to be
+            // dereferenced.
+            self.put_access_chain(pointer, policy, context)?;
+        }
+
+        Ok(())
+    }
+
+    fn put_return_value(
+        &mut self,
+        level: back::Level,
+        expr_handle: Handle<crate::Expression>,
+        result_struct: Option<&str>,
+        context: &ExpressionContext,
+    ) -> BackendResult {
+        match result_struct {
+            Some(struct_name) => {
+                let mut has_point_size = false;
+                let result_ty = context.function.result.as_ref().unwrap().ty;
+                match context.module.types[result_ty].inner {
+                    crate::TypeInner::Struct { ref members, .. } => {
+                        let tmp = "_tmp";
+                        write!(self.out, "{level}const auto {tmp} = ")?;
+                        self.put_expression(expr_handle, context, true)?;
+                        writeln!(self.out, ";")?;
+                        write!(self.out, "{level}return {struct_name} {{")?;
+
+                        let mut is_first = true;
+
+                        for (index, member) in members.iter().enumerate() {
+                            if let Some(crate::Binding::BuiltIn(crate::BuiltIn::PointSize)) =
+                                member.binding
+                            {
+                                has_point_size = true;
+                                if !context.pipeline_options.allow_and_force_point_size {
+                                    continue;
+                                }
+                            }
+
+                            let comma = if is_first { "" } else { "," };
+                            is_first = false;
+                            let name = &self.names[&NameKey::StructMember(result_ty, index as u32)];
+                            // HACK: we are forcefully deduplicating the expression here
+                            // to convert from a wrapped struct to a raw array, e.g.
+                            // `float gl_ClipDistance1 [[clip_distance]] [1];`.
+                            if let crate::TypeInner::Array {
+                                size: crate::ArraySize::Constant(size),
+                                ..
+                            } = context.module.types[member.ty].inner
+                            {
+                                write!(self.out, "{comma} {{")?;
+                                for j in 0..size.get() {
+                                    if j != 0 {
+                                        write!(self.out, ",")?;
+                                    }
+                                    write!(self.out, "{tmp}.{name}.{WRAPPED_ARRAY_FIELD}[{j}]")?;
+                                }
+                                write!(self.out, "}}")?;
+                            } else {
+                                write!(self.out, "{comma} {tmp}.{name}")?;
+                            }
+                        }
+                    }
+                    _ => {
+                        write!(self.out, "{level}return {struct_name} {{ ")?;
+                        self.put_expression(expr_handle, context, true)?;
+                    }
+                }
+
+                if let FunctionOrigin::EntryPoint(ep_index) = context.origin {
+                    let stage = context.module.entry_points[ep_index as usize].stage;
+                    if context.pipeline_options.allow_and_force_point_size
+                        && stage == crate::ShaderStage::Vertex
+                        && !has_point_size
+                    {
+                        // point size was injected and comes last
+                        write!(self.out, ", 1.0")?;
+                    }
+                }
+                write!(self.out, " }}")?;
+            }
+            None => {
+                write!(self.out, "{level}return ")?;
+                self.put_expression(expr_handle, context, true)?;
+            }
+        }
+        writeln!(self.out, ";")?;
+        Ok(())
+    }
+
+    /// Helper method used to find which expressions of a given function require baking
+    ///
+    /// # Notes
+    /// This function overwrites the contents of `self.need_bake_expressions`
+    fn update_expressions_to_bake(
+        &mut self,
+        func: &crate::Function,
+        info: &valid::FunctionInfo,
+        context: &ExpressionContext,
+    ) {
+        use crate::Expression;
+        self.need_bake_expressions.clear();
+
+        for (expr_handle, expr) in func.expressions.iter() {
+            // Expressions whose reference count is above the
+            // threshold should always be stored in temporaries.
+            let expr_info = &info[expr_handle];
+            let min_ref_count = func.expressions[expr_handle].bake_ref_count();
+            if min_ref_count <= expr_info.ref_count {
+                self.need_bake_expressions.insert(expr_handle);
+            } else {
+                match expr_info.ty {
+                    // force ray desc to be baked: it's used multiple times internally
+                    TypeResolution::Handle(h)
+                        if Some(h) == context.module.special_types.ray_desc =>
+                    {
+                        self.need_bake_expressions.insert(expr_handle);
+                    }
+                    _ => {}
+                }
+            }
+
+            if let Expression::Math { fun, arg, arg1, .. } = *expr {
+                match fun {
+                    crate::MathFunction::Dot => {
+                        // WGSL's `dot` function works on any `vecN` type, but Metal's only
+                        // works on floating-point vectors, so we emit inline code for
+                        // integer vector `dot` calls. But that code uses each argument `N`
+                        // times, once for each component (see `put_dot_product`), so to
+                        // avoid duplicated evaluation, we must bake integer operands.
+
+                        // check what kind of product this is depending
+                        // on the resolve type of the Dot function itself
+                        let inner = context.resolve_type(expr_handle);
+                        if let crate::TypeInner::Scalar(scalar) = *inner {
+                            match scalar.kind {
+                                crate::ScalarKind::Sint | crate::ScalarKind::Uint => {
+                                    self.need_bake_expressions.insert(arg);
+                                    self.need_bake_expressions.insert(arg1.unwrap());
+                                }
+                                _ => {}
+                            }
+                        }
+                    }
+                    crate::MathFunction::FindMsb => {
+                        self.need_bake_expressions.insert(arg);
+                    }
+                    crate::MathFunction::Sign => {
+                        // WGSL's `sign` function works also on signed ints, but Metal's only
+                        // works on floating points, so we emit inline code for integer `sign`
+                        // calls. But that code uses each argument 2 times (see `put_isign`),
+                        // so to avoid duplicated evaluation, we must bake the argument.
+                        let inner = context.resolve_type(expr_handle);
+                        if inner.scalar_kind() == Some(crate::ScalarKind::Sint) {
+                            self.need_bake_expressions.insert(arg);
+                        }
+                    }
+                    _ => {}
+                }
+            }
+        }
+    }
+
+    fn start_baking_expression(
+        &mut self,
+        handle: Handle<crate::Expression>,
+        context: &ExpressionContext,
+        name: &str,
+    ) -> BackendResult {
+        match context.info[handle].ty {
+            TypeResolution::Handle(ty_handle) => {
+                let ty_name = TypeContext {
+                    handle: ty_handle,
+                    gctx: context.module.to_ctx(),
+                    names: &self.names,
+                    access: crate::StorageAccess::empty(),
+                    binding: None,
+                    first_time: false,
+                };
+                write!(self.out, "{ty_name}")?;
+            }
+            TypeResolution::Value(crate::TypeInner::Scalar(scalar)) => {
+                put_numeric_type(&mut self.out, scalar, &[])?;
+            }
+            TypeResolution::Value(crate::TypeInner::Vector { size, scalar }) => {
+                put_numeric_type(&mut self.out, scalar, &[size])?;
+            }
+            TypeResolution::Value(crate::TypeInner::Matrix {
+                columns,
+                rows,
+                scalar,
+            }) => {
+                put_numeric_type(&mut self.out, scalar, &[rows, columns])?;
+            }
+            TypeResolution::Value(ref other) => {
+                log::warn!("Type {:?} isn't a known local", other); //TEMP!
+                return Err(Error::FeatureNotImplemented("weird local type".to_string()));
+            }
+        }
+
+        //TODO: figure out the naming scheme that wouldn't collide with user names.
+        write!(self.out, " {name} = ")?;
+
+        Ok(())
+    }
+
+    /// Cache a clamped level of detail value, if necessary.
+    ///
+    /// [`ImageLoad`] accesses covered by [`BoundsCheckPolicy::Restrict`] use a
+    /// properly clamped level of detail value both in the access itself, and
+    /// for fetching the size of the requested MIP level, needed to clamp the
+    /// coordinates. To avoid recomputing this clamped level of detail, we cache
+    /// it in a temporary variable, as part of the [`Emit`] statement covering
+    /// the [`ImageLoad`] expression.
+    ///
+    /// [`ImageLoad`]: crate::Expression::ImageLoad
+    /// [`BoundsCheckPolicy::Restrict`]: index::BoundsCheckPolicy::Restrict
+    /// [`Emit`]: crate::Statement::Emit
+    fn put_cache_restricted_level(
+        &mut self,
+        load: Handle<crate::Expression>,
+        image: Handle<crate::Expression>,
+        mip_level: Option<Handle<crate::Expression>>,
+        indent: back::Level,
+        context: &StatementContext,
+    ) -> BackendResult {
+        // Does this image access actually require (or even permit) a
+        // level-of-detail, and does the policy require us to restrict it?
+        let level_of_detail = match mip_level {
+            Some(level) => level,
+            None => return Ok(()),
+        };
+
+        if context.expression.policies.image_load != index::BoundsCheckPolicy::Restrict
+            || !context.expression.image_needs_lod(image)
+        {
+            return Ok(());
+        }
+
+        write!(
+            self.out,
+            "{}uint {}{} = ",
+            indent,
+            CLAMPED_LOD_LOAD_PREFIX,
+            load.index(),
+        )?;
+        self.put_restricted_scalar_image_index(
+            image,
+            level_of_detail,
+            "get_num_mip_levels",
+            &context.expression,
+        )?;
+        writeln!(self.out, ";")?;
+
+        Ok(())
+    }
+
+    fn put_block(
+        &mut self,
+        level: back::Level,
+        statements: &[crate::Statement],
+        context: &StatementContext,
+    ) -> BackendResult {
+        // Add to the set in order to track the stack size.
+        #[cfg(test)]
+        #[allow(trivial_casts)]
+        self.put_block_stack_pointers
+            .insert(&level as *const _ as *const ());
+
+        for statement in statements {
+            log::trace!("statement[{}] {:?}", level.0, statement);
+            match *statement {
+                crate::Statement::Emit(ref range) => {
+                    for handle in range.clone() {
+                        // `ImageLoad` expressions covered by the `Restrict` bounds check policy
+                        // may need to cache a clamped version of their level-of-detail argument.
+                        if let crate::Expression::ImageLoad {
+                            image,
+                            level: mip_level,
+                            ..
+                        } = context.expression.function.expressions[handle]
+                        {
+                            self.put_cache_restricted_level(
+                                handle, image, mip_level, level, context,
+                            )?;
+                        }
+
+                        let ptr_class = context.expression.resolve_type(handle).pointer_space();
+                        let expr_name = if ptr_class.is_some() {
+                            None // don't bake pointer expressions (just yet)
+                        } else if let Some(name) =
+                            context.expression.function.named_expressions.get(&handle)
+                        {
+                            // The `crate::Function::named_expressions` table holds
+                            // expressions that should be saved in temporaries once they
+                            // are `Emit`ted. We only add them to `self.named_expressions`
+                            // when we reach the `Emit` that covers them, so that we don't
+                            // try to use their names before we've actually initialized
+                            // the temporary that holds them.
+                            //
+                            // Don't assume the names in `named_expressions` are unique,
+                            // or even valid. Use the `Namer`.
+                            Some(self.namer.call(name))
+                        } else {
+                            // If this expression is an index that we're going to first compare
+                            // against a limit, and then actually use as an index, then we may
+                            // want to cache it in a temporary, to avoid evaluating it twice.
+                            let bake =
+                                if context.expression.guarded_indices.contains(handle.index()) {
+                                    true
+                                } else {
+                                    self.need_bake_expressions.contains(&handle)
+                                };
+
+                            if bake {
+                                Some(format!("{}{}", back::BAKE_PREFIX, handle.index()))
+                            } else {
+                                None
+                            }
+                        };
+
+                        if let Some(name) = expr_name {
+                            write!(self.out, "{level}")?;
+                            self.start_baking_expression(handle, &context.expression, &name)?;
+                            self.put_expression(handle, &context.expression, true)?;
+                            self.named_expressions.insert(handle, name);
+                            writeln!(self.out, ";")?;
+                        }
+                    }
+                }
+                crate::Statement::Block(ref block) => {
+                    if !block.is_empty() {
+                        writeln!(self.out, "{level}{{")?;
+                        self.put_block(level.next(), block, context)?;
+                        writeln!(self.out, "{level}}}")?;
+                    }
+                }
+                crate::Statement::If {
+                    condition,
+                    ref accept,
+                    ref reject,
+                } => {
+                    write!(self.out, "{level}if (")?;
+                    self.put_expression(condition, &context.expression, true)?;
+                    writeln!(self.out, ") {{")?;
+                    self.put_block(level.next(), accept, context)?;
+                    if !reject.is_empty() {
+                        writeln!(self.out, "{level}}} else {{")?;
+                        self.put_block(level.next(), reject, context)?;
+                    }
+                    writeln!(self.out, "{level}}}")?;
+                }
+                crate::Statement::Switch {
+                    selector,
+                    ref cases,
+                } => {
+                    write!(self.out, "{level}switch(")?;
+                    self.put_expression(selector, &context.expression, true)?;
+                    writeln!(self.out, ") {{")?;
+                    let lcase = level.next();
+                    for case in cases.iter() {
+                        match case.value {
+                            crate::SwitchValue::I32(value) => {
+                                write!(self.out, "{lcase}case {value}:")?;
+                            }
+                            crate::SwitchValue::U32(value) => {
+                                write!(self.out, "{lcase}case {value}u:")?;
+                            }
+                            crate::SwitchValue::Default => {
+                                write!(self.out, "{lcase}default:")?;
+                            }
+                        }
+
+                        let write_block_braces = !(case.fall_through && case.body.is_empty());
+                        if write_block_braces {
+                            writeln!(self.out, " {{")?;
+                        } else {
+                            writeln!(self.out)?;
+                        }
+
+                        self.put_block(lcase.next(), &case.body, context)?;
+                        if !case.fall_through
+                            && case.body.last().map_or(true, |s| !s.is_terminator())
+                        {
+                            writeln!(self.out, "{}break;", lcase.next())?;
+                        }
+
+                        if write_block_braces {
+                            writeln!(self.out, "{lcase}}}")?;
+                        }
+                    }
+                    writeln!(self.out, "{level}}}")?;
+                }
+                crate::Statement::Loop {
+                    ref body,
+                    ref continuing,
+                    break_if,
+                } => {
+                    if !continuing.is_empty() || break_if.is_some() {
+                        let gate_name = self.namer.call("loop_init");
+                        writeln!(self.out, "{level}bool {gate_name} = true;")?;
+                        writeln!(self.out, "{level}while(true) {{")?;
+                        let lif = level.next();
+                        let lcontinuing = lif.next();
+                        writeln!(self.out, "{lif}if (!{gate_name}) {{")?;
+                        self.put_block(lcontinuing, continuing, context)?;
+                        if let Some(condition) = break_if {
+                            write!(self.out, "{lcontinuing}if (")?;
+                            self.put_expression(condition, &context.expression, true)?;
+                            writeln!(self.out, ") {{")?;
+                            writeln!(self.out, "{}break;", lcontinuing.next())?;
+                            writeln!(self.out, "{lcontinuing}}}")?;
+                        }
+                        writeln!(self.out, "{lif}}}")?;
+                        writeln!(self.out, "{lif}{gate_name} = false;")?;
+                    } else {
+                        writeln!(self.out, "{level}while(true) {{")?;
+                    }
+                    self.put_block(level.next(), body, context)?;
+                    writeln!(self.out, "{level}}}")?;
+                }
+                crate::Statement::Break => {
+                    writeln!(self.out, "{level}break;")?;
+                }
+                crate::Statement::Continue => {
+                    writeln!(self.out, "{level}continue;")?;
+                }
+                crate::Statement::Return {
+                    value: Some(expr_handle),
+                } => {
+                    self.put_return_value(
+                        level,
+                        expr_handle,
+                        context.result_struct,
+                        &context.expression,
+                    )?;
+                }
+                crate::Statement::Return { value: None } => {
+                    writeln!(self.out, "{level}return;")?;
+                }
+                crate::Statement::Kill => {
+                    writeln!(self.out, "{level}{NAMESPACE}::discard_fragment();")?;
+                }
+                crate::Statement::Barrier(flags) => {
+                    self.write_barrier(flags, level)?;
+                }
+                crate::Statement::Store { pointer, value } => {
+                    self.put_store(pointer, value, level, context)?
+                }
+                crate::Statement::ImageStore {
+                    image,
+                    coordinate,
+                    array_index,
+                    value,
+                } => {
+                    let address = TexelAddress {
+                        coordinate,
+                        array_index,
+                        sample: None,
+                        level: None,
+                    };
+                    self.put_image_store(level, image, &address, value, context)?
+                }
+                crate::Statement::Call {
+                    function,
+                    ref arguments,
+                    result,
+                } => {
+                    write!(self.out, "{level}")?;
+                    if let Some(expr) = result {
+                        let name = format!("{}{}", back::BAKE_PREFIX, expr.index());
+                        self.start_baking_expression(expr, &context.expression, &name)?;
+                        self.named_expressions.insert(expr, name);
+                    }
+                    let fun_name = &self.names[&NameKey::Function(function)];
+                    write!(self.out, "{fun_name}(")?;
+                    // first, write down the actual arguments
+                    for (i, &handle) in arguments.iter().enumerate() {
+                        if i != 0 {
+                            write!(self.out, ", ")?;
+                        }
+                        self.put_expression(handle, &context.expression, true)?;
+                    }
+                    // follow-up with any global resources used
+                    let mut separate = !arguments.is_empty();
+                    let fun_info = &context.expression.mod_info[function];
+                    let mut supports_array_length = false;
+                    for (handle, var) in context.expression.module.global_variables.iter() {
+                        if fun_info[handle].is_empty() {
+                            continue;
+                        }
+                        if var.space.needs_pass_through() {
+                            let name = &self.names[&NameKey::GlobalVariable(handle)];
+                            if separate {
+                                write!(self.out, ", ")?;
+                            } else {
+                                separate = true;
+                            }
+                            write!(self.out, "{name}")?;
+                        }
+                        supports_array_length |=
+                            needs_array_length(var.ty, &context.expression.module.types);
+                    }
+                    if supports_array_length {
+                        if separate {
+                            write!(self.out, ", ")?;
+                        }
+                        write!(self.out, "_buffer_sizes")?;
+                    }
+
+                    // done
+                    writeln!(self.out, ");")?;
+                }
+                crate::Statement::Atomic {
+                    pointer,
+                    ref fun,
+                    value,
+                    result,
+                } => {
+                    write!(self.out, "{level}")?;
+                    let res_name = format!("{}{}", back::BAKE_PREFIX, result.index());
+                    self.start_baking_expression(result, &context.expression, &res_name)?;
+                    self.named_expressions.insert(result, res_name);
+                    match *fun {
+                        crate::AtomicFunction::Add => {
+                            self.put_atomic_fetch(pointer, "add", value, &context.expression)?;
+                        }
+                        crate::AtomicFunction::Subtract => {
+                            self.put_atomic_fetch(pointer, "sub", value, &context.expression)?;
+                        }
+                        crate::AtomicFunction::And => {
+                            self.put_atomic_fetch(pointer, "and", value, &context.expression)?;
+                        }
+                        crate::AtomicFunction::InclusiveOr => {
+                            self.put_atomic_fetch(pointer, "or", value, &context.expression)?;
+                        }
+                        crate::AtomicFunction::ExclusiveOr => {
+                            self.put_atomic_fetch(pointer, "xor", value, &context.expression)?;
+                        }
+                        crate::AtomicFunction::Min => {
+                            self.put_atomic_fetch(pointer, "min", value, &context.expression)?;
+                        }
+                        crate::AtomicFunction::Max => {
+                            self.put_atomic_fetch(pointer, "max", value, &context.expression)?;
+                        }
+                        crate::AtomicFunction::Exchange { compare: None } => {
+                            self.put_atomic_operation(
+                                pointer,
+                                "exchange",
+                                "",
+                                value,
+                                &context.expression,
+                            )?;
+                        }
+                        crate::AtomicFunction::Exchange { .. } => {
+                            return Err(Error::FeatureNotImplemented(
+                                "atomic CompareExchange".to_string(),
+                            ));
+                        }
+                    }
+                    // done
+                    writeln!(self.out, ";")?;
+                }
+                crate::Statement::WorkGroupUniformLoad { pointer, result } => {
+                    self.write_barrier(crate::Barrier::WORK_GROUP, level)?;
+
+                    write!(self.out, "{level}")?;
+                    let name = self.namer.call("");
+                    self.start_baking_expression(result, &context.expression, &name)?;
+                    self.put_load(pointer, &context.expression, true)?;
+                    self.named_expressions.insert(result, name);
+
+                    writeln!(self.out, ";")?;
+                    self.write_barrier(crate::Barrier::WORK_GROUP, level)?;
+                }
+                crate::Statement::RayQuery { query, ref fun } => {
+                    if context.expression.lang_version < (2, 4) {
+                        return Err(Error::UnsupportedRayTracing);
+                    }
+
+                    match *fun {
+                        crate::RayQueryFunction::Initialize {
+                            acceleration_structure,
+                            descriptor,
+                        } => {
+                            //TODO: how to deal with winding?
+                            write!(self.out, "{level}")?;
+                            self.put_expression(query, &context.expression, true)?;
+                            writeln!(self.out, ".{RAY_QUERY_FIELD_INTERSECTOR}.assume_geometry_type({RT_NAMESPACE}::geometry_type::triangle);")?;
+                            {
+                                let f_opaque = back::RayFlag::CULL_OPAQUE.bits();
+                                let f_no_opaque = back::RayFlag::CULL_NO_OPAQUE.bits();
+                                write!(self.out, "{level}")?;
+                                self.put_expression(query, &context.expression, true)?;
+                                write!(
+                                    self.out,
+                                    ".{RAY_QUERY_FIELD_INTERSECTOR}.set_opacity_cull_mode(("
+                                )?;
+                                self.put_expression(descriptor, &context.expression, true)?;
+                                write!(self.out, ".flags & {f_opaque}) != 0 ? {RT_NAMESPACE}::opacity_cull_mode::opaque : (")?;
+                                self.put_expression(descriptor, &context.expression, true)?;
+                                write!(self.out, ".flags & {f_no_opaque}) != 0 ? {RT_NAMESPACE}::opacity_cull_mode::non_opaque : ")?;
+                                writeln!(self.out, "{RT_NAMESPACE}::opacity_cull_mode::none);")?;
+                            }
+                            {
+                                let f_opaque = back::RayFlag::OPAQUE.bits();
+                                let f_no_opaque = back::RayFlag::NO_OPAQUE.bits();
+                                write!(self.out, "{level}")?;
+                                self.put_expression(query, &context.expression, true)?;
+                                write!(self.out, ".{RAY_QUERY_FIELD_INTERSECTOR}.force_opacity((")?;
+                                self.put_expression(descriptor, &context.expression, true)?;
+                                write!(self.out, ".flags & {f_opaque}) != 0 ? {RT_NAMESPACE}::forced_opacity::opaque : (")?;
+                                self.put_expression(descriptor, &context.expression, true)?;
+                                write!(self.out, ".flags & {f_no_opaque}) != 0 ? {RT_NAMESPACE}::forced_opacity::non_opaque : ")?;
+                                writeln!(self.out, "{RT_NAMESPACE}::forced_opacity::none);")?;
+                            }
+                            {
+                                let flag = back::RayFlag::TERMINATE_ON_FIRST_HIT.bits();
+                                write!(self.out, "{level}")?;
+                                self.put_expression(query, &context.expression, true)?;
+                                write!(
+                                    self.out,
+                                    ".{RAY_QUERY_FIELD_INTERSECTOR}.accept_any_intersection(("
+                                )?;
+                                self.put_expression(descriptor, &context.expression, true)?;
+                                writeln!(self.out, ".flags & {flag}) != 0);")?;
+                            }
+
+                            write!(self.out, "{level}")?;
+                            self.put_expression(query, &context.expression, true)?;
+                            write!(self.out, ".{RAY_QUERY_FIELD_INTERSECTION} = ")?;
+                            self.put_expression(query, &context.expression, true)?;
+                            write!(
+                                self.out,
+                                ".{RAY_QUERY_FIELD_INTERSECTOR}.intersect({RT_NAMESPACE}::ray("
+                            )?;
+                            self.put_expression(descriptor, &context.expression, true)?;
+                            write!(self.out, ".origin, ")?;
+                            self.put_expression(descriptor, &context.expression, true)?;
+                            write!(self.out, ".dir, ")?;
+                            self.put_expression(descriptor, &context.expression, true)?;
+                            write!(self.out, ".tmin, ")?;
+                            self.put_expression(descriptor, &context.expression, true)?;
+                            write!(self.out, ".tmax), ")?;
+                            self.put_expression(acceleration_structure, &context.expression, true)?;
+                            write!(self.out, ", ")?;
+                            self.put_expression(descriptor, &context.expression, true)?;
+                            write!(self.out, ".cull_mask);")?;
+
+                            write!(self.out, "{level}")?;
+                            self.put_expression(query, &context.expression, true)?;
+                            writeln!(self.out, ".{RAY_QUERY_FIELD_READY} = true;")?;
+                        }
+                        crate::RayQueryFunction::Proceed { result } => {
+                            write!(self.out, "{level}")?;
+                            let name = format!("{}{}", back::BAKE_PREFIX, result.index());
+                            self.start_baking_expression(result, &context.expression, &name)?;
+                            self.named_expressions.insert(result, name);
+                            self.put_expression(query, &context.expression, true)?;
+                            writeln!(self.out, ".{RAY_QUERY_FIELD_READY};")?;
+                            //TODO: actually proceed?
+
+                            write!(self.out, "{level}")?;
+                            self.put_expression(query, &context.expression, true)?;
+                            writeln!(self.out, ".{RAY_QUERY_FIELD_READY} = false;")?;
+                        }
+                        crate::RayQueryFunction::Terminate => {
+                            write!(self.out, "{level}")?;
+                            self.put_expression(query, &context.expression, true)?;
+                            writeln!(self.out, ".{RAY_QUERY_FIELD_INTERSECTION}.abort();")?;
+                        }
+                    }
+                }
+            }
+        }
+
+        // un-emit expressions
+        //TODO: take care of loop/continuing?
+        for statement in statements {
+            if let crate::Statement::Emit(ref range) = *statement {
+                for handle in range.clone() {
+                    self.named_expressions.remove(&handle);
+                }
+            }
+        }
+        Ok(())
+    }
+
+    fn put_store(
+        &mut self,
+        pointer: Handle<crate::Expression>,
+        value: Handle<crate::Expression>,
+        level: back::Level,
+        context: &StatementContext,
+    ) -> BackendResult {
+        let policy = context.expression.choose_bounds_check_policy(pointer);
+        if policy == index::BoundsCheckPolicy::ReadZeroSkipWrite
+            && self.put_bounds_checks(pointer, &context.expression, level, "if (")?
+        {
+            writeln!(self.out, ") {{")?;
+            self.put_unchecked_store(pointer, value, policy, level.next(), context)?;
+            writeln!(self.out, "{level}}}")?;
+        } else {
+            self.put_unchecked_store(pointer, value, policy, level, context)?;
+        }
+
+        Ok(())
+    }
+
+    fn put_unchecked_store(
+        &mut self,
+        pointer: Handle<crate::Expression>,
+        value: Handle<crate::Expression>,
+        policy: index::BoundsCheckPolicy,
+        level: back::Level,
+        context: &StatementContext,
+    ) -> BackendResult {
+        let is_atomic_pointer = context
+            .expression
+            .resolve_type(pointer)
+            .is_atomic_pointer(&context.expression.module.types);
+
+        if is_atomic_pointer {
+            write!(
+                self.out,
+                "{level}{NAMESPACE}::atomic_store_explicit({ATOMIC_REFERENCE}"
+            )?;
+            self.put_access_chain(pointer, policy, &context.expression)?;
+            write!(self.out, ", ")?;
+            self.put_expression(value, &context.expression, true)?;
+            writeln!(self.out, ", {NAMESPACE}::memory_order_relaxed);")?;
+        } else {
+            write!(self.out, "{level}")?;
+            self.put_access_chain(pointer, policy, &context.expression)?;
+            write!(self.out, " = ")?;
+            self.put_expression(value, &context.expression, true)?;
+            writeln!(self.out, ";")?;
+        }
+
+        Ok(())
+    }
+
+    pub fn write(
+        &mut self,
+        module: &crate::Module,
+        info: &valid::ModuleInfo,
+        options: &Options,
+        pipeline_options: &PipelineOptions,
+    ) -> Result<TranslationInfo, Error> {
+        self.names.clear();
+        self.namer.reset(
+            module,
+            super::keywords::RESERVED,
+            &[],
+            &[],
+            &[CLAMPED_LOD_LOAD_PREFIX],
+            &mut self.names,
+        );
+        self.struct_member_pads.clear();
+
+        writeln!(
+            self.out,
+            "// language: metal{}.{}",
+            options.lang_version.0, options.lang_version.1
+        )?;
+        writeln!(self.out, "#include <metal_stdlib>")?;
+        writeln!(self.out, "#include <simd/simd.h>")?;
+        writeln!(self.out)?;
+        // Work around Metal bug where `uint` is not available by default
+        writeln!(self.out, "using {NAMESPACE}::uint;")?;
+
+        let mut uses_ray_query = false;
+        for (_, ty) in module.types.iter() {
+            match ty.inner {
+                crate::TypeInner::AccelerationStructure => {
+                    if options.lang_version < (2, 4) {
+                        return Err(Error::UnsupportedRayTracing);
+                    }
+                }
+                crate::TypeInner::RayQuery => {
+                    if options.lang_version < (2, 4) {
+                        return Err(Error::UnsupportedRayTracing);
+                    }
+                    uses_ray_query = true;
+                }
+                _ => (),
+            }
+        }
+
+        if module.special_types.ray_desc.is_some()
+            || module.special_types.ray_intersection.is_some()
+        {
+            if options.lang_version < (2, 4) {
+                return Err(Error::UnsupportedRayTracing);
+            }
+        }
+
+        if uses_ray_query {
+            self.put_ray_query_type()?;
+        }
+
+        if options
+            .bounds_check_policies
+            .contains(index::BoundsCheckPolicy::ReadZeroSkipWrite)
+        {
+            self.put_default_constructible()?;
+        }
+        writeln!(self.out)?;
+
+        {
+            let mut indices = vec![];
+            for (handle, var) in module.global_variables.iter() {
+                if needs_array_length(var.ty, &module.types) {
+                    let idx = handle.index();
+                    indices.push(idx);
+                }
+            }
+
+            if !indices.is_empty() {
+                writeln!(self.out, "struct _mslBufferSizes {{")?;
+
+                for idx in indices {
+                    writeln!(self.out, "{}uint size{};", back::INDENT, idx)?;
+                }
+
+                writeln!(self.out, "}};")?;
+                writeln!(self.out)?;
+            }
+        };
+
+        self.write_type_defs(module)?;
+        self.write_global_constants(module, info)?;
+        self.write_functions(module, info, options, pipeline_options)
+    }
+
+    /// Write the definition for the `DefaultConstructible` class.
+    ///
+    /// The [`ReadZeroSkipWrite`] bounds check policy requires us to be able to
+    /// produce 'zero' values for any type, including structs, arrays, and so
+    /// on. We could do this by emitting default constructor applications, but
+    /// that would entail printing the name of the type, which is more trouble
+    /// than you'd think. Instead, we just construct this magic C++14 class that
+    /// can be converted to any type that can be default constructed, using
+    /// template parameter inference to detect which type is needed, so we don't
+    /// have to figure out the name.
+    ///
+    /// [`ReadZeroSkipWrite`]: index::BoundsCheckPolicy::ReadZeroSkipWrite
+    fn put_default_constructible(&mut self) -> BackendResult {
+        let tab = back::INDENT;
+        writeln!(self.out, "struct DefaultConstructible {{")?;
+        writeln!(self.out, "{tab}template<typename T>")?;
+        writeln!(self.out, "{tab}operator T() && {{")?;
+        writeln!(self.out, "{tab}{tab}return T {{}};")?;
+        writeln!(self.out, "{tab}}}")?;
+        writeln!(self.out, "}};")?;
+        Ok(())
+    }
+
+    fn put_ray_query_type(&mut self) -> BackendResult {
+        let tab = back::INDENT;
+        writeln!(self.out, "struct {RAY_QUERY_TYPE} {{")?;
+        let full_type = format!("{RT_NAMESPACE}::intersector<{RT_NAMESPACE}::instancing, {RT_NAMESPACE}::triangle_data, {RT_NAMESPACE}::world_space_data>");
+        writeln!(self.out, "{tab}{full_type} {RAY_QUERY_FIELD_INTERSECTOR};")?;
+        writeln!(
+            self.out,
+            "{tab}{full_type}::result_type {RAY_QUERY_FIELD_INTERSECTION};"
+        )?;
+        writeln!(self.out, "{tab}bool {RAY_QUERY_FIELD_READY} = false;")?;
+        writeln!(self.out, "}};")?;
+        writeln!(self.out, "constexpr {NAMESPACE}::uint {RAY_QUERY_FUN_MAP_INTERSECTION}(const {RT_NAMESPACE}::intersection_type ty) {{")?;
+        let v_triangle = back::RayIntersectionType::Triangle as u32;
+        let v_bbox = back::RayIntersectionType::BoundingBox as u32;
+        writeln!(
+            self.out,
+            "{tab}return ty=={RT_NAMESPACE}::intersection_type::triangle ? {v_triangle} : "
+        )?;
+        writeln!(
+            self.out,
+            "{tab}{tab}ty=={RT_NAMESPACE}::intersection_type::bounding_box ? {v_bbox} : 0;"
+        )?;
+        writeln!(self.out, "}}")?;
+        Ok(())
+    }
+
+    fn write_type_defs(&mut self, module: &crate::Module) -> BackendResult {
+        for (handle, ty) in module.types.iter() {
+            if !ty.needs_alias() {
+                continue;
+            }
+            let name = &self.names[&NameKey::Type(handle)];
+            match ty.inner {
+                // Naga IR can pass around arrays by value, but Metal, following
+                // C++, performs an array-to-pointer conversion (C++ [conv.array])
+                // on expressions of array type, so assigning the array by value
+                // isn't possible. However, Metal *does* assign structs by
+                // value. So in our Metal output, we wrap all array types in
+                // synthetic struct types:
+                //
+                //     struct type1 {
+                //         float inner[10]
+                //     };
+                //
+                // Then we carefully include `.inner` (`WRAPPED_ARRAY_FIELD`) in
+                // any expression that actually wants access to the array.
+                crate::TypeInner::Array {
+                    base,
+                    size,
+                    stride: _,
+                } => {
+                    let base_name = TypeContext {
+                        handle: base,
+                        gctx: module.to_ctx(),
+                        names: &self.names,
+                        access: crate::StorageAccess::empty(),
+                        binding: None,
+                        first_time: false,
+                    };
+
+                    match size {
+                        crate::ArraySize::Constant(size) => {
+                            writeln!(self.out, "struct {name} {{")?;
+                            writeln!(
+                                self.out,
+                                "{}{} {}[{}];",
+                                back::INDENT,
+                                base_name,
+                                WRAPPED_ARRAY_FIELD,
+                                size
+                            )?;
+                            writeln!(self.out, "}};")?;
+                        }
+                        crate::ArraySize::Dynamic => {
+                            writeln!(self.out, "typedef {base_name} {name}[1];")?;
+                        }
+                    }
+                }
+                crate::TypeInner::Struct {
+                    ref members, span, ..
+                } => {
+                    writeln!(self.out, "struct {name} {{")?;
+                    let mut last_offset = 0;
+                    for (index, member) in members.iter().enumerate() {
+                        if member.offset > last_offset {
+                            self.struct_member_pads.insert((handle, index as u32));
+                            let pad = member.offset - last_offset;
+                            writeln!(self.out, "{}char _pad{}[{}];", back::INDENT, index, pad)?;
+                        }
+                        let ty_inner = &module.types[member.ty].inner;
+                        last_offset = member.offset + ty_inner.size(module.to_ctx());
+
+                        let member_name = &self.names[&NameKey::StructMember(handle, index as u32)];
+
+                        // If the member should be packed (as is the case for a misaligned vec3) issue a packed vector
+                        match should_pack_struct_member(members, span, index, module) {
+                            Some(scalar) => {
+                                writeln!(
+                                    self.out,
+                                    "{}{}::packed_{}3 {};",
+                                    back::INDENT,
+                                    NAMESPACE,
+                                    scalar.to_msl_name(),
+                                    member_name
+                                )?;
+                            }
+                            None => {
+                                let base_name = TypeContext {
+                                    handle: member.ty,
+                                    gctx: module.to_ctx(),
+                                    names: &self.names,
+                                    access: crate::StorageAccess::empty(),
+                                    binding: None,
+                                    first_time: false,
+                                };
+                                writeln!(
+                                    self.out,
+                                    "{}{} {};",
+                                    back::INDENT,
+                                    base_name,
+                                    member_name
+                                )?;
+
+                                // for 3-component vectors, add one component
+                                if let crate::TypeInner::Vector {
+                                    size: crate::VectorSize::Tri,
+                                    scalar,
+                                } = *ty_inner
+                                {
+                                    last_offset += scalar.width as u32;
+                                }
+                            }
+                        }
+                    }
+                    writeln!(self.out, "}};")?;
+                }
+                _ => {
+                    let ty_name = TypeContext {
+                        handle,
+                        gctx: module.to_ctx(),
+                        names: &self.names,
+                        access: crate::StorageAccess::empty(),
+                        binding: None,
+                        first_time: true,
+                    };
+                    writeln!(self.out, "typedef {ty_name} {name};")?;
+                }
+            }
+        }
+
+        // Write functions to create special types.
+        for (type_key, struct_ty) in module.special_types.predeclared_types.iter() {
+            match type_key {
+                &crate::PredeclaredType::ModfResult { size, width }
+                | &crate::PredeclaredType::FrexpResult { size, width } => {
+                    let arg_type_name_owner;
+                    let arg_type_name = if let Some(size) = size {
+                        arg_type_name_owner = format!(
+                            "{NAMESPACE}::{}{}",
+                            if width == 8 { "double" } else { "float" },
+                            size as u8
+                        );
+                        &arg_type_name_owner
+                    } else if width == 8 {
+                        "double"
+                    } else {
+                        "float"
+                    };
+
+                    let other_type_name_owner;
+                    let (defined_func_name, called_func_name, other_type_name) =
+                        if matches!(type_key, &crate::PredeclaredType::ModfResult { .. }) {
+                            (MODF_FUNCTION, "modf", arg_type_name)
+                        } else {
+                            let other_type_name = if let Some(size) = size {
+                                other_type_name_owner = format!("int{}", size as u8);
+                                &other_type_name_owner
+                            } else {
+                                "int"
+                            };
+                            (FREXP_FUNCTION, "frexp", other_type_name)
+                        };
+
+                    let struct_name = &self.names[&NameKey::Type(*struct_ty)];
+
+                    writeln!(self.out)?;
+                    writeln!(
+                        self.out,
+                        "{} {defined_func_name}({arg_type_name} arg) {{
+    {other_type_name} other;
+    {arg_type_name} fract = {NAMESPACE}::{called_func_name}(arg, other);
+    return {}{{ fract, other }};
+}}",
+                        struct_name, struct_name
+                    )?;
+                }
+                &crate::PredeclaredType::AtomicCompareExchangeWeakResult { .. } => {}
+            }
+        }
+
+        Ok(())
+    }
+
+    /// Writes all named constants
+    fn write_global_constants(
+        &mut self,
+        module: &crate::Module,
+        mod_info: &valid::ModuleInfo,
+    ) -> BackendResult {
+        let constants = module.constants.iter().filter(|&(_, c)| c.name.is_some());
+
+        for (handle, constant) in constants {
+            let ty_name = TypeContext {
+                handle: constant.ty,
+                gctx: module.to_ctx(),
+                names: &self.names,
+                access: crate::StorageAccess::empty(),
+                binding: None,
+                first_time: false,
+            };
+            let name = &self.names[&NameKey::Constant(handle)];
+            write!(self.out, "constant {ty_name} {name} = ")?;
+            self.put_const_expression(constant.init, module, mod_info)?;
+            writeln!(self.out, ";")?;
+        }
+
+        Ok(())
+    }
+
+    fn put_inline_sampler_properties(
+        &mut self,
+        level: back::Level,
+        sampler: &sm::InlineSampler,
+    ) -> BackendResult {
+        for (&letter, address) in ['s', 't', 'r'].iter().zip(sampler.address.iter()) {
+            writeln!(
+                self.out,
+                "{}{}::{}_address::{},",
+                level,
+                NAMESPACE,
+                letter,
+                address.as_str(),
+            )?;
+        }
+        writeln!(
+            self.out,
+            "{}{}::mag_filter::{},",
+            level,
+            NAMESPACE,
+            sampler.mag_filter.as_str(),
+        )?;
+        writeln!(
+            self.out,
+            "{}{}::min_filter::{},",
+            level,
+            NAMESPACE,
+            sampler.min_filter.as_str(),
+        )?;
+        if let Some(filter) = sampler.mip_filter {
+            writeln!(
+                self.out,
+                "{}{}::mip_filter::{},",
+                level,
+                NAMESPACE,
+                filter.as_str(),
+            )?;
+        }
+        // avoid setting it on platforms that don't support it
+        if sampler.border_color != sm::BorderColor::TransparentBlack {
+            writeln!(
+                self.out,
+                "{}{}::border_color::{},",
+                level,
+                NAMESPACE,
+                sampler.border_color.as_str(),
+            )?;
+        }
+        //TODO: I'm not able to feed this in a way that MSL likes:
+        //>error: use of undeclared identifier 'lod_clamp'
+        //>error: no member named 'max_anisotropy' in namespace 'metal'
+        if false {
+            if let Some(ref lod) = sampler.lod_clamp {
+                writeln!(self.out, "{}lod_clamp({},{}),", level, lod.start, lod.end,)?;
+            }
+            if let Some(aniso) = sampler.max_anisotropy {
+                writeln!(self.out, "{}max_anisotropy({}),", level, aniso.get(),)?;
+            }
+        }
+        if sampler.compare_func != sm::CompareFunc::Never {
+            writeln!(
+                self.out,
+                "{}{}::compare_func::{},",
+                level,
+                NAMESPACE,
+                sampler.compare_func.as_str(),
+            )?;
+        }
+        writeln!(
+            self.out,
+            "{}{}::coord::{}",
+            level,
+            NAMESPACE,
+            sampler.coord.as_str()
+        )?;
+        Ok(())
+    }
+
+    // Returns the array of mapped entry point names.
+    fn write_functions(
+        &mut self,
+        module: &crate::Module,
+        mod_info: &valid::ModuleInfo,
+        options: &Options,
+        pipeline_options: &PipelineOptions,
+    ) -> Result<TranslationInfo, Error> {
+        let mut pass_through_globals = Vec::new();
+        for (fun_handle, fun) in module.functions.iter() {
+            log::trace!(
+                "function {:?}, handle {:?}",
+                fun.name.as_deref().unwrap_or("(anonymous)"),
+                fun_handle
+            );
+
+            let fun_info = &mod_info[fun_handle];
+            pass_through_globals.clear();
+            let mut supports_array_length = false;
+            for (handle, var) in module.global_variables.iter() {
+                if !fun_info[handle].is_empty() {
+                    if var.space.needs_pass_through() {
+                        pass_through_globals.push(handle);
+                    }
+                    supports_array_length |= needs_array_length(var.ty, &module.types);
+                }
+            }
+
+            writeln!(self.out)?;
+            let fun_name = &self.names[&NameKey::Function(fun_handle)];
+            match fun.result {
+                Some(ref result) => {
+                    let ty_name = TypeContext {
+                        handle: result.ty,
+                        gctx: module.to_ctx(),
+                        names: &self.names,
+                        access: crate::StorageAccess::empty(),
+                        binding: None,
+                        first_time: false,
+                    };
+                    write!(self.out, "{ty_name}")?;
+                }
+                None => {
+                    write!(self.out, "void")?;
+                }
+            }
+            writeln!(self.out, " {fun_name}(")?;
+
+            for (index, arg) in fun.arguments.iter().enumerate() {
+                let name = &self.names[&NameKey::FunctionArgument(fun_handle, index as u32)];
+                let param_type_name = TypeContext {
+                    handle: arg.ty,
+                    gctx: module.to_ctx(),
+                    names: &self.names,
+                    access: crate::StorageAccess::empty(),
+                    binding: None,
+                    first_time: false,
+                };
+                let separator = separate(
+                    !pass_through_globals.is_empty()
+                        || index + 1 != fun.arguments.len()
+                        || supports_array_length,
+                );
+                writeln!(
+                    self.out,
+                    "{}{} {}{}",
+                    back::INDENT,
+                    param_type_name,
+                    name,
+                    separator
+                )?;
+            }
+            for (index, &handle) in pass_through_globals.iter().enumerate() {
+                let tyvar = TypedGlobalVariable {
+                    module,
+                    names: &self.names,
+                    handle,
+                    usage: fun_info[handle],
+                    binding: None,
+                    reference: true,
+                };
+                let separator =
+                    separate(index + 1 != pass_through_globals.len() || supports_array_length);
+                write!(self.out, "{}", back::INDENT)?;
+                tyvar.try_fmt(&mut self.out)?;
+                writeln!(self.out, "{separator}")?;
+            }
+
+            if supports_array_length {
+                writeln!(
+                    self.out,
+                    "{}constant _mslBufferSizes& _buffer_sizes",
+                    back::INDENT
+                )?;
+            }
+
+            writeln!(self.out, ") {{")?;
+
+            let guarded_indices =
+                index::find_checked_indexes(module, fun, fun_info, options.bounds_check_policies);
+
+            let context = StatementContext {
+                expression: ExpressionContext {
+                    function: fun,
+                    origin: FunctionOrigin::Handle(fun_handle),
+                    info: fun_info,
+                    lang_version: options.lang_version,
+                    policies: options.bounds_check_policies,
+                    guarded_indices,
+                    module,
+                    mod_info,
+                    pipeline_options,
+                },
+                result_struct: None,
+            };
+
+            for (local_handle, local) in fun.local_variables.iter() {
+                let ty_name = TypeContext {
+                    handle: local.ty,
+                    gctx: module.to_ctx(),
+                    names: &self.names,
+                    access: crate::StorageAccess::empty(),
+                    binding: None,
+                    first_time: false,
+                };
+                let local_name = &self.names[&NameKey::FunctionLocal(fun_handle, local_handle)];
+                write!(self.out, "{}{} {}", back::INDENT, ty_name, local_name)?;
+                match local.init {
+                    Some(value) => {
+                        write!(self.out, " = ")?;
+                        self.put_expression(value, &context.expression, true)?;
+                    }
+                    None => {
+                        write!(self.out, " = {{}}")?;
+                    }
+                };
+                writeln!(self.out, ";")?;
+            }
+
+            self.update_expressions_to_bake(fun, fun_info, &context.expression);
+            self.put_block(back::Level(1), &fun.body, &context)?;
+            writeln!(self.out, "}}")?;
+            self.named_expressions.clear();
+        }
+
+        let mut info = TranslationInfo {
+            entry_point_names: Vec::with_capacity(module.entry_points.len()),
+        };
+        for (ep_index, ep) in module.entry_points.iter().enumerate() {
+            let fun = &ep.function;
+            let fun_info = mod_info.get_entry_point(ep_index);
+            let mut ep_error = None;
+
+            log::trace!(
+                "entry point {:?}, index {:?}",
+                fun.name.as_deref().unwrap_or("(anonymous)"),
+                ep_index
+            );
+
+            // Is any global variable used by this entry point dynamically sized?
+            let supports_array_length = module
+                .global_variables
+                .iter()
+                .filter(|&(handle, _)| !fun_info[handle].is_empty())
+                .any(|(_, var)| needs_array_length(var.ty, &module.types));
+
+            // skip this entry point if any global bindings are missing,
+            // or their types are incompatible.
+            if !options.fake_missing_bindings {
+                for (var_handle, var) in module.global_variables.iter() {
+                    if fun_info[var_handle].is_empty() {
+                        continue;
+                    }
+                    match var.space {
+                        crate::AddressSpace::Uniform
+                        | crate::AddressSpace::Storage { .. }
+                        | crate::AddressSpace::Handle => {
+                            let br = match var.binding {
+                                Some(ref br) => br,
+                                None => {
+                                    let var_name = var.name.clone().unwrap_or_default();
+                                    ep_error =
+                                        Some(super::EntryPointError::MissingBinding(var_name));
+                                    break;
+                                }
+                            };
+                            let target = options.get_resource_binding_target(ep, br);
+                            let good = match target {
+                                Some(target) => {
+                                    let binding_ty = match module.types[var.ty].inner {
+                                        crate::TypeInner::BindingArray { base, .. } => {
+                                            &module.types[base].inner
+                                        }
+                                        ref ty => ty,
+                                    };
+                                    match *binding_ty {
+                                        crate::TypeInner::Image { .. } => target.texture.is_some(),
+                                        crate::TypeInner::Sampler { .. } => {
+                                            target.sampler.is_some()
+                                        }
+                                        _ => target.buffer.is_some(),
+                                    }
+                                }
+                                None => false,
+                            };
+                            if !good {
+                                ep_error =
+                                    Some(super::EntryPointError::MissingBindTarget(br.clone()));
+                                break;
+                            }
+                        }
+                        crate::AddressSpace::PushConstant => {
+                            if let Err(e) = options.resolve_push_constants(ep) {
+                                ep_error = Some(e);
+                                break;
+                            }
+                        }
+                        crate::AddressSpace::Function
+                        | crate::AddressSpace::Private
+                        | crate::AddressSpace::WorkGroup => {}
+                    }
+                }
+                if supports_array_length {
+                    if let Err(err) = options.resolve_sizes_buffer(ep) {
+                        ep_error = Some(err);
+                    }
+                }
+            }
+
+            if let Some(err) = ep_error {
+                info.entry_point_names.push(Err(err));
+                continue;
+            }
+            let fun_name = &self.names[&NameKey::EntryPoint(ep_index as _)];
+            info.entry_point_names.push(Ok(fun_name.clone()));
+
+            writeln!(self.out)?;
+
+            let (em_str, in_mode, out_mode) = match ep.stage {
+                crate::ShaderStage::Vertex => (
+                    "vertex",
+                    LocationMode::VertexInput,
+                    LocationMode::VertexOutput,
+                ),
+                crate::ShaderStage::Fragment { .. } => (
+                    "fragment",
+                    LocationMode::FragmentInput,
+                    LocationMode::FragmentOutput,
+                ),
+                crate::ShaderStage::Compute { .. } => {
+                    ("kernel", LocationMode::Uniform, LocationMode::Uniform)
+                }
+            };
+
+            // Since `Namer.reset` wasn't expecting struct members to be
+            // suddenly injected into another namespace like this,
+            // `self.names` doesn't keep them distinct from other variables.
+            // Generate fresh names for these arguments, and remember the
+            // mapping.
+            let mut flattened_member_names = FastHashMap::default();
+            // Varyings' members get their own namespace
+            let mut varyings_namer = crate::proc::Namer::default();
+
+            // List all the Naga `EntryPoint`'s `Function`'s arguments,
+            // flattening structs into their members. In Metal, we will pass
+            // each of these values to the entry point as a separate argument—
+            // except for the varyings, handled next.
+            let mut flattened_arguments = Vec::new();
+            for (arg_index, arg) in fun.arguments.iter().enumerate() {
+                match module.types[arg.ty].inner {
+                    crate::TypeInner::Struct { ref members, .. } => {
+                        for (member_index, member) in members.iter().enumerate() {
+                            let member_index = member_index as u32;
+                            flattened_arguments.push((
+                                NameKey::StructMember(arg.ty, member_index),
+                                member.ty,
+                                member.binding.as_ref(),
+                            ));
+                            let name_key = NameKey::StructMember(arg.ty, member_index);
+                            let name = match member.binding {
+                                Some(crate::Binding::Location { .. }) => {
+                                    varyings_namer.call(&self.names[&name_key])
+                                }
+                                _ => self.namer.call(&self.names[&name_key]),
+                            };
+                            flattened_member_names.insert(name_key, name);
+                        }
+                    }
+                    _ => flattened_arguments.push((
+                        NameKey::EntryPointArgument(ep_index as _, arg_index as u32),
+                        arg.ty,
+                        arg.binding.as_ref(),
+                    )),
+                }
+            }
+
+            // Identify the varyings among the argument values, and emit a
+            // struct type named `<fun>Input` to hold them.
+            let stage_in_name = format!("{fun_name}Input");
+            let varyings_member_name = self.namer.call("varyings");
+            let mut has_varyings = false;
+            if !flattened_arguments.is_empty() {
+                writeln!(self.out, "struct {stage_in_name} {{")?;
+                for &(ref name_key, ty, binding) in flattened_arguments.iter() {
+                    let binding = match binding {
+                        Some(ref binding @ &crate::Binding::Location { .. }) => binding,
+                        _ => continue,
+                    };
+                    has_varyings = true;
+                    let name = match *name_key {
+                        NameKey::StructMember(..) => &flattened_member_names[name_key],
+                        _ => &self.names[name_key],
+                    };
+                    let ty_name = TypeContext {
+                        handle: ty,
+                        gctx: module.to_ctx(),
+                        names: &self.names,
+                        access: crate::StorageAccess::empty(),
+                        binding: None,
+                        first_time: false,
+                    };
+                    let resolved = options.resolve_local_binding(binding, in_mode)?;
+                    write!(self.out, "{}{} {}", back::INDENT, ty_name, name)?;
+                    resolved.try_fmt(&mut self.out)?;
+                    writeln!(self.out, ";")?;
+                }
+                writeln!(self.out, "}};")?;
+            }
+
+            // Define a struct type named for the return value, if any, named
+            // `<fun>Output`.
+            let stage_out_name = format!("{fun_name}Output");
+            let result_member_name = self.namer.call("member");
+            let result_type_name = match fun.result {
+                Some(ref result) => {
+                    let mut result_members = Vec::new();
+                    if let crate::TypeInner::Struct { ref members, .. } =
+                        module.types[result.ty].inner
+                    {
+                        for (member_index, member) in members.iter().enumerate() {
+                            result_members.push((
+                                &self.names[&NameKey::StructMember(result.ty, member_index as u32)],
+                                member.ty,
+                                member.binding.as_ref(),
+                            ));
+                        }
+                    } else {
+                        result_members.push((
+                            &result_member_name,
+                            result.ty,
+                            result.binding.as_ref(),
+                        ));
+                    }
+
+                    writeln!(self.out, "struct {stage_out_name} {{")?;
+                    let mut has_point_size = false;
+                    for (name, ty, binding) in result_members {
+                        let ty_name = TypeContext {
+                            handle: ty,
+                            gctx: module.to_ctx(),
+                            names: &self.names,
+                            access: crate::StorageAccess::empty(),
+                            binding: None,
+                            first_time: true,
+                        };
+                        let binding = binding.ok_or(Error::Validation)?;
+
+                        if let crate::Binding::BuiltIn(crate::BuiltIn::PointSize) = *binding {
+                            has_point_size = true;
+                            if !pipeline_options.allow_and_force_point_size {
+                                continue;
+                            }
+                        }
+
+                        let array_len = match module.types[ty].inner {
+                            crate::TypeInner::Array {
+                                size: crate::ArraySize::Constant(size),
+                                ..
+                            } => Some(size),
+                            _ => None,
+                        };
+                        let resolved = options.resolve_local_binding(binding, out_mode)?;
+                        write!(self.out, "{}{} {}", back::INDENT, ty_name, name)?;
+                        if let Some(array_len) = array_len {
+                            write!(self.out, " [{array_len}]")?;
+                        }
+                        resolved.try_fmt(&mut self.out)?;
+                        writeln!(self.out, ";")?;
+                    }
+
+                    if pipeline_options.allow_and_force_point_size
+                        && ep.stage == crate::ShaderStage::Vertex
+                        && !has_point_size
+                    {
+                        // inject the point size output last
+                        writeln!(
+                            self.out,
+                            "{}float _point_size [[point_size]];",
+                            back::INDENT
+                        )?;
+                    }
+                    writeln!(self.out, "}};")?;
+                    &stage_out_name
+                }
+                None => "void",
+            };
+
+            // Write the entry point function's name, and begin its argument list.
+            writeln!(self.out, "{em_str} {result_type_name} {fun_name}(")?;
+            let mut is_first_argument = true;
+
+            // If we have produced a struct holding the `EntryPoint`'s
+            // `Function`'s arguments' varyings, pass that struct first.
+            if has_varyings {
+                writeln!(
+                    self.out,
+                    "  {stage_in_name} {varyings_member_name} [[stage_in]]"
+                )?;
+                is_first_argument = false;
+            }
+
+            let mut local_invocation_id = None;
+
+            // Then pass the remaining arguments not included in the varyings
+            // struct.
+            for &(ref name_key, ty, binding) in flattened_arguments.iter() {
+                let binding = match binding {
+                    Some(binding @ &crate::Binding::BuiltIn { .. }) => binding,
+                    _ => continue,
+                };
+                let name = match *name_key {
+                    NameKey::StructMember(..) => &flattened_member_names[name_key],
+                    _ => &self.names[name_key],
+                };
+
+                if binding == &crate::Binding::BuiltIn(crate::BuiltIn::LocalInvocationId) {
+                    local_invocation_id = Some(name_key);
+                }
+
+                let ty_name = TypeContext {
+                    handle: ty,
+                    gctx: module.to_ctx(),
+                    names: &self.names,
+                    access: crate::StorageAccess::empty(),
+                    binding: None,
+                    first_time: false,
+                };
+                let resolved = options.resolve_local_binding(binding, in_mode)?;
+                let separator = if is_first_argument {
+                    is_first_argument = false;
+                    ' '
+                } else {
+                    ','
+                };
+                write!(self.out, "{separator} {ty_name} {name}")?;
+                resolved.try_fmt(&mut self.out)?;
+                writeln!(self.out)?;
+            }
+
+            let need_workgroup_variables_initialization =
+                self.need_workgroup_variables_initialization(options, ep, module, fun_info);
+
+            if need_workgroup_variables_initialization && local_invocation_id.is_none() {
+                let separator = if is_first_argument {
+                    is_first_argument = false;
+                    ' '
+                } else {
+                    ','
+                };
+                writeln!(
+                    self.out,
+                    "{separator} {NAMESPACE}::uint3 __local_invocation_id [[thread_position_in_threadgroup]]"
+                )?;
+            }
+
+            // Those global variables used by this entry point and its callees
+            // get passed as arguments. `Private` globals are an exception, they
+            // don't outlive this invocation, so we declare them below as locals
+            // within the entry point.
+            for (handle, var) in module.global_variables.iter() {
+                let usage = fun_info[handle];
+                if usage.is_empty() || var.space == crate::AddressSpace::Private {
+                    continue;
+                }
+
+                if options.lang_version < (1, 2) {
+                    match var.space {
+                        // This restriction is not documented in the MSL spec
+                        // but validation will fail if it is not upheld.
+                        //
+                        // We infer the required version from the "Function
+                        // Buffer Read-Writes" section of [what's new], where
+                        // the feature sets listed correspond with the ones
+                        // supporting MSL 1.2.
+                        //
+                        // [what's new]: https://developer.apple.com/library/archive/documentation/Miscellaneous/Conceptual/MetalProgrammingGuide/WhatsNewiniOS10tvOS10andOSX1012/WhatsNewiniOS10tvOS10andOSX1012.html
+                        crate::AddressSpace::Storage { access }
+                            if access.contains(crate::StorageAccess::STORE)
+                                && ep.stage == crate::ShaderStage::Fragment =>
+                        {
+                            return Err(Error::UnsupportedWriteableStorageBuffer)
+                        }
+                        crate::AddressSpace::Handle => {
+                            match module.types[var.ty].inner {
+                                crate::TypeInner::Image {
+                                    class: crate::ImageClass::Storage { access, .. },
+                                    ..
+                                } => {
+                                    // This restriction is not documented in the MSL spec
+                                    // but validation will fail if it is not upheld.
+                                    //
+                                    // We infer the required version from the "Function
+                                    // Texture Read-Writes" section of [what's new], where
+                                    // the feature sets listed correspond with the ones
+                                    // supporting MSL 1.2.
+                                    //
+                                    // [what's new]: https://developer.apple.com/library/archive/documentation/Miscellaneous/Conceptual/MetalProgrammingGuide/WhatsNewiniOS10tvOS10andOSX1012/WhatsNewiniOS10tvOS10andOSX1012.html
+                                    if access.contains(crate::StorageAccess::STORE)
+                                        && (ep.stage == crate::ShaderStage::Vertex
+                                            || ep.stage == crate::ShaderStage::Fragment)
+                                    {
+                                        return Err(Error::UnsupportedWriteableStorageTexture(
+                                            ep.stage,
+                                        ));
+                                    }
+
+                                    if access.contains(
+                                        crate::StorageAccess::LOAD | crate::StorageAccess::STORE,
+                                    ) {
+                                        return Err(Error::UnsupportedRWStorageTexture);
+                                    }
+                                }
+                                _ => {}
+                            }
+                        }
+                        _ => {}
+                    }
+                }
+
+                // Check min MSL version for binding arrays
+                match var.space {
+                    crate::AddressSpace::Handle => match module.types[var.ty].inner {
+                        crate::TypeInner::BindingArray { base, .. } => {
+                            match module.types[base].inner {
+                                crate::TypeInner::Sampler { .. } => {
+                                    if options.lang_version < (2, 0) {
+                                        return Err(Error::UnsupportedArrayOf(
+                                            "samplers".to_string(),
+                                        ));
+                                    }
+                                }
+                                crate::TypeInner::Image { class, .. } => match class {
+                                    crate::ImageClass::Sampled { .. }
+                                    | crate::ImageClass::Depth { .. }
+                                    | crate::ImageClass::Storage {
+                                        access: crate::StorageAccess::LOAD,
+                                        ..
+                                    } => {
+                                        // Array of textures since:
+                                        // - iOS: Metal 1.2 (check depends on https://github.com/gfx-rs/naga/issues/2164)
+                                        // - macOS: Metal 2
+
+                                        if options.lang_version < (2, 0) {
+                                            return Err(Error::UnsupportedArrayOf(
+                                                "textures".to_string(),
+                                            ));
+                                        }
+                                    }
+                                    crate::ImageClass::Storage {
+                                        access: crate::StorageAccess::STORE,
+                                        ..
+                                    } => {
+                                        // Array of write-only textures since:
+                                        // - iOS: Metal 2.2 (check depends on https://github.com/gfx-rs/naga/issues/2164)
+                                        // - macOS: Metal 2
+
+                                        if options.lang_version < (2, 0) {
+                                            return Err(Error::UnsupportedArrayOf(
+                                                "write-only textures".to_string(),
+                                            ));
+                                        }
+                                    }
+                                    crate::ImageClass::Storage { .. } => {
+                                        return Err(Error::UnsupportedArrayOf(
+                                            "read-write textures".to_string(),
+                                        ));
+                                    }
+                                },
+                                _ => {
+                                    return Err(Error::UnsupportedArrayOfType(base));
+                                }
+                            }
+                        }
+                        _ => {}
+                    },
+                    _ => {}
+                }
+
+                // the resolves have already been checked for `!fake_missing_bindings` case
+                let resolved = match var.space {
+                    crate::AddressSpace::PushConstant => options.resolve_push_constants(ep).ok(),
+                    crate::AddressSpace::WorkGroup => None,
+                    _ => options
+                        .resolve_resource_binding(ep, var.binding.as_ref().unwrap())
+                        .ok(),
+                };
+                if let Some(ref resolved) = resolved {
+                    // Inline samplers are be defined in the EP body
+                    if resolved.as_inline_sampler(options).is_some() {
+                        continue;
+                    }
+                }
+
+                let tyvar = TypedGlobalVariable {
+                    module,
+                    names: &self.names,
+                    handle,
+                    usage,
+                    binding: resolved.as_ref(),
+                    reference: true,
+                };
+                let separator = if is_first_argument {
+                    is_first_argument = false;
+                    ' '
+                } else {
+                    ','
+                };
+                write!(self.out, "{separator} ")?;
+                tyvar.try_fmt(&mut self.out)?;
+                if let Some(resolved) = resolved {
+                    resolved.try_fmt(&mut self.out)?;
+                }
+                if let Some(value) = var.init {
+                    write!(self.out, " = ")?;
+                    self.put_const_expression(value, module, mod_info)?;
+                }
+                writeln!(self.out)?;
+            }
+
+            // If this entry uses any variable-length arrays, their sizes are
+            // passed as a final struct-typed argument.
+            if supports_array_length {
+                // this is checked earlier
+                let resolved = options.resolve_sizes_buffer(ep).unwrap();
+                let separator = if module.global_variables.is_empty() {
+                    ' '
+                } else {
+                    ','
+                };
+                write!(
+                    self.out,
+                    "{separator} constant _mslBufferSizes& _buffer_sizes",
+                )?;
+                resolved.try_fmt(&mut self.out)?;
+                writeln!(self.out)?;
+            }
+
+            // end of the entry point argument list
+            writeln!(self.out, ") {{")?;
+
+            if need_workgroup_variables_initialization {
+                self.write_workgroup_variables_initialization(
+                    module,
+                    mod_info,
+                    fun_info,
+                    local_invocation_id,
+                )?;
+            }
+
+            // Metal doesn't support private mutable variables outside of functions,
+            // so we put them here, just like the locals.
+            for (handle, var) in module.global_variables.iter() {
+                let usage = fun_info[handle];
+                if usage.is_empty() {
+                    continue;
+                }
+                if var.space == crate::AddressSpace::Private {
+                    let tyvar = TypedGlobalVariable {
+                        module,
+                        names: &self.names,
+                        handle,
+                        usage,
+                        binding: None,
+                        reference: false,
+                    };
+                    write!(self.out, "{}", back::INDENT)?;
+                    tyvar.try_fmt(&mut self.out)?;
+                    match var.init {
+                        Some(value) => {
+                            write!(self.out, " = ")?;
+                            self.put_const_expression(value, module, mod_info)?;
+                            writeln!(self.out, ";")?;
+                        }
+                        None => {
+                            writeln!(self.out, " = {{}};")?;
+                        }
+                    };
+                } else if let Some(ref binding) = var.binding {
+                    // write an inline sampler
+                    let resolved = options.resolve_resource_binding(ep, binding).unwrap();
+                    if let Some(sampler) = resolved.as_inline_sampler(options) {
+                        let name = &self.names[&NameKey::GlobalVariable(handle)];
+                        writeln!(
+                            self.out,
+                            "{}constexpr {}::sampler {}(",
+                            back::INDENT,
+                            NAMESPACE,
+                            name
+                        )?;
+                        self.put_inline_sampler_properties(back::Level(2), sampler)?;
+                        writeln!(self.out, "{});", back::INDENT)?;
+                    }
+                }
+            }
+
+            // Now take the arguments that we gathered into structs, and the
+            // structs that we flattened into arguments, and emit local
+            // variables with initializers that put everything back the way the
+            // body code expects.
+            //
+            // If we had to generate fresh names for struct members passed as
+            // arguments, be sure to use those names when rebuilding the struct.
+            //
+            // "Each day, I change some zeros to ones, and some ones to zeros.
+            // The rest, I leave alone."
+            for (arg_index, arg) in fun.arguments.iter().enumerate() {
+                let arg_name =
+                    &self.names[&NameKey::EntryPointArgument(ep_index as _, arg_index as u32)];
+                match module.types[arg.ty].inner {
+                    crate::TypeInner::Struct { ref members, .. } => {
+                        let struct_name = &self.names[&NameKey::Type(arg.ty)];
+                        write!(
+                            self.out,
+                            "{}const {} {} = {{ ",
+                            back::INDENT,
+                            struct_name,
+                            arg_name
+                        )?;
+                        for (member_index, member) in members.iter().enumerate() {
+                            let key = NameKey::StructMember(arg.ty, member_index as u32);
+                            let name = &flattened_member_names[&key];
+                            if member_index != 0 {
+                                write!(self.out, ", ")?;
+                            }
+                            // insert padding initialization, if needed
+                            if self
+                                .struct_member_pads
+                                .contains(&(arg.ty, member_index as u32))
+                            {
+                                write!(self.out, "{{}}, ")?;
+                            }
+                            if let Some(crate::Binding::Location { .. }) = member.binding {
+                                write!(self.out, "{varyings_member_name}.")?;
+                            }
+                            write!(self.out, "{name}")?;
+                        }
+                        writeln!(self.out, " }};")?;
+                    }
+                    _ => {
+                        if let Some(crate::Binding::Location { .. }) = arg.binding {
+                            writeln!(
+                                self.out,
+                                "{}const auto {} = {}.{};",
+                                back::INDENT,
+                                arg_name,
+                                varyings_member_name,
+                                arg_name
+                            )?;
+                        }
+                    }
+                }
+            }
+
+            let guarded_indices =
+                index::find_checked_indexes(module, fun, fun_info, options.bounds_check_policies);
+
+            let context = StatementContext {
+                expression: ExpressionContext {
+                    function: fun,
+                    origin: FunctionOrigin::EntryPoint(ep_index as _),
+                    info: fun_info,
+                    lang_version: options.lang_version,
+                    policies: options.bounds_check_policies,
+                    guarded_indices,
+                    module,
+                    mod_info,
+                    pipeline_options,
+                },
+                result_struct: Some(&stage_out_name),
+            };
+
+            // Finally, declare all the local variables that we need
+            //TODO: we can postpone this till the relevant expressions are emitted
+            for (local_handle, local) in fun.local_variables.iter() {
+                let name = &self.names[&NameKey::EntryPointLocal(ep_index as _, local_handle)];
+                let ty_name = TypeContext {
+                    handle: local.ty,
+                    gctx: module.to_ctx(),
+                    names: &self.names,
+                    access: crate::StorageAccess::empty(),
+                    binding: None,
+                    first_time: false,
+                };
+                write!(self.out, "{}{} {}", back::INDENT, ty_name, name)?;
+                match local.init {
+                    Some(value) => {
+                        write!(self.out, " = ")?;
+                        self.put_expression(value, &context.expression, true)?;
+                    }
+                    None => {
+                        write!(self.out, " = {{}}")?;
+                    }
+                };
+                writeln!(self.out, ";")?;
+            }
+
+            self.update_expressions_to_bake(fun, fun_info, &context.expression);
+            self.put_block(back::Level(1), &fun.body, &context)?;
+            writeln!(self.out, "}}")?;
+            if ep_index + 1 != module.entry_points.len() {
+                writeln!(self.out)?;
+            }
+            self.named_expressions.clear();
+        }
+
+        Ok(info)
+    }
+
+    fn write_barrier(&mut self, flags: crate::Barrier, level: back::Level) -> BackendResult {
+        // Note: OR-ring bitflags requires `__HAVE_MEMFLAG_OPERATORS__`,
+        // so we try to avoid it here.
+        if flags.is_empty() {
+            writeln!(
+                self.out,
+                "{level}{NAMESPACE}::threadgroup_barrier({NAMESPACE}::mem_flags::mem_none);",
+            )?;
+        }
+        if flags.contains(crate::Barrier::STORAGE) {
+            writeln!(
+                self.out,
+                "{level}{NAMESPACE}::threadgroup_barrier({NAMESPACE}::mem_flags::mem_device);",
+            )?;
+        }
+        if flags.contains(crate::Barrier::WORK_GROUP) {
+            writeln!(
+                self.out,
+                "{level}{NAMESPACE}::threadgroup_barrier({NAMESPACE}::mem_flags::mem_threadgroup);",
+            )?;
+        }
+        Ok(())
+    }
+}
+
+/// Initializing workgroup variables is more tricky for Metal because we have to deal
+/// with atomics at the type-level (which don't have a copy constructor).
+mod workgroup_mem_init {
+    use crate::EntryPoint;
+
+    use super::*;
+
+    enum Access {
+        GlobalVariable(Handle<crate::GlobalVariable>),
+        StructMember(Handle<crate::Type>, u32),
+        Array(usize),
+    }
+
+    impl Access {
+        fn write<W: Write>(
+            &self,
+            writer: &mut W,
+            names: &FastHashMap<NameKey, String>,
+        ) -> Result<(), core::fmt::Error> {
+            match *self {
+                Access::GlobalVariable(handle) => {
+                    write!(writer, "{}", &names[&NameKey::GlobalVariable(handle)])
+                }
+                Access::StructMember(handle, index) => {
+                    write!(writer, ".{}", &names[&NameKey::StructMember(handle, index)])
+                }
+                Access::Array(depth) => write!(writer, ".{WRAPPED_ARRAY_FIELD}[__i{depth}]"),
+            }
+        }
+    }
+
+    struct AccessStack {
+        stack: Vec<Access>,
+        array_depth: usize,
+    }
+
+    impl AccessStack {
+        const fn new() -> Self {
+            Self {
+                stack: Vec::new(),
+                array_depth: 0,
+            }
+        }
+
+        fn enter_array<R>(&mut self, cb: impl FnOnce(&mut Self, usize) -> R) -> R {
+            let array_depth = self.array_depth;
+            self.stack.push(Access::Array(array_depth));
+            self.array_depth += 1;
+            let res = cb(self, array_depth);
+            self.stack.pop();
+            self.array_depth -= 1;
+            res
+        }
+
+        fn enter<R>(&mut self, new: Access, cb: impl FnOnce(&mut Self) -> R) -> R {
+            self.stack.push(new);
+            let res = cb(self);
+            self.stack.pop();
+            res
+        }
+
+        fn write<W: Write>(
+            &self,
+            writer: &mut W,
+            names: &FastHashMap<NameKey, String>,
+        ) -> Result<(), core::fmt::Error> {
+            for next in self.stack.iter() {
+                next.write(writer, names)?;
+            }
+            Ok(())
+        }
+    }
+
+    impl<W: Write> Writer<W> {
+        pub(super) fn need_workgroup_variables_initialization(
+            &mut self,
+            options: &Options,
+            ep: &EntryPoint,
+            module: &crate::Module,
+            fun_info: &valid::FunctionInfo,
+        ) -> bool {
+            options.zero_initialize_workgroup_memory
+                && ep.stage == crate::ShaderStage::Compute
+                && module.global_variables.iter().any(|(handle, var)| {
+                    !fun_info[handle].is_empty() && var.space == crate::AddressSpace::WorkGroup
+                })
+        }
+
+        pub(super) fn write_workgroup_variables_initialization(
+            &mut self,
+            module: &crate::Module,
+            module_info: &valid::ModuleInfo,
+            fun_info: &valid::FunctionInfo,
+            local_invocation_id: Option<&NameKey>,
+        ) -> BackendResult {
+            let level = back::Level(1);
+
+            writeln!(
+                self.out,
+                "{}if ({}::all({} == {}::uint3(0u))) {{",
+                level,
+                NAMESPACE,
+                local_invocation_id
+                    .map(|name_key| self.names[name_key].as_str())
+                    .unwrap_or("__local_invocation_id"),
+                NAMESPACE,
+            )?;
+
+            let mut access_stack = AccessStack::new();
+
+            let vars = module.global_variables.iter().filter(|&(handle, var)| {
+                !fun_info[handle].is_empty() && var.space == crate::AddressSpace::WorkGroup
+            });
+
+            for (handle, var) in vars {
+                access_stack.enter(Access::GlobalVariable(handle), |access_stack| {
+                    self.write_workgroup_variable_initialization(
+                        module,
+                        module_info,
+                        var.ty,
+                        access_stack,
+                        level.next(),
+                    )
+                })?;
+            }
+
+            writeln!(self.out, "{level}}}")?;
+            self.write_barrier(crate::Barrier::WORK_GROUP, level)
+        }
+
+        fn write_workgroup_variable_initialization(
+            &mut self,
+            module: &crate::Module,
+            module_info: &valid::ModuleInfo,
+            ty: Handle<crate::Type>,
+            access_stack: &mut AccessStack,
+            level: back::Level,
+        ) -> BackendResult {
+            if module_info[ty].contains(valid::TypeFlags::CONSTRUCTIBLE) {
+                write!(self.out, "{level}")?;
+                access_stack.write(&mut self.out, &self.names)?;
+                writeln!(self.out, " = {{}};")?;
+            } else {
+                match module.types[ty].inner {
+                    crate::TypeInner::Atomic { .. } => {
+                        write!(
+                            self.out,
+                            "{level}{NAMESPACE}::atomic_store_explicit({ATOMIC_REFERENCE}"
+                        )?;
+                        access_stack.write(&mut self.out, &self.names)?;
+                        writeln!(self.out, ", 0, {NAMESPACE}::memory_order_relaxed);")?;
+                    }
+                    crate::TypeInner::Array { base, size, .. } => {
+                        let count = match size.to_indexable_length(module).expect("Bad array size")
+                        {
+                            proc::IndexableLength::Known(count) => count,
+                            proc::IndexableLength::Dynamic => unreachable!(),
+                        };
+
+                        access_stack.enter_array(|access_stack, array_depth| {
+                            writeln!(
+                                self.out,
+                                "{level}for (int __i{array_depth} = 0; __i{array_depth} < {count}; __i{array_depth}++) {{"
+                            )?;
+                            self.write_workgroup_variable_initialization(
+                                module,
+                                module_info,
+                                base,
+                                access_stack,
+                                level.next(),
+                            )?;
+                            writeln!(self.out, "{level}}}")?;
+                            BackendResult::Ok(())
+                        })?;
+                    }
+                    crate::TypeInner::Struct { ref members, .. } => {
+                        for (index, member) in members.iter().enumerate() {
+                            access_stack.enter(
+                                Access::StructMember(ty, index as u32),
+                                |access_stack| {
+                                    self.write_workgroup_variable_initialization(
+                                        module,
+                                        module_info,
+                                        member.ty,
+                                        access_stack,
+                                        level,
+                                    )
+                                },
+                            )?;
+                        }
+                    }
+                    _ => unreachable!(),
+                }
+            }
+
+            Ok(())
+        }
+    }
+}
+
+#[test]
+fn test_stack_size() {
+    use crate::valid::{Capabilities, ValidationFlags};
+    // create a module with at least one expression nested
+    let mut module = crate::Module::default();
+    let mut fun = crate::Function::default();
+    let const_expr = fun.expressions.append(
+        crate::Expression::Literal(crate::Literal::F32(1.0)),
+        Default::default(),
+    );
+    let nested_expr = fun.expressions.append(
+        crate::Expression::Unary {
+            op: crate::UnaryOperator::Negate,
+            expr: const_expr,
+        },
+        Default::default(),
+    );
+    fun.body.push(
+        crate::Statement::Emit(fun.expressions.range_from(1)),
+        Default::default(),
+    );
+    fun.body.push(
+        crate::Statement::If {
+            condition: nested_expr,
+            accept: crate::Block::new(),
+            reject: crate::Block::new(),
+        },
+        Default::default(),
+    );
+    let _ = module.functions.append(fun, Default::default());
+    // analyse the module
+    let info = crate::valid::Validator::new(ValidationFlags::empty(), Capabilities::empty())
+        .validate(&module)
+        .unwrap();
+    // process the module
+    let mut writer = Writer::new(String::new());
+    writer
+        .write(&module, &info, &Default::default(), &Default::default())
+        .unwrap();
+
+    {
+        // check expression stack
+        let mut addresses_start = usize::MAX;
+        let mut addresses_end = 0usize;
+        for pointer in writer.put_expression_stack_pointers {
+            addresses_start = addresses_start.min(pointer as usize);
+            addresses_end = addresses_end.max(pointer as usize);
+        }
+        let stack_size = addresses_end - addresses_start;
+        // check the size (in debug only)
+        // last observed macOS value: 20528 (CI)
+        if !(11000..=25000).contains(&stack_size) {
+            panic!("`put_expression` stack size {stack_size} has changed!");
+        }
+    }
+
+    {
+        // check block stack
+        let mut addresses_start = usize::MAX;
+        let mut addresses_end = 0usize;
+        for pointer in writer.put_block_stack_pointers {
+            addresses_start = addresses_start.min(pointer as usize);
+            addresses_end = addresses_end.max(pointer as usize);
+        }
+        let stack_size = addresses_end - addresses_start;
+        // check the size (in debug only)
+        // last observed macOS value: 19152 (CI)
+        if !(9000..=20000).contains(&stack_size) {
+            panic!("`put_block` stack size {stack_size} has changed!");
+        }
+    }
+}
diff --git a/third_party/rust/naga/src/back/spv/block.rs b/third_party/rust/naga/src/back/spv/block.rs
new file mode 100644
index 0000000000..6c96fa09e3
--- /dev/null
+++ b/third_party/rust/naga/src/back/spv/block.rs
@@ -0,0 +1,2368 @@
+/*!
+Implementations for `BlockContext` methods.
+*/
+
+use super::{
+    helpers, index::BoundsCheckResult, make_local, selection::Selection, Block, BlockContext,
+    Dimension, Error, Instruction, LocalType, LookupType, LoopContext, ResultMember, Writer,
+    WriterFlags,
+};
+use crate::{arena::Handle, proc::TypeResolution, Statement};
+use spirv::Word;
+
+fn get_dimension(type_inner: &crate::TypeInner) -> Dimension {
+    match *type_inner {
+        crate::TypeInner::Scalar(_) => Dimension::Scalar,
+        crate::TypeInner::Vector { .. } => Dimension::Vector,
+        crate::TypeInner::Matrix { .. } => Dimension::Matrix,
+        _ => unreachable!(),
+    }
+}
+
+/// The results of emitting code for a left-hand-side expression.
+///
+/// On success, `write_expression_pointer` returns one of these.
+enum ExpressionPointer {
+    /// The pointer to the expression's value is available, as the value of the
+    /// expression with the given id.
+    Ready { pointer_id: Word },
+
+    /// The access expression must be conditional on the value of `condition`, a boolean
+    /// expression that is true if all indices are in bounds. If `condition` is true, then
+    /// `access` is an `OpAccessChain` instruction that will compute a pointer to the
+    /// expression's value. If `condition` is false, then executing `access` would be
+    /// undefined behavior.
+    Conditional {
+        condition: Word,
+        access: Instruction,
+    },
+}
+
+/// The termination statement to be added to the end of the block
+pub enum BlockExit {
+    /// Generates an OpReturn (void return)
+    Return,
+    /// Generates an OpBranch to the specified block
+    Branch {
+        /// The branch target block
+        target: Word,
+    },
+    /// Translates a loop `break if` into an `OpBranchConditional` to the
+    /// merge block if true (the merge block is passed through [`LoopContext::break_id`]
+    /// or else to the loop header (passed through [`preamble_id`])
+    ///
+    /// [`preamble_id`]: Self::BreakIf::preamble_id
+    BreakIf {
+        /// The condition of the `break if`
+        condition: Handle<crate::Expression>,
+        /// The loop header block id
+        preamble_id: Word,
+    },
+}
+
+#[derive(Debug)]
+pub(crate) struct DebugInfoInner<'a> {
+    pub source_code: &'a str,
+    pub source_file_id: Word,
+}
+
+impl Writer {
+    // Flip Y coordinate to adjust for coordinate space difference
+    // between SPIR-V and our IR.
+    // The `position_id` argument is a pointer to a `vecN<f32>`,
+    // whose `y` component we will negate.
+    fn write_epilogue_position_y_flip(
+        &mut self,
+        position_id: Word,
+        body: &mut Vec<Instruction>,
+    ) -> Result<(), Error> {
+        let float_ptr_type_id = self.get_type_id(LookupType::Local(LocalType::Value {
+            vector_size: None,
+            scalar: crate::Scalar::F32,
+            pointer_space: Some(spirv::StorageClass::Output),
+        }));
+        let index_y_id = self.get_index_constant(1);
+        let access_id = self.id_gen.next();
+        body.push(Instruction::access_chain(
+            float_ptr_type_id,
+            access_id,
+            position_id,
+            &[index_y_id],
+        ));
+
+        let float_type_id = self.get_type_id(LookupType::Local(LocalType::Value {
+            vector_size: None,
+            scalar: crate::Scalar::F32,
+            pointer_space: None,
+        }));
+        let load_id = self.id_gen.next();
+        body.push(Instruction::load(float_type_id, load_id, access_id, None));
+
+        let neg_id = self.id_gen.next();
+        body.push(Instruction::unary(
+            spirv::Op::FNegate,
+            float_type_id,
+            neg_id,
+            load_id,
+        ));
+
+        body.push(Instruction::store(access_id, neg_id, None));
+        Ok(())
+    }
+
+    // Clamp fragment depth between 0 and 1.
+    fn write_epilogue_frag_depth_clamp(
+        &mut self,
+        frag_depth_id: Word,
+        body: &mut Vec<Instruction>,
+    ) -> Result<(), Error> {
+        let float_type_id = self.get_type_id(LookupType::Local(LocalType::Value {
+            vector_size: None,
+            scalar: crate::Scalar::F32,
+            pointer_space: None,
+        }));
+        let zero_scalar_id = self.get_constant_scalar(crate::Literal::F32(0.0));
+        let one_scalar_id = self.get_constant_scalar(crate::Literal::F32(1.0));
+
+        let original_id = self.id_gen.next();
+        body.push(Instruction::load(
+            float_type_id,
+            original_id,
+            frag_depth_id,
+            None,
+        ));
+
+        let clamp_id = self.id_gen.next();
+        body.push(Instruction::ext_inst(
+            self.gl450_ext_inst_id,
+            spirv::GLOp::FClamp,
+            float_type_id,
+            clamp_id,
+            &[original_id, zero_scalar_id, one_scalar_id],
+        ));
+
+        body.push(Instruction::store(frag_depth_id, clamp_id, None));
+        Ok(())
+    }
+
+    fn write_entry_point_return(
+        &mut self,
+        value_id: Word,
+        ir_result: &crate::FunctionResult,
+        result_members: &[ResultMember],
+        body: &mut Vec<Instruction>,
+    ) -> Result<(), Error> {
+        for (index, res_member) in result_members.iter().enumerate() {
+            let member_value_id = match ir_result.binding {
+                Some(_) => value_id,
+                None => {
+                    let member_value_id = self.id_gen.next();
+                    body.push(Instruction::composite_extract(
+                        res_member.type_id,
+                        member_value_id,
+                        value_id,
+                        &[index as u32],
+                    ));
+                    member_value_id
+                }
+            };
+
+            body.push(Instruction::store(res_member.id, member_value_id, None));
+
+            match res_member.built_in {
+                Some(crate::BuiltIn::Position { .. })
+                    if self.flags.contains(WriterFlags::ADJUST_COORDINATE_SPACE) =>
+                {
+                    self.write_epilogue_position_y_flip(res_member.id, body)?;
+                }
+                Some(crate::BuiltIn::FragDepth)
+                    if self.flags.contains(WriterFlags::CLAMP_FRAG_DEPTH) =>
+                {
+                    self.write_epilogue_frag_depth_clamp(res_member.id, body)?;
+                }
+                _ => {}
+            }
+        }
+        Ok(())
+    }
+}
+
+impl<'w> BlockContext<'w> {
+    /// Decide whether to put off emitting instructions for `expr_handle`.
+    ///
+    /// We would like to gather together chains of `Access` and `AccessIndex`
+    /// Naga expressions into a single `OpAccessChain` SPIR-V instruction. To do
+    /// this, we don't generate instructions for these exprs when we first
+    /// encounter them. Their ids in `self.writer.cached.ids` are left as zero. Then,
+    /// once we encounter a `Load` or `Store` expression that actually needs the
+    /// chain's value, we call `write_expression_pointer` to handle the whole
+    /// thing in one fell swoop.
+    fn is_intermediate(&self, expr_handle: Handle<crate::Expression>) -> bool {
+        match self.ir_function.expressions[expr_handle] {
+            crate::Expression::GlobalVariable(handle) => {
+                match self.ir_module.global_variables[handle].space {
+                    crate::AddressSpace::Handle => false,
+                    _ => true,
+                }
+            }
+            crate::Expression::LocalVariable(_) => true,
+            crate::Expression::FunctionArgument(index) => {
+                let arg = &self.ir_function.arguments[index as usize];
+                self.ir_module.types[arg.ty].inner.pointer_space().is_some()
+            }
+
+            // The chain rule: if this `Access...`'s `base` operand was
+            // previously omitted, then omit this one, too.
+            _ => self.cached.ids[expr_handle.index()] == 0,
+        }
+    }
+
+    /// Cache an expression for a value.
+    pub(super) fn cache_expression_value(
+        &mut self,
+        expr_handle: Handle<crate::Expression>,
+        block: &mut Block,
+    ) -> Result<(), Error> {
+        let is_named_expression = self
+            .ir_function
+            .named_expressions
+            .contains_key(&expr_handle);
+
+        if self.fun_info[expr_handle].ref_count == 0 && !is_named_expression {
+            return Ok(());
+        }
+
+        let result_type_id = self.get_expression_type_id(&self.fun_info[expr_handle].ty);
+        let id = match self.ir_function.expressions[expr_handle] {
+            crate::Expression::Literal(literal) => self.writer.get_constant_scalar(literal),
+            crate::Expression::Constant(handle) => {
+                let init = self.ir_module.constants[handle].init;
+                self.writer.constant_ids[init.index()]
+            }
+            crate::Expression::ZeroValue(_) => self.writer.get_constant_null(result_type_id),
+            crate::Expression::Compose { ty, ref components } => {
+                self.temp_list.clear();
+                if self.expression_constness.is_const(expr_handle) {
+                    self.temp_list.extend(
+                        crate::proc::flatten_compose(
+                            ty,
+                            components,
+                            &self.ir_function.expressions,
+                            &self.ir_module.types,
+                        )
+                        .map(|component| self.cached[component]),
+                    );
+                    self.writer
+                        .get_constant_composite(LookupType::Handle(ty), &self.temp_list)
+                } else {
+                    self.temp_list
+                        .extend(components.iter().map(|&component| self.cached[component]));
+
+                    let id = self.gen_id();
+                    block.body.push(Instruction::composite_construct(
+                        result_type_id,
+                        id,
+                        &self.temp_list,
+                    ));
+                    id
+                }
+            }
+            crate::Expression::Splat { size, value } => {
+                let value_id = self.cached[value];
+                let components = &[value_id; 4][..size as usize];
+
+                if self.expression_constness.is_const(expr_handle) {
+                    let ty = self
+                        .writer
+                        .get_expression_lookup_type(&self.fun_info[expr_handle].ty);
+                    self.writer.get_constant_composite(ty, components)
+                } else {
+                    let id = self.gen_id();
+                    block.body.push(Instruction::composite_construct(
+                        result_type_id,
+                        id,
+                        components,
+                    ));
+                    id
+                }
+            }
+            crate::Expression::Access { base, index: _ } if self.is_intermediate(base) => {
+                // See `is_intermediate`; we'll handle this later in
+                // `write_expression_pointer`.
+                0
+            }
+            crate::Expression::Access { base, index } => {
+                let base_ty_inner = self.fun_info[base].ty.inner_with(&self.ir_module.types);
+                match *base_ty_inner {
+                    crate::TypeInner::Vector { .. } => {
+                        self.write_vector_access(expr_handle, base, index, block)?
+                    }
+                    // Only binding arrays in the Handle address space will take this path (due to `is_intermediate`)
+                    crate::TypeInner::BindingArray {
+                        base: binding_type, ..
+                    } => {
+                        let space = match self.ir_function.expressions[base] {
+                            crate::Expression::GlobalVariable(gvar) => {
+                                self.ir_module.global_variables[gvar].space
+                            }
+                            _ => unreachable!(),
+                        };
+                        let binding_array_false_pointer = LookupType::Local(LocalType::Pointer {
+                            base: binding_type,
+                            class: helpers::map_storage_class(space),
+                        });
+
+                        let result_id = match self.write_expression_pointer(
+                            expr_handle,
+                            block,
+                            Some(binding_array_false_pointer),
+                        )? {
+                            ExpressionPointer::Ready { pointer_id } => pointer_id,
+                            ExpressionPointer::Conditional { .. } => {
+                                return Err(Error::FeatureNotImplemented(
+                                    "Texture array out-of-bounds handling",
+                                ));
+                            }
+                        };
+
+                        let binding_type_id = self.get_type_id(LookupType::Handle(binding_type));
+
+                        let load_id = self.gen_id();
+                        block.body.push(Instruction::load(
+                            binding_type_id,
+                            load_id,
+                            result_id,
+                            None,
+                        ));
+
+                        // Subsequent image operations require the image/sampler to be decorated as NonUniform
+                        // if the image/sampler binding array was accessed with a non-uniform index
+                        // see VUID-RuntimeSpirv-NonUniform-06274
+                        if self.fun_info[index].uniformity.non_uniform_result.is_some() {
+                            self.writer
+                                .decorate_non_uniform_binding_array_access(load_id)?;
+                        }
+
+                        load_id
+                    }
+                    ref other => {
+                        log::error!(
+                            "Unable to access base {:?} of type {:?}",
+                            self.ir_function.expressions[base],
+                            other
+                        );
+                        return Err(Error::Validation(
+                            "only vectors may be dynamically indexed by value",
+                        ));
+                    }
+                }
+            }
+            crate::Expression::AccessIndex { base, index: _ } if self.is_intermediate(base) => {
+                // See `is_intermediate`; we'll handle this later in
+                // `write_expression_pointer`.
+                0
+            }
+            crate::Expression::AccessIndex { base, index } => {
+                match *self.fun_info[base].ty.inner_with(&self.ir_module.types) {
+                    crate::TypeInner::Vector { .. }
+                    | crate::TypeInner::Matrix { .. }
+                    | crate::TypeInner::Array { .. }
+                    | crate::TypeInner::Struct { .. } => {
+                        // We never need bounds checks here: dynamically sized arrays can
+                        // only appear behind pointers, and are thus handled by the
+                        // `is_intermediate` case above. Everything else's size is
+                        // statically known and checked in validation.
+                        let id = self.gen_id();
+                        let base_id = self.cached[base];
+                        block.body.push(Instruction::composite_extract(
+                            result_type_id,
+                            id,
+                            base_id,
+                            &[index],
+                        ));
+                        id
+                    }
+                    // Only binding arrays in the Handle address space will take this path (due to `is_intermediate`)
+                    crate::TypeInner::BindingArray {
+                        base: binding_type, ..
+                    } => {
+                        let space = match self.ir_function.expressions[base] {
+                            crate::Expression::GlobalVariable(gvar) => {
+                                self.ir_module.global_variables[gvar].space
+                            }
+                            _ => unreachable!(),
+                        };
+                        let binding_array_false_pointer = LookupType::Local(LocalType::Pointer {
+                            base: binding_type,
+                            class: helpers::map_storage_class(space),
+                        });
+
+                        let result_id = match self.write_expression_pointer(
+                            expr_handle,
+                            block,
+                            Some(binding_array_false_pointer),
+                        )? {
+                            ExpressionPointer::Ready { pointer_id } => pointer_id,
+                            ExpressionPointer::Conditional { .. } => {
+                                return Err(Error::FeatureNotImplemented(
+                                    "Texture array out-of-bounds handling",
+                                ));
+                            }
+                        };
+
+                        let binding_type_id = self.get_type_id(LookupType::Handle(binding_type));
+
+                        let load_id = self.gen_id();
+                        block.body.push(Instruction::load(
+                            binding_type_id,
+                            load_id,
+                            result_id,
+                            None,
+                        ));
+
+                        load_id
+                    }
+                    ref other => {
+                        log::error!("Unable to access index of {:?}", other);
+                        return Err(Error::FeatureNotImplemented("access index for type"));
+                    }
+                }
+            }
+            crate::Expression::GlobalVariable(handle) => {
+                self.writer.global_variables[handle.index()].access_id
+            }
+            crate::Expression::Swizzle {
+                size,
+                vector,
+                pattern,
+            } => {
+                let vector_id = self.cached[vector];
+                self.temp_list.clear();
+                for &sc in pattern[..size as usize].iter() {
+                    self.temp_list.push(sc as Word);
+                }
+                let id = self.gen_id();
+                block.body.push(Instruction::vector_shuffle(
+                    result_type_id,
+                    id,
+                    vector_id,
+                    vector_id,
+                    &self.temp_list,
+                ));
+                id
+            }
+            crate::Expression::Unary { op, expr } => {
+                let id = self.gen_id();
+                let expr_id = self.cached[expr];
+                let expr_ty_inner = self.fun_info[expr].ty.inner_with(&self.ir_module.types);
+
+                let spirv_op = match op {
+                    crate::UnaryOperator::Negate => match expr_ty_inner.scalar_kind() {
+                        Some(crate::ScalarKind::Float) => spirv::Op::FNegate,
+                        Some(crate::ScalarKind::Sint) => spirv::Op::SNegate,
+                        _ => return Err(Error::Validation("Unexpected kind for negation")),
+                    },
+                    crate::UnaryOperator::LogicalNot => spirv::Op::LogicalNot,
+                    crate::UnaryOperator::BitwiseNot => spirv::Op::Not,
+                };
+
+                block
+                    .body
+                    .push(Instruction::unary(spirv_op, result_type_id, id, expr_id));
+                id
+            }
+            crate::Expression::Binary { op, left, right } => {
+                let id = self.gen_id();
+                let left_id = self.cached[left];
+                let right_id = self.cached[right];
+
+                let left_ty_inner = self.fun_info[left].ty.inner_with(&self.ir_module.types);
+                let right_ty_inner = self.fun_info[right].ty.inner_with(&self.ir_module.types);
+
+                let left_dimension = get_dimension(left_ty_inner);
+                let right_dimension = get_dimension(right_ty_inner);
+
+                let mut reverse_operands = false;
+
+                let spirv_op = match op {
+                    crate::BinaryOperator::Add => match *left_ty_inner {
+                        crate::TypeInner::Scalar(scalar)
+                        | crate::TypeInner::Vector { scalar, .. } => match scalar.kind {
+                            crate::ScalarKind::Float => spirv::Op::FAdd,
+                            _ => spirv::Op::IAdd,
+                        },
+                        crate::TypeInner::Matrix {
+                            columns,
+                            rows,
+                            scalar,
+                        } => {
+                            self.write_matrix_matrix_column_op(
+                                block,
+                                id,
+                                result_type_id,
+                                left_id,
+                                right_id,
+                                columns,
+                                rows,
+                                scalar.width,
+                                spirv::Op::FAdd,
+                            );
+
+                            self.cached[expr_handle] = id;
+                            return Ok(());
+                        }
+                        _ => unimplemented!(),
+                    },
+                    crate::BinaryOperator::Subtract => match *left_ty_inner {
+                        crate::TypeInner::Scalar(scalar)
+                        | crate::TypeInner::Vector { scalar, .. } => match scalar.kind {
+                            crate::ScalarKind::Float => spirv::Op::FSub,
+                            _ => spirv::Op::ISub,
+                        },
+                        crate::TypeInner::Matrix {
+                            columns,
+                            rows,
+                            scalar,
+                        } => {
+                            self.write_matrix_matrix_column_op(
+                                block,
+                                id,
+                                result_type_id,
+                                left_id,
+                                right_id,
+                                columns,
+                                rows,
+                                scalar.width,
+                                spirv::Op::FSub,
+                            );
+
+                            self.cached[expr_handle] = id;
+                            return Ok(());
+                        }
+                        _ => unimplemented!(),
+                    },
+                    crate::BinaryOperator::Multiply => match (left_dimension, right_dimension) {
+                        (Dimension::Scalar, Dimension::Vector) => {
+                            self.write_vector_scalar_mult(
+                                block,
+                                id,
+                                result_type_id,
+                                right_id,
+                                left_id,
+                                right_ty_inner,
+                            );
+
+                            self.cached[expr_handle] = id;
+                            return Ok(());
+                        }
+                        (Dimension::Vector, Dimension::Scalar) => {
+                            self.write_vector_scalar_mult(
+                                block,
+                                id,
+                                result_type_id,
+                                left_id,
+                                right_id,
+                                left_ty_inner,
+                            );
+
+                            self.cached[expr_handle] = id;
+                            return Ok(());
+                        }
+                        (Dimension::Vector, Dimension::Matrix) => spirv::Op::VectorTimesMatrix,
+                        (Dimension::Matrix, Dimension::Scalar) => spirv::Op::MatrixTimesScalar,
+                        (Dimension::Scalar, Dimension::Matrix) => {
+                            reverse_operands = true;
+                            spirv::Op::MatrixTimesScalar
+                        }
+                        (Dimension::Matrix, Dimension::Vector) => spirv::Op::MatrixTimesVector,
+                        (Dimension::Matrix, Dimension::Matrix) => spirv::Op::MatrixTimesMatrix,
+                        (Dimension::Vector, Dimension::Vector)
+                        | (Dimension::Scalar, Dimension::Scalar)
+                            if left_ty_inner.scalar_kind() == Some(crate::ScalarKind::Float) =>
+                        {
+                            spirv::Op::FMul
+                        }
+                        (Dimension::Vector, Dimension::Vector)
+                        | (Dimension::Scalar, Dimension::Scalar) => spirv::Op::IMul,
+                    },
+                    crate::BinaryOperator::Divide => match left_ty_inner.scalar_kind() {
+                        Some(crate::ScalarKind::Sint) => spirv::Op::SDiv,
+                        Some(crate::ScalarKind::Uint) => spirv::Op::UDiv,
+                        Some(crate::ScalarKind::Float) => spirv::Op::FDiv,
+                        _ => unimplemented!(),
+                    },
+                    crate::BinaryOperator::Modulo => match left_ty_inner.scalar_kind() {
+                        // TODO: handle undefined behavior
+                        // if right == 0 return 0
+                        // if left == min(type_of(left)) && right == -1 return 0
+                        Some(crate::ScalarKind::Sint) => spirv::Op::SRem,
+                        // TODO: handle undefined behavior
+                        // if right == 0 return 0
+                        Some(crate::ScalarKind::Uint) => spirv::Op::UMod,
+                        // TODO: handle undefined behavior
+                        // if right == 0 return ? see https://github.com/gpuweb/gpuweb/issues/2798
+                        Some(crate::ScalarKind::Float) => spirv::Op::FRem,
+                        _ => unimplemented!(),
+                    },
+                    crate::BinaryOperator::Equal => match left_ty_inner.scalar_kind() {
+                        Some(crate::ScalarKind::Sint | crate::ScalarKind::Uint) => {
+                            spirv::Op::IEqual
+                        }
+                        Some(crate::ScalarKind::Float) => spirv::Op::FOrdEqual,
+                        Some(crate::ScalarKind::Bool) => spirv::Op::LogicalEqual,
+                        _ => unimplemented!(),
+                    },
+                    crate::BinaryOperator::NotEqual => match left_ty_inner.scalar_kind() {
+                        Some(crate::ScalarKind::Sint | crate::ScalarKind::Uint) => {
+                            spirv::Op::INotEqual
+                        }
+                        Some(crate::ScalarKind::Float) => spirv::Op::FOrdNotEqual,
+                        Some(crate::ScalarKind::Bool) => spirv::Op::LogicalNotEqual,
+                        _ => unimplemented!(),
+                    },
+                    crate::BinaryOperator::Less => match left_ty_inner.scalar_kind() {
+                        Some(crate::ScalarKind::Sint) => spirv::Op::SLessThan,
+                        Some(crate::ScalarKind::Uint) => spirv::Op::ULessThan,
+                        Some(crate::ScalarKind::Float) => spirv::Op::FOrdLessThan,
+                        _ => unimplemented!(),
+                    },
+                    crate::BinaryOperator::LessEqual => match left_ty_inner.scalar_kind() {
+                        Some(crate::ScalarKind::Sint) => spirv::Op::SLessThanEqual,
+                        Some(crate::ScalarKind::Uint) => spirv::Op::ULessThanEqual,
+                        Some(crate::ScalarKind::Float) => spirv::Op::FOrdLessThanEqual,
+                        _ => unimplemented!(),
+                    },
+                    crate::BinaryOperator::Greater => match left_ty_inner.scalar_kind() {
+                        Some(crate::ScalarKind::Sint) => spirv::Op::SGreaterThan,
+                        Some(crate::ScalarKind::Uint) => spirv::Op::UGreaterThan,
+                        Some(crate::ScalarKind::Float) => spirv::Op::FOrdGreaterThan,
+                        _ => unimplemented!(),
+                    },
+                    crate::BinaryOperator::GreaterEqual => match left_ty_inner.scalar_kind() {
+                        Some(crate::ScalarKind::Sint) => spirv::Op::SGreaterThanEqual,
+                        Some(crate::ScalarKind::Uint) => spirv::Op::UGreaterThanEqual,
+                        Some(crate::ScalarKind::Float) => spirv::Op::FOrdGreaterThanEqual,
+                        _ => unimplemented!(),
+                    },
+                    crate::BinaryOperator::And => match left_ty_inner.scalar_kind() {
+                        Some(crate::ScalarKind::Bool) => spirv::Op::LogicalAnd,
+                        _ => spirv::Op::BitwiseAnd,
+                    },
+                    crate::BinaryOperator::ExclusiveOr => spirv::Op::BitwiseXor,
+                    crate::BinaryOperator::InclusiveOr => match left_ty_inner.scalar_kind() {
+                        Some(crate::ScalarKind::Bool) => spirv::Op::LogicalOr,
+                        _ => spirv::Op::BitwiseOr,
+                    },
+                    crate::BinaryOperator::LogicalAnd => spirv::Op::LogicalAnd,
+                    crate::BinaryOperator::LogicalOr => spirv::Op::LogicalOr,
+                    crate::BinaryOperator::ShiftLeft => spirv::Op::ShiftLeftLogical,
+                    crate::BinaryOperator::ShiftRight => match left_ty_inner.scalar_kind() {
+                        Some(crate::ScalarKind::Sint) => spirv::Op::ShiftRightArithmetic,
+                        Some(crate::ScalarKind::Uint) => spirv::Op::ShiftRightLogical,
+                        _ => unimplemented!(),
+                    },
+                };
+
+                block.body.push(Instruction::binary(
+                    spirv_op,
+                    result_type_id,
+                    id,
+                    if reverse_operands { right_id } else { left_id },
+                    if reverse_operands { left_id } else { right_id },
+                ));
+                id
+            }
+            crate::Expression::Math {
+                fun,
+                arg,
+                arg1,
+                arg2,
+                arg3,
+            } => {
+                use crate::MathFunction as Mf;
+                enum MathOp {
+                    Ext(spirv::GLOp),
+                    Custom(Instruction),
+                }
+
+                let arg0_id = self.cached[arg];
+                let arg_ty = self.fun_info[arg].ty.inner_with(&self.ir_module.types);
+                let arg_scalar_kind = arg_ty.scalar_kind();
+                let arg1_id = match arg1 {
+                    Some(handle) => self.cached[handle],
+                    None => 0,
+                };
+                let arg2_id = match arg2 {
+                    Some(handle) => self.cached[handle],
+                    None => 0,
+                };
+                let arg3_id = match arg3 {
+                    Some(handle) => self.cached[handle],
+                    None => 0,
+                };
+
+                let id = self.gen_id();
+                let math_op = match fun {
+                    // comparison
+                    Mf::Abs => {
+                        match arg_scalar_kind {
+                            Some(crate::ScalarKind::Float) => MathOp::Ext(spirv::GLOp::FAbs),
+                            Some(crate::ScalarKind::Sint) => MathOp::Ext(spirv::GLOp::SAbs),
+                            Some(crate::ScalarKind::Uint) => {
+                                MathOp::Custom(Instruction::unary(
+                                    spirv::Op::CopyObject, // do nothing
+                                    result_type_id,
+                                    id,
+                                    arg0_id,
+                                ))
+                            }
+                            other => unimplemented!("Unexpected abs({:?})", other),
+                        }
+                    }
+                    Mf::Min => MathOp::Ext(match arg_scalar_kind {
+                        Some(crate::ScalarKind::Float) => spirv::GLOp::FMin,
+                        Some(crate::ScalarKind::Sint) => spirv::GLOp::SMin,
+                        Some(crate::ScalarKind::Uint) => spirv::GLOp::UMin,
+                        other => unimplemented!("Unexpected min({:?})", other),
+                    }),
+                    Mf::Max => MathOp::Ext(match arg_scalar_kind {
+                        Some(crate::ScalarKind::Float) => spirv::GLOp::FMax,
+                        Some(crate::ScalarKind::Sint) => spirv::GLOp::SMax,
+                        Some(crate::ScalarKind::Uint) => spirv::GLOp::UMax,
+                        other => unimplemented!("Unexpected max({:?})", other),
+                    }),
+                    Mf::Clamp => MathOp::Ext(match arg_scalar_kind {
+                        Some(crate::ScalarKind::Float) => spirv::GLOp::FClamp,
+                        Some(crate::ScalarKind::Sint) => spirv::GLOp::SClamp,
+                        Some(crate::ScalarKind::Uint) => spirv::GLOp::UClamp,
+                        other => unimplemented!("Unexpected max({:?})", other),
+                    }),
+                    Mf::Saturate => {
+                        let (maybe_size, scalar) = match *arg_ty {
+                            crate::TypeInner::Vector { size, scalar } => (Some(size), scalar),
+                            crate::TypeInner::Scalar(scalar) => (None, scalar),
+                            ref other => unimplemented!("Unexpected saturate({:?})", other),
+                        };
+                        let scalar = crate::Scalar::float(scalar.width);
+                        let mut arg1_id = self.writer.get_constant_scalar_with(0, scalar)?;
+                        let mut arg2_id = self.writer.get_constant_scalar_with(1, scalar)?;
+
+                        if let Some(size) = maybe_size {
+                            let ty = LocalType::Value {
+                                vector_size: Some(size),
+                                scalar,
+                                pointer_space: None,
+                            }
+                            .into();
+
+                            self.temp_list.clear();
+                            self.temp_list.resize(size as _, arg1_id);
+
+                            arg1_id = self.writer.get_constant_composite(ty, &self.temp_list);
+
+                            self.temp_list.fill(arg2_id);
+
+                            arg2_id = self.writer.get_constant_composite(ty, &self.temp_list);
+                        }
+
+                        MathOp::Custom(Instruction::ext_inst(
+                            self.writer.gl450_ext_inst_id,
+                            spirv::GLOp::FClamp,
+                            result_type_id,
+                            id,
+                            &[arg0_id, arg1_id, arg2_id],
+                        ))
+                    }
+                    // trigonometry
+                    Mf::Sin => MathOp::Ext(spirv::GLOp::Sin),
+                    Mf::Sinh => MathOp::Ext(spirv::GLOp::Sinh),
+                    Mf::Asin => MathOp::Ext(spirv::GLOp::Asin),
+                    Mf::Cos => MathOp::Ext(spirv::GLOp::Cos),
+                    Mf::Cosh => MathOp::Ext(spirv::GLOp::Cosh),
+                    Mf::Acos => MathOp::Ext(spirv::GLOp::Acos),
+                    Mf::Tan => MathOp::Ext(spirv::GLOp::Tan),
+                    Mf::Tanh => MathOp::Ext(spirv::GLOp::Tanh),
+                    Mf::Atan => MathOp::Ext(spirv::GLOp::Atan),
+                    Mf::Atan2 => MathOp::Ext(spirv::GLOp::Atan2),
+                    Mf::Asinh => MathOp::Ext(spirv::GLOp::Asinh),
+                    Mf::Acosh => MathOp::Ext(spirv::GLOp::Acosh),
+                    Mf::Atanh => MathOp::Ext(spirv::GLOp::Atanh),
+                    Mf::Radians => MathOp::Ext(spirv::GLOp::Radians),
+                    Mf::Degrees => MathOp::Ext(spirv::GLOp::Degrees),
+                    // decomposition
+                    Mf::Ceil => MathOp::Ext(spirv::GLOp::Ceil),
+                    Mf::Round => MathOp::Ext(spirv::GLOp::RoundEven),
+                    Mf::Floor => MathOp::Ext(spirv::GLOp::Floor),
+                    Mf::Fract => MathOp::Ext(spirv::GLOp::Fract),
+                    Mf::Trunc => MathOp::Ext(spirv::GLOp::Trunc),
+                    Mf::Modf => MathOp::Ext(spirv::GLOp::ModfStruct),
+                    Mf::Frexp => MathOp::Ext(spirv::GLOp::FrexpStruct),
+                    Mf::Ldexp => MathOp::Ext(spirv::GLOp::Ldexp),
+                    // geometry
+                    Mf::Dot => match *self.fun_info[arg].ty.inner_with(&self.ir_module.types) {
+                        crate::TypeInner::Vector {
+                            scalar:
+                                crate::Scalar {
+                                    kind: crate::ScalarKind::Float,
+                                    ..
+                                },
+                            ..
+                        } => MathOp::Custom(Instruction::binary(
+                            spirv::Op::Dot,
+                            result_type_id,
+                            id,
+                            arg0_id,
+                            arg1_id,
+                        )),
+                        // TODO: consider using integer dot product if VK_KHR_shader_integer_dot_product is available
+                        crate::TypeInner::Vector { size, .. } => {
+                            self.write_dot_product(
+                                id,
+                                result_type_id,
+                                arg0_id,
+                                arg1_id,
+                                size as u32,
+                                block,
+                            );
+                            self.cached[expr_handle] = id;
+                            return Ok(());
+                        }
+                        _ => unreachable!(
+                            "Correct TypeInner for dot product should be already validated"
+                        ),
+                    },
+                    Mf::Outer => MathOp::Custom(Instruction::binary(
+                        spirv::Op::OuterProduct,
+                        result_type_id,
+                        id,
+                        arg0_id,
+                        arg1_id,
+                    )),
+                    Mf::Cross => MathOp::Ext(spirv::GLOp::Cross),
+                    Mf::Distance => MathOp::Ext(spirv::GLOp::Distance),
+                    Mf::Length => MathOp::Ext(spirv::GLOp::Length),
+                    Mf::Normalize => MathOp::Ext(spirv::GLOp::Normalize),
+                    Mf::FaceForward => MathOp::Ext(spirv::GLOp::FaceForward),
+                    Mf::Reflect => MathOp::Ext(spirv::GLOp::Reflect),
+                    Mf::Refract => MathOp::Ext(spirv::GLOp::Refract),
+                    // exponent
+                    Mf::Exp => MathOp::Ext(spirv::GLOp::Exp),
+                    Mf::Exp2 => MathOp::Ext(spirv::GLOp::Exp2),
+                    Mf::Log => MathOp::Ext(spirv::GLOp::Log),
+                    Mf::Log2 => MathOp::Ext(spirv::GLOp::Log2),
+                    Mf::Pow => MathOp::Ext(spirv::GLOp::Pow),
+                    // computational
+                    Mf::Sign => MathOp::Ext(match arg_scalar_kind {
+                        Some(crate::ScalarKind::Float) => spirv::GLOp::FSign,
+                        Some(crate::ScalarKind::Sint) => spirv::GLOp::SSign,
+                        other => unimplemented!("Unexpected sign({:?})", other),
+                    }),
+                    Mf::Fma => MathOp::Ext(spirv::GLOp::Fma),
+                    Mf::Mix => {
+                        let selector = arg2.unwrap();
+                        let selector_ty =
+                            self.fun_info[selector].ty.inner_with(&self.ir_module.types);
+                        match (arg_ty, selector_ty) {
+                            // if the selector is a scalar, we need to splat it
+                            (
+                                &crate::TypeInner::Vector { size, .. },
+                                &crate::TypeInner::Scalar(scalar),
+                            ) => {
+                                let selector_type_id =
+                                    self.get_type_id(LookupType::Local(LocalType::Value {
+                                        vector_size: Some(size),
+                                        scalar,
+                                        pointer_space: None,
+                                    }));
+                                self.temp_list.clear();
+                                self.temp_list.resize(size as usize, arg2_id);
+
+                                let selector_id = self.gen_id();
+                                block.body.push(Instruction::composite_construct(
+                                    selector_type_id,
+                                    selector_id,
+                                    &self.temp_list,
+                                ));
+
+                                MathOp::Custom(Instruction::ext_inst(
+                                    self.writer.gl450_ext_inst_id,
+                                    spirv::GLOp::FMix,
+                                    result_type_id,
+                                    id,
+                                    &[arg0_id, arg1_id, selector_id],
+                                ))
+                            }
+                            _ => MathOp::Ext(spirv::GLOp::FMix),
+                        }
+                    }
+                    Mf::Step => MathOp::Ext(spirv::GLOp::Step),
+                    Mf::SmoothStep => MathOp::Ext(spirv::GLOp::SmoothStep),
+                    Mf::Sqrt => MathOp::Ext(spirv::GLOp::Sqrt),
+                    Mf::InverseSqrt => MathOp::Ext(spirv::GLOp::InverseSqrt),
+                    Mf::Inverse => MathOp::Ext(spirv::GLOp::MatrixInverse),
+                    Mf::Transpose => MathOp::Custom(Instruction::unary(
+                        spirv::Op::Transpose,
+                        result_type_id,
+                        id,
+                        arg0_id,
+                    )),
+                    Mf::Determinant => MathOp::Ext(spirv::GLOp::Determinant),
+                    Mf::ReverseBits => MathOp::Custom(Instruction::unary(
+                        spirv::Op::BitReverse,
+                        result_type_id,
+                        id,
+                        arg0_id,
+                    )),
+                    Mf::CountTrailingZeros => {
+                        let uint_id = match *arg_ty {
+                            crate::TypeInner::Vector { size, mut scalar } => {
+                                scalar.kind = crate::ScalarKind::Uint;
+                                let ty = LocalType::Value {
+                                    vector_size: Some(size),
+                                    scalar,
+                                    pointer_space: None,
+                                }
+                                .into();
+
+                                self.temp_list.clear();
+                                self.temp_list.resize(
+                                    size as _,
+                                    self.writer.get_constant_scalar_with(32, scalar)?,
+                                );
+
+                                self.writer.get_constant_composite(ty, &self.temp_list)
+                            }
+                            crate::TypeInner::Scalar(mut scalar) => {
+                                scalar.kind = crate::ScalarKind::Uint;
+                                self.writer.get_constant_scalar_with(32, scalar)?
+                            }
+                            _ => unreachable!(),
+                        };
+
+                        let lsb_id = self.gen_id();
+                        block.body.push(Instruction::ext_inst(
+                            self.writer.gl450_ext_inst_id,
+                            spirv::GLOp::FindILsb,
+                            result_type_id,
+                            lsb_id,
+                            &[arg0_id],
+                        ));
+
+                        MathOp::Custom(Instruction::ext_inst(
+                            self.writer.gl450_ext_inst_id,
+                            spirv::GLOp::UMin,
+                            result_type_id,
+                            id,
+                            &[uint_id, lsb_id],
+                        ))
+                    }
+                    Mf::CountLeadingZeros => {
+                        let (int_type_id, int_id) = match *arg_ty {
+                            crate::TypeInner::Vector { size, mut scalar } => {
+                                scalar.kind = crate::ScalarKind::Sint;
+                                let ty = LocalType::Value {
+                                    vector_size: Some(size),
+                                    scalar,
+                                    pointer_space: None,
+                                }
+                                .into();
+
+                                self.temp_list.clear();
+                                self.temp_list.resize(
+                                    size as _,
+                                    self.writer.get_constant_scalar_with(31, scalar)?,
+                                );
+
+                                (
+                                    self.get_type_id(ty),
+                                    self.writer.get_constant_composite(ty, &self.temp_list),
+                                )
+                            }
+                            crate::TypeInner::Scalar(mut scalar) => {
+                                scalar.kind = crate::ScalarKind::Sint;
+                                (
+                                    self.get_type_id(LookupType::Local(LocalType::Value {
+                                        vector_size: None,
+                                        scalar,
+                                        pointer_space: None,
+                                    })),
+                                    self.writer.get_constant_scalar_with(31, scalar)?,
+                                )
+                            }
+                            _ => unreachable!(),
+                        };
+
+                        let msb_id = self.gen_id();
+                        block.body.push(Instruction::ext_inst(
+                            self.writer.gl450_ext_inst_id,
+                            spirv::GLOp::FindUMsb,
+                            int_type_id,
+                            msb_id,
+                            &[arg0_id],
+                        ));
+
+                        MathOp::Custom(Instruction::binary(
+                            spirv::Op::ISub,
+                            result_type_id,
+                            id,
+                            int_id,
+                            msb_id,
+                        ))
+                    }
+                    Mf::CountOneBits => MathOp::Custom(Instruction::unary(
+                        spirv::Op::BitCount,
+                        result_type_id,
+                        id,
+                        arg0_id,
+                    )),
+                    Mf::ExtractBits => {
+                        let op = match arg_scalar_kind {
+                            Some(crate::ScalarKind::Uint) => spirv::Op::BitFieldUExtract,
+                            Some(crate::ScalarKind::Sint) => spirv::Op::BitFieldSExtract,
+                            other => unimplemented!("Unexpected sign({:?})", other),
+                        };
+                        MathOp::Custom(Instruction::ternary(
+                            op,
+                            result_type_id,
+                            id,
+                            arg0_id,
+                            arg1_id,
+                            arg2_id,
+                        ))
+                    }
+                    Mf::InsertBits => MathOp::Custom(Instruction::quaternary(
+                        spirv::Op::BitFieldInsert,
+                        result_type_id,
+                        id,
+                        arg0_id,
+                        arg1_id,
+                        arg2_id,
+                        arg3_id,
+                    )),
+                    Mf::FindLsb => MathOp::Ext(spirv::GLOp::FindILsb),
+                    Mf::FindMsb => MathOp::Ext(match arg_scalar_kind {
+                        Some(crate::ScalarKind::Uint) => spirv::GLOp::FindUMsb,
+                        Some(crate::ScalarKind::Sint) => spirv::GLOp::FindSMsb,
+                        other => unimplemented!("Unexpected findMSB({:?})", other),
+                    }),
+                    Mf::Pack4x8unorm => MathOp::Ext(spirv::GLOp::PackUnorm4x8),
+                    Mf::Pack4x8snorm => MathOp::Ext(spirv::GLOp::PackSnorm4x8),
+                    Mf::Pack2x16float => MathOp::Ext(spirv::GLOp::PackHalf2x16),
+                    Mf::Pack2x16unorm => MathOp::Ext(spirv::GLOp::PackUnorm2x16),
+                    Mf::Pack2x16snorm => MathOp::Ext(spirv::GLOp::PackSnorm2x16),
+                    Mf::Unpack4x8unorm => MathOp::Ext(spirv::GLOp::UnpackUnorm4x8),
+                    Mf::Unpack4x8snorm => MathOp::Ext(spirv::GLOp::UnpackSnorm4x8),
+                    Mf::Unpack2x16float => MathOp::Ext(spirv::GLOp::UnpackHalf2x16),
+                    Mf::Unpack2x16unorm => MathOp::Ext(spirv::GLOp::UnpackUnorm2x16),
+                    Mf::Unpack2x16snorm => MathOp::Ext(spirv::GLOp::UnpackSnorm2x16),
+                };
+
+                block.body.push(match math_op {
+                    MathOp::Ext(op) => Instruction::ext_inst(
+                        self.writer.gl450_ext_inst_id,
+                        op,
+                        result_type_id,
+                        id,
+                        &[arg0_id, arg1_id, arg2_id, arg3_id][..fun.argument_count()],
+                    ),
+                    MathOp::Custom(inst) => inst,
+                });
+                id
+            }
+            crate::Expression::LocalVariable(variable) => self.function.variables[&variable].id,
+            crate::Expression::Load { pointer } => {
+                match self.write_expression_pointer(pointer, block, None)? {
+                    ExpressionPointer::Ready { pointer_id } => {
+                        let id = self.gen_id();
+                        let atomic_space =
+                            match *self.fun_info[pointer].ty.inner_with(&self.ir_module.types) {
+                                crate::TypeInner::Pointer { base, space } => {
+                                    match self.ir_module.types[base].inner {
+                                        crate::TypeInner::Atomic { .. } => Some(space),
+                                        _ => None,
+                                    }
+                                }
+                                _ => None,
+                            };
+                        let instruction = if let Some(space) = atomic_space {
+                            let (semantics, scope) = space.to_spirv_semantics_and_scope();
+                            let scope_constant_id = self.get_scope_constant(scope as u32);
+                            let semantics_id = self.get_index_constant(semantics.bits());
+                            Instruction::atomic_load(
+                                result_type_id,
+                                id,
+                                pointer_id,
+                                scope_constant_id,
+                                semantics_id,
+                            )
+                        } else {
+                            Instruction::load(result_type_id, id, pointer_id, None)
+                        };
+                        block.body.push(instruction);
+                        id
+                    }
+                    ExpressionPointer::Conditional { condition, access } => {
+                        //TODO: support atomics?
+                        self.write_conditional_indexed_load(
+                            result_type_id,
+                            condition,
+                            block,
+                            move |id_gen, block| {
+                                // The in-bounds path. Perform the access and the load.
+                                let pointer_id = access.result_id.unwrap();
+                                let value_id = id_gen.next();
+                                block.body.push(access);
+                                block.body.push(Instruction::load(
+                                    result_type_id,
+                                    value_id,
+                                    pointer_id,
+                                    None,
+                                ));
+                                value_id
+                            },
+                        )
+                    }
+                }
+            }
+            crate::Expression::FunctionArgument(index) => self.function.parameter_id(index),
+            crate::Expression::CallResult(_)
+            | crate::Expression::AtomicResult { .. }
+            | crate::Expression::WorkGroupUniformLoadResult { .. }
+            | crate::Expression::RayQueryProceedResult => self.cached[expr_handle],
+            crate::Expression::As {
+                expr,
+                kind,
+                convert,
+            } => {
+                use crate::ScalarKind as Sk;
+
+                let expr_id = self.cached[expr];
+                let (src_scalar, src_size, is_matrix) =
+                    match *self.fun_info[expr].ty.inner_with(&self.ir_module.types) {
+                        crate::TypeInner::Scalar(scalar) => (scalar, None, false),
+                        crate::TypeInner::Vector { scalar, size } => (scalar, Some(size), false),
+                        crate::TypeInner::Matrix { scalar, .. } => (scalar, None, true),
+                        ref other => {
+                            log::error!("As source {:?}", other);
+                            return Err(Error::Validation("Unexpected Expression::As source"));
+                        }
+                    };
+
+                enum Cast {
+                    Identity,
+                    Unary(spirv::Op),
+                    Binary(spirv::Op, Word),
+                    Ternary(spirv::Op, Word, Word),
+                }
+
+                let cast = if is_matrix {
+                    // we only support identity casts for matrices
+                    Cast::Unary(spirv::Op::CopyObject)
+                } else {
+                    match (src_scalar.kind, kind, convert) {
+                        // Filter out identity casts. Some Adreno drivers are
+                        // confused by no-op OpBitCast instructions.
+                        (src_kind, kind, convert)
+                            if src_kind == kind
+                                && convert.filter(|&width| width != src_scalar.width).is_none() =>
+                        {
+                            Cast::Identity
+                        }
+                        (Sk::Bool, Sk::Bool, _) => Cast::Unary(spirv::Op::CopyObject),
+                        (_, _, None) => Cast::Unary(spirv::Op::Bitcast),
+                        // casting to a bool - generate `OpXxxNotEqual`
+                        (_, Sk::Bool, Some(_)) => {
+                            let op = match src_scalar.kind {
+                                Sk::Sint | Sk::Uint => spirv::Op::INotEqual,
+                                Sk::Float => spirv::Op::FUnordNotEqual,
+                                Sk::Bool | Sk::AbstractInt | Sk::AbstractFloat => unreachable!(),
+                            };
+                            let zero_scalar_id =
+                                self.writer.get_constant_scalar_with(0, src_scalar)?;
+                            let zero_id = match src_size {
+                                Some(size) => {
+                                    let ty = LocalType::Value {
+                                        vector_size: Some(size),
+                                        scalar: src_scalar,
+                                        pointer_space: None,
+                                    }
+                                    .into();
+
+                                    self.temp_list.clear();
+                                    self.temp_list.resize(size as _, zero_scalar_id);
+
+                                    self.writer.get_constant_composite(ty, &self.temp_list)
+                                }
+                                None => zero_scalar_id,
+                            };
+
+                            Cast::Binary(op, zero_id)
+                        }
+                        // casting from a bool - generate `OpSelect`
+                        (Sk::Bool, _, Some(dst_width)) => {
+                            let dst_scalar = crate::Scalar {
+                                kind,
+                                width: dst_width,
+                            };
+                            let zero_scalar_id =
+                                self.writer.get_constant_scalar_with(0, dst_scalar)?;
+                            let one_scalar_id =
+                                self.writer.get_constant_scalar_with(1, dst_scalar)?;
+                            let (accept_id, reject_id) = match src_size {
+                                Some(size) => {
+                                    let ty = LocalType::Value {
+                                        vector_size: Some(size),
+                                        scalar: dst_scalar,
+                                        pointer_space: None,
+                                    }
+                                    .into();
+
+                                    self.temp_list.clear();
+                                    self.temp_list.resize(size as _, zero_scalar_id);
+
+                                    let vec0_id =
+                                        self.writer.get_constant_composite(ty, &self.temp_list);
+
+                                    self.temp_list.fill(one_scalar_id);
+
+                                    let vec1_id =
+                                        self.writer.get_constant_composite(ty, &self.temp_list);
+
+                                    (vec1_id, vec0_id)
+                                }
+                                None => (one_scalar_id, zero_scalar_id),
+                            };
+
+                            Cast::Ternary(spirv::Op::Select, accept_id, reject_id)
+                        }
+                        (Sk::Float, Sk::Uint, Some(_)) => Cast::Unary(spirv::Op::ConvertFToU),
+                        (Sk::Float, Sk::Sint, Some(_)) => Cast::Unary(spirv::Op::ConvertFToS),
+                        (Sk::Float, Sk::Float, Some(dst_width))
+                            if src_scalar.width != dst_width =>
+                        {
+                            Cast::Unary(spirv::Op::FConvert)
+                        }
+                        (Sk::Sint, Sk::Float, Some(_)) => Cast::Unary(spirv::Op::ConvertSToF),
+                        (Sk::Sint, Sk::Sint, Some(dst_width)) if src_scalar.width != dst_width => {
+                            Cast::Unary(spirv::Op::SConvert)
+                        }
+                        (Sk::Uint, Sk::Float, Some(_)) => Cast::Unary(spirv::Op::ConvertUToF),
+                        (Sk::Uint, Sk::Uint, Some(dst_width)) if src_scalar.width != dst_width => {
+                            Cast::Unary(spirv::Op::UConvert)
+                        }
+                        // We assume it's either an identity cast, or int-uint.
+                        _ => Cast::Unary(spirv::Op::Bitcast),
+                    }
+                };
+
+                let id = self.gen_id();
+                let instruction = match cast {
+                    Cast::Identity => None,
+                    Cast::Unary(op) => Some(Instruction::unary(op, result_type_id, id, expr_id)),
+                    Cast::Binary(op, operand) => Some(Instruction::binary(
+                        op,
+                        result_type_id,
+                        id,
+                        expr_id,
+                        operand,
+                    )),
+                    Cast::Ternary(op, op1, op2) => Some(Instruction::ternary(
+                        op,
+                        result_type_id,
+                        id,
+                        expr_id,
+                        op1,
+                        op2,
+                    )),
+                };
+                if let Some(instruction) = instruction {
+                    block.body.push(instruction);
+                    id
+                } else {
+                    expr_id
+                }
+            }
+            crate::Expression::ImageLoad {
+                image,
+                coordinate,
+                array_index,
+                sample,
+                level,
+            } => self.write_image_load(
+                result_type_id,
+                image,
+                coordinate,
+                array_index,
+                level,
+                sample,
+                block,
+            )?,
+            crate::Expression::ImageSample {
+                image,
+                sampler,
+                gather,
+                coordinate,
+                array_index,
+                offset,
+                level,
+                depth_ref,
+            } => self.write_image_sample(
+                result_type_id,
+                image,
+                sampler,
+                gather,
+                coordinate,
+                array_index,
+                offset,
+                level,
+                depth_ref,
+                block,
+            )?,
+            crate::Expression::Select {
+                condition,
+                accept,
+                reject,
+            } => {
+                let id = self.gen_id();
+                let mut condition_id = self.cached[condition];
+                let accept_id = self.cached[accept];
+                let reject_id = self.cached[reject];
+
+                let condition_ty = self.fun_info[condition]
+                    .ty
+                    .inner_with(&self.ir_module.types);
+                let object_ty = self.fun_info[accept].ty.inner_with(&self.ir_module.types);
+
+                if let (
+                    &crate::TypeInner::Scalar(
+                        condition_scalar @ crate::Scalar {
+                            kind: crate::ScalarKind::Bool,
+                            ..
+                        },
+                    ),
+                    &crate::TypeInner::Vector { size, .. },
+                ) = (condition_ty, object_ty)
+                {
+                    self.temp_list.clear();
+                    self.temp_list.resize(size as usize, condition_id);
+
+                    let bool_vector_type_id =
+                        self.get_type_id(LookupType::Local(LocalType::Value {
+                            vector_size: Some(size),
+                            scalar: condition_scalar,
+                            pointer_space: None,
+                        }));
+
+                    let id = self.gen_id();
+                    block.body.push(Instruction::composite_construct(
+                        bool_vector_type_id,
+                        id,
+                        &self.temp_list,
+                    ));
+                    condition_id = id
+                }
+
+                let instruction =
+                    Instruction::select(result_type_id, id, condition_id, accept_id, reject_id);
+                block.body.push(instruction);
+                id
+            }
+            crate::Expression::Derivative { axis, ctrl, expr } => {
+                use crate::{DerivativeAxis as Axis, DerivativeControl as Ctrl};
+                match ctrl {
+                    Ctrl::Coarse | Ctrl::Fine => {
+                        self.writer.require_any(
+                            "DerivativeControl",
+                            &[spirv::Capability::DerivativeControl],
+                        )?;
+                    }
+                    Ctrl::None => {}
+                }
+                let id = self.gen_id();
+                let expr_id = self.cached[expr];
+                let op = match (axis, ctrl) {
+                    (Axis::X, Ctrl::Coarse) => spirv::Op::DPdxCoarse,
+                    (Axis::X, Ctrl::Fine) => spirv::Op::DPdxFine,
+                    (Axis::X, Ctrl::None) => spirv::Op::DPdx,
+                    (Axis::Y, Ctrl::Coarse) => spirv::Op::DPdyCoarse,
+                    (Axis::Y, Ctrl::Fine) => spirv::Op::DPdyFine,
+                    (Axis::Y, Ctrl::None) => spirv::Op::DPdy,
+                    (Axis::Width, Ctrl::Coarse) => spirv::Op::FwidthCoarse,
+                    (Axis::Width, Ctrl::Fine) => spirv::Op::FwidthFine,
+                    (Axis::Width, Ctrl::None) => spirv::Op::Fwidth,
+                };
+                block
+                    .body
+                    .push(Instruction::derivative(op, result_type_id, id, expr_id));
+                id
+            }
+            crate::Expression::ImageQuery { image, query } => {
+                self.write_image_query(result_type_id, image, query, block)?
+            }
+            crate::Expression::Relational { fun, argument } => {
+                use crate::RelationalFunction as Rf;
+                let arg_id = self.cached[argument];
+                let op = match fun {
+                    Rf::All => spirv::Op::All,
+                    Rf::Any => spirv::Op::Any,
+                    Rf::IsNan => spirv::Op::IsNan,
+                    Rf::IsInf => spirv::Op::IsInf,
+                };
+                let id = self.gen_id();
+                block
+                    .body
+                    .push(Instruction::relational(op, result_type_id, id, arg_id));
+                id
+            }
+            crate::Expression::ArrayLength(expr) => self.write_runtime_array_length(expr, block)?,
+            crate::Expression::RayQueryGetIntersection { query, committed } => {
+                if !committed {
+                    return Err(Error::FeatureNotImplemented("candidate intersection"));
+                }
+                self.write_ray_query_get_intersection(query, block)
+            }
+        };
+
+        self.cached[expr_handle] = id;
+        Ok(())
+    }
+
+    /// Build an `OpAccessChain` instruction.
+    ///
+    /// Emit any needed bounds-checking expressions to `block`.
+    ///
+    /// Some cases we need to generate a different return type than what the IR gives us.
+    /// This is because pointers to binding arrays of handles (such as images or samplers)
+    /// don't exist in the IR, but we need to create them to create an access chain in SPIRV.
+    ///
+    /// On success, the return value is an [`ExpressionPointer`] value; see the
+    /// documentation for that type.
+    fn write_expression_pointer(
+        &mut self,
+        mut expr_handle: Handle<crate::Expression>,
+        block: &mut Block,
+        return_type_override: Option<LookupType>,
+    ) -> Result<ExpressionPointer, Error> {
+        let result_lookup_ty = match self.fun_info[expr_handle].ty {
+            TypeResolution::Handle(ty_handle) => match return_type_override {
+                // We use the return type override as a special case for handle binding arrays as the OpAccessChain
+                // needs to return a pointer, but indexing into a handle binding array just gives you the type of
+                // the binding in the IR.
+                Some(ty) => ty,
+                None => LookupType::Handle(ty_handle),
+            },
+            TypeResolution::Value(ref inner) => LookupType::Local(make_local(inner).unwrap()),
+        };
+        let result_type_id = self.get_type_id(result_lookup_ty);
+
+        // The id of the boolean `and` of all dynamic bounds checks up to this point. If
+        // `None`, then we haven't done any dynamic bounds checks yet.
+        //
+        // When we have a chain of bounds checks, we combine them with `OpLogicalAnd`, not
+        // a short-circuit branch. This means we might do comparisons we don't need to,
+        // but we expect these checks to almost always succeed, and keeping branches to a
+        // minimum is essential.
+        let mut accumulated_checks = None;
+        // Is true if we are accessing into a binding array with a non-uniform index.
+        let mut is_non_uniform_binding_array = false;
+
+        self.temp_list.clear();
+        let root_id = loop {
+            expr_handle = match self.ir_function.expressions[expr_handle] {
+                crate::Expression::Access { base, index } => {
+                    if let crate::Expression::GlobalVariable(var_handle) =
+                        self.ir_function.expressions[base]
+                    {
+                        // The access chain needs to be decorated as NonUniform
+                        // see VUID-RuntimeSpirv-NonUniform-06274
+                        let gvar = &self.ir_module.global_variables[var_handle];
+                        if let crate::TypeInner::BindingArray { .. } =
+                            self.ir_module.types[gvar.ty].inner
+                        {
+                            is_non_uniform_binding_array =
+                                self.fun_info[index].uniformity.non_uniform_result.is_some();
+                        }
+                    }
+
+                    let index_id = match self.write_bounds_check(base, index, block)? {
+                        BoundsCheckResult::KnownInBounds(known_index) => {
+                            // Even if the index is known, `OpAccessIndex`
+                            // requires expression operands, not literals.
+                            let scalar = crate::Literal::U32(known_index);
+                            self.writer.get_constant_scalar(scalar)
+                        }
+                        BoundsCheckResult::Computed(computed_index_id) => computed_index_id,
+                        BoundsCheckResult::Conditional(comparison_id) => {
+                            match accumulated_checks {
+                                Some(prior_checks) => {
+                                    let combined = self.gen_id();
+                                    block.body.push(Instruction::binary(
+                                        spirv::Op::LogicalAnd,
+                                        self.writer.get_bool_type_id(),
+                                        combined,
+                                        prior_checks,
+                                        comparison_id,
+                                    ));
+                                    accumulated_checks = Some(combined);
+                                }
+                                None => {
+                                    // Start a fresh chain of checks.
+                                    accumulated_checks = Some(comparison_id);
+                                }
+                            }
+
+                            // Either way, the index to use is unchanged.
+                            self.cached[index]
+                        }
+                    };
+                    self.temp_list.push(index_id);
+                    base
+                }
+                crate::Expression::AccessIndex { base, index } => {
+                    let const_id = self.get_index_constant(index);
+                    self.temp_list.push(const_id);
+                    base
+                }
+                crate::Expression::GlobalVariable(handle) => {
+                    let gv = &self.writer.global_variables[handle.index()];
+                    break gv.access_id;
+                }
+                crate::Expression::LocalVariable(variable) => {
+                    let local_var = &self.function.variables[&variable];
+                    break local_var.id;
+                }
+                crate::Expression::FunctionArgument(index) => {
+                    break self.function.parameter_id(index);
+                }
+                ref other => unimplemented!("Unexpected pointer expression {:?}", other),
+            }
+        };
+
+        let (pointer_id, expr_pointer) = if self.temp_list.is_empty() {
+            (
+                root_id,
+                ExpressionPointer::Ready {
+                    pointer_id: root_id,
+                },
+            )
+        } else {
+            self.temp_list.reverse();
+            let pointer_id = self.gen_id();
+            let access =
+                Instruction::access_chain(result_type_id, pointer_id, root_id, &self.temp_list);
+
+            // If we generated some bounds checks, we need to leave it to our
+            // caller to generate the branch, the access, the load or store, and
+            // the zero value (for loads). Otherwise, we can emit the access
+            // ourselves, and just hand them the id of the pointer.
+            let expr_pointer = match accumulated_checks {
+                Some(condition) => ExpressionPointer::Conditional { condition, access },
+                None => {
+                    block.body.push(access);
+                    ExpressionPointer::Ready { pointer_id }
+                }
+            };
+            (pointer_id, expr_pointer)
+        };
+        // Subsequent load, store and atomic operations require the pointer to be decorated as NonUniform
+        // if the binding array was accessed with a non-uniform index
+        // see VUID-RuntimeSpirv-NonUniform-06274
+        if is_non_uniform_binding_array {
+            self.writer
+                .decorate_non_uniform_binding_array_access(pointer_id)?;
+        }
+
+        Ok(expr_pointer)
+    }
+
+    /// Build the instructions for matrix - matrix column operations
+    #[allow(clippy::too_many_arguments)]
+    fn write_matrix_matrix_column_op(
+        &mut self,
+        block: &mut Block,
+        result_id: Word,
+        result_type_id: Word,
+        left_id: Word,
+        right_id: Word,
+        columns: crate::VectorSize,
+        rows: crate::VectorSize,
+        width: u8,
+        op: spirv::Op,
+    ) {
+        self.temp_list.clear();
+
+        let vector_type_id = self.get_type_id(LookupType::Local(LocalType::Value {
+            vector_size: Some(rows),
+            scalar: crate::Scalar::float(width),
+            pointer_space: None,
+        }));
+
+        for index in 0..columns as u32 {
+            let column_id_left = self.gen_id();
+            let column_id_right = self.gen_id();
+            let column_id_res = self.gen_id();
+
+            block.body.push(Instruction::composite_extract(
+                vector_type_id,
+                column_id_left,
+                left_id,
+                &[index],
+            ));
+            block.body.push(Instruction::composite_extract(
+                vector_type_id,
+                column_id_right,
+                right_id,
+                &[index],
+            ));
+            block.body.push(Instruction::binary(
+                op,
+                vector_type_id,
+                column_id_res,
+                column_id_left,
+                column_id_right,
+            ));
+
+            self.temp_list.push(column_id_res);
+        }
+
+        block.body.push(Instruction::composite_construct(
+            result_type_id,
+            result_id,
+            &self.temp_list,
+        ));
+    }
+
+    /// Build the instructions for vector - scalar multiplication
+    fn write_vector_scalar_mult(
+        &mut self,
+        block: &mut Block,
+        result_id: Word,
+        result_type_id: Word,
+        vector_id: Word,
+        scalar_id: Word,
+        vector: &crate::TypeInner,
+    ) {
+        let (size, kind) = match *vector {
+            crate::TypeInner::Vector {
+                size,
+                scalar: crate::Scalar { kind, .. },
+            } => (size, kind),
+            _ => unreachable!(),
+        };
+
+        let (op, operand_id) = match kind {
+            crate::ScalarKind::Float => (spirv::Op::VectorTimesScalar, scalar_id),
+            _ => {
+                let operand_id = self.gen_id();
+                self.temp_list.clear();
+                self.temp_list.resize(size as usize, scalar_id);
+                block.body.push(Instruction::composite_construct(
+                    result_type_id,
+                    operand_id,
+                    &self.temp_list,
+                ));
+                (spirv::Op::IMul, operand_id)
+            }
+        };
+
+        block.body.push(Instruction::binary(
+            op,
+            result_type_id,
+            result_id,
+            vector_id,
+            operand_id,
+        ));
+    }
+
+    /// Build the instructions for the arithmetic expression of a dot product
+    fn write_dot_product(
+        &mut self,
+        result_id: Word,
+        result_type_id: Word,
+        arg0_id: Word,
+        arg1_id: Word,
+        size: u32,
+        block: &mut Block,
+    ) {
+        let mut partial_sum = self.writer.get_constant_null(result_type_id);
+        let last_component = size - 1;
+        for index in 0..=last_component {
+            // compute the product of the current components
+            let a_id = self.gen_id();
+            block.body.push(Instruction::composite_extract(
+                result_type_id,
+                a_id,
+                arg0_id,
+                &[index],
+            ));
+            let b_id = self.gen_id();
+            block.body.push(Instruction::composite_extract(
+                result_type_id,
+                b_id,
+                arg1_id,
+                &[index],
+            ));
+            let prod_id = self.gen_id();
+            block.body.push(Instruction::binary(
+                spirv::Op::IMul,
+                result_type_id,
+                prod_id,
+                a_id,
+                b_id,
+            ));
+
+            // choose the id for the next sum, depending on current index
+            let id = if index == last_component {
+                result_id
+            } else {
+                self.gen_id()
+            };
+
+            // sum the computed product with the partial sum
+            block.body.push(Instruction::binary(
+                spirv::Op::IAdd,
+                result_type_id,
+                id,
+                partial_sum,
+                prod_id,
+            ));
+            // set the id of the result as the previous partial sum
+            partial_sum = id;
+        }
+    }
+
+    pub(super) fn write_block(
+        &mut self,
+        label_id: Word,
+        naga_block: &crate::Block,
+        exit: BlockExit,
+        loop_context: LoopContext,
+        debug_info: Option<&DebugInfoInner>,
+    ) -> Result<(), Error> {
+        let mut block = Block::new(label_id);
+        for (statement, span) in naga_block.span_iter() {
+            if let (Some(debug_info), false) = (
+                debug_info,
+                matches!(
+                    statement,
+                    &(Statement::Block(..)
+                        | Statement::Break
+                        | Statement::Continue
+                        | Statement::Kill
+                        | Statement::Return { .. }
+                        | Statement::Loop { .. })
+                ),
+            ) {
+                let loc: crate::SourceLocation = span.location(debug_info.source_code);
+                block.body.push(Instruction::line(
+                    debug_info.source_file_id,
+                    loc.line_number,
+                    loc.line_position,
+                ));
+            };
+            match *statement {
+                crate::Statement::Emit(ref range) => {
+                    for handle in range.clone() {
+                        // omit const expressions as we've already cached those
+                        if !self.expression_constness.is_const(handle) {
+                            self.cache_expression_value(handle, &mut block)?;
+                        }
+                    }
+                }
+                crate::Statement::Block(ref block_statements) => {
+                    let scope_id = self.gen_id();
+                    self.function.consume(block, Instruction::branch(scope_id));
+
+                    let merge_id = self.gen_id();
+                    self.write_block(
+                        scope_id,
+                        block_statements,
+                        BlockExit::Branch { target: merge_id },
+                        loop_context,
+                        debug_info,
+                    )?;
+
+                    block = Block::new(merge_id);
+                }
+                crate::Statement::If {
+                    condition,
+                    ref accept,
+                    ref reject,
+                } => {
+                    let condition_id = self.cached[condition];
+
+                    let merge_id = self.gen_id();
+                    block.body.push(Instruction::selection_merge(
+                        merge_id,
+                        spirv::SelectionControl::NONE,
+                    ));
+
+                    let accept_id = if accept.is_empty() {
+                        None
+                    } else {
+                        Some(self.gen_id())
+                    };
+                    let reject_id = if reject.is_empty() {
+                        None
+                    } else {
+                        Some(self.gen_id())
+                    };
+
+                    self.function.consume(
+                        block,
+                        Instruction::branch_conditional(
+                            condition_id,
+                            accept_id.unwrap_or(merge_id),
+                            reject_id.unwrap_or(merge_id),
+                        ),
+                    );
+
+                    if let Some(block_id) = accept_id {
+                        self.write_block(
+                            block_id,
+                            accept,
+                            BlockExit::Branch { target: merge_id },
+                            loop_context,
+                            debug_info,
+                        )?;
+                    }
+                    if let Some(block_id) = reject_id {
+                        self.write_block(
+                            block_id,
+                            reject,
+                            BlockExit::Branch { target: merge_id },
+                            loop_context,
+                            debug_info,
+                        )?;
+                    }
+
+                    block = Block::new(merge_id);
+                }
+                crate::Statement::Switch {
+                    selector,
+                    ref cases,
+                } => {
+                    let selector_id = self.cached[selector];
+
+                    let merge_id = self.gen_id();
+                    block.body.push(Instruction::selection_merge(
+                        merge_id,
+                        spirv::SelectionControl::NONE,
+                    ));
+
+                    let mut default_id = None;
+                    // id of previous empty fall-through case
+                    let mut last_id = None;
+
+                    let mut raw_cases = Vec::with_capacity(cases.len());
+                    let mut case_ids = Vec::with_capacity(cases.len());
+                    for case in cases.iter() {
+                        // take id of previous empty fall-through case or generate a new one
+                        let label_id = last_id.take().unwrap_or_else(|| self.gen_id());
+
+                        if case.fall_through && case.body.is_empty() {
+                            last_id = Some(label_id);
+                        }
+
+                        case_ids.push(label_id);
+
+                        match case.value {
+                            crate::SwitchValue::I32(value) => {
+                                raw_cases.push(super::instructions::Case {
+                                    value: value as Word,
+                                    label_id,
+                                });
+                            }
+                            crate::SwitchValue::U32(value) => {
+                                raw_cases.push(super::instructions::Case { value, label_id });
+                            }
+                            crate::SwitchValue::Default => {
+                                default_id = Some(label_id);
+                            }
+                        }
+                    }
+
+                    let default_id = default_id.unwrap();
+
+                    self.function.consume(
+                        block,
+                        Instruction::switch(selector_id, default_id, &raw_cases),
+                    );
+
+                    let inner_context = LoopContext {
+                        break_id: Some(merge_id),
+                        ..loop_context
+                    };
+
+                    for (i, (case, label_id)) in cases
+                        .iter()
+                        .zip(case_ids.iter())
+                        .filter(|&(case, _)| !(case.fall_through && case.body.is_empty()))
+                        .enumerate()
+                    {
+                        let case_finish_id = if case.fall_through {
+                            case_ids[i + 1]
+                        } else {
+                            merge_id
+                        };
+                        self.write_block(
+                            *label_id,
+                            &case.body,
+                            BlockExit::Branch {
+                                target: case_finish_id,
+                            },
+                            inner_context,
+                            debug_info,
+                        )?;
+                    }
+
+                    block = Block::new(merge_id);
+                }
+                crate::Statement::Loop {
+                    ref body,
+                    ref continuing,
+                    break_if,
+                } => {
+                    let preamble_id = self.gen_id();
+                    self.function
+                        .consume(block, Instruction::branch(preamble_id));
+
+                    let merge_id = self.gen_id();
+                    let body_id = self.gen_id();
+                    let continuing_id = self.gen_id();
+
+                    // SPIR-V requires the continuing to the `OpLoopMerge`,
+                    // so we have to start a new block with it.
+                    block = Block::new(preamble_id);
+                    // HACK the loop statement is begin with branch instruction,
+                    // so we need to put `OpLine` debug info before merge instruction
+                    if let Some(debug_info) = debug_info {
+                        let loc: crate::SourceLocation = span.location(debug_info.source_code);
+                        block.body.push(Instruction::line(
+                            debug_info.source_file_id,
+                            loc.line_number,
+                            loc.line_position,
+                        ))
+                    }
+                    block.body.push(Instruction::loop_merge(
+                        merge_id,
+                        continuing_id,
+                        spirv::SelectionControl::NONE,
+                    ));
+                    self.function.consume(block, Instruction::branch(body_id));
+
+                    self.write_block(
+                        body_id,
+                        body,
+                        BlockExit::Branch {
+                            target: continuing_id,
+                        },
+                        LoopContext {
+                            continuing_id: Some(continuing_id),
+                            break_id: Some(merge_id),
+                        },
+                        debug_info,
+                    )?;
+
+                    let exit = match break_if {
+                        Some(condition) => BlockExit::BreakIf {
+                            condition,
+                            preamble_id,
+                        },
+                        None => BlockExit::Branch {
+                            target: preamble_id,
+                        },
+                    };
+
+                    self.write_block(
+                        continuing_id,
+                        continuing,
+                        exit,
+                        LoopContext {
+                            continuing_id: None,
+                            break_id: Some(merge_id),
+                        },
+                        debug_info,
+                    )?;
+
+                    block = Block::new(merge_id);
+                }
+                crate::Statement::Break => {
+                    self.function
+                        .consume(block, Instruction::branch(loop_context.break_id.unwrap()));
+                    return Ok(());
+                }
+                crate::Statement::Continue => {
+                    self.function.consume(
+                        block,
+                        Instruction::branch(loop_context.continuing_id.unwrap()),
+                    );
+                    return Ok(());
+                }
+                crate::Statement::Return { value: Some(value) } => {
+                    let value_id = self.cached[value];
+                    let instruction = match self.function.entry_point_context {
+                        // If this is an entry point, and we need to return anything,
+                        // let's instead store the output variables and return `void`.
+                        Some(ref context) => {
+                            self.writer.write_entry_point_return(
+                                value_id,
+                                self.ir_function.result.as_ref().unwrap(),
+                                &context.results,
+                                &mut block.body,
+                            )?;
+                            Instruction::return_void()
+                        }
+                        None => Instruction::return_value(value_id),
+                    };
+                    self.function.consume(block, instruction);
+                    return Ok(());
+                }
+                crate::Statement::Return { value: None } => {
+                    self.function.consume(block, Instruction::return_void());
+                    return Ok(());
+                }
+                crate::Statement::Kill => {
+                    self.function.consume(block, Instruction::kill());
+                    return Ok(());
+                }
+                crate::Statement::Barrier(flags) => {
+                    self.writer.write_barrier(flags, &mut block);
+                }
+                crate::Statement::Store { pointer, value } => {
+                    let value_id = self.cached[value];
+                    match self.write_expression_pointer(pointer, &mut block, None)? {
+                        ExpressionPointer::Ready { pointer_id } => {
+                            let atomic_space = match *self.fun_info[pointer]
+                                .ty
+                                .inner_with(&self.ir_module.types)
+                            {
+                                crate::TypeInner::Pointer { base, space } => {
+                                    match self.ir_module.types[base].inner {
+                                        crate::TypeInner::Atomic { .. } => Some(space),
+                                        _ => None,
+                                    }
+                                }
+                                _ => None,
+                            };
+                            let instruction = if let Some(space) = atomic_space {
+                                let (semantics, scope) = space.to_spirv_semantics_and_scope();
+                                let scope_constant_id = self.get_scope_constant(scope as u32);
+                                let semantics_id = self.get_index_constant(semantics.bits());
+                                Instruction::atomic_store(
+                                    pointer_id,
+                                    scope_constant_id,
+                                    semantics_id,
+                                    value_id,
+                                )
+                            } else {
+                                Instruction::store(pointer_id, value_id, None)
+                            };
+                            block.body.push(instruction);
+                        }
+                        ExpressionPointer::Conditional { condition, access } => {
+                            let mut selection = Selection::start(&mut block, ());
+                            selection.if_true(self, condition, ());
+
+                            // The in-bounds path. Perform the access and the store.
+                            let pointer_id = access.result_id.unwrap();
+                            selection.block().body.push(access);
+                            selection
+                                .block()
+                                .body
+                                .push(Instruction::store(pointer_id, value_id, None));
+
+                            // Finish the in-bounds block and start the merge block. This
+                            // is the block we'll leave current on return.
+                            selection.finish(self, ());
+                        }
+                    };
+                }
+                crate::Statement::ImageStore {
+                    image,
+                    coordinate,
+                    array_index,
+                    value,
+                } => self.write_image_store(image, coordinate, array_index, value, &mut block)?,
+                crate::Statement::Call {
+                    function: local_function,
+                    ref arguments,
+                    result,
+                } => {
+                    let id = self.gen_id();
+                    self.temp_list.clear();
+                    for &argument in arguments {
+                        self.temp_list.push(self.cached[argument]);
+                    }
+
+                    let type_id = match result {
+                        Some(expr) => {
+                            self.cached[expr] = id;
+                            self.get_expression_type_id(&self.fun_info[expr].ty)
+                        }
+                        None => self.writer.void_type,
+                    };
+
+                    block.body.push(Instruction::function_call(
+                        type_id,
+                        id,
+                        self.writer.lookup_function[&local_function],
+                        &self.temp_list,
+                    ));
+                }
+                crate::Statement::Atomic {
+                    pointer,
+                    ref fun,
+                    value,
+                    result,
+                } => {
+                    let id = self.gen_id();
+                    let result_type_id = self.get_expression_type_id(&self.fun_info[result].ty);
+
+                    self.cached[result] = id;
+
+                    let pointer_id =
+                        match self.write_expression_pointer(pointer, &mut block, None)? {
+                            ExpressionPointer::Ready { pointer_id } => pointer_id,
+                            ExpressionPointer::Conditional { .. } => {
+                                return Err(Error::FeatureNotImplemented(
+                                    "Atomics out-of-bounds handling",
+                                ));
+                            }
+                        };
+
+                    let space = self.fun_info[pointer]
+                        .ty
+                        .inner_with(&self.ir_module.types)
+                        .pointer_space()
+                        .unwrap();
+                    let (semantics, scope) = space.to_spirv_semantics_and_scope();
+                    let scope_constant_id = self.get_scope_constant(scope as u32);
+                    let semantics_id = self.get_index_constant(semantics.bits());
+                    let value_id = self.cached[value];
+                    let value_inner = self.fun_info[value].ty.inner_with(&self.ir_module.types);
+
+                    let instruction = match *fun {
+                        crate::AtomicFunction::Add => Instruction::atomic_binary(
+                            spirv::Op::AtomicIAdd,
+                            result_type_id,
+                            id,
+                            pointer_id,
+                            scope_constant_id,
+                            semantics_id,
+                            value_id,
+                        ),
+                        crate::AtomicFunction::Subtract => Instruction::atomic_binary(
+                            spirv::Op::AtomicISub,
+                            result_type_id,
+                            id,
+                            pointer_id,
+                            scope_constant_id,
+                            semantics_id,
+                            value_id,
+                        ),
+                        crate::AtomicFunction::And => Instruction::atomic_binary(
+                            spirv::Op::AtomicAnd,
+                            result_type_id,
+                            id,
+                            pointer_id,
+                            scope_constant_id,
+                            semantics_id,
+                            value_id,
+                        ),
+                        crate::AtomicFunction::InclusiveOr => Instruction::atomic_binary(
+                            spirv::Op::AtomicOr,
+                            result_type_id,
+                            id,
+                            pointer_id,
+                            scope_constant_id,
+                            semantics_id,
+                            value_id,
+                        ),
+                        crate::AtomicFunction::ExclusiveOr => Instruction::atomic_binary(
+                            spirv::Op::AtomicXor,
+                            result_type_id,
+                            id,
+                            pointer_id,
+                            scope_constant_id,
+                            semantics_id,
+                            value_id,
+                        ),
+                        crate::AtomicFunction::Min => {
+                            let spirv_op = match *value_inner {
+                                crate::TypeInner::Scalar(crate::Scalar {
+                                    kind: crate::ScalarKind::Sint,
+                                    width: _,
+                                }) => spirv::Op::AtomicSMin,
+                                crate::TypeInner::Scalar(crate::Scalar {
+                                    kind: crate::ScalarKind::Uint,
+                                    width: _,
+                                }) => spirv::Op::AtomicUMin,
+                                _ => unimplemented!(),
+                            };
+                            Instruction::atomic_binary(
+                                spirv_op,
+                                result_type_id,
+                                id,
+                                pointer_id,
+                                scope_constant_id,
+                                semantics_id,
+                                value_id,
+                            )
+                        }
+                        crate::AtomicFunction::Max => {
+                            let spirv_op = match *value_inner {
+                                crate::TypeInner::Scalar(crate::Scalar {
+                                    kind: crate::ScalarKind::Sint,
+                                    width: _,
+                                }) => spirv::Op::AtomicSMax,
+                                crate::TypeInner::Scalar(crate::Scalar {
+                                    kind: crate::ScalarKind::Uint,
+                                    width: _,
+                                }) => spirv::Op::AtomicUMax,
+                                _ => unimplemented!(),
+                            };
+                            Instruction::atomic_binary(
+                                spirv_op,
+                                result_type_id,
+                                id,
+                                pointer_id,
+                                scope_constant_id,
+                                semantics_id,
+                                value_id,
+                            )
+                        }
+                        crate::AtomicFunction::Exchange { compare: None } => {
+                            Instruction::atomic_binary(
+                                spirv::Op::AtomicExchange,
+                                result_type_id,
+                                id,
+                                pointer_id,
+                                scope_constant_id,
+                                semantics_id,
+                                value_id,
+                            )
+                        }
+                        crate::AtomicFunction::Exchange { compare: Some(cmp) } => {
+                            let scalar_type_id = match *value_inner {
+                                crate::TypeInner::Scalar(scalar) => {
+                                    self.get_type_id(LookupType::Local(LocalType::Value {
+                                        vector_size: None,
+                                        scalar,
+                                        pointer_space: None,
+                                    }))
+                                }
+                                _ => unimplemented!(),
+                            };
+                            let bool_type_id =
+                                self.get_type_id(LookupType::Local(LocalType::Value {
+                                    vector_size: None,
+                                    scalar: crate::Scalar::BOOL,
+                                    pointer_space: None,
+                                }));
+
+                            let cas_result_id = self.gen_id();
+                            let equality_result_id = self.gen_id();
+                            let mut cas_instr = Instruction::new(spirv::Op::AtomicCompareExchange);
+                            cas_instr.set_type(scalar_type_id);
+                            cas_instr.set_result(cas_result_id);
+                            cas_instr.add_operand(pointer_id);
+                            cas_instr.add_operand(scope_constant_id);
+                            cas_instr.add_operand(semantics_id); // semantics if equal
+                            cas_instr.add_operand(semantics_id); // semantics if not equal
+                            cas_instr.add_operand(value_id);
+                            cas_instr.add_operand(self.cached[cmp]);
+                            block.body.push(cas_instr);
+                            block.body.push(Instruction::binary(
+                                spirv::Op::IEqual,
+                                bool_type_id,
+                                equality_result_id,
+                                cas_result_id,
+                                self.cached[cmp],
+                            ));
+                            Instruction::composite_construct(
+                                result_type_id,
+                                id,
+                                &[cas_result_id, equality_result_id],
+                            )
+                        }
+                    };
+
+                    block.body.push(instruction);
+                }
+                crate::Statement::WorkGroupUniformLoad { pointer, result } => {
+                    self.writer
+                        .write_barrier(crate::Barrier::WORK_GROUP, &mut block);
+                    let result_type_id = self.get_expression_type_id(&self.fun_info[result].ty);
+                    // Embed the body of
+                    match self.write_expression_pointer(pointer, &mut block, None)? {
+                        ExpressionPointer::Ready { pointer_id } => {
+                            let id = self.gen_id();
+                            block.body.push(Instruction::load(
+                                result_type_id,
+                                id,
+                                pointer_id,
+                                None,
+                            ));
+                            self.cached[result] = id;
+                        }
+                        ExpressionPointer::Conditional { condition, access } => {
+                            self.cached[result] = self.write_conditional_indexed_load(
+                                result_type_id,
+                                condition,
+                                &mut block,
+                                move |id_gen, block| {
+                                    // The in-bounds path. Perform the access and the load.
+                                    let pointer_id = access.result_id.unwrap();
+                                    let value_id = id_gen.next();
+                                    block.body.push(access);
+                                    block.body.push(Instruction::load(
+                                        result_type_id,
+                                        value_id,
+                                        pointer_id,
+                                        None,
+                                    ));
+                                    value_id
+                                },
+                            )
+                        }
+                    }
+                    self.writer
+                        .write_barrier(crate::Barrier::WORK_GROUP, &mut block);
+                }
+                crate::Statement::RayQuery { query, ref fun } => {
+                    self.write_ray_query_function(query, fun, &mut block);
+                }
+            }
+        }
+
+        let termination = match exit {
+            // We're generating code for the top-level Block of the function, so we
+            // need to end it with some kind of return instruction.
+            BlockExit::Return => match self.ir_function.result {
+                Some(ref result) if self.function.entry_point_context.is_none() => {
+                    let type_id = self.get_type_id(LookupType::Handle(result.ty));
+                    let null_id = self.writer.get_constant_null(type_id);
+                    Instruction::return_value(null_id)
+                }
+                _ => Instruction::return_void(),
+            },
+            BlockExit::Branch { target } => Instruction::branch(target),
+            BlockExit::BreakIf {
+                condition,
+                preamble_id,
+            } => {
+                let condition_id = self.cached[condition];
+
+                Instruction::branch_conditional(
+                    condition_id,
+                    loop_context.break_id.unwrap(),
+                    preamble_id,
+                )
+            }
+        };
+
+        self.function.consume(block, termination);
+        Ok(())
+    }
+}
diff --git a/third_party/rust/naga/src/back/spv/helpers.rs b/third_party/rust/naga/src/back/spv/helpers.rs
new file mode 100644
index 0000000000..5b6226db85
--- /dev/null
+++ b/third_party/rust/naga/src/back/spv/helpers.rs
@@ -0,0 +1,109 @@
+use crate::{Handle, UniqueArena};
+use spirv::Word;
+
+pub(super) fn bytes_to_words(bytes: &[u8]) -> Vec<Word> {
+    bytes
+        .chunks(4)
+        .map(|chars| chars.iter().rev().fold(0u32, |u, c| (u << 8) | *c as u32))
+        .collect()
+}
+
+pub(super) fn string_to_words(input: &str) -> Vec<Word> {
+    let bytes = input.as_bytes();
+    let mut words = bytes_to_words(bytes);
+
+    if bytes.len() % 4 == 0 {
+        // nul-termination
+        words.push(0x0u32);
+    }
+
+    words
+}
+
+pub(super) const fn map_storage_class(space: crate::AddressSpace) -> spirv::StorageClass {
+    match space {
+        crate::AddressSpace::Handle => spirv::StorageClass::UniformConstant,
+        crate::AddressSpace::Function => spirv::StorageClass::Function,
+        crate::AddressSpace::Private => spirv::StorageClass::Private,
+        crate::AddressSpace::Storage { .. } => spirv::StorageClass::StorageBuffer,
+        crate::AddressSpace::Uniform => spirv::StorageClass::Uniform,
+        crate::AddressSpace::WorkGroup => spirv::StorageClass::Workgroup,
+        crate::AddressSpace::PushConstant => spirv::StorageClass::PushConstant,
+    }
+}
+
+pub(super) fn contains_builtin(
+    binding: Option<&crate::Binding>,
+    ty: Handle<crate::Type>,
+    arena: &UniqueArena<crate::Type>,
+    built_in: crate::BuiltIn,
+) -> bool {
+    if let Some(&crate::Binding::BuiltIn(bi)) = binding {
+        bi == built_in
+    } else if let crate::TypeInner::Struct { ref members, .. } = arena[ty].inner {
+        members
+            .iter()
+            .any(|member| contains_builtin(member.binding.as_ref(), member.ty, arena, built_in))
+    } else {
+        false // unreachable
+    }
+}
+
+impl crate::AddressSpace {
+    pub(super) const fn to_spirv_semantics_and_scope(
+        self,
+    ) -> (spirv::MemorySemantics, spirv::Scope) {
+        match self {
+            Self::Storage { .. } => (spirv::MemorySemantics::UNIFORM_MEMORY, spirv::Scope::Device),
+            Self::WorkGroup => (
+                spirv::MemorySemantics::WORKGROUP_MEMORY,
+                spirv::Scope::Workgroup,
+            ),
+            _ => (spirv::MemorySemantics::empty(), spirv::Scope::Invocation),
+        }
+    }
+}
+
+/// Return true if the global requires a type decorated with `Block`.
+///
+/// Vulkan spec v1.3 §15.6.2, "Descriptor Set Interface", says:
+///
+/// > Variables identified with the `Uniform` storage class are used to
+/// > access transparent buffer backed resources. Such variables must
+/// > be:
+/// >
+/// > -   typed as `OpTypeStruct`, or an array of this type,
+/// >
+/// > -   identified with a `Block` or `BufferBlock` decoration, and
+/// >
+/// > -   laid out explicitly using the `Offset`, `ArrayStride`, and
+/// >     `MatrixStride` decorations as specified in §15.6.4, "Offset
+/// >     and Stride Assignment."
+// See `back::spv::GlobalVariable::access_id` for details.
+pub fn global_needs_wrapper(ir_module: &crate::Module, var: &crate::GlobalVariable) -> bool {
+    match var.space {
+        crate::AddressSpace::Uniform
+        | crate::AddressSpace::Storage { .. }
+        | crate::AddressSpace::PushConstant => {}
+        _ => return false,
+    };
+    match ir_module.types[var.ty].inner {
+        crate::TypeInner::Struct {
+            ref members,
+            span: _,
+        } => match members.last() {
+            Some(member) => match ir_module.types[member.ty].inner {
+                // Structs with dynamically sized arrays can't be copied and can't be wrapped.
+                crate::TypeInner::Array {
+                    size: crate::ArraySize::Dynamic,
+                    ..
+                } => false,
+                _ => true,
+            },
+            None => false,
+        },
+        crate::TypeInner::BindingArray { .. } => false,
+        // if it's not a structure or a binding array, let's wrap it to be able to put "Block"
+        _ => true,
+    }
+}
diff --git a/third_party/rust/naga/src/back/spv/image.rs b/third_party/rust/naga/src/back/spv/image.rs
new file mode 100644
index 0000000000..c0fc41cbb6
--- /dev/null
+++ b/third_party/rust/naga/src/back/spv/image.rs
@@ -0,0 +1,1210 @@
+/*!
+Generating SPIR-V for image operations.
+*/
+
+use super::{
+    selection::{MergeTuple, Selection},
+    Block, BlockContext, Error, IdGenerator, Instruction, LocalType, LookupType,
+};
+use crate::arena::Handle;
+use spirv::Word;
+
+/// Information about a vector of coordinates.
+///
+/// The coordinate vectors expected by SPIR-V `OpImageRead` and `OpImageFetch`
+/// supply the array index for arrayed images as an additional component at
+/// the end, whereas Naga's `ImageLoad`, `ImageStore`, and `ImageSample` carry
+/// the array index as a separate field.
+///
+/// In the process of generating code to compute the combined vector, we also
+/// produce SPIR-V types and vector lengths that are useful elsewhere. This
+/// struct gathers that information into one place, with standard names.
+struct ImageCoordinates {
+    /// The SPIR-V id of the combined coordinate/index vector value.
+    ///
+    /// Note: when indexing a non-arrayed 1D image, this will be a scalar.
+    value_id: Word,
+
+    /// The SPIR-V id of the type of `value`.
+    type_id: Word,
+
+    /// The number of components in `value`, if it is a vector, or `None` if it
+    /// is a scalar.
+    size: Option<crate::VectorSize>,
+}
+
+/// A trait for image access (load or store) code generators.
+///
+/// Types implementing this trait hold information about an `ImageStore` or
+/// `ImageLoad` operation that is not affected by the bounds check policy. The
+/// `generate` method emits code for the access, given the results of bounds
+/// checking.
+///
+/// The [`image`] bounds checks policy affects access coordinates, level of
+/// detail, and sample index, but never the image id, result type (if any), or
+/// the specific SPIR-V instruction used. Types that implement this trait gather
+/// together the latter category, so we don't have to plumb them through the
+/// bounds-checking code.
+///
+/// [`image`]: crate::proc::BoundsCheckPolicies::index
+trait Access {
+    /// The Rust type that represents SPIR-V values and types for this access.
+    ///
+    /// For operations like loads, this is `Word`. For operations like stores,
+    /// this is `()`.
+    ///
+    /// For `ReadZeroSkipWrite`, this will be the type of the selection
+    /// construct that performs the bounds checks, so it must implement
+    /// `MergeTuple`.
+    type Output: MergeTuple + Copy + Clone;
+
+    /// Write an image access to `block`.
+    ///
+    /// Access the texel at `coordinates_id`. The optional `level_id` indicates
+    /// the level of detail, and `sample_id` is the index of the sample to
+    /// access in a multisampled texel.
+    ///
+    /// This method assumes that `coordinates_id` has already had the image array
+    /// index, if any, folded in, as done by `write_image_coordinates`.
+    ///
+    /// Return the value id produced by the instruction, if any.
+    ///
+    /// Use `id_gen` to generate SPIR-V ids as necessary.
+    fn generate(
+        &self,
+        id_gen: &mut IdGenerator,
+        coordinates_id: Word,
+        level_id: Option<Word>,
+        sample_id: Option<Word>,
+        block: &mut Block,
+    ) -> Self::Output;
+
+    /// Return the SPIR-V type of the value produced by the code written by
+    /// `generate`. If the access does not produce a value, `Self::Output`
+    /// should be `()`.
+    fn result_type(&self) -> Self::Output;
+
+    /// Construct the SPIR-V 'zero' value to be returned for an out-of-bounds
+    /// access under the `ReadZeroSkipWrite` policy. If the access does not
+    /// produce a value, `Self::Output` should be `()`.
+    fn out_of_bounds_value(&self, ctx: &mut BlockContext<'_>) -> Self::Output;
+}
+
+/// Texel access information for an [`ImageLoad`] expression.
+///
+/// [`ImageLoad`]: crate::Expression::ImageLoad
+struct Load {
+    /// The specific opcode we'll use to perform the fetch. Storage images
+    /// require `OpImageRead`, while sampled images require `OpImageFetch`.
+    opcode: spirv::Op,
+
+    /// The type id produced by the actual image access instruction.
+    type_id: Word,
+
+    /// The id of the image being accessed.
+    image_id: Word,
+}
+
+impl Load {
+    fn from_image_expr(
+        ctx: &mut BlockContext<'_>,
+        image_id: Word,
+        image_class: crate::ImageClass,
+        result_type_id: Word,
+    ) -> Result<Load, Error> {
+        let opcode = match image_class {
+            crate::ImageClass::Storage { .. } => spirv::Op::ImageRead,
+            crate::ImageClass::Depth { .. } | crate::ImageClass::Sampled { .. } => {
+                spirv::Op::ImageFetch
+            }
+        };
+
+        // `OpImageRead` and `OpImageFetch` instructions produce vec4<f32>
+        // values. Most of the time, we can just use `result_type_id` for
+        // this. The exception is that `Expression::ImageLoad` from a depth
+        // image produces a scalar `f32`, so in that case we need to find
+        // the right SPIR-V type for the access instruction here.
+        let type_id = match image_class {
+            crate::ImageClass::Depth { .. } => {
+                ctx.get_type_id(LookupType::Local(LocalType::Value {
+                    vector_size: Some(crate::VectorSize::Quad),
+                    scalar: crate::Scalar::F32,
+                    pointer_space: None,
+                }))
+            }
+            _ => result_type_id,
+        };
+
+        Ok(Load {
+            opcode,
+            type_id,
+            image_id,
+        })
+    }
+}
+
+impl Access for Load {
+    type Output = Word;
+
+    /// Write an instruction to access a given texel of this image.
+    fn generate(
+        &self,
+        id_gen: &mut IdGenerator,
+        coordinates_id: Word,
+        level_id: Option<Word>,
+        sample_id: Option<Word>,
+        block: &mut Block,
+    ) -> Word {
+        let texel_id = id_gen.next();
+        let mut instruction = Instruction::image_fetch_or_read(
+            self.opcode,
+            self.type_id,
+            texel_id,
+            self.image_id,
+            coordinates_id,
+        );
+
+        match (level_id, sample_id) {
+            (None, None) => {}
+            (Some(level_id), None) => {
+                instruction.add_operand(spirv::ImageOperands::LOD.bits());
+                instruction.add_operand(level_id);
+            }
+            (None, Some(sample_id)) => {
+                instruction.add_operand(spirv::ImageOperands::SAMPLE.bits());
+                instruction.add_operand(sample_id);
+            }
+            // There's no such thing as a multi-sampled mipmap.
+            (Some(_), Some(_)) => unreachable!(),
+        }
+
+        block.body.push(instruction);
+
+        texel_id
+    }
+
+    fn result_type(&self) -> Word {
+        self.type_id
+    }
+
+    fn out_of_bounds_value(&self, ctx: &mut BlockContext<'_>) -> Word {
+        ctx.writer.get_constant_null(self.type_id)
+    }
+}
+
+/// Texel access information for a [`Store`] statement.
+///
+/// [`Store`]: crate::Statement::Store
+struct Store {
+    /// The id of the image being written to.
+    image_id: Word,
+
+    /// The value we're going to write to the texel.
+    value_id: Word,
+}
+
+impl Access for Store {
+    /// Stores don't generate any value.
+    type Output = ();
+
+    fn generate(
+        &self,
+        _id_gen: &mut IdGenerator,
+        coordinates_id: Word,
+        _level_id: Option<Word>,
+        _sample_id: Option<Word>,
+        block: &mut Block,
+    ) {
+        block.body.push(Instruction::image_write(
+            self.image_id,
+            coordinates_id,
+            self.value_id,
+        ));
+    }
+
+    /// Stores don't generate any value, so this just returns `()`.
+    fn result_type(&self) {}
+
+    /// Stores don't generate any value, so this just returns `()`.
+    fn out_of_bounds_value(&self, _ctx: &mut BlockContext<'_>) {}
+}
+
+impl<'w> BlockContext<'w> {
+    /// Extend image coordinates with an array index, if necessary.
+    ///
+    /// Whereas [`Expression::ImageLoad`] and [`ImageSample`] treat the array
+    /// index as a separate operand from the coordinates, SPIR-V image access
+    /// instructions include the array index in the `coordinates` operand. This
+    /// function builds a SPIR-V coordinate vector from a Naga coordinate vector
+    /// and array index, if one is supplied, and returns a `ImageCoordinates`
+    /// struct describing what it built.
+    ///
+    /// If `array_index` is `Some(expr)`, then this function constructs a new
+    /// vector that is `coordinates` with `array_index` concatenated onto the
+    /// end: a `vec2` becomes a `vec3`, a scalar becomes a `vec2`, and so on.
+    ///
+    /// If `array_index` is `None`, then the return value uses `coordinates`
+    /// unchanged. Note that, when indexing a non-arrayed 1D image, this will be
+    /// a scalar value.
+    ///
+    /// If needed, this function generates code to convert the array index,
+    /// always an integer scalar, to match the component type of `coordinates`.
+    /// Naga's `ImageLoad` and SPIR-V's `OpImageRead`, `OpImageFetch`, and
+    /// `OpImageWrite` all use integer coordinates, while Naga's `ImageSample`
+    /// and SPIR-V's `OpImageSample...` instructions all take floating-point
+    /// coordinate vectors.
+    ///
+    /// [`Expression::ImageLoad`]: crate::Expression::ImageLoad
+    /// [`ImageSample`]: crate::Expression::ImageSample
+    fn write_image_coordinates(
+        &mut self,
+        coordinates: Handle<crate::Expression>,
+        array_index: Option<Handle<crate::Expression>>,
+        block: &mut Block,
+    ) -> Result<ImageCoordinates, Error> {
+        use crate::TypeInner as Ti;
+        use crate::VectorSize as Vs;
+
+        let coordinates_id = self.cached[coordinates];
+        let ty = &self.fun_info[coordinates].ty;
+        let inner_ty = ty.inner_with(&self.ir_module.types);
+
+        // If there's no array index, the image coordinates are exactly the
+        // `coordinate` field of the `Expression::ImageLoad`. No work is needed.
+        let array_index = match array_index {
+            None => {
+                let value_id = coordinates_id;
+                let type_id = self.get_expression_type_id(ty);
+                let size = match *inner_ty {
+                    Ti::Scalar { .. } => None,
+                    Ti::Vector { size, .. } => Some(size),
+                    _ => return Err(Error::Validation("coordinate type")),
+                };
+                return Ok(ImageCoordinates {
+                    value_id,
+                    type_id,
+                    size,
+                });
+            }
+            Some(ix) => ix,
+        };
+
+        // Find the component type of `coordinates`, and figure out the size the
+        // combined coordinate vector will have.
+        let (component_scalar, size) = match *inner_ty {
+            Ti::Scalar(scalar @ crate::Scalar { width: 4, .. }) => (scalar, Some(Vs::Bi)),
+            Ti::Vector {
+                scalar: scalar @ crate::Scalar { width: 4, .. },
+                size: Vs::Bi,
+            } => (scalar, Some(Vs::Tri)),
+            Ti::Vector {
+                scalar: scalar @ crate::Scalar { width: 4, .. },
+                size: Vs::Tri,
+            } => (scalar, Some(Vs::Quad)),
+            Ti::Vector { size: Vs::Quad, .. } => {
+                return Err(Error::Validation("extending vec4 coordinate"));
+            }
+            ref other => {
+                log::error!("wrong coordinate type {:?}", other);
+                return Err(Error::Validation("coordinate type"));
+            }
+        };
+
+        // Convert the index to the coordinate component type, if necessary.
+        let array_index_id = self.cached[array_index];
+        let ty = &self.fun_info[array_index].ty;
+        let inner_ty = ty.inner_with(&self.ir_module.types);
+        let array_index_scalar = match *inner_ty {
+            Ti::Scalar(
+                scalar @ crate::Scalar {
+                    kind: crate::ScalarKind::Sint | crate::ScalarKind::Uint,
+                    width: 4,
+                },
+            ) => scalar,
+            _ => unreachable!("we only allow i32 and u32"),
+        };
+        let cast = match (component_scalar.kind, array_index_scalar.kind) {
+            (crate::ScalarKind::Sint, crate::ScalarKind::Sint)
+            | (crate::ScalarKind::Uint, crate::ScalarKind::Uint) => None,
+            (crate::ScalarKind::Sint, crate::ScalarKind::Uint)
+            | (crate::ScalarKind::Uint, crate::ScalarKind::Sint) => Some(spirv::Op::Bitcast),
+            (crate::ScalarKind::Float, crate::ScalarKind::Sint) => Some(spirv::Op::ConvertSToF),
+            (crate::ScalarKind::Float, crate::ScalarKind::Uint) => Some(spirv::Op::ConvertUToF),
+            (crate::ScalarKind::Bool, _) => unreachable!("we don't allow bool for component"),
+            (_, crate::ScalarKind::Bool | crate::ScalarKind::Float) => {
+                unreachable!("we don't allow bool or float for array index")
+            }
+            (crate::ScalarKind::AbstractInt | crate::ScalarKind::AbstractFloat, _)
+            | (_, crate::ScalarKind::AbstractInt | crate::ScalarKind::AbstractFloat) => {
+                unreachable!("abstract types should never reach backends")
+            }
+        };
+        let reconciled_array_index_id = if let Some(cast) = cast {
+            let component_ty_id = self.get_type_id(LookupType::Local(LocalType::Value {
+                vector_size: None,
+                scalar: component_scalar,
+                pointer_space: None,
+            }));
+            let reconciled_id = self.gen_id();
+            block.body.push(Instruction::unary(
+                cast,
+                component_ty_id,
+                reconciled_id,
+                array_index_id,
+            ));
+            reconciled_id
+        } else {
+            array_index_id
+        };
+
+        // Find the SPIR-V type for the combined coordinates/index vector.
+        let type_id = self.get_type_id(LookupType::Local(LocalType::Value {
+            vector_size: size,
+            scalar: component_scalar,
+            pointer_space: None,
+        }));
+
+        // Schmear the coordinates and index together.
+        let value_id = self.gen_id();
+        block.body.push(Instruction::composite_construct(
+            type_id,
+            value_id,
+            &[coordinates_id, reconciled_array_index_id],
+        ));
+        Ok(ImageCoordinates {
+            value_id,
+            type_id,
+            size,
+        })
+    }
+
+    pub(super) fn get_handle_id(&mut self, expr_handle: Handle<crate::Expression>) -> Word {
+        let id = match self.ir_function.expressions[expr_handle] {
+            crate::Expression::GlobalVariable(handle) => {
+                self.writer.global_variables[handle.index()].handle_id
+            }
+            crate::Expression::FunctionArgument(i) => {
+                self.function.parameters[i as usize].handle_id
+            }
+            crate::Expression::Access { .. } | crate::Expression::AccessIndex { .. } => {
+                self.cached[expr_handle]
+            }
+            ref other => unreachable!("Unexpected image expression {:?}", other),
+        };
+
+        if id == 0 {
+            unreachable!(
+                "Image expression {:?} doesn't have a handle ID",
+                expr_handle
+            );
+        }
+
+        id
+    }
+
+    /// Generate a vector or scalar 'one' for arithmetic on `coordinates`.
+    ///
+    /// If `coordinates` is a scalar, return a scalar one. Otherwise, return
+    /// a vector of ones.
+    fn write_coordinate_one(&mut self, coordinates: &ImageCoordinates) -> Result<Word, Error> {
+        let one = self.get_scope_constant(1);
+        match coordinates.size {
+            None => Ok(one),
+            Some(vector_size) => {
+                let ones = [one; 4];
+                let id = self.gen_id();
+                Instruction::constant_composite(
+                    coordinates.type_id,
+                    id,
+                    &ones[..vector_size as usize],
+                )
+                .to_words(&mut self.writer.logical_layout.declarations);
+                Ok(id)
+            }
+        }
+    }
+
+    /// Generate code to restrict `input` to fall between zero and one less than
+    /// `size_id`.
+    ///
+    /// Both must be 32-bit scalar integer values, whose type is given by
+    /// `type_id`. The computed value is also of type `type_id`.
+    fn restrict_scalar(
+        &mut self,
+        type_id: Word,
+        input_id: Word,
+        size_id: Word,
+        block: &mut Block,
+    ) -> Result<Word, Error> {
+        let i32_one_id = self.get_scope_constant(1);
+
+        // Subtract one from `size` to get the largest valid value.
+        let limit_id = self.gen_id();
+        block.body.push(Instruction::binary(
+            spirv::Op::ISub,
+            type_id,
+            limit_id,
+            size_id,
+            i32_one_id,
+        ));
+
+        // Use an unsigned minimum, to handle both positive out-of-range values
+        // and negative values in a single instruction: negative values of
+        // `input_id` get treated as very large positive values.
+        let restricted_id = self.gen_id();
+        block.body.push(Instruction::ext_inst(
+            self.writer.gl450_ext_inst_id,
+            spirv::GLOp::UMin,
+            type_id,
+            restricted_id,
+            &[input_id, limit_id],
+        ));
+
+        Ok(restricted_id)
+    }
+
+    /// Write instructions to query the size of an image.
+    ///
+    /// This takes care of selecting the right instruction depending on whether
+    /// a level of detail parameter is present.
+    fn write_coordinate_bounds(
+        &mut self,
+        type_id: Word,
+        image_id: Word,
+        level_id: Option<Word>,
+        block: &mut Block,
+    ) -> Word {
+        let coordinate_bounds_id = self.gen_id();
+        match level_id {
+            Some(level_id) => {
+                // A level of detail was provided, so fetch the image size for
+                // that level.
+                let mut inst = Instruction::image_query(
+                    spirv::Op::ImageQuerySizeLod,
+                    type_id,
+                    coordinate_bounds_id,
+                    image_id,
+                );
+                inst.add_operand(level_id);
+                block.body.push(inst);
+            }
+            _ => {
+                // No level of detail was given.
+                block.body.push(Instruction::image_query(
+                    spirv::Op::ImageQuerySize,
+                    type_id,
+                    coordinate_bounds_id,
+                    image_id,
+                ));
+            }
+        }
+
+        coordinate_bounds_id
+    }
+
+    /// Write code to restrict coordinates for an image reference.
+    ///
+    /// First, clamp the level of detail or sample index to fall within bounds.
+    /// Then, obtain the image size, possibly using the clamped level of detail.
+    /// Finally, use an unsigned minimum instruction to force all coordinates
+    /// into range.
+    ///
+    /// Return a triple `(COORDS, LEVEL, SAMPLE)`, where `COORDS` is a coordinate
+    /// vector (including the array index, if any), `LEVEL` is an optional level
+    /// of detail, and `SAMPLE` is an optional sample index, all guaranteed to
+    /// be in-bounds for `image_id`.
+    ///
+    /// The result is usually a vector, but it is a scalar when indexing
+    /// non-arrayed 1D images.
+    fn write_restricted_coordinates(
+        &mut self,
+        image_id: Word,
+        coordinates: ImageCoordinates,
+        level_id: Option<Word>,
+        sample_id: Option<Word>,
+        block: &mut Block,
+    ) -> Result<(Word, Option<Word>, Option<Word>), Error> {
+        self.writer.require_any(
+            "the `Restrict` image bounds check policy",
+            &[spirv::Capability::ImageQuery],
+        )?;
+
+        let i32_type_id = self.get_type_id(LookupType::Local(LocalType::Value {
+            vector_size: None,
+            scalar: crate::Scalar::I32,
+            pointer_space: None,
+        }));
+
+        // If `level` is `Some`, clamp it to fall within bounds. This must
+        // happen first, because we'll use it to query the image size for
+        // clamping the actual coordinates.
+        let level_id = level_id
+            .map(|level_id| {
+                // Find the number of mipmap levels in this image.
+                let num_levels_id = self.gen_id();
+                block.body.push(Instruction::image_query(
+                    spirv::Op::ImageQueryLevels,
+                    i32_type_id,
+                    num_levels_id,
+                    image_id,
+                ));
+
+                self.restrict_scalar(i32_type_id, level_id, num_levels_id, block)
+            })
+            .transpose()?;
+
+        // If `sample_id` is `Some`, clamp it to fall within bounds.
+        let sample_id = sample_id
+            .map(|sample_id| {
+                // Find the number of samples per texel.
+                let num_samples_id = self.gen_id();
+                block.body.push(Instruction::image_query(
+                    spirv::Op::ImageQuerySamples,
+                    i32_type_id,
+                    num_samples_id,
+                    image_id,
+                ));
+
+                self.restrict_scalar(i32_type_id, sample_id, num_samples_id, block)
+            })
+            .transpose()?;
+
+        // Obtain the image bounds, including the array element count.
+        let coordinate_bounds_id =
+            self.write_coordinate_bounds(coordinates.type_id, image_id, level_id, block);
+
+        // Compute maximum valid values from the bounds.
+        let ones = self.write_coordinate_one(&coordinates)?;
+        let coordinate_limit_id = self.gen_id();
+        block.body.push(Instruction::binary(
+            spirv::Op::ISub,
+            coordinates.type_id,
+            coordinate_limit_id,
+            coordinate_bounds_id,
+            ones,
+        ));
+
+        // Restrict the coordinates to fall within those bounds.
+        //
+        // Use an unsigned minimum, to handle both positive out-of-range values
+        // and negative values in a single instruction: negative values of
+        // `coordinates` get treated as very large positive values.
+        let restricted_coordinates_id = self.gen_id();
+        block.body.push(Instruction::ext_inst(
+            self.writer.gl450_ext_inst_id,
+            spirv::GLOp::UMin,
+            coordinates.type_id,
+            restricted_coordinates_id,
+            &[coordinates.value_id, coordinate_limit_id],
+        ));
+
+        Ok((restricted_coordinates_id, level_id, sample_id))
+    }
+
+    fn write_conditional_image_access<A: Access>(
+        &mut self,
+        image_id: Word,
+        coordinates: ImageCoordinates,
+        level_id: Option<Word>,
+        sample_id: Option<Word>,
+        block: &mut Block,
+        access: &A,
+    ) -> Result<A::Output, Error> {
+        self.writer.require_any(
+            "the `ReadZeroSkipWrite` image bounds check policy",
+            &[spirv::Capability::ImageQuery],
+        )?;
+
+        let bool_type_id = self.writer.get_bool_type_id();
+        let i32_type_id = self.get_type_id(LookupType::Local(LocalType::Value {
+            vector_size: None,
+            scalar: crate::Scalar::I32,
+            pointer_space: None,
+        }));
+
+        let null_id = access.out_of_bounds_value(self);
+
+        let mut selection = Selection::start(block, access.result_type());
+
+        // If `level_id` is `Some`, check whether it is within bounds. This must
+        // happen first, because we'll be supplying this as an argument when we
+        // query the image size.
+        if let Some(level_id) = level_id {
+            // Find the number of mipmap levels in this image.
+            let num_levels_id = self.gen_id();
+            selection.block().body.push(Instruction::image_query(
+                spirv::Op::ImageQueryLevels,
+                i32_type_id,
+                num_levels_id,
+                image_id,
+            ));
+
+            let lod_cond_id = self.gen_id();
+            selection.block().body.push(Instruction::binary(
+                spirv::Op::ULessThan,
+                bool_type_id,
+                lod_cond_id,
+                level_id,
+                num_levels_id,
+            ));
+
+            selection.if_true(self, lod_cond_id, null_id);
+        }
+
+        // If `sample_id` is `Some`, check whether it is in bounds.
+        if let Some(sample_id) = sample_id {
+            // Find the number of samples per texel.
+            let num_samples_id = self.gen_id();
+            selection.block().body.push(Instruction::image_query(
+                spirv::Op::ImageQuerySamples,
+                i32_type_id,
+                num_samples_id,
+                image_id,
+            ));
+
+            let samples_cond_id = self.gen_id();
+            selection.block().body.push(Instruction::binary(
+                spirv::Op::ULessThan,
+                bool_type_id,
+                samples_cond_id,
+                sample_id,
+                num_samples_id,
+            ));
+
+            selection.if_true(self, samples_cond_id, null_id);
+        }
+
+        // Obtain the image bounds, including any array element count.
+        let coordinate_bounds_id = self.write_coordinate_bounds(
+            coordinates.type_id,
+            image_id,
+            level_id,
+            selection.block(),
+        );
+
+        // Compare the coordinates against the bounds.
+        let coords_bool_type_id = self.get_type_id(LookupType::Local(LocalType::Value {
+            vector_size: coordinates.size,
+            scalar: crate::Scalar::BOOL,
+            pointer_space: None,
+        }));
+        let coords_conds_id = self.gen_id();
+        selection.block().body.push(Instruction::binary(
+            spirv::Op::ULessThan,
+            coords_bool_type_id,
+            coords_conds_id,
+            coordinates.value_id,
+            coordinate_bounds_id,
+        ));
+
+        // If the comparison above was a vector comparison, then we need to
+        // check that all components of the comparison are true.
+        let coords_cond_id = if coords_bool_type_id != bool_type_id {
+            let id = self.gen_id();
+            selection.block().body.push(Instruction::relational(
+                spirv::Op::All,
+                bool_type_id,
+                id,
+                coords_conds_id,
+            ));
+            id
+        } else {
+            coords_conds_id
+        };
+
+        selection.if_true(self, coords_cond_id, null_id);
+
+        // All conditions are met. We can carry out the access.
+        let texel_id = access.generate(
+            &mut self.writer.id_gen,
+            coordinates.value_id,
+            level_id,
+            sample_id,
+            selection.block(),
+        );
+
+        // This, then, is the value of the 'true' branch.
+        Ok(selection.finish(self, texel_id))
+    }
+
+    /// Generate code for an `ImageLoad` expression.
+    ///
+    /// The arguments are the components of an `Expression::ImageLoad` variant.
+    #[allow(clippy::too_many_arguments)]
+    pub(super) fn write_image_load(
+        &mut self,
+        result_type_id: Word,
+        image: Handle<crate::Expression>,
+        coordinate: Handle<crate::Expression>,
+        array_index: Option<Handle<crate::Expression>>,
+        level: Option<Handle<crate::Expression>>,
+        sample: Option<Handle<crate::Expression>>,
+        block: &mut Block,
+    ) -> Result<Word, Error> {
+        let image_id = self.get_handle_id(image);
+        let image_type = self.fun_info[image].ty.inner_with(&self.ir_module.types);
+        let image_class = match *image_type {
+            crate::TypeInner::Image { class, .. } => class,
+            _ => return Err(Error::Validation("image type")),
+        };
+
+        let access = Load::from_image_expr(self, image_id, image_class, result_type_id)?;
+        let coordinates = self.write_image_coordinates(coordinate, array_index, block)?;
+
+        let level_id = level.map(|expr| self.cached[expr]);
+        let sample_id = sample.map(|expr| self.cached[expr]);
+
+        // Perform the access, according to the bounds check policy.
+        let access_id = match self.writer.bounds_check_policies.image_load {
+            crate::proc::BoundsCheckPolicy::Restrict => {
+                let (coords, level_id, sample_id) = self.write_restricted_coordinates(
+                    image_id,
+                    coordinates,
+                    level_id,
+                    sample_id,
+                    block,
+                )?;
+                access.generate(&mut self.writer.id_gen, coords, level_id, sample_id, block)
+            }
+            crate::proc::BoundsCheckPolicy::ReadZeroSkipWrite => self
+                .write_conditional_image_access(
+                    image_id,
+                    coordinates,
+                    level_id,
+                    sample_id,
+                    block,
+                    &access,
+                )?,
+            crate::proc::BoundsCheckPolicy::Unchecked => access.generate(
+                &mut self.writer.id_gen,
+                coordinates.value_id,
+                level_id,
+                sample_id,
+                block,
+            ),
+        };
+
+        // For depth images, `ImageLoad` expressions produce a single f32,
+        // whereas the SPIR-V instructions always produce a vec4. So we may have
+        // to pull out the component we need.
+        let result_id = if result_type_id == access.result_type() {
+            // The instruction produced the type we expected. We can use
+            // its result as-is.
+            access_id
+        } else {
+            // For `ImageClass::Depth` images, SPIR-V gave us four components,
+            // but we only want the first one.
+            let component_id = self.gen_id();
+            block.body.push(Instruction::composite_extract(
+                result_type_id,
+                component_id,
+                access_id,
+                &[0],
+            ));
+            component_id
+        };
+
+        Ok(result_id)
+    }
+
+    /// Generate code for an `ImageSample` expression.
+    ///
+    /// The arguments are the components of an `Expression::ImageSample` variant.
+    #[allow(clippy::too_many_arguments)]
+    pub(super) fn write_image_sample(
+        &mut self,
+        result_type_id: Word,
+        image: Handle<crate::Expression>,
+        sampler: Handle<crate::Expression>,
+        gather: Option<crate::SwizzleComponent>,
+        coordinate: Handle<crate::Expression>,
+        array_index: Option<Handle<crate::Expression>>,
+        offset: Option<Handle<crate::Expression>>,
+        level: crate::SampleLevel,
+        depth_ref: Option<Handle<crate::Expression>>,
+        block: &mut Block,
+    ) -> Result<Word, Error> {
+        use super::instructions::SampleLod;
+        // image
+        let image_id = self.get_handle_id(image);
+        let image_type = self.fun_info[image].ty.handle().unwrap();
+        // SPIR-V doesn't know about our `Depth` class, and it returns
+        // `vec4<f32>`, so we need to grab the first component out of it.
+        let needs_sub_access = match self.ir_module.types[image_type].inner {
+            crate::TypeInner::Image {
+                class: crate::ImageClass::Depth { .. },
+                ..
+            } => depth_ref.is_none() && gather.is_none(),
+            _ => false,
+        };
+        let sample_result_type_id = if needs_sub_access {
+            self.get_type_id(LookupType::Local(LocalType::Value {
+                vector_size: Some(crate::VectorSize::Quad),
+                scalar: crate::Scalar::F32,
+                pointer_space: None,
+            }))
+        } else {
+            result_type_id
+        };
+
+        // OpTypeSampledImage
+        let image_type_id = self.get_type_id(LookupType::Handle(image_type));
+        let sampled_image_type_id =
+            self.get_type_id(LookupType::Local(LocalType::SampledImage { image_type_id }));
+
+        let sampler_id = self.get_handle_id(sampler);
+        let coordinates_id = self
+            .write_image_coordinates(coordinate, array_index, block)?
+            .value_id;
+
+        let sampled_image_id = self.gen_id();
+        block.body.push(Instruction::sampled_image(
+            sampled_image_type_id,
+            sampled_image_id,
+            image_id,
+            sampler_id,
+        ));
+        let id = self.gen_id();
+
+        let depth_id = depth_ref.map(|handle| self.cached[handle]);
+        let mut mask = spirv::ImageOperands::empty();
+        mask.set(spirv::ImageOperands::CONST_OFFSET, offset.is_some());
+
+        let mut main_instruction = match (level, gather) {
+            (_, Some(component)) => {
+                let component_id = self.get_index_constant(component as u32);
+                let mut inst = Instruction::image_gather(
+                    sample_result_type_id,
+                    id,
+                    sampled_image_id,
+                    coordinates_id,
+                    component_id,
+                    depth_id,
+                );
+                if !mask.is_empty() {
+                    inst.add_operand(mask.bits());
+                }
+                inst
+            }
+            (crate::SampleLevel::Zero, None) => {
+                let mut inst = Instruction::image_sample(
+                    sample_result_type_id,
+                    id,
+                    SampleLod::Explicit,
+                    sampled_image_id,
+                    coordinates_id,
+                    depth_id,
+                );
+
+                let zero_id = self.writer.get_constant_scalar(crate::Literal::F32(0.0));
+
+                mask |= spirv::ImageOperands::LOD;
+                inst.add_operand(mask.bits());
+                inst.add_operand(zero_id);
+
+                inst
+            }
+            (crate::SampleLevel::Auto, None) => {
+                let mut inst = Instruction::image_sample(
+                    sample_result_type_id,
+                    id,
+                    SampleLod::Implicit,
+                    sampled_image_id,
+                    coordinates_id,
+                    depth_id,
+                );
+                if !mask.is_empty() {
+                    inst.add_operand(mask.bits());
+                }
+                inst
+            }
+            (crate::SampleLevel::Exact(lod_handle), None) => {
+                let mut inst = Instruction::image_sample(
+                    sample_result_type_id,
+                    id,
+                    SampleLod::Explicit,
+                    sampled_image_id,
+                    coordinates_id,
+                    depth_id,
+                );
+
+                let lod_id = self.cached[lod_handle];
+                mask |= spirv::ImageOperands::LOD;
+                inst.add_operand(mask.bits());
+                inst.add_operand(lod_id);
+
+                inst
+            }
+            (crate::SampleLevel::Bias(bias_handle), None) => {
+                let mut inst = Instruction::image_sample(
+                    sample_result_type_id,
+                    id,
+                    SampleLod::Implicit,
+                    sampled_image_id,
+                    coordinates_id,
+                    depth_id,
+                );
+
+                let bias_id = self.cached[bias_handle];
+                mask |= spirv::ImageOperands::BIAS;
+                inst.add_operand(mask.bits());
+                inst.add_operand(bias_id);
+
+                inst
+            }
+            (crate::SampleLevel::Gradient { x, y }, None) => {
+                let mut inst = Instruction::image_sample(
+                    sample_result_type_id,
+                    id,
+                    SampleLod::Explicit,
+                    sampled_image_id,
+                    coordinates_id,
+                    depth_id,
+                );
+
+                let x_id = self.cached[x];
+                let y_id = self.cached[y];
+                mask |= spirv::ImageOperands::GRAD;
+                inst.add_operand(mask.bits());
+                inst.add_operand(x_id);
+                inst.add_operand(y_id);
+
+                inst
+            }
+        };
+
+        if let Some(offset_const) = offset {
+            let offset_id = self.writer.constant_ids[offset_const.index()];
+            main_instruction.add_operand(offset_id);
+        }
+
+        block.body.push(main_instruction);
+
+        let id = if needs_sub_access {
+            let sub_id = self.gen_id();
+            block.body.push(Instruction::composite_extract(
+                result_type_id,
+                sub_id,
+                id,
+                &[0],
+            ));
+            sub_id
+        } else {
+            id
+        };
+
+        Ok(id)
+    }
+
+    /// Generate code for an `ImageQuery` expression.
+    ///
+    /// The arguments are the components of an `Expression::ImageQuery` variant.
+    pub(super) fn write_image_query(
+        &mut self,
+        result_type_id: Word,
+        image: Handle<crate::Expression>,
+        query: crate::ImageQuery,
+        block: &mut Block,
+    ) -> Result<Word, Error> {
+        use crate::{ImageClass as Ic, ImageDimension as Id, ImageQuery as Iq};
+
+        let image_id = self.get_handle_id(image);
+        let image_type = self.fun_info[image].ty.handle().unwrap();
+        let (dim, arrayed, class) = match self.ir_module.types[image_type].inner {
+            crate::TypeInner::Image {
+                dim,
+                arrayed,
+                class,
+            } => (dim, arrayed, class),
+            _ => {
+                return Err(Error::Validation("image type"));
+            }
+        };
+
+        self.writer
+            .require_any("image queries", &[spirv::Capability::ImageQuery])?;
+
+        let id = match query {
+            Iq::Size { level } => {
+                let dim_coords = match dim {
+                    Id::D1 => 1,
+                    Id::D2 | Id::Cube => 2,
+                    Id::D3 => 3,
+                };
+                let array_coords = usize::from(arrayed);
+                let vector_size = match dim_coords + array_coords {
+                    2 => Some(crate::VectorSize::Bi),
+                    3 => Some(crate::VectorSize::Tri),
+                    4 => Some(crate::VectorSize::Quad),
+                    _ => None,
+                };
+                let extended_size_type_id = self.get_type_id(LookupType::Local(LocalType::Value {
+                    vector_size,
+                    scalar: crate::Scalar::U32,
+                    pointer_space: None,
+                }));
+
+                let (query_op, level_id) = match class {
+                    Ic::Sampled { multi: true, .. }
+                    | Ic::Depth { multi: true }
+                    | Ic::Storage { .. } => (spirv::Op::ImageQuerySize, None),
+                    _ => {
+                        let level_id = match level {
+                            Some(expr) => self.cached[expr],
+                            None => self.get_index_constant(0),
+                        };
+                        (spirv::Op::ImageQuerySizeLod, Some(level_id))
+                    }
+                };
+
+                // The ID of the vector returned by SPIR-V, which contains the dimensions
+                // as well as the layer count.
+                let id_extended = self.gen_id();
+                let mut inst = Instruction::image_query(
+                    query_op,
+                    extended_size_type_id,
+                    id_extended,
+                    image_id,
+                );
+                if let Some(expr_id) = level_id {
+                    inst.add_operand(expr_id);
+                }
+                block.body.push(inst);
+
+                if result_type_id != extended_size_type_id {
+                    let id = self.gen_id();
+                    let components = match dim {
+                        // always pick the first component, and duplicate it for all 3 dimensions
+                        Id::Cube => &[0u32, 0][..],
+                        _ => &[0u32, 1, 2, 3][..dim_coords],
+                    };
+                    block.body.push(Instruction::vector_shuffle(
+                        result_type_id,
+                        id,
+                        id_extended,
+                        id_extended,
+                        components,
+                    ));
+
+                    id
+                } else {
+                    id_extended
+                }
+            }
+            Iq::NumLevels => {
+                let query_id = self.gen_id();
+                block.body.push(Instruction::image_query(
+                    spirv::Op::ImageQueryLevels,
+                    result_type_id,
+                    query_id,
+                    image_id,
+                ));
+
+                query_id
+            }
+            Iq::NumLayers => {
+                let vec_size = match dim {
+                    Id::D1 => crate::VectorSize::Bi,
+                    Id::D2 | Id::Cube => crate::VectorSize::Tri,
+                    Id::D3 => crate::VectorSize::Quad,
+                };
+                let extended_size_type_id = self.get_type_id(LookupType::Local(LocalType::Value {
+                    vector_size: Some(vec_size),
+                    scalar: crate::Scalar::U32,
+                    pointer_space: None,
+                }));
+                let id_extended = self.gen_id();
+                let mut inst = Instruction::image_query(
+                    spirv::Op::ImageQuerySizeLod,
+                    extended_size_type_id,
+                    id_extended,
+                    image_id,
+                );
+                inst.add_operand(self.get_index_constant(0));
+                block.body.push(inst);
+
+                let extract_id = self.gen_id();
+                block.body.push(Instruction::composite_extract(
+                    result_type_id,
+                    extract_id,
+                    id_extended,
+                    &[vec_size as u32 - 1],
+                ));
+
+                extract_id
+            }
+            Iq::NumSamples => {
+                let query_id = self.gen_id();
+                block.body.push(Instruction::image_query(
+                    spirv::Op::ImageQuerySamples,
+                    result_type_id,
+                    query_id,
+                    image_id,
+                ));
+
+                query_id
+            }
+        };
+
+        Ok(id)
+    }
+
+    pub(super) fn write_image_store(
+        &mut self,
+        image: Handle<crate::Expression>,
+        coordinate: Handle<crate::Expression>,
+        array_index: Option<Handle<crate::Expression>>,
+        value: Handle<crate::Expression>,
+        block: &mut Block,
+    ) -> Result<(), Error> {
+        let image_id = self.get_handle_id(image);
+        let coordinates = self.write_image_coordinates(coordinate, array_index, block)?;
+        let value_id = self.cached[value];
+
+        let write = Store { image_id, value_id };
+
+        match *self.fun_info[image].ty.inner_with(&self.ir_module.types) {
+            crate::TypeInner::Image {
+                class:
+                    crate::ImageClass::Storage {
+                        format: crate::StorageFormat::Bgra8Unorm,
+                        ..
+                    },
+                ..
+            } => self.writer.require_any(
+                "Bgra8Unorm storage write",
+                &[spirv::Capability::StorageImageWriteWithoutFormat],
+            )?,
+            _ => {}
+        }
+
+        match self.writer.bounds_check_policies.image_store {
+            crate::proc::BoundsCheckPolicy::Restrict => {
+                let (coords, _, _) =
+                    self.write_restricted_coordinates(image_id, coordinates, None, None, block)?;
+                write.generate(&mut self.writer.id_gen, coords, None, None, block);
+            }
+            crate::proc::BoundsCheckPolicy::ReadZeroSkipWrite => {
+                self.write_conditional_image_access(
+                    image_id,
+                    coordinates,
+                    None,
+                    None,
+                    block,
+                    &write,
+                )?;
+            }
+            crate::proc::BoundsCheckPolicy::Unchecked => {
+                write.generate(
+                    &mut self.writer.id_gen,
+                    coordinates.value_id,
+                    None,
+                    None,
+                    block,
+                );
+            }
+        }
+
+        Ok(())
+    }
+}
diff --git a/third_party/rust/naga/src/back/spv/index.rs b/third_party/rust/naga/src/back/spv/index.rs
new file mode 100644
index 0000000000..92e0f88d9a
--- /dev/null
+++ b/third_party/rust/naga/src/back/spv/index.rs
@@ -0,0 +1,421 @@
+/*!
+Bounds-checking for SPIR-V output.
+*/
+
+use super::{
+    helpers::global_needs_wrapper, selection::Selection, Block, BlockContext, Error, IdGenerator,
+    Instruction, Word,
+};
+use crate::{arena::Handle, proc::BoundsCheckPolicy};
+
+/// The results of performing a bounds check.
+///
+/// On success, `write_bounds_check` returns a value of this type.
+pub(super) enum BoundsCheckResult {
+    /// The index is statically known and in bounds, with the given value.
+    KnownInBounds(u32),
+
+    /// The given instruction computes the index to be used.
+    Computed(Word),
+
+    /// The given instruction computes a boolean condition which is true
+    /// if the index is in bounds.
+    Conditional(Word),
+}
+
+/// A value that we either know at translation time, or need to compute at runtime.
+pub(super) enum MaybeKnown<T> {
+    /// The value is known at shader translation time.
+    Known(T),
+
+    /// The value is computed by the instruction with the given id.
+    Computed(Word),
+}
+
+impl<'w> BlockContext<'w> {
+    /// Emit code to compute the length of a run-time array.
+    ///
+    /// Given `array`, an expression referring a runtime-sized array, return the
+    /// instruction id for the array's length.
+    pub(super) fn write_runtime_array_length(
+        &mut self,
+        array: Handle<crate::Expression>,
+        block: &mut Block,
+    ) -> Result<Word, Error> {
+        // Naga IR permits runtime-sized arrays as global variables or as the
+        // final member of a struct that is a global variable. SPIR-V permits
+        // only the latter, so this back end wraps bare runtime-sized arrays
+        // in a made-up struct; see `helpers::global_needs_wrapper` and its uses.
+        // This code must handle both cases.
+        let (structure_id, last_member_index) = match self.ir_function.expressions[array] {
+            crate::Expression::AccessIndex { base, index } => {
+                match self.ir_function.expressions[base] {
+                    crate::Expression::GlobalVariable(handle) => (
+                        self.writer.global_variables[handle.index()].access_id,
+                        index,
+                    ),
+                    _ => return Err(Error::Validation("array length expression")),
+                }
+            }
+            crate::Expression::GlobalVariable(handle) => {
+                let global = &self.ir_module.global_variables[handle];
+                if !global_needs_wrapper(self.ir_module, global) {
+                    return Err(Error::Validation("array length expression"));
+                }
+
+                (self.writer.global_variables[handle.index()].var_id, 0)
+            }
+            _ => return Err(Error::Validation("array length expression")),
+        };
+
+        let length_id = self.gen_id();
+        block.body.push(Instruction::array_length(
+            self.writer.get_uint_type_id(),
+            length_id,
+            structure_id,
+            last_member_index,
+        ));
+
+        Ok(length_id)
+    }
+
+    /// Compute the length of a subscriptable value.
+    ///
+    /// Given `sequence`, an expression referring to some indexable type, return
+    /// its length. The result may either be computed by SPIR-V instructions, or
+    /// known at shader translation time.
+    ///
+    /// `sequence` may be a `Vector`, `Matrix`, or `Array`, a `Pointer` to any
+    /// of those, or a `ValuePointer`. An array may be fixed-size, dynamically
+    /// sized, or use a specializable constant as its length.
+    fn write_sequence_length(
+        &mut self,
+        sequence: Handle<crate::Expression>,
+        block: &mut Block,
+    ) -> Result<MaybeKnown<u32>, Error> {
+        let sequence_ty = self.fun_info[sequence].ty.inner_with(&self.ir_module.types);
+        match sequence_ty.indexable_length(self.ir_module) {
+            Ok(crate::proc::IndexableLength::Known(known_length)) => {
+                Ok(MaybeKnown::Known(known_length))
+            }
+            Ok(crate::proc::IndexableLength::Dynamic) => {
+                let length_id = self.write_runtime_array_length(sequence, block)?;
+                Ok(MaybeKnown::Computed(length_id))
+            }
+            Err(err) => {
+                log::error!("Sequence length for {:?} failed: {}", sequence, err);
+                Err(Error::Validation("indexable length"))
+            }
+        }
+    }
+
+    /// Compute the maximum valid index of a subscriptable value.
+    ///
+    /// Given `sequence`, an expression referring to some indexable type, return
+    /// its maximum valid index - one less than its length. The result may
+    /// either be computed, or known at shader translation time.
+    ///
+    /// `sequence` may be a `Vector`, `Matrix`, or `Array`, a `Pointer` to any
+    /// of those, or a `ValuePointer`. An array may be fixed-size, dynamically
+    /// sized, or use a specializable constant as its length.
+    fn write_sequence_max_index(
+        &mut self,
+        sequence: Handle<crate::Expression>,
+        block: &mut Block,
+    ) -> Result<MaybeKnown<u32>, Error> {
+        match self.write_sequence_length(sequence, block)? {
+            MaybeKnown::Known(known_length) => {
+                // We should have thrown out all attempts to subscript zero-length
+                // sequences during validation, so the following subtraction should never
+                // underflow.
+                assert!(known_length > 0);
+                // Compute the max index from the length now.
+                Ok(MaybeKnown::Known(known_length - 1))
+            }
+            MaybeKnown::Computed(length_id) => {
+                // Emit code to compute the max index from the length.
+                let const_one_id = self.get_index_constant(1);
+                let max_index_id = self.gen_id();
+                block.body.push(Instruction::binary(
+                    spirv::Op::ISub,
+                    self.writer.get_uint_type_id(),
+                    max_index_id,
+                    length_id,
+                    const_one_id,
+                ));
+                Ok(MaybeKnown::Computed(max_index_id))
+            }
+        }
+    }
+
+    /// Restrict an index to be in range for a vector, matrix, or array.
+    ///
+    /// This is used to implement `BoundsCheckPolicy::Restrict`. An in-bounds
+    /// index is left unchanged. An out-of-bounds index is replaced with some
+    /// arbitrary in-bounds index. Note,this is not necessarily clamping; for
+    /// example, negative indices might be changed to refer to the last element
+    /// of the sequence, not the first, as clamping would do.
+    ///
+    /// Either return the restricted index value, if known, or add instructions
+    /// to `block` to compute it, and return the id of the result. See the
+    /// documentation for `BoundsCheckResult` for details.
+    ///
+    /// The `sequence` expression may be a `Vector`, `Matrix`, or `Array`, a
+    /// `Pointer` to any of those, or a `ValuePointer`. An array may be
+    /// fixed-size, dynamically sized, or use a specializable constant as its
+    /// length.
+    pub(super) fn write_restricted_index(
+        &mut self,
+        sequence: Handle<crate::Expression>,
+        index: Handle<crate::Expression>,
+        block: &mut Block,
+    ) -> Result<BoundsCheckResult, Error> {
+        let index_id = self.cached[index];
+
+        // Get the sequence's maximum valid index. Return early if we've already
+        // done the bounds check.
+        let max_index_id = match self.write_sequence_max_index(sequence, block)? {
+            MaybeKnown::Known(known_max_index) => {
+                if let Ok(known_index) = self
+                    .ir_module
+                    .to_ctx()
+                    .eval_expr_to_u32_from(index, &self.ir_function.expressions)
+                {
+                    // Both the index and length are known at compile time.
+                    //
+                    // In strict WGSL compliance mode, out-of-bounds indices cannot be
+                    // reported at shader translation time, and must be replaced with
+                    // in-bounds indices at run time. So we cannot assume that
+                    // validation ensured the index was in bounds. Restrict now.
+                    let restricted = std::cmp::min(known_index, known_max_index);
+                    return Ok(BoundsCheckResult::KnownInBounds(restricted));
+                }
+
+                self.get_index_constant(known_max_index)
+            }
+            MaybeKnown::Computed(max_index_id) => max_index_id,
+        };
+
+        // One or the other of the index or length is dynamic, so emit code for
+        // BoundsCheckPolicy::Restrict.
+        let restricted_index_id = self.gen_id();
+        block.body.push(Instruction::ext_inst(
+            self.writer.gl450_ext_inst_id,
+            spirv::GLOp::UMin,
+            self.writer.get_uint_type_id(),
+            restricted_index_id,
+            &[index_id, max_index_id],
+        ));
+        Ok(BoundsCheckResult::Computed(restricted_index_id))
+    }
+
+    /// Write an index bounds comparison to `block`, if needed.
+    ///
+    /// If we're able to determine statically that `index` is in bounds for
+    /// `sequence`, return `KnownInBounds(value)`, where `value` is the actual
+    /// value of the index. (In principle, one could know that the index is in
+    /// bounds without knowing its specific value, but in our simple-minded
+    /// situation, we always know it.)
+    ///
+    /// If instead we must generate code to perform the comparison at run time,
+    /// return `Conditional(comparison_id)`, where `comparison_id` is an
+    /// instruction producing a boolean value that is true if `index` is in
+    /// bounds for `sequence`.
+    ///
+    /// The `sequence` expression may be a `Vector`, `Matrix`, or `Array`, a
+    /// `Pointer` to any of those, or a `ValuePointer`. An array may be
+    /// fixed-size, dynamically sized, or use a specializable constant as its
+    /// length.
+    fn write_index_comparison(
+        &mut self,
+        sequence: Handle<crate::Expression>,
+        index: Handle<crate::Expression>,
+        block: &mut Block,
+    ) -> Result<BoundsCheckResult, Error> {
+        let index_id = self.cached[index];
+
+        // Get the sequence's length. Return early if we've already done the
+        // bounds check.
+        let length_id = match self.write_sequence_length(sequence, block)? {
+            MaybeKnown::Known(known_length) => {
+                if let Ok(known_index) = self
+                    .ir_module
+                    .to_ctx()
+                    .eval_expr_to_u32_from(index, &self.ir_function.expressions)
+                {
+                    // Both the index and length are known at compile time.
+                    //
+                    // It would be nice to assume that, since we are using the
+                    // `ReadZeroSkipWrite` policy, we are not in strict WGSL
+                    // compliance mode, and thus we can count on the validator to have
+                    // rejected any programs with known out-of-bounds indices, and
+                    // thus just return `KnownInBounds` here without actually
+                    // checking.
+                    //
+                    // But it's also reasonable to expect that bounds check policies
+                    // and error reporting policies should be able to vary
+                    // independently without introducing security holes. So, we should
+                    // support the case where bad indices do not cause validation
+                    // errors, and are handled via `ReadZeroSkipWrite`.
+                    //
+                    // In theory, when `known_index` is bad, we could return a new
+                    // `KnownOutOfBounds` variant here. But it's simpler just to fall
+                    // through and let the bounds check take place. The shader is
+                    // broken anyway, so it doesn't make sense to invest in emitting
+                    // the ideal code for it.
+                    if known_index < known_length {
+                        return Ok(BoundsCheckResult::KnownInBounds(known_index));
+                    }
+                }
+
+                self.get_index_constant(known_length)
+            }
+            MaybeKnown::Computed(length_id) => length_id,
+        };
+
+        // Compare the index against the length.
+        let condition_id = self.gen_id();
+        block.body.push(Instruction::binary(
+            spirv::Op::ULessThan,
+            self.writer.get_bool_type_id(),
+            condition_id,
+            index_id,
+            length_id,
+        ));
+
+        // Indicate that we did generate the check.
+        Ok(BoundsCheckResult::Conditional(condition_id))
+    }
+
+    /// Emit a conditional load for `BoundsCheckPolicy::ReadZeroSkipWrite`.
+    ///
+    /// Generate code to load a value of `result_type` if `condition` is true,
+    /// and generate a null value of that type if it is false. Call `emit_load`
+    /// to emit the instructions to perform the load. Return the id of the
+    /// merged value of the two branches.
+    pub(super) fn write_conditional_indexed_load<F>(
+        &mut self,
+        result_type: Word,
+        condition: Word,
+        block: &mut Block,
+        emit_load: F,
+    ) -> Word
+    where
+        F: FnOnce(&mut IdGenerator, &mut Block) -> Word,
+    {
+        // For the out-of-bounds case, we produce a zero value.
+        let null_id = self.writer.get_constant_null(result_type);
+
+        let mut selection = Selection::start(block, result_type);
+
+        // As it turns out, we don't actually need a full 'if-then-else'
+        // structure for this: SPIR-V constants are declared up front, so the
+        // 'else' block would have no instructions. Instead we emit something
+        // like this:
+        //
+        //     result = zero;
+        //     if in_bounds {
+        //         result = do the load;
+        //     }
+        //     use result;
+
+        // Continue only if the index was in bounds. Otherwise, branch to the
+        // merge block.
+        selection.if_true(self, condition, null_id);
+
+        // The in-bounds path. Perform the access and the load.
+        let loaded_value = emit_load(&mut self.writer.id_gen, selection.block());
+
+        selection.finish(self, loaded_value)
+    }
+
+    /// Emit code for bounds checks for an array, vector, or matrix access.
+    ///
+    /// This implements either `index_bounds_check_policy` or
+    /// `buffer_bounds_check_policy`, depending on the address space of the
+    /// pointer being accessed.
+    ///
+    /// Return a `BoundsCheckResult` indicating how the index should be
+    /// consumed. See that type's documentation for details.
+    pub(super) fn write_bounds_check(
+        &mut self,
+        base: Handle<crate::Expression>,
+        index: Handle<crate::Expression>,
+        block: &mut Block,
+    ) -> Result<BoundsCheckResult, Error> {
+        let policy = self.writer.bounds_check_policies.choose_policy(
+            base,
+            &self.ir_module.types,
+            self.fun_info,
+        );
+
+        Ok(match policy {
+            BoundsCheckPolicy::Restrict => self.write_restricted_index(base, index, block)?,
+            BoundsCheckPolicy::ReadZeroSkipWrite => {
+                self.write_index_comparison(base, index, block)?
+            }
+            BoundsCheckPolicy::Unchecked => BoundsCheckResult::Computed(self.cached[index]),
+        })
+    }
+
+    /// Emit code to subscript a vector by value with a computed index.
+    ///
+    /// Return the id of the element value.
+    pub(super) fn write_vector_access(
+        &mut self,
+        expr_handle: Handle<crate::Expression>,
+        base: Handle<crate::Expression>,
+        index: Handle<crate::Expression>,
+        block: &mut Block,
+    ) -> Result<Word, Error> {
+        let result_type_id = self.get_expression_type_id(&self.fun_info[expr_handle].ty);
+
+        let base_id = self.cached[base];
+        let index_id = self.cached[index];
+
+        let result_id = match self.write_bounds_check(base, index, block)? {
+            BoundsCheckResult::KnownInBounds(known_index) => {
+                let result_id = self.gen_id();
+                block.body.push(Instruction::composite_extract(
+                    result_type_id,
+                    result_id,
+                    base_id,
+                    &[known_index],
+                ));
+                result_id
+            }
+            BoundsCheckResult::Computed(computed_index_id) => {
+                let result_id = self.gen_id();
+                block.body.push(Instruction::vector_extract_dynamic(
+                    result_type_id,
+                    result_id,
+                    base_id,
+                    computed_index_id,
+                ));
+                result_id
+            }
+            BoundsCheckResult::Conditional(comparison_id) => {
+                // Run-time bounds checks were required. Emit
+                // conditional load.
+                self.write_conditional_indexed_load(
+                    result_type_id,
+                    comparison_id,
+                    block,
+                    |id_gen, block| {
+                        // The in-bounds path. Generate the access.
+                        let element_id = id_gen.next();
+                        block.body.push(Instruction::vector_extract_dynamic(
+                            result_type_id,
+                            element_id,
+                            base_id,
+                            index_id,
+                        ));
+                        element_id
+                    },
+                )
+            }
+        };
+
+        Ok(result_id)
+    }
+}
diff --git a/third_party/rust/naga/src/back/spv/instructions.rs b/third_party/rust/naga/src/back/spv/instructions.rs
new file mode 100644
index 0000000000..b963793ad3
--- /dev/null
+++ b/third_party/rust/naga/src/back/spv/instructions.rs
@@ -0,0 +1,1100 @@
+use super::{block::DebugInfoInner, helpers};
+use spirv::{Op, Word};
+
+pub(super) enum Signedness {
+    Unsigned = 0,
+    Signed = 1,
+}
+
+pub(super) enum SampleLod {
+    Explicit,
+    Implicit,
+}
+
+pub(super) struct Case {
+    pub value: Word,
+    pub label_id: Word,
+}
+
+impl super::Instruction {
+    //
+    //  Debug Instructions
+    //
+
+    pub(super) fn string(name: &str, id: Word) -> Self {
+        let mut instruction = Self::new(Op::String);
+        instruction.set_result(id);
+        instruction.add_operands(helpers::string_to_words(name));
+        instruction
+    }
+
+    pub(super) fn source(
+        source_language: spirv::SourceLanguage,
+        version: u32,
+        source: &Option<DebugInfoInner>,
+    ) -> Self {
+        let mut instruction = Self::new(Op::Source);
+        instruction.add_operand(source_language as u32);
+        instruction.add_operands(helpers::bytes_to_words(&version.to_le_bytes()));
+        if let Some(source) = source.as_ref() {
+            instruction.add_operand(source.source_file_id);
+            instruction.add_operands(helpers::string_to_words(source.source_code));
+        }
+        instruction
+    }
+
+    pub(super) fn name(target_id: Word, name: &str) -> Self {
+        let mut instruction = Self::new(Op::Name);
+        instruction.add_operand(target_id);
+        instruction.add_operands(helpers::string_to_words(name));
+        instruction
+    }
+
+    pub(super) fn member_name(target_id: Word, member: Word, name: &str) -> Self {
+        let mut instruction = Self::new(Op::MemberName);
+        instruction.add_operand(target_id);
+        instruction.add_operand(member);
+        instruction.add_operands(helpers::string_to_words(name));
+        instruction
+    }
+
+    pub(super) fn line(file: Word, line: Word, column: Word) -> Self {
+        let mut instruction = Self::new(Op::Line);
+        instruction.add_operand(file);
+        instruction.add_operand(line);
+        instruction.add_operand(column);
+        instruction
+    }
+
+    pub(super) const fn no_line() -> Self {
+        Self::new(Op::NoLine)
+    }
+
+    //
+    //  Annotation Instructions
+    //
+
+    pub(super) fn decorate(
+        target_id: Word,
+        decoration: spirv::Decoration,
+        operands: &[Word],
+    ) -> Self {
+        let mut instruction = Self::new(Op::Decorate);
+        instruction.add_operand(target_id);
+        instruction.add_operand(decoration as u32);
+        for operand in operands {
+            instruction.add_operand(*operand)
+        }
+        instruction
+    }
+
+    pub(super) fn member_decorate(
+        target_id: Word,
+        member_index: Word,
+        decoration: spirv::Decoration,
+        operands: &[Word],
+    ) -> Self {
+        let mut instruction = Self::new(Op::MemberDecorate);
+        instruction.add_operand(target_id);
+        instruction.add_operand(member_index);
+        instruction.add_operand(decoration as u32);
+        for operand in operands {
+            instruction.add_operand(*operand)
+        }
+        instruction
+    }
+
+    //
+    //  Extension Instructions
+    //
+
+    pub(super) fn extension(name: &str) -> Self {
+        let mut instruction = Self::new(Op::Extension);
+        instruction.add_operands(helpers::string_to_words(name));
+        instruction
+    }
+
+    pub(super) fn ext_inst_import(id: Word, name: &str) -> Self {
+        let mut instruction = Self::new(Op::ExtInstImport);
+        instruction.set_result(id);
+        instruction.add_operands(helpers::string_to_words(name));
+        instruction
+    }
+
+    pub(super) fn ext_inst(
+        set_id: Word,
+        op: spirv::GLOp,
+        result_type_id: Word,
+        id: Word,
+        operands: &[Word],
+    ) -> Self {
+        let mut instruction = Self::new(Op::ExtInst);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(set_id);
+        instruction.add_operand(op as u32);
+        for operand in operands {
+            instruction.add_operand(*operand)
+        }
+        instruction
+    }
+
+    //
+    //  Mode-Setting Instructions
+    //
+
+    pub(super) fn memory_model(
+        addressing_model: spirv::AddressingModel,
+        memory_model: spirv::MemoryModel,
+    ) -> Self {
+        let mut instruction = Self::new(Op::MemoryModel);
+        instruction.add_operand(addressing_model as u32);
+        instruction.add_operand(memory_model as u32);
+        instruction
+    }
+
+    pub(super) fn entry_point(
+        execution_model: spirv::ExecutionModel,
+        entry_point_id: Word,
+        name: &str,
+        interface_ids: &[Word],
+    ) -> Self {
+        let mut instruction = Self::new(Op::EntryPoint);
+        instruction.add_operand(execution_model as u32);
+        instruction.add_operand(entry_point_id);
+        instruction.add_operands(helpers::string_to_words(name));
+
+        for interface_id in interface_ids {
+            instruction.add_operand(*interface_id);
+        }
+
+        instruction
+    }
+
+    pub(super) fn execution_mode(
+        entry_point_id: Word,
+        execution_mode: spirv::ExecutionMode,
+        args: &[Word],
+    ) -> Self {
+        let mut instruction = Self::new(Op::ExecutionMode);
+        instruction.add_operand(entry_point_id);
+        instruction.add_operand(execution_mode as u32);
+        for arg in args {
+            instruction.add_operand(*arg);
+        }
+        instruction
+    }
+
+    pub(super) fn capability(capability: spirv::Capability) -> Self {
+        let mut instruction = Self::new(Op::Capability);
+        instruction.add_operand(capability as u32);
+        instruction
+    }
+
+    //
+    //  Type-Declaration Instructions
+    //
+
+    pub(super) fn type_void(id: Word) -> Self {
+        let mut instruction = Self::new(Op::TypeVoid);
+        instruction.set_result(id);
+        instruction
+    }
+
+    pub(super) fn type_bool(id: Word) -> Self {
+        let mut instruction = Self::new(Op::TypeBool);
+        instruction.set_result(id);
+        instruction
+    }
+
+    pub(super) fn type_int(id: Word, width: Word, signedness: Signedness) -> Self {
+        let mut instruction = Self::new(Op::TypeInt);
+        instruction.set_result(id);
+        instruction.add_operand(width);
+        instruction.add_operand(signedness as u32);
+        instruction
+    }
+
+    pub(super) fn type_float(id: Word, width: Word) -> Self {
+        let mut instruction = Self::new(Op::TypeFloat);
+        instruction.set_result(id);
+        instruction.add_operand(width);
+        instruction
+    }
+
+    pub(super) fn type_vector(
+        id: Word,
+        component_type_id: Word,
+        component_count: crate::VectorSize,
+    ) -> Self {
+        let mut instruction = Self::new(Op::TypeVector);
+        instruction.set_result(id);
+        instruction.add_operand(component_type_id);
+        instruction.add_operand(component_count as u32);
+        instruction
+    }
+
+    pub(super) fn type_matrix(
+        id: Word,
+        column_type_id: Word,
+        column_count: crate::VectorSize,
+    ) -> Self {
+        let mut instruction = Self::new(Op::TypeMatrix);
+        instruction.set_result(id);
+        instruction.add_operand(column_type_id);
+        instruction.add_operand(column_count as u32);
+        instruction
+    }
+
+    #[allow(clippy::too_many_arguments)]
+    pub(super) fn type_image(
+        id: Word,
+        sampled_type_id: Word,
+        dim: spirv::Dim,
+        flags: super::ImageTypeFlags,
+        image_format: spirv::ImageFormat,
+    ) -> Self {
+        let mut instruction = Self::new(Op::TypeImage);
+        instruction.set_result(id);
+        instruction.add_operand(sampled_type_id);
+        instruction.add_operand(dim as u32);
+        instruction.add_operand(flags.contains(super::ImageTypeFlags::DEPTH) as u32);
+        instruction.add_operand(flags.contains(super::ImageTypeFlags::ARRAYED) as u32);
+        instruction.add_operand(flags.contains(super::ImageTypeFlags::MULTISAMPLED) as u32);
+        instruction.add_operand(if flags.contains(super::ImageTypeFlags::SAMPLED) {
+            1
+        } else {
+            2
+        });
+        instruction.add_operand(image_format as u32);
+        instruction
+    }
+
+    pub(super) fn type_sampler(id: Word) -> Self {
+        let mut instruction = Self::new(Op::TypeSampler);
+        instruction.set_result(id);
+        instruction
+    }
+
+    pub(super) fn type_acceleration_structure(id: Word) -> Self {
+        let mut instruction = Self::new(Op::TypeAccelerationStructureKHR);
+        instruction.set_result(id);
+        instruction
+    }
+
+    pub(super) fn type_ray_query(id: Word) -> Self {
+        let mut instruction = Self::new(Op::TypeRayQueryKHR);
+        instruction.set_result(id);
+        instruction
+    }
+
+    pub(super) fn type_sampled_image(id: Word, image_type_id: Word) -> Self {
+        let mut instruction = Self::new(Op::TypeSampledImage);
+        instruction.set_result(id);
+        instruction.add_operand(image_type_id);
+        instruction
+    }
+
+    pub(super) fn type_array(id: Word, element_type_id: Word, length_id: Word) -> Self {
+        let mut instruction = Self::new(Op::TypeArray);
+        instruction.set_result(id);
+        instruction.add_operand(element_type_id);
+        instruction.add_operand(length_id);
+        instruction
+    }
+
+    pub(super) fn type_runtime_array(id: Word, element_type_id: Word) -> Self {
+        let mut instruction = Self::new(Op::TypeRuntimeArray);
+        instruction.set_result(id);
+        instruction.add_operand(element_type_id);
+        instruction
+    }
+
+    pub(super) fn type_struct(id: Word, member_ids: &[Word]) -> Self {
+        let mut instruction = Self::new(Op::TypeStruct);
+        instruction.set_result(id);
+
+        for member_id in member_ids {
+            instruction.add_operand(*member_id)
+        }
+
+        instruction
+    }
+
+    pub(super) fn type_pointer(
+        id: Word,
+        storage_class: spirv::StorageClass,
+        type_id: Word,
+    ) -> Self {
+        let mut instruction = Self::new(Op::TypePointer);
+        instruction.set_result(id);
+        instruction.add_operand(storage_class as u32);
+        instruction.add_operand(type_id);
+        instruction
+    }
+
+    pub(super) fn type_function(id: Word, return_type_id: Word, parameter_ids: &[Word]) -> Self {
+        let mut instruction = Self::new(Op::TypeFunction);
+        instruction.set_result(id);
+        instruction.add_operand(return_type_id);
+
+        for parameter_id in parameter_ids {
+            instruction.add_operand(*parameter_id);
+        }
+
+        instruction
+    }
+
+    //
+    //  Constant-Creation Instructions
+    //
+
+    pub(super) fn constant_null(result_type_id: Word, id: Word) -> Self {
+        let mut instruction = Self::new(Op::ConstantNull);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction
+    }
+
+    pub(super) fn constant_true(result_type_id: Word, id: Word) -> Self {
+        let mut instruction = Self::new(Op::ConstantTrue);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction
+    }
+
+    pub(super) fn constant_false(result_type_id: Word, id: Word) -> Self {
+        let mut instruction = Self::new(Op::ConstantFalse);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction
+    }
+
+    pub(super) fn constant_32bit(result_type_id: Word, id: Word, value: Word) -> Self {
+        Self::constant(result_type_id, id, &[value])
+    }
+
+    pub(super) fn constant_64bit(result_type_id: Word, id: Word, low: Word, high: Word) -> Self {
+        Self::constant(result_type_id, id, &[low, high])
+    }
+
+    pub(super) fn constant(result_type_id: Word, id: Word, values: &[Word]) -> Self {
+        let mut instruction = Self::new(Op::Constant);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+
+        for value in values {
+            instruction.add_operand(*value);
+        }
+
+        instruction
+    }
+
+    pub(super) fn constant_composite(
+        result_type_id: Word,
+        id: Word,
+        constituent_ids: &[Word],
+    ) -> Self {
+        let mut instruction = Self::new(Op::ConstantComposite);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+
+        for constituent_id in constituent_ids {
+            instruction.add_operand(*constituent_id);
+        }
+
+        instruction
+    }
+
+    //
+    //  Memory Instructions
+    //
+
+    pub(super) fn variable(
+        result_type_id: Word,
+        id: Word,
+        storage_class: spirv::StorageClass,
+        initializer_id: Option<Word>,
+    ) -> Self {
+        let mut instruction = Self::new(Op::Variable);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(storage_class as u32);
+
+        if let Some(initializer_id) = initializer_id {
+            instruction.add_operand(initializer_id);
+        }
+
+        instruction
+    }
+
+    pub(super) fn load(
+        result_type_id: Word,
+        id: Word,
+        pointer_id: Word,
+        memory_access: Option<spirv::MemoryAccess>,
+    ) -> Self {
+        let mut instruction = Self::new(Op::Load);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(pointer_id);
+
+        if let Some(memory_access) = memory_access {
+            instruction.add_operand(memory_access.bits());
+        }
+
+        instruction
+    }
+
+    pub(super) fn atomic_load(
+        result_type_id: Word,
+        id: Word,
+        pointer_id: Word,
+        scope_id: Word,
+        semantics_id: Word,
+    ) -> Self {
+        let mut instruction = Self::new(Op::AtomicLoad);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(pointer_id);
+        instruction.add_operand(scope_id);
+        instruction.add_operand(semantics_id);
+        instruction
+    }
+
+    pub(super) fn store(
+        pointer_id: Word,
+        value_id: Word,
+        memory_access: Option<spirv::MemoryAccess>,
+    ) -> Self {
+        let mut instruction = Self::new(Op::Store);
+        instruction.add_operand(pointer_id);
+        instruction.add_operand(value_id);
+
+        if let Some(memory_access) = memory_access {
+            instruction.add_operand(memory_access.bits());
+        }
+
+        instruction
+    }
+
+    pub(super) fn atomic_store(
+        pointer_id: Word,
+        scope_id: Word,
+        semantics_id: Word,
+        value_id: Word,
+    ) -> Self {
+        let mut instruction = Self::new(Op::AtomicStore);
+        instruction.add_operand(pointer_id);
+        instruction.add_operand(scope_id);
+        instruction.add_operand(semantics_id);
+        instruction.add_operand(value_id);
+        instruction
+    }
+
+    pub(super) fn access_chain(
+        result_type_id: Word,
+        id: Word,
+        base_id: Word,
+        index_ids: &[Word],
+    ) -> Self {
+        let mut instruction = Self::new(Op::AccessChain);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(base_id);
+
+        for index_id in index_ids {
+            instruction.add_operand(*index_id);
+        }
+
+        instruction
+    }
+
+    pub(super) fn array_length(
+        result_type_id: Word,
+        id: Word,
+        structure_id: Word,
+        array_member: Word,
+    ) -> Self {
+        let mut instruction = Self::new(Op::ArrayLength);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(structure_id);
+        instruction.add_operand(array_member);
+        instruction
+    }
+
+    //
+    //  Function Instructions
+    //
+
+    pub(super) fn function(
+        return_type_id: Word,
+        id: Word,
+        function_control: spirv::FunctionControl,
+        function_type_id: Word,
+    ) -> Self {
+        let mut instruction = Self::new(Op::Function);
+        instruction.set_type(return_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(function_control.bits());
+        instruction.add_operand(function_type_id);
+        instruction
+    }
+
+    pub(super) fn function_parameter(result_type_id: Word, id: Word) -> Self {
+        let mut instruction = Self::new(Op::FunctionParameter);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction
+    }
+
+    pub(super) const fn function_end() -> Self {
+        Self::new(Op::FunctionEnd)
+    }
+
+    pub(super) fn function_call(
+        result_type_id: Word,
+        id: Word,
+        function_id: Word,
+        argument_ids: &[Word],
+    ) -> Self {
+        let mut instruction = Self::new(Op::FunctionCall);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(function_id);
+
+        for argument_id in argument_ids {
+            instruction.add_operand(*argument_id);
+        }
+
+        instruction
+    }
+
+    //
+    //  Image Instructions
+    //
+
+    pub(super) fn sampled_image(
+        result_type_id: Word,
+        id: Word,
+        image: Word,
+        sampler: Word,
+    ) -> Self {
+        let mut instruction = Self::new(Op::SampledImage);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(image);
+        instruction.add_operand(sampler);
+        instruction
+    }
+
+    pub(super) fn image_sample(
+        result_type_id: Word,
+        id: Word,
+        lod: SampleLod,
+        sampled_image: Word,
+        coordinates: Word,
+        depth_ref: Option<Word>,
+    ) -> Self {
+        let op = match (lod, depth_ref) {
+            (SampleLod::Explicit, None) => Op::ImageSampleExplicitLod,
+            (SampleLod::Implicit, None) => Op::ImageSampleImplicitLod,
+            (SampleLod::Explicit, Some(_)) => Op::ImageSampleDrefExplicitLod,
+            (SampleLod::Implicit, Some(_)) => Op::ImageSampleDrefImplicitLod,
+        };
+
+        let mut instruction = Self::new(op);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(sampled_image);
+        instruction.add_operand(coordinates);
+        if let Some(dref) = depth_ref {
+            instruction.add_operand(dref);
+        }
+
+        instruction
+    }
+
+    pub(super) fn image_gather(
+        result_type_id: Word,
+        id: Word,
+        sampled_image: Word,
+        coordinates: Word,
+        component_id: Word,
+        depth_ref: Option<Word>,
+    ) -> Self {
+        let op = match depth_ref {
+            None => Op::ImageGather,
+            Some(_) => Op::ImageDrefGather,
+        };
+
+        let mut instruction = Self::new(op);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(sampled_image);
+        instruction.add_operand(coordinates);
+        if let Some(dref) = depth_ref {
+            instruction.add_operand(dref);
+        } else {
+            instruction.add_operand(component_id);
+        }
+
+        instruction
+    }
+
+    pub(super) fn image_fetch_or_read(
+        op: Op,
+        result_type_id: Word,
+        id: Word,
+        image: Word,
+        coordinates: Word,
+    ) -> Self {
+        let mut instruction = Self::new(op);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(image);
+        instruction.add_operand(coordinates);
+        instruction
+    }
+
+    pub(super) fn image_write(image: Word, coordinates: Word, value: Word) -> Self {
+        let mut instruction = Self::new(Op::ImageWrite);
+        instruction.add_operand(image);
+        instruction.add_operand(coordinates);
+        instruction.add_operand(value);
+        instruction
+    }
+
+    pub(super) fn image_query(op: Op, result_type_id: Word, id: Word, image: Word) -> Self {
+        let mut instruction = Self::new(op);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(image);
+        instruction
+    }
+
+    //
+    //  Ray Query Instructions
+    //
+    #[allow(clippy::too_many_arguments)]
+    pub(super) fn ray_query_initialize(
+        query: Word,
+        acceleration_structure: Word,
+        ray_flags: Word,
+        cull_mask: Word,
+        ray_origin: Word,
+        ray_tmin: Word,
+        ray_dir: Word,
+        ray_tmax: Word,
+    ) -> Self {
+        let mut instruction = Self::new(Op::RayQueryInitializeKHR);
+        instruction.add_operand(query);
+        instruction.add_operand(acceleration_structure);
+        instruction.add_operand(ray_flags);
+        instruction.add_operand(cull_mask);
+        instruction.add_operand(ray_origin);
+        instruction.add_operand(ray_tmin);
+        instruction.add_operand(ray_dir);
+        instruction.add_operand(ray_tmax);
+        instruction
+    }
+
+    pub(super) fn ray_query_proceed(result_type_id: Word, id: Word, query: Word) -> Self {
+        let mut instruction = Self::new(Op::RayQueryProceedKHR);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(query);
+        instruction
+    }
+
+    pub(super) fn ray_query_get_intersection(
+        op: Op,
+        result_type_id: Word,
+        id: Word,
+        query: Word,
+        intersection: Word,
+    ) -> Self {
+        let mut instruction = Self::new(op);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(query);
+        instruction.add_operand(intersection);
+        instruction
+    }
+
+    //
+    //  Conversion Instructions
+    //
+    pub(super) fn unary(op: Op, result_type_id: Word, id: Word, value: Word) -> Self {
+        let mut instruction = Self::new(op);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(value);
+        instruction
+    }
+
+    //
+    //  Composite Instructions
+    //
+
+    pub(super) fn composite_construct(
+        result_type_id: Word,
+        id: Word,
+        constituent_ids: &[Word],
+    ) -> Self {
+        let mut instruction = Self::new(Op::CompositeConstruct);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+
+        for constituent_id in constituent_ids {
+            instruction.add_operand(*constituent_id);
+        }
+
+        instruction
+    }
+
+    pub(super) fn composite_extract(
+        result_type_id: Word,
+        id: Word,
+        composite_id: Word,
+        indices: &[Word],
+    ) -> Self {
+        let mut instruction = Self::new(Op::CompositeExtract);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+
+        instruction.add_operand(composite_id);
+        for index in indices {
+            instruction.add_operand(*index);
+        }
+
+        instruction
+    }
+
+    pub(super) fn vector_extract_dynamic(
+        result_type_id: Word,
+        id: Word,
+        vector_id: Word,
+        index_id: Word,
+    ) -> Self {
+        let mut instruction = Self::new(Op::VectorExtractDynamic);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+
+        instruction.add_operand(vector_id);
+        instruction.add_operand(index_id);
+
+        instruction
+    }
+
+    pub(super) fn vector_shuffle(
+        result_type_id: Word,
+        id: Word,
+        v1_id: Word,
+        v2_id: Word,
+        components: &[Word],
+    ) -> Self {
+        let mut instruction = Self::new(Op::VectorShuffle);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(v1_id);
+        instruction.add_operand(v2_id);
+
+        for &component in components {
+            instruction.add_operand(component);
+        }
+
+        instruction
+    }
+
+    //
+    // Arithmetic Instructions
+    //
+    pub(super) fn binary(
+        op: Op,
+        result_type_id: Word,
+        id: Word,
+        operand_1: Word,
+        operand_2: Word,
+    ) -> Self {
+        let mut instruction = Self::new(op);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(operand_1);
+        instruction.add_operand(operand_2);
+        instruction
+    }
+
+    pub(super) fn ternary(
+        op: Op,
+        result_type_id: Word,
+        id: Word,
+        operand_1: Word,
+        operand_2: Word,
+        operand_3: Word,
+    ) -> Self {
+        let mut instruction = Self::new(op);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(operand_1);
+        instruction.add_operand(operand_2);
+        instruction.add_operand(operand_3);
+        instruction
+    }
+
+    pub(super) fn quaternary(
+        op: Op,
+        result_type_id: Word,
+        id: Word,
+        operand_1: Word,
+        operand_2: Word,
+        operand_3: Word,
+        operand_4: Word,
+    ) -> Self {
+        let mut instruction = Self::new(op);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(operand_1);
+        instruction.add_operand(operand_2);
+        instruction.add_operand(operand_3);
+        instruction.add_operand(operand_4);
+        instruction
+    }
+
+    pub(super) fn relational(op: Op, result_type_id: Word, id: Word, expr_id: Word) -> Self {
+        let mut instruction = Self::new(op);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(expr_id);
+        instruction
+    }
+
+    pub(super) fn atomic_binary(
+        op: Op,
+        result_type_id: Word,
+        id: Word,
+        pointer: Word,
+        scope_id: Word,
+        semantics_id: Word,
+        value: Word,
+    ) -> Self {
+        let mut instruction = Self::new(op);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(pointer);
+        instruction.add_operand(scope_id);
+        instruction.add_operand(semantics_id);
+        instruction.add_operand(value);
+        instruction
+    }
+
+    //
+    // Bit Instructions
+    //
+
+    //
+    // Relational and Logical Instructions
+    //
+
+    //
+    // Derivative Instructions
+    //
+
+    pub(super) fn derivative(op: Op, result_type_id: Word, id: Word, expr_id: Word) -> Self {
+        let mut instruction = Self::new(op);
+        instruction.set_type(result_type_id);
+        instruction.set_result(id);
+        instruction.add_operand(expr_id);
+        instruction
+    }
+
+    //
+    // Control-Flow Instructions
+    //
+
+    pub(super) fn phi(
+        result_type_id: Word,
+        result_id: Word,
+        var_parent_pairs: &[(Word, Word)],
+    ) -> Self {
+        let mut instruction = Self::new(Op::Phi);
+        instruction.add_operand(result_type_id);
+        instruction.add_operand(result_id);
+        for &(variable, parent) in var_parent_pairs {
+            instruction.add_operand(variable);
+            instruction.add_operand(parent);
+        }
+        instruction
+    }
+
+    pub(super) fn selection_merge(
+        merge_id: Word,
+        selection_control: spirv::SelectionControl,
+    ) -> Self {
+        let mut instruction = Self::new(Op::SelectionMerge);
+        instruction.add_operand(merge_id);
+        instruction.add_operand(selection_control.bits());
+        instruction
+    }
+
+    pub(super) fn loop_merge(
+        merge_id: Word,
+        continuing_id: Word,
+        selection_control: spirv::SelectionControl,
+    ) -> Self {
+        let mut instruction = Self::new(Op::LoopMerge);
+        instruction.add_operand(merge_id);
+        instruction.add_operand(continuing_id);
+        instruction.add_operand(selection_control.bits());
+        instruction
+    }
+
+    pub(super) fn label(id: Word) -> Self {
+        let mut instruction = Self::new(Op::Label);
+        instruction.set_result(id);
+        instruction
+    }
+
+    pub(super) fn branch(id: Word) -> Self {
+        let mut instruction = Self::new(Op::Branch);
+        instruction.add_operand(id);
+        instruction
+    }
+
+    // TODO Branch Weights not implemented.
+    pub(super) fn branch_conditional(
+        condition_id: Word,
+        true_label: Word,
+        false_label: Word,
+    ) -> Self {
+        let mut instruction = Self::new(Op::BranchConditional);
+        instruction.add_operand(condition_id);
+        instruction.add_operand(true_label);
+        instruction.add_operand(false_label);
+        instruction
+    }
+
+    pub(super) fn switch(selector_id: Word, default_id: Word, cases: &[Case]) -> Self {
+        let mut instruction = Self::new(Op::Switch);
+        instruction.add_operand(selector_id);
+        instruction.add_operand(default_id);
+        for case in cases {
+            instruction.add_operand(case.value);
+            instruction.add_operand(case.label_id);
+        }
+        instruction
+    }
+
+    pub(super) fn select(
+        result_type_id: Word,
+        id: Word,
+        condition_id: Word,
+        accept_id: Word,
+        reject_id: Word,
+    ) -> Self {
+        let mut instruction = Self::new(Op::Select);
+        instruction.add_operand(result_type_id);
+        instruction.add_operand(id);
+        instruction.add_operand(condition_id);
+        instruction.add_operand(accept_id);
+        instruction.add_operand(reject_id);
+        instruction
+    }
+
+    pub(super) const fn kill() -> Self {
+        Self::new(Op::Kill)
+    }
+
+    pub(super) const fn return_void() -> Self {
+        Self::new(Op::Return)
+    }
+
+    pub(super) fn return_value(value_id: Word) -> Self {
+        let mut instruction = Self::new(Op::ReturnValue);
+        instruction.add_operand(value_id);
+        instruction
+    }
+
+    //
+    //  Atomic Instructions
+    //
+
+    //
+    //  Primitive Instructions
+    //
+
+    // Barriers
+
+    pub(super) fn control_barrier(
+        exec_scope_id: Word,
+        mem_scope_id: Word,
+        semantics_id: Word,
+    ) -> Self {
+        let mut instruction = Self::new(Op::ControlBarrier);
+        instruction.add_operand(exec_scope_id);
+        instruction.add_operand(mem_scope_id);
+        instruction.add_operand(semantics_id);
+        instruction
+    }
+}
+
+impl From<crate::StorageFormat> for spirv::ImageFormat {
+    fn from(format: crate::StorageFormat) -> Self {
+        use crate::StorageFormat as Sf;
+        match format {
+            Sf::R8Unorm => Self::R8,
+            Sf::R8Snorm => Self::R8Snorm,
+            Sf::R8Uint => Self::R8ui,
+            Sf::R8Sint => Self::R8i,
+            Sf::R16Uint => Self::R16ui,
+            Sf::R16Sint => Self::R16i,
+            Sf::R16Float => Self::R16f,
+            Sf::Rg8Unorm => Self::Rg8,
+            Sf::Rg8Snorm => Self::Rg8Snorm,
+            Sf::Rg8Uint => Self::Rg8ui,
+            Sf::Rg8Sint => Self::Rg8i,
+            Sf::R32Uint => Self::R32ui,
+            Sf::R32Sint => Self::R32i,
+            Sf::R32Float => Self::R32f,
+            Sf::Rg16Uint => Self::Rg16ui,
+            Sf::Rg16Sint => Self::Rg16i,
+            Sf::Rg16Float => Self::Rg16f,
+            Sf::Rgba8Unorm => Self::Rgba8,
+            Sf::Rgba8Snorm => Self::Rgba8Snorm,
+            Sf::Rgba8Uint => Self::Rgba8ui,
+            Sf::Rgba8Sint => Self::Rgba8i,
+            Sf::Bgra8Unorm => Self::Unknown,
+            Sf::Rgb10a2Uint => Self::Rgb10a2ui,
+            Sf::Rgb10a2Unorm => Self::Rgb10A2,
+            Sf::Rg11b10Float => Self::R11fG11fB10f,
+            Sf::Rg32Uint => Self::Rg32ui,
+            Sf::Rg32Sint => Self::Rg32i,
+            Sf::Rg32Float => Self::Rg32f,
+            Sf::Rgba16Uint => Self::Rgba16ui,
+            Sf::Rgba16Sint => Self::Rgba16i,
+            Sf::Rgba16Float => Self::Rgba16f,
+            Sf::Rgba32Uint => Self::Rgba32ui,
+            Sf::Rgba32Sint => Self::Rgba32i,
+            Sf::Rgba32Float => Self::Rgba32f,
+            Sf::R16Unorm => Self::R16,
+            Sf::R16Snorm => Self::R16Snorm,
+            Sf::Rg16Unorm => Self::Rg16,
+            Sf::Rg16Snorm => Self::Rg16Snorm,
+            Sf::Rgba16Unorm => Self::Rgba16,
+            Sf::Rgba16Snorm => Self::Rgba16Snorm,
+        }
+    }
+}
+
+impl From<crate::ImageDimension> for spirv::Dim {
+    fn from(dim: crate::ImageDimension) -> Self {
+        use crate::ImageDimension as Id;
+        match dim {
+            Id::D1 => Self::Dim1D,
+            Id::D2 => Self::Dim2D,
+            Id::D3 => Self::Dim3D,
+            Id::Cube => Self::DimCube,
+        }
+    }
+}
diff --git a/third_party/rust/naga/src/back/spv/layout.rs b/third_party/rust/naga/src/back/spv/layout.rs
new file mode 100644
index 0000000000..39117a3d2a
--- /dev/null
+++ b/third_party/rust/naga/src/back/spv/layout.rs
@@ -0,0 +1,210 @@
+use super::{Instruction, LogicalLayout, PhysicalLayout};
+use spirv::{Op, Word, MAGIC_NUMBER};
+use std::iter;
+
+// https://github.com/KhronosGroup/SPIRV-Headers/pull/195
+const GENERATOR: Word = 28;
+
+impl PhysicalLayout {
+    pub(super) const fn new(version: Word) -> Self {
+        PhysicalLayout {
+            magic_number: MAGIC_NUMBER,
+            version,
+            generator: GENERATOR,
+            bound: 0,
+            instruction_schema: 0x0u32,
+        }
+    }
+
+    pub(super) fn in_words(&self, sink: &mut impl Extend<Word>) {
+        sink.extend(iter::once(self.magic_number));
+        sink.extend(iter::once(self.version));
+        sink.extend(iter::once(self.generator));
+        sink.extend(iter::once(self.bound));
+        sink.extend(iter::once(self.instruction_schema));
+    }
+}
+
+impl super::recyclable::Recyclable for PhysicalLayout {
+    fn recycle(self) -> Self {
+        PhysicalLayout {
+            magic_number: self.magic_number,
+            version: self.version,
+            generator: self.generator,
+            instruction_schema: self.instruction_schema,
+            bound: 0,
+        }
+    }
+}
+
+impl LogicalLayout {
+    pub(super) fn in_words(&self, sink: &mut impl Extend<Word>) {
+        sink.extend(self.capabilities.iter().cloned());
+        sink.extend(self.extensions.iter().cloned());
+        sink.extend(self.ext_inst_imports.iter().cloned());
+        sink.extend(self.memory_model.iter().cloned());
+        sink.extend(self.entry_points.iter().cloned());
+        sink.extend(self.execution_modes.iter().cloned());
+        sink.extend(self.debugs.iter().cloned());
+        sink.extend(self.annotations.iter().cloned());
+        sink.extend(self.declarations.iter().cloned());
+        sink.extend(self.function_declarations.iter().cloned());
+        sink.extend(self.function_definitions.iter().cloned());
+    }
+}
+
+impl super::recyclable::Recyclable for LogicalLayout {
+    fn recycle(self) -> Self {
+        Self {
+            capabilities: self.capabilities.recycle(),
+            extensions: self.extensions.recycle(),
+            ext_inst_imports: self.ext_inst_imports.recycle(),
+            memory_model: self.memory_model.recycle(),
+            entry_points: self.entry_points.recycle(),
+            execution_modes: self.execution_modes.recycle(),
+            debugs: self.debugs.recycle(),
+            annotations: self.annotations.recycle(),
+            declarations: self.declarations.recycle(),
+            function_declarations: self.function_declarations.recycle(),
+            function_definitions: self.function_definitions.recycle(),
+        }
+    }
+}
+
+impl Instruction {
+    pub(super) const fn new(op: Op) -> Self {
+        Instruction {
+            op,
+            wc: 1, // Always start at 1 for the first word (OP + WC),
+            type_id: None,
+            result_id: None,
+            operands: vec![],
+        }
+    }
+
+    #[allow(clippy::panic)]
+    pub(super) fn set_type(&mut self, id: Word) {
+        assert!(self.type_id.is_none(), "Type can only be set once");
+        self.type_id = Some(id);
+        self.wc += 1;
+    }
+
+    #[allow(clippy::panic)]
+    pub(super) fn set_result(&mut self, id: Word) {
+        assert!(self.result_id.is_none(), "Result can only be set once");
+        self.result_id = Some(id);
+        self.wc += 1;
+    }
+
+    pub(super) fn add_operand(&mut self, operand: Word) {
+        self.operands.push(operand);
+        self.wc += 1;
+    }
+
+    pub(super) fn add_operands(&mut self, operands: Vec<Word>) {
+        for operand in operands.into_iter() {
+            self.add_operand(operand)
+        }
+    }
+
+    pub(super) fn to_words(&self, sink: &mut impl Extend<Word>) {
+        sink.extend(Some(self.wc << 16 | self.op as u32));
+        sink.extend(self.type_id);
+        sink.extend(self.result_id);
+        sink.extend(self.operands.iter().cloned());
+    }
+}
+
+impl Instruction {
+    #[cfg(test)]
+    fn validate(&self, words: &[Word]) {
+        let mut inst_index = 0;
+        let (wc, op) = ((words[inst_index] >> 16) as u16, words[inst_index] as u16);
+        inst_index += 1;
+
+        assert_eq!(wc, words.len() as u16);
+        assert_eq!(op, self.op as u16);
+
+        if self.type_id.is_some() {
+            assert_eq!(words[inst_index], self.type_id.unwrap());
+            inst_index += 1;
+        }
+
+        if self.result_id.is_some() {
+            assert_eq!(words[inst_index], self.result_id.unwrap());
+            inst_index += 1;
+        }
+
+        for (op_index, i) in (inst_index..wc as usize).enumerate() {
+            assert_eq!(words[i], self.operands[op_index]);
+        }
+    }
+}
+
+#[test]
+fn test_physical_layout_in_words() {
+    let bound = 5;
+    let version = 0x10203;
+
+    let mut output = vec![];
+    let mut layout = PhysicalLayout::new(version);
+    layout.bound = bound;
+
+    layout.in_words(&mut output);
+
+    assert_eq!(&output, &[MAGIC_NUMBER, version, GENERATOR, bound, 0,]);
+}
+
+#[test]
+fn test_logical_layout_in_words() {
+    let mut output = vec![];
+    let mut layout = LogicalLayout::default();
+    let layout_vectors = 11;
+    let mut instructions = Vec::with_capacity(layout_vectors);
+
+    let vector_names = &[
+        "Capabilities",
+        "Extensions",
+        "External Instruction Imports",
+        "Memory Model",
+        "Entry Points",
+        "Execution Modes",
+        "Debugs",
+        "Annotations",
+        "Declarations",
+        "Function Declarations",
+        "Function Definitions",
+    ];
+
+    for (i, _) in vector_names.iter().enumerate().take(layout_vectors) {
+        let mut dummy_instruction = Instruction::new(Op::Constant);
+        dummy_instruction.set_type((i + 1) as u32);
+        dummy_instruction.set_result((i + 2) as u32);
+        dummy_instruction.add_operand((i + 3) as u32);
+        dummy_instruction.add_operands(super::helpers::string_to_words(
+            format!("This is the vector: {}", vector_names[i]).as_str(),
+        ));
+        instructions.push(dummy_instruction);
+    }
+
+    instructions[0].to_words(&mut layout.capabilities);
+    instructions[1].to_words(&mut layout.extensions);
+    instructions[2].to_words(&mut layout.ext_inst_imports);
+    instructions[3].to_words(&mut layout.memory_model);
+    instructions[4].to_words(&mut layout.entry_points);
+    instructions[5].to_words(&mut layout.execution_modes);
+    instructions[6].to_words(&mut layout.debugs);
+    instructions[7].to_words(&mut layout.annotations);
+    instructions[8].to_words(&mut layout.declarations);
+    instructions[9].to_words(&mut layout.function_declarations);
+    instructions[10].to_words(&mut layout.function_definitions);
+
+    layout.in_words(&mut output);
+
+    let mut index: usize = 0;
+    for instruction in instructions {
+        let wc = instruction.wc as usize;
+        instruction.validate(&output[index..index + wc]);
+        index += wc;
+    }
+}
diff --git a/third_party/rust/naga/src/back/spv/mod.rs b/third_party/rust/naga/src/back/spv/mod.rs
new file mode 100644
index 0000000000..b7d57be0d4
--- /dev/null
+++ b/third_party/rust/naga/src/back/spv/mod.rs
@@ -0,0 +1,748 @@
+/*!
+Backend for [SPIR-V][spv] (Standard Portable Intermediate Representation).
+
+[spv]: https://www.khronos.org/registry/SPIR-V/
+*/
+
+mod block;
+mod helpers;
+mod image;
+mod index;
+mod instructions;
+mod layout;
+mod ray;
+mod recyclable;
+mod selection;
+mod writer;
+
+pub use spirv::Capability;
+
+use crate::arena::Handle;
+use crate::proc::{BoundsCheckPolicies, TypeResolution};
+
+use spirv::Word;
+use std::ops;
+use thiserror::Error;
+
+#[derive(Clone)]
+struct PhysicalLayout {
+    magic_number: Word,
+    version: Word,
+    generator: Word,
+    bound: Word,
+    instruction_schema: Word,
+}
+
+#[derive(Default)]
+struct LogicalLayout {
+    capabilities: Vec<Word>,
+    extensions: Vec<Word>,
+    ext_inst_imports: Vec<Word>,
+    memory_model: Vec<Word>,
+    entry_points: Vec<Word>,
+    execution_modes: Vec<Word>,
+    debugs: Vec<Word>,
+    annotations: Vec<Word>,
+    declarations: Vec<Word>,
+    function_declarations: Vec<Word>,
+    function_definitions: Vec<Word>,
+}
+
+struct Instruction {
+    op: spirv::Op,
+    wc: u32,
+    type_id: Option<Word>,
+    result_id: Option<Word>,
+    operands: Vec<Word>,
+}
+
+const BITS_PER_BYTE: crate::Bytes = 8;
+
+#[derive(Clone, Debug, Error)]
+pub enum Error {
+    #[error("The requested entry point couldn't be found")]
+    EntryPointNotFound,
+    #[error("target SPIRV-{0}.{1} is not supported")]
+    UnsupportedVersion(u8, u8),
+    #[error("using {0} requires at least one of the capabilities {1:?}, but none are available")]
+    MissingCapabilities(&'static str, Vec<Capability>),
+    #[error("unimplemented {0}")]
+    FeatureNotImplemented(&'static str),
+    #[error("module is not validated properly: {0}")]
+    Validation(&'static str),
+}
+
+#[derive(Default)]
+struct IdGenerator(Word);
+
+impl IdGenerator {
+    fn next(&mut self) -> Word {
+        self.0 += 1;
+        self.0
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct DebugInfo<'a> {
+    pub source_code: &'a str,
+    pub file_name: &'a std::path::Path,
+}
+
+/// A SPIR-V block to which we are still adding instructions.
+///
+/// A `Block` represents a SPIR-V block that does not yet have a termination
+/// instruction like `OpBranch` or `OpReturn`.
+///
+/// The `OpLabel` that starts the block is implicit. It will be emitted based on
+/// `label_id` when we write the block to a `LogicalLayout`.
+///
+/// To terminate a `Block`, pass the block and the termination instruction to
+/// `Function::consume`. This takes ownership of the `Block` and transforms it
+/// into a `TerminatedBlock`.
+struct Block {
+    label_id: Word,
+    body: Vec<Instruction>,
+}
+
+/// A SPIR-V block that ends with a termination instruction.
+struct TerminatedBlock {
+    label_id: Word,
+    body: Vec<Instruction>,
+}
+
+impl Block {
+    const fn new(label_id: Word) -> Self {
+        Block {
+            label_id,
+            body: Vec::new(),
+        }
+    }
+}
+
+struct LocalVariable {
+    id: Word,
+    instruction: Instruction,
+}
+
+struct ResultMember {
+    id: Word,
+    type_id: Word,
+    built_in: Option<crate::BuiltIn>,
+}
+
+struct EntryPointContext {
+    argument_ids: Vec<Word>,
+    results: Vec<ResultMember>,
+}
+
+#[derive(Default)]
+struct Function {
+    signature: Option<Instruction>,
+    parameters: Vec<FunctionArgument>,
+    variables: crate::FastHashMap<Handle<crate::LocalVariable>, LocalVariable>,
+    blocks: Vec<TerminatedBlock>,
+    entry_point_context: Option<EntryPointContext>,
+}
+
+impl Function {
+    fn consume(&mut self, mut block: Block, termination: Instruction) {
+        block.body.push(termination);
+        self.blocks.push(TerminatedBlock {
+            label_id: block.label_id,
+            body: block.body,
+        })
+    }
+
+    fn parameter_id(&self, index: u32) -> Word {
+        match self.entry_point_context {
+            Some(ref context) => context.argument_ids[index as usize],
+            None => self.parameters[index as usize]
+                .instruction
+                .result_id
+                .unwrap(),
+        }
+    }
+}
+
+/// Characteristics of a SPIR-V `OpTypeImage` type.
+///
+/// SPIR-V requires non-composite types to be unique, including images. Since we
+/// use `LocalType` for this deduplication, it's essential that `LocalImageType`
+/// be equal whenever the corresponding `OpTypeImage`s would be. To reduce the
+/// likelihood of mistakes, we use fields that correspond exactly to the
+/// operands of an `OpTypeImage` instruction, using the actual SPIR-V types
+/// where practical.
+#[derive(Debug, PartialEq, Hash, Eq, Copy, Clone)]
+struct LocalImageType {
+    sampled_type: crate::ScalarKind,
+    dim: spirv::Dim,
+    flags: ImageTypeFlags,
+    image_format: spirv::ImageFormat,
+}
+
+bitflags::bitflags! {
+    /// Flags corresponding to the boolean(-ish) parameters to OpTypeImage.
+    #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
+    pub struct ImageTypeFlags: u8 {
+        const DEPTH = 0x1;
+        const ARRAYED = 0x2;
+        const MULTISAMPLED = 0x4;
+        const SAMPLED = 0x8;
+    }
+}
+
+impl LocalImageType {
+    /// Construct a `LocalImageType` from the fields of a `TypeInner::Image`.
+    fn from_inner(dim: crate::ImageDimension, arrayed: bool, class: crate::ImageClass) -> Self {
+        let make_flags = |multi: bool, other: ImageTypeFlags| -> ImageTypeFlags {
+            let mut flags = other;
+            flags.set(ImageTypeFlags::ARRAYED, arrayed);
+            flags.set(ImageTypeFlags::MULTISAMPLED, multi);
+            flags
+        };
+
+        let dim = spirv::Dim::from(dim);
+
+        match class {
+            crate::ImageClass::Sampled { kind, multi } => LocalImageType {
+                sampled_type: kind,
+                dim,
+                flags: make_flags(multi, ImageTypeFlags::SAMPLED),
+                image_format: spirv::ImageFormat::Unknown,
+            },
+            crate::ImageClass::Depth { multi } => LocalImageType {
+                sampled_type: crate::ScalarKind::Float,
+                dim,
+                flags: make_flags(multi, ImageTypeFlags::DEPTH | ImageTypeFlags::SAMPLED),
+                image_format: spirv::ImageFormat::Unknown,
+            },
+            crate::ImageClass::Storage { format, access: _ } => LocalImageType {
+                sampled_type: crate::ScalarKind::from(format),
+                dim,
+                flags: make_flags(false, ImageTypeFlags::empty()),
+                image_format: format.into(),
+            },
+        }
+    }
+}
+
+/// A SPIR-V type constructed during code generation.
+///
+/// This is the variant of [`LookupType`] used to represent types that might not
+/// be available in the arena. Variants are present here for one of two reasons:
+///
+/// -   They represent types synthesized during code generation, as explained
+///     in the documentation for [`LookupType`].
+///
+/// -   They represent types for which SPIR-V forbids duplicate `OpType...`
+///     instructions, requiring deduplication.
+///
+/// This is not a complete copy of [`TypeInner`]: for example, SPIR-V generation
+/// never synthesizes new struct types, so `LocalType` has nothing for that.
+///
+/// Each `LocalType` variant should be handled identically to its analogous
+/// `TypeInner` variant. You can use the [`make_local`] function to help with
+/// this, by converting everything possible to a `LocalType` before inspecting
+/// it.
+///
+/// ## `Localtype` equality and SPIR-V `OpType` uniqueness
+///
+/// The definition of `Eq` on `LocalType` is carefully chosen to help us follow
+/// certain SPIR-V rules. SPIR-V §2.8 requires some classes of `OpType...`
+/// instructions to be unique; for example, you can't have two `OpTypeInt 32 1`
+/// instructions in the same module. All 32-bit signed integers must use the
+/// same type id.
+///
+/// All SPIR-V types that must be unique can be represented as a `LocalType`,
+/// and two `LocalType`s are always `Eq` if SPIR-V would require them to use the
+/// same `OpType...` instruction. This lets us avoid duplicates by recording the
+/// ids of the type instructions we've already generated in a hash table,
+/// [`Writer::lookup_type`], keyed by `LocalType`.
+///
+/// As another example, [`LocalImageType`], stored in the `LocalType::Image`
+/// variant, is designed to help us deduplicate `OpTypeImage` instructions. See
+/// its documentation for details.
+///
+/// `LocalType` also includes variants like `Pointer` that do not need to be
+/// unique - but it is harmless to avoid the duplication.
+///
+/// As it always must, the `Hash` implementation respects the `Eq` relation.
+///
+/// [`TypeInner`]: crate::TypeInner
+#[derive(Debug, PartialEq, Hash, Eq, Copy, Clone)]
+enum LocalType {
+    /// A scalar, vector, or pointer to one of those.
+    Value {
+        /// If `None`, this represents a scalar type. If `Some`, this represents
+        /// a vector type of the given size.
+        vector_size: Option<crate::VectorSize>,
+        scalar: crate::Scalar,
+        pointer_space: Option<spirv::StorageClass>,
+    },
+    /// A matrix of floating-point values.
+    Matrix {
+        columns: crate::VectorSize,
+        rows: crate::VectorSize,
+        width: crate::Bytes,
+    },
+    Pointer {
+        base: Handle<crate::Type>,
+        class: spirv::StorageClass,
+    },
+    Image(LocalImageType),
+    SampledImage {
+        image_type_id: Word,
+    },
+    Sampler,
+    /// Equivalent to a [`LocalType::Pointer`] whose `base` is a Naga IR [`BindingArray`]. SPIR-V
+    /// permits duplicated `OpTypePointer` ids, so it's fine to have two different [`LocalType`]
+    /// representations for pointer types.
+    ///
+    /// [`BindingArray`]: crate::TypeInner::BindingArray
+    PointerToBindingArray {
+        base: Handle<crate::Type>,
+        size: u32,
+        space: crate::AddressSpace,
+    },
+    BindingArray {
+        base: Handle<crate::Type>,
+        size: u32,
+    },
+    AccelerationStructure,
+    RayQuery,
+}
+
+/// A type encountered during SPIR-V generation.
+///
+/// In the process of writing SPIR-V, we need to synthesize various types for
+/// intermediate results and such: pointer types, vector/matrix component types,
+/// or even booleans, which usually appear in SPIR-V code even when they're not
+/// used by the module source.
+///
+/// However, we can't use `crate::Type` or `crate::TypeInner` for these, as the
+/// type arena may not contain what we need (it only contains types used
+/// directly by other parts of the IR), and the IR module is immutable, so we
+/// can't add anything to it.
+///
+/// So for local use in the SPIR-V writer, we use this type, which holds either
+/// a handle into the arena, or a [`LocalType`] containing something synthesized
+/// locally.
+///
+/// This is very similar to the [`proc::TypeResolution`] enum, with `LocalType`
+/// playing the role of `TypeInner`. However, `LocalType` also has other
+/// properties needed for SPIR-V generation; see the description of
+/// [`LocalType`] for details.
+///
+/// [`proc::TypeResolution`]: crate::proc::TypeResolution
+#[derive(Debug, PartialEq, Hash, Eq, Copy, Clone)]
+enum LookupType {
+    Handle(Handle<crate::Type>),
+    Local(LocalType),
+}
+
+impl From<LocalType> for LookupType {
+    fn from(local: LocalType) -> Self {
+        Self::Local(local)
+    }
+}
+
+#[derive(Debug, PartialEq, Clone, Hash, Eq)]
+struct LookupFunctionType {
+    parameter_type_ids: Vec<Word>,
+    return_type_id: Word,
+}
+
+fn make_local(inner: &crate::TypeInner) -> Option<LocalType> {
+    Some(match *inner {
+        crate::TypeInner::Scalar(scalar) | crate::TypeInner::Atomic(scalar) => LocalType::Value {
+            vector_size: None,
+            scalar,
+            pointer_space: None,
+        },
+        crate::TypeInner::Vector { size, scalar } => LocalType::Value {
+            vector_size: Some(size),
+            scalar,
+            pointer_space: None,
+        },
+        crate::TypeInner::Matrix {
+            columns,
+            rows,
+            scalar,
+        } => LocalType::Matrix {
+            columns,
+            rows,
+            width: scalar.width,
+        },
+        crate::TypeInner::Pointer { base, space } => LocalType::Pointer {
+            base,
+            class: helpers::map_storage_class(space),
+        },
+        crate::TypeInner::ValuePointer {
+            size,
+            scalar,
+            space,
+        } => LocalType::Value {
+            vector_size: size,
+            scalar,
+            pointer_space: Some(helpers::map_storage_class(space)),
+        },
+        crate::TypeInner::Image {
+            dim,
+            arrayed,
+            class,
+        } => LocalType::Image(LocalImageType::from_inner(dim, arrayed, class)),
+        crate::TypeInner::Sampler { comparison: _ } => LocalType::Sampler,
+        crate::TypeInner::AccelerationStructure => LocalType::AccelerationStructure,
+        crate::TypeInner::RayQuery => LocalType::RayQuery,
+        crate::TypeInner::Array { .. }
+        | crate::TypeInner::Struct { .. }
+        | crate::TypeInner::BindingArray { .. } => return None,
+    })
+}
+
+#[derive(Debug)]
+enum Dimension {
+    Scalar,
+    Vector,
+    Matrix,
+}
+
+/// A map from evaluated [`Expression`](crate::Expression)s to their SPIR-V ids.
+///
+/// When we emit code to evaluate a given `Expression`, we record the
+/// SPIR-V id of its value here, under its `Handle<Expression>` index.
+///
+/// A `CachedExpressions` value can be indexed by a `Handle<Expression>` value.
+///
+/// [emit]: index.html#expression-evaluation-time-and-scope
+#[derive(Default)]
+struct CachedExpressions {
+    ids: Vec<Word>,
+}
+impl CachedExpressions {
+    fn reset(&mut self, length: usize) {
+        self.ids.clear();
+        self.ids.resize(length, 0);
+    }
+}
+impl ops::Index<Handle<crate::Expression>> for CachedExpressions {
+    type Output = Word;
+    fn index(&self, h: Handle<crate::Expression>) -> &Word {
+        let id = &self.ids[h.index()];
+        if *id == 0 {
+            unreachable!("Expression {:?} is not cached!", h);
+        }
+        id
+    }
+}
+impl ops::IndexMut<Handle<crate::Expression>> for CachedExpressions {
+    fn index_mut(&mut self, h: Handle<crate::Expression>) -> &mut Word {
+        let id = &mut self.ids[h.index()];
+        if *id != 0 {
+            unreachable!("Expression {:?} is already cached!", h);
+        }
+        id
+    }
+}
+impl recyclable::Recyclable for CachedExpressions {
+    fn recycle(self) -> Self {
+        CachedExpressions {
+            ids: self.ids.recycle(),
+        }
+    }
+}
+
+#[derive(Eq, Hash, PartialEq)]
+enum CachedConstant {
+    Literal(crate::Literal),
+    Composite {
+        ty: LookupType,
+        constituent_ids: Vec<Word>,
+    },
+    ZeroValue(Word),
+}
+
+#[derive(Clone)]
+struct GlobalVariable {
+    /// ID of the OpVariable that declares the global.
+    ///
+    /// If you need the variable's value, use [`access_id`] instead of this
+    /// field. If we wrapped the Naga IR `GlobalVariable`'s type in a struct to
+    /// comply with Vulkan's requirements, then this points to the `OpVariable`
+    /// with the synthesized struct type, whereas `access_id` points to the
+    /// field of said struct that holds the variable's actual value.
+    ///
+    /// This is used to compute the `access_id` pointer in function prologues,
+    /// and used for `ArrayLength` expressions, which do need the struct.
+    ///
+    /// [`access_id`]: GlobalVariable::access_id
+    var_id: Word,
+
+    /// For `AddressSpace::Handle` variables, this ID is recorded in the function
+    /// prelude block (and reset before every function) as `OpLoad` of the variable.
+    /// It is then used for all the global ops, such as `OpImageSample`.
+    handle_id: Word,
+
+    /// Actual ID used to access this variable.
+    /// For wrapped buffer variables, this ID is `OpAccessChain` into the
+    /// wrapper. Otherwise, the same as `var_id`.
+    ///
+    /// Vulkan requires that globals in the `StorageBuffer` and `Uniform` storage
+    /// classes must be structs with the `Block` decoration, but WGSL and Naga IR
+    /// make no such requirement. So for such variables, we generate a wrapper struct
+    /// type with a single element of the type given by Naga, generate an
+    /// `OpAccessChain` for that member in the function prelude, and use that pointer
+    /// to refer to the global in the function body. This is the id of that access,
+    /// updated for each function in `write_function`.
+    access_id: Word,
+}
+
+impl GlobalVariable {
+    const fn dummy() -> Self {
+        Self {
+            var_id: 0,
+            handle_id: 0,
+            access_id: 0,
+        }
+    }
+
+    const fn new(id: Word) -> Self {
+        Self {
+            var_id: id,
+            handle_id: 0,
+            access_id: 0,
+        }
+    }
+
+    /// Prepare `self` for use within a single function.
+    fn reset_for_function(&mut self) {
+        self.handle_id = 0;
+        self.access_id = 0;
+    }
+}
+
+struct FunctionArgument {
+    /// Actual instruction of the argument.
+    instruction: Instruction,
+    handle_id: Word,
+}
+
+/// General information needed to emit SPIR-V for Naga statements.
+struct BlockContext<'w> {
+    /// The writer handling the module to which this code belongs.
+    writer: &'w mut Writer,
+
+    /// The [`Module`](crate::Module) for which we're generating code.
+    ir_module: &'w crate::Module,
+
+    /// The [`Function`](crate::Function) for which we're generating code.
+    ir_function: &'w crate::Function,
+
+    /// Information module validation produced about
+    /// [`ir_function`](BlockContext::ir_function).
+    fun_info: &'w crate::valid::FunctionInfo,
+
+    /// The [`spv::Function`](Function) to which we are contributing SPIR-V instructions.
+    function: &'w mut Function,
+
+    /// SPIR-V ids for expressions we've evaluated.
+    cached: CachedExpressions,
+
+    /// The `Writer`'s temporary vector, for convenience.
+    temp_list: Vec<Word>,
+
+    /// Tracks the constness of `Expression`s residing in `self.ir_function.expressions`
+    expression_constness: crate::proc::ExpressionConstnessTracker,
+}
+
+impl BlockContext<'_> {
+    fn gen_id(&mut self) -> Word {
+        self.writer.id_gen.next()
+    }
+
+    fn get_type_id(&mut self, lookup_type: LookupType) -> Word {
+        self.writer.get_type_id(lookup_type)
+    }
+
+    fn get_expression_type_id(&mut self, tr: &TypeResolution) -> Word {
+        self.writer.get_expression_type_id(tr)
+    }
+
+    fn get_index_constant(&mut self, index: Word) -> Word {
+        self.writer.get_constant_scalar(crate::Literal::U32(index))
+    }
+
+    fn get_scope_constant(&mut self, scope: Word) -> Word {
+        self.writer
+            .get_constant_scalar(crate::Literal::I32(scope as _))
+    }
+}
+
+#[derive(Clone, Copy, Default)]
+struct LoopContext {
+    continuing_id: Option<Word>,
+    break_id: Option<Word>,
+}
+
+pub struct Writer {
+    physical_layout: PhysicalLayout,
+    logical_layout: LogicalLayout,
+    id_gen: IdGenerator,
+
+    /// The set of capabilities modules are permitted to use.
+    ///
+    /// This is initialized from `Options::capabilities`.
+    capabilities_available: Option<crate::FastHashSet<Capability>>,
+
+    /// The set of capabilities used by this module.
+    ///
+    /// If `capabilities_available` is `Some`, then this is always a subset of
+    /// that.
+    capabilities_used: crate::FastIndexSet<Capability>,
+
+    /// The set of spirv extensions used.
+    extensions_used: crate::FastIndexSet<&'static str>,
+
+    debugs: Vec<Instruction>,
+    annotations: Vec<Instruction>,
+    flags: WriterFlags,
+    bounds_check_policies: BoundsCheckPolicies,
+    zero_initialize_workgroup_memory: ZeroInitializeWorkgroupMemoryMode,
+    void_type: Word,
+    //TODO: convert most of these into vectors, addressable by handle indices
+    lookup_type: crate::FastHashMap<LookupType, Word>,
+    lookup_function: crate::FastHashMap<Handle<crate::Function>, Word>,
+    lookup_function_type: crate::FastHashMap<LookupFunctionType, Word>,
+    /// Indexed by const-expression handle indexes
+    constant_ids: Vec<Word>,
+    cached_constants: crate::FastHashMap<CachedConstant, Word>,
+    global_variables: Vec<GlobalVariable>,
+    binding_map: BindingMap,
+
+    // Cached expressions are only meaningful within a BlockContext, but we
+    // retain the table here between functions to save heap allocations.
+    saved_cached: CachedExpressions,
+
+    gl450_ext_inst_id: Word,
+
+    // Just a temporary list of SPIR-V ids
+    temp_list: Vec<Word>,
+}
+
+bitflags::bitflags! {
+    #[derive(Clone, Copy, Debug, Eq, PartialEq)]
+    pub struct WriterFlags: u32 {
+        /// Include debug labels for everything.
+        const DEBUG = 0x1;
+        /// Flip Y coordinate of `BuiltIn::Position` output.
+        const ADJUST_COORDINATE_SPACE = 0x2;
+        /// Emit `OpName` for input/output locations.
+        /// Contrary to spec, some drivers treat it as semantic, not allowing
+        /// any conflicts.
+        const LABEL_VARYINGS = 0x4;
+        /// Emit `PointSize` output builtin to vertex shaders, which is
+        /// required for drawing with `PointList` topology.
+        const FORCE_POINT_SIZE = 0x8;
+        /// Clamp `BuiltIn::FragDepth` output between 0 and 1.
+        const CLAMP_FRAG_DEPTH = 0x10;
+    }
+}
+
+#[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub struct BindingInfo {
+    /// If the binding is an unsized binding array, this overrides the size.
+    pub binding_array_size: Option<u32>,
+}
+
+// Using `BTreeMap` instead of `HashMap` so that we can hash itself.
+pub type BindingMap = std::collections::BTreeMap<crate::ResourceBinding, BindingInfo>;
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum ZeroInitializeWorkgroupMemoryMode {
+    /// Via `VK_KHR_zero_initialize_workgroup_memory` or Vulkan 1.3
+    Native,
+    /// Via assignments + barrier
+    Polyfill,
+    None,
+}
+
+#[derive(Debug, Clone)]
+pub struct Options<'a> {
+    /// (Major, Minor) target version of the SPIR-V.
+    pub lang_version: (u8, u8),
+
+    /// Configuration flags for the writer.
+    pub flags: WriterFlags,
+
+    /// Map of resources to information about the binding.
+    pub binding_map: BindingMap,
+
+    /// If given, the set of capabilities modules are allowed to use. Code that
+    /// requires capabilities beyond these is rejected with an error.
+    ///
+    /// If this is `None`, all capabilities are permitted.
+    pub capabilities: Option<crate::FastHashSet<Capability>>,
+
+    /// How should generate code handle array, vector, matrix, or image texel
+    /// indices that are out of range?
+    pub bounds_check_policies: BoundsCheckPolicies,
+
+    /// Dictates the way workgroup variables should be zero initialized
+    pub zero_initialize_workgroup_memory: ZeroInitializeWorkgroupMemoryMode,
+
+    pub debug_info: Option<DebugInfo<'a>>,
+}
+
+impl<'a> Default for Options<'a> {
+    fn default() -> Self {
+        let mut flags = WriterFlags::ADJUST_COORDINATE_SPACE
+            | WriterFlags::LABEL_VARYINGS
+            | WriterFlags::CLAMP_FRAG_DEPTH;
+        if cfg!(debug_assertions) {
+            flags |= WriterFlags::DEBUG;
+        }
+        Options {
+            lang_version: (1, 0),
+            flags,
+            binding_map: BindingMap::default(),
+            capabilities: None,
+            bounds_check_policies: crate::proc::BoundsCheckPolicies::default(),
+            zero_initialize_workgroup_memory: ZeroInitializeWorkgroupMemoryMode::Polyfill,
+            debug_info: None,
+        }
+    }
+}
+
+// A subset of options meant to be changed per pipeline.
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub struct PipelineOptions {
+    /// The stage of the entry point.
+    pub shader_stage: crate::ShaderStage,
+    /// The name of the entry point.
+    ///
+    /// If no entry point that matches is found while creating a [`Writer`], a error will be thrown.
+    pub entry_point: String,
+}
+
+pub fn write_vec(
+    module: &crate::Module,
+    info: &crate::valid::ModuleInfo,
+    options: &Options,
+    pipeline_options: Option<&PipelineOptions>,
+) -> Result<Vec<u32>, Error> {
+    let mut words: Vec<u32> = Vec::new();
+    let mut w = Writer::new(options)?;
+
+    w.write(
+        module,
+        info,
+        pipeline_options,
+        &options.debug_info,
+        &mut words,
+    )?;
+    Ok(words)
+}
diff --git a/third_party/rust/naga/src/back/spv/ray.rs b/third_party/rust/naga/src/back/spv/ray.rs
new file mode 100644
index 0000000000..bc2c4ce3c6
--- /dev/null
+++ b/third_party/rust/naga/src/back/spv/ray.rs
@@ -0,0 +1,261 @@
+/*!
+Generating SPIR-V for ray query operations.
+*/
+
+use super::{Block, BlockContext, Instruction, LocalType, LookupType};
+use crate::arena::Handle;
+
+impl<'w> BlockContext<'w> {
+    pub(super) fn write_ray_query_function(
+        &mut self,
+        query: Handle<crate::Expression>,
+        function: &crate::RayQueryFunction,
+        block: &mut Block,
+    ) {
+        let query_id = self.cached[query];
+        match *function {
+            crate::RayQueryFunction::Initialize {
+                acceleration_structure,
+                descriptor,
+            } => {
+                //Note: composite extract indices and types must match `generate_ray_desc_type`
+                let desc_id = self.cached[descriptor];
+                let acc_struct_id = self.get_handle_id(acceleration_structure);
+
+                let flag_type_id = self.get_type_id(LookupType::Local(LocalType::Value {
+                    vector_size: None,
+                    scalar: crate::Scalar::U32,
+                    pointer_space: None,
+                }));
+                let ray_flags_id = self.gen_id();
+                block.body.push(Instruction::composite_extract(
+                    flag_type_id,
+                    ray_flags_id,
+                    desc_id,
+                    &[0],
+                ));
+                let cull_mask_id = self.gen_id();
+                block.body.push(Instruction::composite_extract(
+                    flag_type_id,
+                    cull_mask_id,
+                    desc_id,
+                    &[1],
+                ));
+
+                let scalar_type_id = self.get_type_id(LookupType::Local(LocalType::Value {
+                    vector_size: None,
+                    scalar: crate::Scalar::F32,
+                    pointer_space: None,
+                }));
+                let tmin_id = self.gen_id();
+                block.body.push(Instruction::composite_extract(
+                    scalar_type_id,
+                    tmin_id,
+                    desc_id,
+                    &[2],
+                ));
+                let tmax_id = self.gen_id();
+                block.body.push(Instruction::composite_extract(
+                    scalar_type_id,
+                    tmax_id,
+                    desc_id,
+                    &[3],
+                ));
+
+                let vector_type_id = self.get_type_id(LookupType::Local(LocalType::Value {
+                    vector_size: Some(crate::VectorSize::Tri),
+                    scalar: crate::Scalar::F32,
+                    pointer_space: None,
+                }));
+                let ray_origin_id = self.gen_id();
+                block.body.push(Instruction::composite_extract(
+                    vector_type_id,
+                    ray_origin_id,
+                    desc_id,
+                    &[4],
+                ));
+                let ray_dir_id = self.gen_id();
+                block.body.push(Instruction::composite_extract(
+                    vector_type_id,
+                    ray_dir_id,
+                    desc_id,
+                    &[5],
+                ));
+
+                block.body.push(Instruction::ray_query_initialize(
+                    query_id,
+                    acc_struct_id,
+                    ray_flags_id,
+                    cull_mask_id,
+                    ray_origin_id,
+                    tmin_id,
+                    ray_dir_id,
+                    tmax_id,
+                ));
+            }
+            crate::RayQueryFunction::Proceed { result } => {
+                let id = self.gen_id();
+                self.cached[result] = id;
+                let result_type_id = self.get_expression_type_id(&self.fun_info[result].ty);
+
+                block
+                    .body
+                    .push(Instruction::ray_query_proceed(result_type_id, id, query_id));
+            }
+            crate::RayQueryFunction::Terminate => {}
+        }
+    }
+
+    pub(super) fn write_ray_query_get_intersection(
+        &mut self,
+        query: Handle<crate::Expression>,
+        block: &mut Block,
+    ) -> spirv::Word {
+        let query_id = self.cached[query];
+        let intersection_id = self.writer.get_constant_scalar(crate::Literal::U32(
+            spirv::RayQueryIntersection::RayQueryCommittedIntersectionKHR as _,
+        ));
+
+        let flag_type_id = self.get_type_id(LookupType::Local(LocalType::Value {
+            vector_size: None,
+            scalar: crate::Scalar::U32,
+            pointer_space: None,
+        }));
+        let kind_id = self.gen_id();
+        block.body.push(Instruction::ray_query_get_intersection(
+            spirv::Op::RayQueryGetIntersectionTypeKHR,
+            flag_type_id,
+            kind_id,
+            query_id,
+            intersection_id,
+        ));
+        let instance_custom_index_id = self.gen_id();
+        block.body.push(Instruction::ray_query_get_intersection(
+            spirv::Op::RayQueryGetIntersectionInstanceCustomIndexKHR,
+            flag_type_id,
+            instance_custom_index_id,
+            query_id,
+            intersection_id,
+        ));
+        let instance_id = self.gen_id();
+        block.body.push(Instruction::ray_query_get_intersection(
+            spirv::Op::RayQueryGetIntersectionInstanceIdKHR,
+            flag_type_id,
+            instance_id,
+            query_id,
+            intersection_id,
+        ));
+        let sbt_record_offset_id = self.gen_id();
+        block.body.push(Instruction::ray_query_get_intersection(
+            spirv::Op::RayQueryGetIntersectionInstanceShaderBindingTableRecordOffsetKHR,
+            flag_type_id,
+            sbt_record_offset_id,
+            query_id,
+            intersection_id,
+        ));
+        let geometry_index_id = self.gen_id();
+        block.body.push(Instruction::ray_query_get_intersection(
+            spirv::Op::RayQueryGetIntersectionGeometryIndexKHR,
+            flag_type_id,
+            geometry_index_id,
+            query_id,
+            intersection_id,
+        ));
+        let primitive_index_id = self.gen_id();
+        block.body.push(Instruction::ray_query_get_intersection(
+            spirv::Op::RayQueryGetIntersectionPrimitiveIndexKHR,
+            flag_type_id,
+            primitive_index_id,
+            query_id,
+            intersection_id,
+        ));
+
+        let scalar_type_id = self.get_type_id(LookupType::Local(LocalType::Value {
+            vector_size: None,
+            scalar: crate::Scalar::F32,
+            pointer_space: None,
+        }));
+        let t_id = self.gen_id();
+        block.body.push(Instruction::ray_query_get_intersection(
+            spirv::Op::RayQueryGetIntersectionTKHR,
+            scalar_type_id,
+            t_id,
+            query_id,
+            intersection_id,
+        ));
+
+        let barycentrics_type_id = self.get_type_id(LookupType::Local(LocalType::Value {
+            vector_size: Some(crate::VectorSize::Bi),
+            scalar: crate::Scalar::F32,
+            pointer_space: None,
+        }));
+        let barycentrics_id = self.gen_id();
+        block.body.push(Instruction::ray_query_get_intersection(
+            spirv::Op::RayQueryGetIntersectionBarycentricsKHR,
+            barycentrics_type_id,
+            barycentrics_id,
+            query_id,
+            intersection_id,
+        ));
+
+        let bool_type_id = self.get_type_id(LookupType::Local(LocalType::Value {
+            vector_size: None,
+            scalar: crate::Scalar::BOOL,
+            pointer_space: None,
+        }));
+        let front_face_id = self.gen_id();
+        block.body.push(Instruction::ray_query_get_intersection(
+            spirv::Op::RayQueryGetIntersectionFrontFaceKHR,
+            bool_type_id,
+            front_face_id,
+            query_id,
+            intersection_id,
+        ));
+
+        let transform_type_id = self.get_type_id(LookupType::Local(LocalType::Matrix {
+            columns: crate::VectorSize::Quad,
+            rows: crate::VectorSize::Tri,
+            width: 4,
+        }));
+        let object_to_world_id = self.gen_id();
+        block.body.push(Instruction::ray_query_get_intersection(
+            spirv::Op::RayQueryGetIntersectionObjectToWorldKHR,
+            transform_type_id,
+            object_to_world_id,
+            query_id,
+            intersection_id,
+        ));
+        let world_to_object_id = self.gen_id();
+        block.body.push(Instruction::ray_query_get_intersection(
+            spirv::Op::RayQueryGetIntersectionWorldToObjectKHR,
+            transform_type_id,
+            world_to_object_id,
+            query_id,
+            intersection_id,
+        ));
+
+        let id = self.gen_id();
+        let intersection_type_id = self.get_type_id(LookupType::Handle(
+            self.ir_module.special_types.ray_intersection.unwrap(),
+        ));
+        //Note: the arguments must match `generate_ray_intersection_type` layout
+        block.body.push(Instruction::composite_construct(
+            intersection_type_id,
+            id,
+            &[
+                kind_id,
+                t_id,
+                instance_custom_index_id,
+                instance_id,
+                sbt_record_offset_id,
+                geometry_index_id,
+                primitive_index_id,
+                barycentrics_id,
+                front_face_id,
+                object_to_world_id,
+                world_to_object_id,
+            ],
+        ));
+        id
+    }
+}
diff --git a/third_party/rust/naga/src/back/spv/recyclable.rs b/third_party/rust/naga/src/back/spv/recyclable.rs
new file mode 100644
index 0000000000..cd1466e3c7
--- /dev/null
+++ b/third_party/rust/naga/src/back/spv/recyclable.rs
@@ -0,0 +1,67 @@
+/*!
+Reusing collections' previous allocations.
+*/
+
+/// A value that can be reset to its initial state, retaining its current allocations.
+///
+/// Naga attempts to lower the cost of SPIR-V generation by allowing clients to
+/// reuse the same `Writer` for multiple Module translations. Reusing a `Writer`
+/// means that the `Vec`s, `HashMap`s, and other heap-allocated structures the
+/// `Writer` uses internally begin the translation with heap-allocated buffers
+/// ready to use.
+///
+/// But this approach introduces the risk of `Writer` state leaking from one
+/// module to the next. When a developer adds fields to `Writer` or its internal
+/// types, they must remember to reset their contents between modules.
+///
+/// One trick to ensure that every field has been accounted for is to use Rust's
+/// struct literal syntax to construct a new, reset value. If a developer adds a
+/// field, but neglects to update the reset code, the compiler will complain
+/// that a field is missing from the literal. This trait's `recycle` method
+/// takes `self` by value, and returns `Self` by value, encouraging the use of
+/// struct literal expressions in its implementation.
+pub trait Recyclable {
+    /// Clear `self`, retaining its current memory allocations.
+    ///
+    /// Shrink the buffer if it's currently much larger than was actually used.
+    /// This prevents a module with exceptionally large allocations from causing
+    /// the `Writer` to retain more memory than it needs indefinitely.
+    fn recycle(self) -> Self;
+}
+
+// Stock values for various collections.
+
+impl<T> Recyclable for Vec<T> {
+    fn recycle(mut self) -> Self {
+        self.clear();
+        self
+    }
+}
+
+impl<K, V, S: Clone> Recyclable for std::collections::HashMap<K, V, S> {
+    fn recycle(mut self) -> Self {
+        self.clear();
+        self
+    }
+}
+
+impl<K, S: Clone> Recyclable for std::collections::HashSet<K, S> {
+    fn recycle(mut self) -> Self {
+        self.clear();
+        self
+    }
+}
+
+impl<K, S: Clone> Recyclable for indexmap::IndexSet<K, S> {
+    fn recycle(mut self) -> Self {
+        self.clear();
+        self
+    }
+}
+
+impl<K: Ord, V> Recyclable for std::collections::BTreeMap<K, V> {
+    fn recycle(mut self) -> Self {
+        self.clear();
+        self
+    }
+}
diff --git a/third_party/rust/naga/src/back/spv/selection.rs b/third_party/rust/naga/src/back/spv/selection.rs
new file mode 100644
index 0000000000..788b1f10ab
--- /dev/null
+++ b/third_party/rust/naga/src/back/spv/selection.rs
@@ -0,0 +1,257 @@
+/*!
+Generate SPIR-V conditional structures.
+
+Builders for `if` structures with `and`s.
+
+The types in this module track the information needed to emit SPIR-V code
+for complex conditional structures, like those whose conditions involve
+short-circuiting 'and' and 'or' structures. These track labels and can emit
+`OpPhi` instructions to merge values produced along different paths.
+
+This currently only supports exactly the forms Naga uses, so it doesn't
+support `or` or `else`, and only supports zero or one merged values.
+
+Naga needs to emit code roughly like this:
+
+```ignore
+
+    value = DEFAULT;
+    if COND1 && COND2 {
+        value = THEN_VALUE;
+    }
+    // use value
+
+```
+
+Assuming `ctx` and `block` are a mutable references to a [`BlockContext`]
+and the current [`Block`], and `merge_type` is the SPIR-V type for the
+merged value `value`, we can build SPIR-V for the code above like so:
+
+```ignore
+
+    let cond = Selection::start(block, merge_type);
+        // ... compute `cond1` ...
+    cond.if_true(ctx, cond1, DEFAULT);
+        // ... compute `cond2` ...
+    cond.if_true(ctx, cond2, DEFAULT);
+        // ... compute THEN_VALUE
+    let merged_value = cond.finish(ctx, THEN_VALUE);
+
+```
+
+After this, `merged_value` is either `DEFAULT` or `THEN_VALUE`, depending on
+the path by which the merged block was reached.
+
+This takes care of writing all branch instructions, including an
+`OpSelectionMerge` annotation in the header block; starting new blocks and
+assigning them labels; and emitting the `OpPhi` that gathers together the
+right sources for the merged values, for every path through the selection
+construct.
+
+When there is no merged value to produce, you can pass `()` for `merge_type`
+and the merge values. In this case no `OpPhi` instructions are produced, and
+the `finish` method returns `()`.
+
+To enforce proper nesting, a `Selection` takes ownership of the `&mut Block`
+pointer for the duration of its lifetime. To obtain the block for generating
+code in the selection's body, call the `Selection::block` method.
+*/
+
+use super::{Block, BlockContext, Instruction};
+use spirv::Word;
+
+/// A private struct recording what we know about the selection construct so far.
+pub(super) struct Selection<'b, M: MergeTuple> {
+    /// The block pointer we're emitting code into.
+    block: &'b mut Block,
+
+    /// The label of the selection construct's merge block, or `None` if we
+    /// haven't yet written the `OpSelectionMerge` merge instruction.
+    merge_label: Option<Word>,
+
+    /// A set of `(VALUES, PARENT)` pairs, used to build `OpPhi` instructions in
+    /// the merge block. Each `PARENT` is the label of a predecessor block of
+    /// the merge block. The corresponding `VALUES` holds the ids of the values
+    /// that `PARENT` contributes to the merged values.
+    ///
+    /// We emit all branches to the merge block, so we know all its
+    /// predecessors. And we refuse to emit a branch unless we're given the
+    /// values the branching block contributes to the merge, so we always have
+    /// everything we need to emit the correct phis, by construction.
+    values: Vec<(M, Word)>,
+
+    /// The types of the values in each element of `values`.
+    merge_types: M,
+}
+
+impl<'b, M: MergeTuple> Selection<'b, M> {
+    /// Start a new selection construct.
+    ///
+    /// The `block` argument indicates the selection's header block.
+    ///
+    /// The `merge_types` argument should be a `Word` or tuple of `Word`s, each
+    /// value being the SPIR-V result type id of an `OpPhi` instruction that
+    /// will be written to the selection's merge block when this selection's
+    /// [`finish`] method is called. This argument may also be `()`, for
+    /// selections that produce no values.
+    ///
+    /// (This function writes no code to `block` itself; it simply constructs a
+    /// fresh `Selection`.)
+    ///
+    /// [`finish`]: Selection::finish
+    pub(super) fn start(block: &'b mut Block, merge_types: M) -> Self {
+        Selection {
+            block,
+            merge_label: None,
+            values: vec![],
+            merge_types,
+        }
+    }
+
+    pub(super) fn block(&mut self) -> &mut Block {
+        self.block
+    }
+
+    /// Branch to a successor block if `cond` is true, otherwise merge.
+    ///
+    /// If `cond` is false, branch to the merge block, using `values` as the
+    /// merged values. Otherwise, proceed to a new block.
+    ///
+    /// The `values` argument must be the same shape as the `merge_types`
+    /// argument passed to `Selection::start`.
+    pub(super) fn if_true(&mut self, ctx: &mut BlockContext, cond: Word, values: M) {
+        self.values.push((values, self.block.label_id));
+
+        let merge_label = self.make_merge_label(ctx);
+        let next_label = ctx.gen_id();
+        ctx.function.consume(
+            std::mem::replace(self.block, Block::new(next_label)),
+            Instruction::branch_conditional(cond, next_label, merge_label),
+        );
+    }
+
+    /// Emit an unconditional branch to the merge block, and compute merged
+    /// values.
+    ///
+    /// Use `final_values` as the merged values contributed by the current
+    /// block, and transition to the merge block, emitting `OpPhi` instructions
+    /// to produce the merged values. This must be the same shape as the
+    /// `merge_types` argument passed to [`Selection::start`].
+    ///
+    /// Return the SPIR-V ids of the merged values. This value has the same
+    /// shape as the `merge_types` argument passed to `Selection::start`.
+    pub(super) fn finish(self, ctx: &mut BlockContext, final_values: M) -> M {
+        match self {
+            Selection {
+                merge_label: None, ..
+            } => {
+                // We didn't actually emit any branches, so `self.values` must
+                // be empty, and `final_values` are the only sources we have for
+                // the merged values. Easy peasy.
+                final_values
+            }
+
+            Selection {
+                block,
+                merge_label: Some(merge_label),
+                mut values,
+                merge_types,
+            } => {
+                // Emit the final branch and transition to the merge block.
+                values.push((final_values, block.label_id));
+                ctx.function.consume(
+                    std::mem::replace(block, Block::new(merge_label)),
+                    Instruction::branch(merge_label),
+                );
+
+                // Now that we're in the merge block, build the phi instructions.
+                merge_types.write_phis(ctx, block, &values)
+            }
+        }
+    }
+
+    /// Return the id of the merge block, writing a merge instruction if needed.
+    fn make_merge_label(&mut self, ctx: &mut BlockContext) -> Word {
+        match self.merge_label {
+            None => {
+                let merge_label = ctx.gen_id();
+                self.block.body.push(Instruction::selection_merge(
+                    merge_label,
+                    spirv::SelectionControl::NONE,
+                ));
+                self.merge_label = Some(merge_label);
+                merge_label
+            }
+            Some(merge_label) => merge_label,
+        }
+    }
+}
+
+/// A trait to help `Selection` manage any number of merged values.
+///
+/// Some selection constructs, like a `ReadZeroSkipWrite` bounds check on a
+/// [`Load`] expression, produce a single merged value. Others produce no merged
+/// value, like a bounds check on a [`Store`] statement.
+///
+/// To let `Selection` work nicely with both cases, we let the merge type
+/// argument passed to [`Selection::start`] be any type that implements this
+/// `MergeTuple` trait. `MergeTuple` is then implemented for `()`, `Word`,
+/// `(Word, Word)`, and so on.
+///
+/// A `MergeTuple` type can represent either a bunch of SPIR-V types or values;
+/// the `merge_types` argument to `Selection::start` are type ids, whereas the
+/// `values` arguments to the [`if_true`] and [`finish`] methods are value ids.
+/// The set of merged value returned by `finish` is a tuple of value ids.
+///
+/// In fact, since Naga only uses zero- and single-valued selection constructs
+/// at present, we only implement `MergeTuple` for `()` and `Word`. But if you
+/// add more cases, feel free to add more implementations. Once const generics
+/// are available, we could have a single implementation of `MergeTuple` for all
+/// lengths of arrays, and be done with it.
+///
+/// [`Load`]: crate::Expression::Load
+/// [`Store`]: crate::Statement::Store
+/// [`if_true`]: Selection::if_true
+/// [`finish`]: Selection::finish
+pub(super) trait MergeTuple: Sized {
+    /// Write OpPhi instructions for the given set of predecessors.
+    ///
+    /// The `predecessors` vector should be a vector of `(LABEL, VALUES)` pairs,
+    /// where each `VALUES` holds the values contributed by the branch from
+    /// `LABEL`, which should be one of the current block's predecessors.
+    fn write_phis(
+        self,
+        ctx: &mut BlockContext,
+        block: &mut Block,
+        predecessors: &[(Self, Word)],
+    ) -> Self;
+}
+
+/// Selections that produce a single merged value.
+///
+/// For example, `ImageLoad` with `BoundsCheckPolicy::ReadZeroSkipWrite` either
+/// returns a texel value or zeros.
+impl MergeTuple for Word {
+    fn write_phis(
+        self,
+        ctx: &mut BlockContext,
+        block: &mut Block,
+        predecessors: &[(Word, Word)],
+    ) -> Word {
+        let merged_value = ctx.gen_id();
+        block
+            .body
+            .push(Instruction::phi(self, merged_value, predecessors));
+        merged_value
+    }
+}
+
+/// Selections that produce no merged values.
+///
+/// For example, `ImageStore` under `BoundsCheckPolicy::ReadZeroSkipWrite`
+/// either does the store or skips it, but in neither case does it produce a
+/// value.
+impl MergeTuple for () {
+    /// No phis need to be generated.
+    fn write_phis(self, _: &mut BlockContext, _: &mut Block, _: &[((), Word)]) {}
+}
diff --git a/third_party/rust/naga/src/back/spv/writer.rs b/third_party/rust/naga/src/back/spv/writer.rs
new file mode 100644
index 0000000000..4db86c93a7
--- /dev/null
+++ b/third_party/rust/naga/src/back/spv/writer.rs
@@ -0,0 +1,2063 @@
+use super::{
+    block::DebugInfoInner,
+    helpers::{contains_builtin, global_needs_wrapper, map_storage_class},
+    make_local, Block, BlockContext, CachedConstant, CachedExpressions, DebugInfo,
+    EntryPointContext, Error, Function, FunctionArgument, GlobalVariable, IdGenerator, Instruction,
+    LocalType, LocalVariable, LogicalLayout, LookupFunctionType, LookupType, LoopContext, Options,
+    PhysicalLayout, PipelineOptions, ResultMember, Writer, WriterFlags, BITS_PER_BYTE,
+};
+use crate::{
+    arena::{Handle, UniqueArena},
+    back::spv::BindingInfo,
+    proc::{Alignment, TypeResolution},
+    valid::{FunctionInfo, ModuleInfo},
+};
+use spirv::Word;
+use std::collections::hash_map::Entry;
+
+struct FunctionInterface<'a> {
+    varying_ids: &'a mut Vec<Word>,
+    stage: crate::ShaderStage,
+}
+
+impl Function {
+    fn to_words(&self, sink: &mut impl Extend<Word>) {
+        self.signature.as_ref().unwrap().to_words(sink);
+        for argument in self.parameters.iter() {
+            argument.instruction.to_words(sink);
+        }
+        for (index, block) in self.blocks.iter().enumerate() {
+            Instruction::label(block.label_id).to_words(sink);
+            if index == 0 {
+                for local_var in self.variables.values() {
+                    local_var.instruction.to_words(sink);
+                }
+            }
+            for instruction in block.body.iter() {
+                instruction.to_words(sink);
+            }
+        }
+    }
+}
+
+impl Writer {
+    pub fn new(options: &Options) -> Result<Self, Error> {
+        let (major, minor) = options.lang_version;
+        if major != 1 {
+            return Err(Error::UnsupportedVersion(major, minor));
+        }
+        let raw_version = ((major as u32) << 16) | ((minor as u32) << 8);
+
+        let mut capabilities_used = crate::FastIndexSet::default();
+        capabilities_used.insert(spirv::Capability::Shader);
+
+        let mut id_gen = IdGenerator::default();
+        let gl450_ext_inst_id = id_gen.next();
+        let void_type = id_gen.next();
+
+        Ok(Writer {
+            physical_layout: PhysicalLayout::new(raw_version),
+            logical_layout: LogicalLayout::default(),
+            id_gen,
+            capabilities_available: options.capabilities.clone(),
+            capabilities_used,
+            extensions_used: crate::FastIndexSet::default(),
+            debugs: vec![],
+            annotations: vec![],
+            flags: options.flags,
+            bounds_check_policies: options.bounds_check_policies,
+            zero_initialize_workgroup_memory: options.zero_initialize_workgroup_memory,
+            void_type,
+            lookup_type: crate::FastHashMap::default(),
+            lookup_function: crate::FastHashMap::default(),
+            lookup_function_type: crate::FastHashMap::default(),
+            constant_ids: Vec::new(),
+            cached_constants: crate::FastHashMap::default(),
+            global_variables: Vec::new(),
+            binding_map: options.binding_map.clone(),
+            saved_cached: CachedExpressions::default(),
+            gl450_ext_inst_id,
+            temp_list: Vec::new(),
+        })
+    }
+
+    /// Reset `Writer` to its initial state, retaining any allocations.
+    ///
+    /// Why not just implement `Recyclable` for `Writer`? By design,
+    /// `Recyclable::recycle` requires ownership of the value, not just
+    /// `&mut`; see the trait documentation. But we need to use this method
+    /// from functions like `Writer::write`, which only have `&mut Writer`.
+    /// Workarounds include unsafe code (`std::ptr::read`, then `write`, ugh)
+    /// or something like a `Default` impl that returns an oddly-initialized
+    /// `Writer`, which is worse.
+    fn reset(&mut self) {
+        use super::recyclable::Recyclable;
+        use std::mem::take;
+
+        let mut id_gen = IdGenerator::default();
+        let gl450_ext_inst_id = id_gen.next();
+        let void_type = id_gen.next();
+
+        // Every field of the old writer that is not determined by the `Options`
+        // passed to `Writer::new` should be reset somehow.
+        let fresh = Writer {
+            // Copied from the old Writer:
+            flags: self.flags,
+            bounds_check_policies: self.bounds_check_policies,
+            zero_initialize_workgroup_memory: self.zero_initialize_workgroup_memory,
+            capabilities_available: take(&mut self.capabilities_available),
+            binding_map: take(&mut self.binding_map),
+
+            // Initialized afresh:
+            id_gen,
+            void_type,
+            gl450_ext_inst_id,
+
+            // Recycled:
+            capabilities_used: take(&mut self.capabilities_used).recycle(),
+            extensions_used: take(&mut self.extensions_used).recycle(),
+            physical_layout: self.physical_layout.clone().recycle(),
+            logical_layout: take(&mut self.logical_layout).recycle(),
+            debugs: take(&mut self.debugs).recycle(),
+            annotations: take(&mut self.annotations).recycle(),
+            lookup_type: take(&mut self.lookup_type).recycle(),
+            lookup_function: take(&mut self.lookup_function).recycle(),
+            lookup_function_type: take(&mut self.lookup_function_type).recycle(),
+            constant_ids: take(&mut self.constant_ids).recycle(),
+            cached_constants: take(&mut self.cached_constants).recycle(),
+            global_variables: take(&mut self.global_variables).recycle(),
+            saved_cached: take(&mut self.saved_cached).recycle(),
+            temp_list: take(&mut self.temp_list).recycle(),
+        };
+
+        *self = fresh;
+
+        self.capabilities_used.insert(spirv::Capability::Shader);
+    }
+
+    /// Indicate that the code requires any one of the listed capabilities.
+    ///
+    /// If nothing in `capabilities` appears in the available capabilities
+    /// specified in the [`Options`] from which this `Writer` was created,
+    /// return an error. The `what` string is used in the error message to
+    /// explain what provoked the requirement. (If no available capabilities were
+    /// given, assume everything is available.)
+    ///
+    /// The first acceptable capability will be added to this `Writer`'s
+    /// [`capabilities_used`] table, and an `OpCapability` emitted for it in the
+    /// result. For this reason, more specific capabilities should be listed
+    /// before more general.
+    ///
+    /// [`capabilities_used`]: Writer::capabilities_used
+    pub(super) fn require_any(
+        &mut self,
+        what: &'static str,
+        capabilities: &[spirv::Capability],
+    ) -> Result<(), Error> {
+        match *capabilities {
+            [] => Ok(()),
+            [first, ..] => {
+                // Find the first acceptable capability, or return an error if
+                // there is none.
+                let selected = match self.capabilities_available {
+                    None => first,
+                    Some(ref available) => {
+                        match capabilities.iter().find(|cap| available.contains(cap)) {
+                            Some(&cap) => cap,
+                            None => {
+                                return Err(Error::MissingCapabilities(what, capabilities.to_vec()))
+                            }
+                        }
+                    }
+                };
+                self.capabilities_used.insert(selected);
+                Ok(())
+            }
+        }
+    }
+
+    /// Indicate that the code uses the given extension.
+    pub(super) fn use_extension(&mut self, extension: &'static str) {
+        self.extensions_used.insert(extension);
+    }
+
+    pub(super) fn get_type_id(&mut self, lookup_ty: LookupType) -> Word {
+        match self.lookup_type.entry(lookup_ty) {
+            Entry::Occupied(e) => *e.get(),
+            Entry::Vacant(e) => {
+                let local = match lookup_ty {
+                    LookupType::Handle(_handle) => unreachable!("Handles are populated at start"),
+                    LookupType::Local(local) => local,
+                };
+
+                let id = self.id_gen.next();
+                e.insert(id);
+                self.write_type_declaration_local(id, local);
+                id
+            }
+        }
+    }
+
+    pub(super) fn get_expression_lookup_type(&mut self, tr: &TypeResolution) -> LookupType {
+        match *tr {
+            TypeResolution::Handle(ty_handle) => LookupType::Handle(ty_handle),
+            TypeResolution::Value(ref inner) => LookupType::Local(make_local(inner).unwrap()),
+        }
+    }
+
+    pub(super) fn get_expression_type_id(&mut self, tr: &TypeResolution) -> Word {
+        let lookup_ty = self.get_expression_lookup_type(tr);
+        self.get_type_id(lookup_ty)
+    }
+
+    pub(super) fn get_pointer_id(
+        &mut self,
+        arena: &UniqueArena<crate::Type>,
+        handle: Handle<crate::Type>,
+        class: spirv::StorageClass,
+    ) -> Result<Word, Error> {
+        let ty_id = self.get_type_id(LookupType::Handle(handle));
+        if let crate::TypeInner::Pointer { .. } = arena[handle].inner {
+            return Ok(ty_id);
+        }
+        let lookup_type = LookupType::Local(LocalType::Pointer {
+            base: handle,
+            class,
+        });
+        Ok(if let Some(&id) = self.lookup_type.get(&lookup_type) {
+            id
+        } else {
+            let id = self.id_gen.next();
+            let instruction = Instruction::type_pointer(id, class, ty_id);
+            instruction.to_words(&mut self.logical_layout.declarations);
+            self.lookup_type.insert(lookup_type, id);
+            id
+        })
+    }
+
+    pub(super) fn get_uint_type_id(&mut self) -> Word {
+        let local_type = LocalType::Value {
+            vector_size: None,
+            scalar: crate::Scalar::U32,
+            pointer_space: None,
+        };
+        self.get_type_id(local_type.into())
+    }
+
+    pub(super) fn get_float_type_id(&mut self) -> Word {
+        let local_type = LocalType::Value {
+            vector_size: None,
+            scalar: crate::Scalar::F32,
+            pointer_space: None,
+        };
+        self.get_type_id(local_type.into())
+    }
+
+    pub(super) fn get_uint3_type_id(&mut self) -> Word {
+        let local_type = LocalType::Value {
+            vector_size: Some(crate::VectorSize::Tri),
+            scalar: crate::Scalar::U32,
+            pointer_space: None,
+        };
+        self.get_type_id(local_type.into())
+    }
+
+    pub(super) fn get_float_pointer_type_id(&mut self, class: spirv::StorageClass) -> Word {
+        let lookup_type = LookupType::Local(LocalType::Value {
+            vector_size: None,
+            scalar: crate::Scalar::F32,
+            pointer_space: Some(class),
+        });
+        if let Some(&id) = self.lookup_type.get(&lookup_type) {
+            id
+        } else {
+            let id = self.id_gen.next();
+            let ty_id = self.get_float_type_id();
+            let instruction = Instruction::type_pointer(id, class, ty_id);
+            instruction.to_words(&mut self.logical_layout.declarations);
+            self.lookup_type.insert(lookup_type, id);
+            id
+        }
+    }
+
+    pub(super) fn get_uint3_pointer_type_id(&mut self, class: spirv::StorageClass) -> Word {
+        let lookup_type = LookupType::Local(LocalType::Value {
+            vector_size: Some(crate::VectorSize::Tri),
+            scalar: crate::Scalar::U32,
+            pointer_space: Some(class),
+        });
+        if let Some(&id) = self.lookup_type.get(&lookup_type) {
+            id
+        } else {
+            let id = self.id_gen.next();
+            let ty_id = self.get_uint3_type_id();
+            let instruction = Instruction::type_pointer(id, class, ty_id);
+            instruction.to_words(&mut self.logical_layout.declarations);
+            self.lookup_type.insert(lookup_type, id);
+            id
+        }
+    }
+
+    pub(super) fn get_bool_type_id(&mut self) -> Word {
+        let local_type = LocalType::Value {
+            vector_size: None,
+            scalar: crate::Scalar::BOOL,
+            pointer_space: None,
+        };
+        self.get_type_id(local_type.into())
+    }
+
+    pub(super) fn get_bool3_type_id(&mut self) -> Word {
+        let local_type = LocalType::Value {
+            vector_size: Some(crate::VectorSize::Tri),
+            scalar: crate::Scalar::BOOL,
+            pointer_space: None,
+        };
+        self.get_type_id(local_type.into())
+    }
+
+    pub(super) fn decorate(&mut self, id: Word, decoration: spirv::Decoration, operands: &[Word]) {
+        self.annotations
+            .push(Instruction::decorate(id, decoration, operands));
+    }
+
+    fn write_function(
+        &mut self,
+        ir_function: &crate::Function,
+        info: &FunctionInfo,
+        ir_module: &crate::Module,
+        mut interface: Option<FunctionInterface>,
+        debug_info: &Option<DebugInfoInner>,
+    ) -> Result<Word, Error> {
+        let mut function = Function::default();
+
+        let prelude_id = self.id_gen.next();
+        let mut prelude = Block::new(prelude_id);
+        let mut ep_context = EntryPointContext {
+            argument_ids: Vec::new(),
+            results: Vec::new(),
+        };
+
+        let mut local_invocation_id = None;
+
+        let mut parameter_type_ids = Vec::with_capacity(ir_function.arguments.len());
+        for argument in ir_function.arguments.iter() {
+            let class = spirv::StorageClass::Input;
+            let handle_ty = ir_module.types[argument.ty].inner.is_handle();
+            let argument_type_id = match handle_ty {
+                true => self.get_pointer_id(
+                    &ir_module.types,
+                    argument.ty,
+                    spirv::StorageClass::UniformConstant,
+                )?,
+                false => self.get_type_id(LookupType::Handle(argument.ty)),
+            };
+
+            if let Some(ref mut iface) = interface {
+                let id = if let Some(ref binding) = argument.binding {
+                    let name = argument.name.as_deref();
+
+                    let varying_id = self.write_varying(
+                        ir_module,
+                        iface.stage,
+                        class,
+                        name,
+                        argument.ty,
+                        binding,
+                    )?;
+                    iface.varying_ids.push(varying_id);
+                    let id = self.id_gen.next();
+                    prelude
+                        .body
+                        .push(Instruction::load(argument_type_id, id, varying_id, None));
+
+                    if binding == &crate::Binding::BuiltIn(crate::BuiltIn::LocalInvocationId) {
+                        local_invocation_id = Some(id);
+                    }
+
+                    id
+                } else if let crate::TypeInner::Struct { ref members, .. } =
+                    ir_module.types[argument.ty].inner
+                {
+                    let struct_id = self.id_gen.next();
+                    let mut constituent_ids = Vec::with_capacity(members.len());
+                    for member in members {
+                        let type_id = self.get_type_id(LookupType::Handle(member.ty));
+                        let name = member.name.as_deref();
+                        let binding = member.binding.as_ref().unwrap();
+                        let varying_id = self.write_varying(
+                            ir_module,
+                            iface.stage,
+                            class,
+                            name,
+                            member.ty,
+                            binding,
+                        )?;
+                        iface.varying_ids.push(varying_id);
+                        let id = self.id_gen.next();
+                        prelude
+                            .body
+                            .push(Instruction::load(type_id, id, varying_id, None));
+                        constituent_ids.push(id);
+
+                        if binding == &crate::Binding::BuiltIn(crate::BuiltIn::GlobalInvocationId) {
+                            local_invocation_id = Some(id);
+                        }
+                    }
+                    prelude.body.push(Instruction::composite_construct(
+                        argument_type_id,
+                        struct_id,
+                        &constituent_ids,
+                    ));
+                    struct_id
+                } else {
+                    unreachable!("Missing argument binding on an entry point");
+                };
+                ep_context.argument_ids.push(id);
+            } else {
+                let argument_id = self.id_gen.next();
+                let instruction = Instruction::function_parameter(argument_type_id, argument_id);
+                if self.flags.contains(WriterFlags::DEBUG) {
+                    if let Some(ref name) = argument.name {
+                        self.debugs.push(Instruction::name(argument_id, name));
+                    }
+                }
+                function.parameters.push(FunctionArgument {
+                    instruction,
+                    handle_id: if handle_ty {
+                        let id = self.id_gen.next();
+                        prelude.body.push(Instruction::load(
+                            self.get_type_id(LookupType::Handle(argument.ty)),
+                            id,
+                            argument_id,
+                            None,
+                        ));
+                        id
+                    } else {
+                        0
+                    },
+                });
+                parameter_type_ids.push(argument_type_id);
+            };
+        }
+
+        let return_type_id = match ir_function.result {
+            Some(ref result) => {
+                if let Some(ref mut iface) = interface {
+                    let mut has_point_size = false;
+                    let class = spirv::StorageClass::Output;
+                    if let Some(ref binding) = result.binding {
+                        has_point_size |=
+                            *binding == crate::Binding::BuiltIn(crate::BuiltIn::PointSize);
+                        let type_id = self.get_type_id(LookupType::Handle(result.ty));
+                        let varying_id = self.write_varying(
+                            ir_module,
+                            iface.stage,
+                            class,
+                            None,
+                            result.ty,
+                            binding,
+                        )?;
+                        iface.varying_ids.push(varying_id);
+                        ep_context.results.push(ResultMember {
+                            id: varying_id,
+                            type_id,
+                            built_in: binding.to_built_in(),
+                        });
+                    } else if let crate::TypeInner::Struct { ref members, .. } =
+                        ir_module.types[result.ty].inner
+                    {
+                        for member in members {
+                            let type_id = self.get_type_id(LookupType::Handle(member.ty));
+                            let name = member.name.as_deref();
+                            let binding = member.binding.as_ref().unwrap();
+                            has_point_size |=
+                                *binding == crate::Binding::BuiltIn(crate::BuiltIn::PointSize);
+                            let varying_id = self.write_varying(
+                                ir_module,
+                                iface.stage,
+                                class,
+                                name,
+                                member.ty,
+                                binding,
+                            )?;
+                            iface.varying_ids.push(varying_id);
+                            ep_context.results.push(ResultMember {
+                                id: varying_id,
+                                type_id,
+                                built_in: binding.to_built_in(),
+                            });
+                        }
+                    } else {
+                        unreachable!("Missing result binding on an entry point");
+                    }
+
+                    if self.flags.contains(WriterFlags::FORCE_POINT_SIZE)
+                        && iface.stage == crate::ShaderStage::Vertex
+                        && !has_point_size
+                    {
+                        // add point size artificially
+                        let varying_id = self.id_gen.next();
+                        let pointer_type_id = self.get_float_pointer_type_id(class);
+                        Instruction::variable(pointer_type_id, varying_id, class, None)
+                            .to_words(&mut self.logical_layout.declarations);
+                        self.decorate(
+                            varying_id,
+                            spirv::Decoration::BuiltIn,
+                            &[spirv::BuiltIn::PointSize as u32],
+                        );
+                        iface.varying_ids.push(varying_id);
+
+                        let default_value_id = self.get_constant_scalar(crate::Literal::F32(1.0));
+                        prelude
+                            .body
+                            .push(Instruction::store(varying_id, default_value_id, None));
+                    }
+                    self.void_type
+                } else {
+                    self.get_type_id(LookupType::Handle(result.ty))
+                }
+            }
+            None => self.void_type,
+        };
+
+        let lookup_function_type = LookupFunctionType {
+            parameter_type_ids,
+            return_type_id,
+        };
+
+        let function_id = self.id_gen.next();
+        if self.flags.contains(WriterFlags::DEBUG) {
+            if let Some(ref name) = ir_function.name {
+                self.debugs.push(Instruction::name(function_id, name));
+            }
+        }
+
+        let function_type = self.get_function_type(lookup_function_type);
+        function.signature = Some(Instruction::function(
+            return_type_id,
+            function_id,
+            spirv::FunctionControl::empty(),
+            function_type,
+        ));
+
+        if interface.is_some() {
+            function.entry_point_context = Some(ep_context);
+        }
+
+        // fill up the `GlobalVariable::access_id`
+        for gv in self.global_variables.iter_mut() {
+            gv.reset_for_function();
+        }
+        for (handle, var) in ir_module.global_variables.iter() {
+            if info[handle].is_empty() {
+                continue;
+            }
+
+            let mut gv = self.global_variables[handle.index()].clone();
+            if let Some(ref mut iface) = interface {
+                // Have to include global variables in the interface
+                if self.physical_layout.version >= 0x10400 {
+                    iface.varying_ids.push(gv.var_id);
+                }
+            }
+
+            // Handle globals are pre-emitted and should be loaded automatically.
+            //
+            // Any that are binding arrays we skip as we cannot load the array, we must load the result after indexing.
+            let is_binding_array = match ir_module.types[var.ty].inner {
+                crate::TypeInner::BindingArray { .. } => true,
+                _ => false,
+            };
+
+            if var.space == crate::AddressSpace::Handle && !is_binding_array {
+                let var_type_id = self.get_type_id(LookupType::Handle(var.ty));
+                let id = self.id_gen.next();
+                prelude
+                    .body
+                    .push(Instruction::load(var_type_id, id, gv.var_id, None));
+                gv.access_id = gv.var_id;
+                gv.handle_id = id;
+            } else if global_needs_wrapper(ir_module, var) {
+                let class = map_storage_class(var.space);
+                let pointer_type_id = self.get_pointer_id(&ir_module.types, var.ty, class)?;
+                let index_id = self.get_index_constant(0);
+
+                let id = self.id_gen.next();
+                prelude.body.push(Instruction::access_chain(
+                    pointer_type_id,
+                    id,
+                    gv.var_id,
+                    &[index_id],
+                ));
+                gv.access_id = id;
+            } else {
+                // by default, the variable ID is accessed as is
+                gv.access_id = gv.var_id;
+            };
+
+            // work around borrow checking in the presence of `self.xxx()` calls
+            self.global_variables[handle.index()] = gv;
+        }
+
+        // Create a `BlockContext` for generating SPIR-V for the function's
+        // body.
+        let mut context = BlockContext {
+            ir_module,
+            ir_function,
+            fun_info: info,
+            function: &mut function,
+            // Re-use the cached expression table from prior functions.
+            cached: std::mem::take(&mut self.saved_cached),
+
+            // Steal the Writer's temp list for a bit.
+            temp_list: std::mem::take(&mut self.temp_list),
+            writer: self,
+            expression_constness: crate::proc::ExpressionConstnessTracker::from_arena(
+                &ir_function.expressions,
+            ),
+        };
+
+        // fill up the pre-emitted and const expressions
+        context.cached.reset(ir_function.expressions.len());
+        for (handle, expr) in ir_function.expressions.iter() {
+            if (expr.needs_pre_emit() && !matches!(*expr, crate::Expression::LocalVariable(_)))
+                || context.expression_constness.is_const(handle)
+            {
+                context.cache_expression_value(handle, &mut prelude)?;
+            }
+        }
+
+        for (handle, variable) in ir_function.local_variables.iter() {
+            let id = context.gen_id();
+
+            if context.writer.flags.contains(WriterFlags::DEBUG) {
+                if let Some(ref name) = variable.name {
+                    context.writer.debugs.push(Instruction::name(id, name));
+                }
+            }
+
+            let init_word = variable.init.map(|constant| context.cached[constant]);
+            let pointer_type_id = context.writer.get_pointer_id(
+                &ir_module.types,
+                variable.ty,
+                spirv::StorageClass::Function,
+            )?;
+            let instruction = Instruction::variable(
+                pointer_type_id,
+                id,
+                spirv::StorageClass::Function,
+                init_word.or_else(|| match ir_module.types[variable.ty].inner {
+                    crate::TypeInner::RayQuery => None,
+                    _ => {
+                        let type_id = context.get_type_id(LookupType::Handle(variable.ty));
+                        Some(context.writer.write_constant_null(type_id))
+                    }
+                }),
+            );
+            context
+                .function
+                .variables
+                .insert(handle, LocalVariable { id, instruction });
+        }
+
+        // cache local variable expressions
+        for (handle, expr) in ir_function.expressions.iter() {
+            if matches!(*expr, crate::Expression::LocalVariable(_)) {
+                context.cache_expression_value(handle, &mut prelude)?;
+            }
+        }
+
+        let next_id = context.gen_id();
+
+        context
+            .function
+            .consume(prelude, Instruction::branch(next_id));
+
+        let workgroup_vars_init_exit_block_id =
+            match (context.writer.zero_initialize_workgroup_memory, interface) {
+                (
+                    super::ZeroInitializeWorkgroupMemoryMode::Polyfill,
+                    Some(
+                        ref mut interface @ FunctionInterface {
+                            stage: crate::ShaderStage::Compute,
+                            ..
+                        },
+                    ),
+                ) => context.writer.generate_workgroup_vars_init_block(
+                    next_id,
+                    ir_module,
+                    info,
+                    local_invocation_id,
+                    interface,
+                    context.function,
+                ),
+                _ => None,
+            };
+
+        let main_id = if let Some(exit_id) = workgroup_vars_init_exit_block_id {
+            exit_id
+        } else {
+            next_id
+        };
+
+        context.write_block(
+            main_id,
+            &ir_function.body,
+            super::block::BlockExit::Return,
+            LoopContext::default(),
+            debug_info.as_ref(),
+        )?;
+
+        // Consume the `BlockContext`, ending its borrows and letting the
+        // `Writer` steal back its cached expression table and temp_list.
+        let BlockContext {
+            cached, temp_list, ..
+        } = context;
+        self.saved_cached = cached;
+        self.temp_list = temp_list;
+
+        function.to_words(&mut self.logical_layout.function_definitions);
+        Instruction::function_end().to_words(&mut self.logical_layout.function_definitions);
+
+        Ok(function_id)
+    }
+
+    fn write_execution_mode(
+        &mut self,
+        function_id: Word,
+        mode: spirv::ExecutionMode,
+    ) -> Result<(), Error> {
+        //self.check(mode.required_capabilities())?;
+        Instruction::execution_mode(function_id, mode, &[])
+            .to_words(&mut self.logical_layout.execution_modes);
+        Ok(())
+    }
+
+    // TODO Move to instructions module
+    fn write_entry_point(
+        &mut self,
+        entry_point: &crate::EntryPoint,
+        info: &FunctionInfo,
+        ir_module: &crate::Module,
+        debug_info: &Option<DebugInfoInner>,
+    ) -> Result<Instruction, Error> {
+        let mut interface_ids = Vec::new();
+        let function_id = self.write_function(
+            &entry_point.function,
+            info,
+            ir_module,
+            Some(FunctionInterface {
+                varying_ids: &mut interface_ids,
+                stage: entry_point.stage,
+            }),
+            debug_info,
+        )?;
+
+        let exec_model = match entry_point.stage {
+            crate::ShaderStage::Vertex => spirv::ExecutionModel::Vertex,
+            crate::ShaderStage::Fragment => {
+                self.write_execution_mode(function_id, spirv::ExecutionMode::OriginUpperLeft)?;
+                if let Some(ref result) = entry_point.function.result {
+                    if contains_builtin(
+                        result.binding.as_ref(),
+                        result.ty,
+                        &ir_module.types,
+                        crate::BuiltIn::FragDepth,
+                    ) {
+                        self.write_execution_mode(
+                            function_id,
+                            spirv::ExecutionMode::DepthReplacing,
+                        )?;
+                    }
+                }
+                spirv::ExecutionModel::Fragment
+            }
+            crate::ShaderStage::Compute => {
+                let execution_mode = spirv::ExecutionMode::LocalSize;
+                //self.check(execution_mode.required_capabilities())?;
+                Instruction::execution_mode(
+                    function_id,
+                    execution_mode,
+                    &entry_point.workgroup_size,
+                )
+                .to_words(&mut self.logical_layout.execution_modes);
+                spirv::ExecutionModel::GLCompute
+            }
+        };
+        //self.check(exec_model.required_capabilities())?;
+
+        Ok(Instruction::entry_point(
+            exec_model,
+            function_id,
+            &entry_point.name,
+            interface_ids.as_slice(),
+        ))
+    }
+
+    fn make_scalar(&mut self, id: Word, scalar: crate::Scalar) -> Instruction {
+        use crate::ScalarKind as Sk;
+
+        let bits = (scalar.width * BITS_PER_BYTE) as u32;
+        match scalar.kind {
+            Sk::Sint | Sk::Uint => {
+                let signedness = if scalar.kind == Sk::Sint {
+                    super::instructions::Signedness::Signed
+                } else {
+                    super::instructions::Signedness::Unsigned
+                };
+                let cap = match bits {
+                    8 => Some(spirv::Capability::Int8),
+                    16 => Some(spirv::Capability::Int16),
+                    64 => Some(spirv::Capability::Int64),
+                    _ => None,
+                };
+                if let Some(cap) = cap {
+                    self.capabilities_used.insert(cap);
+                }
+                Instruction::type_int(id, bits, signedness)
+            }
+            Sk::Float => {
+                if bits == 64 {
+                    self.capabilities_used.insert(spirv::Capability::Float64);
+                }
+                Instruction::type_float(id, bits)
+            }
+            Sk::Bool => Instruction::type_bool(id),
+            Sk::AbstractInt | Sk::AbstractFloat => {
+                unreachable!("abstract types should never reach the backend");
+            }
+        }
+    }
+
+    fn request_type_capabilities(&mut self, inner: &crate::TypeInner) -> Result<(), Error> {
+        match *inner {
+            crate::TypeInner::Image {
+                dim,
+                arrayed,
+                class,
+            } => {
+                let sampled = match class {
+                    crate::ImageClass::Sampled { .. } => true,
+                    crate::ImageClass::Depth { .. } => true,
+                    crate::ImageClass::Storage { format, .. } => {
+                        self.request_image_format_capabilities(format.into())?;
+                        false
+                    }
+                };
+
+                match dim {
+                    crate::ImageDimension::D1 => {
+                        if sampled {
+                            self.require_any("sampled 1D images", &[spirv::Capability::Sampled1D])?;
+                        } else {
+                            self.require_any("1D storage images", &[spirv::Capability::Image1D])?;
+                        }
+                    }
+                    crate::ImageDimension::Cube if arrayed => {
+                        if sampled {
+                            self.require_any(
+                                "sampled cube array images",
+                                &[spirv::Capability::SampledCubeArray],
+                            )?;
+                        } else {
+                            self.require_any(
+                                "cube array storage images",
+                                &[spirv::Capability::ImageCubeArray],
+                            )?;
+                        }
+                    }
+                    _ => {}
+                }
+            }
+            crate::TypeInner::AccelerationStructure => {
+                self.require_any("Acceleration Structure", &[spirv::Capability::RayQueryKHR])?;
+            }
+            crate::TypeInner::RayQuery => {
+                self.require_any("Ray Query", &[spirv::Capability::RayQueryKHR])?;
+            }
+            _ => {}
+        }
+        Ok(())
+    }
+
+    fn write_type_declaration_local(&mut self, id: Word, local_ty: LocalType) {
+        let instruction = match local_ty {
+            LocalType::Value {
+                vector_size: None,
+                scalar,
+                pointer_space: None,
+            } => self.make_scalar(id, scalar),
+            LocalType::Value {
+                vector_size: Some(size),
+                scalar,
+                pointer_space: None,
+            } => {
+                let scalar_id = self.get_type_id(LookupType::Local(LocalType::Value {
+                    vector_size: None,
+                    scalar,
+                    pointer_space: None,
+                }));
+                Instruction::type_vector(id, scalar_id, size)
+            }
+            LocalType::Matrix {
+                columns,
+                rows,
+                width,
+            } => {
+                let vector_id = self.get_type_id(LookupType::Local(LocalType::Value {
+                    vector_size: Some(rows),
+                    scalar: crate::Scalar::float(width),
+                    pointer_space: None,
+                }));
+                Instruction::type_matrix(id, vector_id, columns)
+            }
+            LocalType::Pointer { base, class } => {
+                let type_id = self.get_type_id(LookupType::Handle(base));
+                Instruction::type_pointer(id, class, type_id)
+            }
+            LocalType::Value {
+                vector_size,
+                scalar,
+                pointer_space: Some(class),
+            } => {
+                let type_id = self.get_type_id(LookupType::Local(LocalType::Value {
+                    vector_size,
+                    scalar,
+                    pointer_space: None,
+                }));
+                Instruction::type_pointer(id, class, type_id)
+            }
+            LocalType::Image(image) => {
+                let local_type = LocalType::Value {
+                    vector_size: None,
+                    scalar: crate::Scalar {
+                        kind: image.sampled_type,
+                        width: 4,
+                    },
+                    pointer_space: None,
+                };
+                let type_id = self.get_type_id(LookupType::Local(local_type));
+                Instruction::type_image(id, type_id, image.dim, image.flags, image.image_format)
+            }
+            LocalType::Sampler => Instruction::type_sampler(id),
+            LocalType::SampledImage { image_type_id } => {
+                Instruction::type_sampled_image(id, image_type_id)
+            }
+            LocalType::BindingArray { base, size } => {
+                let inner_ty = self.get_type_id(LookupType::Handle(base));
+                let scalar_id = self.get_constant_scalar(crate::Literal::U32(size));
+                Instruction::type_array(id, inner_ty, scalar_id)
+            }
+            LocalType::PointerToBindingArray { base, size, space } => {
+                let inner_ty =
+                    self.get_type_id(LookupType::Local(LocalType::BindingArray { base, size }));
+                let class = map_storage_class(space);
+                Instruction::type_pointer(id, class, inner_ty)
+            }
+            LocalType::AccelerationStructure => Instruction::type_acceleration_structure(id),
+            LocalType::RayQuery => Instruction::type_ray_query(id),
+        };
+
+        instruction.to_words(&mut self.logical_layout.declarations);
+    }
+
+    fn write_type_declaration_arena(
+        &mut self,
+        arena: &UniqueArena<crate::Type>,
+        handle: Handle<crate::Type>,
+    ) -> Result<Word, Error> {
+        let ty = &arena[handle];
+        let id = if let Some(local) = make_local(&ty.inner) {
+            // This type can be represented as a `LocalType`, so check if we've
+            // already written an instruction for it. If not, do so now, with
+            // `write_type_declaration_local`.
+            match self.lookup_type.entry(LookupType::Local(local)) {
+                // We already have an id for this `LocalType`.
+                Entry::Occupied(e) => *e.get(),
+
+                // It's a type we haven't seen before.
+                Entry::Vacant(e) => {
+                    let id = self.id_gen.next();
+                    e.insert(id);
+
+                    self.write_type_declaration_local(id, local);
+
+                    // If it's a type that needs SPIR-V capabilities, request them now,
+                    // so write_type_declaration_local can stay infallible.
+                    self.request_type_capabilities(&ty.inner)?;
+
+                    id
+                }
+            }
+        } else {
+            use spirv::Decoration;
+
+            let id = self.id_gen.next();
+            let instruction = match ty.inner {
+                crate::TypeInner::Array { base, size, stride } => {
+                    self.decorate(id, Decoration::ArrayStride, &[stride]);
+
+                    let type_id = self.get_type_id(LookupType::Handle(base));
+                    match size {
+                        crate::ArraySize::Constant(length) => {
+                            let length_id = self.get_index_constant(length.get());
+                            Instruction::type_array(id, type_id, length_id)
+                        }
+                        crate::ArraySize::Dynamic => Instruction::type_runtime_array(id, type_id),
+                    }
+                }
+                crate::TypeInner::BindingArray { base, size } => {
+                    let type_id = self.get_type_id(LookupType::Handle(base));
+                    match size {
+                        crate::ArraySize::Constant(length) => {
+                            let length_id = self.get_index_constant(length.get());
+                            Instruction::type_array(id, type_id, length_id)
+                        }
+                        crate::ArraySize::Dynamic => Instruction::type_runtime_array(id, type_id),
+                    }
+                }
+                crate::TypeInner::Struct {
+                    ref members,
+                    span: _,
+                } => {
+                    let mut has_runtime_array = false;
+                    let mut member_ids = Vec::with_capacity(members.len());
+                    for (index, member) in members.iter().enumerate() {
+                        let member_ty = &arena[member.ty];
+                        match member_ty.inner {
+                            crate::TypeInner::Array {
+                                base: _,
+                                size: crate::ArraySize::Dynamic,
+                                stride: _,
+                            } => {
+                                has_runtime_array = true;
+                            }
+                            _ => (),
+                        }
+                        self.decorate_struct_member(id, index, member, arena)?;
+                        let member_id = self.get_type_id(LookupType::Handle(member.ty));
+                        member_ids.push(member_id);
+                    }
+                    if has_runtime_array {
+                        self.decorate(id, Decoration::Block, &[]);
+                    }
+                    Instruction::type_struct(id, member_ids.as_slice())
+                }
+
+                // These all have TypeLocal representations, so they should have been
+                // handled by `write_type_declaration_local` above.
+                crate::TypeInner::Scalar(_)
+                | crate::TypeInner::Atomic(_)
+                | crate::TypeInner::Vector { .. }
+                | crate::TypeInner::Matrix { .. }
+                | crate::TypeInner::Pointer { .. }
+                | crate::TypeInner::ValuePointer { .. }
+                | crate::TypeInner::Image { .. }
+                | crate::TypeInner::Sampler { .. }
+                | crate::TypeInner::AccelerationStructure
+                | crate::TypeInner::RayQuery => unreachable!(),
+            };
+
+            instruction.to_words(&mut self.logical_layout.declarations);
+            id
+        };
+
+        // Add this handle as a new alias for that type.
+        self.lookup_type.insert(LookupType::Handle(handle), id);
+
+        if self.flags.contains(WriterFlags::DEBUG) {
+            if let Some(ref name) = ty.name {
+                self.debugs.push(Instruction::name(id, name));
+            }
+        }
+
+        Ok(id)
+    }
+
+    fn request_image_format_capabilities(
+        &mut self,
+        format: spirv::ImageFormat,
+    ) -> Result<(), Error> {
+        use spirv::ImageFormat as If;
+        match format {
+            If::Rg32f
+            | If::Rg16f
+            | If::R11fG11fB10f
+            | If::R16f
+            | If::Rgba16
+            | If::Rgb10A2
+            | If::Rg16
+            | If::Rg8
+            | If::R16
+            | If::R8
+            | If::Rgba16Snorm
+            | If::Rg16Snorm
+            | If::Rg8Snorm
+            | If::R16Snorm
+            | If::R8Snorm
+            | If::Rg32i
+            | If::Rg16i
+            | If::Rg8i
+            | If::R16i
+            | If::R8i
+            | If::Rgb10a2ui
+            | If::Rg32ui
+            | If::Rg16ui
+            | If::Rg8ui
+            | If::R16ui
+            | If::R8ui => self.require_any(
+                "storage image format",
+                &[spirv::Capability::StorageImageExtendedFormats],
+            ),
+            If::R64ui | If::R64i => self.require_any(
+                "64-bit integer storage image format",
+                &[spirv::Capability::Int64ImageEXT],
+            ),
+            If::Unknown
+            | If::Rgba32f
+            | If::Rgba16f
+            | If::R32f
+            | If::Rgba8
+            | If::Rgba8Snorm
+            | If::Rgba32i
+            | If::Rgba16i
+            | If::Rgba8i
+            | If::R32i
+            | If::Rgba32ui
+            | If::Rgba16ui
+            | If::Rgba8ui
+            | If::R32ui => Ok(()),
+        }
+    }
+
+    pub(super) fn get_index_constant(&mut self, index: Word) -> Word {
+        self.get_constant_scalar(crate::Literal::U32(index))
+    }
+
+    pub(super) fn get_constant_scalar_with(
+        &mut self,
+        value: u8,
+        scalar: crate::Scalar,
+    ) -> Result<Word, Error> {
+        Ok(
+            self.get_constant_scalar(crate::Literal::new(value, scalar).ok_or(
+                Error::Validation("Unexpected kind and/or width for Literal"),
+            )?),
+        )
+    }
+
+    pub(super) fn get_constant_scalar(&mut self, value: crate::Literal) -> Word {
+        let scalar = CachedConstant::Literal(value);
+        if let Some(&id) = self.cached_constants.get(&scalar) {
+            return id;
+        }
+        let id = self.id_gen.next();
+        self.write_constant_scalar(id, &value, None);
+        self.cached_constants.insert(scalar, id);
+        id
+    }
+
+    fn write_constant_scalar(
+        &mut self,
+        id: Word,
+        value: &crate::Literal,
+        debug_name: Option<&String>,
+    ) {
+        if self.flags.contains(WriterFlags::DEBUG) {
+            if let Some(name) = debug_name {
+                self.debugs.push(Instruction::name(id, name));
+            }
+        }
+        let type_id = self.get_type_id(LookupType::Local(LocalType::Value {
+            vector_size: None,
+            scalar: value.scalar(),
+            pointer_space: None,
+        }));
+        let instruction = match *value {
+            crate::Literal::F64(value) => {
+                let bits = value.to_bits();
+                Instruction::constant_64bit(type_id, id, bits as u32, (bits >> 32) as u32)
+            }
+            crate::Literal::F32(value) => Instruction::constant_32bit(type_id, id, value.to_bits()),
+            crate::Literal::U32(value) => Instruction::constant_32bit(type_id, id, value),
+            crate::Literal::I32(value) => Instruction::constant_32bit(type_id, id, value as u32),
+            crate::Literal::I64(value) => {
+                Instruction::constant_64bit(type_id, id, value as u32, (value >> 32) as u32)
+            }
+            crate::Literal::Bool(true) => Instruction::constant_true(type_id, id),
+            crate::Literal::Bool(false) => Instruction::constant_false(type_id, id),
+            crate::Literal::AbstractInt(_) | crate::Literal::AbstractFloat(_) => {
+                unreachable!("Abstract types should not appear in IR presented to backends");
+            }
+        };
+
+        instruction.to_words(&mut self.logical_layout.declarations);
+    }
+
+    pub(super) fn get_constant_composite(
+        &mut self,
+        ty: LookupType,
+        constituent_ids: &[Word],
+    ) -> Word {
+        let composite = CachedConstant::Composite {
+            ty,
+            constituent_ids: constituent_ids.to_vec(),
+        };
+        if let Some(&id) = self.cached_constants.get(&composite) {
+            return id;
+        }
+        let id = self.id_gen.next();
+        self.write_constant_composite(id, ty, constituent_ids, None);
+        self.cached_constants.insert(composite, id);
+        id
+    }
+
+    fn write_constant_composite(
+        &mut self,
+        id: Word,
+        ty: LookupType,
+        constituent_ids: &[Word],
+        debug_name: Option<&String>,
+    ) {
+        if self.flags.contains(WriterFlags::DEBUG) {
+            if let Some(name) = debug_name {
+                self.debugs.push(Instruction::name(id, name));
+            }
+        }
+        let type_id = self.get_type_id(ty);
+        Instruction::constant_composite(type_id, id, constituent_ids)
+            .to_words(&mut self.logical_layout.declarations);
+    }
+
+    pub(super) fn get_constant_null(&mut self, type_id: Word) -> Word {
+        let null = CachedConstant::ZeroValue(type_id);
+        if let Some(&id) = self.cached_constants.get(&null) {
+            return id;
+        }
+        let id = self.write_constant_null(type_id);
+        self.cached_constants.insert(null, id);
+        id
+    }
+
+    pub(super) fn write_constant_null(&mut self, type_id: Word) -> Word {
+        let null_id = self.id_gen.next();
+        Instruction::constant_null(type_id, null_id)
+            .to_words(&mut self.logical_layout.declarations);
+        null_id
+    }
+
+    fn write_constant_expr(
+        &mut self,
+        handle: Handle<crate::Expression>,
+        ir_module: &crate::Module,
+        mod_info: &ModuleInfo,
+    ) -> Result<Word, Error> {
+        let id = match ir_module.const_expressions[handle] {
+            crate::Expression::Literal(literal) => self.get_constant_scalar(literal),
+            crate::Expression::Constant(constant) => {
+                let constant = &ir_module.constants[constant];
+                self.constant_ids[constant.init.index()]
+            }
+            crate::Expression::ZeroValue(ty) => {
+                let type_id = self.get_type_id(LookupType::Handle(ty));
+                self.get_constant_null(type_id)
+            }
+            crate::Expression::Compose { ty, ref components } => {
+                let component_ids: Vec<_> = crate::proc::flatten_compose(
+                    ty,
+                    components,
+                    &ir_module.const_expressions,
+                    &ir_module.types,
+                )
+                .map(|component| self.constant_ids[component.index()])
+                .collect();
+                self.get_constant_composite(LookupType::Handle(ty), component_ids.as_slice())
+            }
+            crate::Expression::Splat { size, value } => {
+                let value_id = self.constant_ids[value.index()];
+                let component_ids = &[value_id; 4][..size as usize];
+
+                let ty = self.get_expression_lookup_type(&mod_info[handle]);
+
+                self.get_constant_composite(ty, component_ids)
+            }
+            _ => unreachable!(),
+        };
+
+        self.constant_ids[handle.index()] = id;
+
+        Ok(id)
+    }
+
+    pub(super) fn write_barrier(&mut self, flags: crate::Barrier, block: &mut Block) {
+        let memory_scope = if flags.contains(crate::Barrier::STORAGE) {
+            spirv::Scope::Device
+        } else {
+            spirv::Scope::Workgroup
+        };
+        let mut semantics = spirv::MemorySemantics::ACQUIRE_RELEASE;
+        semantics.set(
+            spirv::MemorySemantics::UNIFORM_MEMORY,
+            flags.contains(crate::Barrier::STORAGE),
+        );
+        semantics.set(
+            spirv::MemorySemantics::WORKGROUP_MEMORY,
+            flags.contains(crate::Barrier::WORK_GROUP),
+        );
+        let exec_scope_id = self.get_index_constant(spirv::Scope::Workgroup as u32);
+        let mem_scope_id = self.get_index_constant(memory_scope as u32);
+        let semantics_id = self.get_index_constant(semantics.bits());
+        block.body.push(Instruction::control_barrier(
+            exec_scope_id,
+            mem_scope_id,
+            semantics_id,
+        ));
+    }
+
+    fn generate_workgroup_vars_init_block(
+        &mut self,
+        entry_id: Word,
+        ir_module: &crate::Module,
+        info: &FunctionInfo,
+        local_invocation_id: Option<Word>,
+        interface: &mut FunctionInterface,
+        function: &mut Function,
+    ) -> Option<Word> {
+        let body = ir_module
+            .global_variables
+            .iter()
+            .filter(|&(handle, var)| {
+                !info[handle].is_empty() && var.space == crate::AddressSpace::WorkGroup
+            })
+            .map(|(handle, var)| {
+                // It's safe to use `var_id` here, not `access_id`, because only
+                // variables in the `Uniform` and `StorageBuffer` address spaces
+                // get wrapped, and we're initializing `WorkGroup` variables.
+                let var_id = self.global_variables[handle.index()].var_id;
+                let var_type_id = self.get_type_id(LookupType::Handle(var.ty));
+                let init_word = self.get_constant_null(var_type_id);
+                Instruction::store(var_id, init_word, None)
+            })
+            .collect::<Vec<_>>();
+
+        if body.is_empty() {
+            return None;
+        }
+
+        let uint3_type_id = self.get_uint3_type_id();
+
+        let mut pre_if_block = Block::new(entry_id);
+
+        let local_invocation_id = if let Some(local_invocation_id) = local_invocation_id {
+            local_invocation_id
+        } else {
+            let varying_id = self.id_gen.next();
+            let class = spirv::StorageClass::Input;
+            let pointer_type_id = self.get_uint3_pointer_type_id(class);
+
+            Instruction::variable(pointer_type_id, varying_id, class, None)
+                .to_words(&mut self.logical_layout.declarations);
+
+            self.decorate(
+                varying_id,
+                spirv::Decoration::BuiltIn,
+                &[spirv::BuiltIn::LocalInvocationId as u32],
+            );
+
+            interface.varying_ids.push(varying_id);
+            let id = self.id_gen.next();
+            pre_if_block
+                .body
+                .push(Instruction::load(uint3_type_id, id, varying_id, None));
+
+            id
+        };
+
+        let zero_id = self.get_constant_null(uint3_type_id);
+        let bool3_type_id = self.get_bool3_type_id();
+
+        let eq_id = self.id_gen.next();
+        pre_if_block.body.push(Instruction::binary(
+            spirv::Op::IEqual,
+            bool3_type_id,
+            eq_id,
+            local_invocation_id,
+            zero_id,
+        ));
+
+        let condition_id = self.id_gen.next();
+        let bool_type_id = self.get_bool_type_id();
+        pre_if_block.body.push(Instruction::relational(
+            spirv::Op::All,
+            bool_type_id,
+            condition_id,
+            eq_id,
+        ));
+
+        let merge_id = self.id_gen.next();
+        pre_if_block.body.push(Instruction::selection_merge(
+            merge_id,
+            spirv::SelectionControl::NONE,
+        ));
+
+        let accept_id = self.id_gen.next();
+        function.consume(
+            pre_if_block,
+            Instruction::branch_conditional(condition_id, accept_id, merge_id),
+        );
+
+        let accept_block = Block {
+            label_id: accept_id,
+            body,
+        };
+        function.consume(accept_block, Instruction::branch(merge_id));
+
+        let mut post_if_block = Block::new(merge_id);
+
+        self.write_barrier(crate::Barrier::WORK_GROUP, &mut post_if_block);
+
+        let next_id = self.id_gen.next();
+        function.consume(post_if_block, Instruction::branch(next_id));
+        Some(next_id)
+    }
+
+    /// Generate an `OpVariable` for one value in an [`EntryPoint`]'s IO interface.
+    ///
+    /// The [`Binding`]s of the arguments and result of an [`EntryPoint`]'s
+    /// [`Function`] describe a SPIR-V shader interface. In SPIR-V, the
+    /// interface is represented by global variables in the `Input` and `Output`
+    /// storage classes, with decorations indicating which builtin or location
+    /// each variable corresponds to.
+    ///
+    /// This function emits a single global `OpVariable` for a single value from
+    /// the interface, and adds appropriate decorations to indicate which
+    /// builtin or location it represents, how it should be interpolated, and so
+    /// on. The `class` argument gives the variable's SPIR-V storage class,
+    /// which should be either [`Input`] or [`Output`].
+    ///
+    /// [`Binding`]: crate::Binding
+    /// [`Function`]: crate::Function
+    /// [`EntryPoint`]: crate::EntryPoint
+    /// [`Input`]: spirv::StorageClass::Input
+    /// [`Output`]: spirv::StorageClass::Output
+    fn write_varying(
+        &mut self,
+        ir_module: &crate::Module,
+        stage: crate::ShaderStage,
+        class: spirv::StorageClass,
+        debug_name: Option<&str>,
+        ty: Handle<crate::Type>,
+        binding: &crate::Binding,
+    ) -> Result<Word, Error> {
+        let id = self.id_gen.next();
+        let pointer_type_id = self.get_pointer_id(&ir_module.types, ty, class)?;
+        Instruction::variable(pointer_type_id, id, class, None)
+            .to_words(&mut self.logical_layout.declarations);
+
+        if self
+            .flags
+            .contains(WriterFlags::DEBUG | WriterFlags::LABEL_VARYINGS)
+        {
+            if let Some(name) = debug_name {
+                self.debugs.push(Instruction::name(id, name));
+            }
+        }
+
+        use spirv::{BuiltIn, Decoration};
+
+        match *binding {
+            crate::Binding::Location {
+                location,
+                interpolation,
+                sampling,
+                second_blend_source,
+            } => {
+                self.decorate(id, Decoration::Location, &[location]);
+
+                let no_decorations =
+                    // VUID-StandaloneSpirv-Flat-06202
+                    // > The Flat, NoPerspective, Sample, and Centroid decorations
+                    // > must not be used on variables with the Input storage class in a vertex shader
+                    (class == spirv::StorageClass::Input && stage == crate::ShaderStage::Vertex) ||
+                    // VUID-StandaloneSpirv-Flat-06201
+                    // > The Flat, NoPerspective, Sample, and Centroid decorations
+                    // > must not be used on variables with the Output storage class in a fragment shader
+                    (class == spirv::StorageClass::Output && stage == crate::ShaderStage::Fragment);
+
+                if !no_decorations {
+                    match interpolation {
+                        // Perspective-correct interpolation is the default in SPIR-V.
+                        None | Some(crate::Interpolation::Perspective) => (),
+                        Some(crate::Interpolation::Flat) => {
+                            self.decorate(id, Decoration::Flat, &[]);
+                        }
+                        Some(crate::Interpolation::Linear) => {
+                            self.decorate(id, Decoration::NoPerspective, &[]);
+                        }
+                    }
+                    match sampling {
+                        // Center sampling is the default in SPIR-V.
+                        None | Some(crate::Sampling::Center) => (),
+                        Some(crate::Sampling::Centroid) => {
+                            self.decorate(id, Decoration::Centroid, &[]);
+                        }
+                        Some(crate::Sampling::Sample) => {
+                            self.require_any(
+                                "per-sample interpolation",
+                                &[spirv::Capability::SampleRateShading],
+                            )?;
+                            self.decorate(id, Decoration::Sample, &[]);
+                        }
+                    }
+                }
+                if second_blend_source {
+                    self.decorate(id, Decoration::Index, &[1]);
+                }
+            }
+            crate::Binding::BuiltIn(built_in) => {
+                use crate::BuiltIn as Bi;
+                let built_in = match built_in {
+                    Bi::Position { invariant } => {
+                        if invariant {
+                            self.decorate(id, Decoration::Invariant, &[]);
+                        }
+
+                        if class == spirv::StorageClass::Output {
+                            BuiltIn::Position
+                        } else {
+                            BuiltIn::FragCoord
+                        }
+                    }
+                    Bi::ViewIndex => {
+                        self.require_any("`view_index` built-in", &[spirv::Capability::MultiView])?;
+                        BuiltIn::ViewIndex
+                    }
+                    // vertex
+                    Bi::BaseInstance => BuiltIn::BaseInstance,
+                    Bi::BaseVertex => BuiltIn::BaseVertex,
+                    Bi::ClipDistance => {
+                        self.require_any(
+                            "`clip_distance` built-in",
+                            &[spirv::Capability::ClipDistance],
+                        )?;
+                        BuiltIn::ClipDistance
+                    }
+                    Bi::CullDistance => {
+                        self.require_any(
+                            "`cull_distance` built-in",
+                            &[spirv::Capability::CullDistance],
+                        )?;
+                        BuiltIn::CullDistance
+                    }
+                    Bi::InstanceIndex => BuiltIn::InstanceIndex,
+                    Bi::PointSize => BuiltIn::PointSize,
+                    Bi::VertexIndex => BuiltIn::VertexIndex,
+                    // fragment
+                    Bi::FragDepth => BuiltIn::FragDepth,
+                    Bi::PointCoord => BuiltIn::PointCoord,
+                    Bi::FrontFacing => BuiltIn::FrontFacing,
+                    Bi::PrimitiveIndex => {
+                        self.require_any(
+                            "`primitive_index` built-in",
+                            &[spirv::Capability::Geometry],
+                        )?;
+                        BuiltIn::PrimitiveId
+                    }
+                    Bi::SampleIndex => {
+                        self.require_any(
+                            "`sample_index` built-in",
+                            &[spirv::Capability::SampleRateShading],
+                        )?;
+
+                        BuiltIn::SampleId
+                    }
+                    Bi::SampleMask => BuiltIn::SampleMask,
+                    // compute
+                    Bi::GlobalInvocationId => BuiltIn::GlobalInvocationId,
+                    Bi::LocalInvocationId => BuiltIn::LocalInvocationId,
+                    Bi::LocalInvocationIndex => BuiltIn::LocalInvocationIndex,
+                    Bi::WorkGroupId => BuiltIn::WorkgroupId,
+                    Bi::WorkGroupSize => BuiltIn::WorkgroupSize,
+                    Bi::NumWorkGroups => BuiltIn::NumWorkgroups,
+                };
+
+                self.decorate(id, Decoration::BuiltIn, &[built_in as u32]);
+
+                use crate::ScalarKind as Sk;
+
+                // Per the Vulkan spec, `VUID-StandaloneSpirv-Flat-04744`:
+                //
+                // > Any variable with integer or double-precision floating-
+                // > point type and with Input storage class in a fragment
+                // > shader, must be decorated Flat
+                if class == spirv::StorageClass::Input && stage == crate::ShaderStage::Fragment {
+                    let is_flat = match ir_module.types[ty].inner {
+                        crate::TypeInner::Scalar(scalar)
+                        | crate::TypeInner::Vector { scalar, .. } => match scalar.kind {
+                            Sk::Uint | Sk::Sint | Sk::Bool => true,
+                            Sk::Float => false,
+                            Sk::AbstractInt | Sk::AbstractFloat => {
+                                return Err(Error::Validation(
+                                    "Abstract types should not appear in IR presented to backends",
+                                ))
+                            }
+                        },
+                        _ => false,
+                    };
+
+                    if is_flat {
+                        self.decorate(id, Decoration::Flat, &[]);
+                    }
+                }
+            }
+        }
+
+        Ok(id)
+    }
+
+    fn write_global_variable(
+        &mut self,
+        ir_module: &crate::Module,
+        global_variable: &crate::GlobalVariable,
+    ) -> Result<Word, Error> {
+        use spirv::Decoration;
+
+        let id = self.id_gen.next();
+        let class = map_storage_class(global_variable.space);
+
+        //self.check(class.required_capabilities())?;
+
+        if self.flags.contains(WriterFlags::DEBUG) {
+            if let Some(ref name) = global_variable.name {
+                self.debugs.push(Instruction::name(id, name));
+            }
+        }
+
+        let storage_access = match global_variable.space {
+            crate::AddressSpace::Storage { access } => Some(access),
+            _ => match ir_module.types[global_variable.ty].inner {
+                crate::TypeInner::Image {
+                    class: crate::ImageClass::Storage { access, .. },
+                    ..
+                } => Some(access),
+                _ => None,
+            },
+        };
+        if let Some(storage_access) = storage_access {
+            if !storage_access.contains(crate::StorageAccess::LOAD) {
+                self.decorate(id, Decoration::NonReadable, &[]);
+            }
+            if !storage_access.contains(crate::StorageAccess::STORE) {
+                self.decorate(id, Decoration::NonWritable, &[]);
+            }
+        }
+
+        // Note: we should be able to substitute `binding_array<Foo, 0>`,
+        // but there is still code that tries to register the pre-substituted type,
+        // and it is failing on 0.
+        let mut substitute_inner_type_lookup = None;
+        if let Some(ref res_binding) = global_variable.binding {
+            self.decorate(id, Decoration::DescriptorSet, &[res_binding.group]);
+            self.decorate(id, Decoration::Binding, &[res_binding.binding]);
+
+            if let Some(&BindingInfo {
+                binding_array_size: Some(remapped_binding_array_size),
+            }) = self.binding_map.get(res_binding)
+            {
+                if let crate::TypeInner::BindingArray { base, .. } =
+                    ir_module.types[global_variable.ty].inner
+                {
+                    substitute_inner_type_lookup =
+                        Some(LookupType::Local(LocalType::PointerToBindingArray {
+                            base,
+                            size: remapped_binding_array_size,
+                            space: global_variable.space,
+                        }))
+                }
+            }
+        };
+
+        let init_word = global_variable
+            .init
+            .map(|constant| self.constant_ids[constant.index()]);
+        let inner_type_id = self.get_type_id(
+            substitute_inner_type_lookup.unwrap_or(LookupType::Handle(global_variable.ty)),
+        );
+
+        // generate the wrapping structure if needed
+        let pointer_type_id = if global_needs_wrapper(ir_module, global_variable) {
+            let wrapper_type_id = self.id_gen.next();
+
+            self.decorate(wrapper_type_id, Decoration::Block, &[]);
+            let member = crate::StructMember {
+                name: None,
+                ty: global_variable.ty,
+                binding: None,
+                offset: 0,
+            };
+            self.decorate_struct_member(wrapper_type_id, 0, &member, &ir_module.types)?;
+
+            Instruction::type_struct(wrapper_type_id, &[inner_type_id])
+                .to_words(&mut self.logical_layout.declarations);
+
+            let pointer_type_id = self.id_gen.next();
+            Instruction::type_pointer(pointer_type_id, class, wrapper_type_id)
+                .to_words(&mut self.logical_layout.declarations);
+
+            pointer_type_id
+        } else {
+            // This is a global variable in the Storage address space. The only
+            // way it could have `global_needs_wrapper() == false` is if it has
+            // a runtime-sized or binding array.
+            // Runtime-sized arrays were decorated when iterating through struct content.
+            // Now binding arrays require Block decorating.
+            if let crate::AddressSpace::Storage { .. } = global_variable.space {
+                match ir_module.types[global_variable.ty].inner {
+                    crate::TypeInner::BindingArray { base, .. } => {
+                        let decorated_id = self.get_type_id(LookupType::Handle(base));
+                        self.decorate(decorated_id, Decoration::Block, &[]);
+                    }
+                    _ => (),
+                };
+            }
+            if substitute_inner_type_lookup.is_some() {
+                inner_type_id
+            } else {
+                self.get_pointer_id(&ir_module.types, global_variable.ty, class)?
+            }
+        };
+
+        let init_word = match (global_variable.space, self.zero_initialize_workgroup_memory) {
+            (crate::AddressSpace::Private, _)
+            | (crate::AddressSpace::WorkGroup, super::ZeroInitializeWorkgroupMemoryMode::Native) => {
+                init_word.or_else(|| Some(self.get_constant_null(inner_type_id)))
+            }
+            _ => init_word,
+        };
+
+        Instruction::variable(pointer_type_id, id, class, init_word)
+            .to_words(&mut self.logical_layout.declarations);
+        Ok(id)
+    }
+
+    /// Write the necessary decorations for a struct member.
+    ///
+    /// Emit decorations for the `index`'th member of the struct type
+    /// designated by `struct_id`, described by `member`.
+    fn decorate_struct_member(
+        &mut self,
+        struct_id: Word,
+        index: usize,
+        member: &crate::StructMember,
+        arena: &UniqueArena<crate::Type>,
+    ) -> Result<(), Error> {
+        use spirv::Decoration;
+
+        self.annotations.push(Instruction::member_decorate(
+            struct_id,
+            index as u32,
+            Decoration::Offset,
+            &[member.offset],
+        ));
+
+        if self.flags.contains(WriterFlags::DEBUG) {
+            if let Some(ref name) = member.name {
+                self.debugs
+                    .push(Instruction::member_name(struct_id, index as u32, name));
+            }
+        }
+
+        // Matrices and arrays of matrices both require decorations,
+        // so "see through" an array to determine if they're needed.
+        let member_array_subty_inner = match arena[member.ty].inner {
+            crate::TypeInner::Array { base, .. } => &arena[base].inner,
+            ref other => other,
+        };
+        if let crate::TypeInner::Matrix {
+            columns: _,
+            rows,
+            scalar,
+        } = *member_array_subty_inner
+        {
+            let byte_stride = Alignment::from(rows) * scalar.width as u32;
+            self.annotations.push(Instruction::member_decorate(
+                struct_id,
+                index as u32,
+                Decoration::ColMajor,
+                &[],
+            ));
+            self.annotations.push(Instruction::member_decorate(
+                struct_id,
+                index as u32,
+                Decoration::MatrixStride,
+                &[byte_stride],
+            ));
+        }
+
+        Ok(())
+    }
+
+    fn get_function_type(&mut self, lookup_function_type: LookupFunctionType) -> Word {
+        match self
+            .lookup_function_type
+            .entry(lookup_function_type.clone())
+        {
+            Entry::Occupied(e) => *e.get(),
+            Entry::Vacant(_) => {
+                let id = self.id_gen.next();
+                let instruction = Instruction::type_function(
+                    id,
+                    lookup_function_type.return_type_id,
+                    &lookup_function_type.parameter_type_ids,
+                );
+                instruction.to_words(&mut self.logical_layout.declarations);
+                self.lookup_function_type.insert(lookup_function_type, id);
+                id
+            }
+        }
+    }
+
+    fn write_physical_layout(&mut self) {
+        self.physical_layout.bound = self.id_gen.0 + 1;
+    }
+
+    fn write_logical_layout(
+        &mut self,
+        ir_module: &crate::Module,
+        mod_info: &ModuleInfo,
+        ep_index: Option<usize>,
+        debug_info: &Option<DebugInfo>,
+    ) -> Result<(), Error> {
+        fn has_view_index_check(
+            ir_module: &crate::Module,
+            binding: Option<&crate::Binding>,
+            ty: Handle<crate::Type>,
+        ) -> bool {
+            match ir_module.types[ty].inner {
+                crate::TypeInner::Struct { ref members, .. } => members.iter().any(|member| {
+                    has_view_index_check(ir_module, member.binding.as_ref(), member.ty)
+                }),
+                _ => binding == Some(&crate::Binding::BuiltIn(crate::BuiltIn::ViewIndex)),
+            }
+        }
+
+        let has_storage_buffers =
+            ir_module
+                .global_variables
+                .iter()
+                .any(|(_, var)| match var.space {
+                    crate::AddressSpace::Storage { .. } => true,
+                    _ => false,
+                });
+        let has_view_index = ir_module
+            .entry_points
+            .iter()
+            .flat_map(|entry| entry.function.arguments.iter())
+            .any(|arg| has_view_index_check(ir_module, arg.binding.as_ref(), arg.ty));
+        let has_ray_query = ir_module.special_types.ray_desc.is_some()
+            | ir_module.special_types.ray_intersection.is_some();
+
+        if self.physical_layout.version < 0x10300 && has_storage_buffers {
+            // enable the storage buffer class on < SPV-1.3
+            Instruction::extension("SPV_KHR_storage_buffer_storage_class")
+                .to_words(&mut self.logical_layout.extensions);
+        }
+        if has_view_index {
+            Instruction::extension("SPV_KHR_multiview")
+                .to_words(&mut self.logical_layout.extensions)
+        }
+        if has_ray_query {
+            Instruction::extension("SPV_KHR_ray_query")
+                .to_words(&mut self.logical_layout.extensions)
+        }
+        Instruction::type_void(self.void_type).to_words(&mut self.logical_layout.declarations);
+        Instruction::ext_inst_import(self.gl450_ext_inst_id, "GLSL.std.450")
+            .to_words(&mut self.logical_layout.ext_inst_imports);
+
+        let mut debug_info_inner = None;
+        if self.flags.contains(WriterFlags::DEBUG) {
+            if let Some(debug_info) = debug_info.as_ref() {
+                let source_file_id = self.id_gen.next();
+                self.debugs.push(Instruction::string(
+                    &debug_info.file_name.display().to_string(),
+                    source_file_id,
+                ));
+
+                debug_info_inner = Some(DebugInfoInner {
+                    source_code: debug_info.source_code,
+                    source_file_id,
+                });
+                self.debugs.push(Instruction::source(
+                    spirv::SourceLanguage::Unknown,
+                    0,
+                    &debug_info_inner,
+                ));
+            }
+        }
+
+        // write all types
+        for (handle, _) in ir_module.types.iter() {
+            self.write_type_declaration_arena(&ir_module.types, handle)?;
+        }
+
+        // write all const-expressions as constants
+        self.constant_ids
+            .resize(ir_module.const_expressions.len(), 0);
+        for (handle, _) in ir_module.const_expressions.iter() {
+            self.write_constant_expr(handle, ir_module, mod_info)?;
+        }
+        debug_assert!(self.constant_ids.iter().all(|&id| id != 0));
+
+        // write the name of constants on their respective const-expression initializer
+        if self.flags.contains(WriterFlags::DEBUG) {
+            for (_, constant) in ir_module.constants.iter() {
+                if let Some(ref name) = constant.name {
+                    let id = self.constant_ids[constant.init.index()];
+                    self.debugs.push(Instruction::name(id, name));
+                }
+            }
+        }
+
+        // write all global variables
+        for (handle, var) in ir_module.global_variables.iter() {
+            // If a single entry point was specified, only write `OpVariable` instructions
+            // for the globals it actually uses. Emit dummies for the others,
+            // to preserve the indices in `global_variables`.
+            let gvar = match ep_index {
+                Some(index) if mod_info.get_entry_point(index)[handle].is_empty() => {
+                    GlobalVariable::dummy()
+                }
+                _ => {
+                    let id = self.write_global_variable(ir_module, var)?;
+                    GlobalVariable::new(id)
+                }
+            };
+            self.global_variables.push(gvar);
+        }
+
+        // write all functions
+        for (handle, ir_function) in ir_module.functions.iter() {
+            let info = &mod_info[handle];
+            if let Some(index) = ep_index {
+                let ep_info = mod_info.get_entry_point(index);
+                // If this function uses globals that we omitted from the SPIR-V
+                // because the entry point and its callees didn't use them,
+                // then we must skip it.
+                if !ep_info.dominates_global_use(info) {
+                    log::info!("Skip function {:?}", ir_function.name);
+                    continue;
+                }
+
+                // Skip functions that that are not compatible with this entry point's stage.
+                //
+                // When validation is enabled, it rejects modules whose entry points try to call
+                // incompatible functions, so if we got this far, then any functions incompatible
+                // with our selected entry point must not be used.
+                //
+                // When validation is disabled, `fun_info.available_stages` is always just
+                // `ShaderStages::all()`, so this will write all functions in the module, and
+                // the downstream GLSL compiler will catch any problems.
+                if !info.available_stages.contains(ep_info.available_stages) {
+                    continue;
+                }
+            }
+            let id = self.write_function(ir_function, info, ir_module, None, &debug_info_inner)?;
+            self.lookup_function.insert(handle, id);
+        }
+
+        // write all or one entry points
+        for (index, ir_ep) in ir_module.entry_points.iter().enumerate() {
+            if ep_index.is_some() && ep_index != Some(index) {
+                continue;
+            }
+            let info = mod_info.get_entry_point(index);
+            let ep_instruction =
+                self.write_entry_point(ir_ep, info, ir_module, &debug_info_inner)?;
+            ep_instruction.to_words(&mut self.logical_layout.entry_points);
+        }
+
+        for capability in self.capabilities_used.iter() {
+            Instruction::capability(*capability).to_words(&mut self.logical_layout.capabilities);
+        }
+        for extension in self.extensions_used.iter() {
+            Instruction::extension(extension).to_words(&mut self.logical_layout.extensions);
+        }
+        if ir_module.entry_points.is_empty() {
+            // SPIR-V doesn't like modules without entry points
+            Instruction::capability(spirv::Capability::Linkage)
+                .to_words(&mut self.logical_layout.capabilities);
+        }
+
+        let addressing_model = spirv::AddressingModel::Logical;
+        let memory_model = spirv::MemoryModel::GLSL450;
+        //self.check(addressing_model.required_capabilities())?;
+        //self.check(memory_model.required_capabilities())?;
+
+        Instruction::memory_model(addressing_model, memory_model)
+            .to_words(&mut self.logical_layout.memory_model);
+
+        if self.flags.contains(WriterFlags::DEBUG) {
+            for debug in self.debugs.iter() {
+                debug.to_words(&mut self.logical_layout.debugs);
+            }
+        }
+
+        for annotation in self.annotations.iter() {
+            annotation.to_words(&mut self.logical_layout.annotations);
+        }
+
+        Ok(())
+    }
+
+    pub fn write(
+        &mut self,
+        ir_module: &crate::Module,
+        info: &ModuleInfo,
+        pipeline_options: Option<&PipelineOptions>,
+        debug_info: &Option<DebugInfo>,
+        words: &mut Vec<Word>,
+    ) -> Result<(), Error> {
+        self.reset();
+
+        // Try to find the entry point and corresponding index
+        let ep_index = match pipeline_options {
+            Some(po) => {
+                let index = ir_module
+                    .entry_points
+                    .iter()
+                    .position(|ep| po.shader_stage == ep.stage && po.entry_point == ep.name)
+                    .ok_or(Error::EntryPointNotFound)?;
+                Some(index)
+            }
+            None => None,
+        };
+
+        self.write_logical_layout(ir_module, info, ep_index, debug_info)?;
+        self.write_physical_layout();
+
+        self.physical_layout.in_words(words);
+        self.logical_layout.in_words(words);
+        Ok(())
+    }
+
+    /// Return the set of capabilities the last module written used.
+    pub const fn get_capabilities_used(&self) -> &crate::FastIndexSet<spirv::Capability> {
+        &self.capabilities_used
+    }
+
+    pub fn decorate_non_uniform_binding_array_access(&mut self, id: Word) -> Result<(), Error> {
+        self.require_any("NonUniformEXT", &[spirv::Capability::ShaderNonUniform])?;
+        self.use_extension("SPV_EXT_descriptor_indexing");
+        self.decorate(id, spirv::Decoration::NonUniform, &[]);
+        Ok(())
+    }
+}
+
+#[test]
+fn test_write_physical_layout() {
+    let mut writer = Writer::new(&Options::default()).unwrap();
+    assert_eq!(writer.physical_layout.bound, 0);
+    writer.write_physical_layout();
+    assert_eq!(writer.physical_layout.bound, 3);
+}
diff --git a/third_party/rust/naga/src/back/wgsl/mod.rs b/third_party/rust/naga/src/back/wgsl/mod.rs
new file mode 100644
index 0000000000..d731b1ca0c
--- /dev/null
+++ b/third_party/rust/naga/src/back/wgsl/mod.rs
@@ -0,0 +1,52 @@
+/*!
+Backend for [WGSL][wgsl] (WebGPU Shading Language).
+
+[wgsl]: https://gpuweb.github.io/gpuweb/wgsl.html
+*/
+
+mod writer;
+
+use thiserror::Error;
+
+pub use writer::{Writer, WriterFlags};
+
+#[derive(Error, Debug)]
+pub enum Error {
+    #[error(transparent)]
+    FmtError(#[from] std::fmt::Error),
+    #[error("{0}")]
+    Custom(String),
+    #[error("{0}")]
+    Unimplemented(String), // TODO: Error used only during development
+    #[error("Unsupported math function: {0:?}")]
+    UnsupportedMathFunction(crate::MathFunction),
+    #[error("Unsupported relational function: {0:?}")]
+    UnsupportedRelationalFunction(crate::RelationalFunction),
+}
+
+pub fn write_string(
+    module: &crate::Module,
+    info: &crate::valid::ModuleInfo,
+    flags: WriterFlags,
+) -> Result<String, Error> {
+    let mut w = Writer::new(String::new(), flags);
+    w.write(module, info)?;
+    let output = w.finish();
+    Ok(output)
+}
+
+impl crate::AtomicFunction {
+    const fn to_wgsl(self) -> &'static str {
+        match self {
+            Self::Add => "Add",
+            Self::Subtract => "Sub",
+            Self::And => "And",
+            Self::InclusiveOr => "Or",
+            Self::ExclusiveOr => "Xor",
+            Self::Min => "Min",
+            Self::Max => "Max",
+            Self::Exchange { compare: None } => "Exchange",
+            Self::Exchange { .. } => "CompareExchangeWeak",
+        }
+    }
+}
diff --git a/third_party/rust/naga/src/back/wgsl/writer.rs b/third_party/rust/naga/src/back/wgsl/writer.rs
new file mode 100644
index 0000000000..c737934f5e
--- /dev/null
+++ b/third_party/rust/naga/src/back/wgsl/writer.rs
@@ -0,0 +1,1961 @@
+use super::Error;
+use crate::{
+    back,
+    proc::{self, NameKey},
+    valid, Handle, Module, ShaderStage, TypeInner,
+};
+use std::fmt::Write;
+
+/// Shorthand result used internally by the backend
+type BackendResult = Result<(), Error>;
+
+/// WGSL [attribute](https://gpuweb.github.io/gpuweb/wgsl/#attributes)
+enum Attribute {
+    Binding(u32),
+    BuiltIn(crate::BuiltIn),
+    Group(u32),
+    Invariant,
+    Interpolate(Option<crate::Interpolation>, Option<crate::Sampling>),
+    Location(u32),
+    SecondBlendSource,
+    Stage(ShaderStage),
+    WorkGroupSize([u32; 3]),
+}
+
+/// The WGSL form that `write_expr_with_indirection` should use to render a Naga
+/// expression.
+///
+/// Sometimes a Naga `Expression` alone doesn't provide enough information to
+/// choose the right rendering for it in WGSL. For example, one natural WGSL
+/// rendering of a Naga `LocalVariable(x)` expression might be `&x`, since
+/// `LocalVariable` produces a pointer to the local variable's storage. But when
+/// rendering a `Store` statement, the `pointer` operand must be the left hand
+/// side of a WGSL assignment, so the proper rendering is `x`.
+///
+/// The caller of `write_expr_with_indirection` must provide an `Expected` value
+/// to indicate how ambiguous expressions should be rendered.
+#[derive(Clone, Copy, Debug)]
+enum Indirection {
+    /// Render pointer-construction expressions as WGSL `ptr`-typed expressions.
+    ///
+    /// This is the right choice for most cases. Whenever a Naga pointer
+    /// expression is not the `pointer` operand of a `Load` or `Store`, it
+    /// must be a WGSL pointer expression.
+    Ordinary,
+
+    /// Render pointer-construction expressions as WGSL reference-typed
+    /// expressions.
+    ///
+    /// For example, this is the right choice for the `pointer` operand when
+    /// rendering a `Store` statement as a WGSL assignment.
+    Reference,
+}
+
+bitflags::bitflags! {
+    #[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+    #[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+    #[derive(Clone, Copy, Debug, Eq, PartialEq)]
+    pub struct WriterFlags: u32 {
+        /// Always annotate the type information instead of inferring.
+        const EXPLICIT_TYPES = 0x1;
+    }
+}
+
+pub struct Writer<W> {
+    out: W,
+    flags: WriterFlags,
+    names: crate::FastHashMap<NameKey, String>,
+    namer: proc::Namer,
+    named_expressions: crate::NamedExpressions,
+    ep_results: Vec<(ShaderStage, Handle<crate::Type>)>,
+}
+
+impl<W: Write> Writer<W> {
+    pub fn new(out: W, flags: WriterFlags) -> Self {
+        Writer {
+            out,
+            flags,
+            names: crate::FastHashMap::default(),
+            namer: proc::Namer::default(),
+            named_expressions: crate::NamedExpressions::default(),
+            ep_results: vec![],
+        }
+    }
+
+    fn reset(&mut self, module: &Module) {
+        self.names.clear();
+        self.namer.reset(
+            module,
+            crate::keywords::wgsl::RESERVED,
+            // an identifier must not start with two underscore
+            &[],
+            &[],
+            &["__"],
+            &mut self.names,
+        );
+        self.named_expressions.clear();
+        self.ep_results.clear();
+    }
+
+    fn is_builtin_wgsl_struct(&self, module: &Module, handle: Handle<crate::Type>) -> bool {
+        module
+            .special_types
+            .predeclared_types
+            .values()
+            .any(|t| *t == handle)
+    }
+
+    pub fn write(&mut self, module: &Module, info: &valid::ModuleInfo) -> BackendResult {
+        self.reset(module);
+
+        // Save all ep result types
+        for (_, ep) in module.entry_points.iter().enumerate() {
+            if let Some(ref result) = ep.function.result {
+                self.ep_results.push((ep.stage, result.ty));
+            }
+        }
+
+        // Write all structs
+        for (handle, ty) in module.types.iter() {
+            if let TypeInner::Struct { ref members, .. } = ty.inner {
+                {
+                    if !self.is_builtin_wgsl_struct(module, handle) {
+                        self.write_struct(module, handle, members)?;
+                        writeln!(self.out)?;
+                    }
+                }
+            }
+        }
+
+        // Write all named constants
+        let mut constants = module
+            .constants
+            .iter()
+            .filter(|&(_, c)| c.name.is_some())
+            .peekable();
+        while let Some((handle, _)) = constants.next() {
+            self.write_global_constant(module, handle)?;
+            // Add extra newline for readability on last iteration
+            if constants.peek().is_none() {
+                writeln!(self.out)?;
+            }
+        }
+
+        // Write all globals
+        for (ty, global) in module.global_variables.iter() {
+            self.write_global(module, global, ty)?;
+        }
+
+        if !module.global_variables.is_empty() {
+            // Add extra newline for readability
+            writeln!(self.out)?;
+        }
+
+        // Write all regular functions
+        for (handle, function) in module.functions.iter() {
+            let fun_info = &info[handle];
+
+            let func_ctx = back::FunctionCtx {
+                ty: back::FunctionType::Function(handle),
+                info: fun_info,
+                expressions: &function.expressions,
+                named_expressions: &function.named_expressions,
+            };
+
+            // Write the function
+            self.write_function(module, function, &func_ctx)?;
+
+            writeln!(self.out)?;
+        }
+
+        // Write all entry points
+        for (index, ep) in module.entry_points.iter().enumerate() {
+            let attributes = match ep.stage {
+                ShaderStage::Vertex | ShaderStage::Fragment => vec![Attribute::Stage(ep.stage)],
+                ShaderStage::Compute => vec![
+                    Attribute::Stage(ShaderStage::Compute),
+                    Attribute::WorkGroupSize(ep.workgroup_size),
+                ],
+            };
+
+            self.write_attributes(&attributes)?;
+            // Add a newline after attribute
+            writeln!(self.out)?;
+
+            let func_ctx = back::FunctionCtx {
+                ty: back::FunctionType::EntryPoint(index as u16),
+                info: info.get_entry_point(index),
+                expressions: &ep.function.expressions,
+                named_expressions: &ep.function.named_expressions,
+            };
+            self.write_function(module, &ep.function, &func_ctx)?;
+
+            if index < module.entry_points.len() - 1 {
+                writeln!(self.out)?;
+            }
+        }
+
+        Ok(())
+    }
+
+    /// Helper method used to write struct name
+    ///
+    /// # Notes
+    /// Adds no trailing or leading whitespace
+    fn write_struct_name(&mut self, module: &Module, handle: Handle<crate::Type>) -> BackendResult {
+        if module.types[handle].name.is_none() {
+            if let Some(&(stage, _)) = self.ep_results.iter().find(|&&(_, ty)| ty == handle) {
+                let name = match stage {
+                    ShaderStage::Compute => "ComputeOutput",
+                    ShaderStage::Fragment => "FragmentOutput",
+                    ShaderStage::Vertex => "VertexOutput",
+                };
+
+                write!(self.out, "{name}")?;
+                return Ok(());
+            }
+        }
+
+        write!(self.out, "{}", self.names[&NameKey::Type(handle)])?;
+
+        Ok(())
+    }
+
+    /// Helper method used to write
+    /// [functions](https://gpuweb.github.io/gpuweb/wgsl/#functions)
+    ///
+    /// # Notes
+    /// Ends in a newline
+    fn write_function(
+        &mut self,
+        module: &Module,
+        func: &crate::Function,
+        func_ctx: &back::FunctionCtx<'_>,
+    ) -> BackendResult {
+        let func_name = match func_ctx.ty {
+            back::FunctionType::EntryPoint(index) => &self.names[&NameKey::EntryPoint(index)],
+            back::FunctionType::Function(handle) => &self.names[&NameKey::Function(handle)],
+        };
+
+        // Write function name
+        write!(self.out, "fn {func_name}(")?;
+
+        // Write function arguments
+        for (index, arg) in func.arguments.iter().enumerate() {
+            // Write argument attribute if a binding is present
+            if let Some(ref binding) = arg.binding {
+                self.write_attributes(&map_binding_to_attribute(binding))?;
+            }
+            // Write argument name
+            let argument_name = &self.names[&func_ctx.argument_key(index as u32)];
+
+            write!(self.out, "{argument_name}: ")?;
+            // Write argument type
+            self.write_type(module, arg.ty)?;
+            if index < func.arguments.len() - 1 {
+                // Add a separator between args
+                write!(self.out, ", ")?;
+            }
+        }
+
+        write!(self.out, ")")?;
+
+        // Write function return type
+        if let Some(ref result) = func.result {
+            write!(self.out, " -> ")?;
+            if let Some(ref binding) = result.binding {
+                self.write_attributes(&map_binding_to_attribute(binding))?;
+            }
+            self.write_type(module, result.ty)?;
+        }
+
+        write!(self.out, " {{")?;
+        writeln!(self.out)?;
+
+        // Write function local variables
+        for (handle, local) in func.local_variables.iter() {
+            // Write indentation (only for readability)
+            write!(self.out, "{}", back::INDENT)?;
+
+            // Write the local name
+            // The leading space is important
+            write!(self.out, "var {}: ", self.names[&func_ctx.name_key(handle)])?;
+
+            // Write the local type
+            self.write_type(module, local.ty)?;
+
+            // Write the local initializer if needed
+            if let Some(init) = local.init {
+                // Put the equal signal only if there's a initializer
+                // The leading and trailing spaces aren't needed but help with readability
+                write!(self.out, " = ")?;
+
+                // Write the constant
+                // `write_constant` adds no trailing or leading space/newline
+                self.write_expr(module, init, func_ctx)?;
+            }
+
+            // Finish the local with `;` and add a newline (only for readability)
+            writeln!(self.out, ";")?
+        }
+
+        if !func.local_variables.is_empty() {
+            writeln!(self.out)?;
+        }
+
+        // Write the function body (statement list)
+        for sta in func.body.iter() {
+            // The indentation should always be 1 when writing the function body
+            self.write_stmt(module, sta, func_ctx, back::Level(1))?;
+        }
+
+        writeln!(self.out, "}}")?;
+
+        self.named_expressions.clear();
+
+        Ok(())
+    }
+
+    /// Helper method to write a attribute
+    fn write_attributes(&mut self, attributes: &[Attribute]) -> BackendResult {
+        for attribute in attributes {
+            match *attribute {
+                Attribute::Location(id) => write!(self.out, "@location({id}) ")?,
+                Attribute::SecondBlendSource => write!(self.out, "@second_blend_source ")?,
+                Attribute::BuiltIn(builtin_attrib) => {
+                    let builtin = builtin_str(builtin_attrib)?;
+                    write!(self.out, "@builtin({builtin}) ")?;
+                }
+                Attribute::Stage(shader_stage) => {
+                    let stage_str = match shader_stage {
+                        ShaderStage::Vertex => "vertex",
+                        ShaderStage::Fragment => "fragment",
+                        ShaderStage::Compute => "compute",
+                    };
+                    write!(self.out, "@{stage_str} ")?;
+                }
+                Attribute::WorkGroupSize(size) => {
+                    write!(
+                        self.out,
+                        "@workgroup_size({}, {}, {}) ",
+                        size[0], size[1], size[2]
+                    )?;
+                }
+                Attribute::Binding(id) => write!(self.out, "@binding({id}) ")?,
+                Attribute::Group(id) => write!(self.out, "@group({id}) ")?,
+                Attribute::Invariant => write!(self.out, "@invariant ")?,
+                Attribute::Interpolate(interpolation, sampling) => {
+                    if sampling.is_some() && sampling != Some(crate::Sampling::Center) {
+                        write!(
+                            self.out,
+                            "@interpolate({}, {}) ",
+                            interpolation_str(
+                                interpolation.unwrap_or(crate::Interpolation::Perspective)
+                            ),
+                            sampling_str(sampling.unwrap_or(crate::Sampling::Center))
+                        )?;
+                    } else if interpolation.is_some()
+                        && interpolation != Some(crate::Interpolation::Perspective)
+                    {
+                        write!(
+                            self.out,
+                            "@interpolate({}) ",
+                            interpolation_str(
+                                interpolation.unwrap_or(crate::Interpolation::Perspective)
+                            )
+                        )?;
+                    }
+                }
+            };
+        }
+        Ok(())
+    }
+
+    /// Helper method used to write structs
+    ///
+    /// # Notes
+    /// Ends in a newline
+    fn write_struct(
+        &mut self,
+        module: &Module,
+        handle: Handle<crate::Type>,
+        members: &[crate::StructMember],
+    ) -> BackendResult {
+        write!(self.out, "struct ")?;
+        self.write_struct_name(module, handle)?;
+        write!(self.out, " {{")?;
+        writeln!(self.out)?;
+        for (index, member) in members.iter().enumerate() {
+            // The indentation is only for readability
+            write!(self.out, "{}", back::INDENT)?;
+            if let Some(ref binding) = member.binding {
+                self.write_attributes(&map_binding_to_attribute(binding))?;
+            }
+            // Write struct member name and type
+            let member_name = &self.names[&NameKey::StructMember(handle, index as u32)];
+            write!(self.out, "{member_name}: ")?;
+            self.write_type(module, member.ty)?;
+            write!(self.out, ",")?;
+            writeln!(self.out)?;
+        }
+
+        write!(self.out, "}}")?;
+
+        writeln!(self.out)?;
+
+        Ok(())
+    }
+
+    /// Helper method used to write non image/sampler types
+    ///
+    /// # Notes
+    /// Adds no trailing or leading whitespace
+    fn write_type(&mut self, module: &Module, ty: Handle<crate::Type>) -> BackendResult {
+        let inner = &module.types[ty].inner;
+        match *inner {
+            TypeInner::Struct { .. } => self.write_struct_name(module, ty)?,
+            ref other => self.write_value_type(module, other)?,
+        }
+
+        Ok(())
+    }
+
+    /// Helper method used to write value types
+    ///
+    /// # Notes
+    /// Adds no trailing or leading whitespace
+    fn write_value_type(&mut self, module: &Module, inner: &TypeInner) -> BackendResult {
+        match *inner {
+            TypeInner::Vector { size, scalar } => write!(
+                self.out,
+                "vec{}<{}>",
+                back::vector_size_str(size),
+                scalar_kind_str(scalar),
+            )?,
+            TypeInner::Sampler { comparison: false } => {
+                write!(self.out, "sampler")?;
+            }
+            TypeInner::Sampler { comparison: true } => {
+                write!(self.out, "sampler_comparison")?;
+            }
+            TypeInner::Image {
+                dim,
+                arrayed,
+                class,
+            } => {
+                // More about texture types: https://gpuweb.github.io/gpuweb/wgsl/#sampled-texture-type
+                use crate::ImageClass as Ic;
+
+                let dim_str = image_dimension_str(dim);
+                let arrayed_str = if arrayed { "_array" } else { "" };
+                let (class_str, multisampled_str, format_str, storage_str) = match class {
+                    Ic::Sampled { kind, multi } => (
+                        "",
+                        if multi { "multisampled_" } else { "" },
+                        scalar_kind_str(crate::Scalar { kind, width: 4 }),
+                        "",
+                    ),
+                    Ic::Depth { multi } => {
+                        ("depth_", if multi { "multisampled_" } else { "" }, "", "")
+                    }
+                    Ic::Storage { format, access } => (
+                        "storage_",
+                        "",
+                        storage_format_str(format),
+                        if access.contains(crate::StorageAccess::LOAD | crate::StorageAccess::STORE)
+                        {
+                            ",read_write"
+                        } else if access.contains(crate::StorageAccess::LOAD) {
+                            ",read"
+                        } else {
+                            ",write"
+                        },
+                    ),
+                };
+                write!(
+                    self.out,
+                    "texture_{class_str}{multisampled_str}{dim_str}{arrayed_str}"
+                )?;
+
+                if !format_str.is_empty() {
+                    write!(self.out, "<{format_str}{storage_str}>")?;
+                }
+            }
+            TypeInner::Scalar(scalar) => {
+                write!(self.out, "{}", scalar_kind_str(scalar))?;
+            }
+            TypeInner::Atomic(scalar) => {
+                write!(self.out, "atomic<{}>", scalar_kind_str(scalar))?;
+            }
+            TypeInner::Array {
+                base,
+                size,
+                stride: _,
+            } => {
+                // More info https://gpuweb.github.io/gpuweb/wgsl/#array-types
+                // array<A, 3> -- Constant array
+                // array<A> -- Dynamic array
+                write!(self.out, "array<")?;
+                match size {
+                    crate::ArraySize::Constant(len) => {
+                        self.write_type(module, base)?;
+                        write!(self.out, ", {len}")?;
+                    }
+                    crate::ArraySize::Dynamic => {
+                        self.write_type(module, base)?;
+                    }
+                }
+                write!(self.out, ">")?;
+            }
+            TypeInner::BindingArray { base, size } => {
+                // More info https://github.com/gpuweb/gpuweb/issues/2105
+                write!(self.out, "binding_array<")?;
+                match size {
+                    crate::ArraySize::Constant(len) => {
+                        self.write_type(module, base)?;
+                        write!(self.out, ", {len}")?;
+                    }
+                    crate::ArraySize::Dynamic => {
+                        self.write_type(module, base)?;
+                    }
+                }
+                write!(self.out, ">")?;
+            }
+            TypeInner::Matrix {
+                columns,
+                rows,
+                scalar,
+            } => {
+                write!(
+                    self.out,
+                    "mat{}x{}<{}>",
+                    back::vector_size_str(columns),
+                    back::vector_size_str(rows),
+                    scalar_kind_str(scalar)
+                )?;
+            }
+            TypeInner::Pointer { base, space } => {
+                let (address, maybe_access) = address_space_str(space);
+                // Everything but `AddressSpace::Handle` gives us a `address` name, but
+                // Naga IR never produces pointers to handles, so it doesn't matter much
+                // how we write such a type. Just write it as the base type alone.
+                if let Some(space) = address {
+                    write!(self.out, "ptr<{space}, ")?;
+                }
+                self.write_type(module, base)?;
+                if address.is_some() {
+                    if let Some(access) = maybe_access {
+                        write!(self.out, ", {access}")?;
+                    }
+                    write!(self.out, ">")?;
+                }
+            }
+            TypeInner::ValuePointer {
+                size: None,
+                scalar,
+                space,
+            } => {
+                let (address, maybe_access) = address_space_str(space);
+                if let Some(space) = address {
+                    write!(self.out, "ptr<{}, {}", space, scalar_kind_str(scalar))?;
+                    if let Some(access) = maybe_access {
+                        write!(self.out, ", {access}")?;
+                    }
+                    write!(self.out, ">")?;
+                } else {
+                    return Err(Error::Unimplemented(format!(
+                        "ValuePointer to AddressSpace::Handle {inner:?}"
+                    )));
+                }
+            }
+            TypeInner::ValuePointer {
+                size: Some(size),
+                scalar,
+                space,
+            } => {
+                let (address, maybe_access) = address_space_str(space);
+                if let Some(space) = address {
+                    write!(
+                        self.out,
+                        "ptr<{}, vec{}<{}>",
+                        space,
+                        back::vector_size_str(size),
+                        scalar_kind_str(scalar)
+                    )?;
+                    if let Some(access) = maybe_access {
+                        write!(self.out, ", {access}")?;
+                    }
+                    write!(self.out, ">")?;
+                } else {
+                    return Err(Error::Unimplemented(format!(
+                        "ValuePointer to AddressSpace::Handle {inner:?}"
+                    )));
+                }
+                write!(self.out, ">")?;
+            }
+            _ => {
+                return Err(Error::Unimplemented(format!("write_value_type {inner:?}")));
+            }
+        }
+
+        Ok(())
+    }
+    /// Helper method used to write statements
+    ///
+    /// # Notes
+    /// Always adds a newline
+    fn write_stmt(
+        &mut self,
+        module: &Module,
+        stmt: &crate::Statement,
+        func_ctx: &back::FunctionCtx<'_>,
+        level: back::Level,
+    ) -> BackendResult {
+        use crate::{Expression, Statement};
+
+        match *stmt {
+            Statement::Emit(ref range) => {
+                for handle in range.clone() {
+                    let info = &func_ctx.info[handle];
+                    let expr_name = if let Some(name) = func_ctx.named_expressions.get(&handle) {
+                        // Front end provides names for all variables at the start of writing.
+                        // But we write them to step by step. We need to recache them
+                        // Otherwise, we could accidentally write variable name instead of full expression.
+                        // Also, we use sanitized names! It defense backend from generating variable with name from reserved keywords.
+                        Some(self.namer.call(name))
+                    } else {
+                        let expr = &func_ctx.expressions[handle];
+                        let min_ref_count = expr.bake_ref_count();
+                        // Forcefully creating baking expressions in some cases to help with readability
+                        let required_baking_expr = match *expr {
+                            Expression::ImageLoad { .. }
+                            | Expression::ImageQuery { .. }
+                            | Expression::ImageSample { .. } => true,
+                            _ => false,
+                        };
+                        if min_ref_count <= info.ref_count || required_baking_expr {
+                            Some(format!("{}{}", back::BAKE_PREFIX, handle.index()))
+                        } else {
+                            None
+                        }
+                    };
+
+                    if let Some(name) = expr_name {
+                        write!(self.out, "{level}")?;
+                        self.start_named_expr(module, handle, func_ctx, &name)?;
+                        self.write_expr(module, handle, func_ctx)?;
+                        self.named_expressions.insert(handle, name);
+                        writeln!(self.out, ";")?;
+                    }
+                }
+            }
+            // TODO: copy-paste from glsl-out
+            Statement::If {
+                condition,
+                ref accept,
+                ref reject,
+            } => {
+                write!(self.out, "{level}")?;
+                write!(self.out, "if ")?;
+                self.write_expr(module, condition, func_ctx)?;
+                writeln!(self.out, " {{")?;
+
+                let l2 = level.next();
+                for sta in accept {
+                    // Increase indentation to help with readability
+                    self.write_stmt(module, sta, func_ctx, l2)?;
+                }
+
+                // If there are no statements in the reject block we skip writing it
+                // This is only for readability
+                if !reject.is_empty() {
+                    writeln!(self.out, "{level}}} else {{")?;
+
+                    for sta in reject {
+                        // Increase indentation to help with readability
+                        self.write_stmt(module, sta, func_ctx, l2)?;
+                    }
+                }
+
+                writeln!(self.out, "{level}}}")?
+            }
+            Statement::Return { value } => {
+                write!(self.out, "{level}")?;
+                write!(self.out, "return")?;
+                if let Some(return_value) = value {
+                    // The leading space is important
+                    write!(self.out, " ")?;
+                    self.write_expr(module, return_value, func_ctx)?;
+                }
+                writeln!(self.out, ";")?;
+            }
+            // TODO: copy-paste from glsl-out
+            Statement::Kill => {
+                write!(self.out, "{level}")?;
+                writeln!(self.out, "discard;")?
+            }
+            Statement::Store { pointer, value } => {
+                write!(self.out, "{level}")?;
+
+                let is_atomic_pointer = func_ctx
+                    .resolve_type(pointer, &module.types)
+                    .is_atomic_pointer(&module.types);
+
+                if is_atomic_pointer {
+                    write!(self.out, "atomicStore(")?;
+                    self.write_expr(module, pointer, func_ctx)?;
+                    write!(self.out, ", ")?;
+                    self.write_expr(module, value, func_ctx)?;
+                    write!(self.out, ")")?;
+                } else {
+                    self.write_expr_with_indirection(
+                        module,
+                        pointer,
+                        func_ctx,
+                        Indirection::Reference,
+                    )?;
+                    write!(self.out, " = ")?;
+                    self.write_expr(module, value, func_ctx)?;
+                }
+                writeln!(self.out, ";")?
+            }
+            Statement::Call {
+                function,
+                ref arguments,
+                result,
+            } => {
+                write!(self.out, "{level}")?;
+                if let Some(expr) = result {
+                    let name = format!("{}{}", back::BAKE_PREFIX, expr.index());
+                    self.start_named_expr(module, expr, func_ctx, &name)?;
+                    self.named_expressions.insert(expr, name);
+                }
+                let func_name = &self.names[&NameKey::Function(function)];
+                write!(self.out, "{func_name}(")?;
+                for (index, &argument) in arguments.iter().enumerate() {
+                    if index != 0 {
+                        write!(self.out, ", ")?;
+                    }
+                    self.write_expr(module, argument, func_ctx)?;
+                }
+                writeln!(self.out, ");")?
+            }
+            Statement::Atomic {
+                pointer,
+                ref fun,
+                value,
+                result,
+            } => {
+                write!(self.out, "{level}")?;
+                let res_name = format!("{}{}", back::BAKE_PREFIX, result.index());
+                self.start_named_expr(module, result, func_ctx, &res_name)?;
+                self.named_expressions.insert(result, res_name);
+
+                let fun_str = fun.to_wgsl();
+                write!(self.out, "atomic{fun_str}(")?;
+                self.write_expr(module, pointer, func_ctx)?;
+                if let crate::AtomicFunction::Exchange { compare: Some(cmp) } = *fun {
+                    write!(self.out, ", ")?;
+                    self.write_expr(module, cmp, func_ctx)?;
+                }
+                write!(self.out, ", ")?;
+                self.write_expr(module, value, func_ctx)?;
+                writeln!(self.out, ");")?
+            }
+            Statement::WorkGroupUniformLoad { pointer, result } => {
+                write!(self.out, "{level}")?;
+                // TODO: Obey named expressions here.
+                let res_name = format!("{}{}", back::BAKE_PREFIX, result.index());
+                self.start_named_expr(module, result, func_ctx, &res_name)?;
+                self.named_expressions.insert(result, res_name);
+                write!(self.out, "workgroupUniformLoad(")?;
+                self.write_expr(module, pointer, func_ctx)?;
+                writeln!(self.out, ");")?;
+            }
+            Statement::ImageStore {
+                image,
+                coordinate,
+                array_index,
+                value,
+            } => {
+                write!(self.out, "{level}")?;
+                write!(self.out, "textureStore(")?;
+                self.write_expr(module, image, func_ctx)?;
+                write!(self.out, ", ")?;
+                self.write_expr(module, coordinate, func_ctx)?;
+                if let Some(array_index_expr) = array_index {
+                    write!(self.out, ", ")?;
+                    self.write_expr(module, array_index_expr, func_ctx)?;
+                }
+                write!(self.out, ", ")?;
+                self.write_expr(module, value, func_ctx)?;
+                writeln!(self.out, ");")?;
+            }
+            // TODO: copy-paste from glsl-out
+            Statement::Block(ref block) => {
+                write!(self.out, "{level}")?;
+                writeln!(self.out, "{{")?;
+                for sta in block.iter() {
+                    // Increase the indentation to help with readability
+                    self.write_stmt(module, sta, func_ctx, level.next())?
+                }
+                writeln!(self.out, "{level}}}")?
+            }
+            Statement::Switch {
+                selector,
+                ref cases,
+            } => {
+                // Start the switch
+                write!(self.out, "{level}")?;
+                write!(self.out, "switch ")?;
+                self.write_expr(module, selector, func_ctx)?;
+                writeln!(self.out, " {{")?;
+
+                let l2 = level.next();
+                let mut new_case = true;
+                for case in cases {
+                    if case.fall_through && !case.body.is_empty() {
+                        // TODO: we could do the same workaround as we did for the HLSL backend
+                        return Err(Error::Unimplemented(
+                            "fall-through switch case block".into(),
+                        ));
+                    }
+
+                    match case.value {
+                        crate::SwitchValue::I32(value) => {
+                            if new_case {
+                                write!(self.out, "{l2}case ")?;
+                            }
+                            write!(self.out, "{value}")?;
+                        }
+                        crate::SwitchValue::U32(value) => {
+                            if new_case {
+                                write!(self.out, "{l2}case ")?;
+                            }
+                            write!(self.out, "{value}u")?;
+                        }
+                        crate::SwitchValue::Default => {
+                            if new_case {
+                                if case.fall_through {
+                                    write!(self.out, "{l2}case ")?;
+                                } else {
+                                    write!(self.out, "{l2}")?;
+                                }
+                            }
+                            write!(self.out, "default")?;
+                        }
+                    }
+
+                    new_case = !case.fall_through;
+
+                    if case.fall_through {
+                        write!(self.out, ", ")?;
+                    } else {
+                        writeln!(self.out, ": {{")?;
+                    }
+
+                    for sta in case.body.iter() {
+                        self.write_stmt(module, sta, func_ctx, l2.next())?;
+                    }
+
+                    if !case.fall_through {
+                        writeln!(self.out, "{l2}}}")?;
+                    }
+                }
+
+                writeln!(self.out, "{level}}}")?
+            }
+            Statement::Loop {
+                ref body,
+                ref continuing,
+                break_if,
+            } => {
+                write!(self.out, "{level}")?;
+                writeln!(self.out, "loop {{")?;
+
+                let l2 = level.next();
+                for sta in body.iter() {
+                    self.write_stmt(module, sta, func_ctx, l2)?;
+                }
+
+                // The continuing is optional so we don't need to write it if
+                // it is empty, but the `break if` counts as a continuing statement
+                // so even if `continuing` is empty we must generate it if a
+                // `break if` exists
+                if !continuing.is_empty() || break_if.is_some() {
+                    writeln!(self.out, "{l2}continuing {{")?;
+                    for sta in continuing.iter() {
+                        self.write_stmt(module, sta, func_ctx, l2.next())?;
+                    }
+
+                    // The `break if` is always the last
+                    // statement of the `continuing` block
+                    if let Some(condition) = break_if {
+                        // The trailing space is important
+                        write!(self.out, "{}break if ", l2.next())?;
+                        self.write_expr(module, condition, func_ctx)?;
+                        // Close the `break if` statement
+                        writeln!(self.out, ";")?;
+                    }
+
+                    writeln!(self.out, "{l2}}}")?;
+                }
+
+                writeln!(self.out, "{level}}}")?
+            }
+            Statement::Break => {
+                writeln!(self.out, "{level}break;")?;
+            }
+            Statement::Continue => {
+                writeln!(self.out, "{level}continue;")?;
+            }
+            Statement::Barrier(barrier) => {
+                if barrier.contains(crate::Barrier::STORAGE) {
+                    writeln!(self.out, "{level}storageBarrier();")?;
+                }
+
+                if barrier.contains(crate::Barrier::WORK_GROUP) {
+                    writeln!(self.out, "{level}workgroupBarrier();")?;
+                }
+            }
+            Statement::RayQuery { .. } => unreachable!(),
+        }
+
+        Ok(())
+    }
+
+    /// Return the sort of indirection that `expr`'s plain form evaluates to.
+    ///
+    /// An expression's 'plain form' is the most general rendition of that
+    /// expression into WGSL, lacking `&` or `*` operators:
+    ///
+    /// - The plain form of `LocalVariable(x)` is simply `x`, which is a reference
+    ///   to the local variable's storage.
+    ///
+    /// - The plain form of `GlobalVariable(g)` is simply `g`, which is usually a
+    ///   reference to the global variable's storage. However, globals in the
+    ///   `Handle` address space are immutable, and `GlobalVariable` expressions for
+    ///   those produce the value directly, not a pointer to it. Such
+    ///   `GlobalVariable` expressions are `Ordinary`.
+    ///
+    /// - `Access` and `AccessIndex` are `Reference` when their `base` operand is a
+    ///   pointer. If they are applied directly to a composite value, they are
+    ///   `Ordinary`.
+    ///
+    /// Note that `FunctionArgument` expressions are never `Reference`, even when
+    /// the argument's type is `Pointer`. `FunctionArgument` always evaluates to the
+    /// argument's value directly, so any pointer it produces is merely the value
+    /// passed by the caller.
+    fn plain_form_indirection(
+        &self,
+        expr: Handle<crate::Expression>,
+        module: &Module,
+        func_ctx: &back::FunctionCtx<'_>,
+    ) -> Indirection {
+        use crate::Expression as Ex;
+
+        // Named expressions are `let` expressions, which apply the Load Rule,
+        // so if their type is a Naga pointer, then that must be a WGSL pointer
+        // as well.
+        if self.named_expressions.contains_key(&expr) {
+            return Indirection::Ordinary;
+        }
+
+        match func_ctx.expressions[expr] {
+            Ex::LocalVariable(_) => Indirection::Reference,
+            Ex::GlobalVariable(handle) => {
+                let global = &module.global_variables[handle];
+                match global.space {
+                    crate::AddressSpace::Handle => Indirection::Ordinary,
+                    _ => Indirection::Reference,
+                }
+            }
+            Ex::Access { base, .. } | Ex::AccessIndex { base, .. } => {
+                let base_ty = func_ctx.resolve_type(base, &module.types);
+                match *base_ty {
+                    crate::TypeInner::Pointer { .. } | crate::TypeInner::ValuePointer { .. } => {
+                        Indirection::Reference
+                    }
+                    _ => Indirection::Ordinary,
+                }
+            }
+            _ => Indirection::Ordinary,
+        }
+    }
+
+    fn start_named_expr(
+        &mut self,
+        module: &Module,
+        handle: Handle<crate::Expression>,
+        func_ctx: &back::FunctionCtx,
+        name: &str,
+    ) -> BackendResult {
+        // Write variable name
+        write!(self.out, "let {name}")?;
+        if self.flags.contains(WriterFlags::EXPLICIT_TYPES) {
+            write!(self.out, ": ")?;
+            let ty = &func_ctx.info[handle].ty;
+            // Write variable type
+            match *ty {
+                proc::TypeResolution::Handle(handle) => {
+                    self.write_type(module, handle)?;
+                }
+                proc::TypeResolution::Value(ref inner) => {
+                    self.write_value_type(module, inner)?;
+                }
+            }
+        }
+
+        write!(self.out, " = ")?;
+        Ok(())
+    }
+
+    /// Write the ordinary WGSL form of `expr`.
+    ///
+    /// See `write_expr_with_indirection` for details.
+    fn write_expr(
+        &mut self,
+        module: &Module,
+        expr: Handle<crate::Expression>,
+        func_ctx: &back::FunctionCtx<'_>,
+    ) -> BackendResult {
+        self.write_expr_with_indirection(module, expr, func_ctx, Indirection::Ordinary)
+    }
+
+    /// Write `expr` as a WGSL expression with the requested indirection.
+    ///
+    /// In terms of the WGSL grammar, the resulting expression is a
+    /// `singular_expression`. It may be parenthesized. This makes it suitable
+    /// for use as the operand of a unary or binary operator without worrying
+    /// about precedence.
+    ///
+    /// This does not produce newlines or indentation.
+    ///
+    /// The `requested` argument indicates (roughly) whether Naga
+    /// `Pointer`-valued expressions represent WGSL references or pointers. See
+    /// `Indirection` for details.
+    fn write_expr_with_indirection(
+        &mut self,
+        module: &Module,
+        expr: Handle<crate::Expression>,
+        func_ctx: &back::FunctionCtx<'_>,
+        requested: Indirection,
+    ) -> BackendResult {
+        // If the plain form of the expression is not what we need, emit the
+        // operator necessary to correct that.
+        let plain = self.plain_form_indirection(expr, module, func_ctx);
+        match (requested, plain) {
+            (Indirection::Ordinary, Indirection::Reference) => {
+                write!(self.out, "(&")?;
+                self.write_expr_plain_form(module, expr, func_ctx, plain)?;
+                write!(self.out, ")")?;
+            }
+            (Indirection::Reference, Indirection::Ordinary) => {
+                write!(self.out, "(*")?;
+                self.write_expr_plain_form(module, expr, func_ctx, plain)?;
+                write!(self.out, ")")?;
+            }
+            (_, _) => self.write_expr_plain_form(module, expr, func_ctx, plain)?,
+        }
+
+        Ok(())
+    }
+
+    fn write_const_expression(
+        &mut self,
+        module: &Module,
+        expr: Handle<crate::Expression>,
+    ) -> BackendResult {
+        self.write_possibly_const_expression(
+            module,
+            expr,
+            &module.const_expressions,
+            |writer, expr| writer.write_const_expression(module, expr),
+        )
+    }
+
+    fn write_possibly_const_expression<E>(
+        &mut self,
+        module: &Module,
+        expr: Handle<crate::Expression>,
+        expressions: &crate::Arena<crate::Expression>,
+        write_expression: E,
+    ) -> BackendResult
+    where
+        E: Fn(&mut Self, Handle<crate::Expression>) -> BackendResult,
+    {
+        use crate::Expression;
+
+        match expressions[expr] {
+            Expression::Literal(literal) => match literal {
+                crate::Literal::F32(value) => write!(self.out, "{}f", value)?,
+                crate::Literal::U32(value) => write!(self.out, "{}u", value)?,
+                crate::Literal::I32(value) => {
+                    // `-2147483648i` is not valid WGSL. The most negative `i32`
+                    // value can only be expressed in WGSL using AbstractInt and
+                    // a unary negation operator.
+                    if value == i32::MIN {
+                        write!(self.out, "i32(-2147483648)")?;
+                    } else {
+                        write!(self.out, "{}i", value)?;
+                    }
+                }
+                crate::Literal::Bool(value) => write!(self.out, "{}", value)?,
+                crate::Literal::F64(value) => write!(self.out, "{:?}lf", value)?,
+                crate::Literal::I64(_) => {
+                    return Err(Error::Custom("unsupported i64 literal".to_string()));
+                }
+                crate::Literal::AbstractInt(_) | crate::Literal::AbstractFloat(_) => {
+                    return Err(Error::Custom(
+                        "Abstract types should not appear in IR presented to backends".into(),
+                    ));
+                }
+            },
+            Expression::Constant(handle) => {
+                let constant = &module.constants[handle];
+                if constant.name.is_some() {
+                    write!(self.out, "{}", self.names[&NameKey::Constant(handle)])?;
+                } else {
+                    self.write_const_expression(module, constant.init)?;
+                }
+            }
+            Expression::ZeroValue(ty) => {
+                self.write_type(module, ty)?;
+                write!(self.out, "()")?;
+            }
+            Expression::Compose { ty, ref components } => {
+                self.write_type(module, ty)?;
+                write!(self.out, "(")?;
+                for (index, component) in components.iter().enumerate() {
+                    if index != 0 {
+                        write!(self.out, ", ")?;
+                    }
+                    write_expression(self, *component)?;
+                }
+                write!(self.out, ")")?
+            }
+            Expression::Splat { size, value } => {
+                let size = back::vector_size_str(size);
+                write!(self.out, "vec{size}(")?;
+                write_expression(self, value)?;
+                write!(self.out, ")")?;
+            }
+            _ => unreachable!(),
+        }
+
+        Ok(())
+    }
+
+    /// Write the 'plain form' of `expr`.
+    ///
+    /// An expression's 'plain form' is the most general rendition of that
+    /// expression into WGSL, lacking `&` or `*` operators. The plain forms of
+    /// `LocalVariable(x)` and `GlobalVariable(g)` are simply `x` and `g`. Such
+    /// Naga expressions represent both WGSL pointers and references; it's the
+    /// caller's responsibility to distinguish those cases appropriately.
+    fn write_expr_plain_form(
+        &mut self,
+        module: &Module,
+        expr: Handle<crate::Expression>,
+        func_ctx: &back::FunctionCtx<'_>,
+        indirection: Indirection,
+    ) -> BackendResult {
+        use crate::Expression;
+
+        if let Some(name) = self.named_expressions.get(&expr) {
+            write!(self.out, "{name}")?;
+            return Ok(());
+        }
+
+        let expression = &func_ctx.expressions[expr];
+
+        // Write the plain WGSL form of a Naga expression.
+        //
+        // The plain form of `LocalVariable` and `GlobalVariable` expressions is
+        // simply the variable name; `*` and `&` operators are never emitted.
+        //
+        // The plain form of `Access` and `AccessIndex` expressions are WGSL
+        // `postfix_expression` forms for member/component access and
+        // subscripting.
+        match *expression {
+            Expression::Literal(_)
+            | Expression::Constant(_)
+            | Expression::ZeroValue(_)
+            | Expression::Compose { .. }
+            | Expression::Splat { .. } => {
+                self.write_possibly_const_expression(
+                    module,
+                    expr,
+                    func_ctx.expressions,
+                    |writer, expr| writer.write_expr(module, expr, func_ctx),
+                )?;
+            }
+            Expression::FunctionArgument(pos) => {
+                let name_key = func_ctx.argument_key(pos);
+                let name = &self.names[&name_key];
+                write!(self.out, "{name}")?;
+            }
+            Expression::Binary { op, left, right } => {
+                write!(self.out, "(")?;
+                self.write_expr(module, left, func_ctx)?;
+                write!(self.out, " {} ", back::binary_operation_str(op))?;
+                self.write_expr(module, right, func_ctx)?;
+                write!(self.out, ")")?;
+            }
+            Expression::Access { base, index } => {
+                self.write_expr_with_indirection(module, base, func_ctx, indirection)?;
+                write!(self.out, "[")?;
+                self.write_expr(module, index, func_ctx)?;
+                write!(self.out, "]")?
+            }
+            Expression::AccessIndex { base, index } => {
+                let base_ty_res = &func_ctx.info[base].ty;
+                let mut resolved = base_ty_res.inner_with(&module.types);
+
+                self.write_expr_with_indirection(module, base, func_ctx, indirection)?;
+
+                let base_ty_handle = match *resolved {
+                    TypeInner::Pointer { base, space: _ } => {
+                        resolved = &module.types[base].inner;
+                        Some(base)
+                    }
+                    _ => base_ty_res.handle(),
+                };
+
+                match *resolved {
+                    TypeInner::Vector { .. } => {
+                        // Write vector access as a swizzle
+                        write!(self.out, ".{}", back::COMPONENTS[index as usize])?
+                    }
+                    TypeInner::Matrix { .. }
+                    | TypeInner::Array { .. }
+                    | TypeInner::BindingArray { .. }
+                    | TypeInner::ValuePointer { .. } => write!(self.out, "[{index}]")?,
+                    TypeInner::Struct { .. } => {
+                        // This will never panic in case the type is a `Struct`, this is not true
+                        // for other types so we can only check while inside this match arm
+                        let ty = base_ty_handle.unwrap();
+
+                        write!(
+                            self.out,
+                            ".{}",
+                            &self.names[&NameKey::StructMember(ty, index)]
+                        )?
+                    }
+                    ref other => return Err(Error::Custom(format!("Cannot index {other:?}"))),
+                }
+            }
+            Expression::ImageSample {
+                image,
+                sampler,
+                gather: None,
+                coordinate,
+                array_index,
+                offset,
+                level,
+                depth_ref,
+            } => {
+                use crate::SampleLevel as Sl;
+
+                let suffix_cmp = match depth_ref {
+                    Some(_) => "Compare",
+                    None => "",
+                };
+                let suffix_level = match level {
+                    Sl::Auto => "",
+                    Sl::Zero | Sl::Exact(_) => "Level",
+                    Sl::Bias(_) => "Bias",
+                    Sl::Gradient { .. } => "Grad",
+                };
+
+                write!(self.out, "textureSample{suffix_cmp}{suffix_level}(")?;
+                self.write_expr(module, image, func_ctx)?;
+                write!(self.out, ", ")?;
+                self.write_expr(module, sampler, func_ctx)?;
+                write!(self.out, ", ")?;
+                self.write_expr(module, coordinate, func_ctx)?;
+
+                if let Some(array_index) = array_index {
+                    write!(self.out, ", ")?;
+                    self.write_expr(module, array_index, func_ctx)?;
+                }
+
+                if let Some(depth_ref) = depth_ref {
+                    write!(self.out, ", ")?;
+                    self.write_expr(module, depth_ref, func_ctx)?;
+                }
+
+                match level {
+                    Sl::Auto => {}
+                    Sl::Zero => {
+                        // Level 0 is implied for depth comparison
+                        if depth_ref.is_none() {
+                            write!(self.out, ", 0.0")?;
+                        }
+                    }
+                    Sl::Exact(expr) => {
+                        write!(self.out, ", ")?;
+                        self.write_expr(module, expr, func_ctx)?;
+                    }
+                    Sl::Bias(expr) => {
+                        write!(self.out, ", ")?;
+                        self.write_expr(module, expr, func_ctx)?;
+                    }
+                    Sl::Gradient { x, y } => {
+                        write!(self.out, ", ")?;
+                        self.write_expr(module, x, func_ctx)?;
+                        write!(self.out, ", ")?;
+                        self.write_expr(module, y, func_ctx)?;
+                    }
+                }
+
+                if let Some(offset) = offset {
+                    write!(self.out, ", ")?;
+                    self.write_const_expression(module, offset)?;
+                }
+
+                write!(self.out, ")")?;
+            }
+
+            Expression::ImageSample {
+                image,
+                sampler,
+                gather: Some(component),
+                coordinate,
+                array_index,
+                offset,
+                level: _,
+                depth_ref,
+            } => {
+                let suffix_cmp = match depth_ref {
+                    Some(_) => "Compare",
+                    None => "",
+                };
+
+                write!(self.out, "textureGather{suffix_cmp}(")?;
+                match *func_ctx.resolve_type(image, &module.types) {
+                    TypeInner::Image {
+                        class: crate::ImageClass::Depth { multi: _ },
+                        ..
+                    } => {}
+                    _ => {
+                        write!(self.out, "{}, ", component as u8)?;
+                    }
+                }
+                self.write_expr(module, image, func_ctx)?;
+                write!(self.out, ", ")?;
+                self.write_expr(module, sampler, func_ctx)?;
+                write!(self.out, ", ")?;
+                self.write_expr(module, coordinate, func_ctx)?;
+
+                if let Some(array_index) = array_index {
+                    write!(self.out, ", ")?;
+                    self.write_expr(module, array_index, func_ctx)?;
+                }
+
+                if let Some(depth_ref) = depth_ref {
+                    write!(self.out, ", ")?;
+                    self.write_expr(module, depth_ref, func_ctx)?;
+                }
+
+                if let Some(offset) = offset {
+                    write!(self.out, ", ")?;
+                    self.write_const_expression(module, offset)?;
+                }
+
+                write!(self.out, ")")?;
+            }
+            Expression::ImageQuery { image, query } => {
+                use crate::ImageQuery as Iq;
+
+                let texture_function = match query {
+                    Iq::Size { .. } => "textureDimensions",
+                    Iq::NumLevels => "textureNumLevels",
+                    Iq::NumLayers => "textureNumLayers",
+                    Iq::NumSamples => "textureNumSamples",
+                };
+
+                write!(self.out, "{texture_function}(")?;
+                self.write_expr(module, image, func_ctx)?;
+                if let Iq::Size { level: Some(level) } = query {
+                    write!(self.out, ", ")?;
+                    self.write_expr(module, level, func_ctx)?;
+                };
+                write!(self.out, ")")?;
+            }
+
+            Expression::ImageLoad {
+                image,
+                coordinate,
+                array_index,
+                sample,
+                level,
+            } => {
+                write!(self.out, "textureLoad(")?;
+                self.write_expr(module, image, func_ctx)?;
+                write!(self.out, ", ")?;
+                self.write_expr(module, coordinate, func_ctx)?;
+                if let Some(array_index) = array_index {
+                    write!(self.out, ", ")?;
+                    self.write_expr(module, array_index, func_ctx)?;
+                }
+                if let Some(index) = sample.or(level) {
+                    write!(self.out, ", ")?;
+                    self.write_expr(module, index, func_ctx)?;
+                }
+                write!(self.out, ")")?;
+            }
+            Expression::GlobalVariable(handle) => {
+                let name = &self.names[&NameKey::GlobalVariable(handle)];
+                write!(self.out, "{name}")?;
+            }
+
+            Expression::As {
+                expr,
+                kind,
+                convert,
+            } => {
+                let inner = func_ctx.resolve_type(expr, &module.types);
+                match *inner {
+                    TypeInner::Matrix {
+                        columns,
+                        rows,
+                        scalar,
+                    } => {
+                        let scalar = crate::Scalar {
+                            kind,
+                            width: convert.unwrap_or(scalar.width),
+                        };
+                        let scalar_kind_str = scalar_kind_str(scalar);
+                        write!(
+                            self.out,
+                            "mat{}x{}<{}>",
+                            back::vector_size_str(columns),
+                            back::vector_size_str(rows),
+                            scalar_kind_str
+                        )?;
+                    }
+                    TypeInner::Vector {
+                        size,
+                        scalar: crate::Scalar { width, .. },
+                    } => {
+                        let scalar = crate::Scalar {
+                            kind,
+                            width: convert.unwrap_or(width),
+                        };
+                        let vector_size_str = back::vector_size_str(size);
+                        let scalar_kind_str = scalar_kind_str(scalar);
+                        if convert.is_some() {
+                            write!(self.out, "vec{vector_size_str}<{scalar_kind_str}>")?;
+                        } else {
+                            write!(self.out, "bitcast<vec{vector_size_str}<{scalar_kind_str}>>")?;
+                        }
+                    }
+                    TypeInner::Scalar(crate::Scalar { width, .. }) => {
+                        let scalar = crate::Scalar {
+                            kind,
+                            width: convert.unwrap_or(width),
+                        };
+                        let scalar_kind_str = scalar_kind_str(scalar);
+                        if convert.is_some() {
+                            write!(self.out, "{scalar_kind_str}")?
+                        } else {
+                            write!(self.out, "bitcast<{scalar_kind_str}>")?
+                        }
+                    }
+                    _ => {
+                        return Err(Error::Unimplemented(format!(
+                            "write_expr expression::as {inner:?}"
+                        )));
+                    }
+                };
+                write!(self.out, "(")?;
+                self.write_expr(module, expr, func_ctx)?;
+                write!(self.out, ")")?;
+            }
+            Expression::Load { pointer } => {
+                let is_atomic_pointer = func_ctx
+                    .resolve_type(pointer, &module.types)
+                    .is_atomic_pointer(&module.types);
+
+                if is_atomic_pointer {
+                    write!(self.out, "atomicLoad(")?;
+                    self.write_expr(module, pointer, func_ctx)?;
+                    write!(self.out, ")")?;
+                } else {
+                    self.write_expr_with_indirection(
+                        module,
+                        pointer,
+                        func_ctx,
+                        Indirection::Reference,
+                    )?;
+                }
+            }
+            Expression::LocalVariable(handle) => {
+                write!(self.out, "{}", self.names[&func_ctx.name_key(handle)])?
+            }
+            Expression::ArrayLength(expr) => {
+                write!(self.out, "arrayLength(")?;
+                self.write_expr(module, expr, func_ctx)?;
+                write!(self.out, ")")?;
+            }
+
+            Expression::Math {
+                fun,
+                arg,
+                arg1,
+                arg2,
+                arg3,
+            } => {
+                use crate::MathFunction as Mf;
+
+                enum Function {
+                    Regular(&'static str),
+                }
+
+                let function = match fun {
+                    Mf::Abs => Function::Regular("abs"),
+                    Mf::Min => Function::Regular("min"),
+                    Mf::Max => Function::Regular("max"),
+                    Mf::Clamp => Function::Regular("clamp"),
+                    Mf::Saturate => Function::Regular("saturate"),
+                    // trigonometry
+                    Mf::Cos => Function::Regular("cos"),
+                    Mf::Cosh => Function::Regular("cosh"),
+                    Mf::Sin => Function::Regular("sin"),
+                    Mf::Sinh => Function::Regular("sinh"),
+                    Mf::Tan => Function::Regular("tan"),
+                    Mf::Tanh => Function::Regular("tanh"),
+                    Mf::Acos => Function::Regular("acos"),
+                    Mf::Asin => Function::Regular("asin"),
+                    Mf::Atan => Function::Regular("atan"),
+                    Mf::Atan2 => Function::Regular("atan2"),
+                    Mf::Asinh => Function::Regular("asinh"),
+                    Mf::Acosh => Function::Regular("acosh"),
+                    Mf::Atanh => Function::Regular("atanh"),
+                    Mf::Radians => Function::Regular("radians"),
+                    Mf::Degrees => Function::Regular("degrees"),
+                    // decomposition
+                    Mf::Ceil => Function::Regular("ceil"),
+                    Mf::Floor => Function::Regular("floor"),
+                    Mf::Round => Function::Regular("round"),
+                    Mf::Fract => Function::Regular("fract"),
+                    Mf::Trunc => Function::Regular("trunc"),
+                    Mf::Modf => Function::Regular("modf"),
+                    Mf::Frexp => Function::Regular("frexp"),
+                    Mf::Ldexp => Function::Regular("ldexp"),
+                    // exponent
+                    Mf::Exp => Function::Regular("exp"),
+                    Mf::Exp2 => Function::Regular("exp2"),
+                    Mf::Log => Function::Regular("log"),
+                    Mf::Log2 => Function::Regular("log2"),
+                    Mf::Pow => Function::Regular("pow"),
+                    // geometry
+                    Mf::Dot => Function::Regular("dot"),
+                    Mf::Cross => Function::Regular("cross"),
+                    Mf::Distance => Function::Regular("distance"),
+                    Mf::Length => Function::Regular("length"),
+                    Mf::Normalize => Function::Regular("normalize"),
+                    Mf::FaceForward => Function::Regular("faceForward"),
+                    Mf::Reflect => Function::Regular("reflect"),
+                    Mf::Refract => Function::Regular("refract"),
+                    // computational
+                    Mf::Sign => Function::Regular("sign"),
+                    Mf::Fma => Function::Regular("fma"),
+                    Mf::Mix => Function::Regular("mix"),
+                    Mf::Step => Function::Regular("step"),
+                    Mf::SmoothStep => Function::Regular("smoothstep"),
+                    Mf::Sqrt => Function::Regular("sqrt"),
+                    Mf::InverseSqrt => Function::Regular("inverseSqrt"),
+                    Mf::Transpose => Function::Regular("transpose"),
+                    Mf::Determinant => Function::Regular("determinant"),
+                    // bits
+                    Mf::CountTrailingZeros => Function::Regular("countTrailingZeros"),
+                    Mf::CountLeadingZeros => Function::Regular("countLeadingZeros"),
+                    Mf::CountOneBits => Function::Regular("countOneBits"),
+                    Mf::ReverseBits => Function::Regular("reverseBits"),
+                    Mf::ExtractBits => Function::Regular("extractBits"),
+                    Mf::InsertBits => Function::Regular("insertBits"),
+                    Mf::FindLsb => Function::Regular("firstTrailingBit"),
+                    Mf::FindMsb => Function::Regular("firstLeadingBit"),
+                    // data packing
+                    Mf::Pack4x8snorm => Function::Regular("pack4x8snorm"),
+                    Mf::Pack4x8unorm => Function::Regular("pack4x8unorm"),
+                    Mf::Pack2x16snorm => Function::Regular("pack2x16snorm"),
+                    Mf::Pack2x16unorm => Function::Regular("pack2x16unorm"),
+                    Mf::Pack2x16float => Function::Regular("pack2x16float"),
+                    // data unpacking
+                    Mf::Unpack4x8snorm => Function::Regular("unpack4x8snorm"),
+                    Mf::Unpack4x8unorm => Function::Regular("unpack4x8unorm"),
+                    Mf::Unpack2x16snorm => Function::Regular("unpack2x16snorm"),
+                    Mf::Unpack2x16unorm => Function::Regular("unpack2x16unorm"),
+                    Mf::Unpack2x16float => Function::Regular("unpack2x16float"),
+                    Mf::Inverse | Mf::Outer => {
+                        return Err(Error::UnsupportedMathFunction(fun));
+                    }
+                };
+
+                match function {
+                    Function::Regular(fun_name) => {
+                        write!(self.out, "{fun_name}(")?;
+                        self.write_expr(module, arg, func_ctx)?;
+                        for arg in IntoIterator::into_iter([arg1, arg2, arg3]).flatten() {
+                            write!(self.out, ", ")?;
+                            self.write_expr(module, arg, func_ctx)?;
+                        }
+                        write!(self.out, ")")?
+                    }
+                }
+            }
+
+            Expression::Swizzle {
+                size,
+                vector,
+                pattern,
+            } => {
+                self.write_expr(module, vector, func_ctx)?;
+                write!(self.out, ".")?;
+                for &sc in pattern[..size as usize].iter() {
+                    self.out.write_char(back::COMPONENTS[sc as usize])?;
+                }
+            }
+            Expression::Unary { op, expr } => {
+                let unary = match op {
+                    crate::UnaryOperator::Negate => "-",
+                    crate::UnaryOperator::LogicalNot => "!",
+                    crate::UnaryOperator::BitwiseNot => "~",
+                };
+
+                write!(self.out, "{unary}(")?;
+                self.write_expr(module, expr, func_ctx)?;
+
+                write!(self.out, ")")?
+            }
+
+            Expression::Select {
+                condition,
+                accept,
+                reject,
+            } => {
+                write!(self.out, "select(")?;
+                self.write_expr(module, reject, func_ctx)?;
+                write!(self.out, ", ")?;
+                self.write_expr(module, accept, func_ctx)?;
+                write!(self.out, ", ")?;
+                self.write_expr(module, condition, func_ctx)?;
+                write!(self.out, ")")?
+            }
+            Expression::Derivative { axis, ctrl, expr } => {
+                use crate::{DerivativeAxis as Axis, DerivativeControl as Ctrl};
+                let op = match (axis, ctrl) {
+                    (Axis::X, Ctrl::Coarse) => "dpdxCoarse",
+                    (Axis::X, Ctrl::Fine) => "dpdxFine",
+                    (Axis::X, Ctrl::None) => "dpdx",
+                    (Axis::Y, Ctrl::Coarse) => "dpdyCoarse",
+                    (Axis::Y, Ctrl::Fine) => "dpdyFine",
+                    (Axis::Y, Ctrl::None) => "dpdy",
+                    (Axis::Width, Ctrl::Coarse) => "fwidthCoarse",
+                    (Axis::Width, Ctrl::Fine) => "fwidthFine",
+                    (Axis::Width, Ctrl::None) => "fwidth",
+                };
+                write!(self.out, "{op}(")?;
+                self.write_expr(module, expr, func_ctx)?;
+                write!(self.out, ")")?
+            }
+            Expression::Relational { fun, argument } => {
+                use crate::RelationalFunction as Rf;
+
+                let fun_name = match fun {
+                    Rf::All => "all",
+                    Rf::Any => "any",
+                    _ => return Err(Error::UnsupportedRelationalFunction(fun)),
+                };
+                write!(self.out, "{fun_name}(")?;
+
+                self.write_expr(module, argument, func_ctx)?;
+
+                write!(self.out, ")")?
+            }
+            // Not supported yet
+            Expression::RayQueryGetIntersection { .. } => unreachable!(),
+            // Nothing to do here, since call expression already cached
+            Expression::CallResult(_)
+            | Expression::AtomicResult { .. }
+            | Expression::RayQueryProceedResult
+            | Expression::WorkGroupUniformLoadResult { .. } => {}
+        }
+
+        Ok(())
+    }
+
+    /// Helper method used to write global variables
+    /// # Notes
+    /// Always adds a newline
+    fn write_global(
+        &mut self,
+        module: &Module,
+        global: &crate::GlobalVariable,
+        handle: Handle<crate::GlobalVariable>,
+    ) -> BackendResult {
+        // Write group and binding attributes if present
+        if let Some(ref binding) = global.binding {
+            self.write_attributes(&[
+                Attribute::Group(binding.group),
+                Attribute::Binding(binding.binding),
+            ])?;
+            writeln!(self.out)?;
+        }
+
+        // First write global name and address space if supported
+        write!(self.out, "var")?;
+        let (address, maybe_access) = address_space_str(global.space);
+        if let Some(space) = address {
+            write!(self.out, "<{space}")?;
+            if let Some(access) = maybe_access {
+                write!(self.out, ", {access}")?;
+            }
+            write!(self.out, ">")?;
+        }
+        write!(
+            self.out,
+            " {}: ",
+            &self.names[&NameKey::GlobalVariable(handle)]
+        )?;
+
+        // Write global type
+        self.write_type(module, global.ty)?;
+
+        // Write initializer
+        if let Some(init) = global.init {
+            write!(self.out, " = ")?;
+            self.write_const_expression(module, init)?;
+        }
+
+        // End with semicolon
+        writeln!(self.out, ";")?;
+
+        Ok(())
+    }
+
+    /// Helper method used to write global constants
+    ///
+    /// # Notes
+    /// Ends in a newline
+    fn write_global_constant(
+        &mut self,
+        module: &Module,
+        handle: Handle<crate::Constant>,
+    ) -> BackendResult {
+        let name = &self.names[&NameKey::Constant(handle)];
+        // First write only constant name
+        write!(self.out, "const {name}: ")?;
+        self.write_type(module, module.constants[handle].ty)?;
+        write!(self.out, " = ")?;
+        let init = module.constants[handle].init;
+        self.write_const_expression(module, init)?;
+        writeln!(self.out, ";")?;
+
+        Ok(())
+    }
+
+    // See https://github.com/rust-lang/rust-clippy/issues/4979.
+    #[allow(clippy::missing_const_for_fn)]
+    pub fn finish(self) -> W {
+        self.out
+    }
+}
+
+fn builtin_str(built_in: crate::BuiltIn) -> Result<&'static str, Error> {
+    use crate::BuiltIn as Bi;
+
+    Ok(match built_in {
+        Bi::VertexIndex => "vertex_index",
+        Bi::InstanceIndex => "instance_index",
+        Bi::Position { .. } => "position",
+        Bi::FrontFacing => "front_facing",
+        Bi::FragDepth => "frag_depth",
+        Bi::LocalInvocationId => "local_invocation_id",
+        Bi::LocalInvocationIndex => "local_invocation_index",
+        Bi::GlobalInvocationId => "global_invocation_id",
+        Bi::WorkGroupId => "workgroup_id",
+        Bi::NumWorkGroups => "num_workgroups",
+        Bi::SampleIndex => "sample_index",
+        Bi::SampleMask => "sample_mask",
+        Bi::PrimitiveIndex => "primitive_index",
+        Bi::ViewIndex => "view_index",
+        Bi::BaseInstance
+        | Bi::BaseVertex
+        | Bi::ClipDistance
+        | Bi::CullDistance
+        | Bi::PointSize
+        | Bi::PointCoord
+        | Bi::WorkGroupSize => {
+            return Err(Error::Custom(format!("Unsupported builtin {built_in:?}")))
+        }
+    })
+}
+
+const fn image_dimension_str(dim: crate::ImageDimension) -> &'static str {
+    use crate::ImageDimension as IDim;
+
+    match dim {
+        IDim::D1 => "1d",
+        IDim::D2 => "2d",
+        IDim::D3 => "3d",
+        IDim::Cube => "cube",
+    }
+}
+
+const fn scalar_kind_str(scalar: crate::Scalar) -> &'static str {
+    use crate::Scalar;
+    use crate::ScalarKind as Sk;
+
+    match scalar {
+        Scalar {
+            kind: Sk::Float,
+            width: 8,
+        } => "f64",
+        Scalar {
+            kind: Sk::Float,
+            width: 4,
+        } => "f32",
+        Scalar {
+            kind: Sk::Sint,
+            width: 4,
+        } => "i32",
+        Scalar {
+            kind: Sk::Uint,
+            width: 4,
+        } => "u32",
+        Scalar {
+            kind: Sk::Bool,
+            width: 1,
+        } => "bool",
+        _ => unreachable!(),
+    }
+}
+
+const fn storage_format_str(format: crate::StorageFormat) -> &'static str {
+    use crate::StorageFormat as Sf;
+
+    match format {
+        Sf::R8Unorm => "r8unorm",
+        Sf::R8Snorm => "r8snorm",
+        Sf::R8Uint => "r8uint",
+        Sf::R8Sint => "r8sint",
+        Sf::R16Uint => "r16uint",
+        Sf::R16Sint => "r16sint",
+        Sf::R16Float => "r16float",
+        Sf::Rg8Unorm => "rg8unorm",
+        Sf::Rg8Snorm => "rg8snorm",
+        Sf::Rg8Uint => "rg8uint",
+        Sf::Rg8Sint => "rg8sint",
+        Sf::R32Uint => "r32uint",
+        Sf::R32Sint => "r32sint",
+        Sf::R32Float => "r32float",
+        Sf::Rg16Uint => "rg16uint",
+        Sf::Rg16Sint => "rg16sint",
+        Sf::Rg16Float => "rg16float",
+        Sf::Rgba8Unorm => "rgba8unorm",
+        Sf::Rgba8Snorm => "rgba8snorm",
+        Sf::Rgba8Uint => "rgba8uint",
+        Sf::Rgba8Sint => "rgba8sint",
+        Sf::Bgra8Unorm => "bgra8unorm",
+        Sf::Rgb10a2Uint => "rgb10a2uint",
+        Sf::Rgb10a2Unorm => "rgb10a2unorm",
+        Sf::Rg11b10Float => "rg11b10float",
+        Sf::Rg32Uint => "rg32uint",
+        Sf::Rg32Sint => "rg32sint",
+        Sf::Rg32Float => "rg32float",
+        Sf::Rgba16Uint => "rgba16uint",
+        Sf::Rgba16Sint => "rgba16sint",
+        Sf::Rgba16Float => "rgba16float",
+        Sf::Rgba32Uint => "rgba32uint",
+        Sf::Rgba32Sint => "rgba32sint",
+        Sf::Rgba32Float => "rgba32float",
+        Sf::R16Unorm => "r16unorm",
+        Sf::R16Snorm => "r16snorm",
+        Sf::Rg16Unorm => "rg16unorm",
+        Sf::Rg16Snorm => "rg16snorm",
+        Sf::Rgba16Unorm => "rgba16unorm",
+        Sf::Rgba16Snorm => "rgba16snorm",
+    }
+}
+
+/// Helper function that returns the string corresponding to the WGSL interpolation qualifier
+const fn interpolation_str(interpolation: crate::Interpolation) -> &'static str {
+    use crate::Interpolation as I;
+
+    match interpolation {
+        I::Perspective => "perspective",
+        I::Linear => "linear",
+        I::Flat => "flat",
+    }
+}
+
+/// Return the WGSL auxiliary qualifier for the given sampling value.
+const fn sampling_str(sampling: crate::Sampling) -> &'static str {
+    use crate::Sampling as S;
+
+    match sampling {
+        S::Center => "",
+        S::Centroid => "centroid",
+        S::Sample => "sample",
+    }
+}
+
+const fn address_space_str(
+    space: crate::AddressSpace,
+) -> (Option<&'static str>, Option<&'static str>) {
+    use crate::AddressSpace as As;
+
+    (
+        Some(match space {
+            As::Private => "private",
+            As::Uniform => "uniform",
+            As::Storage { access } => {
+                if access.contains(crate::StorageAccess::STORE) {
+                    return (Some("storage"), Some("read_write"));
+                } else {
+                    "storage"
+                }
+            }
+            As::PushConstant => "push_constant",
+            As::WorkGroup => "workgroup",
+            As::Handle => return (None, None),
+            As::Function => "function",
+        }),
+        None,
+    )
+}
+
+fn map_binding_to_attribute(binding: &crate::Binding) -> Vec<Attribute> {
+    match *binding {
+        crate::Binding::BuiltIn(built_in) => {
+            if let crate::BuiltIn::Position { invariant: true } = built_in {
+                vec![Attribute::BuiltIn(built_in), Attribute::Invariant]
+            } else {
+                vec![Attribute::BuiltIn(built_in)]
+            }
+        }
+        crate::Binding::Location {
+            location,
+            interpolation,
+            sampling,
+            second_blend_source: false,
+        } => vec![
+            Attribute::Location(location),
+            Attribute::Interpolate(interpolation, sampling),
+        ],
+        crate::Binding::Location {
+            location,
+            interpolation,
+            sampling,
+            second_blend_source: true,
+        } => vec![
+            Attribute::Location(location),
+            Attribute::SecondBlendSource,
+            Attribute::Interpolate(interpolation, sampling),
+        ],
+    }
+}
diff --git a/third_party/rust/naga/src/block.rs b/third_party/rust/naga/src/block.rs
new file mode 100644
index 0000000000..0abda9da7c
--- /dev/null
+++ b/third_party/rust/naga/src/block.rs
@@ -0,0 +1,123 @@
+use crate::{Span, Statement};
+use std::ops::{Deref, DerefMut, RangeBounds};
+
+/// A code block is a vector of statements, with maybe a vector of spans.
+#[derive(Debug, Clone, Default)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "serialize", serde(transparent))]
+#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
+pub struct Block {
+    body: Vec<Statement>,
+    #[cfg_attr(feature = "serialize", serde(skip))]
+    span_info: Vec<Span>,
+}
+
+impl Block {
+    pub const fn new() -> Self {
+        Self {
+            body: Vec::new(),
+            span_info: Vec::new(),
+        }
+    }
+
+    pub fn from_vec(body: Vec<Statement>) -> Self {
+        let span_info = std::iter::repeat(Span::default())
+            .take(body.len())
+            .collect();
+        Self { body, span_info }
+    }
+
+    pub fn with_capacity(capacity: usize) -> Self {
+        Self {
+            body: Vec::with_capacity(capacity),
+            span_info: Vec::with_capacity(capacity),
+        }
+    }
+
+    #[allow(unused_variables)]
+    pub fn push(&mut self, end: Statement, span: Span) {
+        self.body.push(end);
+        self.span_info.push(span);
+    }
+
+    pub fn extend(&mut self, item: Option<(Statement, Span)>) {
+        if let Some((end, span)) = item {
+            self.push(end, span)
+        }
+    }
+
+    pub fn extend_block(&mut self, other: Self) {
+        self.span_info.extend(other.span_info);
+        self.body.extend(other.body);
+    }
+
+    pub fn append(&mut self, other: &mut Self) {
+        self.span_info.append(&mut other.span_info);
+        self.body.append(&mut other.body);
+    }
+
+    pub fn cull<R: RangeBounds<usize> + Clone>(&mut self, range: R) {
+        self.span_info.drain(range.clone());
+        self.body.drain(range);
+    }
+
+    pub fn splice<R: RangeBounds<usize> + Clone>(&mut self, range: R, other: Self) {
+        self.span_info.splice(range.clone(), other.span_info);
+        self.body.splice(range, other.body);
+    }
+    pub fn span_iter(&self) -> impl Iterator<Item = (&Statement, &Span)> {
+        let span_iter = self.span_info.iter();
+        self.body.iter().zip(span_iter)
+    }
+
+    pub fn span_iter_mut(&mut self) -> impl Iterator<Item = (&mut Statement, Option<&mut Span>)> {
+        let span_iter = self.span_info.iter_mut().map(Some);
+        self.body.iter_mut().zip(span_iter)
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.body.is_empty()
+    }
+
+    pub fn len(&self) -> usize {
+        self.body.len()
+    }
+}
+
+impl Deref for Block {
+    type Target = [Statement];
+    fn deref(&self) -> &[Statement] {
+        &self.body
+    }
+}
+
+impl DerefMut for Block {
+    fn deref_mut(&mut self) -> &mut [Statement] {
+        &mut self.body
+    }
+}
+
+impl<'a> IntoIterator for &'a Block {
+    type Item = &'a Statement;
+    type IntoIter = std::slice::Iter<'a, Statement>;
+
+    fn into_iter(self) -> std::slice::Iter<'a, Statement> {
+        self.iter()
+    }
+}
+
+#[cfg(feature = "deserialize")]
+impl<'de> serde::Deserialize<'de> for Block {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        Ok(Self::from_vec(Vec::deserialize(deserializer)?))
+    }
+}
+
+impl From<Vec<Statement>> for Block {
+    fn from(body: Vec<Statement>) -> Self {
+        Self::from_vec(body)
+    }
+}
diff --git a/third_party/rust/naga/src/compact/expressions.rs b/third_party/rust/naga/src/compact/expressions.rs
new file mode 100644
index 0000000000..301bbe3240
--- /dev/null
+++ b/third_party/rust/naga/src/compact/expressions.rs
@@ -0,0 +1,389 @@
+use super::{HandleMap, HandleSet, ModuleMap};
+use crate::arena::{Arena, Handle};
+
+pub struct ExpressionTracer<'tracer> {
+    pub constants: &'tracer Arena<crate::Constant>,
+
+    /// The arena in which we are currently tracing expressions.
+    pub expressions: &'tracer Arena<crate::Expression>,
+
+    /// The used map for `types`.
+    pub types_used: &'tracer mut HandleSet<crate::Type>,
+
+    /// The used map for `constants`.
+    pub constants_used: &'tracer mut HandleSet<crate::Constant>,
+
+    /// The used set for `arena`.
+    ///
+    /// This points to whatever arena holds the expressions we are
+    /// currently tracing: either a function's expression arena, or
+    /// the module's constant expression arena.
+    pub expressions_used: &'tracer mut HandleSet<crate::Expression>,
+
+    /// The used set for the module's `const_expressions` arena.
+    ///
+    /// If `None`, we are already tracing the constant expressions,
+    /// and `expressions_used` already refers to their handle set.
+    pub const_expressions_used: Option<&'tracer mut HandleSet<crate::Expression>>,
+}
+
+impl<'tracer> ExpressionTracer<'tracer> {
+    /// Propagate usage through `self.expressions`, starting with `self.expressions_used`.
+    ///
+    /// Treat `self.expressions_used` as the initial set of "known
+    /// live" expressions, and follow through to identify all
+    /// transitively used expressions.
+    ///
+    /// Mark types, constants, and constant expressions used directly
+    /// by `self.expressions` as used. Items used indirectly are not
+    /// marked.
+    ///
+    /// [fe]: crate::Function::expressions
+    /// [ce]: crate::Module::const_expressions
+    pub fn trace_expressions(&mut self) {
+        log::trace!(
+            "entering trace_expression of {}",
+            if self.const_expressions_used.is_some() {
+                "function expressions"
+            } else {
+                "const expressions"
+            }
+        );
+
+        // We don't need recursion or a work list. Because an
+        // expression may only refer to other expressions that precede
+        // it in the arena, it suffices to make a single pass over the
+        // arena from back to front, marking the referents of used
+        // expressions as used themselves.
+        for (handle, expr) in self.expressions.iter().rev() {
+            // If this expression isn't used, it doesn't matter what it uses.
+            if !self.expressions_used.contains(handle) {
+                continue;
+            }
+
+            log::trace!("tracing new expression {:?}", expr);
+
+            use crate::Expression as Ex;
+            match *expr {
+                // Expressions that do not contain handles that need to be traced.
+                Ex::Literal(_)
+                | Ex::FunctionArgument(_)
+                | Ex::GlobalVariable(_)
+                | Ex::LocalVariable(_)
+                | Ex::CallResult(_)
+                | Ex::RayQueryProceedResult => {}
+
+                Ex::Constant(handle) => {
+                    self.constants_used.insert(handle);
+                    // Constants and expressions are mutually recursive, which
+                    // complicates our nice one-pass algorithm. However, since
+                    // constants don't refer to each other, we can get around
+                    // this by looking *through* each constant and marking its
+                    // initializer as used. Since `expr` refers to the constant,
+                    // and the constant refers to the initializer, it must
+                    // precede `expr` in the arena.
+                    let init = self.constants[handle].init;
+                    match self.const_expressions_used {
+                        Some(ref mut used) => used.insert(init),
+                        None => self.expressions_used.insert(init),
+                    }
+                }
+                Ex::ZeroValue(ty) => self.types_used.insert(ty),
+                Ex::Compose { ty, ref components } => {
+                    self.types_used.insert(ty);
+                    self.expressions_used
+                        .insert_iter(components.iter().cloned());
+                }
+                Ex::Access { base, index } => self.expressions_used.insert_iter([base, index]),
+                Ex::AccessIndex { base, index: _ } => self.expressions_used.insert(base),
+                Ex::Splat { size: _, value } => self.expressions_used.insert(value),
+                Ex::Swizzle {
+                    size: _,
+                    vector,
+                    pattern: _,
+                } => self.expressions_used.insert(vector),
+                Ex::Load { pointer } => self.expressions_used.insert(pointer),
+                Ex::ImageSample {
+                    image,
+                    sampler,
+                    gather: _,
+                    coordinate,
+                    array_index,
+                    offset,
+                    ref level,
+                    depth_ref,
+                } => {
+                    self.expressions_used
+                        .insert_iter([image, sampler, coordinate]);
+                    self.expressions_used.insert_iter(array_index);
+                    match self.const_expressions_used {
+                        Some(ref mut used) => used.insert_iter(offset),
+                        None => self.expressions_used.insert_iter(offset),
+                    }
+                    use crate::SampleLevel as Sl;
+                    match *level {
+                        Sl::Auto | Sl::Zero => {}
+                        Sl::Exact(expr) | Sl::Bias(expr) => self.expressions_used.insert(expr),
+                        Sl::Gradient { x, y } => self.expressions_used.insert_iter([x, y]),
+                    }
+                    self.expressions_used.insert_iter(depth_ref);
+                }
+                Ex::ImageLoad {
+                    image,
+                    coordinate,
+                    array_index,
+                    sample,
+                    level,
+                } => {
+                    self.expressions_used.insert(image);
+                    self.expressions_used.insert(coordinate);
+                    self.expressions_used.insert_iter(array_index);
+                    self.expressions_used.insert_iter(sample);
+                    self.expressions_used.insert_iter(level);
+                }
+                Ex::ImageQuery { image, ref query } => {
+                    self.expressions_used.insert(image);
+                    use crate::ImageQuery as Iq;
+                    match *query {
+                        Iq::Size { level } => self.expressions_used.insert_iter(level),
+                        Iq::NumLevels | Iq::NumLayers | Iq::NumSamples => {}
+                    }
+                }
+                Ex::Unary { op: _, expr } => self.expressions_used.insert(expr),
+                Ex::Binary { op: _, left, right } => {
+                    self.expressions_used.insert_iter([left, right]);
+                }
+                Ex::Select {
+                    condition,
+                    accept,
+                    reject,
+                } => self
+                    .expressions_used
+                    .insert_iter([condition, accept, reject]),
+                Ex::Derivative {
+                    axis: _,
+                    ctrl: _,
+                    expr,
+                } => self.expressions_used.insert(expr),
+                Ex::Relational { fun: _, argument } => self.expressions_used.insert(argument),
+                Ex::Math {
+                    fun: _,
+                    arg,
+                    arg1,
+                    arg2,
+                    arg3,
+                } => {
+                    self.expressions_used.insert(arg);
+                    self.expressions_used.insert_iter(arg1);
+                    self.expressions_used.insert_iter(arg2);
+                    self.expressions_used.insert_iter(arg3);
+                }
+                Ex::As {
+                    expr,
+                    kind: _,
+                    convert: _,
+                } => self.expressions_used.insert(expr),
+                Ex::AtomicResult { ty, comparison: _ } => self.types_used.insert(ty),
+                Ex::WorkGroupUniformLoadResult { ty } => self.types_used.insert(ty),
+                Ex::ArrayLength(expr) => self.expressions_used.insert(expr),
+                Ex::RayQueryGetIntersection {
+                    query,
+                    committed: _,
+                } => self.expressions_used.insert(query),
+            }
+        }
+    }
+}
+
+impl ModuleMap {
+    /// Fix up all handles in `expr`.
+    ///
+    /// Use the expression handle remappings in `operand_map`, and all
+    /// other mappings from `self`.
+    pub fn adjust_expression(
+        &self,
+        expr: &mut crate::Expression,
+        operand_map: &HandleMap<crate::Expression>,
+    ) {
+        let adjust = |expr: &mut Handle<crate::Expression>| {
+            operand_map.adjust(expr);
+        };
+
+        use crate::Expression as Ex;
+        match *expr {
+            // Expressions that do not contain handles that need to be adjusted.
+            Ex::Literal(_)
+            | Ex::FunctionArgument(_)
+            | Ex::GlobalVariable(_)
+            | Ex::LocalVariable(_)
+            | Ex::CallResult(_)
+            | Ex::RayQueryProceedResult => {}
+
+            // Expressions that contain handles that need to be adjusted.
+            Ex::Constant(ref mut constant) => self.constants.adjust(constant),
+            Ex::ZeroValue(ref mut ty) => self.types.adjust(ty),
+            Ex::Compose {
+                ref mut ty,
+                ref mut components,
+            } => {
+                self.types.adjust(ty);
+                for component in components {
+                    adjust(component);
+                }
+            }
+            Ex::Access {
+                ref mut base,
+                ref mut index,
+            } => {
+                adjust(base);
+                adjust(index);
+            }
+            Ex::AccessIndex {
+                ref mut base,
+                index: _,
+            } => adjust(base),
+            Ex::Splat {
+                size: _,
+                ref mut value,
+            } => adjust(value),
+            Ex::Swizzle {
+                size: _,
+                ref mut vector,
+                pattern: _,
+            } => adjust(vector),
+            Ex::Load { ref mut pointer } => adjust(pointer),
+            Ex::ImageSample {
+                ref mut image,
+                ref mut sampler,
+                gather: _,
+                ref mut coordinate,
+                ref mut array_index,
+                ref mut offset,
+                ref mut level,
+                ref mut depth_ref,
+            } => {
+                adjust(image);
+                adjust(sampler);
+                adjust(coordinate);
+                operand_map.adjust_option(array_index);
+                if let Some(ref mut offset) = *offset {
+                    self.const_expressions.adjust(offset);
+                }
+                self.adjust_sample_level(level, operand_map);
+                operand_map.adjust_option(depth_ref);
+            }
+            Ex::ImageLoad {
+                ref mut image,
+                ref mut coordinate,
+                ref mut array_index,
+                ref mut sample,
+                ref mut level,
+            } => {
+                adjust(image);
+                adjust(coordinate);
+                operand_map.adjust_option(array_index);
+                operand_map.adjust_option(sample);
+                operand_map.adjust_option(level);
+            }
+            Ex::ImageQuery {
+                ref mut image,
+                ref mut query,
+            } => {
+                adjust(image);
+                self.adjust_image_query(query, operand_map);
+            }
+            Ex::Unary {
+                op: _,
+                ref mut expr,
+            } => adjust(expr),
+            Ex::Binary {
+                op: _,
+                ref mut left,
+                ref mut right,
+            } => {
+                adjust(left);
+                adjust(right);
+            }
+            Ex::Select {
+                ref mut condition,
+                ref mut accept,
+                ref mut reject,
+            } => {
+                adjust(condition);
+                adjust(accept);
+                adjust(reject);
+            }
+            Ex::Derivative {
+                axis: _,
+                ctrl: _,
+                ref mut expr,
+            } => adjust(expr),
+            Ex::Relational {
+                fun: _,
+                ref mut argument,
+            } => adjust(argument),
+            Ex::Math {
+                fun: _,
+                ref mut arg,
+                ref mut arg1,
+                ref mut arg2,
+                ref mut arg3,
+            } => {
+                adjust(arg);
+                operand_map.adjust_option(arg1);
+                operand_map.adjust_option(arg2);
+                operand_map.adjust_option(arg3);
+            }
+            Ex::As {
+                ref mut expr,
+                kind: _,
+                convert: _,
+            } => adjust(expr),
+            Ex::AtomicResult {
+                ref mut ty,
+                comparison: _,
+            } => self.types.adjust(ty),
+            Ex::WorkGroupUniformLoadResult { ref mut ty } => self.types.adjust(ty),
+            Ex::ArrayLength(ref mut expr) => adjust(expr),
+            Ex::RayQueryGetIntersection {
+                ref mut query,
+                committed: _,
+            } => adjust(query),
+        }
+    }
+
+    fn adjust_sample_level(
+        &self,
+        level: &mut crate::SampleLevel,
+        operand_map: &HandleMap<crate::Expression>,
+    ) {
+        let adjust = |expr: &mut Handle<crate::Expression>| operand_map.adjust(expr);
+
+        use crate::SampleLevel as Sl;
+        match *level {
+            Sl::Auto | Sl::Zero => {}
+            Sl::Exact(ref mut expr) => adjust(expr),
+            Sl::Bias(ref mut expr) => adjust(expr),
+            Sl::Gradient {
+                ref mut x,
+                ref mut y,
+            } => {
+                adjust(x);
+                adjust(y);
+            }
+        }
+    }
+
+    fn adjust_image_query(
+        &self,
+        query: &mut crate::ImageQuery,
+        operand_map: &HandleMap<crate::Expression>,
+    ) {
+        use crate::ImageQuery as Iq;
+
+        match *query {
+            Iq::Size { ref mut level } => operand_map.adjust_option(level),
+            Iq::NumLevels | Iq::NumLayers | Iq::NumSamples => {}
+        }
+    }
+}
diff --git a/third_party/rust/naga/src/compact/functions.rs b/third_party/rust/naga/src/compact/functions.rs
new file mode 100644
index 0000000000..b0d08c7e96
--- /dev/null
+++ b/third_party/rust/naga/src/compact/functions.rs
@@ -0,0 +1,106 @@
+use super::handle_set_map::HandleSet;
+use super::{FunctionMap, ModuleMap};
+
+pub struct FunctionTracer<'a> {
+    pub function: &'a crate::Function,
+    pub constants: &'a crate::Arena<crate::Constant>,
+
+    pub types_used: &'a mut HandleSet<crate::Type>,
+    pub constants_used: &'a mut HandleSet<crate::Constant>,
+    pub const_expressions_used: &'a mut HandleSet<crate::Expression>,
+
+    /// Function-local expressions used.
+    pub expressions_used: HandleSet<crate::Expression>,
+}
+
+impl<'a> FunctionTracer<'a> {
+    pub fn trace(&mut self) {
+        for argument in self.function.arguments.iter() {
+            self.types_used.insert(argument.ty);
+        }
+
+        if let Some(ref result) = self.function.result {
+            self.types_used.insert(result.ty);
+        }
+
+        for (_, local) in self.function.local_variables.iter() {
+            self.types_used.insert(local.ty);
+            if let Some(init) = local.init {
+                self.expressions_used.insert(init);
+            }
+        }
+
+        // Treat named expressions as alive, for the sake of our test suite,
+        // which uses `let blah = expr;` to exercise lots of things.
+        for (&value, _name) in &self.function.named_expressions {
+            self.expressions_used.insert(value);
+        }
+
+        self.trace_block(&self.function.body);
+
+        // Given that `trace_block` has marked the expressions used
+        // directly by statements, walk the arena to find all
+        // expressions used, directly or indirectly.
+        self.as_expression().trace_expressions();
+    }
+
+    fn as_expression(&mut self) -> super::expressions::ExpressionTracer {
+        super::expressions::ExpressionTracer {
+            constants: self.constants,
+            expressions: &self.function.expressions,
+
+            types_used: self.types_used,
+            constants_used: self.constants_used,
+            expressions_used: &mut self.expressions_used,
+            const_expressions_used: Some(&mut self.const_expressions_used),
+        }
+    }
+}
+
+impl FunctionMap {
+    pub fn compact(
+        &self,
+        function: &mut crate::Function,
+        module_map: &ModuleMap,
+        reuse: &mut crate::NamedExpressions,
+    ) {
+        assert!(reuse.is_empty());
+
+        for argument in function.arguments.iter_mut() {
+            module_map.types.adjust(&mut argument.ty);
+        }
+
+        if let Some(ref mut result) = function.result {
+            module_map.types.adjust(&mut result.ty);
+        }
+
+        for (_, local) in function.local_variables.iter_mut() {
+            log::trace!("adjusting local variable {:?}", local.name);
+            module_map.types.adjust(&mut local.ty);
+            if let Some(ref mut init) = local.init {
+                self.expressions.adjust(init);
+            }
+        }
+
+        // Drop unused expressions, reusing existing storage.
+        function.expressions.retain_mut(|handle, expr| {
+            if self.expressions.used(handle) {
+                module_map.adjust_expression(expr, &self.expressions);
+                true
+            } else {
+                false
+            }
+        });
+
+        // Adjust named expressions.
+        for (mut handle, name) in function.named_expressions.drain(..) {
+            self.expressions.adjust(&mut handle);
+            reuse.insert(handle, name);
+        }
+        std::mem::swap(&mut function.named_expressions, reuse);
+        assert!(reuse.is_empty());
+
+        // Adjust statements.
+        self.adjust_body(function);
+    }
+}
diff --git a/third_party/rust/naga/src/compact/handle_set_map.rs b/third_party/rust/naga/src/compact/handle_set_map.rs
new file mode 100644
index 0000000000..c716ca8294
--- /dev/null
+++ b/third_party/rust/naga/src/compact/handle_set_map.rs
@@ -0,0 +1,170 @@
+use crate::arena::{Arena, Handle, Range, UniqueArena};
+
+type Index = std::num::NonZeroU32;
+
+/// A set of `Handle<T>` values.
+pub struct HandleSet<T> {
+    /// Bound on zero-based indexes of handles stored in this set.
+    len: usize,
+
+    /// `members[i]` is true if the handle with zero-based index `i`
+    /// is a member.
+    members: bit_set::BitSet,
+
+    /// This type is indexed by values of type `T`.
+    as_keys: std::marker::PhantomData<T>,
+}
+
+impl<T> HandleSet<T> {
+    pub fn for_arena(arena: &impl ArenaType<T>) -> Self {
+        let len = arena.len();
+        Self {
+            len,
+            members: bit_set::BitSet::with_capacity(len),
+            as_keys: std::marker::PhantomData,
+        }
+    }
+
+    /// Add `handle` to the set.
+    pub fn insert(&mut self, handle: Handle<T>) {
+        // Note that, oddly, `Handle::index` does not return a 1-based
+        // `Index`, but rather a zero-based `usize`.
+        self.members.insert(handle.index());
+    }
+
+    /// Add handles from `iter` to the set.
+    pub fn insert_iter(&mut self, iter: impl IntoIterator<Item = Handle<T>>) {
+        for handle in iter {
+            self.insert(handle);
+        }
+    }
+
+    pub fn contains(&self, handle: Handle<T>) -> bool {
+        // Note that, oddly, `Handle::index` does not return a 1-based
+        // `Index`, but rather a zero-based `usize`.
+        self.members.contains(handle.index())
+    }
+}
+
+pub trait ArenaType<T> {
+    fn len(&self) -> usize;
+}
+
+impl<T> ArenaType<T> for Arena<T> {
+    fn len(&self) -> usize {
+        self.len()
+    }
+}
+
+impl<T: std::hash::Hash + Eq> ArenaType<T> for UniqueArena<T> {
+    fn len(&self) -> usize {
+        self.len()
+    }
+}
+
+/// A map from old handle indices to new, compressed handle indices.
+pub struct HandleMap<T> {
+    /// The indices assigned to handles in the compacted module.
+    ///
+    /// If `new_index[i]` is `Some(n)`, then `n` is the 1-based
+    /// `Index` of the compacted `Handle` corresponding to the
+    /// pre-compacted `Handle` whose zero-based index is `i`. ("Clear
+    /// as mud.")
+    new_index: Vec<Option<Index>>,
+
+    /// This type is indexed by values of type `T`.
+    as_keys: std::marker::PhantomData<T>,
+}
+
+impl<T: 'static> HandleMap<T> {
+    pub fn from_set(set: HandleSet<T>) -> Self {
+        let mut next_index = Index::new(1).unwrap();
+        Self {
+            new_index: (0..set.len)
+                .map(|zero_based_index| {
+                    if set.members.contains(zero_based_index) {
+                        // This handle will be retained in the compacted version,
+                        // so assign it a new index.
+                        let this = next_index;
+                        next_index = next_index.checked_add(1).unwrap();
+                        Some(this)
+                    } else {
+                        // This handle will be omitted in the compacted version.
+                        None
+                    }
+                })
+                .collect(),
+            as_keys: std::marker::PhantomData,
+        }
+    }
+
+    /// Return true if `old` is used in the compacted module.
+    pub fn used(&self, old: Handle<T>) -> bool {
+        self.new_index[old.index()].is_some()
+    }
+
+    /// Return the counterpart to `old` in the compacted module.
+    ///
+    /// If we thought `old` wouldn't be used in the compacted module, return
+    /// `None`.
+    pub fn try_adjust(&self, old: Handle<T>) -> Option<Handle<T>> {
+        log::trace!(
+            "adjusting {} handle [{}] -> [{:?}]",
+            std::any::type_name::<T>(),
+            old.index() + 1,
+            self.new_index[old.index()]
+        );
+        // Note that `Handle::index` returns a zero-based index,
+        // but `Handle::new` accepts a 1-based `Index`.
+        self.new_index[old.index()].map(Handle::new)
+    }
+
+    /// Return the counterpart to `old` in the compacted module.
+    ///
+    /// If we thought `old` wouldn't be used in the compacted module, panic.
+    pub fn adjust(&self, handle: &mut Handle<T>) {
+        *handle = self.try_adjust(*handle).unwrap();
+    }
+
+    /// Like `adjust`, but for optional handles.
+    pub fn adjust_option(&self, handle: &mut Option<Handle<T>>) {
+        if let Some(ref mut handle) = *handle {
+            self.adjust(handle);
+        }
+    }
+
+    /// Shrink `range` to include only used handles.
+    ///
+    /// Fortunately, compaction doesn't arbitrarily scramble the expressions
+    /// in the arena, but instead preserves the order of the elements while
+    /// squeezing out unused ones. That means that a contiguous range in the
+    /// pre-compacted arena always maps to a contiguous range in the
+    /// post-compacted arena. So we just need to adjust the endpoints.
+    ///
+    /// Compaction may have eliminated the endpoints themselves.
+    ///
+    /// Use `compacted_arena` to bounds-check the result.
+    pub fn adjust_range(&self, range: &mut Range<T>, compacted_arena: &Arena<T>) {
+        let mut index_range = range.zero_based_index_range();
+        let compacted;
+        // Remember that the indices we retrieve from `new_index` are 1-based
+        // compacted indices, but the index range we're computing is zero-based
+        // compacted indices.
+        if let Some(first1) = index_range.find_map(|i| self.new_index[i as usize]) {
+            // The first call to `find_map` mutated `index_range` to hold the
+            // remainder of original range, which is exactly the range we need
+            // to search for the new last handle.
+            if let Some(last1) = index_range.rev().find_map(|i| self.new_index[i as usize]) {
+                // Build a zero-based end-exclusive range, given one-based handle indices.
+                compacted = first1.get() - 1..last1.get();
+            } else {
+                // The range contains only a single live handle, which
+                // we identified with the first `find_map` call.
+                compacted = first1.get() - 1..first1.get();
+            }
+        } else {
+            compacted = 0..0;
+        };
+        *range = Range::from_zero_based_index_range(compacted, compacted_arena);
+    }
+}
diff --git a/third_party/rust/naga/src/compact/mod.rs b/third_party/rust/naga/src/compact/mod.rs
new file mode 100644
index 0000000000..b4e57ed5c9
--- /dev/null
+++ b/third_party/rust/naga/src/compact/mod.rs
@@ -0,0 +1,307 @@
+mod expressions;
+mod functions;
+mod handle_set_map;
+mod statements;
+mod types;
+
+use crate::{arena, compact::functions::FunctionTracer};
+use handle_set_map::{HandleMap, HandleSet};
+
+/// Remove unused types, expressions, and constants from `module`.
+///
+/// Assuming that all globals, named constants, special types,
+/// functions and entry points in `module` are used, determine which
+/// types, constants, and expressions (both function-local and global
+/// constant expressions) are actually used, and remove the rest,
+/// adjusting all handles as necessary. The result should be a module
+/// functionally identical to the original.
+///
+/// This may be useful to apply to modules generated in the snapshot
+/// tests. Our backends often generate temporary names based on handle
+/// indices, which means that adding or removing unused arena entries
+/// can affect the output even though they have no semantic effect.
+/// Such meaningless changes add noise to snapshot diffs, making
+/// accurate patch review difficult. Compacting the modules before
+/// generating snapshots makes the output independent of unused arena
+/// entries.
+///
+/// # Panics
+///
+/// If `module` has not passed validation, this may panic.
+pub fn compact(module: &mut crate::Module) {
+    let mut module_tracer = ModuleTracer::new(module);
+
+    // We treat all globals as used by definition.
+    log::trace!("tracing global variables");
+    {
+        for (_, global) in module.global_variables.iter() {
+            log::trace!("tracing global {:?}", global.name);
+            module_tracer.types_used.insert(global.ty);
+            if let Some(init) = global.init {
+                module_tracer.const_expressions_used.insert(init);
+            }
+        }
+    }
+
+    // We treat all special types as used by definition.
+    module_tracer.trace_special_types(&module.special_types);
+
+    // We treat all named constants as used by definition.
+    for (handle, constant) in module.constants.iter() {
+        if constant.name.is_some() {
+            module_tracer.constants_used.insert(handle);
+            module_tracer.const_expressions_used.insert(constant.init);
+        }
+    }
+
+    // We assume that all functions are used.
+    //
+    // Observe which types, constant expressions, constants, and
+    // expressions each function uses, and produce maps for each
+    // function from pre-compaction to post-compaction expression
+    // handles.
+    log::trace!("tracing functions");
+    let function_maps: Vec<FunctionMap> = module
+        .functions
+        .iter()
+        .map(|(_, f)| {
+            log::trace!("tracing function {:?}", f.name);
+            let mut function_tracer = module_tracer.as_function(f);
+            function_tracer.trace();
+            FunctionMap::from(function_tracer)
+        })
+        .collect();
+
+    // Similarly, observe what each entry point actually uses.
+    log::trace!("tracing entry points");
+    let entry_point_maps: Vec<FunctionMap> = module
+        .entry_points
+        .iter()
+        .map(|e| {
+            log::trace!("tracing entry point {:?}", e.function.name);
+            let mut used = module_tracer.as_function(&e.function);
+            used.trace();
+            FunctionMap::from(used)
+        })
+        .collect();
+
+    // Given that the above steps have marked all the constant
+    // expressions used directly by globals, constants, functions, and
+    // entry points, walk the constant expression arena to find all
+    // constant expressions used, directly or indirectly.
+    module_tracer.as_const_expression().trace_expressions();
+
+    // Constants' initializers are taken care of already, because
+    // expression tracing sees through constants. But we still need to
+    // note type usage.
+    for (handle, constant) in module.constants.iter() {
+        if module_tracer.constants_used.contains(handle) {
+            module_tracer.types_used.insert(constant.ty);
+        }
+    }
+
+    // Treat all named types as used.
+    for (handle, ty) in module.types.iter() {
+        log::trace!("tracing type {:?}, name {:?}", handle, ty.name);
+        if ty.name.is_some() {
+            module_tracer.types_used.insert(handle);
+        }
+    }
+
+    // Propagate usage through types.
+    module_tracer.as_type().trace_types();
+
+    // Now that we know what is used and what is never touched,
+    // produce maps from the `Handle`s that appear in `module` now to
+    // the corresponding `Handle`s that will refer to the same items
+    // in the compacted module.
+    let module_map = ModuleMap::from(module_tracer);
+
+    // Drop unused types from the type arena.
+    //
+    // `FastIndexSet`s don't have an underlying Vec<T> that we can
+    // steal, compact in place, and then rebuild the `FastIndexSet`
+    // from. So we have to rebuild the type arena from scratch.
+    log::trace!("compacting types");
+    let mut new_types = arena::UniqueArena::new();
+    for (old_handle, mut ty, span) in module.types.drain_all() {
+        if let Some(expected_new_handle) = module_map.types.try_adjust(old_handle) {
+            module_map.adjust_type(&mut ty);
+            let actual_new_handle = new_types.insert(ty, span);
+            assert_eq!(actual_new_handle, expected_new_handle);
+        }
+    }
+    module.types = new_types;
+    log::trace!("adjusting special types");
+    module_map.adjust_special_types(&mut module.special_types);
+
+    // Drop unused constant expressions, reusing existing storage.
+    log::trace!("adjusting constant expressions");
+    module.const_expressions.retain_mut(|handle, expr| {
+        if module_map.const_expressions.used(handle) {
+            module_map.adjust_expression(expr, &module_map.const_expressions);
+            true
+        } else {
+            false
+        }
+    });
+
+    // Drop unused constants in place, reusing existing storage.
+    log::trace!("adjusting constants");
+    module.constants.retain_mut(|handle, constant| {
+        if module_map.constants.used(handle) {
+            module_map.types.adjust(&mut constant.ty);
+            module_map.const_expressions.adjust(&mut constant.init);
+            true
+        } else {
+            false
+        }
+    });
+
+    // Adjust global variables' types and initializers.
+    log::trace!("adjusting global variables");
+    for (_, global) in module.global_variables.iter_mut() {
+        log::trace!("adjusting global {:?}", global.name);
+        module_map.types.adjust(&mut global.ty);
+        if let Some(ref mut init) = global.init {
+            module_map.const_expressions.adjust(init);
+        }
+    }
+
+    // Temporary storage to help us reuse allocations of existing
+    // named expression tables.
+    let mut reused_named_expressions = crate::NamedExpressions::default();
+
+    // Compact each function.
+    for ((_, function), map) in module.functions.iter_mut().zip(function_maps.iter()) {
+        log::trace!("compacting function {:?}", function.name);
+        map.compact(function, &module_map, &mut reused_named_expressions);
+    }
+
+    // Compact each entry point.
+    for (entry, map) in module.entry_points.iter_mut().zip(entry_point_maps.iter()) {
+        log::trace!("compacting entry point {:?}", entry.function.name);
+        map.compact(
+            &mut entry.function,
+            &module_map,
+            &mut reused_named_expressions,
+        );
+    }
+}
+
+struct ModuleTracer<'module> {
+    module: &'module crate::Module,
+    types_used: HandleSet<crate::Type>,
+    constants_used: HandleSet<crate::Constant>,
+    const_expressions_used: HandleSet<crate::Expression>,
+}
+
+impl<'module> ModuleTracer<'module> {
+    fn new(module: &'module crate::Module) -> Self {
+        Self {
+            module,
+            types_used: HandleSet::for_arena(&module.types),
+            constants_used: HandleSet::for_arena(&module.constants),
+            const_expressions_used: HandleSet::for_arena(&module.const_expressions),
+        }
+    }
+
+    fn trace_special_types(&mut self, special_types: &crate::SpecialTypes) {
+        let crate::SpecialTypes {
+            ref ray_desc,
+            ref ray_intersection,
+            ref predeclared_types,
+        } = *special_types;
+
+        if let Some(ray_desc) = *ray_desc {
+            self.types_used.insert(ray_desc);
+        }
+        if let Some(ray_intersection) = *ray_intersection {
+            self.types_used.insert(ray_intersection);
+        }
+        for (_, &handle) in predeclared_types {
+            self.types_used.insert(handle);
+        }
+    }
+
+    fn as_type(&mut self) -> types::TypeTracer {
+        types::TypeTracer {
+            types: &self.module.types,
+            types_used: &mut self.types_used,
+        }
+    }
+
+    fn as_const_expression(&mut self) -> expressions::ExpressionTracer {
+        expressions::ExpressionTracer {
+            expressions: &self.module.const_expressions,
+            constants: &self.module.constants,
+            types_used: &mut self.types_used,
+            constants_used: &mut self.constants_used,
+            expressions_used: &mut self.const_expressions_used,
+            const_expressions_used: None,
+        }
+    }
+
+    pub fn as_function<'tracer>(
+        &'tracer mut self,
+        function: &'tracer crate::Function,
+    ) -> FunctionTracer<'tracer> {
+        FunctionTracer {
+            function,
+            constants: &self.module.constants,
+            types_used: &mut self.types_used,
+            constants_used: &mut self.constants_used,
+            const_expressions_used: &mut self.const_expressions_used,
+            expressions_used: HandleSet::for_arena(&function.expressions),
+        }
+    }
+}
+
+struct ModuleMap {
+    types: HandleMap<crate::Type>,
+    constants: HandleMap<crate::Constant>,
+    const_expressions: HandleMap<crate::Expression>,
+}
+
+impl From<ModuleTracer<'_>> for ModuleMap {
+    fn from(used: ModuleTracer) -> Self {
+        ModuleMap {
+            types: HandleMap::from_set(used.types_used),
+            constants: HandleMap::from_set(used.constants_used),
+            const_expressions: HandleMap::from_set(used.const_expressions_used),
+        }
+    }
+}
+
+impl ModuleMap {
+    fn adjust_special_types(&self, special: &mut crate::SpecialTypes) {
+        let crate::SpecialTypes {
+            ref mut ray_desc,
+            ref mut ray_intersection,
+            ref mut predeclared_types,
+        } = *special;
+
+        if let Some(ref mut ray_desc) = *ray_desc {
+            self.types.adjust(ray_desc);
+        }
+        if let Some(ref mut ray_intersection) = *ray_intersection {
+            self.types.adjust(ray_intersection);
+        }
+
+        for handle in predeclared_types.values_mut() {
+            self.types.adjust(handle);
+        }
+    }
+}
+
+struct FunctionMap {
+    expressions: HandleMap<crate::Expression>,
+}
+
+impl From<FunctionTracer<'_>> for FunctionMap {
+    fn from(used: FunctionTracer) -> Self {
+        FunctionMap {
+            expressions: HandleMap::from_set(used.expressions_used),
+        }
+    }
+}
diff --git a/third_party/rust/naga/src/compact/statements.rs b/third_party/rust/naga/src/compact/statements.rs
new file mode 100644
index 0000000000..0698b57258
--- /dev/null
+++ b/third_party/rust/naga/src/compact/statements.rs
@@ -0,0 +1,300 @@
+use super::functions::FunctionTracer;
+use super::FunctionMap;
+use crate::arena::Handle;
+
+impl FunctionTracer<'_> {
+    pub fn trace_block(&mut self, block: &[crate::Statement]) {
+        let mut worklist: Vec<&[crate::Statement]> = vec![block];
+        while let Some(last) = worklist.pop() {
+            for stmt in last {
+                use crate::Statement as St;
+                match *stmt {
+                    St::Emit(ref _range) => {
+                        // If we come across a statement that actually uses an
+                        // expression in this range, it'll get traced from
+                        // there. But since evaluating expressions has no
+                        // effect, we don't need to assume that everything
+                        // emitted is live.
+                    }
+                    St::Block(ref block) => worklist.push(block),
+                    St::If {
+                        condition,
+                        ref accept,
+                        ref reject,
+                    } => {
+                        self.expressions_used.insert(condition);
+                        worklist.push(accept);
+                        worklist.push(reject);
+                    }
+                    St::Switch {
+                        selector,
+                        ref cases,
+                    } => {
+                        self.expressions_used.insert(selector);
+                        for case in cases {
+                            worklist.push(&case.body);
+                        }
+                    }
+                    St::Loop {
+                        ref body,
+                        ref continuing,
+                        break_if,
+                    } => {
+                        if let Some(break_if) = break_if {
+                            self.expressions_used.insert(break_if);
+                        }
+                        worklist.push(body);
+                        worklist.push(continuing);
+                    }
+                    St::Return { value: Some(value) } => {
+                        self.expressions_used.insert(value);
+                    }
+                    St::Store { pointer, value } => {
+                        self.expressions_used.insert(pointer);
+                        self.expressions_used.insert(value);
+                    }
+                    St::ImageStore {
+                        image,
+                        coordinate,
+                        array_index,
+                        value,
+                    } => {
+                        self.expressions_used.insert(image);
+                        self.expressions_used.insert(coordinate);
+                        if let Some(array_index) = array_index {
+                            self.expressions_used.insert(array_index);
+                        }
+                        self.expressions_used.insert(value);
+                    }
+                    St::Atomic {
+                        pointer,
+                        ref fun,
+                        value,
+                        result,
+                    } => {
+                        self.expressions_used.insert(pointer);
+                        self.trace_atomic_function(fun);
+                        self.expressions_used.insert(value);
+                        self.expressions_used.insert(result);
+                    }
+                    St::WorkGroupUniformLoad { pointer, result } => {
+                        self.expressions_used.insert(pointer);
+                        self.expressions_used.insert(result);
+                    }
+                    St::Call {
+                        function: _,
+                        ref arguments,
+                        result,
+                    } => {
+                        for expr in arguments {
+                            self.expressions_used.insert(*expr);
+                        }
+                        if let Some(result) = result {
+                            self.expressions_used.insert(result);
+                        }
+                    }
+                    St::RayQuery { query, ref fun } => {
+                        self.expressions_used.insert(query);
+                        self.trace_ray_query_function(fun);
+                    }
+
+                    // Trivial statements.
+                    St::Break
+                    | St::Continue
+                    | St::Kill
+                    | St::Barrier(_)
+                    | St::Return { value: None } => {}
+                }
+            }
+        }
+    }
+
+    fn trace_atomic_function(&mut self, fun: &crate::AtomicFunction) {
+        use crate::AtomicFunction as Af;
+        match *fun {
+            Af::Exchange {
+                compare: Some(expr),
+            } => {
+                self.expressions_used.insert(expr);
+            }
+            Af::Exchange { compare: None }
+            | Af::Add
+            | Af::Subtract
+            | Af::And
+            | Af::ExclusiveOr
+            | Af::InclusiveOr
+            | Af::Min
+            | Af::Max => {}
+        }
+    }
+
+    fn trace_ray_query_function(&mut self, fun: &crate::RayQueryFunction) {
+        use crate::RayQueryFunction as Qf;
+        match *fun {
+            Qf::Initialize {
+                acceleration_structure,
+                descriptor,
+            } => {
+                self.expressions_used.insert(acceleration_structure);
+                self.expressions_used.insert(descriptor);
+            }
+            Qf::Proceed { result } => {
+                self.expressions_used.insert(result);
+            }
+            Qf::Terminate => {}
+        }
+    }
+}
+
+impl FunctionMap {
+    pub fn adjust_body(&self, function: &mut crate::Function) {
+        let block = &mut function.body;
+        let mut worklist: Vec<&mut [crate::Statement]> = vec![block];
+        let adjust = |handle: &mut Handle<crate::Expression>| {
+            self.expressions.adjust(handle);
+        };
+        while let Some(last) = worklist.pop() {
+            for stmt in last {
+                use crate::Statement as St;
+                match *stmt {
+                    St::Emit(ref mut range) => {
+                        self.expressions.adjust_range(range, &function.expressions);
+                    }
+                    St::Block(ref mut block) => worklist.push(block),
+                    St::If {
+                        ref mut condition,
+                        ref mut accept,
+                        ref mut reject,
+                    } => {
+                        adjust(condition);
+                        worklist.push(accept);
+                        worklist.push(reject);
+                    }
+                    St::Switch {
+                        ref mut selector,
+                        ref mut cases,
+                    } => {
+                        adjust(selector);
+                        for case in cases {
+                            worklist.push(&mut case.body);
+                        }
+                    }
+                    St::Loop {
+                        ref mut body,
+                        ref mut continuing,
+                        ref mut break_if,
+                    } => {
+                        if let Some(ref mut break_if) = *break_if {
+                            adjust(break_if);
+                        }
+                        worklist.push(body);
+                        worklist.push(continuing);
+                    }
+                    St::Return {
+                        value: Some(ref mut value),
+                    } => adjust(value),
+                    St::Store {
+                        ref mut pointer,
+                        ref mut value,
+                    } => {
+                        adjust(pointer);
+                        adjust(value);
+                    }
+                    St::ImageStore {
+                        ref mut image,
+                        ref mut coordinate,
+                        ref mut array_index,
+                        ref mut value,
+                    } => {
+                        adjust(image);
+                        adjust(coordinate);
+                        if let Some(ref mut array_index) = *array_index {
+                            adjust(array_index);
+                        }
+                        adjust(value);
+                    }
+                    St::Atomic {
+                        ref mut pointer,
+                        ref mut fun,
+                        ref mut value,
+                        ref mut result,
+                    } => {
+                        adjust(pointer);
+                        self.adjust_atomic_function(fun);
+                        adjust(value);
+                        adjust(result);
+                    }
+                    St::WorkGroupUniformLoad {
+                        ref mut pointer,
+                        ref mut result,
+                    } => {
+                        adjust(pointer);
+                        adjust(result);
+                    }
+                    St::Call {
+                        function: _,
+                        ref mut arguments,
+                        ref mut result,
+                    } => {
+                        for expr in arguments {
+                            adjust(expr);
+                        }
+                        if let Some(ref mut result) = *result {
+                            adjust(result);
+                        }
+                    }
+                    St::RayQuery {
+                        ref mut query,
+                        ref mut fun,
+                    } => {
+                        adjust(query);
+                        self.adjust_ray_query_function(fun);
+                    }
+
+                    // Trivial statements.
+                    St::Break
+                    | St::Continue
+                    | St::Kill
+                    | St::Barrier(_)
+                    | St::Return { value: None } => {}
+                }
+            }
+        }
+    }
+
+    fn adjust_atomic_function(&self, fun: &mut crate::AtomicFunction) {
+        use crate::AtomicFunction as Af;
+        match *fun {
+            Af::Exchange {
+                compare: Some(ref mut expr),
+            } => {
+                self.expressions.adjust(expr);
+            }
+            Af::Exchange { compare: None }
+            | Af::Add
+            | Af::Subtract
+            | Af::And
+            | Af::ExclusiveOr
+            | Af::InclusiveOr
+            | Af::Min
+            | Af::Max => {}
+        }
+    }
+
+    fn adjust_ray_query_function(&self, fun: &mut crate::RayQueryFunction) {
+        use crate::RayQueryFunction as Qf;
+        match *fun {
+            Qf::Initialize {
+                ref mut acceleration_structure,
+                ref mut descriptor,
+            } => {
+                self.expressions.adjust(acceleration_structure);
+                self.expressions.adjust(descriptor);
+            }
+            Qf::Proceed { ref mut result } => {
+                self.expressions.adjust(result);
+            }
+            Qf::Terminate => {}
+        }
+    }
+}
diff --git a/third_party/rust/naga/src/compact/types.rs b/third_party/rust/naga/src/compact/types.rs
new file mode 100644
index 0000000000..b78619d9a8
--- /dev/null
+++ b/third_party/rust/naga/src/compact/types.rs
@@ -0,0 +1,102 @@
+use super::{HandleSet, ModuleMap};
+use crate::{Handle, UniqueArena};
+
+pub struct TypeTracer<'a> {
+    pub types: &'a UniqueArena<crate::Type>,
+    pub types_used: &'a mut HandleSet<crate::Type>,
+}
+
+impl<'a> TypeTracer<'a> {
+    /// Propagate usage through `self.types`, starting with `self.types_used`.
+    ///
+    /// Treat `self.types_used` as the initial set of "known
+    /// live" types, and follow through to identify all
+    /// transitively used types.
+    pub fn trace_types(&mut self) {
+        // We don't need recursion or a work list. Because an
+        // expression may only refer to other expressions that precede
+        // it in the arena, it suffices to make a single pass over the
+        // arena from back to front, marking the referents of used
+        // expressions as used themselves.
+        for (handle, ty) in self.types.iter().rev() {
+            // If this type isn't used, it doesn't matter what it uses.
+            if !self.types_used.contains(handle) {
+                continue;
+            }
+
+            use crate::TypeInner as Ti;
+            match ty.inner {
+                // Types that do not contain handles.
+                Ti::Scalar { .. }
+                | Ti::Vector { .. }
+                | Ti::Matrix { .. }
+                | Ti::Atomic { .. }
+                | Ti::ValuePointer { .. }
+                | Ti::Image { .. }
+                | Ti::Sampler { .. }
+                | Ti::AccelerationStructure
+                | Ti::RayQuery => {}
+
+                // Types that do contain handles.
+                Ti::Pointer { base, space: _ }
+                | Ti::Array {
+                    base,
+                    size: _,
+                    stride: _,
+                }
+                | Ti::BindingArray { base, size: _ } => self.types_used.insert(base),
+                Ti::Struct {
+                    ref members,
+                    span: _,
+                } => {
+                    self.types_used.insert_iter(members.iter().map(|m| m.ty));
+                }
+            }
+        }
+    }
+}
+
+impl ModuleMap {
+    pub fn adjust_type(&self, ty: &mut crate::Type) {
+        let adjust = |ty: &mut Handle<crate::Type>| self.types.adjust(ty);
+
+        use crate::TypeInner as Ti;
+        match ty.inner {
+            // Types that do not contain handles.
+            Ti::Scalar(_)
+            | Ti::Vector { .. }
+            | Ti::Matrix { .. }
+            | Ti::Atomic(_)
+            | Ti::ValuePointer { .. }
+            | Ti::Image { .. }
+            | Ti::Sampler { .. }
+            | Ti::AccelerationStructure
+            | Ti::RayQuery => {}
+
+            // Types that do contain handles.
+            Ti::Pointer {
+                ref mut base,
+                space: _,
+            } => adjust(base),
+            Ti::Array {
+                ref mut base,
+                size: _,
+                stride: _,
+            } => adjust(base),
+            Ti::Struct {
+                ref mut members,
+                span: _,
+            } => {
+                for member in members {
+                    self.types.adjust(&mut member.ty);
+                }
+            }
+            Ti::BindingArray {
+                ref mut base,
+                size: _,
+            } => {
+                adjust(base);
+            }
+        };
+    }
+}
diff --git a/third_party/rust/naga/src/front/glsl/ast.rs b/third_party/rust/naga/src/front/glsl/ast.rs
new file mode 100644
index 0000000000..96b676dd6d
--- /dev/null
+++ b/third_party/rust/naga/src/front/glsl/ast.rs
@@ -0,0 +1,394 @@
+use std::{borrow::Cow, fmt};
+
+use super::{builtins::MacroCall, context::ExprPos, Span};
+use crate::{
+    AddressSpace, BinaryOperator, Binding, Constant, Expression, Function, GlobalVariable, Handle,
+    Interpolation, Literal, Sampling, StorageAccess, Type, UnaryOperator,
+};
+
+#[derive(Debug, Clone, Copy)]
+pub enum GlobalLookupKind {
+    Variable(Handle<GlobalVariable>),
+    Constant(Handle<Constant>, Handle<Type>),
+    BlockSelect(Handle<GlobalVariable>, u32),
+}
+
+#[derive(Debug, Clone, Copy)]
+pub struct GlobalLookup {
+    pub kind: GlobalLookupKind,
+    pub entry_arg: Option<usize>,
+    pub mutable: bool,
+}
+
+#[derive(Debug, Clone)]
+pub struct ParameterInfo {
+    pub qualifier: ParameterQualifier,
+    /// Whether the parameter should be treated as a depth image instead of a
+    /// sampled image.
+    pub depth: bool,
+}
+
+/// How the function is implemented
+#[derive(Clone, Copy)]
+pub enum FunctionKind {
+    /// The function is user defined
+    Call(Handle<Function>),
+    /// The function is a builtin
+    Macro(MacroCall),
+}
+
+impl fmt::Debug for FunctionKind {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match *self {
+            Self::Call(_) => write!(f, "Call"),
+            Self::Macro(_) => write!(f, "Macro"),
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct Overload {
+    /// Normalized function parameters, modifiers are not applied
+    pub parameters: Vec<Handle<Type>>,
+    pub parameters_info: Vec<ParameterInfo>,
+    /// How the function is implemented
+    pub kind: FunctionKind,
+    /// Whether this function was already defined or is just a prototype
+    pub defined: bool,
+    /// Whether this overload is the one provided by the language or has
+    /// been redeclared by the user (builtins only)
+    pub internal: bool,
+    /// Whether or not this function returns void (nothing)
+    pub void: bool,
+}
+
+bitflags::bitflags! {
+    /// Tracks the variations of the builtin already generated, this is needed because some
+    /// builtins overloads can't be generated unless explicitly used, since they might cause
+    /// unneeded capabilities to be requested
+    #[derive(Default)]
+    #[derive(Clone, Copy, Debug, Eq, PartialEq)]
+    pub struct BuiltinVariations: u32 {
+        /// Request the standard overloads
+        const STANDARD = 1 << 0;
+        /// Request overloads that use the double type
+        const DOUBLE = 1 << 1;
+        /// Request overloads that use samplerCubeArray(Shadow)
+        const CUBE_TEXTURES_ARRAY = 1 << 2;
+        /// Request overloads that use sampler2DMSArray
+        const D2_MULTI_TEXTURES_ARRAY = 1 << 3;
+    }
+}
+
+#[derive(Debug, Default)]
+pub struct FunctionDeclaration {
+    pub overloads: Vec<Overload>,
+    /// Tracks the builtin overload variations that were already generated
+    pub variations: BuiltinVariations,
+}
+
+#[derive(Debug)]
+pub struct EntryArg {
+    pub name: Option<String>,
+    pub binding: Binding,
+    pub handle: Handle<GlobalVariable>,
+    pub storage: StorageQualifier,
+}
+
+#[derive(Debug, Clone)]
+pub struct VariableReference {
+    pub expr: Handle<Expression>,
+    /// Whether the variable is of a pointer type (and needs loading) or not
+    pub load: bool,
+    /// Whether the value of the variable can be changed or not
+    pub mutable: bool,
+    pub constant: Option<(Handle<Constant>, Handle<Type>)>,
+    pub entry_arg: Option<usize>,
+}
+
+#[derive(Debug, Clone)]
+pub struct HirExpr {
+    pub kind: HirExprKind,
+    pub meta: Span,
+}
+
+#[derive(Debug, Clone)]
+pub enum HirExprKind {
+    Access {
+        base: Handle<HirExpr>,
+        index: Handle<HirExpr>,
+    },
+    Select {
+        base: Handle<HirExpr>,
+        field: String,
+    },
+    Literal(Literal),
+    Binary {
+        left: Handle<HirExpr>,
+        op: BinaryOperator,
+        right: Handle<HirExpr>,
+    },
+    Unary {
+        op: UnaryOperator,
+        expr: Handle<HirExpr>,
+    },
+    Variable(VariableReference),
+    Call(FunctionCall),
+    /// Represents the ternary operator in glsl (`:?`)
+    Conditional {
+        /// The expression that will decide which branch to take, must evaluate to a boolean
+        condition: Handle<HirExpr>,
+        /// The expression that will be evaluated if [`condition`] returns `true`
+        ///
+        /// [`condition`]: Self::Conditional::condition
+        accept: Handle<HirExpr>,
+        /// The expression that will be evaluated if [`condition`] returns `false`
+        ///
+        /// [`condition`]: Self::Conditional::condition
+        reject: Handle<HirExpr>,
+    },
+    Assign {
+        tgt: Handle<HirExpr>,
+        value: Handle<HirExpr>,
+    },
+    /// A prefix/postfix operator like `++`
+    PrePostfix {
+        /// The operation to be performed
+        op: BinaryOperator,
+        /// Whether this is a postfix or a prefix
+        postfix: bool,
+        /// The target expression
+        expr: Handle<HirExpr>,
+    },
+    /// A method call like `what.something(a, b, c)`
+    Method {
+        /// expression the method call applies to (`what` in the example)
+        expr: Handle<HirExpr>,
+        /// the method name (`something` in the example)
+        name: String,
+        /// the arguments to the method (`a`, `b`, and `c` in the example)
+        args: Vec<Handle<HirExpr>>,
+    },
+}
+
+#[derive(Debug, Hash, PartialEq, Eq)]
+pub enum QualifierKey<'a> {
+    String(Cow<'a, str>),
+    /// Used for `std140` and `std430` layout qualifiers
+    Layout,
+    /// Used for image formats
+    Format,
+}
+
+#[derive(Debug)]
+pub enum QualifierValue {
+    None,
+    Uint(u32),
+    Layout(StructLayout),
+    Format(crate::StorageFormat),
+}
+
+#[derive(Debug, Default)]
+pub struct TypeQualifiers<'a> {
+    pub span: Span,
+    pub storage: (StorageQualifier, Span),
+    pub invariant: Option<Span>,
+    pub interpolation: Option<(Interpolation, Span)>,
+    pub precision: Option<(Precision, Span)>,
+    pub sampling: Option<(Sampling, Span)>,
+    /// Memory qualifiers used in the declaration to set the storage access to be used
+    /// in declarations that support it (storage images and buffers)
+    pub storage_access: Option<(StorageAccess, Span)>,
+    pub layout_qualifiers: crate::FastHashMap<QualifierKey<'a>, (QualifierValue, Span)>,
+}
+
+impl<'a> TypeQualifiers<'a> {
+    /// Appends `errors` with errors for all unused qualifiers
+    pub fn unused_errors(&self, errors: &mut Vec<super::Error>) {
+        if let Some(meta) = self.invariant {
+            errors.push(super::Error {
+                kind: super::ErrorKind::SemanticError(
+                    "Invariant qualifier can only be used in in/out variables".into(),
+                ),
+                meta,
+            });
+        }
+
+        if let Some((_, meta)) = self.interpolation {
+            errors.push(super::Error {
+                kind: super::ErrorKind::SemanticError(
+                    "Interpolation qualifiers can only be used in in/out variables".into(),
+                ),
+                meta,
+            });
+        }
+
+        if let Some((_, meta)) = self.sampling {
+            errors.push(super::Error {
+                kind: super::ErrorKind::SemanticError(
+                    "Sampling qualifiers can only be used in in/out variables".into(),
+                ),
+                meta,
+            });
+        }
+
+        if let Some((_, meta)) = self.storage_access {
+            errors.push(super::Error {
+                kind: super::ErrorKind::SemanticError(
+                    "Memory qualifiers can only be used in storage variables".into(),
+                ),
+                meta,
+            });
+        }
+
+        for &(_, meta) in self.layout_qualifiers.values() {
+            errors.push(super::Error {
+                kind: super::ErrorKind::SemanticError("Unexpected qualifier".into()),
+                meta,
+            });
+        }
+    }
+
+    /// Removes the layout qualifier with `name`, if it exists and adds an error if it isn't
+    /// a [`QualifierValue::Uint`]
+    pub fn uint_layout_qualifier(
+        &mut self,
+        name: &'a str,
+        errors: &mut Vec<super::Error>,
+    ) -> Option<u32> {
+        match self
+            .layout_qualifiers
+            .remove(&QualifierKey::String(name.into()))
+        {
+            Some((QualifierValue::Uint(v), _)) => Some(v),
+            Some((_, meta)) => {
+                errors.push(super::Error {
+                    kind: super::ErrorKind::SemanticError("Qualifier expects a uint value".into()),
+                    meta,
+                });
+                // Return a dummy value instead of `None` to differentiate from
+                // the qualifier not existing, since some parts might require the
+                // qualifier to exist and throwing another error that it doesn't
+                // exist would be unhelpful
+                Some(0)
+            }
+            _ => None,
+        }
+    }
+
+    /// Removes the layout qualifier with `name`, if it exists and adds an error if it isn't
+    /// a [`QualifierValue::None`]
+    pub fn none_layout_qualifier(&mut self, name: &'a str, errors: &mut Vec<super::Error>) -> bool {
+        match self
+            .layout_qualifiers
+            .remove(&QualifierKey::String(name.into()))
+        {
+            Some((QualifierValue::None, _)) => true,
+            Some((_, meta)) => {
+                errors.push(super::Error {
+                    kind: super::ErrorKind::SemanticError(
+                        "Qualifier doesn't expect a value".into(),
+                    ),
+                    meta,
+                });
+                // Return a `true` to since the qualifier is defined and adding
+                // another error for it not being defined would be unhelpful
+                true
+            }
+            _ => false,
+        }
+    }
+}
+
+#[derive(Debug, Clone)]
+pub enum FunctionCallKind {
+    TypeConstructor(Handle<Type>),
+    Function(String),
+}
+
+#[derive(Debug, Clone)]
+pub struct FunctionCall {
+    pub kind: FunctionCallKind,
+    pub args: Vec<Handle<HirExpr>>,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub enum StorageQualifier {
+    AddressSpace(AddressSpace),
+    Input,
+    Output,
+    Const,
+}
+
+impl Default for StorageQualifier {
+    fn default() -> Self {
+        StorageQualifier::AddressSpace(AddressSpace::Function)
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum StructLayout {
+    Std140,
+    Std430,
+}
+
+// TODO: Encode precision hints in the IR
+/// A precision hint used in GLSL declarations.
+///
+/// Precision hints can be used to either speed up shader execution or control
+/// the precision of arithmetic operations.
+///
+/// To use a precision hint simply add it before the type in the declaration.
+/// ```glsl
+/// mediump float a;
+/// ```
+///
+/// The default when no precision is declared is `highp` which means that all
+/// operations operate with the type defined width.
+///
+/// For `mediump` and `lowp` operations follow the spir-v
+/// [`RelaxedPrecision`][RelaxedPrecision] decoration semantics.
+///
+/// [RelaxedPrecision]: https://www.khronos.org/registry/SPIR-V/specs/unified1/SPIRV.html#_a_id_relaxedprecisionsection_a_relaxed_precision
+#[derive(Debug, Clone, PartialEq, Copy)]
+pub enum Precision {
+    /// `lowp` precision
+    Low,
+    /// `mediump` precision
+    Medium,
+    /// `highp` precision
+    High,
+}
+
+#[derive(Debug, Clone, PartialEq, Copy)]
+pub enum ParameterQualifier {
+    In,
+    Out,
+    InOut,
+    Const,
+}
+
+impl ParameterQualifier {
+    /// Returns true if the argument should be passed as a lhs expression
+    pub const fn is_lhs(&self) -> bool {
+        match *self {
+            ParameterQualifier::Out | ParameterQualifier::InOut => true,
+            _ => false,
+        }
+    }
+
+    /// Converts from a parameter qualifier into a [`ExprPos`]
+    pub const fn as_pos(&self) -> ExprPos {
+        match *self {
+            ParameterQualifier::Out | ParameterQualifier::InOut => ExprPos::Lhs,
+            _ => ExprPos::Rhs,
+        }
+    }
+}
+
+/// The GLSL profile used by a shader.
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub enum Profile {
+    /// The `core` profile, default when no profile is specified.
+    Core,
+}
diff --git a/third_party/rust/naga/src/front/glsl/builtins.rs b/third_party/rust/naga/src/front/glsl/builtins.rs
new file mode 100644
index 0000000000..9e3a578c6b
--- /dev/null
+++ b/third_party/rust/naga/src/front/glsl/builtins.rs
@@ -0,0 +1,2314 @@
+use super::{
+    ast::{
+        BuiltinVariations, FunctionDeclaration, FunctionKind, Overload, ParameterInfo,
+        ParameterQualifier,
+    },
+    context::Context,
+    Error, ErrorKind, Frontend, Result,
+};
+use crate::{
+    BinaryOperator, DerivativeAxis as Axis, DerivativeControl as Ctrl, Expression, Handle,
+    ImageClass, ImageDimension as Dim, ImageQuery, MathFunction, Module, RelationalFunction,
+    SampleLevel, Scalar, ScalarKind as Sk, Span, Type, TypeInner, UnaryOperator, VectorSize,
+};
+
+impl crate::ScalarKind {
+    const fn dummy_storage_format(&self) -> crate::StorageFormat {
+        match *self {
+            Sk::Sint => crate::StorageFormat::R16Sint,
+            Sk::Uint => crate::StorageFormat::R16Uint,
+            _ => crate::StorageFormat::R16Float,
+        }
+    }
+}
+
+impl Module {
+    /// Helper function, to create a function prototype for a builtin
+    fn add_builtin(&mut self, args: Vec<TypeInner>, builtin: MacroCall) -> Overload {
+        let mut parameters = Vec::with_capacity(args.len());
+        let mut parameters_info = Vec::with_capacity(args.len());
+
+        for arg in args {
+            parameters.push(self.types.insert(
+                Type {
+                    name: None,
+                    inner: arg,
+                },
+                Span::default(),
+            ));
+            parameters_info.push(ParameterInfo {
+                qualifier: ParameterQualifier::In,
+                depth: false,
+            });
+        }
+
+        Overload {
+            parameters,
+            parameters_info,
+            kind: FunctionKind::Macro(builtin),
+            defined: false,
+            internal: true,
+            void: false,
+        }
+    }
+}
+
+const fn make_coords_arg(number_of_components: usize, kind: Sk) -> TypeInner {
+    let scalar = Scalar { kind, width: 4 };
+
+    match number_of_components {
+        1 => TypeInner::Scalar(scalar),
+        _ => TypeInner::Vector {
+            size: match number_of_components {
+                2 => VectorSize::Bi,
+                3 => VectorSize::Tri,
+                _ => VectorSize::Quad,
+            },
+            scalar,
+        },
+    }
+}
+
+/// Inject builtins into the declaration
+///
+/// This is done to not add a large startup cost and not increase memory
+/// usage if it isn't needed.
+pub fn inject_builtin(
+    declaration: &mut FunctionDeclaration,
+    module: &mut Module,
+    name: &str,
+    mut variations: BuiltinVariations,
+) {
+    log::trace!(
+        "{} variations: {:?} {:?}",
+        name,
+        variations,
+        declaration.variations
+    );
+    // Don't regeneate variations
+    variations.remove(declaration.variations);
+    declaration.variations |= variations;
+
+    if variations.contains(BuiltinVariations::STANDARD) {
+        inject_standard_builtins(declaration, module, name)
+    }
+
+    if variations.contains(BuiltinVariations::DOUBLE) {
+        inject_double_builtin(declaration, module, name)
+    }
+
+    match name {
+        "texture"
+        | "textureGrad"
+        | "textureGradOffset"
+        | "textureLod"
+        | "textureLodOffset"
+        | "textureOffset"
+        | "textureProj"
+        | "textureProjGrad"
+        | "textureProjGradOffset"
+        | "textureProjLod"
+        | "textureProjLodOffset"
+        | "textureProjOffset" => {
+            let f = |kind, dim, arrayed, multi, shadow| {
+                for bits in 0..=0b11 {
+                    let variant = bits & 0b1 != 0;
+                    let bias = bits & 0b10 != 0;
+
+                    let (proj, offset, level_type) = match name {
+                        // texture(gsampler, gvec P, [float bias]);
+                        "texture" => (false, false, TextureLevelType::None),
+                        // textureGrad(gsampler, gvec P, gvec dPdx, gvec dPdy);
+                        "textureGrad" => (false, false, TextureLevelType::Grad),
+                        // textureGradOffset(gsampler, gvec P, gvec dPdx, gvec dPdy, ivec offset);
+                        "textureGradOffset" => (false, true, TextureLevelType::Grad),
+                        // textureLod(gsampler, gvec P, float lod);
+                        "textureLod" => (false, false, TextureLevelType::Lod),
+                        // textureLodOffset(gsampler, gvec P, float lod, ivec offset);
+                        "textureLodOffset" => (false, true, TextureLevelType::Lod),
+                        // textureOffset(gsampler, gvec+1 P, ivec offset, [float bias]);
+                        "textureOffset" => (false, true, TextureLevelType::None),
+                        // textureProj(gsampler, gvec+1 P, [float bias]);
+                        "textureProj" => (true, false, TextureLevelType::None),
+                        // textureProjGrad(gsampler, gvec+1 P, gvec dPdx, gvec dPdy);
+                        "textureProjGrad" => (true, false, TextureLevelType::Grad),
+                        // textureProjGradOffset(gsampler, gvec+1 P, gvec dPdx, gvec dPdy, ivec offset);
+                        "textureProjGradOffset" => (true, true, TextureLevelType::Grad),
+                        // textureProjLod(gsampler, gvec+1 P, float lod);
+                        "textureProjLod" => (true, false, TextureLevelType::Lod),
+                        // textureProjLodOffset(gsampler, gvec+1 P, gvec dPdx, gvec dPdy, ivec offset);
+                        "textureProjLodOffset" => (true, true, TextureLevelType::Lod),
+                        // textureProjOffset(gsampler, gvec+1 P, ivec offset, [float bias]);
+                        "textureProjOffset" => (true, true, TextureLevelType::None),
+                        _ => unreachable!(),
+                    };
+
+                    let builtin = MacroCall::Texture {
+                        proj,
+                        offset,
+                        shadow,
+                        level_type,
+                    };
+
+                    // Parse out the variant settings.
+                    let grad = level_type == TextureLevelType::Grad;
+                    let lod = level_type == TextureLevelType::Lod;
+
+                    let supports_variant = proj && !shadow;
+                    if variant && !supports_variant {
+                        continue;
+                    }
+
+                    if bias && !matches!(level_type, TextureLevelType::None) {
+                        continue;
+                    }
+
+                    // Proj doesn't work with arrayed or Cube
+                    if proj && (arrayed || dim == Dim::Cube) {
+                        continue;
+                    }
+
+                    // texture operations with offset are not supported for cube maps
+                    if dim == Dim::Cube && offset {
+                        continue;
+                    }
+
+                    // sampler2DArrayShadow can't be used in textureLod or in texture with bias
+                    if (lod || bias) && arrayed && shadow && dim == Dim::D2 {
+                        continue;
+                    }
+
+                    // TODO: glsl supports using bias with depth samplers but naga doesn't
+                    if bias && shadow {
+                        continue;
+                    }
+
+                    let class = match shadow {
+                        true => ImageClass::Depth { multi },
+                        false => ImageClass::Sampled { kind, multi },
+                    };
+
+                    let image = TypeInner::Image {
+                        dim,
+                        arrayed,
+                        class,
+                    };
+
+                    let num_coords_from_dim = image_dims_to_coords_size(dim).min(3);
+                    let mut num_coords = num_coords_from_dim;
+
+                    if shadow && proj {
+                        num_coords = 4;
+                    } else if dim == Dim::D1 && shadow {
+                        num_coords = 3;
+                    } else if shadow {
+                        num_coords += 1;
+                    } else if proj {
+                        if variant && num_coords == 4 {
+                            // Normal form already has 4 components, no need to have a variant form.
+                            continue;
+                        } else if variant {
+                            num_coords = 4;
+                        } else {
+                            num_coords += 1;
+                        }
+                    }
+
+                    if !(dim == Dim::D1 && shadow) {
+                        num_coords += arrayed as usize;
+                    }
+
+                    // Special case: texture(gsamplerCubeArrayShadow) kicks the shadow compare ref to a separate argument,
+                    // since it would otherwise take five arguments. It also can't take a bias, nor can it be proj/grad/lod/offset
+                    // (presumably because nobody asked for it, and implementation complexity?)
+                    if num_coords >= 5 {
+                        if lod || grad || offset || proj || bias {
+                            continue;
+                        }
+                        debug_assert!(dim == Dim::Cube && shadow && arrayed);
+                    }
+                    debug_assert!(num_coords <= 5);
+
+                    let vector = make_coords_arg(num_coords, Sk::Float);
+                    let mut args = vec![image, vector];
+
+                    if num_coords == 5 {
+                        args.push(TypeInner::Scalar(Scalar::F32));
+                    }
+
+                    match level_type {
+                        TextureLevelType::Lod => {
+                            args.push(TypeInner::Scalar(Scalar::F32));
+                        }
+                        TextureLevelType::Grad => {
+                            args.push(make_coords_arg(num_coords_from_dim, Sk::Float));
+                            args.push(make_coords_arg(num_coords_from_dim, Sk::Float));
+                        }
+                        TextureLevelType::None => {}
+                    };
+
+                    if offset {
+                        args.push(make_coords_arg(num_coords_from_dim, Sk::Sint));
+                    }
+
+                    if bias {
+                        args.push(TypeInner::Scalar(Scalar::F32));
+                    }
+
+                    declaration
+                        .overloads
+                        .push(module.add_builtin(args, builtin));
+                }
+            };
+
+            texture_args_generator(TextureArgsOptions::SHADOW | variations.into(), f)
+        }
+        "textureSize" => {
+            let f = |kind, dim, arrayed, multi, shadow| {
+                let class = match shadow {
+                    true => ImageClass::Depth { multi },
+                    false => ImageClass::Sampled { kind, multi },
+                };
+
+                let image = TypeInner::Image {
+                    dim,
+                    arrayed,
+                    class,
+                };
+
+                let mut args = vec![image];
+
+                if !multi {
+                    args.push(TypeInner::Scalar(Scalar::I32))
+                }
+
+                declaration
+                    .overloads
+                    .push(module.add_builtin(args, MacroCall::TextureSize { arrayed }))
+            };
+
+            texture_args_generator(
+                TextureArgsOptions::SHADOW | TextureArgsOptions::MULTI | variations.into(),
+                f,
+            )
+        }
+        "texelFetch" | "texelFetchOffset" => {
+            let offset = "texelFetchOffset" == name;
+            let f = |kind, dim, arrayed, multi, _shadow| {
+                // Cube images aren't supported
+                if let Dim::Cube = dim {
+                    return;
+                }
+
+                let image = TypeInner::Image {
+                    dim,
+                    arrayed,
+                    class: ImageClass::Sampled { kind, multi },
+                };
+
+                let dim_value = image_dims_to_coords_size(dim);
+                let coordinates = make_coords_arg(dim_value + arrayed as usize, Sk::Sint);
+
+                let mut args = vec![image, coordinates, TypeInner::Scalar(Scalar::I32)];
+
+                if offset {
+                    args.push(make_coords_arg(dim_value, Sk::Sint));
+                }
+
+                declaration
+                    .overloads
+                    .push(module.add_builtin(args, MacroCall::ImageLoad { multi }))
+            };
+
+            // Don't generate shadow images since they aren't supported
+            texture_args_generator(TextureArgsOptions::MULTI | variations.into(), f)
+        }
+        "imageSize" => {
+            let f = |kind: Sk, dim, arrayed, _, _| {
+                // Naga doesn't support cube images and it's usefulness
+                // is questionable, so they won't be supported for now
+                if dim == Dim::Cube {
+                    return;
+                }
+
+                let image = TypeInner::Image {
+                    dim,
+                    arrayed,
+                    class: ImageClass::Storage {
+                        format: kind.dummy_storage_format(),
+                        access: crate::StorageAccess::empty(),
+                    },
+                };
+
+                declaration
+                    .overloads
+                    .push(module.add_builtin(vec![image], MacroCall::TextureSize { arrayed }))
+            };
+
+            texture_args_generator(variations.into(), f)
+        }
+        "imageLoad" => {
+            let f = |kind: Sk, dim, arrayed, _, _| {
+                // Naga doesn't support cube images and it's usefulness
+                // is questionable, so they won't be supported for now
+                if dim == Dim::Cube {
+                    return;
+                }
+
+                let image = TypeInner::Image {
+                    dim,
+                    arrayed,
+                    class: ImageClass::Storage {
+                        format: kind.dummy_storage_format(),
+                        access: crate::StorageAccess::LOAD,
+                    },
+                };
+
+                let dim_value = image_dims_to_coords_size(dim);
+                let mut coord_size = dim_value + arrayed as usize;
+                // > Every OpenGL API call that operates on cubemap array
+                // > textures takes layer-faces, not array layers
+                //
+                // So this means that imageCubeArray only takes a three component
+                // vector coordinate and the third component is a layer index.
+                if Dim::Cube == dim && arrayed {
+                    coord_size = 3
+                }
+                let coordinates = make_coords_arg(coord_size, Sk::Sint);
+
+                let args = vec![image, coordinates];
+
+                declaration
+                    .overloads
+                    .push(module.add_builtin(args, MacroCall::ImageLoad { multi: false }))
+            };
+
+            // Don't generate shadow nor multisampled images since they aren't supported
+            texture_args_generator(variations.into(), f)
+        }
+        "imageStore" => {
+            let f = |kind: Sk, dim, arrayed, _, _| {
+                // Naga doesn't support cube images and it's usefulness
+                // is questionable, so they won't be supported for now
+                if dim == Dim::Cube {
+                    return;
+                }
+
+                let image = TypeInner::Image {
+                    dim,
+                    arrayed,
+                    class: ImageClass::Storage {
+                        format: kind.dummy_storage_format(),
+                        access: crate::StorageAccess::STORE,
+                    },
+                };
+
+                let dim_value = image_dims_to_coords_size(dim);
+                let mut coord_size = dim_value + arrayed as usize;
+                // > Every OpenGL API call that operates on cubemap array
+                // > textures takes layer-faces, not array layers
+                //
+                // So this means that imageCubeArray only takes a three component
+                // vector coordinate and the third component is a layer index.
+                if Dim::Cube == dim && arrayed {
+                    coord_size = 3
+                }
+                let coordinates = make_coords_arg(coord_size, Sk::Sint);
+
+                let args = vec![
+                    image,
+                    coordinates,
+                    TypeInner::Vector {
+                        size: VectorSize::Quad,
+                        scalar: Scalar { kind, width: 4 },
+                    },
+                ];
+
+                let mut overload = module.add_builtin(args, MacroCall::ImageStore);
+                overload.void = true;
+                declaration.overloads.push(overload)
+            };
+
+            // Don't generate shadow nor multisampled images since they aren't supported
+            texture_args_generator(variations.into(), f)
+        }
+        _ => {}
+    }
+}
+
+/// Injects the builtins into declaration that don't need any special variations
+fn inject_standard_builtins(
+    declaration: &mut FunctionDeclaration,
+    module: &mut Module,
+    name: &str,
+) {
+    match name {
+        "sampler1D" | "sampler1DArray" | "sampler2D" | "sampler2DArray" | "sampler2DMS"
+        | "sampler2DMSArray" | "sampler3D" | "samplerCube" | "samplerCubeArray" => {
+            declaration.overloads.push(module.add_builtin(
+                vec![
+                    TypeInner::Image {
+                        dim: match name {
+                            "sampler1D" | "sampler1DArray" => Dim::D1,
+                            "sampler2D" | "sampler2DArray" | "sampler2DMS" | "sampler2DMSArray" => {
+                                Dim::D2
+                            }
+                            "sampler3D" => Dim::D3,
+                            _ => Dim::Cube,
+                        },
+                        arrayed: matches!(
+                            name,
+                            "sampler1DArray"
+                                | "sampler2DArray"
+                                | "sampler2DMSArray"
+                                | "samplerCubeArray"
+                        ),
+                        class: ImageClass::Sampled {
+                            kind: Sk::Float,
+                            multi: matches!(name, "sampler2DMS" | "sampler2DMSArray"),
+                        },
+                    },
+                    TypeInner::Sampler { comparison: false },
+                ],
+                MacroCall::Sampler,
+            ))
+        }
+        "sampler1DShadow"
+        | "sampler1DArrayShadow"
+        | "sampler2DShadow"
+        | "sampler2DArrayShadow"
+        | "samplerCubeShadow"
+        | "samplerCubeArrayShadow" => {
+            let dim = match name {
+                "sampler1DShadow" | "sampler1DArrayShadow" => Dim::D1,
+                "sampler2DShadow" | "sampler2DArrayShadow" => Dim::D2,
+                _ => Dim::Cube,
+            };
+            let arrayed = matches!(
+                name,
+                "sampler1DArrayShadow" | "sampler2DArrayShadow" | "samplerCubeArrayShadow"
+            );
+
+            for i in 0..2 {
+                let ty = TypeInner::Image {
+                    dim,
+                    arrayed,
+                    class: match i {
+                        0 => ImageClass::Sampled {
+                            kind: Sk::Float,
+                            multi: false,
+                        },
+                        _ => ImageClass::Depth { multi: false },
+                    },
+                };
+
+                declaration.overloads.push(module.add_builtin(
+                    vec![ty, TypeInner::Sampler { comparison: true }],
+                    MacroCall::SamplerShadow,
+                ))
+            }
+        }
+        "sin" | "exp" | "exp2" | "sinh" | "cos" | "cosh" | "tan" | "tanh" | "acos" | "asin"
+        | "log" | "log2" | "radians" | "degrees" | "asinh" | "acosh" | "atanh"
+        | "floatBitsToInt" | "floatBitsToUint" | "dFdx" | "dFdxFine" | "dFdxCoarse" | "dFdy"
+        | "dFdyFine" | "dFdyCoarse" | "fwidth" | "fwidthFine" | "fwidthCoarse" => {
+            // bits layout
+            // bit 0 through 1 - dims
+            for bits in 0..0b100 {
+                let size = match bits {
+                    0b00 => None,
+                    0b01 => Some(VectorSize::Bi),
+                    0b10 => Some(VectorSize::Tri),
+                    _ => Some(VectorSize::Quad),
+                };
+                let scalar = Scalar::F32;
+
+                declaration.overloads.push(module.add_builtin(
+                    vec![match size {
+                        Some(size) => TypeInner::Vector { size, scalar },
+                        None => TypeInner::Scalar(scalar),
+                    }],
+                    match name {
+                        "sin" => MacroCall::MathFunction(MathFunction::Sin),
+                        "exp" => MacroCall::MathFunction(MathFunction::Exp),
+                        "exp2" => MacroCall::MathFunction(MathFunction::Exp2),
+                        "sinh" => MacroCall::MathFunction(MathFunction::Sinh),
+                        "cos" => MacroCall::MathFunction(MathFunction::Cos),
+                        "cosh" => MacroCall::MathFunction(MathFunction::Cosh),
+                        "tan" => MacroCall::MathFunction(MathFunction::Tan),
+                        "tanh" => MacroCall::MathFunction(MathFunction::Tanh),
+                        "acos" => MacroCall::MathFunction(MathFunction::Acos),
+                        "asin" => MacroCall::MathFunction(MathFunction::Asin),
+                        "log" => MacroCall::MathFunction(MathFunction::Log),
+                        "log2" => MacroCall::MathFunction(MathFunction::Log2),
+                        "asinh" => MacroCall::MathFunction(MathFunction::Asinh),
+                        "acosh" => MacroCall::MathFunction(MathFunction::Acosh),
+                        "atanh" => MacroCall::MathFunction(MathFunction::Atanh),
+                        "radians" => MacroCall::MathFunction(MathFunction::Radians),
+                        "degrees" => MacroCall::MathFunction(MathFunction::Degrees),
+                        "floatBitsToInt" => MacroCall::BitCast(Sk::Sint),
+                        "floatBitsToUint" => MacroCall::BitCast(Sk::Uint),
+                        "dFdxCoarse" => MacroCall::Derivate(Axis::X, Ctrl::Coarse),
+                        "dFdyCoarse" => MacroCall::Derivate(Axis::Y, Ctrl::Coarse),
+                        "fwidthCoarse" => MacroCall::Derivate(Axis::Width, Ctrl::Coarse),
+                        "dFdxFine" => MacroCall::Derivate(Axis::X, Ctrl::Fine),
+                        "dFdyFine" => MacroCall::Derivate(Axis::Y, Ctrl::Fine),
+                        "fwidthFine" => MacroCall::Derivate(Axis::Width, Ctrl::Fine),
+                        "dFdx" => MacroCall::Derivate(Axis::X, Ctrl::None),
+                        "dFdy" => MacroCall::Derivate(Axis::Y, Ctrl::None),
+                        "fwidth" => MacroCall::Derivate(Axis::Width, Ctrl::None),
+                        _ => unreachable!(),
+                    },
+                ))
+            }
+        }
+        "intBitsToFloat" | "uintBitsToFloat" => {
+            // bits layout
+            // bit 0 through 1 - dims
+            for bits in 0..0b100 {
+                let size = match bits {
+                    0b00 => None,
+                    0b01 => Some(VectorSize::Bi),
+                    0b10 => Some(VectorSize::Tri),
+                    _ => Some(VectorSize::Quad),
+                };
+                let scalar = match name {
+                    "intBitsToFloat" => Scalar::I32,
+                    _ => Scalar::U32,
+                };
+
+                declaration.overloads.push(module.add_builtin(
+                    vec![match size {
+                        Some(size) => TypeInner::Vector { size, scalar },
+                        None => TypeInner::Scalar(scalar),
+                    }],
+                    MacroCall::BitCast(Sk::Float),
+                ))
+            }
+        }
+        "pow" => {
+            // bits layout
+            // bit 0 through 1 - dims
+            for bits in 0..0b100 {
+                let size = match bits {
+                    0b00 => None,
+                    0b01 => Some(VectorSize::Bi),
+                    0b10 => Some(VectorSize::Tri),
+                    _ => Some(VectorSize::Quad),
+                };
+                let scalar = Scalar::F32;
+                let ty = || match size {
+                    Some(size) => TypeInner::Vector { size, scalar },
+                    None => TypeInner::Scalar(scalar),
+                };
+
+                declaration.overloads.push(
+                    module
+                        .add_builtin(vec![ty(), ty()], MacroCall::MathFunction(MathFunction::Pow)),
+                )
+            }
+        }
+        "abs" | "sign" => {
+            // bits layout
+            // bit 0 through 1 - dims
+            // bit 2 - float/sint
+            for bits in 0..0b1000 {
+                let size = match bits & 0b11 {
+                    0b00 => None,
+                    0b01 => Some(VectorSize::Bi),
+                    0b10 => Some(VectorSize::Tri),
+                    _ => Some(VectorSize::Quad),
+                };
+                let scalar = match bits >> 2 {
+                    0b0 => Scalar::F32,
+                    _ => Scalar::I32,
+                };
+
+                let args = vec![match size {
+                    Some(size) => TypeInner::Vector { size, scalar },
+                    None => TypeInner::Scalar(scalar),
+                }];
+
+                declaration.overloads.push(module.add_builtin(
+                    args,
+                    MacroCall::MathFunction(match name {
+                        "abs" => MathFunction::Abs,
+                        "sign" => MathFunction::Sign,
+                        _ => unreachable!(),
+                    }),
+                ))
+            }
+        }
+        "bitCount" | "bitfieldReverse" | "bitfieldExtract" | "bitfieldInsert" | "findLSB"
+        | "findMSB" => {
+            let fun = match name {
+                "bitCount" => MathFunction::CountOneBits,
+                "bitfieldReverse" => MathFunction::ReverseBits,
+                "bitfieldExtract" => MathFunction::ExtractBits,
+                "bitfieldInsert" => MathFunction::InsertBits,
+                "findLSB" => MathFunction::FindLsb,
+                "findMSB" => MathFunction::FindMsb,
+                _ => unreachable!(),
+            };
+
+            let mc = match fun {
+                MathFunction::ExtractBits => MacroCall::BitfieldExtract,
+                MathFunction::InsertBits => MacroCall::BitfieldInsert,
+                _ => MacroCall::MathFunction(fun),
+            };
+
+            // bits layout
+            // bit 0 - int/uint
+            // bit 1 through 2 - dims
+            for bits in 0..0b1000 {
+                let scalar = match bits & 0b1 {
+                    0b0 => Scalar::I32,
+                    _ => Scalar::U32,
+                };
+                let size = match bits >> 1 {
+                    0b00 => None,
+                    0b01 => Some(VectorSize::Bi),
+                    0b10 => Some(VectorSize::Tri),
+                    _ => Some(VectorSize::Quad),
+                };
+
+                let ty = || match size {
+                    Some(size) => TypeInner::Vector { size, scalar },
+                    None => TypeInner::Scalar(scalar),
+                };
+
+                let mut args = vec![ty()];
+
+                match fun {
+                    MathFunction::ExtractBits => {
+                        args.push(TypeInner::Scalar(Scalar::I32));
+                        args.push(TypeInner::Scalar(Scalar::I32));
+                    }
+                    MathFunction::InsertBits => {
+                        args.push(ty());
+                        args.push(TypeInner::Scalar(Scalar::I32));
+                        args.push(TypeInner::Scalar(Scalar::I32));
+                    }
+                    _ => {}
+                }
+
+                // we need to cast the return type of findLsb / findMsb
+                let mc = if scalar.kind == Sk::Uint {
+                    match mc {
+                        MacroCall::MathFunction(MathFunction::FindLsb) => MacroCall::FindLsbUint,
+                        MacroCall::MathFunction(MathFunction::FindMsb) => MacroCall::FindMsbUint,
+                        mc => mc,
+                    }
+                } else {
+                    mc
+                };
+
+                declaration.overloads.push(module.add_builtin(args, mc))
+            }
+        }
+        "packSnorm4x8" | "packUnorm4x8" | "packSnorm2x16" | "packUnorm2x16" | "packHalf2x16" => {
+            let fun = match name {
+                "packSnorm4x8" => MathFunction::Pack4x8snorm,
+                "packUnorm4x8" => MathFunction::Pack4x8unorm,
+                "packSnorm2x16" => MathFunction::Pack2x16unorm,
+                "packUnorm2x16" => MathFunction::Pack2x16snorm,
+                "packHalf2x16" => MathFunction::Pack2x16float,
+                _ => unreachable!(),
+            };
+
+            let ty = match fun {
+                MathFunction::Pack4x8snorm | MathFunction::Pack4x8unorm => TypeInner::Vector {
+                    size: crate::VectorSize::Quad,
+                    scalar: Scalar::F32,
+                },
+                MathFunction::Pack2x16unorm
+                | MathFunction::Pack2x16snorm
+                | MathFunction::Pack2x16float => TypeInner::Vector {
+                    size: crate::VectorSize::Bi,
+                    scalar: Scalar::F32,
+                },
+                _ => unreachable!(),
+            };
+
+            let args = vec![ty];
+
+            declaration
+                .overloads
+                .push(module.add_builtin(args, MacroCall::MathFunction(fun)));
+        }
+        "unpackSnorm4x8" | "unpackUnorm4x8" | "unpackSnorm2x16" | "unpackUnorm2x16"
+        | "unpackHalf2x16" => {
+            let fun = match name {
+                "unpackSnorm4x8" => MathFunction::Unpack4x8snorm,
+                "unpackUnorm4x8" => MathFunction::Unpack4x8unorm,
+                "unpackSnorm2x16" => MathFunction::Unpack2x16snorm,
+                "unpackUnorm2x16" => MathFunction::Unpack2x16unorm,
+                "unpackHalf2x16" => MathFunction::Unpack2x16float,
+                _ => unreachable!(),
+            };
+
+            let args = vec![TypeInner::Scalar(Scalar::U32)];
+
+            declaration
+                .overloads
+                .push(module.add_builtin(args, MacroCall::MathFunction(fun)));
+        }
+        "atan" => {
+            // bits layout
+            // bit 0 - atan/atan2
+            // bit 1 through 2 - dims
+            for bits in 0..0b1000 {
+                let fun = match bits & 0b1 {
+                    0b0 => MathFunction::Atan,
+                    _ => MathFunction::Atan2,
+                };
+                let size = match bits >> 1 {
+                    0b00 => None,
+                    0b01 => Some(VectorSize::Bi),
+                    0b10 => Some(VectorSize::Tri),
+                    _ => Some(VectorSize::Quad),
+                };
+                let scalar = Scalar::F32;
+                let ty = || match size {
+                    Some(size) => TypeInner::Vector { size, scalar },
+                    None => TypeInner::Scalar(scalar),
+                };
+
+                let mut args = vec![ty()];
+
+                if fun == MathFunction::Atan2 {
+                    args.push(ty())
+                }
+
+                declaration
+                    .overloads
+                    .push(module.add_builtin(args, MacroCall::MathFunction(fun)))
+            }
+        }
+        "all" | "any" | "not" => {
+            // bits layout
+            // bit 0 through 1 - dims
+            for bits in 0..0b11 {
+                let size = match bits {
+                    0b00 => VectorSize::Bi,
+                    0b01 => VectorSize::Tri,
+                    _ => VectorSize::Quad,
+                };
+
+                let args = vec![TypeInner::Vector {
+                    size,
+                    scalar: Scalar::BOOL,
+                }];
+
+                let fun = match name {
+                    "all" => MacroCall::Relational(RelationalFunction::All),
+                    "any" => MacroCall::Relational(RelationalFunction::Any),
+                    "not" => MacroCall::Unary(UnaryOperator::LogicalNot),
+                    _ => unreachable!(),
+                };
+
+                declaration.overloads.push(module.add_builtin(args, fun))
+            }
+        }
+        "lessThan" | "greaterThan" | "lessThanEqual" | "greaterThanEqual" => {
+            for bits in 0..0b1001 {
+                let (size, scalar) = match bits {
+                    0b0000 => (VectorSize::Bi, Scalar::F32),
+                    0b0001 => (VectorSize::Tri, Scalar::F32),
+                    0b0010 => (VectorSize::Quad, Scalar::F32),
+                    0b0011 => (VectorSize::Bi, Scalar::I32),
+                    0b0100 => (VectorSize::Tri, Scalar::I32),
+                    0b0101 => (VectorSize::Quad, Scalar::I32),
+                    0b0110 => (VectorSize::Bi, Scalar::U32),
+                    0b0111 => (VectorSize::Tri, Scalar::U32),
+                    _ => (VectorSize::Quad, Scalar::U32),
+                };
+
+                let ty = || TypeInner::Vector { size, scalar };
+                let args = vec![ty(), ty()];
+
+                let fun = MacroCall::Binary(match name {
+                    "lessThan" => BinaryOperator::Less,
+                    "greaterThan" => BinaryOperator::Greater,
+                    "lessThanEqual" => BinaryOperator::LessEqual,
+                    "greaterThanEqual" => BinaryOperator::GreaterEqual,
+                    _ => unreachable!(),
+                });
+
+                declaration.overloads.push(module.add_builtin(args, fun))
+            }
+        }
+        "equal" | "notEqual" => {
+            for bits in 0..0b1100 {
+                let (size, scalar) = match bits {
+                    0b0000 => (VectorSize::Bi, Scalar::F32),
+                    0b0001 => (VectorSize::Tri, Scalar::F32),
+                    0b0010 => (VectorSize::Quad, Scalar::F32),
+                    0b0011 => (VectorSize::Bi, Scalar::I32),
+                    0b0100 => (VectorSize::Tri, Scalar::I32),
+                    0b0101 => (VectorSize::Quad, Scalar::I32),
+                    0b0110 => (VectorSize::Bi, Scalar::U32),
+                    0b0111 => (VectorSize::Tri, Scalar::U32),
+                    0b1000 => (VectorSize::Quad, Scalar::U32),
+                    0b1001 => (VectorSize::Bi, Scalar::BOOL),
+                    0b1010 => (VectorSize::Tri, Scalar::BOOL),
+                    _ => (VectorSize::Quad, Scalar::BOOL),
+                };
+
+                let ty = || TypeInner::Vector { size, scalar };
+                let args = vec![ty(), ty()];
+
+                let fun = MacroCall::Binary(match name {
+                    "equal" => BinaryOperator::Equal,
+                    "notEqual" => BinaryOperator::NotEqual,
+                    _ => unreachable!(),
+                });
+
+                declaration.overloads.push(module.add_builtin(args, fun))
+            }
+        }
+        "min" | "max" => {
+            // bits layout
+            // bit 0 through 1 - scalar kind
+            // bit 2 through 4 - dims
+            for bits in 0..0b11100 {
+                let scalar = match bits & 0b11 {
+                    0b00 => Scalar::F32,
+                    0b01 => Scalar::I32,
+                    0b10 => Scalar::U32,
+                    _ => continue,
+                };
+                let (size, second_size) = match bits >> 2 {
+                    0b000 => (None, None),
+                    0b001 => (Some(VectorSize::Bi), None),
+                    0b010 => (Some(VectorSize::Tri), None),
+                    0b011 => (Some(VectorSize::Quad), None),
+                    0b100 => (Some(VectorSize::Bi), Some(VectorSize::Bi)),
+                    0b101 => (Some(VectorSize::Tri), Some(VectorSize::Tri)),
+                    _ => (Some(VectorSize::Quad), Some(VectorSize::Quad)),
+                };
+
+                let args = vec![
+                    match size {
+                        Some(size) => TypeInner::Vector { size, scalar },
+                        None => TypeInner::Scalar(scalar),
+                    },
+                    match second_size {
+                        Some(size) => TypeInner::Vector { size, scalar },
+                        None => TypeInner::Scalar(scalar),
+                    },
+                ];
+
+                let fun = match name {
+                    "max" => MacroCall::Splatted(MathFunction::Max, size, 1),
+                    "min" => MacroCall::Splatted(MathFunction::Min, size, 1),
+                    _ => unreachable!(),
+                };
+
+                declaration.overloads.push(module.add_builtin(args, fun))
+            }
+        }
+        "mix" => {
+            // bits layout
+            // bit 0 through 1 - dims
+            // bit 2 through 4 - types
+            //
+            // 0b10011 is the last element since splatted single elements
+            // were already added
+            for bits in 0..0b10011 {
+                let size = match bits & 0b11 {
+                    0b00 => Some(VectorSize::Bi),
+                    0b01 => Some(VectorSize::Tri),
+                    0b10 => Some(VectorSize::Quad),
+                    _ => None,
+                };
+                let (scalar, splatted, boolean) = match bits >> 2 {
+                    0b000 => (Scalar::I32, false, true),
+                    0b001 => (Scalar::U32, false, true),
+                    0b010 => (Scalar::F32, false, true),
+                    0b011 => (Scalar::F32, false, false),
+                    _ => (Scalar::F32, true, false),
+                };
+
+                let ty = |scalar| match size {
+                    Some(size) => TypeInner::Vector { size, scalar },
+                    None => TypeInner::Scalar(scalar),
+                };
+                let args = vec![
+                    ty(scalar),
+                    ty(scalar),
+                    match (boolean, splatted) {
+                        (true, _) => ty(Scalar::BOOL),
+                        (_, false) => TypeInner::Scalar(scalar),
+                        _ => ty(scalar),
+                    },
+                ];
+
+                declaration.overloads.push(module.add_builtin(
+                    args,
+                    match boolean {
+                        true => MacroCall::MixBoolean,
+                        false => MacroCall::Splatted(MathFunction::Mix, size, 2),
+                    },
+                ))
+            }
+        }
+        "clamp" => {
+            // bits layout
+            // bit 0 through 1 - float/int/uint
+            // bit 2 through 3 - dims
+            // bit 4 - splatted
+            //
+            // 0b11010 is the last element since splatted single elements
+            // were already added
+            for bits in 0..0b11011 {
+                let scalar = match bits & 0b11 {
+                    0b00 => Scalar::F32,
+                    0b01 => Scalar::I32,
+                    0b10 => Scalar::U32,
+                    _ => continue,
+                };
+                let size = match (bits >> 2) & 0b11 {
+                    0b00 => Some(VectorSize::Bi),
+                    0b01 => Some(VectorSize::Tri),
+                    0b10 => Some(VectorSize::Quad),
+                    _ => None,
+                };
+                let splatted = bits & 0b10000 == 0b10000;
+
+                let base_ty = || match size {
+                    Some(size) => TypeInner::Vector { size, scalar },
+                    None => TypeInner::Scalar(scalar),
+                };
+                let limit_ty = || match splatted {
+                    true => TypeInner::Scalar(scalar),
+                    false => base_ty(),
+                };
+
+                let args = vec![base_ty(), limit_ty(), limit_ty()];
+
+                declaration
+                    .overloads
+                    .push(module.add_builtin(args, MacroCall::Clamp(size)))
+            }
+        }
+        "barrier" => declaration
+            .overloads
+            .push(module.add_builtin(Vec::new(), MacroCall::Barrier)),
+        // Add common builtins with floats
+        _ => inject_common_builtin(declaration, module, name, 4),
+    }
+}
+
+/// Injects the builtins into declaration that need doubles
+fn inject_double_builtin(declaration: &mut FunctionDeclaration, module: &mut Module, name: &str) {
+    match name {
+        "abs" | "sign" => {
+            // bits layout
+            // bit 0 through 1 - dims
+            for bits in 0..0b100 {
+                let size = match bits {
+                    0b00 => None,
+                    0b01 => Some(VectorSize::Bi),
+                    0b10 => Some(VectorSize::Tri),
+                    _ => Some(VectorSize::Quad),
+                };
+                let scalar = Scalar::F64;
+
+                let args = vec![match size {
+                    Some(size) => TypeInner::Vector { size, scalar },
+                    None => TypeInner::Scalar(scalar),
+                }];
+
+                declaration.overloads.push(module.add_builtin(
+                    args,
+                    MacroCall::MathFunction(match name {
+                        "abs" => MathFunction::Abs,
+                        "sign" => MathFunction::Sign,
+                        _ => unreachable!(),
+                    }),
+                ))
+            }
+        }
+        "min" | "max" => {
+            // bits layout
+            // bit 0 through 2 - dims
+            for bits in 0..0b111 {
+                let (size, second_size) = match bits {
+                    0b000 => (None, None),
+                    0b001 => (Some(VectorSize::Bi), None),
+                    0b010 => (Some(VectorSize::Tri), None),
+                    0b011 => (Some(VectorSize::Quad), None),
+                    0b100 => (Some(VectorSize::Bi), Some(VectorSize::Bi)),
+                    0b101 => (Some(VectorSize::Tri), Some(VectorSize::Tri)),
+                    _ => (Some(VectorSize::Quad), Some(VectorSize::Quad)),
+                };
+                let scalar = Scalar::F64;
+
+                let args = vec![
+                    match size {
+                        Some(size) => TypeInner::Vector { size, scalar },
+                        None => TypeInner::Scalar(scalar),
+                    },
+                    match second_size {
+                        Some(size) => TypeInner::Vector { size, scalar },
+                        None => TypeInner::Scalar(scalar),
+                    },
+                ];
+
+                let fun = match name {
+                    "max" => MacroCall::Splatted(MathFunction::Max, size, 1),
+                    "min" => MacroCall::Splatted(MathFunction::Min, size, 1),
+                    _ => unreachable!(),
+                };
+
+                declaration.overloads.push(module.add_builtin(args, fun))
+            }
+        }
+        "mix" => {
+            // bits layout
+            // bit 0 through 1 - dims
+            // bit 2 through 3 - splatted/boolean
+            //
+            // 0b1010 is the last element since splatted with single elements
+            // is equal to normal single elements
+            for bits in 0..0b1011 {
+                let size = match bits & 0b11 {
+                    0b00 => Some(VectorSize::Quad),
+                    0b01 => Some(VectorSize::Bi),
+                    0b10 => Some(VectorSize::Tri),
+                    _ => None,
+                };
+                let scalar = Scalar::F64;
+                let (splatted, boolean) = match bits >> 2 {
+                    0b00 => (false, false),
+                    0b01 => (false, true),
+                    _ => (true, false),
+                };
+
+                let ty = |scalar| match size {
+                    Some(size) => TypeInner::Vector { size, scalar },
+                    None => TypeInner::Scalar(scalar),
+                };
+                let args = vec![
+                    ty(scalar),
+                    ty(scalar),
+                    match (boolean, splatted) {
+                        (true, _) => ty(Scalar::BOOL),
+                        (_, false) => TypeInner::Scalar(scalar),
+                        _ => ty(scalar),
+                    },
+                ];
+
+                declaration.overloads.push(module.add_builtin(
+                    args,
+                    match boolean {
+                        true => MacroCall::MixBoolean,
+                        false => MacroCall::Splatted(MathFunction::Mix, size, 2),
+                    },
+                ))
+            }
+        }
+        "clamp" => {
+            // bits layout
+            // bit 0 through 1 - dims
+            // bit 2 - splatted
+            //
+            // 0b110 is the last element since splatted with single elements
+            // is equal to normal single elements
+            for bits in 0..0b111 {
+                let scalar = Scalar::F64;
+                let size = match bits & 0b11 {
+                    0b00 => Some(VectorSize::Bi),
+                    0b01 => Some(VectorSize::Tri),
+                    0b10 => Some(VectorSize::Quad),
+                    _ => None,
+                };
+                let splatted = bits & 0b100 == 0b100;
+
+                let base_ty = || match size {
+                    Some(size) => TypeInner::Vector { size, scalar },
+                    None => TypeInner::Scalar(scalar),
+                };
+                let limit_ty = || match splatted {
+                    true => TypeInner::Scalar(scalar),
+                    false => base_ty(),
+                };
+
+                let args = vec![base_ty(), limit_ty(), limit_ty()];
+
+                declaration
+                    .overloads
+                    .push(module.add_builtin(args, MacroCall::Clamp(size)))
+            }
+        }
+        "lessThan" | "greaterThan" | "lessThanEqual" | "greaterThanEqual" | "equal"
+        | "notEqual" => {
+            let scalar = Scalar::F64;
+            for bits in 0..0b11 {
+                let size = match bits {
+                    0b00 => VectorSize::Bi,
+                    0b01 => VectorSize::Tri,
+                    _ => VectorSize::Quad,
+                };
+
+                let ty = || TypeInner::Vector { size, scalar };
+                let args = vec![ty(), ty()];
+
+                let fun = MacroCall::Binary(match name {
+                    "lessThan" => BinaryOperator::Less,
+                    "greaterThan" => BinaryOperator::Greater,
+                    "lessThanEqual" => BinaryOperator::LessEqual,
+                    "greaterThanEqual" => BinaryOperator::GreaterEqual,
+                    "equal" => BinaryOperator::Equal,
+                    "notEqual" => BinaryOperator::NotEqual,
+                    _ => unreachable!(),
+                });
+
+                declaration.overloads.push(module.add_builtin(args, fun))
+            }
+        }
+        // Add common builtins with doubles
+        _ => inject_common_builtin(declaration, module, name, 8),
+    }
+}
+
+/// Injects the builtins into declaration that can used either float or doubles
+fn inject_common_builtin(
+    declaration: &mut FunctionDeclaration,
+    module: &mut Module,
+    name: &str,
+    float_width: crate::Bytes,
+) {
+    let float_scalar = Scalar {
+        kind: Sk::Float,
+        width: float_width,
+    };
+    match name {
+        "ceil" | "round" | "roundEven" | "floor" | "fract" | "trunc" | "sqrt" | "inversesqrt"
+        | "normalize" | "length" | "isinf" | "isnan" => {
+            // bits layout
+            // bit 0 through 1 - dims
+            for bits in 0..0b100 {
+                let size = match bits {
+                    0b00 => None,
+                    0b01 => Some(VectorSize::Bi),
+                    0b10 => Some(VectorSize::Tri),
+                    _ => Some(VectorSize::Quad),
+                };
+
+                let args = vec![match size {
+                    Some(size) => TypeInner::Vector {
+                        size,
+                        scalar: float_scalar,
+                    },
+                    None => TypeInner::Scalar(float_scalar),
+                }];
+
+                let fun = match name {
+                    "ceil" => MacroCall::MathFunction(MathFunction::Ceil),
+                    "round" | "roundEven" => MacroCall::MathFunction(MathFunction::Round),
+                    "floor" => MacroCall::MathFunction(MathFunction::Floor),
+                    "fract" => MacroCall::MathFunction(MathFunction::Fract),
+                    "trunc" => MacroCall::MathFunction(MathFunction::Trunc),
+                    "sqrt" => MacroCall::MathFunction(MathFunction::Sqrt),
+                    "inversesqrt" => MacroCall::MathFunction(MathFunction::InverseSqrt),
+                    "normalize" => MacroCall::MathFunction(MathFunction::Normalize),
+                    "length" => MacroCall::MathFunction(MathFunction::Length),
+                    "isinf" => MacroCall::Relational(RelationalFunction::IsInf),
+                    "isnan" => MacroCall::Relational(RelationalFunction::IsNan),
+                    _ => unreachable!(),
+                };
+
+                declaration.overloads.push(module.add_builtin(args, fun))
+            }
+        }
+        "dot" | "reflect" | "distance" | "ldexp" => {
+            // bits layout
+            // bit 0 through 1 - dims
+            for bits in 0..0b100 {
+                let size = match bits {
+                    0b00 => None,
+                    0b01 => Some(VectorSize::Bi),
+                    0b10 => Some(VectorSize::Tri),
+                    _ => Some(VectorSize::Quad),
+                };
+                let ty = |scalar| match size {
+                    Some(size) => TypeInner::Vector { size, scalar },
+                    None => TypeInner::Scalar(scalar),
+                };
+
+                let fun = match name {
+                    "dot" => MacroCall::MathFunction(MathFunction::Dot),
+                    "reflect" => MacroCall::MathFunction(MathFunction::Reflect),
+                    "distance" => MacroCall::MathFunction(MathFunction::Distance),
+                    "ldexp" => MacroCall::MathFunction(MathFunction::Ldexp),
+                    _ => unreachable!(),
+                };
+
+                let second_scalar = match fun {
+                    MacroCall::MathFunction(MathFunction::Ldexp) => Scalar::I32,
+                    _ => float_scalar,
+                };
+
+                declaration
+                    .overloads
+                    .push(module.add_builtin(vec![ty(float_scalar), ty(second_scalar)], fun))
+            }
+        }
+        "transpose" => {
+            // bits layout
+            // bit 0 through 3 - dims
+            for bits in 0..0b1001 {
+                let (rows, columns) = match bits {
+                    0b0000 => (VectorSize::Bi, VectorSize::Bi),
+                    0b0001 => (VectorSize::Bi, VectorSize::Tri),
+                    0b0010 => (VectorSize::Bi, VectorSize::Quad),
+                    0b0011 => (VectorSize::Tri, VectorSize::Bi),
+                    0b0100 => (VectorSize::Tri, VectorSize::Tri),
+                    0b0101 => (VectorSize::Tri, VectorSize::Quad),
+                    0b0110 => (VectorSize::Quad, VectorSize::Bi),
+                    0b0111 => (VectorSize::Quad, VectorSize::Tri),
+                    _ => (VectorSize::Quad, VectorSize::Quad),
+                };
+
+                declaration.overloads.push(module.add_builtin(
+                    vec![TypeInner::Matrix {
+                        columns,
+                        rows,
+                        scalar: float_scalar,
+                    }],
+                    MacroCall::MathFunction(MathFunction::Transpose),
+                ))
+            }
+        }
+        "inverse" | "determinant" => {
+            // bits layout
+            // bit 0 through 1 - dims
+            for bits in 0..0b11 {
+                let (rows, columns) = match bits {
+                    0b00 => (VectorSize::Bi, VectorSize::Bi),
+                    0b01 => (VectorSize::Tri, VectorSize::Tri),
+                    _ => (VectorSize::Quad, VectorSize::Quad),
+                };
+
+                let args = vec![TypeInner::Matrix {
+                    columns,
+                    rows,
+                    scalar: float_scalar,
+                }];
+
+                declaration.overloads.push(module.add_builtin(
+                    args,
+                    MacroCall::MathFunction(match name {
+                        "inverse" => MathFunction::Inverse,
+                        "determinant" => MathFunction::Determinant,
+                        _ => unreachable!(),
+                    }),
+                ))
+            }
+        }
+        "mod" | "step" => {
+            // bits layout
+            // bit 0 through 2 - dims
+            for bits in 0..0b111 {
+                let (size, second_size) = match bits {
+                    0b000 => (None, None),
+                    0b001 => (Some(VectorSize::Bi), None),
+                    0b010 => (Some(VectorSize::Tri), None),
+                    0b011 => (Some(VectorSize::Quad), None),
+                    0b100 => (Some(VectorSize::Bi), Some(VectorSize::Bi)),
+                    0b101 => (Some(VectorSize::Tri), Some(VectorSize::Tri)),
+                    _ => (Some(VectorSize::Quad), Some(VectorSize::Quad)),
+                };
+
+                let mut args = Vec::with_capacity(2);
+                let step = name == "step";
+
+                for i in 0..2 {
+                    let maybe_size = match i == step as u32 {
+                        true => size,
+                        false => second_size,
+                    };
+
+                    args.push(match maybe_size {
+                        Some(size) => TypeInner::Vector {
+                            size,
+                            scalar: float_scalar,
+                        },
+                        None => TypeInner::Scalar(float_scalar),
+                    })
+                }
+
+                let fun = match name {
+                    "mod" => MacroCall::Mod(size),
+                    "step" => MacroCall::Splatted(MathFunction::Step, size, 0),
+                    _ => unreachable!(),
+                };
+
+                declaration.overloads.push(module.add_builtin(args, fun))
+            }
+        }
+        // TODO: https://github.com/gfx-rs/naga/issues/2526
+        // "modf" | "frexp" => { ... }
+        "cross" => {
+            let args = vec![
+                TypeInner::Vector {
+                    size: VectorSize::Tri,
+                    scalar: float_scalar,
+                },
+                TypeInner::Vector {
+                    size: VectorSize::Tri,
+                    scalar: float_scalar,
+                },
+            ];
+
+            declaration
+                .overloads
+                .push(module.add_builtin(args, MacroCall::MathFunction(MathFunction::Cross)))
+        }
+        "outerProduct" => {
+            // bits layout
+            // bit 0 through 3 - dims
+            for bits in 0..0b1001 {
+                let (size1, size2) = match bits {
+                    0b0000 => (VectorSize::Bi, VectorSize::Bi),
+                    0b0001 => (VectorSize::Bi, VectorSize::Tri),
+                    0b0010 => (VectorSize::Bi, VectorSize::Quad),
+                    0b0011 => (VectorSize::Tri, VectorSize::Bi),
+                    0b0100 => (VectorSize::Tri, VectorSize::Tri),
+                    0b0101 => (VectorSize::Tri, VectorSize::Quad),
+                    0b0110 => (VectorSize::Quad, VectorSize::Bi),
+                    0b0111 => (VectorSize::Quad, VectorSize::Tri),
+                    _ => (VectorSize::Quad, VectorSize::Quad),
+                };
+
+                let args = vec![
+                    TypeInner::Vector {
+                        size: size1,
+                        scalar: float_scalar,
+                    },
+                    TypeInner::Vector {
+                        size: size2,
+                        scalar: float_scalar,
+                    },
+                ];
+
+                declaration
+                    .overloads
+                    .push(module.add_builtin(args, MacroCall::MathFunction(MathFunction::Outer)))
+            }
+        }
+        "faceforward" | "fma" => {
+            // bits layout
+            // bit 0 through 1 - dims
+            for bits in 0..0b100 {
+                let size = match bits {
+                    0b00 => None,
+                    0b01 => Some(VectorSize::Bi),
+                    0b10 => Some(VectorSize::Tri),
+                    _ => Some(VectorSize::Quad),
+                };
+
+                let ty = || match size {
+                    Some(size) => TypeInner::Vector {
+                        size,
+                        scalar: float_scalar,
+                    },
+                    None => TypeInner::Scalar(float_scalar),
+                };
+                let args = vec![ty(), ty(), ty()];
+
+                let fun = match name {
+                    "faceforward" => MacroCall::MathFunction(MathFunction::FaceForward),
+                    "fma" => MacroCall::MathFunction(MathFunction::Fma),
+                    _ => unreachable!(),
+                };
+
+                declaration.overloads.push(module.add_builtin(args, fun))
+            }
+        }
+        "refract" => {
+            // bits layout
+            // bit 0 through 1 - dims
+            for bits in 0..0b100 {
+                let size = match bits {
+                    0b00 => None,
+                    0b01 => Some(VectorSize::Bi),
+                    0b10 => Some(VectorSize::Tri),
+                    _ => Some(VectorSize::Quad),
+                };
+
+                let ty = || match size {
+                    Some(size) => TypeInner::Vector {
+                        size,
+                        scalar: float_scalar,
+                    },
+                    None => TypeInner::Scalar(float_scalar),
+                };
+                let args = vec![ty(), ty(), TypeInner::Scalar(Scalar::F32)];
+                declaration
+                    .overloads
+                    .push(module.add_builtin(args, MacroCall::MathFunction(MathFunction::Refract)))
+            }
+        }
+        "smoothstep" => {
+            // bit 0 - splatted
+            // bit 1 through 2 - dims
+            for bits in 0..0b1000 {
+                let splatted = bits & 0b1 == 0b1;
+                let size = match bits >> 1 {
+                    0b00 => None,
+                    0b01 => Some(VectorSize::Bi),
+                    0b10 => Some(VectorSize::Tri),
+                    _ => Some(VectorSize::Quad),
+                };
+
+                if splatted && size.is_none() {
+                    continue;
+                }
+
+                let base_ty = || match size {
+                    Some(size) => TypeInner::Vector {
+                        size,
+                        scalar: float_scalar,
+                    },
+                    None => TypeInner::Scalar(float_scalar),
+                };
+                let ty = || match splatted {
+                    true => TypeInner::Scalar(float_scalar),
+                    false => base_ty(),
+                };
+                declaration.overloads.push(module.add_builtin(
+                    vec![ty(), ty(), base_ty()],
+                    MacroCall::SmoothStep { splatted: size },
+                ))
+            }
+        }
+        // The function isn't a builtin or we don't yet support it
+        _ => {}
+    }
+}
+
+#[derive(Clone, Copy, PartialEq, Debug)]
+pub enum TextureLevelType {
+    None,
+    Lod,
+    Grad,
+}
+
+/// A compiler defined builtin function
+#[derive(Clone, Copy, PartialEq, Debug)]
+pub enum MacroCall {
+    Sampler,
+    SamplerShadow,
+    Texture {
+        proj: bool,
+        offset: bool,
+        shadow: bool,
+        level_type: TextureLevelType,
+    },
+    TextureSize {
+        arrayed: bool,
+    },
+    ImageLoad {
+        multi: bool,
+    },
+    ImageStore,
+    MathFunction(MathFunction),
+    FindLsbUint,
+    FindMsbUint,
+    BitfieldExtract,
+    BitfieldInsert,
+    Relational(RelationalFunction),
+    Unary(UnaryOperator),
+    Binary(BinaryOperator),
+    Mod(Option<VectorSize>),
+    Splatted(MathFunction, Option<VectorSize>, usize),
+    MixBoolean,
+    Clamp(Option<VectorSize>),
+    BitCast(Sk),
+    Derivate(Axis, Ctrl),
+    Barrier,
+    /// SmoothStep needs a separate variant because it might need it's inputs
+    /// to be splatted depending on the overload
+    SmoothStep {
+        /// The size of the splat operation if some
+        splatted: Option<VectorSize>,
+    },
+}
+
+impl MacroCall {
+    /// Adds the necessary expressions and statements to the passed body and
+    /// finally returns the final expression with the correct result
+    pub fn call(
+        &self,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+        args: &mut [Handle<Expression>],
+        meta: Span,
+    ) -> Result<Option<Handle<Expression>>> {
+        Ok(Some(match *self {
+            MacroCall::Sampler => {
+                ctx.samplers.insert(args[0], args[1]);
+                args[0]
+            }
+            MacroCall::SamplerShadow => {
+                sampled_to_depth(ctx, args[0], meta, &mut frontend.errors);
+                ctx.invalidate_expression(args[0], meta)?;
+                ctx.samplers.insert(args[0], args[1]);
+                args[0]
+            }
+            MacroCall::Texture {
+                proj,
+                offset,
+                shadow,
+                level_type,
+            } => {
+                let mut coords = args[1];
+
+                if proj {
+                    let size = match *ctx.resolve_type(coords, meta)? {
+                        TypeInner::Vector { size, .. } => size,
+                        _ => unreachable!(),
+                    };
+                    let mut right = ctx.add_expression(
+                        Expression::AccessIndex {
+                            base: coords,
+                            index: size as u32 - 1,
+                        },
+                        Span::default(),
+                    )?;
+                    let left = if let VectorSize::Bi = size {
+                        ctx.add_expression(
+                            Expression::AccessIndex {
+                                base: coords,
+                                index: 0,
+                            },
+                            Span::default(),
+                        )?
+                    } else {
+                        let size = match size {
+                            VectorSize::Tri => VectorSize::Bi,
+                            _ => VectorSize::Tri,
+                        };
+                        right = ctx.add_expression(
+                            Expression::Splat { size, value: right },
+                            Span::default(),
+                        )?;
+                        ctx.vector_resize(size, coords, Span::default())?
+                    };
+                    coords = ctx.add_expression(
+                        Expression::Binary {
+                            op: BinaryOperator::Divide,
+                            left,
+                            right,
+                        },
+                        Span::default(),
+                    )?;
+                }
+
+                let extra = args.get(2).copied();
+                let comps = frontend.coordinate_components(ctx, args[0], coords, extra, meta)?;
+
+                let mut num_args = 2;
+
+                if comps.used_extra {
+                    num_args += 1;
+                };
+
+                // Parse out explicit texture level.
+                let mut level = match level_type {
+                    TextureLevelType::None => SampleLevel::Auto,
+
+                    TextureLevelType::Lod => {
+                        num_args += 1;
+
+                        if shadow {
+                            log::warn!("Assuming LOD {:?} is zero", args[2],);
+
+                            SampleLevel::Zero
+                        } else {
+                            SampleLevel::Exact(args[2])
+                        }
+                    }
+
+                    TextureLevelType::Grad => {
+                        num_args += 2;
+
+                        if shadow {
+                            log::warn!(
+                                "Assuming gradients {:?} and {:?} are not greater than 1",
+                                args[2],
+                                args[3],
+                            );
+                            SampleLevel::Zero
+                        } else {
+                            SampleLevel::Gradient {
+                                x: args[2],
+                                y: args[3],
+                            }
+                        }
+                    }
+                };
+
+                let texture_offset = match offset {
+                    true => {
+                        let offset_arg = args[num_args];
+                        num_args += 1;
+                        match ctx.lift_up_const_expression(offset_arg) {
+                            Ok(v) => Some(v),
+                            Err(e) => {
+                                frontend.errors.push(e);
+                                None
+                            }
+                        }
+                    }
+                    false => None,
+                };
+
+                // Now go back and look for optional bias arg (if available)
+                if let TextureLevelType::None = level_type {
+                    level = args
+                        .get(num_args)
+                        .copied()
+                        .map_or(SampleLevel::Auto, SampleLevel::Bias);
+                }
+
+                texture_call(ctx, args[0], level, comps, texture_offset, meta)?
+            }
+
+            MacroCall::TextureSize { arrayed } => {
+                let mut expr = ctx.add_expression(
+                    Expression::ImageQuery {
+                        image: args[0],
+                        query: ImageQuery::Size {
+                            level: args.get(1).copied(),
+                        },
+                    },
+                    Span::default(),
+                )?;
+
+                if arrayed {
+                    let mut components = Vec::with_capacity(4);
+
+                    let size = match *ctx.resolve_type(expr, meta)? {
+                        TypeInner::Vector { size: ori_size, .. } => {
+                            for index in 0..(ori_size as u32) {
+                                components.push(ctx.add_expression(
+                                    Expression::AccessIndex { base: expr, index },
+                                    Span::default(),
+                                )?)
+                            }
+
+                            match ori_size {
+                                VectorSize::Bi => VectorSize::Tri,
+                                _ => VectorSize::Quad,
+                            }
+                        }
+                        _ => {
+                            components.push(expr);
+                            VectorSize::Bi
+                        }
+                    };
+
+                    components.push(ctx.add_expression(
+                        Expression::ImageQuery {
+                            image: args[0],
+                            query: ImageQuery::NumLayers,
+                        },
+                        Span::default(),
+                    )?);
+
+                    let ty = ctx.module.types.insert(
+                        Type {
+                            name: None,
+                            inner: TypeInner::Vector {
+                                size,
+                                scalar: Scalar::U32,
+                            },
+                        },
+                        Span::default(),
+                    );
+
+                    expr = ctx.add_expression(Expression::Compose { components, ty }, meta)?
+                }
+
+                ctx.add_expression(
+                    Expression::As {
+                        expr,
+                        kind: Sk::Sint,
+                        convert: Some(4),
+                    },
+                    Span::default(),
+                )?
+            }
+            MacroCall::ImageLoad { multi } => {
+                let comps = frontend.coordinate_components(ctx, args[0], args[1], None, meta)?;
+                let (sample, level) = match (multi, args.get(2)) {
+                    (_, None) => (None, None),
+                    (true, Some(&arg)) => (Some(arg), None),
+                    (false, Some(&arg)) => (None, Some(arg)),
+                };
+                ctx.add_expression(
+                    Expression::ImageLoad {
+                        image: args[0],
+                        coordinate: comps.coordinate,
+                        array_index: comps.array_index,
+                        sample,
+                        level,
+                    },
+                    Span::default(),
+                )?
+            }
+            MacroCall::ImageStore => {
+                let comps = frontend.coordinate_components(ctx, args[0], args[1], None, meta)?;
+                ctx.emit_restart();
+                ctx.body.push(
+                    crate::Statement::ImageStore {
+                        image: args[0],
+                        coordinate: comps.coordinate,
+                        array_index: comps.array_index,
+                        value: args[2],
+                    },
+                    meta,
+                );
+                return Ok(None);
+            }
+            MacroCall::MathFunction(fun) => ctx.add_expression(
+                Expression::Math {
+                    fun,
+                    arg: args[0],
+                    arg1: args.get(1).copied(),
+                    arg2: args.get(2).copied(),
+                    arg3: args.get(3).copied(),
+                },
+                Span::default(),
+            )?,
+            mc @ (MacroCall::FindLsbUint | MacroCall::FindMsbUint) => {
+                let fun = match mc {
+                    MacroCall::FindLsbUint => MathFunction::FindLsb,
+                    MacroCall::FindMsbUint => MathFunction::FindMsb,
+                    _ => unreachable!(),
+                };
+                let res = ctx.add_expression(
+                    Expression::Math {
+                        fun,
+                        arg: args[0],
+                        arg1: None,
+                        arg2: None,
+                        arg3: None,
+                    },
+                    Span::default(),
+                )?;
+                ctx.add_expression(
+                    Expression::As {
+                        expr: res,
+                        kind: Sk::Sint,
+                        convert: Some(4),
+                    },
+                    Span::default(),
+                )?
+            }
+            MacroCall::BitfieldInsert => {
+                let conv_arg_2 = ctx.add_expression(
+                    Expression::As {
+                        expr: args[2],
+                        kind: Sk::Uint,
+                        convert: Some(4),
+                    },
+                    Span::default(),
+                )?;
+                let conv_arg_3 = ctx.add_expression(
+                    Expression::As {
+                        expr: args[3],
+                        kind: Sk::Uint,
+                        convert: Some(4),
+                    },
+                    Span::default(),
+                )?;
+                ctx.add_expression(
+                    Expression::Math {
+                        fun: MathFunction::InsertBits,
+                        arg: args[0],
+                        arg1: Some(args[1]),
+                        arg2: Some(conv_arg_2),
+                        arg3: Some(conv_arg_3),
+                    },
+                    Span::default(),
+                )?
+            }
+            MacroCall::BitfieldExtract => {
+                let conv_arg_1 = ctx.add_expression(
+                    Expression::As {
+                        expr: args[1],
+                        kind: Sk::Uint,
+                        convert: Some(4),
+                    },
+                    Span::default(),
+                )?;
+                let conv_arg_2 = ctx.add_expression(
+                    Expression::As {
+                        expr: args[2],
+                        kind: Sk::Uint,
+                        convert: Some(4),
+                    },
+                    Span::default(),
+                )?;
+                ctx.add_expression(
+                    Expression::Math {
+                        fun: MathFunction::ExtractBits,
+                        arg: args[0],
+                        arg1: Some(conv_arg_1),
+                        arg2: Some(conv_arg_2),
+                        arg3: None,
+                    },
+                    Span::default(),
+                )?
+            }
+            MacroCall::Relational(fun) => ctx.add_expression(
+                Expression::Relational {
+                    fun,
+                    argument: args[0],
+                },
+                Span::default(),
+            )?,
+            MacroCall::Unary(op) => {
+                ctx.add_expression(Expression::Unary { op, expr: args[0] }, Span::default())?
+            }
+            MacroCall::Binary(op) => ctx.add_expression(
+                Expression::Binary {
+                    op,
+                    left: args[0],
+                    right: args[1],
+                },
+                Span::default(),
+            )?,
+            MacroCall::Mod(size) => {
+                ctx.implicit_splat(&mut args[1], meta, size)?;
+
+                // x - y * floor(x / y)
+
+                let div = ctx.add_expression(
+                    Expression::Binary {
+                        op: BinaryOperator::Divide,
+                        left: args[0],
+                        right: args[1],
+                    },
+                    Span::default(),
+                )?;
+                let floor = ctx.add_expression(
+                    Expression::Math {
+                        fun: MathFunction::Floor,
+                        arg: div,
+                        arg1: None,
+                        arg2: None,
+                        arg3: None,
+                    },
+                    Span::default(),
+                )?;
+                let mult = ctx.add_expression(
+                    Expression::Binary {
+                        op: BinaryOperator::Multiply,
+                        left: floor,
+                        right: args[1],
+                    },
+                    Span::default(),
+                )?;
+                ctx.add_expression(
+                    Expression::Binary {
+                        op: BinaryOperator::Subtract,
+                        left: args[0],
+                        right: mult,
+                    },
+                    Span::default(),
+                )?
+            }
+            MacroCall::Splatted(fun, size, i) => {
+                ctx.implicit_splat(&mut args[i], meta, size)?;
+
+                ctx.add_expression(
+                    Expression::Math {
+                        fun,
+                        arg: args[0],
+                        arg1: args.get(1).copied(),
+                        arg2: args.get(2).copied(),
+                        arg3: args.get(3).copied(),
+                    },
+                    Span::default(),
+                )?
+            }
+            MacroCall::MixBoolean => ctx.add_expression(
+                Expression::Select {
+                    condition: args[2],
+                    accept: args[1],
+                    reject: args[0],
+                },
+                Span::default(),
+            )?,
+            MacroCall::Clamp(size) => {
+                ctx.implicit_splat(&mut args[1], meta, size)?;
+                ctx.implicit_splat(&mut args[2], meta, size)?;
+
+                ctx.add_expression(
+                    Expression::Math {
+                        fun: MathFunction::Clamp,
+                        arg: args[0],
+                        arg1: args.get(1).copied(),
+                        arg2: args.get(2).copied(),
+                        arg3: args.get(3).copied(),
+                    },
+                    Span::default(),
+                )?
+            }
+            MacroCall::BitCast(kind) => ctx.add_expression(
+                Expression::As {
+                    expr: args[0],
+                    kind,
+                    convert: None,
+                },
+                Span::default(),
+            )?,
+            MacroCall::Derivate(axis, ctrl) => ctx.add_expression(
+                Expression::Derivative {
+                    axis,
+                    ctrl,
+                    expr: args[0],
+                },
+                Span::default(),
+            )?,
+            MacroCall::Barrier => {
+                ctx.emit_restart();
+                ctx.body
+                    .push(crate::Statement::Barrier(crate::Barrier::all()), meta);
+                return Ok(None);
+            }
+            MacroCall::SmoothStep { splatted } => {
+                ctx.implicit_splat(&mut args[0], meta, splatted)?;
+                ctx.implicit_splat(&mut args[1], meta, splatted)?;
+
+                ctx.add_expression(
+                    Expression::Math {
+                        fun: MathFunction::SmoothStep,
+                        arg: args[0],
+                        arg1: args.get(1).copied(),
+                        arg2: args.get(2).copied(),
+                        arg3: None,
+                    },
+                    Span::default(),
+                )?
+            }
+        }))
+    }
+}
+
+fn texture_call(
+    ctx: &mut Context,
+    image: Handle<Expression>,
+    level: SampleLevel,
+    comps: CoordComponents,
+    offset: Option<Handle<Expression>>,
+    meta: Span,
+) -> Result<Handle<Expression>> {
+    if let Some(sampler) = ctx.samplers.get(&image).copied() {
+        let mut array_index = comps.array_index;
+
+        if let Some(ref mut array_index_expr) = array_index {
+            ctx.conversion(array_index_expr, meta, Scalar::I32)?;
+        }
+
+        Ok(ctx.add_expression(
+            Expression::ImageSample {
+                image,
+                sampler,
+                gather: None, //TODO
+                coordinate: comps.coordinate,
+                array_index,
+                offset,
+                level,
+                depth_ref: comps.depth_ref,
+            },
+            meta,
+        )?)
+    } else {
+        Err(Error {
+            kind: ErrorKind::SemanticError("Bad call".into()),
+            meta,
+        })
+    }
+}
+
+/// Helper struct for texture calls with the separate components from the vector argument
+///
+/// Obtained by calling [`coordinate_components`](Frontend::coordinate_components)
+#[derive(Debug)]
+struct CoordComponents {
+    coordinate: Handle<Expression>,
+    depth_ref: Option<Handle<Expression>>,
+    array_index: Option<Handle<Expression>>,
+    used_extra: bool,
+}
+
+impl Frontend {
+    /// Helper function for texture calls, splits the vector argument into it's components
+    fn coordinate_components(
+        &mut self,
+        ctx: &mut Context,
+        image: Handle<Expression>,
+        coord: Handle<Expression>,
+        extra: Option<Handle<Expression>>,
+        meta: Span,
+    ) -> Result<CoordComponents> {
+        if let TypeInner::Image {
+            dim,
+            arrayed,
+            class,
+        } = *ctx.resolve_type(image, meta)?
+        {
+            let image_size = match dim {
+                Dim::D1 => None,
+                Dim::D2 => Some(VectorSize::Bi),
+                Dim::D3 => Some(VectorSize::Tri),
+                Dim::Cube => Some(VectorSize::Tri),
+            };
+            let coord_size = match *ctx.resolve_type(coord, meta)? {
+                TypeInner::Vector { size, .. } => Some(size),
+                _ => None,
+            };
+            let (shadow, storage) = match class {
+                ImageClass::Depth { .. } => (true, false),
+                ImageClass::Storage { .. } => (false, true),
+                ImageClass::Sampled { .. } => (false, false),
+            };
+
+            let coordinate = match (image_size, coord_size) {
+                (Some(size), Some(coord_s)) if size != coord_s => {
+                    ctx.vector_resize(size, coord, Span::default())?
+                }
+                (None, Some(_)) => ctx.add_expression(
+                    Expression::AccessIndex {
+                        base: coord,
+                        index: 0,
+                    },
+                    Span::default(),
+                )?,
+                _ => coord,
+            };
+
+            let mut coord_index = image_size.map_or(1, |s| s as u32);
+
+            let array_index = if arrayed && !(storage && dim == Dim::Cube) {
+                let index = coord_index;
+                coord_index += 1;
+
+                Some(ctx.add_expression(
+                    Expression::AccessIndex { base: coord, index },
+                    Span::default(),
+                )?)
+            } else {
+                None
+            };
+            let mut used_extra = false;
+            let depth_ref = match shadow {
+                true => {
+                    let index = coord_index;
+
+                    if index == 4 {
+                        used_extra = true;
+                        extra
+                    } else {
+                        Some(ctx.add_expression(
+                            Expression::AccessIndex { base: coord, index },
+                            Span::default(),
+                        )?)
+                    }
+                }
+                false => None,
+            };
+
+            Ok(CoordComponents {
+                coordinate,
+                depth_ref,
+                array_index,
+                used_extra,
+            })
+        } else {
+            self.errors.push(Error {
+                kind: ErrorKind::SemanticError("Type is not an image".into()),
+                meta,
+            });
+
+            Ok(CoordComponents {
+                coordinate: coord,
+                depth_ref: None,
+                array_index: None,
+                used_extra: false,
+            })
+        }
+    }
+}
+
+/// Helper function to cast a expression holding a sampled image to a
+/// depth image.
+pub fn sampled_to_depth(
+    ctx: &mut Context,
+    image: Handle<Expression>,
+    meta: Span,
+    errors: &mut Vec<Error>,
+) {
+    // Get the a mutable type handle of the underlying image storage
+    let ty = match ctx[image] {
+        Expression::GlobalVariable(handle) => &mut ctx.module.global_variables.get_mut(handle).ty,
+        Expression::FunctionArgument(i) => {
+            // Mark the function argument as carrying a depth texture
+            ctx.parameters_info[i as usize].depth = true;
+            // NOTE: We need to later also change the parameter type
+            &mut ctx.arguments[i as usize].ty
+        }
+        _ => {
+            // Only globals and function arguments are allowed to carry an image
+            return errors.push(Error {
+                kind: ErrorKind::SemanticError("Not a valid texture expression".into()),
+                meta,
+            });
+        }
+    };
+
+    match ctx.module.types[*ty].inner {
+        // Update the image class to depth in case it already isn't
+        TypeInner::Image {
+            class,
+            dim,
+            arrayed,
+        } => match class {
+            ImageClass::Sampled { multi, .. } => {
+                *ty = ctx.module.types.insert(
+                    Type {
+                        name: None,
+                        inner: TypeInner::Image {
+                            dim,
+                            arrayed,
+                            class: ImageClass::Depth { multi },
+                        },
+                    },
+                    Span::default(),
+                )
+            }
+            ImageClass::Depth { .. } => {}
+            // Other image classes aren't allowed to be transformed to depth
+            ImageClass::Storage { .. } => errors.push(Error {
+                kind: ErrorKind::SemanticError("Not a texture".into()),
+                meta,
+            }),
+        },
+        _ => errors.push(Error {
+            kind: ErrorKind::SemanticError("Not a texture".into()),
+            meta,
+        }),
+    };
+
+    // Copy the handle to allow borrowing the `ctx` again
+    let ty = *ty;
+
+    // If the image was passed through a function argument we also need to change
+    // the corresponding parameter
+    if let Expression::FunctionArgument(i) = ctx[image] {
+        ctx.parameters[i as usize] = ty;
+    }
+}
+
+bitflags::bitflags! {
+    /// Influences the operation `texture_args_generator`
+    struct TextureArgsOptions: u32 {
+        /// Generates multisampled variants of images
+        const MULTI = 1 << 0;
+        /// Generates shadow variants of images
+        const SHADOW = 1 << 1;
+        /// Generates standard images
+        const STANDARD = 1 << 2;
+        /// Generates cube arrayed images
+        const CUBE_ARRAY = 1 << 3;
+        /// Generates cube arrayed images
+        const D2_MULTI_ARRAY = 1 << 4;
+    }
+}
+
+impl From<BuiltinVariations> for TextureArgsOptions {
+    fn from(variations: BuiltinVariations) -> Self {
+        let mut options = TextureArgsOptions::empty();
+        if variations.contains(BuiltinVariations::STANDARD) {
+            options |= TextureArgsOptions::STANDARD
+        }
+        if variations.contains(BuiltinVariations::CUBE_TEXTURES_ARRAY) {
+            options |= TextureArgsOptions::CUBE_ARRAY
+        }
+        if variations.contains(BuiltinVariations::D2_MULTI_TEXTURES_ARRAY) {
+            options |= TextureArgsOptions::D2_MULTI_ARRAY
+        }
+        options
+    }
+}
+
+/// Helper function to generate the image components for texture/image builtins
+///
+/// Calls the passed function `f` with:
+/// ```text
+/// f(ScalarKind, ImageDimension, arrayed, multi, shadow)
+/// ```
+///
+/// `options` controls extra image variants generation like multisampling and depth,
+/// see the struct documentation
+fn texture_args_generator(
+    options: TextureArgsOptions,
+    mut f: impl FnMut(crate::ScalarKind, Dim, bool, bool, bool),
+) {
+    for kind in [Sk::Float, Sk::Uint, Sk::Sint].iter().copied() {
+        for dim in [Dim::D1, Dim::D2, Dim::D3, Dim::Cube].iter().copied() {
+            for arrayed in [false, true].iter().copied() {
+                if dim == Dim::Cube && arrayed {
+                    if !options.contains(TextureArgsOptions::CUBE_ARRAY) {
+                        continue;
+                    }
+                } else if Dim::D2 == dim
+                    && options.contains(TextureArgsOptions::MULTI)
+                    && arrayed
+                    && options.contains(TextureArgsOptions::D2_MULTI_ARRAY)
+                {
+                    // multisampling for sampler2DMSArray
+                    f(kind, dim, arrayed, true, false);
+                } else if !options.contains(TextureArgsOptions::STANDARD) {
+                    continue;
+                }
+
+                f(kind, dim, arrayed, false, false);
+
+                // 3D images can't be neither arrayed nor shadow
+                // so we break out early, this way arrayed will always
+                // be false and we won't hit the shadow branch
+                if let Dim::D3 = dim {
+                    break;
+                }
+
+                if Dim::D2 == dim && options.contains(TextureArgsOptions::MULTI) && !arrayed {
+                    // multisampling
+                    f(kind, dim, arrayed, true, false);
+                }
+
+                if Sk::Float == kind && options.contains(TextureArgsOptions::SHADOW) {
+                    // shadow
+                    f(kind, dim, arrayed, false, true);
+                }
+            }
+        }
+    }
+}
+
+/// Helper functions used to convert from a image dimension into a integer representing the
+/// number of components needed for the coordinates vector (1 means scalar instead of vector)
+const fn image_dims_to_coords_size(dim: Dim) -> usize {
+    match dim {
+        Dim::D1 => 1,
+        Dim::D2 => 2,
+        _ => 3,
+    }
+}
diff --git a/third_party/rust/naga/src/front/glsl/context.rs b/third_party/rust/naga/src/front/glsl/context.rs
new file mode 100644
index 0000000000..f26c57965d
--- /dev/null
+++ b/third_party/rust/naga/src/front/glsl/context.rs
@@ -0,0 +1,1506 @@
+use super::{
+    ast::{
+        GlobalLookup, GlobalLookupKind, HirExpr, HirExprKind, ParameterInfo, ParameterQualifier,
+        VariableReference,
+    },
+    error::{Error, ErrorKind},
+    types::{scalar_components, type_power},
+    Frontend, Result,
+};
+use crate::{
+    front::Typifier, proc::Emitter, AddressSpace, Arena, BinaryOperator, Block, Expression,
+    FastHashMap, FunctionArgument, Handle, Literal, LocalVariable, RelationalFunction, Scalar,
+    Span, Statement, Type, TypeInner, VectorSize,
+};
+use std::ops::Index;
+
+/// The position at which an expression is, used while lowering
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+pub enum ExprPos {
+    /// The expression is in the left hand side of an assignment
+    Lhs,
+    /// The expression is in the right hand side of an assignment
+    Rhs,
+    /// The expression is an array being indexed, needed to allow constant
+    /// arrays to be dynamically indexed
+    AccessBase {
+        /// The index is a constant
+        constant_index: bool,
+    },
+}
+
+impl ExprPos {
+    /// Returns an lhs position if the current position is lhs otherwise AccessBase
+    const fn maybe_access_base(&self, constant_index: bool) -> Self {
+        match *self {
+            ExprPos::Lhs
+            | ExprPos::AccessBase {
+                constant_index: false,
+            } => *self,
+            _ => ExprPos::AccessBase { constant_index },
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct Context<'a> {
+    pub expressions: Arena<Expression>,
+    pub locals: Arena<LocalVariable>,
+
+    /// The [`FunctionArgument`]s for the final [`crate::Function`].
+    ///
+    /// Parameters with the `out` and `inout` qualifiers have [`Pointer`] types
+    /// here. For example, an `inout vec2 a` argument would be a [`Pointer`] to
+    /// a [`Vector`].
+    ///
+    /// [`Pointer`]: crate::TypeInner::Pointer
+    /// [`Vector`]: crate::TypeInner::Vector
+    pub arguments: Vec<FunctionArgument>,
+
+    /// The parameter types given in the source code.
+    ///
+    /// The `out` and `inout` qualifiers don't affect the types that appear
+    /// here. For example, an `inout vec2 a` argument would simply be a
+    /// [`Vector`], not a pointer to one.
+    ///
+    /// [`Vector`]: crate::TypeInner::Vector
+    pub parameters: Vec<Handle<Type>>,
+    pub parameters_info: Vec<ParameterInfo>,
+
+    pub symbol_table: crate::front::SymbolTable<String, VariableReference>,
+    pub samplers: FastHashMap<Handle<Expression>, Handle<Expression>>,
+
+    pub const_typifier: Typifier,
+    pub typifier: Typifier,
+    emitter: Emitter,
+    stmt_ctx: Option<StmtContext>,
+    pub body: Block,
+    pub module: &'a mut crate::Module,
+    pub is_const: bool,
+    /// Tracks the constness of `Expression`s residing in `self.expressions`
+    pub expression_constness: crate::proc::ExpressionConstnessTracker,
+}
+
+impl<'a> Context<'a> {
+    pub fn new(frontend: &Frontend, module: &'a mut crate::Module, is_const: bool) -> Result<Self> {
+        let mut this = Context {
+            expressions: Arena::new(),
+            locals: Arena::new(),
+            arguments: Vec::new(),
+
+            parameters: Vec::new(),
+            parameters_info: Vec::new(),
+
+            symbol_table: crate::front::SymbolTable::default(),
+            samplers: FastHashMap::default(),
+
+            const_typifier: Typifier::new(),
+            typifier: Typifier::new(),
+            emitter: Emitter::default(),
+            stmt_ctx: Some(StmtContext::new()),
+            body: Block::new(),
+            module,
+            is_const: false,
+            expression_constness: crate::proc::ExpressionConstnessTracker::new(),
+        };
+
+        this.emit_start();
+
+        for &(ref name, lookup) in frontend.global_variables.iter() {
+            this.add_global(name, lookup)?
+        }
+        this.is_const = is_const;
+
+        Ok(this)
+    }
+
+    pub fn new_body<F>(&mut self, cb: F) -> Result<Block>
+    where
+        F: FnOnce(&mut Self) -> Result<()>,
+    {
+        self.new_body_with_ret(cb).map(|(b, _)| b)
+    }
+
+    pub fn new_body_with_ret<F, R>(&mut self, cb: F) -> Result<(Block, R)>
+    where
+        F: FnOnce(&mut Self) -> Result<R>,
+    {
+        self.emit_restart();
+        let old_body = std::mem::replace(&mut self.body, Block::new());
+        let res = cb(self);
+        self.emit_restart();
+        let new_body = std::mem::replace(&mut self.body, old_body);
+        res.map(|r| (new_body, r))
+    }
+
+    pub fn with_body<F>(&mut self, body: Block, cb: F) -> Result<Block>
+    where
+        F: FnOnce(&mut Self) -> Result<()>,
+    {
+        self.emit_restart();
+        let old_body = std::mem::replace(&mut self.body, body);
+        let res = cb(self);
+        self.emit_restart();
+        let body = std::mem::replace(&mut self.body, old_body);
+        res.map(|_| body)
+    }
+
+    pub fn add_global(
+        &mut self,
+        name: &str,
+        GlobalLookup {
+            kind,
+            entry_arg,
+            mutable,
+        }: GlobalLookup,
+    ) -> Result<()> {
+        let (expr, load, constant) = match kind {
+            GlobalLookupKind::Variable(v) => {
+                let span = self.module.global_variables.get_span(v);
+                (
+                    self.add_expression(Expression::GlobalVariable(v), span)?,
+                    self.module.global_variables[v].space != AddressSpace::Handle,
+                    None,
+                )
+            }
+            GlobalLookupKind::BlockSelect(handle, index) => {
+                let span = self.module.global_variables.get_span(handle);
+                let base = self.add_expression(Expression::GlobalVariable(handle), span)?;
+                let expr = self.add_expression(Expression::AccessIndex { base, index }, span)?;
+
+                (
+                    expr,
+                    {
+                        let ty = self.module.global_variables[handle].ty;
+
+                        match self.module.types[ty].inner {
+                            TypeInner::Struct { ref members, .. } => {
+                                if let TypeInner::Array {
+                                    size: crate::ArraySize::Dynamic,
+                                    ..
+                                } = self.module.types[members[index as usize].ty].inner
+                                {
+                                    false
+                                } else {
+                                    true
+                                }
+                            }
+                            _ => true,
+                        }
+                    },
+                    None,
+                )
+            }
+            GlobalLookupKind::Constant(v, ty) => {
+                let span = self.module.constants.get_span(v);
+                (
+                    self.add_expression(Expression::Constant(v), span)?,
+                    false,
+                    Some((v, ty)),
+                )
+            }
+        };
+
+        let var = VariableReference {
+            expr,
+            load,
+            mutable,
+            constant,
+            entry_arg,
+        };
+
+        self.symbol_table.add(name.into(), var);
+
+        Ok(())
+    }
+
+    /// Starts the expression emitter
+    ///
+    /// # Panics
+    ///
+    /// - If called twice in a row without calling [`emit_end`][Self::emit_end].
+    #[inline]
+    pub fn emit_start(&mut self) {
+        self.emitter.start(&self.expressions)
+    }
+
+    /// Emits all the expressions captured by the emitter to the current body
+    ///
+    /// # Panics
+    ///
+    /// - If called before calling [`emit_start`].
+    /// - If called twice in a row without calling [`emit_start`].
+    ///
+    /// [`emit_start`]: Self::emit_start
+    pub fn emit_end(&mut self) {
+        self.body.extend(self.emitter.finish(&self.expressions))
+    }
+
+    /// Emits all the expressions captured by the emitter to the current body
+    /// and starts the emitter again
+    ///
+    /// # Panics
+    ///
+    /// - If called before calling [`emit_start`][Self::emit_start].
+    pub fn emit_restart(&mut self) {
+        self.emit_end();
+        self.emit_start()
+    }
+
+    pub fn add_expression(&mut self, expr: Expression, meta: Span) -> Result<Handle<Expression>> {
+        let mut eval = if self.is_const {
+            crate::proc::ConstantEvaluator::for_glsl_module(self.module)
+        } else {
+            crate::proc::ConstantEvaluator::for_glsl_function(
+                self.module,
+                &mut self.expressions,
+                &mut self.expression_constness,
+                &mut self.emitter,
+                &mut self.body,
+            )
+        };
+
+        let res = eval.try_eval_and_append(&expr, meta).map_err(|e| Error {
+            kind: e.into(),
+            meta,
+        });
+
+        match res {
+            Ok(expr) => Ok(expr),
+            Err(e) => {
+                if self.is_const {
+                    Err(e)
+                } else {
+                    let needs_pre_emit = expr.needs_pre_emit();
+                    if needs_pre_emit {
+                        self.body.extend(self.emitter.finish(&self.expressions));
+                    }
+                    let h = self.expressions.append(expr, meta);
+                    if needs_pre_emit {
+                        self.emitter.start(&self.expressions);
+                    }
+                    Ok(h)
+                }
+            }
+        }
+    }
+
+    /// Add variable to current scope
+    ///
+    /// Returns a variable if a variable with the same name was already defined,
+    /// otherwise returns `None`
+    pub fn add_local_var(
+        &mut self,
+        name: String,
+        expr: Handle<Expression>,
+        mutable: bool,
+    ) -> Option<VariableReference> {
+        let var = VariableReference {
+            expr,
+            load: true,
+            mutable,
+            constant: None,
+            entry_arg: None,
+        };
+
+        self.symbol_table.add(name, var)
+    }
+
+    /// Add function argument to current scope
+    pub fn add_function_arg(
+        &mut self,
+        name_meta: Option<(String, Span)>,
+        ty: Handle<Type>,
+        qualifier: ParameterQualifier,
+    ) -> Result<()> {
+        let index = self.arguments.len();
+        let mut arg = FunctionArgument {
+            name: name_meta.as_ref().map(|&(ref name, _)| name.clone()),
+            ty,
+            binding: None,
+        };
+        self.parameters.push(ty);
+
+        let opaque = match self.module.types[ty].inner {
+            TypeInner::Image { .. } | TypeInner::Sampler { .. } => true,
+            _ => false,
+        };
+
+        if qualifier.is_lhs() {
+            let span = self.module.types.get_span(arg.ty);
+            arg.ty = self.module.types.insert(
+                Type {
+                    name: None,
+                    inner: TypeInner::Pointer {
+                        base: arg.ty,
+                        space: AddressSpace::Function,
+                    },
+                },
+                span,
+            )
+        }
+
+        self.arguments.push(arg);
+
+        self.parameters_info.push(ParameterInfo {
+            qualifier,
+            depth: false,
+        });
+
+        if let Some((name, meta)) = name_meta {
+            let expr = self.add_expression(Expression::FunctionArgument(index as u32), meta)?;
+            let mutable = qualifier != ParameterQualifier::Const && !opaque;
+            let load = qualifier.is_lhs();
+
+            let var = if mutable && !load {
+                let handle = self.locals.append(
+                    LocalVariable {
+                        name: Some(name.clone()),
+                        ty,
+                        init: None,
+                    },
+                    meta,
+                );
+                let local_expr = self.add_expression(Expression::LocalVariable(handle), meta)?;
+
+                self.emit_restart();
+
+                self.body.push(
+                    Statement::Store {
+                        pointer: local_expr,
+                        value: expr,
+                    },
+                    meta,
+                );
+
+                VariableReference {
+                    expr: local_expr,
+                    load: true,
+                    mutable,
+                    constant: None,
+                    entry_arg: None,
+                }
+            } else {
+                VariableReference {
+                    expr,
+                    load,
+                    mutable,
+                    constant: None,
+                    entry_arg: None,
+                }
+            };
+
+            self.symbol_table.add(name, var);
+        }
+
+        Ok(())
+    }
+
+    /// Returns a [`StmtContext`] to be used in parsing and lowering
+    ///
+    /// # Panics
+    ///
+    /// - If more than one [`StmtContext`] are active at the same time or if the
+    /// previous call didn't use it in lowering.
+    #[must_use]
+    pub fn stmt_ctx(&mut self) -> StmtContext {
+        self.stmt_ctx.take().unwrap()
+    }
+
+    /// Lowers a [`HirExpr`] which might produce a [`Expression`].
+    ///
+    /// consumes a [`StmtContext`] returning it to the context so that it can be
+    /// used again later.
+    pub fn lower(
+        &mut self,
+        mut stmt: StmtContext,
+        frontend: &mut Frontend,
+        expr: Handle<HirExpr>,
+        pos: ExprPos,
+    ) -> Result<(Option<Handle<Expression>>, Span)> {
+        let res = self.lower_inner(&stmt, frontend, expr, pos);
+
+        stmt.hir_exprs.clear();
+        self.stmt_ctx = Some(stmt);
+
+        res
+    }
+
+    /// Similar to [`lower`](Self::lower) but returns an error if the expression
+    /// returns void (ie. doesn't produce a [`Expression`]).
+    ///
+    /// consumes a [`StmtContext`] returning it to the context so that it can be
+    /// used again later.
+    pub fn lower_expect(
+        &mut self,
+        mut stmt: StmtContext,
+        frontend: &mut Frontend,
+        expr: Handle<HirExpr>,
+        pos: ExprPos,
+    ) -> Result<(Handle<Expression>, Span)> {
+        let res = self.lower_expect_inner(&stmt, frontend, expr, pos);
+
+        stmt.hir_exprs.clear();
+        self.stmt_ctx = Some(stmt);
+
+        res
+    }
+
+    /// internal implementation of [`lower_expect`](Self::lower_expect)
+    ///
+    /// this method is only public because it's used in
+    /// [`function_call`](Frontend::function_call), unless you know what
+    /// you're doing use [`lower_expect`](Self::lower_expect)
+    pub fn lower_expect_inner(
+        &mut self,
+        stmt: &StmtContext,
+        frontend: &mut Frontend,
+        expr: Handle<HirExpr>,
+        pos: ExprPos,
+    ) -> Result<(Handle<Expression>, Span)> {
+        let (maybe_expr, meta) = self.lower_inner(stmt, frontend, expr, pos)?;
+
+        let expr = match maybe_expr {
+            Some(e) => e,
+            None => {
+                return Err(Error {
+                    kind: ErrorKind::SemanticError("Expression returns void".into()),
+                    meta,
+                })
+            }
+        };
+
+        Ok((expr, meta))
+    }
+
+    fn lower_store(
+        &mut self,
+        pointer: Handle<Expression>,
+        value: Handle<Expression>,
+        meta: Span,
+    ) -> Result<()> {
+        if let Expression::Swizzle {
+            size,
+            mut vector,
+            pattern,
+        } = self.expressions[pointer]
+        {
+            // Stores to swizzled values are not directly supported,
+            // lower them as series of per-component stores.
+            let size = match size {
+                VectorSize::Bi => 2,
+                VectorSize::Tri => 3,
+                VectorSize::Quad => 4,
+            };
+
+            if let Expression::Load { pointer } = self.expressions[vector] {
+                vector = pointer;
+            }
+
+            #[allow(clippy::needless_range_loop)]
+            for index in 0..size {
+                let dst = self.add_expression(
+                    Expression::AccessIndex {
+                        base: vector,
+                        index: pattern[index].index(),
+                    },
+                    meta,
+                )?;
+                let src = self.add_expression(
+                    Expression::AccessIndex {
+                        base: value,
+                        index: index as u32,
+                    },
+                    meta,
+                )?;
+
+                self.emit_restart();
+
+                self.body.push(
+                    Statement::Store {
+                        pointer: dst,
+                        value: src,
+                    },
+                    meta,
+                );
+            }
+        } else {
+            self.emit_restart();
+
+            self.body.push(Statement::Store { pointer, value }, meta);
+        }
+
+        Ok(())
+    }
+
+    /// Internal implementation of [`lower`](Self::lower)
+    fn lower_inner(
+        &mut self,
+        stmt: &StmtContext,
+        frontend: &mut Frontend,
+        expr: Handle<HirExpr>,
+        pos: ExprPos,
+    ) -> Result<(Option<Handle<Expression>>, Span)> {
+        let HirExpr { ref kind, meta } = stmt.hir_exprs[expr];
+
+        log::debug!("Lowering {:?} (kind {:?}, pos {:?})", expr, kind, pos);
+
+        let handle = match *kind {
+            HirExprKind::Access { base, index } => {
+                let (index, _) = self.lower_expect_inner(stmt, frontend, index, ExprPos::Rhs)?;
+                let maybe_constant_index = match pos {
+                    // Don't try to generate `AccessIndex` if in a LHS position, since it
+                    // wouldn't produce a pointer.
+                    ExprPos::Lhs => None,
+                    _ => self
+                        .module
+                        .to_ctx()
+                        .eval_expr_to_u32_from(index, &self.expressions)
+                        .ok(),
+                };
+
+                let base = self
+                    .lower_expect_inner(
+                        stmt,
+                        frontend,
+                        base,
+                        pos.maybe_access_base(maybe_constant_index.is_some()),
+                    )?
+                    .0;
+
+                let pointer = maybe_constant_index
+                    .map(|index| self.add_expression(Expression::AccessIndex { base, index }, meta))
+                    .unwrap_or_else(|| {
+                        self.add_expression(Expression::Access { base, index }, meta)
+                    })?;
+
+                if ExprPos::Rhs == pos {
+                    let resolved = self.resolve_type(pointer, meta)?;
+                    if resolved.pointer_space().is_some() {
+                        return Ok((
+                            Some(self.add_expression(Expression::Load { pointer }, meta)?),
+                            meta,
+                        ));
+                    }
+                }
+
+                pointer
+            }
+            HirExprKind::Select { base, ref field } => {
+                let base = self.lower_expect_inner(stmt, frontend, base, pos)?.0;
+
+                frontend.field_selection(self, pos, base, field, meta)?
+            }
+            HirExprKind::Literal(literal) if pos != ExprPos::Lhs => {
+                self.add_expression(Expression::Literal(literal), meta)?
+            }
+            HirExprKind::Binary { left, op, right } if pos != ExprPos::Lhs => {
+                let (mut left, left_meta) =
+                    self.lower_expect_inner(stmt, frontend, left, ExprPos::Rhs)?;
+                let (mut right, right_meta) =
+                    self.lower_expect_inner(stmt, frontend, right, ExprPos::Rhs)?;
+
+                match op {
+                    BinaryOperator::ShiftLeft | BinaryOperator::ShiftRight => {
+                        self.implicit_conversion(&mut right, right_meta, Scalar::U32)?
+                    }
+                    _ => self
+                        .binary_implicit_conversion(&mut left, left_meta, &mut right, right_meta)?,
+                }
+
+                self.typifier_grow(left, left_meta)?;
+                self.typifier_grow(right, right_meta)?;
+
+                let left_inner = self.get_type(left);
+                let right_inner = self.get_type(right);
+
+                match (left_inner, right_inner) {
+                    (
+                        &TypeInner::Matrix {
+                            columns: left_columns,
+                            rows: left_rows,
+                            scalar: left_scalar,
+                        },
+                        &TypeInner::Matrix {
+                            columns: right_columns,
+                            rows: right_rows,
+                            scalar: right_scalar,
+                        },
+                    ) => {
+                        let dimensions_ok = if op == BinaryOperator::Multiply {
+                            left_columns == right_rows
+                        } else {
+                            left_columns == right_columns && left_rows == right_rows
+                        };
+
+                        // Check that the two arguments have the same dimensions
+                        if !dimensions_ok || left_scalar != right_scalar {
+                            frontend.errors.push(Error {
+                                kind: ErrorKind::SemanticError(
+                                    format!(
+                                        "Cannot apply operation to {left_inner:?} and {right_inner:?}"
+                                    )
+                                    .into(),
+                                ),
+                                meta,
+                            })
+                        }
+
+                        match op {
+                            BinaryOperator::Divide => {
+                                // Naga IR doesn't support matrix division so we need to
+                                // divide the columns individually and reassemble the matrix
+                                let mut components = Vec::with_capacity(left_columns as usize);
+
+                                for index in 0..left_columns as u32 {
+                                    // Get the column vectors
+                                    let left_vector = self.add_expression(
+                                        Expression::AccessIndex { base: left, index },
+                                        meta,
+                                    )?;
+                                    let right_vector = self.add_expression(
+                                        Expression::AccessIndex { base: right, index },
+                                        meta,
+                                    )?;
+
+                                    // Divide the vectors
+                                    let column = self.add_expression(
+                                        Expression::Binary {
+                                            op,
+                                            left: left_vector,
+                                            right: right_vector,
+                                        },
+                                        meta,
+                                    )?;
+
+                                    components.push(column)
+                                }
+
+                                let ty = self.module.types.insert(
+                                    Type {
+                                        name: None,
+                                        inner: TypeInner::Matrix {
+                                            columns: left_columns,
+                                            rows: left_rows,
+                                            scalar: left_scalar,
+                                        },
+                                    },
+                                    Span::default(),
+                                );
+
+                                // Rebuild the matrix from the divided vectors
+                                self.add_expression(Expression::Compose { ty, components }, meta)?
+                            }
+                            BinaryOperator::Equal | BinaryOperator::NotEqual => {
+                                // Naga IR doesn't support matrix comparisons so we need to
+                                // compare the columns individually and then fold them together
+                                //
+                                // The folding is done using a logical and for equality and
+                                // a logical or for inequality
+                                let equals = op == BinaryOperator::Equal;
+
+                                let (op, combine, fun) = match equals {
+                                    true => (
+                                        BinaryOperator::Equal,
+                                        BinaryOperator::LogicalAnd,
+                                        RelationalFunction::All,
+                                    ),
+                                    false => (
+                                        BinaryOperator::NotEqual,
+                                        BinaryOperator::LogicalOr,
+                                        RelationalFunction::Any,
+                                    ),
+                                };
+
+                                let mut root = None;
+
+                                for index in 0..left_columns as u32 {
+                                    // Get the column vectors
+                                    let left_vector = self.add_expression(
+                                        Expression::AccessIndex { base: left, index },
+                                        meta,
+                                    )?;
+                                    let right_vector = self.add_expression(
+                                        Expression::AccessIndex { base: right, index },
+                                        meta,
+                                    )?;
+
+                                    let argument = self.add_expression(
+                                        Expression::Binary {
+                                            op,
+                                            left: left_vector,
+                                            right: right_vector,
+                                        },
+                                        meta,
+                                    )?;
+
+                                    // The result of comparing two vectors is a boolean vector
+                                    // so use a relational function like all to get a single
+                                    // boolean value
+                                    let compare = self.add_expression(
+                                        Expression::Relational { fun, argument },
+                                        meta,
+                                    )?;
+
+                                    // Fold the result
+                                    root = Some(match root {
+                                        Some(right) => self.add_expression(
+                                            Expression::Binary {
+                                                op: combine,
+                                                left: compare,
+                                                right,
+                                            },
+                                            meta,
+                                        )?,
+                                        None => compare,
+                                    });
+                                }
+
+                                root.unwrap()
+                            }
+                            _ => {
+                                self.add_expression(Expression::Binary { left, op, right }, meta)?
+                            }
+                        }
+                    }
+                    (&TypeInner::Vector { .. }, &TypeInner::Vector { .. }) => match op {
+                        BinaryOperator::Equal | BinaryOperator::NotEqual => {
+                            let equals = op == BinaryOperator::Equal;
+
+                            let (op, fun) = match equals {
+                                true => (BinaryOperator::Equal, RelationalFunction::All),
+                                false => (BinaryOperator::NotEqual, RelationalFunction::Any),
+                            };
+
+                            let argument =
+                                self.add_expression(Expression::Binary { op, left, right }, meta)?;
+
+                            self.add_expression(Expression::Relational { fun, argument }, meta)?
+                        }
+                        _ => self.add_expression(Expression::Binary { left, op, right }, meta)?,
+                    },
+                    (&TypeInner::Vector { size, .. }, &TypeInner::Scalar { .. }) => match op {
+                        BinaryOperator::Add
+                        | BinaryOperator::Subtract
+                        | BinaryOperator::Divide
+                        | BinaryOperator::And
+                        | BinaryOperator::ExclusiveOr
+                        | BinaryOperator::InclusiveOr
+                        | BinaryOperator::ShiftLeft
+                        | BinaryOperator::ShiftRight => {
+                            let scalar_vector = self
+                                .add_expression(Expression::Splat { size, value: right }, meta)?;
+
+                            self.add_expression(
+                                Expression::Binary {
+                                    op,
+                                    left,
+                                    right: scalar_vector,
+                                },
+                                meta,
+                            )?
+                        }
+                        _ => self.add_expression(Expression::Binary { left, op, right }, meta)?,
+                    },
+                    (&TypeInner::Scalar { .. }, &TypeInner::Vector { size, .. }) => match op {
+                        BinaryOperator::Add
+                        | BinaryOperator::Subtract
+                        | BinaryOperator::Divide
+                        | BinaryOperator::And
+                        | BinaryOperator::ExclusiveOr
+                        | BinaryOperator::InclusiveOr => {
+                            let scalar_vector =
+                                self.add_expression(Expression::Splat { size, value: left }, meta)?;
+
+                            self.add_expression(
+                                Expression::Binary {
+                                    op,
+                                    left: scalar_vector,
+                                    right,
+                                },
+                                meta,
+                            )?
+                        }
+                        _ => self.add_expression(Expression::Binary { left, op, right }, meta)?,
+                    },
+                    (
+                        &TypeInner::Scalar(left_scalar),
+                        &TypeInner::Matrix {
+                            rows,
+                            columns,
+                            scalar: right_scalar,
+                        },
+                    ) => {
+                        // Check that the two arguments have the same scalar type
+                        if left_scalar != right_scalar {
+                            frontend.errors.push(Error {
+                                kind: ErrorKind::SemanticError(
+                                    format!(
+                                        "Cannot apply operation to {left_inner:?} and {right_inner:?}"
+                                    )
+                                    .into(),
+                                ),
+                                meta,
+                            })
+                        }
+
+                        match op {
+                            BinaryOperator::Divide
+                            | BinaryOperator::Add
+                            | BinaryOperator::Subtract => {
+                                // Naga IR doesn't support all matrix by scalar operations so
+                                // we need for some to turn the scalar into a vector by
+                                // splatting it and then for each column vector apply the
+                                // operation and finally reconstruct the matrix
+                                let scalar_vector = self.add_expression(
+                                    Expression::Splat {
+                                        size: rows,
+                                        value: left,
+                                    },
+                                    meta,
+                                )?;
+
+                                let mut components = Vec::with_capacity(columns as usize);
+
+                                for index in 0..columns as u32 {
+                                    // Get the column vector
+                                    let matrix_column = self.add_expression(
+                                        Expression::AccessIndex { base: right, index },
+                                        meta,
+                                    )?;
+
+                                    // Apply the operation to the splatted vector and
+                                    // the column vector
+                                    let column = self.add_expression(
+                                        Expression::Binary {
+                                            op,
+                                            left: scalar_vector,
+                                            right: matrix_column,
+                                        },
+                                        meta,
+                                    )?;
+
+                                    components.push(column)
+                                }
+
+                                let ty = self.module.types.insert(
+                                    Type {
+                                        name: None,
+                                        inner: TypeInner::Matrix {
+                                            columns,
+                                            rows,
+                                            scalar: left_scalar,
+                                        },
+                                    },
+                                    Span::default(),
+                                );
+
+                                // Rebuild the matrix from the operation result vectors
+                                self.add_expression(Expression::Compose { ty, components }, meta)?
+                            }
+                            _ => {
+                                self.add_expression(Expression::Binary { left, op, right }, meta)?
+                            }
+                        }
+                    }
+                    (
+                        &TypeInner::Matrix {
+                            rows,
+                            columns,
+                            scalar: left_scalar,
+                        },
+                        &TypeInner::Scalar(right_scalar),
+                    ) => {
+                        // Check that the two arguments have the same scalar type
+                        if left_scalar != right_scalar {
+                            frontend.errors.push(Error {
+                                kind: ErrorKind::SemanticError(
+                                    format!(
+                                        "Cannot apply operation to {left_inner:?} and {right_inner:?}"
+                                    )
+                                    .into(),
+                                ),
+                                meta,
+                            })
+                        }
+
+                        match op {
+                            BinaryOperator::Divide
+                            | BinaryOperator::Add
+                            | BinaryOperator::Subtract => {
+                                // Naga IR doesn't support all matrix by scalar operations so
+                                // we need for some to turn the scalar into a vector by
+                                // splatting it and then for each column vector apply the
+                                // operation and finally reconstruct the matrix
+
+                                let scalar_vector = self.add_expression(
+                                    Expression::Splat {
+                                        size: rows,
+                                        value: right,
+                                    },
+                                    meta,
+                                )?;
+
+                                let mut components = Vec::with_capacity(columns as usize);
+
+                                for index in 0..columns as u32 {
+                                    // Get the column vector
+                                    let matrix_column = self.add_expression(
+                                        Expression::AccessIndex { base: left, index },
+                                        meta,
+                                    )?;
+
+                                    // Apply the operation to the splatted vector and
+                                    // the column vector
+                                    let column = self.add_expression(
+                                        Expression::Binary {
+                                            op,
+                                            left: matrix_column,
+                                            right: scalar_vector,
+                                        },
+                                        meta,
+                                    )?;
+
+                                    components.push(column)
+                                }
+
+                                let ty = self.module.types.insert(
+                                    Type {
+                                        name: None,
+                                        inner: TypeInner::Matrix {
+                                            columns,
+                                            rows,
+                                            scalar: left_scalar,
+                                        },
+                                    },
+                                    Span::default(),
+                                );
+
+                                // Rebuild the matrix from the operation result vectors
+                                self.add_expression(Expression::Compose { ty, components }, meta)?
+                            }
+                            _ => {
+                                self.add_expression(Expression::Binary { left, op, right }, meta)?
+                            }
+                        }
+                    }
+                    _ => self.add_expression(Expression::Binary { left, op, right }, meta)?,
+                }
+            }
+            HirExprKind::Unary { op, expr } if pos != ExprPos::Lhs => {
+                let expr = self
+                    .lower_expect_inner(stmt, frontend, expr, ExprPos::Rhs)?
+                    .0;
+
+                self.add_expression(Expression::Unary { op, expr }, meta)?
+            }
+            HirExprKind::Variable(ref var) => match pos {
+                ExprPos::Lhs => {
+                    if !var.mutable {
+                        frontend.errors.push(Error {
+                            kind: ErrorKind::SemanticError(
+                                "Variable cannot be used in LHS position".into(),
+                            ),
+                            meta,
+                        })
+                    }
+
+                    var.expr
+                }
+                ExprPos::AccessBase { constant_index } => {
+                    // If the index isn't constant all accesses backed by a constant base need
+                    // to be done through a proxy local variable, since constants have a non
+                    // pointer type which is required for dynamic indexing
+                    if !constant_index {
+                        if let Some((constant, ty)) = var.constant {
+                            let init = self
+                                .add_expression(Expression::Constant(constant), Span::default())?;
+                            let local = self.locals.append(
+                                LocalVariable {
+                                    name: None,
+                                    ty,
+                                    init: Some(init),
+                                },
+                                Span::default(),
+                            );
+
+                            self.add_expression(Expression::LocalVariable(local), Span::default())?
+                        } else {
+                            var.expr
+                        }
+                    } else {
+                        var.expr
+                    }
+                }
+                _ if var.load => {
+                    self.add_expression(Expression::Load { pointer: var.expr }, meta)?
+                }
+                ExprPos::Rhs => {
+                    if let Some((constant, _)) = self.is_const.then_some(var.constant).flatten() {
+                        self.add_expression(Expression::Constant(constant), meta)?
+                    } else {
+                        var.expr
+                    }
+                }
+            },
+            HirExprKind::Call(ref call) if pos != ExprPos::Lhs => {
+                let maybe_expr = frontend.function_or_constructor_call(
+                    self,
+                    stmt,
+                    call.kind.clone(),
+                    &call.args,
+                    meta,
+                )?;
+                return Ok((maybe_expr, meta));
+            }
+            // `HirExprKind::Conditional` represents the ternary operator in glsl (`:?`)
+            //
+            // The ternary operator is defined to only evaluate one of the two possible
+            // expressions which means that it's behavior is that of an `if` statement,
+            // and it's merely syntactic sugar for it.
+            HirExprKind::Conditional {
+                condition,
+                accept,
+                reject,
+            } if ExprPos::Lhs != pos => {
+                // Given an expression `a ? b : c`, we need to produce a Naga
+                // statement roughly like:
+                //
+                //     var temp;
+                //     if a {
+                //         temp = convert(b);
+                //     } else  {
+                //         temp = convert(c);
+                //     }
+                //
+                // where `convert` stands for type conversions to bring `b` and `c` to
+                // the same type, and then use `temp` to represent the value of the whole
+                // conditional expression in subsequent code.
+
+                // Lower the condition first to the current bodyy
+                let condition = self
+                    .lower_expect_inner(stmt, frontend, condition, ExprPos::Rhs)?
+                    .0;
+
+                let (mut accept_body, (mut accept, accept_meta)) =
+                    self.new_body_with_ret(|ctx| {
+                        // Lower the `true` branch
+                        ctx.lower_expect_inner(stmt, frontend, accept, pos)
+                    })?;
+
+                let (mut reject_body, (mut reject, reject_meta)) =
+                    self.new_body_with_ret(|ctx| {
+                        // Lower the `false` branch
+                        ctx.lower_expect_inner(stmt, frontend, reject, pos)
+                    })?;
+
+                // We need to do some custom implicit conversions since the two target expressions
+                // are in different bodies
+                if let (Some((accept_power, accept_scalar)), Some((reject_power, reject_scalar))) = (
+                    // Get the components of both branches and calculate the type power
+                    self.expr_scalar_components(accept, accept_meta)?
+                        .and_then(|scalar| Some((type_power(scalar)?, scalar))),
+                    self.expr_scalar_components(reject, reject_meta)?
+                        .and_then(|scalar| Some((type_power(scalar)?, scalar))),
+                ) {
+                    match accept_power.cmp(&reject_power) {
+                        std::cmp::Ordering::Less => {
+                            accept_body = self.with_body(accept_body, |ctx| {
+                                ctx.conversion(&mut accept, accept_meta, reject_scalar)?;
+                                Ok(())
+                            })?;
+                        }
+                        std::cmp::Ordering::Equal => {}
+                        std::cmp::Ordering::Greater => {
+                            reject_body = self.with_body(reject_body, |ctx| {
+                                ctx.conversion(&mut reject, reject_meta, accept_scalar)?;
+                                Ok(())
+                            })?;
+                        }
+                    }
+                }
+
+                // We need to get the type of the resulting expression to create the local,
+                // this must be done after implicit conversions to ensure both branches have
+                // the same type.
+                let ty = self.resolve_type_handle(accept, accept_meta)?;
+
+                // Add the local that will hold the result of our conditional
+                let local = self.locals.append(
+                    LocalVariable {
+                        name: None,
+                        ty,
+                        init: None,
+                    },
+                    meta,
+                );
+
+                let local_expr = self.add_expression(Expression::LocalVariable(local), meta)?;
+
+                // Add to each  the store to the result variable
+                accept_body.push(
+                    Statement::Store {
+                        pointer: local_expr,
+                        value: accept,
+                    },
+                    accept_meta,
+                );
+                reject_body.push(
+                    Statement::Store {
+                        pointer: local_expr,
+                        value: reject,
+                    },
+                    reject_meta,
+                );
+
+                // Finally add the `If` to the main body with the `condition` we lowered
+                // earlier and the branches we prepared.
+                self.body.push(
+                    Statement::If {
+                        condition,
+                        accept: accept_body,
+                        reject: reject_body,
+                    },
+                    meta,
+                );
+
+                // Note: `Expression::Load` must be emitted before it's used so make
+                // sure the emitter is active here.
+                self.add_expression(
+                    Expression::Load {
+                        pointer: local_expr,
+                    },
+                    meta,
+                )?
+            }
+            HirExprKind::Assign { tgt, value } if ExprPos::Lhs != pos => {
+                let (pointer, ptr_meta) =
+                    self.lower_expect_inner(stmt, frontend, tgt, ExprPos::Lhs)?;
+                let (mut value, value_meta) =
+                    self.lower_expect_inner(stmt, frontend, value, ExprPos::Rhs)?;
+
+                let ty = match *self.resolve_type(pointer, ptr_meta)? {
+                    TypeInner::Pointer { base, .. } => &self.module.types[base].inner,
+                    ref ty => ty,
+                };
+
+                if let Some(scalar) = scalar_components(ty) {
+                    self.implicit_conversion(&mut value, value_meta, scalar)?;
+                }
+
+                self.lower_store(pointer, value, meta)?;
+
+                value
+            }
+            HirExprKind::PrePostfix { op, postfix, expr } if ExprPos::Lhs != pos => {
+                let (pointer, _) = self.lower_expect_inner(stmt, frontend, expr, ExprPos::Lhs)?;
+                let left = if let Expression::Swizzle { .. } = self.expressions[pointer] {
+                    pointer
+                } else {
+                    self.add_expression(Expression::Load { pointer }, meta)?
+                };
+
+                let res = match *self.resolve_type(left, meta)? {
+                    TypeInner::Scalar(scalar) => {
+                        let ty = TypeInner::Scalar(scalar);
+                        Literal::one(scalar).map(|i| (ty, i, None, None))
+                    }
+                    TypeInner::Vector { size, scalar } => {
+                        let ty = TypeInner::Vector { size, scalar };
+                        Literal::one(scalar).map(|i| (ty, i, Some(size), None))
+                    }
+                    TypeInner::Matrix {
+                        columns,
+                        rows,
+                        scalar,
+                    } => {
+                        let ty = TypeInner::Matrix {
+                            columns,
+                            rows,
+                            scalar,
+                        };
+                        Literal::one(scalar).map(|i| (ty, i, Some(rows), Some(columns)))
+                    }
+                    _ => None,
+                };
+                let (ty_inner, literal, rows, columns) = match res {
+                    Some(res) => res,
+                    None => {
+                        frontend.errors.push(Error {
+                            kind: ErrorKind::SemanticError(
+                                "Increment/decrement only works on scalar/vector/matrix".into(),
+                            ),
+                            meta,
+                        });
+                        return Ok((Some(left), meta));
+                    }
+                };
+
+                let mut right = self.add_expression(Expression::Literal(literal), meta)?;
+
+                // Glsl allows pre/postfixes operations on vectors and matrices, so if the
+                // target is either of them change the right side of the addition to be splatted
+                // to the same size as the target, furthermore if the target is a matrix
+                // use a composed matrix using the splatted value.
+                if let Some(size) = rows {
+                    right = self.add_expression(Expression::Splat { size, value: right }, meta)?;
+
+                    if let Some(cols) = columns {
+                        let ty = self.module.types.insert(
+                            Type {
+                                name: None,
+                                inner: ty_inner,
+                            },
+                            meta,
+                        );
+
+                        right = self.add_expression(
+                            Expression::Compose {
+                                ty,
+                                components: std::iter::repeat(right).take(cols as usize).collect(),
+                            },
+                            meta,
+                        )?;
+                    }
+                }
+
+                let value = self.add_expression(Expression::Binary { op, left, right }, meta)?;
+
+                self.lower_store(pointer, value, meta)?;
+
+                if postfix {
+                    left
+                } else {
+                    value
+                }
+            }
+            HirExprKind::Method {
+                expr: object,
+                ref name,
+                ref args,
+            } if ExprPos::Lhs != pos => {
+                let args = args
+                    .iter()
+                    .map(|e| self.lower_expect_inner(stmt, frontend, *e, ExprPos::Rhs))
+                    .collect::<Result<Vec<_>>>()?;
+                match name.as_ref() {
+                    "length" => {
+                        if !args.is_empty() {
+                            frontend.errors.push(Error {
+                                kind: ErrorKind::SemanticError(
+                                    ".length() doesn't take any arguments".into(),
+                                ),
+                                meta,
+                            });
+                        }
+                        let lowered_array = self.lower_expect_inner(stmt, frontend, object, pos)?.0;
+                        let array_type = self.resolve_type(lowered_array, meta)?;
+
+                        match *array_type {
+                            TypeInner::Array {
+                                size: crate::ArraySize::Constant(size),
+                                ..
+                            } => {
+                                let mut array_length = self.add_expression(
+                                    Expression::Literal(Literal::U32(size.get())),
+                                    meta,
+                                )?;
+                                self.forced_conversion(&mut array_length, meta, Scalar::I32)?;
+                                array_length
+                            }
+                            // let the error be handled in type checking if it's not a dynamic array
+                            _ => {
+                                let mut array_length = self
+                                    .add_expression(Expression::ArrayLength(lowered_array), meta)?;
+                                self.conversion(&mut array_length, meta, Scalar::I32)?;
+                                array_length
+                            }
+                        }
+                    }
+                    _ => {
+                        return Err(Error {
+                            kind: ErrorKind::SemanticError(
+                                format!("unknown method '{name}'").into(),
+                            ),
+                            meta,
+                        });
+                    }
+                }
+            }
+            _ => {
+                return Err(Error {
+                    kind: ErrorKind::SemanticError(
+                        format!("{:?} cannot be in the left hand side", stmt.hir_exprs[expr])
+                            .into(),
+                    ),
+                    meta,
+                })
+            }
+        };
+
+        log::trace!(
+            "Lowered {:?}\n\tKind = {:?}\n\tPos = {:?}\n\tResult = {:?}",
+            expr,
+            kind,
+            pos,
+            handle
+        );
+
+        Ok((Some(handle), meta))
+    }
+
+    pub fn expr_scalar_components(
+        &mut self,
+        expr: Handle<Expression>,
+        meta: Span,
+    ) -> Result<Option<Scalar>> {
+        let ty = self.resolve_type(expr, meta)?;
+        Ok(scalar_components(ty))
+    }
+
+    pub fn expr_power(&mut self, expr: Handle<Expression>, meta: Span) -> Result<Option<u32>> {
+        Ok(self
+            .expr_scalar_components(expr, meta)?
+            .and_then(type_power))
+    }
+
+    pub fn conversion(
+        &mut self,
+        expr: &mut Handle<Expression>,
+        meta: Span,
+        scalar: Scalar,
+    ) -> Result<()> {
+        *expr = self.add_expression(
+            Expression::As {
+                expr: *expr,
+                kind: scalar.kind,
+                convert: Some(scalar.width),
+            },
+            meta,
+        )?;
+
+        Ok(())
+    }
+
+    pub fn implicit_conversion(
+        &mut self,
+        expr: &mut Handle<Expression>,
+        meta: Span,
+        scalar: Scalar,
+    ) -> Result<()> {
+        if let (Some(tgt_power), Some(expr_power)) =
+            (type_power(scalar), self.expr_power(*expr, meta)?)
+        {
+            if tgt_power > expr_power {
+                self.conversion(expr, meta, scalar)?;
+            }
+        }
+
+        Ok(())
+    }
+
+    pub fn forced_conversion(
+        &mut self,
+        expr: &mut Handle<Expression>,
+        meta: Span,
+        scalar: Scalar,
+    ) -> Result<()> {
+        if let Some(expr_scalar) = self.expr_scalar_components(*expr, meta)? {
+            if expr_scalar != scalar {
+                self.conversion(expr, meta, scalar)?;
+            }
+        }
+
+        Ok(())
+    }
+
+    pub fn binary_implicit_conversion(
+        &mut self,
+        left: &mut Handle<Expression>,
+        left_meta: Span,
+        right: &mut Handle<Expression>,
+        right_meta: Span,
+    ) -> Result<()> {
+        let left_components = self.expr_scalar_components(*left, left_meta)?;
+        let right_components = self.expr_scalar_components(*right, right_meta)?;
+
+        if let (Some((left_power, left_scalar)), Some((right_power, right_scalar))) = (
+            left_components.and_then(|scalar| Some((type_power(scalar)?, scalar))),
+            right_components.and_then(|scalar| Some((type_power(scalar)?, scalar))),
+        ) {
+            match left_power.cmp(&right_power) {
+                std::cmp::Ordering::Less => {
+                    self.conversion(left, left_meta, right_scalar)?;
+                }
+                std::cmp::Ordering::Equal => {}
+                std::cmp::Ordering::Greater => {
+                    self.conversion(right, right_meta, left_scalar)?;
+                }
+            }
+        }
+
+        Ok(())
+    }
+
+    pub fn implicit_splat(
+        &mut self,
+        expr: &mut Handle<Expression>,
+        meta: Span,
+        vector_size: Option<VectorSize>,
+    ) -> Result<()> {
+        let expr_type = self.resolve_type(*expr, meta)?;
+
+        if let (&TypeInner::Scalar { .. }, Some(size)) = (expr_type, vector_size) {
+            *expr = self.add_expression(Expression::Splat { size, value: *expr }, meta)?
+        }
+
+        Ok(())
+    }
+
+    pub fn vector_resize(
+        &mut self,
+        size: VectorSize,
+        vector: Handle<Expression>,
+        meta: Span,
+    ) -> Result<Handle<Expression>> {
+        self.add_expression(
+            Expression::Swizzle {
+                size,
+                vector,
+                pattern: crate::SwizzleComponent::XYZW,
+            },
+            meta,
+        )
+    }
+}
+
+impl Index<Handle<Expression>> for Context<'_> {
+    type Output = Expression;
+
+    fn index(&self, index: Handle<Expression>) -> &Self::Output {
+        if self.is_const {
+            &self.module.const_expressions[index]
+        } else {
+            &self.expressions[index]
+        }
+    }
+}
+
+/// Helper struct passed when parsing expressions
+///
+/// This struct should only be obtained through [`stmt_ctx`](Context::stmt_ctx)
+/// and only one of these may be active at any time per context.
+#[derive(Debug)]
+pub struct StmtContext {
+    /// A arena of high level expressions which can be lowered through a
+    /// [`Context`] to Naga's [`Expression`]s
+    pub hir_exprs: Arena<HirExpr>,
+}
+
+impl StmtContext {
+    const fn new() -> Self {
+        StmtContext {
+            hir_exprs: Arena::new(),
+        }
+    }
+}
diff --git a/third_party/rust/naga/src/front/glsl/error.rs b/third_party/rust/naga/src/front/glsl/error.rs
new file mode 100644
index 0000000000..bd16ee30bc
--- /dev/null
+++ b/third_party/rust/naga/src/front/glsl/error.rs
@@ -0,0 +1,191 @@
+use super::token::TokenValue;
+use crate::{proc::ConstantEvaluatorError, Span};
+use codespan_reporting::diagnostic::{Diagnostic, Label};
+use codespan_reporting::files::SimpleFile;
+use codespan_reporting::term;
+use pp_rs::token::PreprocessorError;
+use std::borrow::Cow;
+use termcolor::{NoColor, WriteColor};
+use thiserror::Error;
+
+fn join_with_comma(list: &[ExpectedToken]) -> String {
+    let mut string = "".to_string();
+    for (i, val) in list.iter().enumerate() {
+        string.push_str(&val.to_string());
+        match i {
+            i if i == list.len() - 1 => {}
+            i if i == list.len() - 2 => string.push_str(" or "),
+            _ => string.push_str(", "),
+        }
+    }
+    string
+}
+
+/// One of the expected tokens returned in [`InvalidToken`](ErrorKind::InvalidToken).
+#[derive(Clone, Debug, PartialEq)]
+pub enum ExpectedToken {
+    /// A specific token was expected.
+    Token(TokenValue),
+    /// A type was expected.
+    TypeName,
+    /// An identifier was expected.
+    Identifier,
+    /// An integer literal was expected.
+    IntLiteral,
+    /// A float literal was expected.
+    FloatLiteral,
+    /// A boolean literal was expected.
+    BoolLiteral,
+    /// The end of file was expected.
+    Eof,
+}
+impl From<TokenValue> for ExpectedToken {
+    fn from(token: TokenValue) -> Self {
+        ExpectedToken::Token(token)
+    }
+}
+impl std::fmt::Display for ExpectedToken {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match *self {
+            ExpectedToken::Token(ref token) => write!(f, "{token:?}"),
+            ExpectedToken::TypeName => write!(f, "a type"),
+            ExpectedToken::Identifier => write!(f, "identifier"),
+            ExpectedToken::IntLiteral => write!(f, "integer literal"),
+            ExpectedToken::FloatLiteral => write!(f, "float literal"),
+            ExpectedToken::BoolLiteral => write!(f, "bool literal"),
+            ExpectedToken::Eof => write!(f, "end of file"),
+        }
+    }
+}
+
+/// Information about the cause of an error.
+#[derive(Clone, Debug, Error)]
+#[cfg_attr(test, derive(PartialEq))]
+pub enum ErrorKind {
+    /// Whilst parsing as encountered an unexpected EOF.
+    #[error("Unexpected end of file")]
+    EndOfFile,
+    /// The shader specified an unsupported or invalid profile.
+    #[error("Invalid profile: {0}")]
+    InvalidProfile(String),
+    /// The shader requested an unsupported or invalid version.
+    #[error("Invalid version: {0}")]
+    InvalidVersion(u64),
+    /// Whilst parsing an unexpected token was encountered.
+    ///
+    /// A list of expected tokens is also returned.
+    #[error("Expected {}, found {0:?}", join_with_comma(.1))]
+    InvalidToken(TokenValue, Vec<ExpectedToken>),
+    /// A specific feature is not yet implemented.
+    ///
+    /// To help prioritize work please open an issue in the github issue tracker
+    /// if none exist already or react to the already existing one.
+    #[error("Not implemented: {0}")]
+    NotImplemented(&'static str),
+    /// A reference to a variable that wasn't declared was used.
+    #[error("Unknown variable: {0}")]
+    UnknownVariable(String),
+    /// A reference to a type that wasn't declared was used.
+    #[error("Unknown type: {0}")]
+    UnknownType(String),
+    /// A reference to a non existent member of a type was made.
+    #[error("Unknown field: {0}")]
+    UnknownField(String),
+    /// An unknown layout qualifier was used.
+    ///
+    /// If the qualifier does exist please open an issue in the github issue tracker
+    /// if none exist already or react to the already existing one to help
+    /// prioritize work.
+    #[error("Unknown layout qualifier: {0}")]
+    UnknownLayoutQualifier(String),
+    /// Unsupported matrix of the form matCx2
+    ///
+    /// Our IR expects matrices of the form matCx2 to have a stride of 8 however
+    /// matrices in the std140 layout have a stride of at least 16
+    #[error("unsupported matrix of the form matCx2 in std140 block layout")]
+    UnsupportedMatrixTypeInStd140,
+    /// A variable with the same name already exists in the current scope.
+    #[error("Variable already declared: {0}")]
+    VariableAlreadyDeclared(String),
+    /// A semantic error was detected in the shader.
+    #[error("{0}")]
+    SemanticError(Cow<'static, str>),
+    /// An error was returned by the preprocessor.
+    #[error("{0:?}")]
+    PreprocessorError(PreprocessorError),
+    /// The parser entered an illegal state and exited
+    ///
+    /// This obviously is a bug and as such should be reported in the github issue tracker
+    #[error("Internal error: {0}")]
+    InternalError(&'static str),
+}
+
+impl From<ConstantEvaluatorError> for ErrorKind {
+    fn from(err: ConstantEvaluatorError) -> Self {
+        ErrorKind::SemanticError(err.to_string().into())
+    }
+}
+
+/// Error returned during shader parsing.
+#[derive(Clone, Debug, Error)]
+#[error("{kind}")]
+#[cfg_attr(test, derive(PartialEq))]
+pub struct Error {
+    /// Holds the information about the error itself.
+    pub kind: ErrorKind,
+    /// Holds information about the range of the source code where the error happened.
+    pub meta: Span,
+}
+
+/// A collection of errors returned during shader parsing.
+#[derive(Clone, Debug)]
+#[cfg_attr(test, derive(PartialEq))]
+pub struct ParseError {
+    pub errors: Vec<Error>,
+}
+
+impl ParseError {
+    pub fn emit_to_writer(&self, writer: &mut impl WriteColor, source: &str) {
+        self.emit_to_writer_with_path(writer, source, "glsl");
+    }
+
+    pub fn emit_to_writer_with_path(&self, writer: &mut impl WriteColor, source: &str, path: &str) {
+        let path = path.to_string();
+        let files = SimpleFile::new(path, source);
+        let config = codespan_reporting::term::Config::default();
+
+        for err in &self.errors {
+            let mut diagnostic = Diagnostic::error().with_message(err.kind.to_string());
+
+            if let Some(range) = err.meta.to_range() {
+                diagnostic = diagnostic.with_labels(vec![Label::primary((), range)]);
+            }
+
+            term::emit(writer, &config, &files, &diagnostic).expect("cannot write error");
+        }
+    }
+
+    pub fn emit_to_string(&self, source: &str) -> String {
+        let mut writer = NoColor::new(Vec::new());
+        self.emit_to_writer(&mut writer, source);
+        String::from_utf8(writer.into_inner()).unwrap()
+    }
+}
+
+impl std::fmt::Display for ParseError {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        self.errors.iter().try_for_each(|e| write!(f, "{e:?}"))
+    }
+}
+
+impl std::error::Error for ParseError {
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+        None
+    }
+}
+
+impl From<Vec<Error>> for ParseError {
+    fn from(errors: Vec<Error>) -> Self {
+        Self { errors }
+    }
+}
diff --git a/third_party/rust/naga/src/front/glsl/functions.rs b/third_party/rust/naga/src/front/glsl/functions.rs
new file mode 100644
index 0000000000..df8cc8a30e
--- /dev/null
+++ b/third_party/rust/naga/src/front/glsl/functions.rs
@@ -0,0 +1,1602 @@
+use super::{
+    ast::*,
+    builtins::{inject_builtin, sampled_to_depth},
+    context::{Context, ExprPos, StmtContext},
+    error::{Error, ErrorKind},
+    types::scalar_components,
+    Frontend, Result,
+};
+use crate::{
+    front::glsl::types::type_power, proc::ensure_block_returns, AddressSpace, Block, EntryPoint,
+    Expression, Function, FunctionArgument, FunctionResult, Handle, Literal, LocalVariable, Scalar,
+    ScalarKind, Span, Statement, StructMember, Type, TypeInner,
+};
+use std::iter;
+
+/// Struct detailing a store operation that must happen after a function call
+struct ProxyWrite {
+    /// The store target
+    target: Handle<Expression>,
+    /// A pointer to read the value of the store
+    value: Handle<Expression>,
+    /// An optional conversion to be applied
+    convert: Option<Scalar>,
+}
+
+impl Frontend {
+    pub(crate) fn function_or_constructor_call(
+        &mut self,
+        ctx: &mut Context,
+        stmt: &StmtContext,
+        fc: FunctionCallKind,
+        raw_args: &[Handle<HirExpr>],
+        meta: Span,
+    ) -> Result<Option<Handle<Expression>>> {
+        let args: Vec<_> = raw_args
+            .iter()
+            .map(|e| ctx.lower_expect_inner(stmt, self, *e, ExprPos::Rhs))
+            .collect::<Result<_>>()?;
+
+        match fc {
+            FunctionCallKind::TypeConstructor(ty) => {
+                if args.len() == 1 {
+                    self.constructor_single(ctx, ty, args[0], meta).map(Some)
+                } else {
+                    self.constructor_many(ctx, ty, args, meta).map(Some)
+                }
+            }
+            FunctionCallKind::Function(name) => {
+                self.function_call(ctx, stmt, name, args, raw_args, meta)
+            }
+        }
+    }
+
+    fn constructor_single(
+        &mut self,
+        ctx: &mut Context,
+        ty: Handle<Type>,
+        (mut value, expr_meta): (Handle<Expression>, Span),
+        meta: Span,
+    ) -> Result<Handle<Expression>> {
+        let expr_type = ctx.resolve_type(value, expr_meta)?;
+
+        let vector_size = match *expr_type {
+            TypeInner::Vector { size, .. } => Some(size),
+            _ => None,
+        };
+
+        let expr_is_bool = expr_type.scalar_kind() == Some(ScalarKind::Bool);
+
+        // Special case: if casting from a bool, we need to use Select and not As.
+        match ctx.module.types[ty].inner.scalar() {
+            Some(result_scalar) if expr_is_bool && result_scalar.kind != ScalarKind::Bool => {
+                let result_scalar = Scalar {
+                    width: 4,
+                    ..result_scalar
+                };
+                let l0 = Literal::zero(result_scalar).unwrap();
+                let l1 = Literal::one(result_scalar).unwrap();
+                let mut reject = ctx.add_expression(Expression::Literal(l0), expr_meta)?;
+                let mut accept = ctx.add_expression(Expression::Literal(l1), expr_meta)?;
+
+                ctx.implicit_splat(&mut reject, meta, vector_size)?;
+                ctx.implicit_splat(&mut accept, meta, vector_size)?;
+
+                let h = ctx.add_expression(
+                    Expression::Select {
+                        accept,
+                        reject,
+                        condition: value,
+                    },
+                    expr_meta,
+                )?;
+
+                return Ok(h);
+            }
+            _ => {}
+        }
+
+        Ok(match ctx.module.types[ty].inner {
+            TypeInner::Vector { size, scalar } if vector_size.is_none() => {
+                ctx.forced_conversion(&mut value, expr_meta, scalar)?;
+
+                if let TypeInner::Scalar { .. } = *ctx.resolve_type(value, expr_meta)? {
+                    ctx.add_expression(Expression::Splat { size, value }, meta)?
+                } else {
+                    self.vector_constructor(ctx, ty, size, scalar, &[(value, expr_meta)], meta)?
+                }
+            }
+            TypeInner::Scalar(scalar) => {
+                let mut expr = value;
+                if let TypeInner::Vector { .. } | TypeInner::Matrix { .. } =
+                    *ctx.resolve_type(value, expr_meta)?
+                {
+                    expr = ctx.add_expression(
+                        Expression::AccessIndex {
+                            base: expr,
+                            index: 0,
+                        },
+                        meta,
+                    )?;
+                }
+
+                if let TypeInner::Matrix { .. } = *ctx.resolve_type(value, expr_meta)? {
+                    expr = ctx.add_expression(
+                        Expression::AccessIndex {
+                            base: expr,
+                            index: 0,
+                        },
+                        meta,
+                    )?;
+                }
+
+                ctx.add_expression(
+                    Expression::As {
+                        kind: scalar.kind,
+                        expr,
+                        convert: Some(scalar.width),
+                    },
+                    meta,
+                )?
+            }
+            TypeInner::Vector { size, scalar } => {
+                if vector_size.map_or(true, |s| s != size) {
+                    value = ctx.vector_resize(size, value, expr_meta)?;
+                }
+
+                ctx.add_expression(
+                    Expression::As {
+                        kind: scalar.kind,
+                        expr: value,
+                        convert: Some(scalar.width),
+                    },
+                    meta,
+                )?
+            }
+            TypeInner::Matrix {
+                columns,
+                rows,
+                scalar,
+            } => self.matrix_one_arg(ctx, ty, columns, rows, scalar, (value, expr_meta), meta)?,
+            TypeInner::Struct { ref members, .. } => {
+                let scalar_components = members
+                    .get(0)
+                    .and_then(|member| scalar_components(&ctx.module.types[member.ty].inner));
+                if let Some(scalar) = scalar_components {
+                    ctx.implicit_conversion(&mut value, expr_meta, scalar)?;
+                }
+
+                ctx.add_expression(
+                    Expression::Compose {
+                        ty,
+                        components: vec![value],
+                    },
+                    meta,
+                )?
+            }
+
+            TypeInner::Array { base, .. } => {
+                let scalar_components = scalar_components(&ctx.module.types[base].inner);
+                if let Some(scalar) = scalar_components {
+                    ctx.implicit_conversion(&mut value, expr_meta, scalar)?;
+                }
+
+                ctx.add_expression(
+                    Expression::Compose {
+                        ty,
+                        components: vec![value],
+                    },
+                    meta,
+                )?
+            }
+            _ => {
+                self.errors.push(Error {
+                    kind: ErrorKind::SemanticError("Bad type constructor".into()),
+                    meta,
+                });
+
+                value
+            }
+        })
+    }
+
+    #[allow(clippy::too_many_arguments)]
+    fn matrix_one_arg(
+        &mut self,
+        ctx: &mut Context,
+        ty: Handle<Type>,
+        columns: crate::VectorSize,
+        rows: crate::VectorSize,
+        element_scalar: Scalar,
+        (mut value, expr_meta): (Handle<Expression>, Span),
+        meta: Span,
+    ) -> Result<Handle<Expression>> {
+        let mut components = Vec::with_capacity(columns as usize);
+        // TODO: casts
+        // `Expression::As` doesn't support matrix width
+        // casts so we need to do some extra work for casts
+
+        ctx.forced_conversion(&mut value, expr_meta, element_scalar)?;
+        match *ctx.resolve_type(value, expr_meta)? {
+            TypeInner::Scalar(_) => {
+                // If a matrix is constructed with a single scalar value, then that
+                // value is used to initialize all the values along the diagonal of
+                // the matrix; the rest are given zeros.
+                let vector_ty = ctx.module.types.insert(
+                    Type {
+                        name: None,
+                        inner: TypeInner::Vector {
+                            size: rows,
+                            scalar: element_scalar,
+                        },
+                    },
+                    meta,
+                );
+
+                let zero_literal = Literal::zero(element_scalar).unwrap();
+                let zero = ctx.add_expression(Expression::Literal(zero_literal), meta)?;
+
+                for i in 0..columns as u32 {
+                    components.push(
+                        ctx.add_expression(
+                            Expression::Compose {
+                                ty: vector_ty,
+                                components: (0..rows as u32)
+                                    .map(|r| match r == i {
+                                        true => value,
+                                        false => zero,
+                                    })
+                                    .collect(),
+                            },
+                            meta,
+                        )?,
+                    )
+                }
+            }
+            TypeInner::Matrix {
+                rows: ori_rows,
+                columns: ori_cols,
+                ..
+            } => {
+                // If a matrix is constructed from a matrix, then each component
+                // (column i, row j) in the result that has a corresponding component
+                // (column i, row j) in the argument will be initialized from there. All
+                // other components will be initialized to the identity matrix.
+
+                let zero_literal = Literal::zero(element_scalar).unwrap();
+                let one_literal = Literal::one(element_scalar).unwrap();
+
+                let zero = ctx.add_expression(Expression::Literal(zero_literal), meta)?;
+                let one = ctx.add_expression(Expression::Literal(one_literal), meta)?;
+
+                let vector_ty = ctx.module.types.insert(
+                    Type {
+                        name: None,
+                        inner: TypeInner::Vector {
+                            size: rows,
+                            scalar: element_scalar,
+                        },
+                    },
+                    meta,
+                );
+
+                for i in 0..columns as u32 {
+                    if i < ori_cols as u32 {
+                        use std::cmp::Ordering;
+
+                        let vector = ctx.add_expression(
+                            Expression::AccessIndex {
+                                base: value,
+                                index: i,
+                            },
+                            meta,
+                        )?;
+
+                        components.push(match ori_rows.cmp(&rows) {
+                            Ordering::Less => {
+                                let components = (0..rows as u32)
+                                    .map(|r| {
+                                        if r < ori_rows as u32 {
+                                            ctx.add_expression(
+                                                Expression::AccessIndex {
+                                                    base: vector,
+                                                    index: r,
+                                                },
+                                                meta,
+                                            )
+                                        } else if r == i {
+                                            Ok(one)
+                                        } else {
+                                            Ok(zero)
+                                        }
+                                    })
+                                    .collect::<Result<_>>()?;
+
+                                ctx.add_expression(
+                                    Expression::Compose {
+                                        ty: vector_ty,
+                                        components,
+                                    },
+                                    meta,
+                                )?
+                            }
+                            Ordering::Equal => vector,
+                            Ordering::Greater => ctx.vector_resize(rows, vector, meta)?,
+                        })
+                    } else {
+                        let compose_expr = Expression::Compose {
+                            ty: vector_ty,
+                            components: (0..rows as u32)
+                                .map(|r| match r == i {
+                                    true => one,
+                                    false => zero,
+                                })
+                                .collect(),
+                        };
+
+                        let vec = ctx.add_expression(compose_expr, meta)?;
+
+                        components.push(vec)
+                    }
+                }
+            }
+            _ => {
+                components = iter::repeat(value).take(columns as usize).collect();
+            }
+        }
+
+        ctx.add_expression(Expression::Compose { ty, components }, meta)
+    }
+
+    #[allow(clippy::too_many_arguments)]
+    fn vector_constructor(
+        &mut self,
+        ctx: &mut Context,
+        ty: Handle<Type>,
+        size: crate::VectorSize,
+        scalar: Scalar,
+        args: &[(Handle<Expression>, Span)],
+        meta: Span,
+    ) -> Result<Handle<Expression>> {
+        let mut components = Vec::with_capacity(size as usize);
+
+        for (mut arg, expr_meta) in args.iter().copied() {
+            ctx.forced_conversion(&mut arg, expr_meta, scalar)?;
+
+            if components.len() >= size as usize {
+                break;
+            }
+
+            match *ctx.resolve_type(arg, expr_meta)? {
+                TypeInner::Scalar { .. } => components.push(arg),
+                TypeInner::Matrix { rows, columns, .. } => {
+                    components.reserve(rows as usize * columns as usize);
+                    for c in 0..(columns as u32) {
+                        let base = ctx.add_expression(
+                            Expression::AccessIndex {
+                                base: arg,
+                                index: c,
+                            },
+                            expr_meta,
+                        )?;
+                        for r in 0..(rows as u32) {
+                            components.push(ctx.add_expression(
+                                Expression::AccessIndex { base, index: r },
+                                expr_meta,
+                            )?)
+                        }
+                    }
+                }
+                TypeInner::Vector { size: ori_size, .. } => {
+                    components.reserve(ori_size as usize);
+                    for index in 0..(ori_size as u32) {
+                        components.push(ctx.add_expression(
+                            Expression::AccessIndex { base: arg, index },
+                            expr_meta,
+                        )?)
+                    }
+                }
+                _ => components.push(arg),
+            }
+        }
+
+        components.truncate(size as usize);
+
+        ctx.add_expression(Expression::Compose { ty, components }, meta)
+    }
+
+    fn constructor_many(
+        &mut self,
+        ctx: &mut Context,
+        ty: Handle<Type>,
+        args: Vec<(Handle<Expression>, Span)>,
+        meta: Span,
+    ) -> Result<Handle<Expression>> {
+        let mut components = Vec::with_capacity(args.len());
+
+        let struct_member_data = match ctx.module.types[ty].inner {
+            TypeInner::Matrix {
+                columns,
+                rows,
+                scalar: element_scalar,
+            } => {
+                let mut flattened = Vec::with_capacity(columns as usize * rows as usize);
+
+                for (mut arg, meta) in args.iter().copied() {
+                    ctx.forced_conversion(&mut arg, meta, element_scalar)?;
+
+                    match *ctx.resolve_type(arg, meta)? {
+                        TypeInner::Vector { size, .. } => {
+                            for i in 0..(size as u32) {
+                                flattened.push(ctx.add_expression(
+                                    Expression::AccessIndex {
+                                        base: arg,
+                                        index: i,
+                                    },
+                                    meta,
+                                )?)
+                            }
+                        }
+                        _ => flattened.push(arg),
+                    }
+                }
+
+                let ty = ctx.module.types.insert(
+                    Type {
+                        name: None,
+                        inner: TypeInner::Vector {
+                            size: rows,
+                            scalar: element_scalar,
+                        },
+                    },
+                    meta,
+                );
+
+                for chunk in flattened.chunks(rows as usize) {
+                    components.push(ctx.add_expression(
+                        Expression::Compose {
+                            ty,
+                            components: Vec::from(chunk),
+                        },
+                        meta,
+                    )?)
+                }
+                None
+            }
+            TypeInner::Vector { size, scalar } => {
+                return self.vector_constructor(ctx, ty, size, scalar, &args, meta)
+            }
+            TypeInner::Array { base, .. } => {
+                for (mut arg, meta) in args.iter().copied() {
+                    let scalar_components = scalar_components(&ctx.module.types[base].inner);
+                    if let Some(scalar) = scalar_components {
+                        ctx.implicit_conversion(&mut arg, meta, scalar)?;
+                    }
+
+                    components.push(arg)
+                }
+                None
+            }
+            TypeInner::Struct { ref members, .. } => Some(
+                members
+                    .iter()
+                    .map(|member| scalar_components(&ctx.module.types[member.ty].inner))
+                    .collect::<Vec<_>>(),
+            ),
+            _ => {
+                return Err(Error {
+                    kind: ErrorKind::SemanticError("Constructor: Too many arguments".into()),
+                    meta,
+                })
+            }
+        };
+
+        if let Some(struct_member_data) = struct_member_data {
+            for ((mut arg, meta), scalar_components) in
+                args.iter().copied().zip(struct_member_data.iter().copied())
+            {
+                if let Some(scalar) = scalar_components {
+                    ctx.implicit_conversion(&mut arg, meta, scalar)?;
+                }
+
+                components.push(arg)
+            }
+        }
+
+        ctx.add_expression(Expression::Compose { ty, components }, meta)
+    }
+
+    #[allow(clippy::too_many_arguments)]
+    fn function_call(
+        &mut self,
+        ctx: &mut Context,
+        stmt: &StmtContext,
+        name: String,
+        args: Vec<(Handle<Expression>, Span)>,
+        raw_args: &[Handle<HirExpr>],
+        meta: Span,
+    ) -> Result<Option<Handle<Expression>>> {
+        // Grow the typifier to be able to index it later without needing
+        // to hold the context mutably
+        for &(expr, span) in args.iter() {
+            ctx.typifier_grow(expr, span)?;
+        }
+
+        // Check if the passed arguments require any special variations
+        let mut variations =
+            builtin_required_variations(args.iter().map(|&(expr, _)| ctx.get_type(expr)));
+
+        // Initiate the declaration if it wasn't previously initialized and inject builtins
+        let declaration = self.lookup_function.entry(name.clone()).or_insert_with(|| {
+            variations |= BuiltinVariations::STANDARD;
+            Default::default()
+        });
+        inject_builtin(declaration, ctx.module, &name, variations);
+
+        // Borrow again but without mutability, at this point a declaration is guaranteed
+        let declaration = self.lookup_function.get(&name).unwrap();
+
+        // Possibly contains the overload to be used in the call
+        let mut maybe_overload = None;
+        // The conversions needed for the best analyzed overload, this is initialized all to
+        // `NONE` to make sure that conversions always pass the first time without ambiguity
+        let mut old_conversions = vec![Conversion::None; args.len()];
+        // Tracks whether the comparison between overloads lead to an ambiguity
+        let mut ambiguous = false;
+
+        // Iterate over all the available overloads to select either an exact match or a
+        // overload which has suitable implicit conversions
+        'outer: for (overload_idx, overload) in declaration.overloads.iter().enumerate() {
+            // If the overload and the function call don't have the same number of arguments
+            // continue to the next overload
+            if args.len() != overload.parameters.len() {
+                continue;
+            }
+
+            log::trace!("Testing overload {}", overload_idx);
+
+            // Stores whether the current overload matches exactly the function call
+            let mut exact = true;
+            // State of the selection
+            // If None we still don't know what is the best overload
+            // If Some(true) the new overload is better
+            // If Some(false) the old overload is better
+            let mut superior = None;
+            // Store the conversions for the current overload so that later they can replace the
+            // conversions used for querying the best overload
+            let mut new_conversions = vec![Conversion::None; args.len()];
+
+            // Loop through the overload parameters and check if the current overload is better
+            // compared to the previous best overload.
+            for (i, overload_parameter) in overload.parameters.iter().enumerate() {
+                let call_argument = &args[i];
+                let parameter_info = &overload.parameters_info[i];
+
+                // If the image is used in the overload as a depth texture convert it
+                // before comparing, otherwise exact matches wouldn't be reported
+                if parameter_info.depth {
+                    sampled_to_depth(ctx, call_argument.0, call_argument.1, &mut self.errors);
+                    ctx.invalidate_expression(call_argument.0, call_argument.1)?
+                }
+
+                ctx.typifier_grow(call_argument.0, call_argument.1)?;
+
+                let overload_param_ty = &ctx.module.types[*overload_parameter].inner;
+                let call_arg_ty = ctx.get_type(call_argument.0);
+
+                log::trace!(
+                    "Testing parameter {}\n\tOverload = {:?}\n\tCall = {:?}",
+                    i,
+                    overload_param_ty,
+                    call_arg_ty
+                );
+
+                // Storage images cannot be directly compared since while the access is part of the
+                // type in naga's IR, in glsl they are a qualifier and don't enter in the match as
+                // long as the access needed is satisfied.
+                if let (
+                    &TypeInner::Image {
+                        class:
+                            crate::ImageClass::Storage {
+                                format: overload_format,
+                                access: overload_access,
+                            },
+                        dim: overload_dim,
+                        arrayed: overload_arrayed,
+                    },
+                    &TypeInner::Image {
+                        class:
+                            crate::ImageClass::Storage {
+                                format: call_format,
+                                access: call_access,
+                            },
+                        dim: call_dim,
+                        arrayed: call_arrayed,
+                    },
+                ) = (overload_param_ty, call_arg_ty)
+                {
+                    // Images size must match otherwise the overload isn't what we want
+                    let good_size = call_dim == overload_dim && call_arrayed == overload_arrayed;
+                    // Glsl requires the formats to strictly match unless you are builtin
+                    // function overload and have not been replaced, in which case we only
+                    // check that the format scalar kind matches
+                    let good_format = overload_format == call_format
+                        || (overload.internal
+                            && ScalarKind::from(overload_format) == ScalarKind::from(call_format));
+                    if !(good_size && good_format) {
+                        continue 'outer;
+                    }
+
+                    // While storage access mismatch is an error it isn't one that causes
+                    // the overload matching to fail so we defer the error and consider
+                    // that the images match exactly
+                    if !call_access.contains(overload_access) {
+                        self.errors.push(Error {
+                            kind: ErrorKind::SemanticError(
+                                format!(
+                                    "'{name}': image needs {overload_access:?} access but only {call_access:?} was provided"
+                                )
+                                .into(),
+                            ),
+                            meta,
+                        });
+                    }
+
+                    // The images satisfy the conditions to be considered as an exact match
+                    new_conversions[i] = Conversion::Exact;
+                    continue;
+                } else if overload_param_ty == call_arg_ty {
+                    // If the types match there's no need to check for conversions so continue
+                    new_conversions[i] = Conversion::Exact;
+                    continue;
+                }
+
+                // Glsl defines that inout follows both the conversions for input parameters and
+                // output parameters, this means that the type must have a conversion from both the
+                // call argument to the function parameter and the function parameter to the call
+                // argument, the only way this is possible is for the conversion to be an identity
+                // (i.e. call argument = function parameter)
+                if let ParameterQualifier::InOut = parameter_info.qualifier {
+                    continue 'outer;
+                }
+
+                // The function call argument and the function definition
+                // parameter are not equal at this point, so we need to try
+                // implicit conversions.
+                //
+                // Now there are two cases, the argument is defined as a normal
+                // parameter (`in` or `const`), in this case an implicit
+                // conversion is made from the calling argument to the
+                // definition argument. If the parameter is `out` the
+                // opposite needs to be done, so the implicit conversion is made
+                // from the definition argument to the calling argument.
+                let maybe_conversion = if parameter_info.qualifier.is_lhs() {
+                    conversion(call_arg_ty, overload_param_ty)
+                } else {
+                    conversion(overload_param_ty, call_arg_ty)
+                };
+
+                let conversion = match maybe_conversion {
+                    Some(info) => info,
+                    None => continue 'outer,
+                };
+
+                // At this point a conversion will be needed so the overload no longer
+                // exactly matches the call arguments
+                exact = false;
+
+                // Compare the conversions needed for this overload parameter to that of the
+                // last overload analyzed respective parameter, the value is:
+                // - `true` when the new overload argument has a better conversion
+                // - `false` when the old overload argument has a better conversion
+                let best_arg = match (conversion, old_conversions[i]) {
+                    // An exact match is always better, we don't need to check this for the
+                    // current overload since it was checked earlier
+                    (_, Conversion::Exact) => false,
+                    // No overload was yet analyzed so this one is the best yet
+                    (_, Conversion::None) => true,
+                    // A conversion from a float to a double is the best possible conversion
+                    (Conversion::FloatToDouble, _) => true,
+                    (_, Conversion::FloatToDouble) => false,
+                    // A conversion from a float to an integer is preferred than one
+                    // from double to an integer
+                    (Conversion::IntToFloat, Conversion::IntToDouble) => true,
+                    (Conversion::IntToDouble, Conversion::IntToFloat) => false,
+                    // This case handles things like no conversion and exact which were already
+                    // treated and other cases which no conversion is better than the other
+                    _ => continue,
+                };
+
+                // Check if the best parameter corresponds to the current selected overload
+                // to pass to the next comparison, if this isn't true mark it as ambiguous
+                match best_arg {
+                    true => match superior {
+                        Some(false) => ambiguous = true,
+                        _ => {
+                            superior = Some(true);
+                            new_conversions[i] = conversion
+                        }
+                    },
+                    false => match superior {
+                        Some(true) => ambiguous = true,
+                        _ => superior = Some(false),
+                    },
+                }
+            }
+
+            // The overload matches exactly the function call so there's no ambiguity (since
+            // repeated overload aren't allowed) and the current overload is selected, no
+            // further querying is needed.
+            if exact {
+                maybe_overload = Some(overload);
+                ambiguous = false;
+                break;
+            }
+
+            match superior {
+                // New overload is better keep it
+                Some(true) => {
+                    maybe_overload = Some(overload);
+                    // Replace the conversions
+                    old_conversions = new_conversions;
+                }
+                // Old overload is better do nothing
+                Some(false) => {}
+                // No overload was better than the other this can be caused
+                // when all conversions are ambiguous in which the overloads themselves are
+                // ambiguous.
+                None => {
+                    ambiguous = true;
+                    // Assign the new overload, this helps ensures that in this case of
+                    // ambiguity the parsing won't end immediately and allow for further
+                    // collection of errors.
+                    maybe_overload = Some(overload);
+                }
+            }
+        }
+
+        if ambiguous {
+            self.errors.push(Error {
+                kind: ErrorKind::SemanticError(
+                    format!("Ambiguous best function for '{name}'").into(),
+                ),
+                meta,
+            })
+        }
+
+        let overload = maybe_overload.ok_or_else(|| Error {
+            kind: ErrorKind::SemanticError(format!("Unknown function '{name}'").into()),
+            meta,
+        })?;
+
+        let parameters_info = overload.parameters_info.clone();
+        let parameters = overload.parameters.clone();
+        let is_void = overload.void;
+        let kind = overload.kind;
+
+        let mut arguments = Vec::with_capacity(args.len());
+        let mut proxy_writes = Vec::new();
+
+        // Iterate through the function call arguments applying transformations as needed
+        for (((parameter_info, call_argument), expr), parameter) in parameters_info
+            .iter()
+            .zip(&args)
+            .zip(raw_args)
+            .zip(&parameters)
+        {
+            let (mut handle, meta) =
+                ctx.lower_expect_inner(stmt, self, *expr, parameter_info.qualifier.as_pos())?;
+
+            if parameter_info.qualifier.is_lhs() {
+                self.process_lhs_argument(
+                    ctx,
+                    meta,
+                    *parameter,
+                    parameter_info,
+                    handle,
+                    call_argument,
+                    &mut proxy_writes,
+                    &mut arguments,
+                )?;
+
+                continue;
+            }
+
+            let scalar_comps = scalar_components(&ctx.module.types[*parameter].inner);
+
+            // Apply implicit conversions as needed
+            if let Some(scalar) = scalar_comps {
+                ctx.implicit_conversion(&mut handle, meta, scalar)?;
+            }
+
+            arguments.push(handle)
+        }
+
+        match kind {
+            FunctionKind::Call(function) => {
+                ctx.emit_end();
+
+                let result = if !is_void {
+                    Some(ctx.add_expression(Expression::CallResult(function), meta)?)
+                } else {
+                    None
+                };
+
+                ctx.body.push(
+                    crate::Statement::Call {
+                        function,
+                        arguments,
+                        result,
+                    },
+                    meta,
+                );
+
+                ctx.emit_start();
+
+                // Write back all the variables that were scheduled to their original place
+                for proxy_write in proxy_writes {
+                    let mut value = ctx.add_expression(
+                        Expression::Load {
+                            pointer: proxy_write.value,
+                        },
+                        meta,
+                    )?;
+
+                    if let Some(scalar) = proxy_write.convert {
+                        ctx.conversion(&mut value, meta, scalar)?;
+                    }
+
+                    ctx.emit_restart();
+
+                    ctx.body.push(
+                        Statement::Store {
+                            pointer: proxy_write.target,
+                            value,
+                        },
+                        meta,
+                    );
+                }
+
+                Ok(result)
+            }
+            FunctionKind::Macro(builtin) => builtin.call(self, ctx, arguments.as_mut_slice(), meta),
+        }
+    }
+
+    /// Processes a function call argument that appears in place of an output
+    /// parameter.
+    #[allow(clippy::too_many_arguments)]
+    fn process_lhs_argument(
+        &mut self,
+        ctx: &mut Context,
+        meta: Span,
+        parameter_ty: Handle<Type>,
+        parameter_info: &ParameterInfo,
+        original: Handle<Expression>,
+        call_argument: &(Handle<Expression>, Span),
+        proxy_writes: &mut Vec<ProxyWrite>,
+        arguments: &mut Vec<Handle<Expression>>,
+    ) -> Result<()> {
+        let original_ty = ctx.resolve_type(original, meta)?;
+        let original_pointer_space = original_ty.pointer_space();
+
+        // The type of a possible spill variable needed for a proxy write
+        let mut maybe_ty = match *original_ty {
+            // If the argument is to be passed as a pointer but the type of the
+            // expression returns a vector it must mean that it was for example
+            // swizzled and it must be spilled into a local before calling
+            TypeInner::Vector { size, scalar } => Some(ctx.module.types.insert(
+                Type {
+                    name: None,
+                    inner: TypeInner::Vector { size, scalar },
+                },
+                Span::default(),
+            )),
+            // If the argument is a pointer whose address space isn't `Function`, an
+            // indirection through a local variable is needed to align the address
+            // spaces of the call argument and the overload parameter.
+            TypeInner::Pointer { base, space } if space != AddressSpace::Function => Some(base),
+            TypeInner::ValuePointer {
+                size,
+                scalar,
+                space,
+            } if space != AddressSpace::Function => {
+                let inner = match size {
+                    Some(size) => TypeInner::Vector { size, scalar },
+                    None => TypeInner::Scalar(scalar),
+                };
+
+                Some(
+                    ctx.module
+                        .types
+                        .insert(Type { name: None, inner }, Span::default()),
+                )
+            }
+            _ => None,
+        };
+
+        // Since the original expression might be a pointer and we want a value
+        // for the proxy writes, we might need to load the pointer.
+        let value = if original_pointer_space.is_some() {
+            ctx.add_expression(Expression::Load { pointer: original }, Span::default())?
+        } else {
+            original
+        };
+
+        ctx.typifier_grow(call_argument.0, call_argument.1)?;
+
+        let overload_param_ty = &ctx.module.types[parameter_ty].inner;
+        let call_arg_ty = ctx.get_type(call_argument.0);
+        let needs_conversion = call_arg_ty != overload_param_ty;
+
+        let arg_scalar_comps = scalar_components(call_arg_ty);
+
+        // Since output parameters also allow implicit conversions from the
+        // parameter to the argument, we need to spill the conversion to a
+        // variable and create a proxy write for the original variable.
+        if needs_conversion {
+            maybe_ty = Some(parameter_ty);
+        }
+
+        if let Some(ty) = maybe_ty {
+            // Create the spill variable
+            let spill_var = ctx.locals.append(
+                LocalVariable {
+                    name: None,
+                    ty,
+                    init: None,
+                },
+                Span::default(),
+            );
+            let spill_expr =
+                ctx.add_expression(Expression::LocalVariable(spill_var), Span::default())?;
+
+            // If the argument is also copied in we must store the value of the
+            // original variable to the spill variable.
+            if let ParameterQualifier::InOut = parameter_info.qualifier {
+                ctx.body.push(
+                    Statement::Store {
+                        pointer: spill_expr,
+                        value,
+                    },
+                    Span::default(),
+                );
+            }
+
+            // Add the spill variable as an argument to the function call
+            arguments.push(spill_expr);
+
+            let convert = if needs_conversion {
+                arg_scalar_comps
+            } else {
+                None
+            };
+
+            // Register the temporary local to be written back to it's original
+            // place after the function call
+            if let Expression::Swizzle {
+                size,
+                mut vector,
+                pattern,
+            } = ctx.expressions[original]
+            {
+                if let Expression::Load { pointer } = ctx.expressions[vector] {
+                    vector = pointer;
+                }
+
+                for (i, component) in pattern.iter().take(size as usize).enumerate() {
+                    let original = ctx.add_expression(
+                        Expression::AccessIndex {
+                            base: vector,
+                            index: *component as u32,
+                        },
+                        Span::default(),
+                    )?;
+
+                    let spill_component = ctx.add_expression(
+                        Expression::AccessIndex {
+                            base: spill_expr,
+                            index: i as u32,
+                        },
+                        Span::default(),
+                    )?;
+
+                    proxy_writes.push(ProxyWrite {
+                        target: original,
+                        value: spill_component,
+                        convert,
+                    });
+                }
+            } else {
+                proxy_writes.push(ProxyWrite {
+                    target: original,
+                    value: spill_expr,
+                    convert,
+                });
+            }
+        } else {
+            arguments.push(original);
+        }
+
+        Ok(())
+    }
+
+    pub(crate) fn add_function(
+        &mut self,
+        mut ctx: Context,
+        name: String,
+        result: Option<FunctionResult>,
+        meta: Span,
+    ) {
+        ensure_block_returns(&mut ctx.body);
+
+        let void = result.is_none();
+
+        // Check if the passed arguments require any special variations
+        let mut variations = builtin_required_variations(
+            ctx.parameters
+                .iter()
+                .map(|&arg| &ctx.module.types[arg].inner),
+        );
+
+        // Initiate the declaration if it wasn't previously initialized and inject builtins
+        let declaration = self.lookup_function.entry(name.clone()).or_insert_with(|| {
+            variations |= BuiltinVariations::STANDARD;
+            Default::default()
+        });
+        inject_builtin(declaration, ctx.module, &name, variations);
+
+        let Context {
+            expressions,
+            locals,
+            arguments,
+            parameters,
+            parameters_info,
+            body,
+            module,
+            ..
+        } = ctx;
+
+        let function = Function {
+            name: Some(name),
+            arguments,
+            result,
+            local_variables: locals,
+            expressions,
+            named_expressions: crate::NamedExpressions::default(),
+            body,
+        };
+
+        'outer: for decl in declaration.overloads.iter_mut() {
+            if parameters.len() != decl.parameters.len() {
+                continue;
+            }
+
+            for (new_parameter, old_parameter) in parameters.iter().zip(decl.parameters.iter()) {
+                let new_inner = &module.types[*new_parameter].inner;
+                let old_inner = &module.types[*old_parameter].inner;
+
+                if new_inner != old_inner {
+                    continue 'outer;
+                }
+            }
+
+            if decl.defined {
+                return self.errors.push(Error {
+                    kind: ErrorKind::SemanticError("Function already defined".into()),
+                    meta,
+                });
+            }
+
+            decl.defined = true;
+            decl.parameters_info = parameters_info;
+            match decl.kind {
+                FunctionKind::Call(handle) => *module.functions.get_mut(handle) = function,
+                FunctionKind::Macro(_) => {
+                    let handle = module.functions.append(function, meta);
+                    decl.kind = FunctionKind::Call(handle)
+                }
+            }
+            return;
+        }
+
+        let handle = module.functions.append(function, meta);
+        declaration.overloads.push(Overload {
+            parameters,
+            parameters_info,
+            kind: FunctionKind::Call(handle),
+            defined: true,
+            internal: false,
+            void,
+        });
+    }
+
+    pub(crate) fn add_prototype(
+        &mut self,
+        ctx: Context,
+        name: String,
+        result: Option<FunctionResult>,
+        meta: Span,
+    ) {
+        let void = result.is_none();
+
+        // Check if the passed arguments require any special variations
+        let mut variations = builtin_required_variations(
+            ctx.parameters
+                .iter()
+                .map(|&arg| &ctx.module.types[arg].inner),
+        );
+
+        // Initiate the declaration if it wasn't previously initialized and inject builtins
+        let declaration = self.lookup_function.entry(name.clone()).or_insert_with(|| {
+            variations |= BuiltinVariations::STANDARD;
+            Default::default()
+        });
+        inject_builtin(declaration, ctx.module, &name, variations);
+
+        let Context {
+            arguments,
+            parameters,
+            parameters_info,
+            module,
+            ..
+        } = ctx;
+
+        let function = Function {
+            name: Some(name),
+            arguments,
+            result,
+            ..Default::default()
+        };
+
+        'outer: for decl in declaration.overloads.iter() {
+            if parameters.len() != decl.parameters.len() {
+                continue;
+            }
+
+            for (new_parameter, old_parameter) in parameters.iter().zip(decl.parameters.iter()) {
+                let new_inner = &module.types[*new_parameter].inner;
+                let old_inner = &module.types[*old_parameter].inner;
+
+                if new_inner != old_inner {
+                    continue 'outer;
+                }
+            }
+
+            return self.errors.push(Error {
+                kind: ErrorKind::SemanticError("Prototype already defined".into()),
+                meta,
+            });
+        }
+
+        let handle = module.functions.append(function, meta);
+        declaration.overloads.push(Overload {
+            parameters,
+            parameters_info,
+            kind: FunctionKind::Call(handle),
+            defined: false,
+            internal: false,
+            void,
+        });
+    }
+
+    /// Create a Naga [`EntryPoint`] that calls the GLSL `main` function.
+    ///
+    /// We compile the GLSL `main` function as an ordinary Naga [`Function`].
+    /// This function synthesizes a Naga [`EntryPoint`] to call that.
+    ///
+    /// Each GLSL input and output variable (including builtins) becomes a Naga
+    /// [`GlobalVariable`]s in the [`Private`] address space, which `main` can
+    /// access in the usual way.
+    ///
+    /// The `EntryPoint` we synthesize here has an argument for each GLSL input
+    /// variable, and returns a struct with a member for each GLSL output
+    /// variable. The entry point contains code to:
+    ///
+    /// - copy its arguments into the Naga globals representing the GLSL input
+    ///   variables,
+    ///
+    /// - call the Naga `Function` representing the GLSL `main` function, and then
+    ///
+    /// - build its return value from whatever values the GLSL `main` left in
+    ///   the Naga globals representing GLSL `output` variables.
+    ///
+    /// Upon entry, [`ctx.body`] should contain code, accumulated by prior calls
+    /// to [`ParsingContext::parse_external_declaration`][pxd], to initialize
+    /// private global variables as needed. This code gets spliced into the
+    /// entry point before the call to `main`.
+    ///
+    /// [`GlobalVariable`]: crate::GlobalVariable
+    /// [`Private`]: crate::AddressSpace::Private
+    /// [`ctx.body`]: Context::body
+    /// [pxd]: super::ParsingContext::parse_external_declaration
+    pub(crate) fn add_entry_point(
+        &mut self,
+        function: Handle<Function>,
+        mut ctx: Context,
+    ) -> Result<()> {
+        let mut arguments = Vec::new();
+
+        let body = Block::with_capacity(
+            // global init body
+            ctx.body.len() +
+            // prologue and epilogue
+            self.entry_args.len() * 2
+            // Call, Emit for composing struct and return
+            + 3,
+        );
+
+        let global_init_body = std::mem::replace(&mut ctx.body, body);
+
+        for arg in self.entry_args.iter() {
+            if arg.storage != StorageQualifier::Input {
+                continue;
+            }
+
+            let pointer = ctx
+                .expressions
+                .append(Expression::GlobalVariable(arg.handle), Default::default());
+
+            let ty = ctx.module.global_variables[arg.handle].ty;
+
+            ctx.arg_type_walker(
+                arg.name.clone(),
+                arg.binding.clone(),
+                pointer,
+                ty,
+                &mut |ctx, name, pointer, ty, binding| {
+                    let idx = arguments.len() as u32;
+
+                    arguments.push(FunctionArgument {
+                        name,
+                        ty,
+                        binding: Some(binding),
+                    });
+
+                    let value = ctx
+                        .expressions
+                        .append(Expression::FunctionArgument(idx), Default::default());
+                    ctx.body
+                        .push(Statement::Store { pointer, value }, Default::default());
+                },
+            )?
+        }
+
+        ctx.body.extend_block(global_init_body);
+
+        ctx.body.push(
+            Statement::Call {
+                function,
+                arguments: Vec::new(),
+                result: None,
+            },
+            Default::default(),
+        );
+
+        let mut span = 0;
+        let mut members = Vec::new();
+        let mut components = Vec::new();
+
+        for arg in self.entry_args.iter() {
+            if arg.storage != StorageQualifier::Output {
+                continue;
+            }
+
+            let pointer = ctx
+                .expressions
+                .append(Expression::GlobalVariable(arg.handle), Default::default());
+
+            let ty = ctx.module.global_variables[arg.handle].ty;
+
+            ctx.arg_type_walker(
+                arg.name.clone(),
+                arg.binding.clone(),
+                pointer,
+                ty,
+                &mut |ctx, name, pointer, ty, binding| {
+                    members.push(StructMember {
+                        name,
+                        ty,
+                        binding: Some(binding),
+                        offset: span,
+                    });
+
+                    span += ctx.module.types[ty].inner.size(ctx.module.to_ctx());
+
+                    let len = ctx.expressions.len();
+                    let load = ctx
+                        .expressions
+                        .append(Expression::Load { pointer }, Default::default());
+                    ctx.body.push(
+                        Statement::Emit(ctx.expressions.range_from(len)),
+                        Default::default(),
+                    );
+                    components.push(load)
+                },
+            )?
+        }
+
+        let (ty, value) = if !components.is_empty() {
+            let ty = ctx.module.types.insert(
+                Type {
+                    name: None,
+                    inner: TypeInner::Struct { members, span },
+                },
+                Default::default(),
+            );
+
+            let len = ctx.expressions.len();
+            let res = ctx
+                .expressions
+                .append(Expression::Compose { ty, components }, Default::default());
+            ctx.body.push(
+                Statement::Emit(ctx.expressions.range_from(len)),
+                Default::default(),
+            );
+
+            (Some(ty), Some(res))
+        } else {
+            (None, None)
+        };
+
+        ctx.body
+            .push(Statement::Return { value }, Default::default());
+
+        let Context {
+            body, expressions, ..
+        } = ctx;
+
+        ctx.module.entry_points.push(EntryPoint {
+            name: "main".to_string(),
+            stage: self.meta.stage,
+            early_depth_test: Some(crate::EarlyDepthTest { conservative: None })
+                .filter(|_| self.meta.early_fragment_tests),
+            workgroup_size: self.meta.workgroup_size,
+            function: Function {
+                arguments,
+                expressions,
+                body,
+                result: ty.map(|ty| FunctionResult { ty, binding: None }),
+                ..Default::default()
+            },
+        });
+
+        Ok(())
+    }
+}
+
+impl Context<'_> {
+    /// Helper function for building the input/output interface of the entry point
+    ///
+    /// Calls `f` with the data of the entry point argument, flattening composite types
+    /// recursively
+    ///
+    /// The passed arguments to the callback are:
+    /// - The ctx
+    /// - The name
+    /// - The pointer expression to the global storage
+    /// - The handle to the type of the entry point argument
+    /// - The binding of the entry point argument
+    fn arg_type_walker(
+        &mut self,
+        name: Option<String>,
+        binding: crate::Binding,
+        pointer: Handle<Expression>,
+        ty: Handle<Type>,
+        f: &mut impl FnMut(
+            &mut Context,
+            Option<String>,
+            Handle<Expression>,
+            Handle<Type>,
+            crate::Binding,
+        ),
+    ) -> Result<()> {
+        match self.module.types[ty].inner {
+            // TODO: Better error reporting
+            // right now we just don't walk the array if the size isn't known at
+            // compile time and let validation catch it
+            TypeInner::Array {
+                base,
+                size: crate::ArraySize::Constant(size),
+                ..
+            } => {
+                let mut location = match binding {
+                    crate::Binding::Location { location, .. } => location,
+                    crate::Binding::BuiltIn(_) => return Ok(()),
+                };
+
+                let interpolation =
+                    self.module.types[base]
+                        .inner
+                        .scalar_kind()
+                        .map(|kind| match kind {
+                            ScalarKind::Float => crate::Interpolation::Perspective,
+                            _ => crate::Interpolation::Flat,
+                        });
+
+                for index in 0..size.get() {
+                    let member_pointer = self.add_expression(
+                        Expression::AccessIndex {
+                            base: pointer,
+                            index,
+                        },
+                        crate::Span::default(),
+                    )?;
+
+                    let binding = crate::Binding::Location {
+                        location,
+                        interpolation,
+                        sampling: None,
+                        second_blend_source: false,
+                    };
+                    location += 1;
+
+                    self.arg_type_walker(name.clone(), binding, member_pointer, base, f)?
+                }
+            }
+            TypeInner::Struct { ref members, .. } => {
+                let mut location = match binding {
+                    crate::Binding::Location { location, .. } => location,
+                    crate::Binding::BuiltIn(_) => return Ok(()),
+                };
+
+                for (i, member) in members.clone().into_iter().enumerate() {
+                    let member_pointer = self.add_expression(
+                        Expression::AccessIndex {
+                            base: pointer,
+                            index: i as u32,
+                        },
+                        crate::Span::default(),
+                    )?;
+
+                    let binding = match member.binding {
+                        Some(binding) => binding,
+                        None => {
+                            let interpolation = self.module.types[member.ty]
+                                .inner
+                                .scalar_kind()
+                                .map(|kind| match kind {
+                                    ScalarKind::Float => crate::Interpolation::Perspective,
+                                    _ => crate::Interpolation::Flat,
+                                });
+                            let binding = crate::Binding::Location {
+                                location,
+                                interpolation,
+                                sampling: None,
+                                second_blend_source: false,
+                            };
+                            location += 1;
+                            binding
+                        }
+                    };
+
+                    self.arg_type_walker(member.name, binding, member_pointer, member.ty, f)?
+                }
+            }
+            _ => f(self, name, pointer, ty, binding),
+        }
+
+        Ok(())
+    }
+}
+
+/// Helper enum containing the type of conversion need for a call
+#[derive(PartialEq, Eq, Clone, Copy, Debug)]
+enum Conversion {
+    /// No conversion needed
+    Exact,
+    /// Float to double conversion needed
+    FloatToDouble,
+    /// Int or uint to float conversion needed
+    IntToFloat,
+    /// Int or uint to double conversion needed
+    IntToDouble,
+    /// Other type of conversion needed
+    Other,
+    /// No conversion was yet registered
+    None,
+}
+
+/// Helper function, returns the type of conversion from `source` to `target`, if a
+/// conversion is not possible returns None.
+fn conversion(target: &TypeInner, source: &TypeInner) -> Option<Conversion> {
+    use ScalarKind::*;
+
+    // Gather the `ScalarKind` and scalar width from both the target and the source
+    let (target_scalar, source_scalar) = match (target, source) {
+        // Conversions between scalars are allowed
+        (&TypeInner::Scalar(tgt_scalar), &TypeInner::Scalar(src_scalar)) => {
+            (tgt_scalar, src_scalar)
+        }
+        // Conversions between vectors of the same size are allowed
+        (
+            &TypeInner::Vector {
+                size: tgt_size,
+                scalar: tgt_scalar,
+            },
+            &TypeInner::Vector {
+                size: src_size,
+                scalar: src_scalar,
+            },
+        ) if tgt_size == src_size => (tgt_scalar, src_scalar),
+        // Conversions between matrices of the same size are allowed
+        (
+            &TypeInner::Matrix {
+                rows: tgt_rows,
+                columns: tgt_cols,
+                scalar: tgt_scalar,
+            },
+            &TypeInner::Matrix {
+                rows: src_rows,
+                columns: src_cols,
+                scalar: src_scalar,
+            },
+        ) if tgt_cols == src_cols && tgt_rows == src_rows => (tgt_scalar, src_scalar),
+        _ => return None,
+    };
+
+    // Check if source can be converted into target, if this is the case then the type
+    // power of target must be higher than that of source
+    let target_power = type_power(target_scalar);
+    let source_power = type_power(source_scalar);
+    if target_power < source_power {
+        return None;
+    }
+
+    Some(match (target_scalar, source_scalar) {
+        // A conversion from a float to a double is special
+        (Scalar::F64, Scalar::F32) => Conversion::FloatToDouble,
+        // A conversion from an integer to a float is special
+        (
+            Scalar::F32,
+            Scalar {
+                kind: Sint | Uint,
+                width: _,
+            },
+        ) => Conversion::IntToFloat,
+        // A conversion from an integer to a double is special
+        (
+            Scalar::F64,
+            Scalar {
+                kind: Sint | Uint,
+                width: _,
+            },
+        ) => Conversion::IntToDouble,
+        _ => Conversion::Other,
+    })
+}
+
+/// Helper method returning all the non standard builtin variations needed
+/// to process the function call with the passed arguments
+fn builtin_required_variations<'a>(args: impl Iterator<Item = &'a TypeInner>) -> BuiltinVariations {
+    let mut variations = BuiltinVariations::empty();
+
+    for ty in args {
+        match *ty {
+            TypeInner::ValuePointer { scalar, .. }
+            | TypeInner::Scalar(scalar)
+            | TypeInner::Vector { scalar, .. }
+            | TypeInner::Matrix { scalar, .. } => {
+                if scalar == Scalar::F64 {
+                    variations |= BuiltinVariations::DOUBLE
+                }
+            }
+            TypeInner::Image {
+                dim,
+                arrayed,
+                class,
+            } => {
+                if dim == crate::ImageDimension::Cube && arrayed {
+                    variations |= BuiltinVariations::CUBE_TEXTURES_ARRAY
+                }
+
+                if dim == crate::ImageDimension::D2 && arrayed && class.is_multisampled() {
+                    variations |= BuiltinVariations::D2_MULTI_TEXTURES_ARRAY
+                }
+            }
+            _ => {}
+        }
+    }
+
+    variations
+}
diff --git a/third_party/rust/naga/src/front/glsl/lex.rs b/third_party/rust/naga/src/front/glsl/lex.rs
new file mode 100644
index 0000000000..1b59a9bf3e
--- /dev/null
+++ b/third_party/rust/naga/src/front/glsl/lex.rs
@@ -0,0 +1,301 @@
+use super::{
+    ast::Precision,
+    token::{Directive, DirectiveKind, Token, TokenValue},
+    types::parse_type,
+};
+use crate::{FastHashMap, Span, StorageAccess};
+use pp_rs::{
+    pp::Preprocessor,
+    token::{PreprocessorError, Punct, TokenValue as PPTokenValue},
+};
+
+#[derive(Debug)]
+#[cfg_attr(test, derive(PartialEq))]
+pub struct LexerResult {
+    pub kind: LexerResultKind,
+    pub meta: Span,
+}
+
+#[derive(Debug)]
+#[cfg_attr(test, derive(PartialEq))]
+pub enum LexerResultKind {
+    Token(Token),
+    Directive(Directive),
+    Error(PreprocessorError),
+}
+
+pub struct Lexer<'a> {
+    pp: Preprocessor<'a>,
+}
+
+impl<'a> Lexer<'a> {
+    pub fn new(input: &'a str, defines: &'a FastHashMap<String, String>) -> Self {
+        let mut pp = Preprocessor::new(input);
+        for (define, value) in defines {
+            pp.add_define(define, value).unwrap(); //TODO: handle error
+        }
+        Lexer { pp }
+    }
+}
+
+impl<'a> Iterator for Lexer<'a> {
+    type Item = LexerResult;
+    fn next(&mut self) -> Option<Self::Item> {
+        let pp_token = match self.pp.next()? {
+            Ok(t) => t,
+            Err((err, loc)) => {
+                return Some(LexerResult {
+                    kind: LexerResultKind::Error(err),
+                    meta: loc.into(),
+                });
+            }
+        };
+
+        let meta = pp_token.location.into();
+        let value = match pp_token.value {
+            PPTokenValue::Extension(extension) => {
+                return Some(LexerResult {
+                    kind: LexerResultKind::Directive(Directive {
+                        kind: DirectiveKind::Extension,
+                        tokens: extension.tokens,
+                    }),
+                    meta,
+                })
+            }
+            PPTokenValue::Float(float) => TokenValue::FloatConstant(float),
+            PPTokenValue::Ident(ident) => {
+                match ident.as_str() {
+                    // Qualifiers
+                    "layout" => TokenValue::Layout,
+                    "in" => TokenValue::In,
+                    "out" => TokenValue::Out,
+                    "uniform" => TokenValue::Uniform,
+                    "buffer" => TokenValue::Buffer,
+                    "shared" => TokenValue::Shared,
+                    "invariant" => TokenValue::Invariant,
+                    "flat" => TokenValue::Interpolation(crate::Interpolation::Flat),
+                    "noperspective" => TokenValue::Interpolation(crate::Interpolation::Linear),
+                    "smooth" => TokenValue::Interpolation(crate::Interpolation::Perspective),
+                    "centroid" => TokenValue::Sampling(crate::Sampling::Centroid),
+                    "sample" => TokenValue::Sampling(crate::Sampling::Sample),
+                    "const" => TokenValue::Const,
+                    "inout" => TokenValue::InOut,
+                    "precision" => TokenValue::Precision,
+                    "highp" => TokenValue::PrecisionQualifier(Precision::High),
+                    "mediump" => TokenValue::PrecisionQualifier(Precision::Medium),
+                    "lowp" => TokenValue::PrecisionQualifier(Precision::Low),
+                    "restrict" => TokenValue::Restrict,
+                    "readonly" => TokenValue::MemoryQualifier(StorageAccess::LOAD),
+                    "writeonly" => TokenValue::MemoryQualifier(StorageAccess::STORE),
+                    // values
+                    "true" => TokenValue::BoolConstant(true),
+                    "false" => TokenValue::BoolConstant(false),
+                    // jump statements
+                    "continue" => TokenValue::Continue,
+                    "break" => TokenValue::Break,
+                    "return" => TokenValue::Return,
+                    "discard" => TokenValue::Discard,
+                    // selection statements
+                    "if" => TokenValue::If,
+                    "else" => TokenValue::Else,
+                    "switch" => TokenValue::Switch,
+                    "case" => TokenValue::Case,
+                    "default" => TokenValue::Default,
+                    // iteration statements
+                    "while" => TokenValue::While,
+                    "do" => TokenValue::Do,
+                    "for" => TokenValue::For,
+                    // types
+                    "void" => TokenValue::Void,
+                    "struct" => TokenValue::Struct,
+                    word => match parse_type(word) {
+                        Some(t) => TokenValue::TypeName(t),
+                        None => TokenValue::Identifier(String::from(word)),
+                    },
+                }
+            }
+            PPTokenValue::Integer(integer) => TokenValue::IntConstant(integer),
+            PPTokenValue::Punct(punct) => match punct {
+                // Compound assignments
+                Punct::AddAssign => TokenValue::AddAssign,
+                Punct::SubAssign => TokenValue::SubAssign,
+                Punct::MulAssign => TokenValue::MulAssign,
+                Punct::DivAssign => TokenValue::DivAssign,
+                Punct::ModAssign => TokenValue::ModAssign,
+                Punct::LeftShiftAssign => TokenValue::LeftShiftAssign,
+                Punct::RightShiftAssign => TokenValue::RightShiftAssign,
+                Punct::AndAssign => TokenValue::AndAssign,
+                Punct::XorAssign => TokenValue::XorAssign,
+                Punct::OrAssign => TokenValue::OrAssign,
+
+                // Two character punctuation
+                Punct::Increment => TokenValue::Increment,
+                Punct::Decrement => TokenValue::Decrement,
+                Punct::LogicalAnd => TokenValue::LogicalAnd,
+                Punct::LogicalOr => TokenValue::LogicalOr,
+                Punct::LogicalXor => TokenValue::LogicalXor,
+                Punct::LessEqual => TokenValue::LessEqual,
+                Punct::GreaterEqual => TokenValue::GreaterEqual,
+                Punct::EqualEqual => TokenValue::Equal,
+                Punct::NotEqual => TokenValue::NotEqual,
+                Punct::LeftShift => TokenValue::LeftShift,
+                Punct::RightShift => TokenValue::RightShift,
+
+                // Parenthesis or similar
+                Punct::LeftBrace => TokenValue::LeftBrace,
+                Punct::RightBrace => TokenValue::RightBrace,
+                Punct::LeftParen => TokenValue::LeftParen,
+                Punct::RightParen => TokenValue::RightParen,
+                Punct::LeftBracket => TokenValue::LeftBracket,
+                Punct::RightBracket => TokenValue::RightBracket,
+
+                // Other one character punctuation
+                Punct::LeftAngle => TokenValue::LeftAngle,
+                Punct::RightAngle => TokenValue::RightAngle,
+                Punct::Semicolon => TokenValue::Semicolon,
+                Punct::Comma => TokenValue::Comma,
+                Punct::Colon => TokenValue::Colon,
+                Punct::Dot => TokenValue::Dot,
+                Punct::Equal => TokenValue::Assign,
+                Punct::Bang => TokenValue::Bang,
+                Punct::Minus => TokenValue::Dash,
+                Punct::Tilde => TokenValue::Tilde,
+                Punct::Plus => TokenValue::Plus,
+                Punct::Star => TokenValue::Star,
+                Punct::Slash => TokenValue::Slash,
+                Punct::Percent => TokenValue::Percent,
+                Punct::Pipe => TokenValue::VerticalBar,
+                Punct::Caret => TokenValue::Caret,
+                Punct::Ampersand => TokenValue::Ampersand,
+                Punct::Question => TokenValue::Question,
+            },
+            PPTokenValue::Pragma(pragma) => {
+                return Some(LexerResult {
+                    kind: LexerResultKind::Directive(Directive {
+                        kind: DirectiveKind::Pragma,
+                        tokens: pragma.tokens,
+                    }),
+                    meta,
+                })
+            }
+            PPTokenValue::Version(version) => {
+                return Some(LexerResult {
+                    kind: LexerResultKind::Directive(Directive {
+                        kind: DirectiveKind::Version {
+                            is_first_directive: version.is_first_directive,
+                        },
+                        tokens: version.tokens,
+                    }),
+                    meta,
+                })
+            }
+        };
+
+        Some(LexerResult {
+            kind: LexerResultKind::Token(Token { value, meta }),
+            meta,
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use pp_rs::token::{Integer, Location, Token as PPToken, TokenValue as PPTokenValue};
+
+    use super::{
+        super::token::{Directive, DirectiveKind, Token, TokenValue},
+        Lexer, LexerResult, LexerResultKind,
+    };
+    use crate::Span;
+
+    #[test]
+    fn lex_tokens() {
+        let defines = crate::FastHashMap::default();
+
+        // line comments
+        let mut lex = Lexer::new("#version 450\nvoid main () {}", &defines);
+        let mut location = Location::default();
+        location.start = 9;
+        location.end = 12;
+        assert_eq!(
+            lex.next().unwrap(),
+            LexerResult {
+                kind: LexerResultKind::Directive(Directive {
+                    kind: DirectiveKind::Version {
+                        is_first_directive: true
+                    },
+                    tokens: vec![PPToken {
+                        value: PPTokenValue::Integer(Integer {
+                            signed: true,
+                            value: 450,
+                            width: 32
+                        }),
+                        location
+                    }]
+                }),
+                meta: Span::new(1, 8)
+            }
+        );
+        assert_eq!(
+            lex.next().unwrap(),
+            LexerResult {
+                kind: LexerResultKind::Token(Token {
+                    value: TokenValue::Void,
+                    meta: Span::new(13, 17)
+                }),
+                meta: Span::new(13, 17)
+            }
+        );
+        assert_eq!(
+            lex.next().unwrap(),
+            LexerResult {
+                kind: LexerResultKind::Token(Token {
+                    value: TokenValue::Identifier("main".into()),
+                    meta: Span::new(18, 22)
+                }),
+                meta: Span::new(18, 22)
+            }
+        );
+        assert_eq!(
+            lex.next().unwrap(),
+            LexerResult {
+                kind: LexerResultKind::Token(Token {
+                    value: TokenValue::LeftParen,
+                    meta: Span::new(23, 24)
+                }),
+                meta: Span::new(23, 24)
+            }
+        );
+        assert_eq!(
+            lex.next().unwrap(),
+            LexerResult {
+                kind: LexerResultKind::Token(Token {
+                    value: TokenValue::RightParen,
+                    meta: Span::new(24, 25)
+                }),
+                meta: Span::new(24, 25)
+            }
+        );
+        assert_eq!(
+            lex.next().unwrap(),
+            LexerResult {
+                kind: LexerResultKind::Token(Token {
+                    value: TokenValue::LeftBrace,
+                    meta: Span::new(26, 27)
+                }),
+                meta: Span::new(26, 27)
+            }
+        );
+        assert_eq!(
+            lex.next().unwrap(),
+            LexerResult {
+                kind: LexerResultKind::Token(Token {
+                    value: TokenValue::RightBrace,
+                    meta: Span::new(27, 28)
+                }),
+                meta: Span::new(27, 28)
+            }
+        );
+        assert_eq!(lex.next(), None);
+    }
+}
diff --git a/third_party/rust/naga/src/front/glsl/mod.rs b/third_party/rust/naga/src/front/glsl/mod.rs
new file mode 100644
index 0000000000..75f3929db4
--- /dev/null
+++ b/third_party/rust/naga/src/front/glsl/mod.rs
@@ -0,0 +1,232 @@
+/*!
+Frontend for [GLSL][glsl] (OpenGL Shading Language).
+
+To begin, take a look at the documentation for the [`Frontend`].
+
+# Supported versions
+## Vulkan
+- 440 (partial)
+- 450
+- 460
+
+[glsl]: https://www.khronos.org/registry/OpenGL/index_gl.php
+*/
+
+pub use ast::{Precision, Profile};
+pub use error::{Error, ErrorKind, ExpectedToken, ParseError};
+pub use token::TokenValue;
+
+use crate::{proc::Layouter, FastHashMap, FastHashSet, Handle, Module, ShaderStage, Span, Type};
+use ast::{EntryArg, FunctionDeclaration, GlobalLookup};
+use parser::ParsingContext;
+
+mod ast;
+mod builtins;
+mod context;
+mod error;
+mod functions;
+mod lex;
+mod offset;
+mod parser;
+#[cfg(test)]
+mod parser_tests;
+mod token;
+mod types;
+mod variables;
+
+type Result<T> = std::result::Result<T, Error>;
+
+/// Per-shader options passed to [`parse`](Frontend::parse).
+///
+/// The [`From`] trait is implemented for [`ShaderStage`] to provide a quick way
+/// to create an `Options` instance.
+///
+/// ```rust
+/// # use naga::ShaderStage;
+/// # use naga::front::glsl::Options;
+/// Options::from(ShaderStage::Vertex);
+/// ```
+#[derive(Debug)]
+pub struct Options {
+    /// The shader stage in the pipeline.
+    pub stage: ShaderStage,
+    /// Preprocessor definitions to be used, akin to having
+    /// ```glsl
+    /// #define key value
+    /// ```
+    /// for each key value pair in the map.
+    pub defines: FastHashMap<String, String>,
+}
+
+impl From<ShaderStage> for Options {
+    fn from(stage: ShaderStage) -> Self {
+        Options {
+            stage,
+            defines: FastHashMap::default(),
+        }
+    }
+}
+
+/// Additional information about the GLSL shader.
+///
+/// Stores additional information about the GLSL shader which might not be
+/// stored in the shader [`Module`].
+#[derive(Debug)]
+pub struct ShaderMetadata {
+    /// The GLSL version specified in the shader through the use of the
+    /// `#version` preprocessor directive.
+    pub version: u16,
+    /// The GLSL profile specified in the shader through the use of the
+    /// `#version` preprocessor directive.
+    pub profile: Profile,
+    /// The shader stage in the pipeline, passed to the [`parse`](Frontend::parse)
+    /// method via the [`Options`] struct.
+    pub stage: ShaderStage,
+
+    /// The workgroup size for compute shaders, defaults to `[1; 3]` for
+    /// compute shaders and `[0; 3]` for non compute shaders.
+    pub workgroup_size: [u32; 3],
+    /// Whether or not early fragment tests where requested by the shader.
+    /// Defaults to `false`.
+    pub early_fragment_tests: bool,
+
+    /// The shader can request extensions via the
+    /// `#extension` preprocessor directive, in the directive a behavior
+    /// parameter is used to control whether the extension should be disabled,
+    /// warn on usage, enabled if possible or required.
+    ///
+    /// This field only stores extensions which were required or requested to
+    /// be enabled if possible and they are supported.
+    pub extensions: FastHashSet<String>,
+}
+
+impl ShaderMetadata {
+    fn reset(&mut self, stage: ShaderStage) {
+        self.version = 0;
+        self.profile = Profile::Core;
+        self.stage = stage;
+        self.workgroup_size = [u32::from(stage == ShaderStage::Compute); 3];
+        self.early_fragment_tests = false;
+        self.extensions.clear();
+    }
+}
+
+impl Default for ShaderMetadata {
+    fn default() -> Self {
+        ShaderMetadata {
+            version: 0,
+            profile: Profile::Core,
+            stage: ShaderStage::Vertex,
+            workgroup_size: [0; 3],
+            early_fragment_tests: false,
+            extensions: FastHashSet::default(),
+        }
+    }
+}
+
+/// The `Frontend` is the central structure of the GLSL frontend.
+///
+/// To instantiate a new `Frontend` the [`Default`] trait is used, so a
+/// call to the associated function [`Frontend::default`](Frontend::default) will
+/// return a new `Frontend` instance.
+///
+/// To parse a shader simply call the [`parse`](Frontend::parse) method with a
+/// [`Options`] struct and a [`&str`](str) holding the glsl code.
+///
+/// The `Frontend` also provides the [`metadata`](Frontend::metadata) to get some
+/// further information about the previously parsed shader, like version and
+/// extensions used (see the documentation for
+/// [`ShaderMetadata`] to see all the returned information)
+///
+/// # Example usage
+/// ```rust
+/// use naga::ShaderStage;
+/// use naga::front::glsl::{Frontend, Options};
+///
+/// let glsl = r#"
+///     #version 450 core
+///
+///     void main() {}
+/// "#;
+///
+/// let mut frontend = Frontend::default();
+/// let options = Options::from(ShaderStage::Vertex);
+/// frontend.parse(&options, glsl);
+/// ```
+///
+/// # Reusability
+///
+/// If there's a need to parse more than one shader reusing the same `Frontend`
+/// instance may be beneficial since internal allocations will be reused.
+///
+/// Calling the [`parse`](Frontend::parse) method multiple times will reset the
+/// `Frontend` so no extra care is needed when reusing.
+#[derive(Debug, Default)]
+pub struct Frontend {
+    meta: ShaderMetadata,
+
+    lookup_function: FastHashMap<String, FunctionDeclaration>,
+    lookup_type: FastHashMap<String, Handle<Type>>,
+
+    global_variables: Vec<(String, GlobalLookup)>,
+
+    entry_args: Vec<EntryArg>,
+
+    layouter: Layouter,
+
+    errors: Vec<Error>,
+}
+
+impl Frontend {
+    fn reset(&mut self, stage: ShaderStage) {
+        self.meta.reset(stage);
+
+        self.lookup_function.clear();
+        self.lookup_type.clear();
+        self.global_variables.clear();
+        self.entry_args.clear();
+        self.layouter.clear();
+    }
+
+    /// Parses a shader either outputting a shader [`Module`] or a list of
+    /// [`Error`]s.
+    ///
+    /// Multiple calls using the same `Frontend` and different shaders are supported.
+    pub fn parse(
+        &mut self,
+        options: &Options,
+        source: &str,
+    ) -> std::result::Result<Module, ParseError> {
+        self.reset(options.stage);
+
+        let lexer = lex::Lexer::new(source, &options.defines);
+        let mut ctx = ParsingContext::new(lexer);
+
+        match ctx.parse(self) {
+            Ok(module) => {
+                if self.errors.is_empty() {
+                    Ok(module)
+                } else {
+                    Err(std::mem::take(&mut self.errors).into())
+                }
+            }
+            Err(e) => {
+                self.errors.push(e);
+                Err(std::mem::take(&mut self.errors).into())
+            }
+        }
+    }
+
+    /// Returns additional information about the parsed shader which might not
+    /// be stored in the [`Module`], see the documentation for
+    /// [`ShaderMetadata`] for more information about the returned data.
+    ///
+    /// # Notes
+    ///
+    /// Following an unsuccessful parsing the state of the returned information
+    /// is undefined, it might contain only partial information about the
+    /// current shader, the previous shader or both.
+    pub const fn metadata(&self) -> &ShaderMetadata {
+        &self.meta
+    }
+}
diff --git a/third_party/rust/naga/src/front/glsl/offset.rs b/third_party/rust/naga/src/front/glsl/offset.rs
new file mode 100644
index 0000000000..c88c46598d
--- /dev/null
+++ b/third_party/rust/naga/src/front/glsl/offset.rs
@@ -0,0 +1,173 @@
+/*!
+Module responsible for calculating the offset and span for types.
+
+There exists two types of layouts std140 and std430 (there's technically
+two more layouts, shared and packed. Shared is not supported by spirv. Packed is
+implementation dependent and for now it's just implemented as an alias to
+std140).
+
+The OpenGl spec (the layout rules are defined by the OpenGl spec in section
+7.6.2.2 as opposed to the GLSL spec) uses the term basic machine units which are
+equivalent to bytes.
+*/
+
+use super::{
+    ast::StructLayout,
+    error::{Error, ErrorKind},
+    Span,
+};
+use crate::{proc::Alignment, Handle, Scalar, Type, TypeInner, UniqueArena};
+
+/// Struct with information needed for defining a struct member.
+///
+/// Returned by [`calculate_offset`].
+#[derive(Debug)]
+pub struct TypeAlignSpan {
+    /// The handle to the type, this might be the same handle passed to
+    /// [`calculate_offset`] or a new such a new array type with a different
+    /// stride set.
+    pub ty: Handle<Type>,
+    /// The alignment required by the type.
+    pub align: Alignment,
+    /// The size of the type.
+    pub span: u32,
+}
+
+/// Returns the type, alignment and span of a struct member according to a [`StructLayout`].
+///
+/// The functions returns a [`TypeAlignSpan`] which has a `ty` member this
+/// should be used as the struct member type because for example arrays may have
+/// to change the stride and as such need to have a different type.
+pub fn calculate_offset(
+    mut ty: Handle<Type>,
+    meta: Span,
+    layout: StructLayout,
+    types: &mut UniqueArena<Type>,
+    errors: &mut Vec<Error>,
+) -> TypeAlignSpan {
+    // When using the std430 storage layout, shader storage blocks will be laid out in buffer storage
+    // identically to uniform and shader storage blocks using the std140 layout, except
+    // that the base alignment and stride of arrays of scalars and vectors in rule 4 and of
+    // structures in rule 9 are not rounded up a multiple of the base alignment of a vec4.
+
+    let (align, span) = match types[ty].inner {
+        // 1. If the member is a scalar consuming N basic machine units,
+        // the base alignment is N.
+        TypeInner::Scalar(Scalar { width, .. }) => (Alignment::from_width(width), width as u32),
+        // 2. If the member is a two- or four-component vector with components
+        // consuming N basic machine units, the base alignment is 2N or 4N, respectively.
+        // 3. If the member is a three-component vector with components consuming N
+        // basic machine units, the base alignment is 4N.
+        TypeInner::Vector {
+            size,
+            scalar: Scalar { width, .. },
+        } => (
+            Alignment::from(size) * Alignment::from_width(width),
+            size as u32 * width as u32,
+        ),
+        // 4. If the member is an array of scalars or vectors, the base alignment and array
+        // stride are set to match the base alignment of a single array element, according
+        // to rules (1), (2), and (3), and rounded up to the base alignment of a vec4.
+        // TODO: Matrices array
+        TypeInner::Array { base, size, .. } => {
+            let info = calculate_offset(base, meta, layout, types, errors);
+
+            let name = types[ty].name.clone();
+
+            // See comment at the beginning of the function
+            let (align, stride) = if StructLayout::Std430 == layout {
+                (info.align, info.align.round_up(info.span))
+            } else {
+                let align = info.align.max(Alignment::MIN_UNIFORM);
+                (align, align.round_up(info.span))
+            };
+
+            let span = match size {
+                crate::ArraySize::Constant(size) => size.get() * stride,
+                crate::ArraySize::Dynamic => stride,
+            };
+
+            let ty_span = types.get_span(ty);
+            ty = types.insert(
+                Type {
+                    name,
+                    inner: TypeInner::Array {
+                        base: info.ty,
+                        size,
+                        stride,
+                    },
+                },
+                ty_span,
+            );
+
+            (align, span)
+        }
+        // 5. If the member is a column-major matrix with C columns and R rows, the
+        // matrix is stored identically to an array of C column vectors with R
+        // components each, according to rule (4)
+        // TODO: Row major matrices
+        TypeInner::Matrix {
+            columns,
+            rows,
+            scalar,
+        } => {
+            let mut align = Alignment::from(rows) * Alignment::from_width(scalar.width);
+
+            // See comment at the beginning of the function
+            if StructLayout::Std430 != layout {
+                align = align.max(Alignment::MIN_UNIFORM);
+            }
+
+            // See comment on the error kind
+            if StructLayout::Std140 == layout && rows == crate::VectorSize::Bi {
+                errors.push(Error {
+                    kind: ErrorKind::UnsupportedMatrixTypeInStd140,
+                    meta,
+                });
+            }
+
+            (align, align * columns as u32)
+        }
+        TypeInner::Struct { ref members, .. } => {
+            let mut span = 0;
+            let mut align = Alignment::ONE;
+            let mut members = members.clone();
+            let name = types[ty].name.clone();
+
+            for member in members.iter_mut() {
+                let info = calculate_offset(member.ty, meta, layout, types, errors);
+
+                let member_alignment = info.align;
+                span = member_alignment.round_up(span);
+                align = member_alignment.max(align);
+
+                member.ty = info.ty;
+                member.offset = span;
+
+                span += info.span;
+            }
+
+            span = align.round_up(span);
+
+            let ty_span = types.get_span(ty);
+            ty = types.insert(
+                Type {
+                    name,
+                    inner: TypeInner::Struct { members, span },
+                },
+                ty_span,
+            );
+
+            (align, span)
+        }
+        _ => {
+            errors.push(Error {
+                kind: ErrorKind::SemanticError("Invalid struct member type".into()),
+                meta,
+            });
+            (Alignment::ONE, 0)
+        }
+    };
+
+    TypeAlignSpan { ty, align, span }
+}
diff --git a/third_party/rust/naga/src/front/glsl/parser.rs b/third_party/rust/naga/src/front/glsl/parser.rs
new file mode 100644
index 0000000000..851d2e1d79
--- /dev/null
+++ b/third_party/rust/naga/src/front/glsl/parser.rs
@@ -0,0 +1,431 @@
+use super::{
+    ast::{FunctionKind, Profile, TypeQualifiers},
+    context::{Context, ExprPos},
+    error::ExpectedToken,
+    error::{Error, ErrorKind},
+    lex::{Lexer, LexerResultKind},
+    token::{Directive, DirectiveKind},
+    token::{Token, TokenValue},
+    variables::{GlobalOrConstant, VarDeclaration},
+    Frontend, Result,
+};
+use crate::{arena::Handle, proc::U32EvalError, Expression, Module, Span, Type};
+use pp_rs::token::{PreprocessorError, Token as PPToken, TokenValue as PPTokenValue};
+use std::iter::Peekable;
+
+mod declarations;
+mod expressions;
+mod functions;
+mod types;
+
+pub struct ParsingContext<'source> {
+    lexer: Peekable<Lexer<'source>>,
+    /// Used to store tokens already consumed by the parser but that need to be backtracked
+    backtracked_token: Option<Token>,
+    last_meta: Span,
+}
+
+impl<'source> ParsingContext<'source> {
+    pub fn new(lexer: Lexer<'source>) -> Self {
+        ParsingContext {
+            lexer: lexer.peekable(),
+            backtracked_token: None,
+            last_meta: Span::default(),
+        }
+    }
+
+    /// Helper method for backtracking from a consumed token
+    ///
+    /// This method should always be used instead of assigning to `backtracked_token` since
+    /// it validates that backtracking hasn't occurred more than one time in a row
+    ///
+    /// # Panics
+    /// - If the parser already backtracked without bumping in between
+    pub fn backtrack(&mut self, token: Token) -> Result<()> {
+        // This should never happen
+        if let Some(ref prev_token) = self.backtracked_token {
+            return Err(Error {
+                kind: ErrorKind::InternalError("The parser tried to backtrack twice in a row"),
+                meta: prev_token.meta,
+            });
+        }
+
+        self.backtracked_token = Some(token);
+
+        Ok(())
+    }
+
+    pub fn expect_ident(&mut self, frontend: &mut Frontend) -> Result<(String, Span)> {
+        let token = self.bump(frontend)?;
+
+        match token.value {
+            TokenValue::Identifier(name) => Ok((name, token.meta)),
+            _ => Err(Error {
+                kind: ErrorKind::InvalidToken(token.value, vec![ExpectedToken::Identifier]),
+                meta: token.meta,
+            }),
+        }
+    }
+
+    pub fn expect(&mut self, frontend: &mut Frontend, value: TokenValue) -> Result<Token> {
+        let token = self.bump(frontend)?;
+
+        if token.value != value {
+            Err(Error {
+                kind: ErrorKind::InvalidToken(token.value, vec![value.into()]),
+                meta: token.meta,
+            })
+        } else {
+            Ok(token)
+        }
+    }
+
+    pub fn next(&mut self, frontend: &mut Frontend) -> Option<Token> {
+        loop {
+            if let Some(token) = self.backtracked_token.take() {
+                self.last_meta = token.meta;
+                break Some(token);
+            }
+
+            let res = self.lexer.next()?;
+
+            match res.kind {
+                LexerResultKind::Token(token) => {
+                    self.last_meta = token.meta;
+                    break Some(token);
+                }
+                LexerResultKind::Directive(directive) => {
+                    frontend.handle_directive(directive, res.meta)
+                }
+                LexerResultKind::Error(error) => frontend.errors.push(Error {
+                    kind: ErrorKind::PreprocessorError(error),
+                    meta: res.meta,
+                }),
+            }
+        }
+    }
+
+    pub fn bump(&mut self, frontend: &mut Frontend) -> Result<Token> {
+        self.next(frontend).ok_or(Error {
+            kind: ErrorKind::EndOfFile,
+            meta: self.last_meta,
+        })
+    }
+
+    /// Returns None on the end of the file rather than an error like other methods
+    pub fn bump_if(&mut self, frontend: &mut Frontend, value: TokenValue) -> Option<Token> {
+        if self.peek(frontend).filter(|t| t.value == value).is_some() {
+            self.bump(frontend).ok()
+        } else {
+            None
+        }
+    }
+
+    pub fn peek(&mut self, frontend: &mut Frontend) -> Option<&Token> {
+        loop {
+            if let Some(ref token) = self.backtracked_token {
+                break Some(token);
+            }
+
+            match self.lexer.peek()?.kind {
+                LexerResultKind::Token(_) => {
+                    let res = self.lexer.peek()?;
+
+                    match res.kind {
+                        LexerResultKind::Token(ref token) => break Some(token),
+                        _ => unreachable!(),
+                    }
+                }
+                LexerResultKind::Error(_) | LexerResultKind::Directive(_) => {
+                    let res = self.lexer.next()?;
+
+                    match res.kind {
+                        LexerResultKind::Directive(directive) => {
+                            frontend.handle_directive(directive, res.meta)
+                        }
+                        LexerResultKind::Error(error) => frontend.errors.push(Error {
+                            kind: ErrorKind::PreprocessorError(error),
+                            meta: res.meta,
+                        }),
+                        LexerResultKind::Token(_) => unreachable!(),
+                    }
+                }
+            }
+        }
+    }
+
+    pub fn expect_peek(&mut self, frontend: &mut Frontend) -> Result<&Token> {
+        let meta = self.last_meta;
+        self.peek(frontend).ok_or(Error {
+            kind: ErrorKind::EndOfFile,
+            meta,
+        })
+    }
+
+    pub fn parse(&mut self, frontend: &mut Frontend) -> Result<Module> {
+        let mut module = Module::default();
+
+        // Body and expression arena for global initialization
+        let mut ctx = Context::new(frontend, &mut module, false)?;
+
+        while self.peek(frontend).is_some() {
+            self.parse_external_declaration(frontend, &mut ctx)?;
+        }
+
+        // Add an `EntryPoint` to `parser.module` for `main`, if a
+        // suitable overload exists. Error out if we can't find one.
+        if let Some(declaration) = frontend.lookup_function.get("main") {
+            for decl in declaration.overloads.iter() {
+                if let FunctionKind::Call(handle) = decl.kind {
+                    if decl.defined && decl.parameters.is_empty() {
+                        frontend.add_entry_point(handle, ctx)?;
+                        return Ok(module);
+                    }
+                }
+            }
+        }
+
+        Err(Error {
+            kind: ErrorKind::SemanticError("Missing entry point".into()),
+            meta: Span::default(),
+        })
+    }
+
+    fn parse_uint_constant(
+        &mut self,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+    ) -> Result<(u32, Span)> {
+        let (const_expr, meta) = self.parse_constant_expression(frontend, ctx.module)?;
+
+        let res = ctx.module.to_ctx().eval_expr_to_u32(const_expr);
+
+        let int = match res {
+            Ok(value) => Ok(value),
+            Err(U32EvalError::Negative) => Err(Error {
+                kind: ErrorKind::SemanticError("int constant overflows".into()),
+                meta,
+            }),
+            Err(U32EvalError::NonConst) => Err(Error {
+                kind: ErrorKind::SemanticError("Expected a uint constant".into()),
+                meta,
+            }),
+        }?;
+
+        Ok((int, meta))
+    }
+
+    fn parse_constant_expression(
+        &mut self,
+        frontend: &mut Frontend,
+        module: &mut Module,
+    ) -> Result<(Handle<Expression>, Span)> {
+        let mut ctx = Context::new(frontend, module, true)?;
+
+        let mut stmt_ctx = ctx.stmt_ctx();
+        let expr = self.parse_conditional(frontend, &mut ctx, &mut stmt_ctx, None)?;
+        let (root, meta) = ctx.lower_expect(stmt_ctx, frontend, expr, ExprPos::Rhs)?;
+
+        Ok((root, meta))
+    }
+}
+
+impl Frontend {
+    fn handle_directive(&mut self, directive: Directive, meta: Span) {
+        let mut tokens = directive.tokens.into_iter();
+
+        match directive.kind {
+            DirectiveKind::Version { is_first_directive } => {
+                if !is_first_directive {
+                    self.errors.push(Error {
+                        kind: ErrorKind::SemanticError(
+                            "#version must occur first in shader".into(),
+                        ),
+                        meta,
+                    })
+                }
+
+                match tokens.next() {
+                    Some(PPToken {
+                        value: PPTokenValue::Integer(int),
+                        location,
+                    }) => match int.value {
+                        440 | 450 | 460 => self.meta.version = int.value as u16,
+                        _ => self.errors.push(Error {
+                            kind: ErrorKind::InvalidVersion(int.value),
+                            meta: location.into(),
+                        }),
+                    },
+                    Some(PPToken { value, location }) => self.errors.push(Error {
+                        kind: ErrorKind::PreprocessorError(PreprocessorError::UnexpectedToken(
+                            value,
+                        )),
+                        meta: location.into(),
+                    }),
+                    None => self.errors.push(Error {
+                        kind: ErrorKind::PreprocessorError(PreprocessorError::UnexpectedNewLine),
+                        meta,
+                    }),
+                };
+
+                match tokens.next() {
+                    Some(PPToken {
+                        value: PPTokenValue::Ident(name),
+                        location,
+                    }) => match name.as_str() {
+                        "core" => self.meta.profile = Profile::Core,
+                        _ => self.errors.push(Error {
+                            kind: ErrorKind::InvalidProfile(name),
+                            meta: location.into(),
+                        }),
+                    },
+                    Some(PPToken { value, location }) => self.errors.push(Error {
+                        kind: ErrorKind::PreprocessorError(PreprocessorError::UnexpectedToken(
+                            value,
+                        )),
+                        meta: location.into(),
+                    }),
+                    None => {}
+                };
+
+                if let Some(PPToken { value, location }) = tokens.next() {
+                    self.errors.push(Error {
+                        kind: ErrorKind::PreprocessorError(PreprocessorError::UnexpectedToken(
+                            value,
+                        )),
+                        meta: location.into(),
+                    })
+                }
+            }
+            DirectiveKind::Extension => {
+                // TODO: Proper extension handling
+                // - Checking for extension support in the compiler
+                // - Handle behaviors such as warn
+                // - Handle the all extension
+                let name = match tokens.next() {
+                    Some(PPToken {
+                        value: PPTokenValue::Ident(name),
+                        ..
+                    }) => Some(name),
+                    Some(PPToken { value, location }) => {
+                        self.errors.push(Error {
+                            kind: ErrorKind::PreprocessorError(PreprocessorError::UnexpectedToken(
+                                value,
+                            )),
+                            meta: location.into(),
+                        });
+
+                        None
+                    }
+                    None => {
+                        self.errors.push(Error {
+                            kind: ErrorKind::PreprocessorError(
+                                PreprocessorError::UnexpectedNewLine,
+                            ),
+                            meta,
+                        });
+
+                        None
+                    }
+                };
+
+                match tokens.next() {
+                    Some(PPToken {
+                        value: PPTokenValue::Punct(pp_rs::token::Punct::Colon),
+                        ..
+                    }) => {}
+                    Some(PPToken { value, location }) => self.errors.push(Error {
+                        kind: ErrorKind::PreprocessorError(PreprocessorError::UnexpectedToken(
+                            value,
+                        )),
+                        meta: location.into(),
+                    }),
+                    None => self.errors.push(Error {
+                        kind: ErrorKind::PreprocessorError(PreprocessorError::UnexpectedNewLine),
+                        meta,
+                    }),
+                };
+
+                match tokens.next() {
+                    Some(PPToken {
+                        value: PPTokenValue::Ident(behavior),
+                        location,
+                    }) => match behavior.as_str() {
+                        "require" | "enable" | "warn" | "disable" => {
+                            if let Some(name) = name {
+                                self.meta.extensions.insert(name);
+                            }
+                        }
+                        _ => self.errors.push(Error {
+                            kind: ErrorKind::PreprocessorError(PreprocessorError::UnexpectedToken(
+                                PPTokenValue::Ident(behavior),
+                            )),
+                            meta: location.into(),
+                        }),
+                    },
+                    Some(PPToken { value, location }) => self.errors.push(Error {
+                        kind: ErrorKind::PreprocessorError(PreprocessorError::UnexpectedToken(
+                            value,
+                        )),
+                        meta: location.into(),
+                    }),
+                    None => self.errors.push(Error {
+                        kind: ErrorKind::PreprocessorError(PreprocessorError::UnexpectedNewLine),
+                        meta,
+                    }),
+                }
+
+                if let Some(PPToken { value, location }) = tokens.next() {
+                    self.errors.push(Error {
+                        kind: ErrorKind::PreprocessorError(PreprocessorError::UnexpectedToken(
+                            value,
+                        )),
+                        meta: location.into(),
+                    })
+                }
+            }
+            DirectiveKind::Pragma => {
+                // TODO: handle some common pragmas?
+            }
+        }
+    }
+}
+
+pub struct DeclarationContext<'ctx, 'qualifiers, 'a> {
+    qualifiers: TypeQualifiers<'qualifiers>,
+    /// Indicates a global declaration
+    external: bool,
+    is_inside_loop: bool,
+    ctx: &'ctx mut Context<'a>,
+}
+
+impl<'ctx, 'qualifiers, 'a> DeclarationContext<'ctx, 'qualifiers, 'a> {
+    fn add_var(
+        &mut self,
+        frontend: &mut Frontend,
+        ty: Handle<Type>,
+        name: String,
+        init: Option<Handle<Expression>>,
+        meta: Span,
+    ) -> Result<Handle<Expression>> {
+        let decl = VarDeclaration {
+            qualifiers: &mut self.qualifiers,
+            ty,
+            name: Some(name),
+            init,
+            meta,
+        };
+
+        match self.external {
+            true => {
+                let global = frontend.add_global_var(self.ctx, decl)?;
+                let expr = match global {
+                    GlobalOrConstant::Global(handle) => Expression::GlobalVariable(handle),
+                    GlobalOrConstant::Constant(handle) => Expression::Constant(handle),
+                };
+                Ok(self.ctx.add_expression(expr, meta)?)
+            }
+            false => frontend.add_local_var(self.ctx, decl),
+        }
+    }
+}
diff --git a/third_party/rust/naga/src/front/glsl/parser/declarations.rs b/third_party/rust/naga/src/front/glsl/parser/declarations.rs
new file mode 100644
index 0000000000..f5e38fb016
--- /dev/null
+++ b/third_party/rust/naga/src/front/glsl/parser/declarations.rs
@@ -0,0 +1,677 @@
+use crate::{
+    front::glsl::{
+        ast::{
+            GlobalLookup, GlobalLookupKind, Precision, QualifierKey, QualifierValue,
+            StorageQualifier, StructLayout, TypeQualifiers,
+        },
+        context::{Context, ExprPos},
+        error::ExpectedToken,
+        offset,
+        token::{Token, TokenValue},
+        types::scalar_components,
+        variables::{GlobalOrConstant, VarDeclaration},
+        Error, ErrorKind, Frontend, Span,
+    },
+    proc::Alignment,
+    AddressSpace, Expression, FunctionResult, Handle, Scalar, ScalarKind, Statement, StructMember,
+    Type, TypeInner,
+};
+
+use super::{DeclarationContext, ParsingContext, Result};
+
+/// Helper method used to retrieve the child type of `ty` at
+/// index `i`.
+///
+/// # Note
+///
+/// Does not check if the index is valid and returns the same type
+/// when indexing out-of-bounds a struct or indexing a non indexable
+/// type.
+fn element_or_member_type(
+    ty: Handle<Type>,
+    i: usize,
+    types: &mut crate::UniqueArena<Type>,
+) -> Handle<Type> {
+    match types[ty].inner {
+        // The child type of a vector is a scalar of the same kind and width
+        TypeInner::Vector { scalar, .. } => types.insert(
+            Type {
+                name: None,
+                inner: TypeInner::Scalar(scalar),
+            },
+            Default::default(),
+        ),
+        // The child type of a matrix is a vector of floats with the same
+        // width and the size of the matrix rows.
+        TypeInner::Matrix { rows, scalar, .. } => types.insert(
+            Type {
+                name: None,
+                inner: TypeInner::Vector { size: rows, scalar },
+            },
+            Default::default(),
+        ),
+        // The child type of an array is the base type of the array
+        TypeInner::Array { base, .. } => base,
+        // The child type of a struct at index `i` is the type of it's
+        // member at that same index.
+        //
+        // In case the index is out of bounds the same type is returned
+        TypeInner::Struct { ref members, .. } => {
+            members.get(i).map(|member| member.ty).unwrap_or(ty)
+        }
+        // The type isn't indexable, the same type is returned
+        _ => ty,
+    }
+}
+
+impl<'source> ParsingContext<'source> {
+    pub fn parse_external_declaration(
+        &mut self,
+        frontend: &mut Frontend,
+        global_ctx: &mut Context,
+    ) -> Result<()> {
+        if self
+            .parse_declaration(frontend, global_ctx, true, false)?
+            .is_none()
+        {
+            let token = self.bump(frontend)?;
+            match token.value {
+                TokenValue::Semicolon if frontend.meta.version == 460 => Ok(()),
+                _ => {
+                    let expected = match frontend.meta.version {
+                        460 => vec![TokenValue::Semicolon.into(), ExpectedToken::Eof],
+                        _ => vec![ExpectedToken::Eof],
+                    };
+                    Err(Error {
+                        kind: ErrorKind::InvalidToken(token.value, expected),
+                        meta: token.meta,
+                    })
+                }
+            }
+        } else {
+            Ok(())
+        }
+    }
+
+    pub fn parse_initializer(
+        &mut self,
+        frontend: &mut Frontend,
+        ty: Handle<Type>,
+        ctx: &mut Context,
+    ) -> Result<(Handle<Expression>, Span)> {
+        // initializer:
+        //     assignment_expression
+        //     LEFT_BRACE initializer_list RIGHT_BRACE
+        //     LEFT_BRACE initializer_list COMMA RIGHT_BRACE
+        //
+        // initializer_list:
+        //     initializer
+        //     initializer_list COMMA initializer
+        if let Some(Token { mut meta, .. }) = self.bump_if(frontend, TokenValue::LeftBrace) {
+            // initializer_list
+            let mut components = Vec::new();
+            loop {
+                // The type expected to be parsed inside the initializer list
+                let new_ty = element_or_member_type(ty, components.len(), &mut ctx.module.types);
+
+                components.push(self.parse_initializer(frontend, new_ty, ctx)?.0);
+
+                let token = self.bump(frontend)?;
+                match token.value {
+                    TokenValue::Comma => {
+                        if let Some(Token { meta: end_meta, .. }) =
+                            self.bump_if(frontend, TokenValue::RightBrace)
+                        {
+                            meta.subsume(end_meta);
+                            break;
+                        }
+                    }
+                    TokenValue::RightBrace => {
+                        meta.subsume(token.meta);
+                        break;
+                    }
+                    _ => {
+                        return Err(Error {
+                            kind: ErrorKind::InvalidToken(
+                                token.value,
+                                vec![TokenValue::Comma.into(), TokenValue::RightBrace.into()],
+                            ),
+                            meta: token.meta,
+                        })
+                    }
+                }
+            }
+
+            Ok((
+                ctx.add_expression(Expression::Compose { ty, components }, meta)?,
+                meta,
+            ))
+        } else {
+            let mut stmt = ctx.stmt_ctx();
+            let expr = self.parse_assignment(frontend, ctx, &mut stmt)?;
+            let (mut init, init_meta) = ctx.lower_expect(stmt, frontend, expr, ExprPos::Rhs)?;
+
+            let scalar_components = scalar_components(&ctx.module.types[ty].inner);
+            if let Some(scalar) = scalar_components {
+                ctx.implicit_conversion(&mut init, init_meta, scalar)?;
+            }
+
+            Ok((init, init_meta))
+        }
+    }
+
+    // Note: caller preparsed the type and qualifiers
+    // Note: caller skips this if the fallthrough token is not expected to be consumed here so this
+    // produced Error::InvalidToken if it isn't consumed
+    pub fn parse_init_declarator_list(
+        &mut self,
+        frontend: &mut Frontend,
+        mut ty: Handle<Type>,
+        ctx: &mut DeclarationContext,
+    ) -> Result<()> {
+        // init_declarator_list:
+        //     single_declaration
+        //     init_declarator_list COMMA IDENTIFIER
+        //     init_declarator_list COMMA IDENTIFIER array_specifier
+        //     init_declarator_list COMMA IDENTIFIER array_specifier EQUAL initializer
+        //     init_declarator_list COMMA IDENTIFIER EQUAL initializer
+        //
+        // single_declaration:
+        //     fully_specified_type
+        //     fully_specified_type IDENTIFIER
+        //     fully_specified_type IDENTIFIER array_specifier
+        //     fully_specified_type IDENTIFIER array_specifier EQUAL initializer
+        //     fully_specified_type IDENTIFIER EQUAL initializer
+
+        // Consume any leading comma, e.g. this is valid: `float, a=1;`
+        if self
+            .peek(frontend)
+            .map_or(false, |t| t.value == TokenValue::Comma)
+        {
+            self.next(frontend);
+        }
+
+        loop {
+            let token = self.bump(frontend)?;
+            let name = match token.value {
+                TokenValue::Semicolon => break,
+                TokenValue::Identifier(name) => name,
+                _ => {
+                    return Err(Error {
+                        kind: ErrorKind::InvalidToken(
+                            token.value,
+                            vec![ExpectedToken::Identifier, TokenValue::Semicolon.into()],
+                        ),
+                        meta: token.meta,
+                    })
+                }
+            };
+            let mut meta = token.meta;
+
+            // array_specifier
+            // array_specifier EQUAL initializer
+            // EQUAL initializer
+
+            // parse an array specifier if it exists
+            // NOTE: unlike other parse methods this one doesn't expect an array specifier and
+            // returns Ok(None) rather than an error if there is not one
+            self.parse_array_specifier(frontend, ctx.ctx, &mut meta, &mut ty)?;
+
+            let is_global_const =
+                ctx.qualifiers.storage.0 == StorageQualifier::Const && ctx.external;
+
+            let init = self
+                .bump_if(frontend, TokenValue::Assign)
+                .map::<Result<_>, _>(|_| {
+                    let prev_const = ctx.ctx.is_const;
+                    ctx.ctx.is_const = is_global_const;
+
+                    let (mut expr, init_meta) = self.parse_initializer(frontend, ty, ctx.ctx)?;
+
+                    let scalar_components = scalar_components(&ctx.ctx.module.types[ty].inner);
+                    if let Some(scalar) = scalar_components {
+                        ctx.ctx.implicit_conversion(&mut expr, init_meta, scalar)?;
+                    }
+
+                    ctx.ctx.is_const = prev_const;
+
+                    meta.subsume(init_meta);
+
+                    Ok(expr)
+                })
+                .transpose()?;
+
+            let decl_initializer;
+            let late_initializer;
+            if is_global_const {
+                decl_initializer = init;
+                late_initializer = None;
+            } else if ctx.external {
+                decl_initializer =
+                    init.and_then(|expr| ctx.ctx.lift_up_const_expression(expr).ok());
+                late_initializer = None;
+            } else if let Some(init) = init {
+                if ctx.is_inside_loop || !ctx.ctx.expression_constness.is_const(init) {
+                    decl_initializer = None;
+                    late_initializer = Some(init);
+                } else {
+                    decl_initializer = Some(init);
+                    late_initializer = None;
+                }
+            } else {
+                decl_initializer = None;
+                late_initializer = None;
+            };
+
+            let pointer = ctx.add_var(frontend, ty, name, decl_initializer, meta)?;
+
+            if let Some(value) = late_initializer {
+                ctx.ctx.emit_restart();
+                ctx.ctx.body.push(Statement::Store { pointer, value }, meta);
+            }
+
+            let token = self.bump(frontend)?;
+            match token.value {
+                TokenValue::Semicolon => break,
+                TokenValue::Comma => {}
+                _ => {
+                    return Err(Error {
+                        kind: ErrorKind::InvalidToken(
+                            token.value,
+                            vec![TokenValue::Comma.into(), TokenValue::Semicolon.into()],
+                        ),
+                        meta: token.meta,
+                    })
+                }
+            }
+        }
+
+        Ok(())
+    }
+
+    /// `external` whether or not we are in a global or local context
+    pub fn parse_declaration(
+        &mut self,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+        external: bool,
+        is_inside_loop: bool,
+    ) -> Result<Option<Span>> {
+        //declaration:
+        //    function_prototype  SEMICOLON
+        //
+        //    init_declarator_list SEMICOLON
+        //    PRECISION precision_qualifier type_specifier SEMICOLON
+        //
+        //    type_qualifier IDENTIFIER LEFT_BRACE struct_declaration_list RIGHT_BRACE SEMICOLON
+        //    type_qualifier IDENTIFIER LEFT_BRACE struct_declaration_list RIGHT_BRACE IDENTIFIER SEMICOLON
+        //    type_qualifier IDENTIFIER LEFT_BRACE struct_declaration_list RIGHT_BRACE IDENTIFIER array_specifier SEMICOLON
+        //    type_qualifier SEMICOLON type_qualifier IDENTIFIER SEMICOLON
+        //    type_qualifier IDENTIFIER identifier_list SEMICOLON
+
+        if self.peek_type_qualifier(frontend) || self.peek_type_name(frontend) {
+            let mut qualifiers = self.parse_type_qualifiers(frontend, ctx)?;
+
+            if self.peek_type_name(frontend) {
+                // This branch handles variables and function prototypes and if
+                // external is true also function definitions
+                let (ty, mut meta) = self.parse_type(frontend, ctx)?;
+
+                let token = self.bump(frontend)?;
+                let token_fallthrough = match token.value {
+                    TokenValue::Identifier(name) => match self.expect_peek(frontend)?.value {
+                        TokenValue::LeftParen => {
+                            // This branch handles function definition and prototypes
+                            self.bump(frontend)?;
+
+                            let result = ty.map(|ty| FunctionResult { ty, binding: None });
+
+                            let mut context = Context::new(frontend, ctx.module, false)?;
+
+                            self.parse_function_args(frontend, &mut context)?;
+
+                            let end_meta = self.expect(frontend, TokenValue::RightParen)?.meta;
+                            meta.subsume(end_meta);
+
+                            let token = self.bump(frontend)?;
+                            return match token.value {
+                                TokenValue::Semicolon => {
+                                    // This branch handles function prototypes
+                                    frontend.add_prototype(context, name, result, meta);
+
+                                    Ok(Some(meta))
+                                }
+                                TokenValue::LeftBrace if external => {
+                                    // This branch handles function definitions
+                                    // as you can see by the guard this branch
+                                    // only happens if external is also true
+
+                                    // parse the body
+                                    self.parse_compound_statement(
+                                        token.meta,
+                                        frontend,
+                                        &mut context,
+                                        &mut None,
+                                        false,
+                                    )?;
+
+                                    frontend.add_function(context, name, result, meta);
+
+                                    Ok(Some(meta))
+                                }
+                                _ if external => Err(Error {
+                                    kind: ErrorKind::InvalidToken(
+                                        token.value,
+                                        vec![
+                                            TokenValue::LeftBrace.into(),
+                                            TokenValue::Semicolon.into(),
+                                        ],
+                                    ),
+                                    meta: token.meta,
+                                }),
+                                _ => Err(Error {
+                                    kind: ErrorKind::InvalidToken(
+                                        token.value,
+                                        vec![TokenValue::Semicolon.into()],
+                                    ),
+                                    meta: token.meta,
+                                }),
+                            };
+                        }
+                        // Pass the token to the init_declarator_list parser
+                        _ => Token {
+                            value: TokenValue::Identifier(name),
+                            meta: token.meta,
+                        },
+                    },
+                    // Pass the token to the init_declarator_list parser
+                    _ => token,
+                };
+
+                // If program execution has reached here then this will be a
+                // init_declarator_list
+                // token_fallthrough will have a token that was already bumped
+                if let Some(ty) = ty {
+                    let mut ctx = DeclarationContext {
+                        qualifiers,
+                        external,
+                        is_inside_loop,
+                        ctx,
+                    };
+
+                    self.backtrack(token_fallthrough)?;
+                    self.parse_init_declarator_list(frontend, ty, &mut ctx)?;
+                } else {
+                    frontend.errors.push(Error {
+                        kind: ErrorKind::SemanticError("Declaration cannot have void type".into()),
+                        meta,
+                    })
+                }
+
+                Ok(Some(meta))
+            } else {
+                // This branch handles struct definitions and modifiers like
+                // ```glsl
+                // layout(early_fragment_tests);
+                // ```
+                let token = self.bump(frontend)?;
+                match token.value {
+                    TokenValue::Identifier(ty_name) => {
+                        if self.bump_if(frontend, TokenValue::LeftBrace).is_some() {
+                            self.parse_block_declaration(
+                                frontend,
+                                ctx,
+                                &mut qualifiers,
+                                ty_name,
+                                token.meta,
+                            )
+                            .map(Some)
+                        } else {
+                            if qualifiers.invariant.take().is_some() {
+                                frontend.make_variable_invariant(ctx, &ty_name, token.meta)?;
+
+                                qualifiers.unused_errors(&mut frontend.errors);
+                                self.expect(frontend, TokenValue::Semicolon)?;
+                                return Ok(Some(qualifiers.span));
+                            }
+
+                            //TODO: declaration
+                            // type_qualifier IDENTIFIER SEMICOLON
+                            // type_qualifier IDENTIFIER identifier_list SEMICOLON
+                            Err(Error {
+                                kind: ErrorKind::NotImplemented("variable qualifier"),
+                                meta: token.meta,
+                            })
+                        }
+                    }
+                    TokenValue::Semicolon => {
+                        if let Some(value) =
+                            qualifiers.uint_layout_qualifier("local_size_x", &mut frontend.errors)
+                        {
+                            frontend.meta.workgroup_size[0] = value;
+                        }
+                        if let Some(value) =
+                            qualifiers.uint_layout_qualifier("local_size_y", &mut frontend.errors)
+                        {
+                            frontend.meta.workgroup_size[1] = value;
+                        }
+                        if let Some(value) =
+                            qualifiers.uint_layout_qualifier("local_size_z", &mut frontend.errors)
+                        {
+                            frontend.meta.workgroup_size[2] = value;
+                        }
+
+                        frontend.meta.early_fragment_tests |= qualifiers
+                            .none_layout_qualifier("early_fragment_tests", &mut frontend.errors);
+
+                        qualifiers.unused_errors(&mut frontend.errors);
+
+                        Ok(Some(qualifiers.span))
+                    }
+                    _ => Err(Error {
+                        kind: ErrorKind::InvalidToken(
+                            token.value,
+                            vec![ExpectedToken::Identifier, TokenValue::Semicolon.into()],
+                        ),
+                        meta: token.meta,
+                    }),
+                }
+            }
+        } else {
+            match self.peek(frontend).map(|t| &t.value) {
+                Some(&TokenValue::Precision) => {
+                    // PRECISION precision_qualifier type_specifier SEMICOLON
+                    self.bump(frontend)?;
+
+                    let token = self.bump(frontend)?;
+                    let _ = match token.value {
+                        TokenValue::PrecisionQualifier(p) => p,
+                        _ => {
+                            return Err(Error {
+                                kind: ErrorKind::InvalidToken(
+                                    token.value,
+                                    vec![
+                                        TokenValue::PrecisionQualifier(Precision::High).into(),
+                                        TokenValue::PrecisionQualifier(Precision::Medium).into(),
+                                        TokenValue::PrecisionQualifier(Precision::Low).into(),
+                                    ],
+                                ),
+                                meta: token.meta,
+                            })
+                        }
+                    };
+
+                    let (ty, meta) = self.parse_type_non_void(frontend, ctx)?;
+
+                    match ctx.module.types[ty].inner {
+                        TypeInner::Scalar(Scalar {
+                            kind: ScalarKind::Float | ScalarKind::Sint,
+                            ..
+                        }) => {}
+                        _ => frontend.errors.push(Error {
+                            kind: ErrorKind::SemanticError(
+                                "Precision statement can only work on floats and ints".into(),
+                            ),
+                            meta,
+                        }),
+                    }
+
+                    self.expect(frontend, TokenValue::Semicolon)?;
+
+                    Ok(Some(meta))
+                }
+                _ => Ok(None),
+            }
+        }
+    }
+
+    pub fn parse_block_declaration(
+        &mut self,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+        qualifiers: &mut TypeQualifiers,
+        ty_name: String,
+        mut meta: Span,
+    ) -> Result<Span> {
+        let layout = match qualifiers.layout_qualifiers.remove(&QualifierKey::Layout) {
+            Some((QualifierValue::Layout(l), _)) => l,
+            None => {
+                if let StorageQualifier::AddressSpace(AddressSpace::Storage { .. }) =
+                    qualifiers.storage.0
+                {
+                    StructLayout::Std430
+                } else {
+                    StructLayout::Std140
+                }
+            }
+            _ => unreachable!(),
+        };
+
+        let mut members = Vec::new();
+        let span = self.parse_struct_declaration_list(frontend, ctx, &mut members, layout)?;
+        self.expect(frontend, TokenValue::RightBrace)?;
+
+        let mut ty = ctx.module.types.insert(
+            Type {
+                name: Some(ty_name),
+                inner: TypeInner::Struct {
+                    members: members.clone(),
+                    span,
+                },
+            },
+            Default::default(),
+        );
+
+        let token = self.bump(frontend)?;
+        let name = match token.value {
+            TokenValue::Semicolon => None,
+            TokenValue::Identifier(name) => {
+                self.parse_array_specifier(frontend, ctx, &mut meta, &mut ty)?;
+
+                self.expect(frontend, TokenValue::Semicolon)?;
+
+                Some(name)
+            }
+            _ => {
+                return Err(Error {
+                    kind: ErrorKind::InvalidToken(
+                        token.value,
+                        vec![ExpectedToken::Identifier, TokenValue::Semicolon.into()],
+                    ),
+                    meta: token.meta,
+                })
+            }
+        };
+
+        let global = frontend.add_global_var(
+            ctx,
+            VarDeclaration {
+                qualifiers,
+                ty,
+                name,
+                init: None,
+                meta,
+            },
+        )?;
+
+        for (i, k, ty) in members.into_iter().enumerate().filter_map(|(i, m)| {
+            let ty = m.ty;
+            m.name.map(|s| (i as u32, s, ty))
+        }) {
+            let lookup = GlobalLookup {
+                kind: match global {
+                    GlobalOrConstant::Global(handle) => GlobalLookupKind::BlockSelect(handle, i),
+                    GlobalOrConstant::Constant(handle) => GlobalLookupKind::Constant(handle, ty),
+                },
+                entry_arg: None,
+                mutable: true,
+            };
+            ctx.add_global(&k, lookup)?;
+
+            frontend.global_variables.push((k, lookup));
+        }
+
+        Ok(meta)
+    }
+
+    // TODO: Accept layout arguments
+    pub fn parse_struct_declaration_list(
+        &mut self,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+        members: &mut Vec<StructMember>,
+        layout: StructLayout,
+    ) -> Result<u32> {
+        let mut span = 0;
+        let mut align = Alignment::ONE;
+
+        loop {
+            // TODO: type_qualifier
+
+            let (base_ty, mut meta) = self.parse_type_non_void(frontend, ctx)?;
+
+            loop {
+                let (name, name_meta) = self.expect_ident(frontend)?;
+                let mut ty = base_ty;
+                self.parse_array_specifier(frontend, ctx, &mut meta, &mut ty)?;
+
+                meta.subsume(name_meta);
+
+                let info = offset::calculate_offset(
+                    ty,
+                    meta,
+                    layout,
+                    &mut ctx.module.types,
+                    &mut frontend.errors,
+                );
+
+                let member_alignment = info.align;
+                span = member_alignment.round_up(span);
+                align = member_alignment.max(align);
+
+                members.push(StructMember {
+                    name: Some(name),
+                    ty: info.ty,
+                    binding: None,
+                    offset: span,
+                });
+
+                span += info.span;
+
+                if self.bump_if(frontend, TokenValue::Comma).is_none() {
+                    break;
+                }
+            }
+
+            self.expect(frontend, TokenValue::Semicolon)?;
+
+            if let TokenValue::RightBrace = self.expect_peek(frontend)?.value {
+                break;
+            }
+        }
+
+        span = align.round_up(span);
+
+        Ok(span)
+    }
+}
diff --git a/third_party/rust/naga/src/front/glsl/parser/expressions.rs b/third_party/rust/naga/src/front/glsl/parser/expressions.rs
new file mode 100644
index 0000000000..1b8febce90
--- /dev/null
+++ b/third_party/rust/naga/src/front/glsl/parser/expressions.rs
@@ -0,0 +1,542 @@
+use std::num::NonZeroU32;
+
+use crate::{
+    front::glsl::{
+        ast::{FunctionCall, FunctionCallKind, HirExpr, HirExprKind},
+        context::{Context, StmtContext},
+        error::{ErrorKind, ExpectedToken},
+        parser::ParsingContext,
+        token::{Token, TokenValue},
+        Error, Frontend, Result, Span,
+    },
+    ArraySize, BinaryOperator, Handle, Literal, Type, TypeInner, UnaryOperator,
+};
+
+impl<'source> ParsingContext<'source> {
+    pub fn parse_primary(
+        &mut self,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+        stmt: &mut StmtContext,
+    ) -> Result<Handle<HirExpr>> {
+        let mut token = self.bump(frontend)?;
+
+        let literal = match token.value {
+            TokenValue::IntConstant(int) => {
+                if int.width != 32 {
+                    frontend.errors.push(Error {
+                        kind: ErrorKind::SemanticError("Unsupported non-32bit integer".into()),
+                        meta: token.meta,
+                    });
+                }
+                if int.signed {
+                    Literal::I32(int.value as i32)
+                } else {
+                    Literal::U32(int.value as u32)
+                }
+            }
+            TokenValue::FloatConstant(float) => {
+                if float.width != 32 {
+                    frontend.errors.push(Error {
+                        kind: ErrorKind::SemanticError("Unsupported floating-point value (expected single-precision floating-point number)".into()),
+                        meta: token.meta,
+                    });
+                }
+                Literal::F32(float.value)
+            }
+            TokenValue::BoolConstant(value) => Literal::Bool(value),
+            TokenValue::LeftParen => {
+                let expr = self.parse_expression(frontend, ctx, stmt)?;
+                let meta = self.expect(frontend, TokenValue::RightParen)?.meta;
+
+                token.meta.subsume(meta);
+
+                return Ok(expr);
+            }
+            _ => {
+                return Err(Error {
+                    kind: ErrorKind::InvalidToken(
+                        token.value,
+                        vec![
+                            TokenValue::LeftParen.into(),
+                            ExpectedToken::IntLiteral,
+                            ExpectedToken::FloatLiteral,
+                            ExpectedToken::BoolLiteral,
+                        ],
+                    ),
+                    meta: token.meta,
+                });
+            }
+        };
+
+        Ok(stmt.hir_exprs.append(
+            HirExpr {
+                kind: HirExprKind::Literal(literal),
+                meta: token.meta,
+            },
+            Default::default(),
+        ))
+    }
+
+    pub fn parse_function_call_args(
+        &mut self,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+        stmt: &mut StmtContext,
+        meta: &mut Span,
+    ) -> Result<Vec<Handle<HirExpr>>> {
+        let mut args = Vec::new();
+        if let Some(token) = self.bump_if(frontend, TokenValue::RightParen) {
+            meta.subsume(token.meta);
+        } else {
+            loop {
+                args.push(self.parse_assignment(frontend, ctx, stmt)?);
+
+                let token = self.bump(frontend)?;
+                match token.value {
+                    TokenValue::Comma => {}
+                    TokenValue::RightParen => {
+                        meta.subsume(token.meta);
+                        break;
+                    }
+                    _ => {
+                        return Err(Error {
+                            kind: ErrorKind::InvalidToken(
+                                token.value,
+                                vec![TokenValue::Comma.into(), TokenValue::RightParen.into()],
+                            ),
+                            meta: token.meta,
+                        });
+                    }
+                }
+            }
+        }
+
+        Ok(args)
+    }
+
+    pub fn parse_postfix(
+        &mut self,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+        stmt: &mut StmtContext,
+    ) -> Result<Handle<HirExpr>> {
+        let mut base = if self.peek_type_name(frontend) {
+            let (mut handle, mut meta) = self.parse_type_non_void(frontend, ctx)?;
+
+            self.expect(frontend, TokenValue::LeftParen)?;
+            let args = self.parse_function_call_args(frontend, ctx, stmt, &mut meta)?;
+
+            if let TypeInner::Array {
+                size: ArraySize::Dynamic,
+                stride,
+                base,
+            } = ctx.module.types[handle].inner
+            {
+                let span = ctx.module.types.get_span(handle);
+
+                let size = u32::try_from(args.len())
+                    .ok()
+                    .and_then(NonZeroU32::new)
+                    .ok_or(Error {
+                        kind: ErrorKind::SemanticError(
+                            "There must be at least one argument".into(),
+                        ),
+                        meta,
+                    })?;
+
+                handle = ctx.module.types.insert(
+                    Type {
+                        name: None,
+                        inner: TypeInner::Array {
+                            stride,
+                            base,
+                            size: ArraySize::Constant(size),
+                        },
+                    },
+                    span,
+                )
+            }
+
+            stmt.hir_exprs.append(
+                HirExpr {
+                    kind: HirExprKind::Call(FunctionCall {
+                        kind: FunctionCallKind::TypeConstructor(handle),
+                        args,
+                    }),
+                    meta,
+                },
+                Default::default(),
+            )
+        } else if let TokenValue::Identifier(_) = self.expect_peek(frontend)?.value {
+            let (name, mut meta) = self.expect_ident(frontend)?;
+
+            let expr = if self.bump_if(frontend, TokenValue::LeftParen).is_some() {
+                let args = self.parse_function_call_args(frontend, ctx, stmt, &mut meta)?;
+
+                let kind = match frontend.lookup_type.get(&name) {
+                    Some(ty) => FunctionCallKind::TypeConstructor(*ty),
+                    None => FunctionCallKind::Function(name),
+                };
+
+                HirExpr {
+                    kind: HirExprKind::Call(FunctionCall { kind, args }),
+                    meta,
+                }
+            } else {
+                let var = match frontend.lookup_variable(ctx, &name, meta)? {
+                    Some(var) => var,
+                    None => {
+                        return Err(Error {
+                            kind: ErrorKind::UnknownVariable(name),
+                            meta,
+                        })
+                    }
+                };
+
+                HirExpr {
+                    kind: HirExprKind::Variable(var),
+                    meta,
+                }
+            };
+
+            stmt.hir_exprs.append(expr, Default::default())
+        } else {
+            self.parse_primary(frontend, ctx, stmt)?
+        };
+
+        while let TokenValue::LeftBracket
+        | TokenValue::Dot
+        | TokenValue::Increment
+        | TokenValue::Decrement = self.expect_peek(frontend)?.value
+        {
+            let Token { value, mut meta } = self.bump(frontend)?;
+
+            match value {
+                TokenValue::LeftBracket => {
+                    let index = self.parse_expression(frontend, ctx, stmt)?;
+                    let end_meta = self.expect(frontend, TokenValue::RightBracket)?.meta;
+
+                    meta.subsume(end_meta);
+                    base = stmt.hir_exprs.append(
+                        HirExpr {
+                            kind: HirExprKind::Access { base, index },
+                            meta,
+                        },
+                        Default::default(),
+                    )
+                }
+                TokenValue::Dot => {
+                    let (field, end_meta) = self.expect_ident(frontend)?;
+
+                    if self.bump_if(frontend, TokenValue::LeftParen).is_some() {
+                        let args = self.parse_function_call_args(frontend, ctx, stmt, &mut meta)?;
+
+                        base = stmt.hir_exprs.append(
+                            HirExpr {
+                                kind: HirExprKind::Method {
+                                    expr: base,
+                                    name: field,
+                                    args,
+                                },
+                                meta,
+                            },
+                            Default::default(),
+                        );
+                        continue;
+                    }
+
+                    meta.subsume(end_meta);
+                    base = stmt.hir_exprs.append(
+                        HirExpr {
+                            kind: HirExprKind::Select { base, field },
+                            meta,
+                        },
+                        Default::default(),
+                    )
+                }
+                TokenValue::Increment | TokenValue::Decrement => {
+                    base = stmt.hir_exprs.append(
+                        HirExpr {
+                            kind: HirExprKind::PrePostfix {
+                                op: match value {
+                                    TokenValue::Increment => crate::BinaryOperator::Add,
+                                    _ => crate::BinaryOperator::Subtract,
+                                },
+                                postfix: true,
+                                expr: base,
+                            },
+                            meta,
+                        },
+                        Default::default(),
+                    )
+                }
+                _ => unreachable!(),
+            }
+        }
+
+        Ok(base)
+    }
+
+    pub fn parse_unary(
+        &mut self,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+        stmt: &mut StmtContext,
+    ) -> Result<Handle<HirExpr>> {
+        Ok(match self.expect_peek(frontend)?.value {
+            TokenValue::Plus | TokenValue::Dash | TokenValue::Bang | TokenValue::Tilde => {
+                let Token { value, mut meta } = self.bump(frontend)?;
+
+                let expr = self.parse_unary(frontend, ctx, stmt)?;
+                let end_meta = stmt.hir_exprs[expr].meta;
+
+                let kind = match value {
+                    TokenValue::Dash => HirExprKind::Unary {
+                        op: UnaryOperator::Negate,
+                        expr,
+                    },
+                    TokenValue::Bang => HirExprKind::Unary {
+                        op: UnaryOperator::LogicalNot,
+                        expr,
+                    },
+                    TokenValue::Tilde => HirExprKind::Unary {
+                        op: UnaryOperator::BitwiseNot,
+                        expr,
+                    },
+                    _ => return Ok(expr),
+                };
+
+                meta.subsume(end_meta);
+                stmt.hir_exprs
+                    .append(HirExpr { kind, meta }, Default::default())
+            }
+            TokenValue::Increment | TokenValue::Decrement => {
+                let Token { value, meta } = self.bump(frontend)?;
+
+                let expr = self.parse_unary(frontend, ctx, stmt)?;
+
+                stmt.hir_exprs.append(
+                    HirExpr {
+                        kind: HirExprKind::PrePostfix {
+                            op: match value {
+                                TokenValue::Increment => crate::BinaryOperator::Add,
+                                _ => crate::BinaryOperator::Subtract,
+                            },
+                            postfix: false,
+                            expr,
+                        },
+                        meta,
+                    },
+                    Default::default(),
+                )
+            }
+            _ => self.parse_postfix(frontend, ctx, stmt)?,
+        })
+    }
+
+    pub fn parse_binary(
+        &mut self,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+        stmt: &mut StmtContext,
+        passthrough: Option<Handle<HirExpr>>,
+        min_bp: u8,
+    ) -> Result<Handle<HirExpr>> {
+        let mut left = passthrough
+            .ok_or(ErrorKind::EndOfFile /* Dummy error */)
+            .or_else(|_| self.parse_unary(frontend, ctx, stmt))?;
+        let mut meta = stmt.hir_exprs[left].meta;
+
+        while let Some((l_bp, r_bp)) = binding_power(&self.expect_peek(frontend)?.value) {
+            if l_bp < min_bp {
+                break;
+            }
+
+            let Token { value, .. } = self.bump(frontend)?;
+
+            let right = self.parse_binary(frontend, ctx, stmt, None, r_bp)?;
+            let end_meta = stmt.hir_exprs[right].meta;
+
+            meta.subsume(end_meta);
+            left = stmt.hir_exprs.append(
+                HirExpr {
+                    kind: HirExprKind::Binary {
+                        left,
+                        op: match value {
+                            TokenValue::LogicalOr => BinaryOperator::LogicalOr,
+                            TokenValue::LogicalXor => BinaryOperator::NotEqual,
+                            TokenValue::LogicalAnd => BinaryOperator::LogicalAnd,
+                            TokenValue::VerticalBar => BinaryOperator::InclusiveOr,
+                            TokenValue::Caret => BinaryOperator::ExclusiveOr,
+                            TokenValue::Ampersand => BinaryOperator::And,
+                            TokenValue::Equal => BinaryOperator::Equal,
+                            TokenValue::NotEqual => BinaryOperator::NotEqual,
+                            TokenValue::GreaterEqual => BinaryOperator::GreaterEqual,
+                            TokenValue::LessEqual => BinaryOperator::LessEqual,
+                            TokenValue::LeftAngle => BinaryOperator::Less,
+                            TokenValue::RightAngle => BinaryOperator::Greater,
+                            TokenValue::LeftShift => BinaryOperator::ShiftLeft,
+                            TokenValue::RightShift => BinaryOperator::ShiftRight,
+                            TokenValue::Plus => BinaryOperator::Add,
+                            TokenValue::Dash => BinaryOperator::Subtract,
+                            TokenValue::Star => BinaryOperator::Multiply,
+                            TokenValue::Slash => BinaryOperator::Divide,
+                            TokenValue::Percent => BinaryOperator::Modulo,
+                            _ => unreachable!(),
+                        },
+                        right,
+                    },
+                    meta,
+                },
+                Default::default(),
+            )
+        }
+
+        Ok(left)
+    }
+
+    pub fn parse_conditional(
+        &mut self,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+        stmt: &mut StmtContext,
+        passthrough: Option<Handle<HirExpr>>,
+    ) -> Result<Handle<HirExpr>> {
+        let mut condition = self.parse_binary(frontend, ctx, stmt, passthrough, 0)?;
+        let mut meta = stmt.hir_exprs[condition].meta;
+
+        if self.bump_if(frontend, TokenValue::Question).is_some() {
+            let accept = self.parse_expression(frontend, ctx, stmt)?;
+            self.expect(frontend, TokenValue::Colon)?;
+            let reject = self.parse_assignment(frontend, ctx, stmt)?;
+            let end_meta = stmt.hir_exprs[reject].meta;
+
+            meta.subsume(end_meta);
+            condition = stmt.hir_exprs.append(
+                HirExpr {
+                    kind: HirExprKind::Conditional {
+                        condition,
+                        accept,
+                        reject,
+                    },
+                    meta,
+                },
+                Default::default(),
+            )
+        }
+
+        Ok(condition)
+    }
+
+    pub fn parse_assignment(
+        &mut self,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+        stmt: &mut StmtContext,
+    ) -> Result<Handle<HirExpr>> {
+        let tgt = self.parse_unary(frontend, ctx, stmt)?;
+        let mut meta = stmt.hir_exprs[tgt].meta;
+
+        Ok(match self.expect_peek(frontend)?.value {
+            TokenValue::Assign => {
+                self.bump(frontend)?;
+                let value = self.parse_assignment(frontend, ctx, stmt)?;
+                let end_meta = stmt.hir_exprs[value].meta;
+
+                meta.subsume(end_meta);
+                stmt.hir_exprs.append(
+                    HirExpr {
+                        kind: HirExprKind::Assign { tgt, value },
+                        meta,
+                    },
+                    Default::default(),
+                )
+            }
+            TokenValue::OrAssign
+            | TokenValue::AndAssign
+            | TokenValue::AddAssign
+            | TokenValue::DivAssign
+            | TokenValue::ModAssign
+            | TokenValue::SubAssign
+            | TokenValue::MulAssign
+            | TokenValue::LeftShiftAssign
+            | TokenValue::RightShiftAssign
+            | TokenValue::XorAssign => {
+                let token = self.bump(frontend)?;
+                let right = self.parse_assignment(frontend, ctx, stmt)?;
+                let end_meta = stmt.hir_exprs[right].meta;
+
+                meta.subsume(end_meta);
+                let value = stmt.hir_exprs.append(
+                    HirExpr {
+                        meta,
+                        kind: HirExprKind::Binary {
+                            left: tgt,
+                            op: match token.value {
+                                TokenValue::OrAssign => BinaryOperator::InclusiveOr,
+                                TokenValue::AndAssign => BinaryOperator::And,
+                                TokenValue::AddAssign => BinaryOperator::Add,
+                                TokenValue::DivAssign => BinaryOperator::Divide,
+                                TokenValue::ModAssign => BinaryOperator::Modulo,
+                                TokenValue::SubAssign => BinaryOperator::Subtract,
+                                TokenValue::MulAssign => BinaryOperator::Multiply,
+                                TokenValue::LeftShiftAssign => BinaryOperator::ShiftLeft,
+                                TokenValue::RightShiftAssign => BinaryOperator::ShiftRight,
+                                TokenValue::XorAssign => BinaryOperator::ExclusiveOr,
+                                _ => unreachable!(),
+                            },
+                            right,
+                        },
+                    },
+                    Default::default(),
+                );
+
+                stmt.hir_exprs.append(
+                    HirExpr {
+                        kind: HirExprKind::Assign { tgt, value },
+                        meta,
+                    },
+                    Default::default(),
+                )
+            }
+            _ => self.parse_conditional(frontend, ctx, stmt, Some(tgt))?,
+        })
+    }
+
+    pub fn parse_expression(
+        &mut self,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+        stmt: &mut StmtContext,
+    ) -> Result<Handle<HirExpr>> {
+        let mut expr = self.parse_assignment(frontend, ctx, stmt)?;
+
+        while let TokenValue::Comma = self.expect_peek(frontend)?.value {
+            self.bump(frontend)?;
+            expr = self.parse_assignment(frontend, ctx, stmt)?;
+        }
+
+        Ok(expr)
+    }
+}
+
+const fn binding_power(value: &TokenValue) -> Option<(u8, u8)> {
+    Some(match *value {
+        TokenValue::LogicalOr => (1, 2),
+        TokenValue::LogicalXor => (3, 4),
+        TokenValue::LogicalAnd => (5, 6),
+        TokenValue::VerticalBar => (7, 8),
+        TokenValue::Caret => (9, 10),
+        TokenValue::Ampersand => (11, 12),
+        TokenValue::Equal | TokenValue::NotEqual => (13, 14),
+        TokenValue::GreaterEqual
+        | TokenValue::LessEqual
+        | TokenValue::LeftAngle
+        | TokenValue::RightAngle => (15, 16),
+        TokenValue::LeftShift | TokenValue::RightShift => (17, 18),
+        TokenValue::Plus | TokenValue::Dash => (19, 20),
+        TokenValue::Star | TokenValue::Slash | TokenValue::Percent => (21, 22),
+        _ => return None,
+    })
+}
diff --git a/third_party/rust/naga/src/front/glsl/parser/functions.rs b/third_party/rust/naga/src/front/glsl/parser/functions.rs
new file mode 100644
index 0000000000..38184eedf7
--- /dev/null
+++ b/third_party/rust/naga/src/front/glsl/parser/functions.rs
@@ -0,0 +1,656 @@
+use crate::front::glsl::context::ExprPos;
+use crate::front::glsl::Span;
+use crate::Literal;
+use crate::{
+    front::glsl::{
+        ast::ParameterQualifier,
+        context::Context,
+        parser::ParsingContext,
+        token::{Token, TokenValue},
+        variables::VarDeclaration,
+        Error, ErrorKind, Frontend, Result,
+    },
+    Block, Expression, Statement, SwitchCase, UnaryOperator,
+};
+
+impl<'source> ParsingContext<'source> {
+    pub fn peek_parameter_qualifier(&mut self, frontend: &mut Frontend) -> bool {
+        self.peek(frontend).map_or(false, |t| match t.value {
+            TokenValue::In | TokenValue::Out | TokenValue::InOut | TokenValue::Const => true,
+            _ => false,
+        })
+    }
+
+    /// Returns the parsed `ParameterQualifier` or `ParameterQualifier::In`
+    pub fn parse_parameter_qualifier(&mut self, frontend: &mut Frontend) -> ParameterQualifier {
+        if self.peek_parameter_qualifier(frontend) {
+            match self.bump(frontend).unwrap().value {
+                TokenValue::In => ParameterQualifier::In,
+                TokenValue::Out => ParameterQualifier::Out,
+                TokenValue::InOut => ParameterQualifier::InOut,
+                TokenValue::Const => ParameterQualifier::Const,
+                _ => unreachable!(),
+            }
+        } else {
+            ParameterQualifier::In
+        }
+    }
+
+    pub fn parse_statement(
+        &mut self,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+        terminator: &mut Option<usize>,
+        is_inside_loop: bool,
+    ) -> Result<Option<Span>> {
+        // Type qualifiers always identify a declaration statement
+        if self.peek_type_qualifier(frontend) {
+            return self.parse_declaration(frontend, ctx, false, is_inside_loop);
+        }
+
+        // Type names can identify either declaration statements or type constructors
+        // depending on whether the token following the type name is a `(` (LeftParen)
+        if self.peek_type_name(frontend) {
+            // Start by consuming the type name so that we can peek the token after it
+            let token = self.bump(frontend)?;
+            // Peek the next token and check if it's a `(` (LeftParen) if so the statement
+            // is a constructor, otherwise it's a declaration. We need to do the check
+            // beforehand and not in the if since we will backtrack before the if
+            let declaration = TokenValue::LeftParen != self.expect_peek(frontend)?.value;
+
+            self.backtrack(token)?;
+
+            if declaration {
+                return self.parse_declaration(frontend, ctx, false, is_inside_loop);
+            }
+        }
+
+        let new_break = || {
+            let mut block = Block::new();
+            block.push(Statement::Break, crate::Span::default());
+            block
+        };
+
+        let &Token {
+            ref value,
+            mut meta,
+        } = self.expect_peek(frontend)?;
+
+        let meta_rest = match *value {
+            TokenValue::Continue => {
+                let meta = self.bump(frontend)?.meta;
+                ctx.body.push(Statement::Continue, meta);
+                terminator.get_or_insert(ctx.body.len());
+                self.expect(frontend, TokenValue::Semicolon)?.meta
+            }
+            TokenValue::Break => {
+                let meta = self.bump(frontend)?.meta;
+                ctx.body.push(Statement::Break, meta);
+                terminator.get_or_insert(ctx.body.len());
+                self.expect(frontend, TokenValue::Semicolon)?.meta
+            }
+            TokenValue::Return => {
+                self.bump(frontend)?;
+                let (value, meta) = match self.expect_peek(frontend)?.value {
+                    TokenValue::Semicolon => (None, self.bump(frontend)?.meta),
+                    _ => {
+                        // TODO: Implicit conversions
+                        let mut stmt = ctx.stmt_ctx();
+                        let expr = self.parse_expression(frontend, ctx, &mut stmt)?;
+                        self.expect(frontend, TokenValue::Semicolon)?;
+                        let (handle, meta) =
+                            ctx.lower_expect(stmt, frontend, expr, ExprPos::Rhs)?;
+                        (Some(handle), meta)
+                    }
+                };
+
+                ctx.emit_restart();
+
+                ctx.body.push(Statement::Return { value }, meta);
+                terminator.get_or_insert(ctx.body.len());
+
+                meta
+            }
+            TokenValue::Discard => {
+                let meta = self.bump(frontend)?.meta;
+                ctx.body.push(Statement::Kill, meta);
+                terminator.get_or_insert(ctx.body.len());
+
+                self.expect(frontend, TokenValue::Semicolon)?.meta
+            }
+            TokenValue::If => {
+                let mut meta = self.bump(frontend)?.meta;
+
+                self.expect(frontend, TokenValue::LeftParen)?;
+                let condition = {
+                    let mut stmt = ctx.stmt_ctx();
+                    let expr = self.parse_expression(frontend, ctx, &mut stmt)?;
+                    let (handle, more_meta) =
+                        ctx.lower_expect(stmt, frontend, expr, ExprPos::Rhs)?;
+                    meta.subsume(more_meta);
+                    handle
+                };
+                self.expect(frontend, TokenValue::RightParen)?;
+
+                let accept = ctx.new_body(|ctx| {
+                    if let Some(more_meta) =
+                        self.parse_statement(frontend, ctx, &mut None, is_inside_loop)?
+                    {
+                        meta.subsume(more_meta);
+                    }
+                    Ok(())
+                })?;
+
+                let reject = ctx.new_body(|ctx| {
+                    if self.bump_if(frontend, TokenValue::Else).is_some() {
+                        if let Some(more_meta) =
+                            self.parse_statement(frontend, ctx, &mut None, is_inside_loop)?
+                        {
+                            meta.subsume(more_meta);
+                        }
+                    }
+                    Ok(())
+                })?;
+
+                ctx.body.push(
+                    Statement::If {
+                        condition,
+                        accept,
+                        reject,
+                    },
+                    meta,
+                );
+
+                meta
+            }
+            TokenValue::Switch => {
+                let mut meta = self.bump(frontend)?.meta;
+                let end_meta;
+
+                self.expect(frontend, TokenValue::LeftParen)?;
+
+                let (selector, uint) = {
+                    let mut stmt = ctx.stmt_ctx();
+                    let expr = self.parse_expression(frontend, ctx, &mut stmt)?;
+                    let (root, meta) = ctx.lower_expect(stmt, frontend, expr, ExprPos::Rhs)?;
+                    let uint = ctx.resolve_type(root, meta)?.scalar_kind()
+                        == Some(crate::ScalarKind::Uint);
+                    (root, uint)
+                };
+
+                self.expect(frontend, TokenValue::RightParen)?;
+
+                ctx.emit_restart();
+
+                let mut cases = Vec::new();
+                // Track if any default case is present in the switch statement.
+                let mut default_present = false;
+
+                self.expect(frontend, TokenValue::LeftBrace)?;
+                loop {
+                    let value = match self.expect_peek(frontend)?.value {
+                        TokenValue::Case => {
+                            self.bump(frontend)?;
+
+                            let (const_expr, meta) =
+                                self.parse_constant_expression(frontend, ctx.module)?;
+
+                            match ctx.module.const_expressions[const_expr] {
+                                Expression::Literal(Literal::I32(value)) => match uint {
+                                    // This unchecked cast isn't good, but since
+                                    // we only reach this code when the selector
+                                    // is unsigned but the case label is signed,
+                                    // verification will reject the module
+                                    // anyway (which also matches GLSL's rules).
+                                    true => crate::SwitchValue::U32(value as u32),
+                                    false => crate::SwitchValue::I32(value),
+                                },
+                                Expression::Literal(Literal::U32(value)) => {
+                                    crate::SwitchValue::U32(value)
+                                }
+                                _ => {
+                                    frontend.errors.push(Error {
+                                        kind: ErrorKind::SemanticError(
+                                            "Case values can only be integers".into(),
+                                        ),
+                                        meta,
+                                    });
+
+                                    crate::SwitchValue::I32(0)
+                                }
+                            }
+                        }
+                        TokenValue::Default => {
+                            self.bump(frontend)?;
+                            default_present = true;
+                            crate::SwitchValue::Default
+                        }
+                        TokenValue::RightBrace => {
+                            end_meta = self.bump(frontend)?.meta;
+                            break;
+                        }
+                        _ => {
+                            let Token { value, meta } = self.bump(frontend)?;
+                            return Err(Error {
+                                kind: ErrorKind::InvalidToken(
+                                    value,
+                                    vec![
+                                        TokenValue::Case.into(),
+                                        TokenValue::Default.into(),
+                                        TokenValue::RightBrace.into(),
+                                    ],
+                                ),
+                                meta,
+                            });
+                        }
+                    };
+
+                    self.expect(frontend, TokenValue::Colon)?;
+
+                    let mut fall_through = true;
+
+                    let body = ctx.new_body(|ctx| {
+                        let mut case_terminator = None;
+                        loop {
+                            match self.expect_peek(frontend)?.value {
+                                TokenValue::Case | TokenValue::Default | TokenValue::RightBrace => {
+                                    break
+                                }
+                                _ => {
+                                    self.parse_statement(
+                                        frontend,
+                                        ctx,
+                                        &mut case_terminator,
+                                        is_inside_loop,
+                                    )?;
+                                }
+                            }
+                        }
+
+                        if let Some(mut idx) = case_terminator {
+                            if let Statement::Break = ctx.body[idx - 1] {
+                                fall_through = false;
+                                idx -= 1;
+                            }
+
+                            ctx.body.cull(idx..)
+                        }
+
+                        Ok(())
+                    })?;
+
+                    cases.push(SwitchCase {
+                        value,
+                        body,
+                        fall_through,
+                    })
+                }
+
+                meta.subsume(end_meta);
+
+                // NOTE: do not unwrap here since a switch statement isn't required
+                // to have any cases.
+                if let Some(case) = cases.last_mut() {
+                    // GLSL requires that the last case not be empty, so we check
+                    // that here and produce an error otherwise (fall_through must
+                    // also be checked because `break`s count as statements but
+                    // they aren't added to the body)
+                    if case.body.is_empty() && case.fall_through {
+                        frontend.errors.push(Error {
+                            kind: ErrorKind::SemanticError(
+                                "last case/default label must be followed by statements".into(),
+                            ),
+                            meta,
+                        })
+                    }
+
+                    // GLSL allows the last case to not have any `break` statement,
+                    // this would mark it as fall through but naga's IR requires that
+                    // the last case must not be fall through, so we mark need to mark
+                    // the last case as not fall through always.
+                    case.fall_through = false;
+                }
+
+                // Add an empty default case in case non was present, this is needed because
+                // naga's IR requires that all switch statements must have a default case but
+                // GLSL doesn't require that, so we might need to add an empty default case.
+                if !default_present {
+                    cases.push(SwitchCase {
+                        value: crate::SwitchValue::Default,
+                        body: Block::new(),
+                        fall_through: false,
+                    })
+                }
+
+                ctx.body.push(Statement::Switch { selector, cases }, meta);
+
+                meta
+            }
+            TokenValue::While => {
+                let mut meta = self.bump(frontend)?.meta;
+
+                let loop_body = ctx.new_body(|ctx| {
+                    let mut stmt = ctx.stmt_ctx();
+                    self.expect(frontend, TokenValue::LeftParen)?;
+                    let root = self.parse_expression(frontend, ctx, &mut stmt)?;
+                    meta.subsume(self.expect(frontend, TokenValue::RightParen)?.meta);
+
+                    let (expr, expr_meta) = ctx.lower_expect(stmt, frontend, root, ExprPos::Rhs)?;
+                    let condition = ctx.add_expression(
+                        Expression::Unary {
+                            op: UnaryOperator::LogicalNot,
+                            expr,
+                        },
+                        expr_meta,
+                    )?;
+
+                    ctx.emit_restart();
+
+                    ctx.body.push(
+                        Statement::If {
+                            condition,
+                            accept: new_break(),
+                            reject: Block::new(),
+                        },
+                        crate::Span::default(),
+                    );
+
+                    meta.subsume(expr_meta);
+
+                    if let Some(body_meta) = self.parse_statement(frontend, ctx, &mut None, true)? {
+                        meta.subsume(body_meta);
+                    }
+                    Ok(())
+                })?;
+
+                ctx.body.push(
+                    Statement::Loop {
+                        body: loop_body,
+                        continuing: Block::new(),
+                        break_if: None,
+                    },
+                    meta,
+                );
+
+                meta
+            }
+            TokenValue::Do => {
+                let mut meta = self.bump(frontend)?.meta;
+
+                let loop_body = ctx.new_body(|ctx| {
+                    let mut terminator = None;
+                    self.parse_statement(frontend, ctx, &mut terminator, true)?;
+
+                    let mut stmt = ctx.stmt_ctx();
+
+                    self.expect(frontend, TokenValue::While)?;
+                    self.expect(frontend, TokenValue::LeftParen)?;
+                    let root = self.parse_expression(frontend, ctx, &mut stmt)?;
+                    let end_meta = self.expect(frontend, TokenValue::RightParen)?.meta;
+
+                    meta.subsume(end_meta);
+
+                    let (expr, expr_meta) = ctx.lower_expect(stmt, frontend, root, ExprPos::Rhs)?;
+                    let condition = ctx.add_expression(
+                        Expression::Unary {
+                            op: UnaryOperator::LogicalNot,
+                            expr,
+                        },
+                        expr_meta,
+                    )?;
+
+                    ctx.emit_restart();
+
+                    ctx.body.push(
+                        Statement::If {
+                            condition,
+                            accept: new_break(),
+                            reject: Block::new(),
+                        },
+                        crate::Span::default(),
+                    );
+
+                    if let Some(idx) = terminator {
+                        ctx.body.cull(idx..)
+                    }
+                    Ok(())
+                })?;
+
+                ctx.body.push(
+                    Statement::Loop {
+                        body: loop_body,
+                        continuing: Block::new(),
+                        break_if: None,
+                    },
+                    meta,
+                );
+
+                meta
+            }
+            TokenValue::For => {
+                let mut meta = self.bump(frontend)?.meta;
+
+                ctx.symbol_table.push_scope();
+                self.expect(frontend, TokenValue::LeftParen)?;
+
+                if self.bump_if(frontend, TokenValue::Semicolon).is_none() {
+                    if self.peek_type_name(frontend) || self.peek_type_qualifier(frontend) {
+                        self.parse_declaration(frontend, ctx, false, false)?;
+                    } else {
+                        let mut stmt = ctx.stmt_ctx();
+                        let expr = self.parse_expression(frontend, ctx, &mut stmt)?;
+                        ctx.lower(stmt, frontend, expr, ExprPos::Rhs)?;
+                        self.expect(frontend, TokenValue::Semicolon)?;
+                    }
+                }
+
+                let loop_body = ctx.new_body(|ctx| {
+                    if self.bump_if(frontend, TokenValue::Semicolon).is_none() {
+                        let (expr, expr_meta) = if self.peek_type_name(frontend)
+                            || self.peek_type_qualifier(frontend)
+                        {
+                            let mut qualifiers = self.parse_type_qualifiers(frontend, ctx)?;
+                            let (ty, mut meta) = self.parse_type_non_void(frontend, ctx)?;
+                            let name = self.expect_ident(frontend)?.0;
+
+                            self.expect(frontend, TokenValue::Assign)?;
+
+                            let (value, end_meta) = self.parse_initializer(frontend, ty, ctx)?;
+                            meta.subsume(end_meta);
+
+                            let decl = VarDeclaration {
+                                qualifiers: &mut qualifiers,
+                                ty,
+                                name: Some(name),
+                                init: None,
+                                meta,
+                            };
+
+                            let pointer = frontend.add_local_var(ctx, decl)?;
+
+                            ctx.emit_restart();
+
+                            ctx.body.push(Statement::Store { pointer, value }, meta);
+
+                            (value, end_meta)
+                        } else {
+                            let mut stmt = ctx.stmt_ctx();
+                            let root = self.parse_expression(frontend, ctx, &mut stmt)?;
+                            ctx.lower_expect(stmt, frontend, root, ExprPos::Rhs)?
+                        };
+
+                        let condition = ctx.add_expression(
+                            Expression::Unary {
+                                op: UnaryOperator::LogicalNot,
+                                expr,
+                            },
+                            expr_meta,
+                        )?;
+
+                        ctx.emit_restart();
+
+                        ctx.body.push(
+                            Statement::If {
+                                condition,
+                                accept: new_break(),
+                                reject: Block::new(),
+                            },
+                            crate::Span::default(),
+                        );
+
+                        self.expect(frontend, TokenValue::Semicolon)?;
+                    }
+                    Ok(())
+                })?;
+
+                let continuing = ctx.new_body(|ctx| {
+                    match self.expect_peek(frontend)?.value {
+                        TokenValue::RightParen => {}
+                        _ => {
+                            let mut stmt = ctx.stmt_ctx();
+                            let rest = self.parse_expression(frontend, ctx, &mut stmt)?;
+                            ctx.lower(stmt, frontend, rest, ExprPos::Rhs)?;
+                        }
+                    }
+                    Ok(())
+                })?;
+
+                meta.subsume(self.expect(frontend, TokenValue::RightParen)?.meta);
+
+                let loop_body = ctx.with_body(loop_body, |ctx| {
+                    if let Some(stmt_meta) = self.parse_statement(frontend, ctx, &mut None, true)? {
+                        meta.subsume(stmt_meta);
+                    }
+                    Ok(())
+                })?;
+
+                ctx.body.push(
+                    Statement::Loop {
+                        body: loop_body,
+                        continuing,
+                        break_if: None,
+                    },
+                    meta,
+                );
+
+                ctx.symbol_table.pop_scope();
+
+                meta
+            }
+            TokenValue::LeftBrace => {
+                let mut meta = self.bump(frontend)?.meta;
+
+                let mut block_terminator = None;
+
+                let block = ctx.new_body(|ctx| {
+                    let block_meta = self.parse_compound_statement(
+                        meta,
+                        frontend,
+                        ctx,
+                        &mut block_terminator,
+                        is_inside_loop,
+                    )?;
+                    meta.subsume(block_meta);
+                    Ok(())
+                })?;
+
+                ctx.body.push(Statement::Block(block), meta);
+                if block_terminator.is_some() {
+                    terminator.get_or_insert(ctx.body.len());
+                }
+
+                meta
+            }
+            TokenValue::Semicolon => self.bump(frontend)?.meta,
+            _ => {
+                // Attempt to force expression parsing for remainder of the
+                // tokens. Unknown or invalid tokens will be caught there and
+                // turned into an error.
+                let mut stmt = ctx.stmt_ctx();
+                let expr = self.parse_expression(frontend, ctx, &mut stmt)?;
+                ctx.lower(stmt, frontend, expr, ExprPos::Rhs)?;
+                self.expect(frontend, TokenValue::Semicolon)?.meta
+            }
+        };
+
+        meta.subsume(meta_rest);
+        Ok(Some(meta))
+    }
+
+    pub fn parse_compound_statement(
+        &mut self,
+        mut meta: Span,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+        terminator: &mut Option<usize>,
+        is_inside_loop: bool,
+    ) -> Result<Span> {
+        ctx.symbol_table.push_scope();
+
+        loop {
+            if let Some(Token {
+                meta: brace_meta, ..
+            }) = self.bump_if(frontend, TokenValue::RightBrace)
+            {
+                meta.subsume(brace_meta);
+                break;
+            }
+
+            let stmt = self.parse_statement(frontend, ctx, terminator, is_inside_loop)?;
+
+            if let Some(stmt_meta) = stmt {
+                meta.subsume(stmt_meta);
+            }
+        }
+
+        if let Some(idx) = *terminator {
+            ctx.body.cull(idx..)
+        }
+
+        ctx.symbol_table.pop_scope();
+
+        Ok(meta)
+    }
+
+    pub fn parse_function_args(
+        &mut self,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+    ) -> Result<()> {
+        if self.bump_if(frontend, TokenValue::Void).is_some() {
+            return Ok(());
+        }
+
+        loop {
+            if self.peek_type_name(frontend) || self.peek_parameter_qualifier(frontend) {
+                let qualifier = self.parse_parameter_qualifier(frontend);
+                let mut ty = self.parse_type_non_void(frontend, ctx)?.0;
+
+                match self.expect_peek(frontend)?.value {
+                    TokenValue::Comma => {
+                        self.bump(frontend)?;
+                        ctx.add_function_arg(None, ty, qualifier)?;
+                        continue;
+                    }
+                    TokenValue::Identifier(_) => {
+                        let mut name = self.expect_ident(frontend)?;
+                        self.parse_array_specifier(frontend, ctx, &mut name.1, &mut ty)?;
+
+                        ctx.add_function_arg(Some(name), ty, qualifier)?;
+
+                        if self.bump_if(frontend, TokenValue::Comma).is_some() {
+                            continue;
+                        }
+
+                        break;
+                    }
+                    _ => break,
+                }
+            }
+
+            break;
+        }
+
+        Ok(())
+    }
+}
diff --git a/third_party/rust/naga/src/front/glsl/parser/types.rs b/third_party/rust/naga/src/front/glsl/parser/types.rs
new file mode 100644
index 0000000000..1b612b298d
--- /dev/null
+++ b/third_party/rust/naga/src/front/glsl/parser/types.rs
@@ -0,0 +1,443 @@
+use std::num::NonZeroU32;
+
+use crate::{
+    front::glsl::{
+        ast::{QualifierKey, QualifierValue, StorageQualifier, StructLayout, TypeQualifiers},
+        context::Context,
+        error::ExpectedToken,
+        parser::ParsingContext,
+        token::{Token, TokenValue},
+        Error, ErrorKind, Frontend, Result,
+    },
+    AddressSpace, ArraySize, Handle, Span, Type, TypeInner,
+};
+
+impl<'source> ParsingContext<'source> {
+    /// Parses an optional array_specifier returning whether or not it's present
+    /// and modifying the type handle if it exists
+    pub fn parse_array_specifier(
+        &mut self,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+        span: &mut Span,
+        ty: &mut Handle<Type>,
+    ) -> Result<()> {
+        while self.parse_array_specifier_single(frontend, ctx, span, ty)? {}
+        Ok(())
+    }
+
+    /// Implementation of [`Self::parse_array_specifier`] for a single array_specifier
+    fn parse_array_specifier_single(
+        &mut self,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+        span: &mut Span,
+        ty: &mut Handle<Type>,
+    ) -> Result<bool> {
+        if self.bump_if(frontend, TokenValue::LeftBracket).is_some() {
+            let size = if let Some(Token { meta, .. }) =
+                self.bump_if(frontend, TokenValue::RightBracket)
+            {
+                span.subsume(meta);
+                ArraySize::Dynamic
+            } else {
+                let (value, constant_span) = self.parse_uint_constant(frontend, ctx)?;
+                let size = NonZeroU32::new(value).ok_or(Error {
+                    kind: ErrorKind::SemanticError("Array size must be greater than zero".into()),
+                    meta: constant_span,
+                })?;
+                let end_span = self.expect(frontend, TokenValue::RightBracket)?.meta;
+                span.subsume(end_span);
+                ArraySize::Constant(size)
+            };
+
+            frontend.layouter.update(ctx.module.to_ctx()).unwrap();
+            let stride = frontend.layouter[*ty].to_stride();
+            *ty = ctx.module.types.insert(
+                Type {
+                    name: None,
+                    inner: TypeInner::Array {
+                        base: *ty,
+                        size,
+                        stride,
+                    },
+                },
+                *span,
+            );
+
+            Ok(true)
+        } else {
+            Ok(false)
+        }
+    }
+
+    pub fn parse_type(
+        &mut self,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+    ) -> Result<(Option<Handle<Type>>, Span)> {
+        let token = self.bump(frontend)?;
+        let mut handle = match token.value {
+            TokenValue::Void => return Ok((None, token.meta)),
+            TokenValue::TypeName(ty) => ctx.module.types.insert(ty, token.meta),
+            TokenValue::Struct => {
+                let mut meta = token.meta;
+                let ty_name = self.expect_ident(frontend)?.0;
+                self.expect(frontend, TokenValue::LeftBrace)?;
+                let mut members = Vec::new();
+                let span = self.parse_struct_declaration_list(
+                    frontend,
+                    ctx,
+                    &mut members,
+                    StructLayout::Std140,
+                )?;
+                let end_meta = self.expect(frontend, TokenValue::RightBrace)?.meta;
+                meta.subsume(end_meta);
+                let ty = ctx.module.types.insert(
+                    Type {
+                        name: Some(ty_name.clone()),
+                        inner: TypeInner::Struct { members, span },
+                    },
+                    meta,
+                );
+                frontend.lookup_type.insert(ty_name, ty);
+                ty
+            }
+            TokenValue::Identifier(ident) => match frontend.lookup_type.get(&ident) {
+                Some(ty) => *ty,
+                None => {
+                    return Err(Error {
+                        kind: ErrorKind::UnknownType(ident),
+                        meta: token.meta,
+                    })
+                }
+            },
+            _ => {
+                return Err(Error {
+                    kind: ErrorKind::InvalidToken(
+                        token.value,
+                        vec![
+                            TokenValue::Void.into(),
+                            TokenValue::Struct.into(),
+                            ExpectedToken::TypeName,
+                        ],
+                    ),
+                    meta: token.meta,
+                });
+            }
+        };
+
+        let mut span = token.meta;
+        self.parse_array_specifier(frontend, ctx, &mut span, &mut handle)?;
+        Ok((Some(handle), span))
+    }
+
+    pub fn parse_type_non_void(
+        &mut self,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+    ) -> Result<(Handle<Type>, Span)> {
+        let (maybe_ty, meta) = self.parse_type(frontend, ctx)?;
+        let ty = maybe_ty.ok_or_else(|| Error {
+            kind: ErrorKind::SemanticError("Type can't be void".into()),
+            meta,
+        })?;
+
+        Ok((ty, meta))
+    }
+
+    pub fn peek_type_qualifier(&mut self, frontend: &mut Frontend) -> bool {
+        self.peek(frontend).map_or(false, |t| match t.value {
+            TokenValue::Invariant
+            | TokenValue::Interpolation(_)
+            | TokenValue::Sampling(_)
+            | TokenValue::PrecisionQualifier(_)
+            | TokenValue::Const
+            | TokenValue::In
+            | TokenValue::Out
+            | TokenValue::Uniform
+            | TokenValue::Shared
+            | TokenValue::Buffer
+            | TokenValue::Restrict
+            | TokenValue::MemoryQualifier(_)
+            | TokenValue::Layout => true,
+            _ => false,
+        })
+    }
+
+    pub fn parse_type_qualifiers<'a>(
+        &mut self,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+    ) -> Result<TypeQualifiers<'a>> {
+        let mut qualifiers = TypeQualifiers::default();
+
+        while self.peek_type_qualifier(frontend) {
+            let token = self.bump(frontend)?;
+
+            // Handle layout qualifiers outside the match since this can push multiple values
+            if token.value == TokenValue::Layout {
+                self.parse_layout_qualifier_id_list(frontend, ctx, &mut qualifiers)?;
+                continue;
+            }
+
+            qualifiers.span.subsume(token.meta);
+
+            match token.value {
+                TokenValue::Invariant => {
+                    if qualifiers.invariant.is_some() {
+                        frontend.errors.push(Error {
+                            kind: ErrorKind::SemanticError(
+                                "Cannot use more than one invariant qualifier per declaration"
+                                    .into(),
+                            ),
+                            meta: token.meta,
+                        })
+                    }
+
+                    qualifiers.invariant = Some(token.meta);
+                }
+                TokenValue::Interpolation(i) => {
+                    if qualifiers.interpolation.is_some() {
+                        frontend.errors.push(Error {
+                            kind: ErrorKind::SemanticError(
+                                "Cannot use more than one interpolation qualifier per declaration"
+                                    .into(),
+                            ),
+                            meta: token.meta,
+                        })
+                    }
+
+                    qualifiers.interpolation = Some((i, token.meta));
+                }
+                TokenValue::Const
+                | TokenValue::In
+                | TokenValue::Out
+                | TokenValue::Uniform
+                | TokenValue::Shared
+                | TokenValue::Buffer => {
+                    let storage = match token.value {
+                        TokenValue::Const => StorageQualifier::Const,
+                        TokenValue::In => StorageQualifier::Input,
+                        TokenValue::Out => StorageQualifier::Output,
+                        TokenValue::Uniform => {
+                            StorageQualifier::AddressSpace(AddressSpace::Uniform)
+                        }
+                        TokenValue::Shared => {
+                            StorageQualifier::AddressSpace(AddressSpace::WorkGroup)
+                        }
+                        TokenValue::Buffer => {
+                            StorageQualifier::AddressSpace(AddressSpace::Storage {
+                                access: crate::StorageAccess::all(),
+                            })
+                        }
+                        _ => unreachable!(),
+                    };
+
+                    if StorageQualifier::AddressSpace(AddressSpace::Function)
+                        != qualifiers.storage.0
+                    {
+                        frontend.errors.push(Error {
+                            kind: ErrorKind::SemanticError(
+                                "Cannot use more than one storage qualifier per declaration".into(),
+                            ),
+                            meta: token.meta,
+                        });
+                    }
+
+                    qualifiers.storage = (storage, token.meta);
+                }
+                TokenValue::Sampling(s) => {
+                    if qualifiers.sampling.is_some() {
+                        frontend.errors.push(Error {
+                            kind: ErrorKind::SemanticError(
+                                "Cannot use more than one sampling qualifier per declaration"
+                                    .into(),
+                            ),
+                            meta: token.meta,
+                        })
+                    }
+
+                    qualifiers.sampling = Some((s, token.meta));
+                }
+                TokenValue::PrecisionQualifier(p) => {
+                    if qualifiers.precision.is_some() {
+                        frontend.errors.push(Error {
+                            kind: ErrorKind::SemanticError(
+                                "Cannot use more than one precision qualifier per declaration"
+                                    .into(),
+                            ),
+                            meta: token.meta,
+                        })
+                    }
+
+                    qualifiers.precision = Some((p, token.meta));
+                }
+                TokenValue::MemoryQualifier(access) => {
+                    let storage_access = qualifiers
+                        .storage_access
+                        .get_or_insert((crate::StorageAccess::all(), Span::default()));
+                    if !storage_access.0.contains(!access) {
+                        frontend.errors.push(Error {
+                            kind: ErrorKind::SemanticError(
+                                "The same memory qualifier can only be used once".into(),
+                            ),
+                            meta: token.meta,
+                        })
+                    }
+
+                    storage_access.0 &= access;
+                    storage_access.1.subsume(token.meta);
+                }
+                TokenValue::Restrict => continue,
+                _ => unreachable!(),
+            };
+        }
+
+        Ok(qualifiers)
+    }
+
+    pub fn parse_layout_qualifier_id_list(
+        &mut self,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+        qualifiers: &mut TypeQualifiers,
+    ) -> Result<()> {
+        self.expect(frontend, TokenValue::LeftParen)?;
+        loop {
+            self.parse_layout_qualifier_id(frontend, ctx, &mut qualifiers.layout_qualifiers)?;
+
+            if self.bump_if(frontend, TokenValue::Comma).is_some() {
+                continue;
+            }
+
+            break;
+        }
+        let token = self.expect(frontend, TokenValue::RightParen)?;
+        qualifiers.span.subsume(token.meta);
+
+        Ok(())
+    }
+
+    pub fn parse_layout_qualifier_id(
+        &mut self,
+        frontend: &mut Frontend,
+        ctx: &mut Context,
+        qualifiers: &mut crate::FastHashMap<QualifierKey, (QualifierValue, Span)>,
+    ) -> Result<()> {
+        // layout_qualifier_id:
+        //     IDENTIFIER
+        //     IDENTIFIER EQUAL constant_expression
+        //     SHARED
+        let mut token = self.bump(frontend)?;
+        match token.value {
+            TokenValue::Identifier(name) => {
+                let (key, value) = match name.as_str() {
+                    "std140" => (
+                        QualifierKey::Layout,
+                        QualifierValue::Layout(StructLayout::Std140),
+                    ),
+                    "std430" => (
+                        QualifierKey::Layout,
+                        QualifierValue::Layout(StructLayout::Std430),
+                    ),
+                    word => {
+                        if let Some(format) = map_image_format(word) {
+                            (QualifierKey::Format, QualifierValue::Format(format))
+                        } else {
+                            let key = QualifierKey::String(name.into());
+                            let value = if self.bump_if(frontend, TokenValue::Assign).is_some() {
+                                let (value, end_meta) =
+                                    match self.parse_uint_constant(frontend, ctx) {
+                                        Ok(v) => v,
+                                        Err(e) => {
+                                            frontend.errors.push(e);
+                                            (0, Span::default())
+                                        }
+                                    };
+                                token.meta.subsume(end_meta);
+
+                                QualifierValue::Uint(value)
+                            } else {
+                                QualifierValue::None
+                            };
+
+                            (key, value)
+                        }
+                    }
+                };
+
+                qualifiers.insert(key, (value, token.meta));
+            }
+            _ => frontend.errors.push(Error {
+                kind: ErrorKind::InvalidToken(token.value, vec![ExpectedToken::Identifier]),
+                meta: token.meta,
+            }),
+        }
+
+        Ok(())
+    }
+
+    pub fn peek_type_name(&mut self, frontend: &mut Frontend) -> bool {
+        self.peek(frontend).map_or(false, |t| match t.value {
+            TokenValue::TypeName(_) | TokenValue::Void => true,
+            TokenValue::Struct => true,
+            TokenValue::Identifier(ref ident) => frontend.lookup_type.contains_key(ident),
+            _ => false,
+        })
+    }
+}
+
+fn map_image_format(word: &str) -> Option<crate::StorageFormat> {
+    use crate::StorageFormat as Sf;
+
+    let format = match word {
+        // float-image-format-qualifier:
+        "rgba32f" => Sf::Rgba32Float,
+        "rgba16f" => Sf::Rgba16Float,
+        "rg32f" => Sf::Rg32Float,
+        "rg16f" => Sf::Rg16Float,
+        "r11f_g11f_b10f" => Sf::Rg11b10Float,
+        "r32f" => Sf::R32Float,
+        "r16f" => Sf::R16Float,
+        "rgba16" => Sf::Rgba16Unorm,
+        "rgb10_a2ui" => Sf::Rgb10a2Uint,
+        "rgb10_a2" => Sf::Rgb10a2Unorm,
+        "rgba8" => Sf::Rgba8Unorm,
+        "rg16" => Sf::Rg16Unorm,
+        "rg8" => Sf::Rg8Unorm,
+        "r16" => Sf::R16Unorm,
+        "r8" => Sf::R8Unorm,
+        "rgba16_snorm" => Sf::Rgba16Snorm,
+        "rgba8_snorm" => Sf::Rgba8Snorm,
+        "rg16_snorm" => Sf::Rg16Snorm,
+        "rg8_snorm" => Sf::Rg8Snorm,
+        "r16_snorm" => Sf::R16Snorm,
+        "r8_snorm" => Sf::R8Snorm,
+        // int-image-format-qualifier:
+        "rgba32i" => Sf::Rgba32Sint,
+        "rgba16i" => Sf::Rgba16Sint,
+        "rgba8i" => Sf::Rgba8Sint,
+        "rg32i" => Sf::Rg32Sint,
+        "rg16i" => Sf::Rg16Sint,
+        "rg8i" => Sf::Rg8Sint,
+        "r32i" => Sf::R32Sint,
+        "r16i" => Sf::R16Sint,
+        "r8i" => Sf::R8Sint,
+        // uint-image-format-qualifier:
+        "rgba32ui" => Sf::Rgba32Uint,
+        "rgba16ui" => Sf::Rgba16Uint,
+        "rgba8ui" => Sf::Rgba8Uint,
+        "rg32ui" => Sf::Rg32Uint,
+        "rg16ui" => Sf::Rg16Uint,
+        "rg8ui" => Sf::Rg8Uint,
+        "r32ui" => Sf::R32Uint,
+        "r16ui" => Sf::R16Uint,
+        "r8ui" => Sf::R8Uint,
+        // TODO: These next ones seem incorrect to me
+        // "rgb10_a2ui" => Sf::Rgb10a2Unorm,
+        _ => return None,
+    };
+
+    Some(format)
+}
diff --git a/third_party/rust/naga/src/front/glsl/parser_tests.rs b/third_party/rust/naga/src/front/glsl/parser_tests.rs
new file mode 100644
index 0000000000..259052cd27
--- /dev/null
+++ b/third_party/rust/naga/src/front/glsl/parser_tests.rs
@@ -0,0 +1,858 @@
+use super::{
+    ast::Profile,
+    error::ExpectedToken,
+    error::{Error, ErrorKind, ParseError},
+    token::TokenValue,
+    Frontend, Options, Span,
+};
+use crate::ShaderStage;
+use pp_rs::token::PreprocessorError;
+
+#[test]
+fn version() {
+    let mut frontend = Frontend::default();
+
+    // invalid versions
+    assert_eq!(
+        frontend
+            .parse(
+                &Options::from(ShaderStage::Vertex),
+                "#version 99000\n void main(){}",
+            )
+            .err()
+            .unwrap(),
+        ParseError {
+            errors: vec![Error {
+                kind: ErrorKind::InvalidVersion(99000),
+                meta: Span::new(9, 14)
+            }],
+        },
+    );
+
+    assert_eq!(
+        frontend
+            .parse(
+                &Options::from(ShaderStage::Vertex),
+                "#version 449\n void main(){}",
+            )
+            .err()
+            .unwrap(),
+        ParseError {
+            errors: vec![Error {
+                kind: ErrorKind::InvalidVersion(449),
+                meta: Span::new(9, 12)
+            }]
+        },
+    );
+
+    assert_eq!(
+        frontend
+            .parse(
+                &Options::from(ShaderStage::Vertex),
+                "#version 450 smart\n void main(){}",
+            )
+            .err()
+            .unwrap(),
+        ParseError {
+            errors: vec![Error {
+                kind: ErrorKind::InvalidProfile("smart".into()),
+                meta: Span::new(13, 18),
+            }]
+        },
+    );
+
+    assert_eq!(
+        frontend
+            .parse(
+                &Options::from(ShaderStage::Vertex),
+                "#version 450\nvoid main(){} #version 450",
+            )
+            .err()
+            .unwrap(),
+        ParseError {
+            errors: vec![
+                Error {
+                    kind: ErrorKind::PreprocessorError(PreprocessorError::UnexpectedHash,),
+                    meta: Span::new(27, 28),
+                },
+                Error {
+                    kind: ErrorKind::InvalidToken(
+                        TokenValue::Identifier("version".into()),
+                        vec![ExpectedToken::Eof]
+                    ),
+                    meta: Span::new(28, 35)
+                }
+            ]
+        },
+    );
+
+    // valid versions
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            "  #  version 450\nvoid main() {}",
+        )
+        .unwrap();
+    assert_eq!(
+        (frontend.metadata().version, frontend.metadata().profile),
+        (450, Profile::Core)
+    );
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            "#version 450\nvoid main() {}",
+        )
+        .unwrap();
+    assert_eq!(
+        (frontend.metadata().version, frontend.metadata().profile),
+        (450, Profile::Core)
+    );
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            "#version 450 core\nvoid main(void) {}",
+        )
+        .unwrap();
+    assert_eq!(
+        (frontend.metadata().version, frontend.metadata().profile),
+        (450, Profile::Core)
+    );
+}
+
+#[test]
+fn control_flow() {
+    let mut frontend = Frontend::default();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        void main() {
+            if (true) {
+                return 1;
+            } else {
+                return 2;
+            }
+        }
+        "#,
+        )
+        .unwrap();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        void main() {
+            if (true) {
+                return 1;
+            }
+        }
+        "#,
+        )
+        .unwrap();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        void main() {
+            int x;
+            int y = 3;
+            switch (5) {
+                case 2:
+                    x = 2;
+                case 5:
+                    x = 5;
+                    y = 2;
+                    break;
+                default:
+                    x = 0;
+            }
+        }
+        "#,
+        )
+        .unwrap();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        void main() {
+            int x = 0;
+            while(x < 5) {
+                x = x + 1;
+            }
+            do {
+                x = x - 1;
+            } while(x >= 4)
+        }
+        "#,
+        )
+        .unwrap();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        void main() {
+            int x = 0;
+            for(int i = 0; i < 10;) {
+                x = x + 2;
+            }
+            for(;;);
+            return x;
+        }
+        "#,
+        )
+        .unwrap();
+}
+
+#[test]
+fn declarations() {
+    let mut frontend = Frontend::default();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #version 450
+        layout(location = 0) in vec2 v_uv;
+        layout(location = 0) out vec4 o_color;
+        layout(set = 1, binding = 1) uniform texture2D tex;
+        layout(set = 1, binding = 2) uniform sampler tex_sampler;
+
+        layout(early_fragment_tests) in;
+
+        void main() {}
+        "#,
+        )
+        .unwrap();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #version 450
+        layout(std140, set = 2, binding = 0)
+        uniform u_locals {
+            vec3 model_offs;
+            float load_time;
+            ivec4 atlas_offs;
+        };
+
+        void main() {}
+        "#,
+        )
+        .unwrap();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #version 450
+        layout(push_constant)
+        uniform u_locals {
+            vec3 model_offs;
+            float load_time;
+            ivec4 atlas_offs;
+        };
+
+        void main() {}
+        "#,
+        )
+        .unwrap();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #version 450
+        layout(std430, set = 2, binding = 0)
+        uniform u_locals {
+            vec3 model_offs;
+            float load_time;
+            ivec4 atlas_offs;
+        };
+
+        void main() {}
+        "#,
+        )
+        .unwrap();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #version 450
+        layout(std140, set = 2, binding = 0)
+        uniform u_locals {
+            vec3 model_offs;
+            float load_time;
+        } block_var;
+
+        void main() {
+            load_time * model_offs;
+            block_var.load_time * block_var.model_offs;
+        }
+        "#,
+        )
+        .unwrap();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #version 450
+        float vector = vec4(1.0 / 17.0,  9.0 / 17.0,  3.0 / 17.0, 11.0 / 17.0);
+
+        void main() {}
+        "#,
+        )
+        .unwrap();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #version 450
+        precision highp float;
+
+        void main() {}
+        "#,
+        )
+        .unwrap();
+}
+
+#[test]
+fn textures() {
+    let mut frontend = Frontend::default();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #version 450
+        layout(location = 0) in vec2 v_uv;
+        layout(location = 0) out vec4 o_color;
+        layout(set = 1, binding = 1) uniform texture2D tex;
+        layout(set = 1, binding = 2) uniform sampler tex_sampler;
+        void main() {
+            o_color = texture(sampler2D(tex, tex_sampler), v_uv);
+            o_color.a = texture(sampler2D(tex, tex_sampler), v_uv, 2.0).a;
+        }
+        "#,
+        )
+        .unwrap();
+}
+
+#[test]
+fn functions() {
+    let mut frontend = Frontend::default();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        void test1(float);
+        void test1(float) {}
+
+        void main() {}
+        "#,
+        )
+        .unwrap();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        void test2(float a) {}
+        void test3(float a, float b) {}
+        void test4(float, float) {}
+
+        void main() {}
+        "#,
+        )
+        .unwrap();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        float test(float a) { return a; }
+
+        void main() {}
+        "#,
+        )
+        .unwrap();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        float test(vec4 p) {
+            return p.x;
+        }
+
+        void main() {}
+        "#,
+        )
+        .unwrap();
+
+    // Function overloading
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        float test(vec2 p);
+        float test(vec3 p);
+        float test(vec4 p);
+
+        float test(vec2 p) {
+            return p.x;
+        }
+
+        float test(vec3 p) {
+            return p.x;
+        }
+
+        float test(vec4 p) {
+            return p.x;
+        }
+
+        void main() {}
+        "#,
+        )
+        .unwrap();
+
+    assert_eq!(
+        frontend
+            .parse(
+                &Options::from(ShaderStage::Vertex),
+                r#"
+                #  version 450
+                int test(vec4 p) {
+                    return p.x;
+                }
+
+                float test(vec4 p) {
+                    return p.x;
+                }
+
+                void main() {}
+                "#,
+            )
+            .err()
+            .unwrap(),
+        ParseError {
+            errors: vec![Error {
+                kind: ErrorKind::SemanticError("Function already defined".into()),
+                meta: Span::new(134, 152),
+            }]
+        },
+    );
+
+    println!();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        float callee(uint q) {
+            return float(q);
+        }
+
+        float caller() {
+            callee(1u);
+        }
+
+        void main() {}
+        "#,
+        )
+        .unwrap();
+
+    // Nested function call
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+            #  version 450
+            layout(set = 0, binding = 1) uniform texture2D t_noise;
+            layout(set = 0, binding = 2) uniform sampler s_noise;
+
+            void main() {
+                textureLod(sampler2D(t_noise, s_noise), vec2(1.0), 0);
+            }
+        "#,
+        )
+        .unwrap();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        void fun(vec2 in_parameter, out float out_parameter) {
+            ivec2 _ = ivec2(in_parameter);
+        }
+
+        void main() {
+            float a;
+            fun(vec2(1.0), a);
+        }
+        "#,
+        )
+        .unwrap();
+}
+
+#[test]
+fn constants() {
+    use crate::{Constant, Expression, Type, TypeInner};
+
+    let mut frontend = Frontend::default();
+
+    let module = frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        const float a = 1.0;
+        float global = a;
+        const float b = a;
+
+        void main() {}
+        "#,
+        )
+        .unwrap();
+
+    let mut types = module.types.iter();
+    let mut constants = module.constants.iter();
+    let mut const_expressions = module.const_expressions.iter();
+
+    let (ty_handle, ty) = types.next().unwrap();
+    assert_eq!(
+        ty,
+        &Type {
+            name: None,
+            inner: TypeInner::Scalar(crate::Scalar::F32)
+        }
+    );
+
+    let (init_handle, init) = const_expressions.next().unwrap();
+    assert_eq!(init, &Expression::Literal(crate::Literal::F32(1.0)));
+
+    assert_eq!(
+        constants.next().unwrap().1,
+        &Constant {
+            name: Some("a".to_owned()),
+            r#override: crate::Override::None,
+            ty: ty_handle,
+            init: init_handle
+        }
+    );
+
+    assert_eq!(
+        constants.next().unwrap().1,
+        &Constant {
+            name: Some("b".to_owned()),
+            r#override: crate::Override::None,
+            ty: ty_handle,
+            init: init_handle
+        }
+    );
+
+    assert!(constants.next().is_none());
+}
+
+#[test]
+fn function_overloading() {
+    let mut frontend = Frontend::default();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+
+        float saturate(float v) { return clamp(v, 0.0, 1.0); }
+        vec2 saturate(vec2 v) { return clamp(v, vec2(0.0), vec2(1.0)); }
+        vec3 saturate(vec3 v) { return clamp(v, vec3(0.0), vec3(1.0)); }
+        vec4 saturate(vec4 v) { return clamp(v, vec4(0.0), vec4(1.0)); }
+
+        void main() {
+            float v1 = saturate(1.5);
+            vec2 v2 = saturate(vec2(0.5, 1.5));
+            vec3 v3 = saturate(vec3(0.5, 1.5, 2.5));
+            vec3 v4 = saturate(vec4(0.5, 1.5, 2.5, 3.5));
+        }
+        "#,
+        )
+        .unwrap();
+}
+
+#[test]
+fn implicit_conversions() {
+    let mut frontend = Frontend::default();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        void main() {
+            mat4 a = mat4(1);
+            float b = 1u;
+            float c = 1 + 2.0;
+        }
+        "#,
+        )
+        .unwrap();
+
+    assert_eq!(
+        frontend
+            .parse(
+                &Options::from(ShaderStage::Vertex),
+                r#"
+                #  version 450
+                void test(int a) {}
+                void test(uint a) {}
+
+                void main() {
+                    test(1.0);
+                }
+                "#,
+            )
+            .err()
+            .unwrap(),
+        ParseError {
+            errors: vec![Error {
+                kind: ErrorKind::SemanticError("Unknown function \'test\'".into()),
+                meta: Span::new(156, 165),
+            }]
+        },
+    );
+
+    assert_eq!(
+        frontend
+            .parse(
+                &Options::from(ShaderStage::Vertex),
+                r#"
+                #  version 450
+                void test(float a) {}
+                void test(uint a) {}
+
+                void main() {
+                    test(1);
+                }
+                "#,
+            )
+            .err()
+            .unwrap(),
+        ParseError {
+            errors: vec![Error {
+                kind: ErrorKind::SemanticError("Ambiguous best function for \'test\'".into()),
+                meta: Span::new(158, 165),
+            }]
+        }
+    );
+}
+
+#[test]
+fn structs() {
+    let mut frontend = Frontend::default();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        Test {
+            vec4 pos;
+          } xx;
+
+        void main() {}
+        "#,
+        )
+        .unwrap_err();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        struct Test {
+            vec4 pos;
+        };
+
+        void main() {}
+        "#,
+        )
+        .unwrap();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        const int NUM_VECS = 42;
+        struct Test {
+            vec4 vecs[NUM_VECS];
+        };
+
+        void main() {}
+        "#,
+        )
+        .unwrap();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        struct Hello {
+            vec4 test;
+        } test() {
+            return Hello( vec4(1.0) );
+        }
+
+        void main() {}
+        "#,
+        )
+        .unwrap();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        struct Test {};
+
+        void main() {}
+        "#,
+        )
+        .unwrap_err();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        inout struct Test {
+            vec4 x;
+        };
+
+        void main() {}
+        "#,
+        )
+        .unwrap_err();
+}
+
+#[test]
+fn swizzles() {
+    let mut frontend = Frontend::default();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        void main() {
+            vec4 v = vec4(1);
+            v.xyz = vec3(2);
+            v.x = 5.0;
+            v.xyz.zxy.yx.xy = vec2(5.0, 1.0);
+        }
+        "#,
+        )
+        .unwrap();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        void main() {
+            vec4 v = vec4(1);
+            v.xx = vec2(5.0);
+        }
+        "#,
+        )
+        .unwrap_err();
+
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        void main() {
+            vec3 v = vec3(1);
+            v.w = 2.0;
+        }
+        "#,
+        )
+        .unwrap_err();
+}
+
+#[test]
+fn expressions() {
+    let mut frontend = Frontend::default();
+
+    // Vector indexing
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        float test(int index) {
+            vec4 v = vec4(1.0, 2.0, 3.0, 4.0);
+            return v[index] + 1.0;
+        }
+
+        void main() {}
+        "#,
+        )
+        .unwrap();
+
+    // Prefix increment/decrement
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        void main() {
+            uint index = 0;
+
+            --index;
+            ++index;
+        }
+        "#,
+        )
+        .unwrap();
+
+    // Dynamic indexing of array
+    frontend
+        .parse(
+            &Options::from(ShaderStage::Vertex),
+            r#"
+        #  version 450
+        void main() {
+            const vec4 positions[1] = { vec4(0) };
+
+            gl_Position = positions[gl_VertexIndex];
+        }
+        "#,
+        )
+        .unwrap();
+}
diff --git a/third_party/rust/naga/src/front/glsl/token.rs b/third_party/rust/naga/src/front/glsl/token.rs
new file mode 100644
index 0000000000..303723a27b
--- /dev/null
+++ b/third_party/rust/naga/src/front/glsl/token.rs
@@ -0,0 +1,137 @@
+pub use pp_rs::token::{Float, Integer, Location, Token as PPToken};
+
+use super::ast::Precision;
+use crate::{Interpolation, Sampling, Span, Type};
+
+impl From<Location> for Span {
+    fn from(loc: Location) -> Self {
+        Span::new(loc.start, loc.end)
+    }
+}
+
+#[derive(Debug)]
+#[cfg_attr(test, derive(PartialEq))]
+pub struct Token {
+    pub value: TokenValue,
+    pub meta: Span,
+}
+
+/// A token passed from the lexing used in the parsing.
+///
+/// This type is exported since it's returned in the
+/// [`InvalidToken`](super::ErrorKind::InvalidToken) error.
+#[derive(Clone, Debug, PartialEq)]
+pub enum TokenValue {
+    Identifier(String),
+
+    FloatConstant(Float),
+    IntConstant(Integer),
+    BoolConstant(bool),
+
+    Layout,
+    In,
+    Out,
+    InOut,
+    Uniform,
+    Buffer,
+    Const,
+    Shared,
+
+    Restrict,
+    /// A `glsl` memory qualifier such as `writeonly`
+    ///
+    /// The associated [`crate::StorageAccess`] is the access being allowed
+    /// (for example `writeonly` has an associated value of [`crate::StorageAccess::STORE`])
+    MemoryQualifier(crate::StorageAccess),
+
+    Invariant,
+    Interpolation(Interpolation),
+    Sampling(Sampling),
+    Precision,
+    PrecisionQualifier(Precision),
+
+    Continue,
+    Break,
+    Return,
+    Discard,
+
+    If,
+    Else,
+    Switch,
+    Case,
+    Default,
+    While,
+    Do,
+    For,
+
+    Void,
+    Struct,
+    TypeName(Type),
+
+    Assign,
+    AddAssign,
+    SubAssign,
+    MulAssign,
+    DivAssign,
+    ModAssign,
+    LeftShiftAssign,
+    RightShiftAssign,
+    AndAssign,
+    XorAssign,
+    OrAssign,
+
+    Increment,
+    Decrement,
+
+    LogicalOr,
+    LogicalAnd,
+    LogicalXor,
+
+    LessEqual,
+    GreaterEqual,
+    Equal,
+    NotEqual,
+
+    LeftShift,
+    RightShift,
+
+    LeftBrace,
+    RightBrace,
+    LeftParen,
+    RightParen,
+    LeftBracket,
+    RightBracket,
+    LeftAngle,
+    RightAngle,
+
+    Comma,
+    Semicolon,
+    Colon,
+    Dot,
+    Bang,
+    Dash,
+    Tilde,
+    Plus,
+    Star,
+    Slash,
+    Percent,
+    VerticalBar,
+    Caret,
+    Ampersand,
+    Question,
+}
+
+#[derive(Debug)]
+#[cfg_attr(test, derive(PartialEq))]
+pub struct Directive {
+    pub kind: DirectiveKind,
+    pub tokens: Vec<PPToken>,
+}
+
+#[derive(Debug)]
+#[cfg_attr(test, derive(PartialEq))]
+pub enum DirectiveKind {
+    Version { is_first_directive: bool },
+    Extension,
+    Pragma,
+}
diff --git a/third_party/rust/naga/src/front/glsl/types.rs b/third_party/rust/naga/src/front/glsl/types.rs
new file mode 100644
index 0000000000..e87d76fffc
--- /dev/null
+++ b/third_party/rust/naga/src/front/glsl/types.rs
@@ -0,0 +1,360 @@
+use super::{context::Context, Error, ErrorKind, Result, Span};
+use crate::{
+    proc::ResolveContext, Expression, Handle, ImageClass, ImageDimension, Scalar, ScalarKind, Type,
+    TypeInner, VectorSize,
+};
+
+pub fn parse_type(type_name: &str) -> Option<Type> {
+    match type_name {
+        "bool" => Some(Type {
+            name: None,
+            inner: TypeInner::Scalar(Scalar::BOOL),
+        }),
+        "float" => Some(Type {
+            name: None,
+            inner: TypeInner::Scalar(Scalar::F32),
+        }),
+        "double" => Some(Type {
+            name: None,
+            inner: TypeInner::Scalar(Scalar::F64),
+        }),
+        "int" => Some(Type {
+            name: None,
+            inner: TypeInner::Scalar(Scalar::I32),
+        }),
+        "uint" => Some(Type {
+            name: None,
+            inner: TypeInner::Scalar(Scalar::U32),
+        }),
+        "sampler" | "samplerShadow" => Some(Type {
+            name: None,
+            inner: TypeInner::Sampler {
+                comparison: type_name == "samplerShadow",
+            },
+        }),
+        word => {
+            fn kind_width_parse(ty: &str) -> Option<Scalar> {
+                Some(match ty {
+                    "" => Scalar::F32,
+                    "b" => Scalar::BOOL,
+                    "i" => Scalar::I32,
+                    "u" => Scalar::U32,
+                    "d" => Scalar::F64,
+                    _ => return None,
+                })
+            }
+
+            fn size_parse(n: &str) -> Option<VectorSize> {
+                Some(match n {
+                    "2" => VectorSize::Bi,
+                    "3" => VectorSize::Tri,
+                    "4" => VectorSize::Quad,
+                    _ => return None,
+                })
+            }
+
+            let vec_parse = |word: &str| {
+                let mut iter = word.split("vec");
+
+                let kind = iter.next()?;
+                let size = iter.next()?;
+                let scalar = kind_width_parse(kind)?;
+                let size = size_parse(size)?;
+
+                Some(Type {
+                    name: None,
+                    inner: TypeInner::Vector { size, scalar },
+                })
+            };
+
+            let mat_parse = |word: &str| {
+                let mut iter = word.split("mat");
+
+                let kind = iter.next()?;
+                let size = iter.next()?;
+                let scalar = kind_width_parse(kind)?;
+
+                let (columns, rows) = if let Some(size) = size_parse(size) {
+                    (size, size)
+                } else {
+                    let mut iter = size.split('x');
+                    match (iter.next()?, iter.next()?, iter.next()) {
+                        (col, row, None) => (size_parse(col)?, size_parse(row)?),
+                        _ => return None,
+                    }
+                };
+
+                Some(Type {
+                    name: None,
+                    inner: TypeInner::Matrix {
+                        columns,
+                        rows,
+                        scalar,
+                    },
+                })
+            };
+
+            let texture_parse = |word: &str| {
+                let mut iter = word.split("texture");
+
+                let texture_kind = |ty| {
+                    Some(match ty {
+                        "" => ScalarKind::Float,
+                        "i" => ScalarKind::Sint,
+                        "u" => ScalarKind::Uint,
+                        _ => return None,
+                    })
+                };
+
+                let kind = iter.next()?;
+                let size = iter.next()?;
+                let kind = texture_kind(kind)?;
+
+                let sampled = |multi| ImageClass::Sampled { kind, multi };
+
+                let (dim, arrayed, class) = match size {
+                    "1D" => (ImageDimension::D1, false, sampled(false)),
+                    "1DArray" => (ImageDimension::D1, true, sampled(false)),
+                    "2D" => (ImageDimension::D2, false, sampled(false)),
+                    "2DArray" => (ImageDimension::D2, true, sampled(false)),
+                    "2DMS" => (ImageDimension::D2, false, sampled(true)),
+                    "2DMSArray" => (ImageDimension::D2, true, sampled(true)),
+                    "3D" => (ImageDimension::D3, false, sampled(false)),
+                    "Cube" => (ImageDimension::Cube, false, sampled(false)),
+                    "CubeArray" => (ImageDimension::Cube, true, sampled(false)),
+                    _ => return None,
+                };
+
+                Some(Type {
+                    name: None,
+                    inner: TypeInner::Image {
+                        dim,
+                        arrayed,
+                        class,
+                    },
+                })
+            };
+
+            let image_parse = |word: &str| {
+                let mut iter = word.split("image");
+
+                let texture_kind = |ty| {
+                    Some(match ty {
+                        "" => ScalarKind::Float,
+                        "i" => ScalarKind::Sint,
+                        "u" => ScalarKind::Uint,
+                        _ => return None,
+                    })
+                };
+
+                let kind = iter.next()?;
+                let size = iter.next()?;
+                // TODO: Check that the texture format and the kind match
+                let _ = texture_kind(kind)?;
+
+                let class = ImageClass::Storage {
+                    format: crate::StorageFormat::R8Uint,
+                    access: crate::StorageAccess::all(),
+                };
+
+                // TODO: glsl support multisampled storage images, naga doesn't
+                let (dim, arrayed) = match size {
+                    "1D" => (ImageDimension::D1, false),
+                    "1DArray" => (ImageDimension::D1, true),
+                    "2D" => (ImageDimension::D2, false),
+                    "2DArray" => (ImageDimension::D2, true),
+                    "3D" => (ImageDimension::D3, false),
+                    // Naga doesn't support cube images and it's usefulness
+                    // is questionable, so they won't be supported for now
+                    // "Cube" => (ImageDimension::Cube, false),
+                    // "CubeArray" => (ImageDimension::Cube, true),
+                    _ => return None,
+                };
+
+                Some(Type {
+                    name: None,
+                    inner: TypeInner::Image {
+                        dim,
+                        arrayed,
+                        class,
+                    },
+                })
+            };
+
+            vec_parse(word)
+                .or_else(|| mat_parse(word))
+                .or_else(|| texture_parse(word))
+                .or_else(|| image_parse(word))
+        }
+    }
+}
+
+pub const fn scalar_components(ty: &TypeInner) -> Option<Scalar> {
+    match *ty {
+        TypeInner::Scalar(scalar)
+        | TypeInner::Vector { scalar, .. }
+        | TypeInner::ValuePointer { scalar, .. }
+        | TypeInner::Matrix { scalar, .. } => Some(scalar),
+        _ => None,
+    }
+}
+
+pub const fn type_power(scalar: Scalar) -> Option<u32> {
+    Some(match scalar.kind {
+        ScalarKind::Sint => 0,
+        ScalarKind::Uint => 1,
+        ScalarKind::Float if scalar.width == 4 => 2,
+        ScalarKind::Float => 3,
+        ScalarKind::Bool | ScalarKind::AbstractInt | ScalarKind::AbstractFloat => return None,
+    })
+}
+
+impl Context<'_> {
+    /// Resolves the types of the expressions until `expr` (inclusive)
+    ///
+    /// This needs to be done before the [`typifier`] can be queried for
+    /// the types of the expressions in the range between the last grow and `expr`.
+    ///
+    /// # Note
+    ///
+    /// The `resolve_type*` methods (like [`resolve_type`]) automatically
+    /// grow the [`typifier`] so calling this method is not necessary when using
+    /// them.
+    ///
+    /// [`typifier`]: Context::typifier
+    /// [`resolve_type`]: Self::resolve_type
+    pub(crate) fn typifier_grow(&mut self, expr: Handle<Expression>, meta: Span) -> Result<()> {
+        let resolve_ctx = ResolveContext::with_locals(self.module, &self.locals, &self.arguments);
+
+        let typifier = if self.is_const {
+            &mut self.const_typifier
+        } else {
+            &mut self.typifier
+        };
+
+        let expressions = if self.is_const {
+            &self.module.const_expressions
+        } else {
+            &self.expressions
+        };
+
+        typifier
+            .grow(expr, expressions, &resolve_ctx)
+            .map_err(|error| Error {
+                kind: ErrorKind::SemanticError(format!("Can't resolve type: {error:?}").into()),
+                meta,
+            })
+    }
+
+    pub(crate) fn get_type(&self, expr: Handle<Expression>) -> &TypeInner {
+        let typifier = if self.is_const {
+            &self.const_typifier
+        } else {
+            &self.typifier
+        };
+
+        typifier.get(expr, &self.module.types)
+    }
+
+    /// Gets the type for the result of the `expr` expression
+    ///
+    /// Automatically grows the [`typifier`] to `expr` so calling
+    /// [`typifier_grow`] is not necessary
+    ///
+    /// [`typifier`]: Context::typifier
+    /// [`typifier_grow`]: Self::typifier_grow
+    pub(crate) fn resolve_type(
+        &mut self,
+        expr: Handle<Expression>,
+        meta: Span,
+    ) -> Result<&TypeInner> {
+        self.typifier_grow(expr, meta)?;
+        Ok(self.get_type(expr))
+    }
+
+    /// Gets the type handle for the result of the `expr` expression
+    ///
+    /// Automatically grows the [`typifier`] to `expr` so calling
+    /// [`typifier_grow`] is not necessary
+    ///
+    /// # Note
+    ///
+    /// Consider using [`resolve_type`] whenever possible
+    /// since it doesn't require adding each type to the [`types`] arena
+    /// and it doesn't need to mutably borrow the [`Parser`][Self]
+    ///
+    /// [`types`]: crate::Module::types
+    /// [`typifier`]: Context::typifier
+    /// [`typifier_grow`]: Self::typifier_grow
+    /// [`resolve_type`]: Self::resolve_type
+    pub(crate) fn resolve_type_handle(
+        &mut self,
+        expr: Handle<Expression>,
+        meta: Span,
+    ) -> Result<Handle<Type>> {
+        self.typifier_grow(expr, meta)?;
+
+        let typifier = if self.is_const {
+            &mut self.const_typifier
+        } else {
+            &mut self.typifier
+        };
+
+        Ok(typifier.register_type(expr, &mut self.module.types))
+    }
+
+    /// Invalidates the cached type resolution for `expr` forcing a recomputation
+    pub(crate) fn invalidate_expression(
+        &mut self,
+        expr: Handle<Expression>,
+        meta: Span,
+    ) -> Result<()> {
+        let resolve_ctx = ResolveContext::with_locals(self.module, &self.locals, &self.arguments);
+
+        let typifier = if self.is_const {
+            &mut self.const_typifier
+        } else {
+            &mut self.typifier
+        };
+
+        typifier
+            .invalidate(expr, &self.expressions, &resolve_ctx)
+            .map_err(|error| Error {
+                kind: ErrorKind::SemanticError(format!("Can't resolve type: {error:?}").into()),
+                meta,
+            })
+    }
+
+    pub(crate) fn lift_up_const_expression(
+        &mut self,
+        expr: Handle<Expression>,
+    ) -> Result<Handle<Expression>> {
+        let meta = self.expressions.get_span(expr);
+        Ok(match self.expressions[expr] {
+            ref expr @ (Expression::Literal(_)
+            | Expression::Constant(_)
+            | Expression::ZeroValue(_)) => self.module.const_expressions.append(expr.clone(), meta),
+            Expression::Compose { ty, ref components } => {
+                let mut components = components.clone();
+                for component in &mut components {
+                    *component = self.lift_up_const_expression(*component)?;
+                }
+                self.module
+                    .const_expressions
+                    .append(Expression::Compose { ty, components }, meta)
+            }
+            Expression::Splat { size, value } => {
+                let value = self.lift_up_const_expression(value)?;
+                self.module
+                    .const_expressions
+                    .append(Expression::Splat { size, value }, meta)
+            }
+            _ => {
+                return Err(Error {
+                    kind: ErrorKind::SemanticError("Expression is not const-expression".into()),
+                    meta,
+                })
+            }
+        })
+    }
+}
diff --git a/third_party/rust/naga/src/front/glsl/variables.rs b/third_party/rust/naga/src/front/glsl/variables.rs
new file mode 100644
index 0000000000..5af2b228f0
--- /dev/null
+++ b/third_party/rust/naga/src/front/glsl/variables.rs
@@ -0,0 +1,646 @@
+use super::{
+    ast::*,
+    context::{Context, ExprPos},
+    error::{Error, ErrorKind},
+    Frontend, Result, Span,
+};
+use crate::{
+    AddressSpace, Binding, BuiltIn, Constant, Expression, GlobalVariable, Handle, Interpolation,
+    LocalVariable, ResourceBinding, Scalar, ScalarKind, ShaderStage, SwizzleComponent, Type,
+    TypeInner, VectorSize,
+};
+
+pub struct VarDeclaration<'a, 'key> {
+    pub qualifiers: &'a mut TypeQualifiers<'key>,
+    pub ty: Handle<Type>,
+    pub name: Option<String>,
+    pub init: Option<Handle<Expression>>,
+    pub meta: Span,
+}
+
+/// Information about a builtin used in [`add_builtin`](Frontend::add_builtin).
+struct BuiltInData {
+    /// The type of the builtin.
+    inner: TypeInner,
+    /// The associated builtin class.
+    builtin: BuiltIn,
+    /// Whether the builtin can be written to or not.
+    mutable: bool,
+    /// The storage used for the builtin.
+    storage: StorageQualifier,
+}
+
+pub enum GlobalOrConstant {
+    Global(Handle<GlobalVariable>),
+    Constant(Handle<Constant>),
+}
+
+impl Frontend {
+    /// Adds a builtin and returns a variable reference to it
+    fn add_builtin(
+        &mut self,
+        ctx: &mut Context,
+        name: &str,
+        data: BuiltInData,
+        meta: Span,
+    ) -> Result<Option<VariableReference>> {
+        let ty = ctx.module.types.insert(
+            Type {
+                name: None,
+                inner: data.inner,
+            },
+            meta,
+        );
+
+        let handle = ctx.module.global_variables.append(
+            GlobalVariable {
+                name: Some(name.into()),
+                space: AddressSpace::Private,
+                binding: None,
+                ty,
+                init: None,
+            },
+            meta,
+        );
+
+        let idx = self.entry_args.len();
+        self.entry_args.push(EntryArg {
+            name: None,
+            binding: Binding::BuiltIn(data.builtin),
+            handle,
+            storage: data.storage,
+        });
+
+        self.global_variables.push((
+            name.into(),
+            GlobalLookup {
+                kind: GlobalLookupKind::Variable(handle),
+                entry_arg: Some(idx),
+                mutable: data.mutable,
+            },
+        ));
+
+        let expr = ctx.add_expression(Expression::GlobalVariable(handle), meta)?;
+
+        let var = VariableReference {
+            expr,
+            load: true,
+            mutable: data.mutable,
+            constant: None,
+            entry_arg: Some(idx),
+        };
+
+        ctx.symbol_table.add_root(name.into(), var.clone());
+
+        Ok(Some(var))
+    }
+
+    pub(crate) fn lookup_variable(
+        &mut self,
+        ctx: &mut Context,
+        name: &str,
+        meta: Span,
+    ) -> Result<Option<VariableReference>> {
+        if let Some(var) = ctx.symbol_table.lookup(name).cloned() {
+            return Ok(Some(var));
+        }
+
+        let data = match name {
+            "gl_Position" => BuiltInData {
+                inner: TypeInner::Vector {
+                    size: VectorSize::Quad,
+                    scalar: Scalar::F32,
+                },
+                builtin: BuiltIn::Position { invariant: false },
+                mutable: true,
+                storage: StorageQualifier::Output,
+            },
+            "gl_FragCoord" => BuiltInData {
+                inner: TypeInner::Vector {
+                    size: VectorSize::Quad,
+                    scalar: Scalar::F32,
+                },
+                builtin: BuiltIn::Position { invariant: false },
+                mutable: false,
+                storage: StorageQualifier::Input,
+            },
+            "gl_PointCoord" => BuiltInData {
+                inner: TypeInner::Vector {
+                    size: VectorSize::Bi,
+                    scalar: Scalar::F32,
+                },
+                builtin: BuiltIn::PointCoord,
+                mutable: false,
+                storage: StorageQualifier::Input,
+            },
+            "gl_GlobalInvocationID"
+            | "gl_NumWorkGroups"
+            | "gl_WorkGroupSize"
+            | "gl_WorkGroupID"
+            | "gl_LocalInvocationID" => BuiltInData {
+                inner: TypeInner::Vector {
+                    size: VectorSize::Tri,
+                    scalar: Scalar::U32,
+                },
+                builtin: match name {
+                    "gl_GlobalInvocationID" => BuiltIn::GlobalInvocationId,
+                    "gl_NumWorkGroups" => BuiltIn::NumWorkGroups,
+                    "gl_WorkGroupSize" => BuiltIn::WorkGroupSize,
+                    "gl_WorkGroupID" => BuiltIn::WorkGroupId,
+                    "gl_LocalInvocationID" => BuiltIn::LocalInvocationId,
+                    _ => unreachable!(),
+                },
+                mutable: false,
+                storage: StorageQualifier::Input,
+            },
+            "gl_FrontFacing" => BuiltInData {
+                inner: TypeInner::Scalar(Scalar::BOOL),
+                builtin: BuiltIn::FrontFacing,
+                mutable: false,
+                storage: StorageQualifier::Input,
+            },
+            "gl_PointSize" | "gl_FragDepth" => BuiltInData {
+                inner: TypeInner::Scalar(Scalar::F32),
+                builtin: match name {
+                    "gl_PointSize" => BuiltIn::PointSize,
+                    "gl_FragDepth" => BuiltIn::FragDepth,
+                    _ => unreachable!(),
+                },
+                mutable: true,
+                storage: StorageQualifier::Output,
+            },
+            "gl_ClipDistance" | "gl_CullDistance" => {
+                let base = ctx.module.types.insert(
+                    Type {
+                        name: None,
+                        inner: TypeInner::Scalar(Scalar::F32),
+                    },
+                    meta,
+                );
+
+                BuiltInData {
+                    inner: TypeInner::Array {
+                        base,
+                        size: crate::ArraySize::Dynamic,
+                        stride: 4,
+                    },
+                    builtin: match name {
+                        "gl_ClipDistance" => BuiltIn::ClipDistance,
+                        "gl_CullDistance" => BuiltIn::CullDistance,
+                        _ => unreachable!(),
+                    },
+                    mutable: self.meta.stage == ShaderStage::Vertex,
+                    storage: StorageQualifier::Output,
+                }
+            }
+            _ => {
+                let builtin = match name {
+                    "gl_BaseVertex" => BuiltIn::BaseVertex,
+                    "gl_BaseInstance" => BuiltIn::BaseInstance,
+                    "gl_PrimitiveID" => BuiltIn::PrimitiveIndex,
+                    "gl_InstanceIndex" => BuiltIn::InstanceIndex,
+                    "gl_VertexIndex" => BuiltIn::VertexIndex,
+                    "gl_SampleID" => BuiltIn::SampleIndex,
+                    "gl_LocalInvocationIndex" => BuiltIn::LocalInvocationIndex,
+                    _ => return Ok(None),
+                };
+
+                BuiltInData {
+                    inner: TypeInner::Scalar(Scalar::U32),
+                    builtin,
+                    mutable: false,
+                    storage: StorageQualifier::Input,
+                }
+            }
+        };
+
+        self.add_builtin(ctx, name, data, meta)
+    }
+
+    pub(crate) fn make_variable_invariant(
+        &mut self,
+        ctx: &mut Context,
+        name: &str,
+        meta: Span,
+    ) -> Result<()> {
+        if let Some(var) = self.lookup_variable(ctx, name, meta)? {
+            if let Some(index) = var.entry_arg {
+                if let Binding::BuiltIn(BuiltIn::Position { ref mut invariant }) =
+                    self.entry_args[index].binding
+                {
+                    *invariant = true;
+                }
+            }
+        }
+        Ok(())
+    }
+
+    pub(crate) fn field_selection(
+        &mut self,
+        ctx: &mut Context,
+        pos: ExprPos,
+        expression: Handle<Expression>,
+        name: &str,
+        meta: Span,
+    ) -> Result<Handle<Expression>> {
+        let (ty, is_pointer) = match *ctx.resolve_type(expression, meta)? {
+            TypeInner::Pointer { base, .. } => (&ctx.module.types[base].inner, true),
+            ref ty => (ty, false),
+        };
+        match *ty {
+            TypeInner::Struct { ref members, .. } => {
+                let index = members
+                    .iter()
+                    .position(|m| m.name == Some(name.into()))
+                    .ok_or_else(|| Error {
+                        kind: ErrorKind::UnknownField(name.into()),
+                        meta,
+                    })?;
+                let pointer = ctx.add_expression(
+                    Expression::AccessIndex {
+                        base: expression,
+                        index: index as u32,
+                    },
+                    meta,
+                )?;
+
+                Ok(match pos {
+                    ExprPos::Rhs if is_pointer => {
+                        ctx.add_expression(Expression::Load { pointer }, meta)?
+                    }
+                    _ => pointer,
+                })
+            }
+            // swizzles (xyzw, rgba, stpq)
+            TypeInner::Vector { size, .. } => {
+                let check_swizzle_components = |comps: &str| {
+                    name.chars()
+                        .map(|c| {
+                            comps
+                                .find(c)
+                                .filter(|i| *i < size as usize)
+                                .map(|i| SwizzleComponent::from_index(i as u32))
+                        })
+                        .collect::<Option<Vec<SwizzleComponent>>>()
+                };
+
+                let components = check_swizzle_components("xyzw")
+                    .or_else(|| check_swizzle_components("rgba"))
+                    .or_else(|| check_swizzle_components("stpq"));
+
+                if let Some(components) = components {
+                    if let ExprPos::Lhs = pos {
+                        let not_unique = (1..components.len())
+                            .any(|i| components[i..].contains(&components[i - 1]));
+                        if not_unique {
+                            self.errors.push(Error {
+                                kind:
+                                ErrorKind::SemanticError(
+                                format!(
+                                    "swizzle cannot have duplicate components in left-hand-side expression for \"{name:?}\""
+                                )
+                                .into(),
+                            ),
+                                meta ,
+                            })
+                        }
+                    }
+
+                    let mut pattern = [SwizzleComponent::X; 4];
+                    for (pat, component) in pattern.iter_mut().zip(&components) {
+                        *pat = *component;
+                    }
+
+                    // flatten nested swizzles (vec.zyx.xy.x => vec.z)
+                    let mut expression = expression;
+                    if let Expression::Swizzle {
+                        size: _,
+                        vector,
+                        pattern: ref src_pattern,
+                    } = ctx[expression]
+                    {
+                        expression = vector;
+                        for pat in &mut pattern {
+                            *pat = src_pattern[pat.index() as usize];
+                        }
+                    }
+
+                    let size = match components.len() {
+                        // Swizzles with just one component are accesses and not swizzles
+                        1 => {
+                            match pos {
+                                // If the position is in the right hand side and the base
+                                // vector is a pointer, load it, otherwise the swizzle would
+                                // produce a pointer
+                                ExprPos::Rhs if is_pointer => {
+                                    expression = ctx.add_expression(
+                                        Expression::Load {
+                                            pointer: expression,
+                                        },
+                                        meta,
+                                    )?;
+                                }
+                                _ => {}
+                            };
+                            return ctx.add_expression(
+                                Expression::AccessIndex {
+                                    base: expression,
+                                    index: pattern[0].index(),
+                                },
+                                meta,
+                            );
+                        }
+                        2 => VectorSize::Bi,
+                        3 => VectorSize::Tri,
+                        4 => VectorSize::Quad,
+                        _ => {
+                            self.errors.push(Error {
+                                kind: ErrorKind::SemanticError(
+                                    format!("Bad swizzle size for \"{name:?}\"").into(),
+                                ),
+                                meta,
+                            });
+
+                            VectorSize::Quad
+                        }
+                    };
+
+                    if is_pointer {
+                        // NOTE: for lhs expression, this extra load ends up as an unused expr, because the
+                        // assignment will extract the pointer and use it directly anyway. Unfortunately we
+                        // need it for validation to pass, as swizzles cannot operate on pointer values.
+                        expression = ctx.add_expression(
+                            Expression::Load {
+                                pointer: expression,
+                            },
+                            meta,
+                        )?;
+                    }
+
+                    Ok(ctx.add_expression(
+                        Expression::Swizzle {
+                            size,
+                            vector: expression,
+                            pattern,
+                        },
+                        meta,
+                    )?)
+                } else {
+                    Err(Error {
+                        kind: ErrorKind::SemanticError(
+                            format!("Invalid swizzle for vector \"{name}\"").into(),
+                        ),
+                        meta,
+                    })
+                }
+            }
+            _ => Err(Error {
+                kind: ErrorKind::SemanticError(
+                    format!("Can't lookup field on this type \"{name}\"").into(),
+                ),
+                meta,
+            }),
+        }
+    }
+
+    pub(crate) fn add_global_var(
+        &mut self,
+        ctx: &mut Context,
+        VarDeclaration {
+            qualifiers,
+            mut ty,
+            name,
+            init,
+            meta,
+        }: VarDeclaration,
+    ) -> Result<GlobalOrConstant> {
+        let storage = qualifiers.storage.0;
+        let (ret, lookup) = match storage {
+            StorageQualifier::Input | StorageQualifier::Output => {
+                let input = storage == StorageQualifier::Input;
+                // TODO: glslang seems to use a counter for variables without
+                // explicit location (even if that causes collisions)
+                let location = qualifiers
+                    .uint_layout_qualifier("location", &mut self.errors)
+                    .unwrap_or(0);
+                let interpolation = qualifiers.interpolation.take().map(|(i, _)| i).or_else(|| {
+                    let kind = ctx.module.types[ty].inner.scalar_kind()?;
+                    Some(match kind {
+                        ScalarKind::Float => Interpolation::Perspective,
+                        _ => Interpolation::Flat,
+                    })
+                });
+                let sampling = qualifiers.sampling.take().map(|(s, _)| s);
+
+                let handle = ctx.module.global_variables.append(
+                    GlobalVariable {
+                        name: name.clone(),
+                        space: AddressSpace::Private,
+                        binding: None,
+                        ty,
+                        init,
+                    },
+                    meta,
+                );
+
+                let idx = self.entry_args.len();
+                self.entry_args.push(EntryArg {
+                    name: name.clone(),
+                    binding: Binding::Location {
+                        location,
+                        interpolation,
+                        sampling,
+                        second_blend_source: false,
+                    },
+                    handle,
+                    storage,
+                });
+
+                let lookup = GlobalLookup {
+                    kind: GlobalLookupKind::Variable(handle),
+                    entry_arg: Some(idx),
+                    mutable: !input,
+                };
+
+                (GlobalOrConstant::Global(handle), lookup)
+            }
+            StorageQualifier::Const => {
+                let init = init.ok_or_else(|| Error {
+                    kind: ErrorKind::SemanticError("const values must have an initializer".into()),
+                    meta,
+                })?;
+
+                let constant = Constant {
+                    name: name.clone(),
+                    r#override: crate::Override::None,
+                    ty,
+                    init,
+                };
+                let handle = ctx.module.constants.fetch_or_append(constant, meta);
+
+                let lookup = GlobalLookup {
+                    kind: GlobalLookupKind::Constant(handle, ty),
+                    entry_arg: None,
+                    mutable: false,
+                };
+
+                (GlobalOrConstant::Constant(handle), lookup)
+            }
+            StorageQualifier::AddressSpace(mut space) => {
+                match space {
+                    AddressSpace::Storage { ref mut access } => {
+                        if let Some((allowed_access, _)) = qualifiers.storage_access.take() {
+                            *access = allowed_access;
+                        }
+                    }
+                    AddressSpace::Uniform => match ctx.module.types[ty].inner {
+                        TypeInner::Image {
+                            class,
+                            dim,
+                            arrayed,
+                        } => {
+                            if let crate::ImageClass::Storage {
+                                mut access,
+                                mut format,
+                            } = class
+                            {
+                                if let Some((allowed_access, _)) = qualifiers.storage_access.take()
+                                {
+                                    access = allowed_access;
+                                }
+
+                                match qualifiers.layout_qualifiers.remove(&QualifierKey::Format) {
+                                    Some((QualifierValue::Format(f), _)) => format = f,
+                                    // TODO: glsl supports images without format qualifier
+                                    // if they are `writeonly`
+                                    None => self.errors.push(Error {
+                                        kind: ErrorKind::SemanticError(
+                                            "image types require a format layout qualifier".into(),
+                                        ),
+                                        meta,
+                                    }),
+                                    _ => unreachable!(),
+                                }
+
+                                ty = ctx.module.types.insert(
+                                    Type {
+                                        name: None,
+                                        inner: TypeInner::Image {
+                                            dim,
+                                            arrayed,
+                                            class: crate::ImageClass::Storage { format, access },
+                                        },
+                                    },
+                                    meta,
+                                );
+                            }
+
+                            space = AddressSpace::Handle
+                        }
+                        TypeInner::Sampler { .. } => space = AddressSpace::Handle,
+                        _ => {
+                            if qualifiers.none_layout_qualifier("push_constant", &mut self.errors) {
+                                space = AddressSpace::PushConstant
+                            }
+                        }
+                    },
+                    AddressSpace::Function => space = AddressSpace::Private,
+                    _ => {}
+                };
+
+                let binding = match space {
+                    AddressSpace::Uniform | AddressSpace::Storage { .. } | AddressSpace::Handle => {
+                        let binding = qualifiers.uint_layout_qualifier("binding", &mut self.errors);
+                        if binding.is_none() {
+                            self.errors.push(Error {
+                                kind: ErrorKind::SemanticError(
+                                    "uniform/buffer blocks require layout(binding=X)".into(),
+                                ),
+                                meta,
+                            });
+                        }
+                        let set = qualifiers.uint_layout_qualifier("set", &mut self.errors);
+                        binding.map(|binding| ResourceBinding {
+                            group: set.unwrap_or(0),
+                            binding,
+                        })
+                    }
+                    _ => None,
+                };
+
+                let handle = ctx.module.global_variables.append(
+                    GlobalVariable {
+                        name: name.clone(),
+                        space,
+                        binding,
+                        ty,
+                        init,
+                    },
+                    meta,
+                );
+
+                let lookup = GlobalLookup {
+                    kind: GlobalLookupKind::Variable(handle),
+                    entry_arg: None,
+                    mutable: true,
+                };
+
+                (GlobalOrConstant::Global(handle), lookup)
+            }
+        };
+
+        if let Some(name) = name {
+            ctx.add_global(&name, lookup)?;
+
+            self.global_variables.push((name, lookup));
+        }
+
+        qualifiers.unused_errors(&mut self.errors);
+
+        Ok(ret)
+    }
+
+    pub(crate) fn add_local_var(
+        &mut self,
+        ctx: &mut Context,
+        decl: VarDeclaration,
+    ) -> Result<Handle<Expression>> {
+        let storage = decl.qualifiers.storage;
+        let mutable = match storage.0 {
+            StorageQualifier::AddressSpace(AddressSpace::Function) => true,
+            StorageQualifier::Const => false,
+            _ => {
+                self.errors.push(Error {
+                    kind: ErrorKind::SemanticError("Locals cannot have a storage qualifier".into()),
+                    meta: storage.1,
+                });
+                true
+            }
+        };
+
+        let handle = ctx.locals.append(
+            LocalVariable {
+                name: decl.name.clone(),
+                ty: decl.ty,
+                init: decl.init,
+            },
+            decl.meta,
+        );
+        let expr = ctx.add_expression(Expression::LocalVariable(handle), decl.meta)?;
+
+        if let Some(name) = decl.name {
+            let maybe_var = ctx.add_local_var(name.clone(), expr, mutable);
+
+            if maybe_var.is_some() {
+                self.errors.push(Error {
+                    kind: ErrorKind::VariableAlreadyDeclared(name),
+                    meta: decl.meta,
+                })
+            }
+        }
+
+        decl.qualifiers.unused_errors(&mut self.errors);
+
+        Ok(expr)
+    }
+}
diff --git a/third_party/rust/naga/src/front/interpolator.rs b/third_party/rust/naga/src/front/interpolator.rs
new file mode 100644
index 0000000000..0196a2254d
--- /dev/null
+++ b/third_party/rust/naga/src/front/interpolator.rs
@@ -0,0 +1,62 @@
+/*!
+Interpolation defaults.
+*/
+
+impl crate::Binding {
+    /// Apply the usual default interpolation for `ty` to `binding`.
+    ///
+    /// This function is a utility front ends may use to satisfy the Naga IR's
+    /// requirement, meant to ensure that input languages' policies have been
+    /// applied appropriately, that all I/O `Binding`s from the vertex shader to the
+    /// fragment shader must have non-`None` `interpolation` values.
+    ///
+    /// All the shader languages Naga supports have similar rules:
+    /// perspective-correct, center-sampled interpolation is the default for any
+    /// binding that can vary, and everything else either defaults to flat, or
+    /// requires an explicit flat qualifier/attribute/what-have-you.
+    ///
+    /// If `binding` is not a [`Location`] binding, or if its [`interpolation`] is
+    /// already set, then make no changes. Otherwise, set `binding`'s interpolation
+    /// and sampling to reasonable defaults depending on `ty`, the type of the value
+    /// being interpolated:
+    ///
+    /// - If `ty` is a floating-point scalar, vector, or matrix type, then
+    ///   default to [`Perspective`] interpolation and [`Center`] sampling.
+    ///
+    /// - If `ty` is an integral scalar or vector, then default to [`Flat`]
+    ///   interpolation, which has no associated sampling.
+    ///
+    /// - For any other types, make no change. Such types are not permitted as
+    ///   user-defined IO values, and will probably be flagged by the verifier
+    ///
+    /// When structs appear in input or output types, each member ought to have its
+    /// own [`Binding`], so structs are simply covered by the third case.
+    ///
+    /// [`Binding`]: crate::Binding
+    /// [`Location`]: crate::Binding::Location
+    /// [`interpolation`]: crate::Binding::Location::interpolation
+    /// [`Perspective`]: crate::Interpolation::Perspective
+    /// [`Flat`]: crate::Interpolation::Flat
+    /// [`Center`]: crate::Sampling::Center
+    pub fn apply_default_interpolation(&mut self, ty: &crate::TypeInner) {
+        if let crate::Binding::Location {
+            location: _,
+            interpolation: ref mut interpolation @ None,
+            ref mut sampling,
+            second_blend_source: _,
+        } = *self
+        {
+            match ty.scalar_kind() {
+                Some(crate::ScalarKind::Float) => {
+                    *interpolation = Some(crate::Interpolation::Perspective);
+                    *sampling = Some(crate::Sampling::Center);
+                }
+                Some(crate::ScalarKind::Sint | crate::ScalarKind::Uint) => {
+                    *interpolation = Some(crate::Interpolation::Flat);
+                    *sampling = None;
+                }
+                Some(_) | None => {}
+            }
+        }
+    }
+}
diff --git a/third_party/rust/naga/src/front/mod.rs b/third_party/rust/naga/src/front/mod.rs
new file mode 100644
index 0000000000..e1f99452e1
--- /dev/null
+++ b/third_party/rust/naga/src/front/mod.rs
@@ -0,0 +1,328 @@
+/*!
+Frontend parsers that consume binary and text shaders and load them into [`Module`](super::Module)s.
+*/
+
+mod interpolator;
+mod type_gen;
+
+#[cfg(feature = "glsl-in")]
+pub mod glsl;
+#[cfg(feature = "spv-in")]
+pub mod spv;
+#[cfg(feature = "wgsl-in")]
+pub mod wgsl;
+
+use crate::{
+    arena::{Arena, Handle, UniqueArena},
+    proc::{ResolveContext, ResolveError, TypeResolution},
+    FastHashMap,
+};
+use std::ops;
+
+/// A table of types for an `Arena<Expression>`.
+///
+/// A front end can use a `Typifier` to get types for an arena's expressions
+/// while it is still contributing expressions to it. At any point, you can call
+/// [`typifier.grow(expr, arena, ctx)`], where `expr` is a `Handle<Expression>`
+/// referring to something in `arena`, and the `Typifier` will resolve the types
+/// of all the expressions up to and including `expr`. Then you can write
+/// `typifier[handle]` to get the type of any handle at or before `expr`.
+///
+/// Note that `Typifier` does *not* build an `Arena<Type>` as a part of its
+/// usual operation. Ideally, a module's type arena should only contain types
+/// actually needed by `Handle<Type>`s elsewhere in the module — functions,
+/// variables, [`Compose`] expressions, other types, and so on — so we don't
+/// want every little thing that occurs as the type of some intermediate
+/// expression to show up there.
+///
+/// Instead, `Typifier` accumulates a [`TypeResolution`] for each expression,
+/// which refers to the `Arena<Type>` in the [`ResolveContext`] passed to `grow`
+/// as needed. [`TypeResolution`] is a lightweight representation for
+/// intermediate types like this; see its documentation for details.
+///
+/// If you do need to register a `Typifier`'s conclusion in an `Arena<Type>`
+/// (say, for a [`LocalVariable`] whose type you've inferred), you can use
+/// [`register_type`] to do so.
+///
+/// [`typifier.grow(expr, arena)`]: Typifier::grow
+/// [`register_type`]: Typifier::register_type
+/// [`Compose`]: crate::Expression::Compose
+/// [`LocalVariable`]: crate::LocalVariable
+#[derive(Debug, Default)]
+pub struct Typifier {
+    resolutions: Vec<TypeResolution>,
+}
+
+impl Typifier {
+    pub const fn new() -> Self {
+        Typifier {
+            resolutions: Vec::new(),
+        }
+    }
+
+    pub fn reset(&mut self) {
+        self.resolutions.clear()
+    }
+
+    pub fn get<'a>(
+        &'a self,
+        expr_handle: Handle<crate::Expression>,
+        types: &'a UniqueArena<crate::Type>,
+    ) -> &'a crate::TypeInner {
+        self.resolutions[expr_handle.index()].inner_with(types)
+    }
+
+    /// Add an expression's type to an `Arena<Type>`.
+    ///
+    /// Add the type of `expr_handle` to `types`, and return a `Handle<Type>`
+    /// referring to it.
+    ///
+    /// # Note
+    ///
+    /// If you just need a [`TypeInner`] for `expr_handle`'s type, consider
+    /// using `typifier[expression].inner_with(types)` instead. Calling
+    /// [`TypeResolution::inner_with`] often lets us avoid adding anything to
+    /// the arena, which can significantly reduce the number of types that end
+    /// up in the final module.
+    ///
+    /// [`TypeInner`]: crate::TypeInner
+    pub fn register_type(
+        &self,
+        expr_handle: Handle<crate::Expression>,
+        types: &mut UniqueArena<crate::Type>,
+    ) -> Handle<crate::Type> {
+        match self[expr_handle].clone() {
+            TypeResolution::Handle(handle) => handle,
+            TypeResolution::Value(inner) => {
+                types.insert(crate::Type { name: None, inner }, crate::Span::UNDEFINED)
+            }
+        }
+    }
+
+    /// Grow this typifier until it contains a type for `expr_handle`.
+    pub fn grow(
+        &mut self,
+        expr_handle: Handle<crate::Expression>,
+        expressions: &Arena<crate::Expression>,
+        ctx: &ResolveContext,
+    ) -> Result<(), ResolveError> {
+        if self.resolutions.len() <= expr_handle.index() {
+            for (eh, expr) in expressions.iter().skip(self.resolutions.len()) {
+                //Note: the closure can't `Err` by construction
+                let resolution = ctx.resolve(expr, |h| Ok(&self.resolutions[h.index()]))?;
+                log::debug!("Resolving {:?} = {:?} : {:?}", eh, expr, resolution);
+                self.resolutions.push(resolution);
+            }
+        }
+        Ok(())
+    }
+
+    /// Recompute the type resolution for `expr_handle`.
+    ///
+    /// If the type of `expr_handle` hasn't yet been calculated, call
+    /// [`grow`](Self::grow) to ensure it is covered.
+    ///
+    /// In either case, when this returns, `self[expr_handle]` should be an
+    /// updated type resolution for `expr_handle`.
+    pub fn invalidate(
+        &mut self,
+        expr_handle: Handle<crate::Expression>,
+        expressions: &Arena<crate::Expression>,
+        ctx: &ResolveContext,
+    ) -> Result<(), ResolveError> {
+        if self.resolutions.len() <= expr_handle.index() {
+            self.grow(expr_handle, expressions, ctx)
+        } else {
+            let expr = &expressions[expr_handle];
+            //Note: the closure can't `Err` by construction
+            let resolution = ctx.resolve(expr, |h| Ok(&self.resolutions[h.index()]))?;
+            self.resolutions[expr_handle.index()] = resolution;
+            Ok(())
+        }
+    }
+}
+
+impl ops::Index<Handle<crate::Expression>> for Typifier {
+    type Output = TypeResolution;
+    fn index(&self, handle: Handle<crate::Expression>) -> &Self::Output {
+        &self.resolutions[handle.index()]
+    }
+}
+
+/// Type representing a lexical scope, associating a name to a single variable
+///
+/// The scope is generic over the variable representation and name representation
+/// in order to allow larger flexibility on the frontends on how they might
+/// represent them.
+type Scope<Name, Var> = FastHashMap<Name, Var>;
+
+/// Structure responsible for managing variable lookups and keeping track of
+/// lexical scopes
+///
+/// The symbol table is generic over the variable representation and its name
+/// to allow larger flexibility on the frontends on how they might represent them.
+///
+/// ```
+/// use naga::front::SymbolTable;
+///
+/// // Create a new symbol table with `u32`s representing the variable
+/// let mut symbol_table: SymbolTable<&str, u32> = SymbolTable::default();
+///
+/// // Add two variables named `var1` and `var2` with 0 and 2 respectively
+/// symbol_table.add("var1", 0);
+/// symbol_table.add("var2", 2);
+///
+/// // Check that `var1` exists and is `0`
+/// assert_eq!(symbol_table.lookup("var1"), Some(&0));
+///
+/// // Push a new scope and add a variable to it named `var1` shadowing the
+/// // variable of our previous scope
+/// symbol_table.push_scope();
+/// symbol_table.add("var1", 1);
+///
+/// // Check that `var1` now points to the new value of `1` and `var2` still
+/// // exists with its value of `2`
+/// assert_eq!(symbol_table.lookup("var1"), Some(&1));
+/// assert_eq!(symbol_table.lookup("var2"), Some(&2));
+///
+/// // Pop the scope
+/// symbol_table.pop_scope();
+///
+/// // Check that `var1` now refers to our initial variable with value `0`
+/// assert_eq!(symbol_table.lookup("var1"), Some(&0));
+/// ```
+///
+/// Scopes are ordered as a LIFO stack so a variable defined in a later scope
+/// with the same name as another variable defined in a earlier scope will take
+/// precedence in the lookup. Scopes can be added with [`push_scope`] and
+/// removed with [`pop_scope`].
+///
+/// A root scope is added when the symbol table is created and must always be
+/// present. Trying to pop it will result in a panic.
+///
+/// Variables can be added with [`add`] and looked up with [`lookup`]. Adding a
+/// variable will do so in the currently active scope and as mentioned
+/// previously a lookup will search from the current scope to the root scope.
+///
+/// [`push_scope`]: Self::push_scope
+/// [`pop_scope`]: Self::push_scope
+/// [`add`]: Self::add
+/// [`lookup`]: Self::lookup
+pub struct SymbolTable<Name, Var> {
+    /// Stack of lexical scopes. Not all scopes are active; see [`cursor`].
+    ///
+    /// [`cursor`]: Self::cursor
+    scopes: Vec<Scope<Name, Var>>,
+    /// Limit of the [`scopes`] stack (exclusive). By using a separate value for
+    /// the stack length instead of `Vec`'s own internal length, the scopes can
+    /// be reused to cache memory allocations.
+    ///
+    /// [`scopes`]: Self::scopes
+    cursor: usize,
+}
+
+impl<Name, Var> SymbolTable<Name, Var> {
+    /// Adds a new lexical scope.
+    ///
+    /// All variables declared after this point will be added to this scope
+    /// until another scope is pushed or [`pop_scope`] is called, causing this
+    /// scope to be removed along with all variables added to it.
+    ///
+    /// [`pop_scope`]: Self::pop_scope
+    pub fn push_scope(&mut self) {
+        // If the cursor is equal to the scope's stack length then we need to
+        // push another empty scope. Otherwise we can reuse the already existing
+        // scope.
+        if self.scopes.len() == self.cursor {
+            self.scopes.push(FastHashMap::default())
+        } else {
+            self.scopes[self.cursor].clear();
+        }
+
+        self.cursor += 1;
+    }
+
+    /// Removes the current lexical scope and all its variables
+    ///
+    /// # PANICS
+    /// - If the current lexical scope is the root scope
+    pub fn pop_scope(&mut self) {
+        // Despite the method title, the variables are only deleted when the
+        // scope is reused. This is because while a clear is inevitable if the
+        // scope needs to be reused, there are cases where the scope might be
+        // popped and not reused, i.e. if another scope with the same nesting
+        // level is never pushed again.
+        assert!(self.cursor != 1, "Tried to pop the root scope");
+
+        self.cursor -= 1;
+    }
+}
+
+impl<Name, Var> SymbolTable<Name, Var>
+where
+    Name: std::hash::Hash + Eq,
+{
+    /// Perform a lookup for a variable named `name`.
+    ///
+    /// As stated in the struct level documentation the lookup will proceed from
+    /// the current scope to the root scope, returning `Some` when a variable is
+    /// found or `None` if there doesn't exist a variable with `name` in any
+    /// scope.
+    pub fn lookup<Q: ?Sized>(&self, name: &Q) -> Option<&Var>
+    where
+        Name: std::borrow::Borrow<Q>,
+        Q: std::hash::Hash + Eq,
+    {
+        // Iterate backwards trough the scopes and try to find the variable
+        for scope in self.scopes[..self.cursor].iter().rev() {
+            if let Some(var) = scope.get(name) {
+                return Some(var);
+            }
+        }
+
+        None
+    }
+
+    /// Adds a new variable to the current scope.
+    ///
+    /// Returns the previous variable with the same name in this scope if it
+    /// exists, so that the frontend might handle it in case variable shadowing
+    /// is disallowed.
+    pub fn add(&mut self, name: Name, var: Var) -> Option<Var> {
+        self.scopes[self.cursor - 1].insert(name, var)
+    }
+
+    /// Adds a new variable to the root scope.
+    ///
+    /// This is used in GLSL for builtins which aren't known in advance and only
+    /// when used for the first time, so there must be a way to add those
+    /// declarations to the root unconditionally from the current scope.
+    ///
+    /// Returns the previous variable with the same name in the root scope if it
+    /// exists, so that the frontend might handle it in case variable shadowing
+    /// is disallowed.
+    pub fn add_root(&mut self, name: Name, var: Var) -> Option<Var> {
+        self.scopes[0].insert(name, var)
+    }
+}
+
+impl<Name, Var> Default for SymbolTable<Name, Var> {
+    /// Constructs a new symbol table with a root scope
+    fn default() -> Self {
+        Self {
+            scopes: vec![FastHashMap::default()],
+            cursor: 1,
+        }
+    }
+}
+
+use std::fmt;
+
+impl<Name: fmt::Debug, Var: fmt::Debug> fmt::Debug for SymbolTable<Name, Var> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_str("SymbolTable ")?;
+        f.debug_list()
+            .entries(self.scopes[..self.cursor].iter())
+            .finish()
+    }
+}
diff --git a/third_party/rust/naga/src/front/spv/convert.rs b/third_party/rust/naga/src/front/spv/convert.rs
new file mode 100644
index 0000000000..f0a714fbeb
--- /dev/null
+++ b/third_party/rust/naga/src/front/spv/convert.rs
@@ -0,0 +1,179 @@
+use super::error::Error;
+use std::convert::TryInto;
+
+pub(super) const fn map_binary_operator(word: spirv::Op) -> Result<crate::BinaryOperator, Error> {
+    use crate::BinaryOperator;
+    use spirv::Op;
+
+    match word {
+        // Arithmetic Instructions +, -, *, /, %
+        Op::IAdd | Op::FAdd => Ok(BinaryOperator::Add),
+        Op::ISub | Op::FSub => Ok(BinaryOperator::Subtract),
+        Op::IMul | Op::FMul => Ok(BinaryOperator::Multiply),
+        Op::UDiv | Op::SDiv | Op::FDiv => Ok(BinaryOperator::Divide),
+        Op::SRem => Ok(BinaryOperator::Modulo),
+        // Relational and Logical Instructions
+        Op::IEqual | Op::FOrdEqual | Op::FUnordEqual | Op::LogicalEqual => {
+            Ok(BinaryOperator::Equal)
+        }
+        Op::INotEqual | Op::FOrdNotEqual | Op::FUnordNotEqual | Op::LogicalNotEqual => {
+            Ok(BinaryOperator::NotEqual)
+        }
+        Op::ULessThan | Op::SLessThan | Op::FOrdLessThan | Op::FUnordLessThan => {
+            Ok(BinaryOperator::Less)
+        }
+        Op::ULessThanEqual
+        | Op::SLessThanEqual
+        | Op::FOrdLessThanEqual
+        | Op::FUnordLessThanEqual => Ok(BinaryOperator::LessEqual),
+        Op::UGreaterThan | Op::SGreaterThan | Op::FOrdGreaterThan | Op::FUnordGreaterThan => {
+            Ok(BinaryOperator::Greater)
+        }
+        Op::UGreaterThanEqual
+        | Op::SGreaterThanEqual
+        | Op::FOrdGreaterThanEqual
+        | Op::FUnordGreaterThanEqual => Ok(BinaryOperator::GreaterEqual),
+        Op::BitwiseOr => Ok(BinaryOperator::InclusiveOr),
+        Op::BitwiseXor => Ok(BinaryOperator::ExclusiveOr),
+        Op::BitwiseAnd => Ok(BinaryOperator::And),
+        _ => Err(Error::UnknownBinaryOperator(word)),
+    }
+}
+
+pub(super) const fn map_relational_fun(
+    word: spirv::Op,
+) -> Result<crate::RelationalFunction, Error> {
+    use crate::RelationalFunction as Rf;
+    use spirv::Op;
+
+    match word {
+        Op::All => Ok(Rf::All),
+        Op::Any => Ok(Rf::Any),
+        Op::IsNan => Ok(Rf::IsNan),
+        Op::IsInf => Ok(Rf::IsInf),
+        _ => Err(Error::UnknownRelationalFunction(word)),
+    }
+}
+
+pub(super) const fn map_vector_size(word: spirv::Word) -> Result<crate::VectorSize, Error> {
+    match word {
+        2 => Ok(crate::VectorSize::Bi),
+        3 => Ok(crate::VectorSize::Tri),
+        4 => Ok(crate::VectorSize::Quad),
+        _ => Err(Error::InvalidVectorSize(word)),
+    }
+}
+
+pub(super) fn map_image_dim(word: spirv::Word) -> Result<crate::ImageDimension, Error> {
+    use spirv::Dim as D;
+    match D::from_u32(word) {
+        Some(D::Dim1D) => Ok(crate::ImageDimension::D1),
+        Some(D::Dim2D) => Ok(crate::ImageDimension::D2),
+        Some(D::Dim3D) => Ok(crate::ImageDimension::D3),
+        Some(D::DimCube) => Ok(crate::ImageDimension::Cube),
+        _ => Err(Error::UnsupportedImageDim(word)),
+    }
+}
+
+pub(super) fn map_image_format(word: spirv::Word) -> Result<crate::StorageFormat, Error> {
+    match spirv::ImageFormat::from_u32(word) {
+        Some(spirv::ImageFormat::R8) => Ok(crate::StorageFormat::R8Unorm),
+        Some(spirv::ImageFormat::R8Snorm) => Ok(crate::StorageFormat::R8Snorm),
+        Some(spirv::ImageFormat::R8ui) => Ok(crate::StorageFormat::R8Uint),
+        Some(spirv::ImageFormat::R8i) => Ok(crate::StorageFormat::R8Sint),
+        Some(spirv::ImageFormat::R16) => Ok(crate::StorageFormat::R16Unorm),
+        Some(spirv::ImageFormat::R16Snorm) => Ok(crate::StorageFormat::R16Snorm),
+        Some(spirv::ImageFormat::R16ui) => Ok(crate::StorageFormat::R16Uint),
+        Some(spirv::ImageFormat::R16i) => Ok(crate::StorageFormat::R16Sint),
+        Some(spirv::ImageFormat::R16f) => Ok(crate::StorageFormat::R16Float),
+        Some(spirv::ImageFormat::Rg8) => Ok(crate::StorageFormat::Rg8Unorm),
+        Some(spirv::ImageFormat::Rg8Snorm) => Ok(crate::StorageFormat::Rg8Snorm),
+        Some(spirv::ImageFormat::Rg8ui) => Ok(crate::StorageFormat::Rg8Uint),
+        Some(spirv::ImageFormat::Rg8i) => Ok(crate::StorageFormat::Rg8Sint),
+        Some(spirv::ImageFormat::R32ui) => Ok(crate::StorageFormat::R32Uint),
+        Some(spirv::ImageFormat::R32i) => Ok(crate::StorageFormat::R32Sint),
+        Some(spirv::ImageFormat::R32f) => Ok(crate::StorageFormat::R32Float),
+        Some(spirv::ImageFormat::Rg16) => Ok(crate::StorageFormat::Rg16Unorm),
+        Some(spirv::ImageFormat::Rg16Snorm) => Ok(crate::StorageFormat::Rg16Snorm),
+        Some(spirv::ImageFormat::Rg16ui) => Ok(crate::StorageFormat::Rg16Uint),
+        Some(spirv::ImageFormat::Rg16i) => Ok(crate::StorageFormat::Rg16Sint),
+        Some(spirv::ImageFormat::Rg16f) => Ok(crate::StorageFormat::Rg16Float),
+        Some(spirv::ImageFormat::Rgba8) => Ok(crate::StorageFormat::Rgba8Unorm),
+        Some(spirv::ImageFormat::Rgba8Snorm) => Ok(crate::StorageFormat::Rgba8Snorm),
+        Some(spirv::ImageFormat::Rgba8ui) => Ok(crate::StorageFormat::Rgba8Uint),
+        Some(spirv::ImageFormat::Rgba8i) => Ok(crate::StorageFormat::Rgba8Sint),
+        Some(spirv::ImageFormat::Rgb10a2ui) => Ok(crate::StorageFormat::Rgb10a2Uint),
+        Some(spirv::ImageFormat::Rgb10A2) => Ok(crate::StorageFormat::Rgb10a2Unorm),
+        Some(spirv::ImageFormat::R11fG11fB10f) => Ok(crate::StorageFormat::Rg11b10Float),
+        Some(spirv::ImageFormat::Rg32ui) => Ok(crate::StorageFormat::Rg32Uint),
+        Some(spirv::ImageFormat::Rg32i) => Ok(crate::StorageFormat::Rg32Sint),
+        Some(spirv::ImageFormat::Rg32f) => Ok(crate::StorageFormat::Rg32Float),
+        Some(spirv::ImageFormat::Rgba16) => Ok(crate::StorageFormat::Rgba16Unorm),
+        Some(spirv::ImageFormat::Rgba16Snorm) => Ok(crate::StorageFormat::Rgba16Snorm),
+        Some(spirv::ImageFormat::Rgba16ui) => Ok(crate::StorageFormat::Rgba16Uint),
+        Some(spirv::ImageFormat::Rgba16i) => Ok(crate::StorageFormat::Rgba16Sint),
+        Some(spirv::ImageFormat::Rgba16f) => Ok(crate::StorageFormat::Rgba16Float),
+        Some(spirv::ImageFormat::Rgba32ui) => Ok(crate::StorageFormat::Rgba32Uint),
+        Some(spirv::ImageFormat::Rgba32i) => Ok(crate::StorageFormat::Rgba32Sint),
+        Some(spirv::ImageFormat::Rgba32f) => Ok(crate::StorageFormat::Rgba32Float),
+        _ => Err(Error::UnsupportedImageFormat(word)),
+    }
+}
+
+pub(super) fn map_width(word: spirv::Word) -> Result<crate::Bytes, Error> {
+    (word >> 3) // bits to bytes
+        .try_into()
+        .map_err(|_| Error::InvalidTypeWidth(word))
+}
+
+pub(super) fn map_builtin(word: spirv::Word, invariant: bool) -> Result<crate::BuiltIn, Error> {
+    use spirv::BuiltIn as Bi;
+    Ok(match spirv::BuiltIn::from_u32(word) {
+        Some(Bi::Position | Bi::FragCoord) => crate::BuiltIn::Position { invariant },
+        Some(Bi::ViewIndex) => crate::BuiltIn::ViewIndex,
+        // vertex
+        Some(Bi::BaseInstance) => crate::BuiltIn::BaseInstance,
+        Some(Bi::BaseVertex) => crate::BuiltIn::BaseVertex,
+        Some(Bi::ClipDistance) => crate::BuiltIn::ClipDistance,
+        Some(Bi::CullDistance) => crate::BuiltIn::CullDistance,
+        Some(Bi::InstanceIndex) => crate::BuiltIn::InstanceIndex,
+        Some(Bi::PointSize) => crate::BuiltIn::PointSize,
+        Some(Bi::VertexIndex) => crate::BuiltIn::VertexIndex,
+        // fragment
+        Some(Bi::FragDepth) => crate::BuiltIn::FragDepth,
+        Some(Bi::PointCoord) => crate::BuiltIn::PointCoord,
+        Some(Bi::FrontFacing) => crate::BuiltIn::FrontFacing,
+        Some(Bi::PrimitiveId) => crate::BuiltIn::PrimitiveIndex,
+        Some(Bi::SampleId) => crate::BuiltIn::SampleIndex,
+        Some(Bi::SampleMask) => crate::BuiltIn::SampleMask,
+        // compute
+        Some(Bi::GlobalInvocationId) => crate::BuiltIn::GlobalInvocationId,
+        Some(Bi::LocalInvocationId) => crate::BuiltIn::LocalInvocationId,
+        Some(Bi::LocalInvocationIndex) => crate::BuiltIn::LocalInvocationIndex,
+        Some(Bi::WorkgroupId) => crate::BuiltIn::WorkGroupId,
+        Some(Bi::WorkgroupSize) => crate::BuiltIn::WorkGroupSize,
+        Some(Bi::NumWorkgroups) => crate::BuiltIn::NumWorkGroups,
+        _ => return Err(Error::UnsupportedBuiltIn(word)),
+    })
+}
+
+pub(super) fn map_storage_class(word: spirv::Word) -> Result<super::ExtendedClass, Error> {
+    use super::ExtendedClass as Ec;
+    use spirv::StorageClass as Sc;
+    Ok(match Sc::from_u32(word) {
+        Some(Sc::Function) => Ec::Global(crate::AddressSpace::Function),
+        Some(Sc::Input) => Ec::Input,
+        Some(Sc::Output) => Ec::Output,
+        Some(Sc::Private) => Ec::Global(crate::AddressSpace::Private),
+        Some(Sc::UniformConstant) => Ec::Global(crate::AddressSpace::Handle),
+        Some(Sc::StorageBuffer) => Ec::Global(crate::AddressSpace::Storage {
+            //Note: this is restricted by decorations later
+            access: crate::StorageAccess::all(),
+        }),
+        // we expect the `Storage` case to be filtered out before calling this function.
+        Some(Sc::Uniform) => Ec::Global(crate::AddressSpace::Uniform),
+        Some(Sc::Workgroup) => Ec::Global(crate::AddressSpace::WorkGroup),
+        Some(Sc::PushConstant) => Ec::Global(crate::AddressSpace::PushConstant),
+        _ => return Err(Error::UnsupportedStorageClass(word)),
+    })
+}
diff --git a/third_party/rust/naga/src/front/spv/error.rs b/third_party/rust/naga/src/front/spv/error.rs
new file mode 100644
index 0000000000..af025636c0
--- /dev/null
+++ b/third_party/rust/naga/src/front/spv/error.rs
@@ -0,0 +1,154 @@
+use super::ModuleState;
+use crate::arena::Handle;
+use codespan_reporting::diagnostic::Diagnostic;
+use codespan_reporting::files::SimpleFile;
+use codespan_reporting::term;
+use termcolor::{NoColor, WriteColor};
+
+#[derive(Debug, thiserror::Error)]
+pub enum Error {
+    #[error("invalid header")]
+    InvalidHeader,
+    #[error("invalid word count")]
+    InvalidWordCount,
+    #[error("unknown instruction {0}")]
+    UnknownInstruction(u16),
+    #[error("unknown capability %{0}")]
+    UnknownCapability(spirv::Word),
+    #[error("unsupported instruction {1:?} at {0:?}")]
+    UnsupportedInstruction(ModuleState, spirv::Op),
+    #[error("unsupported capability {0:?}")]
+    UnsupportedCapability(spirv::Capability),
+    #[error("unsupported extension {0}")]
+    UnsupportedExtension(String),
+    #[error("unsupported extension set {0}")]
+    UnsupportedExtSet(String),
+    #[error("unsupported extension instantiation set %{0}")]
+    UnsupportedExtInstSet(spirv::Word),
+    #[error("unsupported extension instantiation %{0}")]
+    UnsupportedExtInst(spirv::Word),
+    #[error("unsupported type {0:?}")]
+    UnsupportedType(Handle<crate::Type>),
+    #[error("unsupported execution model %{0}")]
+    UnsupportedExecutionModel(spirv::Word),
+    #[error("unsupported execution mode %{0}")]
+    UnsupportedExecutionMode(spirv::Word),
+    #[error("unsupported storage class %{0}")]
+    UnsupportedStorageClass(spirv::Word),
+    #[error("unsupported image dimension %{0}")]
+    UnsupportedImageDim(spirv::Word),
+    #[error("unsupported image format %{0}")]
+    UnsupportedImageFormat(spirv::Word),
+    #[error("unsupported builtin %{0}")]
+    UnsupportedBuiltIn(spirv::Word),
+    #[error("unsupported control flow %{0}")]
+    UnsupportedControlFlow(spirv::Word),
+    #[error("unsupported binary operator %{0}")]
+    UnsupportedBinaryOperator(spirv::Word),
+    #[error("Naga supports OpTypeRuntimeArray in the StorageBuffer storage class only")]
+    UnsupportedRuntimeArrayStorageClass,
+    #[error("unsupported matrix stride {stride} for a {columns}x{rows} matrix with scalar width={width}")]
+    UnsupportedMatrixStride {
+        stride: u32,
+        columns: u8,
+        rows: u8,
+        width: u8,
+    },
+    #[error("unknown binary operator {0:?}")]
+    UnknownBinaryOperator(spirv::Op),
+    #[error("unknown relational function {0:?}")]
+    UnknownRelationalFunction(spirv::Op),
+    #[error("invalid parameter {0:?}")]
+    InvalidParameter(spirv::Op),
+    #[error("invalid operand count {1} for {0:?}")]
+    InvalidOperandCount(spirv::Op, u16),
+    #[error("invalid operand")]
+    InvalidOperand,
+    #[error("invalid id %{0}")]
+    InvalidId(spirv::Word),
+    #[error("invalid decoration %{0}")]
+    InvalidDecoration(spirv::Word),
+    #[error("invalid type width %{0}")]
+    InvalidTypeWidth(spirv::Word),
+    #[error("invalid sign %{0}")]
+    InvalidSign(spirv::Word),
+    #[error("invalid inner type %{0}")]
+    InvalidInnerType(spirv::Word),
+    #[error("invalid vector size %{0}")]
+    InvalidVectorSize(spirv::Word),
+    #[error("invalid access type %{0}")]
+    InvalidAccessType(spirv::Word),
+    #[error("invalid access {0:?}")]
+    InvalidAccess(crate::Expression),
+    #[error("invalid access index %{0}")]
+    InvalidAccessIndex(spirv::Word),
+    #[error("invalid index type %{0}")]
+    InvalidIndexType(spirv::Word),
+    #[error("invalid binding %{0}")]
+    InvalidBinding(spirv::Word),
+    #[error("invalid global var {0:?}")]
+    InvalidGlobalVar(crate::Expression),
+    #[error("invalid image/sampler expression {0:?}")]
+    InvalidImageExpression(crate::Expression),
+    #[error("invalid image base type {0:?}")]
+    InvalidImageBaseType(Handle<crate::Type>),
+    #[error("invalid image {0:?}")]
+    InvalidImage(Handle<crate::Type>),
+    #[error("invalid as type {0:?}")]
+    InvalidAsType(Handle<crate::Type>),
+    #[error("invalid vector type {0:?}")]
+    InvalidVectorType(Handle<crate::Type>),
+    #[error("inconsistent comparison sampling {0:?}")]
+    InconsistentComparisonSampling(Handle<crate::GlobalVariable>),
+    #[error("wrong function result type %{0}")]
+    WrongFunctionResultType(spirv::Word),
+    #[error("wrong function argument type %{0}")]
+    WrongFunctionArgumentType(spirv::Word),
+    #[error("missing decoration {0:?}")]
+    MissingDecoration(spirv::Decoration),
+    #[error("bad string")]
+    BadString,
+    #[error("incomplete data")]
+    IncompleteData,
+    #[error("invalid terminator")]
+    InvalidTerminator,
+    #[error("invalid edge classification")]
+    InvalidEdgeClassification,
+    #[error("cycle detected in the CFG during traversal at {0}")]
+    ControlFlowGraphCycle(crate::front::spv::BlockId),
+    #[error("recursive function call %{0}")]
+    FunctionCallCycle(spirv::Word),
+    #[error("invalid array size {0:?}")]
+    InvalidArraySize(Handle<crate::Constant>),
+    #[error("invalid barrier scope %{0}")]
+    InvalidBarrierScope(spirv::Word),
+    #[error("invalid barrier memory semantics %{0}")]
+    InvalidBarrierMemorySemantics(spirv::Word),
+    #[error(
+        "arrays of images / samplers are supported only through bindings for \
+         now (i.e. you can't create an array of images or samplers that doesn't \
+         come from a binding)"
+    )]
+    NonBindingArrayOfImageOrSamplers,
+}
+
+impl Error {
+    pub fn emit_to_writer(&self, writer: &mut impl WriteColor, source: &str) {
+        self.emit_to_writer_with_path(writer, source, "glsl");
+    }
+
+    pub fn emit_to_writer_with_path(&self, writer: &mut impl WriteColor, source: &str, path: &str) {
+        let path = path.to_string();
+        let files = SimpleFile::new(path, source);
+        let config = codespan_reporting::term::Config::default();
+        let diagnostic = Diagnostic::error().with_message(format!("{self:?}"));
+
+        term::emit(writer, &config, &files, &diagnostic).expect("cannot write error");
+    }
+
+    pub fn emit_to_string(&self, source: &str) -> String {
+        let mut writer = NoColor::new(Vec::new());
+        self.emit_to_writer(&mut writer, source);
+        String::from_utf8(writer.into_inner()).unwrap()
+    }
+}
diff --git a/third_party/rust/naga/src/front/spv/function.rs b/third_party/rust/naga/src/front/spv/function.rs
new file mode 100644
index 0000000000..198d9c52dd
--- /dev/null
+++ b/third_party/rust/naga/src/front/spv/function.rs
@@ -0,0 +1,674 @@
+use crate::{
+    arena::{Arena, Handle},
+    front::spv::{BlockContext, BodyIndex},
+};
+
+use super::{Error, Instruction, LookupExpression, LookupHelper as _};
+use crate::proc::Emitter;
+
+pub type BlockId = u32;
+
+#[derive(Copy, Clone, Debug)]
+pub struct MergeInstruction {
+    pub merge_block_id: BlockId,
+    pub continue_block_id: Option<BlockId>,
+}
+
+impl<I: Iterator<Item = u32>> super::Frontend<I> {
+    // Registers a function call. It will generate a dummy handle to call, which
+    // gets resolved after all the functions are processed.
+    pub(super) fn add_call(
+        &mut self,
+        from: spirv::Word,
+        to: spirv::Word,
+    ) -> Handle<crate::Function> {
+        let dummy_handle = self
+            .dummy_functions
+            .append(crate::Function::default(), Default::default());
+        self.deferred_function_calls.push(to);
+        self.function_call_graph.add_edge(from, to, ());
+        dummy_handle
+    }
+
+    pub(super) fn parse_function(&mut self, module: &mut crate::Module) -> Result<(), Error> {
+        let start = self.data_offset;
+        self.lookup_expression.clear();
+        self.lookup_load_override.clear();
+        self.lookup_sampled_image.clear();
+
+        let result_type_id = self.next()?;
+        let fun_id = self.next()?;
+        let _fun_control = self.next()?;
+        let fun_type_id = self.next()?;
+
+        let mut fun = {
+            let ft = self.lookup_function_type.lookup(fun_type_id)?;
+            if ft.return_type_id != result_type_id {
+                return Err(Error::WrongFunctionResultType(result_type_id));
+            }
+            crate::Function {
+                name: self.future_decor.remove(&fun_id).and_then(|dec| dec.name),
+                arguments: Vec::with_capacity(ft.parameter_type_ids.len()),
+                result: if self.lookup_void_type == Some(result_type_id) {
+                    None
+                } else {
+                    let lookup_result_ty = self.lookup_type.lookup(result_type_id)?;
+                    Some(crate::FunctionResult {
+                        ty: lookup_result_ty.handle,
+                        binding: None,
+                    })
+                },
+                local_variables: Arena::new(),
+                expressions: self
+                    .make_expression_storage(&module.global_variables, &module.constants),
+                named_expressions: crate::NamedExpressions::default(),
+                body: crate::Block::new(),
+            }
+        };
+
+        // read parameters
+        for i in 0..fun.arguments.capacity() {
+            let start = self.data_offset;
+            match self.next_inst()? {
+                Instruction {
+                    op: spirv::Op::FunctionParameter,
+                    wc: 3,
+                } => {
+                    let type_id = self.next()?;
+                    let id = self.next()?;
+                    let handle = fun.expressions.append(
+                        crate::Expression::FunctionArgument(i as u32),
+                        self.span_from(start),
+                    );
+                    self.lookup_expression.insert(
+                        id,
+                        LookupExpression {
+                            handle,
+                            type_id,
+                            // Setting this to an invalid id will cause get_expr_handle
+                            // to default to the main body making sure no load/stores
+                            // are added.
+                            block_id: 0,
+                        },
+                    );
+                    //Note: we redo the lookup in order to work around `self` borrowing
+
+                    if type_id
+                        != self
+                            .lookup_function_type
+                            .lookup(fun_type_id)?
+                            .parameter_type_ids[i]
+                    {
+                        return Err(Error::WrongFunctionArgumentType(type_id));
+                    }
+                    let ty = self.lookup_type.lookup(type_id)?.handle;
+                    let decor = self.future_decor.remove(&id).unwrap_or_default();
+                    fun.arguments.push(crate::FunctionArgument {
+                        name: decor.name,
+                        ty,
+                        binding: None,
+                    });
+                }
+                Instruction { op, .. } => return Err(Error::InvalidParameter(op)),
+            }
+        }
+
+        // Read body
+        self.function_call_graph.add_node(fun_id);
+        let mut parameters_sampling =
+            vec![super::image::SamplingFlags::empty(); fun.arguments.len()];
+
+        let mut block_ctx = BlockContext {
+            phis: Default::default(),
+            blocks: Default::default(),
+            body_for_label: Default::default(),
+            mergers: Default::default(),
+            bodies: Default::default(),
+            function_id: fun_id,
+            expressions: &mut fun.expressions,
+            local_arena: &mut fun.local_variables,
+            const_arena: &mut module.constants,
+            const_expressions: &mut module.const_expressions,
+            type_arena: &module.types,
+            global_arena: &module.global_variables,
+            arguments: &fun.arguments,
+            parameter_sampling: &mut parameters_sampling,
+        };
+        // Insert the main body whose parent is also himself
+        block_ctx.bodies.push(super::Body::with_parent(0));
+
+        // Scan the blocks and add them as nodes
+        loop {
+            let fun_inst = self.next_inst()?;
+            log::debug!("{:?}", fun_inst.op);
+            match fun_inst.op {
+                spirv::Op::Line => {
+                    fun_inst.expect(4)?;
+                    let _file_id = self.next()?;
+                    let _row_id = self.next()?;
+                    let _col_id = self.next()?;
+                }
+                spirv::Op::Label => {
+                    // Read the label ID
+                    fun_inst.expect(2)?;
+                    let block_id = self.next()?;
+
+                    self.next_block(block_id, &mut block_ctx)?;
+                }
+                spirv::Op::FunctionEnd => {
+                    fun_inst.expect(1)?;
+                    break;
+                }
+                _ => {
+                    return Err(Error::UnsupportedInstruction(self.state, fun_inst.op));
+                }
+            }
+        }
+
+        if let Some(ref prefix) = self.options.block_ctx_dump_prefix {
+            let dump_suffix = match self.lookup_entry_point.get(&fun_id) {
+                Some(ep) => format!("block_ctx.{:?}-{}.txt", ep.stage, ep.name),
+                None => format!("block_ctx.Fun-{}.txt", module.functions.len()),
+            };
+            let dest = prefix.join(dump_suffix);
+            let dump = format!("{block_ctx:#?}");
+            if let Err(e) = std::fs::write(&dest, dump) {
+                log::error!("Unable to dump the block context into {:?}: {}", dest, e);
+            }
+        }
+
+        // Emit `Store` statements to properly initialize all the local variables we
+        // created for `phi` expressions.
+        //
+        // Note that get_expr_handle also contributes slightly odd entries to this table,
+        // to get the spill.
+        for phi in block_ctx.phis.iter() {
+            // Get a pointer to the local variable for the phi's value.
+            let phi_pointer = block_ctx.expressions.append(
+                crate::Expression::LocalVariable(phi.local),
+                crate::Span::default(),
+            );
+
+            // At the end of each of `phi`'s predecessor blocks, store the corresponding
+            // source value in the phi's local variable.
+            for &(source, predecessor) in phi.expressions.iter() {
+                let source_lexp = &self.lookup_expression[&source];
+                let predecessor_body_idx = block_ctx.body_for_label[&predecessor];
+                // If the expression is a global/argument it will have a 0 block
+                // id so we must use a default value instead of panicking
+                let source_body_idx = block_ctx
+                    .body_for_label
+                    .get(&source_lexp.block_id)
+                    .copied()
+                    .unwrap_or(0);
+
+                // If the Naga `Expression` generated for `source` is in scope, then we
+                // can simply store that in the phi's local variable.
+                //
+                // Otherwise, spill the source value to a local variable in the block that
+                // defines it. (We know this store dominates the predecessor; otherwise,
+                // the phi wouldn't have been able to refer to that source expression in
+                // the first place.) Then, the predecessor block can count on finding the
+                // source's value in that local variable.
+                let value = if super::is_parent(predecessor_body_idx, source_body_idx, &block_ctx) {
+                    source_lexp.handle
+                } else {
+                    // The source SPIR-V expression is not defined in the phi's
+                    // predecessor block, nor is it a globally available expression. So it
+                    // must be defined off in some other block that merely dominates the
+                    // predecessor. This means that the corresponding Naga `Expression`
+                    // may not be in scope in the predecessor block.
+                    //
+                    // In the block that defines `source`, spill it to a fresh local
+                    // variable, to ensure we can still use it at the end of the
+                    // predecessor.
+                    let ty = self.lookup_type[&source_lexp.type_id].handle;
+                    let local = block_ctx.local_arena.append(
+                        crate::LocalVariable {
+                            name: None,
+                            ty,
+                            init: None,
+                        },
+                        crate::Span::default(),
+                    );
+
+                    let pointer = block_ctx.expressions.append(
+                        crate::Expression::LocalVariable(local),
+                        crate::Span::default(),
+                    );
+
+                    // Get the spilled value of the source expression.
+                    let start = block_ctx.expressions.len();
+                    let expr = block_ctx
+                        .expressions
+                        .append(crate::Expression::Load { pointer }, crate::Span::default());
+                    let range = block_ctx.expressions.range_from(start);
+
+                    block_ctx
+                        .blocks
+                        .get_mut(&predecessor)
+                        .unwrap()
+                        .push(crate::Statement::Emit(range), crate::Span::default());
+
+                    // At the end of the block that defines it, spill the source
+                    // expression's value.
+                    block_ctx
+                        .blocks
+                        .get_mut(&source_lexp.block_id)
+                        .unwrap()
+                        .push(
+                            crate::Statement::Store {
+                                pointer,
+                                value: source_lexp.handle,
+                            },
+                            crate::Span::default(),
+                        );
+
+                    expr
+                };
+
+                // At the end of the phi predecessor block, store the source
+                // value in the phi's value.
+                block_ctx.blocks.get_mut(&predecessor).unwrap().push(
+                    crate::Statement::Store {
+                        pointer: phi_pointer,
+                        value,
+                    },
+                    crate::Span::default(),
+                )
+            }
+        }
+
+        fun.body = block_ctx.lower();
+
+        // done
+        let fun_handle = module.functions.append(fun, self.span_from_with_op(start));
+        self.lookup_function.insert(
+            fun_id,
+            super::LookupFunction {
+                handle: fun_handle,
+                parameters_sampling,
+            },
+        );
+
+        if let Some(ep) = self.lookup_entry_point.remove(&fun_id) {
+            // create a wrapping function
+            let mut function = crate::Function {
+                name: Some(format!("{}_wrap", ep.name)),
+                arguments: Vec::new(),
+                result: None,
+                local_variables: Arena::new(),
+                expressions: Arena::new(),
+                named_expressions: crate::NamedExpressions::default(),
+                body: crate::Block::new(),
+            };
+
+            // 1. copy the inputs from arguments to privates
+            for &v_id in ep.variable_ids.iter() {
+                let lvar = self.lookup_variable.lookup(v_id)?;
+                if let super::Variable::Input(ref arg) = lvar.inner {
+                    let span = module.global_variables.get_span(lvar.handle);
+                    let arg_expr = function.expressions.append(
+                        crate::Expression::FunctionArgument(function.arguments.len() as u32),
+                        span,
+                    );
+                    let load_expr = if arg.ty == module.global_variables[lvar.handle].ty {
+                        arg_expr
+                    } else {
+                        // The only case where the type is different is if we need to treat
+                        // unsigned integer as signed.
+                        let mut emitter = Emitter::default();
+                        emitter.start(&function.expressions);
+                        let handle = function.expressions.append(
+                            crate::Expression::As {
+                                expr: arg_expr,
+                                kind: crate::ScalarKind::Sint,
+                                convert: Some(4),
+                            },
+                            span,
+                        );
+                        function.body.extend(emitter.finish(&function.expressions));
+                        handle
+                    };
+                    function.body.push(
+                        crate::Statement::Store {
+                            pointer: function
+                                .expressions
+                                .append(crate::Expression::GlobalVariable(lvar.handle), span),
+                            value: load_expr,
+                        },
+                        span,
+                    );
+
+                    let mut arg = arg.clone();
+                    if ep.stage == crate::ShaderStage::Fragment {
+                        if let Some(ref mut binding) = arg.binding {
+                            binding.apply_default_interpolation(&module.types[arg.ty].inner);
+                        }
+                    }
+                    function.arguments.push(arg);
+                }
+            }
+            // 2. call the wrapped function
+            let fake_id = !(module.entry_points.len() as u32); // doesn't matter, as long as it's not a collision
+            let dummy_handle = self.add_call(fake_id, fun_id);
+            function.body.push(
+                crate::Statement::Call {
+                    function: dummy_handle,
+                    arguments: Vec::new(),
+                    result: None,
+                },
+                crate::Span::default(),
+            );
+
+            // 3. copy the outputs from privates to the result
+            let mut members = Vec::new();
+            let mut components = Vec::new();
+            for &v_id in ep.variable_ids.iter() {
+                let lvar = self.lookup_variable.lookup(v_id)?;
+                if let super::Variable::Output(ref result) = lvar.inner {
+                    let span = module.global_variables.get_span(lvar.handle);
+                    let expr_handle = function
+                        .expressions
+                        .append(crate::Expression::GlobalVariable(lvar.handle), span);
+
+                    // Cull problematic builtins of gl_PerVertex.
+                    // See the docs for `Frontend::gl_per_vertex_builtin_access`.
+                    {
+                        let ty = &module.types[result.ty];
+                        match ty.inner {
+                            crate::TypeInner::Struct {
+                                members: ref original_members,
+                                span,
+                            } if ty.name.as_deref() == Some("gl_PerVertex") => {
+                                let mut new_members = original_members.clone();
+                                for member in &mut new_members {
+                                    if let Some(crate::Binding::BuiltIn(built_in)) = member.binding
+                                    {
+                                        if !self.gl_per_vertex_builtin_access.contains(&built_in) {
+                                            member.binding = None
+                                        }
+                                    }
+                                }
+                                if &new_members != original_members {
+                                    module.types.replace(
+                                        result.ty,
+                                        crate::Type {
+                                            name: ty.name.clone(),
+                                            inner: crate::TypeInner::Struct {
+                                                members: new_members,
+                                                span,
+                                            },
+                                        },
+                                    );
+                                }
+                            }
+                            _ => {}
+                        }
+                    }
+
+                    match module.types[result.ty].inner {
+                        crate::TypeInner::Struct {
+                            members: ref sub_members,
+                            ..
+                        } => {
+                            for (index, sm) in sub_members.iter().enumerate() {
+                                if sm.binding.is_none() {
+                                    continue;
+                                }
+                                let mut sm = sm.clone();
+
+                                if let Some(ref mut binding) = sm.binding {
+                                    if ep.stage == crate::ShaderStage::Vertex {
+                                        binding.apply_default_interpolation(
+                                            &module.types[sm.ty].inner,
+                                        );
+                                    }
+                                }
+
+                                members.push(sm);
+
+                                components.push(function.expressions.append(
+                                    crate::Expression::AccessIndex {
+                                        base: expr_handle,
+                                        index: index as u32,
+                                    },
+                                    span,
+                                ));
+                            }
+                        }
+                        ref inner => {
+                            let mut binding = result.binding.clone();
+                            if let Some(ref mut binding) = binding {
+                                if ep.stage == crate::ShaderStage::Vertex {
+                                    binding.apply_default_interpolation(inner);
+                                }
+                            }
+
+                            members.push(crate::StructMember {
+                                name: None,
+                                ty: result.ty,
+                                binding,
+                                offset: 0,
+                            });
+                            // populate just the globals first, then do `Load` in a
+                            // separate step, so that we can get a range.
+                            components.push(expr_handle);
+                        }
+                    }
+                }
+            }
+
+            for (member_index, member) in members.iter().enumerate() {
+                match member.binding {
+                    Some(crate::Binding::BuiltIn(crate::BuiltIn::Position { .. }))
+                        if self.options.adjust_coordinate_space =>
+                    {
+                        let mut emitter = Emitter::default();
+                        emitter.start(&function.expressions);
+                        let global_expr = components[member_index];
+                        let span = function.expressions.get_span(global_expr);
+                        let access_expr = function.expressions.append(
+                            crate::Expression::AccessIndex {
+                                base: global_expr,
+                                index: 1,
+                            },
+                            span,
+                        );
+                        let load_expr = function.expressions.append(
+                            crate::Expression::Load {
+                                pointer: access_expr,
+                            },
+                            span,
+                        );
+                        let neg_expr = function.expressions.append(
+                            crate::Expression::Unary {
+                                op: crate::UnaryOperator::Negate,
+                                expr: load_expr,
+                            },
+                            span,
+                        );
+                        function.body.extend(emitter.finish(&function.expressions));
+                        function.body.push(
+                            crate::Statement::Store {
+                                pointer: access_expr,
+                                value: neg_expr,
+                            },
+                            span,
+                        );
+                    }
+                    _ => {}
+                }
+            }
+
+            let mut emitter = Emitter::default();
+            emitter.start(&function.expressions);
+            for component in components.iter_mut() {
+                let load_expr = crate::Expression::Load {
+                    pointer: *component,
+                };
+                let span = function.expressions.get_span(*component);
+                *component = function.expressions.append(load_expr, span);
+            }
+
+            match members[..] {
+                [] => {}
+                [ref member] => {
+                    function.body.extend(emitter.finish(&function.expressions));
+                    let span = function.expressions.get_span(components[0]);
+                    function.body.push(
+                        crate::Statement::Return {
+                            value: components.first().cloned(),
+                        },
+                        span,
+                    );
+                    function.result = Some(crate::FunctionResult {
+                        ty: member.ty,
+                        binding: member.binding.clone(),
+                    });
+                }
+                _ => {
+                    let span = crate::Span::total_span(
+                        components.iter().map(|h| function.expressions.get_span(*h)),
+                    );
+                    let ty = module.types.insert(
+                        crate::Type {
+                            name: None,
+                            inner: crate::TypeInner::Struct {
+                                members,
+                                span: 0xFFFF, // shouldn't matter
+                            },
+                        },
+                        span,
+                    );
+                    let result_expr = function
+                        .expressions
+                        .append(crate::Expression::Compose { ty, components }, span);
+                    function.body.extend(emitter.finish(&function.expressions));
+                    function.body.push(
+                        crate::Statement::Return {
+                            value: Some(result_expr),
+                        },
+                        span,
+                    );
+                    function.result = Some(crate::FunctionResult { ty, binding: None });
+                }
+            }
+
+            module.entry_points.push(crate::EntryPoint {
+                name: ep.name,
+                stage: ep.stage,
+                early_depth_test: ep.early_depth_test,
+                workgroup_size: ep.workgroup_size,
+                function,
+            });
+        }
+
+        Ok(())
+    }
+}
+
+impl<'function> BlockContext<'function> {
+    pub(super) fn gctx(&self) -> crate::proc::GlobalCtx {
+        crate::proc::GlobalCtx {
+            types: self.type_arena,
+            constants: self.const_arena,
+            const_expressions: self.const_expressions,
+        }
+    }
+
+    /// Consumes the `BlockContext` producing a Ir [`Block`](crate::Block)
+    fn lower(mut self) -> crate::Block {
+        fn lower_impl(
+            blocks: &mut crate::FastHashMap<spirv::Word, crate::Block>,
+            bodies: &[super::Body],
+            body_idx: BodyIndex,
+        ) -> crate::Block {
+            let mut block = crate::Block::new();
+
+            for item in bodies[body_idx].data.iter() {
+                match *item {
+                    super::BodyFragment::BlockId(id) => block.append(blocks.get_mut(&id).unwrap()),
+                    super::BodyFragment::If {
+                        condition,
+                        accept,
+                        reject,
+                    } => {
+                        let accept = lower_impl(blocks, bodies, accept);
+                        let reject = lower_impl(blocks, bodies, reject);
+
+                        block.push(
+                            crate::Statement::If {
+                                condition,
+                                accept,
+                                reject,
+                            },
+                            crate::Span::default(),
+                        )
+                    }
+                    super::BodyFragment::Loop {
+                        body,
+                        continuing,
+                        break_if,
+                    } => {
+                        let body = lower_impl(blocks, bodies, body);
+                        let continuing = lower_impl(blocks, bodies, continuing);
+
+                        block.push(
+                            crate::Statement::Loop {
+                                body,
+                                continuing,
+                                break_if,
+                            },
+                            crate::Span::default(),
+                        )
+                    }
+                    super::BodyFragment::Switch {
+                        selector,
+                        ref cases,
+                        default,
+                    } => {
+                        let mut ir_cases: Vec<_> = cases
+                            .iter()
+                            .map(|&(value, body_idx)| {
+                                let body = lower_impl(blocks, bodies, body_idx);
+
+                                // Handle simple cases that would make a fallthrough statement unreachable code
+                                let fall_through = body.last().map_or(true, |s| !s.is_terminator());
+
+                                crate::SwitchCase {
+                                    value: crate::SwitchValue::I32(value),
+                                    body,
+                                    fall_through,
+                                }
+                            })
+                            .collect();
+                        ir_cases.push(crate::SwitchCase {
+                            value: crate::SwitchValue::Default,
+                            body: lower_impl(blocks, bodies, default),
+                            fall_through: false,
+                        });
+
+                        block.push(
+                            crate::Statement::Switch {
+                                selector,
+                                cases: ir_cases,
+                            },
+                            crate::Span::default(),
+                        )
+                    }
+                    super::BodyFragment::Break => {
+                        block.push(crate::Statement::Break, crate::Span::default())
+                    }
+                    super::BodyFragment::Continue => {
+                        block.push(crate::Statement::Continue, crate::Span::default())
+                    }
+                }
+            }
+
+            block
+        }
+
+        lower_impl(&mut self.blocks, &self.bodies, 0)
+    }
+}
diff --git a/third_party/rust/naga/src/front/spv/image.rs b/third_party/rust/naga/src/front/spv/image.rs
new file mode 100644
index 0000000000..0f25dd626b
--- /dev/null
+++ b/third_party/rust/naga/src/front/spv/image.rs
@@ -0,0 +1,767 @@
+use crate::{
+    arena::{Handle, UniqueArena},
+    Scalar,
+};
+
+use super::{Error, LookupExpression, LookupHelper as _};
+
+#[derive(Clone, Debug)]
+pub(super) struct LookupSampledImage {
+    image: Handle<crate::Expression>,
+    sampler: Handle<crate::Expression>,
+}
+
+bitflags::bitflags! {
+    /// Flags describing sampling method.
+    #[derive(Clone, Copy, Debug, Eq, PartialEq)]
+    pub struct SamplingFlags: u32 {
+        /// Regular sampling.
+        const REGULAR = 0x1;
+        /// Comparison sampling.
+        const COMPARISON = 0x2;
+    }
+}
+
+impl<'function> super::BlockContext<'function> {
+    fn get_image_expr_ty(
+        &self,
+        handle: Handle<crate::Expression>,
+    ) -> Result<Handle<crate::Type>, Error> {
+        match self.expressions[handle] {
+            crate::Expression::GlobalVariable(handle) => Ok(self.global_arena[handle].ty),
+            crate::Expression::FunctionArgument(i) => Ok(self.arguments[i as usize].ty),
+            ref other => Err(Error::InvalidImageExpression(other.clone())),
+        }
+    }
+}
+
+/// Options of a sampling operation.
+#[derive(Debug)]
+pub struct SamplingOptions {
+    /// Projection sampling: the division by W is expected to happen
+    /// in the texture unit.
+    pub project: bool,
+    /// Depth comparison sampling with a reference value.
+    pub compare: bool,
+}
+
+enum ExtraCoordinate {
+    ArrayLayer,
+    Projection,
+    Garbage,
+}
+
+/// Return the texture coordinates separated from the array layer,
+/// and/or divided by the projection term.
+///
+/// The Proj sampling ops expect an extra coordinate for the W.
+/// The arrayed (can't be Proj!) images expect an extra coordinate for the layer.
+fn extract_image_coordinates(
+    image_dim: crate::ImageDimension,
+    extra_coordinate: ExtraCoordinate,
+    base: Handle<crate::Expression>,
+    coordinate_ty: Handle<crate::Type>,
+    ctx: &mut super::BlockContext,
+) -> (Handle<crate::Expression>, Option<Handle<crate::Expression>>) {
+    let (given_size, kind) = match ctx.type_arena[coordinate_ty].inner {
+        crate::TypeInner::Scalar(Scalar { kind, .. }) => (None, kind),
+        crate::TypeInner::Vector {
+            size,
+            scalar: Scalar { kind, .. },
+        } => (Some(size), kind),
+        ref other => unreachable!("Unexpected texture coordinate {:?}", other),
+    };
+
+    let required_size = image_dim.required_coordinate_size();
+    let required_ty = required_size.map(|size| {
+        ctx.type_arena
+            .get(&crate::Type {
+                name: None,
+                inner: crate::TypeInner::Vector {
+                    size,
+                    scalar: Scalar { kind, width: 4 },
+                },
+            })
+            .expect("Required coordinate type should have been set up by `parse_type_image`!")
+    });
+    let extra_expr = crate::Expression::AccessIndex {
+        base,
+        index: required_size.map_or(1, |size| size as u32),
+    };
+
+    let base_span = ctx.expressions.get_span(base);
+
+    match extra_coordinate {
+        ExtraCoordinate::ArrayLayer => {
+            let extracted = match required_size {
+                None => ctx
+                    .expressions
+                    .append(crate::Expression::AccessIndex { base, index: 0 }, base_span),
+                Some(size) => {
+                    let mut components = Vec::with_capacity(size as usize);
+                    for index in 0..size as u32 {
+                        let comp = ctx
+                            .expressions
+                            .append(crate::Expression::AccessIndex { base, index }, base_span);
+                        components.push(comp);
+                    }
+                    ctx.expressions.append(
+                        crate::Expression::Compose {
+                            ty: required_ty.unwrap(),
+                            components,
+                        },
+                        base_span,
+                    )
+                }
+            };
+            let array_index_f32 = ctx.expressions.append(extra_expr, base_span);
+            let array_index = ctx.expressions.append(
+                crate::Expression::As {
+                    kind: crate::ScalarKind::Sint,
+                    expr: array_index_f32,
+                    convert: Some(4),
+                },
+                base_span,
+            );
+            (extracted, Some(array_index))
+        }
+        ExtraCoordinate::Projection => {
+            let projection = ctx.expressions.append(extra_expr, base_span);
+            let divided = match required_size {
+                None => {
+                    let temp = ctx
+                        .expressions
+                        .append(crate::Expression::AccessIndex { base, index: 0 }, base_span);
+                    ctx.expressions.append(
+                        crate::Expression::Binary {
+                            op: crate::BinaryOperator::Divide,
+                            left: temp,
+                            right: projection,
+                        },
+                        base_span,
+                    )
+                }
+                Some(size) => {
+                    let mut components = Vec::with_capacity(size as usize);
+                    for index in 0..size as u32 {
+                        let temp = ctx
+                            .expressions
+                            .append(crate::Expression::AccessIndex { base, index }, base_span);
+                        let comp = ctx.expressions.append(
+                            crate::Expression::Binary {
+                                op: crate::BinaryOperator::Divide,
+                                left: temp,
+                                right: projection,
+                            },
+                            base_span,
+                        );
+                        components.push(comp);
+                    }
+                    ctx.expressions.append(
+                        crate::Expression::Compose {
+                            ty: required_ty.unwrap(),
+                            components,
+                        },
+                        base_span,
+                    )
+                }
+            };
+            (divided, None)
+        }
+        ExtraCoordinate::Garbage if given_size == required_size => (base, None),
+        ExtraCoordinate::Garbage => {
+            use crate::SwizzleComponent as Sc;
+            let cut_expr = match required_size {
+                None => crate::Expression::AccessIndex { base, index: 0 },
+                Some(size) => crate::Expression::Swizzle {
+                    size,
+                    vector: base,
+                    pattern: [Sc::X, Sc::Y, Sc::Z, Sc::W],
+                },
+            };
+            (ctx.expressions.append(cut_expr, base_span), None)
+        }
+    }
+}
+
+pub(super) fn patch_comparison_type(
+    flags: SamplingFlags,
+    var: &mut crate::GlobalVariable,
+    arena: &mut UniqueArena<crate::Type>,
+) -> bool {
+    if !flags.contains(SamplingFlags::COMPARISON) {
+        return true;
+    }
+    if flags == SamplingFlags::all() {
+        return false;
+    }
+
+    log::debug!("Flipping comparison for {:?}", var);
+    let original_ty = &arena[var.ty];
+    let original_ty_span = arena.get_span(var.ty);
+    let ty_inner = match original_ty.inner {
+        crate::TypeInner::Image {
+            class: crate::ImageClass::Sampled { multi, .. },
+            dim,
+            arrayed,
+        } => crate::TypeInner::Image {
+            class: crate::ImageClass::Depth { multi },
+            dim,
+            arrayed,
+        },
+        crate::TypeInner::Sampler { .. } => crate::TypeInner::Sampler { comparison: true },
+        ref other => unreachable!("Unexpected type for comparison mutation: {:?}", other),
+    };
+
+    let name = original_ty.name.clone();
+    var.ty = arena.insert(
+        crate::Type {
+            name,
+            inner: ty_inner,
+        },
+        original_ty_span,
+    );
+    true
+}
+
+impl<I: Iterator<Item = u32>> super::Frontend<I> {
+    pub(super) fn parse_image_couple(&mut self) -> Result<(), Error> {
+        let _result_type_id = self.next()?;
+        let result_id = self.next()?;
+        let image_id = self.next()?;
+        let sampler_id = self.next()?;
+        let image_lexp = self.lookup_expression.lookup(image_id)?;
+        let sampler_lexp = self.lookup_expression.lookup(sampler_id)?;
+        self.lookup_sampled_image.insert(
+            result_id,
+            LookupSampledImage {
+                image: image_lexp.handle,
+                sampler: sampler_lexp.handle,
+            },
+        );
+        Ok(())
+    }
+
+    pub(super) fn parse_image_uncouple(&mut self, block_id: spirv::Word) -> Result<(), Error> {
+        let result_type_id = self.next()?;
+        let result_id = self.next()?;
+        let sampled_image_id = self.next()?;
+        self.lookup_expression.insert(
+            result_id,
+            LookupExpression {
+                handle: self.lookup_sampled_image.lookup(sampled_image_id)?.image,
+                type_id: result_type_id,
+                block_id,
+            },
+        );
+        Ok(())
+    }
+
+    pub(super) fn parse_image_write(
+        &mut self,
+        words_left: u16,
+        ctx: &mut super::BlockContext,
+        emitter: &mut crate::proc::Emitter,
+        block: &mut crate::Block,
+        body_idx: usize,
+    ) -> Result<crate::Statement, Error> {
+        let image_id = self.next()?;
+        let coordinate_id = self.next()?;
+        let value_id = self.next()?;
+
+        let image_ops = if words_left != 0 { self.next()? } else { 0 };
+
+        if image_ops != 0 {
+            let other = spirv::ImageOperands::from_bits_truncate(image_ops);
+            log::warn!("Unknown image write ops {:?}", other);
+            for _ in 1..words_left {
+                self.next()?;
+            }
+        }
+
+        let image_lexp = self.lookup_expression.lookup(image_id)?;
+        let image_ty = ctx.get_image_expr_ty(image_lexp.handle)?;
+
+        let coord_lexp = self.lookup_expression.lookup(coordinate_id)?;
+        let coord_handle =
+            self.get_expr_handle(coordinate_id, coord_lexp, ctx, emitter, block, body_idx);
+        let coord_type_handle = self.lookup_type.lookup(coord_lexp.type_id)?.handle;
+        let (coordinate, array_index) = match ctx.type_arena[image_ty].inner {
+            crate::TypeInner::Image {
+                dim,
+                arrayed,
+                class: _,
+            } => extract_image_coordinates(
+                dim,
+                if arrayed {
+                    ExtraCoordinate::ArrayLayer
+                } else {
+                    ExtraCoordinate::Garbage
+                },
+                coord_handle,
+                coord_type_handle,
+                ctx,
+            ),
+            _ => return Err(Error::InvalidImage(image_ty)),
+        };
+
+        let value_lexp = self.lookup_expression.lookup(value_id)?;
+        let value = self.get_expr_handle(value_id, value_lexp, ctx, emitter, block, body_idx);
+
+        Ok(crate::Statement::ImageStore {
+            image: image_lexp.handle,
+            coordinate,
+            array_index,
+            value,
+        })
+    }
+
+    pub(super) fn parse_image_load(
+        &mut self,
+        mut words_left: u16,
+        ctx: &mut super::BlockContext,
+        emitter: &mut crate::proc::Emitter,
+        block: &mut crate::Block,
+        block_id: spirv::Word,
+        body_idx: usize,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        let result_type_id = self.next()?;
+        let result_id = self.next()?;
+        let image_id = self.next()?;
+        let coordinate_id = self.next()?;
+
+        let mut image_ops = if words_left != 0 {
+            words_left -= 1;
+            self.next()?
+        } else {
+            0
+        };
+
+        let mut sample = None;
+        let mut level = None;
+        while image_ops != 0 {
+            let bit = 1 << image_ops.trailing_zeros();
+            match spirv::ImageOperands::from_bits_truncate(bit) {
+                spirv::ImageOperands::LOD => {
+                    let lod_expr = self.next()?;
+                    let lod_lexp = self.lookup_expression.lookup(lod_expr)?;
+                    let lod_handle =
+                        self.get_expr_handle(lod_expr, lod_lexp, ctx, emitter, block, body_idx);
+                    level = Some(lod_handle);
+                    words_left -= 1;
+                }
+                spirv::ImageOperands::SAMPLE => {
+                    let sample_expr = self.next()?;
+                    let sample_handle = self.lookup_expression.lookup(sample_expr)?.handle;
+                    sample = Some(sample_handle);
+                    words_left -= 1;
+                }
+                other => {
+                    log::warn!("Unknown image load op {:?}", other);
+                    for _ in 0..words_left {
+                        self.next()?;
+                    }
+                    break;
+                }
+            }
+            image_ops ^= bit;
+        }
+
+        // No need to call get_expr_handle here since only globals/arguments are
+        // allowed as images and they are always in the root scope
+        let image_lexp = self.lookup_expression.lookup(image_id)?;
+        let image_ty = ctx.get_image_expr_ty(image_lexp.handle)?;
+
+        let coord_lexp = self.lookup_expression.lookup(coordinate_id)?;
+        let coord_handle =
+            self.get_expr_handle(coordinate_id, coord_lexp, ctx, emitter, block, body_idx);
+        let coord_type_handle = self.lookup_type.lookup(coord_lexp.type_id)?.handle;
+        let (coordinate, array_index) = match ctx.type_arena[image_ty].inner {
+            crate::TypeInner::Image {
+                dim,
+                arrayed,
+                class: _,
+            } => extract_image_coordinates(
+                dim,
+                if arrayed {
+                    ExtraCoordinate::ArrayLayer
+                } else {
+                    ExtraCoordinate::Garbage
+                },
+                coord_handle,
+                coord_type_handle,
+                ctx,
+            ),
+            _ => return Err(Error::InvalidImage(image_ty)),
+        };
+
+        let expr = crate::Expression::ImageLoad {
+            image: image_lexp.handle,
+            coordinate,
+            array_index,
+            sample,
+            level,
+        };
+        self.lookup_expression.insert(
+            result_id,
+            LookupExpression {
+                handle: ctx.expressions.append(expr, self.span_from_with_op(start)),
+                type_id: result_type_id,
+                block_id,
+            },
+        );
+        Ok(())
+    }
+
+    #[allow(clippy::too_many_arguments)]
+    pub(super) fn parse_image_sample(
+        &mut self,
+        mut words_left: u16,
+        options: SamplingOptions,
+        ctx: &mut super::BlockContext,
+        emitter: &mut crate::proc::Emitter,
+        block: &mut crate::Block,
+        block_id: spirv::Word,
+        body_idx: usize,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        let result_type_id = self.next()?;
+        let result_id = self.next()?;
+        let sampled_image_id = self.next()?;
+        let coordinate_id = self.next()?;
+        let dref_id = if options.compare {
+            Some(self.next()?)
+        } else {
+            None
+        };
+
+        let mut image_ops = if words_left != 0 {
+            words_left -= 1;
+            self.next()?
+        } else {
+            0
+        };
+
+        let mut level = crate::SampleLevel::Auto;
+        let mut offset = None;
+        while image_ops != 0 {
+            let bit = 1 << image_ops.trailing_zeros();
+            match spirv::ImageOperands::from_bits_truncate(bit) {
+                spirv::ImageOperands::BIAS => {
+                    let bias_expr = self.next()?;
+                    let bias_lexp = self.lookup_expression.lookup(bias_expr)?;
+                    let bias_handle =
+                        self.get_expr_handle(bias_expr, bias_lexp, ctx, emitter, block, body_idx);
+                    level = crate::SampleLevel::Bias(bias_handle);
+                    words_left -= 1;
+                }
+                spirv::ImageOperands::LOD => {
+                    let lod_expr = self.next()?;
+                    let lod_lexp = self.lookup_expression.lookup(lod_expr)?;
+                    let lod_handle =
+                        self.get_expr_handle(lod_expr, lod_lexp, ctx, emitter, block, body_idx);
+                    level = if options.compare {
+                        log::debug!("Assuming {:?} is zero", lod_handle);
+                        crate::SampleLevel::Zero
+                    } else {
+                        crate::SampleLevel::Exact(lod_handle)
+                    };
+                    words_left -= 1;
+                }
+                spirv::ImageOperands::GRAD => {
+                    let grad_x_expr = self.next()?;
+                    let grad_x_lexp = self.lookup_expression.lookup(grad_x_expr)?;
+                    let grad_x_handle = self.get_expr_handle(
+                        grad_x_expr,
+                        grad_x_lexp,
+                        ctx,
+                        emitter,
+                        block,
+                        body_idx,
+                    );
+                    let grad_y_expr = self.next()?;
+                    let grad_y_lexp = self.lookup_expression.lookup(grad_y_expr)?;
+                    let grad_y_handle = self.get_expr_handle(
+                        grad_y_expr,
+                        grad_y_lexp,
+                        ctx,
+                        emitter,
+                        block,
+                        body_idx,
+                    );
+                    level = if options.compare {
+                        log::debug!(
+                            "Assuming gradients {:?} and {:?} are not greater than 1",
+                            grad_x_handle,
+                            grad_y_handle
+                        );
+                        crate::SampleLevel::Zero
+                    } else {
+                        crate::SampleLevel::Gradient {
+                            x: grad_x_handle,
+                            y: grad_y_handle,
+                        }
+                    };
+                    words_left -= 2;
+                }
+                spirv::ImageOperands::CONST_OFFSET => {
+                    let offset_constant = self.next()?;
+                    let offset_handle = self.lookup_constant.lookup(offset_constant)?.handle;
+                    let offset_handle = ctx.const_expressions.append(
+                        crate::Expression::Constant(offset_handle),
+                        Default::default(),
+                    );
+                    offset = Some(offset_handle);
+                    words_left -= 1;
+                }
+                other => {
+                    log::warn!("Unknown image sample operand {:?}", other);
+                    for _ in 0..words_left {
+                        self.next()?;
+                    }
+                    break;
+                }
+            }
+            image_ops ^= bit;
+        }
+
+        let si_lexp = self.lookup_sampled_image.lookup(sampled_image_id)?;
+        let coord_lexp = self.lookup_expression.lookup(coordinate_id)?;
+        let coord_handle =
+            self.get_expr_handle(coordinate_id, coord_lexp, ctx, emitter, block, body_idx);
+        let coord_type_handle = self.lookup_type.lookup(coord_lexp.type_id)?.handle;
+
+        let sampling_bit = if options.compare {
+            SamplingFlags::COMPARISON
+        } else {
+            SamplingFlags::REGULAR
+        };
+
+        let image_ty = match ctx.expressions[si_lexp.image] {
+            crate::Expression::GlobalVariable(handle) => {
+                if let Some(flags) = self.handle_sampling.get_mut(&handle) {
+                    *flags |= sampling_bit;
+                }
+
+                ctx.global_arena[handle].ty
+            }
+
+            crate::Expression::FunctionArgument(i) => {
+                ctx.parameter_sampling[i as usize] |= sampling_bit;
+                ctx.arguments[i as usize].ty
+            }
+
+            crate::Expression::Access { base, .. } => match ctx.expressions[base] {
+                crate::Expression::GlobalVariable(handle) => {
+                    if let Some(flags) = self.handle_sampling.get_mut(&handle) {
+                        *flags |= sampling_bit;
+                    }
+
+                    match ctx.type_arena[ctx.global_arena[handle].ty].inner {
+                        crate::TypeInner::BindingArray { base, .. } => base,
+                        _ => return Err(Error::InvalidGlobalVar(ctx.expressions[base].clone())),
+                    }
+                }
+
+                ref other => return Err(Error::InvalidGlobalVar(other.clone())),
+            },
+
+            ref other => return Err(Error::InvalidGlobalVar(other.clone())),
+        };
+
+        match ctx.expressions[si_lexp.sampler] {
+            crate::Expression::GlobalVariable(handle) => {
+                *self.handle_sampling.get_mut(&handle).unwrap() |= sampling_bit;
+            }
+
+            crate::Expression::FunctionArgument(i) => {
+                ctx.parameter_sampling[i as usize] |= sampling_bit;
+            }
+
+            crate::Expression::Access { base, .. } => match ctx.expressions[base] {
+                crate::Expression::GlobalVariable(handle) => {
+                    *self.handle_sampling.get_mut(&handle).unwrap() |= sampling_bit;
+                }
+
+                ref other => return Err(Error::InvalidGlobalVar(other.clone())),
+            },
+
+            ref other => return Err(Error::InvalidGlobalVar(other.clone())),
+        }
+
+        let ((coordinate, array_index), depth_ref) = match ctx.type_arena[image_ty].inner {
+            crate::TypeInner::Image {
+                dim,
+                arrayed,
+                class: _,
+            } => (
+                extract_image_coordinates(
+                    dim,
+                    if options.project {
+                        ExtraCoordinate::Projection
+                    } else if arrayed {
+                        ExtraCoordinate::ArrayLayer
+                    } else {
+                        ExtraCoordinate::Garbage
+                    },
+                    coord_handle,
+                    coord_type_handle,
+                    ctx,
+                ),
+                {
+                    match dref_id {
+                        Some(id) => {
+                            let expr_lexp = self.lookup_expression.lookup(id)?;
+                            let mut expr =
+                                self.get_expr_handle(id, expr_lexp, ctx, emitter, block, body_idx);
+
+                            if options.project {
+                                let required_size = dim.required_coordinate_size();
+                                let right = ctx.expressions.append(
+                                    crate::Expression::AccessIndex {
+                                        base: coord_handle,
+                                        index: required_size.map_or(1, |size| size as u32),
+                                    },
+                                    crate::Span::default(),
+                                );
+                                expr = ctx.expressions.append(
+                                    crate::Expression::Binary {
+                                        op: crate::BinaryOperator::Divide,
+                                        left: expr,
+                                        right,
+                                    },
+                                    crate::Span::default(),
+                                )
+                            };
+                            Some(expr)
+                        }
+                        None => None,
+                    }
+                },
+            ),
+            _ => return Err(Error::InvalidImage(image_ty)),
+        };
+
+        let expr = crate::Expression::ImageSample {
+            image: si_lexp.image,
+            sampler: si_lexp.sampler,
+            gather: None, //TODO
+            coordinate,
+            array_index,
+            offset,
+            level,
+            depth_ref,
+        };
+        self.lookup_expression.insert(
+            result_id,
+            LookupExpression {
+                handle: ctx.expressions.append(expr, self.span_from_with_op(start)),
+                type_id: result_type_id,
+                block_id,
+            },
+        );
+        Ok(())
+    }
+
+    pub(super) fn parse_image_query_size(
+        &mut self,
+        at_level: bool,
+        ctx: &mut super::BlockContext,
+        emitter: &mut crate::proc::Emitter,
+        block: &mut crate::Block,
+        block_id: spirv::Word,
+        body_idx: usize,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        let result_type_id = self.next()?;
+        let result_id = self.next()?;
+        let image_id = self.next()?;
+        let level = if at_level {
+            let level_id = self.next()?;
+            let level_lexp = self.lookup_expression.lookup(level_id)?;
+            Some(self.get_expr_handle(level_id, level_lexp, ctx, emitter, block, body_idx))
+        } else {
+            None
+        };
+
+        // No need to call get_expr_handle here since only globals/arguments are
+        // allowed as images and they are always in the root scope
+        //TODO: handle arrays and cubes
+        let image_lexp = self.lookup_expression.lookup(image_id)?;
+
+        let expr = crate::Expression::ImageQuery {
+            image: image_lexp.handle,
+            query: crate::ImageQuery::Size { level },
+        };
+
+        let result_type_handle = self.lookup_type.lookup(result_type_id)?.handle;
+        let maybe_scalar_kind = ctx.type_arena[result_type_handle].inner.scalar_kind();
+
+        let expr = if maybe_scalar_kind == Some(crate::ScalarKind::Sint) {
+            crate::Expression::As {
+                expr: ctx.expressions.append(expr, self.span_from_with_op(start)),
+                kind: crate::ScalarKind::Sint,
+                convert: Some(4),
+            }
+        } else {
+            expr
+        };
+
+        self.lookup_expression.insert(
+            result_id,
+            LookupExpression {
+                handle: ctx.expressions.append(expr, self.span_from_with_op(start)),
+                type_id: result_type_id,
+                block_id,
+            },
+        );
+
+        Ok(())
+    }
+
+    pub(super) fn parse_image_query_other(
+        &mut self,
+        query: crate::ImageQuery,
+        ctx: &mut super::BlockContext,
+        block_id: spirv::Word,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        let result_type_id = self.next()?;
+        let result_id = self.next()?;
+        let image_id = self.next()?;
+
+        // No need to call get_expr_handle here since only globals/arguments are
+        // allowed as images and they are always in the root scope
+        let image_lexp = self.lookup_expression.lookup(image_id)?.clone();
+
+        let expr = crate::Expression::ImageQuery {
+            image: image_lexp.handle,
+            query,
+        };
+
+        let result_type_handle = self.lookup_type.lookup(result_type_id)?.handle;
+        let maybe_scalar_kind = ctx.type_arena[result_type_handle].inner.scalar_kind();
+
+        let expr = if maybe_scalar_kind == Some(crate::ScalarKind::Sint) {
+            crate::Expression::As {
+                expr: ctx.expressions.append(expr, self.span_from_with_op(start)),
+                kind: crate::ScalarKind::Sint,
+                convert: Some(4),
+            }
+        } else {
+            expr
+        };
+
+        self.lookup_expression.insert(
+            result_id,
+            LookupExpression {
+                handle: ctx.expressions.append(expr, self.span_from_with_op(start)),
+                type_id: result_type_id,
+                block_id,
+            },
+        );
+
+        Ok(())
+    }
+}
diff --git a/third_party/rust/naga/src/front/spv/mod.rs b/third_party/rust/naga/src/front/spv/mod.rs
new file mode 100644
index 0000000000..8b1c854358
--- /dev/null
+++ b/third_party/rust/naga/src/front/spv/mod.rs
@@ -0,0 +1,5356 @@
+/*!
+Frontend for [SPIR-V][spv] (Standard Portable Intermediate Representation).
+
+## ID lookups
+
+Our IR links to everything with `Handle`, while SPIR-V uses IDs.
+In order to keep track of the associations, the parser has many lookup tables.
+There map `spv::Word` into a specific IR handle, plus potentially a bit of
+extra info, such as the related SPIR-V type ID.
+TODO: would be nice to find ways that avoid looking up as much
+
+## Inputs/Outputs
+
+We create a private variable for each input/output. The relevant inputs are
+populated at the start of an entry point. The outputs are saved at the end.
+
+The function associated with an entry point is wrapped in another function,
+such that we can handle any `Return` statements without problems.
+
+## Row-major matrices
+
+We don't handle them natively, since the IR only expects column majority.
+Instead, we detect when such matrix is accessed in the `OpAccessChain`,
+and we generate a parallel expression that loads the value, but transposed.
+This value then gets used instead of `OpLoad` result later on.
+
+[spv]: https://www.khronos.org/registry/SPIR-V/
+*/
+
+mod convert;
+mod error;
+mod function;
+mod image;
+mod null;
+
+use convert::*;
+pub use error::Error;
+use function::*;
+
+use crate::{
+    arena::{Arena, Handle, UniqueArena},
+    proc::{Alignment, Layouter},
+    FastHashMap, FastHashSet, FastIndexMap,
+};
+
+use petgraph::graphmap::GraphMap;
+use std::{convert::TryInto, mem, num::NonZeroU32, path::PathBuf};
+
+pub const SUPPORTED_CAPABILITIES: &[spirv::Capability] = &[
+    spirv::Capability::Shader,
+    spirv::Capability::VulkanMemoryModel,
+    spirv::Capability::ClipDistance,
+    spirv::Capability::CullDistance,
+    spirv::Capability::SampleRateShading,
+    spirv::Capability::DerivativeControl,
+    spirv::Capability::Matrix,
+    spirv::Capability::ImageQuery,
+    spirv::Capability::Sampled1D,
+    spirv::Capability::Image1D,
+    spirv::Capability::SampledCubeArray,
+    spirv::Capability::ImageCubeArray,
+    spirv::Capability::StorageImageExtendedFormats,
+    spirv::Capability::Int8,
+    spirv::Capability::Int16,
+    spirv::Capability::Int64,
+    spirv::Capability::Float16,
+    spirv::Capability::Float64,
+    spirv::Capability::Geometry,
+    spirv::Capability::MultiView,
+    // tricky ones
+    spirv::Capability::UniformBufferArrayDynamicIndexing,
+    spirv::Capability::StorageBufferArrayDynamicIndexing,
+];
+pub const SUPPORTED_EXTENSIONS: &[&str] = &[
+    "SPV_KHR_storage_buffer_storage_class",
+    "SPV_KHR_vulkan_memory_model",
+    "SPV_KHR_multiview",
+];
+pub const SUPPORTED_EXT_SETS: &[&str] = &["GLSL.std.450"];
+
+#[derive(Copy, Clone)]
+pub struct Instruction {
+    op: spirv::Op,
+    wc: u16,
+}
+
+impl Instruction {
+    const fn expect(self, count: u16) -> Result<(), Error> {
+        if self.wc == count {
+            Ok(())
+        } else {
+            Err(Error::InvalidOperandCount(self.op, self.wc))
+        }
+    }
+
+    fn expect_at_least(self, count: u16) -> Result<u16, Error> {
+        self.wc
+            .checked_sub(count)
+            .ok_or(Error::InvalidOperandCount(self.op, self.wc))
+    }
+}
+
+impl crate::TypeInner {
+    fn can_comparison_sample(&self, module: &crate::Module) -> bool {
+        match *self {
+            crate::TypeInner::Image {
+                class:
+                    crate::ImageClass::Sampled {
+                        kind: crate::ScalarKind::Float,
+                        multi: false,
+                    },
+                ..
+            } => true,
+            crate::TypeInner::Sampler { .. } => true,
+            crate::TypeInner::BindingArray { base, .. } => {
+                module.types[base].inner.can_comparison_sample(module)
+            }
+            _ => false,
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, PartialOrd)]
+pub enum ModuleState {
+    Empty,
+    Capability,
+    Extension,
+    ExtInstImport,
+    MemoryModel,
+    EntryPoint,
+    ExecutionMode,
+    Source,
+    Name,
+    ModuleProcessed,
+    Annotation,
+    Type,
+    Function,
+}
+
+trait LookupHelper {
+    type Target;
+    fn lookup(&self, key: spirv::Word) -> Result<&Self::Target, Error>;
+}
+
+impl<T> LookupHelper for FastHashMap<spirv::Word, T> {
+    type Target = T;
+    fn lookup(&self, key: spirv::Word) -> Result<&T, Error> {
+        self.get(&key).ok_or(Error::InvalidId(key))
+    }
+}
+
+impl crate::ImageDimension {
+    const fn required_coordinate_size(&self) -> Option<crate::VectorSize> {
+        match *self {
+            crate::ImageDimension::D1 => None,
+            crate::ImageDimension::D2 => Some(crate::VectorSize::Bi),
+            crate::ImageDimension::D3 => Some(crate::VectorSize::Tri),
+            crate::ImageDimension::Cube => Some(crate::VectorSize::Tri),
+        }
+    }
+}
+
+type MemberIndex = u32;
+
+bitflags::bitflags! {
+    #[derive(Clone, Copy, Debug, Default)]
+    struct DecorationFlags: u32 {
+        const NON_READABLE = 0x1;
+        const NON_WRITABLE = 0x2;
+    }
+}
+
+impl DecorationFlags {
+    fn to_storage_access(self) -> crate::StorageAccess {
+        let mut access = crate::StorageAccess::all();
+        if self.contains(DecorationFlags::NON_READABLE) {
+            access &= !crate::StorageAccess::LOAD;
+        }
+        if self.contains(DecorationFlags::NON_WRITABLE) {
+            access &= !crate::StorageAccess::STORE;
+        }
+        access
+    }
+}
+
+#[derive(Debug, PartialEq)]
+enum Majority {
+    Column,
+    Row,
+}
+
+#[derive(Debug, Default)]
+struct Decoration {
+    name: Option<String>,
+    built_in: Option<spirv::Word>,
+    location: Option<spirv::Word>,
+    desc_set: Option<spirv::Word>,
+    desc_index: Option<spirv::Word>,
+    specialization: Option<spirv::Word>,
+    storage_buffer: bool,
+    offset: Option<spirv::Word>,
+    array_stride: Option<NonZeroU32>,
+    matrix_stride: Option<NonZeroU32>,
+    matrix_major: Option<Majority>,
+    invariant: bool,
+    interpolation: Option<crate::Interpolation>,
+    sampling: Option<crate::Sampling>,
+    flags: DecorationFlags,
+}
+
+impl Decoration {
+    fn debug_name(&self) -> &str {
+        match self.name {
+            Some(ref name) => name.as_str(),
+            None => "?",
+        }
+    }
+
+    fn specialization(&self) -> crate::Override {
+        self.specialization
+            .map_or(crate::Override::None, crate::Override::ByNameOrId)
+    }
+
+    const fn resource_binding(&self) -> Option<crate::ResourceBinding> {
+        match *self {
+            Decoration {
+                desc_set: Some(group),
+                desc_index: Some(binding),
+                ..
+            } => Some(crate::ResourceBinding { group, binding }),
+            _ => None,
+        }
+    }
+
+    fn io_binding(&self) -> Result<crate::Binding, Error> {
+        match *self {
+            Decoration {
+                built_in: Some(built_in),
+                location: None,
+                invariant,
+                ..
+            } => Ok(crate::Binding::BuiltIn(map_builtin(built_in, invariant)?)),
+            Decoration {
+                built_in: None,
+                location: Some(location),
+                interpolation,
+                sampling,
+                ..
+            } => Ok(crate::Binding::Location {
+                location,
+                interpolation,
+                sampling,
+                second_blend_source: false,
+            }),
+            _ => Err(Error::MissingDecoration(spirv::Decoration::Location)),
+        }
+    }
+}
+
+#[derive(Debug)]
+struct LookupFunctionType {
+    parameter_type_ids: Vec<spirv::Word>,
+    return_type_id: spirv::Word,
+}
+
+struct LookupFunction {
+    handle: Handle<crate::Function>,
+    parameters_sampling: Vec<image::SamplingFlags>,
+}
+
+#[derive(Debug)]
+struct EntryPoint {
+    stage: crate::ShaderStage,
+    name: String,
+    early_depth_test: Option<crate::EarlyDepthTest>,
+    workgroup_size: [u32; 3],
+    variable_ids: Vec<spirv::Word>,
+}
+
+#[derive(Clone, Debug)]
+struct LookupType {
+    handle: Handle<crate::Type>,
+    base_id: Option<spirv::Word>,
+}
+
+#[derive(Debug)]
+struct LookupConstant {
+    handle: Handle<crate::Constant>,
+    type_id: spirv::Word,
+}
+
+#[derive(Debug)]
+enum Variable {
+    Global,
+    Input(crate::FunctionArgument),
+    Output(crate::FunctionResult),
+}
+
+#[derive(Debug)]
+struct LookupVariable {
+    inner: Variable,
+    handle: Handle<crate::GlobalVariable>,
+    type_id: spirv::Word,
+}
+
+/// Information about SPIR-V result ids, stored in `Parser::lookup_expression`.
+#[derive(Clone, Debug)]
+struct LookupExpression {
+    /// The `Expression` constructed for this result.
+    ///
+    /// Note that, while a SPIR-V result id can be used in any block dominated
+    /// by its definition, a Naga `Expression` is only in scope for the rest of
+    /// its subtree. `Parser::get_expr_handle` takes care of spilling the result
+    /// to a `LocalVariable` which can then be used anywhere.
+    handle: Handle<crate::Expression>,
+
+    /// The SPIR-V type of this result.
+    type_id: spirv::Word,
+
+    /// The label id of the block that defines this expression.
+    ///
+    /// This is zero for globals, constants, and function parameters, since they
+    /// originate outside any function's block.
+    block_id: spirv::Word,
+}
+
+#[derive(Debug)]
+struct LookupMember {
+    type_id: spirv::Word,
+    // This is true for either matrices, or arrays of matrices (yikes).
+    row_major: bool,
+}
+
+#[derive(Clone, Debug)]
+enum LookupLoadOverride {
+    /// For arrays of matrices, we track them but not loading yet.
+    Pending,
+    /// For matrices, vectors, and scalars, we pre-load the data.
+    Loaded(Handle<crate::Expression>),
+}
+
+#[derive(PartialEq)]
+enum ExtendedClass {
+    Global(crate::AddressSpace),
+    Input,
+    Output,
+}
+
+#[derive(Clone, Debug)]
+pub struct Options {
+    /// The IR coordinate space matches all the APIs except SPIR-V,
+    /// so by default we flip the Y coordinate of the `BuiltIn::Position`.
+    /// This flag can be used to avoid this.
+    pub adjust_coordinate_space: bool,
+    /// Only allow shaders with the known set of capabilities.
+    pub strict_capabilities: bool,
+    pub block_ctx_dump_prefix: Option<PathBuf>,
+}
+
+impl Default for Options {
+    fn default() -> Self {
+        Options {
+            adjust_coordinate_space: true,
+            strict_capabilities: false,
+            block_ctx_dump_prefix: None,
+        }
+    }
+}
+
+/// An index into the `BlockContext::bodies` table.
+type BodyIndex = usize;
+
+/// An intermediate representation of a Naga [`Statement`].
+///
+/// `Body` and `BodyFragment` values form a tree: the `BodyIndex` fields of the
+/// variants are indices of the child `Body` values in [`BlockContext::bodies`].
+/// The `lower` function assembles the final `Statement` tree from this `Body`
+/// tree. See [`BlockContext`] for details.
+///
+/// [`Statement`]: crate::Statement
+#[derive(Debug)]
+enum BodyFragment {
+    BlockId(spirv::Word),
+    If {
+        condition: Handle<crate::Expression>,
+        accept: BodyIndex,
+        reject: BodyIndex,
+    },
+    Loop {
+        /// The body of the loop. Its [`Body::parent`] is the block containing
+        /// this `Loop` fragment.
+        body: BodyIndex,
+
+        /// The loop's continuing block. This is a grandchild: its
+        /// [`Body::parent`] is the loop body block, whose index is above.
+        continuing: BodyIndex,
+
+        /// If the SPIR-V loop's back-edge branch is conditional, this is the
+        /// expression that must be `false` for the back-edge to be taken, with
+        /// `true` being for the "loop merge" (which breaks out of the loop).
+        break_if: Option<Handle<crate::Expression>>,
+    },
+    Switch {
+        selector: Handle<crate::Expression>,
+        cases: Vec<(i32, BodyIndex)>,
+        default: BodyIndex,
+    },
+    Break,
+    Continue,
+}
+
+/// An intermediate representation of a Naga [`Block`].
+///
+/// This will be assembled into a `Block` once we've added spills for phi nodes
+/// and out-of-scope expressions. See [`BlockContext`] for details.
+///
+/// [`Block`]: crate::Block
+#[derive(Debug)]
+struct Body {
+    /// The index of the direct parent of this body
+    parent: usize,
+    data: Vec<BodyFragment>,
+}
+
+impl Body {
+    /// Creates a new empty `Body` with the specified `parent`
+    pub const fn with_parent(parent: usize) -> Self {
+        Body {
+            parent,
+            data: Vec::new(),
+        }
+    }
+}
+
+#[derive(Debug)]
+struct PhiExpression {
+    /// The local variable used for the phi node
+    local: Handle<crate::LocalVariable>,
+    /// List of (expression, block)
+    expressions: Vec<(spirv::Word, spirv::Word)>,
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+enum MergeBlockInformation {
+    LoopMerge,
+    LoopContinue,
+    SelectionMerge,
+    SwitchMerge,
+}
+
+/// Fragments of Naga IR, to be assembled into `Statements` once data flow is
+/// resolved.
+///
+/// We can't build a Naga `Statement` tree directly from SPIR-V blocks for three
+/// main reasons:
+///
+/// - We parse a function's SPIR-V blocks in the order they appear in the file.
+///   Within a function, SPIR-V requires that a block must precede any blocks it
+///   structurally dominates, but doesn't say much else about the order in which
+///   they must appear. So while we know we'll see control flow header blocks
+///   before their child constructs and merge blocks, those children and the
+///   merge blocks may appear in any order - perhaps even intermingled with
+///   children of other constructs.
+///
+/// - A SPIR-V expression can be used in any SPIR-V block dominated by its
+///   definition, whereas Naga expressions are scoped to the rest of their
+///   subtree. This means that discovering an expression use later in the
+///   function retroactively requires us to have spilled that expression into a
+///   local variable back before we left its scope.
+///
+/// - We translate SPIR-V OpPhi expressions as Naga local variables in which we
+///   store the appropriate value before jumping to the OpPhi's block.
+///
+/// All these cases require us to go back and amend previously generated Naga IR
+/// based on things we discover later. But modifying old blocks in arbitrary
+/// spots in a `Statement` tree is awkward.
+///
+/// Instead, as we iterate through the function's body, we accumulate
+/// control-flow-free fragments of Naga IR in the [`blocks`] table, while
+/// building a skeleton of the Naga `Statement` tree in [`bodies`]. We note any
+/// spills and temporaries we must introduce in [`phis`].
+///
+/// Finally, once we've processed the entire function, we add temporaries and
+/// spills to the fragmentary `Blocks` as directed by `phis`, and assemble them
+/// into the final Naga `Statement` tree as directed by `bodies`.
+///
+/// [`blocks`]: BlockContext::blocks
+/// [`bodies`]: BlockContext::bodies
+/// [`phis`]: BlockContext::phis
+/// [`lower`]: function::lower
+#[derive(Debug)]
+struct BlockContext<'function> {
+    /// Phi nodes encountered when parsing the function, used to generate spills
+    /// to local variables.
+    phis: Vec<PhiExpression>,
+
+    /// Fragments of control-flow-free Naga IR.
+    ///
+    /// These will be stitched together into a proper [`Statement`] tree according
+    /// to `bodies`, once parsing is complete.
+    ///
+    /// [`Statement`]: crate::Statement
+    blocks: FastHashMap<spirv::Word, crate::Block>,
+
+    /// Map from each SPIR-V block's label id to the index of the [`Body`] in
+    /// [`bodies`] the block should append its contents to.
+    ///
+    /// Since each statement in a Naga [`Block`] dominates the next, we are sure
+    /// to encounter their SPIR-V blocks in order. Thus, by having this table
+    /// map a SPIR-V structured control flow construct's merge block to the same
+    /// body index as its header block, when we encounter the merge block, we
+    /// will simply pick up building the [`Body`] where the header left off.
+    ///
+    /// A function's first block is special: it is the only block we encounter
+    /// without having seen its label mentioned in advance. (It's simply the
+    /// first `OpLabel` after the `OpFunction`.) We thus assume that any block
+    /// missing an entry here must be the first block, which always has body
+    /// index zero.
+    ///
+    /// [`bodies`]: BlockContext::bodies
+    /// [`Block`]: crate::Block
+    body_for_label: FastHashMap<spirv::Word, BodyIndex>,
+
+    /// SPIR-V metadata about merge/continue blocks.
+    mergers: FastHashMap<spirv::Word, MergeBlockInformation>,
+
+    /// A table of `Body` values, each representing a block in the final IR.
+    ///
+    /// The first element is always the function's top-level block.
+    bodies: Vec<Body>,
+
+    /// Id of the function currently being processed
+    function_id: spirv::Word,
+    /// Expression arena of the function currently being processed
+    expressions: &'function mut Arena<crate::Expression>,
+    /// Local variables arena of the function currently being processed
+    local_arena: &'function mut Arena<crate::LocalVariable>,
+    /// Constants arena of the module being processed
+    const_arena: &'function mut Arena<crate::Constant>,
+    const_expressions: &'function mut Arena<crate::Expression>,
+    /// Type arena of the module being processed
+    type_arena: &'function UniqueArena<crate::Type>,
+    /// Global arena of the module being processed
+    global_arena: &'function Arena<crate::GlobalVariable>,
+    /// Arguments of the function currently being processed
+    arguments: &'function [crate::FunctionArgument],
+    /// Metadata about the usage of function parameters as sampling objects
+    parameter_sampling: &'function mut [image::SamplingFlags],
+}
+
+enum SignAnchor {
+    Result,
+    Operand,
+}
+
+pub struct Frontend<I> {
+    data: I,
+    data_offset: usize,
+    state: ModuleState,
+    layouter: Layouter,
+    temp_bytes: Vec<u8>,
+    ext_glsl_id: Option<spirv::Word>,
+    future_decor: FastHashMap<spirv::Word, Decoration>,
+    future_member_decor: FastHashMap<(spirv::Word, MemberIndex), Decoration>,
+    lookup_member: FastHashMap<(Handle<crate::Type>, MemberIndex), LookupMember>,
+    handle_sampling: FastHashMap<Handle<crate::GlobalVariable>, image::SamplingFlags>,
+    lookup_type: FastHashMap<spirv::Word, LookupType>,
+    lookup_void_type: Option<spirv::Word>,
+    lookup_storage_buffer_types: FastHashMap<Handle<crate::Type>, crate::StorageAccess>,
+    // Lookup for samplers and sampled images, storing flags on how they are used.
+    lookup_constant: FastHashMap<spirv::Word, LookupConstant>,
+    lookup_variable: FastHashMap<spirv::Word, LookupVariable>,
+    lookup_expression: FastHashMap<spirv::Word, LookupExpression>,
+    // Load overrides are used to work around row-major matrices
+    lookup_load_override: FastHashMap<spirv::Word, LookupLoadOverride>,
+    lookup_sampled_image: FastHashMap<spirv::Word, image::LookupSampledImage>,
+    lookup_function_type: FastHashMap<spirv::Word, LookupFunctionType>,
+    lookup_function: FastHashMap<spirv::Word, LookupFunction>,
+    lookup_entry_point: FastHashMap<spirv::Word, EntryPoint>,
+    //Note: each `OpFunctionCall` gets a single entry here, indexed by the
+    // dummy `Handle<crate::Function>` of the call site.
+    deferred_function_calls: Vec<spirv::Word>,
+    dummy_functions: Arena<crate::Function>,
+    // Graph of all function calls through the module.
+    // It's used to sort the functions (as nodes) topologically,
+    // so that in the IR any called function is already known.
+    function_call_graph: GraphMap<spirv::Word, (), petgraph::Directed>,
+    options: Options,
+
+    /// Maps for a switch from a case target to the respective body and associated literals that
+    /// use that target block id.
+    ///
+    /// Used to preserve allocations between instruction parsing.
+    switch_cases: FastIndexMap<spirv::Word, (BodyIndex, Vec<i32>)>,
+
+    /// Tracks access to gl_PerVertex's builtins, it is used to cull unused builtins since initializing those can
+    /// affect performance and the mere presence of some of these builtins might cause backends to error since they
+    /// might be unsupported.
+    ///
+    /// The problematic builtins are: PointSize, ClipDistance and CullDistance.
+    ///
+    /// glslang declares those by default even though they are never written to
+    /// (see <https://github.com/KhronosGroup/glslang/issues/1868>)
+    gl_per_vertex_builtin_access: FastHashSet<crate::BuiltIn>,
+}
+
+impl<I: Iterator<Item = u32>> Frontend<I> {
+    pub fn new(data: I, options: &Options) -> Self {
+        Frontend {
+            data,
+            data_offset: 0,
+            state: ModuleState::Empty,
+            layouter: Layouter::default(),
+            temp_bytes: Vec::new(),
+            ext_glsl_id: None,
+            future_decor: FastHashMap::default(),
+            future_member_decor: FastHashMap::default(),
+            handle_sampling: FastHashMap::default(),
+            lookup_member: FastHashMap::default(),
+            lookup_type: FastHashMap::default(),
+            lookup_void_type: None,
+            lookup_storage_buffer_types: FastHashMap::default(),
+            lookup_constant: FastHashMap::default(),
+            lookup_variable: FastHashMap::default(),
+            lookup_expression: FastHashMap::default(),
+            lookup_load_override: FastHashMap::default(),
+            lookup_sampled_image: FastHashMap::default(),
+            lookup_function_type: FastHashMap::default(),
+            lookup_function: FastHashMap::default(),
+            lookup_entry_point: FastHashMap::default(),
+            deferred_function_calls: Vec::default(),
+            dummy_functions: Arena::new(),
+            function_call_graph: GraphMap::new(),
+            options: options.clone(),
+            switch_cases: FastIndexMap::default(),
+            gl_per_vertex_builtin_access: FastHashSet::default(),
+        }
+    }
+
+    fn span_from(&self, from: usize) -> crate::Span {
+        crate::Span::from(from..self.data_offset)
+    }
+
+    fn span_from_with_op(&self, from: usize) -> crate::Span {
+        crate::Span::from((from - 4)..self.data_offset)
+    }
+
+    fn next(&mut self) -> Result<u32, Error> {
+        if let Some(res) = self.data.next() {
+            self.data_offset += 4;
+            Ok(res)
+        } else {
+            Err(Error::IncompleteData)
+        }
+    }
+
+    fn next_inst(&mut self) -> Result<Instruction, Error> {
+        let word = self.next()?;
+        let (wc, opcode) = ((word >> 16) as u16, (word & 0xffff) as u16);
+        if wc == 0 {
+            return Err(Error::InvalidWordCount);
+        }
+        let op = spirv::Op::from_u32(opcode as u32).ok_or(Error::UnknownInstruction(opcode))?;
+
+        Ok(Instruction { op, wc })
+    }
+
+    fn next_string(&mut self, mut count: u16) -> Result<(String, u16), Error> {
+        self.temp_bytes.clear();
+        loop {
+            if count == 0 {
+                return Err(Error::BadString);
+            }
+            count -= 1;
+            let chars = self.next()?.to_le_bytes();
+            let pos = chars.iter().position(|&c| c == 0).unwrap_or(4);
+            self.temp_bytes.extend_from_slice(&chars[..pos]);
+            if pos < 4 {
+                break;
+            }
+        }
+        std::str::from_utf8(&self.temp_bytes)
+            .map(|s| (s.to_owned(), count))
+            .map_err(|_| Error::BadString)
+    }
+
+    fn next_decoration(
+        &mut self,
+        inst: Instruction,
+        base_words: u16,
+        dec: &mut Decoration,
+    ) -> Result<(), Error> {
+        let raw = self.next()?;
+        let dec_typed = spirv::Decoration::from_u32(raw).ok_or(Error::InvalidDecoration(raw))?;
+        log::trace!("\t\t{}: {:?}", dec.debug_name(), dec_typed);
+        match dec_typed {
+            spirv::Decoration::BuiltIn => {
+                inst.expect(base_words + 2)?;
+                dec.built_in = Some(self.next()?);
+            }
+            spirv::Decoration::Location => {
+                inst.expect(base_words + 2)?;
+                dec.location = Some(self.next()?);
+            }
+            spirv::Decoration::DescriptorSet => {
+                inst.expect(base_words + 2)?;
+                dec.desc_set = Some(self.next()?);
+            }
+            spirv::Decoration::Binding => {
+                inst.expect(base_words + 2)?;
+                dec.desc_index = Some(self.next()?);
+            }
+            spirv::Decoration::BufferBlock => {
+                dec.storage_buffer = true;
+            }
+            spirv::Decoration::Offset => {
+                inst.expect(base_words + 2)?;
+                dec.offset = Some(self.next()?);
+            }
+            spirv::Decoration::ArrayStride => {
+                inst.expect(base_words + 2)?;
+                dec.array_stride = NonZeroU32::new(self.next()?);
+            }
+            spirv::Decoration::MatrixStride => {
+                inst.expect(base_words + 2)?;
+                dec.matrix_stride = NonZeroU32::new(self.next()?);
+            }
+            spirv::Decoration::Invariant => {
+                dec.invariant = true;
+            }
+            spirv::Decoration::NoPerspective => {
+                dec.interpolation = Some(crate::Interpolation::Linear);
+            }
+            spirv::Decoration::Flat => {
+                dec.interpolation = Some(crate::Interpolation::Flat);
+            }
+            spirv::Decoration::Centroid => {
+                dec.sampling = Some(crate::Sampling::Centroid);
+            }
+            spirv::Decoration::Sample => {
+                dec.sampling = Some(crate::Sampling::Sample);
+            }
+            spirv::Decoration::NonReadable => {
+                dec.flags |= DecorationFlags::NON_READABLE;
+            }
+            spirv::Decoration::NonWritable => {
+                dec.flags |= DecorationFlags::NON_WRITABLE;
+            }
+            spirv::Decoration::ColMajor => {
+                dec.matrix_major = Some(Majority::Column);
+            }
+            spirv::Decoration::RowMajor => {
+                dec.matrix_major = Some(Majority::Row);
+            }
+            spirv::Decoration::SpecId => {
+                dec.specialization = Some(self.next()?);
+            }
+            other => {
+                log::warn!("Unknown decoration {:?}", other);
+                for _ in base_words + 1..inst.wc {
+                    let _var = self.next()?;
+                }
+            }
+        }
+        Ok(())
+    }
+
+    /// Return the Naga `Expression` for a given SPIR-V result `id`.
+    ///
+    /// `lookup` must be the `LookupExpression` for `id`.
+    ///
+    /// SPIR-V result ids can be used by any block dominated by the id's
+    /// definition, but Naga `Expressions` are only in scope for the remainder
+    /// of their `Statement` subtree. This means that the `Expression` generated
+    /// for `id` may no longer be in scope. In such cases, this function takes
+    /// care of spilling the value of `id` to a `LocalVariable` which can then
+    /// be used anywhere. The SPIR-V domination rule ensures that the
+    /// `LocalVariable` has been initialized before it is used.
+    ///
+    /// The `body_idx` argument should be the index of the `Body` that hopes to
+    /// use `id`'s `Expression`.
+    fn get_expr_handle(
+        &self,
+        id: spirv::Word,
+        lookup: &LookupExpression,
+        ctx: &mut BlockContext,
+        emitter: &mut crate::proc::Emitter,
+        block: &mut crate::Block,
+        body_idx: BodyIndex,
+    ) -> Handle<crate::Expression> {
+        // What `Body` was `id` defined in?
+        let expr_body_idx = ctx
+            .body_for_label
+            .get(&lookup.block_id)
+            .copied()
+            .unwrap_or(0);
+
+        // Don't need to do a load/store if the expression is in the main body
+        // or if the expression is in the same body as where the query was
+        // requested. The body_idx might actually not be the final one if a loop
+        // or conditional occurs but in those cases we know that the new body
+        // will be a subscope of the body that was passed so we can still reuse
+        // the handle and not issue a load/store.
+        if is_parent(body_idx, expr_body_idx, ctx) {
+            lookup.handle
+        } else {
+            // Add a temporary variable of the same type which will be used to
+            // store the original expression and used in the current block
+            let ty = self.lookup_type[&lookup.type_id].handle;
+            let local = ctx.local_arena.append(
+                crate::LocalVariable {
+                    name: None,
+                    ty,
+                    init: None,
+                },
+                crate::Span::default(),
+            );
+
+            block.extend(emitter.finish(ctx.expressions));
+            let pointer = ctx.expressions.append(
+                crate::Expression::LocalVariable(local),
+                crate::Span::default(),
+            );
+            emitter.start(ctx.expressions);
+            let expr = ctx
+                .expressions
+                .append(crate::Expression::Load { pointer }, crate::Span::default());
+
+            // Add a slightly odd entry to the phi table, so that while `id`'s
+            // `Expression` is still in scope, the usual phi processing will
+            // spill its value to `local`, where we can find it later.
+            //
+            // This pretends that the block in which `id` is defined is the
+            // predecessor of some other block with a phi in it that cites id as
+            // one of its sources, and uses `local` as its variable. There is no
+            // such phi, but nobody needs to know that.
+            ctx.phis.push(PhiExpression {
+                local,
+                expressions: vec![(id, lookup.block_id)],
+            });
+
+            expr
+        }
+    }
+
+    fn parse_expr_unary_op(
+        &mut self,
+        ctx: &mut BlockContext,
+        emitter: &mut crate::proc::Emitter,
+        block: &mut crate::Block,
+        block_id: spirv::Word,
+        body_idx: usize,
+        op: crate::UnaryOperator,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        let result_type_id = self.next()?;
+        let result_id = self.next()?;
+        let p_id = self.next()?;
+
+        let p_lexp = self.lookup_expression.lookup(p_id)?;
+        let handle = self.get_expr_handle(p_id, p_lexp, ctx, emitter, block, body_idx);
+
+        let expr = crate::Expression::Unary { op, expr: handle };
+        self.lookup_expression.insert(
+            result_id,
+            LookupExpression {
+                handle: ctx.expressions.append(expr, self.span_from_with_op(start)),
+                type_id: result_type_id,
+                block_id,
+            },
+        );
+        Ok(())
+    }
+
+    fn parse_expr_binary_op(
+        &mut self,
+        ctx: &mut BlockContext,
+        emitter: &mut crate::proc::Emitter,
+        block: &mut crate::Block,
+        block_id: spirv::Word,
+        body_idx: usize,
+        op: crate::BinaryOperator,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        let result_type_id = self.next()?;
+        let result_id = self.next()?;
+        let p1_id = self.next()?;
+        let p2_id = self.next()?;
+
+        let p1_lexp = self.lookup_expression.lookup(p1_id)?;
+        let left = self.get_expr_handle(p1_id, p1_lexp, ctx, emitter, block, body_idx);
+        let p2_lexp = self.lookup_expression.lookup(p2_id)?;
+        let right = self.get_expr_handle(p2_id, p2_lexp, ctx, emitter, block, body_idx);
+
+        let expr = crate::Expression::Binary { op, left, right };
+        self.lookup_expression.insert(
+            result_id,
+            LookupExpression {
+                handle: ctx.expressions.append(expr, self.span_from_with_op(start)),
+                type_id: result_type_id,
+                block_id,
+            },
+        );
+        Ok(())
+    }
+
+    /// A more complicated version of the unary op,
+    /// where we force the operand to have the same type as the result.
+    fn parse_expr_unary_op_sign_adjusted(
+        &mut self,
+        ctx: &mut BlockContext,
+        emitter: &mut crate::proc::Emitter,
+        block: &mut crate::Block,
+        block_id: spirv::Word,
+        body_idx: usize,
+        op: crate::UnaryOperator,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        let result_type_id = self.next()?;
+        let result_id = self.next()?;
+        let p1_id = self.next()?;
+        let span = self.span_from_with_op(start);
+
+        let p1_lexp = self.lookup_expression.lookup(p1_id)?;
+        let left = self.get_expr_handle(p1_id, p1_lexp, ctx, emitter, block, body_idx);
+
+        let result_lookup_ty = self.lookup_type.lookup(result_type_id)?;
+        let kind = ctx.type_arena[result_lookup_ty.handle]
+            .inner
+            .scalar_kind()
+            .unwrap();
+
+        let expr = crate::Expression::Unary {
+            op,
+            expr: if p1_lexp.type_id == result_type_id {
+                left
+            } else {
+                ctx.expressions.append(
+                    crate::Expression::As {
+                        expr: left,
+                        kind,
+                        convert: None,
+                    },
+                    span,
+                )
+            },
+        };
+
+        self.lookup_expression.insert(
+            result_id,
+            LookupExpression {
+                handle: ctx.expressions.append(expr, span),
+                type_id: result_type_id,
+                block_id,
+            },
+        );
+        Ok(())
+    }
+
+    /// A more complicated version of the binary op,
+    /// where we force the operand to have the same type as the result.
+    /// This is mostly needed for "i++" and "i--" coming from GLSL.
+    #[allow(clippy::too_many_arguments)]
+    fn parse_expr_binary_op_sign_adjusted(
+        &mut self,
+        ctx: &mut BlockContext,
+        emitter: &mut crate::proc::Emitter,
+        block: &mut crate::Block,
+        block_id: spirv::Word,
+        body_idx: usize,
+        op: crate::BinaryOperator,
+        // For arithmetic operations, we need the sign of operands to match the result.
+        // For boolean operations, however, the operands need to match the signs, but
+        // result is always different - a boolean.
+        anchor: SignAnchor,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        let result_type_id = self.next()?;
+        let result_id = self.next()?;
+        let p1_id = self.next()?;
+        let p2_id = self.next()?;
+        let span = self.span_from_with_op(start);
+
+        let p1_lexp = self.lookup_expression.lookup(p1_id)?;
+        let left = self.get_expr_handle(p1_id, p1_lexp, ctx, emitter, block, body_idx);
+        let p2_lexp = self.lookup_expression.lookup(p2_id)?;
+        let right = self.get_expr_handle(p2_id, p2_lexp, ctx, emitter, block, body_idx);
+
+        let expected_type_id = match anchor {
+            SignAnchor::Result => result_type_id,
+            SignAnchor::Operand => p1_lexp.type_id,
+        };
+        let expected_lookup_ty = self.lookup_type.lookup(expected_type_id)?;
+        let kind = ctx.type_arena[expected_lookup_ty.handle]
+            .inner
+            .scalar_kind()
+            .unwrap();
+
+        let expr = crate::Expression::Binary {
+            op,
+            left: if p1_lexp.type_id == expected_type_id {
+                left
+            } else {
+                ctx.expressions.append(
+                    crate::Expression::As {
+                        expr: left,
+                        kind,
+                        convert: None,
+                    },
+                    span,
+                )
+            },
+            right: if p2_lexp.type_id == expected_type_id {
+                right
+            } else {
+                ctx.expressions.append(
+                    crate::Expression::As {
+                        expr: right,
+                        kind,
+                        convert: None,
+                    },
+                    span,
+                )
+            },
+        };
+
+        self.lookup_expression.insert(
+            result_id,
+            LookupExpression {
+                handle: ctx.expressions.append(expr, span),
+                type_id: result_type_id,
+                block_id,
+            },
+        );
+        Ok(())
+    }
+
+    /// A version of the binary op where one or both of the arguments might need to be casted to a
+    /// specific integer kind (unsigned or signed), used for operations like OpINotEqual or
+    /// OpUGreaterThan.
+    #[allow(clippy::too_many_arguments)]
+    fn parse_expr_int_comparison(
+        &mut self,
+        ctx: &mut BlockContext,
+        emitter: &mut crate::proc::Emitter,
+        block: &mut crate::Block,
+        block_id: spirv::Word,
+        body_idx: usize,
+        op: crate::BinaryOperator,
+        kind: crate::ScalarKind,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        let result_type_id = self.next()?;
+        let result_id = self.next()?;
+        let p1_id = self.next()?;
+        let p2_id = self.next()?;
+        let span = self.span_from_with_op(start);
+
+        let p1_lexp = self.lookup_expression.lookup(p1_id)?;
+        let left = self.get_expr_handle(p1_id, p1_lexp, ctx, emitter, block, body_idx);
+        let p1_lookup_ty = self.lookup_type.lookup(p1_lexp.type_id)?;
+        let p1_kind = ctx.type_arena[p1_lookup_ty.handle]
+            .inner
+            .scalar_kind()
+            .unwrap();
+        let p2_lexp = self.lookup_expression.lookup(p2_id)?;
+        let right = self.get_expr_handle(p2_id, p2_lexp, ctx, emitter, block, body_idx);
+        let p2_lookup_ty = self.lookup_type.lookup(p2_lexp.type_id)?;
+        let p2_kind = ctx.type_arena[p2_lookup_ty.handle]
+            .inner
+            .scalar_kind()
+            .unwrap();
+
+        let expr = crate::Expression::Binary {
+            op,
+            left: if p1_kind == kind {
+                left
+            } else {
+                ctx.expressions.append(
+                    crate::Expression::As {
+                        expr: left,
+                        kind,
+                        convert: None,
+                    },
+                    span,
+                )
+            },
+            right: if p2_kind == kind {
+                right
+            } else {
+                ctx.expressions.append(
+                    crate::Expression::As {
+                        expr: right,
+                        kind,
+                        convert: None,
+                    },
+                    span,
+                )
+            },
+        };
+
+        self.lookup_expression.insert(
+            result_id,
+            LookupExpression {
+                handle: ctx.expressions.append(expr, span),
+                type_id: result_type_id,
+                block_id,
+            },
+        );
+        Ok(())
+    }
+
+    fn parse_expr_shift_op(
+        &mut self,
+        ctx: &mut BlockContext,
+        emitter: &mut crate::proc::Emitter,
+        block: &mut crate::Block,
+        block_id: spirv::Word,
+        body_idx: usize,
+        op: crate::BinaryOperator,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        let result_type_id = self.next()?;
+        let result_id = self.next()?;
+        let p1_id = self.next()?;
+        let p2_id = self.next()?;
+
+        let span = self.span_from_with_op(start);
+
+        let p1_lexp = self.lookup_expression.lookup(p1_id)?;
+        let left = self.get_expr_handle(p1_id, p1_lexp, ctx, emitter, block, body_idx);
+        let p2_lexp = self.lookup_expression.lookup(p2_id)?;
+        let p2_handle = self.get_expr_handle(p2_id, p2_lexp, ctx, emitter, block, body_idx);
+        // convert the shift to Uint
+        let right = ctx.expressions.append(
+            crate::Expression::As {
+                expr: p2_handle,
+                kind: crate::ScalarKind::Uint,
+                convert: None,
+            },
+            span,
+        );
+
+        let expr = crate::Expression::Binary { op, left, right };
+        self.lookup_expression.insert(
+            result_id,
+            LookupExpression {
+                handle: ctx.expressions.append(expr, span),
+                type_id: result_type_id,
+                block_id,
+            },
+        );
+        Ok(())
+    }
+
+    fn parse_expr_derivative(
+        &mut self,
+        ctx: &mut BlockContext,
+        emitter: &mut crate::proc::Emitter,
+        block: &mut crate::Block,
+        block_id: spirv::Word,
+        body_idx: usize,
+        (axis, ctrl): (crate::DerivativeAxis, crate::DerivativeControl),
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        let result_type_id = self.next()?;
+        let result_id = self.next()?;
+        let arg_id = self.next()?;
+
+        let arg_lexp = self.lookup_expression.lookup(arg_id)?;
+        let arg_handle = self.get_expr_handle(arg_id, arg_lexp, ctx, emitter, block, body_idx);
+
+        let expr = crate::Expression::Derivative {
+            axis,
+            ctrl,
+            expr: arg_handle,
+        };
+        self.lookup_expression.insert(
+            result_id,
+            LookupExpression {
+                handle: ctx.expressions.append(expr, self.span_from_with_op(start)),
+                type_id: result_type_id,
+                block_id,
+            },
+        );
+        Ok(())
+    }
+
+    #[allow(clippy::too_many_arguments)]
+    fn insert_composite(
+        &self,
+        root_expr: Handle<crate::Expression>,
+        root_type_id: spirv::Word,
+        object_expr: Handle<crate::Expression>,
+        selections: &[spirv::Word],
+        type_arena: &UniqueArena<crate::Type>,
+        expressions: &mut Arena<crate::Expression>,
+        span: crate::Span,
+    ) -> Result<Handle<crate::Expression>, Error> {
+        let selection = match selections.first() {
+            Some(&index) => index,
+            None => return Ok(object_expr),
+        };
+        let root_span = expressions.get_span(root_expr);
+        let root_lookup = self.lookup_type.lookup(root_type_id)?;
+
+        let (count, child_type_id) = match type_arena[root_lookup.handle].inner {
+            crate::TypeInner::Struct { ref members, .. } => {
+                let child_member = self
+                    .lookup_member
+                    .get(&(root_lookup.handle, selection))
+                    .ok_or(Error::InvalidAccessType(root_type_id))?;
+                (members.len(), child_member.type_id)
+            }
+            crate::TypeInner::Array { size, .. } => {
+                let size = match size {
+                    crate::ArraySize::Constant(size) => size.get(),
+                    // A runtime sized array is not a composite type
+                    crate::ArraySize::Dynamic => {
+                        return Err(Error::InvalidAccessType(root_type_id))
+                    }
+                };
+
+                let child_type_id = root_lookup
+                    .base_id
+                    .ok_or(Error::InvalidAccessType(root_type_id))?;
+
+                (size as usize, child_type_id)
+            }
+            crate::TypeInner::Vector { size, .. }
+            | crate::TypeInner::Matrix { columns: size, .. } => {
+                let child_type_id = root_lookup
+                    .base_id
+                    .ok_or(Error::InvalidAccessType(root_type_id))?;
+                (size as usize, child_type_id)
+            }
+            _ => return Err(Error::InvalidAccessType(root_type_id)),
+        };
+
+        let mut components = Vec::with_capacity(count);
+        for index in 0..count as u32 {
+            let expr = expressions.append(
+                crate::Expression::AccessIndex {
+                    base: root_expr,
+                    index,
+                },
+                if index == selection { span } else { root_span },
+            );
+            components.push(expr);
+        }
+        components[selection as usize] = self.insert_composite(
+            components[selection as usize],
+            child_type_id,
+            object_expr,
+            &selections[1..],
+            type_arena,
+            expressions,
+            span,
+        )?;
+
+        Ok(expressions.append(
+            crate::Expression::Compose {
+                ty: root_lookup.handle,
+                components,
+            },
+            span,
+        ))
+    }
+
+    /// Add the next SPIR-V block's contents to `block_ctx`.
+    ///
+    /// Except for the function's entry block, `block_id` should be the label of
+    /// a block we've seen mentioned before, with an entry in
+    /// `block_ctx.body_for_label` to tell us which `Body` it contributes to.
+    fn next_block(&mut self, block_id: spirv::Word, ctx: &mut BlockContext) -> Result<(), Error> {
+        // Extend `body` with the correct form for a branch to `target`.
+        fn merger(body: &mut Body, target: &MergeBlockInformation) {
+            body.data.push(match *target {
+                MergeBlockInformation::LoopContinue => BodyFragment::Continue,
+                MergeBlockInformation::LoopMerge | MergeBlockInformation::SwitchMerge => {
+                    BodyFragment::Break
+                }
+
+                // Finishing a selection merge means just falling off the end of
+                // the `accept` or `reject` block of the `If` statement.
+                MergeBlockInformation::SelectionMerge => return,
+            })
+        }
+
+        let mut emitter = crate::proc::Emitter::default();
+        emitter.start(ctx.expressions);
+
+        // Find the `Body` to which this block contributes.
+        //
+        // If this is some SPIR-V structured control flow construct's merge
+        // block, then `body_idx` will refer to the same `Body` as the header,
+        // so that we simply pick up accumulating the `Body` where the header
+        // left off. Each of the statements in a block dominates the next, so
+        // we're sure to encounter their SPIR-V blocks in order, ensuring that
+        // the `Body` will be assembled in the proper order.
+        //
+        // Note that, unlike every other kind of SPIR-V block, we don't know the
+        // function's first block's label in advance. Thus, we assume that if
+        // this block has no entry in `ctx.body_for_label`, it must be the
+        // function's first block. This always has body index zero.
+        let mut body_idx = *ctx.body_for_label.entry(block_id).or_default();
+
+        // The Naga IR block this call builds. This will end up as
+        // `ctx.blocks[&block_id]`, and `ctx.bodies[body_idx]` will refer to it
+        // via a `BodyFragment::BlockId`.
+        let mut block = crate::Block::new();
+
+        // Stores the merge block as defined by a `OpSelectionMerge` otherwise is `None`
+        //
+        // This is used in `OpSwitch` to promote the `MergeBlockInformation` from
+        // `SelectionMerge` to `SwitchMerge` to allow `Break`s this isn't desirable for
+        // `LoopMerge`s because otherwise `Continue`s wouldn't be allowed
+        let mut selection_merge_block = None;
+
+        macro_rules! get_expr_handle {
+            ($id:expr, $lexp:expr) => {
+                self.get_expr_handle($id, $lexp, ctx, &mut emitter, &mut block, body_idx)
+            };
+        }
+        macro_rules! parse_expr_op {
+            ($op:expr, BINARY) => {
+                self.parse_expr_binary_op(ctx, &mut emitter, &mut block, block_id, body_idx, $op)
+            };
+
+            ($op:expr, SHIFT) => {
+                self.parse_expr_shift_op(ctx, &mut emitter, &mut block, block_id, body_idx, $op)
+            };
+            ($op:expr, UNARY) => {
+                self.parse_expr_unary_op(ctx, &mut emitter, &mut block, block_id, body_idx, $op)
+            };
+            ($axis:expr, $ctrl:expr, DERIVATIVE) => {
+                self.parse_expr_derivative(
+                    ctx,
+                    &mut emitter,
+                    &mut block,
+                    block_id,
+                    body_idx,
+                    ($axis, $ctrl),
+                )
+            };
+        }
+
+        let terminator = loop {
+            use spirv::Op;
+            let start = self.data_offset;
+            let inst = self.next_inst()?;
+            let span = crate::Span::from(start..(start + 4 * (inst.wc as usize)));
+            log::debug!("\t\t{:?} [{}]", inst.op, inst.wc);
+
+            match inst.op {
+                Op::Line => {
+                    inst.expect(4)?;
+                    let _file_id = self.next()?;
+                    let _row_id = self.next()?;
+                    let _col_id = self.next()?;
+                }
+                Op::NoLine => inst.expect(1)?,
+                Op::Undef => {
+                    inst.expect(3)?;
+                    let type_id = self.next()?;
+                    let id = self.next()?;
+                    let type_lookup = self.lookup_type.lookup(type_id)?;
+                    let ty = type_lookup.handle;
+
+                    self.lookup_expression.insert(
+                        id,
+                        LookupExpression {
+                            handle: ctx
+                                .expressions
+                                .append(crate::Expression::ZeroValue(ty), span),
+                            type_id,
+                            block_id,
+                        },
+                    );
+                }
+                Op::Variable => {
+                    inst.expect_at_least(4)?;
+                    block.extend(emitter.finish(ctx.expressions));
+
+                    let result_type_id = self.next()?;
+                    let result_id = self.next()?;
+                    let _storage_class = self.next()?;
+                    let init = if inst.wc > 4 {
+                        inst.expect(5)?;
+                        let init_id = self.next()?;
+                        let lconst = self.lookup_constant.lookup(init_id)?;
+                        Some(
+                            ctx.expressions
+                                .append(crate::Expression::Constant(lconst.handle), span),
+                        )
+                    } else {
+                        None
+                    };
+
+                    let name = self
+                        .future_decor
+                        .remove(&result_id)
+                        .and_then(|decor| decor.name);
+                    if let Some(ref name) = name {
+                        log::debug!("\t\t\tid={} name={}", result_id, name);
+                    }
+                    let lookup_ty = self.lookup_type.lookup(result_type_id)?;
+                    let var_handle = ctx.local_arena.append(
+                        crate::LocalVariable {
+                            name,
+                            ty: match ctx.type_arena[lookup_ty.handle].inner {
+                                crate::TypeInner::Pointer { base, .. } => base,
+                                _ => lookup_ty.handle,
+                            },
+                            init,
+                        },
+                        span,
+                    );
+
+                    self.lookup_expression.insert(
+                        result_id,
+                        LookupExpression {
+                            handle: ctx
+                                .expressions
+                                .append(crate::Expression::LocalVariable(var_handle), span),
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                    emitter.start(ctx.expressions);
+                }
+                Op::Phi => {
+                    inst.expect_at_least(3)?;
+                    block.extend(emitter.finish(ctx.expressions));
+
+                    let result_type_id = self.next()?;
+                    let result_id = self.next()?;
+
+                    let name = format!("phi_{result_id}");
+                    let local = ctx.local_arena.append(
+                        crate::LocalVariable {
+                            name: Some(name),
+                            ty: self.lookup_type.lookup(result_type_id)?.handle,
+                            init: None,
+                        },
+                        self.span_from(start),
+                    );
+                    let pointer = ctx
+                        .expressions
+                        .append(crate::Expression::LocalVariable(local), span);
+
+                    let in_count = (inst.wc - 3) / 2;
+                    let mut phi = PhiExpression {
+                        local,
+                        expressions: Vec::with_capacity(in_count as usize),
+                    };
+                    for _ in 0..in_count {
+                        let expr = self.next()?;
+                        let block = self.next()?;
+                        phi.expressions.push((expr, block));
+                    }
+
+                    ctx.phis.push(phi);
+                    emitter.start(ctx.expressions);
+
+                    // Associate the lookup with an actual value, which is emitted
+                    // into the current block.
+                    self.lookup_expression.insert(
+                        result_id,
+                        LookupExpression {
+                            handle: ctx
+                                .expressions
+                                .append(crate::Expression::Load { pointer }, span),
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                }
+                Op::AccessChain | Op::InBoundsAccessChain => {
+                    struct AccessExpression {
+                        base_handle: Handle<crate::Expression>,
+                        type_id: spirv::Word,
+                        load_override: Option<LookupLoadOverride>,
+                    }
+
+                    inst.expect_at_least(4)?;
+
+                    let result_type_id = self.next()?;
+                    let result_id = self.next()?;
+                    let base_id = self.next()?;
+                    log::trace!("\t\t\tlooking up expr {:?}", base_id);
+
+                    let mut acex = {
+                        let lexp = self.lookup_expression.lookup(base_id)?;
+                        let lty = self.lookup_type.lookup(lexp.type_id)?;
+
+                        // HACK `OpAccessChain` and `OpInBoundsAccessChain`
+                        // require for the result type to be a pointer, but if
+                        // we're given a pointer to an image / sampler, it will
+                        // be *already* dereferenced, since we do that early
+                        // during `parse_type_pointer()`.
+                        //
+                        // This can happen only through `BindingArray`, since
+                        // that's the only case where one can obtain a pointer
+                        // to an image / sampler, and so let's match on that:
+                        let dereference = match ctx.type_arena[lty.handle].inner {
+                            crate::TypeInner::BindingArray { .. } => false,
+                            _ => true,
+                        };
+
+                        let type_id = if dereference {
+                            lty.base_id.ok_or(Error::InvalidAccessType(lexp.type_id))?
+                        } else {
+                            lexp.type_id
+                        };
+
+                        AccessExpression {
+                            base_handle: get_expr_handle!(base_id, lexp),
+                            type_id,
+                            load_override: self.lookup_load_override.get(&base_id).cloned(),
+                        }
+                    };
+
+                    for _ in 4..inst.wc {
+                        let access_id = self.next()?;
+                        log::trace!("\t\t\tlooking up index expr {:?}", access_id);
+                        let index_expr = self.lookup_expression.lookup(access_id)?.clone();
+                        let index_expr_handle = get_expr_handle!(access_id, &index_expr);
+                        let index_expr_data = &ctx.expressions[index_expr.handle];
+                        let index_maybe = match *index_expr_data {
+                            crate::Expression::Constant(const_handle) => Some(
+                                ctx.gctx()
+                                    .eval_expr_to_u32(ctx.const_arena[const_handle].init)
+                                    .map_err(|_| {
+                                        Error::InvalidAccess(crate::Expression::Constant(
+                                            const_handle,
+                                        ))
+                                    })?,
+                            ),
+                            _ => None,
+                        };
+
+                        log::trace!("\t\t\tlooking up type {:?}", acex.type_id);
+                        let type_lookup = self.lookup_type.lookup(acex.type_id)?;
+                        let ty = &ctx.type_arena[type_lookup.handle];
+                        acex = match ty.inner {
+                            // can only index a struct with a constant
+                            crate::TypeInner::Struct { ref members, .. } => {
+                                let index = index_maybe
+                                    .ok_or_else(|| Error::InvalidAccess(index_expr_data.clone()))?;
+
+                                let lookup_member = self
+                                    .lookup_member
+                                    .get(&(type_lookup.handle, index))
+                                    .ok_or(Error::InvalidAccessType(acex.type_id))?;
+                                let base_handle = ctx.expressions.append(
+                                    crate::Expression::AccessIndex {
+                                        base: acex.base_handle,
+                                        index,
+                                    },
+                                    span,
+                                );
+
+                                if ty.name.as_deref() == Some("gl_PerVertex") {
+                                    if let Some(crate::Binding::BuiltIn(built_in)) =
+                                        members[index as usize].binding
+                                    {
+                                        self.gl_per_vertex_builtin_access.insert(built_in);
+                                    }
+                                }
+
+                                AccessExpression {
+                                    base_handle,
+                                    type_id: lookup_member.type_id,
+                                    load_override: if lookup_member.row_major {
+                                        debug_assert!(acex.load_override.is_none());
+                                        let sub_type_lookup =
+                                            self.lookup_type.lookup(lookup_member.type_id)?;
+                                        Some(match ctx.type_arena[sub_type_lookup.handle].inner {
+                                            // load it transposed, to match column major expectations
+                                            crate::TypeInner::Matrix { .. } => {
+                                                let loaded = ctx.expressions.append(
+                                                    crate::Expression::Load {
+                                                        pointer: base_handle,
+                                                    },
+                                                    span,
+                                                );
+                                                let transposed = ctx.expressions.append(
+                                                    crate::Expression::Math {
+                                                        fun: crate::MathFunction::Transpose,
+                                                        arg: loaded,
+                                                        arg1: None,
+                                                        arg2: None,
+                                                        arg3: None,
+                                                    },
+                                                    span,
+                                                );
+                                                LookupLoadOverride::Loaded(transposed)
+                                            }
+                                            _ => LookupLoadOverride::Pending,
+                                        })
+                                    } else {
+                                        None
+                                    },
+                                }
+                            }
+                            crate::TypeInner::Matrix { .. } => {
+                                let load_override = match acex.load_override {
+                                    // We are indexing inside a row-major matrix
+                                    Some(LookupLoadOverride::Loaded(load_expr)) => {
+                                        let index = index_maybe.ok_or_else(|| {
+                                            Error::InvalidAccess(index_expr_data.clone())
+                                        })?;
+                                        let sub_handle = ctx.expressions.append(
+                                            crate::Expression::AccessIndex {
+                                                base: load_expr,
+                                                index,
+                                            },
+                                            span,
+                                        );
+                                        Some(LookupLoadOverride::Loaded(sub_handle))
+                                    }
+                                    _ => None,
+                                };
+                                let sub_expr = match index_maybe {
+                                    Some(index) => crate::Expression::AccessIndex {
+                                        base: acex.base_handle,
+                                        index,
+                                    },
+                                    None => crate::Expression::Access {
+                                        base: acex.base_handle,
+                                        index: index_expr_handle,
+                                    },
+                                };
+                                AccessExpression {
+                                    base_handle: ctx.expressions.append(sub_expr, span),
+                                    type_id: type_lookup
+                                        .base_id
+                                        .ok_or(Error::InvalidAccessType(acex.type_id))?,
+                                    load_override,
+                                }
+                            }
+                            // This must be a vector or an array.
+                            _ => {
+                                let base_handle = ctx.expressions.append(
+                                    crate::Expression::Access {
+                                        base: acex.base_handle,
+                                        index: index_expr_handle,
+                                    },
+                                    span,
+                                );
+                                let load_override = match acex.load_override {
+                                    // If there is a load override in place, then we always end up
+                                    // with a side-loaded value here.
+                                    Some(lookup_load_override) => {
+                                        let sub_expr = match lookup_load_override {
+                                            // We must be indexing into the array of row-major matrices.
+                                            // Let's load the result of indexing and transpose it.
+                                            LookupLoadOverride::Pending => {
+                                                let loaded = ctx.expressions.append(
+                                                    crate::Expression::Load {
+                                                        pointer: base_handle,
+                                                    },
+                                                    span,
+                                                );
+                                                ctx.expressions.append(
+                                                    crate::Expression::Math {
+                                                        fun: crate::MathFunction::Transpose,
+                                                        arg: loaded,
+                                                        arg1: None,
+                                                        arg2: None,
+                                                        arg3: None,
+                                                    },
+                                                    span,
+                                                )
+                                            }
+                                            // We are indexing inside a row-major matrix.
+                                            LookupLoadOverride::Loaded(load_expr) => {
+                                                ctx.expressions.append(
+                                                    crate::Expression::Access {
+                                                        base: load_expr,
+                                                        index: index_expr_handle,
+                                                    },
+                                                    span,
+                                                )
+                                            }
+                                        };
+                                        Some(LookupLoadOverride::Loaded(sub_expr))
+                                    }
+                                    None => None,
+                                };
+                                AccessExpression {
+                                    base_handle,
+                                    type_id: type_lookup
+                                        .base_id
+                                        .ok_or(Error::InvalidAccessType(acex.type_id))?,
+                                    load_override,
+                                }
+                            }
+                        };
+                    }
+
+                    if let Some(load_expr) = acex.load_override {
+                        self.lookup_load_override.insert(result_id, load_expr);
+                    }
+                    let lookup_expression = LookupExpression {
+                        handle: acex.base_handle,
+                        type_id: result_type_id,
+                        block_id,
+                    };
+                    self.lookup_expression.insert(result_id, lookup_expression);
+                }
+                Op::VectorExtractDynamic => {
+                    inst.expect(5)?;
+
+                    let result_type_id = self.next()?;
+                    let id = self.next()?;
+                    let composite_id = self.next()?;
+                    let index_id = self.next()?;
+
+                    let root_lexp = self.lookup_expression.lookup(composite_id)?;
+                    let root_handle = get_expr_handle!(composite_id, root_lexp);
+                    let root_type_lookup = self.lookup_type.lookup(root_lexp.type_id)?;
+                    let index_lexp = self.lookup_expression.lookup(index_id)?;
+                    let index_handle = get_expr_handle!(index_id, index_lexp);
+                    let index_type = self.lookup_type.lookup(index_lexp.type_id)?.handle;
+
+                    let num_components = match ctx.type_arena[root_type_lookup.handle].inner {
+                        crate::TypeInner::Vector { size, .. } => size as u32,
+                        _ => return Err(Error::InvalidVectorType(root_type_lookup.handle)),
+                    };
+
+                    let mut make_index = |ctx: &mut BlockContext, index: u32| {
+                        make_index_literal(
+                            ctx,
+                            index,
+                            &mut block,
+                            &mut emitter,
+                            index_type,
+                            index_lexp.type_id,
+                            span,
+                        )
+                    };
+
+                    let index_expr = make_index(ctx, 0)?;
+                    let mut handle = ctx.expressions.append(
+                        crate::Expression::Access {
+                            base: root_handle,
+                            index: index_expr,
+                        },
+                        span,
+                    );
+                    for index in 1..num_components {
+                        let index_expr = make_index(ctx, index)?;
+                        let access_expr = ctx.expressions.append(
+                            crate::Expression::Access {
+                                base: root_handle,
+                                index: index_expr,
+                            },
+                            span,
+                        );
+                        let cond = ctx.expressions.append(
+                            crate::Expression::Binary {
+                                op: crate::BinaryOperator::Equal,
+                                left: index_expr,
+                                right: index_handle,
+                            },
+                            span,
+                        );
+                        handle = ctx.expressions.append(
+                            crate::Expression::Select {
+                                condition: cond,
+                                accept: access_expr,
+                                reject: handle,
+                            },
+                            span,
+                        );
+                    }
+
+                    self.lookup_expression.insert(
+                        id,
+                        LookupExpression {
+                            handle,
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                }
+                Op::VectorInsertDynamic => {
+                    inst.expect(6)?;
+
+                    let result_type_id = self.next()?;
+                    let id = self.next()?;
+                    let composite_id = self.next()?;
+                    let object_id = self.next()?;
+                    let index_id = self.next()?;
+
+                    let object_lexp = self.lookup_expression.lookup(object_id)?;
+                    let object_handle = get_expr_handle!(object_id, object_lexp);
+                    let root_lexp = self.lookup_expression.lookup(composite_id)?;
+                    let root_handle = get_expr_handle!(composite_id, root_lexp);
+                    let root_type_lookup = self.lookup_type.lookup(root_lexp.type_id)?;
+                    let index_lexp = self.lookup_expression.lookup(index_id)?;
+                    let index_handle = get_expr_handle!(index_id, index_lexp);
+                    let index_type = self.lookup_type.lookup(index_lexp.type_id)?.handle;
+
+                    let num_components = match ctx.type_arena[root_type_lookup.handle].inner {
+                        crate::TypeInner::Vector { size, .. } => size as u32,
+                        _ => return Err(Error::InvalidVectorType(root_type_lookup.handle)),
+                    };
+
+                    let mut components = Vec::with_capacity(num_components as usize);
+                    for index in 0..num_components {
+                        let index_expr = make_index_literal(
+                            ctx,
+                            index,
+                            &mut block,
+                            &mut emitter,
+                            index_type,
+                            index_lexp.type_id,
+                            span,
+                        )?;
+                        let access_expr = ctx.expressions.append(
+                            crate::Expression::Access {
+                                base: root_handle,
+                                index: index_expr,
+                            },
+                            span,
+                        );
+                        let cond = ctx.expressions.append(
+                            crate::Expression::Binary {
+                                op: crate::BinaryOperator::Equal,
+                                left: index_expr,
+                                right: index_handle,
+                            },
+                            span,
+                        );
+                        let handle = ctx.expressions.append(
+                            crate::Expression::Select {
+                                condition: cond,
+                                accept: object_handle,
+                                reject: access_expr,
+                            },
+                            span,
+                        );
+                        components.push(handle);
+                    }
+                    let handle = ctx.expressions.append(
+                        crate::Expression::Compose {
+                            ty: root_type_lookup.handle,
+                            components,
+                        },
+                        span,
+                    );
+
+                    self.lookup_expression.insert(
+                        id,
+                        LookupExpression {
+                            handle,
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                }
+                Op::CompositeExtract => {
+                    inst.expect_at_least(4)?;
+
+                    let result_type_id = self.next()?;
+                    let result_id = self.next()?;
+                    let base_id = self.next()?;
+                    log::trace!("\t\t\tlooking up expr {:?}", base_id);
+                    let mut lexp = self.lookup_expression.lookup(base_id)?.clone();
+                    lexp.handle = get_expr_handle!(base_id, &lexp);
+                    for _ in 4..inst.wc {
+                        let index = self.next()?;
+                        log::trace!("\t\t\tlooking up type {:?}", lexp.type_id);
+                        let type_lookup = self.lookup_type.lookup(lexp.type_id)?;
+                        let type_id = match ctx.type_arena[type_lookup.handle].inner {
+                            crate::TypeInner::Struct { .. } => {
+                                self.lookup_member
+                                    .get(&(type_lookup.handle, index))
+                                    .ok_or(Error::InvalidAccessType(lexp.type_id))?
+                                    .type_id
+                            }
+                            crate::TypeInner::Array { .. }
+                            | crate::TypeInner::Vector { .. }
+                            | crate::TypeInner::Matrix { .. } => type_lookup
+                                .base_id
+                                .ok_or(Error::InvalidAccessType(lexp.type_id))?,
+                            ref other => {
+                                log::warn!("composite type {:?}", other);
+                                return Err(Error::UnsupportedType(type_lookup.handle));
+                            }
+                        };
+                        lexp = LookupExpression {
+                            handle: ctx.expressions.append(
+                                crate::Expression::AccessIndex {
+                                    base: lexp.handle,
+                                    index,
+                                },
+                                span,
+                            ),
+                            type_id,
+                            block_id,
+                        };
+                    }
+
+                    self.lookup_expression.insert(
+                        result_id,
+                        LookupExpression {
+                            handle: lexp.handle,
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                }
+                Op::CompositeInsert => {
+                    inst.expect_at_least(5)?;
+
+                    let result_type_id = self.next()?;
+                    let id = self.next()?;
+                    let object_id = self.next()?;
+                    let composite_id = self.next()?;
+                    let mut selections = Vec::with_capacity(inst.wc as usize - 5);
+                    for _ in 5..inst.wc {
+                        selections.push(self.next()?);
+                    }
+
+                    let object_lexp = self.lookup_expression.lookup(object_id)?.clone();
+                    let object_handle = get_expr_handle!(object_id, &object_lexp);
+                    let root_lexp = self.lookup_expression.lookup(composite_id)?.clone();
+                    let root_handle = get_expr_handle!(composite_id, &root_lexp);
+                    let handle = self.insert_composite(
+                        root_handle,
+                        result_type_id,
+                        object_handle,
+                        &selections,
+                        ctx.type_arena,
+                        ctx.expressions,
+                        span,
+                    )?;
+
+                    self.lookup_expression.insert(
+                        id,
+                        LookupExpression {
+                            handle,
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                }
+                Op::CompositeConstruct => {
+                    inst.expect_at_least(3)?;
+
+                    let result_type_id = self.next()?;
+                    let id = self.next()?;
+                    let mut components = Vec::with_capacity(inst.wc as usize - 2);
+                    for _ in 3..inst.wc {
+                        let comp_id = self.next()?;
+                        log::trace!("\t\t\tlooking up expr {:?}", comp_id);
+                        let lexp = self.lookup_expression.lookup(comp_id)?;
+                        let handle = get_expr_handle!(comp_id, lexp);
+                        components.push(handle);
+                    }
+                    let ty = self.lookup_type.lookup(result_type_id)?.handle;
+                    let first = components[0];
+                    let expr = match ctx.type_arena[ty].inner {
+                        // this is an optimization to detect the splat
+                        crate::TypeInner::Vector { size, .. }
+                            if components.len() == size as usize
+                                && components[1..].iter().all(|&c| c == first) =>
+                        {
+                            crate::Expression::Splat { size, value: first }
+                        }
+                        _ => crate::Expression::Compose { ty, components },
+                    };
+                    self.lookup_expression.insert(
+                        id,
+                        LookupExpression {
+                            handle: ctx.expressions.append(expr, span),
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                }
+                Op::Load => {
+                    inst.expect_at_least(4)?;
+
+                    let result_type_id = self.next()?;
+                    let result_id = self.next()?;
+                    let pointer_id = self.next()?;
+                    if inst.wc != 4 {
+                        inst.expect(5)?;
+                        let _memory_access = self.next()?;
+                    }
+
+                    let base_lexp = self.lookup_expression.lookup(pointer_id)?;
+                    let base_handle = get_expr_handle!(pointer_id, base_lexp);
+                    let type_lookup = self.lookup_type.lookup(base_lexp.type_id)?;
+                    let handle = match ctx.type_arena[type_lookup.handle].inner {
+                        crate::TypeInner::Image { .. } | crate::TypeInner::Sampler { .. } => {
+                            base_handle
+                        }
+                        _ => match self.lookup_load_override.get(&pointer_id) {
+                            Some(&LookupLoadOverride::Loaded(handle)) => handle,
+                            //Note: we aren't handling `LookupLoadOverride::Pending` properly here
+                            _ => ctx.expressions.append(
+                                crate::Expression::Load {
+                                    pointer: base_handle,
+                                },
+                                span,
+                            ),
+                        },
+                    };
+
+                    self.lookup_expression.insert(
+                        result_id,
+                        LookupExpression {
+                            handle,
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                }
+                Op::Store => {
+                    inst.expect_at_least(3)?;
+
+                    let pointer_id = self.next()?;
+                    let value_id = self.next()?;
+                    if inst.wc != 3 {
+                        inst.expect(4)?;
+                        let _memory_access = self.next()?;
+                    }
+                    let base_expr = self.lookup_expression.lookup(pointer_id)?;
+                    let base_handle = get_expr_handle!(pointer_id, base_expr);
+                    let value_expr = self.lookup_expression.lookup(value_id)?;
+                    let value_handle = get_expr_handle!(value_id, value_expr);
+
+                    block.extend(emitter.finish(ctx.expressions));
+                    block.push(
+                        crate::Statement::Store {
+                            pointer: base_handle,
+                            value: value_handle,
+                        },
+                        span,
+                    );
+                    emitter.start(ctx.expressions);
+                }
+                // Arithmetic Instructions +, -, *, /, %
+                Op::SNegate | Op::FNegate => {
+                    inst.expect(4)?;
+                    self.parse_expr_unary_op_sign_adjusted(
+                        ctx,
+                        &mut emitter,
+                        &mut block,
+                        block_id,
+                        body_idx,
+                        crate::UnaryOperator::Negate,
+                    )?;
+                }
+                Op::IAdd
+                | Op::ISub
+                | Op::IMul
+                | Op::BitwiseOr
+                | Op::BitwiseXor
+                | Op::BitwiseAnd
+                | Op::SDiv
+                | Op::SRem => {
+                    inst.expect(5)?;
+                    let operator = map_binary_operator(inst.op)?;
+                    self.parse_expr_binary_op_sign_adjusted(
+                        ctx,
+                        &mut emitter,
+                        &mut block,
+                        block_id,
+                        body_idx,
+                        operator,
+                        SignAnchor::Result,
+                    )?;
+                }
+                Op::IEqual | Op::INotEqual => {
+                    inst.expect(5)?;
+                    let operator = map_binary_operator(inst.op)?;
+                    self.parse_expr_binary_op_sign_adjusted(
+                        ctx,
+                        &mut emitter,
+                        &mut block,
+                        block_id,
+                        body_idx,
+                        operator,
+                        SignAnchor::Operand,
+                    )?;
+                }
+                Op::FAdd => {
+                    inst.expect(5)?;
+                    parse_expr_op!(crate::BinaryOperator::Add, BINARY)?;
+                }
+                Op::FSub => {
+                    inst.expect(5)?;
+                    parse_expr_op!(crate::BinaryOperator::Subtract, BINARY)?;
+                }
+                Op::FMul => {
+                    inst.expect(5)?;
+                    parse_expr_op!(crate::BinaryOperator::Multiply, BINARY)?;
+                }
+                Op::UDiv | Op::FDiv => {
+                    inst.expect(5)?;
+                    parse_expr_op!(crate::BinaryOperator::Divide, BINARY)?;
+                }
+                Op::UMod | Op::FRem => {
+                    inst.expect(5)?;
+                    parse_expr_op!(crate::BinaryOperator::Modulo, BINARY)?;
+                }
+                Op::SMod => {
+                    inst.expect(5)?;
+
+                    // x - y * int(floor(float(x) / float(y)))
+
+                    let start = self.data_offset;
+                    let result_type_id = self.next()?;
+                    let result_id = self.next()?;
+                    let p1_id = self.next()?;
+                    let p2_id = self.next()?;
+                    let span = self.span_from_with_op(start);
+
+                    let p1_lexp = self.lookup_expression.lookup(p1_id)?;
+                    let left = self.get_expr_handle(
+                        p1_id,
+                        p1_lexp,
+                        ctx,
+                        &mut emitter,
+                        &mut block,
+                        body_idx,
+                    );
+                    let p2_lexp = self.lookup_expression.lookup(p2_id)?;
+                    let right = self.get_expr_handle(
+                        p2_id,
+                        p2_lexp,
+                        ctx,
+                        &mut emitter,
+                        &mut block,
+                        body_idx,
+                    );
+
+                    let result_ty = self.lookup_type.lookup(result_type_id)?;
+                    let inner = &ctx.type_arena[result_ty.handle].inner;
+                    let kind = inner.scalar_kind().unwrap();
+                    let size = inner.size(ctx.gctx()) as u8;
+
+                    let left_cast = ctx.expressions.append(
+                        crate::Expression::As {
+                            expr: left,
+                            kind: crate::ScalarKind::Float,
+                            convert: Some(size),
+                        },
+                        span,
+                    );
+                    let right_cast = ctx.expressions.append(
+                        crate::Expression::As {
+                            expr: right,
+                            kind: crate::ScalarKind::Float,
+                            convert: Some(size),
+                        },
+                        span,
+                    );
+                    let div = ctx.expressions.append(
+                        crate::Expression::Binary {
+                            op: crate::BinaryOperator::Divide,
+                            left: left_cast,
+                            right: right_cast,
+                        },
+                        span,
+                    );
+                    let floor = ctx.expressions.append(
+                        crate::Expression::Math {
+                            fun: crate::MathFunction::Floor,
+                            arg: div,
+                            arg1: None,
+                            arg2: None,
+                            arg3: None,
+                        },
+                        span,
+                    );
+                    let cast = ctx.expressions.append(
+                        crate::Expression::As {
+                            expr: floor,
+                            kind,
+                            convert: Some(size),
+                        },
+                        span,
+                    );
+                    let mult = ctx.expressions.append(
+                        crate::Expression::Binary {
+                            op: crate::BinaryOperator::Multiply,
+                            left: cast,
+                            right,
+                        },
+                        span,
+                    );
+                    let sub = ctx.expressions.append(
+                        crate::Expression::Binary {
+                            op: crate::BinaryOperator::Subtract,
+                            left,
+                            right: mult,
+                        },
+                        span,
+                    );
+                    self.lookup_expression.insert(
+                        result_id,
+                        LookupExpression {
+                            handle: sub,
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                }
+                Op::FMod => {
+                    inst.expect(5)?;
+
+                    // x - y * floor(x / y)
+
+                    let start = self.data_offset;
+                    let span = self.span_from_with_op(start);
+
+                    let result_type_id = self.next()?;
+                    let result_id = self.next()?;
+                    let p1_id = self.next()?;
+                    let p2_id = self.next()?;
+
+                    let p1_lexp = self.lookup_expression.lookup(p1_id)?;
+                    let left = self.get_expr_handle(
+                        p1_id,
+                        p1_lexp,
+                        ctx,
+                        &mut emitter,
+                        &mut block,
+                        body_idx,
+                    );
+                    let p2_lexp = self.lookup_expression.lookup(p2_id)?;
+                    let right = self.get_expr_handle(
+                        p2_id,
+                        p2_lexp,
+                        ctx,
+                        &mut emitter,
+                        &mut block,
+                        body_idx,
+                    );
+
+                    let div = ctx.expressions.append(
+                        crate::Expression::Binary {
+                            op: crate::BinaryOperator::Divide,
+                            left,
+                            right,
+                        },
+                        span,
+                    );
+                    let floor = ctx.expressions.append(
+                        crate::Expression::Math {
+                            fun: crate::MathFunction::Floor,
+                            arg: div,
+                            arg1: None,
+                            arg2: None,
+                            arg3: None,
+                        },
+                        span,
+                    );
+                    let mult = ctx.expressions.append(
+                        crate::Expression::Binary {
+                            op: crate::BinaryOperator::Multiply,
+                            left: floor,
+                            right,
+                        },
+                        span,
+                    );
+                    let sub = ctx.expressions.append(
+                        crate::Expression::Binary {
+                            op: crate::BinaryOperator::Subtract,
+                            left,
+                            right: mult,
+                        },
+                        span,
+                    );
+                    self.lookup_expression.insert(
+                        result_id,
+                        LookupExpression {
+                            handle: sub,
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                }
+                Op::VectorTimesScalar
+                | Op::VectorTimesMatrix
+                | Op::MatrixTimesScalar
+                | Op::MatrixTimesVector
+                | Op::MatrixTimesMatrix => {
+                    inst.expect(5)?;
+                    parse_expr_op!(crate::BinaryOperator::Multiply, BINARY)?;
+                }
+                Op::Transpose => {
+                    inst.expect(4)?;
+
+                    let result_type_id = self.next()?;
+                    let result_id = self.next()?;
+                    let matrix_id = self.next()?;
+                    let matrix_lexp = self.lookup_expression.lookup(matrix_id)?;
+                    let matrix_handle = get_expr_handle!(matrix_id, matrix_lexp);
+                    let expr = crate::Expression::Math {
+                        fun: crate::MathFunction::Transpose,
+                        arg: matrix_handle,
+                        arg1: None,
+                        arg2: None,
+                        arg3: None,
+                    };
+                    self.lookup_expression.insert(
+                        result_id,
+                        LookupExpression {
+                            handle: ctx.expressions.append(expr, span),
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                }
+                Op::Dot => {
+                    inst.expect(5)?;
+
+                    let result_type_id = self.next()?;
+                    let result_id = self.next()?;
+                    let left_id = self.next()?;
+                    let right_id = self.next()?;
+                    let left_lexp = self.lookup_expression.lookup(left_id)?;
+                    let left_handle = get_expr_handle!(left_id, left_lexp);
+                    let right_lexp = self.lookup_expression.lookup(right_id)?;
+                    let right_handle = get_expr_handle!(right_id, right_lexp);
+                    let expr = crate::Expression::Math {
+                        fun: crate::MathFunction::Dot,
+                        arg: left_handle,
+                        arg1: Some(right_handle),
+                        arg2: None,
+                        arg3: None,
+                    };
+                    self.lookup_expression.insert(
+                        result_id,
+                        LookupExpression {
+                            handle: ctx.expressions.append(expr, span),
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                }
+                Op::BitFieldInsert => {
+                    inst.expect(7)?;
+
+                    let start = self.data_offset;
+                    let span = self.span_from_with_op(start);
+
+                    let result_type_id = self.next()?;
+                    let result_id = self.next()?;
+                    let base_id = self.next()?;
+                    let insert_id = self.next()?;
+                    let offset_id = self.next()?;
+                    let count_id = self.next()?;
+                    let base_lexp = self.lookup_expression.lookup(base_id)?;
+                    let base_handle = get_expr_handle!(base_id, base_lexp);
+                    let insert_lexp = self.lookup_expression.lookup(insert_id)?;
+                    let insert_handle = get_expr_handle!(insert_id, insert_lexp);
+                    let offset_lexp = self.lookup_expression.lookup(offset_id)?;
+                    let offset_handle = get_expr_handle!(offset_id, offset_lexp);
+                    let offset_lookup_ty = self.lookup_type.lookup(offset_lexp.type_id)?;
+                    let count_lexp = self.lookup_expression.lookup(count_id)?;
+                    let count_handle = get_expr_handle!(count_id, count_lexp);
+                    let count_lookup_ty = self.lookup_type.lookup(count_lexp.type_id)?;
+
+                    let offset_kind = ctx.type_arena[offset_lookup_ty.handle]
+                        .inner
+                        .scalar_kind()
+                        .unwrap();
+                    let count_kind = ctx.type_arena[count_lookup_ty.handle]
+                        .inner
+                        .scalar_kind()
+                        .unwrap();
+
+                    let offset_cast_handle = if offset_kind != crate::ScalarKind::Uint {
+                        ctx.expressions.append(
+                            crate::Expression::As {
+                                expr: offset_handle,
+                                kind: crate::ScalarKind::Uint,
+                                convert: None,
+                            },
+                            span,
+                        )
+                    } else {
+                        offset_handle
+                    };
+
+                    let count_cast_handle = if count_kind != crate::ScalarKind::Uint {
+                        ctx.expressions.append(
+                            crate::Expression::As {
+                                expr: count_handle,
+                                kind: crate::ScalarKind::Uint,
+                                convert: None,
+                            },
+                            span,
+                        )
+                    } else {
+                        count_handle
+                    };
+
+                    let expr = crate::Expression::Math {
+                        fun: crate::MathFunction::InsertBits,
+                        arg: base_handle,
+                        arg1: Some(insert_handle),
+                        arg2: Some(offset_cast_handle),
+                        arg3: Some(count_cast_handle),
+                    };
+                    self.lookup_expression.insert(
+                        result_id,
+                        LookupExpression {
+                            handle: ctx.expressions.append(expr, span),
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                }
+                Op::BitFieldSExtract | Op::BitFieldUExtract => {
+                    inst.expect(6)?;
+
+                    let result_type_id = self.next()?;
+                    let result_id = self.next()?;
+                    let base_id = self.next()?;
+                    let offset_id = self.next()?;
+                    let count_id = self.next()?;
+                    let base_lexp = self.lookup_expression.lookup(base_id)?;
+                    let base_handle = get_expr_handle!(base_id, base_lexp);
+                    let offset_lexp = self.lookup_expression.lookup(offset_id)?;
+                    let offset_handle = get_expr_handle!(offset_id, offset_lexp);
+                    let offset_lookup_ty = self.lookup_type.lookup(offset_lexp.type_id)?;
+                    let count_lexp = self.lookup_expression.lookup(count_id)?;
+                    let count_handle = get_expr_handle!(count_id, count_lexp);
+                    let count_lookup_ty = self.lookup_type.lookup(count_lexp.type_id)?;
+
+                    let offset_kind = ctx.type_arena[offset_lookup_ty.handle]
+                        .inner
+                        .scalar_kind()
+                        .unwrap();
+                    let count_kind = ctx.type_arena[count_lookup_ty.handle]
+                        .inner
+                        .scalar_kind()
+                        .unwrap();
+
+                    let offset_cast_handle = if offset_kind != crate::ScalarKind::Uint {
+                        ctx.expressions.append(
+                            crate::Expression::As {
+                                expr: offset_handle,
+                                kind: crate::ScalarKind::Uint,
+                                convert: None,
+                            },
+                            span,
+                        )
+                    } else {
+                        offset_handle
+                    };
+
+                    let count_cast_handle = if count_kind != crate::ScalarKind::Uint {
+                        ctx.expressions.append(
+                            crate::Expression::As {
+                                expr: count_handle,
+                                kind: crate::ScalarKind::Uint,
+                                convert: None,
+                            },
+                            span,
+                        )
+                    } else {
+                        count_handle
+                    };
+
+                    let expr = crate::Expression::Math {
+                        fun: crate::MathFunction::ExtractBits,
+                        arg: base_handle,
+                        arg1: Some(offset_cast_handle),
+                        arg2: Some(count_cast_handle),
+                        arg3: None,
+                    };
+                    self.lookup_expression.insert(
+                        result_id,
+                        LookupExpression {
+                            handle: ctx.expressions.append(expr, span),
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                }
+                Op::BitReverse | Op::BitCount => {
+                    inst.expect(4)?;
+
+                    let result_type_id = self.next()?;
+                    let result_id = self.next()?;
+                    let base_id = self.next()?;
+                    let base_lexp = self.lookup_expression.lookup(base_id)?;
+                    let base_handle = get_expr_handle!(base_id, base_lexp);
+                    let expr = crate::Expression::Math {
+                        fun: match inst.op {
+                            Op::BitReverse => crate::MathFunction::ReverseBits,
+                            Op::BitCount => crate::MathFunction::CountOneBits,
+                            _ => unreachable!(),
+                        },
+                        arg: base_handle,
+                        arg1: None,
+                        arg2: None,
+                        arg3: None,
+                    };
+                    self.lookup_expression.insert(
+                        result_id,
+                        LookupExpression {
+                            handle: ctx.expressions.append(expr, span),
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                }
+                Op::OuterProduct => {
+                    inst.expect(5)?;
+
+                    let result_type_id = self.next()?;
+                    let result_id = self.next()?;
+                    let left_id = self.next()?;
+                    let right_id = self.next()?;
+                    let left_lexp = self.lookup_expression.lookup(left_id)?;
+                    let left_handle = get_expr_handle!(left_id, left_lexp);
+                    let right_lexp = self.lookup_expression.lookup(right_id)?;
+                    let right_handle = get_expr_handle!(right_id, right_lexp);
+                    let expr = crate::Expression::Math {
+                        fun: crate::MathFunction::Outer,
+                        arg: left_handle,
+                        arg1: Some(right_handle),
+                        arg2: None,
+                        arg3: None,
+                    };
+                    self.lookup_expression.insert(
+                        result_id,
+                        LookupExpression {
+                            handle: ctx.expressions.append(expr, span),
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                }
+                // Bitwise instructions
+                Op::Not => {
+                    inst.expect(4)?;
+                    self.parse_expr_unary_op_sign_adjusted(
+                        ctx,
+                        &mut emitter,
+                        &mut block,
+                        block_id,
+                        body_idx,
+                        crate::UnaryOperator::BitwiseNot,
+                    )?;
+                }
+                Op::ShiftRightLogical => {
+                    inst.expect(5)?;
+                    //TODO: convert input and result to unsigned
+                    parse_expr_op!(crate::BinaryOperator::ShiftRight, SHIFT)?;
+                }
+                Op::ShiftRightArithmetic => {
+                    inst.expect(5)?;
+                    //TODO: convert input and result to signed
+                    parse_expr_op!(crate::BinaryOperator::ShiftRight, SHIFT)?;
+                }
+                Op::ShiftLeftLogical => {
+                    inst.expect(5)?;
+                    parse_expr_op!(crate::BinaryOperator::ShiftLeft, SHIFT)?;
+                }
+                // Sampling
+                Op::Image => {
+                    inst.expect(4)?;
+                    self.parse_image_uncouple(block_id)?;
+                }
+                Op::SampledImage => {
+                    inst.expect(5)?;
+                    self.parse_image_couple()?;
+                }
+                Op::ImageWrite => {
+                    let extra = inst.expect_at_least(4)?;
+                    let stmt =
+                        self.parse_image_write(extra, ctx, &mut emitter, &mut block, body_idx)?;
+                    block.extend(emitter.finish(ctx.expressions));
+                    block.push(stmt, span);
+                    emitter.start(ctx.expressions);
+                }
+                Op::ImageFetch | Op::ImageRead => {
+                    let extra = inst.expect_at_least(5)?;
+                    self.parse_image_load(
+                        extra,
+                        ctx,
+                        &mut emitter,
+                        &mut block,
+                        block_id,
+                        body_idx,
+                    )?;
+                }
+                Op::ImageSampleImplicitLod | Op::ImageSampleExplicitLod => {
+                    let extra = inst.expect_at_least(5)?;
+                    let options = image::SamplingOptions {
+                        compare: false,
+                        project: false,
+                    };
+                    self.parse_image_sample(
+                        extra,
+                        options,
+                        ctx,
+                        &mut emitter,
+                        &mut block,
+                        block_id,
+                        body_idx,
+                    )?;
+                }
+                Op::ImageSampleProjImplicitLod | Op::ImageSampleProjExplicitLod => {
+                    let extra = inst.expect_at_least(5)?;
+                    let options = image::SamplingOptions {
+                        compare: false,
+                        project: true,
+                    };
+                    self.parse_image_sample(
+                        extra,
+                        options,
+                        ctx,
+                        &mut emitter,
+                        &mut block,
+                        block_id,
+                        body_idx,
+                    )?;
+                }
+                Op::ImageSampleDrefImplicitLod | Op::ImageSampleDrefExplicitLod => {
+                    let extra = inst.expect_at_least(6)?;
+                    let options = image::SamplingOptions {
+                        compare: true,
+                        project: false,
+                    };
+                    self.parse_image_sample(
+                        extra,
+                        options,
+                        ctx,
+                        &mut emitter,
+                        &mut block,
+                        block_id,
+                        body_idx,
+                    )?;
+                }
+                Op::ImageSampleProjDrefImplicitLod | Op::ImageSampleProjDrefExplicitLod => {
+                    let extra = inst.expect_at_least(6)?;
+                    let options = image::SamplingOptions {
+                        compare: true,
+                        project: true,
+                    };
+                    self.parse_image_sample(
+                        extra,
+                        options,
+                        ctx,
+                        &mut emitter,
+                        &mut block,
+                        block_id,
+                        body_idx,
+                    )?;
+                }
+                Op::ImageQuerySize => {
+                    inst.expect(4)?;
+                    self.parse_image_query_size(
+                        false,
+                        ctx,
+                        &mut emitter,
+                        &mut block,
+                        block_id,
+                        body_idx,
+                    )?;
+                }
+                Op::ImageQuerySizeLod => {
+                    inst.expect(5)?;
+                    self.parse_image_query_size(
+                        true,
+                        ctx,
+                        &mut emitter,
+                        &mut block,
+                        block_id,
+                        body_idx,
+                    )?;
+                }
+                Op::ImageQueryLevels => {
+                    inst.expect(4)?;
+                    self.parse_image_query_other(crate::ImageQuery::NumLevels, ctx, block_id)?;
+                }
+                Op::ImageQuerySamples => {
+                    inst.expect(4)?;
+                    self.parse_image_query_other(crate::ImageQuery::NumSamples, ctx, block_id)?;
+                }
+                // other ops
+                Op::Select => {
+                    inst.expect(6)?;
+                    let result_type_id = self.next()?;
+                    let result_id = self.next()?;
+                    let condition = self.next()?;
+                    let o1_id = self.next()?;
+                    let o2_id = self.next()?;
+
+                    let cond_lexp = self.lookup_expression.lookup(condition)?;
+                    let cond_handle = get_expr_handle!(condition, cond_lexp);
+                    let o1_lexp = self.lookup_expression.lookup(o1_id)?;
+                    let o1_handle = get_expr_handle!(o1_id, o1_lexp);
+                    let o2_lexp = self.lookup_expression.lookup(o2_id)?;
+                    let o2_handle = get_expr_handle!(o2_id, o2_lexp);
+
+                    let expr = crate::Expression::Select {
+                        condition: cond_handle,
+                        accept: o1_handle,
+                        reject: o2_handle,
+                    };
+                    self.lookup_expression.insert(
+                        result_id,
+                        LookupExpression {
+                            handle: ctx.expressions.append(expr, span),
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                }
+                Op::VectorShuffle => {
+                    inst.expect_at_least(5)?;
+                    let result_type_id = self.next()?;
+                    let result_id = self.next()?;
+                    let v1_id = self.next()?;
+                    let v2_id = self.next()?;
+
+                    let v1_lexp = self.lookup_expression.lookup(v1_id)?;
+                    let v1_lty = self.lookup_type.lookup(v1_lexp.type_id)?;
+                    let v1_handle = get_expr_handle!(v1_id, v1_lexp);
+                    let n1 = match ctx.type_arena[v1_lty.handle].inner {
+                        crate::TypeInner::Vector { size, .. } => size as u32,
+                        _ => return Err(Error::InvalidInnerType(v1_lexp.type_id)),
+                    };
+                    let v2_lexp = self.lookup_expression.lookup(v2_id)?;
+                    let v2_lty = self.lookup_type.lookup(v2_lexp.type_id)?;
+                    let v2_handle = get_expr_handle!(v2_id, v2_lexp);
+                    let n2 = match ctx.type_arena[v2_lty.handle].inner {
+                        crate::TypeInner::Vector { size, .. } => size as u32,
+                        _ => return Err(Error::InvalidInnerType(v2_lexp.type_id)),
+                    };
+
+                    self.temp_bytes.clear();
+                    let mut max_component = 0;
+                    for _ in 5..inst.wc as usize {
+                        let mut index = self.next()?;
+                        if index == u32::MAX {
+                            // treat Undefined as X
+                            index = 0;
+                        }
+                        max_component = max_component.max(index);
+                        self.temp_bytes.push(index as u8);
+                    }
+
+                    // Check for swizzle first.
+                    let expr = if max_component < n1 {
+                        use crate::SwizzleComponent as Sc;
+                        let size = match self.temp_bytes.len() {
+                            2 => crate::VectorSize::Bi,
+                            3 => crate::VectorSize::Tri,
+                            _ => crate::VectorSize::Quad,
+                        };
+                        let mut pattern = [Sc::X; 4];
+                        for (pat, index) in pattern.iter_mut().zip(self.temp_bytes.drain(..)) {
+                            *pat = match index {
+                                0 => Sc::X,
+                                1 => Sc::Y,
+                                2 => Sc::Z,
+                                _ => Sc::W,
+                            };
+                        }
+                        crate::Expression::Swizzle {
+                            size,
+                            vector: v1_handle,
+                            pattern,
+                        }
+                    } else {
+                        // Fall back to access + compose
+                        let mut components = Vec::with_capacity(self.temp_bytes.len());
+                        for index in self.temp_bytes.drain(..).map(|i| i as u32) {
+                            let expr = if index < n1 {
+                                crate::Expression::AccessIndex {
+                                    base: v1_handle,
+                                    index,
+                                }
+                            } else if index < n1 + n2 {
+                                crate::Expression::AccessIndex {
+                                    base: v2_handle,
+                                    index: index - n1,
+                                }
+                            } else {
+                                return Err(Error::InvalidAccessIndex(index));
+                            };
+                            components.push(ctx.expressions.append(expr, span));
+                        }
+                        crate::Expression::Compose {
+                            ty: self.lookup_type.lookup(result_type_id)?.handle,
+                            components,
+                        }
+                    };
+
+                    self.lookup_expression.insert(
+                        result_id,
+                        LookupExpression {
+                            handle: ctx.expressions.append(expr, span),
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                }
+                Op::Bitcast
+                | Op::ConvertSToF
+                | Op::ConvertUToF
+                | Op::ConvertFToU
+                | Op::ConvertFToS
+                | Op::FConvert
+                | Op::UConvert
+                | Op::SConvert => {
+                    inst.expect(4)?;
+                    let result_type_id = self.next()?;
+                    let result_id = self.next()?;
+                    let value_id = self.next()?;
+
+                    let value_lexp = self.lookup_expression.lookup(value_id)?;
+                    let ty_lookup = self.lookup_type.lookup(result_type_id)?;
+                    let scalar = match ctx.type_arena[ty_lookup.handle].inner {
+                        crate::TypeInner::Scalar(scalar)
+                        | crate::TypeInner::Vector { scalar, .. }
+                        | crate::TypeInner::Matrix { scalar, .. } => scalar,
+                        _ => return Err(Error::InvalidAsType(ty_lookup.handle)),
+                    };
+
+                    let expr = crate::Expression::As {
+                        expr: get_expr_handle!(value_id, value_lexp),
+                        kind: scalar.kind,
+                        convert: if scalar.kind == crate::ScalarKind::Bool {
+                            Some(crate::BOOL_WIDTH)
+                        } else if inst.op == Op::Bitcast {
+                            None
+                        } else {
+                            Some(scalar.width)
+                        },
+                    };
+                    self.lookup_expression.insert(
+                        result_id,
+                        LookupExpression {
+                            handle: ctx.expressions.append(expr, span),
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                }
+                Op::FunctionCall => {
+                    inst.expect_at_least(4)?;
+                    block.extend(emitter.finish(ctx.expressions));
+
+                    let result_type_id = self.next()?;
+                    let result_id = self.next()?;
+                    let func_id = self.next()?;
+
+                    let mut arguments = Vec::with_capacity(inst.wc as usize - 4);
+                    for _ in 0..arguments.capacity() {
+                        let arg_id = self.next()?;
+                        let lexp = self.lookup_expression.lookup(arg_id)?;
+                        arguments.push(get_expr_handle!(arg_id, lexp));
+                    }
+
+                    // We just need an unique handle here, nothing more.
+                    let function = self.add_call(ctx.function_id, func_id);
+
+                    let result = if self.lookup_void_type == Some(result_type_id) {
+                        None
+                    } else {
+                        let expr_handle = ctx
+                            .expressions
+                            .append(crate::Expression::CallResult(function), span);
+                        self.lookup_expression.insert(
+                            result_id,
+                            LookupExpression {
+                                handle: expr_handle,
+                                type_id: result_type_id,
+                                block_id,
+                            },
+                        );
+                        Some(expr_handle)
+                    };
+                    block.push(
+                        crate::Statement::Call {
+                            function,
+                            arguments,
+                            result,
+                        },
+                        span,
+                    );
+                    emitter.start(ctx.expressions);
+                }
+                Op::ExtInst => {
+                    use crate::MathFunction as Mf;
+                    use spirv::GLOp as Glo;
+
+                    let base_wc = 5;
+                    inst.expect_at_least(base_wc)?;
+
+                    let result_type_id = self.next()?;
+                    let result_id = self.next()?;
+                    let set_id = self.next()?;
+                    if Some(set_id) != self.ext_glsl_id {
+                        return Err(Error::UnsupportedExtInstSet(set_id));
+                    }
+                    let inst_id = self.next()?;
+                    let gl_op = Glo::from_u32(inst_id).ok_or(Error::UnsupportedExtInst(inst_id))?;
+
+                    let fun = match gl_op {
+                        Glo::Round => Mf::Round,
+                        Glo::RoundEven => Mf::Round,
+                        Glo::Trunc => Mf::Trunc,
+                        Glo::FAbs | Glo::SAbs => Mf::Abs,
+                        Glo::FSign | Glo::SSign => Mf::Sign,
+                        Glo::Floor => Mf::Floor,
+                        Glo::Ceil => Mf::Ceil,
+                        Glo::Fract => Mf::Fract,
+                        Glo::Sin => Mf::Sin,
+                        Glo::Cos => Mf::Cos,
+                        Glo::Tan => Mf::Tan,
+                        Glo::Asin => Mf::Asin,
+                        Glo::Acos => Mf::Acos,
+                        Glo::Atan => Mf::Atan,
+                        Glo::Sinh => Mf::Sinh,
+                        Glo::Cosh => Mf::Cosh,
+                        Glo::Tanh => Mf::Tanh,
+                        Glo::Atan2 => Mf::Atan2,
+                        Glo::Asinh => Mf::Asinh,
+                        Glo::Acosh => Mf::Acosh,
+                        Glo::Atanh => Mf::Atanh,
+                        Glo::Radians => Mf::Radians,
+                        Glo::Degrees => Mf::Degrees,
+                        Glo::Pow => Mf::Pow,
+                        Glo::Exp => Mf::Exp,
+                        Glo::Log => Mf::Log,
+                        Glo::Exp2 => Mf::Exp2,
+                        Glo::Log2 => Mf::Log2,
+                        Glo::Sqrt => Mf::Sqrt,
+                        Glo::InverseSqrt => Mf::InverseSqrt,
+                        Glo::MatrixInverse => Mf::Inverse,
+                        Glo::Determinant => Mf::Determinant,
+                        Glo::ModfStruct => Mf::Modf,
+                        Glo::FMin | Glo::UMin | Glo::SMin | Glo::NMin => Mf::Min,
+                        Glo::FMax | Glo::UMax | Glo::SMax | Glo::NMax => Mf::Max,
+                        Glo::FClamp | Glo::UClamp | Glo::SClamp | Glo::NClamp => Mf::Clamp,
+                        Glo::FMix => Mf::Mix,
+                        Glo::Step => Mf::Step,
+                        Glo::SmoothStep => Mf::SmoothStep,
+                        Glo::Fma => Mf::Fma,
+                        Glo::FrexpStruct => Mf::Frexp,
+                        Glo::Ldexp => Mf::Ldexp,
+                        Glo::Length => Mf::Length,
+                        Glo::Distance => Mf::Distance,
+                        Glo::Cross => Mf::Cross,
+                        Glo::Normalize => Mf::Normalize,
+                        Glo::FaceForward => Mf::FaceForward,
+                        Glo::Reflect => Mf::Reflect,
+                        Glo::Refract => Mf::Refract,
+                        Glo::PackUnorm4x8 => Mf::Pack4x8unorm,
+                        Glo::PackSnorm4x8 => Mf::Pack4x8snorm,
+                        Glo::PackHalf2x16 => Mf::Pack2x16float,
+                        Glo::PackUnorm2x16 => Mf::Pack2x16unorm,
+                        Glo::PackSnorm2x16 => Mf::Pack2x16snorm,
+                        Glo::UnpackUnorm4x8 => Mf::Unpack4x8unorm,
+                        Glo::UnpackSnorm4x8 => Mf::Unpack4x8snorm,
+                        Glo::UnpackHalf2x16 => Mf::Unpack2x16float,
+                        Glo::UnpackUnorm2x16 => Mf::Unpack2x16unorm,
+                        Glo::UnpackSnorm2x16 => Mf::Unpack2x16snorm,
+                        Glo::FindILsb => Mf::FindLsb,
+                        Glo::FindUMsb | Glo::FindSMsb => Mf::FindMsb,
+                        // TODO: https://github.com/gfx-rs/naga/issues/2526
+                        Glo::Modf | Glo::Frexp => return Err(Error::UnsupportedExtInst(inst_id)),
+                        Glo::IMix
+                        | Glo::PackDouble2x32
+                        | Glo::UnpackDouble2x32
+                        | Glo::InterpolateAtCentroid
+                        | Glo::InterpolateAtSample
+                        | Glo::InterpolateAtOffset => {
+                            return Err(Error::UnsupportedExtInst(inst_id))
+                        }
+                    };
+
+                    let arg_count = fun.argument_count();
+                    inst.expect(base_wc + arg_count as u16)?;
+                    let arg = {
+                        let arg_id = self.next()?;
+                        let lexp = self.lookup_expression.lookup(arg_id)?;
+                        get_expr_handle!(arg_id, lexp)
+                    };
+                    let arg1 = if arg_count > 1 {
+                        let arg_id = self.next()?;
+                        let lexp = self.lookup_expression.lookup(arg_id)?;
+                        Some(get_expr_handle!(arg_id, lexp))
+                    } else {
+                        None
+                    };
+                    let arg2 = if arg_count > 2 {
+                        let arg_id = self.next()?;
+                        let lexp = self.lookup_expression.lookup(arg_id)?;
+                        Some(get_expr_handle!(arg_id, lexp))
+                    } else {
+                        None
+                    };
+                    let arg3 = if arg_count > 3 {
+                        let arg_id = self.next()?;
+                        let lexp = self.lookup_expression.lookup(arg_id)?;
+                        Some(get_expr_handle!(arg_id, lexp))
+                    } else {
+                        None
+                    };
+
+                    let expr = crate::Expression::Math {
+                        fun,
+                        arg,
+                        arg1,
+                        arg2,
+                        arg3,
+                    };
+                    self.lookup_expression.insert(
+                        result_id,
+                        LookupExpression {
+                            handle: ctx.expressions.append(expr, span),
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                }
+                // Relational and Logical Instructions
+                Op::LogicalNot => {
+                    inst.expect(4)?;
+                    parse_expr_op!(crate::UnaryOperator::LogicalNot, UNARY)?;
+                }
+                Op::LogicalOr => {
+                    inst.expect(5)?;
+                    parse_expr_op!(crate::BinaryOperator::LogicalOr, BINARY)?;
+                }
+                Op::LogicalAnd => {
+                    inst.expect(5)?;
+                    parse_expr_op!(crate::BinaryOperator::LogicalAnd, BINARY)?;
+                }
+                Op::SGreaterThan | Op::SGreaterThanEqual | Op::SLessThan | Op::SLessThanEqual => {
+                    inst.expect(5)?;
+                    self.parse_expr_int_comparison(
+                        ctx,
+                        &mut emitter,
+                        &mut block,
+                        block_id,
+                        body_idx,
+                        map_binary_operator(inst.op)?,
+                        crate::ScalarKind::Sint,
+                    )?;
+                }
+                Op::UGreaterThan | Op::UGreaterThanEqual | Op::ULessThan | Op::ULessThanEqual => {
+                    inst.expect(5)?;
+                    self.parse_expr_int_comparison(
+                        ctx,
+                        &mut emitter,
+                        &mut block,
+                        block_id,
+                        body_idx,
+                        map_binary_operator(inst.op)?,
+                        crate::ScalarKind::Uint,
+                    )?;
+                }
+                Op::FOrdEqual
+                | Op::FUnordEqual
+                | Op::FOrdNotEqual
+                | Op::FUnordNotEqual
+                | Op::FOrdLessThan
+                | Op::FUnordLessThan
+                | Op::FOrdGreaterThan
+                | Op::FUnordGreaterThan
+                | Op::FOrdLessThanEqual
+                | Op::FUnordLessThanEqual
+                | Op::FOrdGreaterThanEqual
+                | Op::FUnordGreaterThanEqual
+                | Op::LogicalEqual
+                | Op::LogicalNotEqual => {
+                    inst.expect(5)?;
+                    let operator = map_binary_operator(inst.op)?;
+                    parse_expr_op!(operator, BINARY)?;
+                }
+                Op::Any | Op::All | Op::IsNan | Op::IsInf | Op::IsFinite | Op::IsNormal => {
+                    inst.expect(4)?;
+                    let result_type_id = self.next()?;
+                    let result_id = self.next()?;
+                    let arg_id = self.next()?;
+
+                    let arg_lexp = self.lookup_expression.lookup(arg_id)?;
+                    let arg_handle = get_expr_handle!(arg_id, arg_lexp);
+
+                    let expr = crate::Expression::Relational {
+                        fun: map_relational_fun(inst.op)?,
+                        argument: arg_handle,
+                    };
+                    self.lookup_expression.insert(
+                        result_id,
+                        LookupExpression {
+                            handle: ctx.expressions.append(expr, span),
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                }
+                Op::Kill => {
+                    inst.expect(1)?;
+                    break Some(crate::Statement::Kill);
+                }
+                Op::Unreachable => {
+                    inst.expect(1)?;
+                    break None;
+                }
+                Op::Return => {
+                    inst.expect(1)?;
+                    break Some(crate::Statement::Return { value: None });
+                }
+                Op::ReturnValue => {
+                    inst.expect(2)?;
+                    let value_id = self.next()?;
+                    let value_lexp = self.lookup_expression.lookup(value_id)?;
+                    let value_handle = get_expr_handle!(value_id, value_lexp);
+                    break Some(crate::Statement::Return {
+                        value: Some(value_handle),
+                    });
+                }
+                Op::Branch => {
+                    inst.expect(2)?;
+                    let target_id = self.next()?;
+
+                    // If this is a branch to a merge or continue block, then
+                    // that ends the current body.
+                    //
+                    // Why can we count on finding an entry here when it's
+                    // needed? SPIR-V requires dominators to appear before
+                    // blocks they dominate, so we will have visited a
+                    // structured control construct's header block before
+                    // anything that could exit it.
+                    if let Some(info) = ctx.mergers.get(&target_id) {
+                        block.extend(emitter.finish(ctx.expressions));
+                        ctx.blocks.insert(block_id, block);
+                        let body = &mut ctx.bodies[body_idx];
+                        body.data.push(BodyFragment::BlockId(block_id));
+
+                        merger(body, info);
+
+                        return Ok(());
+                    }
+
+                    // If `target_id` has no entry in `ctx.body_for_label`, then
+                    // this must be the only branch to it:
+                    //
+                    // - We've already established that it's not anybody's merge
+                    //   block.
+                    //
+                    // - It can't be a switch case. Only switch header blocks
+                    //   and other switch cases can branch to a switch case.
+                    //   Switch header blocks must dominate all their cases, so
+                    //   they must appear in the file before them, and when we
+                    //   see `Op::Switch` we populate `ctx.body_for_label` for
+                    //   every switch case.
+                    //
+                    // Thus, `target_id` must be a simple extension of the
+                    // current block, which we dominate, so we know we'll
+                    // encounter it later in the file.
+                    ctx.body_for_label.entry(target_id).or_insert(body_idx);
+
+                    break None;
+                }
+                Op::BranchConditional => {
+                    inst.expect_at_least(4)?;
+
+                    let condition = {
+                        let condition_id = self.next()?;
+                        let lexp = self.lookup_expression.lookup(condition_id)?;
+                        get_expr_handle!(condition_id, lexp)
+                    };
+
+                    // HACK(eddyb) Naga doesn't seem to have this helper,
+                    // so it's declared on the fly here for convenience.
+                    #[derive(Copy, Clone)]
+                    struct BranchTarget {
+                        label_id: spirv::Word,
+                        merge_info: Option<MergeBlockInformation>,
+                    }
+                    let branch_target = |label_id| BranchTarget {
+                        label_id,
+                        merge_info: ctx.mergers.get(&label_id).copied(),
+                    };
+
+                    let true_target = branch_target(self.next()?);
+                    let false_target = branch_target(self.next()?);
+
+                    // Consume branch weights
+                    for _ in 4..inst.wc {
+                        let _ = self.next()?;
+                    }
+
+                    // Handle `OpBranchConditional`s used at the end of a loop
+                    // body's "continuing" section as a "conditional backedge",
+                    // i.e. a `do`-`while` condition, or `break if` in WGSL.
+
+                    // HACK(eddyb) this has to go to the parent *twice*, because
+                    // `OpLoopMerge` left the "continuing" section nested in the
+                    // loop body in terms of `parent`, but not `BodyFragment`.
+                    let parent_body_idx = ctx.bodies[body_idx].parent;
+                    let parent_parent_body_idx = ctx.bodies[parent_body_idx].parent;
+                    match ctx.bodies[parent_parent_body_idx].data[..] {
+                        // The `OpLoopMerge`'s `continuing` block and the loop's
+                        // backedge block may not be the same, but they'll both
+                        // belong to the same body.
+                        [.., BodyFragment::Loop {
+                            body: loop_body_idx,
+                            continuing: loop_continuing_idx,
+                            break_if: ref mut break_if_slot @ None,
+                        }] if body_idx == loop_continuing_idx => {
+                            // Try both orderings of break-vs-backedge, because
+                            // SPIR-V is symmetrical here, unlike WGSL `break if`.
+                            let break_if_cond = [true, false].into_iter().find_map(|true_breaks| {
+                                let (break_candidate, backedge_candidate) = if true_breaks {
+                                    (true_target, false_target)
+                                } else {
+                                    (false_target, true_target)
+                                };
+
+                                if break_candidate.merge_info
+                                    != Some(MergeBlockInformation::LoopMerge)
+                                {
+                                    return None;
+                                }
+
+                                // HACK(eddyb) since Naga doesn't explicitly track
+                                // backedges, this is checking for the outcome of
+                                // `OpLoopMerge` below (even if it looks weird).
+                                let backedge_candidate_is_backedge =
+                                    backedge_candidate.merge_info.is_none()
+                                        && ctx.body_for_label.get(&backedge_candidate.label_id)
+                                            == Some(&loop_body_idx);
+                                if !backedge_candidate_is_backedge {
+                                    return None;
+                                }
+
+                                Some(if true_breaks {
+                                    condition
+                                } else {
+                                    ctx.expressions.append(
+                                        crate::Expression::Unary {
+                                            op: crate::UnaryOperator::LogicalNot,
+                                            expr: condition,
+                                        },
+                                        span,
+                                    )
+                                })
+                            });
+
+                            if let Some(break_if_cond) = break_if_cond {
+                                *break_if_slot = Some(break_if_cond);
+
+                                // This `OpBranchConditional` ends the "continuing"
+                                // section of the loop body as normal, with the
+                                // `break if` condition having been stashed above.
+                                break None;
+                            }
+                        }
+                        _ => {}
+                    }
+
+                    block.extend(emitter.finish(ctx.expressions));
+                    ctx.blocks.insert(block_id, block);
+                    let body = &mut ctx.bodies[body_idx];
+                    body.data.push(BodyFragment::BlockId(block_id));
+
+                    let same_target = true_target.label_id == false_target.label_id;
+
+                    // Start a body block for the `accept` branch.
+                    let accept = ctx.bodies.len();
+                    let mut accept_block = Body::with_parent(body_idx);
+
+                    // If the `OpBranchConditional` target is somebody else's
+                    // merge or continue block, then put a `Break` or `Continue`
+                    // statement in this new body block.
+                    if let Some(info) = true_target.merge_info {
+                        merger(
+                            match same_target {
+                                true => &mut ctx.bodies[body_idx],
+                                false => &mut accept_block,
+                            },
+                            &info,
+                        )
+                    } else {
+                        // Note the body index for the block we're branching to.
+                        let prev = ctx.body_for_label.insert(
+                            true_target.label_id,
+                            match same_target {
+                                true => body_idx,
+                                false => accept,
+                            },
+                        );
+                        debug_assert!(prev.is_none());
+                    }
+
+                    if same_target {
+                        return Ok(());
+                    }
+
+                    ctx.bodies.push(accept_block);
+
+                    // Handle the `reject` branch just like the `accept` block.
+                    let reject = ctx.bodies.len();
+                    let mut reject_block = Body::with_parent(body_idx);
+
+                    if let Some(info) = false_target.merge_info {
+                        merger(&mut reject_block, &info)
+                    } else {
+                        let prev = ctx.body_for_label.insert(false_target.label_id, reject);
+                        debug_assert!(prev.is_none());
+                    }
+
+                    ctx.bodies.push(reject_block);
+
+                    let body = &mut ctx.bodies[body_idx];
+                    body.data.push(BodyFragment::If {
+                        condition,
+                        accept,
+                        reject,
+                    });
+
+                    return Ok(());
+                }
+                Op::Switch => {
+                    inst.expect_at_least(3)?;
+                    let selector = self.next()?;
+                    let default_id = self.next()?;
+
+                    // If the previous instruction was a `OpSelectionMerge` then we must
+                    // promote the `MergeBlockInformation` to a `SwitchMerge`
+                    if let Some(merge) = selection_merge_block {
+                        ctx.mergers
+                            .insert(merge, MergeBlockInformation::SwitchMerge);
+                    }
+
+                    let default = ctx.bodies.len();
+                    ctx.bodies.push(Body::with_parent(body_idx));
+                    ctx.body_for_label.entry(default_id).or_insert(default);
+
+                    let selector_lexp = &self.lookup_expression[&selector];
+                    let selector_lty = self.lookup_type.lookup(selector_lexp.type_id)?;
+                    let selector_handle = get_expr_handle!(selector, selector_lexp);
+                    let selector = match ctx.type_arena[selector_lty.handle].inner {
+                        crate::TypeInner::Scalar(crate::Scalar {
+                            kind: crate::ScalarKind::Uint,
+                            width: _,
+                        }) => {
+                            // IR expects a signed integer, so do a bitcast
+                            ctx.expressions.append(
+                                crate::Expression::As {
+                                    kind: crate::ScalarKind::Sint,
+                                    expr: selector_handle,
+                                    convert: None,
+                                },
+                                span,
+                            )
+                        }
+                        crate::TypeInner::Scalar(crate::Scalar {
+                            kind: crate::ScalarKind::Sint,
+                            width: _,
+                        }) => selector_handle,
+                        ref other => unimplemented!("Unexpected selector {:?}", other),
+                    };
+
+                    // Clear past switch cases to prevent them from entering this one
+                    self.switch_cases.clear();
+
+                    for _ in 0..(inst.wc - 3) / 2 {
+                        let literal = self.next()?;
+                        let target = self.next()?;
+
+                        let case_body_idx = ctx.bodies.len();
+
+                        // Check if any previous case already used this target block id, if so
+                        // group them together to reorder them later so that no weird
+                        // fallthrough cases happen.
+                        if let Some(&mut (_, ref mut literals)) = self.switch_cases.get_mut(&target)
+                        {
+                            literals.push(literal as i32);
+                            continue;
+                        }
+
+                        let mut body = Body::with_parent(body_idx);
+
+                        if let Some(info) = ctx.mergers.get(&target) {
+                            merger(&mut body, info);
+                        }
+
+                        ctx.bodies.push(body);
+                        ctx.body_for_label.entry(target).or_insert(case_body_idx);
+
+                        // Register this target block id as already having been processed and
+                        // the respective body index assigned and the first case value
+                        self.switch_cases
+                            .insert(target, (case_body_idx, vec![literal as i32]));
+                    }
+
+                    // Loop trough the collected target blocks creating a new case for each
+                    // literal pointing to it, only one case will have the true body and all the
+                    // others will be empty fallthrough so that they all execute the same body
+                    // without duplicating code.
+                    //
+                    // Since `switch_cases` is an indexmap the order of insertion is preserved
+                    // this is needed because spir-v defines fallthrough order in the switch
+                    // instruction.
+                    let mut cases = Vec::with_capacity((inst.wc as usize - 3) / 2);
+                    for &(case_body_idx, ref literals) in self.switch_cases.values() {
+                        let value = literals[0];
+
+                        for &literal in literals.iter().skip(1) {
+                            let empty_body_idx = ctx.bodies.len();
+                            let body = Body::with_parent(body_idx);
+
+                            ctx.bodies.push(body);
+
+                            cases.push((literal, empty_body_idx));
+                        }
+
+                        cases.push((value, case_body_idx));
+                    }
+
+                    block.extend(emitter.finish(ctx.expressions));
+
+                    let body = &mut ctx.bodies[body_idx];
+                    ctx.blocks.insert(block_id, block);
+                    // Make sure the vector has space for at least two more allocations
+                    body.data.reserve(2);
+                    body.data.push(BodyFragment::BlockId(block_id));
+                    body.data.push(BodyFragment::Switch {
+                        selector,
+                        cases,
+                        default,
+                    });
+
+                    return Ok(());
+                }
+                Op::SelectionMerge => {
+                    inst.expect(3)?;
+                    let merge_block_id = self.next()?;
+                    // TODO: Selection Control Mask
+                    let _selection_control = self.next()?;
+
+                    // Indicate that the merge block is a continuation of the
+                    // current `Body`.
+                    ctx.body_for_label.entry(merge_block_id).or_insert(body_idx);
+
+                    // Let subsequent branches to the merge block know that
+                    // they've reached the end of the selection construct.
+                    ctx.mergers
+                        .insert(merge_block_id, MergeBlockInformation::SelectionMerge);
+
+                    selection_merge_block = Some(merge_block_id);
+                }
+                Op::LoopMerge => {
+                    inst.expect_at_least(4)?;
+                    let merge_block_id = self.next()?;
+                    let continuing = self.next()?;
+
+                    // TODO: Loop Control Parameters
+                    for _ in 0..inst.wc - 3 {
+                        self.next()?;
+                    }
+
+                    // Indicate that the merge block is a continuation of the
+                    // current `Body`.
+                    ctx.body_for_label.entry(merge_block_id).or_insert(body_idx);
+                    // Let subsequent branches to the merge block know that
+                    // they're `Break` statements.
+                    ctx.mergers
+                        .insert(merge_block_id, MergeBlockInformation::LoopMerge);
+
+                    let loop_body_idx = ctx.bodies.len();
+                    ctx.bodies.push(Body::with_parent(body_idx));
+
+                    let continue_idx = ctx.bodies.len();
+                    // The continue block inherits the scope of the loop body
+                    ctx.bodies.push(Body::with_parent(loop_body_idx));
+                    ctx.body_for_label.entry(continuing).or_insert(continue_idx);
+                    // Let subsequent branches to the continue block know that
+                    // they're `Continue` statements.
+                    ctx.mergers
+                        .insert(continuing, MergeBlockInformation::LoopContinue);
+
+                    // The loop header always belongs to the loop body
+                    ctx.body_for_label.insert(block_id, loop_body_idx);
+
+                    let parent_body = &mut ctx.bodies[body_idx];
+                    parent_body.data.push(BodyFragment::Loop {
+                        body: loop_body_idx,
+                        continuing: continue_idx,
+                        break_if: None,
+                    });
+                    body_idx = loop_body_idx;
+                }
+                Op::DPdxCoarse => {
+                    parse_expr_op!(
+                        crate::DerivativeAxis::X,
+                        crate::DerivativeControl::Coarse,
+                        DERIVATIVE
+                    )?;
+                }
+                Op::DPdyCoarse => {
+                    parse_expr_op!(
+                        crate::DerivativeAxis::Y,
+                        crate::DerivativeControl::Coarse,
+                        DERIVATIVE
+                    )?;
+                }
+                Op::FwidthCoarse => {
+                    parse_expr_op!(
+                        crate::DerivativeAxis::Width,
+                        crate::DerivativeControl::Coarse,
+                        DERIVATIVE
+                    )?;
+                }
+                Op::DPdxFine => {
+                    parse_expr_op!(
+                        crate::DerivativeAxis::X,
+                        crate::DerivativeControl::Fine,
+                        DERIVATIVE
+                    )?;
+                }
+                Op::DPdyFine => {
+                    parse_expr_op!(
+                        crate::DerivativeAxis::Y,
+                        crate::DerivativeControl::Fine,
+                        DERIVATIVE
+                    )?;
+                }
+                Op::FwidthFine => {
+                    parse_expr_op!(
+                        crate::DerivativeAxis::Width,
+                        crate::DerivativeControl::Fine,
+                        DERIVATIVE
+                    )?;
+                }
+                Op::DPdx => {
+                    parse_expr_op!(
+                        crate::DerivativeAxis::X,
+                        crate::DerivativeControl::None,
+                        DERIVATIVE
+                    )?;
+                }
+                Op::DPdy => {
+                    parse_expr_op!(
+                        crate::DerivativeAxis::Y,
+                        crate::DerivativeControl::None,
+                        DERIVATIVE
+                    )?;
+                }
+                Op::Fwidth => {
+                    parse_expr_op!(
+                        crate::DerivativeAxis::Width,
+                        crate::DerivativeControl::None,
+                        DERIVATIVE
+                    )?;
+                }
+                Op::ArrayLength => {
+                    inst.expect(5)?;
+                    let result_type_id = self.next()?;
+                    let result_id = self.next()?;
+                    let structure_id = self.next()?;
+                    let member_index = self.next()?;
+
+                    // We're assuming that the validation pass, if it's run, will catch if the
+                    // wrong types or parameters are supplied here.
+
+                    let structure_ptr = self.lookup_expression.lookup(structure_id)?;
+                    let structure_handle = get_expr_handle!(structure_id, structure_ptr);
+
+                    let member_ptr = ctx.expressions.append(
+                        crate::Expression::AccessIndex {
+                            base: structure_handle,
+                            index: member_index,
+                        },
+                        span,
+                    );
+
+                    let length = ctx
+                        .expressions
+                        .append(crate::Expression::ArrayLength(member_ptr), span);
+
+                    self.lookup_expression.insert(
+                        result_id,
+                        LookupExpression {
+                            handle: length,
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                }
+                Op::CopyMemory => {
+                    inst.expect_at_least(3)?;
+                    let target_id = self.next()?;
+                    let source_id = self.next()?;
+                    let _memory_access = if inst.wc != 3 {
+                        inst.expect(4)?;
+                        spirv::MemoryAccess::from_bits(self.next()?)
+                            .ok_or(Error::InvalidParameter(Op::CopyMemory))?
+                    } else {
+                        spirv::MemoryAccess::NONE
+                    };
+
+                    // TODO: check if the source and target types are the same?
+                    let target = self.lookup_expression.lookup(target_id)?;
+                    let target_handle = get_expr_handle!(target_id, target);
+                    let source = self.lookup_expression.lookup(source_id)?;
+                    let source_handle = get_expr_handle!(source_id, source);
+
+                    // This operation is practically the same as loading and then storing, I think.
+                    let value_expr = ctx.expressions.append(
+                        crate::Expression::Load {
+                            pointer: source_handle,
+                        },
+                        span,
+                    );
+
+                    block.extend(emitter.finish(ctx.expressions));
+                    block.push(
+                        crate::Statement::Store {
+                            pointer: target_handle,
+                            value: value_expr,
+                        },
+                        span,
+                    );
+
+                    emitter.start(ctx.expressions);
+                }
+                Op::ControlBarrier => {
+                    inst.expect(4)?;
+                    let exec_scope_id = self.next()?;
+                    let _mem_scope_raw = self.next()?;
+                    let semantics_id = self.next()?;
+                    let exec_scope_const = self.lookup_constant.lookup(exec_scope_id)?;
+                    let semantics_const = self.lookup_constant.lookup(semantics_id)?;
+
+                    let exec_scope = resolve_constant(ctx.gctx(), exec_scope_const.handle)
+                        .ok_or(Error::InvalidBarrierScope(exec_scope_id))?;
+                    let semantics = resolve_constant(ctx.gctx(), semantics_const.handle)
+                        .ok_or(Error::InvalidBarrierMemorySemantics(semantics_id))?;
+
+                    if exec_scope == spirv::Scope::Workgroup as u32 {
+                        let mut flags = crate::Barrier::empty();
+                        flags.set(
+                            crate::Barrier::STORAGE,
+                            semantics & spirv::MemorySemantics::UNIFORM_MEMORY.bits() != 0,
+                        );
+                        flags.set(
+                            crate::Barrier::WORK_GROUP,
+                            semantics
+                                & (spirv::MemorySemantics::SUBGROUP_MEMORY
+                                    | spirv::MemorySemantics::WORKGROUP_MEMORY)
+                                    .bits()
+                                != 0,
+                        );
+                        block.push(crate::Statement::Barrier(flags), span);
+                    } else {
+                        log::warn!("Unsupported barrier execution scope: {}", exec_scope);
+                    }
+                }
+                Op::CopyObject => {
+                    inst.expect(4)?;
+                    let result_type_id = self.next()?;
+                    let result_id = self.next()?;
+                    let operand_id = self.next()?;
+
+                    let lookup = self.lookup_expression.lookup(operand_id)?;
+                    let handle = get_expr_handle!(operand_id, lookup);
+
+                    self.lookup_expression.insert(
+                        result_id,
+                        LookupExpression {
+                            handle,
+                            type_id: result_type_id,
+                            block_id,
+                        },
+                    );
+                }
+                _ => return Err(Error::UnsupportedInstruction(self.state, inst.op)),
+            }
+        };
+
+        block.extend(emitter.finish(ctx.expressions));
+        if let Some(stmt) = terminator {
+            block.push(stmt, crate::Span::default());
+        }
+
+        // Save this block fragment in `block_ctx.blocks`, and mark it to be
+        // incorporated into the current body at `Statement` assembly time.
+        ctx.blocks.insert(block_id, block);
+        let body = &mut ctx.bodies[body_idx];
+        body.data.push(BodyFragment::BlockId(block_id));
+        Ok(())
+    }
+
+    fn make_expression_storage(
+        &mut self,
+        globals: &Arena<crate::GlobalVariable>,
+        constants: &Arena<crate::Constant>,
+    ) -> Arena<crate::Expression> {
+        let mut expressions = Arena::new();
+        #[allow(clippy::panic)]
+        {
+            assert!(self.lookup_expression.is_empty());
+        }
+        // register global variables
+        for (&id, var) in self.lookup_variable.iter() {
+            let span = globals.get_span(var.handle);
+            let handle = expressions.append(crate::Expression::GlobalVariable(var.handle), span);
+            self.lookup_expression.insert(
+                id,
+                LookupExpression {
+                    type_id: var.type_id,
+                    handle,
+                    // Setting this to an invalid id will cause get_expr_handle
+                    // to default to the main body making sure no load/stores
+                    // are added.
+                    block_id: 0,
+                },
+            );
+        }
+        // register constants
+        for (&id, con) in self.lookup_constant.iter() {
+            let span = constants.get_span(con.handle);
+            let handle = expressions.append(crate::Expression::Constant(con.handle), span);
+            self.lookup_expression.insert(
+                id,
+                LookupExpression {
+                    type_id: con.type_id,
+                    handle,
+                    // Setting this to an invalid id will cause get_expr_handle
+                    // to default to the main body making sure no load/stores
+                    // are added.
+                    block_id: 0,
+                },
+            );
+        }
+        // done
+        expressions
+    }
+
+    fn switch(&mut self, state: ModuleState, op: spirv::Op) -> Result<(), Error> {
+        if state < self.state {
+            Err(Error::UnsupportedInstruction(self.state, op))
+        } else {
+            self.state = state;
+            Ok(())
+        }
+    }
+
+    /// Walk the statement tree and patch it in the following cases:
+    /// 1. Function call targets are replaced by `deferred_function_calls` map
+    fn patch_statements(
+        &mut self,
+        statements: &mut crate::Block,
+        expressions: &mut Arena<crate::Expression>,
+        fun_parameter_sampling: &mut [image::SamplingFlags],
+    ) -> Result<(), Error> {
+        use crate::Statement as S;
+        let mut i = 0usize;
+        while i < statements.len() {
+            match statements[i] {
+                S::Emit(_) => {}
+                S::Block(ref mut block) => {
+                    self.patch_statements(block, expressions, fun_parameter_sampling)?;
+                }
+                S::If {
+                    condition: _,
+                    ref mut accept,
+                    ref mut reject,
+                } => {
+                    self.patch_statements(reject, expressions, fun_parameter_sampling)?;
+                    self.patch_statements(accept, expressions, fun_parameter_sampling)?;
+                }
+                S::Switch {
+                    selector: _,
+                    ref mut cases,
+                } => {
+                    for case in cases.iter_mut() {
+                        self.patch_statements(&mut case.body, expressions, fun_parameter_sampling)?;
+                    }
+                }
+                S::Loop {
+                    ref mut body,
+                    ref mut continuing,
+                    break_if: _,
+                } => {
+                    self.patch_statements(body, expressions, fun_parameter_sampling)?;
+                    self.patch_statements(continuing, expressions, fun_parameter_sampling)?;
+                }
+                S::Break
+                | S::Continue
+                | S::Return { .. }
+                | S::Kill
+                | S::Barrier(_)
+                | S::Store { .. }
+                | S::ImageStore { .. }
+                | S::Atomic { .. }
+                | S::RayQuery { .. } => {}
+                S::Call {
+                    function: ref mut callee,
+                    ref arguments,
+                    ..
+                } => {
+                    let fun_id = self.deferred_function_calls[callee.index()];
+                    let fun_lookup = self.lookup_function.lookup(fun_id)?;
+                    *callee = fun_lookup.handle;
+
+                    // Patch sampling flags
+                    for (arg_index, arg) in arguments.iter().enumerate() {
+                        let flags = match fun_lookup.parameters_sampling.get(arg_index) {
+                            Some(&flags) if !flags.is_empty() => flags,
+                            _ => continue,
+                        };
+
+                        match expressions[*arg] {
+                            crate::Expression::GlobalVariable(handle) => {
+                                if let Some(sampling) = self.handle_sampling.get_mut(&handle) {
+                                    *sampling |= flags
+                                }
+                            }
+                            crate::Expression::FunctionArgument(i) => {
+                                fun_parameter_sampling[i as usize] |= flags;
+                            }
+                            ref other => return Err(Error::InvalidGlobalVar(other.clone())),
+                        }
+                    }
+                }
+                S::WorkGroupUniformLoad { .. } => unreachable!(),
+            }
+            i += 1;
+        }
+        Ok(())
+    }
+
+    fn patch_function(
+        &mut self,
+        handle: Option<Handle<crate::Function>>,
+        fun: &mut crate::Function,
+    ) -> Result<(), Error> {
+        // Note: this search is a bit unfortunate
+        let (fun_id, mut parameters_sampling) = match handle {
+            Some(h) => {
+                let (&fun_id, lookup) = self
+                    .lookup_function
+                    .iter_mut()
+                    .find(|&(_, ref lookup)| lookup.handle == h)
+                    .unwrap();
+                (fun_id, mem::take(&mut lookup.parameters_sampling))
+            }
+            None => (0, Vec::new()),
+        };
+
+        for (_, expr) in fun.expressions.iter_mut() {
+            if let crate::Expression::CallResult(ref mut function) = *expr {
+                let fun_id = self.deferred_function_calls[function.index()];
+                *function = self.lookup_function.lookup(fun_id)?.handle;
+            }
+        }
+
+        self.patch_statements(
+            &mut fun.body,
+            &mut fun.expressions,
+            &mut parameters_sampling,
+        )?;
+
+        if let Some(lookup) = self.lookup_function.get_mut(&fun_id) {
+            lookup.parameters_sampling = parameters_sampling;
+        }
+        Ok(())
+    }
+
+    pub fn parse(mut self) -> Result<crate::Module, Error> {
+        let mut module = {
+            if self.next()? != spirv::MAGIC_NUMBER {
+                return Err(Error::InvalidHeader);
+            }
+            let version_raw = self.next()?;
+            let generator = self.next()?;
+            let _bound = self.next()?;
+            let _schema = self.next()?;
+            log::info!("Generated by {} version {:x}", generator, version_raw);
+            crate::Module::default()
+        };
+
+        self.layouter.clear();
+        self.dummy_functions = Arena::new();
+        self.lookup_function.clear();
+        self.function_call_graph.clear();
+
+        loop {
+            use spirv::Op;
+
+            let inst = match self.next_inst() {
+                Ok(inst) => inst,
+                Err(Error::IncompleteData) => break,
+                Err(other) => return Err(other),
+            };
+            log::debug!("\t{:?} [{}]", inst.op, inst.wc);
+
+            match inst.op {
+                Op::Capability => self.parse_capability(inst),
+                Op::Extension => self.parse_extension(inst),
+                Op::ExtInstImport => self.parse_ext_inst_import(inst),
+                Op::MemoryModel => self.parse_memory_model(inst),
+                Op::EntryPoint => self.parse_entry_point(inst),
+                Op::ExecutionMode => self.parse_execution_mode(inst),
+                Op::String => self.parse_string(inst),
+                Op::Source => self.parse_source(inst),
+                Op::SourceExtension => self.parse_source_extension(inst),
+                Op::Name => self.parse_name(inst),
+                Op::MemberName => self.parse_member_name(inst),
+                Op::ModuleProcessed => self.parse_module_processed(inst),
+                Op::Decorate => self.parse_decorate(inst),
+                Op::MemberDecorate => self.parse_member_decorate(inst),
+                Op::TypeVoid => self.parse_type_void(inst),
+                Op::TypeBool => self.parse_type_bool(inst, &mut module),
+                Op::TypeInt => self.parse_type_int(inst, &mut module),
+                Op::TypeFloat => self.parse_type_float(inst, &mut module),
+                Op::TypeVector => self.parse_type_vector(inst, &mut module),
+                Op::TypeMatrix => self.parse_type_matrix(inst, &mut module),
+                Op::TypeFunction => self.parse_type_function(inst),
+                Op::TypePointer => self.parse_type_pointer(inst, &mut module),
+                Op::TypeArray => self.parse_type_array(inst, &mut module),
+                Op::TypeRuntimeArray => self.parse_type_runtime_array(inst, &mut module),
+                Op::TypeStruct => self.parse_type_struct(inst, &mut module),
+                Op::TypeImage => self.parse_type_image(inst, &mut module),
+                Op::TypeSampledImage => self.parse_type_sampled_image(inst),
+                Op::TypeSampler => self.parse_type_sampler(inst, &mut module),
+                Op::Constant | Op::SpecConstant => self.parse_constant(inst, &mut module),
+                Op::ConstantComposite => self.parse_composite_constant(inst, &mut module),
+                Op::ConstantNull | Op::Undef => self.parse_null_constant(inst, &mut module),
+                Op::ConstantTrue => self.parse_bool_constant(inst, true, &mut module),
+                Op::ConstantFalse => self.parse_bool_constant(inst, false, &mut module),
+                Op::Variable => self.parse_global_variable(inst, &mut module),
+                Op::Function => {
+                    self.switch(ModuleState::Function, inst.op)?;
+                    inst.expect(5)?;
+                    self.parse_function(&mut module)
+                }
+                _ => Err(Error::UnsupportedInstruction(self.state, inst.op)), //TODO
+            }?;
+        }
+
+        log::info!("Patching...");
+        {
+            let mut nodes = petgraph::algo::toposort(&self.function_call_graph, None)
+                .map_err(|cycle| Error::FunctionCallCycle(cycle.node_id()))?;
+            nodes.reverse(); // we need dominated first
+            let mut functions = mem::take(&mut module.functions);
+            for fun_id in nodes {
+                if fun_id > !(functions.len() as u32) {
+                    // skip all the fake IDs registered for the entry points
+                    continue;
+                }
+                let lookup = self.lookup_function.get_mut(&fun_id).unwrap();
+                // take out the function from the old array
+                let fun = mem::take(&mut functions[lookup.handle]);
+                // add it to the newly formed arena, and adjust the lookup
+                lookup.handle = module
+                    .functions
+                    .append(fun, functions.get_span(lookup.handle));
+            }
+        }
+        // patch all the functions
+        for (handle, fun) in module.functions.iter_mut() {
+            self.patch_function(Some(handle), fun)?;
+        }
+        for ep in module.entry_points.iter_mut() {
+            self.patch_function(None, &mut ep.function)?;
+        }
+
+        // Check all the images and samplers to have consistent comparison property.
+        for (handle, flags) in self.handle_sampling.drain() {
+            if !image::patch_comparison_type(
+                flags,
+                module.global_variables.get_mut(handle),
+                &mut module.types,
+            ) {
+                return Err(Error::InconsistentComparisonSampling(handle));
+            }
+        }
+
+        if !self.future_decor.is_empty() {
+            log::warn!("Unused item decorations: {:?}", self.future_decor);
+            self.future_decor.clear();
+        }
+        if !self.future_member_decor.is_empty() {
+            log::warn!("Unused member decorations: {:?}", self.future_member_decor);
+            self.future_member_decor.clear();
+        }
+
+        Ok(module)
+    }
+
+    fn parse_capability(&mut self, inst: Instruction) -> Result<(), Error> {
+        self.switch(ModuleState::Capability, inst.op)?;
+        inst.expect(2)?;
+        let capability = self.next()?;
+        let cap =
+            spirv::Capability::from_u32(capability).ok_or(Error::UnknownCapability(capability))?;
+        if !SUPPORTED_CAPABILITIES.contains(&cap) {
+            if self.options.strict_capabilities {
+                return Err(Error::UnsupportedCapability(cap));
+            } else {
+                log::warn!("Unknown capability {:?}", cap);
+            }
+        }
+        Ok(())
+    }
+
+    fn parse_extension(&mut self, inst: Instruction) -> Result<(), Error> {
+        self.switch(ModuleState::Extension, inst.op)?;
+        inst.expect_at_least(2)?;
+        let (name, left) = self.next_string(inst.wc - 1)?;
+        if left != 0 {
+            return Err(Error::InvalidOperand);
+        }
+        if !SUPPORTED_EXTENSIONS.contains(&name.as_str()) {
+            return Err(Error::UnsupportedExtension(name));
+        }
+        Ok(())
+    }
+
+    fn parse_ext_inst_import(&mut self, inst: Instruction) -> Result<(), Error> {
+        self.switch(ModuleState::Extension, inst.op)?;
+        inst.expect_at_least(3)?;
+        let result_id = self.next()?;
+        let (name, left) = self.next_string(inst.wc - 2)?;
+        if left != 0 {
+            return Err(Error::InvalidOperand);
+        }
+        if !SUPPORTED_EXT_SETS.contains(&name.as_str()) {
+            return Err(Error::UnsupportedExtSet(name));
+        }
+        self.ext_glsl_id = Some(result_id);
+        Ok(())
+    }
+
+    fn parse_memory_model(&mut self, inst: Instruction) -> Result<(), Error> {
+        self.switch(ModuleState::MemoryModel, inst.op)?;
+        inst.expect(3)?;
+        let _addressing_model = self.next()?;
+        let _memory_model = self.next()?;
+        Ok(())
+    }
+
+    fn parse_entry_point(&mut self, inst: Instruction) -> Result<(), Error> {
+        self.switch(ModuleState::EntryPoint, inst.op)?;
+        inst.expect_at_least(4)?;
+        let exec_model = self.next()?;
+        let exec_model = spirv::ExecutionModel::from_u32(exec_model)
+            .ok_or(Error::UnsupportedExecutionModel(exec_model))?;
+        let function_id = self.next()?;
+        let (name, left) = self.next_string(inst.wc - 3)?;
+        let ep = EntryPoint {
+            stage: match exec_model {
+                spirv::ExecutionModel::Vertex => crate::ShaderStage::Vertex,
+                spirv::ExecutionModel::Fragment => crate::ShaderStage::Fragment,
+                spirv::ExecutionModel::GLCompute => crate::ShaderStage::Compute,
+                _ => return Err(Error::UnsupportedExecutionModel(exec_model as u32)),
+            },
+            name,
+            early_depth_test: None,
+            workgroup_size: [0; 3],
+            variable_ids: self.data.by_ref().take(left as usize).collect(),
+        };
+        self.lookup_entry_point.insert(function_id, ep);
+        Ok(())
+    }
+
+    fn parse_execution_mode(&mut self, inst: Instruction) -> Result<(), Error> {
+        use spirv::ExecutionMode;
+
+        self.switch(ModuleState::ExecutionMode, inst.op)?;
+        inst.expect_at_least(3)?;
+
+        let ep_id = self.next()?;
+        let mode_id = self.next()?;
+        let args: Vec<spirv::Word> = self.data.by_ref().take(inst.wc as usize - 3).collect();
+
+        let ep = self
+            .lookup_entry_point
+            .get_mut(&ep_id)
+            .ok_or(Error::InvalidId(ep_id))?;
+        let mode = spirv::ExecutionMode::from_u32(mode_id)
+            .ok_or(Error::UnsupportedExecutionMode(mode_id))?;
+
+        match mode {
+            ExecutionMode::EarlyFragmentTests => {
+                if ep.early_depth_test.is_none() {
+                    ep.early_depth_test = Some(crate::EarlyDepthTest { conservative: None });
+                }
+            }
+            ExecutionMode::DepthUnchanged => {
+                ep.early_depth_test = Some(crate::EarlyDepthTest {
+                    conservative: Some(crate::ConservativeDepth::Unchanged),
+                });
+            }
+            ExecutionMode::DepthGreater => {
+                ep.early_depth_test = Some(crate::EarlyDepthTest {
+                    conservative: Some(crate::ConservativeDepth::GreaterEqual),
+                });
+            }
+            ExecutionMode::DepthLess => {
+                ep.early_depth_test = Some(crate::EarlyDepthTest {
+                    conservative: Some(crate::ConservativeDepth::LessEqual),
+                });
+            }
+            ExecutionMode::DepthReplacing => {
+                // Ignored because it can be deduced from the IR.
+            }
+            ExecutionMode::OriginUpperLeft => {
+                // Ignored because the other option (OriginLowerLeft) is not valid in Vulkan mode.
+            }
+            ExecutionMode::LocalSize => {
+                ep.workgroup_size = [args[0], args[1], args[2]];
+            }
+            _ => {
+                return Err(Error::UnsupportedExecutionMode(mode_id));
+            }
+        }
+
+        Ok(())
+    }
+
+    fn parse_string(&mut self, inst: Instruction) -> Result<(), Error> {
+        self.switch(ModuleState::Source, inst.op)?;
+        inst.expect_at_least(3)?;
+        let _id = self.next()?;
+        let (_name, _) = self.next_string(inst.wc - 2)?;
+        Ok(())
+    }
+
+    fn parse_source(&mut self, inst: Instruction) -> Result<(), Error> {
+        self.switch(ModuleState::Source, inst.op)?;
+        for _ in 1..inst.wc {
+            let _ = self.next()?;
+        }
+        Ok(())
+    }
+
+    fn parse_source_extension(&mut self, inst: Instruction) -> Result<(), Error> {
+        self.switch(ModuleState::Source, inst.op)?;
+        inst.expect_at_least(2)?;
+        let (_name, _) = self.next_string(inst.wc - 1)?;
+        Ok(())
+    }
+
+    fn parse_name(&mut self, inst: Instruction) -> Result<(), Error> {
+        self.switch(ModuleState::Name, inst.op)?;
+        inst.expect_at_least(3)?;
+        let id = self.next()?;
+        let (name, left) = self.next_string(inst.wc - 2)?;
+        if left != 0 {
+            return Err(Error::InvalidOperand);
+        }
+        self.future_decor.entry(id).or_default().name = Some(name);
+        Ok(())
+    }
+
+    fn parse_member_name(&mut self, inst: Instruction) -> Result<(), Error> {
+        self.switch(ModuleState::Name, inst.op)?;
+        inst.expect_at_least(4)?;
+        let id = self.next()?;
+        let member = self.next()?;
+        let (name, left) = self.next_string(inst.wc - 3)?;
+        if left != 0 {
+            return Err(Error::InvalidOperand);
+        }
+
+        self.future_member_decor
+            .entry((id, member))
+            .or_default()
+            .name = Some(name);
+        Ok(())
+    }
+
+    fn parse_module_processed(&mut self, inst: Instruction) -> Result<(), Error> {
+        self.switch(ModuleState::Name, inst.op)?;
+        inst.expect_at_least(2)?;
+        let (_info, left) = self.next_string(inst.wc - 1)?;
+        //Note: string is ignored
+        if left != 0 {
+            return Err(Error::InvalidOperand);
+        }
+        Ok(())
+    }
+
+    fn parse_decorate(&mut self, inst: Instruction) -> Result<(), Error> {
+        self.switch(ModuleState::Annotation, inst.op)?;
+        inst.expect_at_least(3)?;
+        let id = self.next()?;
+        let mut dec = self.future_decor.remove(&id).unwrap_or_default();
+        self.next_decoration(inst, 2, &mut dec)?;
+        self.future_decor.insert(id, dec);
+        Ok(())
+    }
+
+    fn parse_member_decorate(&mut self, inst: Instruction) -> Result<(), Error> {
+        self.switch(ModuleState::Annotation, inst.op)?;
+        inst.expect_at_least(4)?;
+        let id = self.next()?;
+        let member = self.next()?;
+
+        let mut dec = self
+            .future_member_decor
+            .remove(&(id, member))
+            .unwrap_or_default();
+        self.next_decoration(inst, 3, &mut dec)?;
+        self.future_member_decor.insert((id, member), dec);
+        Ok(())
+    }
+
+    fn parse_type_void(&mut self, inst: Instruction) -> Result<(), Error> {
+        self.switch(ModuleState::Type, inst.op)?;
+        inst.expect(2)?;
+        let id = self.next()?;
+        self.lookup_void_type = Some(id);
+        Ok(())
+    }
+
+    fn parse_type_bool(
+        &mut self,
+        inst: Instruction,
+        module: &mut crate::Module,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        self.switch(ModuleState::Type, inst.op)?;
+        inst.expect(2)?;
+        let id = self.next()?;
+        let inner = crate::TypeInner::Scalar(crate::Scalar::BOOL);
+        self.lookup_type.insert(
+            id,
+            LookupType {
+                handle: module.types.insert(
+                    crate::Type {
+                        name: self.future_decor.remove(&id).and_then(|dec| dec.name),
+                        inner,
+                    },
+                    self.span_from_with_op(start),
+                ),
+                base_id: None,
+            },
+        );
+        Ok(())
+    }
+
+    fn parse_type_int(
+        &mut self,
+        inst: Instruction,
+        module: &mut crate::Module,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        self.switch(ModuleState::Type, inst.op)?;
+        inst.expect(4)?;
+        let id = self.next()?;
+        let width = self.next()?;
+        let sign = self.next()?;
+        let inner = crate::TypeInner::Scalar(crate::Scalar {
+            kind: match sign {
+                0 => crate::ScalarKind::Uint,
+                1 => crate::ScalarKind::Sint,
+                _ => return Err(Error::InvalidSign(sign)),
+            },
+            width: map_width(width)?,
+        });
+        self.lookup_type.insert(
+            id,
+            LookupType {
+                handle: module.types.insert(
+                    crate::Type {
+                        name: self.future_decor.remove(&id).and_then(|dec| dec.name),
+                        inner,
+                    },
+                    self.span_from_with_op(start),
+                ),
+                base_id: None,
+            },
+        );
+        Ok(())
+    }
+
+    fn parse_type_float(
+        &mut self,
+        inst: Instruction,
+        module: &mut crate::Module,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        self.switch(ModuleState::Type, inst.op)?;
+        inst.expect(3)?;
+        let id = self.next()?;
+        let width = self.next()?;
+        let inner = crate::TypeInner::Scalar(crate::Scalar::float(map_width(width)?));
+        self.lookup_type.insert(
+            id,
+            LookupType {
+                handle: module.types.insert(
+                    crate::Type {
+                        name: self.future_decor.remove(&id).and_then(|dec| dec.name),
+                        inner,
+                    },
+                    self.span_from_with_op(start),
+                ),
+                base_id: None,
+            },
+        );
+        Ok(())
+    }
+
+    fn parse_type_vector(
+        &mut self,
+        inst: Instruction,
+        module: &mut crate::Module,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        self.switch(ModuleState::Type, inst.op)?;
+        inst.expect(4)?;
+        let id = self.next()?;
+        let type_id = self.next()?;
+        let type_lookup = self.lookup_type.lookup(type_id)?;
+        let scalar = match module.types[type_lookup.handle].inner {
+            crate::TypeInner::Scalar(scalar) => scalar,
+            _ => return Err(Error::InvalidInnerType(type_id)),
+        };
+        let component_count = self.next()?;
+        let inner = crate::TypeInner::Vector {
+            size: map_vector_size(component_count)?,
+            scalar,
+        };
+        self.lookup_type.insert(
+            id,
+            LookupType {
+                handle: module.types.insert(
+                    crate::Type {
+                        name: self.future_decor.remove(&id).and_then(|dec| dec.name),
+                        inner,
+                    },
+                    self.span_from_with_op(start),
+                ),
+                base_id: Some(type_id),
+            },
+        );
+        Ok(())
+    }
+
+    fn parse_type_matrix(
+        &mut self,
+        inst: Instruction,
+        module: &mut crate::Module,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        self.switch(ModuleState::Type, inst.op)?;
+        inst.expect(4)?;
+        let id = self.next()?;
+        let vector_type_id = self.next()?;
+        let num_columns = self.next()?;
+        let decor = self.future_decor.remove(&id);
+
+        let vector_type_lookup = self.lookup_type.lookup(vector_type_id)?;
+        let inner = match module.types[vector_type_lookup.handle].inner {
+            crate::TypeInner::Vector { size, scalar } => crate::TypeInner::Matrix {
+                columns: map_vector_size(num_columns)?,
+                rows: size,
+                scalar,
+            },
+            _ => return Err(Error::InvalidInnerType(vector_type_id)),
+        };
+
+        self.lookup_type.insert(
+            id,
+            LookupType {
+                handle: module.types.insert(
+                    crate::Type {
+                        name: decor.and_then(|dec| dec.name),
+                        inner,
+                    },
+                    self.span_from_with_op(start),
+                ),
+                base_id: Some(vector_type_id),
+            },
+        );
+        Ok(())
+    }
+
+    fn parse_type_function(&mut self, inst: Instruction) -> Result<(), Error> {
+        self.switch(ModuleState::Type, inst.op)?;
+        inst.expect_at_least(3)?;
+        let id = self.next()?;
+        let return_type_id = self.next()?;
+        let parameter_type_ids = self.data.by_ref().take(inst.wc as usize - 3).collect();
+        self.lookup_function_type.insert(
+            id,
+            LookupFunctionType {
+                parameter_type_ids,
+                return_type_id,
+            },
+        );
+        Ok(())
+    }
+
+    fn parse_type_pointer(
+        &mut self,
+        inst: Instruction,
+        module: &mut crate::Module,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        self.switch(ModuleState::Type, inst.op)?;
+        inst.expect(4)?;
+        let id = self.next()?;
+        let storage_class = self.next()?;
+        let type_id = self.next()?;
+
+        let decor = self.future_decor.remove(&id);
+        let base_lookup_ty = self.lookup_type.lookup(type_id)?;
+        let base_inner = &module.types[base_lookup_ty.handle].inner;
+
+        let space = if let Some(space) = base_inner.pointer_space() {
+            space
+        } else if self
+            .lookup_storage_buffer_types
+            .contains_key(&base_lookup_ty.handle)
+        {
+            crate::AddressSpace::Storage {
+                access: crate::StorageAccess::default(),
+            }
+        } else {
+            match map_storage_class(storage_class)? {
+                ExtendedClass::Global(space) => space,
+                ExtendedClass::Input | ExtendedClass::Output => crate::AddressSpace::Private,
+            }
+        };
+
+        // We don't support pointers to runtime-sized arrays in the `Uniform`
+        // storage class with the `BufferBlock` decoration. Runtime-sized arrays
+        // should be in the StorageBuffer class.
+        if let crate::TypeInner::Array {
+            size: crate::ArraySize::Dynamic,
+            ..
+        } = *base_inner
+        {
+            match space {
+                crate::AddressSpace::Storage { .. } => {}
+                _ => {
+                    return Err(Error::UnsupportedRuntimeArrayStorageClass);
+                }
+            }
+        }
+
+        // Don't bother with pointer stuff for `Handle` types.
+        let lookup_ty = if space == crate::AddressSpace::Handle {
+            base_lookup_ty.clone()
+        } else {
+            LookupType {
+                handle: module.types.insert(
+                    crate::Type {
+                        name: decor.and_then(|dec| dec.name),
+                        inner: crate::TypeInner::Pointer {
+                            base: base_lookup_ty.handle,
+                            space,
+                        },
+                    },
+                    self.span_from_with_op(start),
+                ),
+                base_id: Some(type_id),
+            }
+        };
+        self.lookup_type.insert(id, lookup_ty);
+        Ok(())
+    }
+
+    fn parse_type_array(
+        &mut self,
+        inst: Instruction,
+        module: &mut crate::Module,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        self.switch(ModuleState::Type, inst.op)?;
+        inst.expect(4)?;
+        let id = self.next()?;
+        let type_id = self.next()?;
+        let length_id = self.next()?;
+        let length_const = self.lookup_constant.lookup(length_id)?;
+
+        let size = resolve_constant(module.to_ctx(), length_const.handle)
+            .and_then(NonZeroU32::new)
+            .ok_or(Error::InvalidArraySize(length_const.handle))?;
+
+        let decor = self.future_decor.remove(&id).unwrap_or_default();
+        let base = self.lookup_type.lookup(type_id)?.handle;
+
+        self.layouter.update(module.to_ctx()).unwrap();
+
+        // HACK if the underlying type is an image or a sampler, let's assume
+        //      that we're dealing with a binding-array
+        //
+        // Note that it's not a strictly correct assumption, but rather a trade
+        // off caused by an impedance mismatch between SPIR-V's and Naga's type
+        // systems - Naga distinguishes between arrays and binding-arrays via
+        // types (i.e. both kinds of arrays are just different types), while
+        // SPIR-V distinguishes between them through usage - e.g. given:
+        //
+        // ```
+        // %image = OpTypeImage %float 2D 2 0 0 2 Rgba16f
+        // %uint_256 = OpConstant %uint 256
+        // %image_array = OpTypeArray %image %uint_256
+        // ```
+        //
+        // ```
+        // %image = OpTypeImage %float 2D 2 0 0 2 Rgba16f
+        // %uint_256 = OpConstant %uint 256
+        // %image_array = OpTypeArray %image %uint_256
+        // %image_array_ptr = OpTypePointer UniformConstant %image_array
+        // ```
+        //
+        // ... in the first case, `%image_array` should technically correspond
+        // to `TypeInner::Array`, while in the second case it should say
+        // `TypeInner::BindingArray` (kinda, depending on whether `%image_array`
+        // is ever used as a freestanding type or rather always through the
+        // pointer-indirection).
+        //
+        // Anyway, at the moment we don't support other kinds of image / sampler
+        // arrays than those binding-based, so this assumption is pretty safe
+        // for now.
+        let inner = if let crate::TypeInner::Image { .. } | crate::TypeInner::Sampler { .. } =
+            module.types[base].inner
+        {
+            crate::TypeInner::BindingArray {
+                base,
+                size: crate::ArraySize::Constant(size),
+            }
+        } else {
+            crate::TypeInner::Array {
+                base,
+                size: crate::ArraySize::Constant(size),
+                stride: match decor.array_stride {
+                    Some(stride) => stride.get(),
+                    None => self.layouter[base].to_stride(),
+                },
+            }
+        };
+
+        self.lookup_type.insert(
+            id,
+            LookupType {
+                handle: module.types.insert(
+                    crate::Type {
+                        name: decor.name,
+                        inner,
+                    },
+                    self.span_from_with_op(start),
+                ),
+                base_id: Some(type_id),
+            },
+        );
+        Ok(())
+    }
+
+    fn parse_type_runtime_array(
+        &mut self,
+        inst: Instruction,
+        module: &mut crate::Module,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        self.switch(ModuleState::Type, inst.op)?;
+        inst.expect(3)?;
+        let id = self.next()?;
+        let type_id = self.next()?;
+
+        let decor = self.future_decor.remove(&id).unwrap_or_default();
+        let base = self.lookup_type.lookup(type_id)?.handle;
+
+        self.layouter.update(module.to_ctx()).unwrap();
+
+        // HACK same case as in `parse_type_array()`
+        let inner = if let crate::TypeInner::Image { .. } | crate::TypeInner::Sampler { .. } =
+            module.types[base].inner
+        {
+            crate::TypeInner::BindingArray {
+                base: self.lookup_type.lookup(type_id)?.handle,
+                size: crate::ArraySize::Dynamic,
+            }
+        } else {
+            crate::TypeInner::Array {
+                base: self.lookup_type.lookup(type_id)?.handle,
+                size: crate::ArraySize::Dynamic,
+                stride: match decor.array_stride {
+                    Some(stride) => stride.get(),
+                    None => self.layouter[base].to_stride(),
+                },
+            }
+        };
+
+        self.lookup_type.insert(
+            id,
+            LookupType {
+                handle: module.types.insert(
+                    crate::Type {
+                        name: decor.name,
+                        inner,
+                    },
+                    self.span_from_with_op(start),
+                ),
+                base_id: Some(type_id),
+            },
+        );
+        Ok(())
+    }
+
+    fn parse_type_struct(
+        &mut self,
+        inst: Instruction,
+        module: &mut crate::Module,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        self.switch(ModuleState::Type, inst.op)?;
+        inst.expect_at_least(2)?;
+        let id = self.next()?;
+        let parent_decor = self.future_decor.remove(&id);
+        let is_storage_buffer = parent_decor
+            .as_ref()
+            .map_or(false, |decor| decor.storage_buffer);
+
+        self.layouter.update(module.to_ctx()).unwrap();
+
+        let mut members = Vec::<crate::StructMember>::with_capacity(inst.wc as usize - 2);
+        let mut member_lookups = Vec::with_capacity(members.capacity());
+        let mut storage_access = crate::StorageAccess::empty();
+        let mut span = 0;
+        let mut alignment = Alignment::ONE;
+        for i in 0..u32::from(inst.wc) - 2 {
+            let type_id = self.next()?;
+            let ty = self.lookup_type.lookup(type_id)?.handle;
+            let decor = self
+                .future_member_decor
+                .remove(&(id, i))
+                .unwrap_or_default();
+
+            storage_access |= decor.flags.to_storage_access();
+
+            member_lookups.push(LookupMember {
+                type_id,
+                row_major: decor.matrix_major == Some(Majority::Row),
+            });
+
+            let member_alignment = self.layouter[ty].alignment;
+            span = member_alignment.round_up(span);
+            alignment = member_alignment.max(alignment);
+
+            let binding = decor.io_binding().ok();
+            if let Some(offset) = decor.offset {
+                span = offset;
+            }
+            let offset = span;
+
+            span += self.layouter[ty].size;
+
+            let inner = &module.types[ty].inner;
+            if let crate::TypeInner::Matrix {
+                columns,
+                rows,
+                scalar,
+            } = *inner
+            {
+                if let Some(stride) = decor.matrix_stride {
+                    let expected_stride = Alignment::from(rows) * scalar.width as u32;
+                    if stride.get() != expected_stride {
+                        return Err(Error::UnsupportedMatrixStride {
+                            stride: stride.get(),
+                            columns: columns as u8,
+                            rows: rows as u8,
+                            width: scalar.width,
+                        });
+                    }
+                }
+            }
+
+            members.push(crate::StructMember {
+                name: decor.name,
+                ty,
+                binding,
+                offset,
+            });
+        }
+
+        span = alignment.round_up(span);
+
+        let inner = crate::TypeInner::Struct { span, members };
+
+        let ty_handle = module.types.insert(
+            crate::Type {
+                name: parent_decor.and_then(|dec| dec.name),
+                inner,
+            },
+            self.span_from_with_op(start),
+        );
+
+        if is_storage_buffer {
+            self.lookup_storage_buffer_types
+                .insert(ty_handle, storage_access);
+        }
+        for (i, member_lookup) in member_lookups.into_iter().enumerate() {
+            self.lookup_member
+                .insert((ty_handle, i as u32), member_lookup);
+        }
+        self.lookup_type.insert(
+            id,
+            LookupType {
+                handle: ty_handle,
+                base_id: None,
+            },
+        );
+        Ok(())
+    }
+
+    fn parse_type_image(
+        &mut self,
+        inst: Instruction,
+        module: &mut crate::Module,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        self.switch(ModuleState::Type, inst.op)?;
+        inst.expect(9)?;
+
+        let id = self.next()?;
+        let sample_type_id = self.next()?;
+        let dim = self.next()?;
+        let is_depth = self.next()?;
+        let is_array = self.next()? != 0;
+        let is_msaa = self.next()? != 0;
+        let _is_sampled = self.next()?;
+        let format = self.next()?;
+
+        let dim = map_image_dim(dim)?;
+        let decor = self.future_decor.remove(&id).unwrap_or_default();
+
+        // ensure there is a type for texture coordinate without extra components
+        module.types.insert(
+            crate::Type {
+                name: None,
+                inner: {
+                    let scalar = crate::Scalar::F32;
+                    match dim.required_coordinate_size() {
+                        None => crate::TypeInner::Scalar(scalar),
+                        Some(size) => crate::TypeInner::Vector { size, scalar },
+                    }
+                },
+            },
+            Default::default(),
+        );
+
+        let base_handle = self.lookup_type.lookup(sample_type_id)?.handle;
+        let kind = module.types[base_handle]
+            .inner
+            .scalar_kind()
+            .ok_or(Error::InvalidImageBaseType(base_handle))?;
+
+        let inner = crate::TypeInner::Image {
+            class: if is_depth == 1 {
+                crate::ImageClass::Depth { multi: is_msaa }
+            } else if format != 0 {
+                crate::ImageClass::Storage {
+                    format: map_image_format(format)?,
+                    access: crate::StorageAccess::default(),
+                }
+            } else {
+                crate::ImageClass::Sampled {
+                    kind,
+                    multi: is_msaa,
+                }
+            },
+            dim,
+            arrayed: is_array,
+        };
+
+        let handle = module.types.insert(
+            crate::Type {
+                name: decor.name,
+                inner,
+            },
+            self.span_from_with_op(start),
+        );
+
+        self.lookup_type.insert(
+            id,
+            LookupType {
+                handle,
+                base_id: Some(sample_type_id),
+            },
+        );
+        Ok(())
+    }
+
+    fn parse_type_sampled_image(&mut self, inst: Instruction) -> Result<(), Error> {
+        self.switch(ModuleState::Type, inst.op)?;
+        inst.expect(3)?;
+        let id = self.next()?;
+        let image_id = self.next()?;
+        self.lookup_type.insert(
+            id,
+            LookupType {
+                handle: self.lookup_type.lookup(image_id)?.handle,
+                base_id: Some(image_id),
+            },
+        );
+        Ok(())
+    }
+
+    fn parse_type_sampler(
+        &mut self,
+        inst: Instruction,
+        module: &mut crate::Module,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        self.switch(ModuleState::Type, inst.op)?;
+        inst.expect(2)?;
+        let id = self.next()?;
+        let decor = self.future_decor.remove(&id).unwrap_or_default();
+        let handle = module.types.insert(
+            crate::Type {
+                name: decor.name,
+                inner: crate::TypeInner::Sampler { comparison: false },
+            },
+            self.span_from_with_op(start),
+        );
+        self.lookup_type.insert(
+            id,
+            LookupType {
+                handle,
+                base_id: None,
+            },
+        );
+        Ok(())
+    }
+
+    fn parse_constant(
+        &mut self,
+        inst: Instruction,
+        module: &mut crate::Module,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        self.switch(ModuleState::Type, inst.op)?;
+        inst.expect_at_least(4)?;
+        let type_id = self.next()?;
+        let id = self.next()?;
+        let type_lookup = self.lookup_type.lookup(type_id)?;
+        let ty = type_lookup.handle;
+
+        let literal = match module.types[ty].inner {
+            crate::TypeInner::Scalar(crate::Scalar {
+                kind: crate::ScalarKind::Uint,
+                width,
+            }) => {
+                let low = self.next()?;
+                match width {
+                    4 => crate::Literal::U32(low),
+                    _ => return Err(Error::InvalidTypeWidth(width as u32)),
+                }
+            }
+            crate::TypeInner::Scalar(crate::Scalar {
+                kind: crate::ScalarKind::Sint,
+                width,
+            }) => {
+                let low = self.next()?;
+                match width {
+                    4 => crate::Literal::I32(low as i32),
+                    8 => {
+                        inst.expect(5)?;
+                        let high = self.next()?;
+                        crate::Literal::I64((u64::from(high) << 32 | u64::from(low)) as i64)
+                    }
+                    _ => return Err(Error::InvalidTypeWidth(width as u32)),
+                }
+            }
+            crate::TypeInner::Scalar(crate::Scalar {
+                kind: crate::ScalarKind::Float,
+                width,
+            }) => {
+                let low = self.next()?;
+                match width {
+                    4 => crate::Literal::F32(f32::from_bits(low)),
+                    8 => {
+                        inst.expect(5)?;
+                        let high = self.next()?;
+                        crate::Literal::F64(f64::from_bits(
+                            (u64::from(high) << 32) | u64::from(low),
+                        ))
+                    }
+                    _ => return Err(Error::InvalidTypeWidth(width as u32)),
+                }
+            }
+            _ => return Err(Error::UnsupportedType(type_lookup.handle)),
+        };
+
+        let decor = self.future_decor.remove(&id).unwrap_or_default();
+
+        let span = self.span_from_with_op(start);
+
+        let init = module
+            .const_expressions
+            .append(crate::Expression::Literal(literal), span);
+        self.lookup_constant.insert(
+            id,
+            LookupConstant {
+                handle: module.constants.append(
+                    crate::Constant {
+                        r#override: decor.specialization(),
+                        name: decor.name,
+                        ty,
+                        init,
+                    },
+                    span,
+                ),
+                type_id,
+            },
+        );
+        Ok(())
+    }
+
+    fn parse_composite_constant(
+        &mut self,
+        inst: Instruction,
+        module: &mut crate::Module,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        self.switch(ModuleState::Type, inst.op)?;
+        inst.expect_at_least(3)?;
+        let type_id = self.next()?;
+        let id = self.next()?;
+
+        let type_lookup = self.lookup_type.lookup(type_id)?;
+        let ty = type_lookup.handle;
+
+        let mut components = Vec::with_capacity(inst.wc as usize - 3);
+        for _ in 0..components.capacity() {
+            let start = self.data_offset;
+            let component_id = self.next()?;
+            let span = self.span_from_with_op(start);
+            let constant = self.lookup_constant.lookup(component_id)?;
+            let expr = module
+                .const_expressions
+                .append(crate::Expression::Constant(constant.handle), span);
+            components.push(expr);
+        }
+
+        let decor = self.future_decor.remove(&id).unwrap_or_default();
+
+        let span = self.span_from_with_op(start);
+
+        let init = module
+            .const_expressions
+            .append(crate::Expression::Compose { ty, components }, span);
+        self.lookup_constant.insert(
+            id,
+            LookupConstant {
+                handle: module.constants.append(
+                    crate::Constant {
+                        r#override: decor.specialization(),
+                        name: decor.name,
+                        ty,
+                        init,
+                    },
+                    span,
+                ),
+                type_id,
+            },
+        );
+        Ok(())
+    }
+
+    fn parse_null_constant(
+        &mut self,
+        inst: Instruction,
+        module: &mut crate::Module,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        self.switch(ModuleState::Type, inst.op)?;
+        inst.expect(3)?;
+        let type_id = self.next()?;
+        let id = self.next()?;
+        let span = self.span_from_with_op(start);
+
+        let type_lookup = self.lookup_type.lookup(type_id)?;
+        let ty = type_lookup.handle;
+
+        let decor = self.future_decor.remove(&id).unwrap_or_default();
+
+        let init = module
+            .const_expressions
+            .append(crate::Expression::ZeroValue(ty), span);
+        let handle = module.constants.append(
+            crate::Constant {
+                r#override: decor.specialization(),
+                name: decor.name,
+                ty,
+                init,
+            },
+            span,
+        );
+        self.lookup_constant
+            .insert(id, LookupConstant { handle, type_id });
+        Ok(())
+    }
+
+    fn parse_bool_constant(
+        &mut self,
+        inst: Instruction,
+        value: bool,
+        module: &mut crate::Module,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        self.switch(ModuleState::Type, inst.op)?;
+        inst.expect(3)?;
+        let type_id = self.next()?;
+        let id = self.next()?;
+        let span = self.span_from_with_op(start);
+
+        let type_lookup = self.lookup_type.lookup(type_id)?;
+        let ty = type_lookup.handle;
+
+        let decor = self.future_decor.remove(&id).unwrap_or_default();
+
+        let init = module.const_expressions.append(
+            crate::Expression::Literal(crate::Literal::Bool(value)),
+            span,
+        );
+        self.lookup_constant.insert(
+            id,
+            LookupConstant {
+                handle: module.constants.append(
+                    crate::Constant {
+                        r#override: decor.specialization(),
+                        name: decor.name,
+                        ty,
+                        init,
+                    },
+                    span,
+                ),
+                type_id,
+            },
+        );
+        Ok(())
+    }
+
+    fn parse_global_variable(
+        &mut self,
+        inst: Instruction,
+        module: &mut crate::Module,
+    ) -> Result<(), Error> {
+        let start = self.data_offset;
+        self.switch(ModuleState::Type, inst.op)?;
+        inst.expect_at_least(4)?;
+        let type_id = self.next()?;
+        let id = self.next()?;
+        let storage_class = self.next()?;
+        let init = if inst.wc > 4 {
+            inst.expect(5)?;
+            let start = self.data_offset;
+            let init_id = self.next()?;
+            let span = self.span_from_with_op(start);
+            let lconst = self.lookup_constant.lookup(init_id)?;
+            let expr = module
+                .const_expressions
+                .append(crate::Expression::Constant(lconst.handle), span);
+            Some(expr)
+        } else {
+            None
+        };
+        let span = self.span_from_with_op(start);
+        let mut dec = self.future_decor.remove(&id).unwrap_or_default();
+
+        let original_ty = self.lookup_type.lookup(type_id)?.handle;
+        let mut ty = original_ty;
+
+        if let crate::TypeInner::Pointer { base, space: _ } = module.types[original_ty].inner {
+            ty = base;
+        }
+
+        if let crate::TypeInner::BindingArray { .. } = module.types[original_ty].inner {
+            // Inside `parse_type_array()` we guess that an array of images or
+            // samplers must be a binding array, and here we validate that guess
+            if dec.desc_set.is_none() || dec.desc_index.is_none() {
+                return Err(Error::NonBindingArrayOfImageOrSamplers);
+            }
+        }
+
+        if let crate::TypeInner::Image {
+            dim,
+            arrayed,
+            class: crate::ImageClass::Storage { format, access: _ },
+        } = module.types[ty].inner
+        {
+            // Storage image types in IR have to contain the access, but not in the SPIR-V.
+            // The same image type in SPIR-V can be used (and has to be used) for multiple images.
+            // So we copy the type out and apply the variable access decorations.
+            let access = dec.flags.to_storage_access();
+
+            ty = module.types.insert(
+                crate::Type {
+                    name: None,
+                    inner: crate::TypeInner::Image {
+                        dim,
+                        arrayed,
+                        class: crate::ImageClass::Storage { format, access },
+                    },
+                },
+                Default::default(),
+            );
+        }
+
+        let ext_class = match self.lookup_storage_buffer_types.get(&ty) {
+            Some(&access) => ExtendedClass::Global(crate::AddressSpace::Storage { access }),
+            None => map_storage_class(storage_class)?,
+        };
+
+        // Fix empty name for gl_PerVertex struct generated by glslang
+        if let crate::TypeInner::Pointer { .. } = module.types[original_ty].inner {
+            if ext_class == ExtendedClass::Input || ext_class == ExtendedClass::Output {
+                if let Some(ref dec_name) = dec.name {
+                    if dec_name.is_empty() {
+                        dec.name = Some("perVertexStruct".to_string())
+                    }
+                }
+            }
+        }
+
+        let (inner, var) = match ext_class {
+            ExtendedClass::Global(mut space) => {
+                if let crate::AddressSpace::Storage { ref mut access } = space {
+                    *access &= dec.flags.to_storage_access();
+                }
+                let var = crate::GlobalVariable {
+                    binding: dec.resource_binding(),
+                    name: dec.name,
+                    space,
+                    ty,
+                    init,
+                };
+                (Variable::Global, var)
+            }
+            ExtendedClass::Input => {
+                let binding = dec.io_binding()?;
+                let mut unsigned_ty = ty;
+                if let crate::Binding::BuiltIn(built_in) = binding {
+                    let needs_inner_uint = match built_in {
+                        crate::BuiltIn::BaseInstance
+                        | crate::BuiltIn::BaseVertex
+                        | crate::BuiltIn::InstanceIndex
+                        | crate::BuiltIn::SampleIndex
+                        | crate::BuiltIn::VertexIndex
+                        | crate::BuiltIn::PrimitiveIndex
+                        | crate::BuiltIn::LocalInvocationIndex => {
+                            Some(crate::TypeInner::Scalar(crate::Scalar::U32))
+                        }
+                        crate::BuiltIn::GlobalInvocationId
+                        | crate::BuiltIn::LocalInvocationId
+                        | crate::BuiltIn::WorkGroupId
+                        | crate::BuiltIn::WorkGroupSize => Some(crate::TypeInner::Vector {
+                            size: crate::VectorSize::Tri,
+                            scalar: crate::Scalar::U32,
+                        }),
+                        _ => None,
+                    };
+                    if let (Some(inner), Some(crate::ScalarKind::Sint)) =
+                        (needs_inner_uint, module.types[ty].inner.scalar_kind())
+                    {
+                        unsigned_ty = module
+                            .types
+                            .insert(crate::Type { name: None, inner }, Default::default());
+                    }
+                }
+
+                let var = crate::GlobalVariable {
+                    name: dec.name.clone(),
+                    space: crate::AddressSpace::Private,
+                    binding: None,
+                    ty,
+                    init: None,
+                };
+
+                let inner = Variable::Input(crate::FunctionArgument {
+                    name: dec.name,
+                    ty: unsigned_ty,
+                    binding: Some(binding),
+                });
+                (inner, var)
+            }
+            ExtendedClass::Output => {
+                // For output interface blocks, this would be a structure.
+                let binding = dec.io_binding().ok();
+                let init = match binding {
+                    Some(crate::Binding::BuiltIn(built_in)) => {
+                        match null::generate_default_built_in(
+                            Some(built_in),
+                            ty,
+                            &mut module.const_expressions,
+                            span,
+                        ) {
+                            Ok(handle) => Some(handle),
+                            Err(e) => {
+                                log::warn!("Failed to initialize output built-in: {}", e);
+                                None
+                            }
+                        }
+                    }
+                    Some(crate::Binding::Location { .. }) => None,
+                    None => match module.types[ty].inner {
+                        crate::TypeInner::Struct { ref members, .. } => {
+                            let mut components = Vec::with_capacity(members.len());
+                            for member in members.iter() {
+                                let built_in = match member.binding {
+                                    Some(crate::Binding::BuiltIn(built_in)) => Some(built_in),
+                                    _ => None,
+                                };
+                                let handle = null::generate_default_built_in(
+                                    built_in,
+                                    member.ty,
+                                    &mut module.const_expressions,
+                                    span,
+                                )?;
+                                components.push(handle);
+                            }
+                            Some(
+                                module
+                                    .const_expressions
+                                    .append(crate::Expression::Compose { ty, components }, span),
+                            )
+                        }
+                        _ => None,
+                    },
+                };
+
+                let var = crate::GlobalVariable {
+                    name: dec.name,
+                    space: crate::AddressSpace::Private,
+                    binding: None,
+                    ty,
+                    init,
+                };
+                let inner = Variable::Output(crate::FunctionResult { ty, binding });
+                (inner, var)
+            }
+        };
+
+        let handle = module.global_variables.append(var, span);
+
+        if module.types[ty].inner.can_comparison_sample(module) {
+            log::debug!("\t\ttracking {:?} for sampling properties", handle);
+
+            self.handle_sampling
+                .insert(handle, image::SamplingFlags::empty());
+        }
+
+        self.lookup_variable.insert(
+            id,
+            LookupVariable {
+                inner,
+                handle,
+                type_id,
+            },
+        );
+        Ok(())
+    }
+}
+
+fn make_index_literal(
+    ctx: &mut BlockContext,
+    index: u32,
+    block: &mut crate::Block,
+    emitter: &mut crate::proc::Emitter,
+    index_type: Handle<crate::Type>,
+    index_type_id: spirv::Word,
+    span: crate::Span,
+) -> Result<Handle<crate::Expression>, Error> {
+    block.extend(emitter.finish(ctx.expressions));
+
+    let literal = match ctx.type_arena[index_type].inner.scalar_kind() {
+        Some(crate::ScalarKind::Uint) => crate::Literal::U32(index),
+        Some(crate::ScalarKind::Sint) => crate::Literal::I32(index as i32),
+        _ => return Err(Error::InvalidIndexType(index_type_id)),
+    };
+    let expr = ctx
+        .expressions
+        .append(crate::Expression::Literal(literal), span);
+
+    emitter.start(ctx.expressions);
+    Ok(expr)
+}
+
+fn resolve_constant(
+    gctx: crate::proc::GlobalCtx,
+    constant: Handle<crate::Constant>,
+) -> Option<u32> {
+    match gctx.const_expressions[gctx.constants[constant].init] {
+        crate::Expression::Literal(crate::Literal::U32(id)) => Some(id),
+        crate::Expression::Literal(crate::Literal::I32(id)) => Some(id as u32),
+        _ => None,
+    }
+}
+
+pub fn parse_u8_slice(data: &[u8], options: &Options) -> Result<crate::Module, Error> {
+    if data.len() % 4 != 0 {
+        return Err(Error::IncompleteData);
+    }
+
+    let words = data
+        .chunks(4)
+        .map(|c| u32::from_le_bytes(c.try_into().unwrap()));
+    Frontend::new(words, options).parse()
+}
+
+#[cfg(test)]
+mod test {
+    #[test]
+    fn parse() {
+        let bin = vec![
+            // Magic number.           Version number: 1.0.
+            0x03, 0x02, 0x23, 0x07, 0x00, 0x00, 0x01, 0x00,
+            // Generator number: 0.    Bound: 0.
+            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Reserved word: 0.
+            0x00, 0x00, 0x00, 0x00, // OpMemoryModel.          Logical.
+            0x0e, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, // GLSL450.
+            0x01, 0x00, 0x00, 0x00,
+        ];
+        let _ = super::parse_u8_slice(&bin, &Default::default()).unwrap();
+    }
+}
+
+/// Helper function to check if `child` is in the scope of `parent`
+fn is_parent(mut child: usize, parent: usize, block_ctx: &BlockContext) -> bool {
+    loop {
+        if child == parent {
+            // The child is in the scope parent
+            break true;
+        } else if child == 0 {
+            // Searched finished at the root the child isn't in the parent's body
+            break false;
+        }
+
+        child = block_ctx.bodies[child].parent;
+    }
+}
diff --git a/third_party/rust/naga/src/front/spv/null.rs b/third_party/rust/naga/src/front/spv/null.rs
new file mode 100644
index 0000000000..42cccca80a
--- /dev/null
+++ b/third_party/rust/naga/src/front/spv/null.rs
@@ -0,0 +1,31 @@
+use super::Error;
+use crate::arena::{Arena, Handle};
+
+/// Create a default value for an output built-in.
+pub fn generate_default_built_in(
+    built_in: Option<crate::BuiltIn>,
+    ty: Handle<crate::Type>,
+    const_expressions: &mut Arena<crate::Expression>,
+    span: crate::Span,
+) -> Result<Handle<crate::Expression>, Error> {
+    let expr = match built_in {
+        Some(crate::BuiltIn::Position { .. }) => {
+            let zero = const_expressions
+                .append(crate::Expression::Literal(crate::Literal::F32(0.0)), span);
+            let one = const_expressions
+                .append(crate::Expression::Literal(crate::Literal::F32(1.0)), span);
+            crate::Expression::Compose {
+                ty,
+                components: vec![zero, zero, zero, one],
+            }
+        }
+        Some(crate::BuiltIn::PointSize) => crate::Expression::Literal(crate::Literal::F32(1.0)),
+        Some(crate::BuiltIn::FragDepth) => crate::Expression::Literal(crate::Literal::F32(0.0)),
+        Some(crate::BuiltIn::SampleMask) => {
+            crate::Expression::Literal(crate::Literal::U32(u32::MAX))
+        }
+        // Note: `crate::BuiltIn::ClipDistance` is intentionally left for the default path
+        _ => crate::Expression::ZeroValue(ty),
+    };
+    Ok(const_expressions.append(expr, span))
+}
diff --git a/third_party/rust/naga/src/front/type_gen.rs b/third_party/rust/naga/src/front/type_gen.rs
new file mode 100644
index 0000000000..34730c1db5
--- /dev/null
+++ b/third_party/rust/naga/src/front/type_gen.rs
@@ -0,0 +1,437 @@
+/*!
+Type generators.
+*/
+
+use crate::{arena::Handle, span::Span};
+
+impl crate::Module {
+    /// Populate this module's [`SpecialTypes::ray_desc`] type.
+    ///
+    /// [`SpecialTypes::ray_desc`] is the type of the [`descriptor`] operand of
+    /// an [`Initialize`] [`RayQuery`] statement. In WGSL, it is a struct type
+    /// referred to as `RayDesc`.
+    ///
+    /// Backends consume values of this type to drive platform APIs, so if you
+    /// change any its fields, you must update the backends to match. Look for
+    /// backend code dealing with [`RayQueryFunction::Initialize`].
+    ///
+    /// [`SpecialTypes::ray_desc`]: crate::SpecialTypes::ray_desc
+    /// [`descriptor`]: crate::RayQueryFunction::Initialize::descriptor
+    /// [`Initialize`]: crate::RayQueryFunction::Initialize
+    /// [`RayQuery`]: crate::Statement::RayQuery
+    /// [`RayQueryFunction::Initialize`]: crate::RayQueryFunction::Initialize
+    pub fn generate_ray_desc_type(&mut self) -> Handle<crate::Type> {
+        if let Some(handle) = self.special_types.ray_desc {
+            return handle;
+        }
+
+        let ty_flag = self.types.insert(
+            crate::Type {
+                name: None,
+                inner: crate::TypeInner::Scalar(crate::Scalar::U32),
+            },
+            Span::UNDEFINED,
+        );
+        let ty_scalar = self.types.insert(
+            crate::Type {
+                name: None,
+                inner: crate::TypeInner::Scalar(crate::Scalar::F32),
+            },
+            Span::UNDEFINED,
+        );
+        let ty_vector = self.types.insert(
+            crate::Type {
+                name: None,
+                inner: crate::TypeInner::Vector {
+                    size: crate::VectorSize::Tri,
+                    scalar: crate::Scalar::F32,
+                },
+            },
+            Span::UNDEFINED,
+        );
+
+        let handle = self.types.insert(
+            crate::Type {
+                name: Some("RayDesc".to_string()),
+                inner: crate::TypeInner::Struct {
+                    members: vec![
+                        crate::StructMember {
+                            name: Some("flags".to_string()),
+                            ty: ty_flag,
+                            binding: None,
+                            offset: 0,
+                        },
+                        crate::StructMember {
+                            name: Some("cull_mask".to_string()),
+                            ty: ty_flag,
+                            binding: None,
+                            offset: 4,
+                        },
+                        crate::StructMember {
+                            name: Some("tmin".to_string()),
+                            ty: ty_scalar,
+                            binding: None,
+                            offset: 8,
+                        },
+                        crate::StructMember {
+                            name: Some("tmax".to_string()),
+                            ty: ty_scalar,
+                            binding: None,
+                            offset: 12,
+                        },
+                        crate::StructMember {
+                            name: Some("origin".to_string()),
+                            ty: ty_vector,
+                            binding: None,
+                            offset: 16,
+                        },
+                        crate::StructMember {
+                            name: Some("dir".to_string()),
+                            ty: ty_vector,
+                            binding: None,
+                            offset: 32,
+                        },
+                    ],
+                    span: 48,
+                },
+            },
+            Span::UNDEFINED,
+        );
+
+        self.special_types.ray_desc = Some(handle);
+        handle
+    }
+
+    /// Populate this module's [`SpecialTypes::ray_intersection`] type.
+    ///
+    /// [`SpecialTypes::ray_intersection`] is the type of a
+    /// `RayQueryGetIntersection` expression. In WGSL, it is a struct type
+    /// referred to as `RayIntersection`.
+    ///
+    /// Backends construct values of this type based on platform APIs, so if you
+    /// change any its fields, you must update the backends to match. Look for
+    /// the backend's handling for [`Expression::RayQueryGetIntersection`].
+    ///
+    /// [`SpecialTypes::ray_intersection`]: crate::SpecialTypes::ray_intersection
+    /// [`Expression::RayQueryGetIntersection`]: crate::Expression::RayQueryGetIntersection
+    pub fn generate_ray_intersection_type(&mut self) -> Handle<crate::Type> {
+        if let Some(handle) = self.special_types.ray_intersection {
+            return handle;
+        }
+
+        let ty_flag = self.types.insert(
+            crate::Type {
+                name: None,
+                inner: crate::TypeInner::Scalar(crate::Scalar::U32),
+            },
+            Span::UNDEFINED,
+        );
+        let ty_scalar = self.types.insert(
+            crate::Type {
+                name: None,
+                inner: crate::TypeInner::Scalar(crate::Scalar::F32),
+            },
+            Span::UNDEFINED,
+        );
+        let ty_barycentrics = self.types.insert(
+            crate::Type {
+                name: None,
+                inner: crate::TypeInner::Vector {
+                    size: crate::VectorSize::Bi,
+                    scalar: crate::Scalar::F32,
+                },
+            },
+            Span::UNDEFINED,
+        );
+        let ty_bool = self.types.insert(
+            crate::Type {
+                name: None,
+                inner: crate::TypeInner::Scalar(crate::Scalar::BOOL),
+            },
+            Span::UNDEFINED,
+        );
+        let ty_transform = self.types.insert(
+            crate::Type {
+                name: None,
+                inner: crate::TypeInner::Matrix {
+                    columns: crate::VectorSize::Quad,
+                    rows: crate::VectorSize::Tri,
+                    scalar: crate::Scalar::F32,
+                },
+            },
+            Span::UNDEFINED,
+        );
+
+        let handle = self.types.insert(
+            crate::Type {
+                name: Some("RayIntersection".to_string()),
+                inner: crate::TypeInner::Struct {
+                    members: vec![
+                        crate::StructMember {
+                            name: Some("kind".to_string()),
+                            ty: ty_flag,
+                            binding: None,
+                            offset: 0,
+                        },
+                        crate::StructMember {
+                            name: Some("t".to_string()),
+                            ty: ty_scalar,
+                            binding: None,
+                            offset: 4,
+                        },
+                        crate::StructMember {
+                            name: Some("instance_custom_index".to_string()),
+                            ty: ty_flag,
+                            binding: None,
+                            offset: 8,
+                        },
+                        crate::StructMember {
+                            name: Some("instance_id".to_string()),
+                            ty: ty_flag,
+                            binding: None,
+                            offset: 12,
+                        },
+                        crate::StructMember {
+                            name: Some("sbt_record_offset".to_string()),
+                            ty: ty_flag,
+                            binding: None,
+                            offset: 16,
+                        },
+                        crate::StructMember {
+                            name: Some("geometry_index".to_string()),
+                            ty: ty_flag,
+                            binding: None,
+                            offset: 20,
+                        },
+                        crate::StructMember {
+                            name: Some("primitive_index".to_string()),
+                            ty: ty_flag,
+                            binding: None,
+                            offset: 24,
+                        },
+                        crate::StructMember {
+                            name: Some("barycentrics".to_string()),
+                            ty: ty_barycentrics,
+                            binding: None,
+                            offset: 28,
+                        },
+                        crate::StructMember {
+                            name: Some("front_face".to_string()),
+                            ty: ty_bool,
+                            binding: None,
+                            offset: 36,
+                        },
+                        crate::StructMember {
+                            name: Some("object_to_world".to_string()),
+                            ty: ty_transform,
+                            binding: None,
+                            offset: 48,
+                        },
+                        crate::StructMember {
+                            name: Some("world_to_object".to_string()),
+                            ty: ty_transform,
+                            binding: None,
+                            offset: 112,
+                        },
+                    ],
+                    span: 176,
+                },
+            },
+            Span::UNDEFINED,
+        );
+
+        self.special_types.ray_intersection = Some(handle);
+        handle
+    }
+
+    /// Populate this module's [`SpecialTypes::predeclared_types`] type and return the handle.
+    ///
+    /// [`SpecialTypes::predeclared_types`]: crate::SpecialTypes::predeclared_types
+    pub fn generate_predeclared_type(
+        &mut self,
+        special_type: crate::PredeclaredType,
+    ) -> Handle<crate::Type> {
+        use std::fmt::Write;
+
+        if let Some(value) = self.special_types.predeclared_types.get(&special_type) {
+            return *value;
+        }
+
+        let ty = match special_type {
+            crate::PredeclaredType::AtomicCompareExchangeWeakResult(scalar) => {
+                let bool_ty = self.types.insert(
+                    crate::Type {
+                        name: None,
+                        inner: crate::TypeInner::Scalar(crate::Scalar::BOOL),
+                    },
+                    Span::UNDEFINED,
+                );
+                let scalar_ty = self.types.insert(
+                    crate::Type {
+                        name: None,
+                        inner: crate::TypeInner::Scalar(scalar),
+                    },
+                    Span::UNDEFINED,
+                );
+
+                crate::Type {
+                    name: Some(format!(
+                        "__atomic_compare_exchange_result<{:?},{}>",
+                        scalar.kind, scalar.width,
+                    )),
+                    inner: crate::TypeInner::Struct {
+                        members: vec![
+                            crate::StructMember {
+                                name: Some("old_value".to_string()),
+                                ty: scalar_ty,
+                                binding: None,
+                                offset: 0,
+                            },
+                            crate::StructMember {
+                                name: Some("exchanged".to_string()),
+                                ty: bool_ty,
+                                binding: None,
+                                offset: 4,
+                            },
+                        ],
+                        span: 8,
+                    },
+                }
+            }
+            crate::PredeclaredType::ModfResult { size, width } => {
+                let float_ty = self.types.insert(
+                    crate::Type {
+                        name: None,
+                        inner: crate::TypeInner::Scalar(crate::Scalar::float(width)),
+                    },
+                    Span::UNDEFINED,
+                );
+
+                let (member_ty, second_offset) = if let Some(size) = size {
+                    let vec_ty = self.types.insert(
+                        crate::Type {
+                            name: None,
+                            inner: crate::TypeInner::Vector {
+                                size,
+                                scalar: crate::Scalar::float(width),
+                            },
+                        },
+                        Span::UNDEFINED,
+                    );
+                    (vec_ty, size as u32 * width as u32)
+                } else {
+                    (float_ty, width as u32)
+                };
+
+                let mut type_name = "__modf_result_".to_string();
+                if let Some(size) = size {
+                    let _ = write!(type_name, "vec{}_", size as u8);
+                }
+                let _ = write!(type_name, "f{}", width * 8);
+
+                crate::Type {
+                    name: Some(type_name),
+                    inner: crate::TypeInner::Struct {
+                        members: vec![
+                            crate::StructMember {
+                                name: Some("fract".to_string()),
+                                ty: member_ty,
+                                binding: None,
+                                offset: 0,
+                            },
+                            crate::StructMember {
+                                name: Some("whole".to_string()),
+                                ty: member_ty,
+                                binding: None,
+                                offset: second_offset,
+                            },
+                        ],
+                        span: second_offset * 2,
+                    },
+                }
+            }
+            crate::PredeclaredType::FrexpResult { size, width } => {
+                let float_ty = self.types.insert(
+                    crate::Type {
+                        name: None,
+                        inner: crate::TypeInner::Scalar(crate::Scalar::float(width)),
+                    },
+                    Span::UNDEFINED,
+                );
+
+                let int_ty = self.types.insert(
+                    crate::Type {
+                        name: None,
+                        inner: crate::TypeInner::Scalar(crate::Scalar {
+                            kind: crate::ScalarKind::Sint,
+                            width,
+                        }),
+                    },
+                    Span::UNDEFINED,
+                );
+
+                let (fract_member_ty, exp_member_ty, second_offset) = if let Some(size) = size {
+                    let vec_float_ty = self.types.insert(
+                        crate::Type {
+                            name: None,
+                            inner: crate::TypeInner::Vector {
+                                size,
+                                scalar: crate::Scalar::float(width),
+                            },
+                        },
+                        Span::UNDEFINED,
+                    );
+                    let vec_int_ty = self.types.insert(
+                        crate::Type {
+                            name: None,
+                            inner: crate::TypeInner::Vector {
+                                size,
+                                scalar: crate::Scalar {
+                                    kind: crate::ScalarKind::Sint,
+                                    width,
+                                },
+                            },
+                        },
+                        Span::UNDEFINED,
+                    );
+                    (vec_float_ty, vec_int_ty, size as u32 * width as u32)
+                } else {
+                    (float_ty, int_ty, width as u32)
+                };
+
+                let mut type_name = "__frexp_result_".to_string();
+                if let Some(size) = size {
+                    let _ = write!(type_name, "vec{}_", size as u8);
+                }
+                let _ = write!(type_name, "f{}", width * 8);
+
+                crate::Type {
+                    name: Some(type_name),
+                    inner: crate::TypeInner::Struct {
+                        members: vec![
+                            crate::StructMember {
+                                name: Some("fract".to_string()),
+                                ty: fract_member_ty,
+                                binding: None,
+                                offset: 0,
+                            },
+                            crate::StructMember {
+                                name: Some("exp".to_string()),
+                                ty: exp_member_ty,
+                                binding: None,
+                                offset: second_offset,
+                            },
+                        ],
+                        span: second_offset * 2,
+                    },
+                }
+            }
+        };
+
+        let handle = self.types.insert(ty, Span::UNDEFINED);
+        self.special_types
+            .predeclared_types
+            .insert(special_type, handle);
+        handle
+    }
+}
diff --git a/third_party/rust/naga/src/front/wgsl/error.rs b/third_party/rust/naga/src/front/wgsl/error.rs
new file mode 100644
index 0000000000..07e68f8dd9
--- /dev/null
+++ b/third_party/rust/naga/src/front/wgsl/error.rs
@@ -0,0 +1,775 @@
+use crate::front::wgsl::parse::lexer::Token;
+use crate::front::wgsl::Scalar;
+use crate::proc::{Alignment, ConstantEvaluatorError, ResolveError};
+use crate::{SourceLocation, Span};
+use codespan_reporting::diagnostic::{Diagnostic, Label};
+use codespan_reporting::files::SimpleFile;
+use codespan_reporting::term;
+use std::borrow::Cow;
+use std::ops::Range;
+use termcolor::{ColorChoice, NoColor, StandardStream};
+use thiserror::Error;
+
+#[derive(Clone, Debug)]
+pub struct ParseError {
+    message: String,
+    labels: Vec<(Span, Cow<'static, str>)>,
+    notes: Vec<String>,
+}
+
+impl ParseError {
+    pub fn labels(&self) -> impl ExactSizeIterator<Item = (Span, &str)> + '_ {
+        self.labels
+            .iter()
+            .map(|&(span, ref msg)| (span, msg.as_ref()))
+    }
+
+    pub fn message(&self) -> &str {
+        &self.message
+    }
+
+    fn diagnostic(&self) -> Diagnostic<()> {
+        let diagnostic = Diagnostic::error()
+            .with_message(self.message.to_string())
+            .with_labels(
+                self.labels
+                    .iter()
+                    .filter_map(|label| label.0.to_range().map(|range| (label, range)))
+                    .map(|(label, range)| {
+                        Label::primary((), range).with_message(label.1.to_string())
+                    })
+                    .collect(),
+            )
+            .with_notes(
+                self.notes
+                    .iter()
+                    .map(|note| format!("note: {note}"))
+                    .collect(),
+            );
+        diagnostic
+    }
+
+    /// Emits a summary of the error to standard error stream.
+    pub fn emit_to_stderr(&self, source: &str) {
+        self.emit_to_stderr_with_path(source, "wgsl")
+    }
+
+    /// Emits a summary of the error to standard error stream.
+    pub fn emit_to_stderr_with_path<P>(&self, source: &str, path: P)
+    where
+        P: AsRef<std::path::Path>,
+    {
+        let path = path.as_ref().display().to_string();
+        let files = SimpleFile::new(path, source);
+        let config = codespan_reporting::term::Config::default();
+        let writer = StandardStream::stderr(ColorChoice::Auto);
+        term::emit(&mut writer.lock(), &config, &files, &self.diagnostic())
+            .expect("cannot write error");
+    }
+
+    /// Emits a summary of the error to a string.
+    pub fn emit_to_string(&self, source: &str) -> String {
+        self.emit_to_string_with_path(source, "wgsl")
+    }
+
+    /// Emits a summary of the error to a string.
+    pub fn emit_to_string_with_path<P>(&self, source: &str, path: P) -> String
+    where
+        P: AsRef<std::path::Path>,
+    {
+        let path = path.as_ref().display().to_string();
+        let files = SimpleFile::new(path, source);
+        let config = codespan_reporting::term::Config::default();
+        let mut writer = NoColor::new(Vec::new());
+        term::emit(&mut writer, &config, &files, &self.diagnostic()).expect("cannot write error");
+        String::from_utf8(writer.into_inner()).unwrap()
+    }
+
+    /// Returns a [`SourceLocation`] for the first label in the error message.
+    pub fn location(&self, source: &str) -> Option<SourceLocation> {
+        self.labels.get(0).map(|label| label.0.location(source))
+    }
+}
+
+impl std::fmt::Display for ParseError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.message)
+    }
+}
+
+impl std::error::Error for ParseError {
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+        None
+    }
+}
+
+#[derive(Copy, Clone, Debug, PartialEq)]
+pub enum ExpectedToken<'a> {
+    Token(Token<'a>),
+    Identifier,
+    /// Expected: constant, parenthesized expression, identifier
+    PrimaryExpression,
+    /// Expected: assignment, increment/decrement expression
+    Assignment,
+    /// Expected: 'case', 'default', '}'
+    SwitchItem,
+    /// Expected: ',', ')'
+    WorkgroupSizeSeparator,
+    /// Expected: 'struct', 'let', 'var', 'type', ';', 'fn', eof
+    GlobalItem,
+    /// Expected a type.
+    Type,
+    /// Access of `var`, `let`, `const`.
+    Variable,
+    /// Access of a function
+    Function,
+}
+
+#[derive(Clone, Copy, Debug, Error, PartialEq)]
+pub enum NumberError {
+    #[error("invalid numeric literal format")]
+    Invalid,
+    #[error("numeric literal not representable by target type")]
+    NotRepresentable,
+    #[error("unimplemented f16 type")]
+    UnimplementedF16,
+}
+
+#[derive(Copy, Clone, Debug, PartialEq)]
+pub enum InvalidAssignmentType {
+    Other,
+    Swizzle,
+    ImmutableBinding(Span),
+}
+
+#[derive(Clone, Debug)]
+pub enum Error<'a> {
+    Unexpected(Span, ExpectedToken<'a>),
+    UnexpectedComponents(Span),
+    UnexpectedOperationInConstContext(Span),
+    BadNumber(Span, NumberError),
+    BadMatrixScalarKind(Span, Scalar),
+    BadAccessor(Span),
+    BadTexture(Span),
+    BadTypeCast {
+        span: Span,
+        from_type: String,
+        to_type: String,
+    },
+    BadTextureSampleType {
+        span: Span,
+        scalar: Scalar,
+    },
+    BadIncrDecrReferenceType(Span),
+    InvalidResolve(ResolveError),
+    InvalidForInitializer(Span),
+    /// A break if appeared outside of a continuing block
+    InvalidBreakIf(Span),
+    InvalidGatherComponent(Span),
+    InvalidConstructorComponentType(Span, i32),
+    InvalidIdentifierUnderscore(Span),
+    ReservedIdentifierPrefix(Span),
+    UnknownAddressSpace(Span),
+    RepeatedAttribute(Span),
+    UnknownAttribute(Span),
+    UnknownBuiltin(Span),
+    UnknownAccess(Span),
+    UnknownIdent(Span, &'a str),
+    UnknownScalarType(Span),
+    UnknownType(Span),
+    UnknownStorageFormat(Span),
+    UnknownConservativeDepth(Span),
+    SizeAttributeTooLow(Span, u32),
+    AlignAttributeTooLow(Span, Alignment),
+    NonPowerOfTwoAlignAttribute(Span),
+    InconsistentBinding(Span),
+    TypeNotConstructible(Span),
+    TypeNotInferable(Span),
+    InitializationTypeMismatch {
+        name: Span,
+        expected: String,
+        got: String,
+    },
+    MissingType(Span),
+    MissingAttribute(&'static str, Span),
+    InvalidAtomicPointer(Span),
+    InvalidAtomicOperandType(Span),
+    InvalidRayQueryPointer(Span),
+    Pointer(&'static str, Span),
+    NotPointer(Span),
+    NotReference(&'static str, Span),
+    InvalidAssignment {
+        span: Span,
+        ty: InvalidAssignmentType,
+    },
+    ReservedKeyword(Span),
+    /// Redefinition of an identifier (used for both module-scope and local redefinitions).
+    Redefinition {
+        /// Span of the identifier in the previous definition.
+        previous: Span,
+
+        /// Span of the identifier in the new definition.
+        current: Span,
+    },
+    /// A declaration refers to itself directly.
+    RecursiveDeclaration {
+        /// The location of the name of the declaration.
+        ident: Span,
+
+        /// The point at which it is used.
+        usage: Span,
+    },
+    /// A declaration refers to itself indirectly, through one or more other
+    /// definitions.
+    CyclicDeclaration {
+        /// The location of the name of some declaration in the cycle.
+        ident: Span,
+
+        /// The edges of the cycle of references.
+        ///
+        /// Each `(decl, reference)` pair indicates that the declaration whose
+        /// name is `decl` has an identifier at `reference` whose definition is
+        /// the next declaration in the cycle. The last pair's `reference` is
+        /// the same identifier as `ident`, above.
+        path: Vec<(Span, Span)>,
+    },
+    InvalidSwitchValue {
+        uint: bool,
+        span: Span,
+    },
+    CalledEntryPoint(Span),
+    WrongArgumentCount {
+        span: Span,
+        expected: Range<u32>,
+        found: u32,
+    },
+    FunctionReturnsVoid(Span),
+    InvalidWorkGroupUniformLoad(Span),
+    Internal(&'static str),
+    ExpectedConstExprConcreteIntegerScalar(Span),
+    ExpectedNonNegative(Span),
+    ExpectedPositiveArrayLength(Span),
+    MissingWorkgroupSize(Span),
+    ConstantEvaluatorError(ConstantEvaluatorError, Span),
+    AutoConversion {
+        dest_span: Span,
+        dest_type: String,
+        source_span: Span,
+        source_type: String,
+    },
+    AutoConversionLeafScalar {
+        dest_span: Span,
+        dest_scalar: String,
+        source_span: Span,
+        source_type: String,
+    },
+    ConcretizationFailed {
+        expr_span: Span,
+        expr_type: String,
+        scalar: String,
+        inner: ConstantEvaluatorError,
+    },
+}
+
+impl<'a> Error<'a> {
+    pub(crate) fn as_parse_error(&self, source: &'a str) -> ParseError {
+        match *self {
+            Error::Unexpected(unexpected_span, expected) => {
+                let expected_str = match expected {
+                    ExpectedToken::Token(token) => {
+                        match token {
+                            Token::Separator(c) => format!("'{c}'"),
+                            Token::Paren(c) => format!("'{c}'"),
+                            Token::Attribute => "@".to_string(),
+                            Token::Number(_) => "number".to_string(),
+                            Token::Word(s) => s.to_string(),
+                            Token::Operation(c) => format!("operation ('{c}')"),
+                            Token::LogicalOperation(c) => format!("logical operation ('{c}')"),
+                            Token::ShiftOperation(c) => format!("bitshift ('{c}{c}')"),
+                            Token::AssignmentOperation(c) if c=='<' || c=='>' => format!("bitshift ('{c}{c}=')"),
+                            Token::AssignmentOperation(c) => format!("operation ('{c}=')"),
+                            Token::IncrementOperation => "increment operation".to_string(),
+                            Token::DecrementOperation => "decrement operation".to_string(),
+                            Token::Arrow => "->".to_string(),
+                            Token::Unknown(c) => format!("unknown ('{c}')"),
+                            Token::Trivia => "trivia".to_string(),
+                            Token::End => "end".to_string(),
+                        }
+                    }
+                    ExpectedToken::Identifier => "identifier".to_string(),
+                    ExpectedToken::PrimaryExpression => "expression".to_string(),
+                    ExpectedToken::Assignment => "assignment or increment/decrement".to_string(),
+                    ExpectedToken::SwitchItem => "switch item ('case' or 'default') or a closing curly bracket to signify the end of the switch statement ('}')".to_string(),
+                    ExpectedToken::WorkgroupSizeSeparator => "workgroup size separator (',') or a closing parenthesis".to_string(),
+                    ExpectedToken::GlobalItem => "global item ('struct', 'const', 'var', 'alias', ';', 'fn') or the end of the file".to_string(),
+                    ExpectedToken::Type => "type".to_string(),
+                    ExpectedToken::Variable => "variable access".to_string(),
+                    ExpectedToken::Function => "function name".to_string(),
+                };
+                ParseError {
+                    message: format!(
+                        "expected {}, found '{}'",
+                        expected_str, &source[unexpected_span],
+                    ),
+                    labels: vec![(unexpected_span, format!("expected {expected_str}").into())],
+                    notes: vec![],
+                }
+            }
+            Error::UnexpectedComponents(bad_span) => ParseError {
+                message: "unexpected components".to_string(),
+                labels: vec![(bad_span, "unexpected components".into())],
+                notes: vec![],
+            },
+            Error::UnexpectedOperationInConstContext(span) => ParseError {
+                message: "this operation is not supported in a const context".to_string(),
+                labels: vec![(span, "operation not supported here".into())],
+                notes: vec![],
+            },
+            Error::BadNumber(bad_span, ref err) => ParseError {
+                message: format!("{}: `{}`", err, &source[bad_span],),
+                labels: vec![(bad_span, err.to_string().into())],
+                notes: vec![],
+            },
+            Error::BadMatrixScalarKind(span, scalar) => ParseError {
+                message: format!(
+                    "matrix scalar type must be floating-point, but found `{}`",
+                    scalar.to_wgsl()
+                ),
+                labels: vec![(span, "must be floating-point (e.g. `f32`)".into())],
+                notes: vec![],
+            },
+            Error::BadAccessor(accessor_span) => ParseError {
+                message: format!("invalid field accessor `{}`", &source[accessor_span],),
+                labels: vec![(accessor_span, "invalid accessor".into())],
+                notes: vec![],
+            },
+            Error::UnknownIdent(ident_span, ident) => ParseError {
+                message: format!("no definition in scope for identifier: '{ident}'"),
+                labels: vec![(ident_span, "unknown identifier".into())],
+                notes: vec![],
+            },
+            Error::UnknownScalarType(bad_span) => ParseError {
+                message: format!("unknown scalar type: '{}'", &source[bad_span]),
+                labels: vec![(bad_span, "unknown scalar type".into())],
+                notes: vec!["Valid scalar types are f32, f64, i32, u32, bool".into()],
+            },
+            Error::BadTextureSampleType { span, scalar } => ParseError {
+                message: format!(
+                    "texture sample type must be one of f32, i32 or u32, but found {}",
+                    scalar.to_wgsl()
+                ),
+                labels: vec![(span, "must be one of f32, i32 or u32".into())],
+                notes: vec![],
+            },
+            Error::BadIncrDecrReferenceType(span) => ParseError {
+                message:
+                    "increment/decrement operation requires reference type to be one of i32 or u32"
+                        .to_string(),
+                labels: vec![(span, "must be a reference type of i32 or u32".into())],
+                notes: vec![],
+            },
+            Error::BadTexture(bad_span) => ParseError {
+                message: format!(
+                    "expected an image, but found '{}' which is not an image",
+                    &source[bad_span]
+                ),
+                labels: vec![(bad_span, "not an image".into())],
+                notes: vec![],
+            },
+            Error::BadTypeCast {
+                span,
+                ref from_type,
+                ref to_type,
+            } => {
+                let msg = format!("cannot cast a {from_type} to a {to_type}");
+                ParseError {
+                    message: msg.clone(),
+                    labels: vec![(span, msg.into())],
+                    notes: vec![],
+                }
+            }
+            Error::InvalidResolve(ref resolve_error) => ParseError {
+                message: resolve_error.to_string(),
+                labels: vec![],
+                notes: vec![],
+            },
+            Error::InvalidForInitializer(bad_span) => ParseError {
+                message: format!(
+                    "for(;;) initializer is not an assignment or a function call: '{}'",
+                    &source[bad_span]
+                ),
+                labels: vec![(bad_span, "not an assignment or function call".into())],
+                notes: vec![],
+            },
+            Error::InvalidBreakIf(bad_span) => ParseError {
+                message: "A break if is only allowed in a continuing block".to_string(),
+                labels: vec![(bad_span, "not in a continuing block".into())],
+                notes: vec![],
+            },
+            Error::InvalidGatherComponent(bad_span) => ParseError {
+                message: format!(
+                    "textureGather component '{}' doesn't exist, must be 0, 1, 2, or 3",
+                    &source[bad_span]
+                ),
+                labels: vec![(bad_span, "invalid component".into())],
+                notes: vec![],
+            },
+            Error::InvalidConstructorComponentType(bad_span, component) => ParseError {
+                message: format!("invalid type for constructor component at index [{component}]"),
+                labels: vec![(bad_span, "invalid component type".into())],
+                notes: vec![],
+            },
+            Error::InvalidIdentifierUnderscore(bad_span) => ParseError {
+                message: "Identifier can't be '_'".to_string(),
+                labels: vec![(bad_span, "invalid identifier".into())],
+                notes: vec![
+                    "Use phony assignment instead ('_ =' notice the absence of 'let' or 'var')"
+                        .to_string(),
+                ],
+            },
+            Error::ReservedIdentifierPrefix(bad_span) => ParseError {
+                message: format!(
+                    "Identifier starts with a reserved prefix: '{}'",
+                    &source[bad_span]
+                ),
+                labels: vec![(bad_span, "invalid identifier".into())],
+                notes: vec![],
+            },
+            Error::UnknownAddressSpace(bad_span) => ParseError {
+                message: format!("unknown address space: '{}'", &source[bad_span]),
+                labels: vec![(bad_span, "unknown address space".into())],
+                notes: vec![],
+            },
+            Error::RepeatedAttribute(bad_span) => ParseError {
+                message: format!("repeated attribute: '{}'", &source[bad_span]),
+                labels: vec![(bad_span, "repeated attribute".into())],
+                notes: vec![],
+            },
+            Error::UnknownAttribute(bad_span) => ParseError {
+                message: format!("unknown attribute: '{}'", &source[bad_span]),
+                labels: vec![(bad_span, "unknown attribute".into())],
+                notes: vec![],
+            },
+            Error::UnknownBuiltin(bad_span) => ParseError {
+                message: format!("unknown builtin: '{}'", &source[bad_span]),
+                labels: vec![(bad_span, "unknown builtin".into())],
+                notes: vec![],
+            },
+            Error::UnknownAccess(bad_span) => ParseError {
+                message: format!("unknown access: '{}'", &source[bad_span]),
+                labels: vec![(bad_span, "unknown access".into())],
+                notes: vec![],
+            },
+            Error::UnknownStorageFormat(bad_span) => ParseError {
+                message: format!("unknown storage format: '{}'", &source[bad_span]),
+                labels: vec![(bad_span, "unknown storage format".into())],
+                notes: vec![],
+            },
+            Error::UnknownConservativeDepth(bad_span) => ParseError {
+                message: format!("unknown conservative depth: '{}'", &source[bad_span]),
+                labels: vec![(bad_span, "unknown conservative depth".into())],
+                notes: vec![],
+            },
+            Error::UnknownType(bad_span) => ParseError {
+                message: format!("unknown type: '{}'", &source[bad_span]),
+                labels: vec![(bad_span, "unknown type".into())],
+                notes: vec![],
+            },
+            Error::SizeAttributeTooLow(bad_span, min_size) => ParseError {
+                message: format!("struct member size must be at least {min_size}"),
+                labels: vec![(bad_span, format!("must be at least {min_size}").into())],
+                notes: vec![],
+            },
+            Error::AlignAttributeTooLow(bad_span, min_align) => ParseError {
+                message: format!("struct member alignment must be at least {min_align}"),
+                labels: vec![(bad_span, format!("must be at least {min_align}").into())],
+                notes: vec![],
+            },
+            Error::NonPowerOfTwoAlignAttribute(bad_span) => ParseError {
+                message: "struct member alignment must be a power of 2".to_string(),
+                labels: vec![(bad_span, "must be a power of 2".into())],
+                notes: vec![],
+            },
+            Error::InconsistentBinding(span) => ParseError {
+                message: "input/output binding is not consistent".to_string(),
+                labels: vec![(span, "input/output binding is not consistent".into())],
+                notes: vec![],
+            },
+            Error::TypeNotConstructible(span) => ParseError {
+                message: format!("type `{}` is not constructible", &source[span]),
+                labels: vec![(span, "type is not constructible".into())],
+                notes: vec![],
+            },
+            Error::TypeNotInferable(span) => ParseError {
+                message: "type can't be inferred".to_string(),
+                labels: vec![(span, "type can't be inferred".into())],
+                notes: vec![],
+            },
+            Error::InitializationTypeMismatch { name, ref expected, ref got } => {
+                ParseError {
+                    message: format!(
+                        "the type of `{}` is expected to be `{}`, but got `{}`",
+                        &source[name], expected, got,
+                    ),
+                    labels: vec![(
+                        name,
+                        format!("definition of `{}`", &source[name]).into(),
+                    )],
+                    notes: vec![],
+                }
+            }
+            Error::MissingType(name_span) => ParseError {
+                message: format!("variable `{}` needs a type", &source[name_span]),
+                labels: vec![(
+                    name_span,
+                    format!("definition of `{}`", &source[name_span]).into(),
+                )],
+                notes: vec![],
+            },
+            Error::MissingAttribute(name, name_span) => ParseError {
+                message: format!(
+                    "variable `{}` needs a '{}' attribute",
+                    &source[name_span], name
+                ),
+                labels: vec![(
+                    name_span,
+                    format!("definition of `{}`", &source[name_span]).into(),
+                )],
+                notes: vec![],
+            },
+            Error::InvalidAtomicPointer(span) => ParseError {
+                message: "atomic operation is done on a pointer to a non-atomic".to_string(),
+                labels: vec![(span, "atomic pointer is invalid".into())],
+                notes: vec![],
+            },
+            Error::InvalidAtomicOperandType(span) => ParseError {
+                message: "atomic operand type is inconsistent with the operation".to_string(),
+                labels: vec![(span, "atomic operand type is invalid".into())],
+                notes: vec![],
+            },
+            Error::InvalidRayQueryPointer(span) => ParseError {
+                message: "ray query operation is done on a pointer to a non-ray-query".to_string(),
+                labels: vec![(span, "ray query pointer is invalid".into())],
+                notes: vec![],
+            },
+            Error::NotPointer(span) => ParseError {
+                message: "the operand of the `*` operator must be a pointer".to_string(),
+                labels: vec![(span, "expression is not a pointer".into())],
+                notes: vec![],
+            },
+            Error::NotReference(what, span) => ParseError {
+                message: format!("{what} must be a reference"),
+                labels: vec![(span, "expression is not a reference".into())],
+                notes: vec![],
+            },
+            Error::InvalidAssignment { span, ty } => {
+                let (extra_label, notes) = match ty {
+                    InvalidAssignmentType::Swizzle => (
+                        None,
+                        vec![
+                            "WGSL does not support assignments to swizzles".into(),
+                            "consider assigning each component individually".into(),
+                        ],
+                    ),
+                    InvalidAssignmentType::ImmutableBinding(binding_span) => (
+                        Some((binding_span, "this is an immutable binding".into())),
+                        vec![format!(
+                            "consider declaring '{}' with `var` instead of `let`",
+                            &source[binding_span]
+                        )],
+                    ),
+                    InvalidAssignmentType::Other => (None, vec![]),
+                };
+
+                ParseError {
+                    message: "invalid left-hand side of assignment".into(),
+                    labels: std::iter::once((span, "cannot assign to this expression".into()))
+                        .chain(extra_label)
+                        .collect(),
+                    notes,
+                }
+            }
+            Error::Pointer(what, span) => ParseError {
+                message: format!("{what} must not be a pointer"),
+                labels: vec![(span, "expression is a pointer".into())],
+                notes: vec![],
+            },
+            Error::ReservedKeyword(name_span) => ParseError {
+                message: format!("name `{}` is a reserved keyword", &source[name_span]),
+                labels: vec![(
+                    name_span,
+                    format!("definition of `{}`", &source[name_span]).into(),
+                )],
+                notes: vec![],
+            },
+            Error::Redefinition { previous, current } => ParseError {
+                message: format!("redefinition of `{}`", &source[current]),
+                labels: vec![
+                    (
+                        current,
+                        format!("redefinition of `{}`", &source[current]).into(),
+                    ),
+                    (
+                        previous,
+                        format!("previous definition of `{}`", &source[previous]).into(),
+                    ),
+                ],
+                notes: vec![],
+            },
+            Error::RecursiveDeclaration { ident, usage } => ParseError {
+                message: format!("declaration of `{}` is recursive", &source[ident]),
+                labels: vec![(ident, "".into()), (usage, "uses itself here".into())],
+                notes: vec![],
+            },
+            Error::CyclicDeclaration { ident, ref path } => ParseError {
+                message: format!("declaration of `{}` is cyclic", &source[ident]),
+                labels: path
+                    .iter()
+                    .enumerate()
+                    .flat_map(|(i, &(ident, usage))| {
+                        [
+                            (ident, "".into()),
+                            (
+                                usage,
+                                if i == path.len() - 1 {
+                                    "ending the cycle".into()
+                                } else {
+                                    format!("uses `{}`", &source[ident]).into()
+                                },
+                            ),
+                        ]
+                    })
+                    .collect(),
+                notes: vec![],
+            },
+            Error::InvalidSwitchValue { uint, span } => ParseError {
+                message: "invalid switch value".to_string(),
+                labels: vec![(
+                    span,
+                    if uint {
+                        "expected unsigned integer"
+                    } else {
+                        "expected signed integer"
+                    }
+                    .into(),
+                )],
+                notes: vec![if uint {
+                    format!("suffix the integer with a `u`: '{}u'", &source[span])
+                } else {
+                    let span = span.to_range().unwrap();
+                    format!(
+                        "remove the `u` suffix: '{}'",
+                        &source[span.start..span.end - 1]
+                    )
+                }],
+            },
+            Error::CalledEntryPoint(span) => ParseError {
+                message: "entry point cannot be called".to_string(),
+                labels: vec![(span, "entry point cannot be called".into())],
+                notes: vec![],
+            },
+            Error::WrongArgumentCount {
+                span,
+                ref expected,
+                found,
+            } => ParseError {
+                message: format!(
+                    "wrong number of arguments: expected {}, found {}",
+                    if expected.len() < 2 {
+                        format!("{}", expected.start)
+                    } else {
+                        format!("{}..{}", expected.start, expected.end)
+                    },
+                    found
+                ),
+                labels: vec![(span, "wrong number of arguments".into())],
+                notes: vec![],
+            },
+            Error::FunctionReturnsVoid(span) => ParseError {
+                message: "function does not return any value".to_string(),
+                labels: vec![(span, "".into())],
+                notes: vec![
+                    "perhaps you meant to call the function in a separate statement?".into(),
+                ],
+            },
+            Error::InvalidWorkGroupUniformLoad(span) => ParseError {
+                message: "incorrect type passed to workgroupUniformLoad".into(),
+                labels: vec![(span, "".into())],
+                notes: vec!["passed type must be a workgroup pointer".into()],
+            },
+            Error::Internal(message) => ParseError {
+                message: "internal WGSL front end error".to_string(),
+                labels: vec![],
+                notes: vec![message.into()],
+            },
+            Error::ExpectedConstExprConcreteIntegerScalar(span) => ParseError {
+                message: "must be a const-expression that resolves to a concrete integer scalar (u32 or i32)".to_string(),
+                labels: vec![(span, "must resolve to u32 or i32".into())],
+                notes: vec![],
+            },
+            Error::ExpectedNonNegative(span) => ParseError {
+                message: "must be non-negative (>= 0)".to_string(),
+                labels: vec![(span, "must be non-negative".into())],
+                notes: vec![],
+            },
+            Error::ExpectedPositiveArrayLength(span) => ParseError {
+                message: "array element count must be positive (> 0)".to_string(),
+                labels: vec![(span, "must be positive".into())],
+                notes: vec![],
+            },
+            Error::ConstantEvaluatorError(ref e, span) => ParseError {
+                message: e.to_string(),
+                labels: vec![(span, "see msg".into())],
+                notes: vec![],
+            },
+            Error::MissingWorkgroupSize(span) => ParseError {
+                message: "workgroup size is missing on compute shader entry point".to_string(),
+                labels: vec![(
+                    span,
+                    "must be paired with a @workgroup_size attribute".into(),
+                )],
+                notes: vec![],
+            },
+            Error::AutoConversion { dest_span, ref dest_type, source_span, ref source_type } => ParseError {
+                message: format!("automatic conversions cannot convert `{source_type}` to `{dest_type}`"),
+                labels: vec![
+                    (
+                        dest_span,
+                        format!("a value of type {dest_type} is required here").into(),
+                    ),
+                    (
+                        source_span,
+                        format!("this expression has type {source_type}").into(),
+                    )
+                ],
+                notes: vec![],
+            },
+            Error::AutoConversionLeafScalar { dest_span, ref dest_scalar, source_span, ref source_type } => ParseError {
+                message: format!("automatic conversions cannot convert elements of `{source_type}` to `{dest_scalar}`"),
+                labels: vec![
+                    (
+                        dest_span,
+                        format!("a value with elements of type {dest_scalar} is required here").into(),
+                    ),
+                    (
+                        source_span,
+                        format!("this expression has type {source_type}").into(),
+                    )
+                ],
+                notes: vec![],
+            },
+            Error::ConcretizationFailed { expr_span, ref expr_type, ref scalar, ref inner } => ParseError {
+                message: format!("failed to convert expression to a concrete type: {}", inner),
+                labels: vec![
+                    (
+                        expr_span,
+                        format!("this expression has type {}", expr_type).into(),
+                    )
+                ],
+                notes: vec![
+                    format!("the expression should have been converted to have {} scalar type", scalar),
+                ]
+            },
+        }
+    }
+}
diff --git a/third_party/rust/naga/src/front/wgsl/index.rs b/third_party/rust/naga/src/front/wgsl/index.rs
new file mode 100644
index 0000000000..a5524fe8f1
--- /dev/null
+++ b/third_party/rust/naga/src/front/wgsl/index.rs
@@ -0,0 +1,193 @@
+use super::Error;
+use crate::front::wgsl::parse::ast;
+use crate::{FastHashMap, Handle, Span};
+
+/// A `GlobalDecl` list in which each definition occurs before all its uses.
+pub struct Index<'a> {
+    dependency_order: Vec<Handle<ast::GlobalDecl<'a>>>,
+}
+
+impl<'a> Index<'a> {
+    /// Generate an `Index` for the given translation unit.
+    ///
+    /// Perform a topological sort on `tu`'s global declarations, placing
+    /// referents before the definitions that refer to them.
+    ///
+    /// Return an error if the graph of references between declarations contains
+    /// any cycles.
+    pub fn generate(tu: &ast::TranslationUnit<'a>) -> Result<Self, Error<'a>> {
+        // Produce a map from global definitions' names to their `Handle<GlobalDecl>`s.
+        // While doing so, reject conflicting definitions.
+        let mut globals = FastHashMap::with_capacity_and_hasher(tu.decls.len(), Default::default());
+        for (handle, decl) in tu.decls.iter() {
+            let ident = decl_ident(decl);
+            let name = ident.name;
+            if let Some(old) = globals.insert(name, handle) {
+                return Err(Error::Redefinition {
+                    previous: decl_ident(&tu.decls[old]).span,
+                    current: ident.span,
+                });
+            }
+        }
+
+        let len = tu.decls.len();
+        let solver = DependencySolver {
+            globals: &globals,
+            module: tu,
+            visited: vec![false; len],
+            temp_visited: vec![false; len],
+            path: Vec::new(),
+            out: Vec::with_capacity(len),
+        };
+        let dependency_order = solver.solve()?;
+
+        Ok(Self { dependency_order })
+    }
+
+    /// Iterate over `GlobalDecl`s, visiting each definition before all its uses.
+    ///
+    /// Produce handles for all of the `GlobalDecl`s of the `TranslationUnit`
+    /// passed to `Index::generate`, ordered so that a given declaration is
+    /// produced before any other declaration that uses it.
+    pub fn visit_ordered(&self) -> impl Iterator<Item = Handle<ast::GlobalDecl<'a>>> + '_ {
+        self.dependency_order.iter().copied()
+    }
+}
+
+/// An edge from a reference to its referent in the current depth-first
+/// traversal.
+///
+/// This is like `ast::Dependency`, except that we've determined which
+/// `GlobalDecl` it refers to.
+struct ResolvedDependency<'a> {
+    /// The referent of some identifier used in the current declaration.
+    decl: Handle<ast::GlobalDecl<'a>>,
+
+    /// Where that use occurs within the current declaration.
+    usage: Span,
+}
+
+/// Local state for ordering a `TranslationUnit`'s module-scope declarations.
+///
+/// Values of this type are used temporarily by `Index::generate`
+/// to perform a depth-first sort on the declarations.
+/// Technically, what we want is a topological sort, but a depth-first sort
+/// has one key benefit - it's much more efficient in storing
+/// the path of each node for error generation.
+struct DependencySolver<'source, 'temp> {
+    /// A map from module-scope definitions' names to their handles.
+    globals: &'temp FastHashMap<&'source str, Handle<ast::GlobalDecl<'source>>>,
+
+    /// The translation unit whose declarations we're ordering.
+    module: &'temp ast::TranslationUnit<'source>,
+
+    /// For each handle, whether we have pushed it onto `out` yet.
+    visited: Vec<bool>,
+
+    /// For each handle, whether it is an predecessor in the current depth-first
+    /// traversal. This is used to detect cycles in the reference graph.
+    temp_visited: Vec<bool>,
+
+    /// The current path in our depth-first traversal. Used for generating
+    /// error messages for non-trivial reference cycles.
+    path: Vec<ResolvedDependency<'source>>,
+
+    /// The list of declaration handles, with declarations before uses.
+    out: Vec<Handle<ast::GlobalDecl<'source>>>,
+}
+
+impl<'a> DependencySolver<'a, '_> {
+    /// Produce the sorted list of declaration handles, and check for cycles.
+    fn solve(mut self) -> Result<Vec<Handle<ast::GlobalDecl<'a>>>, Error<'a>> {
+        for (id, _) in self.module.decls.iter() {
+            if self.visited[id.index()] {
+                continue;
+            }
+
+            self.dfs(id)?;
+        }
+
+        Ok(self.out)
+    }
+
+    /// Ensure that all declarations used by `id` have been added to the
+    /// ordering, and then append `id` itself.
+    fn dfs(&mut self, id: Handle<ast::GlobalDecl<'a>>) -> Result<(), Error<'a>> {
+        let decl = &self.module.decls[id];
+        let id_usize = id.index();
+
+        self.temp_visited[id_usize] = true;
+        for dep in decl.dependencies.iter() {
+            if let Some(&dep_id) = self.globals.get(dep.ident) {
+                self.path.push(ResolvedDependency {
+                    decl: dep_id,
+                    usage: dep.usage,
+                });
+                let dep_id_usize = dep_id.index();
+
+                if self.temp_visited[dep_id_usize] {
+                    // Found a cycle.
+                    return if dep_id == id {
+                        // A declaration refers to itself directly.
+                        Err(Error::RecursiveDeclaration {
+                            ident: decl_ident(decl).span,
+                            usage: dep.usage,
+                        })
+                    } else {
+                        // A declaration refers to itself indirectly, through
+                        // one or more other definitions. Report the entire path
+                        // of references.
+                        let start_at = self
+                            .path
+                            .iter()
+                            .rev()
+                            .enumerate()
+                            .find_map(|(i, dep)| (dep.decl == dep_id).then_some(i))
+                            .unwrap_or(0);
+
+                        Err(Error::CyclicDeclaration {
+                            ident: decl_ident(&self.module.decls[dep_id]).span,
+                            path: self.path[start_at..]
+                                .iter()
+                                .map(|curr_dep| {
+                                    let curr_id = curr_dep.decl;
+                                    let curr_decl = &self.module.decls[curr_id];
+
+                                    (decl_ident(curr_decl).span, curr_dep.usage)
+                                })
+                                .collect(),
+                        })
+                    };
+                } else if !self.visited[dep_id_usize] {
+                    self.dfs(dep_id)?;
+                }
+
+                // Remove this edge from the current path.
+                self.path.pop();
+            }
+
+            // Ignore unresolved identifiers; they may be predeclared objects.
+        }
+
+        // Remove this node from the current path.
+        self.temp_visited[id_usize] = false;
+
+        // Now everything this declaration uses has been visited, and is already
+        // present in `out`. That means we we can append this one to the
+        // ordering, and mark it as visited.
+        self.out.push(id);
+        self.visited[id_usize] = true;
+
+        Ok(())
+    }
+}
+
+const fn decl_ident<'a>(decl: &ast::GlobalDecl<'a>) -> ast::Ident<'a> {
+    match decl.kind {
+        ast::GlobalDeclKind::Fn(ref f) => f.name,
+        ast::GlobalDeclKind::Var(ref v) => v.name,
+        ast::GlobalDeclKind::Const(ref c) => c.name,
+        ast::GlobalDeclKind::Struct(ref s) => s.name,
+        ast::GlobalDeclKind::Type(ref t) => t.name,
+    }
+}
diff --git a/third_party/rust/naga/src/front/wgsl/lower/construction.rs b/third_party/rust/naga/src/front/wgsl/lower/construction.rs
new file mode 100644
index 0000000000..de0d11d227
--- /dev/null
+++ b/third_party/rust/naga/src/front/wgsl/lower/construction.rs
@@ -0,0 +1,616 @@
+use std::num::NonZeroU32;
+
+use crate::front::wgsl::parse::ast;
+use crate::{Handle, Span};
+
+use crate::front::wgsl::error::Error;
+use crate::front::wgsl::lower::{ExpressionContext, Lowerer};
+
+/// A cooked form of `ast::ConstructorType` that uses Naga types whenever
+/// possible.
+enum Constructor<T> {
+    /// A vector construction whose component type is inferred from the
+    /// argument: `vec3(1.0)`.
+    PartialVector { size: crate::VectorSize },
+
+    /// A matrix construction whose component type is inferred from the
+    /// argument: `mat2x2(1,2,3,4)`.
+    PartialMatrix {
+        columns: crate::VectorSize,
+        rows: crate::VectorSize,
+    },
+
+    /// An array whose component type and size are inferred from the arguments:
+    /// `array(3,4,5)`.
+    PartialArray,
+
+    /// A known Naga type.
+    ///
+    /// When we match on this type, we need to see the `TypeInner` here, but at
+    /// the point that we build this value we'll still need mutable access to
+    /// the module later. To avoid borrowing from the module, the type parameter
+    /// `T` is `Handle<Type>` initially. Then we use `borrow_inner` to produce a
+    /// version holding a tuple `(Handle<Type>, &TypeInner)`.
+    Type(T),
+}
+
+impl Constructor<Handle<crate::Type>> {
+    /// Return an equivalent `Constructor` value that includes borrowed
+    /// `TypeInner` values alongside any type handles.
+    ///
+    /// The returned form is more convenient to match on, since the patterns
+    /// can actually see what the handle refers to.
+    fn borrow_inner(
+        self,
+        module: &crate::Module,
+    ) -> Constructor<(Handle<crate::Type>, &crate::TypeInner)> {
+        match self {
+            Constructor::PartialVector { size } => Constructor::PartialVector { size },
+            Constructor::PartialMatrix { columns, rows } => {
+                Constructor::PartialMatrix { columns, rows }
+            }
+            Constructor::PartialArray => Constructor::PartialArray,
+            Constructor::Type(handle) => Constructor::Type((handle, &module.types[handle].inner)),
+        }
+    }
+}
+
+impl Constructor<(Handle<crate::Type>, &crate::TypeInner)> {
+    fn to_error_string(&self, ctx: &ExpressionContext) -> String {
+        match *self {
+            Self::PartialVector { size } => {
+                format!("vec{}<?>", size as u32,)
+            }
+            Self::PartialMatrix { columns, rows } => {
+                format!("mat{}x{}<?>", columns as u32, rows as u32,)
+            }
+            Self::PartialArray => "array<?, ?>".to_string(),
+            Self::Type((handle, _inner)) => handle.to_wgsl(&ctx.module.to_ctx()),
+        }
+    }
+}
+
+enum Components<'a> {
+    None,
+    One {
+        component: Handle<crate::Expression>,
+        span: Span,
+        ty_inner: &'a crate::TypeInner,
+    },
+    Many {
+        components: Vec<Handle<crate::Expression>>,
+        spans: Vec<Span>,
+    },
+}
+
+impl Components<'_> {
+    fn into_components_vec(self) -> Vec<Handle<crate::Expression>> {
+        match self {
+            Self::None => vec![],
+            Self::One { component, .. } => vec![component],
+            Self::Many { components, .. } => components,
+        }
+    }
+}
+
+impl<'source, 'temp> Lowerer<'source, 'temp> {
+    /// Generate Naga IR for a type constructor expression.
+    ///
+    /// The `constructor` value represents the head of the constructor
+    /// expression, which is at least a hint of which type is being built; if
+    /// it's one of the `Partial` variants, we need to consider the argument
+    /// types as well.
+    ///
+    /// This is used for [`Construct`] expressions, but also for [`Call`]
+    /// expressions, once we've determined that the "callable" (in WGSL spec
+    /// terms) is actually a type.
+    ///
+    /// [`Construct`]: ast::Expression::Construct
+    /// [`Call`]: ast::Expression::Call
+    pub fn construct(
+        &mut self,
+        span: Span,
+        constructor: &ast::ConstructorType<'source>,
+        ty_span: Span,
+        components: &[Handle<ast::Expression<'source>>],
+        ctx: &mut ExpressionContext<'source, '_, '_>,
+    ) -> Result<Handle<crate::Expression>, Error<'source>> {
+        use crate::proc::TypeResolution as Tr;
+
+        let constructor_h = self.constructor(constructor, ctx)?;
+
+        let components = match *components {
+            [] => Components::None,
+            [component] => {
+                let span = ctx.ast_expressions.get_span(component);
+                let component = self.expression_for_abstract(component, ctx)?;
+                let ty_inner = super::resolve_inner!(ctx, component);
+
+                Components::One {
+                    component,
+                    span,
+                    ty_inner,
+                }
+            }
+            ref ast_components @ [_, _, ..] => {
+                let components = ast_components
+                    .iter()
+                    .map(|&expr| self.expression_for_abstract(expr, ctx))
+                    .collect::<Result<_, _>>()?;
+                let spans = ast_components
+                    .iter()
+                    .map(|&expr| ctx.ast_expressions.get_span(expr))
+                    .collect();
+
+                for &component in &components {
+                    ctx.grow_types(component)?;
+                }
+
+                Components::Many { components, spans }
+            }
+        };
+
+        // Even though we computed `constructor` above, wait until now to borrow
+        // a reference to the `TypeInner`, so that the component-handling code
+        // above can have mutable access to the type arena.
+        let constructor = constructor_h.borrow_inner(ctx.module);
+
+        let expr;
+        match (components, constructor) {
+            // Empty constructor
+            (Components::None, dst_ty) => match dst_ty {
+                Constructor::Type((result_ty, _)) => {
+                    return ctx.append_expression(crate::Expression::ZeroValue(result_ty), span)
+                }
+                Constructor::PartialVector { .. }
+                | Constructor::PartialMatrix { .. }
+                | Constructor::PartialArray => {
+                    // We have no arguments from which to infer the result type, so
+                    // partial constructors aren't acceptable here.
+                    return Err(Error::TypeNotInferable(ty_span));
+                }
+            },
+
+            // Scalar constructor & conversion (scalar -> scalar)
+            (
+                Components::One {
+                    component,
+                    ty_inner: &crate::TypeInner::Scalar { .. },
+                    ..
+                },
+                Constructor::Type((_, &crate::TypeInner::Scalar(scalar))),
+            ) => {
+                expr = crate::Expression::As {
+                    expr: component,
+                    kind: scalar.kind,
+                    convert: Some(scalar.width),
+                };
+            }
+
+            // Vector conversion (vector -> vector)
+            (
+                Components::One {
+                    component,
+                    ty_inner: &crate::TypeInner::Vector { size: src_size, .. },
+                    ..
+                },
+                Constructor::Type((
+                    _,
+                    &crate::TypeInner::Vector {
+                        size: dst_size,
+                        scalar: dst_scalar,
+                    },
+                )),
+            ) if dst_size == src_size => {
+                expr = crate::Expression::As {
+                    expr: component,
+                    kind: dst_scalar.kind,
+                    convert: Some(dst_scalar.width),
+                };
+            }
+
+            // Vector conversion (vector -> vector) - partial
+            (
+                Components::One {
+                    component,
+                    ty_inner: &crate::TypeInner::Vector { size: src_size, .. },
+                    ..
+                },
+                Constructor::PartialVector { size: dst_size },
+            ) if dst_size == src_size => {
+                // This is a trivial conversion: the sizes match, and a Partial
+                // constructor doesn't specify a scalar type, so nothing can
+                // possibly happen.
+                return Ok(component);
+            }
+
+            // Matrix conversion (matrix -> matrix)
+            (
+                Components::One {
+                    component,
+                    ty_inner:
+                        &crate::TypeInner::Matrix {
+                            columns: src_columns,
+                            rows: src_rows,
+                            ..
+                        },
+                    ..
+                },
+                Constructor::Type((
+                    _,
+                    &crate::TypeInner::Matrix {
+                        columns: dst_columns,
+                        rows: dst_rows,
+                        scalar: dst_scalar,
+                    },
+                )),
+            ) if dst_columns == src_columns && dst_rows == src_rows => {
+                expr = crate::Expression::As {
+                    expr: component,
+                    kind: dst_scalar.kind,
+                    convert: Some(dst_scalar.width),
+                };
+            }
+
+            // Matrix conversion (matrix -> matrix) - partial
+            (
+                Components::One {
+                    component,
+                    ty_inner:
+                        &crate::TypeInner::Matrix {
+                            columns: src_columns,
+                            rows: src_rows,
+                            ..
+                        },
+                    ..
+                },
+                Constructor::PartialMatrix {
+                    columns: dst_columns,
+                    rows: dst_rows,
+                },
+            ) if dst_columns == src_columns && dst_rows == src_rows => {
+                // This is a trivial conversion: the sizes match, and a Partial
+                // constructor doesn't specify a scalar type, so nothing can
+                // possibly happen.
+                return Ok(component);
+            }
+
+            // Vector constructor (splat) - infer type
+            (
+                Components::One {
+                    component,
+                    ty_inner: &crate::TypeInner::Scalar { .. },
+                    ..
+                },
+                Constructor::PartialVector { size },
+            ) => {
+                expr = crate::Expression::Splat {
+                    size,
+                    value: component,
+                };
+            }
+
+            // Vector constructor (splat)
+            (
+                Components::One {
+                    mut component,
+                    ty_inner: &crate::TypeInner::Scalar(_),
+                    ..
+                },
+                Constructor::Type((_, &crate::TypeInner::Vector { size, scalar })),
+            ) => {
+                ctx.convert_slice_to_common_leaf_scalar(
+                    std::slice::from_mut(&mut component),
+                    scalar,
+                )?;
+                expr = crate::Expression::Splat {
+                    size,
+                    value: component,
+                };
+            }
+
+            // Vector constructor (by elements), partial
+            (
+                Components::Many {
+                    mut components,
+                    spans,
+                },
+                Constructor::PartialVector { size },
+            ) => {
+                let consensus_scalar =
+                    ctx.automatic_conversion_consensus(&components)
+                        .map_err(|index| {
+                            Error::InvalidConstructorComponentType(spans[index], index as i32)
+                        })?;
+                ctx.convert_slice_to_common_leaf_scalar(&mut components, consensus_scalar)?;
+                let inner = consensus_scalar.to_inner_vector(size);
+                let ty = ctx.ensure_type_exists(inner);
+                expr = crate::Expression::Compose { ty, components };
+            }
+
+            // Vector constructor (by elements), full type given
+            (
+                Components::Many { mut components, .. },
+                Constructor::Type((ty, &crate::TypeInner::Vector { scalar, .. })),
+            ) => {
+                ctx.try_automatic_conversions_for_vector(&mut components, scalar, ty_span)?;
+                expr = crate::Expression::Compose { ty, components };
+            }
+
+            // Matrix constructor (by elements), partial
+            (
+                Components::Many {
+                    mut components,
+                    spans,
+                },
+                Constructor::PartialMatrix { columns, rows },
+            ) if components.len() == columns as usize * rows as usize => {
+                let consensus_scalar =
+                    ctx.automatic_conversion_consensus(&components)
+                        .map_err(|index| {
+                            Error::InvalidConstructorComponentType(spans[index], index as i32)
+                        })?;
+                // We actually only accept floating-point elements.
+                let consensus_scalar = consensus_scalar
+                    .automatic_conversion_combine(crate::Scalar::ABSTRACT_FLOAT)
+                    .unwrap_or(consensus_scalar);
+                ctx.convert_slice_to_common_leaf_scalar(&mut components, consensus_scalar)?;
+                let vec_ty = ctx.ensure_type_exists(consensus_scalar.to_inner_vector(rows));
+
+                let components = components
+                    .chunks(rows as usize)
+                    .map(|vec_components| {
+                        ctx.append_expression(
+                            crate::Expression::Compose {
+                                ty: vec_ty,
+                                components: Vec::from(vec_components),
+                            },
+                            Default::default(),
+                        )
+                    })
+                    .collect::<Result<Vec<_>, _>>()?;
+
+                let ty = ctx.ensure_type_exists(crate::TypeInner::Matrix {
+                    columns,
+                    rows,
+                    scalar: consensus_scalar,
+                });
+                expr = crate::Expression::Compose { ty, components };
+            }
+
+            // Matrix constructor (by elements), type given
+            (
+                Components::Many { mut components, .. },
+                Constructor::Type((
+                    _,
+                    &crate::TypeInner::Matrix {
+                        columns,
+                        rows,
+                        scalar,
+                    },
+                )),
+            ) if components.len() == columns as usize * rows as usize => {
+                let element = Tr::Value(crate::TypeInner::Scalar(scalar));
+                ctx.try_automatic_conversions_slice(&mut components, &element, ty_span)?;
+                let vec_ty = ctx.ensure_type_exists(scalar.to_inner_vector(rows));
+
+                let components = components
+                    .chunks(rows as usize)
+                    .map(|vec_components| {
+                        ctx.append_expression(
+                            crate::Expression::Compose {
+                                ty: vec_ty,
+                                components: Vec::from(vec_components),
+                            },
+                            Default::default(),
+                        )
+                    })
+                    .collect::<Result<Vec<_>, _>>()?;
+
+                let ty = ctx.ensure_type_exists(crate::TypeInner::Matrix {
+                    columns,
+                    rows,
+                    scalar,
+                });
+                expr = crate::Expression::Compose { ty, components };
+            }
+
+            // Matrix constructor (by columns), partial
+            (
+                Components::Many {
+                    mut components,
+                    spans,
+                },
+                Constructor::PartialMatrix { columns, rows },
+            ) => {
+                let consensus_scalar =
+                    ctx.automatic_conversion_consensus(&components)
+                        .map_err(|index| {
+                            Error::InvalidConstructorComponentType(spans[index], index as i32)
+                        })?;
+                ctx.convert_slice_to_common_leaf_scalar(&mut components, consensus_scalar)?;
+                let ty = ctx.ensure_type_exists(crate::TypeInner::Matrix {
+                    columns,
+                    rows,
+                    scalar: consensus_scalar,
+                });
+                expr = crate::Expression::Compose { ty, components };
+            }
+
+            // Matrix constructor (by columns), type given
+            (
+                Components::Many { mut components, .. },
+                Constructor::Type((
+                    ty,
+                    &crate::TypeInner::Matrix {
+                        columns: _,
+                        rows,
+                        scalar,
+                    },
+                )),
+            ) => {
+                let component_ty = crate::TypeInner::Vector { size: rows, scalar };
+                ctx.try_automatic_conversions_slice(
+                    &mut components,
+                    &Tr::Value(component_ty),
+                    ty_span,
+                )?;
+                expr = crate::Expression::Compose { ty, components };
+            }
+
+            // Array constructor - infer type
+            (components, Constructor::PartialArray) => {
+                let mut components = components.into_components_vec();
+                if let Ok(consensus_scalar) = ctx.automatic_conversion_consensus(&components) {
+                    // Note that this will *not* necessarily convert all the
+                    // components to the same type! The `automatic_conversion_consensus`
+                    // method only considers the parameters' leaf scalar
+                    // types; the parameters themselves could be any mix of
+                    // vectors, matrices, and scalars.
+                    //
+                    // But *if* it is possible for this array construction
+                    // expression to be well-typed at all, then all the
+                    // parameters must have the same type constructors (vec,
+                    // matrix, scalar) applied to their leaf scalars, so
+                    // reconciling their scalars is always the right thing to
+                    // do. And if this array construction is not well-typed,
+                    // these conversions will not make it so, and we can let
+                    // validation catch the error.
+                    ctx.convert_slice_to_common_leaf_scalar(&mut components, consensus_scalar)?;
+                } else {
+                    // There's no consensus scalar. Emit the `Compose`
+                    // expression anyway, and let validation catch the problem.
+                }
+
+                let base = ctx.register_type(components[0])?;
+
+                let inner = crate::TypeInner::Array {
+                    base,
+                    size: crate::ArraySize::Constant(
+                        NonZeroU32::new(u32::try_from(components.len()).unwrap()).unwrap(),
+                    ),
+                    stride: {
+                        self.layouter.update(ctx.module.to_ctx()).unwrap();
+                        self.layouter[base].to_stride()
+                    },
+                };
+                let ty = ctx.ensure_type_exists(inner);
+
+                expr = crate::Expression::Compose { ty, components };
+            }
+
+            // Array constructor, explicit type
+            (components, Constructor::Type((ty, &crate::TypeInner::Array { base, .. }))) => {
+                let mut components = components.into_components_vec();
+                ctx.try_automatic_conversions_slice(&mut components, &Tr::Handle(base), ty_span)?;
+                expr = crate::Expression::Compose { ty, components };
+            }
+
+            // Struct constructor
+            (
+                components,
+                Constructor::Type((ty, &crate::TypeInner::Struct { ref members, .. })),
+            ) => {
+                let mut components = components.into_components_vec();
+                let struct_ty_span = ctx.module.types.get_span(ty);
+
+                // Make a vector of the members' type handles in advance, to
+                // avoid borrowing `members` from `ctx` while we generate
+                // new code.
+                let members: Vec<Handle<crate::Type>> = members.iter().map(|m| m.ty).collect();
+
+                for (component, &ty) in components.iter_mut().zip(&members) {
+                    *component =
+                        ctx.try_automatic_conversions(*component, &Tr::Handle(ty), struct_ty_span)?;
+                }
+                expr = crate::Expression::Compose { ty, components };
+            }
+
+            // ERRORS
+
+            // Bad conversion (type cast)
+            (Components::One { span, ty_inner, .. }, constructor) => {
+                let from_type = ty_inner.to_wgsl(&ctx.module.to_ctx());
+                return Err(Error::BadTypeCast {
+                    span,
+                    from_type,
+                    to_type: constructor.to_error_string(ctx),
+                });
+            }
+
+            // Too many parameters for scalar constructor
+            (
+                Components::Many { spans, .. },
+                Constructor::Type((_, &crate::TypeInner::Scalar { .. })),
+            ) => {
+                let span = spans[1].until(spans.last().unwrap());
+                return Err(Error::UnexpectedComponents(span));
+            }
+
+            // Other types can't be constructed
+            _ => return Err(Error::TypeNotConstructible(ty_span)),
+        }
+
+        let expr = ctx.append_expression(expr, span)?;
+        Ok(expr)
+    }
+
+    /// Build a [`Constructor`] for a WGSL construction expression.
+    ///
+    /// If `constructor` conveys enough information to determine which Naga [`Type`]
+    /// we're actually building (i.e., it's not a partial constructor), then
+    /// ensure the `Type` exists in [`ctx.module`], and return
+    /// [`Constructor::Type`].
+    ///
+    /// Otherwise, return the [`Constructor`] partial variant corresponding to
+    /// `constructor`.
+    ///
+    /// [`Type`]: crate::Type
+    /// [`ctx.module`]: ExpressionContext::module
+    fn constructor<'out>(
+        &mut self,
+        constructor: &ast::ConstructorType<'source>,
+        ctx: &mut ExpressionContext<'source, '_, 'out>,
+    ) -> Result<Constructor<Handle<crate::Type>>, Error<'source>> {
+        let handle = match *constructor {
+            ast::ConstructorType::Scalar(scalar) => {
+                let ty = ctx.ensure_type_exists(scalar.to_inner_scalar());
+                Constructor::Type(ty)
+            }
+            ast::ConstructorType::PartialVector { size } => Constructor::PartialVector { size },
+            ast::ConstructorType::Vector { size, scalar } => {
+                let ty = ctx.ensure_type_exists(scalar.to_inner_vector(size));
+                Constructor::Type(ty)
+            }
+            ast::ConstructorType::PartialMatrix { columns, rows } => {
+                Constructor::PartialMatrix { columns, rows }
+            }
+            ast::ConstructorType::Matrix {
+                rows,
+                columns,
+                width,
+            } => {
+                let ty = ctx.ensure_type_exists(crate::TypeInner::Matrix {
+                    columns,
+                    rows,
+                    scalar: crate::Scalar::float(width),
+                });
+                Constructor::Type(ty)
+            }
+            ast::ConstructorType::PartialArray => Constructor::PartialArray,
+            ast::ConstructorType::Array { base, size } => {
+                let base = self.resolve_ast_type(base, &mut ctx.as_global())?;
+                let size = self.array_size(size, &mut ctx.as_global())?;
+
+                self.layouter.update(ctx.module.to_ctx()).unwrap();
+                let stride = self.layouter[base].to_stride();
+
+                let ty = ctx.ensure_type_exists(crate::TypeInner::Array { base, size, stride });
+                Constructor::Type(ty)
+            }
+            ast::ConstructorType::Type(ty) => Constructor::Type(ty),
+        };
+
+        Ok(handle)
+    }
+}
diff --git a/third_party/rust/naga/src/front/wgsl/lower/conversion.rs b/third_party/rust/naga/src/front/wgsl/lower/conversion.rs
new file mode 100644
index 0000000000..2a2690f096
--- /dev/null
+++ b/third_party/rust/naga/src/front/wgsl/lower/conversion.rs
@@ -0,0 +1,503 @@
+//! WGSL's automatic conversions for abstract types.
+
+use crate::{Handle, Span};
+
+impl<'source, 'temp, 'out> super::ExpressionContext<'source, 'temp, 'out> {
+    /// Try to use WGSL's automatic conversions to convert `expr` to `goal_ty`.
+    ///
+    /// If no conversions are necessary, return `expr` unchanged.
+    ///
+    /// If automatic conversions cannot convert `expr` to `goal_ty`, return an
+    /// [`AutoConversion`] error.
+    ///
+    /// Although the Load Rule is one of the automatic conversions, this
+    /// function assumes it has already been applied if appropriate, as
+    /// indicated by the fact that the Rust type of `expr` is not `Typed<_>`.
+    ///
+    /// [`AutoConversion`]: super::Error::AutoConversion
+    pub fn try_automatic_conversions(
+        &mut self,
+        expr: Handle<crate::Expression>,
+        goal_ty: &crate::proc::TypeResolution,
+        goal_span: Span,
+    ) -> Result<Handle<crate::Expression>, super::Error<'source>> {
+        let expr_span = self.get_expression_span(expr);
+        // Keep the TypeResolution so we can get type names for
+        // structs in error messages.
+        let expr_resolution = super::resolve!(self, expr);
+        let types = &self.module.types;
+        let expr_inner = expr_resolution.inner_with(types);
+        let goal_inner = goal_ty.inner_with(types);
+
+        // If `expr` already has the requested type, we're done.
+        if expr_inner.equivalent(goal_inner, types) {
+            return Ok(expr);
+        }
+
+        let (_expr_scalar, goal_scalar) =
+            match expr_inner.automatically_converts_to(goal_inner, types) {
+                Some(scalars) => scalars,
+                None => {
+                    let gctx = &self.module.to_ctx();
+                    let source_type = expr_resolution.to_wgsl(gctx);
+                    let dest_type = goal_ty.to_wgsl(gctx);
+
+                    return Err(super::Error::AutoConversion {
+                        dest_span: goal_span,
+                        dest_type,
+                        source_span: expr_span,
+                        source_type,
+                    });
+                }
+            };
+
+        self.convert_leaf_scalar(expr, expr_span, goal_scalar)
+    }
+
+    /// Try to convert `expr`'s leaf scalar to `goal` using automatic conversions.
+    ///
+    /// If no conversions are necessary, return `expr` unchanged.
+    ///
+    /// If automatic conversions cannot convert `expr` to `goal_scalar`, return
+    /// an [`AutoConversionLeafScalar`] error.
+    ///
+    /// Although the Load Rule is one of the automatic conversions, this
+    /// function assumes it has already been applied if appropriate, as
+    /// indicated by the fact that the Rust type of `expr` is not `Typed<_>`.
+    ///
+    /// [`AutoConversionLeafScalar`]: super::Error::AutoConversionLeafScalar
+    pub fn try_automatic_conversion_for_leaf_scalar(
+        &mut self,
+        expr: Handle<crate::Expression>,
+        goal_scalar: crate::Scalar,
+        goal_span: Span,
+    ) -> Result<Handle<crate::Expression>, super::Error<'source>> {
+        let expr_span = self.get_expression_span(expr);
+        let expr_resolution = super::resolve!(self, expr);
+        let types = &self.module.types;
+        let expr_inner = expr_resolution.inner_with(types);
+
+        let make_error = || {
+            let gctx = &self.module.to_ctx();
+            let source_type = expr_resolution.to_wgsl(gctx);
+            super::Error::AutoConversionLeafScalar {
+                dest_span: goal_span,
+                dest_scalar: goal_scalar.to_wgsl(),
+                source_span: expr_span,
+                source_type,
+            }
+        };
+
+        let expr_scalar = match expr_inner.scalar() {
+            Some(scalar) => scalar,
+            None => return Err(make_error()),
+        };
+
+        if expr_scalar == goal_scalar {
+            return Ok(expr);
+        }
+
+        if !expr_scalar.automatically_converts_to(goal_scalar) {
+            return Err(make_error());
+        }
+
+        assert!(expr_scalar.is_abstract());
+
+        self.convert_leaf_scalar(expr, expr_span, goal_scalar)
+    }
+
+    fn convert_leaf_scalar(
+        &mut self,
+        expr: Handle<crate::Expression>,
+        expr_span: Span,
+        goal_scalar: crate::Scalar,
+    ) -> Result<Handle<crate::Expression>, super::Error<'source>> {
+        let expr_inner = super::resolve_inner!(self, expr);
+        if let crate::TypeInner::Array { .. } = *expr_inner {
+            self.as_const_evaluator()
+                .cast_array(expr, goal_scalar, expr_span)
+                .map_err(|err| super::Error::ConstantEvaluatorError(err, expr_span))
+        } else {
+            let cast = crate::Expression::As {
+                expr,
+                kind: goal_scalar.kind,
+                convert: Some(goal_scalar.width),
+            };
+            self.append_expression(cast, expr_span)
+        }
+    }
+
+    /// Try to convert `exprs` to `goal_ty` using WGSL's automatic conversions.
+    pub fn try_automatic_conversions_slice(
+        &mut self,
+        exprs: &mut [Handle<crate::Expression>],
+        goal_ty: &crate::proc::TypeResolution,
+        goal_span: Span,
+    ) -> Result<(), super::Error<'source>> {
+        for expr in exprs.iter_mut() {
+            *expr = self.try_automatic_conversions(*expr, goal_ty, goal_span)?;
+        }
+
+        Ok(())
+    }
+
+    /// Apply WGSL's automatic conversions to a vector constructor's arguments.
+    ///
+    /// When calling a vector constructor like `vec3<f32>(...)`, the parameters
+    /// can be a mix of scalars and vectors, with the latter being spread out to
+    /// contribute each of their components as a component of the new value.
+    /// When the element type is explicit, as with `<f32>` in the example above,
+    /// WGSL's automatic conversions should convert abstract scalar and vector
+    /// parameters to the constructor's required scalar type.
+    pub fn try_automatic_conversions_for_vector(
+        &mut self,
+        exprs: &mut [Handle<crate::Expression>],
+        goal_scalar: crate::Scalar,
+        goal_span: Span,
+    ) -> Result<(), super::Error<'source>> {
+        use crate::proc::TypeResolution as Tr;
+        use crate::TypeInner as Ti;
+        let goal_scalar_res = Tr::Value(Ti::Scalar(goal_scalar));
+
+        for (i, expr) in exprs.iter_mut().enumerate() {
+            // Keep the TypeResolution so we can get full type names
+            // in error messages.
+            let expr_resolution = super::resolve!(self, *expr);
+            let types = &self.module.types;
+            let expr_inner = expr_resolution.inner_with(types);
+
+            match *expr_inner {
+                Ti::Scalar(_) => {
+                    *expr = self.try_automatic_conversions(*expr, &goal_scalar_res, goal_span)?;
+                }
+                Ti::Vector { size, scalar: _ } => {
+                    let goal_vector_res = Tr::Value(Ti::Vector {
+                        size,
+                        scalar: goal_scalar,
+                    });
+                    *expr = self.try_automatic_conversions(*expr, &goal_vector_res, goal_span)?;
+                }
+                _ => {
+                    let span = self.get_expression_span(*expr);
+                    return Err(super::Error::InvalidConstructorComponentType(
+                        span, i as i32,
+                    ));
+                }
+            }
+        }
+
+        Ok(())
+    }
+
+    /// Convert `expr` to the leaf scalar type `scalar`.
+    pub fn convert_to_leaf_scalar(
+        &mut self,
+        expr: &mut Handle<crate::Expression>,
+        goal: crate::Scalar,
+    ) -> Result<(), super::Error<'source>> {
+        let inner = super::resolve_inner!(self, *expr);
+        // Do nothing if `inner` doesn't even have leaf scalars;
+        // it's a type error that validation will catch.
+        if inner.scalar() != Some(goal) {
+            let cast = crate::Expression::As {
+                expr: *expr,
+                kind: goal.kind,
+                convert: Some(goal.width),
+            };
+            let expr_span = self.get_expression_span(*expr);
+            *expr = self.append_expression(cast, expr_span)?;
+        }
+
+        Ok(())
+    }
+
+    /// Convert all expressions in `exprs` to a common scalar type.
+    ///
+    /// Note that the caller is responsible for making sure these
+    /// conversions are actually justified. This function simply
+    /// generates `As` expressions, regardless of whether they are
+    /// permitted WGSL automatic conversions. Callers intending to
+    /// implement automatic conversions need to determine for
+    /// themselves whether the casts we we generate are justified,
+    /// perhaps by calling `TypeInner::automatically_converts_to` or
+    /// `Scalar::automatic_conversion_combine`.
+    pub fn convert_slice_to_common_leaf_scalar(
+        &mut self,
+        exprs: &mut [Handle<crate::Expression>],
+        goal: crate::Scalar,
+    ) -> Result<(), super::Error<'source>> {
+        for expr in exprs.iter_mut() {
+            self.convert_to_leaf_scalar(expr, goal)?;
+        }
+
+        Ok(())
+    }
+
+    /// Return an expression for the concretized value of `expr`.
+    ///
+    /// If `expr` is already concrete, return it unchanged.
+    pub fn concretize(
+        &mut self,
+        mut expr: Handle<crate::Expression>,
+    ) -> Result<Handle<crate::Expression>, super::Error<'source>> {
+        let inner = super::resolve_inner!(self, expr);
+        if let Some(scalar) = inner.automatically_convertible_scalar(&self.module.types) {
+            let concretized = scalar.concretize();
+            if concretized != scalar {
+                assert!(scalar.is_abstract());
+                let expr_span = self.get_expression_span(expr);
+                expr = self
+                    .as_const_evaluator()
+                    .cast_array(expr, concretized, expr_span)
+                    .map_err(|err| {
+                        // A `TypeResolution` includes the type's full name, if
+                        // it has one. Also, avoid holding the borrow of `inner`
+                        // across the call to `cast_array`.
+                        let expr_type = &self.typifier()[expr];
+                        super::Error::ConcretizationFailed {
+                            expr_span,
+                            expr_type: expr_type.to_wgsl(&self.module.to_ctx()),
+                            scalar: concretized.to_wgsl(),
+                            inner: err,
+                        }
+                    })?;
+            }
+        }
+
+        Ok(expr)
+    }
+
+    /// Find the consensus scalar of `components` under WGSL's automatic
+    /// conversions.
+    ///
+    /// If `components` can all be converted to any common scalar via
+    /// WGSL's automatic conversions, return the best such scalar.
+    ///
+    /// The `components` slice must not be empty. All elements' types must
+    /// have been resolved.
+    ///
+    /// If `components` are definitely not acceptable as arguments to such
+    /// constructors, return `Err(i)`, where `i` is the index in
+    /// `components` of some problematic argument.
+    ///
+    /// This function doesn't fully type-check the arguments - it only
+    /// considers their leaf scalar types. This means it may return `Ok`
+    /// even when the Naga validator will reject the resulting
+    /// construction expression later.
+    pub fn automatic_conversion_consensus<'handle, I>(
+        &self,
+        components: I,
+    ) -> Result<crate::Scalar, usize>
+    where
+        I: IntoIterator<Item = &'handle Handle<crate::Expression>>,
+        I::IntoIter: Clone, // for debugging
+    {
+        let types = &self.module.types;
+        let mut inners = components
+            .into_iter()
+            .map(|&c| self.typifier()[c].inner_with(types));
+        log::debug!(
+            "wgsl automatic_conversion_consensus: {:?}",
+            inners
+                .clone()
+                .map(|inner| inner.to_wgsl(&self.module.to_ctx()))
+                .collect::<Vec<String>>()
+        );
+        let mut best = inners.next().unwrap().scalar().ok_or(0_usize)?;
+        for (inner, i) in inners.zip(1..) {
+            let scalar = inner.scalar().ok_or(i)?;
+            match best.automatic_conversion_combine(scalar) {
+                Some(new_best) => {
+                    best = new_best;
+                }
+                None => return Err(i),
+            }
+        }
+
+        log::debug!("    consensus: {:?}", best.to_wgsl());
+        Ok(best)
+    }
+}
+
+impl crate::TypeInner {
+    /// Determine whether `self` automatically converts to `goal`.
+    ///
+    /// If WGSL's automatic conversions (excluding the Load Rule) will
+    /// convert `self` to `goal`, then return a pair `(from, to)`,
+    /// where `from` and `to` are the scalar types of the leaf values
+    /// of `self` and `goal`.
+    ///
+    /// This function assumes that `self` and `goal` are different
+    /// types. Callers should first check whether any conversion is
+    /// needed at all.
+    ///
+    /// If the automatic conversions cannot convert `self` to `goal`,
+    /// return `None`.
+    fn automatically_converts_to(
+        &self,
+        goal: &Self,
+        types: &crate::UniqueArena<crate::Type>,
+    ) -> Option<(crate::Scalar, crate::Scalar)> {
+        use crate::ScalarKind as Sk;
+        use crate::TypeInner as Ti;
+
+        // Automatic conversions only change the scalar type of a value's leaves
+        // (e.g., `vec4<AbstractFloat>` to `vec4<f32>`), never the type
+        // constructors applied to those scalar types (e.g., never scalar to
+        // `vec4`, or `vec2` to `vec3`). So first we check that the type
+        // constructors match, extracting the leaf scalar types in the process.
+        let expr_scalar;
+        let goal_scalar;
+        match (self, goal) {
+            (&Ti::Scalar(expr), &Ti::Scalar(goal)) => {
+                expr_scalar = expr;
+                goal_scalar = goal;
+            }
+            (
+                &Ti::Vector {
+                    size: expr_size,
+                    scalar: expr,
+                },
+                &Ti::Vector {
+                    size: goal_size,
+                    scalar: goal,
+                },
+            ) if expr_size == goal_size => {
+                expr_scalar = expr;
+                goal_scalar = goal;
+            }
+            (
+                &Ti::Matrix {
+                    rows: expr_rows,
+                    columns: expr_columns,
+                    scalar: expr,
+                },
+                &Ti::Matrix {
+                    rows: goal_rows,
+                    columns: goal_columns,
+                    scalar: goal,
+                },
+            ) if expr_rows == goal_rows && expr_columns == goal_columns => {
+                expr_scalar = expr;
+                goal_scalar = goal;
+            }
+            (
+                &Ti::Array {
+                    base: expr_base,
+                    size: expr_size,
+                    stride: _,
+                },
+                &Ti::Array {
+                    base: goal_base,
+                    size: goal_size,
+                    stride: _,
+                },
+            ) if expr_size == goal_size => {
+                return types[expr_base]
+                    .inner
+                    .automatically_converts_to(&types[goal_base].inner, types);
+            }
+            _ => return None,
+        }
+
+        match (expr_scalar.kind, goal_scalar.kind) {
+            (Sk::AbstractFloat, Sk::Float) => {}
+            (Sk::AbstractInt, Sk::Sint | Sk::Uint | Sk::AbstractFloat | Sk::Float) => {}
+            _ => return None,
+        }
+
+        log::trace!("      okay: expr {expr_scalar:?}, goal {goal_scalar:?}");
+        Some((expr_scalar, goal_scalar))
+    }
+
+    fn automatically_convertible_scalar(
+        &self,
+        types: &crate::UniqueArena<crate::Type>,
+    ) -> Option<crate::Scalar> {
+        use crate::TypeInner as Ti;
+        match *self {
+            Ti::Scalar(scalar) | Ti::Vector { scalar, .. } | Ti::Matrix { scalar, .. } => {
+                Some(scalar)
+            }
+            Ti::Array { base, .. } => types[base].inner.automatically_convertible_scalar(types),
+            Ti::Atomic(_)
+            | Ti::Pointer { .. }
+            | Ti::ValuePointer { .. }
+            | Ti::Struct { .. }
+            | Ti::Image { .. }
+            | Ti::Sampler { .. }
+            | Ti::AccelerationStructure
+            | Ti::RayQuery
+            | Ti::BindingArray { .. } => None,
+        }
+    }
+}
+
+impl crate::Scalar {
+    /// Find the common type of `self` and `other` under WGSL's
+    /// automatic conversions.
+    ///
+    /// If there are any scalars to which WGSL's automatic conversions
+    /// will convert both `self` and `other`, return the best such
+    /// scalar. Otherwise, return `None`.
+    pub const fn automatic_conversion_combine(self, other: Self) -> Option<crate::Scalar> {
+        use crate::ScalarKind as Sk;
+
+        match (self.kind, other.kind) {
+            // When the kinds match...
+            (Sk::AbstractFloat, Sk::AbstractFloat)
+            | (Sk::AbstractInt, Sk::AbstractInt)
+            | (Sk::Sint, Sk::Sint)
+            | (Sk::Uint, Sk::Uint)
+            | (Sk::Float, Sk::Float)
+            | (Sk::Bool, Sk::Bool) => {
+                if self.width == other.width {
+                    // ... either no conversion is necessary ...
+                    Some(self)
+                } else {
+                    // ... or no conversion is possible.
+                    // We never convert concrete to concrete, and
+                    // abstract types should have only one size.
+                    None
+                }
+            }
+
+            // AbstractInt converts to AbstractFloat.
+            (Sk::AbstractFloat, Sk::AbstractInt) => Some(self),
+            (Sk::AbstractInt, Sk::AbstractFloat) => Some(other),
+
+            // AbstractFloat converts to Float.
+            (Sk::AbstractFloat, Sk::Float) => Some(other),
+            (Sk::Float, Sk::AbstractFloat) => Some(self),
+
+            // AbstractInt converts to concrete integer or float.
+            (Sk::AbstractInt, Sk::Uint | Sk::Sint | Sk::Float) => Some(other),
+            (Sk::Uint | Sk::Sint | Sk::Float, Sk::AbstractInt) => Some(self),
+
+            // AbstractFloat can't be reconciled with concrete integer types.
+            (Sk::AbstractFloat, Sk::Uint | Sk::Sint) | (Sk::Uint | Sk::Sint, Sk::AbstractFloat) => {
+                None
+            }
+
+            // Nothing can be reconciled with `bool`.
+            (Sk::Bool, _) | (_, Sk::Bool) => None,
+
+            // Different concrete types cannot be reconciled.
+            (Sk::Sint | Sk::Uint | Sk::Float, Sk::Sint | Sk::Uint | Sk::Float) => None,
+        }
+    }
+
+    /// Return `true` if automatic conversions will covert `self` to `goal`.
+    pub fn automatically_converts_to(self, goal: Self) -> bool {
+        self.automatic_conversion_combine(goal) == Some(goal)
+    }
+
+    const fn concretize(self) -> Self {
+        use crate::ScalarKind as Sk;
+        match self.kind {
+            Sk::Sint | Sk::Uint | Sk::Float | Sk::Bool => self,
+            Sk::AbstractInt => Self::I32,
+            Sk::AbstractFloat => Self::F32,
+        }
+    }
+}
diff --git a/third_party/rust/naga/src/front/wgsl/lower/mod.rs b/third_party/rust/naga/src/front/wgsl/lower/mod.rs
new file mode 100644
index 0000000000..ba9b49e135
--- /dev/null
+++ b/third_party/rust/naga/src/front/wgsl/lower/mod.rs
@@ -0,0 +1,2760 @@
+use std::num::NonZeroU32;
+
+use crate::front::wgsl::error::{Error, ExpectedToken, InvalidAssignmentType};
+use crate::front::wgsl::index::Index;
+use crate::front::wgsl::parse::number::Number;
+use crate::front::wgsl::parse::{ast, conv};
+use crate::front::Typifier;
+use crate::proc::{
+    ensure_block_returns, Alignment, ConstantEvaluator, Emitter, Layouter, ResolveContext,
+};
+use crate::{Arena, FastHashMap, FastIndexMap, Handle, Span};
+
+mod construction;
+mod conversion;
+
+/// Resolves the inner type of a given expression.
+///
+/// Expects a &mut [`ExpressionContext`] and a [`Handle<Expression>`].
+///
+/// Returns a &[`crate::TypeInner`].
+///
+/// Ideally, we would simply have a function that takes a `&mut ExpressionContext`
+/// and returns a `&TypeResolution`. Unfortunately, this leads the borrow checker
+/// to conclude that the mutable borrow lasts for as long as we are using the
+/// `&TypeResolution`, so we can't use the `ExpressionContext` for anything else -
+/// like, say, resolving another operand's type. Using a macro that expands to
+/// two separate calls, only the first of which needs a `&mut`,
+/// lets the borrow checker see that the mutable borrow is over.
+macro_rules! resolve_inner {
+    ($ctx:ident, $expr:expr) => {{
+        $ctx.grow_types($expr)?;
+        $ctx.typifier()[$expr].inner_with(&$ctx.module.types)
+    }};
+}
+pub(super) use resolve_inner;
+
+/// Resolves the inner types of two given expressions.
+///
+/// Expects a &mut [`ExpressionContext`] and two [`Handle<Expression>`]s.
+///
+/// Returns a tuple containing two &[`crate::TypeInner`].
+///
+/// See the documentation of [`resolve_inner!`] for why this macro is necessary.
+macro_rules! resolve_inner_binary {
+    ($ctx:ident, $left:expr, $right:expr) => {{
+        $ctx.grow_types($left)?;
+        $ctx.grow_types($right)?;
+        (
+            $ctx.typifier()[$left].inner_with(&$ctx.module.types),
+            $ctx.typifier()[$right].inner_with(&$ctx.module.types),
+        )
+    }};
+}
+
+/// Resolves the type of a given expression.
+///
+/// Expects a &mut [`ExpressionContext`] and a [`Handle<Expression>`].
+///
+/// Returns a &[`TypeResolution`].
+///
+/// See the documentation of [`resolve_inner!`] for why this macro is necessary.
+///
+/// [`TypeResolution`]: crate::proc::TypeResolution
+macro_rules! resolve {
+    ($ctx:ident, $expr:expr) => {{
+        $ctx.grow_types($expr)?;
+        &$ctx.typifier()[$expr]
+    }};
+}
+pub(super) use resolve;
+
+/// State for constructing a `crate::Module`.
+pub struct GlobalContext<'source, 'temp, 'out> {
+    /// The `TranslationUnit`'s expressions arena.
+    ast_expressions: &'temp Arena<ast::Expression<'source>>,
+
+    /// The `TranslationUnit`'s types arena.
+    types: &'temp Arena<ast::Type<'source>>,
+
+    // Naga IR values.
+    /// The map from the names of module-scope declarations to the Naga IR
+    /// `Handle`s we have built for them, owned by `Lowerer::lower`.
+    globals: &'temp mut FastHashMap<&'source str, LoweredGlobalDecl>,
+
+    /// The module we're constructing.
+    module: &'out mut crate::Module,
+
+    const_typifier: &'temp mut Typifier,
+}
+
+impl<'source> GlobalContext<'source, '_, '_> {
+    fn as_const(&mut self) -> ExpressionContext<'source, '_, '_> {
+        ExpressionContext {
+            ast_expressions: self.ast_expressions,
+            globals: self.globals,
+            types: self.types,
+            module: self.module,
+            const_typifier: self.const_typifier,
+            expr_type: ExpressionContextType::Constant,
+        }
+    }
+
+    fn ensure_type_exists(
+        &mut self,
+        name: Option<String>,
+        inner: crate::TypeInner,
+    ) -> Handle<crate::Type> {
+        self.module
+            .types
+            .insert(crate::Type { inner, name }, Span::UNDEFINED)
+    }
+}
+
+/// State for lowering a statement within a function.
+pub struct StatementContext<'source, 'temp, 'out> {
+    // WGSL AST values.
+    /// A reference to [`TranslationUnit::expressions`] for the translation unit
+    /// we're lowering.
+    ///
+    /// [`TranslationUnit::expressions`]: ast::TranslationUnit::expressions
+    ast_expressions: &'temp Arena<ast::Expression<'source>>,
+
+    /// A reference to [`TranslationUnit::types`] for the translation unit
+    /// we're lowering.
+    ///
+    /// [`TranslationUnit::types`]: ast::TranslationUnit::types
+    types: &'temp Arena<ast::Type<'source>>,
+
+    // Naga IR values.
+    /// The map from the names of module-scope declarations to the Naga IR
+    /// `Handle`s we have built for them, owned by `Lowerer::lower`.
+    globals: &'temp mut FastHashMap<&'source str, LoweredGlobalDecl>,
+
+    /// A map from each `ast::Local` handle to the Naga expression
+    /// we've built for it:
+    ///
+    /// - WGSL function arguments become Naga [`FunctionArgument`] expressions.
+    ///
+    /// - WGSL `var` declarations become Naga [`LocalVariable`] expressions.
+    ///
+    /// - WGSL `let` declararations become arbitrary Naga expressions.
+    ///
+    /// This always borrows the `local_table` local variable in
+    /// [`Lowerer::function`].
+    ///
+    /// [`LocalVariable`]: crate::Expression::LocalVariable
+    /// [`FunctionArgument`]: crate::Expression::FunctionArgument
+    local_table: &'temp mut FastHashMap<Handle<ast::Local>, Typed<Handle<crate::Expression>>>,
+
+    const_typifier: &'temp mut Typifier,
+    typifier: &'temp mut Typifier,
+    function: &'out mut crate::Function,
+    /// Stores the names of expressions that are assigned in `let` statement
+    /// Also stores the spans of the names, for use in errors.
+    named_expressions: &'out mut FastIndexMap<Handle<crate::Expression>, (String, Span)>,
+    module: &'out mut crate::Module,
+
+    /// Which `Expression`s in `self.naga_expressions` are const expressions, in
+    /// the WGSL sense.
+    ///
+    /// According to the WGSL spec, a const expression must not refer to any
+    /// `let` declarations, even if those declarations' initializers are
+    /// themselves const expressions. So this tracker is not simply concerned
+    /// with the form of the expressions; it is also tracking whether WGSL says
+    /// we should consider them to be const. See the use of `force_non_const` in
+    /// the code for lowering `let` bindings.
+    expression_constness: &'temp mut crate::proc::ExpressionConstnessTracker,
+}
+
+impl<'a, 'temp> StatementContext<'a, 'temp, '_> {
+    fn as_expression<'t>(
+        &'t mut self,
+        block: &'t mut crate::Block,
+        emitter: &'t mut Emitter,
+    ) -> ExpressionContext<'a, 't, '_>
+    where
+        'temp: 't,
+    {
+        ExpressionContext {
+            globals: self.globals,
+            types: self.types,
+            ast_expressions: self.ast_expressions,
+            const_typifier: self.const_typifier,
+            module: self.module,
+            expr_type: ExpressionContextType::Runtime(RuntimeExpressionContext {
+                local_table: self.local_table,
+                function: self.function,
+                block,
+                emitter,
+                typifier: self.typifier,
+                expression_constness: self.expression_constness,
+            }),
+        }
+    }
+
+    fn as_global(&mut self) -> GlobalContext<'a, '_, '_> {
+        GlobalContext {
+            ast_expressions: self.ast_expressions,
+            globals: self.globals,
+            types: self.types,
+            module: self.module,
+            const_typifier: self.const_typifier,
+        }
+    }
+
+    fn invalid_assignment_type(&self, expr: Handle<crate::Expression>) -> InvalidAssignmentType {
+        if let Some(&(_, span)) = self.named_expressions.get(&expr) {
+            InvalidAssignmentType::ImmutableBinding(span)
+        } else {
+            match self.function.expressions[expr] {
+                crate::Expression::Swizzle { .. } => InvalidAssignmentType::Swizzle,
+                crate::Expression::Access { base, .. } => self.invalid_assignment_type(base),
+                crate::Expression::AccessIndex { base, .. } => self.invalid_assignment_type(base),
+                _ => InvalidAssignmentType::Other,
+            }
+        }
+    }
+}
+
+pub struct RuntimeExpressionContext<'temp, 'out> {
+    /// A map from [`ast::Local`] handles to the Naga expressions we've built for them.
+    ///
+    /// This is always [`StatementContext::local_table`] for the
+    /// enclosing statement; see that documentation for details.
+    local_table: &'temp FastHashMap<Handle<ast::Local>, Typed<Handle<crate::Expression>>>,
+
+    function: &'out mut crate::Function,
+    block: &'temp mut crate::Block,
+    emitter: &'temp mut Emitter,
+    typifier: &'temp mut Typifier,
+
+    /// Which `Expression`s in `self.naga_expressions` are const expressions, in
+    /// the WGSL sense.
+    ///
+    /// See [`StatementContext::expression_constness`] for details.
+    expression_constness: &'temp mut crate::proc::ExpressionConstnessTracker,
+}
+
+/// The type of Naga IR expression we are lowering an [`ast::Expression`] to.
+pub enum ExpressionContextType<'temp, 'out> {
+    /// We are lowering to an arbitrary runtime expression, to be
+    /// included in a function's body.
+    ///
+    /// The given [`RuntimeExpressionContext`] holds information about local
+    /// variables, arguments, and other definitions available only to runtime
+    /// expressions, not constant or override expressions.
+    Runtime(RuntimeExpressionContext<'temp, 'out>),
+
+    /// We are lowering to a constant expression, to be included in the module's
+    /// constant expression arena.
+    ///
+    /// Everything constant expressions are allowed to refer to is
+    /// available in the [`ExpressionContext`], so this variant
+    /// carries no further information.
+    Constant,
+}
+
+/// State for lowering an [`ast::Expression`] to Naga IR.
+///
+/// [`ExpressionContext`]s come in two kinds, distinguished by
+/// the value of the [`expr_type`] field:
+///
+/// - A [`Runtime`] context contributes [`naga::Expression`]s to a [`naga::Function`]'s
+///   runtime expression arena.
+///
+/// - A [`Constant`] context contributes [`naga::Expression`]s to a [`naga::Module`]'s
+///   constant expression arena.
+///
+/// [`ExpressionContext`]s are constructed in restricted ways:
+///
+/// - To get a [`Runtime`] [`ExpressionContext`], call
+///   [`StatementContext::as_expression`].
+///
+/// - To get a [`Constant`] [`ExpressionContext`], call
+///   [`GlobalContext::as_const`].
+///
+/// - You can demote a [`Runtime`] context to a [`Constant`] context
+///   by calling [`as_const`], but there's no way to go in the other
+///   direction, producing a runtime context from a constant one. This
+///   is because runtime expressions can refer to constant
+///   expressions, via [`Expression::Constant`], but constant
+///   expressions can't refer to a function's expressions.
+///
+/// Not to be confused with `wgsl::parse::ExpressionContext`, which is
+/// for parsing the `ast::Expression` in the first place.
+///
+/// [`expr_type`]: ExpressionContext::expr_type
+/// [`Runtime`]: ExpressionContextType::Runtime
+/// [`naga::Expression`]: crate::Expression
+/// [`naga::Function`]: crate::Function
+/// [`Constant`]: ExpressionContextType::Constant
+/// [`naga::Module`]: crate::Module
+/// [`as_const`]: ExpressionContext::as_const
+/// [`Expression::Constant`]: crate::Expression::Constant
+pub struct ExpressionContext<'source, 'temp, 'out> {
+    // WGSL AST values.
+    ast_expressions: &'temp Arena<ast::Expression<'source>>,
+    types: &'temp Arena<ast::Type<'source>>,
+
+    // Naga IR values.
+    /// The map from the names of module-scope declarations to the Naga IR
+    /// `Handle`s we have built for them, owned by `Lowerer::lower`.
+    globals: &'temp mut FastHashMap<&'source str, LoweredGlobalDecl>,
+
+    /// The IR [`Module`] we're constructing.
+    ///
+    /// [`Module`]: crate::Module
+    module: &'out mut crate::Module,
+
+    /// Type judgments for [`module::const_expressions`].
+    ///
+    /// [`module::const_expressions`]: crate::Module::const_expressions
+    const_typifier: &'temp mut Typifier,
+
+    /// Whether we are lowering a constant expression or a general
+    /// runtime expression, and the data needed in each case.
+    expr_type: ExpressionContextType<'temp, 'out>,
+}
+
+impl<'source, 'temp, 'out> ExpressionContext<'source, 'temp, 'out> {
+    fn as_const(&mut self) -> ExpressionContext<'source, '_, '_> {
+        ExpressionContext {
+            globals: self.globals,
+            types: self.types,
+            ast_expressions: self.ast_expressions,
+            const_typifier: self.const_typifier,
+            module: self.module,
+            expr_type: ExpressionContextType::Constant,
+        }
+    }
+
+    fn as_global(&mut self) -> GlobalContext<'source, '_, '_> {
+        GlobalContext {
+            ast_expressions: self.ast_expressions,
+            globals: self.globals,
+            types: self.types,
+            module: self.module,
+            const_typifier: self.const_typifier,
+        }
+    }
+
+    fn as_const_evaluator(&mut self) -> ConstantEvaluator {
+        match self.expr_type {
+            ExpressionContextType::Runtime(ref mut rctx) => ConstantEvaluator::for_wgsl_function(
+                self.module,
+                &mut rctx.function.expressions,
+                rctx.expression_constness,
+                rctx.emitter,
+                rctx.block,
+            ),
+            ExpressionContextType::Constant => ConstantEvaluator::for_wgsl_module(self.module),
+        }
+    }
+
+    fn append_expression(
+        &mut self,
+        expr: crate::Expression,
+        span: Span,
+    ) -> Result<Handle<crate::Expression>, Error<'source>> {
+        let mut eval = self.as_const_evaluator();
+        match eval.try_eval_and_append(&expr, span) {
+            Ok(expr) => Ok(expr),
+
+            // `expr` is not a constant expression. This is fine as
+            // long as we're not building `Module::const_expressions`.
+            Err(err) => match self.expr_type {
+                ExpressionContextType::Runtime(ref mut rctx) => {
+                    Ok(rctx.function.expressions.append(expr, span))
+                }
+                ExpressionContextType::Constant => Err(Error::ConstantEvaluatorError(err, span)),
+            },
+        }
+    }
+
+    fn const_access(&self, handle: Handle<crate::Expression>) -> Option<u32> {
+        match self.expr_type {
+            ExpressionContextType::Runtime(ref ctx) => {
+                if !ctx.expression_constness.is_const(handle) {
+                    return None;
+                }
+
+                self.module
+                    .to_ctx()
+                    .eval_expr_to_u32_from(handle, &ctx.function.expressions)
+                    .ok()
+            }
+            ExpressionContextType::Constant => self.module.to_ctx().eval_expr_to_u32(handle).ok(),
+        }
+    }
+
+    fn get_expression_span(&self, handle: Handle<crate::Expression>) -> Span {
+        match self.expr_type {
+            ExpressionContextType::Runtime(ref ctx) => ctx.function.expressions.get_span(handle),
+            ExpressionContextType::Constant => self.module.const_expressions.get_span(handle),
+        }
+    }
+
+    fn typifier(&self) -> &Typifier {
+        match self.expr_type {
+            ExpressionContextType::Runtime(ref ctx) => ctx.typifier,
+            ExpressionContextType::Constant => self.const_typifier,
+        }
+    }
+
+    fn runtime_expression_ctx(
+        &mut self,
+        span: Span,
+    ) -> Result<&mut RuntimeExpressionContext<'temp, 'out>, Error<'source>> {
+        match self.expr_type {
+            ExpressionContextType::Runtime(ref mut ctx) => Ok(ctx),
+            ExpressionContextType::Constant => Err(Error::UnexpectedOperationInConstContext(span)),
+        }
+    }
+
+    fn gather_component(
+        &mut self,
+        expr: Handle<crate::Expression>,
+        component_span: Span,
+        gather_span: Span,
+    ) -> Result<crate::SwizzleComponent, Error<'source>> {
+        match self.expr_type {
+            ExpressionContextType::Runtime(ref rctx) => {
+                if !rctx.expression_constness.is_const(expr) {
+                    return Err(Error::ExpectedConstExprConcreteIntegerScalar(
+                        component_span,
+                    ));
+                }
+
+                let index = self
+                    .module
+                    .to_ctx()
+                    .eval_expr_to_u32_from(expr, &rctx.function.expressions)
+                    .map_err(|err| match err {
+                        crate::proc::U32EvalError::NonConst => {
+                            Error::ExpectedConstExprConcreteIntegerScalar(component_span)
+                        }
+                        crate::proc::U32EvalError::Negative => {
+                            Error::ExpectedNonNegative(component_span)
+                        }
+                    })?;
+                crate::SwizzleComponent::XYZW
+                    .get(index as usize)
+                    .copied()
+                    .ok_or(Error::InvalidGatherComponent(component_span))
+            }
+            // This means a `gather` operation appeared in a constant expression.
+            // This error refers to the `gather` itself, not its "component" argument.
+            ExpressionContextType::Constant => {
+                Err(Error::UnexpectedOperationInConstContext(gather_span))
+            }
+        }
+    }
+
+    /// Determine the type of `handle`, and add it to the module's arena.
+    ///
+    /// If you just need a `TypeInner` for `handle`'s type, use the
+    /// [`resolve_inner!`] macro instead. This function
+    /// should only be used when the type of `handle` needs to appear
+    /// in the module's final `Arena<Type>`, for example, if you're
+    /// creating a [`LocalVariable`] whose type is inferred from its
+    /// initializer.
+    ///
+    /// [`LocalVariable`]: crate::LocalVariable
+    fn register_type(
+        &mut self,
+        handle: Handle<crate::Expression>,
+    ) -> Result<Handle<crate::Type>, Error<'source>> {
+        self.grow_types(handle)?;
+        // This is equivalent to calling ExpressionContext::typifier(),
+        // except that this lets the borrow checker see that it's okay
+        // to also borrow self.module.types mutably below.
+        let typifier = match self.expr_type {
+            ExpressionContextType::Runtime(ref ctx) => ctx.typifier,
+            ExpressionContextType::Constant => &*self.const_typifier,
+        };
+        Ok(typifier.register_type(handle, &mut self.module.types))
+    }
+
+    /// Resolve the types of all expressions up through `handle`.
+    ///
+    /// Ensure that [`self.typifier`] has a [`TypeResolution`] for
+    /// every expression in [`self.function.expressions`].
+    ///
+    /// This does not add types to any arena. The [`Typifier`]
+    /// documentation explains the steps we take to avoid filling
+    /// arenas with intermediate types.
+    ///
+    /// This function takes `&mut self`, so it can't conveniently
+    /// return a shared reference to the resulting `TypeResolution`:
+    /// the shared reference would extend the mutable borrow, and you
+    /// wouldn't be able to use `self` for anything else. Instead, you
+    /// should use [`register_type`] or one of [`resolve!`],
+    /// [`resolve_inner!`] or [`resolve_inner_binary!`].
+    ///
+    /// [`self.typifier`]: ExpressionContext::typifier
+    /// [`TypeResolution`]: crate::proc::TypeResolution
+    /// [`register_type`]: Self::register_type
+    /// [`Typifier`]: Typifier
+    fn grow_types(
+        &mut self,
+        handle: Handle<crate::Expression>,
+    ) -> Result<&mut Self, Error<'source>> {
+        let empty_arena = Arena::new();
+        let resolve_ctx;
+        let typifier;
+        let expressions;
+        match self.expr_type {
+            ExpressionContextType::Runtime(ref mut ctx) => {
+                resolve_ctx = ResolveContext::with_locals(
+                    self.module,
+                    &ctx.function.local_variables,
+                    &ctx.function.arguments,
+                );
+                typifier = &mut *ctx.typifier;
+                expressions = &ctx.function.expressions;
+            }
+            ExpressionContextType::Constant => {
+                resolve_ctx = ResolveContext::with_locals(self.module, &empty_arena, &[]);
+                typifier = self.const_typifier;
+                expressions = &self.module.const_expressions;
+            }
+        };
+        typifier
+            .grow(handle, expressions, &resolve_ctx)
+            .map_err(Error::InvalidResolve)?;
+
+        Ok(self)
+    }
+
+    fn image_data(
+        &mut self,
+        image: Handle<crate::Expression>,
+        span: Span,
+    ) -> Result<(crate::ImageClass, bool), Error<'source>> {
+        match *resolve_inner!(self, image) {
+            crate::TypeInner::Image { class, arrayed, .. } => Ok((class, arrayed)),
+            _ => Err(Error::BadTexture(span)),
+        }
+    }
+
+    fn prepare_args<'b>(
+        &mut self,
+        args: &'b [Handle<ast::Expression<'source>>],
+        min_args: u32,
+        span: Span,
+    ) -> ArgumentContext<'b, 'source> {
+        ArgumentContext {
+            args: args.iter(),
+            min_args,
+            args_used: 0,
+            total_args: args.len() as u32,
+            span,
+        }
+    }
+
+    /// Insert splats, if needed by the non-'*' operations.
+    ///
+    /// See the "Binary arithmetic expressions with mixed scalar and vector operands"
+    /// table in the WebGPU Shading Language specification for relevant operators.
+    ///
+    /// Multiply is not handled here as backends are expected to handle vec*scalar
+    /// operations, so inserting splats into the IR increases size needlessly.
+    fn binary_op_splat(
+        &mut self,
+        op: crate::BinaryOperator,
+        left: &mut Handle<crate::Expression>,
+        right: &mut Handle<crate::Expression>,
+    ) -> Result<(), Error<'source>> {
+        if matches!(
+            op,
+            crate::BinaryOperator::Add
+                | crate::BinaryOperator::Subtract
+                | crate::BinaryOperator::Divide
+                | crate::BinaryOperator::Modulo
+        ) {
+            match resolve_inner_binary!(self, *left, *right) {
+                (&crate::TypeInner::Vector { size, .. }, &crate::TypeInner::Scalar { .. }) => {
+                    *right = self.append_expression(
+                        crate::Expression::Splat {
+                            size,
+                            value: *right,
+                        },
+                        self.get_expression_span(*right),
+                    )?;
+                }
+                (&crate::TypeInner::Scalar { .. }, &crate::TypeInner::Vector { size, .. }) => {
+                    *left = self.append_expression(
+                        crate::Expression::Splat { size, value: *left },
+                        self.get_expression_span(*left),
+                    )?;
+                }
+                _ => {}
+            }
+        }
+
+        Ok(())
+    }
+
+    /// Add a single expression to the expression table that is not covered by `self.emitter`.
+    ///
+    /// This is useful for `CallResult` and `AtomicResult` expressions, which should not be covered by
+    /// `Emit` statements.
+    fn interrupt_emitter(
+        &mut self,
+        expression: crate::Expression,
+        span: Span,
+    ) -> Result<Handle<crate::Expression>, Error<'source>> {
+        match self.expr_type {
+            ExpressionContextType::Runtime(ref mut rctx) => {
+                rctx.block
+                    .extend(rctx.emitter.finish(&rctx.function.expressions));
+            }
+            ExpressionContextType::Constant => {}
+        }
+        let result = self.append_expression(expression, span);
+        match self.expr_type {
+            ExpressionContextType::Runtime(ref mut rctx) => {
+                rctx.emitter.start(&rctx.function.expressions);
+            }
+            ExpressionContextType::Constant => {}
+        }
+        result
+    }
+
+    /// Apply the WGSL Load Rule to `expr`.
+    ///
+    /// If `expr` is has type `ref<SC, T, A>`, perform a load to produce a value of type
+    /// `T`. Otherwise, return `expr` unchanged.
+    fn apply_load_rule(
+        &mut self,
+        expr: Typed<Handle<crate::Expression>>,
+    ) -> Result<Handle<crate::Expression>, Error<'source>> {
+        match expr {
+            Typed::Reference(pointer) => {
+                let load = crate::Expression::Load { pointer };
+                let span = self.get_expression_span(pointer);
+                self.append_expression(load, span)
+            }
+            Typed::Plain(handle) => Ok(handle),
+        }
+    }
+
+    fn ensure_type_exists(&mut self, inner: crate::TypeInner) -> Handle<crate::Type> {
+        self.as_global().ensure_type_exists(None, inner)
+    }
+}
+
+struct ArgumentContext<'ctx, 'source> {
+    args: std::slice::Iter<'ctx, Handle<ast::Expression<'source>>>,
+    min_args: u32,
+    args_used: u32,
+    total_args: u32,
+    span: Span,
+}
+
+impl<'source> ArgumentContext<'_, 'source> {
+    pub fn finish(self) -> Result<(), Error<'source>> {
+        if self.args.len() == 0 {
+            Ok(())
+        } else {
+            Err(Error::WrongArgumentCount {
+                found: self.total_args,
+                expected: self.min_args..self.args_used + 1,
+                span: self.span,
+            })
+        }
+    }
+
+    pub fn next(&mut self) -> Result<Handle<ast::Expression<'source>>, Error<'source>> {
+        match self.args.next().copied() {
+            Some(arg) => {
+                self.args_used += 1;
+                Ok(arg)
+            }
+            None => Err(Error::WrongArgumentCount {
+                found: self.total_args,
+                expected: self.min_args..self.args_used + 1,
+                span: self.span,
+            }),
+        }
+    }
+}
+
+/// WGSL type annotations on expressions, types, values, etc.
+///
+/// Naga and WGSL types are very close, but Naga lacks WGSL's `ref` types, which
+/// we need to know to apply the Load Rule. This enum carries some WGSL or Naga
+/// datum along with enough information to determine its corresponding WGSL
+/// type.
+///
+/// The `T` type parameter can be any expression-like thing:
+///
+/// - `Typed<Handle<crate::Type>>` can represent a full WGSL type. For example,
+///   given some Naga `Pointer` type `ptr`, a WGSL reference type is a
+///   `Typed::Reference(ptr)` whereas a WGSL pointer type is a
+///   `Typed::Plain(ptr)`.
+///
+/// - `Typed<crate::Expression>` or `Typed<Handle<crate::Expression>>` can
+///   represent references similarly.
+///
+/// Use the `map` and `try_map` methods to convert from one expression
+/// representation to another.
+///
+/// [`Expression`]: crate::Expression
+#[derive(Debug, Copy, Clone)]
+enum Typed<T> {
+    /// A WGSL reference.
+    Reference(T),
+
+    /// A WGSL plain type.
+    Plain(T),
+}
+
+impl<T> Typed<T> {
+    fn map<U>(self, mut f: impl FnMut(T) -> U) -> Typed<U> {
+        match self {
+            Self::Reference(v) => Typed::Reference(f(v)),
+            Self::Plain(v) => Typed::Plain(f(v)),
+        }
+    }
+
+    fn try_map<U, E>(self, mut f: impl FnMut(T) -> Result<U, E>) -> Result<Typed<U>, E> {
+        Ok(match self {
+            Self::Reference(expr) => Typed::Reference(f(expr)?),
+            Self::Plain(expr) => Typed::Plain(f(expr)?),
+        })
+    }
+}
+
+/// A single vector component or swizzle.
+///
+/// This represents the things that can appear after the `.` in a vector access
+/// expression: either a single component name, or a series of them,
+/// representing a swizzle.
+enum Components {
+    Single(u32),
+    Swizzle {
+        size: crate::VectorSize,
+        pattern: [crate::SwizzleComponent; 4],
+    },
+}
+
+impl Components {
+    const fn letter_component(letter: char) -> Option<crate::SwizzleComponent> {
+        use crate::SwizzleComponent as Sc;
+        match letter {
+            'x' | 'r' => Some(Sc::X),
+            'y' | 'g' => Some(Sc::Y),
+            'z' | 'b' => Some(Sc::Z),
+            'w' | 'a' => Some(Sc::W),
+            _ => None,
+        }
+    }
+
+    fn single_component(name: &str, name_span: Span) -> Result<u32, Error> {
+        let ch = name.chars().next().ok_or(Error::BadAccessor(name_span))?;
+        match Self::letter_component(ch) {
+            Some(sc) => Ok(sc as u32),
+            None => Err(Error::BadAccessor(name_span)),
+        }
+    }
+
+    /// Construct a `Components` value from a 'member' name, like `"wzy"` or `"x"`.
+    ///
+    /// Use `name_span` for reporting errors in parsing the component string.
+    fn new(name: &str, name_span: Span) -> Result<Self, Error> {
+        let size = match name.len() {
+            1 => return Ok(Components::Single(Self::single_component(name, name_span)?)),
+            2 => crate::VectorSize::Bi,
+            3 => crate::VectorSize::Tri,
+            4 => crate::VectorSize::Quad,
+            _ => return Err(Error::BadAccessor(name_span)),
+        };
+
+        let mut pattern = [crate::SwizzleComponent::X; 4];
+        for (comp, ch) in pattern.iter_mut().zip(name.chars()) {
+            *comp = Self::letter_component(ch).ok_or(Error::BadAccessor(name_span))?;
+        }
+
+        Ok(Components::Swizzle { size, pattern })
+    }
+}
+
+/// An `ast::GlobalDecl` for which we have built the Naga IR equivalent.
+enum LoweredGlobalDecl {
+    Function(Handle<crate::Function>),
+    Var(Handle<crate::GlobalVariable>),
+    Const(Handle<crate::Constant>),
+    Type(Handle<crate::Type>),
+    EntryPoint,
+}
+
+enum Texture {
+    Gather,
+    GatherCompare,
+
+    Sample,
+    SampleBias,
+    SampleCompare,
+    SampleCompareLevel,
+    SampleGrad,
+    SampleLevel,
+    // SampleBaseClampToEdge,
+}
+
+impl Texture {
+    pub fn map(word: &str) -> Option<Self> {
+        Some(match word {
+            "textureGather" => Self::Gather,
+            "textureGatherCompare" => Self::GatherCompare,
+
+            "textureSample" => Self::Sample,
+            "textureSampleBias" => Self::SampleBias,
+            "textureSampleCompare" => Self::SampleCompare,
+            "textureSampleCompareLevel" => Self::SampleCompareLevel,
+            "textureSampleGrad" => Self::SampleGrad,
+            "textureSampleLevel" => Self::SampleLevel,
+            // "textureSampleBaseClampToEdge" => Some(Self::SampleBaseClampToEdge),
+            _ => return None,
+        })
+    }
+
+    pub const fn min_argument_count(&self) -> u32 {
+        match *self {
+            Self::Gather => 3,
+            Self::GatherCompare => 4,
+
+            Self::Sample => 3,
+            Self::SampleBias => 5,
+            Self::SampleCompare => 5,
+            Self::SampleCompareLevel => 5,
+            Self::SampleGrad => 6,
+            Self::SampleLevel => 5,
+            // Self::SampleBaseClampToEdge => 3,
+        }
+    }
+}
+
+pub struct Lowerer<'source, 'temp> {
+    index: &'temp Index<'source>,
+    layouter: Layouter,
+}
+
+impl<'source, 'temp> Lowerer<'source, 'temp> {
+    pub fn new(index: &'temp Index<'source>) -> Self {
+        Self {
+            index,
+            layouter: Layouter::default(),
+        }
+    }
+
+    pub fn lower(
+        &mut self,
+        tu: &'temp ast::TranslationUnit<'source>,
+    ) -> Result<crate::Module, Error<'source>> {
+        let mut module = crate::Module::default();
+
+        let mut ctx = GlobalContext {
+            ast_expressions: &tu.expressions,
+            globals: &mut FastHashMap::default(),
+            types: &tu.types,
+            module: &mut module,
+            const_typifier: &mut Typifier::new(),
+        };
+
+        for decl_handle in self.index.visit_ordered() {
+            let span = tu.decls.get_span(decl_handle);
+            let decl = &tu.decls[decl_handle];
+
+            match decl.kind {
+                ast::GlobalDeclKind::Fn(ref f) => {
+                    let lowered_decl = self.function(f, span, &mut ctx)?;
+                    ctx.globals.insert(f.name.name, lowered_decl);
+                }
+                ast::GlobalDeclKind::Var(ref v) => {
+                    let ty = self.resolve_ast_type(v.ty, &mut ctx)?;
+
+                    let init;
+                    if let Some(init_ast) = v.init {
+                        let mut ectx = ctx.as_const();
+                        let lowered = self.expression_for_abstract(init_ast, &mut ectx)?;
+                        let ty_res = crate::proc::TypeResolution::Handle(ty);
+                        let converted = ectx
+                            .try_automatic_conversions(lowered, &ty_res, v.name.span)
+                            .map_err(|error| match error {
+                                Error::AutoConversion {
+                                    dest_span: _,
+                                    dest_type,
+                                    source_span: _,
+                                    source_type,
+                                } => Error::InitializationTypeMismatch {
+                                    name: v.name.span,
+                                    expected: dest_type,
+                                    got: source_type,
+                                },
+                                other => other,
+                            })?;
+                        init = Some(converted);
+                    } else {
+                        init = None;
+                    }
+
+                    let binding = if let Some(ref binding) = v.binding {
+                        Some(crate::ResourceBinding {
+                            group: self.const_u32(binding.group, &mut ctx.as_const())?.0,
+                            binding: self.const_u32(binding.binding, &mut ctx.as_const())?.0,
+                        })
+                    } else {
+                        None
+                    };
+
+                    let handle = ctx.module.global_variables.append(
+                        crate::GlobalVariable {
+                            name: Some(v.name.name.to_string()),
+                            space: v.space,
+                            binding,
+                            ty,
+                            init,
+                        },
+                        span,
+                    );
+
+                    ctx.globals
+                        .insert(v.name.name, LoweredGlobalDecl::Var(handle));
+                }
+                ast::GlobalDeclKind::Const(ref c) => {
+                    let mut ectx = ctx.as_const();
+                    let mut init = self.expression_for_abstract(c.init, &mut ectx)?;
+
+                    let ty;
+                    if let Some(explicit_ty) = c.ty {
+                        let explicit_ty =
+                            self.resolve_ast_type(explicit_ty, &mut ectx.as_global())?;
+                        let explicit_ty_res = crate::proc::TypeResolution::Handle(explicit_ty);
+                        init = ectx
+                            .try_automatic_conversions(init, &explicit_ty_res, c.name.span)
+                            .map_err(|error| match error {
+                                Error::AutoConversion {
+                                    dest_span: _,
+                                    dest_type,
+                                    source_span: _,
+                                    source_type,
+                                } => Error::InitializationTypeMismatch {
+                                    name: c.name.span,
+                                    expected: dest_type,
+                                    got: source_type,
+                                },
+                                other => other,
+                            })?;
+                        ty = explicit_ty;
+                    } else {
+                        init = ectx.concretize(init)?;
+                        ty = ectx.register_type(init)?;
+                    }
+
+                    let handle = ctx.module.constants.append(
+                        crate::Constant {
+                            name: Some(c.name.name.to_string()),
+                            r#override: crate::Override::None,
+                            ty,
+                            init,
+                        },
+                        span,
+                    );
+
+                    ctx.globals
+                        .insert(c.name.name, LoweredGlobalDecl::Const(handle));
+                }
+                ast::GlobalDeclKind::Struct(ref s) => {
+                    let handle = self.r#struct(s, span, &mut ctx)?;
+                    ctx.globals
+                        .insert(s.name.name, LoweredGlobalDecl::Type(handle));
+                }
+                ast::GlobalDeclKind::Type(ref alias) => {
+                    let ty = self.resolve_named_ast_type(
+                        alias.ty,
+                        Some(alias.name.name.to_string()),
+                        &mut ctx,
+                    )?;
+                    ctx.globals
+                        .insert(alias.name.name, LoweredGlobalDecl::Type(ty));
+                }
+            }
+        }
+
+        // Constant evaluation may leave abstract-typed literals and
+        // compositions in expression arenas, so we need to compact the module
+        // to remove unused expressions and types.
+        crate::compact::compact(&mut module);
+
+        Ok(module)
+    }
+
+    fn function(
+        &mut self,
+        f: &ast::Function<'source>,
+        span: Span,
+        ctx: &mut GlobalContext<'source, '_, '_>,
+    ) -> Result<LoweredGlobalDecl, Error<'source>> {
+        let mut local_table = FastHashMap::default();
+        let mut expressions = Arena::new();
+        let mut named_expressions = FastIndexMap::default();
+
+        let arguments = f
+            .arguments
+            .iter()
+            .enumerate()
+            .map(|(i, arg)| {
+                let ty = self.resolve_ast_type(arg.ty, ctx)?;
+                let expr = expressions
+                    .append(crate::Expression::FunctionArgument(i as u32), arg.name.span);
+                local_table.insert(arg.handle, Typed::Plain(expr));
+                named_expressions.insert(expr, (arg.name.name.to_string(), arg.name.span));
+
+                Ok(crate::FunctionArgument {
+                    name: Some(arg.name.name.to_string()),
+                    ty,
+                    binding: self.binding(&arg.binding, ty, ctx)?,
+                })
+            })
+            .collect::<Result<Vec<_>, _>>()?;
+
+        let result = f
+            .result
+            .as_ref()
+            .map(|res| {
+                let ty = self.resolve_ast_type(res.ty, ctx)?;
+                Ok(crate::FunctionResult {
+                    ty,
+                    binding: self.binding(&res.binding, ty, ctx)?,
+                })
+            })
+            .transpose()?;
+
+        let mut function = crate::Function {
+            name: Some(f.name.name.to_string()),
+            arguments,
+            result,
+            local_variables: Arena::new(),
+            expressions,
+            named_expressions: crate::NamedExpressions::default(),
+            body: crate::Block::default(),
+        };
+
+        let mut typifier = Typifier::default();
+        let mut stmt_ctx = StatementContext {
+            local_table: &mut local_table,
+            globals: ctx.globals,
+            ast_expressions: ctx.ast_expressions,
+            const_typifier: ctx.const_typifier,
+            typifier: &mut typifier,
+            function: &mut function,
+            named_expressions: &mut named_expressions,
+            types: ctx.types,
+            module: ctx.module,
+            expression_constness: &mut crate::proc::ExpressionConstnessTracker::new(),
+        };
+        let mut body = self.block(&f.body, false, &mut stmt_ctx)?;
+        ensure_block_returns(&mut body);
+
+        function.body = body;
+        function.named_expressions = named_expressions
+            .into_iter()
+            .map(|(key, (name, _))| (key, name))
+            .collect();
+
+        if let Some(ref entry) = f.entry_point {
+            let workgroup_size = if let Some(workgroup_size) = entry.workgroup_size {
+                // TODO: replace with try_map once stabilized
+                let mut workgroup_size_out = [1; 3];
+                for (i, size) in workgroup_size.into_iter().enumerate() {
+                    if let Some(size_expr) = size {
+                        workgroup_size_out[i] = self.const_u32(size_expr, &mut ctx.as_const())?.0;
+                    }
+                }
+                workgroup_size_out
+            } else {
+                [0; 3]
+            };
+
+            ctx.module.entry_points.push(crate::EntryPoint {
+                name: f.name.name.to_string(),
+                stage: entry.stage,
+                early_depth_test: entry.early_depth_test,
+                workgroup_size,
+                function,
+            });
+            Ok(LoweredGlobalDecl::EntryPoint)
+        } else {
+            let handle = ctx.module.functions.append(function, span);
+            Ok(LoweredGlobalDecl::Function(handle))
+        }
+    }
+
+    fn block(
+        &mut self,
+        b: &ast::Block<'source>,
+        is_inside_loop: bool,
+        ctx: &mut StatementContext<'source, '_, '_>,
+    ) -> Result<crate::Block, Error<'source>> {
+        let mut block = crate::Block::default();
+
+        for stmt in b.stmts.iter() {
+            self.statement(stmt, &mut block, is_inside_loop, ctx)?;
+        }
+
+        Ok(block)
+    }
+
+    fn statement(
+        &mut self,
+        stmt: &ast::Statement<'source>,
+        block: &mut crate::Block,
+        is_inside_loop: bool,
+        ctx: &mut StatementContext<'source, '_, '_>,
+    ) -> Result<(), Error<'source>> {
+        let out = match stmt.kind {
+            ast::StatementKind::Block(ref block) => {
+                let block = self.block(block, is_inside_loop, ctx)?;
+                crate::Statement::Block(block)
+            }
+            ast::StatementKind::LocalDecl(ref decl) => match *decl {
+                ast::LocalDecl::Let(ref l) => {
+                    let mut emitter = Emitter::default();
+                    emitter.start(&ctx.function.expressions);
+
+                    let value =
+                        self.expression(l.init, &mut ctx.as_expression(block, &mut emitter))?;
+
+                    // The WGSL spec says that any expression that refers to a
+                    // `let`-bound variable is not a const expression. This
+                    // affects when errors must be reported, so we can't even
+                    // treat suitable `let` bindings as constant as an
+                    // optimization.
+                    ctx.expression_constness.force_non_const(value);
+
+                    let explicit_ty =
+                        l.ty.map(|ty| self.resolve_ast_type(ty, &mut ctx.as_global()))
+                            .transpose()?;
+
+                    if let Some(ty) = explicit_ty {
+                        let mut ctx = ctx.as_expression(block, &mut emitter);
+                        let init_ty = ctx.register_type(value)?;
+                        if !ctx.module.types[ty]
+                            .inner
+                            .equivalent(&ctx.module.types[init_ty].inner, &ctx.module.types)
+                        {
+                            let gctx = &ctx.module.to_ctx();
+                            return Err(Error::InitializationTypeMismatch {
+                                name: l.name.span,
+                                expected: ty.to_wgsl(gctx),
+                                got: init_ty.to_wgsl(gctx),
+                            });
+                        }
+                    }
+
+                    block.extend(emitter.finish(&ctx.function.expressions));
+                    ctx.local_table.insert(l.handle, Typed::Plain(value));
+                    ctx.named_expressions
+                        .insert(value, (l.name.name.to_string(), l.name.span));
+
+                    return Ok(());
+                }
+                ast::LocalDecl::Var(ref v) => {
+                    let explicit_ty =
+                        v.ty.map(|ast| self.resolve_ast_type(ast, &mut ctx.as_global()))
+                            .transpose()?;
+
+                    let mut emitter = Emitter::default();
+                    emitter.start(&ctx.function.expressions);
+                    let mut ectx = ctx.as_expression(block, &mut emitter);
+
+                    let ty;
+                    let initializer;
+                    match (v.init, explicit_ty) {
+                        (Some(init), Some(explicit_ty)) => {
+                            let init = self.expression_for_abstract(init, &mut ectx)?;
+                            let ty_res = crate::proc::TypeResolution::Handle(explicit_ty);
+                            let init = ectx
+                                .try_automatic_conversions(init, &ty_res, v.name.span)
+                                .map_err(|error| match error {
+                                Error::AutoConversion {
+                                    dest_span: _,
+                                    dest_type,
+                                    source_span: _,
+                                    source_type,
+                                } => Error::InitializationTypeMismatch {
+                                    name: v.name.span,
+                                    expected: dest_type,
+                                    got: source_type,
+                                },
+                                other => other,
+                            })?;
+                            ty = explicit_ty;
+                            initializer = Some(init);
+                        }
+                        (Some(init), None) => {
+                            let concretized = self.expression(init, &mut ectx)?;
+                            ty = ectx.register_type(concretized)?;
+                            initializer = Some(concretized);
+                        }
+                        (None, Some(explicit_ty)) => {
+                            ty = explicit_ty;
+                            initializer = None;
+                        }
+                        (None, None) => return Err(Error::MissingType(v.name.span)),
+                    }
+
+                    let (const_initializer, initializer) = {
+                        match initializer {
+                            Some(init) => {
+                                // It's not correct to hoist the initializer up
+                                // to the top of the function if:
+                                // - the initialization is inside a loop, and should
+                                //   take place on every iteration, or
+                                // - the initialization is not a constant
+                                //   expression, so its value depends on the
+                                //   state at the point of initialization.
+                                if is_inside_loop || !ctx.expression_constness.is_const(init) {
+                                    (None, Some(init))
+                                } else {
+                                    (Some(init), None)
+                                }
+                            }
+                            None => (None, None),
+                        }
+                    };
+
+                    let var = ctx.function.local_variables.append(
+                        crate::LocalVariable {
+                            name: Some(v.name.name.to_string()),
+                            ty,
+                            init: const_initializer,
+                        },
+                        stmt.span,
+                    );
+
+                    let handle = ctx.as_expression(block, &mut emitter).interrupt_emitter(
+                        crate::Expression::LocalVariable(var),
+                        Span::UNDEFINED,
+                    )?;
+                    block.extend(emitter.finish(&ctx.function.expressions));
+                    ctx.local_table.insert(v.handle, Typed::Reference(handle));
+
+                    match initializer {
+                        Some(initializer) => crate::Statement::Store {
+                            pointer: handle,
+                            value: initializer,
+                        },
+                        None => return Ok(()),
+                    }
+                }
+            },
+            ast::StatementKind::If {
+                condition,
+                ref accept,
+                ref reject,
+            } => {
+                let mut emitter = Emitter::default();
+                emitter.start(&ctx.function.expressions);
+
+                let condition =
+                    self.expression(condition, &mut ctx.as_expression(block, &mut emitter))?;
+                block.extend(emitter.finish(&ctx.function.expressions));
+
+                let accept = self.block(accept, is_inside_loop, ctx)?;
+                let reject = self.block(reject, is_inside_loop, ctx)?;
+
+                crate::Statement::If {
+                    condition,
+                    accept,
+                    reject,
+                }
+            }
+            ast::StatementKind::Switch {
+                selector,
+                ref cases,
+            } => {
+                let mut emitter = Emitter::default();
+                emitter.start(&ctx.function.expressions);
+
+                let mut ectx = ctx.as_expression(block, &mut emitter);
+                let selector = self.expression(selector, &mut ectx)?;
+
+                let uint =
+                    resolve_inner!(ectx, selector).scalar_kind() == Some(crate::ScalarKind::Uint);
+                block.extend(emitter.finish(&ctx.function.expressions));
+
+                let cases = cases
+                    .iter()
+                    .map(|case| {
+                        Ok(crate::SwitchCase {
+                            value: match case.value {
+                                ast::SwitchValue::Expr(expr) => {
+                                    let span = ctx.ast_expressions.get_span(expr);
+                                    let expr =
+                                        self.expression(expr, &mut ctx.as_global().as_const())?;
+                                    match ctx.module.to_ctx().eval_expr_to_literal(expr) {
+                                        Some(crate::Literal::I32(value)) if !uint => {
+                                            crate::SwitchValue::I32(value)
+                                        }
+                                        Some(crate::Literal::U32(value)) if uint => {
+                                            crate::SwitchValue::U32(value)
+                                        }
+                                        _ => {
+                                            return Err(Error::InvalidSwitchValue { uint, span });
+                                        }
+                                    }
+                                }
+                                ast::SwitchValue::Default => crate::SwitchValue::Default,
+                            },
+                            body: self.block(&case.body, is_inside_loop, ctx)?,
+                            fall_through: case.fall_through,
+                        })
+                    })
+                    .collect::<Result<_, _>>()?;
+
+                crate::Statement::Switch { selector, cases }
+            }
+            ast::StatementKind::Loop {
+                ref body,
+                ref continuing,
+                break_if,
+            } => {
+                let body = self.block(body, true, ctx)?;
+                let mut continuing = self.block(continuing, true, ctx)?;
+
+                let mut emitter = Emitter::default();
+                emitter.start(&ctx.function.expressions);
+                let break_if = break_if
+                    .map(|expr| {
+                        self.expression(expr, &mut ctx.as_expression(&mut continuing, &mut emitter))
+                    })
+                    .transpose()?;
+                continuing.extend(emitter.finish(&ctx.function.expressions));
+
+                crate::Statement::Loop {
+                    body,
+                    continuing,
+                    break_if,
+                }
+            }
+            ast::StatementKind::Break => crate::Statement::Break,
+            ast::StatementKind::Continue => crate::Statement::Continue,
+            ast::StatementKind::Return { value } => {
+                let mut emitter = Emitter::default();
+                emitter.start(&ctx.function.expressions);
+
+                let value = value
+                    .map(|expr| self.expression(expr, &mut ctx.as_expression(block, &mut emitter)))
+                    .transpose()?;
+                block.extend(emitter.finish(&ctx.function.expressions));
+
+                crate::Statement::Return { value }
+            }
+            ast::StatementKind::Kill => crate::Statement::Kill,
+            ast::StatementKind::Call {
+                ref function,
+                ref arguments,
+            } => {
+                let mut emitter = Emitter::default();
+                emitter.start(&ctx.function.expressions);
+
+                let _ = self.call(
+                    stmt.span,
+                    function,
+                    arguments,
+                    &mut ctx.as_expression(block, &mut emitter),
+                )?;
+                block.extend(emitter.finish(&ctx.function.expressions));
+                return Ok(());
+            }
+            ast::StatementKind::Assign {
+                target: ast_target,
+                op,
+                value,
+            } => {
+                let mut emitter = Emitter::default();
+                emitter.start(&ctx.function.expressions);
+
+                let target = self.expression_for_reference(
+                    ast_target,
+                    &mut ctx.as_expression(block, &mut emitter),
+                )?;
+                let mut value =
+                    self.expression(value, &mut ctx.as_expression(block, &mut emitter))?;
+
+                let target_handle = match target {
+                    Typed::Reference(handle) => handle,
+                    Typed::Plain(handle) => {
+                        let ty = ctx.invalid_assignment_type(handle);
+                        return Err(Error::InvalidAssignment {
+                            span: ctx.ast_expressions.get_span(ast_target),
+                            ty,
+                        });
+                    }
+                };
+
+                let value = match op {
+                    Some(op) => {
+                        let mut ctx = ctx.as_expression(block, &mut emitter);
+                        let mut left = ctx.apply_load_rule(target)?;
+                        ctx.binary_op_splat(op, &mut left, &mut value)?;
+                        ctx.append_expression(
+                            crate::Expression::Binary {
+                                op,
+                                left,
+                                right: value,
+                            },
+                            stmt.span,
+                        )?
+                    }
+                    None => value,
+                };
+                block.extend(emitter.finish(&ctx.function.expressions));
+
+                crate::Statement::Store {
+                    pointer: target_handle,
+                    value,
+                }
+            }
+            ast::StatementKind::Increment(value) | ast::StatementKind::Decrement(value) => {
+                let mut emitter = Emitter::default();
+                emitter.start(&ctx.function.expressions);
+
+                let op = match stmt.kind {
+                    ast::StatementKind::Increment(_) => crate::BinaryOperator::Add,
+                    ast::StatementKind::Decrement(_) => crate::BinaryOperator::Subtract,
+                    _ => unreachable!(),
+                };
+
+                let value_span = ctx.ast_expressions.get_span(value);
+                let target = self
+                    .expression_for_reference(value, &mut ctx.as_expression(block, &mut emitter))?;
+                let target_handle = match target {
+                    Typed::Reference(handle) => handle,
+                    Typed::Plain(_) => return Err(Error::BadIncrDecrReferenceType(value_span)),
+                };
+
+                let mut ectx = ctx.as_expression(block, &mut emitter);
+                let scalar = match *resolve_inner!(ectx, target_handle) {
+                    crate::TypeInner::ValuePointer {
+                        size: None, scalar, ..
+                    } => scalar,
+                    crate::TypeInner::Pointer { base, .. } => match ectx.module.types[base].inner {
+                        crate::TypeInner::Scalar(scalar) => scalar,
+                        _ => return Err(Error::BadIncrDecrReferenceType(value_span)),
+                    },
+                    _ => return Err(Error::BadIncrDecrReferenceType(value_span)),
+                };
+                let literal = match scalar.kind {
+                    crate::ScalarKind::Sint | crate::ScalarKind::Uint => {
+                        crate::Literal::one(scalar)
+                            .ok_or(Error::BadIncrDecrReferenceType(value_span))?
+                    }
+                    _ => return Err(Error::BadIncrDecrReferenceType(value_span)),
+                };
+
+                let right =
+                    ectx.interrupt_emitter(crate::Expression::Literal(literal), Span::UNDEFINED)?;
+                let rctx = ectx.runtime_expression_ctx(stmt.span)?;
+                let left = rctx.function.expressions.append(
+                    crate::Expression::Load {
+                        pointer: target_handle,
+                    },
+                    value_span,
+                );
+                let value = rctx
+                    .function
+                    .expressions
+                    .append(crate::Expression::Binary { op, left, right }, stmt.span);
+
+                block.extend(emitter.finish(&ctx.function.expressions));
+                crate::Statement::Store {
+                    pointer: target_handle,
+                    value,
+                }
+            }
+            ast::StatementKind::Ignore(expr) => {
+                let mut emitter = Emitter::default();
+                emitter.start(&ctx.function.expressions);
+
+                let _ = self.expression(expr, &mut ctx.as_expression(block, &mut emitter))?;
+                block.extend(emitter.finish(&ctx.function.expressions));
+                return Ok(());
+            }
+        };
+
+        block.push(out, stmt.span);
+
+        Ok(())
+    }
+
+    /// Lower `expr` and apply the Load Rule if possible.
+    ///
+    /// For the time being, this concretizes abstract values, to support
+    /// consumers that haven't been adapted to consume them yet. Consumers
+    /// prepared for abstract values can call [`expression_for_abstract`].
+    ///
+    /// [`expression_for_abstract`]: Lowerer::expression_for_abstract
+    fn expression(
+        &mut self,
+        expr: Handle<ast::Expression<'source>>,
+        ctx: &mut ExpressionContext<'source, '_, '_>,
+    ) -> Result<Handle<crate::Expression>, Error<'source>> {
+        let expr = self.expression_for_abstract(expr, ctx)?;
+        ctx.concretize(expr)
+    }
+
+    fn expression_for_abstract(
+        &mut self,
+        expr: Handle<ast::Expression<'source>>,
+        ctx: &mut ExpressionContext<'source, '_, '_>,
+    ) -> Result<Handle<crate::Expression>, Error<'source>> {
+        let expr = self.expression_for_reference(expr, ctx)?;
+        ctx.apply_load_rule(expr)
+    }
+
+    fn expression_for_reference(
+        &mut self,
+        expr: Handle<ast::Expression<'source>>,
+        ctx: &mut ExpressionContext<'source, '_, '_>,
+    ) -> Result<Typed<Handle<crate::Expression>>, Error<'source>> {
+        let span = ctx.ast_expressions.get_span(expr);
+        let expr = &ctx.ast_expressions[expr];
+
+        let expr: Typed<crate::Expression> = match *expr {
+            ast::Expression::Literal(literal) => {
+                let literal = match literal {
+                    ast::Literal::Number(Number::F32(f)) => crate::Literal::F32(f),
+                    ast::Literal::Number(Number::I32(i)) => crate::Literal::I32(i),
+                    ast::Literal::Number(Number::U32(u)) => crate::Literal::U32(u),
+                    ast::Literal::Number(Number::F64(f)) => crate::Literal::F64(f),
+                    ast::Literal::Number(Number::AbstractInt(i)) => crate::Literal::AbstractInt(i),
+                    ast::Literal::Number(Number::AbstractFloat(f)) => {
+                        crate::Literal::AbstractFloat(f)
+                    }
+                    ast::Literal::Bool(b) => crate::Literal::Bool(b),
+                };
+                let handle = ctx.interrupt_emitter(crate::Expression::Literal(literal), span)?;
+                return Ok(Typed::Plain(handle));
+            }
+            ast::Expression::Ident(ast::IdentExpr::Local(local)) => {
+                let rctx = ctx.runtime_expression_ctx(span)?;
+                return Ok(rctx.local_table[&local]);
+            }
+            ast::Expression::Ident(ast::IdentExpr::Unresolved(name)) => {
+                let global = ctx
+                    .globals
+                    .get(name)
+                    .ok_or(Error::UnknownIdent(span, name))?;
+                let expr = match *global {
+                    LoweredGlobalDecl::Var(handle) => {
+                        let expr = crate::Expression::GlobalVariable(handle);
+                        match ctx.module.global_variables[handle].space {
+                            crate::AddressSpace::Handle => Typed::Plain(expr),
+                            _ => Typed::Reference(expr),
+                        }
+                    }
+                    LoweredGlobalDecl::Const(handle) => {
+                        Typed::Plain(crate::Expression::Constant(handle))
+                    }
+                    _ => {
+                        return Err(Error::Unexpected(span, ExpectedToken::Variable));
+                    }
+                };
+
+                return expr.try_map(|handle| ctx.interrupt_emitter(handle, span));
+            }
+            ast::Expression::Construct {
+                ref ty,
+                ty_span,
+                ref components,
+            } => {
+                let handle = self.construct(span, ty, ty_span, components, ctx)?;
+                return Ok(Typed::Plain(handle));
+            }
+            ast::Expression::Unary { op, expr } => {
+                let expr = self.expression_for_abstract(expr, ctx)?;
+                Typed::Plain(crate::Expression::Unary { op, expr })
+            }
+            ast::Expression::AddrOf(expr) => {
+                // The `&` operator simply converts a reference to a pointer. And since a
+                // reference is required, the Load Rule is not applied.
+                match self.expression_for_reference(expr, ctx)? {
+                    Typed::Reference(handle) => {
+                        // No code is generated. We just declare the reference a pointer now.
+                        return Ok(Typed::Plain(handle));
+                    }
+                    Typed::Plain(_) => {
+                        return Err(Error::NotReference("the operand of the `&` operator", span));
+                    }
+                }
+            }
+            ast::Expression::Deref(expr) => {
+                // The pointer we dereference must be loaded.
+                let pointer = self.expression(expr, ctx)?;
+
+                if resolve_inner!(ctx, pointer).pointer_space().is_none() {
+                    return Err(Error::NotPointer(span));
+                }
+
+                // No code is generated. We just declare the pointer a reference now.
+                return Ok(Typed::Reference(pointer));
+            }
+            ast::Expression::Binary { op, left, right } => {
+                self.binary(op, left, right, span, ctx)?
+            }
+            ast::Expression::Call {
+                ref function,
+                ref arguments,
+            } => {
+                let handle = self
+                    .call(span, function, arguments, ctx)?
+                    .ok_or(Error::FunctionReturnsVoid(function.span))?;
+                return Ok(Typed::Plain(handle));
+            }
+            ast::Expression::Index { base, index } => {
+                let lowered_base = self.expression_for_reference(base, ctx)?;
+                let index = self.expression(index, ctx)?;
+
+                if let Typed::Plain(handle) = lowered_base {
+                    if resolve_inner!(ctx, handle).pointer_space().is_some() {
+                        return Err(Error::Pointer(
+                            "the value indexed by a `[]` subscripting expression",
+                            ctx.ast_expressions.get_span(base),
+                        ));
+                    }
+                }
+
+                lowered_base.map(|base| match ctx.const_access(index) {
+                    Some(index) => crate::Expression::AccessIndex { base, index },
+                    None => crate::Expression::Access { base, index },
+                })
+            }
+            ast::Expression::Member { base, ref field } => {
+                let lowered_base = self.expression_for_reference(base, ctx)?;
+
+                let temp_inner;
+                let composite_type: &crate::TypeInner = match lowered_base {
+                    Typed::Reference(handle) => {
+                        let inner = resolve_inner!(ctx, handle);
+                        match *inner {
+                            crate::TypeInner::Pointer { base, .. } => &ctx.module.types[base].inner,
+                            crate::TypeInner::ValuePointer {
+                                size: None, scalar, ..
+                            } => {
+                                temp_inner = crate::TypeInner::Scalar(scalar);
+                                &temp_inner
+                            }
+                            crate::TypeInner::ValuePointer {
+                                size: Some(size),
+                                scalar,
+                                ..
+                            } => {
+                                temp_inner = crate::TypeInner::Vector { size, scalar };
+                                &temp_inner
+                            }
+                            _ => unreachable!(
+                                "In Typed::Reference(handle), handle must be a Naga pointer"
+                            ),
+                        }
+                    }
+
+                    Typed::Plain(handle) => {
+                        let inner = resolve_inner!(ctx, handle);
+                        if let crate::TypeInner::Pointer { .. }
+                        | crate::TypeInner::ValuePointer { .. } = *inner
+                        {
+                            return Err(Error::Pointer(
+                                "the value accessed by a `.member` expression",
+                                ctx.ast_expressions.get_span(base),
+                            ));
+                        }
+                        inner
+                    }
+                };
+
+                let access = match *composite_type {
+                    crate::TypeInner::Struct { ref members, .. } => {
+                        let index = members
+                            .iter()
+                            .position(|m| m.name.as_deref() == Some(field.name))
+                            .ok_or(Error::BadAccessor(field.span))?
+                            as u32;
+
+                        lowered_base.map(|base| crate::Expression::AccessIndex { base, index })
+                    }
+                    crate::TypeInner::Vector { .. } | crate::TypeInner::Matrix { .. } => {
+                        match Components::new(field.name, field.span)? {
+                            Components::Swizzle { size, pattern } => {
+                                // Swizzles aren't allowed on matrices, but
+                                // validation will catch that.
+                                Typed::Plain(crate::Expression::Swizzle {
+                                    size,
+                                    vector: ctx.apply_load_rule(lowered_base)?,
+                                    pattern,
+                                })
+                            }
+                            Components::Single(index) => lowered_base
+                                .map(|base| crate::Expression::AccessIndex { base, index }),
+                        }
+                    }
+                    _ => return Err(Error::BadAccessor(field.span)),
+                };
+
+                access
+            }
+            ast::Expression::Bitcast { expr, to, ty_span } => {
+                let expr = self.expression(expr, ctx)?;
+                let to_resolved = self.resolve_ast_type(to, &mut ctx.as_global())?;
+
+                let element_scalar = match ctx.module.types[to_resolved].inner {
+                    crate::TypeInner::Scalar(scalar) => scalar,
+                    crate::TypeInner::Vector { scalar, .. } => scalar,
+                    _ => {
+                        let ty = resolve!(ctx, expr);
+                        let gctx = &ctx.module.to_ctx();
+                        return Err(Error::BadTypeCast {
+                            from_type: ty.to_wgsl(gctx),
+                            span: ty_span,
+                            to_type: to_resolved.to_wgsl(gctx),
+                        });
+                    }
+                };
+
+                Typed::Plain(crate::Expression::As {
+                    expr,
+                    kind: element_scalar.kind,
+                    convert: None,
+                })
+            }
+        };
+
+        expr.try_map(|handle| ctx.append_expression(handle, span))
+    }
+
+    fn binary(
+        &mut self,
+        op: crate::BinaryOperator,
+        left: Handle<ast::Expression<'source>>,
+        right: Handle<ast::Expression<'source>>,
+        span: Span,
+        ctx: &mut ExpressionContext<'source, '_, '_>,
+    ) -> Result<Typed<crate::Expression>, Error<'source>> {
+        // Load both operands.
+        let mut left = self.expression_for_abstract(left, ctx)?;
+        let mut right = self.expression_for_abstract(right, ctx)?;
+
+        // Convert `scalar op vector` to `vector op vector` by introducing
+        // `Splat` expressions.
+        ctx.binary_op_splat(op, &mut left, &mut right)?;
+
+        // Apply automatic conversions.
+        match op {
+            // Shift operators require the right operand to be `u32` or
+            // `vecN<u32>`. We can let the validator sort out vector length
+            // issues, but the right operand must be, or convert to, a u32 leaf
+            // scalar.
+            crate::BinaryOperator::ShiftLeft | crate::BinaryOperator::ShiftRight => {
+                right =
+                    ctx.try_automatic_conversion_for_leaf_scalar(right, crate::Scalar::U32, span)?;
+            }
+
+            // All other operators follow the same pattern: reconcile the
+            // scalar leaf types. If there's no reconciliation possible,
+            // leave the expressions as they are: validation will report the
+            // problem.
+            _ => {
+                ctx.grow_types(left)?;
+                ctx.grow_types(right)?;
+                if let Ok(consensus_scalar) =
+                    ctx.automatic_conversion_consensus([left, right].iter())
+                {
+                    ctx.convert_to_leaf_scalar(&mut left, consensus_scalar)?;
+                    ctx.convert_to_leaf_scalar(&mut right, consensus_scalar)?;
+                }
+            }
+        }
+
+        Ok(Typed::Plain(crate::Expression::Binary { op, left, right }))
+    }
+
+    /// Generate Naga IR for call expressions and statements, and type
+    /// constructor expressions.
+    ///
+    /// The "function" being called is simply an `Ident` that we know refers to
+    /// some module-scope definition.
+    ///
+    /// - If it is the name of a type, then the expression is a type constructor
+    ///   expression: either constructing a value from components, a conversion
+    ///   expression, or a zero value expression.
+    ///
+    /// - If it is the name of a function, then we're generating a [`Call`]
+    ///   statement. We may be in the midst of generating code for an
+    ///   expression, in which case we must generate an `Emit` statement to
+    ///   force evaluation of the IR expressions we've generated so far, add the
+    ///   `Call` statement to the current block, and then resume generating
+    ///   expressions.
+    ///
+    /// [`Call`]: crate::Statement::Call
+    fn call(
+        &mut self,
+        span: Span,
+        function: &ast::Ident<'source>,
+        arguments: &[Handle<ast::Expression<'source>>],
+        ctx: &mut ExpressionContext<'source, '_, '_>,
+    ) -> Result<Option<Handle<crate::Expression>>, Error<'source>> {
+        match ctx.globals.get(function.name) {
+            Some(&LoweredGlobalDecl::Type(ty)) => {
+                let handle = self.construct(
+                    span,
+                    &ast::ConstructorType::Type(ty),
+                    function.span,
+                    arguments,
+                    ctx,
+                )?;
+                Ok(Some(handle))
+            }
+            Some(&LoweredGlobalDecl::Const(_) | &LoweredGlobalDecl::Var(_)) => {
+                Err(Error::Unexpected(function.span, ExpectedToken::Function))
+            }
+            Some(&LoweredGlobalDecl::EntryPoint) => Err(Error::CalledEntryPoint(function.span)),
+            Some(&LoweredGlobalDecl::Function(function)) => {
+                let arguments = arguments
+                    .iter()
+                    .map(|&arg| self.expression(arg, ctx))
+                    .collect::<Result<Vec<_>, _>>()?;
+
+                let has_result = ctx.module.functions[function].result.is_some();
+                let rctx = ctx.runtime_expression_ctx(span)?;
+                // we need to always do this before a fn call since all arguments need to be emitted before the fn call
+                rctx.block
+                    .extend(rctx.emitter.finish(&rctx.function.expressions));
+                let result = has_result.then(|| {
+                    rctx.function
+                        .expressions
+                        .append(crate::Expression::CallResult(function), span)
+                });
+                rctx.emitter.start(&rctx.function.expressions);
+                rctx.block.push(
+                    crate::Statement::Call {
+                        function,
+                        arguments,
+                        result,
+                    },
+                    span,
+                );
+
+                Ok(result)
+            }
+            None => {
+                let span = function.span;
+                let expr = if let Some(fun) = conv::map_relational_fun(function.name) {
+                    let mut args = ctx.prepare_args(arguments, 1, span);
+                    let argument = self.expression(args.next()?, ctx)?;
+                    args.finish()?;
+
+                    // Check for no-op all(bool) and any(bool):
+                    let argument_unmodified = matches!(
+                        fun,
+                        crate::RelationalFunction::All | crate::RelationalFunction::Any
+                    ) && {
+                        matches!(
+                            resolve_inner!(ctx, argument),
+                            &crate::TypeInner::Scalar(crate::Scalar {
+                                kind: crate::ScalarKind::Bool,
+                                ..
+                            })
+                        )
+                    };
+
+                    if argument_unmodified {
+                        return Ok(Some(argument));
+                    } else {
+                        crate::Expression::Relational { fun, argument }
+                    }
+                } else if let Some((axis, ctrl)) = conv::map_derivative(function.name) {
+                    let mut args = ctx.prepare_args(arguments, 1, span);
+                    let expr = self.expression(args.next()?, ctx)?;
+                    args.finish()?;
+
+                    crate::Expression::Derivative { axis, ctrl, expr }
+                } else if let Some(fun) = conv::map_standard_fun(function.name) {
+                    let expected = fun.argument_count() as _;
+                    let mut args = ctx.prepare_args(arguments, expected, span);
+
+                    let arg = self.expression(args.next()?, ctx)?;
+                    let arg1 = args
+                        .next()
+                        .map(|x| self.expression(x, ctx))
+                        .ok()
+                        .transpose()?;
+                    let arg2 = args
+                        .next()
+                        .map(|x| self.expression(x, ctx))
+                        .ok()
+                        .transpose()?;
+                    let arg3 = args
+                        .next()
+                        .map(|x| self.expression(x, ctx))
+                        .ok()
+                        .transpose()?;
+
+                    args.finish()?;
+
+                    if fun == crate::MathFunction::Modf || fun == crate::MathFunction::Frexp {
+                        if let Some((size, width)) = match *resolve_inner!(ctx, arg) {
+                            crate::TypeInner::Scalar(crate::Scalar { width, .. }) => {
+                                Some((None, width))
+                            }
+                            crate::TypeInner::Vector {
+                                size,
+                                scalar: crate::Scalar { width, .. },
+                                ..
+                            } => Some((Some(size), width)),
+                            _ => None,
+                        } {
+                            ctx.module.generate_predeclared_type(
+                                if fun == crate::MathFunction::Modf {
+                                    crate::PredeclaredType::ModfResult { size, width }
+                                } else {
+                                    crate::PredeclaredType::FrexpResult { size, width }
+                                },
+                            );
+                        }
+                    }
+
+                    crate::Expression::Math {
+                        fun,
+                        arg,
+                        arg1,
+                        arg2,
+                        arg3,
+                    }
+                } else if let Some(fun) = Texture::map(function.name) {
+                    self.texture_sample_helper(fun, arguments, span, ctx)?
+                } else {
+                    match function.name {
+                        "select" => {
+                            let mut args = ctx.prepare_args(arguments, 3, span);
+
+                            let reject = self.expression(args.next()?, ctx)?;
+                            let accept = self.expression(args.next()?, ctx)?;
+                            let condition = self.expression(args.next()?, ctx)?;
+
+                            args.finish()?;
+
+                            crate::Expression::Select {
+                                reject,
+                                accept,
+                                condition,
+                            }
+                        }
+                        "arrayLength" => {
+                            let mut args = ctx.prepare_args(arguments, 1, span);
+                            let expr = self.expression(args.next()?, ctx)?;
+                            args.finish()?;
+
+                            crate::Expression::ArrayLength(expr)
+                        }
+                        "atomicLoad" => {
+                            let mut args = ctx.prepare_args(arguments, 1, span);
+                            let pointer = self.atomic_pointer(args.next()?, ctx)?;
+                            args.finish()?;
+
+                            crate::Expression::Load { pointer }
+                        }
+                        "atomicStore" => {
+                            let mut args = ctx.prepare_args(arguments, 2, span);
+                            let pointer = self.atomic_pointer(args.next()?, ctx)?;
+                            let value = self.expression(args.next()?, ctx)?;
+                            args.finish()?;
+
+                            let rctx = ctx.runtime_expression_ctx(span)?;
+                            rctx.block
+                                .extend(rctx.emitter.finish(&rctx.function.expressions));
+                            rctx.emitter.start(&rctx.function.expressions);
+                            rctx.block
+                                .push(crate::Statement::Store { pointer, value }, span);
+                            return Ok(None);
+                        }
+                        "atomicAdd" => {
+                            return Ok(Some(self.atomic_helper(
+                                span,
+                                crate::AtomicFunction::Add,
+                                arguments,
+                                ctx,
+                            )?))
+                        }
+                        "atomicSub" => {
+                            return Ok(Some(self.atomic_helper(
+                                span,
+                                crate::AtomicFunction::Subtract,
+                                arguments,
+                                ctx,
+                            )?))
+                        }
+                        "atomicAnd" => {
+                            return Ok(Some(self.atomic_helper(
+                                span,
+                                crate::AtomicFunction::And,
+                                arguments,
+                                ctx,
+                            )?))
+                        }
+                        "atomicOr" => {
+                            return Ok(Some(self.atomic_helper(
+                                span,
+                                crate::AtomicFunction::InclusiveOr,
+                                arguments,
+                                ctx,
+                            )?))
+                        }
+                        "atomicXor" => {
+                            return Ok(Some(self.atomic_helper(
+                                span,
+                                crate::AtomicFunction::ExclusiveOr,
+                                arguments,
+                                ctx,
+                            )?))
+                        }
+                        "atomicMin" => {
+                            return Ok(Some(self.atomic_helper(
+                                span,
+                                crate::AtomicFunction::Min,
+                                arguments,
+                                ctx,
+                            )?))
+                        }
+                        "atomicMax" => {
+                            return Ok(Some(self.atomic_helper(
+                                span,
+                                crate::AtomicFunction::Max,
+                                arguments,
+                                ctx,
+                            )?))
+                        }
+                        "atomicExchange" => {
+                            return Ok(Some(self.atomic_helper(
+                                span,
+                                crate::AtomicFunction::Exchange { compare: None },
+                                arguments,
+                                ctx,
+                            )?))
+                        }
+                        "atomicCompareExchangeWeak" => {
+                            let mut args = ctx.prepare_args(arguments, 3, span);
+
+                            let pointer = self.atomic_pointer(args.next()?, ctx)?;
+
+                            let compare = self.expression(args.next()?, ctx)?;
+
+                            let value = args.next()?;
+                            let value_span = ctx.ast_expressions.get_span(value);
+                            let value = self.expression(value, ctx)?;
+
+                            args.finish()?;
+
+                            let expression = match *resolve_inner!(ctx, value) {
+                                crate::TypeInner::Scalar(scalar) => {
+                                    crate::Expression::AtomicResult {
+                                        ty: ctx.module.generate_predeclared_type(
+                                            crate::PredeclaredType::AtomicCompareExchangeWeakResult(
+                                                scalar,
+                                            ),
+                                        ),
+                                        comparison: true,
+                                    }
+                                }
+                                _ => return Err(Error::InvalidAtomicOperandType(value_span)),
+                            };
+
+                            let result = ctx.interrupt_emitter(expression, span)?;
+                            let rctx = ctx.runtime_expression_ctx(span)?;
+                            rctx.block.push(
+                                crate::Statement::Atomic {
+                                    pointer,
+                                    fun: crate::AtomicFunction::Exchange {
+                                        compare: Some(compare),
+                                    },
+                                    value,
+                                    result,
+                                },
+                                span,
+                            );
+                            return Ok(Some(result));
+                        }
+                        "storageBarrier" => {
+                            ctx.prepare_args(arguments, 0, span).finish()?;
+
+                            let rctx = ctx.runtime_expression_ctx(span)?;
+                            rctx.block
+                                .push(crate::Statement::Barrier(crate::Barrier::STORAGE), span);
+                            return Ok(None);
+                        }
+                        "workgroupBarrier" => {
+                            ctx.prepare_args(arguments, 0, span).finish()?;
+
+                            let rctx = ctx.runtime_expression_ctx(span)?;
+                            rctx.block
+                                .push(crate::Statement::Barrier(crate::Barrier::WORK_GROUP), span);
+                            return Ok(None);
+                        }
+                        "workgroupUniformLoad" => {
+                            let mut args = ctx.prepare_args(arguments, 1, span);
+                            let expr = args.next()?;
+                            args.finish()?;
+
+                            let pointer = self.expression(expr, ctx)?;
+                            let result_ty = match *resolve_inner!(ctx, pointer) {
+                                crate::TypeInner::Pointer {
+                                    base,
+                                    space: crate::AddressSpace::WorkGroup,
+                                } => base,
+                                ref other => {
+                                    log::error!("Type {other:?} passed to workgroupUniformLoad");
+                                    let span = ctx.ast_expressions.get_span(expr);
+                                    return Err(Error::InvalidWorkGroupUniformLoad(span));
+                                }
+                            };
+                            let result = ctx.interrupt_emitter(
+                                crate::Expression::WorkGroupUniformLoadResult { ty: result_ty },
+                                span,
+                            )?;
+                            let rctx = ctx.runtime_expression_ctx(span)?;
+                            rctx.block.push(
+                                crate::Statement::WorkGroupUniformLoad { pointer, result },
+                                span,
+                            );
+
+                            return Ok(Some(result));
+                        }
+                        "textureStore" => {
+                            let mut args = ctx.prepare_args(arguments, 3, span);
+
+                            let image = args.next()?;
+                            let image_span = ctx.ast_expressions.get_span(image);
+                            let image = self.expression(image, ctx)?;
+
+                            let coordinate = self.expression(args.next()?, ctx)?;
+
+                            let (_, arrayed) = ctx.image_data(image, image_span)?;
+                            let array_index = arrayed
+                                .then(|| {
+                                    args.min_args += 1;
+                                    self.expression(args.next()?, ctx)
+                                })
+                                .transpose()?;
+
+                            let value = self.expression(args.next()?, ctx)?;
+
+                            args.finish()?;
+
+                            let rctx = ctx.runtime_expression_ctx(span)?;
+                            rctx.block
+                                .extend(rctx.emitter.finish(&rctx.function.expressions));
+                            rctx.emitter.start(&rctx.function.expressions);
+                            let stmt = crate::Statement::ImageStore {
+                                image,
+                                coordinate,
+                                array_index,
+                                value,
+                            };
+                            rctx.block.push(stmt, span);
+                            return Ok(None);
+                        }
+                        "textureLoad" => {
+                            let mut args = ctx.prepare_args(arguments, 2, span);
+
+                            let image = args.next()?;
+                            let image_span = ctx.ast_expressions.get_span(image);
+                            let image = self.expression(image, ctx)?;
+
+                            let coordinate = self.expression(args.next()?, ctx)?;
+
+                            let (class, arrayed) = ctx.image_data(image, image_span)?;
+                            let array_index = arrayed
+                                .then(|| {
+                                    args.min_args += 1;
+                                    self.expression(args.next()?, ctx)
+                                })
+                                .transpose()?;
+
+                            let level = class
+                                .is_mipmapped()
+                                .then(|| {
+                                    args.min_args += 1;
+                                    self.expression(args.next()?, ctx)
+                                })
+                                .transpose()?;
+
+                            let sample = class
+                                .is_multisampled()
+                                .then(|| self.expression(args.next()?, ctx))
+                                .transpose()?;
+
+                            args.finish()?;
+
+                            crate::Expression::ImageLoad {
+                                image,
+                                coordinate,
+                                array_index,
+                                level,
+                                sample,
+                            }
+                        }
+                        "textureDimensions" => {
+                            let mut args = ctx.prepare_args(arguments, 1, span);
+                            let image = self.expression(args.next()?, ctx)?;
+                            let level = args
+                                .next()
+                                .map(|arg| self.expression(arg, ctx))
+                                .ok()
+                                .transpose()?;
+                            args.finish()?;
+
+                            crate::Expression::ImageQuery {
+                                image,
+                                query: crate::ImageQuery::Size { level },
+                            }
+                        }
+                        "textureNumLevels" => {
+                            let mut args = ctx.prepare_args(arguments, 1, span);
+                            let image = self.expression(args.next()?, ctx)?;
+                            args.finish()?;
+
+                            crate::Expression::ImageQuery {
+                                image,
+                                query: crate::ImageQuery::NumLevels,
+                            }
+                        }
+                        "textureNumLayers" => {
+                            let mut args = ctx.prepare_args(arguments, 1, span);
+                            let image = self.expression(args.next()?, ctx)?;
+                            args.finish()?;
+
+                            crate::Expression::ImageQuery {
+                                image,
+                                query: crate::ImageQuery::NumLayers,
+                            }
+                        }
+                        "textureNumSamples" => {
+                            let mut args = ctx.prepare_args(arguments, 1, span);
+                            let image = self.expression(args.next()?, ctx)?;
+                            args.finish()?;
+
+                            crate::Expression::ImageQuery {
+                                image,
+                                query: crate::ImageQuery::NumSamples,
+                            }
+                        }
+                        "rayQueryInitialize" => {
+                            let mut args = ctx.prepare_args(arguments, 3, span);
+                            let query = self.ray_query_pointer(args.next()?, ctx)?;
+                            let acceleration_structure = self.expression(args.next()?, ctx)?;
+                            let descriptor = self.expression(args.next()?, ctx)?;
+                            args.finish()?;
+
+                            let _ = ctx.module.generate_ray_desc_type();
+                            let fun = crate::RayQueryFunction::Initialize {
+                                acceleration_structure,
+                                descriptor,
+                            };
+
+                            let rctx = ctx.runtime_expression_ctx(span)?;
+                            rctx.block
+                                .extend(rctx.emitter.finish(&rctx.function.expressions));
+                            rctx.emitter.start(&rctx.function.expressions);
+                            rctx.block
+                                .push(crate::Statement::RayQuery { query, fun }, span);
+                            return Ok(None);
+                        }
+                        "rayQueryProceed" => {
+                            let mut args = ctx.prepare_args(arguments, 1, span);
+                            let query = self.ray_query_pointer(args.next()?, ctx)?;
+                            args.finish()?;
+
+                            let result = ctx.interrupt_emitter(
+                                crate::Expression::RayQueryProceedResult,
+                                span,
+                            )?;
+                            let fun = crate::RayQueryFunction::Proceed { result };
+                            let rctx = ctx.runtime_expression_ctx(span)?;
+                            rctx.block
+                                .push(crate::Statement::RayQuery { query, fun }, span);
+                            return Ok(Some(result));
+                        }
+                        "rayQueryGetCommittedIntersection" => {
+                            let mut args = ctx.prepare_args(arguments, 1, span);
+                            let query = self.ray_query_pointer(args.next()?, ctx)?;
+                            args.finish()?;
+
+                            let _ = ctx.module.generate_ray_intersection_type();
+
+                            crate::Expression::RayQueryGetIntersection {
+                                query,
+                                committed: true,
+                            }
+                        }
+                        "RayDesc" => {
+                            let ty = ctx.module.generate_ray_desc_type();
+                            let handle = self.construct(
+                                span,
+                                &ast::ConstructorType::Type(ty),
+                                function.span,
+                                arguments,
+                                ctx,
+                            )?;
+                            return Ok(Some(handle));
+                        }
+                        _ => return Err(Error::UnknownIdent(function.span, function.name)),
+                    }
+                };
+
+                let expr = ctx.append_expression(expr, span)?;
+                Ok(Some(expr))
+            }
+        }
+    }
+
+    fn atomic_pointer(
+        &mut self,
+        expr: Handle<ast::Expression<'source>>,
+        ctx: &mut ExpressionContext<'source, '_, '_>,
+    ) -> Result<Handle<crate::Expression>, Error<'source>> {
+        let span = ctx.ast_expressions.get_span(expr);
+        let pointer = self.expression(expr, ctx)?;
+
+        match *resolve_inner!(ctx, pointer) {
+            crate::TypeInner::Pointer { base, .. } => match ctx.module.types[base].inner {
+                crate::TypeInner::Atomic { .. } => Ok(pointer),
+                ref other => {
+                    log::error!("Pointer type to {:?} passed to atomic op", other);
+                    Err(Error::InvalidAtomicPointer(span))
+                }
+            },
+            ref other => {
+                log::error!("Type {:?} passed to atomic op", other);
+                Err(Error::InvalidAtomicPointer(span))
+            }
+        }
+    }
+
+    fn atomic_helper(
+        &mut self,
+        span: Span,
+        fun: crate::AtomicFunction,
+        args: &[Handle<ast::Expression<'source>>],
+        ctx: &mut ExpressionContext<'source, '_, '_>,
+    ) -> Result<Handle<crate::Expression>, Error<'source>> {
+        let mut args = ctx.prepare_args(args, 2, span);
+
+        let pointer = self.atomic_pointer(args.next()?, ctx)?;
+
+        let value = args.next()?;
+        let value = self.expression(value, ctx)?;
+        let ty = ctx.register_type(value)?;
+
+        args.finish()?;
+
+        let result = ctx.interrupt_emitter(
+            crate::Expression::AtomicResult {
+                ty,
+                comparison: false,
+            },
+            span,
+        )?;
+        let rctx = ctx.runtime_expression_ctx(span)?;
+        rctx.block.push(
+            crate::Statement::Atomic {
+                pointer,
+                fun,
+                value,
+                result,
+            },
+            span,
+        );
+        Ok(result)
+    }
+
+    fn texture_sample_helper(
+        &mut self,
+        fun: Texture,
+        args: &[Handle<ast::Expression<'source>>],
+        span: Span,
+        ctx: &mut ExpressionContext<'source, '_, '_>,
+    ) -> Result<crate::Expression, Error<'source>> {
+        let mut args = ctx.prepare_args(args, fun.min_argument_count(), span);
+
+        fn get_image_and_span<'source>(
+            lowerer: &mut Lowerer<'source, '_>,
+            args: &mut ArgumentContext<'_, 'source>,
+            ctx: &mut ExpressionContext<'source, '_, '_>,
+        ) -> Result<(Handle<crate::Expression>, Span), Error<'source>> {
+            let image = args.next()?;
+            let image_span = ctx.ast_expressions.get_span(image);
+            let image = lowerer.expression(image, ctx)?;
+            Ok((image, image_span))
+        }
+
+        let (image, image_span, gather) = match fun {
+            Texture::Gather => {
+                let image_or_component = args.next()?;
+                let image_or_component_span = ctx.ast_expressions.get_span(image_or_component);
+                // Gathers from depth textures don't take an initial `component` argument.
+                let lowered_image_or_component = self.expression(image_or_component, ctx)?;
+
+                match *resolve_inner!(ctx, lowered_image_or_component) {
+                    crate::TypeInner::Image {
+                        class: crate::ImageClass::Depth { .. },
+                        ..
+                    } => (
+                        lowered_image_or_component,
+                        image_or_component_span,
+                        Some(crate::SwizzleComponent::X),
+                    ),
+                    _ => {
+                        let (image, image_span) = get_image_and_span(self, &mut args, ctx)?;
+                        (
+                            image,
+                            image_span,
+                            Some(ctx.gather_component(
+                                lowered_image_or_component,
+                                image_or_component_span,
+                                span,
+                            )?),
+                        )
+                    }
+                }
+            }
+            Texture::GatherCompare => {
+                let (image, image_span) = get_image_and_span(self, &mut args, ctx)?;
+                (image, image_span, Some(crate::SwizzleComponent::X))
+            }
+
+            _ => {
+                let (image, image_span) = get_image_and_span(self, &mut args, ctx)?;
+                (image, image_span, None)
+            }
+        };
+
+        let sampler = self.expression(args.next()?, ctx)?;
+
+        let coordinate = self.expression(args.next()?, ctx)?;
+
+        let (_, arrayed) = ctx.image_data(image, image_span)?;
+        let array_index = arrayed
+            .then(|| self.expression(args.next()?, ctx))
+            .transpose()?;
+
+        let (level, depth_ref) = match fun {
+            Texture::Gather => (crate::SampleLevel::Zero, None),
+            Texture::GatherCompare => {
+                let reference = self.expression(args.next()?, ctx)?;
+                (crate::SampleLevel::Zero, Some(reference))
+            }
+
+            Texture::Sample => (crate::SampleLevel::Auto, None),
+            Texture::SampleBias => {
+                let bias = self.expression(args.next()?, ctx)?;
+                (crate::SampleLevel::Bias(bias), None)
+            }
+            Texture::SampleCompare => {
+                let reference = self.expression(args.next()?, ctx)?;
+                (crate::SampleLevel::Auto, Some(reference))
+            }
+            Texture::SampleCompareLevel => {
+                let reference = self.expression(args.next()?, ctx)?;
+                (crate::SampleLevel::Zero, Some(reference))
+            }
+            Texture::SampleGrad => {
+                let x = self.expression(args.next()?, ctx)?;
+                let y = self.expression(args.next()?, ctx)?;
+                (crate::SampleLevel::Gradient { x, y }, None)
+            }
+            Texture::SampleLevel => {
+                let level = self.expression(args.next()?, ctx)?;
+                (crate::SampleLevel::Exact(level), None)
+            }
+        };
+
+        let offset = args
+            .next()
+            .map(|arg| self.expression(arg, &mut ctx.as_const()))
+            .ok()
+            .transpose()?;
+
+        args.finish()?;
+
+        Ok(crate::Expression::ImageSample {
+            image,
+            sampler,
+            gather,
+            coordinate,
+            array_index,
+            offset,
+            level,
+            depth_ref,
+        })
+    }
+
+    fn r#struct(
+        &mut self,
+        s: &ast::Struct<'source>,
+        span: Span,
+        ctx: &mut GlobalContext<'source, '_, '_>,
+    ) -> Result<Handle<crate::Type>, Error<'source>> {
+        let mut offset = 0;
+        let mut struct_alignment = Alignment::ONE;
+        let mut members = Vec::with_capacity(s.members.len());
+
+        for member in s.members.iter() {
+            let ty = self.resolve_ast_type(member.ty, ctx)?;
+
+            self.layouter.update(ctx.module.to_ctx()).unwrap();
+
+            let member_min_size = self.layouter[ty].size;
+            let member_min_alignment = self.layouter[ty].alignment;
+
+            let member_size = if let Some(size_expr) = member.size {
+                let (size, span) = self.const_u32(size_expr, &mut ctx.as_const())?;
+                if size < member_min_size {
+                    return Err(Error::SizeAttributeTooLow(span, member_min_size));
+                } else {
+                    size
+                }
+            } else {
+                member_min_size
+            };
+
+            let member_alignment = if let Some(align_expr) = member.align {
+                let (align, span) = self.const_u32(align_expr, &mut ctx.as_const())?;
+                if let Some(alignment) = Alignment::new(align) {
+                    if alignment < member_min_alignment {
+                        return Err(Error::AlignAttributeTooLow(span, member_min_alignment));
+                    } else {
+                        alignment
+                    }
+                } else {
+                    return Err(Error::NonPowerOfTwoAlignAttribute(span));
+                }
+            } else {
+                member_min_alignment
+            };
+
+            let binding = self.binding(&member.binding, ty, ctx)?;
+
+            offset = member_alignment.round_up(offset);
+            struct_alignment = struct_alignment.max(member_alignment);
+
+            members.push(crate::StructMember {
+                name: Some(member.name.name.to_owned()),
+                ty,
+                binding,
+                offset,
+            });
+
+            offset += member_size;
+        }
+
+        let size = struct_alignment.round_up(offset);
+        let inner = crate::TypeInner::Struct {
+            members,
+            span: size,
+        };
+
+        let handle = ctx.module.types.insert(
+            crate::Type {
+                name: Some(s.name.name.to_string()),
+                inner,
+            },
+            span,
+        );
+        Ok(handle)
+    }
+
+    fn const_u32(
+        &mut self,
+        expr: Handle<ast::Expression<'source>>,
+        ctx: &mut ExpressionContext<'source, '_, '_>,
+    ) -> Result<(u32, Span), Error<'source>> {
+        let span = ctx.ast_expressions.get_span(expr);
+        let expr = self.expression(expr, ctx)?;
+        let value = ctx
+            .module
+            .to_ctx()
+            .eval_expr_to_u32(expr)
+            .map_err(|err| match err {
+                crate::proc::U32EvalError::NonConst => {
+                    Error::ExpectedConstExprConcreteIntegerScalar(span)
+                }
+                crate::proc::U32EvalError::Negative => Error::ExpectedNonNegative(span),
+            })?;
+        Ok((value, span))
+    }
+
+    fn array_size(
+        &mut self,
+        size: ast::ArraySize<'source>,
+        ctx: &mut GlobalContext<'source, '_, '_>,
+    ) -> Result<crate::ArraySize, Error<'source>> {
+        Ok(match size {
+            ast::ArraySize::Constant(expr) => {
+                let span = ctx.ast_expressions.get_span(expr);
+                let const_expr = self.expression(expr, &mut ctx.as_const())?;
+                let len =
+                    ctx.module
+                        .to_ctx()
+                        .eval_expr_to_u32(const_expr)
+                        .map_err(|err| match err {
+                            crate::proc::U32EvalError::NonConst => {
+                                Error::ExpectedConstExprConcreteIntegerScalar(span)
+                            }
+                            crate::proc::U32EvalError::Negative => {
+                                Error::ExpectedPositiveArrayLength(span)
+                            }
+                        })?;
+                let size = NonZeroU32::new(len).ok_or(Error::ExpectedPositiveArrayLength(span))?;
+                crate::ArraySize::Constant(size)
+            }
+            ast::ArraySize::Dynamic => crate::ArraySize::Dynamic,
+        })
+    }
+
+    /// Build the Naga equivalent of a named AST type.
+    ///
+    /// Return a Naga `Handle<Type>` representing the front-end type
+    /// `handle`, which should be named `name`, if given.
+    ///
+    /// If `handle` refers to a type cached in [`SpecialTypes`],
+    /// `name` may be ignored.
+    ///
+    /// [`SpecialTypes`]: crate::SpecialTypes
+    fn resolve_named_ast_type(
+        &mut self,
+        handle: Handle<ast::Type<'source>>,
+        name: Option<String>,
+        ctx: &mut GlobalContext<'source, '_, '_>,
+    ) -> Result<Handle<crate::Type>, Error<'source>> {
+        let inner = match ctx.types[handle] {
+            ast::Type::Scalar(scalar) => scalar.to_inner_scalar(),
+            ast::Type::Vector { size, scalar } => scalar.to_inner_vector(size),
+            ast::Type::Matrix {
+                rows,
+                columns,
+                width,
+            } => crate::TypeInner::Matrix {
+                columns,
+                rows,
+                scalar: crate::Scalar::float(width),
+            },
+            ast::Type::Atomic(scalar) => scalar.to_inner_atomic(),
+            ast::Type::Pointer { base, space } => {
+                let base = self.resolve_ast_type(base, ctx)?;
+                crate::TypeInner::Pointer { base, space }
+            }
+            ast::Type::Array { base, size } => {
+                let base = self.resolve_ast_type(base, ctx)?;
+                let size = self.array_size(size, ctx)?;
+
+                self.layouter.update(ctx.module.to_ctx()).unwrap();
+                let stride = self.layouter[base].to_stride();
+
+                crate::TypeInner::Array { base, size, stride }
+            }
+            ast::Type::Image {
+                dim,
+                arrayed,
+                class,
+            } => crate::TypeInner::Image {
+                dim,
+                arrayed,
+                class,
+            },
+            ast::Type::Sampler { comparison } => crate::TypeInner::Sampler { comparison },
+            ast::Type::AccelerationStructure => crate::TypeInner::AccelerationStructure,
+            ast::Type::RayQuery => crate::TypeInner::RayQuery,
+            ast::Type::BindingArray { base, size } => {
+                let base = self.resolve_ast_type(base, ctx)?;
+                let size = self.array_size(size, ctx)?;
+                crate::TypeInner::BindingArray { base, size }
+            }
+            ast::Type::RayDesc => {
+                return Ok(ctx.module.generate_ray_desc_type());
+            }
+            ast::Type::RayIntersection => {
+                return Ok(ctx.module.generate_ray_intersection_type());
+            }
+            ast::Type::User(ref ident) => {
+                return match ctx.globals.get(ident.name) {
+                    Some(&LoweredGlobalDecl::Type(handle)) => Ok(handle),
+                    Some(_) => Err(Error::Unexpected(ident.span, ExpectedToken::Type)),
+                    None => Err(Error::UnknownType(ident.span)),
+                }
+            }
+        };
+
+        Ok(ctx.ensure_type_exists(name, inner))
+    }
+
+    /// Return a Naga `Handle<Type>` representing the front-end type `handle`.
+    fn resolve_ast_type(
+        &mut self,
+        handle: Handle<ast::Type<'source>>,
+        ctx: &mut GlobalContext<'source, '_, '_>,
+    ) -> Result<Handle<crate::Type>, Error<'source>> {
+        self.resolve_named_ast_type(handle, None, ctx)
+    }
+
+    fn binding(
+        &mut self,
+        binding: &Option<ast::Binding<'source>>,
+        ty: Handle<crate::Type>,
+        ctx: &mut GlobalContext<'source, '_, '_>,
+    ) -> Result<Option<crate::Binding>, Error<'source>> {
+        Ok(match *binding {
+            Some(ast::Binding::BuiltIn(b)) => Some(crate::Binding::BuiltIn(b)),
+            Some(ast::Binding::Location {
+                location,
+                second_blend_source,
+                interpolation,
+                sampling,
+            }) => {
+                let mut binding = crate::Binding::Location {
+                    location: self.const_u32(location, &mut ctx.as_const())?.0,
+                    second_blend_source,
+                    interpolation,
+                    sampling,
+                };
+                binding.apply_default_interpolation(&ctx.module.types[ty].inner);
+                Some(binding)
+            }
+            None => None,
+        })
+    }
+
+    fn ray_query_pointer(
+        &mut self,
+        expr: Handle<ast::Expression<'source>>,
+        ctx: &mut ExpressionContext<'source, '_, '_>,
+    ) -> Result<Handle<crate::Expression>, Error<'source>> {
+        let span = ctx.ast_expressions.get_span(expr);
+        let pointer = self.expression(expr, ctx)?;
+
+        match *resolve_inner!(ctx, pointer) {
+            crate::TypeInner::Pointer { base, .. } => match ctx.module.types[base].inner {
+                crate::TypeInner::RayQuery => Ok(pointer),
+                ref other => {
+                    log::error!("Pointer type to {:?} passed to ray query op", other);
+                    Err(Error::InvalidRayQueryPointer(span))
+                }
+            },
+            ref other => {
+                log::error!("Type {:?} passed to ray query op", other);
+                Err(Error::InvalidRayQueryPointer(span))
+            }
+        }
+    }
+}
diff --git a/third_party/rust/naga/src/front/wgsl/mod.rs b/third_party/rust/naga/src/front/wgsl/mod.rs
new file mode 100644
index 0000000000..b6151fe1c0
--- /dev/null
+++ b/third_party/rust/naga/src/front/wgsl/mod.rs
@@ -0,0 +1,49 @@
+/*!
+Frontend for [WGSL][wgsl] (WebGPU Shading Language).
+
+[wgsl]: https://gpuweb.github.io/gpuweb/wgsl.html
+*/
+
+mod error;
+mod index;
+mod lower;
+mod parse;
+#[cfg(test)]
+mod tests;
+mod to_wgsl;
+
+use crate::front::wgsl::error::Error;
+use crate::front::wgsl::parse::Parser;
+use thiserror::Error;
+
+pub use crate::front::wgsl::error::ParseError;
+use crate::front::wgsl::lower::Lowerer;
+use crate::Scalar;
+
+pub struct Frontend {
+    parser: Parser,
+}
+
+impl Frontend {
+    pub const fn new() -> Self {
+        Self {
+            parser: Parser::new(),
+        }
+    }
+
+    pub fn parse(&mut self, source: &str) -> Result<crate::Module, ParseError> {
+        self.inner(source).map_err(|x| x.as_parse_error(source))
+    }
+
+    fn inner<'a>(&mut self, source: &'a str) -> Result<crate::Module, Error<'a>> {
+        let tu = self.parser.parse(source)?;
+        let index = index::Index::generate(&tu)?;
+        let module = Lowerer::new(&index).lower(&tu)?;
+
+        Ok(module)
+    }
+}
+
+pub fn parse_str(source: &str) -> Result<crate::Module, ParseError> {
+    Frontend::new().parse(source)
+}
diff --git a/third_party/rust/naga/src/front/wgsl/parse/ast.rs b/third_party/rust/naga/src/front/wgsl/parse/ast.rs
new file mode 100644
index 0000000000..dbaac523cb
--- /dev/null
+++ b/third_party/rust/naga/src/front/wgsl/parse/ast.rs
@@ -0,0 +1,491 @@
+use crate::front::wgsl::parse::number::Number;
+use crate::front::wgsl::Scalar;
+use crate::{Arena, FastIndexSet, Handle, Span};
+use std::hash::Hash;
+
+#[derive(Debug, Default)]
+pub struct TranslationUnit<'a> {
+    pub decls: Arena<GlobalDecl<'a>>,
+    /// The common expressions arena for the entire translation unit.
+    ///
+    /// All functions, global initializers, array lengths, etc. store their
+    /// expressions here. We apportion these out to individual Naga
+    /// [`Function`]s' expression arenas at lowering time. Keeping them all in a
+    /// single arena simplifies handling of things like array lengths (which are
+    /// effectively global and thus don't clearly belong to any function) and
+    /// initializers (which can appear in both function-local and module-scope
+    /// contexts).
+    ///
+    /// [`Function`]: crate::Function
+    pub expressions: Arena<Expression<'a>>,
+
+    /// Non-user-defined types, like `vec4<f32>` or `array<i32, 10>`.
+    ///
+    /// These are referred to by `Handle<ast::Type<'a>>` values.
+    /// User-defined types are referred to by name until lowering.
+    pub types: Arena<Type<'a>>,
+}
+
+#[derive(Debug, Clone, Copy)]
+pub struct Ident<'a> {
+    pub name: &'a str,
+    pub span: Span,
+}
+
+#[derive(Debug)]
+pub enum IdentExpr<'a> {
+    Unresolved(&'a str),
+    Local(Handle<Local>),
+}
+
+/// A reference to a module-scope definition or predeclared object.
+///
+/// Each [`GlobalDecl`] holds a set of these values, to be resolved to
+/// specific definitions later. To support de-duplication, `Eq` and
+/// `Hash` on a `Dependency` value consider only the name, not the
+/// source location at which the reference occurs.
+#[derive(Debug)]
+pub struct Dependency<'a> {
+    /// The name referred to.
+    pub ident: &'a str,
+
+    /// The location at which the reference to that name occurs.
+    pub usage: Span,
+}
+
+impl Hash for Dependency<'_> {
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        self.ident.hash(state);
+    }
+}
+
+impl PartialEq for Dependency<'_> {
+    fn eq(&self, other: &Self) -> bool {
+        self.ident == other.ident
+    }
+}
+
+impl Eq for Dependency<'_> {}
+
+/// A module-scope declaration.
+#[derive(Debug)]
+pub struct GlobalDecl<'a> {
+    pub kind: GlobalDeclKind<'a>,
+
+    /// Names of all module-scope or predeclared objects this
+    /// declaration uses.
+    pub dependencies: FastIndexSet<Dependency<'a>>,
+}
+
+#[derive(Debug)]
+pub enum GlobalDeclKind<'a> {
+    Fn(Function<'a>),
+    Var(GlobalVariable<'a>),
+    Const(Const<'a>),
+    Struct(Struct<'a>),
+    Type(TypeAlias<'a>),
+}
+
+#[derive(Debug)]
+pub struct FunctionArgument<'a> {
+    pub name: Ident<'a>,
+    pub ty: Handle<Type<'a>>,
+    pub binding: Option<Binding<'a>>,
+    pub handle: Handle<Local>,
+}
+
+#[derive(Debug)]
+pub struct FunctionResult<'a> {
+    pub ty: Handle<Type<'a>>,
+    pub binding: Option<Binding<'a>>,
+}
+
+#[derive(Debug)]
+pub struct EntryPoint<'a> {
+    pub stage: crate::ShaderStage,
+    pub early_depth_test: Option<crate::EarlyDepthTest>,
+    pub workgroup_size: Option<[Option<Handle<Expression<'a>>>; 3]>,
+}
+
+#[cfg(doc)]
+use crate::front::wgsl::lower::{RuntimeExpressionContext, StatementContext};
+
+#[derive(Debug)]
+pub struct Function<'a> {
+    pub entry_point: Option<EntryPoint<'a>>,
+    pub name: Ident<'a>,
+    pub arguments: Vec<FunctionArgument<'a>>,
+    pub result: Option<FunctionResult<'a>>,
+
+    /// Local variable and function argument arena.
+    ///
+    /// Note that the `Local` here is actually a zero-sized type. The AST keeps
+    /// all the detailed information about locals - names, types, etc. - in
+    /// [`LocalDecl`] statements. For arguments, that information is kept in
+    /// [`arguments`]. This `Arena`'s only role is to assign a unique `Handle`
+    /// to each of them, and track their definitions' spans for use in
+    /// diagnostics.
+    ///
+    /// In the AST, when an [`Ident`] expression refers to a local variable or
+    /// argument, its [`IdentExpr`] holds the referent's `Handle<Local>` in this
+    /// arena.
+    ///
+    /// During lowering, [`LocalDecl`] statements add entries to a per-function
+    /// table that maps `Handle<Local>` values to their Naga representations,
+    /// accessed via [`StatementContext::local_table`] and
+    /// [`RuntimeExpressionContext::local_table`]. This table is then consulted when
+    /// lowering subsequent [`Ident`] expressions.
+    ///
+    /// [`LocalDecl`]: StatementKind::LocalDecl
+    /// [`arguments`]: Function::arguments
+    /// [`Ident`]: Expression::Ident
+    /// [`StatementContext::local_table`]: StatementContext::local_table
+    /// [`RuntimeExpressionContext::local_table`]: RuntimeExpressionContext::local_table
+    pub locals: Arena<Local>,
+
+    pub body: Block<'a>,
+}
+
+#[derive(Debug)]
+pub enum Binding<'a> {
+    BuiltIn(crate::BuiltIn),
+    Location {
+        location: Handle<Expression<'a>>,
+        second_blend_source: bool,
+        interpolation: Option<crate::Interpolation>,
+        sampling: Option<crate::Sampling>,
+    },
+}
+
+#[derive(Debug)]
+pub struct ResourceBinding<'a> {
+    pub group: Handle<Expression<'a>>,
+    pub binding: Handle<Expression<'a>>,
+}
+
+#[derive(Debug)]
+pub struct GlobalVariable<'a> {
+    pub name: Ident<'a>,
+    pub space: crate::AddressSpace,
+    pub binding: Option<ResourceBinding<'a>>,
+    pub ty: Handle<Type<'a>>,
+    pub init: Option<Handle<Expression<'a>>>,
+}
+
+#[derive(Debug)]
+pub struct StructMember<'a> {
+    pub name: Ident<'a>,
+    pub ty: Handle<Type<'a>>,
+    pub binding: Option<Binding<'a>>,
+    pub align: Option<Handle<Expression<'a>>>,
+    pub size: Option<Handle<Expression<'a>>>,
+}
+
+#[derive(Debug)]
+pub struct Struct<'a> {
+    pub name: Ident<'a>,
+    pub members: Vec<StructMember<'a>>,
+}
+
+#[derive(Debug)]
+pub struct TypeAlias<'a> {
+    pub name: Ident<'a>,
+    pub ty: Handle<Type<'a>>,
+}
+
+#[derive(Debug)]
+pub struct Const<'a> {
+    pub name: Ident<'a>,
+    pub ty: Option<Handle<Type<'a>>>,
+    pub init: Handle<Expression<'a>>,
+}
+
+/// The size of an [`Array`] or [`BindingArray`].
+///
+/// [`Array`]: Type::Array
+/// [`BindingArray`]: Type::BindingArray
+#[derive(Debug, Copy, Clone)]
+pub enum ArraySize<'a> {
+    /// The length as a constant expression.
+    Constant(Handle<Expression<'a>>),
+    Dynamic,
+}
+
+#[derive(Debug)]
+pub enum Type<'a> {
+    Scalar(Scalar),
+    Vector {
+        size: crate::VectorSize,
+        scalar: Scalar,
+    },
+    Matrix {
+        columns: crate::VectorSize,
+        rows: crate::VectorSize,
+        width: crate::Bytes,
+    },
+    Atomic(Scalar),
+    Pointer {
+        base: Handle<Type<'a>>,
+        space: crate::AddressSpace,
+    },
+    Array {
+        base: Handle<Type<'a>>,
+        size: ArraySize<'a>,
+    },
+    Image {
+        dim: crate::ImageDimension,
+        arrayed: bool,
+        class: crate::ImageClass,
+    },
+    Sampler {
+        comparison: bool,
+    },
+    AccelerationStructure,
+    RayQuery,
+    RayDesc,
+    RayIntersection,
+    BindingArray {
+        base: Handle<Type<'a>>,
+        size: ArraySize<'a>,
+    },
+
+    /// A user-defined type, like a struct or a type alias.
+    User(Ident<'a>),
+}
+
+#[derive(Debug, Default)]
+pub struct Block<'a> {
+    pub stmts: Vec<Statement<'a>>,
+}
+
+#[derive(Debug)]
+pub struct Statement<'a> {
+    pub kind: StatementKind<'a>,
+    pub span: Span,
+}
+
+#[derive(Debug)]
+pub enum StatementKind<'a> {
+    LocalDecl(LocalDecl<'a>),
+    Block(Block<'a>),
+    If {
+        condition: Handle<Expression<'a>>,
+        accept: Block<'a>,
+        reject: Block<'a>,
+    },
+    Switch {
+        selector: Handle<Expression<'a>>,
+        cases: Vec<SwitchCase<'a>>,
+    },
+    Loop {
+        body: Block<'a>,
+        continuing: Block<'a>,
+        break_if: Option<Handle<Expression<'a>>>,
+    },
+    Break,
+    Continue,
+    Return {
+        value: Option<Handle<Expression<'a>>>,
+    },
+    Kill,
+    Call {
+        function: Ident<'a>,
+        arguments: Vec<Handle<Expression<'a>>>,
+    },
+    Assign {
+        target: Handle<Expression<'a>>,
+        op: Option<crate::BinaryOperator>,
+        value: Handle<Expression<'a>>,
+    },
+    Increment(Handle<Expression<'a>>),
+    Decrement(Handle<Expression<'a>>),
+    Ignore(Handle<Expression<'a>>),
+}
+
+#[derive(Debug)]
+pub enum SwitchValue<'a> {
+    Expr(Handle<Expression<'a>>),
+    Default,
+}
+
+#[derive(Debug)]
+pub struct SwitchCase<'a> {
+    pub value: SwitchValue<'a>,
+    pub body: Block<'a>,
+    pub fall_through: bool,
+}
+
+/// A type at the head of a [`Construct`] expression.
+///
+/// WGSL has two types of [`type constructor expressions`]:
+///
+/// - Those that fully specify the type being constructed, like
+///   `vec3<f32>(x,y,z)`, which obviously constructs a `vec3<f32>`.
+///
+/// - Those that leave the component type of the composite being constructed
+///   implicit, to be inferred from the argument types, like `vec3(x,y,z)`,
+///   which constructs a `vec3<T>` where `T` is the type of `x`, `y`, and `z`.
+///
+/// This enum represents the head type of both cases. The `PartialFoo` variants
+/// represent the second case, where the component type is implicit.
+///
+/// This does not cover structs or types referred to by type aliases. See the
+/// documentation for [`Construct`] and [`Call`] expressions for details.
+///
+/// [`Construct`]: Expression::Construct
+/// [`type constructor expressions`]: https://gpuweb.github.io/gpuweb/wgsl/#type-constructor-expr
+/// [`Call`]: Expression::Call
+#[derive(Debug)]
+pub enum ConstructorType<'a> {
+    /// A scalar type or conversion: `f32(1)`.
+    Scalar(Scalar),
+
+    /// A vector construction whose component type is inferred from the
+    /// argument: `vec3(1.0)`.
+    PartialVector { size: crate::VectorSize },
+
+    /// A vector construction whose component type is written out:
+    /// `vec3<f32>(1.0)`.
+    Vector {
+        size: crate::VectorSize,
+        scalar: Scalar,
+    },
+
+    /// A matrix construction whose component type is inferred from the
+    /// argument: `mat2x2(1,2,3,4)`.
+    PartialMatrix {
+        columns: crate::VectorSize,
+        rows: crate::VectorSize,
+    },
+
+    /// A matrix construction whose component type is written out:
+    /// `mat2x2<f32>(1,2,3,4)`.
+    Matrix {
+        columns: crate::VectorSize,
+        rows: crate::VectorSize,
+        width: crate::Bytes,
+    },
+
+    /// An array whose component type and size are inferred from the arguments:
+    /// `array(3,4,5)`.
+    PartialArray,
+
+    /// An array whose component type and size are written out:
+    /// `array<u32, 4>(3,4,5)`.
+    Array {
+        base: Handle<Type<'a>>,
+        size: ArraySize<'a>,
+    },
+
+    /// Constructing a value of a known Naga IR type.
+    ///
+    /// This variant is produced only during lowering, when we have Naga types
+    /// available, never during parsing.
+    Type(Handle<crate::Type>),
+}
+
+#[derive(Debug, Copy, Clone)]
+pub enum Literal {
+    Bool(bool),
+    Number(Number),
+}
+
+#[cfg(doc)]
+use crate::front::wgsl::lower::Lowerer;
+
+#[derive(Debug)]
+pub enum Expression<'a> {
+    Literal(Literal),
+    Ident(IdentExpr<'a>),
+
+    /// A type constructor expression.
+    ///
+    /// This is only used for expressions like `KEYWORD(EXPR...)` and
+    /// `KEYWORD<PARAM>(EXPR...)`, where `KEYWORD` is a [type-defining keyword] like
+    /// `vec3`. These keywords cannot be shadowed by user definitions, so we can
+    /// tell that such an expression is a construction immediately.
+    ///
+    /// For ordinary identifiers, we can't tell whether an expression like
+    /// `IDENTIFIER(EXPR, ...)` is a construction expression or a function call
+    /// until we know `IDENTIFIER`'s definition, so we represent those as
+    /// [`Call`] expressions.
+    ///
+    /// [type-defining keyword]: https://gpuweb.github.io/gpuweb/wgsl/#type-defining-keywords
+    /// [`Call`]: Expression::Call
+    Construct {
+        ty: ConstructorType<'a>,
+        ty_span: Span,
+        components: Vec<Handle<Expression<'a>>>,
+    },
+    Unary {
+        op: crate::UnaryOperator,
+        expr: Handle<Expression<'a>>,
+    },
+    AddrOf(Handle<Expression<'a>>),
+    Deref(Handle<Expression<'a>>),
+    Binary {
+        op: crate::BinaryOperator,
+        left: Handle<Expression<'a>>,
+        right: Handle<Expression<'a>>,
+    },
+
+    /// A function call or type constructor expression.
+    ///
+    /// We can't tell whether an expression like `IDENTIFIER(EXPR, ...)` is a
+    /// construction expression or a function call until we know `IDENTIFIER`'s
+    /// definition, so we represent everything of that form as one of these
+    /// expressions until lowering. At that point, [`Lowerer::call`] has
+    /// everything's definition in hand, and can decide whether to emit a Naga
+    /// [`Constant`], [`As`], [`Splat`], or [`Compose`] expression.
+    ///
+    /// [`Lowerer::call`]: Lowerer::call
+    /// [`Constant`]: crate::Expression::Constant
+    /// [`As`]: crate::Expression::As
+    /// [`Splat`]: crate::Expression::Splat
+    /// [`Compose`]: crate::Expression::Compose
+    Call {
+        function: Ident<'a>,
+        arguments: Vec<Handle<Expression<'a>>>,
+    },
+    Index {
+        base: Handle<Expression<'a>>,
+        index: Handle<Expression<'a>>,
+    },
+    Member {
+        base: Handle<Expression<'a>>,
+        field: Ident<'a>,
+    },
+    Bitcast {
+        expr: Handle<Expression<'a>>,
+        to: Handle<Type<'a>>,
+        ty_span: Span,
+    },
+}
+
+#[derive(Debug)]
+pub struct LocalVariable<'a> {
+    pub name: Ident<'a>,
+    pub ty: Option<Handle<Type<'a>>>,
+    pub init: Option<Handle<Expression<'a>>>,
+    pub handle: Handle<Local>,
+}
+
+#[derive(Debug)]
+pub struct Let<'a> {
+    pub name: Ident<'a>,
+    pub ty: Option<Handle<Type<'a>>>,
+    pub init: Handle<Expression<'a>>,
+    pub handle: Handle<Local>,
+}
+
+#[derive(Debug)]
+pub enum LocalDecl<'a> {
+    Var(LocalVariable<'a>),
+    Let(Let<'a>),
+}
+
+#[derive(Debug)]
+/// A placeholder for a local variable declaration.
+///
+/// See [`Function::locals`] for more information.
+pub struct Local;
diff --git a/third_party/rust/naga/src/front/wgsl/parse/conv.rs b/third_party/rust/naga/src/front/wgsl/parse/conv.rs
new file mode 100644
index 0000000000..08f1e39285
--- /dev/null
+++ b/third_party/rust/naga/src/front/wgsl/parse/conv.rs
@@ -0,0 +1,254 @@
+use super::Error;
+use crate::front::wgsl::Scalar;
+use crate::Span;
+
+pub fn map_address_space(word: &str, span: Span) -> Result<crate::AddressSpace, Error<'_>> {
+    match word {
+        "private" => Ok(crate::AddressSpace::Private),
+        "workgroup" => Ok(crate::AddressSpace::WorkGroup),
+        "uniform" => Ok(crate::AddressSpace::Uniform),
+        "storage" => Ok(crate::AddressSpace::Storage {
+            access: crate::StorageAccess::default(),
+        }),
+        "push_constant" => Ok(crate::AddressSpace::PushConstant),
+        "function" => Ok(crate::AddressSpace::Function),
+        _ => Err(Error::UnknownAddressSpace(span)),
+    }
+}
+
+pub fn map_built_in(word: &str, span: Span) -> Result<crate::BuiltIn, Error<'_>> {
+    Ok(match word {
+        "position" => crate::BuiltIn::Position { invariant: false },
+        // vertex
+        "vertex_index" => crate::BuiltIn::VertexIndex,
+        "instance_index" => crate::BuiltIn::InstanceIndex,
+        "view_index" => crate::BuiltIn::ViewIndex,
+        // fragment
+        "front_facing" => crate::BuiltIn::FrontFacing,
+        "frag_depth" => crate::BuiltIn::FragDepth,
+        "primitive_index" => crate::BuiltIn::PrimitiveIndex,
+        "sample_index" => crate::BuiltIn::SampleIndex,
+        "sample_mask" => crate::BuiltIn::SampleMask,
+        // compute
+        "global_invocation_id" => crate::BuiltIn::GlobalInvocationId,
+        "local_invocation_id" => crate::BuiltIn::LocalInvocationId,
+        "local_invocation_index" => crate::BuiltIn::LocalInvocationIndex,
+        "workgroup_id" => crate::BuiltIn::WorkGroupId,
+        "num_workgroups" => crate::BuiltIn::NumWorkGroups,
+        _ => return Err(Error::UnknownBuiltin(span)),
+    })
+}
+
+pub fn map_interpolation(word: &str, span: Span) -> Result<crate::Interpolation, Error<'_>> {
+    match word {
+        "linear" => Ok(crate::Interpolation::Linear),
+        "flat" => Ok(crate::Interpolation::Flat),
+        "perspective" => Ok(crate::Interpolation::Perspective),
+        _ => Err(Error::UnknownAttribute(span)),
+    }
+}
+
+pub fn map_sampling(word: &str, span: Span) -> Result<crate::Sampling, Error<'_>> {
+    match word {
+        "center" => Ok(crate::Sampling::Center),
+        "centroid" => Ok(crate::Sampling::Centroid),
+        "sample" => Ok(crate::Sampling::Sample),
+        _ => Err(Error::UnknownAttribute(span)),
+    }
+}
+
+pub fn map_storage_format(word: &str, span: Span) -> Result<crate::StorageFormat, Error<'_>> {
+    use crate::StorageFormat as Sf;
+    Ok(match word {
+        "r8unorm" => Sf::R8Unorm,
+        "r8snorm" => Sf::R8Snorm,
+        "r8uint" => Sf::R8Uint,
+        "r8sint" => Sf::R8Sint,
+        "r16unorm" => Sf::R16Unorm,
+        "r16snorm" => Sf::R16Snorm,
+        "r16uint" => Sf::R16Uint,
+        "r16sint" => Sf::R16Sint,
+        "r16float" => Sf::R16Float,
+        "rg8unorm" => Sf::Rg8Unorm,
+        "rg8snorm" => Sf::Rg8Snorm,
+        "rg8uint" => Sf::Rg8Uint,
+        "rg8sint" => Sf::Rg8Sint,
+        "r32uint" => Sf::R32Uint,
+        "r32sint" => Sf::R32Sint,
+        "r32float" => Sf::R32Float,
+        "rg16unorm" => Sf::Rg16Unorm,
+        "rg16snorm" => Sf::Rg16Snorm,
+        "rg16uint" => Sf::Rg16Uint,
+        "rg16sint" => Sf::Rg16Sint,
+        "rg16float" => Sf::Rg16Float,
+        "rgba8unorm" => Sf::Rgba8Unorm,
+        "rgba8snorm" => Sf::Rgba8Snorm,
+        "rgba8uint" => Sf::Rgba8Uint,
+        "rgba8sint" => Sf::Rgba8Sint,
+        "rgb10a2uint" => Sf::Rgb10a2Uint,
+        "rgb10a2unorm" => Sf::Rgb10a2Unorm,
+        "rg11b10float" => Sf::Rg11b10Float,
+        "rg32uint" => Sf::Rg32Uint,
+        "rg32sint" => Sf::Rg32Sint,
+        "rg32float" => Sf::Rg32Float,
+        "rgba16unorm" => Sf::Rgba16Unorm,
+        "rgba16snorm" => Sf::Rgba16Snorm,
+        "rgba16uint" => Sf::Rgba16Uint,
+        "rgba16sint" => Sf::Rgba16Sint,
+        "rgba16float" => Sf::Rgba16Float,
+        "rgba32uint" => Sf::Rgba32Uint,
+        "rgba32sint" => Sf::Rgba32Sint,
+        "rgba32float" => Sf::Rgba32Float,
+        "bgra8unorm" => Sf::Bgra8Unorm,
+        _ => return Err(Error::UnknownStorageFormat(span)),
+    })
+}
+
+pub fn get_scalar_type(word: &str) -> Option<Scalar> {
+    use crate::ScalarKind as Sk;
+    match word {
+        // "f16" => Some(Scalar { kind: Sk::Float, width: 2 }),
+        "f32" => Some(Scalar {
+            kind: Sk::Float,
+            width: 4,
+        }),
+        "f64" => Some(Scalar {
+            kind: Sk::Float,
+            width: 8,
+        }),
+        "i32" => Some(Scalar {
+            kind: Sk::Sint,
+            width: 4,
+        }),
+        "u32" => Some(Scalar {
+            kind: Sk::Uint,
+            width: 4,
+        }),
+        "bool" => Some(Scalar {
+            kind: Sk::Bool,
+            width: crate::BOOL_WIDTH,
+        }),
+        _ => None,
+    }
+}
+
+pub fn map_derivative(word: &str) -> Option<(crate::DerivativeAxis, crate::DerivativeControl)> {
+    use crate::{DerivativeAxis as Axis, DerivativeControl as Ctrl};
+    match word {
+        "dpdxCoarse" => Some((Axis::X, Ctrl::Coarse)),
+        "dpdyCoarse" => Some((Axis::Y, Ctrl::Coarse)),
+        "fwidthCoarse" => Some((Axis::Width, Ctrl::Coarse)),
+        "dpdxFine" => Some((Axis::X, Ctrl::Fine)),
+        "dpdyFine" => Some((Axis::Y, Ctrl::Fine)),
+        "fwidthFine" => Some((Axis::Width, Ctrl::Fine)),
+        "dpdx" => Some((Axis::X, Ctrl::None)),
+        "dpdy" => Some((Axis::Y, Ctrl::None)),
+        "fwidth" => Some((Axis::Width, Ctrl::None)),
+        _ => None,
+    }
+}
+
+pub fn map_relational_fun(word: &str) -> Option<crate::RelationalFunction> {
+    match word {
+        "any" => Some(crate::RelationalFunction::Any),
+        "all" => Some(crate::RelationalFunction::All),
+        _ => None,
+    }
+}
+
+pub fn map_standard_fun(word: &str) -> Option<crate::MathFunction> {
+    use crate::MathFunction as Mf;
+    Some(match word {
+        // comparison
+        "abs" => Mf::Abs,
+        "min" => Mf::Min,
+        "max" => Mf::Max,
+        "clamp" => Mf::Clamp,
+        "saturate" => Mf::Saturate,
+        // trigonometry
+        "cos" => Mf::Cos,
+        "cosh" => Mf::Cosh,
+        "sin" => Mf::Sin,
+        "sinh" => Mf::Sinh,
+        "tan" => Mf::Tan,
+        "tanh" => Mf::Tanh,
+        "acos" => Mf::Acos,
+        "acosh" => Mf::Acosh,
+        "asin" => Mf::Asin,
+        "asinh" => Mf::Asinh,
+        "atan" => Mf::Atan,
+        "atanh" => Mf::Atanh,
+        "atan2" => Mf::Atan2,
+        "radians" => Mf::Radians,
+        "degrees" => Mf::Degrees,
+        // decomposition
+        "ceil" => Mf::Ceil,
+        "floor" => Mf::Floor,
+        "round" => Mf::Round,
+        "fract" => Mf::Fract,
+        "trunc" => Mf::Trunc,
+        "modf" => Mf::Modf,
+        "frexp" => Mf::Frexp,
+        "ldexp" => Mf::Ldexp,
+        // exponent
+        "exp" => Mf::Exp,
+        "exp2" => Mf::Exp2,
+        "log" => Mf::Log,
+        "log2" => Mf::Log2,
+        "pow" => Mf::Pow,
+        // geometry
+        "dot" => Mf::Dot,
+        "cross" => Mf::Cross,
+        "distance" => Mf::Distance,
+        "length" => Mf::Length,
+        "normalize" => Mf::Normalize,
+        "faceForward" => Mf::FaceForward,
+        "reflect" => Mf::Reflect,
+        "refract" => Mf::Refract,
+        // computational
+        "sign" => Mf::Sign,
+        "fma" => Mf::Fma,
+        "mix" => Mf::Mix,
+        "step" => Mf::Step,
+        "smoothstep" => Mf::SmoothStep,
+        "sqrt" => Mf::Sqrt,
+        "inverseSqrt" => Mf::InverseSqrt,
+        "transpose" => Mf::Transpose,
+        "determinant" => Mf::Determinant,
+        // bits
+        "countTrailingZeros" => Mf::CountTrailingZeros,
+        "countLeadingZeros" => Mf::CountLeadingZeros,
+        "countOneBits" => Mf::CountOneBits,
+        "reverseBits" => Mf::ReverseBits,
+        "extractBits" => Mf::ExtractBits,
+        "insertBits" => Mf::InsertBits,
+        "firstTrailingBit" => Mf::FindLsb,
+        "firstLeadingBit" => Mf::FindMsb,
+        // data packing
+        "pack4x8snorm" => Mf::Pack4x8snorm,
+        "pack4x8unorm" => Mf::Pack4x8unorm,
+        "pack2x16snorm" => Mf::Pack2x16snorm,
+        "pack2x16unorm" => Mf::Pack2x16unorm,
+        "pack2x16float" => Mf::Pack2x16float,
+        // data unpacking
+        "unpack4x8snorm" => Mf::Unpack4x8snorm,
+        "unpack4x8unorm" => Mf::Unpack4x8unorm,
+        "unpack2x16snorm" => Mf::Unpack2x16snorm,
+        "unpack2x16unorm" => Mf::Unpack2x16unorm,
+        "unpack2x16float" => Mf::Unpack2x16float,
+        _ => return None,
+    })
+}
+
+pub fn map_conservative_depth(
+    word: &str,
+    span: Span,
+) -> Result<crate::ConservativeDepth, Error<'_>> {
+    use crate::ConservativeDepth as Cd;
+    match word {
+        "greater_equal" => Ok(Cd::GreaterEqual),
+        "less_equal" => Ok(Cd::LessEqual),
+        "unchanged" => Ok(Cd::Unchanged),
+        _ => Err(Error::UnknownConservativeDepth(span)),
+    }
+}
diff --git a/third_party/rust/naga/src/front/wgsl/parse/lexer.rs b/third_party/rust/naga/src/front/wgsl/parse/lexer.rs
new file mode 100644
index 0000000000..d03a448561
--- /dev/null
+++ b/third_party/rust/naga/src/front/wgsl/parse/lexer.rs
@@ -0,0 +1,739 @@
+use super::{number::consume_number, Error, ExpectedToken};
+use crate::front::wgsl::error::NumberError;
+use crate::front::wgsl::parse::{conv, Number};
+use crate::front::wgsl::Scalar;
+use crate::Span;
+
+type TokenSpan<'a> = (Token<'a>, Span);
+
+#[derive(Copy, Clone, Debug, PartialEq)]
+pub enum Token<'a> {
+    Separator(char),
+    Paren(char),
+    Attribute,
+    Number(Result<Number, NumberError>),
+    Word(&'a str),
+    Operation(char),
+    LogicalOperation(char),
+    ShiftOperation(char),
+    AssignmentOperation(char),
+    IncrementOperation,
+    DecrementOperation,
+    Arrow,
+    Unknown(char),
+    Trivia,
+    End,
+}
+
+fn consume_any(input: &str, what: impl Fn(char) -> bool) -> (&str, &str) {
+    let pos = input.find(|c| !what(c)).unwrap_or(input.len());
+    input.split_at(pos)
+}
+
+/// Return the token at the start of `input`.
+///
+/// If `generic` is `false`, then the bit shift operators `>>` or `<<`
+/// are valid lookahead tokens for the current parser state (see [§3.1
+/// Parsing] in the WGSL specification). In other words:
+///
+/// -   If `generic` is `true`, then we are expecting an angle bracket
+///     around a generic type parameter, like the `<` and `>` in
+///     `vec3<f32>`, so interpret `<` and `>` as `Token::Paren` tokens,
+///     even if they're part of `<<` or `>>` sequences.
+///
+/// -   Otherwise, interpret `<<` and `>>` as shift operators:
+///     `Token::LogicalOperation` tokens.
+///
+/// [§3.1 Parsing]: https://gpuweb.github.io/gpuweb/wgsl/#parsing
+fn consume_token(input: &str, generic: bool) -> (Token<'_>, &str) {
+    let mut chars = input.chars();
+    let cur = match chars.next() {
+        Some(c) => c,
+        None => return (Token::End, ""),
+    };
+    match cur {
+        ':' | ';' | ',' => (Token::Separator(cur), chars.as_str()),
+        '.' => {
+            let og_chars = chars.as_str();
+            match chars.next() {
+                Some('0'..='9') => consume_number(input),
+                _ => (Token::Separator(cur), og_chars),
+            }
+        }
+        '@' => (Token::Attribute, chars.as_str()),
+        '(' | ')' | '{' | '}' | '[' | ']' => (Token::Paren(cur), chars.as_str()),
+        '<' | '>' => {
+            let og_chars = chars.as_str();
+            match chars.next() {
+                Some('=') if !generic => (Token::LogicalOperation(cur), chars.as_str()),
+                Some(c) if c == cur && !generic => {
+                    let og_chars = chars.as_str();
+                    match chars.next() {
+                        Some('=') => (Token::AssignmentOperation(cur), chars.as_str()),
+                        _ => (Token::ShiftOperation(cur), og_chars),
+                    }
+                }
+                _ => (Token::Paren(cur), og_chars),
+            }
+        }
+        '0'..='9' => consume_number(input),
+        '/' => {
+            let og_chars = chars.as_str();
+            match chars.next() {
+                Some('/') => {
+                    let _ = chars.position(is_comment_end);
+                    (Token::Trivia, chars.as_str())
+                }
+                Some('*') => {
+                    let mut depth = 1;
+                    let mut prev = None;
+
+                    for c in &mut chars {
+                        match (prev, c) {
+                            (Some('*'), '/') => {
+                                prev = None;
+                                depth -= 1;
+                                if depth == 0 {
+                                    return (Token::Trivia, chars.as_str());
+                                }
+                            }
+                            (Some('/'), '*') => {
+                                prev = None;
+                                depth += 1;
+                            }
+                            _ => {
+                                prev = Some(c);
+                            }
+                        }
+                    }
+
+                    (Token::End, "")
+                }
+                Some('=') => (Token::AssignmentOperation(cur), chars.as_str()),
+                _ => (Token::Operation(cur), og_chars),
+            }
+        }
+        '-' => {
+            let og_chars = chars.as_str();
+            match chars.next() {
+                Some('>') => (Token::Arrow, chars.as_str()),
+                Some('-') => (Token::DecrementOperation, chars.as_str()),
+                Some('=') => (Token::AssignmentOperation(cur), chars.as_str()),
+                _ => (Token::Operation(cur), og_chars),
+            }
+        }
+        '+' => {
+            let og_chars = chars.as_str();
+            match chars.next() {
+                Some('+') => (Token::IncrementOperation, chars.as_str()),
+                Some('=') => (Token::AssignmentOperation(cur), chars.as_str()),
+                _ => (Token::Operation(cur), og_chars),
+            }
+        }
+        '*' | '%' | '^' => {
+            let og_chars = chars.as_str();
+            match chars.next() {
+                Some('=') => (Token::AssignmentOperation(cur), chars.as_str()),
+                _ => (Token::Operation(cur), og_chars),
+            }
+        }
+        '~' => (Token::Operation(cur), chars.as_str()),
+        '=' | '!' => {
+            let og_chars = chars.as_str();
+            match chars.next() {
+                Some('=') => (Token::LogicalOperation(cur), chars.as_str()),
+                _ => (Token::Operation(cur), og_chars),
+            }
+        }
+        '&' | '|' => {
+            let og_chars = chars.as_str();
+            match chars.next() {
+                Some(c) if c == cur => (Token::LogicalOperation(cur), chars.as_str()),
+                Some('=') => (Token::AssignmentOperation(cur), chars.as_str()),
+                _ => (Token::Operation(cur), og_chars),
+            }
+        }
+        _ if is_blankspace(cur) => {
+            let (_, rest) = consume_any(input, is_blankspace);
+            (Token::Trivia, rest)
+        }
+        _ if is_word_start(cur) => {
+            let (word, rest) = consume_any(input, is_word_part);
+            (Token::Word(word), rest)
+        }
+        _ => (Token::Unknown(cur), chars.as_str()),
+    }
+}
+
+/// Returns whether or not a char is a comment end
+/// (Unicode Pattern_White_Space excluding U+0020, U+0009, U+200E and U+200F)
+const fn is_comment_end(c: char) -> bool {
+    match c {
+        '\u{000a}'..='\u{000d}' | '\u{0085}' | '\u{2028}' | '\u{2029}' => true,
+        _ => false,
+    }
+}
+
+/// Returns whether or not a char is a blankspace (Unicode Pattern_White_Space)
+const fn is_blankspace(c: char) -> bool {
+    match c {
+        '\u{0020}'
+        | '\u{0009}'..='\u{000d}'
+        | '\u{0085}'
+        | '\u{200e}'
+        | '\u{200f}'
+        | '\u{2028}'
+        | '\u{2029}' => true,
+        _ => false,
+    }
+}
+
+/// Returns whether or not a char is a word start (Unicode XID_Start + '_')
+fn is_word_start(c: char) -> bool {
+    c == '_' || unicode_xid::UnicodeXID::is_xid_start(c)
+}
+
+/// Returns whether or not a char is a word part (Unicode XID_Continue)
+fn is_word_part(c: char) -> bool {
+    unicode_xid::UnicodeXID::is_xid_continue(c)
+}
+
+#[derive(Clone)]
+pub(in crate::front::wgsl) struct Lexer<'a> {
+    input: &'a str,
+    pub(in crate::front::wgsl) source: &'a str,
+    // The byte offset of the end of the last non-trivia token.
+    last_end_offset: usize,
+}
+
+impl<'a> Lexer<'a> {
+    pub(in crate::front::wgsl) const fn new(input: &'a str) -> Self {
+        Lexer {
+            input,
+            source: input,
+            last_end_offset: 0,
+        }
+    }
+
+    /// Calls the function with a lexer and returns the result of the function as well as the span for everything the function parsed
+    ///
+    /// # Examples
+    /// ```ignore
+    /// let lexer = Lexer::new("5");
+    /// let (value, span) = lexer.capture_span(Lexer::next_uint_literal);
+    /// assert_eq!(value, 5);
+    /// ```
+    #[inline]
+    pub fn capture_span<T, E>(
+        &mut self,
+        inner: impl FnOnce(&mut Self) -> Result<T, E>,
+    ) -> Result<(T, Span), E> {
+        let start = self.current_byte_offset();
+        let res = inner(self)?;
+        let end = self.current_byte_offset();
+        Ok((res, Span::from(start..end)))
+    }
+
+    pub(in crate::front::wgsl) fn start_byte_offset(&mut self) -> usize {
+        loop {
+            // Eat all trivia because `next` doesn't eat trailing trivia.
+            let (token, rest) = consume_token(self.input, false);
+            if let Token::Trivia = token {
+                self.input = rest;
+            } else {
+                return self.current_byte_offset();
+            }
+        }
+    }
+
+    fn peek_token_and_rest(&mut self) -> (TokenSpan<'a>, &'a str) {
+        let mut cloned = self.clone();
+        let token = cloned.next();
+        let rest = cloned.input;
+        (token, rest)
+    }
+
+    const fn current_byte_offset(&self) -> usize {
+        self.source.len() - self.input.len()
+    }
+
+    pub(in crate::front::wgsl) fn span_from(&self, offset: usize) -> Span {
+        Span::from(offset..self.last_end_offset)
+    }
+
+    /// Return the next non-whitespace token from `self`.
+    ///
+    /// Assume we are a parse state where bit shift operators may
+    /// occur, but not angle brackets.
+    #[must_use]
+    pub(in crate::front::wgsl) fn next(&mut self) -> TokenSpan<'a> {
+        self.next_impl(false)
+    }
+
+    /// Return the next non-whitespace token from `self`.
+    ///
+    /// Assume we are in a parse state where angle brackets may occur,
+    /// but not bit shift operators.
+    #[must_use]
+    pub(in crate::front::wgsl) fn next_generic(&mut self) -> TokenSpan<'a> {
+        self.next_impl(true)
+    }
+
+    /// Return the next non-whitespace token from `self`, with a span.
+    ///
+    /// See [`consume_token`] for the meaning of `generic`.
+    fn next_impl(&mut self, generic: bool) -> TokenSpan<'a> {
+        let mut start_byte_offset = self.current_byte_offset();
+        loop {
+            let (token, rest) = consume_token(self.input, generic);
+            self.input = rest;
+            match token {
+                Token::Trivia => start_byte_offset = self.current_byte_offset(),
+                _ => {
+                    self.last_end_offset = self.current_byte_offset();
+                    return (token, self.span_from(start_byte_offset));
+                }
+            }
+        }
+    }
+
+    #[must_use]
+    pub(in crate::front::wgsl) fn peek(&mut self) -> TokenSpan<'a> {
+        let (token, _) = self.peek_token_and_rest();
+        token
+    }
+
+    pub(in crate::front::wgsl) fn expect_span(
+        &mut self,
+        expected: Token<'a>,
+    ) -> Result<Span, Error<'a>> {
+        let next = self.next();
+        if next.0 == expected {
+            Ok(next.1)
+        } else {
+            Err(Error::Unexpected(next.1, ExpectedToken::Token(expected)))
+        }
+    }
+
+    pub(in crate::front::wgsl) fn expect(&mut self, expected: Token<'a>) -> Result<(), Error<'a>> {
+        self.expect_span(expected)?;
+        Ok(())
+    }
+
+    pub(in crate::front::wgsl) fn expect_generic_paren(
+        &mut self,
+        expected: char,
+    ) -> Result<(), Error<'a>> {
+        let next = self.next_generic();
+        if next.0 == Token::Paren(expected) {
+            Ok(())
+        } else {
+            Err(Error::Unexpected(
+                next.1,
+                ExpectedToken::Token(Token::Paren(expected)),
+            ))
+        }
+    }
+
+    /// If the next token matches it is skipped and true is returned
+    pub(in crate::front::wgsl) fn skip(&mut self, what: Token<'_>) -> bool {
+        let (peeked_token, rest) = self.peek_token_and_rest();
+        if peeked_token.0 == what {
+            self.input = rest;
+            true
+        } else {
+            false
+        }
+    }
+
+    pub(in crate::front::wgsl) fn next_ident_with_span(
+        &mut self,
+    ) -> Result<(&'a str, Span), Error<'a>> {
+        match self.next() {
+            (Token::Word("_"), span) => Err(Error::InvalidIdentifierUnderscore(span)),
+            (Token::Word(word), span) if word.starts_with("__") => {
+                Err(Error::ReservedIdentifierPrefix(span))
+            }
+            (Token::Word(word), span) => Ok((word, span)),
+            other => Err(Error::Unexpected(other.1, ExpectedToken::Identifier)),
+        }
+    }
+
+    pub(in crate::front::wgsl) fn next_ident(
+        &mut self,
+    ) -> Result<super::ast::Ident<'a>, Error<'a>> {
+        let ident = self
+            .next_ident_with_span()
+            .map(|(name, span)| super::ast::Ident { name, span })?;
+
+        if crate::keywords::wgsl::RESERVED.contains(&ident.name) {
+            return Err(Error::ReservedKeyword(ident.span));
+        }
+
+        Ok(ident)
+    }
+
+    /// Parses a generic scalar type, for example `<f32>`.
+    pub(in crate::front::wgsl) fn next_scalar_generic(&mut self) -> Result<Scalar, Error<'a>> {
+        self.expect_generic_paren('<')?;
+        let pair = match self.next() {
+            (Token::Word(word), span) => {
+                conv::get_scalar_type(word).ok_or(Error::UnknownScalarType(span))
+            }
+            (_, span) => Err(Error::UnknownScalarType(span)),
+        }?;
+        self.expect_generic_paren('>')?;
+        Ok(pair)
+    }
+
+    /// Parses a generic scalar type, for example `<f32>`.
+    ///
+    /// Returns the span covering the inner type, excluding the brackets.
+    pub(in crate::front::wgsl) fn next_scalar_generic_with_span(
+        &mut self,
+    ) -> Result<(Scalar, Span), Error<'a>> {
+        self.expect_generic_paren('<')?;
+        let pair = match self.next() {
+            (Token::Word(word), span) => conv::get_scalar_type(word)
+                .map(|scalar| (scalar, span))
+                .ok_or(Error::UnknownScalarType(span)),
+            (_, span) => Err(Error::UnknownScalarType(span)),
+        }?;
+        self.expect_generic_paren('>')?;
+        Ok(pair)
+    }
+
+    pub(in crate::front::wgsl) fn next_storage_access(
+        &mut self,
+    ) -> Result<crate::StorageAccess, Error<'a>> {
+        let (ident, span) = self.next_ident_with_span()?;
+        match ident {
+            "read" => Ok(crate::StorageAccess::LOAD),
+            "write" => Ok(crate::StorageAccess::STORE),
+            "read_write" => Ok(crate::StorageAccess::LOAD | crate::StorageAccess::STORE),
+            _ => Err(Error::UnknownAccess(span)),
+        }
+    }
+
+    pub(in crate::front::wgsl) fn next_format_generic(
+        &mut self,
+    ) -> Result<(crate::StorageFormat, crate::StorageAccess), Error<'a>> {
+        self.expect(Token::Paren('<'))?;
+        let (ident, ident_span) = self.next_ident_with_span()?;
+        let format = conv::map_storage_format(ident, ident_span)?;
+        self.expect(Token::Separator(','))?;
+        let access = self.next_storage_access()?;
+        self.expect(Token::Paren('>'))?;
+        Ok((format, access))
+    }
+
+    pub(in crate::front::wgsl) fn open_arguments(&mut self) -> Result<(), Error<'a>> {
+        self.expect(Token::Paren('('))
+    }
+
+    pub(in crate::front::wgsl) fn close_arguments(&mut self) -> Result<(), Error<'a>> {
+        let _ = self.skip(Token::Separator(','));
+        self.expect(Token::Paren(')'))
+    }
+
+    pub(in crate::front::wgsl) fn next_argument(&mut self) -> Result<bool, Error<'a>> {
+        let paren = Token::Paren(')');
+        if self.skip(Token::Separator(',')) {
+            Ok(!self.skip(paren))
+        } else {
+            self.expect(paren).map(|()| false)
+        }
+    }
+}
+
+#[cfg(test)]
+#[track_caller]
+fn sub_test(source: &str, expected_tokens: &[Token]) {
+    let mut lex = Lexer::new(source);
+    for &token in expected_tokens {
+        assert_eq!(lex.next().0, token);
+    }
+    assert_eq!(lex.next().0, Token::End);
+}
+
+#[test]
+fn test_numbers() {
+    // WGSL spec examples //
+
+    // decimal integer
+    sub_test(
+        "0x123 0X123u 1u 123 0 0i 0x3f",
+        &[
+            Token::Number(Ok(Number::AbstractInt(291))),
+            Token::Number(Ok(Number::U32(291))),
+            Token::Number(Ok(Number::U32(1))),
+            Token::Number(Ok(Number::AbstractInt(123))),
+            Token::Number(Ok(Number::AbstractInt(0))),
+            Token::Number(Ok(Number::I32(0))),
+            Token::Number(Ok(Number::AbstractInt(63))),
+        ],
+    );
+    // decimal floating point
+    sub_test(
+        "0.e+4f 01. .01 12.34 .0f 0h 1e-3 0xa.fp+2 0x1P+4f 0X.3 0x3p+2h 0X1.fp-4 0x3.2p+2h",
+        &[
+            Token::Number(Ok(Number::F32(0.))),
+            Token::Number(Ok(Number::AbstractFloat(1.))),
+            Token::Number(Ok(Number::AbstractFloat(0.01))),
+            Token::Number(Ok(Number::AbstractFloat(12.34))),
+            Token::Number(Ok(Number::F32(0.))),
+            Token::Number(Err(NumberError::UnimplementedF16)),
+            Token::Number(Ok(Number::AbstractFloat(0.001))),
+            Token::Number(Ok(Number::AbstractFloat(43.75))),
+            Token::Number(Ok(Number::F32(16.))),
+            Token::Number(Ok(Number::AbstractFloat(0.1875))),
+            Token::Number(Err(NumberError::UnimplementedF16)),
+            Token::Number(Ok(Number::AbstractFloat(0.12109375))),
+            Token::Number(Err(NumberError::UnimplementedF16)),
+        ],
+    );
+
+    // MIN / MAX //
+
+    // min / max decimal integer
+    sub_test(
+        "0i 2147483647i 2147483648i",
+        &[
+            Token::Number(Ok(Number::I32(0))),
+            Token::Number(Ok(Number::I32(i32::MAX))),
+            Token::Number(Err(NumberError::NotRepresentable)),
+        ],
+    );
+    // min / max decimal unsigned integer
+    sub_test(
+        "0u 4294967295u 4294967296u",
+        &[
+            Token::Number(Ok(Number::U32(u32::MIN))),
+            Token::Number(Ok(Number::U32(u32::MAX))),
+            Token::Number(Err(NumberError::NotRepresentable)),
+        ],
+    );
+
+    // min / max hexadecimal signed integer
+    sub_test(
+        "0x0i 0x7FFFFFFFi 0x80000000i",
+        &[
+            Token::Number(Ok(Number::I32(0))),
+            Token::Number(Ok(Number::I32(i32::MAX))),
+            Token::Number(Err(NumberError::NotRepresentable)),
+        ],
+    );
+    // min / max hexadecimal unsigned integer
+    sub_test(
+        "0x0u 0xFFFFFFFFu 0x100000000u",
+        &[
+            Token::Number(Ok(Number::U32(u32::MIN))),
+            Token::Number(Ok(Number::U32(u32::MAX))),
+            Token::Number(Err(NumberError::NotRepresentable)),
+        ],
+    );
+
+    // min/max decimal abstract int
+    sub_test(
+        "0 9223372036854775807 9223372036854775808",
+        &[
+            Token::Number(Ok(Number::AbstractInt(0))),
+            Token::Number(Ok(Number::AbstractInt(i64::MAX))),
+            Token::Number(Err(NumberError::NotRepresentable)),
+        ],
+    );
+
+    // min/max hexadecimal abstract int
+    sub_test(
+        "0 0x7fffffffffffffff 0x8000000000000000",
+        &[
+            Token::Number(Ok(Number::AbstractInt(0))),
+            Token::Number(Ok(Number::AbstractInt(i64::MAX))),
+            Token::Number(Err(NumberError::NotRepresentable)),
+        ],
+    );
+
+    /// ≈ 2^-126 * 2^−23 (= 2^−149)
+    const SMALLEST_POSITIVE_SUBNORMAL_F32: f32 = 1e-45;
+    /// ≈ 2^-126 * (1 − 2^−23)
+    const LARGEST_SUBNORMAL_F32: f32 = 1.1754942e-38;
+    /// ≈ 2^-126
+    const SMALLEST_POSITIVE_NORMAL_F32: f32 = f32::MIN_POSITIVE;
+    /// ≈ 1 − 2^−24
+    const LARGEST_F32_LESS_THAN_ONE: f32 = 0.99999994;
+    /// ≈ 1 + 2^−23
+    const SMALLEST_F32_LARGER_THAN_ONE: f32 = 1.0000001;
+    /// ≈ 2^127 * (2 − 2^−23)
+    const LARGEST_NORMAL_F32: f32 = f32::MAX;
+
+    // decimal floating point
+    sub_test(
+        "1e-45f 1.1754942e-38f 1.17549435e-38f 0.99999994f 1.0000001f 3.40282347e+38f",
+        &[
+            Token::Number(Ok(Number::F32(SMALLEST_POSITIVE_SUBNORMAL_F32))),
+            Token::Number(Ok(Number::F32(LARGEST_SUBNORMAL_F32))),
+            Token::Number(Ok(Number::F32(SMALLEST_POSITIVE_NORMAL_F32))),
+            Token::Number(Ok(Number::F32(LARGEST_F32_LESS_THAN_ONE))),
+            Token::Number(Ok(Number::F32(SMALLEST_F32_LARGER_THAN_ONE))),
+            Token::Number(Ok(Number::F32(LARGEST_NORMAL_F32))),
+        ],
+    );
+    sub_test(
+        "3.40282367e+38f",
+        &[
+            Token::Number(Err(NumberError::NotRepresentable)), // ≈ 2^128
+        ],
+    );
+
+    // hexadecimal floating point
+    sub_test(
+        "0x1p-149f 0x7FFFFFp-149f 0x1p-126f 0xFFFFFFp-24f 0x800001p-23f 0xFFFFFFp+104f",
+        &[
+            Token::Number(Ok(Number::F32(SMALLEST_POSITIVE_SUBNORMAL_F32))),
+            Token::Number(Ok(Number::F32(LARGEST_SUBNORMAL_F32))),
+            Token::Number(Ok(Number::F32(SMALLEST_POSITIVE_NORMAL_F32))),
+            Token::Number(Ok(Number::F32(LARGEST_F32_LESS_THAN_ONE))),
+            Token::Number(Ok(Number::F32(SMALLEST_F32_LARGER_THAN_ONE))),
+            Token::Number(Ok(Number::F32(LARGEST_NORMAL_F32))),
+        ],
+    );
+    sub_test(
+        "0x1p128f 0x1.000001p0f",
+        &[
+            Token::Number(Err(NumberError::NotRepresentable)), // = 2^128
+            Token::Number(Err(NumberError::NotRepresentable)),
+        ],
+    );
+}
+
+#[test]
+fn double_floats() {
+    sub_test(
+        "0x1.2p4lf 0x1p8lf 0.0625lf 625e-4lf 10lf 10l",
+        &[
+            Token::Number(Ok(Number::F64(18.0))),
+            Token::Number(Ok(Number::F64(256.0))),
+            Token::Number(Ok(Number::F64(0.0625))),
+            Token::Number(Ok(Number::F64(0.0625))),
+            Token::Number(Ok(Number::F64(10.0))),
+            Token::Number(Ok(Number::AbstractInt(10))),
+            Token::Word("l"),
+        ],
+    )
+}
+
+#[test]
+fn test_tokens() {
+    sub_test("id123_OK", &[Token::Word("id123_OK")]);
+    sub_test(
+        "92No",
+        &[
+            Token::Number(Ok(Number::AbstractInt(92))),
+            Token::Word("No"),
+        ],
+    );
+    sub_test(
+        "2u3o",
+        &[
+            Token::Number(Ok(Number::U32(2))),
+            Token::Number(Ok(Number::AbstractInt(3))),
+            Token::Word("o"),
+        ],
+    );
+    sub_test(
+        "2.4f44po",
+        &[
+            Token::Number(Ok(Number::F32(2.4))),
+            Token::Number(Ok(Number::AbstractInt(44))),
+            Token::Word("po"),
+        ],
+    );
+    sub_test(
+        "Δέλτα réflexion Кызыл 𐰓𐰏𐰇 朝焼け سلام 검정 שָׁלוֹם गुलाबी փիրուզ",
+        &[
+            Token::Word("Δέλτα"),
+            Token::Word("réflexion"),
+            Token::Word("Кызыл"),
+            Token::Word("𐰓𐰏𐰇"),
+            Token::Word("朝焼け"),
+            Token::Word("سلام"),
+            Token::Word("검정"),
+            Token::Word("שָׁלוֹם"),
+            Token::Word("गुलाबी"),
+            Token::Word("փիրուզ"),
+        ],
+    );
+    sub_test("æNoø", &[Token::Word("æNoø")]);
+    sub_test("No¾", &[Token::Word("No"), Token::Unknown('¾')]);
+    sub_test("No好", &[Token::Word("No好")]);
+    sub_test("_No", &[Token::Word("_No")]);
+    sub_test(
+        "*/*/***/*//=/*****//",
+        &[
+            Token::Operation('*'),
+            Token::AssignmentOperation('/'),
+            Token::Operation('/'),
+        ],
+    );
+
+    // Type suffixes are only allowed on hex float literals
+    // if you provided an exponent.
+    sub_test(
+        "0x1.2f 0x1.2f 0x1.2h 0x1.2H 0x1.2lf",
+        &[
+            // The 'f' suffixes are taken as a hex digit:
+            // the fractional part is 0x2f / 256.
+            Token::Number(Ok(Number::AbstractFloat(1.0 + 0x2f as f64 / 256.0))),
+            Token::Number(Ok(Number::AbstractFloat(1.0 + 0x2f as f64 / 256.0))),
+            Token::Number(Ok(Number::AbstractFloat(1.125))),
+            Token::Word("h"),
+            Token::Number(Ok(Number::AbstractFloat(1.125))),
+            Token::Word("H"),
+            Token::Number(Ok(Number::AbstractFloat(1.125))),
+            Token::Word("lf"),
+        ],
+    )
+}
+
+#[test]
+fn test_variable_decl() {
+    sub_test(
+        "@group(0 ) var< uniform> texture:   texture_multisampled_2d <f32 >;",
+        &[
+            Token::Attribute,
+            Token::Word("group"),
+            Token::Paren('('),
+            Token::Number(Ok(Number::AbstractInt(0))),
+            Token::Paren(')'),
+            Token::Word("var"),
+            Token::Paren('<'),
+            Token::Word("uniform"),
+            Token::Paren('>'),
+            Token::Word("texture"),
+            Token::Separator(':'),
+            Token::Word("texture_multisampled_2d"),
+            Token::Paren('<'),
+            Token::Word("f32"),
+            Token::Paren('>'),
+            Token::Separator(';'),
+        ],
+    );
+    sub_test(
+        "var<storage,read_write> buffer: array<u32>;",
+        &[
+            Token::Word("var"),
+            Token::Paren('<'),
+            Token::Word("storage"),
+            Token::Separator(','),
+            Token::Word("read_write"),
+            Token::Paren('>'),
+            Token::Word("buffer"),
+            Token::Separator(':'),
+            Token::Word("array"),
+            Token::Paren('<'),
+            Token::Word("u32"),
+            Token::Paren('>'),
+            Token::Separator(';'),
+        ],
+    );
+}
diff --git a/third_party/rust/naga/src/front/wgsl/parse/mod.rs b/third_party/rust/naga/src/front/wgsl/parse/mod.rs
new file mode 100644
index 0000000000..51fc2f013b
--- /dev/null
+++ b/third_party/rust/naga/src/front/wgsl/parse/mod.rs
@@ -0,0 +1,2350 @@
+use crate::front::wgsl::error::{Error, ExpectedToken};
+use crate::front::wgsl::parse::lexer::{Lexer, Token};
+use crate::front::wgsl::parse::number::Number;
+use crate::front::wgsl::Scalar;
+use crate::front::SymbolTable;
+use crate::{Arena, FastIndexSet, Handle, ShaderStage, Span};
+
+pub mod ast;
+pub mod conv;
+pub mod lexer;
+pub mod number;
+
+/// State for constructing an AST expression.
+///
+/// Not to be confused with [`lower::ExpressionContext`], which is for producing
+/// Naga IR from the AST we produce here.
+///
+/// [`lower::ExpressionContext`]: super::lower::ExpressionContext
+struct ExpressionContext<'input, 'temp, 'out> {
+    /// The [`TranslationUnit::expressions`] arena to which we should contribute
+    /// expressions.
+    ///
+    /// [`TranslationUnit::expressions`]: ast::TranslationUnit::expressions
+    expressions: &'out mut Arena<ast::Expression<'input>>,
+
+    /// The [`TranslationUnit::types`] arena to which we should contribute new
+    /// types.
+    ///
+    /// [`TranslationUnit::types`]: ast::TranslationUnit::types
+    types: &'out mut Arena<ast::Type<'input>>,
+
+    /// A map from identifiers in scope to the locals/arguments they represent.
+    ///
+    /// The handles refer to the [`Function::locals`] area; see that field's
+    /// documentation for details.
+    ///
+    /// [`Function::locals`]: ast::Function::locals
+    local_table: &'temp mut SymbolTable<&'input str, Handle<ast::Local>>,
+
+    /// The [`Function::locals`] arena for the function we're building.
+    ///
+    /// [`Function::locals`]: ast::Function::locals
+    locals: &'out mut Arena<ast::Local>,
+
+    /// Identifiers used by the current global declaration that have no local definition.
+    ///
+    /// This becomes the [`GlobalDecl`]'s [`dependencies`] set.
+    ///
+    /// Note that we don't know at parse time what kind of [`GlobalDecl`] the
+    /// name refers to. We can't look up names until we've seen the entire
+    /// translation unit.
+    ///
+    /// [`GlobalDecl`]: ast::GlobalDecl
+    /// [`dependencies`]: ast::GlobalDecl::dependencies
+    unresolved: &'out mut FastIndexSet<ast::Dependency<'input>>,
+}
+
+impl<'a> ExpressionContext<'a, '_, '_> {
+    fn parse_binary_op(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        classifier: impl Fn(Token<'a>) -> Option<crate::BinaryOperator>,
+        mut parser: impl FnMut(
+            &mut Lexer<'a>,
+            &mut Self,
+        ) -> Result<Handle<ast::Expression<'a>>, Error<'a>>,
+    ) -> Result<Handle<ast::Expression<'a>>, Error<'a>> {
+        let start = lexer.start_byte_offset();
+        let mut accumulator = parser(lexer, self)?;
+        while let Some(op) = classifier(lexer.peek().0) {
+            let _ = lexer.next();
+            let left = accumulator;
+            let right = parser(lexer, self)?;
+            accumulator = self.expressions.append(
+                ast::Expression::Binary { op, left, right },
+                lexer.span_from(start),
+            );
+        }
+        Ok(accumulator)
+    }
+
+    fn declare_local(&mut self, name: ast::Ident<'a>) -> Result<Handle<ast::Local>, Error<'a>> {
+        let handle = self.locals.append(ast::Local, name.span);
+        if let Some(old) = self.local_table.add(name.name, handle) {
+            Err(Error::Redefinition {
+                previous: self.locals.get_span(old),
+                current: name.span,
+            })
+        } else {
+            Ok(handle)
+        }
+    }
+}
+
+/// Which grammar rule we are in the midst of parsing.
+///
+/// This is used for error checking. `Parser` maintains a stack of
+/// these and (occasionally) checks that it is being pushed and popped
+/// as expected.
+#[derive(Clone, Debug, PartialEq)]
+enum Rule {
+    Attribute,
+    VariableDecl,
+    TypeDecl,
+    FunctionDecl,
+    Block,
+    Statement,
+    PrimaryExpr,
+    SingularExpr,
+    UnaryExpr,
+    GeneralExpr,
+}
+
+struct ParsedAttribute<T> {
+    value: Option<T>,
+}
+
+impl<T> Default for ParsedAttribute<T> {
+    fn default() -> Self {
+        Self { value: None }
+    }
+}
+
+impl<T> ParsedAttribute<T> {
+    fn set(&mut self, value: T, name_span: Span) -> Result<(), Error<'static>> {
+        if self.value.is_some() {
+            return Err(Error::RepeatedAttribute(name_span));
+        }
+        self.value = Some(value);
+        Ok(())
+    }
+}
+
+#[derive(Default)]
+struct BindingParser<'a> {
+    location: ParsedAttribute<Handle<ast::Expression<'a>>>,
+    second_blend_source: ParsedAttribute<bool>,
+    built_in: ParsedAttribute<crate::BuiltIn>,
+    interpolation: ParsedAttribute<crate::Interpolation>,
+    sampling: ParsedAttribute<crate::Sampling>,
+    invariant: ParsedAttribute<bool>,
+}
+
+impl<'a> BindingParser<'a> {
+    fn parse(
+        &mut self,
+        parser: &mut Parser,
+        lexer: &mut Lexer<'a>,
+        name: &'a str,
+        name_span: Span,
+        ctx: &mut ExpressionContext<'a, '_, '_>,
+    ) -> Result<(), Error<'a>> {
+        match name {
+            "location" => {
+                lexer.expect(Token::Paren('('))?;
+                self.location
+                    .set(parser.general_expression(lexer, ctx)?, name_span)?;
+                lexer.expect(Token::Paren(')'))?;
+            }
+            "builtin" => {
+                lexer.expect(Token::Paren('('))?;
+                let (raw, span) = lexer.next_ident_with_span()?;
+                self.built_in
+                    .set(conv::map_built_in(raw, span)?, name_span)?;
+                lexer.expect(Token::Paren(')'))?;
+            }
+            "interpolate" => {
+                lexer.expect(Token::Paren('('))?;
+                let (raw, span) = lexer.next_ident_with_span()?;
+                self.interpolation
+                    .set(conv::map_interpolation(raw, span)?, name_span)?;
+                if lexer.skip(Token::Separator(',')) {
+                    let (raw, span) = lexer.next_ident_with_span()?;
+                    self.sampling
+                        .set(conv::map_sampling(raw, span)?, name_span)?;
+                }
+                lexer.expect(Token::Paren(')'))?;
+            }
+            "second_blend_source" => {
+                self.second_blend_source.set(true, name_span)?;
+            }
+            "invariant" => {
+                self.invariant.set(true, name_span)?;
+            }
+            _ => return Err(Error::UnknownAttribute(name_span)),
+        }
+        Ok(())
+    }
+
+    fn finish(self, span: Span) -> Result<Option<ast::Binding<'a>>, Error<'a>> {
+        match (
+            self.location.value,
+            self.built_in.value,
+            self.interpolation.value,
+            self.sampling.value,
+            self.invariant.value.unwrap_or_default(),
+        ) {
+            (None, None, None, None, false) => Ok(None),
+            (Some(location), None, interpolation, sampling, false) => {
+                // Before handing over the completed `Module`, we call
+                // `apply_default_interpolation` to ensure that the interpolation and
+                // sampling have been explicitly specified on all vertex shader output and fragment
+                // shader input user bindings, so leaving them potentially `None` here is fine.
+                Ok(Some(ast::Binding::Location {
+                    location,
+                    interpolation,
+                    sampling,
+                    second_blend_source: self.second_blend_source.value.unwrap_or(false),
+                }))
+            }
+            (None, Some(crate::BuiltIn::Position { .. }), None, None, invariant) => {
+                Ok(Some(ast::Binding::BuiltIn(crate::BuiltIn::Position {
+                    invariant,
+                })))
+            }
+            (None, Some(built_in), None, None, false) => Ok(Some(ast::Binding::BuiltIn(built_in))),
+            (_, _, _, _, _) => Err(Error::InconsistentBinding(span)),
+        }
+    }
+}
+
+pub struct Parser {
+    rules: Vec<(Rule, usize)>,
+}
+
+impl Parser {
+    pub const fn new() -> Self {
+        Parser { rules: Vec::new() }
+    }
+
+    fn reset(&mut self) {
+        self.rules.clear();
+    }
+
+    fn push_rule_span(&mut self, rule: Rule, lexer: &mut Lexer<'_>) {
+        self.rules.push((rule, lexer.start_byte_offset()));
+    }
+
+    fn pop_rule_span(&mut self, lexer: &Lexer<'_>) -> Span {
+        let (_, initial) = self.rules.pop().unwrap();
+        lexer.span_from(initial)
+    }
+
+    fn peek_rule_span(&mut self, lexer: &Lexer<'_>) -> Span {
+        let &(_, initial) = self.rules.last().unwrap();
+        lexer.span_from(initial)
+    }
+
+    fn switch_value<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        ctx: &mut ExpressionContext<'a, '_, '_>,
+    ) -> Result<ast::SwitchValue<'a>, Error<'a>> {
+        if let Token::Word("default") = lexer.peek().0 {
+            let _ = lexer.next();
+            return Ok(ast::SwitchValue::Default);
+        }
+
+        let expr = self.general_expression(lexer, ctx)?;
+        Ok(ast::SwitchValue::Expr(expr))
+    }
+
+    /// Decide if we're looking at a construction expression, and return its
+    /// type if so.
+    ///
+    /// If the identifier `word` is a [type-defining keyword], then return a
+    /// [`ConstructorType`] value describing the type to build. Return an error
+    /// if the type is not constructible (like `sampler`).
+    ///
+    /// If `word` isn't a type name, then return `None`.
+    ///
+    /// [type-defining keyword]: https://gpuweb.github.io/gpuweb/wgsl/#type-defining-keywords
+    /// [`ConstructorType`]: ast::ConstructorType
+    fn constructor_type<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        word: &'a str,
+        span: Span,
+        ctx: &mut ExpressionContext<'a, '_, '_>,
+    ) -> Result<Option<ast::ConstructorType<'a>>, Error<'a>> {
+        if let Some(scalar) = conv::get_scalar_type(word) {
+            return Ok(Some(ast::ConstructorType::Scalar(scalar)));
+        }
+
+        let partial = match word {
+            "vec2" => ast::ConstructorType::PartialVector {
+                size: crate::VectorSize::Bi,
+            },
+            "vec2i" => {
+                return Ok(Some(ast::ConstructorType::Vector {
+                    size: crate::VectorSize::Bi,
+                    scalar: Scalar {
+                        kind: crate::ScalarKind::Sint,
+                        width: 4,
+                    },
+                }))
+            }
+            "vec2u" => {
+                return Ok(Some(ast::ConstructorType::Vector {
+                    size: crate::VectorSize::Bi,
+                    scalar: Scalar {
+                        kind: crate::ScalarKind::Uint,
+                        width: 4,
+                    },
+                }))
+            }
+            "vec2f" => {
+                return Ok(Some(ast::ConstructorType::Vector {
+                    size: crate::VectorSize::Bi,
+                    scalar: Scalar::F32,
+                }))
+            }
+            "vec3" => ast::ConstructorType::PartialVector {
+                size: crate::VectorSize::Tri,
+            },
+            "vec3i" => {
+                return Ok(Some(ast::ConstructorType::Vector {
+                    size: crate::VectorSize::Tri,
+                    scalar: Scalar::I32,
+                }))
+            }
+            "vec3u" => {
+                return Ok(Some(ast::ConstructorType::Vector {
+                    size: crate::VectorSize::Tri,
+                    scalar: Scalar::U32,
+                }))
+            }
+            "vec3f" => {
+                return Ok(Some(ast::ConstructorType::Vector {
+                    size: crate::VectorSize::Tri,
+                    scalar: Scalar::F32,
+                }))
+            }
+            "vec4" => ast::ConstructorType::PartialVector {
+                size: crate::VectorSize::Quad,
+            },
+            "vec4i" => {
+                return Ok(Some(ast::ConstructorType::Vector {
+                    size: crate::VectorSize::Quad,
+                    scalar: Scalar::I32,
+                }))
+            }
+            "vec4u" => {
+                return Ok(Some(ast::ConstructorType::Vector {
+                    size: crate::VectorSize::Quad,
+                    scalar: Scalar::U32,
+                }))
+            }
+            "vec4f" => {
+                return Ok(Some(ast::ConstructorType::Vector {
+                    size: crate::VectorSize::Quad,
+                    scalar: Scalar::F32,
+                }))
+            }
+            "mat2x2" => ast::ConstructorType::PartialMatrix {
+                columns: crate::VectorSize::Bi,
+                rows: crate::VectorSize::Bi,
+            },
+            "mat2x2f" => {
+                return Ok(Some(ast::ConstructorType::Matrix {
+                    columns: crate::VectorSize::Bi,
+                    rows: crate::VectorSize::Bi,
+                    width: 4,
+                }))
+            }
+            "mat2x3" => ast::ConstructorType::PartialMatrix {
+                columns: crate::VectorSize::Bi,
+                rows: crate::VectorSize::Tri,
+            },
+            "mat2x3f" => {
+                return Ok(Some(ast::ConstructorType::Matrix {
+                    columns: crate::VectorSize::Bi,
+                    rows: crate::VectorSize::Tri,
+                    width: 4,
+                }))
+            }
+            "mat2x4" => ast::ConstructorType::PartialMatrix {
+                columns: crate::VectorSize::Bi,
+                rows: crate::VectorSize::Quad,
+            },
+            "mat2x4f" => {
+                return Ok(Some(ast::ConstructorType::Matrix {
+                    columns: crate::VectorSize::Bi,
+                    rows: crate::VectorSize::Quad,
+                    width: 4,
+                }))
+            }
+            "mat3x2" => ast::ConstructorType::PartialMatrix {
+                columns: crate::VectorSize::Tri,
+                rows: crate::VectorSize::Bi,
+            },
+            "mat3x2f" => {
+                return Ok(Some(ast::ConstructorType::Matrix {
+                    columns: crate::VectorSize::Tri,
+                    rows: crate::VectorSize::Bi,
+                    width: 4,
+                }))
+            }
+            "mat3x3" => ast::ConstructorType::PartialMatrix {
+                columns: crate::VectorSize::Tri,
+                rows: crate::VectorSize::Tri,
+            },
+            "mat3x3f" => {
+                return Ok(Some(ast::ConstructorType::Matrix {
+                    columns: crate::VectorSize::Tri,
+                    rows: crate::VectorSize::Tri,
+                    width: 4,
+                }))
+            }
+            "mat3x4" => ast::ConstructorType::PartialMatrix {
+                columns: crate::VectorSize::Tri,
+                rows: crate::VectorSize::Quad,
+            },
+            "mat3x4f" => {
+                return Ok(Some(ast::ConstructorType::Matrix {
+                    columns: crate::VectorSize::Tri,
+                    rows: crate::VectorSize::Quad,
+                    width: 4,
+                }))
+            }
+            "mat4x2" => ast::ConstructorType::PartialMatrix {
+                columns: crate::VectorSize::Quad,
+                rows: crate::VectorSize::Bi,
+            },
+            "mat4x2f" => {
+                return Ok(Some(ast::ConstructorType::Matrix {
+                    columns: crate::VectorSize::Quad,
+                    rows: crate::VectorSize::Bi,
+                    width: 4,
+                }))
+            }
+            "mat4x3" => ast::ConstructorType::PartialMatrix {
+                columns: crate::VectorSize::Quad,
+                rows: crate::VectorSize::Tri,
+            },
+            "mat4x3f" => {
+                return Ok(Some(ast::ConstructorType::Matrix {
+                    columns: crate::VectorSize::Quad,
+                    rows: crate::VectorSize::Tri,
+                    width: 4,
+                }))
+            }
+            "mat4x4" => ast::ConstructorType::PartialMatrix {
+                columns: crate::VectorSize::Quad,
+                rows: crate::VectorSize::Quad,
+            },
+            "mat4x4f" => {
+                return Ok(Some(ast::ConstructorType::Matrix {
+                    columns: crate::VectorSize::Quad,
+                    rows: crate::VectorSize::Quad,
+                    width: 4,
+                }))
+            }
+            "array" => ast::ConstructorType::PartialArray,
+            "atomic"
+            | "binding_array"
+            | "sampler"
+            | "sampler_comparison"
+            | "texture_1d"
+            | "texture_1d_array"
+            | "texture_2d"
+            | "texture_2d_array"
+            | "texture_3d"
+            | "texture_cube"
+            | "texture_cube_array"
+            | "texture_multisampled_2d"
+            | "texture_multisampled_2d_array"
+            | "texture_depth_2d"
+            | "texture_depth_2d_array"
+            | "texture_depth_cube"
+            | "texture_depth_cube_array"
+            | "texture_depth_multisampled_2d"
+            | "texture_storage_1d"
+            | "texture_storage_1d_array"
+            | "texture_storage_2d"
+            | "texture_storage_2d_array"
+            | "texture_storage_3d" => return Err(Error::TypeNotConstructible(span)),
+            _ => return Ok(None),
+        };
+
+        // parse component type if present
+        match (lexer.peek().0, partial) {
+            (Token::Paren('<'), ast::ConstructorType::PartialVector { size }) => {
+                let scalar = lexer.next_scalar_generic()?;
+                Ok(Some(ast::ConstructorType::Vector { size, scalar }))
+            }
+            (Token::Paren('<'), ast::ConstructorType::PartialMatrix { columns, rows }) => {
+                let (scalar, span) = lexer.next_scalar_generic_with_span()?;
+                match scalar.kind {
+                    crate::ScalarKind::Float => Ok(Some(ast::ConstructorType::Matrix {
+                        columns,
+                        rows,
+                        width: scalar.width,
+                    })),
+                    _ => Err(Error::BadMatrixScalarKind(span, scalar)),
+                }
+            }
+            (Token::Paren('<'), ast::ConstructorType::PartialArray) => {
+                lexer.expect_generic_paren('<')?;
+                let base = self.type_decl(lexer, ctx)?;
+                let size = if lexer.skip(Token::Separator(',')) {
+                    let expr = self.unary_expression(lexer, ctx)?;
+                    ast::ArraySize::Constant(expr)
+                } else {
+                    ast::ArraySize::Dynamic
+                };
+                lexer.expect_generic_paren('>')?;
+
+                Ok(Some(ast::ConstructorType::Array { base, size }))
+            }
+            (_, partial) => Ok(Some(partial)),
+        }
+    }
+
+    /// Expects `name` to be consumed (not in lexer).
+    fn arguments<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        ctx: &mut ExpressionContext<'a, '_, '_>,
+    ) -> Result<Vec<Handle<ast::Expression<'a>>>, Error<'a>> {
+        lexer.open_arguments()?;
+        let mut arguments = Vec::new();
+        loop {
+            if !arguments.is_empty() {
+                if !lexer.next_argument()? {
+                    break;
+                }
+            } else if lexer.skip(Token::Paren(')')) {
+                break;
+            }
+            let arg = self.general_expression(lexer, ctx)?;
+            arguments.push(arg);
+        }
+
+        Ok(arguments)
+    }
+
+    /// Expects [`Rule::PrimaryExpr`] or [`Rule::SingularExpr`] on top; does not pop it.
+    /// Expects `name` to be consumed (not in lexer).
+    fn function_call<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        name: &'a str,
+        name_span: Span,
+        ctx: &mut ExpressionContext<'a, '_, '_>,
+    ) -> Result<Handle<ast::Expression<'a>>, Error<'a>> {
+        assert!(self.rules.last().is_some());
+
+        let expr = match name {
+            // bitcast looks like a function call, but it's an operator and must be handled differently.
+            "bitcast" => {
+                lexer.expect_generic_paren('<')?;
+                let start = lexer.start_byte_offset();
+                let to = self.type_decl(lexer, ctx)?;
+                let span = lexer.span_from(start);
+                lexer.expect_generic_paren('>')?;
+
+                lexer.open_arguments()?;
+                let expr = self.general_expression(lexer, ctx)?;
+                lexer.close_arguments()?;
+
+                ast::Expression::Bitcast {
+                    expr,
+                    to,
+                    ty_span: span,
+                }
+            }
+            // everything else must be handled later, since they can be hidden by user-defined functions.
+            _ => {
+                let arguments = self.arguments(lexer, ctx)?;
+                ctx.unresolved.insert(ast::Dependency {
+                    ident: name,
+                    usage: name_span,
+                });
+                ast::Expression::Call {
+                    function: ast::Ident {
+                        name,
+                        span: name_span,
+                    },
+                    arguments,
+                }
+            }
+        };
+
+        let span = self.peek_rule_span(lexer);
+        let expr = ctx.expressions.append(expr, span);
+        Ok(expr)
+    }
+
+    fn ident_expr<'a>(
+        &mut self,
+        name: &'a str,
+        name_span: Span,
+        ctx: &mut ExpressionContext<'a, '_, '_>,
+    ) -> ast::IdentExpr<'a> {
+        match ctx.local_table.lookup(name) {
+            Some(&local) => ast::IdentExpr::Local(local),
+            None => {
+                ctx.unresolved.insert(ast::Dependency {
+                    ident: name,
+                    usage: name_span,
+                });
+                ast::IdentExpr::Unresolved(name)
+            }
+        }
+    }
+
+    fn primary_expression<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        ctx: &mut ExpressionContext<'a, '_, '_>,
+    ) -> Result<Handle<ast::Expression<'a>>, Error<'a>> {
+        self.push_rule_span(Rule::PrimaryExpr, lexer);
+
+        let expr = match lexer.peek() {
+            (Token::Paren('('), _) => {
+                let _ = lexer.next();
+                let expr = self.general_expression(lexer, ctx)?;
+                lexer.expect(Token::Paren(')'))?;
+                self.pop_rule_span(lexer);
+                return Ok(expr);
+            }
+            (Token::Word("true"), _) => {
+                let _ = lexer.next();
+                ast::Expression::Literal(ast::Literal::Bool(true))
+            }
+            (Token::Word("false"), _) => {
+                let _ = lexer.next();
+                ast::Expression::Literal(ast::Literal::Bool(false))
+            }
+            (Token::Number(res), span) => {
+                let _ = lexer.next();
+                let num = res.map_err(|err| Error::BadNumber(span, err))?;
+                ast::Expression::Literal(ast::Literal::Number(num))
+            }
+            (Token::Word("RAY_FLAG_NONE"), _) => {
+                let _ = lexer.next();
+                ast::Expression::Literal(ast::Literal::Number(Number::U32(0)))
+            }
+            (Token::Word("RAY_FLAG_TERMINATE_ON_FIRST_HIT"), _) => {
+                let _ = lexer.next();
+                ast::Expression::Literal(ast::Literal::Number(Number::U32(4)))
+            }
+            (Token::Word("RAY_QUERY_INTERSECTION_NONE"), _) => {
+                let _ = lexer.next();
+                ast::Expression::Literal(ast::Literal::Number(Number::U32(0)))
+            }
+            (Token::Word(word), span) => {
+                let start = lexer.start_byte_offset();
+                let _ = lexer.next();
+
+                if let Some(ty) = self.constructor_type(lexer, word, span, ctx)? {
+                    let ty_span = lexer.span_from(start);
+                    let components = self.arguments(lexer, ctx)?;
+                    ast::Expression::Construct {
+                        ty,
+                        ty_span,
+                        components,
+                    }
+                } else if let Token::Paren('(') = lexer.peek().0 {
+                    self.pop_rule_span(lexer);
+                    return self.function_call(lexer, word, span, ctx);
+                } else if word == "bitcast" {
+                    self.pop_rule_span(lexer);
+                    return self.function_call(lexer, word, span, ctx);
+                } else {
+                    let ident = self.ident_expr(word, span, ctx);
+                    ast::Expression::Ident(ident)
+                }
+            }
+            other => return Err(Error::Unexpected(other.1, ExpectedToken::PrimaryExpression)),
+        };
+
+        let span = self.pop_rule_span(lexer);
+        let expr = ctx.expressions.append(expr, span);
+        Ok(expr)
+    }
+
+    fn postfix<'a>(
+        &mut self,
+        span_start: usize,
+        lexer: &mut Lexer<'a>,
+        ctx: &mut ExpressionContext<'a, '_, '_>,
+        expr: Handle<ast::Expression<'a>>,
+    ) -> Result<Handle<ast::Expression<'a>>, Error<'a>> {
+        let mut expr = expr;
+
+        loop {
+            let expression = match lexer.peek().0 {
+                Token::Separator('.') => {
+                    let _ = lexer.next();
+                    let field = lexer.next_ident()?;
+
+                    ast::Expression::Member { base: expr, field }
+                }
+                Token::Paren('[') => {
+                    let _ = lexer.next();
+                    let index = self.general_expression(lexer, ctx)?;
+                    lexer.expect(Token::Paren(']'))?;
+
+                    ast::Expression::Index { base: expr, index }
+                }
+                _ => break,
+            };
+
+            let span = lexer.span_from(span_start);
+            expr = ctx.expressions.append(expression, span);
+        }
+
+        Ok(expr)
+    }
+
+    /// Parse a `unary_expression`.
+    fn unary_expression<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        ctx: &mut ExpressionContext<'a, '_, '_>,
+    ) -> Result<Handle<ast::Expression<'a>>, Error<'a>> {
+        self.push_rule_span(Rule::UnaryExpr, lexer);
+        //TODO: refactor this to avoid backing up
+        let expr = match lexer.peek().0 {
+            Token::Operation('-') => {
+                let _ = lexer.next();
+                let expr = self.unary_expression(lexer, ctx)?;
+                let expr = ast::Expression::Unary {
+                    op: crate::UnaryOperator::Negate,
+                    expr,
+                };
+                let span = self.peek_rule_span(lexer);
+                ctx.expressions.append(expr, span)
+            }
+            Token::Operation('!') => {
+                let _ = lexer.next();
+                let expr = self.unary_expression(lexer, ctx)?;
+                let expr = ast::Expression::Unary {
+                    op: crate::UnaryOperator::LogicalNot,
+                    expr,
+                };
+                let span = self.peek_rule_span(lexer);
+                ctx.expressions.append(expr, span)
+            }
+            Token::Operation('~') => {
+                let _ = lexer.next();
+                let expr = self.unary_expression(lexer, ctx)?;
+                let expr = ast::Expression::Unary {
+                    op: crate::UnaryOperator::BitwiseNot,
+                    expr,
+                };
+                let span = self.peek_rule_span(lexer);
+                ctx.expressions.append(expr, span)
+            }
+            Token::Operation('*') => {
+                let _ = lexer.next();
+                let expr = self.unary_expression(lexer, ctx)?;
+                let expr = ast::Expression::Deref(expr);
+                let span = self.peek_rule_span(lexer);
+                ctx.expressions.append(expr, span)
+            }
+            Token::Operation('&') => {
+                let _ = lexer.next();
+                let expr = self.unary_expression(lexer, ctx)?;
+                let expr = ast::Expression::AddrOf(expr);
+                let span = self.peek_rule_span(lexer);
+                ctx.expressions.append(expr, span)
+            }
+            _ => self.singular_expression(lexer, ctx)?,
+        };
+
+        self.pop_rule_span(lexer);
+        Ok(expr)
+    }
+
+    /// Parse a `singular_expression`.
+    fn singular_expression<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        ctx: &mut ExpressionContext<'a, '_, '_>,
+    ) -> Result<Handle<ast::Expression<'a>>, Error<'a>> {
+        let start = lexer.start_byte_offset();
+        self.push_rule_span(Rule::SingularExpr, lexer);
+        let primary_expr = self.primary_expression(lexer, ctx)?;
+        let singular_expr = self.postfix(start, lexer, ctx, primary_expr)?;
+        self.pop_rule_span(lexer);
+
+        Ok(singular_expr)
+    }
+
+    fn equality_expression<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        context: &mut ExpressionContext<'a, '_, '_>,
+    ) -> Result<Handle<ast::Expression<'a>>, Error<'a>> {
+        // equality_expression
+        context.parse_binary_op(
+            lexer,
+            |token| match token {
+                Token::LogicalOperation('=') => Some(crate::BinaryOperator::Equal),
+                Token::LogicalOperation('!') => Some(crate::BinaryOperator::NotEqual),
+                _ => None,
+            },
+            // relational_expression
+            |lexer, context| {
+                context.parse_binary_op(
+                    lexer,
+                    |token| match token {
+                        Token::Paren('<') => Some(crate::BinaryOperator::Less),
+                        Token::Paren('>') => Some(crate::BinaryOperator::Greater),
+                        Token::LogicalOperation('<') => Some(crate::BinaryOperator::LessEqual),
+                        Token::LogicalOperation('>') => Some(crate::BinaryOperator::GreaterEqual),
+                        _ => None,
+                    },
+                    // shift_expression
+                    |lexer, context| {
+                        context.parse_binary_op(
+                            lexer,
+                            |token| match token {
+                                Token::ShiftOperation('<') => {
+                                    Some(crate::BinaryOperator::ShiftLeft)
+                                }
+                                Token::ShiftOperation('>') => {
+                                    Some(crate::BinaryOperator::ShiftRight)
+                                }
+                                _ => None,
+                            },
+                            // additive_expression
+                            |lexer, context| {
+                                context.parse_binary_op(
+                                    lexer,
+                                    |token| match token {
+                                        Token::Operation('+') => Some(crate::BinaryOperator::Add),
+                                        Token::Operation('-') => {
+                                            Some(crate::BinaryOperator::Subtract)
+                                        }
+                                        _ => None,
+                                    },
+                                    // multiplicative_expression
+                                    |lexer, context| {
+                                        context.parse_binary_op(
+                                            lexer,
+                                            |token| match token {
+                                                Token::Operation('*') => {
+                                                    Some(crate::BinaryOperator::Multiply)
+                                                }
+                                                Token::Operation('/') => {
+                                                    Some(crate::BinaryOperator::Divide)
+                                                }
+                                                Token::Operation('%') => {
+                                                    Some(crate::BinaryOperator::Modulo)
+                                                }
+                                                _ => None,
+                                            },
+                                            |lexer, context| self.unary_expression(lexer, context),
+                                        )
+                                    },
+                                )
+                            },
+                        )
+                    },
+                )
+            },
+        )
+    }
+
+    fn general_expression<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        ctx: &mut ExpressionContext<'a, '_, '_>,
+    ) -> Result<Handle<ast::Expression<'a>>, Error<'a>> {
+        self.general_expression_with_span(lexer, ctx)
+            .map(|(expr, _)| expr)
+    }
+
+    fn general_expression_with_span<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        context: &mut ExpressionContext<'a, '_, '_>,
+    ) -> Result<(Handle<ast::Expression<'a>>, Span), Error<'a>> {
+        self.push_rule_span(Rule::GeneralExpr, lexer);
+        // logical_or_expression
+        let handle = context.parse_binary_op(
+            lexer,
+            |token| match token {
+                Token::LogicalOperation('|') => Some(crate::BinaryOperator::LogicalOr),
+                _ => None,
+            },
+            // logical_and_expression
+            |lexer, context| {
+                context.parse_binary_op(
+                    lexer,
+                    |token| match token {
+                        Token::LogicalOperation('&') => Some(crate::BinaryOperator::LogicalAnd),
+                        _ => None,
+                    },
+                    // inclusive_or_expression
+                    |lexer, context| {
+                        context.parse_binary_op(
+                            lexer,
+                            |token| match token {
+                                Token::Operation('|') => Some(crate::BinaryOperator::InclusiveOr),
+                                _ => None,
+                            },
+                            // exclusive_or_expression
+                            |lexer, context| {
+                                context.parse_binary_op(
+                                    lexer,
+                                    |token| match token {
+                                        Token::Operation('^') => {
+                                            Some(crate::BinaryOperator::ExclusiveOr)
+                                        }
+                                        _ => None,
+                                    },
+                                    // and_expression
+                                    |lexer, context| {
+                                        context.parse_binary_op(
+                                            lexer,
+                                            |token| match token {
+                                                Token::Operation('&') => {
+                                                    Some(crate::BinaryOperator::And)
+                                                }
+                                                _ => None,
+                                            },
+                                            |lexer, context| {
+                                                self.equality_expression(lexer, context)
+                                            },
+                                        )
+                                    },
+                                )
+                            },
+                        )
+                    },
+                )
+            },
+        )?;
+        Ok((handle, self.pop_rule_span(lexer)))
+    }
+
+    fn variable_decl<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        ctx: &mut ExpressionContext<'a, '_, '_>,
+    ) -> Result<ast::GlobalVariable<'a>, Error<'a>> {
+        self.push_rule_span(Rule::VariableDecl, lexer);
+        let mut space = crate::AddressSpace::Handle;
+
+        if lexer.skip(Token::Paren('<')) {
+            let (class_str, span) = lexer.next_ident_with_span()?;
+            space = match class_str {
+                "storage" => {
+                    let access = if lexer.skip(Token::Separator(',')) {
+                        lexer.next_storage_access()?
+                    } else {
+                        // defaulting to `read`
+                        crate::StorageAccess::LOAD
+                    };
+                    crate::AddressSpace::Storage { access }
+                }
+                _ => conv::map_address_space(class_str, span)?,
+            };
+            lexer.expect(Token::Paren('>'))?;
+        }
+        let name = lexer.next_ident()?;
+        lexer.expect(Token::Separator(':'))?;
+        let ty = self.type_decl(lexer, ctx)?;
+
+        let init = if lexer.skip(Token::Operation('=')) {
+            let handle = self.general_expression(lexer, ctx)?;
+            Some(handle)
+        } else {
+            None
+        };
+        lexer.expect(Token::Separator(';'))?;
+        self.pop_rule_span(lexer);
+
+        Ok(ast::GlobalVariable {
+            name,
+            space,
+            binding: None,
+            ty,
+            init,
+        })
+    }
+
+    fn struct_body<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        ctx: &mut ExpressionContext<'a, '_, '_>,
+    ) -> Result<Vec<ast::StructMember<'a>>, Error<'a>> {
+        let mut members = Vec::new();
+
+        lexer.expect(Token::Paren('{'))?;
+        let mut ready = true;
+        while !lexer.skip(Token::Paren('}')) {
+            if !ready {
+                return Err(Error::Unexpected(
+                    lexer.next().1,
+                    ExpectedToken::Token(Token::Separator(',')),
+                ));
+            }
+            let (mut size, mut align) = (ParsedAttribute::default(), ParsedAttribute::default());
+            self.push_rule_span(Rule::Attribute, lexer);
+            let mut bind_parser = BindingParser::default();
+            while lexer.skip(Token::Attribute) {
+                match lexer.next_ident_with_span()? {
+                    ("size", name_span) => {
+                        lexer.expect(Token::Paren('('))?;
+                        let expr = self.general_expression(lexer, ctx)?;
+                        lexer.expect(Token::Paren(')'))?;
+                        size.set(expr, name_span)?;
+                    }
+                    ("align", name_span) => {
+                        lexer.expect(Token::Paren('('))?;
+                        let expr = self.general_expression(lexer, ctx)?;
+                        lexer.expect(Token::Paren(')'))?;
+                        align.set(expr, name_span)?;
+                    }
+                    (word, word_span) => bind_parser.parse(self, lexer, word, word_span, ctx)?,
+                }
+            }
+
+            let bind_span = self.pop_rule_span(lexer);
+            let binding = bind_parser.finish(bind_span)?;
+
+            let name = lexer.next_ident()?;
+            lexer.expect(Token::Separator(':'))?;
+            let ty = self.type_decl(lexer, ctx)?;
+            ready = lexer.skip(Token::Separator(','));
+
+            members.push(ast::StructMember {
+                name,
+                ty,
+                binding,
+                size: size.value,
+                align: align.value,
+            });
+        }
+
+        Ok(members)
+    }
+
+    fn matrix_scalar_type<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        columns: crate::VectorSize,
+        rows: crate::VectorSize,
+    ) -> Result<ast::Type<'a>, Error<'a>> {
+        let (scalar, span) = lexer.next_scalar_generic_with_span()?;
+        match scalar.kind {
+            crate::ScalarKind::Float => Ok(ast::Type::Matrix {
+                columns,
+                rows,
+                width: scalar.width,
+            }),
+            _ => Err(Error::BadMatrixScalarKind(span, scalar)),
+        }
+    }
+
+    fn type_decl_impl<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        word: &'a str,
+        ctx: &mut ExpressionContext<'a, '_, '_>,
+    ) -> Result<Option<ast::Type<'a>>, Error<'a>> {
+        if let Some(scalar) = conv::get_scalar_type(word) {
+            return Ok(Some(ast::Type::Scalar(scalar)));
+        }
+
+        Ok(Some(match word {
+            "vec2" => {
+                let scalar = lexer.next_scalar_generic()?;
+                ast::Type::Vector {
+                    size: crate::VectorSize::Bi,
+                    scalar,
+                }
+            }
+            "vec2i" => ast::Type::Vector {
+                size: crate::VectorSize::Bi,
+                scalar: Scalar {
+                    kind: crate::ScalarKind::Sint,
+                    width: 4,
+                },
+            },
+            "vec2u" => ast::Type::Vector {
+                size: crate::VectorSize::Bi,
+                scalar: Scalar {
+                    kind: crate::ScalarKind::Uint,
+                    width: 4,
+                },
+            },
+            "vec2f" => ast::Type::Vector {
+                size: crate::VectorSize::Bi,
+                scalar: Scalar::F32,
+            },
+            "vec3" => {
+                let scalar = lexer.next_scalar_generic()?;
+                ast::Type::Vector {
+                    size: crate::VectorSize::Tri,
+                    scalar,
+                }
+            }
+            "vec3i" => ast::Type::Vector {
+                size: crate::VectorSize::Tri,
+                scalar: Scalar {
+                    kind: crate::ScalarKind::Sint,
+                    width: 4,
+                },
+            },
+            "vec3u" => ast::Type::Vector {
+                size: crate::VectorSize::Tri,
+                scalar: Scalar {
+                    kind: crate::ScalarKind::Uint,
+                    width: 4,
+                },
+            },
+            "vec3f" => ast::Type::Vector {
+                size: crate::VectorSize::Tri,
+                scalar: Scalar::F32,
+            },
+            "vec4" => {
+                let scalar = lexer.next_scalar_generic()?;
+                ast::Type::Vector {
+                    size: crate::VectorSize::Quad,
+                    scalar,
+                }
+            }
+            "vec4i" => ast::Type::Vector {
+                size: crate::VectorSize::Quad,
+                scalar: Scalar {
+                    kind: crate::ScalarKind::Sint,
+                    width: 4,
+                },
+            },
+            "vec4u" => ast::Type::Vector {
+                size: crate::VectorSize::Quad,
+                scalar: Scalar {
+                    kind: crate::ScalarKind::Uint,
+                    width: 4,
+                },
+            },
+            "vec4f" => ast::Type::Vector {
+                size: crate::VectorSize::Quad,
+                scalar: Scalar::F32,
+            },
+            "mat2x2" => {
+                self.matrix_scalar_type(lexer, crate::VectorSize::Bi, crate::VectorSize::Bi)?
+            }
+            "mat2x2f" => ast::Type::Matrix {
+                columns: crate::VectorSize::Bi,
+                rows: crate::VectorSize::Bi,
+                width: 4,
+            },
+            "mat2x3" => {
+                self.matrix_scalar_type(lexer, crate::VectorSize::Bi, crate::VectorSize::Tri)?
+            }
+            "mat2x3f" => ast::Type::Matrix {
+                columns: crate::VectorSize::Bi,
+                rows: crate::VectorSize::Tri,
+                width: 4,
+            },
+            "mat2x4" => {
+                self.matrix_scalar_type(lexer, crate::VectorSize::Bi, crate::VectorSize::Quad)?
+            }
+            "mat2x4f" => ast::Type::Matrix {
+                columns: crate::VectorSize::Bi,
+                rows: crate::VectorSize::Quad,
+                width: 4,
+            },
+            "mat3x2" => {
+                self.matrix_scalar_type(lexer, crate::VectorSize::Tri, crate::VectorSize::Bi)?
+            }
+            "mat3x2f" => ast::Type::Matrix {
+                columns: crate::VectorSize::Tri,
+                rows: crate::VectorSize::Bi,
+                width: 4,
+            },
+            "mat3x3" => {
+                self.matrix_scalar_type(lexer, crate::VectorSize::Tri, crate::VectorSize::Tri)?
+            }
+            "mat3x3f" => ast::Type::Matrix {
+                columns: crate::VectorSize::Tri,
+                rows: crate::VectorSize::Tri,
+                width: 4,
+            },
+            "mat3x4" => {
+                self.matrix_scalar_type(lexer, crate::VectorSize::Tri, crate::VectorSize::Quad)?
+            }
+            "mat3x4f" => ast::Type::Matrix {
+                columns: crate::VectorSize::Tri,
+                rows: crate::VectorSize::Quad,
+                width: 4,
+            },
+            "mat4x2" => {
+                self.matrix_scalar_type(lexer, crate::VectorSize::Quad, crate::VectorSize::Bi)?
+            }
+            "mat4x2f" => ast::Type::Matrix {
+                columns: crate::VectorSize::Quad,
+                rows: crate::VectorSize::Bi,
+                width: 4,
+            },
+            "mat4x3" => {
+                self.matrix_scalar_type(lexer, crate::VectorSize::Quad, crate::VectorSize::Tri)?
+            }
+            "mat4x3f" => ast::Type::Matrix {
+                columns: crate::VectorSize::Quad,
+                rows: crate::VectorSize::Tri,
+                width: 4,
+            },
+            "mat4x4" => {
+                self.matrix_scalar_type(lexer, crate::VectorSize::Quad, crate::VectorSize::Quad)?
+            }
+            "mat4x4f" => ast::Type::Matrix {
+                columns: crate::VectorSize::Quad,
+                rows: crate::VectorSize::Quad,
+                width: 4,
+            },
+            "atomic" => {
+                let scalar = lexer.next_scalar_generic()?;
+                ast::Type::Atomic(scalar)
+            }
+            "ptr" => {
+                lexer.expect_generic_paren('<')?;
+                let (ident, span) = lexer.next_ident_with_span()?;
+                let mut space = conv::map_address_space(ident, span)?;
+                lexer.expect(Token::Separator(','))?;
+                let base = self.type_decl(lexer, ctx)?;
+                if let crate::AddressSpace::Storage { ref mut access } = space {
+                    *access = if lexer.skip(Token::Separator(',')) {
+                        lexer.next_storage_access()?
+                    } else {
+                        crate::StorageAccess::LOAD
+                    };
+                }
+                lexer.expect_generic_paren('>')?;
+                ast::Type::Pointer { base, space }
+            }
+            "array" => {
+                lexer.expect_generic_paren('<')?;
+                let base = self.type_decl(lexer, ctx)?;
+                let size = if lexer.skip(Token::Separator(',')) {
+                    let size = self.unary_expression(lexer, ctx)?;
+                    ast::ArraySize::Constant(size)
+                } else {
+                    ast::ArraySize::Dynamic
+                };
+                lexer.expect_generic_paren('>')?;
+
+                ast::Type::Array { base, size }
+            }
+            "binding_array" => {
+                lexer.expect_generic_paren('<')?;
+                let base = self.type_decl(lexer, ctx)?;
+                let size = if lexer.skip(Token::Separator(',')) {
+                    let size = self.unary_expression(lexer, ctx)?;
+                    ast::ArraySize::Constant(size)
+                } else {
+                    ast::ArraySize::Dynamic
+                };
+                lexer.expect_generic_paren('>')?;
+
+                ast::Type::BindingArray { base, size }
+            }
+            "sampler" => ast::Type::Sampler { comparison: false },
+            "sampler_comparison" => ast::Type::Sampler { comparison: true },
+            "texture_1d" => {
+                let (scalar, span) = lexer.next_scalar_generic_with_span()?;
+                Self::check_texture_sample_type(scalar, span)?;
+                ast::Type::Image {
+                    dim: crate::ImageDimension::D1,
+                    arrayed: false,
+                    class: crate::ImageClass::Sampled {
+                        kind: scalar.kind,
+                        multi: false,
+                    },
+                }
+            }
+            "texture_1d_array" => {
+                let (scalar, span) = lexer.next_scalar_generic_with_span()?;
+                Self::check_texture_sample_type(scalar, span)?;
+                ast::Type::Image {
+                    dim: crate::ImageDimension::D1,
+                    arrayed: true,
+                    class: crate::ImageClass::Sampled {
+                        kind: scalar.kind,
+                        multi: false,
+                    },
+                }
+            }
+            "texture_2d" => {
+                let (scalar, span) = lexer.next_scalar_generic_with_span()?;
+                Self::check_texture_sample_type(scalar, span)?;
+                ast::Type::Image {
+                    dim: crate::ImageDimension::D2,
+                    arrayed: false,
+                    class: crate::ImageClass::Sampled {
+                        kind: scalar.kind,
+                        multi: false,
+                    },
+                }
+            }
+            "texture_2d_array" => {
+                let (scalar, span) = lexer.next_scalar_generic_with_span()?;
+                Self::check_texture_sample_type(scalar, span)?;
+                ast::Type::Image {
+                    dim: crate::ImageDimension::D2,
+                    arrayed: true,
+                    class: crate::ImageClass::Sampled {
+                        kind: scalar.kind,
+                        multi: false,
+                    },
+                }
+            }
+            "texture_3d" => {
+                let (scalar, span) = lexer.next_scalar_generic_with_span()?;
+                Self::check_texture_sample_type(scalar, span)?;
+                ast::Type::Image {
+                    dim: crate::ImageDimension::D3,
+                    arrayed: false,
+                    class: crate::ImageClass::Sampled {
+                        kind: scalar.kind,
+                        multi: false,
+                    },
+                }
+            }
+            "texture_cube" => {
+                let (scalar, span) = lexer.next_scalar_generic_with_span()?;
+                Self::check_texture_sample_type(scalar, span)?;
+                ast::Type::Image {
+                    dim: crate::ImageDimension::Cube,
+                    arrayed: false,
+                    class: crate::ImageClass::Sampled {
+                        kind: scalar.kind,
+                        multi: false,
+                    },
+                }
+            }
+            "texture_cube_array" => {
+                let (scalar, span) = lexer.next_scalar_generic_with_span()?;
+                Self::check_texture_sample_type(scalar, span)?;
+                ast::Type::Image {
+                    dim: crate::ImageDimension::Cube,
+                    arrayed: true,
+                    class: crate::ImageClass::Sampled {
+                        kind: scalar.kind,
+                        multi: false,
+                    },
+                }
+            }
+            "texture_multisampled_2d" => {
+                let (scalar, span) = lexer.next_scalar_generic_with_span()?;
+                Self::check_texture_sample_type(scalar, span)?;
+                ast::Type::Image {
+                    dim: crate::ImageDimension::D2,
+                    arrayed: false,
+                    class: crate::ImageClass::Sampled {
+                        kind: scalar.kind,
+                        multi: true,
+                    },
+                }
+            }
+            "texture_multisampled_2d_array" => {
+                let (scalar, span) = lexer.next_scalar_generic_with_span()?;
+                Self::check_texture_sample_type(scalar, span)?;
+                ast::Type::Image {
+                    dim: crate::ImageDimension::D2,
+                    arrayed: true,
+                    class: crate::ImageClass::Sampled {
+                        kind: scalar.kind,
+                        multi: true,
+                    },
+                }
+            }
+            "texture_depth_2d" => ast::Type::Image {
+                dim: crate::ImageDimension::D2,
+                arrayed: false,
+                class: crate::ImageClass::Depth { multi: false },
+            },
+            "texture_depth_2d_array" => ast::Type::Image {
+                dim: crate::ImageDimension::D2,
+                arrayed: true,
+                class: crate::ImageClass::Depth { multi: false },
+            },
+            "texture_depth_cube" => ast::Type::Image {
+                dim: crate::ImageDimension::Cube,
+                arrayed: false,
+                class: crate::ImageClass::Depth { multi: false },
+            },
+            "texture_depth_cube_array" => ast::Type::Image {
+                dim: crate::ImageDimension::Cube,
+                arrayed: true,
+                class: crate::ImageClass::Depth { multi: false },
+            },
+            "texture_depth_multisampled_2d" => ast::Type::Image {
+                dim: crate::ImageDimension::D2,
+                arrayed: false,
+                class: crate::ImageClass::Depth { multi: true },
+            },
+            "texture_storage_1d" => {
+                let (format, access) = lexer.next_format_generic()?;
+                ast::Type::Image {
+                    dim: crate::ImageDimension::D1,
+                    arrayed: false,
+                    class: crate::ImageClass::Storage { format, access },
+                }
+            }
+            "texture_storage_1d_array" => {
+                let (format, access) = lexer.next_format_generic()?;
+                ast::Type::Image {
+                    dim: crate::ImageDimension::D1,
+                    arrayed: true,
+                    class: crate::ImageClass::Storage { format, access },
+                }
+            }
+            "texture_storage_2d" => {
+                let (format, access) = lexer.next_format_generic()?;
+                ast::Type::Image {
+                    dim: crate::ImageDimension::D2,
+                    arrayed: false,
+                    class: crate::ImageClass::Storage { format, access },
+                }
+            }
+            "texture_storage_2d_array" => {
+                let (format, access) = lexer.next_format_generic()?;
+                ast::Type::Image {
+                    dim: crate::ImageDimension::D2,
+                    arrayed: true,
+                    class: crate::ImageClass::Storage { format, access },
+                }
+            }
+            "texture_storage_3d" => {
+                let (format, access) = lexer.next_format_generic()?;
+                ast::Type::Image {
+                    dim: crate::ImageDimension::D3,
+                    arrayed: false,
+                    class: crate::ImageClass::Storage { format, access },
+                }
+            }
+            "acceleration_structure" => ast::Type::AccelerationStructure,
+            "ray_query" => ast::Type::RayQuery,
+            "RayDesc" => ast::Type::RayDesc,
+            "RayIntersection" => ast::Type::RayIntersection,
+            _ => return Ok(None),
+        }))
+    }
+
+    const fn check_texture_sample_type(scalar: Scalar, span: Span) -> Result<(), Error<'static>> {
+        use crate::ScalarKind::*;
+        // Validate according to https://gpuweb.github.io/gpuweb/wgsl/#sampled-texture-type
+        match scalar {
+            Scalar {
+                kind: Float | Sint | Uint,
+                width: 4,
+            } => Ok(()),
+            _ => Err(Error::BadTextureSampleType { span, scalar }),
+        }
+    }
+
+    /// Parse type declaration of a given name.
+    fn type_decl<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        ctx: &mut ExpressionContext<'a, '_, '_>,
+    ) -> Result<Handle<ast::Type<'a>>, Error<'a>> {
+        self.push_rule_span(Rule::TypeDecl, lexer);
+
+        let (name, span) = lexer.next_ident_with_span()?;
+
+        let ty = match self.type_decl_impl(lexer, name, ctx)? {
+            Some(ty) => ty,
+            None => {
+                ctx.unresolved.insert(ast::Dependency {
+                    ident: name,
+                    usage: span,
+                });
+                ast::Type::User(ast::Ident { name, span })
+            }
+        };
+
+        self.pop_rule_span(lexer);
+
+        let handle = ctx.types.append(ty, Span::UNDEFINED);
+        Ok(handle)
+    }
+
+    fn assignment_op_and_rhs<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        ctx: &mut ExpressionContext<'a, '_, '_>,
+        block: &mut ast::Block<'a>,
+        target: Handle<ast::Expression<'a>>,
+        span_start: usize,
+    ) -> Result<(), Error<'a>> {
+        use crate::BinaryOperator as Bo;
+
+        let op = lexer.next();
+        let (op, value) = match op {
+            (Token::Operation('='), _) => {
+                let value = self.general_expression(lexer, ctx)?;
+                (None, value)
+            }
+            (Token::AssignmentOperation(c), _) => {
+                let op = match c {
+                    '<' => Bo::ShiftLeft,
+                    '>' => Bo::ShiftRight,
+                    '+' => Bo::Add,
+                    '-' => Bo::Subtract,
+                    '*' => Bo::Multiply,
+                    '/' => Bo::Divide,
+                    '%' => Bo::Modulo,
+                    '&' => Bo::And,
+                    '|' => Bo::InclusiveOr,
+                    '^' => Bo::ExclusiveOr,
+                    // Note: `consume_token` shouldn't produce any other assignment ops
+                    _ => unreachable!(),
+                };
+
+                let value = self.general_expression(lexer, ctx)?;
+                (Some(op), value)
+            }
+            token @ (Token::IncrementOperation | Token::DecrementOperation, _) => {
+                let op = match token.0 {
+                    Token::IncrementOperation => ast::StatementKind::Increment,
+                    Token::DecrementOperation => ast::StatementKind::Decrement,
+                    _ => unreachable!(),
+                };
+
+                let span = lexer.span_from(span_start);
+                block.stmts.push(ast::Statement {
+                    kind: op(target),
+                    span,
+                });
+                return Ok(());
+            }
+            _ => return Err(Error::Unexpected(op.1, ExpectedToken::Assignment)),
+        };
+
+        let span = lexer.span_from(span_start);
+        block.stmts.push(ast::Statement {
+            kind: ast::StatementKind::Assign { target, op, value },
+            span,
+        });
+        Ok(())
+    }
+
+    /// Parse an assignment statement (will also parse increment and decrement statements)
+    fn assignment_statement<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        ctx: &mut ExpressionContext<'a, '_, '_>,
+        block: &mut ast::Block<'a>,
+    ) -> Result<(), Error<'a>> {
+        let span_start = lexer.start_byte_offset();
+        let target = self.general_expression(lexer, ctx)?;
+        self.assignment_op_and_rhs(lexer, ctx, block, target, span_start)
+    }
+
+    /// Parse a function call statement.
+    /// Expects `ident` to be consumed (not in the lexer).
+    fn function_statement<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        ident: &'a str,
+        ident_span: Span,
+        span_start: usize,
+        context: &mut ExpressionContext<'a, '_, '_>,
+        block: &mut ast::Block<'a>,
+    ) -> Result<(), Error<'a>> {
+        self.push_rule_span(Rule::SingularExpr, lexer);
+
+        context.unresolved.insert(ast::Dependency {
+            ident,
+            usage: ident_span,
+        });
+        let arguments = self.arguments(lexer, context)?;
+        let span = lexer.span_from(span_start);
+
+        block.stmts.push(ast::Statement {
+            kind: ast::StatementKind::Call {
+                function: ast::Ident {
+                    name: ident,
+                    span: ident_span,
+                },
+                arguments,
+            },
+            span,
+        });
+
+        self.pop_rule_span(lexer);
+
+        Ok(())
+    }
+
+    fn function_call_or_assignment_statement<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        context: &mut ExpressionContext<'a, '_, '_>,
+        block: &mut ast::Block<'a>,
+    ) -> Result<(), Error<'a>> {
+        let span_start = lexer.start_byte_offset();
+        match lexer.peek() {
+            (Token::Word(name), span) => {
+                // A little hack for 2 token lookahead.
+                let cloned = lexer.clone();
+                let _ = lexer.next();
+                match lexer.peek() {
+                    (Token::Paren('('), _) => {
+                        self.function_statement(lexer, name, span, span_start, context, block)
+                    }
+                    _ => {
+                        *lexer = cloned;
+                        self.assignment_statement(lexer, context, block)
+                    }
+                }
+            }
+            _ => self.assignment_statement(lexer, context, block),
+        }
+    }
+
+    fn statement<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        ctx: &mut ExpressionContext<'a, '_, '_>,
+        block: &mut ast::Block<'a>,
+    ) -> Result<(), Error<'a>> {
+        self.push_rule_span(Rule::Statement, lexer);
+        match lexer.peek() {
+            (Token::Separator(';'), _) => {
+                let _ = lexer.next();
+                self.pop_rule_span(lexer);
+                return Ok(());
+            }
+            (Token::Paren('{'), _) => {
+                let (inner, span) = self.block(lexer, ctx)?;
+                block.stmts.push(ast::Statement {
+                    kind: ast::StatementKind::Block(inner),
+                    span,
+                });
+                self.pop_rule_span(lexer);
+                return Ok(());
+            }
+            (Token::Word(word), _) => {
+                let kind = match word {
+                    "_" => {
+                        let _ = lexer.next();
+                        lexer.expect(Token::Operation('='))?;
+                        let expr = self.general_expression(lexer, ctx)?;
+                        lexer.expect(Token::Separator(';'))?;
+
+                        ast::StatementKind::Ignore(expr)
+                    }
+                    "let" => {
+                        let _ = lexer.next();
+                        let name = lexer.next_ident()?;
+
+                        let given_ty = if lexer.skip(Token::Separator(':')) {
+                            let ty = self.type_decl(lexer, ctx)?;
+                            Some(ty)
+                        } else {
+                            None
+                        };
+                        lexer.expect(Token::Operation('='))?;
+                        let expr_id = self.general_expression(lexer, ctx)?;
+                        lexer.expect(Token::Separator(';'))?;
+
+                        let handle = ctx.declare_local(name)?;
+                        ast::StatementKind::LocalDecl(ast::LocalDecl::Let(ast::Let {
+                            name,
+                            ty: given_ty,
+                            init: expr_id,
+                            handle,
+                        }))
+                    }
+                    "var" => {
+                        let _ = lexer.next();
+
+                        let name = lexer.next_ident()?;
+                        let ty = if lexer.skip(Token::Separator(':')) {
+                            let ty = self.type_decl(lexer, ctx)?;
+                            Some(ty)
+                        } else {
+                            None
+                        };
+
+                        let init = if lexer.skip(Token::Operation('=')) {
+                            let init = self.general_expression(lexer, ctx)?;
+                            Some(init)
+                        } else {
+                            None
+                        };
+
+                        lexer.expect(Token::Separator(';'))?;
+
+                        let handle = ctx.declare_local(name)?;
+                        ast::StatementKind::LocalDecl(ast::LocalDecl::Var(ast::LocalVariable {
+                            name,
+                            ty,
+                            init,
+                            handle,
+                        }))
+                    }
+                    "return" => {
+                        let _ = lexer.next();
+                        let value = if lexer.peek().0 != Token::Separator(';') {
+                            let handle = self.general_expression(lexer, ctx)?;
+                            Some(handle)
+                        } else {
+                            None
+                        };
+                        lexer.expect(Token::Separator(';'))?;
+                        ast::StatementKind::Return { value }
+                    }
+                    "if" => {
+                        let _ = lexer.next();
+                        let condition = self.general_expression(lexer, ctx)?;
+
+                        let accept = self.block(lexer, ctx)?.0;
+
+                        let mut elsif_stack = Vec::new();
+                        let mut elseif_span_start = lexer.start_byte_offset();
+                        let mut reject = loop {
+                            if !lexer.skip(Token::Word("else")) {
+                                break ast::Block::default();
+                            }
+
+                            if !lexer.skip(Token::Word("if")) {
+                                // ... else { ... }
+                                break self.block(lexer, ctx)?.0;
+                            }
+
+                            // ... else if (...) { ... }
+                            let other_condition = self.general_expression(lexer, ctx)?;
+                            let other_block = self.block(lexer, ctx)?;
+                            elsif_stack.push((elseif_span_start, other_condition, other_block));
+                            elseif_span_start = lexer.start_byte_offset();
+                        };
+
+                        // reverse-fold the else-if blocks
+                        //Note: we may consider uplifting this to the IR
+                        for (other_span_start, other_cond, other_block) in
+                            elsif_stack.into_iter().rev()
+                        {
+                            let sub_stmt = ast::StatementKind::If {
+                                condition: other_cond,
+                                accept: other_block.0,
+                                reject,
+                            };
+                            reject = ast::Block::default();
+                            let span = lexer.span_from(other_span_start);
+                            reject.stmts.push(ast::Statement {
+                                kind: sub_stmt,
+                                span,
+                            })
+                        }
+
+                        ast::StatementKind::If {
+                            condition,
+                            accept,
+                            reject,
+                        }
+                    }
+                    "switch" => {
+                        let _ = lexer.next();
+                        let selector = self.general_expression(lexer, ctx)?;
+                        lexer.expect(Token::Paren('{'))?;
+                        let mut cases = Vec::new();
+
+                        loop {
+                            // cases + default
+                            match lexer.next() {
+                                (Token::Word("case"), _) => {
+                                    // parse a list of values
+                                    let value = loop {
+                                        let value = self.switch_value(lexer, ctx)?;
+                                        if lexer.skip(Token::Separator(',')) {
+                                            if lexer.skip(Token::Separator(':')) {
+                                                break value;
+                                            }
+                                        } else {
+                                            lexer.skip(Token::Separator(':'));
+                                            break value;
+                                        }
+                                        cases.push(ast::SwitchCase {
+                                            value,
+                                            body: ast::Block::default(),
+                                            fall_through: true,
+                                        });
+                                    };
+
+                                    let body = self.block(lexer, ctx)?.0;
+
+                                    cases.push(ast::SwitchCase {
+                                        value,
+                                        body,
+                                        fall_through: false,
+                                    });
+                                }
+                                (Token::Word("default"), _) => {
+                                    lexer.skip(Token::Separator(':'));
+                                    let body = self.block(lexer, ctx)?.0;
+                                    cases.push(ast::SwitchCase {
+                                        value: ast::SwitchValue::Default,
+                                        body,
+                                        fall_through: false,
+                                    });
+                                }
+                                (Token::Paren('}'), _) => break,
+                                (_, span) => {
+                                    return Err(Error::Unexpected(span, ExpectedToken::SwitchItem))
+                                }
+                            }
+                        }
+
+                        ast::StatementKind::Switch { selector, cases }
+                    }
+                    "loop" => self.r#loop(lexer, ctx)?,
+                    "while" => {
+                        let _ = lexer.next();
+                        let mut body = ast::Block::default();
+
+                        let (condition, span) = lexer.capture_span(|lexer| {
+                            let condition = self.general_expression(lexer, ctx)?;
+                            Ok(condition)
+                        })?;
+                        let mut reject = ast::Block::default();
+                        reject.stmts.push(ast::Statement {
+                            kind: ast::StatementKind::Break,
+                            span,
+                        });
+
+                        body.stmts.push(ast::Statement {
+                            kind: ast::StatementKind::If {
+                                condition,
+                                accept: ast::Block::default(),
+                                reject,
+                            },
+                            span,
+                        });
+
+                        let (block, span) = self.block(lexer, ctx)?;
+                        body.stmts.push(ast::Statement {
+                            kind: ast::StatementKind::Block(block),
+                            span,
+                        });
+
+                        ast::StatementKind::Loop {
+                            body,
+                            continuing: ast::Block::default(),
+                            break_if: None,
+                        }
+                    }
+                    "for" => {
+                        let _ = lexer.next();
+                        lexer.expect(Token::Paren('('))?;
+
+                        ctx.local_table.push_scope();
+
+                        if !lexer.skip(Token::Separator(';')) {
+                            let num_statements = block.stmts.len();
+                            let (_, span) = {
+                                let ctx = &mut *ctx;
+                                let block = &mut *block;
+                                lexer.capture_span(|lexer| self.statement(lexer, ctx, block))?
+                            };
+
+                            if block.stmts.len() != num_statements {
+                                match block.stmts.last().unwrap().kind {
+                                    ast::StatementKind::Call { .. }
+                                    | ast::StatementKind::Assign { .. }
+                                    | ast::StatementKind::LocalDecl(_) => {}
+                                    _ => return Err(Error::InvalidForInitializer(span)),
+                                }
+                            }
+                        };
+
+                        let mut body = ast::Block::default();
+                        if !lexer.skip(Token::Separator(';')) {
+                            let (condition, span) = lexer.capture_span(|lexer| {
+                                let condition = self.general_expression(lexer, ctx)?;
+                                lexer.expect(Token::Separator(';'))?;
+                                Ok(condition)
+                            })?;
+                            let mut reject = ast::Block::default();
+                            reject.stmts.push(ast::Statement {
+                                kind: ast::StatementKind::Break,
+                                span,
+                            });
+                            body.stmts.push(ast::Statement {
+                                kind: ast::StatementKind::If {
+                                    condition,
+                                    accept: ast::Block::default(),
+                                    reject,
+                                },
+                                span,
+                            });
+                        };
+
+                        let mut continuing = ast::Block::default();
+                        if !lexer.skip(Token::Paren(')')) {
+                            self.function_call_or_assignment_statement(
+                                lexer,
+                                ctx,
+                                &mut continuing,
+                            )?;
+                            lexer.expect(Token::Paren(')'))?;
+                        }
+
+                        let (block, span) = self.block(lexer, ctx)?;
+                        body.stmts.push(ast::Statement {
+                            kind: ast::StatementKind::Block(block),
+                            span,
+                        });
+
+                        ctx.local_table.pop_scope();
+
+                        ast::StatementKind::Loop {
+                            body,
+                            continuing,
+                            break_if: None,
+                        }
+                    }
+                    "break" => {
+                        let (_, span) = lexer.next();
+                        // Check if the next token is an `if`, this indicates
+                        // that the user tried to type out a `break if` which
+                        // is illegal in this position.
+                        let (peeked_token, peeked_span) = lexer.peek();
+                        if let Token::Word("if") = peeked_token {
+                            let span = span.until(&peeked_span);
+                            return Err(Error::InvalidBreakIf(span));
+                        }
+                        lexer.expect(Token::Separator(';'))?;
+                        ast::StatementKind::Break
+                    }
+                    "continue" => {
+                        let _ = lexer.next();
+                        lexer.expect(Token::Separator(';'))?;
+                        ast::StatementKind::Continue
+                    }
+                    "discard" => {
+                        let _ = lexer.next();
+                        lexer.expect(Token::Separator(';'))?;
+                        ast::StatementKind::Kill
+                    }
+                    // assignment or a function call
+                    _ => {
+                        self.function_call_or_assignment_statement(lexer, ctx, block)?;
+                        lexer.expect(Token::Separator(';'))?;
+                        self.pop_rule_span(lexer);
+                        return Ok(());
+                    }
+                };
+
+                let span = self.pop_rule_span(lexer);
+                block.stmts.push(ast::Statement { kind, span });
+            }
+            _ => {
+                self.assignment_statement(lexer, ctx, block)?;
+                lexer.expect(Token::Separator(';'))?;
+                self.pop_rule_span(lexer);
+            }
+        }
+        Ok(())
+    }
+
+    fn r#loop<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        ctx: &mut ExpressionContext<'a, '_, '_>,
+    ) -> Result<ast::StatementKind<'a>, Error<'a>> {
+        let _ = lexer.next();
+        let mut body = ast::Block::default();
+        let mut continuing = ast::Block::default();
+        let mut break_if = None;
+
+        lexer.expect(Token::Paren('{'))?;
+
+        ctx.local_table.push_scope();
+
+        loop {
+            if lexer.skip(Token::Word("continuing")) {
+                // Branch for the `continuing` block, this must be
+                // the last thing in the loop body
+
+                // Expect a opening brace to start the continuing block
+                lexer.expect(Token::Paren('{'))?;
+                loop {
+                    if lexer.skip(Token::Word("break")) {
+                        // Branch for the `break if` statement, this statement
+                        // has the form `break if <expr>;` and must be the last
+                        // statement in a continuing block
+
+                        // The break must be followed by an `if` to form
+                        // the break if
+                        lexer.expect(Token::Word("if"))?;
+
+                        let condition = self.general_expression(lexer, ctx)?;
+                        // Set the condition of the break if to the newly parsed
+                        // expression
+                        break_if = Some(condition);
+
+                        // Expect a semicolon to close the statement
+                        lexer.expect(Token::Separator(';'))?;
+                        // Expect a closing brace to close the continuing block,
+                        // since the break if must be the last statement
+                        lexer.expect(Token::Paren('}'))?;
+                        // Stop parsing the continuing block
+                        break;
+                    } else if lexer.skip(Token::Paren('}')) {
+                        // If we encounter a closing brace it means we have reached
+                        // the end of the continuing block and should stop processing
+                        break;
+                    } else {
+                        // Otherwise try to parse a statement
+                        self.statement(lexer, ctx, &mut continuing)?;
+                    }
+                }
+                // Since the continuing block must be the last part of the loop body,
+                // we expect to see a closing brace to end the loop body
+                lexer.expect(Token::Paren('}'))?;
+                break;
+            }
+            if lexer.skip(Token::Paren('}')) {
+                // If we encounter a closing brace it means we have reached
+                // the end of the loop body and should stop processing
+                break;
+            }
+            // Otherwise try to parse a statement
+            self.statement(lexer, ctx, &mut body)?;
+        }
+
+        ctx.local_table.pop_scope();
+
+        Ok(ast::StatementKind::Loop {
+            body,
+            continuing,
+            break_if,
+        })
+    }
+
+    /// compound_statement
+    fn block<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        ctx: &mut ExpressionContext<'a, '_, '_>,
+    ) -> Result<(ast::Block<'a>, Span), Error<'a>> {
+        self.push_rule_span(Rule::Block, lexer);
+
+        ctx.local_table.push_scope();
+
+        lexer.expect(Token::Paren('{'))?;
+        let mut block = ast::Block::default();
+        while !lexer.skip(Token::Paren('}')) {
+            self.statement(lexer, ctx, &mut block)?;
+        }
+
+        ctx.local_table.pop_scope();
+
+        let span = self.pop_rule_span(lexer);
+        Ok((block, span))
+    }
+
+    fn varying_binding<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        ctx: &mut ExpressionContext<'a, '_, '_>,
+    ) -> Result<Option<ast::Binding<'a>>, Error<'a>> {
+        let mut bind_parser = BindingParser::default();
+        self.push_rule_span(Rule::Attribute, lexer);
+
+        while lexer.skip(Token::Attribute) {
+            let (word, span) = lexer.next_ident_with_span()?;
+            bind_parser.parse(self, lexer, word, span, ctx)?;
+        }
+
+        let span = self.pop_rule_span(lexer);
+        bind_parser.finish(span)
+    }
+
+    fn function_decl<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        out: &mut ast::TranslationUnit<'a>,
+        dependencies: &mut FastIndexSet<ast::Dependency<'a>>,
+    ) -> Result<ast::Function<'a>, Error<'a>> {
+        self.push_rule_span(Rule::FunctionDecl, lexer);
+        // read function name
+        let fun_name = lexer.next_ident()?;
+
+        let mut locals = Arena::new();
+
+        let mut ctx = ExpressionContext {
+            expressions: &mut out.expressions,
+            local_table: &mut SymbolTable::default(),
+            locals: &mut locals,
+            types: &mut out.types,
+            unresolved: dependencies,
+        };
+
+        // start a scope that contains arguments as well as the function body
+        ctx.local_table.push_scope();
+
+        // read parameter list
+        let mut arguments = Vec::new();
+        lexer.expect(Token::Paren('('))?;
+        let mut ready = true;
+        while !lexer.skip(Token::Paren(')')) {
+            if !ready {
+                return Err(Error::Unexpected(
+                    lexer.next().1,
+                    ExpectedToken::Token(Token::Separator(',')),
+                ));
+            }
+            let binding = self.varying_binding(lexer, &mut ctx)?;
+
+            let param_name = lexer.next_ident()?;
+
+            lexer.expect(Token::Separator(':'))?;
+            let param_type = self.type_decl(lexer, &mut ctx)?;
+
+            let handle = ctx.declare_local(param_name)?;
+            arguments.push(ast::FunctionArgument {
+                name: param_name,
+                ty: param_type,
+                binding,
+                handle,
+            });
+            ready = lexer.skip(Token::Separator(','));
+        }
+        // read return type
+        let result = if lexer.skip(Token::Arrow) && !lexer.skip(Token::Word("void")) {
+            let binding = self.varying_binding(lexer, &mut ctx)?;
+            let ty = self.type_decl(lexer, &mut ctx)?;
+            Some(ast::FunctionResult { ty, binding })
+        } else {
+            None
+        };
+
+        // do not use `self.block` here, since we must not push a new scope
+        lexer.expect(Token::Paren('{'))?;
+        let mut body = ast::Block::default();
+        while !lexer.skip(Token::Paren('}')) {
+            self.statement(lexer, &mut ctx, &mut body)?;
+        }
+
+        ctx.local_table.pop_scope();
+
+        let fun = ast::Function {
+            entry_point: None,
+            name: fun_name,
+            arguments,
+            result,
+            body,
+            locals,
+        };
+
+        // done
+        self.pop_rule_span(lexer);
+
+        Ok(fun)
+    }
+
+    fn global_decl<'a>(
+        &mut self,
+        lexer: &mut Lexer<'a>,
+        out: &mut ast::TranslationUnit<'a>,
+    ) -> Result<(), Error<'a>> {
+        // read attributes
+        let mut binding = None;
+        let mut stage = ParsedAttribute::default();
+        let mut compute_span = Span::new(0, 0);
+        let mut workgroup_size = ParsedAttribute::default();
+        let mut early_depth_test = ParsedAttribute::default();
+        let (mut bind_index, mut bind_group) =
+            (ParsedAttribute::default(), ParsedAttribute::default());
+
+        let mut dependencies = FastIndexSet::default();
+        let mut ctx = ExpressionContext {
+            expressions: &mut out.expressions,
+            local_table: &mut SymbolTable::default(),
+            locals: &mut Arena::new(),
+            types: &mut out.types,
+            unresolved: &mut dependencies,
+        };
+
+        self.push_rule_span(Rule::Attribute, lexer);
+        while lexer.skip(Token::Attribute) {
+            match lexer.next_ident_with_span()? {
+                ("binding", name_span) => {
+                    lexer.expect(Token::Paren('('))?;
+                    bind_index.set(self.general_expression(lexer, &mut ctx)?, name_span)?;
+                    lexer.expect(Token::Paren(')'))?;
+                }
+                ("group", name_span) => {
+                    lexer.expect(Token::Paren('('))?;
+                    bind_group.set(self.general_expression(lexer, &mut ctx)?, name_span)?;
+                    lexer.expect(Token::Paren(')'))?;
+                }
+                ("vertex", name_span) => {
+                    stage.set(crate::ShaderStage::Vertex, name_span)?;
+                }
+                ("fragment", name_span) => {
+                    stage.set(crate::ShaderStage::Fragment, name_span)?;
+                }
+                ("compute", name_span) => {
+                    stage.set(crate::ShaderStage::Compute, name_span)?;
+                    compute_span = name_span;
+                }
+                ("workgroup_size", name_span) => {
+                    lexer.expect(Token::Paren('('))?;
+                    let mut new_workgroup_size = [None; 3];
+                    for (i, size) in new_workgroup_size.iter_mut().enumerate() {
+                        *size = Some(self.general_expression(lexer, &mut ctx)?);
+                        match lexer.next() {
+                            (Token::Paren(')'), _) => break,
+                            (Token::Separator(','), _) if i != 2 => (),
+                            other => {
+                                return Err(Error::Unexpected(
+                                    other.1,
+                                    ExpectedToken::WorkgroupSizeSeparator,
+                                ))
+                            }
+                        }
+                    }
+                    workgroup_size.set(new_workgroup_size, name_span)?;
+                }
+                ("early_depth_test", name_span) => {
+                    let conservative = if lexer.skip(Token::Paren('(')) {
+                        let (ident, ident_span) = lexer.next_ident_with_span()?;
+                        let value = conv::map_conservative_depth(ident, ident_span)?;
+                        lexer.expect(Token::Paren(')'))?;
+                        Some(value)
+                    } else {
+                        None
+                    };
+                    early_depth_test.set(crate::EarlyDepthTest { conservative }, name_span)?;
+                }
+                (_, word_span) => return Err(Error::UnknownAttribute(word_span)),
+            }
+        }
+
+        let attrib_span = self.pop_rule_span(lexer);
+        match (bind_group.value, bind_index.value) {
+            (Some(group), Some(index)) => {
+                binding = Some(ast::ResourceBinding {
+                    group,
+                    binding: index,
+                });
+            }
+            (Some(_), None) => return Err(Error::MissingAttribute("binding", attrib_span)),
+            (None, Some(_)) => return Err(Error::MissingAttribute("group", attrib_span)),
+            (None, None) => {}
+        }
+
+        // read item
+        let start = lexer.start_byte_offset();
+        let kind = match lexer.next() {
+            (Token::Separator(';'), _) => None,
+            (Token::Word("struct"), _) => {
+                let name = lexer.next_ident()?;
+
+                let members = self.struct_body(lexer, &mut ctx)?;
+                Some(ast::GlobalDeclKind::Struct(ast::Struct { name, members }))
+            }
+            (Token::Word("alias"), _) => {
+                let name = lexer.next_ident()?;
+
+                lexer.expect(Token::Operation('='))?;
+                let ty = self.type_decl(lexer, &mut ctx)?;
+                lexer.expect(Token::Separator(';'))?;
+                Some(ast::GlobalDeclKind::Type(ast::TypeAlias { name, ty }))
+            }
+            (Token::Word("const"), _) => {
+                let name = lexer.next_ident()?;
+
+                let ty = if lexer.skip(Token::Separator(':')) {
+                    let ty = self.type_decl(lexer, &mut ctx)?;
+                    Some(ty)
+                } else {
+                    None
+                };
+
+                lexer.expect(Token::Operation('='))?;
+                let init = self.general_expression(lexer, &mut ctx)?;
+                lexer.expect(Token::Separator(';'))?;
+
+                Some(ast::GlobalDeclKind::Const(ast::Const { name, ty, init }))
+            }
+            (Token::Word("var"), _) => {
+                let mut var = self.variable_decl(lexer, &mut ctx)?;
+                var.binding = binding.take();
+                Some(ast::GlobalDeclKind::Var(var))
+            }
+            (Token::Word("fn"), _) => {
+                let function = self.function_decl(lexer, out, &mut dependencies)?;
+                Some(ast::GlobalDeclKind::Fn(ast::Function {
+                    entry_point: if let Some(stage) = stage.value {
+                        if stage == ShaderStage::Compute && workgroup_size.value.is_none() {
+                            return Err(Error::MissingWorkgroupSize(compute_span));
+                        }
+                        Some(ast::EntryPoint {
+                            stage,
+                            early_depth_test: early_depth_test.value,
+                            workgroup_size: workgroup_size.value,
+                        })
+                    } else {
+                        None
+                    },
+                    ..function
+                }))
+            }
+            (Token::End, _) => return Ok(()),
+            other => return Err(Error::Unexpected(other.1, ExpectedToken::GlobalItem)),
+        };
+
+        if let Some(kind) = kind {
+            out.decls.append(
+                ast::GlobalDecl { kind, dependencies },
+                lexer.span_from(start),
+            );
+        }
+
+        if !self.rules.is_empty() {
+            log::error!("Reached the end of global decl, but rule stack is not empty");
+            log::error!("Rules: {:?}", self.rules);
+            return Err(Error::Internal("rule stack is not empty"));
+        };
+
+        match binding {
+            None => Ok(()),
+            Some(_) => Err(Error::Internal("we had the attribute but no var?")),
+        }
+    }
+
+    pub fn parse<'a>(&mut self, source: &'a str) -> Result<ast::TranslationUnit<'a>, Error<'a>> {
+        self.reset();
+
+        let mut lexer = Lexer::new(source);
+        let mut tu = ast::TranslationUnit::default();
+        loop {
+            match self.global_decl(&mut lexer, &mut tu) {
+                Err(error) => return Err(error),
+                Ok(()) => {
+                    if lexer.peek().0 == Token::End {
+                        break;
+                    }
+                }
+            }
+        }
+
+        Ok(tu)
+    }
+}
diff --git a/third_party/rust/naga/src/front/wgsl/parse/number.rs b/third_party/rust/naga/src/front/wgsl/parse/number.rs
new file mode 100644
index 0000000000..7b09ac59bb
--- /dev/null
+++ b/third_party/rust/naga/src/front/wgsl/parse/number.rs
@@ -0,0 +1,420 @@
+use crate::front::wgsl::error::NumberError;
+use crate::front::wgsl::parse::lexer::Token;
+
+/// When using this type assume no Abstract Int/Float for now
+#[derive(Copy, Clone, Debug, PartialEq)]
+pub enum Number {
+    /// Abstract Int (-2^63 ≤ i < 2^63)
+    AbstractInt(i64),
+    /// Abstract Float (IEEE-754 binary64)
+    AbstractFloat(f64),
+    /// Concrete i32
+    I32(i32),
+    /// Concrete u32
+    U32(u32),
+    /// Concrete f32
+    F32(f32),
+    /// Concrete f64
+    F64(f64),
+}
+
+pub(in crate::front::wgsl) fn consume_number(input: &str) -> (Token<'_>, &str) {
+    let (result, rest) = parse(input);
+    (Token::Number(result), rest)
+}
+
+enum Kind {
+    Int(IntKind),
+    Float(FloatKind),
+}
+
+enum IntKind {
+    I32,
+    U32,
+}
+
+#[derive(Debug)]
+enum FloatKind {
+    F16,
+    F32,
+    F64,
+}
+
+// The following regexes (from the WGSL spec) will be matched:
+
+// int_literal:
+// | / 0                                                                [iu]?   /
+// | / [1-9][0-9]*                                                      [iu]?   /
+// | / 0[xX][0-9a-fA-F]+                                                [iu]?   /
+
+// decimal_float_literal:
+// | / 0                                                                [fh]    /
+// | / [1-9][0-9]*                                                      [fh]    /
+// | / [0-9]*               \.[0-9]+            ([eE][+-]?[0-9]+)?      [fh]?   /
+// | / [0-9]+               \.[0-9]*            ([eE][+-]?[0-9]+)?      [fh]?   /
+// | / [0-9]+                                    [eE][+-]?[0-9]+        [fh]?   /
+
+// hex_float_literal:
+// | / 0[xX][0-9a-fA-F]*    \.[0-9a-fA-F]+      ([pP][+-]?[0-9]+        [fh]?)? /
+// | / 0[xX][0-9a-fA-F]+    \.[0-9a-fA-F]*      ([pP][+-]?[0-9]+        [fh]?)? /
+// | / 0[xX][0-9a-fA-F]+                         [pP][+-]?[0-9]+        [fh]?   /
+
+// You could visualize the regex below via https://debuggex.com to get a rough idea what `parse` is doing
+// (?:0[xX](?:([0-9a-fA-F]+\.[0-9a-fA-F]*|[0-9a-fA-F]*\.[0-9a-fA-F]+)(?:([pP][+-]?[0-9]+)([fh]?))?|([0-9a-fA-F]+)([pP][+-]?[0-9]+)([fh]?)|([0-9a-fA-F]+)([iu]?))|((?:[0-9]+[eE][+-]?[0-9]+|(?:[0-9]+\.[0-9]*|[0-9]*\.[0-9]+)(?:[eE][+-]?[0-9]+)?))([fh]?)|((?:[0-9]|[1-9][0-9]+))([iufh]?))
+
+// Leading signs are handled as unary operators.
+
+fn parse(input: &str) -> (Result<Number, NumberError>, &str) {
+    /// returns `true` and consumes `X` bytes from the given byte buffer
+    /// if the given `X` nr of patterns are found at the start of the buffer
+    macro_rules! consume {
+        ($bytes:ident, $($pattern:pat),*) => {
+            match $bytes {
+                &[$($pattern),*, ref rest @ ..] => { $bytes = rest; true },
+                _ => false,
+            }
+        };
+    }
+
+    /// consumes one byte from the given byte buffer
+    /// if one of the given patterns are found at the start of the buffer
+    /// returning the corresponding expr for the matched pattern
+    macro_rules! consume_map {
+        ($bytes:ident, [$( $($pattern:pat_param),* => $to:expr),* $(,)?]) => {
+            match $bytes {
+                $( &[ $($pattern),*, ref rest @ ..] => { $bytes = rest; Some($to) }, )*
+                _ => None,
+            }
+        };
+    }
+
+    /// consumes all consecutive bytes matched by the `0-9` pattern from the given byte buffer
+    /// returning the number of consumed bytes
+    macro_rules! consume_dec_digits {
+        ($bytes:ident) => {{
+            let start_len = $bytes.len();
+            while let &[b'0'..=b'9', ref rest @ ..] = $bytes {
+                $bytes = rest;
+            }
+            start_len - $bytes.len()
+        }};
+    }
+
+    /// consumes all consecutive bytes matched by the `0-9 | a-f | A-F` pattern from the given byte buffer
+    /// returning the number of consumed bytes
+    macro_rules! consume_hex_digits {
+        ($bytes:ident) => {{
+            let start_len = $bytes.len();
+            while let &[b'0'..=b'9' | b'a'..=b'f' | b'A'..=b'F', ref rest @ ..] = $bytes {
+                $bytes = rest;
+            }
+            start_len - $bytes.len()
+        }};
+    }
+
+    macro_rules! consume_float_suffix {
+        ($bytes:ident) => {
+            consume_map!($bytes, [
+                b'h' => FloatKind::F16,
+                b'f' => FloatKind::F32,
+                b'l', b'f' => FloatKind::F64,
+            ])
+        };
+    }
+
+    /// maps the given `&[u8]` (tail of the initial `input: &str`) to a `&str`
+    macro_rules! rest_to_str {
+        ($bytes:ident) => {
+            &input[input.len() - $bytes.len()..]
+        };
+    }
+
+    struct ExtractSubStr<'a>(&'a str);
+
+    impl<'a> ExtractSubStr<'a> {
+        /// given an `input` and a `start` (tail of the `input`)
+        /// creates a new [`ExtractSubStr`](`Self`)
+        fn start(input: &'a str, start: &'a [u8]) -> Self {
+            let start = input.len() - start.len();
+            Self(&input[start..])
+        }
+        /// given an `end` (tail of the initial `input`)
+        /// returns a substring of `input`
+        fn end(&self, end: &'a [u8]) -> &'a str {
+            let end = self.0.len() - end.len();
+            &self.0[..end]
+        }
+    }
+
+    let mut bytes = input.as_bytes();
+
+    let general_extract = ExtractSubStr::start(input, bytes);
+
+    if consume!(bytes, b'0', b'x' | b'X') {
+        let digits_extract = ExtractSubStr::start(input, bytes);
+
+        let consumed = consume_hex_digits!(bytes);
+
+        if consume!(bytes, b'.') {
+            let consumed_after_period = consume_hex_digits!(bytes);
+
+            if consumed + consumed_after_period == 0 {
+                return (Err(NumberError::Invalid), rest_to_str!(bytes));
+            }
+
+            let significand = general_extract.end(bytes);
+
+            if consume!(bytes, b'p' | b'P') {
+                consume!(bytes, b'+' | b'-');
+                let consumed = consume_dec_digits!(bytes);
+
+                if consumed == 0 {
+                    return (Err(NumberError::Invalid), rest_to_str!(bytes));
+                }
+
+                let number = general_extract.end(bytes);
+
+                let kind = consume_float_suffix!(bytes);
+
+                (parse_hex_float(number, kind), rest_to_str!(bytes))
+            } else {
+                (
+                    parse_hex_float_missing_exponent(significand, None),
+                    rest_to_str!(bytes),
+                )
+            }
+        } else {
+            if consumed == 0 {
+                return (Err(NumberError::Invalid), rest_to_str!(bytes));
+            }
+
+            let significand = general_extract.end(bytes);
+            let digits = digits_extract.end(bytes);
+
+            let exp_extract = ExtractSubStr::start(input, bytes);
+
+            if consume!(bytes, b'p' | b'P') {
+                consume!(bytes, b'+' | b'-');
+                let consumed = consume_dec_digits!(bytes);
+
+                if consumed == 0 {
+                    return (Err(NumberError::Invalid), rest_to_str!(bytes));
+                }
+
+                let exponent = exp_extract.end(bytes);
+
+                let kind = consume_float_suffix!(bytes);
+
+                (
+                    parse_hex_float_missing_period(significand, exponent, kind),
+                    rest_to_str!(bytes),
+                )
+            } else {
+                let kind = consume_map!(bytes, [b'i' => IntKind::I32, b'u' => IntKind::U32]);
+
+                (parse_hex_int(digits, kind), rest_to_str!(bytes))
+            }
+        }
+    } else {
+        let is_first_zero = bytes.first() == Some(&b'0');
+
+        let consumed = consume_dec_digits!(bytes);
+
+        if consume!(bytes, b'.') {
+            let consumed_after_period = consume_dec_digits!(bytes);
+
+            if consumed + consumed_after_period == 0 {
+                return (Err(NumberError::Invalid), rest_to_str!(bytes));
+            }
+
+            if consume!(bytes, b'e' | b'E') {
+                consume!(bytes, b'+' | b'-');
+                let consumed = consume_dec_digits!(bytes);
+
+                if consumed == 0 {
+                    return (Err(NumberError::Invalid), rest_to_str!(bytes));
+                }
+            }
+
+            let number = general_extract.end(bytes);
+
+            let kind = consume_float_suffix!(bytes);
+
+            (parse_dec_float(number, kind), rest_to_str!(bytes))
+        } else {
+            if consumed == 0 {
+                return (Err(NumberError::Invalid), rest_to_str!(bytes));
+            }
+
+            if consume!(bytes, b'e' | b'E') {
+                consume!(bytes, b'+' | b'-');
+                let consumed = consume_dec_digits!(bytes);
+
+                if consumed == 0 {
+                    return (Err(NumberError::Invalid), rest_to_str!(bytes));
+                }
+
+                let number = general_extract.end(bytes);
+
+                let kind = consume_float_suffix!(bytes);
+
+                (parse_dec_float(number, kind), rest_to_str!(bytes))
+            } else {
+                // make sure the multi-digit numbers don't start with zero
+                if consumed > 1 && is_first_zero {
+                    return (Err(NumberError::Invalid), rest_to_str!(bytes));
+                }
+
+                let digits = general_extract.end(bytes);
+
+                let kind = consume_map!(bytes, [
+                    b'i' => Kind::Int(IntKind::I32),
+                    b'u' => Kind::Int(IntKind::U32),
+                    b'h' => Kind::Float(FloatKind::F16),
+                    b'f' => Kind::Float(FloatKind::F32),
+                    b'l', b'f' => Kind::Float(FloatKind::F64),
+                ]);
+
+                (parse_dec(digits, kind), rest_to_str!(bytes))
+            }
+        }
+    }
+}
+
+fn parse_hex_float_missing_exponent(
+    // format: 0[xX] ( [0-9a-fA-F]+\.[0-9a-fA-F]* | [0-9a-fA-F]*\.[0-9a-fA-F]+ )
+    significand: &str,
+    kind: Option<FloatKind>,
+) -> Result<Number, NumberError> {
+    let hexf_input = format!("{}{}", significand, "p0");
+    parse_hex_float(&hexf_input, kind)
+}
+
+fn parse_hex_float_missing_period(
+    // format: 0[xX] [0-9a-fA-F]+
+    significand: &str,
+    // format: [pP][+-]?[0-9]+
+    exponent: &str,
+    kind: Option<FloatKind>,
+) -> Result<Number, NumberError> {
+    let hexf_input = format!("{significand}.{exponent}");
+    parse_hex_float(&hexf_input, kind)
+}
+
+fn parse_hex_int(
+    // format: [0-9a-fA-F]+
+    digits: &str,
+    kind: Option<IntKind>,
+) -> Result<Number, NumberError> {
+    parse_int(digits, kind, 16)
+}
+
+fn parse_dec(
+    // format: ( [0-9] | [1-9][0-9]+ )
+    digits: &str,
+    kind: Option<Kind>,
+) -> Result<Number, NumberError> {
+    match kind {
+        None => parse_int(digits, None, 10),
+        Some(Kind::Int(kind)) => parse_int(digits, Some(kind), 10),
+        Some(Kind::Float(kind)) => parse_dec_float(digits, Some(kind)),
+    }
+}
+
+// Float parsing notes
+
+// The following chapters of IEEE 754-2019 are relevant:
+//
+// 7.4 Overflow (largest finite number is exceeded by what would have been
+//     the rounded floating-point result were the exponent range unbounded)
+//
+// 7.5 Underflow (tiny non-zero result is detected;
+//     for decimal formats tininess is detected before rounding when a non-zero result
+//     computed as though both the exponent range and the precision were unbounded
+//     would lie strictly between 2^−126)
+//
+// 7.6 Inexact (rounded result differs from what would have been computed
+//     were both exponent range and precision unbounded)
+
+// The WGSL spec requires us to error:
+//   on overflow for decimal floating point literals
+//   on overflow and inexact for hexadecimal floating point literals
+// (underflow is not mentioned)
+
+// hexf_parse errors on overflow, underflow, inexact
+// rust std lib float from str handles overflow, underflow, inexact transparently (rounds and will not error)
+
+// Therefore we only check for overflow manually for decimal floating point literals
+
+// input format: 0[xX] ( [0-9a-fA-F]+\.[0-9a-fA-F]* | [0-9a-fA-F]*\.[0-9a-fA-F]+ ) [pP][+-]?[0-9]+
+fn parse_hex_float(input: &str, kind: Option<FloatKind>) -> Result<Number, NumberError> {
+    match kind {
+        None => match hexf_parse::parse_hexf64(input, false) {
+            Ok(num) => Ok(Number::AbstractFloat(num)),
+            // can only be ParseHexfErrorKind::Inexact but we can't check since it's private
+            _ => Err(NumberError::NotRepresentable),
+        },
+        Some(FloatKind::F16) => Err(NumberError::UnimplementedF16),
+        Some(FloatKind::F32) => match hexf_parse::parse_hexf32(input, false) {
+            Ok(num) => Ok(Number::F32(num)),
+            // can only be ParseHexfErrorKind::Inexact but we can't check since it's private
+            _ => Err(NumberError::NotRepresentable),
+        },
+        Some(FloatKind::F64) => match hexf_parse::parse_hexf64(input, false) {
+            Ok(num) => Ok(Number::F64(num)),
+            // can only be ParseHexfErrorKind::Inexact but we can't check since it's private
+            _ => Err(NumberError::NotRepresentable),
+        },
+    }
+}
+
+// input format: ( [0-9]+\.[0-9]* | [0-9]*\.[0-9]+ ) ([eE][+-]?[0-9]+)?
+//             | [0-9]+ [eE][+-]?[0-9]+
+fn parse_dec_float(input: &str, kind: Option<FloatKind>) -> Result<Number, NumberError> {
+    match kind {
+        None => {
+            let num = input.parse::<f64>().unwrap(); // will never fail
+            num.is_finite()
+                .then_some(Number::AbstractFloat(num))
+                .ok_or(NumberError::NotRepresentable)
+        }
+        Some(FloatKind::F32) => {
+            let num = input.parse::<f32>().unwrap(); // will never fail
+            num.is_finite()
+                .then_some(Number::F32(num))
+                .ok_or(NumberError::NotRepresentable)
+        }
+        Some(FloatKind::F64) => {
+            let num = input.parse::<f64>().unwrap(); // will never fail
+            num.is_finite()
+                .then_some(Number::F64(num))
+                .ok_or(NumberError::NotRepresentable)
+        }
+        Some(FloatKind::F16) => Err(NumberError::UnimplementedF16),
+    }
+}
+
+fn parse_int(input: &str, kind: Option<IntKind>, radix: u32) -> Result<Number, NumberError> {
+    fn map_err(e: core::num::ParseIntError) -> NumberError {
+        match *e.kind() {
+            core::num::IntErrorKind::PosOverflow | core::num::IntErrorKind::NegOverflow => {
+                NumberError::NotRepresentable
+            }
+            _ => unreachable!(),
+        }
+    }
+    match kind {
+        None => match i64::from_str_radix(input, radix) {
+            Ok(num) => Ok(Number::AbstractInt(num)),
+            Err(e) => Err(map_err(e)),
+        },
+        Some(IntKind::I32) => match i32::from_str_radix(input, radix) {
+            Ok(num) => Ok(Number::I32(num)),
+            Err(e) => Err(map_err(e)),
+        },
+        Some(IntKind::U32) => match u32::from_str_radix(input, radix) {
+            Ok(num) => Ok(Number::U32(num)),
+            Err(e) => Err(map_err(e)),
+        },
+    }
+}
diff --git a/third_party/rust/naga/src/front/wgsl/tests.rs b/third_party/rust/naga/src/front/wgsl/tests.rs
new file mode 100644
index 0000000000..eb2f8a2eb3
--- /dev/null
+++ b/third_party/rust/naga/src/front/wgsl/tests.rs
@@ -0,0 +1,637 @@
+use super::parse_str;
+
+#[test]
+fn parse_comment() {
+    parse_str(
+        "//
+        ////
+        ///////////////////////////////////////////////////////// asda
+        //////////////////// dad ////////// /
+        /////////////////////////////////////////////////////////////////////////////////////////////////////
+        //
+    ",
+    )
+    .unwrap();
+}
+
+#[test]
+fn parse_types() {
+    parse_str("const a : i32 = 2;").unwrap();
+    assert!(parse_str("const a : x32 = 2;").is_err());
+    parse_str("var t: texture_2d<f32>;").unwrap();
+    parse_str("var t: texture_cube_array<i32>;").unwrap();
+    parse_str("var t: texture_multisampled_2d<u32>;").unwrap();
+    parse_str("var t: texture_storage_1d<rgba8uint,write>;").unwrap();
+    parse_str("var t: texture_storage_3d<r32float,read>;").unwrap();
+}
+
+#[test]
+fn parse_type_inference() {
+    parse_str(
+        "
+        fn foo() {
+            let a = 2u;
+            let b: u32 = a;
+            var x = 3.;
+            var y = vec2<f32>(1, 2);
+        }",
+    )
+    .unwrap();
+    assert!(parse_str(
+        "
+        fn foo() { let c : i32 = 2.0; }",
+    )
+    .is_err());
+}
+
+#[test]
+fn parse_type_cast() {
+    parse_str(
+        "
+        const a : i32 = 2;
+        fn main() {
+            var x: f32 = f32(a);
+            x = f32(i32(a + 1) / 2);
+        }
+    ",
+    )
+    .unwrap();
+    parse_str(
+        "
+        fn main() {
+            let x: vec2<f32> = vec2<f32>(1.0, 2.0);
+            let y: vec2<u32> = vec2<u32>(x);
+        }
+    ",
+    )
+    .unwrap();
+    parse_str(
+        "
+        fn main() {
+            let x: vec2<f32> = vec2<f32>(0.0);
+        }
+    ",
+    )
+    .unwrap();
+    assert!(parse_str(
+        "
+        fn main() {
+            let x: vec2<f32> = vec2<f32>(0i, 0i);
+        }
+    ",
+    )
+    .is_err());
+}
+
+#[test]
+fn parse_struct() {
+    parse_str(
+        "
+        struct Foo { x: i32 }
+        struct Bar {
+            @size(16) x: vec2<i32>,
+            @align(16) y: f32,
+            @size(32) @align(128) z: vec3<f32>,
+        };
+        struct Empty {}
+        var<storage,read_write> s: Foo;
+    ",
+    )
+    .unwrap();
+}
+
+#[test]
+fn parse_standard_fun() {
+    parse_str(
+        "
+        fn main() {
+            var x: i32 = min(max(1, 2), 3);
+        }
+    ",
+    )
+    .unwrap();
+}
+
+#[test]
+fn parse_statement() {
+    parse_str(
+        "
+        fn main() {
+            ;
+            {}
+            {;}
+        }
+    ",
+    )
+    .unwrap();
+
+    parse_str(
+        "
+        fn foo() {}
+        fn bar() { foo(); }
+    ",
+    )
+    .unwrap();
+}
+
+#[test]
+fn parse_if() {
+    parse_str(
+        "
+        fn main() {
+            if true {
+                discard;
+            } else {}
+            if 0 != 1 {}
+            if false {
+                return;
+            } else if true {
+                return;
+            } else {}
+        }
+    ",
+    )
+    .unwrap();
+}
+
+#[test]
+fn parse_parentheses_if() {
+    parse_str(
+        "
+        fn main() {
+            if (true) {
+                discard;
+            } else {}
+            if (0 != 1) {}
+            if (false) {
+                return;
+            } else if (true) {
+                return;
+            } else {}
+        }
+    ",
+    )
+    .unwrap();
+}
+
+#[test]
+fn parse_loop() {
+    parse_str(
+        "
+        fn main() {
+            var i: i32 = 0;
+            loop {
+                if i == 1 { break; }
+                continuing { i = 1; }
+            }
+            loop {
+                if i == 0 { continue; }
+                break;
+            }
+        }
+    ",
+    )
+    .unwrap();
+    parse_str(
+        "
+        fn main() {
+            var found: bool = false;
+            var i: i32 = 0;
+            while !found {
+                if i == 10 {
+                    found = true;
+                }
+
+                i = i + 1;
+            }
+        }
+    ",
+    )
+    .unwrap();
+    parse_str(
+        "
+        fn main() {
+            while true {
+                break;
+            }
+        }
+    ",
+    )
+    .unwrap();
+    parse_str(
+        "
+        fn main() {
+            var a: i32 = 0;
+            for(var i: i32 = 0; i < 4; i = i + 1) {
+                a = a + 2;
+            }
+        }
+    ",
+    )
+    .unwrap();
+    parse_str(
+        "
+        fn main() {
+            for(;;) {
+                break;
+            }
+        }
+    ",
+    )
+    .unwrap();
+}
+
+#[test]
+fn parse_switch() {
+    parse_str(
+        "
+        fn main() {
+            var pos: f32;
+            switch (3) {
+                case 0, 1: { pos = 0.0; }
+                case 2: { pos = 1.0; }
+                default: { pos = 3.0; }
+            }
+        }
+    ",
+    )
+    .unwrap();
+}
+
+#[test]
+fn parse_switch_optional_colon_in_case() {
+    parse_str(
+        "
+        fn main() {
+            var pos: f32;
+            switch (3) {
+                case 0, 1 { pos = 0.0; }
+                case 2 { pos = 1.0; }
+                default { pos = 3.0; }
+            }
+        }
+    ",
+    )
+    .unwrap();
+}
+
+#[test]
+fn parse_switch_default_in_case() {
+    parse_str(
+        "
+        fn main() {
+            var pos: f32;
+            switch (3) {
+                case 0, 1: { pos = 0.0; }
+                case 2: {}
+                case default, 3: { pos = 3.0; }
+            }
+        }
+    ",
+    )
+    .unwrap();
+}
+
+#[test]
+fn parse_parentheses_switch() {
+    parse_str(
+        "
+        fn main() {
+            var pos: f32;
+            switch pos > 1.0 {
+                default: { pos = 3.0; }
+            }
+        }
+    ",
+    )
+    .unwrap();
+}
+
+#[test]
+fn parse_texture_load() {
+    parse_str(
+        "
+        var t: texture_3d<u32>;
+        fn foo() {
+            let r: vec4<u32> = textureLoad(t, vec3<u32>(0u, 1u, 2u), 1);
+        }
+    ",
+    )
+    .unwrap();
+    parse_str(
+        "
+        var t: texture_multisampled_2d_array<i32>;
+        fn foo() {
+            let r: vec4<i32> = textureLoad(t, vec2<i32>(10, 20), 2, 3);
+        }
+    ",
+    )
+    .unwrap();
+    parse_str(
+        "
+        var t: texture_storage_1d_array<r32float,read>;
+        fn foo() {
+            let r: vec4<f32> = textureLoad(t, 10, 2);
+        }
+    ",
+    )
+    .unwrap();
+}
+
+#[test]
+fn parse_texture_store() {
+    parse_str(
+        "
+        var t: texture_storage_2d<rgba8unorm,write>;
+        fn foo() {
+            textureStore(t, vec2<i32>(10, 20), vec4<f32>(0.0, 1.0, 2.0, 3.0));
+        }
+    ",
+    )
+    .unwrap();
+}
+
+#[test]
+fn parse_texture_query() {
+    parse_str(
+        "
+        var t: texture_multisampled_2d_array<f32>;
+        fn foo() {
+            var dim: vec2<u32> = textureDimensions(t);
+            dim = textureDimensions(t, 0);
+            let layers: u32 = textureNumLayers(t);
+            let samples: u32 = textureNumSamples(t);
+        }
+    ",
+    )
+    .unwrap();
+}
+
+#[test]
+fn parse_postfix() {
+    parse_str(
+        "fn foo() {
+        let x: f32 = vec4<f32>(1.0, 2.0, 3.0, 4.0).xyz.rgbr.aaaa.wz.g;
+        let y: f32 = fract(vec2<f32>(0.5, x)).x;
+    }",
+    )
+    .unwrap();
+}
+
+#[test]
+fn parse_expressions() {
+    parse_str("fn foo() {
+        let x: f32 = select(0.0, 1.0, true);
+        let y: vec2<f32> = select(vec2<f32>(1.0, 1.0), vec2<f32>(x, x), vec2<bool>(x < 0.5, x > 0.5));
+        let z: bool = !(0.0 == 1.0);
+    }").unwrap();
+}
+
+#[test]
+fn binary_expression_mixed_scalar_and_vector_operands() {
+    for (operand, expect_splat) in [
+        ('<', false),
+        ('>', false),
+        ('&', false),
+        ('|', false),
+        ('+', true),
+        ('-', true),
+        ('*', false),
+        ('/', true),
+        ('%', true),
+    ] {
+        let module = parse_str(&format!(
+            "
+            @fragment
+            fn main(@location(0) some_vec: vec3<f32>) -> @location(0) vec4<f32> {{
+                if (all(1.0 {operand} some_vec)) {{
+                    return vec4(0.0);
+                }}
+                return vec4(1.0);
+            }}
+            "
+        ))
+        .unwrap();
+
+        let expressions = &&module.entry_points[0].function.expressions;
+
+        let found_expressions = expressions
+            .iter()
+            .filter(|&(_, e)| {
+                if let crate::Expression::Binary { left, .. } = *e {
+                    matches!(
+                        (expect_splat, &expressions[left]),
+                        (false, &crate::Expression::Literal(crate::Literal::F32(..)))
+                            | (true, &crate::Expression::Splat { .. })
+                    )
+                } else {
+                    false
+                }
+            })
+            .count();
+
+        assert_eq!(
+            found_expressions,
+            1,
+            "expected `{operand}` expression {} splat",
+            if expect_splat { "with" } else { "without" }
+        );
+    }
+
+    let module = parse_str(
+        "@fragment
+        fn main(mat: mat3x3<f32>) {
+            let vec = vec3<f32>(1.0, 1.0, 1.0);
+            let result = mat / vec;
+        }",
+    )
+    .unwrap();
+    let expressions = &&module.entry_points[0].function.expressions;
+    let found_splat = expressions.iter().any(|(_, e)| {
+        if let crate::Expression::Binary { left, .. } = *e {
+            matches!(&expressions[left], &crate::Expression::Splat { .. })
+        } else {
+            false
+        }
+    });
+    assert!(!found_splat, "'mat / vec' should not be splatted");
+}
+
+#[test]
+fn parse_pointers() {
+    parse_str(
+        "fn foo(a: ptr<private, f32>) -> f32 { return *a; }
+    fn bar() {
+        var x: f32 = 1.0;
+        let px = &x;
+        let py = foo(px);
+    }",
+    )
+    .unwrap();
+}
+
+#[test]
+fn parse_struct_instantiation() {
+    parse_str(
+        "
+    struct Foo {
+        a: f32,
+        b: vec3<f32>,
+    }
+
+    @fragment
+    fn fs_main() {
+        var foo: Foo = Foo(0.0, vec3<f32>(0.0, 1.0, 42.0));
+    }
+    ",
+    )
+    .unwrap();
+}
+
+#[test]
+fn parse_array_length() {
+    parse_str(
+        "
+        struct Foo {
+            data: array<u32>
+        } // this is used as both input and output for convenience
+
+        @group(0) @binding(0)
+        var<storage> foo: Foo;
+
+        @group(0) @binding(1)
+        var<storage> bar: array<u32>;
+
+        fn baz() {
+            var x: u32 = arrayLength(foo.data);
+            var y: u32 = arrayLength(bar);
+        }
+        ",
+    )
+    .unwrap();
+}
+
+#[test]
+fn parse_storage_buffers() {
+    parse_str(
+        "
+        @group(0) @binding(0)
+        var<storage> foo: array<u32>;
+        ",
+    )
+    .unwrap();
+    parse_str(
+        "
+        @group(0) @binding(0)
+        var<storage,read> foo: array<u32>;
+        ",
+    )
+    .unwrap();
+    parse_str(
+        "
+        @group(0) @binding(0)
+        var<storage,write> foo: array<u32>;
+        ",
+    )
+    .unwrap();
+    parse_str(
+        "
+        @group(0) @binding(0)
+        var<storage,read_write> foo: array<u32>;
+        ",
+    )
+    .unwrap();
+}
+
+#[test]
+fn parse_alias() {
+    parse_str(
+        "
+        alias Vec4 = vec4<f32>;
+        ",
+    )
+    .unwrap();
+}
+
+#[test]
+fn parse_texture_load_store_expecting_four_args() {
+    for (func, texture) in [
+        (
+            "textureStore",
+            "texture_storage_2d_array<rg11b10float, write>",
+        ),
+        ("textureLoad", "texture_2d_array<i32>"),
+    ] {
+        let error = parse_str(&format!(
+            "
+            @group(0) @binding(0) var tex_los_res: {texture};
+            @compute
+            @workgroup_size(1)
+            fn main(@builtin(global_invocation_id) id: vec3<u32>) {{
+                var color = vec4(1, 1, 1, 1);
+                {func}(tex_los_res, id, color);
+            }}
+            "
+        ))
+        .unwrap_err();
+        assert_eq!(
+            error.message(),
+            "wrong number of arguments: expected 4, found 3"
+        );
+    }
+}
+
+#[test]
+fn parse_repeated_attributes() {
+    use crate::{
+        front::wgsl::{error::Error, Frontend},
+        Span,
+    };
+
+    let template_vs = "@vertex fn vs() -> __REPLACE__ vec4<f32> { return vec4<f32>(0.0); }";
+    let template_struct = "struct A { __REPLACE__ data: vec3<f32> }";
+    let template_resource = "__REPLACE__ var tex_los_res: texture_2d_array<i32>;";
+    let template_stage = "__REPLACE__ fn vs() -> vec4<f32> { return vec4<f32>(0.0); }";
+    for (attribute, template) in [
+        ("align(16)", template_struct),
+        ("binding(0)", template_resource),
+        ("builtin(position)", template_vs),
+        ("compute", template_stage),
+        ("fragment", template_stage),
+        ("group(0)", template_resource),
+        ("interpolate(flat)", template_vs),
+        ("invariant", template_vs),
+        ("location(0)", template_vs),
+        ("size(16)", template_struct),
+        ("vertex", template_stage),
+        ("early_depth_test(less_equal)", template_resource),
+        ("workgroup_size(1)", template_stage),
+    ] {
+        let shader = template.replace("__REPLACE__", &format!("@{attribute} @{attribute}"));
+        let name_length = attribute.rfind('(').unwrap_or(attribute.len()) as u32;
+        let span_start = shader.rfind(attribute).unwrap() as u32;
+        let span_end = span_start + name_length;
+        let expected_span = Span::new(span_start, span_end);
+
+        let result = Frontend::new().inner(&shader);
+        assert!(matches!(
+            result.unwrap_err(),
+            Error::RepeatedAttribute(span) if span == expected_span
+        ));
+    }
+}
+
+#[test]
+fn parse_missing_workgroup_size() {
+    use crate::{
+        front::wgsl::{error::Error, Frontend},
+        Span,
+    };
+
+    let shader = "@compute fn vs() -> vec4<f32> { return vec4<f32>(0.0); }";
+    let result = Frontend::new().inner(shader);
+    assert!(matches!(
+        result.unwrap_err(),
+        Error::MissingWorkgroupSize(span) if span == Span::new(1, 8)
+    ));
+}
diff --git a/third_party/rust/naga/src/front/wgsl/to_wgsl.rs b/third_party/rust/naga/src/front/wgsl/to_wgsl.rs
new file mode 100644
index 0000000000..c8331ace09
--- /dev/null
+++ b/third_party/rust/naga/src/front/wgsl/to_wgsl.rs
@@ -0,0 +1,283 @@
+//! Producing the WGSL forms of types, for use in error messages.
+
+use crate::proc::GlobalCtx;
+use crate::Handle;
+
+impl crate::proc::TypeResolution {
+    pub fn to_wgsl(&self, gctx: &GlobalCtx) -> String {
+        match *self {
+            crate::proc::TypeResolution::Handle(handle) => handle.to_wgsl(gctx),
+            crate::proc::TypeResolution::Value(ref inner) => inner.to_wgsl(gctx),
+        }
+    }
+}
+
+impl Handle<crate::Type> {
+    /// Formats the type as it is written in wgsl.
+    ///
+    /// For example `vec3<f32>`.
+    pub fn to_wgsl(self, gctx: &GlobalCtx) -> String {
+        let ty = &gctx.types[self];
+        match ty.name {
+            Some(ref name) => name.clone(),
+            None => ty.inner.to_wgsl(gctx),
+        }
+    }
+}
+
+impl crate::TypeInner {
+    /// Formats the type as it is written in wgsl.
+    ///
+    /// For example `vec3<f32>`.
+    ///
+    /// Note: `TypeInner::Struct` doesn't include the name of the
+    /// struct type. Therefore this method will simply return "struct"
+    /// for them.
+    pub fn to_wgsl(&self, gctx: &GlobalCtx) -> String {
+        use crate::TypeInner as Ti;
+
+        match *self {
+            Ti::Scalar(scalar) => scalar.to_wgsl(),
+            Ti::Vector { size, scalar } => {
+                format!("vec{}<{}>", size as u32, scalar.to_wgsl())
+            }
+            Ti::Matrix {
+                columns,
+                rows,
+                scalar,
+            } => {
+                format!(
+                    "mat{}x{}<{}>",
+                    columns as u32,
+                    rows as u32,
+                    scalar.to_wgsl(),
+                )
+            }
+            Ti::Atomic(scalar) => {
+                format!("atomic<{}>", scalar.to_wgsl())
+            }
+            Ti::Pointer { base, .. } => {
+                let name = base.to_wgsl(gctx);
+                format!("ptr<{name}>")
+            }
+            Ti::ValuePointer { scalar, .. } => {
+                format!("ptr<{}>", scalar.to_wgsl())
+            }
+            Ti::Array { base, size, .. } => {
+                let base = base.to_wgsl(gctx);
+                match size {
+                    crate::ArraySize::Constant(size) => format!("array<{base}, {size}>"),
+                    crate::ArraySize::Dynamic => format!("array<{base}>"),
+                }
+            }
+            Ti::Struct { .. } => {
+                // TODO: Actually output the struct?
+                "struct".to_string()
+            }
+            Ti::Image {
+                dim,
+                arrayed,
+                class,
+            } => {
+                let dim_suffix = match dim {
+                    crate::ImageDimension::D1 => "_1d",
+                    crate::ImageDimension::D2 => "_2d",
+                    crate::ImageDimension::D3 => "_3d",
+                    crate::ImageDimension::Cube => "_cube",
+                };
+                let array_suffix = if arrayed { "_array" } else { "" };
+
+                let class_suffix = match class {
+                    crate::ImageClass::Sampled { multi: true, .. } => "_multisampled",
+                    crate::ImageClass::Depth { multi: false } => "_depth",
+                    crate::ImageClass::Depth { multi: true } => "_depth_multisampled",
+                    crate::ImageClass::Sampled { multi: false, .. }
+                    | crate::ImageClass::Storage { .. } => "",
+                };
+
+                let type_in_brackets = match class {
+                    crate::ImageClass::Sampled { kind, .. } => {
+                        // Note: The only valid widths are 4 bytes wide.
+                        // The lexer has already verified this, so we can safely assume it here.
+                        // https://gpuweb.github.io/gpuweb/wgsl/#sampled-texture-type
+                        let element_type = crate::Scalar { kind, width: 4 }.to_wgsl();
+                        format!("<{element_type}>")
+                    }
+                    crate::ImageClass::Depth { multi: _ } => String::new(),
+                    crate::ImageClass::Storage { format, access } => {
+                        if access.contains(crate::StorageAccess::STORE) {
+                            format!("<{},write>", format.to_wgsl())
+                        } else {
+                            format!("<{}>", format.to_wgsl())
+                        }
+                    }
+                };
+
+                format!("texture{class_suffix}{dim_suffix}{array_suffix}{type_in_brackets}")
+            }
+            Ti::Sampler { .. } => "sampler".to_string(),
+            Ti::AccelerationStructure => "acceleration_structure".to_string(),
+            Ti::RayQuery => "ray_query".to_string(),
+            Ti::BindingArray { base, size, .. } => {
+                let member_type = &gctx.types[base];
+                let base = member_type.name.as_deref().unwrap_or("unknown");
+                match size {
+                    crate::ArraySize::Constant(size) => format!("binding_array<{base}, {size}>"),
+                    crate::ArraySize::Dynamic => format!("binding_array<{base}>"),
+                }
+            }
+        }
+    }
+}
+
+impl crate::Scalar {
+    /// Format a scalar kind+width as a type is written in wgsl.
+    ///
+    /// Examples: `f32`, `u64`, `bool`.
+    pub fn to_wgsl(self) -> String {
+        let prefix = match self.kind {
+            crate::ScalarKind::Sint => "i",
+            crate::ScalarKind::Uint => "u",
+            crate::ScalarKind::Float => "f",
+            crate::ScalarKind::Bool => return "bool".to_string(),
+            crate::ScalarKind::AbstractInt => return "{AbstractInt}".to_string(),
+            crate::ScalarKind::AbstractFloat => return "{AbstractFloat}".to_string(),
+        };
+        format!("{}{}", prefix, self.width * 8)
+    }
+}
+
+impl crate::StorageFormat {
+    pub const fn to_wgsl(self) -> &'static str {
+        use crate::StorageFormat as Sf;
+        match self {
+            Sf::R8Unorm => "r8unorm",
+            Sf::R8Snorm => "r8snorm",
+            Sf::R8Uint => "r8uint",
+            Sf::R8Sint => "r8sint",
+            Sf::R16Uint => "r16uint",
+            Sf::R16Sint => "r16sint",
+            Sf::R16Float => "r16float",
+            Sf::Rg8Unorm => "rg8unorm",
+            Sf::Rg8Snorm => "rg8snorm",
+            Sf::Rg8Uint => "rg8uint",
+            Sf::Rg8Sint => "rg8sint",
+            Sf::R32Uint => "r32uint",
+            Sf::R32Sint => "r32sint",
+            Sf::R32Float => "r32float",
+            Sf::Rg16Uint => "rg16uint",
+            Sf::Rg16Sint => "rg16sint",
+            Sf::Rg16Float => "rg16float",
+            Sf::Rgba8Unorm => "rgba8unorm",
+            Sf::Rgba8Snorm => "rgba8snorm",
+            Sf::Rgba8Uint => "rgba8uint",
+            Sf::Rgba8Sint => "rgba8sint",
+            Sf::Bgra8Unorm => "bgra8unorm",
+            Sf::Rgb10a2Uint => "rgb10a2uint",
+            Sf::Rgb10a2Unorm => "rgb10a2unorm",
+            Sf::Rg11b10Float => "rg11b10float",
+            Sf::Rg32Uint => "rg32uint",
+            Sf::Rg32Sint => "rg32sint",
+            Sf::Rg32Float => "rg32float",
+            Sf::Rgba16Uint => "rgba16uint",
+            Sf::Rgba16Sint => "rgba16sint",
+            Sf::Rgba16Float => "rgba16float",
+            Sf::Rgba32Uint => "rgba32uint",
+            Sf::Rgba32Sint => "rgba32sint",
+            Sf::Rgba32Float => "rgba32float",
+            Sf::R16Unorm => "r16unorm",
+            Sf::R16Snorm => "r16snorm",
+            Sf::Rg16Unorm => "rg16unorm",
+            Sf::Rg16Snorm => "rg16snorm",
+            Sf::Rgba16Unorm => "rgba16unorm",
+            Sf::Rgba16Snorm => "rgba16snorm",
+        }
+    }
+}
+
+mod tests {
+    #[test]
+    fn to_wgsl() {
+        use std::num::NonZeroU32;
+
+        let mut types = crate::UniqueArena::new();
+
+        let mytype1 = types.insert(
+            crate::Type {
+                name: Some("MyType1".to_string()),
+                inner: crate::TypeInner::Struct {
+                    members: vec![],
+                    span: 0,
+                },
+            },
+            Default::default(),
+        );
+        let mytype2 = types.insert(
+            crate::Type {
+                name: Some("MyType2".to_string()),
+                inner: crate::TypeInner::Struct {
+                    members: vec![],
+                    span: 0,
+                },
+            },
+            Default::default(),
+        );
+
+        let gctx = crate::proc::GlobalCtx {
+            types: &types,
+            constants: &crate::Arena::new(),
+            const_expressions: &crate::Arena::new(),
+        };
+        let array = crate::TypeInner::Array {
+            base: mytype1,
+            stride: 4,
+            size: crate::ArraySize::Constant(unsafe { NonZeroU32::new_unchecked(32) }),
+        };
+        assert_eq!(array.to_wgsl(&gctx), "array<MyType1, 32>");
+
+        let mat = crate::TypeInner::Matrix {
+            rows: crate::VectorSize::Quad,
+            columns: crate::VectorSize::Bi,
+            scalar: crate::Scalar::F64,
+        };
+        assert_eq!(mat.to_wgsl(&gctx), "mat2x4<f64>");
+
+        let ptr = crate::TypeInner::Pointer {
+            base: mytype2,
+            space: crate::AddressSpace::Storage {
+                access: crate::StorageAccess::default(),
+            },
+        };
+        assert_eq!(ptr.to_wgsl(&gctx), "ptr<MyType2>");
+
+        let img1 = crate::TypeInner::Image {
+            dim: crate::ImageDimension::D2,
+            arrayed: false,
+            class: crate::ImageClass::Sampled {
+                kind: crate::ScalarKind::Float,
+                multi: true,
+            },
+        };
+        assert_eq!(img1.to_wgsl(&gctx), "texture_multisampled_2d<f32>");
+
+        let img2 = crate::TypeInner::Image {
+            dim: crate::ImageDimension::Cube,
+            arrayed: true,
+            class: crate::ImageClass::Depth { multi: false },
+        };
+        assert_eq!(img2.to_wgsl(&gctx), "texture_depth_cube_array");
+
+        let img3 = crate::TypeInner::Image {
+            dim: crate::ImageDimension::D2,
+            arrayed: false,
+            class: crate::ImageClass::Depth { multi: true },
+        };
+        assert_eq!(img3.to_wgsl(&gctx), "texture_depth_multisampled_2d");
+
+        let array = crate::TypeInner::BindingArray {
+            base: mytype1,
+            size: crate::ArraySize::Constant(unsafe { NonZeroU32::new_unchecked(32) }),
+        };
+        assert_eq!(array.to_wgsl(&gctx), "binding_array<MyType1, 32>");
+    }
+}
diff --git a/third_party/rust/naga/src/keywords/mod.rs b/third_party/rust/naga/src/keywords/mod.rs
new file mode 100644
index 0000000000..d54a1704f7
--- /dev/null
+++ b/third_party/rust/naga/src/keywords/mod.rs
@@ -0,0 +1,6 @@
+/*!
+Lists of reserved keywords for each shading language with a [frontend][crate::front] or [backend][crate::back].
+*/
+
+#[cfg(any(feature = "wgsl-in", feature = "wgsl-out"))]
+pub mod wgsl;
diff --git a/third_party/rust/naga/src/keywords/wgsl.rs b/third_party/rust/naga/src/keywords/wgsl.rs
new file mode 100644
index 0000000000..7b47a13128
--- /dev/null
+++ b/third_party/rust/naga/src/keywords/wgsl.rs
@@ -0,0 +1,229 @@
+/*!
+Keywords for [WGSL][wgsl] (WebGPU Shading Language).
+
+[wgsl]: https://gpuweb.github.io/gpuweb/wgsl.html
+*/
+
+// https://gpuweb.github.io/gpuweb/wgsl/#keyword-summary
+// last sync: https://github.com/gpuweb/gpuweb/blob/39f2321f547c8f0b7f473cf1d47fba30b1691303/wgsl/index.bs
+pub const RESERVED: &[&str] = &[
+    // Type-defining Keywords
+    "array",
+    "atomic",
+    "bool",
+    "f32",
+    "f16",
+    "i32",
+    "mat2x2",
+    "mat2x3",
+    "mat2x4",
+    "mat3x2",
+    "mat3x3",
+    "mat3x4",
+    "mat4x2",
+    "mat4x3",
+    "mat4x4",
+    "ptr",
+    "sampler",
+    "sampler_comparison",
+    "texture_1d",
+    "texture_2d",
+    "texture_2d_array",
+    "texture_3d",
+    "texture_cube",
+    "texture_cube_array",
+    "texture_multisampled_2d",
+    "texture_storage_1d",
+    "texture_storage_2d",
+    "texture_storage_2d_array",
+    "texture_storage_3d",
+    "texture_depth_2d",
+    "texture_depth_2d_array",
+    "texture_depth_cube",
+    "texture_depth_cube_array",
+    "texture_depth_multisampled_2d",
+    "u32",
+    "vec2",
+    "vec3",
+    "vec4",
+    // Other Keywords
+    "alias",
+    "bitcast",
+    "break",
+    "case",
+    "const",
+    "continue",
+    "continuing",
+    "default",
+    "discard",
+    "else",
+    "enable",
+    "false",
+    "fn",
+    "for",
+    "if",
+    "let",
+    "loop",
+    "override",
+    "return",
+    "static_assert",
+    "struct",
+    "switch",
+    "true",
+    "type",
+    "var",
+    "while",
+    // Reserved Words
+    "CompileShader",
+    "ComputeShader",
+    "DomainShader",
+    "GeometryShader",
+    "Hullshader",
+    "NULL",
+    "Self",
+    "abstract",
+    "active",
+    "alignas",
+    "alignof",
+    "as",
+    "asm",
+    "asm_fragment",
+    "async",
+    "attribute",
+    "auto",
+    "await",
+    "become",
+    "binding_array",
+    "cast",
+    "catch",
+    "class",
+    "co_await",
+    "co_return",
+    "co_yield",
+    "coherent",
+    "column_major",
+    "common",
+    "compile",
+    "compile_fragment",
+    "concept",
+    "const_cast",
+    "consteval",
+    "constexpr",
+    "constinit",
+    "crate",
+    "debugger",
+    "decltype",
+    "delete",
+    "demote",
+    "demote_to_helper",
+    "do",
+    "dynamic_cast",
+    "enum",
+    "explicit",
+    "export",
+    "extends",
+    "extern",
+    "external",
+    "fallthrough",
+    "filter",
+    "final",
+    "finally",
+    "friend",
+    "from",
+    "fxgroup",
+    "get",
+    "goto",
+    "groupshared",
+    "handle",
+    "highp",
+    "impl",
+    "implements",
+    "import",
+    "inline",
+    "inout",
+    "instanceof",
+    "interface",
+    "layout",
+    "lowp",
+    "macro",
+    "macro_rules",
+    "match",
+    "mediump",
+    "meta",
+    "mod",
+    "module",
+    "move",
+    "mut",
+    "mutable",
+    "namespace",
+    "new",
+    "nil",
+    "noexcept",
+    "noinline",
+    "nointerpolation",
+    "noperspective",
+    "null",
+    "nullptr",
+    "of",
+    "operator",
+    "package",
+    "packoffset",
+    "partition",
+    "pass",
+    "patch",
+    "pixelfragment",
+    "precise",
+    "precision",
+    "premerge",
+    "priv",
+    "protected",
+    "pub",
+    "public",
+    "readonly",
+    "ref",
+    "regardless",
+    "register",
+    "reinterpret_cast",
+    "requires",
+    "resource",
+    "restrict",
+    "self",
+    "set",
+    "shared",
+    "signed",
+    "sizeof",
+    "smooth",
+    "snorm",
+    "static",
+    "static_assert",
+    "static_cast",
+    "std",
+    "subroutine",
+    "super",
+    "target",
+    "template",
+    "this",
+    "thread_local",
+    "throw",
+    "trait",
+    "try",
+    "typedef",
+    "typeid",
+    "typename",
+    "typeof",
+    "union",
+    "unless",
+    "unorm",
+    "unsafe",
+    "unsized",
+    "use",
+    "using",
+    "varying",
+    "virtual",
+    "volatile",
+    "wgsl",
+    "where",
+    "with",
+    "writeonly",
+    "yield",
+];
diff --git a/third_party/rust/naga/src/lib.rs b/third_party/rust/naga/src/lib.rs
new file mode 100644
index 0000000000..d6b9c6a7f4
--- /dev/null
+++ b/third_party/rust/naga/src/lib.rs
@@ -0,0 +1,2072 @@
+/*! Universal shader translator.
+
+The central structure of the crate is [`Module`]. A `Module` contains:
+
+- [`Function`]s, which have arguments, a return type, local variables, and a body,
+
+- [`EntryPoint`]s, which are specialized functions that can serve as the entry
+  point for pipeline stages like vertex shading or fragment shading,
+
+- [`Constant`]s and [`GlobalVariable`]s used by `EntryPoint`s and `Function`s, and
+
+- [`Type`]s used by the above.
+
+The body of an `EntryPoint` or `Function` is represented using two types:
+
+- An [`Expression`] produces a value, but has no side effects or control flow.
+  `Expressions` include variable references, unary and binary operators, and so
+  on.
+
+- A [`Statement`] can have side effects and structured control flow.
+  `Statement`s do not produce a value, other than by storing one in some
+  designated place. `Statements` include blocks, conditionals, and loops, but also
+  operations that have side effects, like stores and function calls.
+
+`Statement`s form a tree, with pointers into the DAG of `Expression`s.
+
+Restricting side effects to statements simplifies analysis and code generation.
+A Naga backend can generate code to evaluate an `Expression` however and
+whenever it pleases, as long as it is certain to observe the side effects of all
+previously executed `Statement`s.
+
+Many `Statement` variants use the [`Block`] type, which is `Vec<Statement>`,
+with optional span info, representing a series of statements executed in order. The body of an
+`EntryPoint`s or `Function` is a `Block`, and `Statement` has a
+[`Block`][Statement::Block] variant.
+
+If the `clone` feature is enabled, [`Arena`], [`UniqueArena`], [`Type`], [`TypeInner`],
+[`Constant`], [`Function`], [`EntryPoint`] and [`Module`] can be cloned.
+
+## Arenas
+
+To improve translator performance and reduce memory usage, most structures are
+stored in an [`Arena`]. An `Arena<T>` stores a series of `T` values, indexed by
+[`Handle<T>`](Handle) values, which are just wrappers around integer indexes.
+For example, a `Function`'s expressions are stored in an `Arena<Expression>`,
+and compound expressions refer to their sub-expressions via `Handle<Expression>`
+values. (When examining the serialized form of a `Module`, note that the first
+element of an `Arena` has an index of 1, not 0.)
+
+A [`UniqueArena`] is just like an `Arena`, except that it stores only a single
+instance of each value. The value type must implement `Eq` and `Hash`. Like an
+`Arena`, inserting a value into a `UniqueArena` returns a `Handle` which can be
+used to efficiently access the value, without a hash lookup. Inserting a value
+multiple times returns the same `Handle`.
+
+If the `span` feature is enabled, both `Arena` and `UniqueArena` can associate a
+source code span with each element.
+
+## Function Calls
+
+Naga's representation of function calls is unusual. Most languages treat
+function calls as expressions, but because calls may have side effects, Naga
+represents them as a kind of statement, [`Statement::Call`]. If the function
+returns a value, a call statement designates a particular [`Expression::CallResult`]
+expression to represent its return value, for use by subsequent statements and
+expressions.
+
+## `Expression` evaluation time
+
+It is essential to know when an [`Expression`] should be evaluated, because its
+value may depend on previous [`Statement`]s' effects. But whereas the order of
+execution for a tree of `Statement`s is apparent from its structure, it is not
+so clear for `Expressions`, since an expression may be referred to by any number
+of `Statement`s and other `Expression`s.
+
+Naga's rules for when `Expression`s are evaluated are as follows:
+
+-   [`Literal`], [`Constant`], and [`ZeroValue`] expressions are
+    considered to be implicitly evaluated before execution begins.
+
+-   [`FunctionArgument`] and [`LocalVariable`] expressions are considered
+    implicitly evaluated upon entry to the function to which they belong.
+    Function arguments cannot be assigned to, and `LocalVariable` expressions
+    produce a *pointer to* the variable's value (for use with [`Load`] and
+    [`Store`]). Neither varies while the function executes, so it suffices to
+    consider these expressions evaluated once on entry.
+
+-   Similarly, [`GlobalVariable`] expressions are considered implicitly
+    evaluated before execution begins, since their value does not change while
+    code executes, for one of two reasons:
+
+    -   Most `GlobalVariable` expressions produce a pointer to the variable's
+        value, for use with [`Load`] and [`Store`], as `LocalVariable`
+        expressions do. Although the variable's value may change, its address
+        does not.
+
+    -   A `GlobalVariable` expression referring to a global in the
+        [`AddressSpace::Handle`] address space produces the value directly, not
+        a pointer. Such global variables hold opaque types like shaders or
+        images, and cannot be assigned to.
+
+-   A [`CallResult`] expression that is the `result` of a [`Statement::Call`],
+    representing the call's return value, is evaluated when the `Call` statement
+    is executed.
+
+-   Similarly, an [`AtomicResult`] expression that is the `result` of an
+    [`Atomic`] statement, representing the result of the atomic operation, is
+    evaluated when the `Atomic` statement is executed.
+
+-   A [`RayQueryProceedResult`] expression, which is a boolean
+    indicating if the ray query is finished, is evaluated when the
+    [`RayQuery`] statement whose [`Proceed::result`] points to it is
+    executed.
+
+-   All other expressions are evaluated when the (unique) [`Statement::Emit`]
+    statement that covers them is executed.
+
+Now, strictly speaking, not all `Expression` variants actually care when they're
+evaluated. For example, you can evaluate a [`BinaryOperator::Add`] expression
+any time you like, as long as you give it the right operands. It's really only a
+very small set of expressions that are affected by timing:
+
+-   [`Load`], [`ImageSample`], and [`ImageLoad`] expressions are influenced by
+    stores to the variables or images they access, and must execute at the
+    proper time relative to them.
+
+-   [`Derivative`] expressions are sensitive to control flow uniformity: they
+    must not be moved out of an area of uniform control flow into a non-uniform
+    area.
+
+-   More generally, any expression that's used by more than one other expression
+    or statement should probably be evaluated only once, and then stored in a
+    variable to be cited at each point of use.
+
+Naga tries to help back ends handle all these cases correctly in a somewhat
+circuitous way. The [`ModuleInfo`] structure returned by [`Validator::validate`]
+provides a reference count for each expression in each function in the module.
+Naturally, any expression with a reference count of two or more deserves to be
+evaluated and stored in a temporary variable at the point that the `Emit`
+statement covering it is executed. But if we selectively lower the reference
+count threshold to _one_ for the sensitive expression types listed above, so
+that we _always_ generate a temporary variable and save their value, then the
+same code that manages multiply referenced expressions will take care of
+introducing temporaries for time-sensitive expressions as well. The
+`Expression::bake_ref_count` method (private to the back ends) is meant to help
+with this.
+
+## `Expression` scope
+
+Each `Expression` has a *scope*, which is the region of the function within
+which it can be used by `Statement`s and other `Expression`s. It is a validation
+error to use an `Expression` outside its scope.
+
+An expression's scope is defined as follows:
+
+-   The scope of a [`Constant`], [`GlobalVariable`], [`FunctionArgument`] or
+    [`LocalVariable`] expression covers the entire `Function` in which it
+    occurs.
+
+-   The scope of an expression evaluated by an [`Emit`] statement covers the
+    subsequent expressions in that `Emit`, the subsequent statements in the `Block`
+    to which that `Emit` belongs (if any) and their sub-statements (if any).
+
+-   The `result` expression of a [`Call`] or [`Atomic`] statement has a scope
+    covering the subsequent statements in the `Block` in which the statement
+    occurs (if any) and their sub-statements (if any).
+
+For example, this implies that an expression evaluated by some statement in a
+nested `Block` is not available in the `Block`'s parents. Such a value would
+need to be stored in a local variable to be carried upwards in the statement
+tree.
+
+## Constant expressions
+
+A Naga *constant expression* is one of the following [`Expression`]
+variants, whose operands (if any) are also constant expressions:
+- [`Literal`]
+- [`Constant`], for [`Constant`s][const_type] whose [`override`] is [`None`]
+- [`ZeroValue`], for fixed-size types
+- [`Compose`]
+- [`Access`]
+- [`AccessIndex`]
+- [`Splat`]
+- [`Swizzle`]
+- [`Unary`]
+- [`Binary`]
+- [`Select`]
+- [`Relational`]
+- [`Math`]
+- [`As`]
+
+A constant expression can be evaluated at module translation time.
+
+## Override expressions
+
+A Naga *override expression* is the same as a [constant expression],
+except that it is also allowed to refer to [`Constant`s][const_type]
+whose [`override`] is something other than [`None`].
+
+An override expression can be evaluated at pipeline creation time.
+
+[`AtomicResult`]: Expression::AtomicResult
+[`RayQueryProceedResult`]: Expression::RayQueryProceedResult
+[`CallResult`]: Expression::CallResult
+[`Constant`]: Expression::Constant
+[`ZeroValue`]: Expression::ZeroValue
+[`Literal`]: Expression::Literal
+[`Derivative`]: Expression::Derivative
+[`FunctionArgument`]: Expression::FunctionArgument
+[`GlobalVariable`]: Expression::GlobalVariable
+[`ImageLoad`]: Expression::ImageLoad
+[`ImageSample`]: Expression::ImageSample
+[`Load`]: Expression::Load
+[`LocalVariable`]: Expression::LocalVariable
+
+[`Atomic`]: Statement::Atomic
+[`Call`]: Statement::Call
+[`Emit`]: Statement::Emit
+[`Store`]: Statement::Store
+[`RayQuery`]: Statement::RayQuery
+
+[`Proceed::result`]: RayQueryFunction::Proceed::result
+
+[`Validator::validate`]: valid::Validator::validate
+[`ModuleInfo`]: valid::ModuleInfo
+
+[`Literal`]: Expression::Literal
+[`ZeroValue`]: Expression::ZeroValue
+[`Compose`]: Expression::Compose
+[`Access`]: Expression::Access
+[`AccessIndex`]: Expression::AccessIndex
+[`Splat`]: Expression::Splat
+[`Swizzle`]: Expression::Swizzle
+[`Unary`]: Expression::Unary
+[`Binary`]: Expression::Binary
+[`Select`]: Expression::Select
+[`Relational`]: Expression::Relational
+[`Math`]: Expression::Math
+[`As`]: Expression::As
+
+[const_type]: Constant
+[`override`]: Constant::override
+[`None`]: Override::None
+
+[constant expression]: index.html#constant-expressions
+*/
+
+#![allow(
+    clippy::new_without_default,
+    clippy::unneeded_field_pattern,
+    clippy::match_like_matches_macro,
+    clippy::collapsible_if,
+    clippy::derive_partial_eq_without_eq,
+    clippy::needless_borrowed_reference,
+    clippy::single_match
+)]
+#![warn(
+    trivial_casts,
+    trivial_numeric_casts,
+    unused_extern_crates,
+    unused_qualifications,
+    clippy::pattern_type_mismatch,
+    clippy::missing_const_for_fn,
+    clippy::rest_pat_in_fully_bound_structs,
+    clippy::match_wildcard_for_single_variants
+)]
+#![deny(clippy::exit)]
+#![cfg_attr(
+    not(test),
+    warn(
+        clippy::dbg_macro,
+        clippy::panic,
+        clippy::print_stderr,
+        clippy::print_stdout,
+        clippy::todo
+    )
+)]
+
+mod arena;
+pub mod back;
+mod block;
+#[cfg(feature = "compact")]
+pub mod compact;
+pub mod front;
+pub mod keywords;
+pub mod proc;
+mod span;
+pub mod valid;
+
+pub use crate::arena::{Arena, Handle, Range, UniqueArena};
+
+pub use crate::span::{SourceLocation, Span, SpanContext, WithSpan};
+#[cfg(feature = "arbitrary")]
+use arbitrary::Arbitrary;
+#[cfg(feature = "deserialize")]
+use serde::Deserialize;
+#[cfg(feature = "serialize")]
+use serde::Serialize;
+
+/// Width of a boolean type, in bytes.
+pub const BOOL_WIDTH: Bytes = 1;
+
+/// Width of abstract types, in bytes.
+pub const ABSTRACT_WIDTH: Bytes = 8;
+
+/// Hash map that is faster but not resilient to DoS attacks.
+pub type FastHashMap<K, T> = rustc_hash::FxHashMap<K, T>;
+/// Hash set that is faster but not resilient to DoS attacks.
+pub type FastHashSet<K> = rustc_hash::FxHashSet<K>;
+
+/// Insertion-order-preserving hash set (`IndexSet<K>`), but with the same
+/// hasher as `FastHashSet<K>` (faster but not resilient to DoS attacks).
+pub type FastIndexSet<K> =
+    indexmap::IndexSet<K, std::hash::BuildHasherDefault<rustc_hash::FxHasher>>;
+
+/// Insertion-order-preserving hash map (`IndexMap<K, V>`), but with the same
+/// hasher as `FastHashMap<K, V>` (faster but not resilient to DoS attacks).
+pub type FastIndexMap<K, V> =
+    indexmap::IndexMap<K, V, std::hash::BuildHasherDefault<rustc_hash::FxHasher>>;
+
+/// Map of expressions that have associated variable names
+pub(crate) type NamedExpressions = FastIndexMap<Handle<Expression>, String>;
+
+/// Early fragment tests.
+///
+/// In a standard situation, if a driver determines that it is possible to switch on early depth test, it will.
+///
+/// Typical situations when early depth test is switched off:
+///   - Calling `discard` in a shader.
+///   - Writing to the depth buffer, unless ConservativeDepth is enabled.
+///
+/// To use in a shader:
+///   - GLSL: `layout(early_fragment_tests) in;`
+///   - HLSL: `Attribute earlydepthstencil`
+///   - SPIR-V: `ExecutionMode EarlyFragmentTests`
+///   - WGSL: `@early_depth_test`
+///
+/// For more, see:
+///   - <https://www.khronos.org/opengl/wiki/Early_Fragment_Test#Explicit_specification>
+///   - <https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/sm5-attributes-earlydepthstencil>
+///   - <https://www.khronos.org/registry/SPIR-V/specs/unified1/SPIRV.html#Execution_Mode>
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub struct EarlyDepthTest {
+    pub conservative: Option<ConservativeDepth>,
+}
+/// Enables adjusting depth without disabling early Z.
+///
+/// To use in a shader:
+///   - GLSL: `layout (depth_<greater/less/unchanged/any>) out float gl_FragDepth;`
+///     - `depth_any` option behaves as if the layout qualifier was not present.
+///   - HLSL: `SV_DepthGreaterEqual`/`SV_DepthLessEqual`/`SV_Depth`
+///   - SPIR-V: `ExecutionMode Depth<Greater/Less/Unchanged>`
+///   - WGSL: `@early_depth_test(greater_equal/less_equal/unchanged)`
+///
+/// For more, see:
+///   - <https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_conservative_depth.txt>
+///   - <https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-semantics#system-value-semantics>
+///   - <https://www.khronos.org/registry/SPIR-V/specs/unified1/SPIRV.html#Execution_Mode>
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum ConservativeDepth {
+    /// Shader may rewrite depth only with a value greater than calculated.
+    GreaterEqual,
+
+    /// Shader may rewrite depth smaller than one that would have been written without the modification.
+    LessEqual,
+
+    /// Shader may not rewrite depth value.
+    Unchanged,
+}
+
+/// Stage of the programmable pipeline.
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+#[allow(missing_docs)] // The names are self evident
+pub enum ShaderStage {
+    Vertex,
+    Fragment,
+    Compute,
+}
+
+/// Addressing space of variables.
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum AddressSpace {
+    /// Function locals.
+    Function,
+    /// Private data, per invocation, mutable.
+    Private,
+    /// Workgroup shared data, mutable.
+    WorkGroup,
+    /// Uniform buffer data.
+    Uniform,
+    /// Storage buffer data, potentially mutable.
+    Storage { access: StorageAccess },
+    /// Opaque handles, such as samplers and images.
+    Handle,
+    /// Push constants.
+    PushConstant,
+}
+
+/// Built-in inputs and outputs.
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum BuiltIn {
+    Position { invariant: bool },
+    ViewIndex,
+    // vertex
+    BaseInstance,
+    BaseVertex,
+    ClipDistance,
+    CullDistance,
+    InstanceIndex,
+    PointSize,
+    VertexIndex,
+    // fragment
+    FragDepth,
+    PointCoord,
+    FrontFacing,
+    PrimitiveIndex,
+    SampleIndex,
+    SampleMask,
+    // compute
+    GlobalInvocationId,
+    LocalInvocationId,
+    LocalInvocationIndex,
+    WorkGroupId,
+    WorkGroupSize,
+    NumWorkGroups,
+}
+
+/// Number of bytes per scalar.
+pub type Bytes = u8;
+
+/// Number of components in a vector.
+#[repr(u8)]
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum VectorSize {
+    /// 2D vector
+    Bi = 2,
+    /// 3D vector
+    Tri = 3,
+    /// 4D vector
+    Quad = 4,
+}
+
+impl VectorSize {
+    const MAX: usize = Self::Quad as u8 as usize;
+}
+
+/// Primitive type for a scalar.
+#[repr(u8)]
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum ScalarKind {
+    /// Signed integer type.
+    Sint,
+    /// Unsigned integer type.
+    Uint,
+    /// Floating point type.
+    Float,
+    /// Boolean type.
+    Bool,
+
+    /// WGSL abstract integer type.
+    ///
+    /// These are forbidden by validation, and should never reach backends.
+    AbstractInt,
+
+    /// Abstract floating-point type.
+    ///
+    /// These are forbidden by validation, and should never reach backends.
+    AbstractFloat,
+}
+
+/// Characteristics of a scalar type.
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub struct Scalar {
+    /// How the value's bits are to be interpreted.
+    pub kind: ScalarKind,
+
+    /// This size of the value in bytes.
+    pub width: Bytes,
+}
+
+/// Size of an array.
+#[repr(u8)]
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum ArraySize {
+    /// The array size is constant.
+    Constant(std::num::NonZeroU32),
+    /// The array size can change at runtime.
+    Dynamic,
+}
+
+/// The interpolation qualifier of a binding or struct field.
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum Interpolation {
+    /// The value will be interpolated in a perspective-correct fashion.
+    /// Also known as "smooth" in glsl.
+    Perspective,
+    /// Indicates that linear, non-perspective, correct
+    /// interpolation must be used.
+    /// Also known as "no_perspective" in glsl.
+    Linear,
+    /// Indicates that no interpolation will be performed.
+    Flat,
+}
+
+/// The sampling qualifiers of a binding or struct field.
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum Sampling {
+    /// Interpolate the value at the center of the pixel.
+    Center,
+
+    /// Interpolate the value at a point that lies within all samples covered by
+    /// the fragment within the current primitive. In multisampling, use a
+    /// single value for all samples in the primitive.
+    Centroid,
+
+    /// Interpolate the value at each sample location. In multisampling, invoke
+    /// the fragment shader once per sample.
+    Sample,
+}
+
+/// Member of a user-defined structure.
+// Clone is used only for error reporting and is not intended for end users
+#[derive(Clone, Debug, Eq, Hash, PartialEq)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub struct StructMember {
+    pub name: Option<String>,
+    /// Type of the field.
+    pub ty: Handle<Type>,
+    /// For I/O structs, defines the binding.
+    pub binding: Option<Binding>,
+    /// Offset from the beginning from the struct.
+    pub offset: u32,
+}
+
+/// The number of dimensions an image has.
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum ImageDimension {
+    /// 1D image
+    D1,
+    /// 2D image
+    D2,
+    /// 3D image
+    D3,
+    /// Cube map
+    Cube,
+}
+
+bitflags::bitflags! {
+    /// Flags describing an image.
+    #[cfg_attr(feature = "serialize", derive(Serialize))]
+    #[cfg_attr(feature = "deserialize", derive(Deserialize))]
+    #[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+    #[derive(Clone, Copy, Debug, Default, Eq, Hash, Ord, PartialEq, PartialOrd)]
+    pub struct StorageAccess: u32 {
+        /// Storage can be used as a source for load ops.
+        const LOAD = 0x1;
+        /// Storage can be used as a target for store ops.
+        const STORE = 0x2;
+    }
+}
+
+/// Image storage format.
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum StorageFormat {
+    // 8-bit formats
+    R8Unorm,
+    R8Snorm,
+    R8Uint,
+    R8Sint,
+
+    // 16-bit formats
+    R16Uint,
+    R16Sint,
+    R16Float,
+    Rg8Unorm,
+    Rg8Snorm,
+    Rg8Uint,
+    Rg8Sint,
+
+    // 32-bit formats
+    R32Uint,
+    R32Sint,
+    R32Float,
+    Rg16Uint,
+    Rg16Sint,
+    Rg16Float,
+    Rgba8Unorm,
+    Rgba8Snorm,
+    Rgba8Uint,
+    Rgba8Sint,
+    Bgra8Unorm,
+
+    // Packed 32-bit formats
+    Rgb10a2Uint,
+    Rgb10a2Unorm,
+    Rg11b10Float,
+
+    // 64-bit formats
+    Rg32Uint,
+    Rg32Sint,
+    Rg32Float,
+    Rgba16Uint,
+    Rgba16Sint,
+    Rgba16Float,
+
+    // 128-bit formats
+    Rgba32Uint,
+    Rgba32Sint,
+    Rgba32Float,
+
+    // Normalized 16-bit per channel formats
+    R16Unorm,
+    R16Snorm,
+    Rg16Unorm,
+    Rg16Snorm,
+    Rgba16Unorm,
+    Rgba16Snorm,
+}
+
+/// Sub-class of the image type.
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum ImageClass {
+    /// Regular sampled image.
+    Sampled {
+        /// Kind of values to sample.
+        kind: ScalarKind,
+        /// Multi-sampled image.
+        ///
+        /// A multi-sampled image holds several samples per texel. Multi-sampled
+        /// images cannot have mipmaps.
+        multi: bool,
+    },
+    /// Depth comparison image.
+    Depth {
+        /// Multi-sampled depth image.
+        multi: bool,
+    },
+    /// Storage image.
+    Storage {
+        format: StorageFormat,
+        access: StorageAccess,
+    },
+}
+
+/// A data type declared in the module.
+#[derive(Clone, Debug, Eq, Hash, PartialEq)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub struct Type {
+    /// The name of the type, if any.
+    pub name: Option<String>,
+    /// Inner structure that depends on the kind of the type.
+    pub inner: TypeInner,
+}
+
+/// Enum with additional information, depending on the kind of type.
+#[derive(Clone, Debug, Eq, Hash, PartialEq)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum TypeInner {
+    /// Number of integral or floating-point kind.
+    Scalar(Scalar),
+    /// Vector of numbers.
+    Vector { size: VectorSize, scalar: Scalar },
+    /// Matrix of numbers.
+    Matrix {
+        columns: VectorSize,
+        rows: VectorSize,
+        scalar: Scalar,
+    },
+    /// Atomic scalar.
+    Atomic(Scalar),
+    /// Pointer to another type.
+    ///
+    /// Pointers to scalars and vectors should be treated as equivalent to
+    /// [`ValuePointer`] types. Use the [`TypeInner::equivalent`] method to
+    /// compare types in a way that treats pointers correctly.
+    ///
+    /// ## Pointers to non-`SIZED` types
+    ///
+    /// The `base` type of a pointer may be a non-[`SIZED`] type like a
+    /// dynamically-sized [`Array`], or a [`Struct`] whose last member is a
+    /// dynamically sized array. Such pointers occur as the types of
+    /// [`GlobalVariable`] or [`AccessIndex`] expressions referring to
+    /// dynamically-sized arrays.
+    ///
+    /// However, among pointers to non-`SIZED` types, only pointers to `Struct`s
+    /// are [`DATA`]. Pointers to dynamically sized `Array`s cannot be passed as
+    /// arguments, stored in variables, or held in arrays or structures. Their
+    /// only use is as the types of `AccessIndex` expressions.
+    ///
+    /// [`SIZED`]: valid::TypeFlags::SIZED
+    /// [`DATA`]: valid::TypeFlags::DATA
+    /// [`Array`]: TypeInner::Array
+    /// [`Struct`]: TypeInner::Struct
+    /// [`ValuePointer`]: TypeInner::ValuePointer
+    /// [`GlobalVariable`]: Expression::GlobalVariable
+    /// [`AccessIndex`]: Expression::AccessIndex
+    Pointer {
+        base: Handle<Type>,
+        space: AddressSpace,
+    },
+
+    /// Pointer to a scalar or vector.
+    ///
+    /// A `ValuePointer` type is equivalent to a `Pointer` whose `base` is a
+    /// `Scalar` or `Vector` type. This is for use in [`TypeResolution::Value`]
+    /// variants; see the documentation for [`TypeResolution`] for details.
+    ///
+    /// Use the [`TypeInner::equivalent`] method to compare types that could be
+    /// pointers, to ensure that `Pointer` and `ValuePointer` types are
+    /// recognized as equivalent.
+    ///
+    /// [`TypeResolution`]: proc::TypeResolution
+    /// [`TypeResolution::Value`]: proc::TypeResolution::Value
+    ValuePointer {
+        size: Option<VectorSize>,
+        scalar: Scalar,
+        space: AddressSpace,
+    },
+
+    /// Homogeneous list of elements.
+    ///
+    /// The `base` type must be a [`SIZED`], [`DATA`] type.
+    ///
+    /// ## Dynamically sized arrays
+    ///
+    /// An `Array` is [`SIZED`] unless its `size` is [`Dynamic`].
+    /// Dynamically-sized arrays may only appear in a few situations:
+    ///
+    /// -   They may appear as the type of a [`GlobalVariable`], or as the last
+    ///     member of a [`Struct`].
+    ///
+    /// -   They may appear as the base type of a [`Pointer`]. An
+    ///     [`AccessIndex`] expression referring to a struct's final
+    ///     unsized array member would have such a pointer type. However, such
+    ///     pointer types may only appear as the types of such intermediate
+    ///     expressions. They are not [`DATA`], and cannot be stored in
+    ///     variables, held in arrays or structs, or passed as parameters.
+    ///
+    /// [`SIZED`]: crate::valid::TypeFlags::SIZED
+    /// [`DATA`]: crate::valid::TypeFlags::DATA
+    /// [`Dynamic`]: ArraySize::Dynamic
+    /// [`Struct`]: TypeInner::Struct
+    /// [`Pointer`]: TypeInner::Pointer
+    /// [`AccessIndex`]: Expression::AccessIndex
+    Array {
+        base: Handle<Type>,
+        size: ArraySize,
+        stride: u32,
+    },
+
+    /// User-defined structure.
+    ///
+    /// There must always be at least one member.
+    ///
+    /// A `Struct` type is [`DATA`], and the types of its members must be
+    /// `DATA` as well.
+    ///
+    /// Member types must be [`SIZED`], except for the final member of a
+    /// struct, which may be a dynamically sized [`Array`]. The
+    /// `Struct` type itself is `SIZED` when all its members are `SIZED`.
+    ///
+    /// [`DATA`]: crate::valid::TypeFlags::DATA
+    /// [`SIZED`]: crate::valid::TypeFlags::SIZED
+    /// [`Array`]: TypeInner::Array
+    Struct {
+        members: Vec<StructMember>,
+        //TODO: should this be unaligned?
+        span: u32,
+    },
+    /// Possibly multidimensional array of texels.
+    Image {
+        dim: ImageDimension,
+        arrayed: bool,
+        //TODO: consider moving `multisampled: bool` out
+        class: ImageClass,
+    },
+    /// Can be used to sample values from images.
+    Sampler { comparison: bool },
+
+    /// Opaque object representing an acceleration structure of geometry.
+    AccelerationStructure,
+
+    /// Locally used handle for ray queries.
+    RayQuery,
+
+    /// Array of bindings.
+    ///
+    /// A `BindingArray` represents an array where each element draws its value
+    /// from a separate bound resource. The array's element type `base` may be
+    /// [`Image`], [`Sampler`], or any type that would be permitted for a global
+    /// in the [`Uniform`] or [`Storage`] address spaces. Only global variables
+    /// may be binding arrays; on the host side, their values are provided by
+    /// [`TextureViewArray`], [`SamplerArray`], or [`BufferArray`]
+    /// bindings.
+    ///
+    /// Since each element comes from a distinct resource, a binding array of
+    /// images could have images of varying sizes (but not varying dimensions;
+    /// they must all have the same `Image` type). Or, a binding array of
+    /// buffers could have elements that are dynamically sized arrays, each with
+    /// a different length.
+    ///
+    /// Binding arrays are in the same address spaces as their underlying type.
+    /// As such, referring to an array of images produces an [`Image`] value
+    /// directly (as opposed to a pointer). The only operation permitted on
+    /// `BindingArray` values is indexing, which works transparently: indexing
+    /// a binding array of samplers yields a [`Sampler`], indexing a pointer to the
+    /// binding array of storage buffers produces a pointer to the storage struct.
+    ///
+    /// Unlike textures and samplers, binding arrays are not [`ARGUMENT`], so
+    /// they cannot be passed as arguments to functions.
+    ///
+    /// Naga's WGSL front end supports binding arrays with the type syntax
+    /// `binding_array<T, N>`.
+    ///
+    /// [`Image`]: TypeInner::Image
+    /// [`Sampler`]: TypeInner::Sampler
+    /// [`Uniform`]: AddressSpace::Uniform
+    /// [`Storage`]: AddressSpace::Storage
+    /// [`TextureViewArray`]: https://docs.rs/wgpu/latest/wgpu/enum.BindingResource.html#variant.TextureViewArray
+    /// [`SamplerArray`]: https://docs.rs/wgpu/latest/wgpu/enum.BindingResource.html#variant.SamplerArray
+    /// [`BufferArray`]: https://docs.rs/wgpu/latest/wgpu/enum.BindingResource.html#variant.BufferArray
+    /// [`DATA`]: crate::valid::TypeFlags::DATA
+    /// [`ARGUMENT`]: crate::valid::TypeFlags::ARGUMENT
+    /// [naga#1864]: https://github.com/gfx-rs/naga/issues/1864
+    BindingArray { base: Handle<Type>, size: ArraySize },
+}
+
+#[derive(Debug, Clone, Copy, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum Literal {
+    /// May not be NaN or infinity.
+    F64(f64),
+    /// May not be NaN or infinity.
+    F32(f32),
+    U32(u32),
+    I32(i32),
+    I64(i64),
+    Bool(bool),
+    AbstractInt(i64),
+    AbstractFloat(f64),
+}
+
+#[derive(Debug, PartialEq)]
+#[cfg_attr(feature = "clone", derive(Clone))]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum Override {
+    None,
+    ByName,
+    ByNameOrId(u32),
+}
+
+/// Constant value.
+#[derive(Debug, PartialEq)]
+#[cfg_attr(feature = "clone", derive(Clone))]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub struct Constant {
+    pub name: Option<String>,
+    pub r#override: Override,
+    pub ty: Handle<Type>,
+
+    /// The value of the constant.
+    ///
+    /// This [`Handle`] refers to [`Module::const_expressions`], not
+    /// any [`Function::expressions`] arena.
+    ///
+    /// If [`override`] is [`None`], then this must be a Naga
+    /// [constant expression]. Otherwise, this may be a Naga
+    /// [override expression] or [constant expression].
+    ///
+    /// [`override`]: Constant::override
+    /// [`None`]: Override::None
+    /// [constant expression]: index.html#constant-expressions
+    /// [override expression]: index.html#override-expressions
+    pub init: Handle<Expression>,
+}
+
+/// Describes how an input/output variable is to be bound.
+#[derive(Clone, Debug, Eq, PartialEq, Hash)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum Binding {
+    /// Built-in shader variable.
+    BuiltIn(BuiltIn),
+
+    /// Indexed location.
+    ///
+    /// Values passed from the [`Vertex`] stage to the [`Fragment`] stage must
+    /// have their `interpolation` defaulted (i.e. not `None`) by the front end
+    /// as appropriate for that language.
+    ///
+    /// For other stages, we permit interpolations even though they're ignored.
+    /// When a front end is parsing a struct type, it usually doesn't know what
+    /// stages will be using it for IO, so it's easiest if it can apply the
+    /// defaults to anything with a `Location` binding, just in case.
+    ///
+    /// For anything other than floating-point scalars and vectors, the
+    /// interpolation must be `Flat`.
+    ///
+    /// [`Vertex`]: crate::ShaderStage::Vertex
+    /// [`Fragment`]: crate::ShaderStage::Fragment
+    Location {
+        location: u32,
+        /// Indicates the 2nd input to the blender when dual-source blending.
+        second_blend_source: bool,
+        interpolation: Option<Interpolation>,
+        sampling: Option<Sampling>,
+    },
+}
+
+/// Pipeline binding information for global resources.
+#[derive(Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub struct ResourceBinding {
+    /// The bind group index.
+    pub group: u32,
+    /// Binding number within the group.
+    pub binding: u32,
+}
+
+/// Variable defined at module level.
+#[derive(Clone, Debug, PartialEq)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub struct GlobalVariable {
+    /// Name of the variable, if any.
+    pub name: Option<String>,
+    /// How this variable is to be stored.
+    pub space: AddressSpace,
+    /// For resources, defines the binding point.
+    pub binding: Option<ResourceBinding>,
+    /// The type of this variable.
+    pub ty: Handle<Type>,
+    /// Initial value for this variable.
+    ///
+    /// Expression handle lives in const_expressions
+    pub init: Option<Handle<Expression>>,
+}
+
+/// Variable defined at function level.
+#[derive(Clone, Debug)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub struct LocalVariable {
+    /// Name of the variable, if any.
+    pub name: Option<String>,
+    /// The type of this variable.
+    pub ty: Handle<Type>,
+    /// Initial value for this variable.
+    ///
+    /// This handle refers to this `LocalVariable`'s function's
+    /// [`expressions`] arena, but it is required to be an evaluated
+    /// constant expression.
+    ///
+    /// [`expressions`]: Function::expressions
+    pub init: Option<Handle<Expression>>,
+}
+
+/// Operation that can be applied on a single value.
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum UnaryOperator {
+    Negate,
+    LogicalNot,
+    BitwiseNot,
+}
+
+/// Operation that can be applied on two values.
+///
+/// ## Arithmetic type rules
+///
+/// The arithmetic operations `Add`, `Subtract`, `Multiply`, `Divide`, and
+/// `Modulo` can all be applied to [`Scalar`] types other than [`Bool`], or
+/// [`Vector`]s thereof. Both operands must have the same type.
+///
+/// `Add` and `Subtract` can also be applied to [`Matrix`] values. Both operands
+/// must have the same type.
+///
+/// `Multiply` supports additional cases:
+///
+/// -   A [`Matrix`] or [`Vector`] can be multiplied by a scalar [`Float`],
+///     either on the left or the right.
+///
+/// -   A [`Matrix`] on the left can be multiplied by a [`Vector`] on the right
+///     if the matrix has as many columns as the vector has components (`matCxR
+///     * VecC`).
+///
+/// -   A [`Vector`] on the left can be multiplied by a [`Matrix`] on the right
+///     if the matrix has as many rows as the vector has components (`VecR *
+///     matCxR`).
+///
+/// -   Two matrices can be multiplied if the left operand has as many columns
+///     as the right operand has rows (`matNxR * matCxN`).
+///
+/// In all the above `Multiply` cases, the byte widths of the underlying scalar
+/// types of both operands must be the same.
+///
+/// Note that `Multiply` supports mixed vector and scalar operations directly,
+/// whereas the other arithmetic operations require an explicit [`Splat`] for
+/// mixed-type use.
+///
+/// [`Scalar`]: TypeInner::Scalar
+/// [`Vector`]: TypeInner::Vector
+/// [`Matrix`]: TypeInner::Matrix
+/// [`Float`]: ScalarKind::Float
+/// [`Bool`]: ScalarKind::Bool
+/// [`Splat`]: Expression::Splat
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum BinaryOperator {
+    Add,
+    Subtract,
+    Multiply,
+    Divide,
+    /// Equivalent of the WGSL's `%` operator or SPIR-V's `OpFRem`
+    Modulo,
+    Equal,
+    NotEqual,
+    Less,
+    LessEqual,
+    Greater,
+    GreaterEqual,
+    And,
+    ExclusiveOr,
+    InclusiveOr,
+    LogicalAnd,
+    LogicalOr,
+    ShiftLeft,
+    /// Right shift carries the sign of signed integers only.
+    ShiftRight,
+}
+
+/// Function on an atomic value.
+///
+/// Note: these do not include load/store, which use the existing
+/// [`Expression::Load`] and [`Statement::Store`].
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum AtomicFunction {
+    Add,
+    Subtract,
+    And,
+    ExclusiveOr,
+    InclusiveOr,
+    Min,
+    Max,
+    Exchange { compare: Option<Handle<Expression>> },
+}
+
+/// Hint at which precision to compute a derivative.
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum DerivativeControl {
+    Coarse,
+    Fine,
+    None,
+}
+
+/// Axis on which to compute a derivative.
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum DerivativeAxis {
+    X,
+    Y,
+    Width,
+}
+
+/// Built-in shader function for testing relation between values.
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum RelationalFunction {
+    All,
+    Any,
+    IsNan,
+    IsInf,
+}
+
+/// Built-in shader function for math.
+#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum MathFunction {
+    // comparison
+    Abs,
+    Min,
+    Max,
+    Clamp,
+    Saturate,
+    // trigonometry
+    Cos,
+    Cosh,
+    Sin,
+    Sinh,
+    Tan,
+    Tanh,
+    Acos,
+    Asin,
+    Atan,
+    Atan2,
+    Asinh,
+    Acosh,
+    Atanh,
+    Radians,
+    Degrees,
+    // decomposition
+    Ceil,
+    Floor,
+    Round,
+    Fract,
+    Trunc,
+    Modf,
+    Frexp,
+    Ldexp,
+    // exponent
+    Exp,
+    Exp2,
+    Log,
+    Log2,
+    Pow,
+    // geometry
+    Dot,
+    Outer,
+    Cross,
+    Distance,
+    Length,
+    Normalize,
+    FaceForward,
+    Reflect,
+    Refract,
+    // computational
+    Sign,
+    Fma,
+    Mix,
+    Step,
+    SmoothStep,
+    Sqrt,
+    InverseSqrt,
+    Inverse,
+    Transpose,
+    Determinant,
+    // bits
+    CountTrailingZeros,
+    CountLeadingZeros,
+    CountOneBits,
+    ReverseBits,
+    ExtractBits,
+    InsertBits,
+    FindLsb,
+    FindMsb,
+    // data packing
+    Pack4x8snorm,
+    Pack4x8unorm,
+    Pack2x16snorm,
+    Pack2x16unorm,
+    Pack2x16float,
+    // data unpacking
+    Unpack4x8snorm,
+    Unpack4x8unorm,
+    Unpack2x16snorm,
+    Unpack2x16unorm,
+    Unpack2x16float,
+}
+
+/// Sampling modifier to control the level of detail.
+#[derive(Clone, Copy, Debug, PartialEq)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum SampleLevel {
+    Auto,
+    Zero,
+    Exact(Handle<Expression>),
+    Bias(Handle<Expression>),
+    Gradient {
+        x: Handle<Expression>,
+        y: Handle<Expression>,
+    },
+}
+
+/// Type of an image query.
+#[derive(Clone, Copy, Debug, PartialEq)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum ImageQuery {
+    /// Get the size at the specified level.
+    Size {
+        /// If `None`, the base level is considered.
+        level: Option<Handle<Expression>>,
+    },
+    /// Get the number of mipmap levels.
+    NumLevels,
+    /// Get the number of array layers.
+    NumLayers,
+    /// Get the number of samples.
+    NumSamples,
+}
+
+/// Component selection for a vector swizzle.
+#[repr(u8)]
+#[derive(Clone, Copy, Debug, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum SwizzleComponent {
+    ///
+    X = 0,
+    ///
+    Y = 1,
+    ///
+    Z = 2,
+    ///
+    W = 3,
+}
+
+bitflags::bitflags! {
+    /// Memory barrier flags.
+    #[cfg_attr(feature = "serialize", derive(Serialize))]
+    #[cfg_attr(feature = "deserialize", derive(Deserialize))]
+    #[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+    #[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
+    pub struct Barrier: u32 {
+        /// Barrier affects all `AddressSpace::Storage` accesses.
+        const STORAGE = 0x1;
+        /// Barrier affects all `AddressSpace::WorkGroup` accesses.
+        const WORK_GROUP = 0x2;
+    }
+}
+
+/// An expression that can be evaluated to obtain a value.
+///
+/// This is a Single Static Assignment (SSA) scheme similar to SPIR-V.
+#[derive(Clone, Debug, PartialEq)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum Expression {
+    /// Literal.
+    Literal(Literal),
+    /// Constant value.
+    Constant(Handle<Constant>),
+    /// Zero value of a type.
+    ZeroValue(Handle<Type>),
+    /// Composite expression.
+    Compose {
+        ty: Handle<Type>,
+        components: Vec<Handle<Expression>>,
+    },
+
+    /// Array access with a computed index.
+    ///
+    /// ## Typing rules
+    ///
+    /// The `base` operand must be some composite type: [`Vector`], [`Matrix`],
+    /// [`Array`], a [`Pointer`] to one of those, or a [`ValuePointer`] with a
+    /// `size`.
+    ///
+    /// The `index` operand must be an integer, signed or unsigned.
+    ///
+    /// Indexing a [`Vector`] or [`Array`] produces a value of its element type.
+    /// Indexing a [`Matrix`] produces a [`Vector`].
+    ///
+    /// Indexing a [`Pointer`] to any of the above produces a pointer to the
+    /// element/component type, in the same [`space`]. In the case of [`Array`],
+    /// the result is an actual [`Pointer`], but for vectors and matrices, there
+    /// may not be any type in the arena representing the component's type, so
+    /// those produce [`ValuePointer`] types equivalent to the appropriate
+    /// [`Pointer`].
+    ///
+    /// ## Dynamic indexing restrictions
+    ///
+    /// To accommodate restrictions in some of the shader languages that Naga
+    /// targets, it is not permitted to subscript a matrix or array with a
+    /// dynamically computed index unless that matrix or array appears behind a
+    /// pointer. In other words, if the inner type of `base` is [`Array`] or
+    /// [`Matrix`], then `index` must be a constant. But if the type of `base`
+    /// is a [`Pointer`] to an array or matrix or a [`ValuePointer`] with a
+    /// `size`, then the index may be any expression of integer type.
+    ///
+    /// You can use the [`Expression::is_dynamic_index`] method to determine
+    /// whether a given index expression requires matrix or array base operands
+    /// to be behind a pointer.
+    ///
+    /// (It would be simpler to always require the use of `AccessIndex` when
+    /// subscripting arrays and matrices that are not behind pointers, but to
+    /// accommodate existing front ends, Naga also permits `Access`, with a
+    /// restricted `index`.)
+    ///
+    /// [`Vector`]: TypeInner::Vector
+    /// [`Matrix`]: TypeInner::Matrix
+    /// [`Array`]: TypeInner::Array
+    /// [`Pointer`]: TypeInner::Pointer
+    /// [`space`]: TypeInner::Pointer::space
+    /// [`ValuePointer`]: TypeInner::ValuePointer
+    /// [`Float`]: ScalarKind::Float
+    Access {
+        base: Handle<Expression>,
+        index: Handle<Expression>,
+    },
+    /// Access the same types as [`Access`], plus [`Struct`] with a known index.
+    ///
+    /// [`Access`]: Expression::Access
+    /// [`Struct`]: TypeInner::Struct
+    AccessIndex {
+        base: Handle<Expression>,
+        index: u32,
+    },
+    /// Splat scalar into a vector.
+    Splat {
+        size: VectorSize,
+        value: Handle<Expression>,
+    },
+    /// Vector swizzle.
+    Swizzle {
+        size: VectorSize,
+        vector: Handle<Expression>,
+        pattern: [SwizzleComponent; 4],
+    },
+
+    /// Reference a function parameter, by its index.
+    ///
+    /// A `FunctionArgument` expression evaluates to a pointer to the argument's
+    /// value. You must use a [`Load`] expression to retrieve its value, or a
+    /// [`Store`] statement to assign it a new value.
+    ///
+    /// [`Load`]: Expression::Load
+    /// [`Store`]: Statement::Store
+    FunctionArgument(u32),
+
+    /// Reference a global variable.
+    ///
+    /// If the given `GlobalVariable`'s [`space`] is [`AddressSpace::Handle`],
+    /// then the variable stores some opaque type like a sampler or an image,
+    /// and a `GlobalVariable` expression referring to it produces the
+    /// variable's value directly.
+    ///
+    /// For any other address space, a `GlobalVariable` expression produces a
+    /// pointer to the variable's value. You must use a [`Load`] expression to
+    /// retrieve its value, or a [`Store`] statement to assign it a new value.
+    ///
+    /// [`space`]: GlobalVariable::space
+    /// [`Load`]: Expression::Load
+    /// [`Store`]: Statement::Store
+    GlobalVariable(Handle<GlobalVariable>),
+
+    /// Reference a local variable.
+    ///
+    /// A `LocalVariable` expression evaluates to a pointer to the variable's value.
+    /// You must use a [`Load`](Expression::Load) expression to retrieve its value,
+    /// or a [`Store`](Statement::Store) statement to assign it a new value.
+    LocalVariable(Handle<LocalVariable>),
+
+    /// Load a value indirectly.
+    ///
+    /// For [`TypeInner::Atomic`] the result is a corresponding scalar.
+    /// For other types behind the `pointer<T>`, the result is `T`.
+    Load { pointer: Handle<Expression> },
+    /// Sample a point from a sampled or a depth image.
+    ImageSample {
+        image: Handle<Expression>,
+        sampler: Handle<Expression>,
+        /// If Some(), this operation is a gather operation
+        /// on the selected component.
+        gather: Option<SwizzleComponent>,
+        coordinate: Handle<Expression>,
+        array_index: Option<Handle<Expression>>,
+        /// Expression handle lives in const_expressions
+        offset: Option<Handle<Expression>>,
+        level: SampleLevel,
+        depth_ref: Option<Handle<Expression>>,
+    },
+
+    /// Load a texel from an image.
+    ///
+    /// For most images, this returns a four-element vector of the same
+    /// [`ScalarKind`] as the image. If the format of the image does not have
+    /// four components, default values are provided: the first three components
+    /// (typically R, G, and B) default to zero, and the final component
+    /// (typically alpha) defaults to one.
+    ///
+    /// However, if the image's [`class`] is [`Depth`], then this returns a
+    /// [`Float`] scalar value.
+    ///
+    /// [`ScalarKind`]: ScalarKind
+    /// [`class`]: TypeInner::Image::class
+    /// [`Depth`]: ImageClass::Depth
+    /// [`Float`]: ScalarKind::Float
+    ImageLoad {
+        /// The image to load a texel from. This must have type [`Image`]. (This
+        /// will necessarily be a [`GlobalVariable`] or [`FunctionArgument`]
+        /// expression, since no other expressions are allowed to have that
+        /// type.)
+        ///
+        /// [`Image`]: TypeInner::Image
+        /// [`GlobalVariable`]: Expression::GlobalVariable
+        /// [`FunctionArgument`]: Expression::FunctionArgument
+        image: Handle<Expression>,
+
+        /// The coordinate of the texel we wish to load. This must be a scalar
+        /// for [`D1`] images, a [`Bi`] vector for [`D2`] images, and a [`Tri`]
+        /// vector for [`D3`] images. (Array indices, sample indices, and
+        /// explicit level-of-detail values are supplied separately.) Its
+        /// component type must be [`Sint`].
+        ///
+        /// [`D1`]: ImageDimension::D1
+        /// [`D2`]: ImageDimension::D2
+        /// [`D3`]: ImageDimension::D3
+        /// [`Bi`]: VectorSize::Bi
+        /// [`Tri`]: VectorSize::Tri
+        /// [`Sint`]: ScalarKind::Sint
+        coordinate: Handle<Expression>,
+
+        /// The index into an arrayed image. If the [`arrayed`] flag in
+        /// `image`'s type is `true`, then this must be `Some(expr)`, where
+        /// `expr` is a [`Sint`] scalar. Otherwise, it must be `None`.
+        ///
+        /// [`arrayed`]: TypeInner::Image::arrayed
+        /// [`Sint`]: ScalarKind::Sint
+        array_index: Option<Handle<Expression>>,
+
+        /// A sample index, for multisampled [`Sampled`] and [`Depth`] images.
+        ///
+        /// [`Sampled`]: ImageClass::Sampled
+        /// [`Depth`]: ImageClass::Depth
+        sample: Option<Handle<Expression>>,
+
+        /// A level of detail, for mipmapped images.
+        ///
+        /// This must be present when accessing non-multisampled
+        /// [`Sampled`] and [`Depth`] images, even if only the
+        /// full-resolution level is present (in which case the only
+        /// valid level is zero).
+        ///
+        /// [`Sampled`]: ImageClass::Sampled
+        /// [`Depth`]: ImageClass::Depth
+        level: Option<Handle<Expression>>,
+    },
+
+    /// Query information from an image.
+    ImageQuery {
+        image: Handle<Expression>,
+        query: ImageQuery,
+    },
+    /// Apply an unary operator.
+    Unary {
+        op: UnaryOperator,
+        expr: Handle<Expression>,
+    },
+    /// Apply a binary operator.
+    Binary {
+        op: BinaryOperator,
+        left: Handle<Expression>,
+        right: Handle<Expression>,
+    },
+    /// Select between two values based on a condition.
+    ///
+    /// Note that, because expressions have no side effects, it is unobservable
+    /// whether the non-selected branch is evaluated.
+    Select {
+        /// Boolean expression
+        condition: Handle<Expression>,
+        accept: Handle<Expression>,
+        reject: Handle<Expression>,
+    },
+    /// Compute the derivative on an axis.
+    Derivative {
+        axis: DerivativeAxis,
+        ctrl: DerivativeControl,
+        expr: Handle<Expression>,
+    },
+    /// Call a relational function.
+    Relational {
+        fun: RelationalFunction,
+        argument: Handle<Expression>,
+    },
+    /// Call a math function
+    Math {
+        fun: MathFunction,
+        arg: Handle<Expression>,
+        arg1: Option<Handle<Expression>>,
+        arg2: Option<Handle<Expression>>,
+        arg3: Option<Handle<Expression>>,
+    },
+    /// Cast a simple type to another kind.
+    As {
+        /// Source expression, which can only be a scalar or a vector.
+        expr: Handle<Expression>,
+        /// Target scalar kind.
+        kind: ScalarKind,
+        /// If provided, converts to the specified byte width.
+        /// Otherwise, bitcast.
+        convert: Option<Bytes>,
+    },
+    /// Result of calling another function.
+    CallResult(Handle<Function>),
+    /// Result of an atomic operation.
+    AtomicResult { ty: Handle<Type>, comparison: bool },
+    /// Result of a [`WorkGroupUniformLoad`] statement.
+    ///
+    /// [`WorkGroupUniformLoad`]: Statement::WorkGroupUniformLoad
+    WorkGroupUniformLoadResult {
+        /// The type of the result
+        ty: Handle<Type>,
+    },
+    /// Get the length of an array.
+    /// The expression must resolve to a pointer to an array with a dynamic size.
+    ///
+    /// This doesn't match the semantics of spirv's `OpArrayLength`, which must be passed
+    /// a pointer to a structure containing a runtime array in its' last field.
+    ArrayLength(Handle<Expression>),
+
+    /// Result of a [`Proceed`] [`RayQuery`] statement.
+    ///
+    /// [`Proceed`]: RayQueryFunction::Proceed
+    /// [`RayQuery`]: Statement::RayQuery
+    RayQueryProceedResult,
+
+    /// Return an intersection found by `query`.
+    ///
+    /// If `committed` is true, return the committed result available when
+    RayQueryGetIntersection {
+        query: Handle<Expression>,
+        committed: bool,
+    },
+}
+
+pub use block::Block;
+
+/// The value of the switch case.
+#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum SwitchValue {
+    I32(i32),
+    U32(u32),
+    Default,
+}
+
+/// A case for a switch statement.
+// Clone is used only for error reporting and is not intended for end users
+#[derive(Clone, Debug)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub struct SwitchCase {
+    /// Value, upon which the case is considered true.
+    pub value: SwitchValue,
+    /// Body of the case.
+    pub body: Block,
+    /// If true, the control flow continues to the next case in the list,
+    /// or default.
+    pub fall_through: bool,
+}
+
+/// An operation that a [`RayQuery` statement] applies to its [`query`] operand.
+///
+/// [`RayQuery` statement]: Statement::RayQuery
+/// [`query`]: Statement::RayQuery::query
+#[derive(Clone, Debug)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum RayQueryFunction {
+    /// Initialize the `RayQuery` object.
+    Initialize {
+        /// The acceleration structure within which this query should search for hits.
+        ///
+        /// The expression must be an [`AccelerationStructure`].
+        ///
+        /// [`AccelerationStructure`]: TypeInner::AccelerationStructure
+        acceleration_structure: Handle<Expression>,
+
+        #[allow(rustdoc::private_intra_doc_links)]
+        /// A struct of detailed parameters for the ray query.
+        ///
+        /// This expression should have the struct type given in
+        /// [`SpecialTypes::ray_desc`]. This is available in the WGSL
+        /// front end as the `RayDesc` type.
+        descriptor: Handle<Expression>,
+    },
+
+    /// Start or continue the query given by the statement's [`query`] operand.
+    ///
+    /// After executing this statement, the `result` expression is a
+    /// [`Bool`] scalar indicating whether there are more intersection
+    /// candidates to consider.
+    ///
+    /// [`query`]: Statement::RayQuery::query
+    /// [`Bool`]: ScalarKind::Bool
+    Proceed {
+        result: Handle<Expression>,
+    },
+
+    Terminate,
+}
+
+//TODO: consider removing `Clone`. It's not valid to clone `Statement::Emit` anyway.
+/// Instructions which make up an executable block.
+// Clone is used only for error reporting and is not intended for end users
+#[derive(Clone, Debug)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum Statement {
+    /// Emit a range of expressions, visible to all statements that follow in this block.
+    ///
+    /// See the [module-level documentation][emit] for details.
+    ///
+    /// [emit]: index.html#expression-evaluation-time
+    Emit(Range<Expression>),
+    /// A block containing more statements, to be executed sequentially.
+    Block(Block),
+    /// Conditionally executes one of two blocks, based on the value of the condition.
+    If {
+        condition: Handle<Expression>, //bool
+        accept: Block,
+        reject: Block,
+    },
+    /// Conditionally executes one of multiple blocks, based on the value of the selector.
+    ///
+    /// Each case must have a distinct [`value`], exactly one of which must be
+    /// [`Default`]. The `Default` may appear at any position, and covers all
+    /// values not explicitly appearing in other cases. A `Default` appearing in
+    /// the midst of the list of cases does not shadow the cases that follow.
+    ///
+    /// Some backend languages don't support fallthrough (HLSL due to FXC,
+    /// WGSL), and may translate fallthrough cases in the IR by duplicating
+    /// code. However, all backend languages do support cases selected by
+    /// multiple values, like `case 1: case 2: case 3: { ... }`. This is
+    /// represented in the IR as a series of fallthrough cases with empty
+    /// bodies, except for the last.
+    ///
+    /// [`value`]: SwitchCase::value
+    /// [`body`]: SwitchCase::body
+    /// [`Default`]: SwitchValue::Default
+    Switch {
+        selector: Handle<Expression>,
+        cases: Vec<SwitchCase>,
+    },
+
+    /// Executes a block repeatedly.
+    ///
+    /// Each iteration of the loop executes the `body` block, followed by the
+    /// `continuing` block.
+    ///
+    /// Executing a [`Break`], [`Return`] or [`Kill`] statement exits the loop.
+    ///
+    /// A [`Continue`] statement in `body` jumps to the `continuing` block. The
+    /// `continuing` block is meant to be used to represent structures like the
+    /// third expression of a C-style `for` loop head, to which `continue`
+    /// statements in the loop's body jump.
+    ///
+    /// The `continuing` block and its substatements must not contain `Return`
+    /// or `Kill` statements, or any `Break` or `Continue` statements targeting
+    /// this loop. (It may have `Break` and `Continue` statements targeting
+    /// loops or switches nested within the `continuing` block.) Expressions
+    /// emitted in `body` are in scope in `continuing`.
+    ///
+    /// If present, `break_if` is an expression which is evaluated after the
+    /// continuing block. Expressions emitted in `body` or `continuing` are
+    /// considered to be in scope. If the expression's value is true, control
+    /// continues after the `Loop` statement, rather than branching back to the
+    /// top of body as usual. The `break_if` expression corresponds to a "break
+    /// if" statement in WGSL, or a loop whose back edge is an
+    /// `OpBranchConditional` instruction in SPIR-V.
+    ///
+    /// [`Break`]: Statement::Break
+    /// [`Continue`]: Statement::Continue
+    /// [`Kill`]: Statement::Kill
+    /// [`Return`]: Statement::Return
+    /// [`break if`]: Self::Loop::break_if
+    Loop {
+        body: Block,
+        continuing: Block,
+        break_if: Option<Handle<Expression>>,
+    },
+
+    /// Exits the innermost enclosing [`Loop`] or [`Switch`].
+    ///
+    /// A `Break` statement may only appear within a [`Loop`] or [`Switch`]
+    /// statement. It may not break out of a [`Loop`] from within the loop's
+    /// `continuing` block.
+    ///
+    /// [`Loop`]: Statement::Loop
+    /// [`Switch`]: Statement::Switch
+    Break,
+
+    /// Skips to the `continuing` block of the innermost enclosing [`Loop`].
+    ///
+    /// A `Continue` statement may only appear within the `body` block of the
+    /// innermost enclosing [`Loop`] statement. It must not appear within that
+    /// loop's `continuing` block.
+    ///
+    /// [`Loop`]: Statement::Loop
+    Continue,
+
+    /// Returns from the function (possibly with a value).
+    ///
+    /// `Return` statements are forbidden within the `continuing` block of a
+    /// [`Loop`] statement.
+    ///
+    /// [`Loop`]: Statement::Loop
+    Return { value: Option<Handle<Expression>> },
+
+    /// Aborts the current shader execution.
+    ///
+    /// `Kill` statements are forbidden within the `continuing` block of a
+    /// [`Loop`] statement.
+    ///
+    /// [`Loop`]: Statement::Loop
+    Kill,
+
+    /// Synchronize invocations within the work group.
+    /// The `Barrier` flags control which memory accesses should be synchronized.
+    /// If empty, this becomes purely an execution barrier.
+    Barrier(Barrier),
+    /// Stores a value at an address.
+    ///
+    /// For [`TypeInner::Atomic`] type behind the pointer, the value
+    /// has to be a corresponding scalar.
+    /// For other types behind the `pointer<T>`, the value is `T`.
+    ///
+    /// This statement is a barrier for any operations on the
+    /// `Expression::LocalVariable` or `Expression::GlobalVariable`
+    /// that is the destination of an access chain, started
+    /// from the `pointer`.
+    Store {
+        pointer: Handle<Expression>,
+        value: Handle<Expression>,
+    },
+    /// Stores a texel value to an image.
+    ///
+    /// The `image`, `coordinate`, and `array_index` fields have the same
+    /// meanings as the corresponding operands of an [`ImageLoad`] expression;
+    /// see that documentation for details. Storing into multisampled images or
+    /// images with mipmaps is not supported, so there are no `level` or
+    /// `sample` operands.
+    ///
+    /// This statement is a barrier for any operations on the corresponding
+    /// [`Expression::GlobalVariable`] for this image.
+    ///
+    /// [`ImageLoad`]: Expression::ImageLoad
+    ImageStore {
+        image: Handle<Expression>,
+        coordinate: Handle<Expression>,
+        array_index: Option<Handle<Expression>>,
+        value: Handle<Expression>,
+    },
+    /// Atomic function.
+    Atomic {
+        /// Pointer to an atomic value.
+        pointer: Handle<Expression>,
+        /// Function to run on the atomic.
+        fun: AtomicFunction,
+        /// Value to use in the function.
+        value: Handle<Expression>,
+        /// [`AtomicResult`] expression representing this function's result.
+        ///
+        /// [`AtomicResult`]: crate::Expression::AtomicResult
+        result: Handle<Expression>,
+    },
+    /// Load uniformly from a uniform pointer in the workgroup address space.
+    ///
+    /// Corresponds to the [`workgroupUniformLoad`](https://www.w3.org/TR/WGSL/#workgroupUniformLoad-builtin)
+    /// built-in function of wgsl, and has the same barrier semantics
+    WorkGroupUniformLoad {
+        /// This must be of type [`Pointer`] in the [`WorkGroup`] address space
+        ///
+        /// [`Pointer`]: TypeInner::Pointer
+        /// [`WorkGroup`]: AddressSpace::WorkGroup
+        pointer: Handle<Expression>,
+        /// The [`WorkGroupUniformLoadResult`] expression representing this load's result.
+        ///
+        /// [`WorkGroupUniformLoadResult`]: Expression::WorkGroupUniformLoadResult
+        result: Handle<Expression>,
+    },
+    /// Calls a function.
+    ///
+    /// If the `result` is `Some`, the corresponding expression has to be
+    /// `Expression::CallResult`, and this statement serves as a barrier for any
+    /// operations on that expression.
+    Call {
+        function: Handle<Function>,
+        arguments: Vec<Handle<Expression>>,
+        result: Option<Handle<Expression>>,
+    },
+    RayQuery {
+        /// The [`RayQuery`] object this statement operates on.
+        ///
+        /// [`RayQuery`]: TypeInner::RayQuery
+        query: Handle<Expression>,
+
+        /// The specific operation we're performing on `query`.
+        fun: RayQueryFunction,
+    },
+}
+
+/// A function argument.
+#[derive(Clone, Debug)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub struct FunctionArgument {
+    /// Name of the argument, if any.
+    pub name: Option<String>,
+    /// Type of the argument.
+    pub ty: Handle<Type>,
+    /// For entry points, an argument has to have a binding
+    /// unless it's a structure.
+    pub binding: Option<Binding>,
+}
+
+/// A function result.
+#[derive(Clone, Debug)]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub struct FunctionResult {
+    /// Type of the result.
+    pub ty: Handle<Type>,
+    /// For entry points, the result has to have a binding
+    /// unless it's a structure.
+    pub binding: Option<Binding>,
+}
+
+/// A function defined in the module.
+#[derive(Debug, Default)]
+#[cfg_attr(feature = "clone", derive(Clone))]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub struct Function {
+    /// Name of the function, if any.
+    pub name: Option<String>,
+    /// Information about function argument.
+    pub arguments: Vec<FunctionArgument>,
+    /// The result of this function, if any.
+    pub result: Option<FunctionResult>,
+    /// Local variables defined and used in the function.
+    pub local_variables: Arena<LocalVariable>,
+    /// Expressions used inside this function.
+    ///
+    /// An `Expression` must occur before all other `Expression`s that use its
+    /// value.
+    pub expressions: Arena<Expression>,
+    /// Map of expressions that have associated variable names
+    pub named_expressions: NamedExpressions,
+    /// Block of instructions comprising the body of the function.
+    pub body: Block,
+}
+
+/// The main function for a pipeline stage.
+///
+/// An [`EntryPoint`] is a [`Function`] that serves as the main function for a
+/// graphics or compute pipeline stage. For example, an `EntryPoint` whose
+/// [`stage`] is [`ShaderStage::Vertex`] can serve as a graphics pipeline's
+/// vertex shader.
+///
+/// Since an entry point is called directly by the graphics or compute pipeline,
+/// not by other WGSL functions, you must specify what the pipeline should pass
+/// as the entry point's arguments, and what values it will return. For example,
+/// a vertex shader needs a vertex's attributes as its arguments, but if it's
+/// used for instanced draw calls, it will also want to know the instance id.
+/// The vertex shader's return value will usually include an output vertex
+/// position, and possibly other attributes to be interpolated and passed along
+/// to a fragment shader.
+///
+/// To specify this, the arguments and result of an `EntryPoint`'s [`function`]
+/// must each have a [`Binding`], or be structs whose members all have
+/// `Binding`s. This associates every value passed to or returned from the entry
+/// point with either a [`BuiltIn`] or a [`Location`]:
+///
+/// -   A [`BuiltIn`] has special semantics, usually specific to its pipeline
+///     stage. For example, the result of a vertex shader can include a
+///     [`BuiltIn::Position`] value, which determines the position of a vertex
+///     of a rendered primitive. Or, a compute shader might take an argument
+///     whose binding is [`BuiltIn::WorkGroupSize`], through which the compute
+///     pipeline would pass the number of invocations in your workgroup.
+///
+/// -   A [`Location`] indicates user-defined IO to be passed from one pipeline
+///     stage to the next. For example, a vertex shader might also produce a
+///     `uv` texture location as a user-defined IO value.
+///
+/// In other words, the pipeline stage's input and output interface are
+/// determined by the bindings of the arguments and result of the `EntryPoint`'s
+/// [`function`].
+///
+/// [`Function`]: crate::Function
+/// [`Location`]: Binding::Location
+/// [`function`]: EntryPoint::function
+/// [`stage`]: EntryPoint::stage
+#[derive(Debug)]
+#[cfg_attr(feature = "clone", derive(Clone))]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub struct EntryPoint {
+    /// Name of this entry point, visible externally.
+    ///
+    /// Entry point names for a given `stage` must be distinct within a module.
+    pub name: String,
+    /// Shader stage.
+    pub stage: ShaderStage,
+    /// Early depth test for fragment stages.
+    pub early_depth_test: Option<EarlyDepthTest>,
+    /// Workgroup size for compute stages
+    pub workgroup_size: [u32; 3],
+    /// The entrance function.
+    pub function: Function,
+}
+
+/// Return types predeclared for the frexp, modf, and atomicCompareExchangeWeak built-in functions.
+///
+/// These cannot be spelled in WGSL source.
+///
+/// Stored in [`SpecialTypes::predeclared_types`] and created by [`Module::generate_predeclared_type`].
+#[derive(Debug, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "clone", derive(Clone))]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub enum PredeclaredType {
+    AtomicCompareExchangeWeakResult(Scalar),
+    ModfResult {
+        size: Option<VectorSize>,
+        width: Bytes,
+    },
+    FrexpResult {
+        size: Option<VectorSize>,
+        width: Bytes,
+    },
+}
+
+/// Set of special types that can be optionally generated by the frontends.
+#[derive(Debug, Default)]
+#[cfg_attr(feature = "clone", derive(Clone))]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub struct SpecialTypes {
+    /// Type for `RayDesc`.
+    ///
+    /// Call [`Module::generate_ray_desc_type`] to populate this if
+    /// needed and return the handle.
+    pub ray_desc: Option<Handle<Type>>,
+
+    /// Type for `RayIntersection`.
+    ///
+    /// Call [`Module::generate_ray_intersection_type`] to populate
+    /// this if needed and return the handle.
+    pub ray_intersection: Option<Handle<Type>>,
+
+    /// Types for predeclared wgsl types instantiated on demand.
+    ///
+    /// Call [`Module::generate_predeclared_type`] to populate this if
+    /// needed and return the handle.
+    pub predeclared_types: FastIndexMap<PredeclaredType, Handle<Type>>,
+}
+
+/// Shader module.
+///
+/// A module is a set of constants, global variables and functions, as well as
+/// the types required to define them.
+///
+/// Some functions are marked as entry points, to be used in a certain shader stage.
+///
+/// To create a new module, use the `Default` implementation.
+/// Alternatively, you can load an existing shader using one of the [available front ends][front].
+///
+/// When finished, you can export modules using one of the [available backends][back].
+#[derive(Debug, Default)]
+#[cfg_attr(feature = "clone", derive(Clone))]
+#[cfg_attr(feature = "serialize", derive(Serialize))]
+#[cfg_attr(feature = "deserialize", derive(Deserialize))]
+#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
+pub struct Module {
+    /// Arena for the types defined in this module.
+    pub types: UniqueArena<Type>,
+    /// Dictionary of special type handles.
+    pub special_types: SpecialTypes,
+    /// Arena for the constants defined in this module.
+    pub constants: Arena<Constant>,
+    /// Arena for the global variables defined in this module.
+    pub global_variables: Arena<GlobalVariable>,
+    /// [Constant expressions] and [override expressions] used by this module.
+    ///
+    /// Each `Expression` must occur in the arena before any
+    /// `Expression` that uses its value.
+    ///
+    /// [Constant expressions]: index.html#constant-expressions
+    /// [override expressions]: index.html#override-expressions
+    pub const_expressions: Arena<Expression>,
+    /// Arena for the functions defined in this module.
+    ///
+    /// Each function must appear in this arena strictly before all its callers.
+    /// Recursion is not supported.
+    pub functions: Arena<Function>,
+    /// Entry points.
+    pub entry_points: Vec<EntryPoint>,
+}
diff --git a/third_party/rust/naga/src/proc/constant_evaluator.rs b/third_party/rust/naga/src/proc/constant_evaluator.rs
new file mode 100644
index 0000000000..b3884b04b1
--- /dev/null
+++ b/third_party/rust/naga/src/proc/constant_evaluator.rs
@@ -0,0 +1,2475 @@
+use std::iter;
+
+use arrayvec::ArrayVec;
+
+use crate::{
+    arena::{Arena, Handle, UniqueArena},
+    ArraySize, BinaryOperator, Constant, Expression, Literal, ScalarKind, Span, Type, TypeInner,
+    UnaryOperator,
+};
+
+/// A macro that allows dollar signs (`$`) to be emitted by other macros. Useful for generating
+/// `macro_rules!` items that, in turn, emit their own `macro_rules!` items.
+///
+/// Technique stolen directly from
+/// <https://github.com/rust-lang/rust/issues/35853#issuecomment-415993963>.
+macro_rules! with_dollar_sign {
+    ($($body:tt)*) => {
+        macro_rules! __with_dollar_sign { $($body)* }
+        __with_dollar_sign!($);
+    }
+}
+
+macro_rules! gen_component_wise_extractor {
+    (
+        $ident:ident -> $target:ident,
+        literals: [$( $literal:ident => $mapping:ident: $ty:ident ),+ $(,)?],
+        scalar_kinds: [$( $scalar_kind:ident ),* $(,)?],
+    ) => {
+        /// A subset of [`Literal`]s intended to be used for implementing numeric built-ins.
+        enum $target<const N: usize> {
+            $(
+                #[doc = concat!(
+                    "Maps to [`Literal::",
+                    stringify!($mapping),
+                    "`]",
+                )]
+                $mapping([$ty; N]),
+            )+
+        }
+
+        impl From<$target<1>> for Expression {
+            fn from(value: $target<1>) -> Self {
+                match value {
+                    $(
+                        $target::$mapping([value]) => {
+                            Expression::Literal(Literal::$literal(value))
+                        }
+                    )+
+                }
+            }
+        }
+
+        #[doc = concat!(
+            "Attempts to evaluate multiple `exprs` as a combined [`",
+            stringify!($target),
+            "`] to pass to `handler`. ",
+        )]
+        /// If `exprs` are vectors of the same length, `handler` is called for each corresponding
+        /// component of each vector.
+        ///
+        /// `handler`'s output is registered as a new expression. If `exprs` are vectors of the
+        /// same length, a new vector expression is registered, composed of each component emitted
+        /// by `handler`.
+        fn $ident<const N: usize, const M: usize, F>(
+            eval: &mut ConstantEvaluator<'_>,
+            span: Span,
+            exprs: [Handle<Expression>; N],
+            mut handler: F,
+        ) -> Result<Handle<Expression>, ConstantEvaluatorError>
+        where
+            $target<M>: Into<Expression>,
+            F: FnMut($target<N>) -> Result<$target<M>, ConstantEvaluatorError> + Clone,
+        {
+            assert!(N > 0);
+            let err = ConstantEvaluatorError::InvalidMathArg;
+            let mut exprs = exprs.into_iter();
+
+            macro_rules! sanitize {
+                ($expr:expr) => {
+                    eval.eval_zero_value_and_splat($expr, span)
+                        .map(|expr| &eval.expressions[expr])
+                };
+            }
+
+            let new_expr = match sanitize!(exprs.next().unwrap())? {
+                $(
+                    &Expression::Literal(Literal::$literal(x)) => iter::once(Ok(x))
+                        .chain(exprs.map(|expr| {
+                            sanitize!(expr).and_then(|expr| match expr {
+                                &Expression::Literal(Literal::$literal(x)) => Ok(x),
+                                _ => Err(err.clone()),
+                            })
+                        }))
+                        .collect::<Result<ArrayVec<_, N>, _>>()
+                        .map(|a| a.into_inner().unwrap())
+                        .map($target::$mapping)
+                        .and_then(|comps| Ok(handler(comps)?.into())),
+                )+
+                &Expression::Compose { ty, ref components } => match &eval.types[ty].inner {
+                    &TypeInner::Vector { size, scalar } => match scalar.kind {
+                        $(ScalarKind::$scalar_kind)|* => {
+                            let first_ty = ty;
+                            let mut component_groups =
+                                ArrayVec::<ArrayVec<_, { crate::VectorSize::MAX }>, N>::new();
+                            component_groups.push(crate::proc::flatten_compose(
+                                first_ty,
+                                components,
+                                eval.expressions,
+                                eval.types,
+                            ).collect());
+                            component_groups.extend(
+                                exprs
+                                    .map(|expr| {
+                                        sanitize!(expr).and_then(|expr| match expr {
+                                            &Expression::Compose { ty, ref components }
+                                                if &eval.types[ty].inner
+                                                    == &eval.types[first_ty].inner =>
+                                            {
+                                                Ok(crate::proc::flatten_compose(
+                                                    ty,
+                                                    components,
+                                                    eval.expressions,
+                                                    eval.types,
+                                                ).collect())
+                                            }
+                                            _ => Err(err.clone()),
+                                        })
+                                    })
+                                    .collect::<Result<ArrayVec<_, { crate::VectorSize::MAX }>, _>>(
+                                    )?,
+                            );
+                            let component_groups = component_groups.into_inner().unwrap();
+                            let mut new_components =
+                                ArrayVec::<_, { crate::VectorSize::MAX }>::new();
+                            for idx in 0..(size as u8).into() {
+                                let group = component_groups
+                                    .iter()
+                                    .map(|cs| cs[idx])
+                                    .collect::<ArrayVec<_, N>>()
+                                    .into_inner()
+                                    .unwrap();
+                                new_components.push($ident(
+                                    eval,
+                                    span,
+                                    group,
+                                    handler.clone(),
+                                )?);
+                            }
+                            Ok(Expression::Compose {
+                                ty: first_ty,
+                                components: new_components.into_iter().collect(),
+                            })
+                        }
+                        _ => return Err(err),
+                    },
+                    _ => return Err(err),
+                },
+                _ => return Err(err),
+            }?;
+            eval.register_evaluated_expr(new_expr, span)
+        }
+
+        with_dollar_sign! {
+            ($d:tt) => {
+                #[allow(unused)]
+                #[doc = concat!(
+                    "A convenience macro for using the same RHS for each [`",
+                    stringify!($target),
+                    "`] variant in a call to [`",
+                    stringify!($ident),
+                    "`].",
+                )]
+                macro_rules! $ident {
+                    (
+                        $eval:expr,
+                        $span:expr,
+                        [$d ($d expr:expr),+ $d (,)?],
+                        |$d ($d arg:ident),+| $d tt:tt
+                    ) => {
+                        $ident($eval, $span, [$d ($d expr),+], |args| match args {
+                            $(
+                                $target::$mapping([$d ($d arg),+]) => {
+                                    let res = $d tt;
+                                    Result::map(res, $target::$mapping)
+                                },
+                            )+
+                        })
+                    };
+                }
+            };
+        }
+    };
+}
+
+gen_component_wise_extractor! {
+    component_wise_scalar -> Scalar,
+    literals: [
+        AbstractFloat => AbstractFloat: f64,
+        F32 => F32: f32,
+        AbstractInt => AbstractInt: i64,
+        U32 => U32: u32,
+        I32 => I32: i32,
+    ],
+    scalar_kinds: [
+        Float,
+        AbstractFloat,
+        Sint,
+        Uint,
+        AbstractInt,
+    ],
+}
+
+gen_component_wise_extractor! {
+    component_wise_float -> Float,
+    literals: [
+        AbstractFloat => Abstract: f64,
+        F32 => F32: f32,
+    ],
+    scalar_kinds: [
+        Float,
+        AbstractFloat,
+    ],
+}
+
+gen_component_wise_extractor! {
+    component_wise_concrete_int -> ConcreteInt,
+    literals: [
+        U32 => U32: u32,
+        I32 => I32: i32,
+    ],
+    scalar_kinds: [
+        Sint,
+        Uint,
+    ],
+}
+
+gen_component_wise_extractor! {
+    component_wise_signed -> Signed,
+    literals: [
+        AbstractFloat => AbstractFloat: f64,
+        AbstractInt => AbstractInt: i64,
+        F32 => F32: f32,
+        I32 => I32: i32,
+    ],
+    scalar_kinds: [
+        Sint,
+        AbstractInt,
+        Float,
+        AbstractFloat,
+    ],
+}
+
+#[derive(Debug)]
+enum Behavior {
+    Wgsl,
+    Glsl,
+}
+
+/// A context for evaluating constant expressions.
+///
+/// A `ConstantEvaluator` points at an expression arena to which it can append
+/// newly evaluated expressions: you pass [`try_eval_and_append`] whatever kind
+/// of Naga [`Expression`] you like, and if its value can be computed at compile
+/// time, `try_eval_and_append` appends an expression representing the computed
+/// value - a tree of [`Literal`], [`Compose`], [`ZeroValue`], and [`Swizzle`]
+/// expressions - to the arena. See the [`try_eval_and_append`] method for details.
+///
+/// A `ConstantEvaluator` also holds whatever information we need to carry out
+/// that evaluation: types, other constants, and so on.
+///
+/// [`try_eval_and_append`]: ConstantEvaluator::try_eval_and_append
+/// [`Compose`]: Expression::Compose
+/// [`ZeroValue`]: Expression::ZeroValue
+/// [`Literal`]: Expression::Literal
+/// [`Swizzle`]: Expression::Swizzle
+#[derive(Debug)]
+pub struct ConstantEvaluator<'a> {
+    /// Which language's evaluation rules we should follow.
+    behavior: Behavior,
+
+    /// The module's type arena.
+    ///
+    /// Because expressions like [`Splat`] contain type handles, we need to be
+    /// able to add new types to produce those expressions.
+    ///
+    /// [`Splat`]: Expression::Splat
+    types: &'a mut UniqueArena<Type>,
+
+    /// The module's constant arena.
+    constants: &'a Arena<Constant>,
+
+    /// The arena to which we are contributing expressions.
+    expressions: &'a mut Arena<Expression>,
+
+    /// When `self.expressions` refers to a function's local expression
+    /// arena, this needs to be populated
+    function_local_data: Option<FunctionLocalData<'a>>,
+}
+
+#[derive(Debug)]
+struct FunctionLocalData<'a> {
+    /// Global constant expressions
+    const_expressions: &'a Arena<Expression>,
+    /// Tracks the constness of expressions residing in `ConstantEvaluator.expressions`
+    expression_constness: &'a mut ExpressionConstnessTracker,
+    emitter: &'a mut super::Emitter,
+    block: &'a mut crate::Block,
+}
+
+#[derive(Debug)]
+pub struct ExpressionConstnessTracker {
+    inner: bit_set::BitSet,
+}
+
+impl ExpressionConstnessTracker {
+    pub fn new() -> Self {
+        Self {
+            inner: bit_set::BitSet::new(),
+        }
+    }
+
+    /// Forces the the expression to not be const
+    pub fn force_non_const(&mut self, value: Handle<Expression>) {
+        self.inner.remove(value.index());
+    }
+
+    fn insert(&mut self, value: Handle<Expression>) {
+        self.inner.insert(value.index());
+    }
+
+    pub fn is_const(&self, value: Handle<Expression>) -> bool {
+        self.inner.contains(value.index())
+    }
+
+    pub fn from_arena(arena: &Arena<Expression>) -> Self {
+        let mut tracker = Self::new();
+        for (handle, expr) in arena.iter() {
+            let insert = match *expr {
+                crate::Expression::Literal(_)
+                | crate::Expression::ZeroValue(_)
+                | crate::Expression::Constant(_) => true,
+                crate::Expression::Compose { ref components, .. } => {
+                    components.iter().all(|h| tracker.is_const(*h))
+                }
+                crate::Expression::Splat { value, .. } => tracker.is_const(value),
+                _ => false,
+            };
+            if insert {
+                tracker.insert(handle);
+            }
+        }
+        tracker
+    }
+}
+
+#[derive(Clone, Debug, thiserror::Error)]
+pub enum ConstantEvaluatorError {
+    #[error("Constants cannot access function arguments")]
+    FunctionArg,
+    #[error("Constants cannot access global variables")]
+    GlobalVariable,
+    #[error("Constants cannot access local variables")]
+    LocalVariable,
+    #[error("Cannot get the array length of a non array type")]
+    InvalidArrayLengthArg,
+    #[error("Constants cannot get the array length of a dynamically sized array")]
+    ArrayLengthDynamic,
+    #[error("Constants cannot call functions")]
+    Call,
+    #[error("Constants don't support workGroupUniformLoad")]
+    WorkGroupUniformLoadResult,
+    #[error("Constants don't support atomic functions")]
+    Atomic,
+    #[error("Constants don't support derivative functions")]
+    Derivative,
+    #[error("Constants don't support load expressions")]
+    Load,
+    #[error("Constants don't support image expressions")]
+    ImageExpression,
+    #[error("Constants don't support ray query expressions")]
+    RayQueryExpression,
+    #[error("Cannot access the type")]
+    InvalidAccessBase,
+    #[error("Cannot access at the index")]
+    InvalidAccessIndex,
+    #[error("Cannot access with index of type")]
+    InvalidAccessIndexTy,
+    #[error("Constants don't support array length expressions")]
+    ArrayLength,
+    #[error("Cannot cast scalar components of expression `{from}` to type `{to}`")]
+    InvalidCastArg { from: String, to: String },
+    #[error("Cannot apply the unary op to the argument")]
+    InvalidUnaryOpArg,
+    #[error("Cannot apply the binary op to the arguments")]
+    InvalidBinaryOpArgs,
+    #[error("Cannot apply math function to type")]
+    InvalidMathArg,
+    #[error("{0:?} built-in function expects {1:?} arguments but {2:?} were supplied")]
+    InvalidMathArgCount(crate::MathFunction, usize, usize),
+    #[error("value of `low` is greater than `high` for clamp built-in function")]
+    InvalidClamp,
+    #[error("Splat is defined only on scalar values")]
+    SplatScalarOnly,
+    #[error("Can only swizzle vector constants")]
+    SwizzleVectorOnly,
+    #[error("swizzle component not present in source expression")]
+    SwizzleOutOfBounds,
+    #[error("Type is not constructible")]
+    TypeNotConstructible,
+    #[error("Subexpression(s) are not constant")]
+    SubexpressionsAreNotConstant,
+    #[error("Not implemented as constant expression: {0}")]
+    NotImplemented(String),
+    #[error("{0} operation overflowed")]
+    Overflow(String),
+    #[error(
+        "the concrete type `{to_type}` cannot represent the abstract value `{value}` accurately"
+    )]
+    AutomaticConversionLossy {
+        value: String,
+        to_type: &'static str,
+    },
+    #[error("abstract floating-point values cannot be automatically converted to integers")]
+    AutomaticConversionFloatToInt { to_type: &'static str },
+    #[error("Division by zero")]
+    DivisionByZero,
+    #[error("Remainder by zero")]
+    RemainderByZero,
+    #[error("RHS of shift operation is greater than or equal to 32")]
+    ShiftedMoreThan32Bits,
+    #[error(transparent)]
+    Literal(#[from] crate::valid::LiteralError),
+}
+
+impl<'a> ConstantEvaluator<'a> {
+    /// Return a [`ConstantEvaluator`] that will add expressions to `module`'s
+    /// constant expression arena.
+    ///
+    /// Report errors according to WGSL's rules for constant evaluation.
+    pub fn for_wgsl_module(module: &'a mut crate::Module) -> Self {
+        Self::for_module(Behavior::Wgsl, module)
+    }
+
+    /// Return a [`ConstantEvaluator`] that will add expressions to `module`'s
+    /// constant expression arena.
+    ///
+    /// Report errors according to GLSL's rules for constant evaluation.
+    pub fn for_glsl_module(module: &'a mut crate::Module) -> Self {
+        Self::for_module(Behavior::Glsl, module)
+    }
+
+    fn for_module(behavior: Behavior, module: &'a mut crate::Module) -> Self {
+        Self {
+            behavior,
+            types: &mut module.types,
+            constants: &module.constants,
+            expressions: &mut module.const_expressions,
+            function_local_data: None,
+        }
+    }
+
+    /// Return a [`ConstantEvaluator`] that will add expressions to `function`'s
+    /// expression arena.
+    ///
+    /// Report errors according to WGSL's rules for constant evaluation.
+    pub fn for_wgsl_function(
+        module: &'a mut crate::Module,
+        expressions: &'a mut Arena<Expression>,
+        expression_constness: &'a mut ExpressionConstnessTracker,
+        emitter: &'a mut super::Emitter,
+        block: &'a mut crate::Block,
+    ) -> Self {
+        Self::for_function(
+            Behavior::Wgsl,
+            module,
+            expressions,
+            expression_constness,
+            emitter,
+            block,
+        )
+    }
+
+    /// Return a [`ConstantEvaluator`] that will add expressions to `function`'s
+    /// expression arena.
+    ///
+    /// Report errors according to GLSL's rules for constant evaluation.
+    pub fn for_glsl_function(
+        module: &'a mut crate::Module,
+        expressions: &'a mut Arena<Expression>,
+        expression_constness: &'a mut ExpressionConstnessTracker,
+        emitter: &'a mut super::Emitter,
+        block: &'a mut crate::Block,
+    ) -> Self {
+        Self::for_function(
+            Behavior::Glsl,
+            module,
+            expressions,
+            expression_constness,
+            emitter,
+            block,
+        )
+    }
+
+    fn for_function(
+        behavior: Behavior,
+        module: &'a mut crate::Module,
+        expressions: &'a mut Arena<Expression>,
+        expression_constness: &'a mut ExpressionConstnessTracker,
+        emitter: &'a mut super::Emitter,
+        block: &'a mut crate::Block,
+    ) -> Self {
+        Self {
+            behavior,
+            types: &mut module.types,
+            constants: &module.constants,
+            expressions,
+            function_local_data: Some(FunctionLocalData {
+                const_expressions: &module.const_expressions,
+                expression_constness,
+                emitter,
+                block,
+            }),
+        }
+    }
+
+    pub fn to_ctx(&self) -> crate::proc::GlobalCtx {
+        crate::proc::GlobalCtx {
+            types: self.types,
+            constants: self.constants,
+            const_expressions: match self.function_local_data {
+                Some(ref data) => data.const_expressions,
+                None => self.expressions,
+            },
+        }
+    }
+
+    fn check(&self, expr: Handle<Expression>) -> Result<(), ConstantEvaluatorError> {
+        if let Some(ref function_local_data) = self.function_local_data {
+            if !function_local_data.expression_constness.is_const(expr) {
+                log::debug!("check: SubexpressionsAreNotConstant");
+                return Err(ConstantEvaluatorError::SubexpressionsAreNotConstant);
+            }
+        }
+        Ok(())
+    }
+
+    fn check_and_get(
+        &mut self,
+        expr: Handle<Expression>,
+    ) -> Result<Handle<Expression>, ConstantEvaluatorError> {
+        match self.expressions[expr] {
+            Expression::Constant(c) => {
+                // Are we working in a function's expression arena, or the
+                // module's constant expression arena?
+                if let Some(ref function_local_data) = self.function_local_data {
+                    // Deep-copy the constant's value into our arena.
+                    self.copy_from(
+                        self.constants[c].init,
+                        function_local_data.const_expressions,
+                    )
+                } else {
+                    // "See through" the constant and use its initializer.
+                    Ok(self.constants[c].init)
+                }
+            }
+            _ => {
+                self.check(expr)?;
+                Ok(expr)
+            }
+        }
+    }
+
+    /// Try to evaluate `expr` at compile time.
+    ///
+    /// The `expr` argument can be any sort of Naga [`Expression`] you like. If
+    /// we can determine its value at compile time, we append an expression
+    /// representing its value - a tree of [`Literal`], [`Compose`],
+    /// [`ZeroValue`], and [`Swizzle`] expressions - to the expression arena
+    /// `self` contributes to.
+    ///
+    /// If `expr`'s value cannot be determined at compile time, return a an
+    /// error. If it's acceptable to evaluate `expr` at runtime, this error can
+    /// be ignored, and the caller can append `expr` to the arena itself.
+    ///
+    /// We only consider `expr` itself, without recursing into its operands. Its
+    /// operands must all have been produced by prior calls to
+    /// `try_eval_and_append`, to ensure that they have already been reduced to
+    /// an evaluated form if possible.
+    ///
+    /// [`Literal`]: Expression::Literal
+    /// [`Compose`]: Expression::Compose
+    /// [`ZeroValue`]: Expression::ZeroValue
+    /// [`Swizzle`]: Expression::Swizzle
+    pub fn try_eval_and_append(
+        &mut self,
+        expr: &Expression,
+        span: Span,
+    ) -> Result<Handle<Expression>, ConstantEvaluatorError> {
+        log::trace!("try_eval_and_append: {:?}", expr);
+        match *expr {
+            Expression::Constant(c) if self.function_local_data.is_none() => {
+                // "See through" the constant and use its initializer.
+                // This is mainly done to avoid having constants pointing to other constants.
+                Ok(self.constants[c].init)
+            }
+            Expression::Literal(_) | Expression::ZeroValue(_) | Expression::Constant(_) => {
+                self.register_evaluated_expr(expr.clone(), span)
+            }
+            Expression::Compose { ty, ref components } => {
+                let components = components
+                    .iter()
+                    .map(|component| self.check_and_get(*component))
+                    .collect::<Result<Vec<_>, _>>()?;
+                self.register_evaluated_expr(Expression::Compose { ty, components }, span)
+            }
+            Expression::Splat { size, value } => {
+                let value = self.check_and_get(value)?;
+                self.register_evaluated_expr(Expression::Splat { size, value }, span)
+            }
+            Expression::AccessIndex { base, index } => {
+                let base = self.check_and_get(base)?;
+
+                self.access(base, index as usize, span)
+            }
+            Expression::Access { base, index } => {
+                let base = self.check_and_get(base)?;
+                let index = self.check_and_get(index)?;
+
+                self.access(base, self.constant_index(index)?, span)
+            }
+            Expression::Swizzle {
+                size,
+                vector,
+                pattern,
+            } => {
+                let vector = self.check_and_get(vector)?;
+
+                self.swizzle(size, span, vector, pattern)
+            }
+            Expression::Unary { expr, op } => {
+                let expr = self.check_and_get(expr)?;
+
+                self.unary_op(op, expr, span)
+            }
+            Expression::Binary { left, right, op } => {
+                let left = self.check_and_get(left)?;
+                let right = self.check_and_get(right)?;
+
+                self.binary_op(op, left, right, span)
+            }
+            Expression::Math {
+                fun,
+                arg,
+                arg1,
+                arg2,
+                arg3,
+            } => {
+                let arg = self.check_and_get(arg)?;
+                let arg1 = arg1.map(|arg| self.check_and_get(arg)).transpose()?;
+                let arg2 = arg2.map(|arg| self.check_and_get(arg)).transpose()?;
+                let arg3 = arg3.map(|arg| self.check_and_get(arg)).transpose()?;
+
+                self.math(arg, arg1, arg2, arg3, fun, span)
+            }
+            Expression::As {
+                convert,
+                expr,
+                kind,
+            } => {
+                let expr = self.check_and_get(expr)?;
+
+                match convert {
+                    Some(width) => self.cast(expr, crate::Scalar { kind, width }, span),
+                    None => Err(ConstantEvaluatorError::NotImplemented(
+                        "bitcast built-in function".into(),
+                    )),
+                }
+            }
+            Expression::Select { .. } => Err(ConstantEvaluatorError::NotImplemented(
+                "select built-in function".into(),
+            )),
+            Expression::Relational { fun, .. } => Err(ConstantEvaluatorError::NotImplemented(
+                format!("{fun:?} built-in function"),
+            )),
+            Expression::ArrayLength(expr) => match self.behavior {
+                Behavior::Wgsl => Err(ConstantEvaluatorError::ArrayLength),
+                Behavior::Glsl => {
+                    let expr = self.check_and_get(expr)?;
+                    self.array_length(expr, span)
+                }
+            },
+            Expression::Load { .. } => Err(ConstantEvaluatorError::Load),
+            Expression::LocalVariable(_) => Err(ConstantEvaluatorError::LocalVariable),
+            Expression::Derivative { .. } => Err(ConstantEvaluatorError::Derivative),
+            Expression::CallResult { .. } => Err(ConstantEvaluatorError::Call),
+            Expression::WorkGroupUniformLoadResult { .. } => {
+                Err(ConstantEvaluatorError::WorkGroupUniformLoadResult)
+            }
+            Expression::AtomicResult { .. } => Err(ConstantEvaluatorError::Atomic),
+            Expression::FunctionArgument(_) => Err(ConstantEvaluatorError::FunctionArg),
+            Expression::GlobalVariable(_) => Err(ConstantEvaluatorError::GlobalVariable),
+            Expression::ImageSample { .. }
+            | Expression::ImageLoad { .. }
+            | Expression::ImageQuery { .. } => Err(ConstantEvaluatorError::ImageExpression),
+            Expression::RayQueryProceedResult | Expression::RayQueryGetIntersection { .. } => {
+                Err(ConstantEvaluatorError::RayQueryExpression)
+            }
+        }
+    }
+
+    /// Splat `value` to `size`, without using [`Splat`] expressions.
+    ///
+    /// This constructs [`Compose`] or [`ZeroValue`] expressions to
+    /// build a vector with the given `size` whose components are all
+    /// `value`.
+    ///
+    /// Use `span` as the span of the inserted expressions and
+    /// resulting types.
+    ///
+    /// [`Splat`]: Expression::Splat
+    /// [`Compose`]: Expression::Compose
+    /// [`ZeroValue`]: Expression::ZeroValue
+    fn splat(
+        &mut self,
+        value: Handle<Expression>,
+        size: crate::VectorSize,
+        span: Span,
+    ) -> Result<Handle<Expression>, ConstantEvaluatorError> {
+        match self.expressions[value] {
+            Expression::Literal(literal) => {
+                let scalar = literal.scalar();
+                let ty = self.types.insert(
+                    Type {
+                        name: None,
+                        inner: TypeInner::Vector { size, scalar },
+                    },
+                    span,
+                );
+                let expr = Expression::Compose {
+                    ty,
+                    components: vec![value; size as usize],
+                };
+                self.register_evaluated_expr(expr, span)
+            }
+            Expression::ZeroValue(ty) => {
+                let inner = match self.types[ty].inner {
+                    TypeInner::Scalar(scalar) => TypeInner::Vector { size, scalar },
+                    _ => return Err(ConstantEvaluatorError::SplatScalarOnly),
+                };
+                let res_ty = self.types.insert(Type { name: None, inner }, span);
+                let expr = Expression::ZeroValue(res_ty);
+                self.register_evaluated_expr(expr, span)
+            }
+            _ => Err(ConstantEvaluatorError::SplatScalarOnly),
+        }
+    }
+
+    fn swizzle(
+        &mut self,
+        size: crate::VectorSize,
+        span: Span,
+        src_constant: Handle<Expression>,
+        pattern: [crate::SwizzleComponent; 4],
+    ) -> Result<Handle<Expression>, ConstantEvaluatorError> {
+        let mut get_dst_ty = |ty| match self.types[ty].inner {
+            crate::TypeInner::Vector { size: _, scalar } => Ok(self.types.insert(
+                Type {
+                    name: None,
+                    inner: crate::TypeInner::Vector { size, scalar },
+                },
+                span,
+            )),
+            _ => Err(ConstantEvaluatorError::SwizzleVectorOnly),
+        };
+
+        match self.expressions[src_constant] {
+            Expression::ZeroValue(ty) => {
+                let dst_ty = get_dst_ty(ty)?;
+                let expr = Expression::ZeroValue(dst_ty);
+                self.register_evaluated_expr(expr, span)
+            }
+            Expression::Splat { value, .. } => {
+                let expr = Expression::Splat { size, value };
+                self.register_evaluated_expr(expr, span)
+            }
+            Expression::Compose { ty, ref components } => {
+                let dst_ty = get_dst_ty(ty)?;
+
+                let mut flattened = [src_constant; 4]; // dummy value
+                let len =
+                    crate::proc::flatten_compose(ty, components, self.expressions, self.types)
+                        .zip(flattened.iter_mut())
+                        .map(|(component, elt)| *elt = component)
+                        .count();
+                let flattened = &flattened[..len];
+
+                let swizzled_components = pattern[..size as usize]
+                    .iter()
+                    .map(|&sc| {
+                        let sc = sc as usize;
+                        if let Some(elt) = flattened.get(sc) {
+                            Ok(*elt)
+                        } else {
+                            Err(ConstantEvaluatorError::SwizzleOutOfBounds)
+                        }
+                    })
+                    .collect::<Result<Vec<Handle<Expression>>, _>>()?;
+                let expr = Expression::Compose {
+                    ty: dst_ty,
+                    components: swizzled_components,
+                };
+                self.register_evaluated_expr(expr, span)
+            }
+            _ => Err(ConstantEvaluatorError::SwizzleVectorOnly),
+        }
+    }
+
+    fn math(
+        &mut self,
+        arg: Handle<Expression>,
+        arg1: Option<Handle<Expression>>,
+        arg2: Option<Handle<Expression>>,
+        arg3: Option<Handle<Expression>>,
+        fun: crate::MathFunction,
+        span: Span,
+    ) -> Result<Handle<Expression>, ConstantEvaluatorError> {
+        let expected = fun.argument_count();
+        let given = Some(arg)
+            .into_iter()
+            .chain(arg1)
+            .chain(arg2)
+            .chain(arg3)
+            .count();
+        if expected != given {
+            return Err(ConstantEvaluatorError::InvalidMathArgCount(
+                fun, expected, given,
+            ));
+        }
+
+        // NOTE: We try to match the declaration order of `MathFunction` here.
+        match fun {
+            // comparison
+            crate::MathFunction::Abs => {
+                component_wise_scalar(self, span, [arg], |args| match args {
+                    Scalar::AbstractFloat([e]) => Ok(Scalar::AbstractFloat([e.abs()])),
+                    Scalar::F32([e]) => Ok(Scalar::F32([e.abs()])),
+                    Scalar::AbstractInt([e]) => Ok(Scalar::AbstractInt([e.abs()])),
+                    Scalar::I32([e]) => Ok(Scalar::I32([e.wrapping_abs()])),
+                    Scalar::U32([e]) => Ok(Scalar::U32([e])), // TODO: just re-use the expression, ezpz
+                })
+            }
+            crate::MathFunction::Min => {
+                component_wise_scalar!(self, span, [arg, arg1.unwrap()], |e1, e2| {
+                    Ok([e1.min(e2)])
+                })
+            }
+            crate::MathFunction::Max => {
+                component_wise_scalar!(self, span, [arg, arg1.unwrap()], |e1, e2| {
+                    Ok([e1.max(e2)])
+                })
+            }
+            crate::MathFunction::Clamp => {
+                component_wise_scalar!(
+                    self,
+                    span,
+                    [arg, arg1.unwrap(), arg2.unwrap()],
+                    |e, low, high| {
+                        if low > high {
+                            Err(ConstantEvaluatorError::InvalidClamp)
+                        } else {
+                            Ok([e.clamp(low, high)])
+                        }
+                    }
+                )
+            }
+            crate::MathFunction::Saturate => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.clamp(0., 1.)]) })
+            }
+
+            // trigonometry
+            crate::MathFunction::Cos => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.cos()]) })
+            }
+            crate::MathFunction::Cosh => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.cosh()]) })
+            }
+            crate::MathFunction::Sin => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.sin()]) })
+            }
+            crate::MathFunction::Sinh => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.sinh()]) })
+            }
+            crate::MathFunction::Tan => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.tan()]) })
+            }
+            crate::MathFunction::Tanh => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.tanh()]) })
+            }
+            crate::MathFunction::Acos => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.acos()]) })
+            }
+            crate::MathFunction::Asin => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.asin()]) })
+            }
+            crate::MathFunction::Atan => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.atan()]) })
+            }
+            crate::MathFunction::Asinh => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.asinh()]) })
+            }
+            crate::MathFunction::Acosh => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.acosh()]) })
+            }
+            crate::MathFunction::Atanh => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.atanh()]) })
+            }
+            crate::MathFunction::Radians => {
+                component_wise_float!(self, span, [arg], |e1| { Ok([e1.to_radians()]) })
+            }
+            crate::MathFunction::Degrees => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.to_degrees()]) })
+            }
+
+            // decomposition
+            crate::MathFunction::Ceil => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.ceil()]) })
+            }
+            crate::MathFunction::Floor => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.floor()]) })
+            }
+            crate::MathFunction::Round => {
+                // TODO: Use `f{32,64}.round_ties_even()` when available on stable. This polyfill
+                // is shamelessly [~~stolen from~~ inspired by `ndarray-image`][polyfill source],
+                // which has licensing compatible with ours. See also
+                // <https://github.com/rust-lang/rust/issues/96710>.
+                //
+                // [polyfill source]: https://github.com/imeka/ndarray-ndimage/blob/8b14b4d6ecfbc96a8a052f802e342a7049c68d8f/src/lib.rs#L98
+                fn round_ties_even(x: f64) -> f64 {
+                    let i = x as i64;
+                    let f = (x - i as f64).abs();
+                    if f == 0.5 {
+                        if i & 1 == 1 {
+                            // -1.5, 1.5, 3.5, ...
+                            (x.abs() + 0.5).copysign(x)
+                        } else {
+                            (x.abs() - 0.5).copysign(x)
+                        }
+                    } else {
+                        x.round()
+                    }
+                }
+                component_wise_float(self, span, [arg], |e| match e {
+                    Float::Abstract([e]) => Ok(Float::Abstract([round_ties_even(e)])),
+                    Float::F32([e]) => Ok(Float::F32([(round_ties_even(e as f64) as f32)])),
+                })
+            }
+            crate::MathFunction::Fract => {
+                component_wise_float!(self, span, [arg], |e| {
+                    // N.B., Rust's definition of `fract` is `e - e.trunc()`, so we can't use that
+                    // here.
+                    Ok([e - e.floor()])
+                })
+            }
+            crate::MathFunction::Trunc => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.trunc()]) })
+            }
+
+            // exponent
+            crate::MathFunction::Exp => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.exp()]) })
+            }
+            crate::MathFunction::Exp2 => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.exp2()]) })
+            }
+            crate::MathFunction::Log => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.ln()]) })
+            }
+            crate::MathFunction::Log2 => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.log2()]) })
+            }
+            crate::MathFunction::Pow => {
+                component_wise_float!(self, span, [arg, arg1.unwrap()], |e1, e2| {
+                    Ok([e1.powf(e2)])
+                })
+            }
+
+            // computational
+            crate::MathFunction::Sign => {
+                component_wise_signed!(self, span, [arg], |e| { Ok([e.signum()]) })
+            }
+            crate::MathFunction::Fma => {
+                component_wise_float!(
+                    self,
+                    span,
+                    [arg, arg1.unwrap(), arg2.unwrap()],
+                    |e1, e2, e3| { Ok([e1.mul_add(e2, e3)]) }
+                )
+            }
+            crate::MathFunction::Step => {
+                component_wise_float!(self, span, [arg, arg1.unwrap()], |edge, x| {
+                    Ok([if edge <= x { 1.0 } else { 0.0 }])
+                })
+            }
+            crate::MathFunction::Sqrt => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.sqrt()]) })
+            }
+            crate::MathFunction::InverseSqrt => {
+                component_wise_float!(self, span, [arg], |e| { Ok([1. / e.sqrt()]) })
+            }
+
+            // bits
+            crate::MathFunction::CountTrailingZeros => {
+                component_wise_concrete_int!(self, span, [arg], |e| {
+                    #[allow(clippy::useless_conversion)]
+                    Ok([e
+                        .trailing_zeros()
+                        .try_into()
+                        .expect("bit count overflowed 32 bits, somehow!?")])
+                })
+            }
+            crate::MathFunction::CountLeadingZeros => {
+                component_wise_concrete_int!(self, span, [arg], |e| {
+                    #[allow(clippy::useless_conversion)]
+                    Ok([e
+                        .leading_zeros()
+                        .try_into()
+                        .expect("bit count overflowed 32 bits, somehow!?")])
+                })
+            }
+            crate::MathFunction::CountOneBits => {
+                component_wise_concrete_int!(self, span, [arg], |e| {
+                    #[allow(clippy::useless_conversion)]
+                    Ok([e
+                        .count_ones()
+                        .try_into()
+                        .expect("bit count overflowed 32 bits, somehow!?")])
+                })
+            }
+            crate::MathFunction::ReverseBits => {
+                component_wise_concrete_int!(self, span, [arg], |e| { Ok([e.reverse_bits()]) })
+            }
+
+            fun => Err(ConstantEvaluatorError::NotImplemented(format!(
+                "{fun:?} built-in function"
+            ))),
+        }
+    }
+
+    fn array_length(
+        &mut self,
+        array: Handle<Expression>,
+        span: Span,
+    ) -> Result<Handle<Expression>, ConstantEvaluatorError> {
+        match self.expressions[array] {
+            Expression::ZeroValue(ty) | Expression::Compose { ty, .. } => {
+                match self.types[ty].inner {
+                    TypeInner::Array { size, .. } => match size {
+                        crate::ArraySize::Constant(len) => {
+                            let expr = Expression::Literal(Literal::U32(len.get()));
+                            self.register_evaluated_expr(expr, span)
+                        }
+                        crate::ArraySize::Dynamic => {
+                            Err(ConstantEvaluatorError::ArrayLengthDynamic)
+                        }
+                    },
+                    _ => Err(ConstantEvaluatorError::InvalidArrayLengthArg),
+                }
+            }
+            _ => Err(ConstantEvaluatorError::InvalidArrayLengthArg),
+        }
+    }
+
+    fn access(
+        &mut self,
+        base: Handle<Expression>,
+        index: usize,
+        span: Span,
+    ) -> Result<Handle<Expression>, ConstantEvaluatorError> {
+        match self.expressions[base] {
+            Expression::ZeroValue(ty) => {
+                let ty_inner = &self.types[ty].inner;
+                let components = ty_inner
+                    .components()
+                    .ok_or(ConstantEvaluatorError::InvalidAccessBase)?;
+
+                if index >= components as usize {
+                    Err(ConstantEvaluatorError::InvalidAccessBase)
+                } else {
+                    let ty_res = ty_inner
+                        .component_type(index)
+                        .ok_or(ConstantEvaluatorError::InvalidAccessIndex)?;
+                    let ty = match ty_res {
+                        crate::proc::TypeResolution::Handle(ty) => ty,
+                        crate::proc::TypeResolution::Value(inner) => {
+                            self.types.insert(Type { name: None, inner }, span)
+                        }
+                    };
+                    self.register_evaluated_expr(Expression::ZeroValue(ty), span)
+                }
+            }
+            Expression::Splat { size, value } => {
+                if index >= size as usize {
+                    Err(ConstantEvaluatorError::InvalidAccessBase)
+                } else {
+                    Ok(value)
+                }
+            }
+            Expression::Compose { ty, ref components } => {
+                let _ = self.types[ty]
+                    .inner
+                    .components()
+                    .ok_or(ConstantEvaluatorError::InvalidAccessBase)?;
+
+                crate::proc::flatten_compose(ty, components, self.expressions, self.types)
+                    .nth(index)
+                    .ok_or(ConstantEvaluatorError::InvalidAccessIndex)
+            }
+            _ => Err(ConstantEvaluatorError::InvalidAccessBase),
+        }
+    }
+
+    fn constant_index(&self, expr: Handle<Expression>) -> Result<usize, ConstantEvaluatorError> {
+        match self.expressions[expr] {
+            Expression::ZeroValue(ty)
+                if matches!(
+                    self.types[ty].inner,
+                    crate::TypeInner::Scalar(crate::Scalar {
+                        kind: ScalarKind::Uint,
+                        ..
+                    })
+                ) =>
+            {
+                Ok(0)
+            }
+            Expression::Literal(Literal::U32(index)) => Ok(index as usize),
+            _ => Err(ConstantEvaluatorError::InvalidAccessIndexTy),
+        }
+    }
+
+    /// Lower [`ZeroValue`] and [`Splat`] expressions to [`Literal`] and [`Compose`] expressions.
+    ///
+    /// [`ZeroValue`]: Expression::ZeroValue
+    /// [`Splat`]: Expression::Splat
+    /// [`Literal`]: Expression::Literal
+    /// [`Compose`]: Expression::Compose
+    fn eval_zero_value_and_splat(
+        &mut self,
+        expr: Handle<Expression>,
+        span: Span,
+    ) -> Result<Handle<Expression>, ConstantEvaluatorError> {
+        match self.expressions[expr] {
+            Expression::ZeroValue(ty) => self.eval_zero_value_impl(ty, span),
+            Expression::Splat { size, value } => self.splat(value, size, span),
+            _ => Ok(expr),
+        }
+    }
+
+    /// Lower [`ZeroValue`] expressions to [`Literal`] and [`Compose`] expressions.
+    ///
+    /// [`ZeroValue`]: Expression::ZeroValue
+    /// [`Literal`]: Expression::Literal
+    /// [`Compose`]: Expression::Compose
+    fn eval_zero_value(
+        &mut self,
+        expr: Handle<Expression>,
+        span: Span,
+    ) -> Result<Handle<Expression>, ConstantEvaluatorError> {
+        match self.expressions[expr] {
+            Expression::ZeroValue(ty) => self.eval_zero_value_impl(ty, span),
+            _ => Ok(expr),
+        }
+    }
+
+    /// Lower [`ZeroValue`] expressions to [`Literal`] and [`Compose`] expressions.
+    ///
+    /// [`ZeroValue`]: Expression::ZeroValue
+    /// [`Literal`]: Expression::Literal
+    /// [`Compose`]: Expression::Compose
+    fn eval_zero_value_impl(
+        &mut self,
+        ty: Handle<Type>,
+        span: Span,
+    ) -> Result<Handle<Expression>, ConstantEvaluatorError> {
+        match self.types[ty].inner {
+            TypeInner::Scalar(scalar) => {
+                let expr = Expression::Literal(
+                    Literal::zero(scalar).ok_or(ConstantEvaluatorError::TypeNotConstructible)?,
+                );
+                self.register_evaluated_expr(expr, span)
+            }
+            TypeInner::Vector { size, scalar } => {
+                let scalar_ty = self.types.insert(
+                    Type {
+                        name: None,
+                        inner: TypeInner::Scalar(scalar),
+                    },
+                    span,
+                );
+                let el = self.eval_zero_value_impl(scalar_ty, span)?;
+                let expr = Expression::Compose {
+                    ty,
+                    components: vec![el; size as usize],
+                };
+                self.register_evaluated_expr(expr, span)
+            }
+            TypeInner::Matrix {
+                columns,
+                rows,
+                scalar,
+            } => {
+                let vec_ty = self.types.insert(
+                    Type {
+                        name: None,
+                        inner: TypeInner::Vector { size: rows, scalar },
+                    },
+                    span,
+                );
+                let el = self.eval_zero_value_impl(vec_ty, span)?;
+                let expr = Expression::Compose {
+                    ty,
+                    components: vec![el; columns as usize],
+                };
+                self.register_evaluated_expr(expr, span)
+            }
+            TypeInner::Array {
+                base,
+                size: ArraySize::Constant(size),
+                ..
+            } => {
+                let el = self.eval_zero_value_impl(base, span)?;
+                let expr = Expression::Compose {
+                    ty,
+                    components: vec![el; size.get() as usize],
+                };
+                self.register_evaluated_expr(expr, span)
+            }
+            TypeInner::Struct { ref members, .. } => {
+                let types: Vec<_> = members.iter().map(|m| m.ty).collect();
+                let mut components = Vec::with_capacity(members.len());
+                for ty in types {
+                    components.push(self.eval_zero_value_impl(ty, span)?);
+                }
+                let expr = Expression::Compose { ty, components };
+                self.register_evaluated_expr(expr, span)
+            }
+            _ => Err(ConstantEvaluatorError::TypeNotConstructible),
+        }
+    }
+
+    /// Convert the scalar components of `expr` to `target`.
+    ///
+    /// Treat `span` as the location of the resulting expression.
+    pub fn cast(
+        &mut self,
+        expr: Handle<Expression>,
+        target: crate::Scalar,
+        span: Span,
+    ) -> Result<Handle<Expression>, ConstantEvaluatorError> {
+        use crate::Scalar as Sc;
+
+        let expr = self.eval_zero_value(expr, span)?;
+
+        let make_error = || -> Result<_, ConstantEvaluatorError> {
+            let from = format!("{:?} {:?}", expr, self.expressions[expr]);
+
+            #[cfg(feature = "wgsl-in")]
+            let to = target.to_wgsl();
+
+            #[cfg(not(feature = "wgsl-in"))]
+            let to = format!("{target:?}");
+
+            Err(ConstantEvaluatorError::InvalidCastArg { from, to })
+        };
+
+        let expr = match self.expressions[expr] {
+            Expression::Literal(literal) => {
+                let literal = match target {
+                    Sc::I32 => Literal::I32(match literal {
+                        Literal::I32(v) => v,
+                        Literal::U32(v) => v as i32,
+                        Literal::F32(v) => v as i32,
+                        Literal::Bool(v) => v as i32,
+                        Literal::F64(_) | Literal::I64(_) => {
+                            return make_error();
+                        }
+                        Literal::AbstractInt(v) => i32::try_from_abstract(v)?,
+                        Literal::AbstractFloat(v) => i32::try_from_abstract(v)?,
+                    }),
+                    Sc::U32 => Literal::U32(match literal {
+                        Literal::I32(v) => v as u32,
+                        Literal::U32(v) => v,
+                        Literal::F32(v) => v as u32,
+                        Literal::Bool(v) => v as u32,
+                        Literal::F64(_) | Literal::I64(_) => {
+                            return make_error();
+                        }
+                        Literal::AbstractInt(v) => u32::try_from_abstract(v)?,
+                        Literal::AbstractFloat(v) => u32::try_from_abstract(v)?,
+                    }),
+                    Sc::F32 => Literal::F32(match literal {
+                        Literal::I32(v) => v as f32,
+                        Literal::U32(v) => v as f32,
+                        Literal::F32(v) => v,
+                        Literal::Bool(v) => v as u32 as f32,
+                        Literal::F64(_) | Literal::I64(_) => {
+                            return make_error();
+                        }
+                        Literal::AbstractInt(v) => f32::try_from_abstract(v)?,
+                        Literal::AbstractFloat(v) => f32::try_from_abstract(v)?,
+                    }),
+                    Sc::F64 => Literal::F64(match literal {
+                        Literal::I32(v) => v as f64,
+                        Literal::U32(v) => v as f64,
+                        Literal::F32(v) => v as f64,
+                        Literal::F64(v) => v,
+                        Literal::Bool(v) => v as u32 as f64,
+                        Literal::I64(_) => return make_error(),
+                        Literal::AbstractInt(v) => f64::try_from_abstract(v)?,
+                        Literal::AbstractFloat(v) => f64::try_from_abstract(v)?,
+                    }),
+                    Sc::BOOL => Literal::Bool(match literal {
+                        Literal::I32(v) => v != 0,
+                        Literal::U32(v) => v != 0,
+                        Literal::F32(v) => v != 0.0,
+                        Literal::Bool(v) => v,
+                        Literal::F64(_)
+                        | Literal::I64(_)
+                        | Literal::AbstractInt(_)
+                        | Literal::AbstractFloat(_) => {
+                            return make_error();
+                        }
+                    }),
+                    Sc::ABSTRACT_FLOAT => Literal::AbstractFloat(match literal {
+                        Literal::AbstractInt(v) => {
+                            // Overflow is forbidden, but inexact conversions
+                            // are fine. The range of f64 is far larger than
+                            // that of i64, so we don't have to check anything
+                            // here.
+                            v as f64
+                        }
+                        Literal::AbstractFloat(v) => v,
+                        _ => return make_error(),
+                    }),
+                    _ => {
+                        log::debug!("Constant evaluator refused to convert value to {target:?}");
+                        return make_error();
+                    }
+                };
+                Expression::Literal(literal)
+            }
+            Expression::Compose {
+                ty,
+                components: ref src_components,
+            } => {
+                let ty_inner = match self.types[ty].inner {
+                    TypeInner::Vector { size, .. } => TypeInner::Vector {
+                        size,
+                        scalar: target,
+                    },
+                    TypeInner::Matrix { columns, rows, .. } => TypeInner::Matrix {
+                        columns,
+                        rows,
+                        scalar: target,
+                    },
+                    _ => return make_error(),
+                };
+
+                let mut components = src_components.clone();
+                for component in &mut components {
+                    *component = self.cast(*component, target, span)?;
+                }
+
+                let ty = self.types.insert(
+                    Type {
+                        name: None,
+                        inner: ty_inner,
+                    },
+                    span,
+                );
+
+                Expression::Compose { ty, components }
+            }
+            Expression::Splat { size, value } => {
+                let value_span = self.expressions.get_span(value);
+                let cast_value = self.cast(value, target, value_span)?;
+                Expression::Splat {
+                    size,
+                    value: cast_value,
+                }
+            }
+            _ => return make_error(),
+        };
+
+        self.register_evaluated_expr(expr, span)
+    }
+
+    /// Convert the scalar leaves of  `expr` to `target`, handling arrays.
+    ///
+    /// `expr` must be a `Compose` expression whose type is a scalar, vector,
+    /// matrix, or nested arrays of such.
+    ///
+    /// This is basically the same as the [`cast`] method, except that that
+    /// should only handle Naga [`As`] expressions, which cannot convert arrays.
+    ///
+    /// Treat `span` as the location of the resulting expression.
+    ///
+    /// [`cast`]: ConstantEvaluator::cast
+    /// [`As`]: crate::Expression::As
+    pub fn cast_array(
+        &mut self,
+        expr: Handle<Expression>,
+        target: crate::Scalar,
+        span: Span,
+    ) -> Result<Handle<Expression>, ConstantEvaluatorError> {
+        let Expression::Compose { ty, ref components } = self.expressions[expr] else {
+            return self.cast(expr, target, span);
+        };
+
+        let crate::TypeInner::Array {
+            base: _,
+            size,
+            stride: _,
+        } = self.types[ty].inner
+        else {
+            return self.cast(expr, target, span);
+        };
+
+        let mut components = components.clone();
+        for component in &mut components {
+            *component = self.cast_array(*component, target, span)?;
+        }
+
+        let first = components.first().unwrap();
+        let new_base = match self.resolve_type(*first)? {
+            crate::proc::TypeResolution::Handle(ty) => ty,
+            crate::proc::TypeResolution::Value(inner) => {
+                self.types.insert(Type { name: None, inner }, span)
+            }
+        };
+        let new_base_stride = self.types[new_base].inner.size(self.to_ctx());
+        let new_array_ty = self.types.insert(
+            Type {
+                name: None,
+                inner: TypeInner::Array {
+                    base: new_base,
+                    size,
+                    stride: new_base_stride,
+                },
+            },
+            span,
+        );
+
+        let compose = Expression::Compose {
+            ty: new_array_ty,
+            components,
+        };
+        self.register_evaluated_expr(compose, span)
+    }
+
+    fn unary_op(
+        &mut self,
+        op: UnaryOperator,
+        expr: Handle<Expression>,
+        span: Span,
+    ) -> Result<Handle<Expression>, ConstantEvaluatorError> {
+        let expr = self.eval_zero_value_and_splat(expr, span)?;
+
+        let expr = match self.expressions[expr] {
+            Expression::Literal(value) => Expression::Literal(match op {
+                UnaryOperator::Negate => match value {
+                    Literal::I32(v) => Literal::I32(v.wrapping_neg()),
+                    Literal::F32(v) => Literal::F32(-v),
+                    Literal::AbstractInt(v) => Literal::AbstractInt(v.wrapping_neg()),
+                    Literal::AbstractFloat(v) => Literal::AbstractFloat(-v),
+                    _ => return Err(ConstantEvaluatorError::InvalidUnaryOpArg),
+                },
+                UnaryOperator::LogicalNot => match value {
+                    Literal::Bool(v) => Literal::Bool(!v),
+                    _ => return Err(ConstantEvaluatorError::InvalidUnaryOpArg),
+                },
+                UnaryOperator::BitwiseNot => match value {
+                    Literal::I32(v) => Literal::I32(!v),
+                    Literal::U32(v) => Literal::U32(!v),
+                    Literal::AbstractInt(v) => Literal::AbstractInt(!v),
+                    _ => return Err(ConstantEvaluatorError::InvalidUnaryOpArg),
+                },
+            }),
+            Expression::Compose {
+                ty,
+                components: ref src_components,
+            } => {
+                match self.types[ty].inner {
+                    TypeInner::Vector { .. } | TypeInner::Matrix { .. } => (),
+                    _ => return Err(ConstantEvaluatorError::InvalidUnaryOpArg),
+                }
+
+                let mut components = src_components.clone();
+                for component in &mut components {
+                    *component = self.unary_op(op, *component, span)?;
+                }
+
+                Expression::Compose { ty, components }
+            }
+            _ => return Err(ConstantEvaluatorError::InvalidUnaryOpArg),
+        };
+
+        self.register_evaluated_expr(expr, span)
+    }
+
+    fn binary_op(
+        &mut self,
+        op: BinaryOperator,
+        left: Handle<Expression>,
+        right: Handle<Expression>,
+        span: Span,
+    ) -> Result<Handle<Expression>, ConstantEvaluatorError> {
+        let left = self.eval_zero_value_and_splat(left, span)?;
+        let right = self.eval_zero_value_and_splat(right, span)?;
+
+        let expr = match (&self.expressions[left], &self.expressions[right]) {
+            (&Expression::Literal(left_value), &Expression::Literal(right_value)) => {
+                let literal = match op {
+                    BinaryOperator::Equal => Literal::Bool(left_value == right_value),
+                    BinaryOperator::NotEqual => Literal::Bool(left_value != right_value),
+                    BinaryOperator::Less => Literal::Bool(left_value < right_value),
+                    BinaryOperator::LessEqual => Literal::Bool(left_value <= right_value),
+                    BinaryOperator::Greater => Literal::Bool(left_value > right_value),
+                    BinaryOperator::GreaterEqual => Literal::Bool(left_value >= right_value),
+
+                    _ => match (left_value, right_value) {
+                        (Literal::I32(a), Literal::I32(b)) => Literal::I32(match op {
+                            BinaryOperator::Add => a.checked_add(b).ok_or_else(|| {
+                                ConstantEvaluatorError::Overflow("addition".into())
+                            })?,
+                            BinaryOperator::Subtract => a.checked_sub(b).ok_or_else(|| {
+                                ConstantEvaluatorError::Overflow("subtraction".into())
+                            })?,
+                            BinaryOperator::Multiply => a.checked_mul(b).ok_or_else(|| {
+                                ConstantEvaluatorError::Overflow("multiplication".into())
+                            })?,
+                            BinaryOperator::Divide => a.checked_div(b).ok_or_else(|| {
+                                if b == 0 {
+                                    ConstantEvaluatorError::DivisionByZero
+                                } else {
+                                    ConstantEvaluatorError::Overflow("division".into())
+                                }
+                            })?,
+                            BinaryOperator::Modulo => a.checked_rem(b).ok_or_else(|| {
+                                if b == 0 {
+                                    ConstantEvaluatorError::RemainderByZero
+                                } else {
+                                    ConstantEvaluatorError::Overflow("remainder".into())
+                                }
+                            })?,
+                            BinaryOperator::And => a & b,
+                            BinaryOperator::ExclusiveOr => a ^ b,
+                            BinaryOperator::InclusiveOr => a | b,
+                            _ => return Err(ConstantEvaluatorError::InvalidBinaryOpArgs),
+                        }),
+                        (Literal::I32(a), Literal::U32(b)) => Literal::I32(match op {
+                            BinaryOperator::ShiftLeft => a
+                                .checked_shl(b)
+                                .ok_or(ConstantEvaluatorError::ShiftedMoreThan32Bits)?,
+                            BinaryOperator::ShiftRight => a
+                                .checked_shr(b)
+                                .ok_or(ConstantEvaluatorError::ShiftedMoreThan32Bits)?,
+                            _ => return Err(ConstantEvaluatorError::InvalidBinaryOpArgs),
+                        }),
+                        (Literal::U32(a), Literal::U32(b)) => Literal::U32(match op {
+                            BinaryOperator::Add => a.checked_add(b).ok_or_else(|| {
+                                ConstantEvaluatorError::Overflow("addition".into())
+                            })?,
+                            BinaryOperator::Subtract => a.checked_sub(b).ok_or_else(|| {
+                                ConstantEvaluatorError::Overflow("subtraction".into())
+                            })?,
+                            BinaryOperator::Multiply => a.checked_mul(b).ok_or_else(|| {
+                                ConstantEvaluatorError::Overflow("multiplication".into())
+                            })?,
+                            BinaryOperator::Divide => a
+                                .checked_div(b)
+                                .ok_or(ConstantEvaluatorError::DivisionByZero)?,
+                            BinaryOperator::Modulo => a
+                                .checked_rem(b)
+                                .ok_or(ConstantEvaluatorError::RemainderByZero)?,
+                            BinaryOperator::And => a & b,
+                            BinaryOperator::ExclusiveOr => a ^ b,
+                            BinaryOperator::InclusiveOr => a | b,
+                            BinaryOperator::ShiftLeft => a
+                                .checked_shl(b)
+                                .ok_or(ConstantEvaluatorError::ShiftedMoreThan32Bits)?,
+                            BinaryOperator::ShiftRight => a
+                                .checked_shr(b)
+                                .ok_or(ConstantEvaluatorError::ShiftedMoreThan32Bits)?,
+                            _ => return Err(ConstantEvaluatorError::InvalidBinaryOpArgs),
+                        }),
+                        (Literal::F32(a), Literal::F32(b)) => Literal::F32(match op {
+                            BinaryOperator::Add => a + b,
+                            BinaryOperator::Subtract => a - b,
+                            BinaryOperator::Multiply => a * b,
+                            BinaryOperator::Divide => a / b,
+                            BinaryOperator::Modulo => a % b,
+                            _ => return Err(ConstantEvaluatorError::InvalidBinaryOpArgs),
+                        }),
+                        (Literal::AbstractInt(a), Literal::AbstractInt(b)) => {
+                            Literal::AbstractInt(match op {
+                                BinaryOperator::Add => a.checked_add(b).ok_or_else(|| {
+                                    ConstantEvaluatorError::Overflow("addition".into())
+                                })?,
+                                BinaryOperator::Subtract => a.checked_sub(b).ok_or_else(|| {
+                                    ConstantEvaluatorError::Overflow("subtraction".into())
+                                })?,
+                                BinaryOperator::Multiply => a.checked_mul(b).ok_or_else(|| {
+                                    ConstantEvaluatorError::Overflow("multiplication".into())
+                                })?,
+                                BinaryOperator::Divide => a.checked_div(b).ok_or_else(|| {
+                                    if b == 0 {
+                                        ConstantEvaluatorError::DivisionByZero
+                                    } else {
+                                        ConstantEvaluatorError::Overflow("division".into())
+                                    }
+                                })?,
+                                BinaryOperator::Modulo => a.checked_rem(b).ok_or_else(|| {
+                                    if b == 0 {
+                                        ConstantEvaluatorError::RemainderByZero
+                                    } else {
+                                        ConstantEvaluatorError::Overflow("remainder".into())
+                                    }
+                                })?,
+                                BinaryOperator::And => a & b,
+                                BinaryOperator::ExclusiveOr => a ^ b,
+                                BinaryOperator::InclusiveOr => a | b,
+                                _ => return Err(ConstantEvaluatorError::InvalidBinaryOpArgs),
+                            })
+                        }
+                        (Literal::AbstractFloat(a), Literal::AbstractFloat(b)) => {
+                            Literal::AbstractFloat(match op {
+                                BinaryOperator::Add => a + b,
+                                BinaryOperator::Subtract => a - b,
+                                BinaryOperator::Multiply => a * b,
+                                BinaryOperator::Divide => a / b,
+                                BinaryOperator::Modulo => a % b,
+                                _ => return Err(ConstantEvaluatorError::InvalidBinaryOpArgs),
+                            })
+                        }
+                        (Literal::Bool(a), Literal::Bool(b)) => Literal::Bool(match op {
+                            BinaryOperator::LogicalAnd => a && b,
+                            BinaryOperator::LogicalOr => a || b,
+                            _ => return Err(ConstantEvaluatorError::InvalidBinaryOpArgs),
+                        }),
+                        _ => return Err(ConstantEvaluatorError::InvalidBinaryOpArgs),
+                    },
+                };
+                Expression::Literal(literal)
+            }
+            (
+                &Expression::Compose {
+                    components: ref src_components,
+                    ty,
+                },
+                &Expression::Literal(_),
+            ) => {
+                let mut components = src_components.clone();
+                for component in &mut components {
+                    *component = self.binary_op(op, *component, right, span)?;
+                }
+                Expression::Compose { ty, components }
+            }
+            (
+                &Expression::Literal(_),
+                &Expression::Compose {
+                    components: ref src_components,
+                    ty,
+                },
+            ) => {
+                let mut components = src_components.clone();
+                for component in &mut components {
+                    *component = self.binary_op(op, left, *component, span)?;
+                }
+                Expression::Compose { ty, components }
+            }
+            (
+                &Expression::Compose {
+                    components: ref left_components,
+                    ty: left_ty,
+                },
+                &Expression::Compose {
+                    components: ref right_components,
+                    ty: right_ty,
+                },
+            ) => {
+                // We have to make a copy of the component lists, because the
+                // call to `binary_op_vector` needs `&mut self`, but `self` owns
+                // the component lists.
+                let left_flattened = crate::proc::flatten_compose(
+                    left_ty,
+                    left_components,
+                    self.expressions,
+                    self.types,
+                );
+                let right_flattened = crate::proc::flatten_compose(
+                    right_ty,
+                    right_components,
+                    self.expressions,
+                    self.types,
+                );
+
+                // `flatten_compose` doesn't return an `ExactSizeIterator`, so
+                // make a reasonable guess of the capacity we'll need.
+                let mut flattened = Vec::with_capacity(left_components.len());
+                flattened.extend(left_flattened.zip(right_flattened));
+
+                match (&self.types[left_ty].inner, &self.types[right_ty].inner) {
+                    (
+                        &TypeInner::Vector {
+                            size: left_size, ..
+                        },
+                        &TypeInner::Vector {
+                            size: right_size, ..
+                        },
+                    ) if left_size == right_size => {
+                        self.binary_op_vector(op, left_size, &flattened, left_ty, span)?
+                    }
+                    _ => return Err(ConstantEvaluatorError::InvalidBinaryOpArgs),
+                }
+            }
+            _ => return Err(ConstantEvaluatorError::InvalidBinaryOpArgs),
+        };
+
+        self.register_evaluated_expr(expr, span)
+    }
+
+    fn binary_op_vector(
+        &mut self,
+        op: BinaryOperator,
+        size: crate::VectorSize,
+        components: &[(Handle<Expression>, Handle<Expression>)],
+        left_ty: Handle<Type>,
+        span: Span,
+    ) -> Result<Expression, ConstantEvaluatorError> {
+        let ty = match op {
+            // Relational operators produce vectors of booleans.
+            BinaryOperator::Equal
+            | BinaryOperator::NotEqual
+            | BinaryOperator::Less
+            | BinaryOperator::LessEqual
+            | BinaryOperator::Greater
+            | BinaryOperator::GreaterEqual => self.types.insert(
+                Type {
+                    name: None,
+                    inner: TypeInner::Vector {
+                        size,
+                        scalar: crate::Scalar::BOOL,
+                    },
+                },
+                span,
+            ),
+
+            // Other operators produce the same type as their left
+            // operand.
+            BinaryOperator::Add
+            | BinaryOperator::Subtract
+            | BinaryOperator::Multiply
+            | BinaryOperator::Divide
+            | BinaryOperator::Modulo
+            | BinaryOperator::And
+            | BinaryOperator::ExclusiveOr
+            | BinaryOperator::InclusiveOr
+            | BinaryOperator::LogicalAnd
+            | BinaryOperator::LogicalOr
+            | BinaryOperator::ShiftLeft
+            | BinaryOperator::ShiftRight => left_ty,
+        };
+
+        let components = components
+            .iter()
+            .map(|&(left, right)| self.binary_op(op, left, right, span))
+            .collect::<Result<Vec<_>, _>>()?;
+
+        Ok(Expression::Compose { ty, components })
+    }
+
+    /// Deep copy `expr` from `expressions` into `self.expressions`.
+    ///
+    /// Return the root of the new copy.
+    ///
+    /// This is used when we're evaluating expressions in a function's
+    /// expression arena that refer to a constant: we need to copy the
+    /// constant's value into the function's arena so we can operate on it.
+    fn copy_from(
+        &mut self,
+        expr: Handle<Expression>,
+        expressions: &Arena<Expression>,
+    ) -> Result<Handle<Expression>, ConstantEvaluatorError> {
+        let span = expressions.get_span(expr);
+        match expressions[expr] {
+            ref expr @ (Expression::Literal(_)
+            | Expression::Constant(_)
+            | Expression::ZeroValue(_)) => self.register_evaluated_expr(expr.clone(), span),
+            Expression::Compose { ty, ref components } => {
+                let mut components = components.clone();
+                for component in &mut components {
+                    *component = self.copy_from(*component, expressions)?;
+                }
+                self.register_evaluated_expr(Expression::Compose { ty, components }, span)
+            }
+            Expression::Splat { size, value } => {
+                let value = self.copy_from(value, expressions)?;
+                self.register_evaluated_expr(Expression::Splat { size, value }, span)
+            }
+            _ => {
+                log::debug!("copy_from: SubexpressionsAreNotConstant");
+                Err(ConstantEvaluatorError::SubexpressionsAreNotConstant)
+            }
+        }
+    }
+
+    fn register_evaluated_expr(
+        &mut self,
+        expr: Expression,
+        span: Span,
+    ) -> Result<Handle<Expression>, ConstantEvaluatorError> {
+        // It suffices to only check literals, since we only register one
+        // expression at a time, `Compose` expressions can only refer to other
+        // expressions, and `ZeroValue` expressions are always okay.
+        if let Expression::Literal(literal) = expr {
+            crate::valid::check_literal_value(literal)?;
+        }
+
+        if let Some(FunctionLocalData {
+            ref mut emitter,
+            ref mut block,
+            ref mut expression_constness,
+            ..
+        }) = self.function_local_data
+        {
+            let is_running = emitter.is_running();
+            let needs_pre_emit = expr.needs_pre_emit();
+            if is_running && needs_pre_emit {
+                block.extend(emitter.finish(self.expressions));
+                let h = self.expressions.append(expr, span);
+                emitter.start(self.expressions);
+                expression_constness.insert(h);
+                Ok(h)
+            } else {
+                let h = self.expressions.append(expr, span);
+                expression_constness.insert(h);
+                Ok(h)
+            }
+        } else {
+            Ok(self.expressions.append(expr, span))
+        }
+    }
+
+    fn resolve_type(
+        &self,
+        expr: Handle<Expression>,
+    ) -> Result<crate::proc::TypeResolution, ConstantEvaluatorError> {
+        use crate::proc::TypeResolution as Tr;
+        use crate::Expression as Ex;
+        let resolution = match self.expressions[expr] {
+            Ex::Literal(ref literal) => Tr::Value(literal.ty_inner()),
+            Ex::Constant(c) => Tr::Handle(self.constants[c].ty),
+            Ex::ZeroValue(ty) | Ex::Compose { ty, .. } => Tr::Handle(ty),
+            Ex::Splat { size, value } => {
+                let Tr::Value(TypeInner::Scalar(scalar)) = self.resolve_type(value)? else {
+                    return Err(ConstantEvaluatorError::SplatScalarOnly);
+                };
+                Tr::Value(TypeInner::Vector { scalar, size })
+            }
+            _ => {
+                log::debug!("resolve_type: SubexpressionsAreNotConstant");
+                return Err(ConstantEvaluatorError::SubexpressionsAreNotConstant);
+            }
+        };
+
+        Ok(resolution)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::vec;
+
+    use crate::{
+        Arena, Constant, Expression, Literal, ScalarKind, Type, TypeInner, UnaryOperator,
+        UniqueArena, VectorSize,
+    };
+
+    use super::{Behavior, ConstantEvaluator};
+
+    #[test]
+    fn unary_op() {
+        let mut types = UniqueArena::new();
+        let mut constants = Arena::new();
+        let mut const_expressions = Arena::new();
+
+        let scalar_ty = types.insert(
+            Type {
+                name: None,
+                inner: TypeInner::Scalar(crate::Scalar::I32),
+            },
+            Default::default(),
+        );
+
+        let vec_ty = types.insert(
+            Type {
+                name: None,
+                inner: TypeInner::Vector {
+                    size: VectorSize::Bi,
+                    scalar: crate::Scalar::I32,
+                },
+            },
+            Default::default(),
+        );
+
+        let h = constants.append(
+            Constant {
+                name: None,
+                r#override: crate::Override::None,
+                ty: scalar_ty,
+                init: const_expressions
+                    .append(Expression::Literal(Literal::I32(4)), Default::default()),
+            },
+            Default::default(),
+        );
+
+        let h1 = constants.append(
+            Constant {
+                name: None,
+                r#override: crate::Override::None,
+                ty: scalar_ty,
+                init: const_expressions
+                    .append(Expression::Literal(Literal::I32(8)), Default::default()),
+            },
+            Default::default(),
+        );
+
+        let vec_h = constants.append(
+            Constant {
+                name: None,
+                r#override: crate::Override::None,
+                ty: vec_ty,
+                init: const_expressions.append(
+                    Expression::Compose {
+                        ty: vec_ty,
+                        components: vec![constants[h].init, constants[h1].init],
+                    },
+                    Default::default(),
+                ),
+            },
+            Default::default(),
+        );
+
+        let expr = const_expressions.append(Expression::Constant(h), Default::default());
+        let expr1 = const_expressions.append(Expression::Constant(vec_h), Default::default());
+
+        let expr2 = Expression::Unary {
+            op: UnaryOperator::Negate,
+            expr,
+        };
+
+        let expr3 = Expression::Unary {
+            op: UnaryOperator::BitwiseNot,
+            expr,
+        };
+
+        let expr4 = Expression::Unary {
+            op: UnaryOperator::BitwiseNot,
+            expr: expr1,
+        };
+
+        let mut solver = ConstantEvaluator {
+            behavior: Behavior::Wgsl,
+            types: &mut types,
+            constants: &constants,
+            expressions: &mut const_expressions,
+            function_local_data: None,
+        };
+
+        let res1 = solver
+            .try_eval_and_append(&expr2, Default::default())
+            .unwrap();
+        let res2 = solver
+            .try_eval_and_append(&expr3, Default::default())
+            .unwrap();
+        let res3 = solver
+            .try_eval_and_append(&expr4, Default::default())
+            .unwrap();
+
+        assert_eq!(
+            const_expressions[res1],
+            Expression::Literal(Literal::I32(-4))
+        );
+
+        assert_eq!(
+            const_expressions[res2],
+            Expression::Literal(Literal::I32(!4))
+        );
+
+        let res3_inner = &const_expressions[res3];
+
+        match *res3_inner {
+            Expression::Compose {
+                ref ty,
+                ref components,
+            } => {
+                assert_eq!(*ty, vec_ty);
+                let mut components_iter = components.iter().copied();
+                assert_eq!(
+                    const_expressions[components_iter.next().unwrap()],
+                    Expression::Literal(Literal::I32(!4))
+                );
+                assert_eq!(
+                    const_expressions[components_iter.next().unwrap()],
+                    Expression::Literal(Literal::I32(!8))
+                );
+                assert!(components_iter.next().is_none());
+            }
+            _ => panic!("Expected vector"),
+        }
+    }
+
+    #[test]
+    fn cast() {
+        let mut types = UniqueArena::new();
+        let mut constants = Arena::new();
+        let mut const_expressions = Arena::new();
+
+        let scalar_ty = types.insert(
+            Type {
+                name: None,
+                inner: TypeInner::Scalar(crate::Scalar::I32),
+            },
+            Default::default(),
+        );
+
+        let h = constants.append(
+            Constant {
+                name: None,
+                r#override: crate::Override::None,
+                ty: scalar_ty,
+                init: const_expressions
+                    .append(Expression::Literal(Literal::I32(4)), Default::default()),
+            },
+            Default::default(),
+        );
+
+        let expr = const_expressions.append(Expression::Constant(h), Default::default());
+
+        let root = Expression::As {
+            expr,
+            kind: ScalarKind::Bool,
+            convert: Some(crate::BOOL_WIDTH),
+        };
+
+        let mut solver = ConstantEvaluator {
+            behavior: Behavior::Wgsl,
+            types: &mut types,
+            constants: &constants,
+            expressions: &mut const_expressions,
+            function_local_data: None,
+        };
+
+        let res = solver
+            .try_eval_and_append(&root, Default::default())
+            .unwrap();
+
+        assert_eq!(
+            const_expressions[res],
+            Expression::Literal(Literal::Bool(true))
+        );
+    }
+
+    #[test]
+    fn access() {
+        let mut types = UniqueArena::new();
+        let mut constants = Arena::new();
+        let mut const_expressions = Arena::new();
+
+        let matrix_ty = types.insert(
+            Type {
+                name: None,
+                inner: TypeInner::Matrix {
+                    columns: VectorSize::Bi,
+                    rows: VectorSize::Tri,
+                    scalar: crate::Scalar::F32,
+                },
+            },
+            Default::default(),
+        );
+
+        let vec_ty = types.insert(
+            Type {
+                name: None,
+                inner: TypeInner::Vector {
+                    size: VectorSize::Tri,
+                    scalar: crate::Scalar::F32,
+                },
+            },
+            Default::default(),
+        );
+
+        let mut vec1_components = Vec::with_capacity(3);
+        let mut vec2_components = Vec::with_capacity(3);
+
+        for i in 0..3 {
+            let h = const_expressions.append(
+                Expression::Literal(Literal::F32(i as f32)),
+                Default::default(),
+            );
+
+            vec1_components.push(h)
+        }
+
+        for i in 3..6 {
+            let h = const_expressions.append(
+                Expression::Literal(Literal::F32(i as f32)),
+                Default::default(),
+            );
+
+            vec2_components.push(h)
+        }
+
+        let vec1 = constants.append(
+            Constant {
+                name: None,
+                r#override: crate::Override::None,
+                ty: vec_ty,
+                init: const_expressions.append(
+                    Expression::Compose {
+                        ty: vec_ty,
+                        components: vec1_components,
+                    },
+                    Default::default(),
+                ),
+            },
+            Default::default(),
+        );
+
+        let vec2 = constants.append(
+            Constant {
+                name: None,
+                r#override: crate::Override::None,
+                ty: vec_ty,
+                init: const_expressions.append(
+                    Expression::Compose {
+                        ty: vec_ty,
+                        components: vec2_components,
+                    },
+                    Default::default(),
+                ),
+            },
+            Default::default(),
+        );
+
+        let h = constants.append(
+            Constant {
+                name: None,
+                r#override: crate::Override::None,
+                ty: matrix_ty,
+                init: const_expressions.append(
+                    Expression::Compose {
+                        ty: matrix_ty,
+                        components: vec![constants[vec1].init, constants[vec2].init],
+                    },
+                    Default::default(),
+                ),
+            },
+            Default::default(),
+        );
+
+        let base = const_expressions.append(Expression::Constant(h), Default::default());
+
+        let mut solver = ConstantEvaluator {
+            behavior: Behavior::Wgsl,
+            types: &mut types,
+            constants: &constants,
+            expressions: &mut const_expressions,
+            function_local_data: None,
+        };
+
+        let root1 = Expression::AccessIndex { base, index: 1 };
+
+        let res1 = solver
+            .try_eval_and_append(&root1, Default::default())
+            .unwrap();
+
+        let root2 = Expression::AccessIndex {
+            base: res1,
+            index: 2,
+        };
+
+        let res2 = solver
+            .try_eval_and_append(&root2, Default::default())
+            .unwrap();
+
+        match const_expressions[res1] {
+            Expression::Compose {
+                ref ty,
+                ref components,
+            } => {
+                assert_eq!(*ty, vec_ty);
+                let mut components_iter = components.iter().copied();
+                assert_eq!(
+                    const_expressions[components_iter.next().unwrap()],
+                    Expression::Literal(Literal::F32(3.))
+                );
+                assert_eq!(
+                    const_expressions[components_iter.next().unwrap()],
+                    Expression::Literal(Literal::F32(4.))
+                );
+                assert_eq!(
+                    const_expressions[components_iter.next().unwrap()],
+                    Expression::Literal(Literal::F32(5.))
+                );
+                assert!(components_iter.next().is_none());
+            }
+            _ => panic!("Expected vector"),
+        }
+
+        assert_eq!(
+            const_expressions[res2],
+            Expression::Literal(Literal::F32(5.))
+        );
+    }
+
+    #[test]
+    fn compose_of_constants() {
+        let mut types = UniqueArena::new();
+        let mut constants = Arena::new();
+        let mut const_expressions = Arena::new();
+
+        let i32_ty = types.insert(
+            Type {
+                name: None,
+                inner: TypeInner::Scalar(crate::Scalar::I32),
+            },
+            Default::default(),
+        );
+
+        let vec2_i32_ty = types.insert(
+            Type {
+                name: None,
+                inner: TypeInner::Vector {
+                    size: VectorSize::Bi,
+                    scalar: crate::Scalar::I32,
+                },
+            },
+            Default::default(),
+        );
+
+        let h = constants.append(
+            Constant {
+                name: None,
+                r#override: crate::Override::None,
+                ty: i32_ty,
+                init: const_expressions
+                    .append(Expression::Literal(Literal::I32(4)), Default::default()),
+            },
+            Default::default(),
+        );
+
+        let h_expr = const_expressions.append(Expression::Constant(h), Default::default());
+
+        let mut solver = ConstantEvaluator {
+            behavior: Behavior::Wgsl,
+            types: &mut types,
+            constants: &constants,
+            expressions: &mut const_expressions,
+            function_local_data: None,
+        };
+
+        let solved_compose = solver
+            .try_eval_and_append(
+                &Expression::Compose {
+                    ty: vec2_i32_ty,
+                    components: vec![h_expr, h_expr],
+                },
+                Default::default(),
+            )
+            .unwrap();
+        let solved_negate = solver
+            .try_eval_and_append(
+                &Expression::Unary {
+                    op: UnaryOperator::Negate,
+                    expr: solved_compose,
+                },
+                Default::default(),
+            )
+            .unwrap();
+
+        let pass = match const_expressions[solved_negate] {
+            Expression::Compose { ty, ref components } => {
+                ty == vec2_i32_ty
+                    && components.iter().all(|&component| {
+                        let component = &const_expressions[component];
+                        matches!(*component, Expression::Literal(Literal::I32(-4)))
+                    })
+            }
+            _ => false,
+        };
+        if !pass {
+            panic!("unexpected evaluation result")
+        }
+    }
+
+    #[test]
+    fn splat_of_constant() {
+        let mut types = UniqueArena::new();
+        let mut constants = Arena::new();
+        let mut const_expressions = Arena::new();
+
+        let i32_ty = types.insert(
+            Type {
+                name: None,
+                inner: TypeInner::Scalar(crate::Scalar::I32),
+            },
+            Default::default(),
+        );
+
+        let vec2_i32_ty = types.insert(
+            Type {
+                name: None,
+                inner: TypeInner::Vector {
+                    size: VectorSize::Bi,
+                    scalar: crate::Scalar::I32,
+                },
+            },
+            Default::default(),
+        );
+
+        let h = constants.append(
+            Constant {
+                name: None,
+                r#override: crate::Override::None,
+                ty: i32_ty,
+                init: const_expressions
+                    .append(Expression::Literal(Literal::I32(4)), Default::default()),
+            },
+            Default::default(),
+        );
+
+        let h_expr = const_expressions.append(Expression::Constant(h), Default::default());
+
+        let mut solver = ConstantEvaluator {
+            behavior: Behavior::Wgsl,
+            types: &mut types,
+            constants: &constants,
+            expressions: &mut const_expressions,
+            function_local_data: None,
+        };
+
+        let solved_compose = solver
+            .try_eval_and_append(
+                &Expression::Splat {
+                    size: VectorSize::Bi,
+                    value: h_expr,
+                },
+                Default::default(),
+            )
+            .unwrap();
+        let solved_negate = solver
+            .try_eval_and_append(
+                &Expression::Unary {
+                    op: UnaryOperator::Negate,
+                    expr: solved_compose,
+                },
+                Default::default(),
+            )
+            .unwrap();
+
+        let pass = match const_expressions[solved_negate] {
+            Expression::Compose { ty, ref components } => {
+                ty == vec2_i32_ty
+                    && components.iter().all(|&component| {
+                        let component = &const_expressions[component];
+                        matches!(*component, Expression::Literal(Literal::I32(-4)))
+                    })
+            }
+            _ => false,
+        };
+        if !pass {
+            panic!("unexpected evaluation result")
+        }
+    }
+}
+
+/// Trait for conversions of abstract values to concrete types.
+trait TryFromAbstract<T>: Sized {
+    /// Convert an abstract literal `value` to `Self`.
+    ///
+    /// Since Naga's `AbstractInt` and `AbstractFloat` exist to support
+    /// WGSL, we follow WGSL's conversion rules here:
+    ///
+    /// - WGSL §6.1.2. Conversion Rank says that automatic conversions
+    ///   to integers are either lossless or an error.
+    ///
+    /// - WGSL §14.6.4 Floating Point Conversion says that conversions
+    ///   to floating point in constant expressions and override
+    ///   expressions are errors if the value is out of range for the
+    ///   destination type, but rounding is okay.
+    ///
+    /// [`AbstractInt`]: crate::Literal::AbstractInt
+    /// [`Float`]: crate::Literal::Float
+    fn try_from_abstract(value: T) -> Result<Self, ConstantEvaluatorError>;
+}
+
+impl TryFromAbstract<i64> for i32 {
+    fn try_from_abstract(value: i64) -> Result<i32, ConstantEvaluatorError> {
+        i32::try_from(value).map_err(|_| ConstantEvaluatorError::AutomaticConversionLossy {
+            value: format!("{value:?}"),
+            to_type: "i32",
+        })
+    }
+}
+
+impl TryFromAbstract<i64> for u32 {
+    fn try_from_abstract(value: i64) -> Result<u32, ConstantEvaluatorError> {
+        u32::try_from(value).map_err(|_| ConstantEvaluatorError::AutomaticConversionLossy {
+            value: format!("{value:?}"),
+            to_type: "u32",
+        })
+    }
+}
+
+impl TryFromAbstract<i64> for f32 {
+    fn try_from_abstract(value: i64) -> Result<Self, ConstantEvaluatorError> {
+        let f = value as f32;
+        // The range of `i64` is roughly ±18 × 10¹⁸, whereas the range of
+        // `f32` is roughly ±3.4 × 10³⁸, so there's no opportunity for
+        // overflow here.
+        Ok(f)
+    }
+}
+
+impl TryFromAbstract<f64> for f32 {
+    fn try_from_abstract(value: f64) -> Result<f32, ConstantEvaluatorError> {
+        let f = value as f32;
+        if f.is_infinite() {
+            return Err(ConstantEvaluatorError::AutomaticConversionLossy {
+                value: format!("{value:?}"),
+                to_type: "f32",
+            });
+        }
+        Ok(f)
+    }
+}
+
+impl TryFromAbstract<i64> for f64 {
+    fn try_from_abstract(value: i64) -> Result<Self, ConstantEvaluatorError> {
+        let f = value as f64;
+        // The range of `i64` is roughly ±18 × 10¹⁸, whereas the range of
+        // `f64` is roughly ±1.8 × 10³⁰⁸, so there's no opportunity for
+        // overflow here.
+        Ok(f)
+    }
+}
+
+impl TryFromAbstract<f64> for f64 {
+    fn try_from_abstract(value: f64) -> Result<f64, ConstantEvaluatorError> {
+        Ok(value)
+    }
+}
+
+impl TryFromAbstract<f64> for i32 {
+    fn try_from_abstract(_: f64) -> Result<Self, ConstantEvaluatorError> {
+        Err(ConstantEvaluatorError::AutomaticConversionFloatToInt { to_type: "i32" })
+    }
+}
+
+impl TryFromAbstract<f64> for u32 {
+    fn try_from_abstract(_: f64) -> Result<Self, ConstantEvaluatorError> {
+        Err(ConstantEvaluatorError::AutomaticConversionFloatToInt { to_type: "u32" })
+    }
+}
diff --git a/third_party/rust/naga/src/proc/emitter.rs b/third_party/rust/naga/src/proc/emitter.rs
new file mode 100644
index 0000000000..0df804fff2
--- /dev/null
+++ b/third_party/rust/naga/src/proc/emitter.rs
@@ -0,0 +1,39 @@
+use crate::arena::Arena;
+
+/// Helper class to emit expressions
+#[allow(dead_code)]
+#[derive(Default, Debug)]
+pub struct Emitter {
+    start_len: Option<usize>,
+}
+
+#[allow(dead_code)]
+impl Emitter {
+    pub fn start(&mut self, arena: &Arena<crate::Expression>) {
+        if self.start_len.is_some() {
+            unreachable!("Emitting has already started!");
+        }
+        self.start_len = Some(arena.len());
+    }
+    pub const fn is_running(&self) -> bool {
+        self.start_len.is_some()
+    }
+    #[must_use]
+    pub fn finish(
+        &mut self,
+        arena: &Arena<crate::Expression>,
+    ) -> Option<(crate::Statement, crate::span::Span)> {
+        let start_len = self.start_len.take().unwrap();
+        if start_len != arena.len() {
+            #[allow(unused_mut)]
+            let mut span = crate::span::Span::default();
+            let range = arena.range_from(start_len);
+            for handle in range.clone() {
+                span.subsume(arena.get_span(handle))
+            }
+            Some((crate::Statement::Emit(range), span))
+        } else {
+            None
+        }
+    }
+}
diff --git a/third_party/rust/naga/src/proc/index.rs b/third_party/rust/naga/src/proc/index.rs
new file mode 100644
index 0000000000..af3221c0fe
--- /dev/null
+++ b/third_party/rust/naga/src/proc/index.rs
@@ -0,0 +1,435 @@
+/*!
+Definitions for index bounds checking.
+*/
+
+use crate::{valid, Handle, UniqueArena};
+use bit_set::BitSet;
+
+/// How should code generated by Naga do bounds checks?
+///
+/// When a vector, matrix, or array index is out of bounds—either negative, or
+/// greater than or equal to the number of elements in the type—WGSL requires
+/// that some other index of the implementation's choice that is in bounds is
+/// used instead. (There are no types with zero elements.)
+///
+/// Similarly, when out-of-bounds coordinates, array indices, or sample indices
+/// are presented to the WGSL `textureLoad` and `textureStore` operations, the
+/// operation is redirected to do something safe.
+///
+/// Different users of Naga will prefer different defaults:
+///
+/// -   When used as part of a WebGPU implementation, the WGSL specification
+///     requires the `Restrict` behavior for array, vector, and matrix accesses,
+///     and either the `Restrict` or `ReadZeroSkipWrite` behaviors for texture
+///     accesses.
+///
+/// -   When used by the `wgpu` crate for native development, `wgpu` selects
+///     `ReadZeroSkipWrite` as its default.
+///
+/// -   Naga's own default is `Unchecked`, so that shader translations
+///     are as faithful to the original as possible.
+///
+/// Sometimes the underlying hardware and drivers can perform bounds checks
+/// themselves, in a way that performs better than the checks Naga would inject.
+/// If you're using native checks like this, then having Naga inject its own
+/// checks as well would be redundant, and the `Unchecked` policy is
+/// appropriate.
+#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub enum BoundsCheckPolicy {
+    /// Replace out-of-bounds indexes with some arbitrary in-bounds index.
+    ///
+    /// (This does not necessarily mean clamping. For example, interpreting the
+    /// index as unsigned and taking the minimum with the largest valid index
+    /// would also be a valid implementation. That would map negative indices to
+    /// the last element, not the first.)
+    Restrict,
+
+    /// Out-of-bounds reads return zero, and writes have no effect.
+    ///
+    /// When applied to a chain of accesses, like `a[i][j].b[k]`, all index
+    /// expressions are evaluated, regardless of whether prior or later index
+    /// expressions were in bounds. But all the accesses per se are skipped
+    /// if any index is out of bounds.
+    ReadZeroSkipWrite,
+
+    /// Naga adds no checks to indexing operations. Generate the fastest code
+    /// possible. This is the default for Naga, as a translator, but consumers
+    /// should consider defaulting to a safer behavior.
+    Unchecked,
+}
+
+/// Policies for injecting bounds checks during code generation.
+#[derive(Clone, Copy, Debug, Default, Eq, Hash, PartialEq)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub struct BoundsCheckPolicies {
+    /// How should the generated code handle array, vector, or matrix indices
+    /// that are out of range?
+    #[cfg_attr(feature = "deserialize", serde(default))]
+    pub index: BoundsCheckPolicy,
+
+    /// How should the generated code handle array, vector, or matrix indices
+    /// that are out of range, when those values live in a [`GlobalVariable`] in
+    /// the [`Storage`] or [`Uniform`] address spaces?
+    ///
+    /// Some graphics hardware provides "robust buffer access", a feature that
+    /// ensures that using a pointer cannot access memory outside the 'buffer'
+    /// that it was derived from. In Naga terms, this means that the hardware
+    /// ensures that pointers computed by applying [`Access`] and
+    /// [`AccessIndex`] expressions to a [`GlobalVariable`] whose [`space`] is
+    /// [`Storage`] or [`Uniform`] will never read or write memory outside that
+    /// global variable.
+    ///
+    /// When hardware offers such a feature, it is probably undesirable to have
+    /// Naga inject bounds checking code for such accesses, since the hardware
+    /// can probably provide the same protection more efficiently. However,
+    /// bounds checks are still needed on accesses to indexable values that do
+    /// not live in buffers, like local variables.
+    ///
+    /// So, this option provides a separate policy that applies only to accesses
+    /// to storage and uniform globals. When depending on hardware bounds
+    /// checking, this policy can be `Unchecked` to avoid unnecessary overhead.
+    ///
+    /// When special hardware support is not available, this should probably be
+    /// the same as `index_bounds_check_policy`.
+    ///
+    /// [`GlobalVariable`]: crate::GlobalVariable
+    /// [`space`]: crate::GlobalVariable::space
+    /// [`Restrict`]: crate::back::BoundsCheckPolicy::Restrict
+    /// [`ReadZeroSkipWrite`]: crate::back::BoundsCheckPolicy::ReadZeroSkipWrite
+    /// [`Access`]: crate::Expression::Access
+    /// [`AccessIndex`]: crate::Expression::AccessIndex
+    /// [`Storage`]: crate::AddressSpace::Storage
+    /// [`Uniform`]: crate::AddressSpace::Uniform
+    #[cfg_attr(feature = "deserialize", serde(default))]
+    pub buffer: BoundsCheckPolicy,
+
+    /// How should the generated code handle image texel loads that are out
+    /// of range?
+    ///
+    /// This controls the behavior of [`ImageLoad`] expressions when a coordinate,
+    /// texture array index, level of detail, or multisampled sample number is out of range.
+    ///
+    /// [`ImageLoad`]: crate::Expression::ImageLoad
+    #[cfg_attr(feature = "deserialize", serde(default))]
+    pub image_load: BoundsCheckPolicy,
+
+    /// How should the generated code handle image texel stores that are out
+    /// of range?
+    ///
+    /// This controls the behavior of [`ImageStore`] statements when a coordinate,
+    /// texture array index, level of detail, or multisampled sample number is out of range.
+    ///
+    /// This policy should't be needed since all backends should ignore OOB writes.
+    ///
+    /// [`ImageStore`]: crate::Statement::ImageStore
+    #[cfg_attr(feature = "deserialize", serde(default))]
+    pub image_store: BoundsCheckPolicy,
+
+    /// How should the generated code handle binding array indexes that are out of bounds.
+    #[cfg_attr(feature = "deserialize", serde(default))]
+    pub binding_array: BoundsCheckPolicy,
+}
+
+/// The default `BoundsCheckPolicy` is `Unchecked`.
+impl Default for BoundsCheckPolicy {
+    fn default() -> Self {
+        BoundsCheckPolicy::Unchecked
+    }
+}
+
+impl BoundsCheckPolicies {
+    /// Determine which policy applies to `base`.
+    ///
+    /// `base` is the "base" expression (the expression being indexed) of a `Access`
+    /// and `AccessIndex` expression. This is either a pointer, a value, being directly
+    /// indexed, or a binding array.
+    ///
+    /// See the documentation for [`BoundsCheckPolicy`] for details about
+    /// when each policy applies.
+    pub fn choose_policy(
+        &self,
+        base: Handle<crate::Expression>,
+        types: &UniqueArena<crate::Type>,
+        info: &valid::FunctionInfo,
+    ) -> BoundsCheckPolicy {
+        let ty = info[base].ty.inner_with(types);
+
+        if let crate::TypeInner::BindingArray { .. } = *ty {
+            return self.binding_array;
+        }
+
+        match ty.pointer_space() {
+            Some(crate::AddressSpace::Storage { access: _ } | crate::AddressSpace::Uniform) => {
+                self.buffer
+            }
+            // This covers other address spaces, but also accessing vectors and
+            // matrices by value, where no pointer is involved.
+            _ => self.index,
+        }
+    }
+
+    /// Return `true` if any of `self`'s policies are `policy`.
+    pub fn contains(&self, policy: BoundsCheckPolicy) -> bool {
+        self.index == policy
+            || self.buffer == policy
+            || self.image_load == policy
+            || self.image_store == policy
+    }
+}
+
+/// An index that may be statically known, or may need to be computed at runtime.
+///
+/// This enum lets us handle both [`Access`] and [`AccessIndex`] expressions
+/// with the same code.
+///
+/// [`Access`]: crate::Expression::Access
+/// [`AccessIndex`]: crate::Expression::AccessIndex
+#[derive(Clone, Copy, Debug)]
+pub enum GuardedIndex {
+    Known(u32),
+    Expression(Handle<crate::Expression>),
+}
+
+/// Build a set of expressions used as indices, to cache in temporary variables when
+/// emitted.
+///
+/// Given the bounds-check policies `policies`, construct a `BitSet` containing the handle
+/// indices of all the expressions in `function` that are ever used as guarded indices
+/// under the [`ReadZeroSkipWrite`] policy. The `module` argument must be the module to
+/// which `function` belongs, and `info` should be that function's analysis results.
+///
+/// Such index expressions will be used twice in the generated code: first for the
+/// comparison to see if the index is in bounds, and then for the access itself, should
+/// the comparison succeed. To avoid computing the expressions twice, the generated code
+/// should cache them in temporary variables.
+///
+/// Why do we need to build such a set in advance, instead of just processing access
+/// expressions as we encounter them? Whether an expression needs to be cached depends on
+/// whether it appears as something like the [`index`] operand of an [`Access`] expression
+/// or the [`level`] operand of an [`ImageLoad`] expression, and on the index bounds check
+/// policies that apply to those accesses. But [`Emit`] statements just identify a range
+/// of expressions by index; there's no good way to tell what an expression is used
+/// for. The only way to do it is to just iterate over all the expressions looking for
+/// relevant `Access` expressions --- which is what this function does.
+///
+/// Simple expressions like variable loads and constants don't make sense to cache: it's
+/// no better than just re-evaluating them. But constants are not covered by `Emit`
+/// statements, and `Load`s are always cached to ensure they occur at the right time, so
+/// we don't bother filtering them out from this set.
+///
+/// Fortunately, we don't need to deal with [`ImageStore`] statements here. When we emit
+/// code for a statement, the writer isn't in the middle of an expression, so we can just
+/// emit declarations for temporaries, initialized appropriately.
+///
+/// None of these concerns apply for SPIR-V output, since it's easy to just reuse an
+/// instruction ID in two places; that has the same semantics as a temporary variable, and
+/// it's inherent in the design of SPIR-V. This function is more useful for text-based
+/// back ends.
+///
+/// [`ReadZeroSkipWrite`]: BoundsCheckPolicy::ReadZeroSkipWrite
+/// [`index`]: crate::Expression::Access::index
+/// [`Access`]: crate::Expression::Access
+/// [`level`]: crate::Expression::ImageLoad::level
+/// [`ImageLoad`]: crate::Expression::ImageLoad
+/// [`Emit`]: crate::Statement::Emit
+/// [`ImageStore`]: crate::Statement::ImageStore
+pub fn find_checked_indexes(
+    module: &crate::Module,
+    function: &crate::Function,
+    info: &crate::valid::FunctionInfo,
+    policies: BoundsCheckPolicies,
+) -> BitSet {
+    use crate::Expression as Ex;
+
+    let mut guarded_indices = BitSet::new();
+
+    // Don't bother scanning if we never need `ReadZeroSkipWrite`.
+    if policies.contains(BoundsCheckPolicy::ReadZeroSkipWrite) {
+        for (_handle, expr) in function.expressions.iter() {
+            // There's no need to handle `AccessIndex` expressions, as their
+            // indices never need to be cached.
+            match *expr {
+                Ex::Access { base, index } => {
+                    if policies.choose_policy(base, &module.types, info)
+                        == BoundsCheckPolicy::ReadZeroSkipWrite
+                        && access_needs_check(
+                            base,
+                            GuardedIndex::Expression(index),
+                            module,
+                            function,
+                            info,
+                        )
+                        .is_some()
+                    {
+                        guarded_indices.insert(index.index());
+                    }
+                }
+                Ex::ImageLoad {
+                    coordinate,
+                    array_index,
+                    sample,
+                    level,
+                    ..
+                } => {
+                    if policies.image_load == BoundsCheckPolicy::ReadZeroSkipWrite {
+                        guarded_indices.insert(coordinate.index());
+                        if let Some(array_index) = array_index {
+                            guarded_indices.insert(array_index.index());
+                        }
+                        if let Some(sample) = sample {
+                            guarded_indices.insert(sample.index());
+                        }
+                        if let Some(level) = level {
+                            guarded_indices.insert(level.index());
+                        }
+                    }
+                }
+                _ => {}
+            }
+        }
+    }
+
+    guarded_indices
+}
+
+/// Determine whether `index` is statically known to be in bounds for `base`.
+///
+/// If we can't be sure that the index is in bounds, return the limit within
+/// which valid indices must fall.
+///
+/// The return value is one of the following:
+///
+/// - `Some(Known(n))` indicates that `n` is the largest valid index.
+///
+/// - `Some(Computed(global))` indicates that the largest valid index is one
+///   less than the length of the array that is the last member of the
+///   struct held in `global`.
+///
+/// - `None` indicates that the index need not be checked, either because it
+///   is statically known to be in bounds, or because the applicable policy
+///   is `Unchecked`.
+///
+/// This function only handles subscriptable types: arrays, vectors, and
+/// matrices. It does not handle struct member indices; those never require
+/// run-time checks, so it's best to deal with them further up the call
+/// chain.
+pub fn access_needs_check(
+    base: Handle<crate::Expression>,
+    mut index: GuardedIndex,
+    module: &crate::Module,
+    function: &crate::Function,
+    info: &crate::valid::FunctionInfo,
+) -> Option<IndexableLength> {
+    let base_inner = info[base].ty.inner_with(&module.types);
+    // Unwrap safety: `Err` here indicates unindexable base types and invalid
+    // length constants, but `access_needs_check` is only used by back ends, so
+    // validation should have caught those problems.
+    let length = base_inner.indexable_length(module).unwrap();
+    index.try_resolve_to_constant(function, module);
+    if let (&GuardedIndex::Known(index), &IndexableLength::Known(length)) = (&index, &length) {
+        if index < length {
+            // Index is statically known to be in bounds, no check needed.
+            return None;
+        }
+    };
+
+    Some(length)
+}
+
+impl GuardedIndex {
+    /// Make a `GuardedIndex::Known` from a `GuardedIndex::Expression` if possible.
+    ///
+    /// Return values that are already `Known` unchanged.
+    fn try_resolve_to_constant(&mut self, function: &crate::Function, module: &crate::Module) {
+        if let GuardedIndex::Expression(expr) = *self {
+            if let Ok(value) = module
+                .to_ctx()
+                .eval_expr_to_u32_from(expr, &function.expressions)
+            {
+                *self = GuardedIndex::Known(value);
+            }
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, thiserror::Error, PartialEq)]
+pub enum IndexableLengthError {
+    #[error("Type is not indexable, and has no length (validation error)")]
+    TypeNotIndexable,
+    #[error("Array length constant {0:?} is invalid")]
+    InvalidArrayLength(Handle<crate::Expression>),
+}
+
+impl crate::TypeInner {
+    /// Return the length of a subscriptable type.
+    ///
+    /// The `self` parameter should be a handle to a vector, matrix, or array
+    /// type, a pointer to one of those, or a value pointer. Arrays may be
+    /// fixed-size, dynamically sized, or sized by a specializable constant.
+    /// This function does not handle struct member references, as with
+    /// `AccessIndex`.
+    ///
+    /// The value returned is appropriate for bounds checks on subscripting.
+    ///
+    /// Return an error if `self` does not describe a subscriptable type at all.
+    pub fn indexable_length(
+        &self,
+        module: &crate::Module,
+    ) -> Result<IndexableLength, IndexableLengthError> {
+        use crate::TypeInner as Ti;
+        let known_length = match *self {
+            Ti::Vector { size, .. } => size as _,
+            Ti::Matrix { columns, .. } => columns as _,
+            Ti::Array { size, .. } | Ti::BindingArray { size, .. } => {
+                return size.to_indexable_length(module);
+            }
+            Ti::ValuePointer {
+                size: Some(size), ..
+            } => size as _,
+            Ti::Pointer { base, .. } => {
+                // When assigning types to expressions, ResolveContext::Resolve
+                // does a separate sub-match here instead of a full recursion,
+                // so we'll do the same.
+                let base_inner = &module.types[base].inner;
+                match *base_inner {
+                    Ti::Vector { size, .. } => size as _,
+                    Ti::Matrix { columns, .. } => columns as _,
+                    Ti::Array { size, .. } | Ti::BindingArray { size, .. } => {
+                        return size.to_indexable_length(module)
+                    }
+                    _ => return Err(IndexableLengthError::TypeNotIndexable),
+                }
+            }
+            _ => return Err(IndexableLengthError::TypeNotIndexable),
+        };
+        Ok(IndexableLength::Known(known_length))
+    }
+}
+
+/// The number of elements in an indexable type.
+///
+/// This summarizes the length of vectors, matrices, and arrays in a way that is
+/// convenient for indexing and bounds-checking code.
+#[derive(Debug)]
+pub enum IndexableLength {
+    /// Values of this type always have the given number of elements.
+    Known(u32),
+
+    /// The number of elements is determined at runtime.
+    Dynamic,
+}
+
+impl crate::ArraySize {
+    pub const fn to_indexable_length(
+        self,
+        _module: &crate::Module,
+    ) -> Result<IndexableLength, IndexableLengthError> {
+        Ok(match self {
+            Self::Constant(length) => IndexableLength::Known(length.get()),
+            Self::Dynamic => IndexableLength::Dynamic,
+        })
+    }
+}
diff --git a/third_party/rust/naga/src/proc/layouter.rs b/third_party/rust/naga/src/proc/layouter.rs
new file mode 100644
index 0000000000..1c78a594d1
--- /dev/null
+++ b/third_party/rust/naga/src/proc/layouter.rs
@@ -0,0 +1,251 @@
+use crate::arena::Handle;
+use std::{fmt::Display, num::NonZeroU32, ops};
+
+/// A newtype struct where its only valid values are powers of 2
+#[derive(Clone, Copy, Debug, Hash, PartialEq, Eq, PartialOrd, Ord)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub struct Alignment(NonZeroU32);
+
+impl Alignment {
+    pub const ONE: Self = Self(unsafe { NonZeroU32::new_unchecked(1) });
+    pub const TWO: Self = Self(unsafe { NonZeroU32::new_unchecked(2) });
+    pub const FOUR: Self = Self(unsafe { NonZeroU32::new_unchecked(4) });
+    pub const EIGHT: Self = Self(unsafe { NonZeroU32::new_unchecked(8) });
+    pub const SIXTEEN: Self = Self(unsafe { NonZeroU32::new_unchecked(16) });
+
+    pub const MIN_UNIFORM: Self = Self::SIXTEEN;
+
+    pub const fn new(n: u32) -> Option<Self> {
+        if n.is_power_of_two() {
+            // SAFETY: value can't be 0 since we just checked if it's a power of 2
+            Some(Self(unsafe { NonZeroU32::new_unchecked(n) }))
+        } else {
+            None
+        }
+    }
+
+    /// # Panics
+    /// If `width` is not a power of 2
+    pub fn from_width(width: u8) -> Self {
+        Self::new(width as u32).unwrap()
+    }
+
+    /// Returns whether or not `n` is a multiple of this alignment.
+    pub const fn is_aligned(&self, n: u32) -> bool {
+        // equivalent to: `n % self.0.get() == 0` but much faster
+        n & (self.0.get() - 1) == 0
+    }
+
+    /// Round `n` up to the nearest alignment boundary.
+    pub const fn round_up(&self, n: u32) -> u32 {
+        // equivalent to:
+        // match n % self.0.get() {
+        //     0 => n,
+        //     rem => n + (self.0.get() - rem),
+        // }
+        let mask = self.0.get() - 1;
+        (n + mask) & !mask
+    }
+}
+
+impl Display for Alignment {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        self.0.get().fmt(f)
+    }
+}
+
+impl ops::Mul<u32> for Alignment {
+    type Output = u32;
+
+    fn mul(self, rhs: u32) -> Self::Output {
+        self.0.get() * rhs
+    }
+}
+
+impl ops::Mul for Alignment {
+    type Output = Alignment;
+
+    fn mul(self, rhs: Alignment) -> Self::Output {
+        // SAFETY: both lhs and rhs are powers of 2, the result will be a power of 2
+        Self(unsafe { NonZeroU32::new_unchecked(self.0.get() * rhs.0.get()) })
+    }
+}
+
+impl From<crate::VectorSize> for Alignment {
+    fn from(size: crate::VectorSize) -> Self {
+        match size {
+            crate::VectorSize::Bi => Alignment::TWO,
+            crate::VectorSize::Tri => Alignment::FOUR,
+            crate::VectorSize::Quad => Alignment::FOUR,
+        }
+    }
+}
+
+/// Size and alignment information for a type.
+#[derive(Clone, Copy, Debug, Hash, PartialEq)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub struct TypeLayout {
+    pub size: u32,
+    pub alignment: Alignment,
+}
+
+impl TypeLayout {
+    /// Produce the stride as if this type is a base of an array.
+    pub const fn to_stride(&self) -> u32 {
+        self.alignment.round_up(self.size)
+    }
+}
+
+/// Helper processor that derives the sizes of all types.
+///
+/// `Layouter` uses the default layout algorithm/table, described in
+/// [WGSL §4.3.7, "Memory Layout"]
+///
+/// A `Layouter` may be indexed by `Handle<Type>` values: `layouter[handle]` is the
+/// layout of the type whose handle is `handle`.
+///
+/// [WGSL §4.3.7, "Memory Layout"](https://gpuweb.github.io/gpuweb/wgsl/#memory-layouts)
+#[derive(Debug, Default)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub struct Layouter {
+    /// Layouts for types in an arena, indexed by `Handle` index.
+    layouts: Vec<TypeLayout>,
+}
+
+impl ops::Index<Handle<crate::Type>> for Layouter {
+    type Output = TypeLayout;
+    fn index(&self, handle: Handle<crate::Type>) -> &TypeLayout {
+        &self.layouts[handle.index()]
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, thiserror::Error)]
+pub enum LayoutErrorInner {
+    #[error("Array element type {0:?} doesn't exist")]
+    InvalidArrayElementType(Handle<crate::Type>),
+    #[error("Struct member[{0}] type {1:?} doesn't exist")]
+    InvalidStructMemberType(u32, Handle<crate::Type>),
+    #[error("Type width must be a power of two")]
+    NonPowerOfTwoWidth,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, thiserror::Error)]
+#[error("Error laying out type {ty:?}: {inner}")]
+pub struct LayoutError {
+    pub ty: Handle<crate::Type>,
+    pub inner: LayoutErrorInner,
+}
+
+impl LayoutErrorInner {
+    const fn with(self, ty: Handle<crate::Type>) -> LayoutError {
+        LayoutError { ty, inner: self }
+    }
+}
+
+impl Layouter {
+    /// Remove all entries from this `Layouter`, retaining storage.
+    pub fn clear(&mut self) {
+        self.layouts.clear();
+    }
+
+    /// Extend this `Layouter` with layouts for any new entries in `gctx.types`.
+    ///
+    /// Ensure that every type in `gctx.types` has a corresponding [TypeLayout]
+    /// in [`self.layouts`].
+    ///
+    /// Some front ends need to be able to compute layouts for existing types
+    /// while module construction is still in progress and new types are still
+    /// being added. This function assumes that the `TypeLayout` values already
+    /// present in `self.layouts` cover their corresponding entries in `types`,
+    /// and extends `self.layouts` as needed to cover the rest. Thus, a front
+    /// end can call this function at any time, passing its current type and
+    /// constant arenas, and then assume that layouts are available for all
+    /// types.
+    #[allow(clippy::or_fun_call)]
+    pub fn update(&mut self, gctx: super::GlobalCtx) -> Result<(), LayoutError> {
+        use crate::TypeInner as Ti;
+
+        for (ty_handle, ty) in gctx.types.iter().skip(self.layouts.len()) {
+            let size = ty.inner.size(gctx);
+            let layout = match ty.inner {
+                Ti::Scalar(scalar) | Ti::Atomic(scalar) => {
+                    let alignment = Alignment::new(scalar.width as u32)
+                        .ok_or(LayoutErrorInner::NonPowerOfTwoWidth.with(ty_handle))?;
+                    TypeLayout { size, alignment }
+                }
+                Ti::Vector {
+                    size: vec_size,
+                    scalar,
+                } => {
+                    let alignment = Alignment::new(scalar.width as u32)
+                        .ok_or(LayoutErrorInner::NonPowerOfTwoWidth.with(ty_handle))?;
+                    TypeLayout {
+                        size,
+                        alignment: Alignment::from(vec_size) * alignment,
+                    }
+                }
+                Ti::Matrix {
+                    columns: _,
+                    rows,
+                    scalar,
+                } => {
+                    let alignment = Alignment::new(scalar.width as u32)
+                        .ok_or(LayoutErrorInner::NonPowerOfTwoWidth.with(ty_handle))?;
+                    TypeLayout {
+                        size,
+                        alignment: Alignment::from(rows) * alignment,
+                    }
+                }
+                Ti::Pointer { .. } | Ti::ValuePointer { .. } => TypeLayout {
+                    size,
+                    alignment: Alignment::ONE,
+                },
+                Ti::Array {
+                    base,
+                    stride: _,
+                    size: _,
+                } => TypeLayout {
+                    size,
+                    alignment: if base < ty_handle {
+                        self[base].alignment
+                    } else {
+                        return Err(LayoutErrorInner::InvalidArrayElementType(base).with(ty_handle));
+                    },
+                },
+                Ti::Struct { span, ref members } => {
+                    let mut alignment = Alignment::ONE;
+                    for (index, member) in members.iter().enumerate() {
+                        alignment = if member.ty < ty_handle {
+                            alignment.max(self[member.ty].alignment)
+                        } else {
+                            return Err(LayoutErrorInner::InvalidStructMemberType(
+                                index as u32,
+                                member.ty,
+                            )
+                            .with(ty_handle));
+                        };
+                    }
+                    TypeLayout {
+                        size: span,
+                        alignment,
+                    }
+                }
+                Ti::Image { .. }
+                | Ti::Sampler { .. }
+                | Ti::AccelerationStructure
+                | Ti::RayQuery
+                | Ti::BindingArray { .. } => TypeLayout {
+                    size,
+                    alignment: Alignment::ONE,
+                },
+            };
+            debug_assert!(size <= layout.size);
+            self.layouts.push(layout);
+        }
+
+        Ok(())
+    }
+}
diff --git a/third_party/rust/naga/src/proc/mod.rs b/third_party/rust/naga/src/proc/mod.rs
new file mode 100644
index 0000000000..b9ce80b5ea
--- /dev/null
+++ b/third_party/rust/naga/src/proc/mod.rs
@@ -0,0 +1,809 @@
+/*!
+[`Module`](super::Module) processing functionality.
+*/
+
+mod constant_evaluator;
+mod emitter;
+pub mod index;
+mod layouter;
+mod namer;
+mod terminator;
+mod typifier;
+
+pub use constant_evaluator::{
+    ConstantEvaluator, ConstantEvaluatorError, ExpressionConstnessTracker,
+};
+pub use emitter::Emitter;
+pub use index::{BoundsCheckPolicies, BoundsCheckPolicy, IndexableLength, IndexableLengthError};
+pub use layouter::{Alignment, LayoutError, LayoutErrorInner, Layouter, TypeLayout};
+pub use namer::{EntryPointIndex, NameKey, Namer};
+pub use terminator::ensure_block_returns;
+pub use typifier::{ResolveContext, ResolveError, TypeResolution};
+
+impl From<super::StorageFormat> for super::ScalarKind {
+    fn from(format: super::StorageFormat) -> Self {
+        use super::{ScalarKind as Sk, StorageFormat as Sf};
+        match format {
+            Sf::R8Unorm => Sk::Float,
+            Sf::R8Snorm => Sk::Float,
+            Sf::R8Uint => Sk::Uint,
+            Sf::R8Sint => Sk::Sint,
+            Sf::R16Uint => Sk::Uint,
+            Sf::R16Sint => Sk::Sint,
+            Sf::R16Float => Sk::Float,
+            Sf::Rg8Unorm => Sk::Float,
+            Sf::Rg8Snorm => Sk::Float,
+            Sf::Rg8Uint => Sk::Uint,
+            Sf::Rg8Sint => Sk::Sint,
+            Sf::R32Uint => Sk::Uint,
+            Sf::R32Sint => Sk::Sint,
+            Sf::R32Float => Sk::Float,
+            Sf::Rg16Uint => Sk::Uint,
+            Sf::Rg16Sint => Sk::Sint,
+            Sf::Rg16Float => Sk::Float,
+            Sf::Rgba8Unorm => Sk::Float,
+            Sf::Rgba8Snorm => Sk::Float,
+            Sf::Rgba8Uint => Sk::Uint,
+            Sf::Rgba8Sint => Sk::Sint,
+            Sf::Bgra8Unorm => Sk::Float,
+            Sf::Rgb10a2Uint => Sk::Uint,
+            Sf::Rgb10a2Unorm => Sk::Float,
+            Sf::Rg11b10Float => Sk::Float,
+            Sf::Rg32Uint => Sk::Uint,
+            Sf::Rg32Sint => Sk::Sint,
+            Sf::Rg32Float => Sk::Float,
+            Sf::Rgba16Uint => Sk::Uint,
+            Sf::Rgba16Sint => Sk::Sint,
+            Sf::Rgba16Float => Sk::Float,
+            Sf::Rgba32Uint => Sk::Uint,
+            Sf::Rgba32Sint => Sk::Sint,
+            Sf::Rgba32Float => Sk::Float,
+            Sf::R16Unorm => Sk::Float,
+            Sf::R16Snorm => Sk::Float,
+            Sf::Rg16Unorm => Sk::Float,
+            Sf::Rg16Snorm => Sk::Float,
+            Sf::Rgba16Unorm => Sk::Float,
+            Sf::Rgba16Snorm => Sk::Float,
+        }
+    }
+}
+
+impl super::ScalarKind {
+    pub const fn is_numeric(self) -> bool {
+        match self {
+            crate::ScalarKind::Sint
+            | crate::ScalarKind::Uint
+            | crate::ScalarKind::Float
+            | crate::ScalarKind::AbstractInt
+            | crate::ScalarKind::AbstractFloat => true,
+            crate::ScalarKind::Bool => false,
+        }
+    }
+}
+
+impl super::Scalar {
+    pub const I32: Self = Self {
+        kind: crate::ScalarKind::Sint,
+        width: 4,
+    };
+    pub const U32: Self = Self {
+        kind: crate::ScalarKind::Uint,
+        width: 4,
+    };
+    pub const F32: Self = Self {
+        kind: crate::ScalarKind::Float,
+        width: 4,
+    };
+    pub const F64: Self = Self {
+        kind: crate::ScalarKind::Float,
+        width: 8,
+    };
+    pub const I64: Self = Self {
+        kind: crate::ScalarKind::Sint,
+        width: 8,
+    };
+    pub const BOOL: Self = Self {
+        kind: crate::ScalarKind::Bool,
+        width: crate::BOOL_WIDTH,
+    };
+    pub const ABSTRACT_INT: Self = Self {
+        kind: crate::ScalarKind::AbstractInt,
+        width: crate::ABSTRACT_WIDTH,
+    };
+    pub const ABSTRACT_FLOAT: Self = Self {
+        kind: crate::ScalarKind::AbstractFloat,
+        width: crate::ABSTRACT_WIDTH,
+    };
+
+    pub const fn is_abstract(self) -> bool {
+        match self.kind {
+            crate::ScalarKind::AbstractInt | crate::ScalarKind::AbstractFloat => true,
+            crate::ScalarKind::Sint
+            | crate::ScalarKind::Uint
+            | crate::ScalarKind::Float
+            | crate::ScalarKind::Bool => false,
+        }
+    }
+
+    /// Construct a float `Scalar` with the given width.
+    ///
+    /// This is especially common when dealing with
+    /// `TypeInner::Matrix`, where the scalar kind is implicit.
+    pub const fn float(width: crate::Bytes) -> Self {
+        Self {
+            kind: crate::ScalarKind::Float,
+            width,
+        }
+    }
+
+    pub const fn to_inner_scalar(self) -> crate::TypeInner {
+        crate::TypeInner::Scalar(self)
+    }
+
+    pub const fn to_inner_vector(self, size: crate::VectorSize) -> crate::TypeInner {
+        crate::TypeInner::Vector { size, scalar: self }
+    }
+
+    pub const fn to_inner_atomic(self) -> crate::TypeInner {
+        crate::TypeInner::Atomic(self)
+    }
+}
+
+impl PartialEq for crate::Literal {
+    fn eq(&self, other: &Self) -> bool {
+        match (*self, *other) {
+            (Self::F64(a), Self::F64(b)) => a.to_bits() == b.to_bits(),
+            (Self::F32(a), Self::F32(b)) => a.to_bits() == b.to_bits(),
+            (Self::U32(a), Self::U32(b)) => a == b,
+            (Self::I32(a), Self::I32(b)) => a == b,
+            (Self::I64(a), Self::I64(b)) => a == b,
+            (Self::Bool(a), Self::Bool(b)) => a == b,
+            _ => false,
+        }
+    }
+}
+impl Eq for crate::Literal {}
+impl std::hash::Hash for crate::Literal {
+    fn hash<H: std::hash::Hasher>(&self, hasher: &mut H) {
+        match *self {
+            Self::F64(v) | Self::AbstractFloat(v) => {
+                hasher.write_u8(0);
+                v.to_bits().hash(hasher);
+            }
+            Self::F32(v) => {
+                hasher.write_u8(1);
+                v.to_bits().hash(hasher);
+            }
+            Self::U32(v) => {
+                hasher.write_u8(2);
+                v.hash(hasher);
+            }
+            Self::I32(v) => {
+                hasher.write_u8(3);
+                v.hash(hasher);
+            }
+            Self::Bool(v) => {
+                hasher.write_u8(4);
+                v.hash(hasher);
+            }
+            Self::I64(v) | Self::AbstractInt(v) => {
+                hasher.write_u8(5);
+                v.hash(hasher);
+            }
+        }
+    }
+}
+
+impl crate::Literal {
+    pub const fn new(value: u8, scalar: crate::Scalar) -> Option<Self> {
+        match (value, scalar.kind, scalar.width) {
+            (value, crate::ScalarKind::Float, 8) => Some(Self::F64(value as _)),
+            (value, crate::ScalarKind::Float, 4) => Some(Self::F32(value as _)),
+            (value, crate::ScalarKind::Uint, 4) => Some(Self::U32(value as _)),
+            (value, crate::ScalarKind::Sint, 4) => Some(Self::I32(value as _)),
+            (value, crate::ScalarKind::Sint, 8) => Some(Self::I64(value as _)),
+            (1, crate::ScalarKind::Bool, 4) => Some(Self::Bool(true)),
+            (0, crate::ScalarKind::Bool, 4) => Some(Self::Bool(false)),
+            _ => None,
+        }
+    }
+
+    pub const fn zero(scalar: crate::Scalar) -> Option<Self> {
+        Self::new(0, scalar)
+    }
+
+    pub const fn one(scalar: crate::Scalar) -> Option<Self> {
+        Self::new(1, scalar)
+    }
+
+    pub const fn width(&self) -> crate::Bytes {
+        match *self {
+            Self::F64(_) | Self::I64(_) => 8,
+            Self::F32(_) | Self::U32(_) | Self::I32(_) => 4,
+            Self::Bool(_) => crate::BOOL_WIDTH,
+            Self::AbstractInt(_) | Self::AbstractFloat(_) => crate::ABSTRACT_WIDTH,
+        }
+    }
+    pub const fn scalar(&self) -> crate::Scalar {
+        match *self {
+            Self::F64(_) => crate::Scalar::F64,
+            Self::F32(_) => crate::Scalar::F32,
+            Self::U32(_) => crate::Scalar::U32,
+            Self::I32(_) => crate::Scalar::I32,
+            Self::I64(_) => crate::Scalar::I64,
+            Self::Bool(_) => crate::Scalar::BOOL,
+            Self::AbstractInt(_) => crate::Scalar::ABSTRACT_INT,
+            Self::AbstractFloat(_) => crate::Scalar::ABSTRACT_FLOAT,
+        }
+    }
+    pub const fn scalar_kind(&self) -> crate::ScalarKind {
+        self.scalar().kind
+    }
+    pub const fn ty_inner(&self) -> crate::TypeInner {
+        crate::TypeInner::Scalar(self.scalar())
+    }
+}
+
+pub const POINTER_SPAN: u32 = 4;
+
+impl super::TypeInner {
+    /// Return the scalar type of `self`.
+    ///
+    /// If `inner` is a scalar, vector, or matrix type, return
+    /// its scalar type. Otherwise, return `None`.
+    pub const fn scalar(&self) -> Option<super::Scalar> {
+        use crate::TypeInner as Ti;
+        match *self {
+            Ti::Scalar(scalar) | Ti::Vector { scalar, .. } => Some(scalar),
+            Ti::Matrix { scalar, .. } => Some(scalar),
+            _ => None,
+        }
+    }
+
+    pub fn scalar_kind(&self) -> Option<super::ScalarKind> {
+        self.scalar().map(|scalar| scalar.kind)
+    }
+
+    pub fn scalar_width(&self) -> Option<u8> {
+        self.scalar().map(|scalar| scalar.width * 8)
+    }
+
+    pub const fn pointer_space(&self) -> Option<crate::AddressSpace> {
+        match *self {
+            Self::Pointer { space, .. } => Some(space),
+            Self::ValuePointer { space, .. } => Some(space),
+            _ => None,
+        }
+    }
+
+    pub fn is_atomic_pointer(&self, types: &crate::UniqueArena<crate::Type>) -> bool {
+        match *self {
+            crate::TypeInner::Pointer { base, .. } => match types[base].inner {
+                crate::TypeInner::Atomic { .. } => true,
+                _ => false,
+            },
+            _ => false,
+        }
+    }
+
+    /// Get the size of this type.
+    pub fn size(&self, _gctx: GlobalCtx) -> u32 {
+        match *self {
+            Self::Scalar(scalar) | Self::Atomic(scalar) => scalar.width as u32,
+            Self::Vector { size, scalar } => size as u32 * scalar.width as u32,
+            // matrices are treated as arrays of aligned columns
+            Self::Matrix {
+                columns,
+                rows,
+                scalar,
+            } => Alignment::from(rows) * scalar.width as u32 * columns as u32,
+            Self::Pointer { .. } | Self::ValuePointer { .. } => POINTER_SPAN,
+            Self::Array {
+                base: _,
+                size,
+                stride,
+            } => {
+                let count = match size {
+                    super::ArraySize::Constant(count) => count.get(),
+                    // A dynamically-sized array has to have at least one element
+                    super::ArraySize::Dynamic => 1,
+                };
+                count * stride
+            }
+            Self::Struct { span, .. } => span,
+            Self::Image { .. }
+            | Self::Sampler { .. }
+            | Self::AccelerationStructure
+            | Self::RayQuery
+            | Self::BindingArray { .. } => 0,
+        }
+    }
+
+    /// Return the canonical form of `self`, or `None` if it's already in
+    /// canonical form.
+    ///
+    /// Certain types have multiple representations in `TypeInner`. This
+    /// function converts all forms of equivalent types to a single
+    /// representative of their class, so that simply applying `Eq` to the
+    /// result indicates whether the types are equivalent, as far as Naga IR is
+    /// concerned.
+    pub fn canonical_form(
+        &self,
+        types: &crate::UniqueArena<crate::Type>,
+    ) -> Option<crate::TypeInner> {
+        use crate::TypeInner as Ti;
+        match *self {
+            Ti::Pointer { base, space } => match types[base].inner {
+                Ti::Scalar(scalar) => Some(Ti::ValuePointer {
+                    size: None,
+                    scalar,
+                    space,
+                }),
+                Ti::Vector { size, scalar } => Some(Ti::ValuePointer {
+                    size: Some(size),
+                    scalar,
+                    space,
+                }),
+                _ => None,
+            },
+            _ => None,
+        }
+    }
+
+    /// Compare `self` and `rhs` as types.
+    ///
+    /// This is mostly the same as `<TypeInner as Eq>::eq`, but it treats
+    /// `ValuePointer` and `Pointer` types as equivalent.
+    ///
+    /// When you know that one side of the comparison is never a pointer, it's
+    /// fine to not bother with canonicalization, and just compare `TypeInner`
+    /// values with `==`.
+    pub fn equivalent(
+        &self,
+        rhs: &crate::TypeInner,
+        types: &crate::UniqueArena<crate::Type>,
+    ) -> bool {
+        let left = self.canonical_form(types);
+        let right = rhs.canonical_form(types);
+        left.as_ref().unwrap_or(self) == right.as_ref().unwrap_or(rhs)
+    }
+
+    pub fn is_dynamically_sized(&self, types: &crate::UniqueArena<crate::Type>) -> bool {
+        use crate::TypeInner as Ti;
+        match *self {
+            Ti::Array { size, .. } => size == crate::ArraySize::Dynamic,
+            Ti::Struct { ref members, .. } => members
+                .last()
+                .map(|last| types[last.ty].inner.is_dynamically_sized(types))
+                .unwrap_or(false),
+            _ => false,
+        }
+    }
+
+    pub fn components(&self) -> Option<u32> {
+        Some(match *self {
+            Self::Vector { size, .. } => size as u32,
+            Self::Matrix { columns, .. } => columns as u32,
+            Self::Array {
+                size: crate::ArraySize::Constant(len),
+                ..
+            } => len.get(),
+            Self::Struct { ref members, .. } => members.len() as u32,
+            _ => return None,
+        })
+    }
+
+    pub fn component_type(&self, index: usize) -> Option<TypeResolution> {
+        Some(match *self {
+            Self::Vector { scalar, .. } => TypeResolution::Value(crate::TypeInner::Scalar(scalar)),
+            Self::Matrix { rows, scalar, .. } => {
+                TypeResolution::Value(crate::TypeInner::Vector { size: rows, scalar })
+            }
+            Self::Array {
+                base,
+                size: crate::ArraySize::Constant(_),
+                ..
+            } => TypeResolution::Handle(base),
+            Self::Struct { ref members, .. } => TypeResolution::Handle(members[index].ty),
+            _ => return None,
+        })
+    }
+}
+
+impl super::AddressSpace {
+    pub fn access(self) -> crate::StorageAccess {
+        use crate::StorageAccess as Sa;
+        match self {
+            crate::AddressSpace::Function
+            | crate::AddressSpace::Private
+            | crate::AddressSpace::WorkGroup => Sa::LOAD | Sa::STORE,
+            crate::AddressSpace::Uniform => Sa::LOAD,
+            crate::AddressSpace::Storage { access } => access,
+            crate::AddressSpace::Handle => Sa::LOAD,
+            crate::AddressSpace::PushConstant => Sa::LOAD,
+        }
+    }
+}
+
+impl super::MathFunction {
+    pub const fn argument_count(&self) -> usize {
+        match *self {
+            // comparison
+            Self::Abs => 1,
+            Self::Min => 2,
+            Self::Max => 2,
+            Self::Clamp => 3,
+            Self::Saturate => 1,
+            // trigonometry
+            Self::Cos => 1,
+            Self::Cosh => 1,
+            Self::Sin => 1,
+            Self::Sinh => 1,
+            Self::Tan => 1,
+            Self::Tanh => 1,
+            Self::Acos => 1,
+            Self::Asin => 1,
+            Self::Atan => 1,
+            Self::Atan2 => 2,
+            Self::Asinh => 1,
+            Self::Acosh => 1,
+            Self::Atanh => 1,
+            Self::Radians => 1,
+            Self::Degrees => 1,
+            // decomposition
+            Self::Ceil => 1,
+            Self::Floor => 1,
+            Self::Round => 1,
+            Self::Fract => 1,
+            Self::Trunc => 1,
+            Self::Modf => 1,
+            Self::Frexp => 1,
+            Self::Ldexp => 2,
+            // exponent
+            Self::Exp => 1,
+            Self::Exp2 => 1,
+            Self::Log => 1,
+            Self::Log2 => 1,
+            Self::Pow => 2,
+            // geometry
+            Self::Dot => 2,
+            Self::Outer => 2,
+            Self::Cross => 2,
+            Self::Distance => 2,
+            Self::Length => 1,
+            Self::Normalize => 1,
+            Self::FaceForward => 3,
+            Self::Reflect => 2,
+            Self::Refract => 3,
+            // computational
+            Self::Sign => 1,
+            Self::Fma => 3,
+            Self::Mix => 3,
+            Self::Step => 2,
+            Self::SmoothStep => 3,
+            Self::Sqrt => 1,
+            Self::InverseSqrt => 1,
+            Self::Inverse => 1,
+            Self::Transpose => 1,
+            Self::Determinant => 1,
+            // bits
+            Self::CountTrailingZeros => 1,
+            Self::CountLeadingZeros => 1,
+            Self::CountOneBits => 1,
+            Self::ReverseBits => 1,
+            Self::ExtractBits => 3,
+            Self::InsertBits => 4,
+            Self::FindLsb => 1,
+            Self::FindMsb => 1,
+            // data packing
+            Self::Pack4x8snorm => 1,
+            Self::Pack4x8unorm => 1,
+            Self::Pack2x16snorm => 1,
+            Self::Pack2x16unorm => 1,
+            Self::Pack2x16float => 1,
+            // data unpacking
+            Self::Unpack4x8snorm => 1,
+            Self::Unpack4x8unorm => 1,
+            Self::Unpack2x16snorm => 1,
+            Self::Unpack2x16unorm => 1,
+            Self::Unpack2x16float => 1,
+        }
+    }
+}
+
+impl crate::Expression {
+    /// Returns true if the expression is considered emitted at the start of a function.
+    pub const fn needs_pre_emit(&self) -> bool {
+        match *self {
+            Self::Literal(_)
+            | Self::Constant(_)
+            | Self::ZeroValue(_)
+            | Self::FunctionArgument(_)
+            | Self::GlobalVariable(_)
+            | Self::LocalVariable(_) => true,
+            _ => false,
+        }
+    }
+
+    /// Return true if this expression is a dynamic array index, for [`Access`].
+    ///
+    /// This method returns true if this expression is a dynamically computed
+    /// index, and as such can only be used to index matrices and arrays when
+    /// they appear behind a pointer. See the documentation for [`Access`] for
+    /// details.
+    ///
+    /// Note, this does not check the _type_ of the given expression. It's up to
+    /// the caller to establish that the `Access` expression is well-typed
+    /// through other means, like [`ResolveContext`].
+    ///
+    /// [`Access`]: crate::Expression::Access
+    /// [`ResolveContext`]: crate::proc::ResolveContext
+    pub fn is_dynamic_index(&self, module: &crate::Module) -> bool {
+        match *self {
+            Self::Literal(_) | Self::ZeroValue(_) => false,
+            Self::Constant(handle) => {
+                let constant = &module.constants[handle];
+                !matches!(constant.r#override, crate::Override::None)
+            }
+            _ => true,
+        }
+    }
+}
+
+impl crate::Function {
+    /// Return the global variable being accessed by the expression `pointer`.
+    ///
+    /// Assuming that `pointer` is a series of `Access` and `AccessIndex`
+    /// expressions that ultimately access some part of a `GlobalVariable`,
+    /// return a handle for that global.
+    ///
+    /// If the expression does not ultimately access a global variable, return
+    /// `None`.
+    pub fn originating_global(
+        &self,
+        mut pointer: crate::Handle<crate::Expression>,
+    ) -> Option<crate::Handle<crate::GlobalVariable>> {
+        loop {
+            pointer = match self.expressions[pointer] {
+                crate::Expression::Access { base, .. } => base,
+                crate::Expression::AccessIndex { base, .. } => base,
+                crate::Expression::GlobalVariable(handle) => return Some(handle),
+                crate::Expression::LocalVariable(_) => return None,
+                crate::Expression::FunctionArgument(_) => return None,
+                // There are no other expressions that produce pointer values.
+                _ => unreachable!(),
+            }
+        }
+    }
+}
+
+impl crate::SampleLevel {
+    pub const fn implicit_derivatives(&self) -> bool {
+        match *self {
+            Self::Auto | Self::Bias(_) => true,
+            Self::Zero | Self::Exact(_) | Self::Gradient { .. } => false,
+        }
+    }
+}
+
+impl crate::Binding {
+    pub const fn to_built_in(&self) -> Option<crate::BuiltIn> {
+        match *self {
+            crate::Binding::BuiltIn(built_in) => Some(built_in),
+            Self::Location { .. } => None,
+        }
+    }
+}
+
+impl super::SwizzleComponent {
+    pub const XYZW: [Self; 4] = [Self::X, Self::Y, Self::Z, Self::W];
+
+    pub const fn index(&self) -> u32 {
+        match *self {
+            Self::X => 0,
+            Self::Y => 1,
+            Self::Z => 2,
+            Self::W => 3,
+        }
+    }
+    pub const fn from_index(idx: u32) -> Self {
+        match idx {
+            0 => Self::X,
+            1 => Self::Y,
+            2 => Self::Z,
+            _ => Self::W,
+        }
+    }
+}
+
+impl super::ImageClass {
+    pub const fn is_multisampled(self) -> bool {
+        match self {
+            crate::ImageClass::Sampled { multi, .. } | crate::ImageClass::Depth { multi } => multi,
+            crate::ImageClass::Storage { .. } => false,
+        }
+    }
+
+    pub const fn is_mipmapped(self) -> bool {
+        match self {
+            crate::ImageClass::Sampled { multi, .. } | crate::ImageClass::Depth { multi } => !multi,
+            crate::ImageClass::Storage { .. } => false,
+        }
+    }
+}
+
+impl crate::Module {
+    pub const fn to_ctx(&self) -> GlobalCtx<'_> {
+        GlobalCtx {
+            types: &self.types,
+            constants: &self.constants,
+            const_expressions: &self.const_expressions,
+        }
+    }
+}
+
+#[derive(Debug)]
+pub(super) enum U32EvalError {
+    NonConst,
+    Negative,
+}
+
+#[derive(Clone, Copy)]
+pub struct GlobalCtx<'a> {
+    pub types: &'a crate::UniqueArena<crate::Type>,
+    pub constants: &'a crate::Arena<crate::Constant>,
+    pub const_expressions: &'a crate::Arena<crate::Expression>,
+}
+
+impl GlobalCtx<'_> {
+    /// Try to evaluate the expression in `self.const_expressions` using its `handle` and return it as a `u32`.
+    #[allow(dead_code)]
+    pub(super) fn eval_expr_to_u32(
+        &self,
+        handle: crate::Handle<crate::Expression>,
+    ) -> Result<u32, U32EvalError> {
+        self.eval_expr_to_u32_from(handle, self.const_expressions)
+    }
+
+    /// Try to evaluate the expression in the `arena` using its `handle` and return it as a `u32`.
+    pub(super) fn eval_expr_to_u32_from(
+        &self,
+        handle: crate::Handle<crate::Expression>,
+        arena: &crate::Arena<crate::Expression>,
+    ) -> Result<u32, U32EvalError> {
+        match self.eval_expr_to_literal_from(handle, arena) {
+            Some(crate::Literal::U32(value)) => Ok(value),
+            Some(crate::Literal::I32(value)) => {
+                value.try_into().map_err(|_| U32EvalError::Negative)
+            }
+            _ => Err(U32EvalError::NonConst),
+        }
+    }
+
+    #[allow(dead_code)]
+    pub(crate) fn eval_expr_to_literal(
+        &self,
+        handle: crate::Handle<crate::Expression>,
+    ) -> Option<crate::Literal> {
+        self.eval_expr_to_literal_from(handle, self.const_expressions)
+    }
+
+    fn eval_expr_to_literal_from(
+        &self,
+        handle: crate::Handle<crate::Expression>,
+        arena: &crate::Arena<crate::Expression>,
+    ) -> Option<crate::Literal> {
+        fn get(
+            gctx: GlobalCtx,
+            handle: crate::Handle<crate::Expression>,
+            arena: &crate::Arena<crate::Expression>,
+        ) -> Option<crate::Literal> {
+            match arena[handle] {
+                crate::Expression::Literal(literal) => Some(literal),
+                crate::Expression::ZeroValue(ty) => match gctx.types[ty].inner {
+                    crate::TypeInner::Scalar(scalar) => crate::Literal::zero(scalar),
+                    _ => None,
+                },
+                _ => None,
+            }
+        }
+        match arena[handle] {
+            crate::Expression::Constant(c) => {
+                get(*self, self.constants[c].init, self.const_expressions)
+            }
+            _ => get(*self, handle, arena),
+        }
+    }
+}
+
+/// Return an iterator over the individual components assembled by a
+/// `Compose` expression.
+///
+/// Given `ty` and `components` from an `Expression::Compose`, return an
+/// iterator over the components of the resulting value.
+///
+/// Normally, this would just be an iterator over `components`. However,
+/// `Compose` expressions can concatenate vectors, in which case the i'th
+/// value being composed is not generally the i'th element of `components`.
+/// This function consults `ty` to decide if this concatenation is occurring,
+/// and returns an iterator that produces the components of the result of
+/// the `Compose` expression in either case.
+pub fn flatten_compose<'arenas>(
+    ty: crate::Handle<crate::Type>,
+    components: &'arenas [crate::Handle<crate::Expression>],
+    expressions: &'arenas crate::Arena<crate::Expression>,
+    types: &'arenas crate::UniqueArena<crate::Type>,
+) -> impl Iterator<Item = crate::Handle<crate::Expression>> + 'arenas {
+    // Returning `impl Iterator` is a bit tricky. We may or may not
+    // want to flatten the components, but we have to settle on a
+    // single concrete type to return. This function returns a single
+    // iterator chain that handles both the flattening and
+    // non-flattening cases.
+    let (size, is_vector) = if let crate::TypeInner::Vector { size, .. } = types[ty].inner {
+        (size as usize, true)
+    } else {
+        (components.len(), false)
+    };
+
+    /// Flatten `Compose` expressions if `is_vector` is true.
+    fn flatten_compose<'c>(
+        component: &'c crate::Handle<crate::Expression>,
+        is_vector: bool,
+        expressions: &'c crate::Arena<crate::Expression>,
+    ) -> &'c [crate::Handle<crate::Expression>] {
+        if is_vector {
+            if let crate::Expression::Compose {
+                ty: _,
+                components: ref subcomponents,
+            } = expressions[*component]
+            {
+                return subcomponents;
+            }
+        }
+        std::slice::from_ref(component)
+    }
+
+    /// Flatten `Splat` expressions if `is_vector` is true.
+    fn flatten_splat<'c>(
+        component: &'c crate::Handle<crate::Expression>,
+        is_vector: bool,
+        expressions: &'c crate::Arena<crate::Expression>,
+    ) -> impl Iterator<Item = crate::Handle<crate::Expression>> {
+        let mut expr = *component;
+        let mut count = 1;
+        if is_vector {
+            if let crate::Expression::Splat { size, value } = expressions[expr] {
+                expr = value;
+                count = size as usize;
+            }
+        }
+        std::iter::repeat(expr).take(count)
+    }
+
+    // Expressions like `vec4(vec3(vec2(6, 7), 8), 9)` require us to
+    // flatten up to two levels of `Compose` expressions.
+    //
+    // Expressions like `vec4(vec3(1.0), 1.0)` require us to flatten
+    // `Splat` expressions. Fortunately, the operand of a `Splat` must
+    // be a scalar, so we can stop there.
+    components
+        .iter()
+        .flat_map(move |component| flatten_compose(component, is_vector, expressions))
+        .flat_map(move |component| flatten_compose(component, is_vector, expressions))
+        .flat_map(move |component| flatten_splat(component, is_vector, expressions))
+        .take(size)
+}
+
+#[test]
+fn test_matrix_size() {
+    let module = crate::Module::default();
+    assert_eq!(
+        crate::TypeInner::Matrix {
+            columns: crate::VectorSize::Tri,
+            rows: crate::VectorSize::Tri,
+            scalar: crate::Scalar::F32,
+        }
+        .size(module.to_ctx()),
+        48,
+    );
+}
diff --git a/third_party/rust/naga/src/proc/namer.rs b/third_party/rust/naga/src/proc/namer.rs
new file mode 100644
index 0000000000..8afacb593d
--- /dev/null
+++ b/third_party/rust/naga/src/proc/namer.rs
@@ -0,0 +1,281 @@
+use crate::{arena::Handle, FastHashMap, FastHashSet};
+use std::borrow::Cow;
+use std::hash::{Hash, Hasher};
+
+pub type EntryPointIndex = u16;
+const SEPARATOR: char = '_';
+
+#[derive(Debug, Eq, Hash, PartialEq)]
+pub enum NameKey {
+    Constant(Handle<crate::Constant>),
+    GlobalVariable(Handle<crate::GlobalVariable>),
+    Type(Handle<crate::Type>),
+    StructMember(Handle<crate::Type>, u32),
+    Function(Handle<crate::Function>),
+    FunctionArgument(Handle<crate::Function>, u32),
+    FunctionLocal(Handle<crate::Function>, Handle<crate::LocalVariable>),
+    EntryPoint(EntryPointIndex),
+    EntryPointLocal(EntryPointIndex, Handle<crate::LocalVariable>),
+    EntryPointArgument(EntryPointIndex, u32),
+}
+
+/// This processor assigns names to all the things in a module
+/// that may need identifiers in a textual backend.
+#[derive(Default)]
+pub struct Namer {
+    /// The last numeric suffix used for each base name. Zero means "no suffix".
+    unique: FastHashMap<String, u32>,
+    keywords: FastHashSet<&'static str>,
+    keywords_case_insensitive: FastHashSet<AsciiUniCase<&'static str>>,
+    reserved_prefixes: Vec<&'static str>,
+}
+
+impl Namer {
+    /// Return a form of `string` suitable for use as the base of an identifier.
+    ///
+    /// - Drop leading digits.
+    /// - Retain only alphanumeric and `_` characters.
+    /// - Avoid prefixes in [`Namer::reserved_prefixes`].
+    /// - Replace consecutive `_` characters with a single `_` character.
+    ///
+    /// The return value is a valid identifier prefix in all of Naga's output languages,
+    /// and it never ends with a `SEPARATOR` character.
+    /// It is used as a key into the unique table.
+    fn sanitize<'s>(&self, string: &'s str) -> Cow<'s, str> {
+        let string = string
+            .trim_start_matches(|c: char| c.is_numeric())
+            .trim_end_matches(SEPARATOR);
+
+        let base = if !string.is_empty()
+            && !string.contains("__")
+            && string
+                .chars()
+                .all(|c: char| c.is_ascii_alphanumeric() || c == '_')
+        {
+            Cow::Borrowed(string)
+        } else {
+            let mut filtered = string
+                .chars()
+                .filter(|&c| c.is_ascii_alphanumeric() || c == '_')
+                .fold(String::new(), |mut s, c| {
+                    if s.ends_with('_') && c == '_' {
+                        return s;
+                    }
+                    s.push(c);
+                    s
+                });
+            let stripped_len = filtered.trim_end_matches(SEPARATOR).len();
+            filtered.truncate(stripped_len);
+            if filtered.is_empty() {
+                filtered.push_str("unnamed");
+            }
+            Cow::Owned(filtered)
+        };
+
+        for prefix in &self.reserved_prefixes {
+            if base.starts_with(prefix) {
+                return format!("gen_{base}").into();
+            }
+        }
+
+        base
+    }
+
+    /// Return a new identifier based on `label_raw`.
+    ///
+    /// The result:
+    /// - is a valid identifier even if `label_raw` is not
+    /// - conflicts with no keywords listed in `Namer::keywords`, and
+    /// - is different from any identifier previously constructed by this
+    ///   `Namer`.
+    ///
+    /// Guarantee uniqueness by applying a numeric suffix when necessary. If `label_raw`
+    /// itself ends with digits, separate them from the suffix with an underscore.
+    pub fn call(&mut self, label_raw: &str) -> String {
+        use std::fmt::Write as _; // for write!-ing to Strings
+
+        let base = self.sanitize(label_raw);
+        debug_assert!(!base.is_empty() && !base.ends_with(SEPARATOR));
+
+        // This would seem to be a natural place to use `HashMap::entry`. However, `entry`
+        // requires an owned key, and we'd like to avoid heap-allocating strings we're
+        // just going to throw away. The approach below double-hashes only when we create
+        // a new entry, in which case the heap allocation of the owned key was more
+        // expensive anyway.
+        match self.unique.get_mut(base.as_ref()) {
+            Some(count) => {
+                *count += 1;
+                // Add the suffix. This may fit in base's existing allocation.
+                let mut suffixed = base.into_owned();
+                write!(suffixed, "{}{}", SEPARATOR, *count).unwrap();
+                suffixed
+            }
+            None => {
+                let mut suffixed = base.to_string();
+                if base.ends_with(char::is_numeric)
+                    || self.keywords.contains(base.as_ref())
+                    || self
+                        .keywords_case_insensitive
+                        .contains(&AsciiUniCase(base.as_ref()))
+                {
+                    suffixed.push(SEPARATOR);
+                }
+                debug_assert!(!self.keywords.contains::<str>(&suffixed));
+                // `self.unique` wants to own its keys. This allocates only if we haven't
+                // already done so earlier.
+                self.unique.insert(base.into_owned(), 0);
+                suffixed
+            }
+        }
+    }
+
+    pub fn call_or(&mut self, label: &Option<String>, fallback: &str) -> String {
+        self.call(match *label {
+            Some(ref name) => name,
+            None => fallback,
+        })
+    }
+
+    /// Enter a local namespace for things like structs.
+    ///
+    /// Struct member names only need to be unique amongst themselves, not
+    /// globally. This function temporarily establishes a fresh, empty naming
+    /// context for the duration of the call to `body`.
+    fn namespace(&mut self, capacity: usize, body: impl FnOnce(&mut Self)) {
+        let fresh = FastHashMap::with_capacity_and_hasher(capacity, Default::default());
+        let outer = std::mem::replace(&mut self.unique, fresh);
+        body(self);
+        self.unique = outer;
+    }
+
+    pub fn reset(
+        &mut self,
+        module: &crate::Module,
+        reserved_keywords: &[&'static str],
+        extra_reserved_keywords: &[&'static str],
+        reserved_keywords_case_insensitive: &[&'static str],
+        reserved_prefixes: &[&'static str],
+        output: &mut FastHashMap<NameKey, String>,
+    ) {
+        self.reserved_prefixes.clear();
+        self.reserved_prefixes.extend(reserved_prefixes.iter());
+
+        self.unique.clear();
+        self.keywords.clear();
+        self.keywords.extend(reserved_keywords.iter());
+        self.keywords.extend(extra_reserved_keywords.iter());
+
+        debug_assert!(reserved_keywords_case_insensitive
+            .iter()
+            .all(|s| s.is_ascii()));
+        self.keywords_case_insensitive.clear();
+        self.keywords_case_insensitive.extend(
+            reserved_keywords_case_insensitive
+                .iter()
+                .map(|string| (AsciiUniCase(*string))),
+        );
+
+        let mut temp = String::new();
+
+        for (ty_handle, ty) in module.types.iter() {
+            let ty_name = self.call_or(&ty.name, "type");
+            output.insert(NameKey::Type(ty_handle), ty_name);
+
+            if let crate::TypeInner::Struct { ref members, .. } = ty.inner {
+                // struct members have their own namespace, because access is always prefixed
+                self.namespace(members.len(), |namer| {
+                    for (index, member) in members.iter().enumerate() {
+                        let name = namer.call_or(&member.name, "member");
+                        output.insert(NameKey::StructMember(ty_handle, index as u32), name);
+                    }
+                })
+            }
+        }
+
+        for (ep_index, ep) in module.entry_points.iter().enumerate() {
+            let ep_name = self.call(&ep.name);
+            output.insert(NameKey::EntryPoint(ep_index as _), ep_name);
+            for (index, arg) in ep.function.arguments.iter().enumerate() {
+                let name = self.call_or(&arg.name, "param");
+                output.insert(
+                    NameKey::EntryPointArgument(ep_index as _, index as u32),
+                    name,
+                );
+            }
+            for (handle, var) in ep.function.local_variables.iter() {
+                let name = self.call_or(&var.name, "local");
+                output.insert(NameKey::EntryPointLocal(ep_index as _, handle), name);
+            }
+        }
+
+        for (fun_handle, fun) in module.functions.iter() {
+            let fun_name = self.call_or(&fun.name, "function");
+            output.insert(NameKey::Function(fun_handle), fun_name);
+            for (index, arg) in fun.arguments.iter().enumerate() {
+                let name = self.call_or(&arg.name, "param");
+                output.insert(NameKey::FunctionArgument(fun_handle, index as u32), name);
+            }
+            for (handle, var) in fun.local_variables.iter() {
+                let name = self.call_or(&var.name, "local");
+                output.insert(NameKey::FunctionLocal(fun_handle, handle), name);
+            }
+        }
+
+        for (handle, var) in module.global_variables.iter() {
+            let name = self.call_or(&var.name, "global");
+            output.insert(NameKey::GlobalVariable(handle), name);
+        }
+
+        for (handle, constant) in module.constants.iter() {
+            let label = match constant.name {
+                Some(ref name) => name,
+                None => {
+                    use std::fmt::Write;
+                    // Try to be more descriptive about the constant values
+                    temp.clear();
+                    write!(temp, "const_{}", output[&NameKey::Type(constant.ty)]).unwrap();
+                    &temp
+                }
+            };
+            let name = self.call(label);
+            output.insert(NameKey::Constant(handle), name);
+        }
+    }
+}
+
+/// A string wrapper type with an ascii case insensitive Eq and Hash impl
+struct AsciiUniCase<S: AsRef<str> + ?Sized>(S);
+
+impl<S: AsRef<str>> PartialEq<Self> for AsciiUniCase<S> {
+    #[inline]
+    fn eq(&self, other: &Self) -> bool {
+        self.0.as_ref().eq_ignore_ascii_case(other.0.as_ref())
+    }
+}
+
+impl<S: AsRef<str>> Eq for AsciiUniCase<S> {}
+
+impl<S: AsRef<str>> Hash for AsciiUniCase<S> {
+    #[inline]
+    fn hash<H: Hasher>(&self, hasher: &mut H) {
+        for byte in self
+            .0
+            .as_ref()
+            .as_bytes()
+            .iter()
+            .map(|b| b.to_ascii_lowercase())
+        {
+            hasher.write_u8(byte);
+        }
+    }
+}
+
+#[test]
+fn test() {
+    let mut namer = Namer::default();
+    assert_eq!(namer.call("x"), "x");
+    assert_eq!(namer.call("x"), "x_1");
+    assert_eq!(namer.call("x1"), "x1_");
+    assert_eq!(namer.call("__x"), "_x");
+    assert_eq!(namer.call("1___x"), "_x_1");
+}
diff --git a/third_party/rust/naga/src/proc/terminator.rs b/third_party/rust/naga/src/proc/terminator.rs
new file mode 100644
index 0000000000..a5239d4eca
--- /dev/null
+++ b/third_party/rust/naga/src/proc/terminator.rs
@@ -0,0 +1,44 @@
+/// Ensure that the given block has return statements
+/// at the end of its control flow.
+///
+/// Note: we don't want to blindly append a return statement
+/// to the end, because it may be either redundant or invalid,
+/// e.g. when the user already has returns in if/else branches.
+pub fn ensure_block_returns(block: &mut crate::Block) {
+    use crate::Statement as S;
+    match block.last_mut() {
+        Some(&mut S::Block(ref mut b)) => {
+            ensure_block_returns(b);
+        }
+        Some(&mut S::If {
+            condition: _,
+            ref mut accept,
+            ref mut reject,
+        }) => {
+            ensure_block_returns(accept);
+            ensure_block_returns(reject);
+        }
+        Some(&mut S::Switch {
+            selector: _,
+            ref mut cases,
+        }) => {
+            for case in cases.iter_mut() {
+                if !case.fall_through {
+                    ensure_block_returns(&mut case.body);
+                }
+            }
+        }
+        Some(&mut (S::Emit(_) | S::Break | S::Continue | S::Return { .. } | S::Kill)) => (),
+        Some(
+            &mut (S::Loop { .. }
+            | S::Store { .. }
+            | S::ImageStore { .. }
+            | S::Call { .. }
+            | S::RayQuery { .. }
+            | S::Atomic { .. }
+            | S::WorkGroupUniformLoad { .. }
+            | S::Barrier(_)),
+        )
+        | None => block.push(S::Return { value: None }, Default::default()),
+    }
+}
diff --git a/third_party/rust/naga/src/proc/typifier.rs b/third_party/rust/naga/src/proc/typifier.rs
new file mode 100644
index 0000000000..9c4403445c
--- /dev/null
+++ b/third_party/rust/naga/src/proc/typifier.rs
@@ -0,0 +1,893 @@
+use crate::arena::{Arena, Handle, UniqueArena};
+
+use thiserror::Error;
+
+/// The result of computing an expression's type.
+///
+/// This is the (Rust) type returned by [`ResolveContext::resolve`] to represent
+/// the (Naga) type it ascribes to some expression.
+///
+/// You might expect such a function to simply return a `Handle<Type>`. However,
+/// we want type resolution to be a read-only process, and that would limit the
+/// possible results to types already present in the expression's associated
+/// `UniqueArena<Type>`. Naga IR does have certain expressions whose types are
+/// not certain to be present.
+///
+/// So instead, type resolution returns a `TypeResolution` enum: either a
+/// [`Handle`], referencing some type in the arena, or a [`Value`], holding a
+/// free-floating [`TypeInner`]. This extends the range to cover anything that
+/// can be represented with a `TypeInner` referring to the existing arena.
+///
+/// What sorts of expressions can have types not available in the arena?
+///
+/// -   An [`Access`] or [`AccessIndex`] expression applied to a [`Vector`] or
+///     [`Matrix`] must have a [`Scalar`] or [`Vector`] type. But since `Vector`
+///     and `Matrix` represent their element and column types implicitly, not
+///     via a handle, there may not be a suitable type in the expression's
+///     associated arena. Instead, resolving such an expression returns a
+///     `TypeResolution::Value(TypeInner::X { ... })`, where `X` is `Scalar` or
+///     `Vector`.
+///
+/// -   Similarly, the type of an [`Access`] or [`AccessIndex`] expression
+///     applied to a *pointer to* a vector or matrix must produce a *pointer to*
+///     a scalar or vector type. These cannot be represented with a
+///     [`TypeInner::Pointer`], since the `Pointer`'s `base` must point into the
+///     arena, and as before, we cannot assume that a suitable scalar or vector
+///     type is there. So we take things one step further and provide
+///     [`TypeInner::ValuePointer`], specifically for the case of pointers to
+///     scalars or vectors. This type fits in a `TypeInner` and is exactly
+///     equivalent to a `Pointer` to a `Vector` or `Scalar`.
+///
+/// So, for example, the type of an `Access` expression applied to a value of type:
+///
+/// ```ignore
+/// TypeInner::Matrix { columns, rows, width }
+/// ```
+///
+/// might be:
+///
+/// ```ignore
+/// TypeResolution::Value(TypeInner::Vector {
+///     size: rows,
+///     kind: ScalarKind::Float,
+///     width,
+/// })
+/// ```
+///
+/// and the type of an access to a pointer of address space `space` to such a
+/// matrix might be:
+///
+/// ```ignore
+/// TypeResolution::Value(TypeInner::ValuePointer {
+///     size: Some(rows),
+///     kind: ScalarKind::Float,
+///     width,
+///     space,
+/// })
+/// ```
+///
+/// [`Handle`]: TypeResolution::Handle
+/// [`Value`]: TypeResolution::Value
+///
+/// [`Access`]: crate::Expression::Access
+/// [`AccessIndex`]: crate::Expression::AccessIndex
+///
+/// [`TypeInner`]: crate::TypeInner
+/// [`Matrix`]: crate::TypeInner::Matrix
+/// [`Pointer`]: crate::TypeInner::Pointer
+/// [`Scalar`]: crate::TypeInner::Scalar
+/// [`ValuePointer`]: crate::TypeInner::ValuePointer
+/// [`Vector`]: crate::TypeInner::Vector
+///
+/// [`TypeInner::Pointer`]: crate::TypeInner::Pointer
+/// [`TypeInner::ValuePointer`]: crate::TypeInner::ValuePointer
+#[derive(Debug, PartialEq)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub enum TypeResolution {
+    /// A type stored in the associated arena.
+    Handle(Handle<crate::Type>),
+
+    /// A free-floating [`TypeInner`], representing a type that may not be
+    /// available in the associated arena. However, the `TypeInner` itself may
+    /// contain `Handle<Type>` values referring to types from the arena.
+    ///
+    /// [`TypeInner`]: crate::TypeInner
+    Value(crate::TypeInner),
+}
+
+impl TypeResolution {
+    pub const fn handle(&self) -> Option<Handle<crate::Type>> {
+        match *self {
+            Self::Handle(handle) => Some(handle),
+            Self::Value(_) => None,
+        }
+    }
+
+    pub fn inner_with<'a>(&'a self, arena: &'a UniqueArena<crate::Type>) -> &'a crate::TypeInner {
+        match *self {
+            Self::Handle(handle) => &arena[handle].inner,
+            Self::Value(ref inner) => inner,
+        }
+    }
+}
+
+// Clone is only implemented for numeric variants of `TypeInner`.
+impl Clone for TypeResolution {
+    fn clone(&self) -> Self {
+        use crate::TypeInner as Ti;
+        match *self {
+            Self::Handle(handle) => Self::Handle(handle),
+            Self::Value(ref v) => Self::Value(match *v {
+                Ti::Scalar(scalar) => Ti::Scalar(scalar),
+                Ti::Vector { size, scalar } => Ti::Vector { size, scalar },
+                Ti::Matrix {
+                    rows,
+                    columns,
+                    scalar,
+                } => Ti::Matrix {
+                    rows,
+                    columns,
+                    scalar,
+                },
+                Ti::Pointer { base, space } => Ti::Pointer { base, space },
+                Ti::ValuePointer {
+                    size,
+                    scalar,
+                    space,
+                } => Ti::ValuePointer {
+                    size,
+                    scalar,
+                    space,
+                },
+                _ => unreachable!("Unexpected clone type: {:?}", v),
+            }),
+        }
+    }
+}
+
+#[derive(Clone, Debug, Error, PartialEq)]
+pub enum ResolveError {
+    #[error("Index {index} is out of bounds for expression {expr:?}")]
+    OutOfBoundsIndex {
+        expr: Handle<crate::Expression>,
+        index: u32,
+    },
+    #[error("Invalid access into expression {expr:?}, indexed: {indexed}")]
+    InvalidAccess {
+        expr: Handle<crate::Expression>,
+        indexed: bool,
+    },
+    #[error("Invalid sub-access into type {ty:?}, indexed: {indexed}")]
+    InvalidSubAccess {
+        ty: Handle<crate::Type>,
+        indexed: bool,
+    },
+    #[error("Invalid scalar {0:?}")]
+    InvalidScalar(Handle<crate::Expression>),
+    #[error("Invalid vector {0:?}")]
+    InvalidVector(Handle<crate::Expression>),
+    #[error("Invalid pointer {0:?}")]
+    InvalidPointer(Handle<crate::Expression>),
+    #[error("Invalid image {0:?}")]
+    InvalidImage(Handle<crate::Expression>),
+    #[error("Function {name} not defined")]
+    FunctionNotDefined { name: String },
+    #[error("Function without return type")]
+    FunctionReturnsVoid,
+    #[error("Incompatible operands: {0}")]
+    IncompatibleOperands(String),
+    #[error("Function argument {0} doesn't exist")]
+    FunctionArgumentNotFound(u32),
+    #[error("Special type is not registered within the module")]
+    MissingSpecialType,
+}
+
+pub struct ResolveContext<'a> {
+    pub constants: &'a Arena<crate::Constant>,
+    pub types: &'a UniqueArena<crate::Type>,
+    pub special_types: &'a crate::SpecialTypes,
+    pub global_vars: &'a Arena<crate::GlobalVariable>,
+    pub local_vars: &'a Arena<crate::LocalVariable>,
+    pub functions: &'a Arena<crate::Function>,
+    pub arguments: &'a [crate::FunctionArgument],
+}
+
+impl<'a> ResolveContext<'a> {
+    /// Initialize a resolve context from the module.
+    pub const fn with_locals(
+        module: &'a crate::Module,
+        local_vars: &'a Arena<crate::LocalVariable>,
+        arguments: &'a [crate::FunctionArgument],
+    ) -> Self {
+        Self {
+            constants: &module.constants,
+            types: &module.types,
+            special_types: &module.special_types,
+            global_vars: &module.global_variables,
+            local_vars,
+            functions: &module.functions,
+            arguments,
+        }
+    }
+
+    /// Determine the type of `expr`.
+    ///
+    /// The `past` argument must be a closure that can resolve the types of any
+    /// expressions that `expr` refers to. These can be gathered by caching the
+    /// results of prior calls to `resolve`, perhaps as done by the
+    /// [`front::Typifier`] utility type.
+    ///
+    /// Type resolution is a read-only process: this method takes `self` by
+    /// shared reference. However, this means that we cannot add anything to
+    /// `self.types` that we might need to describe `expr`. To work around this,
+    /// this method returns a [`TypeResolution`], rather than simply returning a
+    /// `Handle<Type>`; see the documentation for [`TypeResolution`] for
+    /// details.
+    ///
+    /// [`front::Typifier`]: crate::front::Typifier
+    pub fn resolve(
+        &self,
+        expr: &crate::Expression,
+        past: impl Fn(Handle<crate::Expression>) -> Result<&'a TypeResolution, ResolveError>,
+    ) -> Result<TypeResolution, ResolveError> {
+        use crate::TypeInner as Ti;
+        let types = self.types;
+        Ok(match *expr {
+            crate::Expression::Access { base, .. } => match *past(base)?.inner_with(types) {
+                // Arrays and matrices can only be indexed dynamically behind a
+                // pointer, but that's a validation error, not a type error, so
+                // go ahead provide a type here.
+                Ti::Array { base, .. } => TypeResolution::Handle(base),
+                Ti::Matrix { rows, scalar, .. } => {
+                    TypeResolution::Value(Ti::Vector { size: rows, scalar })
+                }
+                Ti::Vector { size: _, scalar } => TypeResolution::Value(Ti::Scalar(scalar)),
+                Ti::ValuePointer {
+                    size: Some(_),
+                    scalar,
+                    space,
+                } => TypeResolution::Value(Ti::ValuePointer {
+                    size: None,
+                    scalar,
+                    space,
+                }),
+                Ti::Pointer { base, space } => {
+                    TypeResolution::Value(match types[base].inner {
+                        Ti::Array { base, .. } => Ti::Pointer { base, space },
+                        Ti::Vector { size: _, scalar } => Ti::ValuePointer {
+                            size: None,
+                            scalar,
+                            space,
+                        },
+                        // Matrices are only dynamically indexed behind a pointer
+                        Ti::Matrix {
+                            columns: _,
+                            rows,
+                            scalar,
+                        } => Ti::ValuePointer {
+                            size: Some(rows),
+                            scalar,
+                            space,
+                        },
+                        Ti::BindingArray { base, .. } => Ti::Pointer { base, space },
+                        ref other => {
+                            log::error!("Access sub-type {:?}", other);
+                            return Err(ResolveError::InvalidSubAccess {
+                                ty: base,
+                                indexed: false,
+                            });
+                        }
+                    })
+                }
+                Ti::BindingArray { base, .. } => TypeResolution::Handle(base),
+                ref other => {
+                    log::error!("Access type {:?}", other);
+                    return Err(ResolveError::InvalidAccess {
+                        expr: base,
+                        indexed: false,
+                    });
+                }
+            },
+            crate::Expression::AccessIndex { base, index } => {
+                match *past(base)?.inner_with(types) {
+                    Ti::Vector { size, scalar } => {
+                        if index >= size as u32 {
+                            return Err(ResolveError::OutOfBoundsIndex { expr: base, index });
+                        }
+                        TypeResolution::Value(Ti::Scalar(scalar))
+                    }
+                    Ti::Matrix {
+                        columns,
+                        rows,
+                        scalar,
+                    } => {
+                        if index >= columns as u32 {
+                            return Err(ResolveError::OutOfBoundsIndex { expr: base, index });
+                        }
+                        TypeResolution::Value(crate::TypeInner::Vector { size: rows, scalar })
+                    }
+                    Ti::Array { base, .. } => TypeResolution::Handle(base),
+                    Ti::Struct { ref members, .. } => {
+                        let member = members
+                            .get(index as usize)
+                            .ok_or(ResolveError::OutOfBoundsIndex { expr: base, index })?;
+                        TypeResolution::Handle(member.ty)
+                    }
+                    Ti::ValuePointer {
+                        size: Some(size),
+                        scalar,
+                        space,
+                    } => {
+                        if index >= size as u32 {
+                            return Err(ResolveError::OutOfBoundsIndex { expr: base, index });
+                        }
+                        TypeResolution::Value(Ti::ValuePointer {
+                            size: None,
+                            scalar,
+                            space,
+                        })
+                    }
+                    Ti::Pointer {
+                        base: ty_base,
+                        space,
+                    } => TypeResolution::Value(match types[ty_base].inner {
+                        Ti::Array { base, .. } => Ti::Pointer { base, space },
+                        Ti::Vector { size, scalar } => {
+                            if index >= size as u32 {
+                                return Err(ResolveError::OutOfBoundsIndex { expr: base, index });
+                            }
+                            Ti::ValuePointer {
+                                size: None,
+                                scalar,
+                                space,
+                            }
+                        }
+                        Ti::Matrix {
+                            rows,
+                            columns,
+                            scalar,
+                        } => {
+                            if index >= columns as u32 {
+                                return Err(ResolveError::OutOfBoundsIndex { expr: base, index });
+                            }
+                            Ti::ValuePointer {
+                                size: Some(rows),
+                                scalar,
+                                space,
+                            }
+                        }
+                        Ti::Struct { ref members, .. } => {
+                            let member = members
+                                .get(index as usize)
+                                .ok_or(ResolveError::OutOfBoundsIndex { expr: base, index })?;
+                            Ti::Pointer {
+                                base: member.ty,
+                                space,
+                            }
+                        }
+                        Ti::BindingArray { base, .. } => Ti::Pointer { base, space },
+                        ref other => {
+                            log::error!("Access index sub-type {:?}", other);
+                            return Err(ResolveError::InvalidSubAccess {
+                                ty: ty_base,
+                                indexed: true,
+                            });
+                        }
+                    }),
+                    Ti::BindingArray { base, .. } => TypeResolution::Handle(base),
+                    ref other => {
+                        log::error!("Access index type {:?}", other);
+                        return Err(ResolveError::InvalidAccess {
+                            expr: base,
+                            indexed: true,
+                        });
+                    }
+                }
+            }
+            crate::Expression::Splat { size, value } => match *past(value)?.inner_with(types) {
+                Ti::Scalar(scalar) => TypeResolution::Value(Ti::Vector { size, scalar }),
+                ref other => {
+                    log::error!("Scalar type {:?}", other);
+                    return Err(ResolveError::InvalidScalar(value));
+                }
+            },
+            crate::Expression::Swizzle {
+                size,
+                vector,
+                pattern: _,
+            } => match *past(vector)?.inner_with(types) {
+                Ti::Vector { size: _, scalar } => {
+                    TypeResolution::Value(Ti::Vector { size, scalar })
+                }
+                ref other => {
+                    log::error!("Vector type {:?}", other);
+                    return Err(ResolveError::InvalidVector(vector));
+                }
+            },
+            crate::Expression::Literal(lit) => TypeResolution::Value(lit.ty_inner()),
+            crate::Expression::Constant(h) => TypeResolution::Handle(self.constants[h].ty),
+            crate::Expression::ZeroValue(ty) => TypeResolution::Handle(ty),
+            crate::Expression::Compose { ty, .. } => TypeResolution::Handle(ty),
+            crate::Expression::FunctionArgument(index) => {
+                let arg = self
+                    .arguments
+                    .get(index as usize)
+                    .ok_or(ResolveError::FunctionArgumentNotFound(index))?;
+                TypeResolution::Handle(arg.ty)
+            }
+            crate::Expression::GlobalVariable(h) => {
+                let var = &self.global_vars[h];
+                if var.space == crate::AddressSpace::Handle {
+                    TypeResolution::Handle(var.ty)
+                } else {
+                    TypeResolution::Value(Ti::Pointer {
+                        base: var.ty,
+                        space: var.space,
+                    })
+                }
+            }
+            crate::Expression::LocalVariable(h) => {
+                let var = &self.local_vars[h];
+                TypeResolution::Value(Ti::Pointer {
+                    base: var.ty,
+                    space: crate::AddressSpace::Function,
+                })
+            }
+            crate::Expression::Load { pointer } => match *past(pointer)?.inner_with(types) {
+                Ti::Pointer { base, space: _ } => {
+                    if let Ti::Atomic(scalar) = types[base].inner {
+                        TypeResolution::Value(Ti::Scalar(scalar))
+                    } else {
+                        TypeResolution::Handle(base)
+                    }
+                }
+                Ti::ValuePointer {
+                    size,
+                    scalar,
+                    space: _,
+                } => TypeResolution::Value(match size {
+                    Some(size) => Ti::Vector { size, scalar },
+                    None => Ti::Scalar(scalar),
+                }),
+                ref other => {
+                    log::error!("Pointer type {:?}", other);
+                    return Err(ResolveError::InvalidPointer(pointer));
+                }
+            },
+            crate::Expression::ImageSample {
+                image,
+                gather: Some(_),
+                ..
+            } => match *past(image)?.inner_with(types) {
+                Ti::Image { class, .. } => TypeResolution::Value(Ti::Vector {
+                    scalar: crate::Scalar {
+                        kind: match class {
+                            crate::ImageClass::Sampled { kind, multi: _ } => kind,
+                            _ => crate::ScalarKind::Float,
+                        },
+                        width: 4,
+                    },
+                    size: crate::VectorSize::Quad,
+                }),
+                ref other => {
+                    log::error!("Image type {:?}", other);
+                    return Err(ResolveError::InvalidImage(image));
+                }
+            },
+            crate::Expression::ImageSample { image, .. }
+            | crate::Expression::ImageLoad { image, .. } => match *past(image)?.inner_with(types) {
+                Ti::Image { class, .. } => TypeResolution::Value(match class {
+                    crate::ImageClass::Depth { multi: _ } => Ti::Scalar(crate::Scalar::F32),
+                    crate::ImageClass::Sampled { kind, multi: _ } => Ti::Vector {
+                        scalar: crate::Scalar { kind, width: 4 },
+                        size: crate::VectorSize::Quad,
+                    },
+                    crate::ImageClass::Storage { format, .. } => Ti::Vector {
+                        scalar: crate::Scalar {
+                            kind: format.into(),
+                            width: 4,
+                        },
+                        size: crate::VectorSize::Quad,
+                    },
+                }),
+                ref other => {
+                    log::error!("Image type {:?}", other);
+                    return Err(ResolveError::InvalidImage(image));
+                }
+            },
+            crate::Expression::ImageQuery { image, query } => TypeResolution::Value(match query {
+                crate::ImageQuery::Size { level: _ } => match *past(image)?.inner_with(types) {
+                    Ti::Image { dim, .. } => match dim {
+                        crate::ImageDimension::D1 => Ti::Scalar(crate::Scalar::U32),
+                        crate::ImageDimension::D2 | crate::ImageDimension::Cube => Ti::Vector {
+                            size: crate::VectorSize::Bi,
+                            scalar: crate::Scalar::U32,
+                        },
+                        crate::ImageDimension::D3 => Ti::Vector {
+                            size: crate::VectorSize::Tri,
+                            scalar: crate::Scalar::U32,
+                        },
+                    },
+                    ref other => {
+                        log::error!("Image type {:?}", other);
+                        return Err(ResolveError::InvalidImage(image));
+                    }
+                },
+                crate::ImageQuery::NumLevels
+                | crate::ImageQuery::NumLayers
+                | crate::ImageQuery::NumSamples => Ti::Scalar(crate::Scalar::U32),
+            }),
+            crate::Expression::Unary { expr, .. } => past(expr)?.clone(),
+            crate::Expression::Binary { op, left, right } => match op {
+                crate::BinaryOperator::Add
+                | crate::BinaryOperator::Subtract
+                | crate::BinaryOperator::Divide
+                | crate::BinaryOperator::Modulo => past(left)?.clone(),
+                crate::BinaryOperator::Multiply => {
+                    let (res_left, res_right) = (past(left)?, past(right)?);
+                    match (res_left.inner_with(types), res_right.inner_with(types)) {
+                        (
+                            &Ti::Matrix {
+                                columns: _,
+                                rows,
+                                scalar,
+                            },
+                            &Ti::Matrix { columns, .. },
+                        ) => TypeResolution::Value(Ti::Matrix {
+                            columns,
+                            rows,
+                            scalar,
+                        }),
+                        (
+                            &Ti::Matrix {
+                                columns: _,
+                                rows,
+                                scalar,
+                            },
+                            &Ti::Vector { .. },
+                        ) => TypeResolution::Value(Ti::Vector { size: rows, scalar }),
+                        (
+                            &Ti::Vector { .. },
+                            &Ti::Matrix {
+                                columns,
+                                rows: _,
+                                scalar,
+                            },
+                        ) => TypeResolution::Value(Ti::Vector {
+                            size: columns,
+                            scalar,
+                        }),
+                        (&Ti::Scalar { .. }, _) => res_right.clone(),
+                        (_, &Ti::Scalar { .. }) => res_left.clone(),
+                        (&Ti::Vector { .. }, &Ti::Vector { .. }) => res_left.clone(),
+                        (tl, tr) => {
+                            return Err(ResolveError::IncompatibleOperands(format!(
+                                "{tl:?} * {tr:?}"
+                            )))
+                        }
+                    }
+                }
+                crate::BinaryOperator::Equal
+                | crate::BinaryOperator::NotEqual
+                | crate::BinaryOperator::Less
+                | crate::BinaryOperator::LessEqual
+                | crate::BinaryOperator::Greater
+                | crate::BinaryOperator::GreaterEqual
+                | crate::BinaryOperator::LogicalAnd
+                | crate::BinaryOperator::LogicalOr => {
+                    let scalar = crate::Scalar::BOOL;
+                    let inner = match *past(left)?.inner_with(types) {
+                        Ti::Scalar { .. } => Ti::Scalar(scalar),
+                        Ti::Vector { size, .. } => Ti::Vector { size, scalar },
+                        ref other => {
+                            return Err(ResolveError::IncompatibleOperands(format!(
+                                "{op:?}({other:?}, _)"
+                            )))
+                        }
+                    };
+                    TypeResolution::Value(inner)
+                }
+                crate::BinaryOperator::And
+                | crate::BinaryOperator::ExclusiveOr
+                | crate::BinaryOperator::InclusiveOr
+                | crate::BinaryOperator::ShiftLeft
+                | crate::BinaryOperator::ShiftRight => past(left)?.clone(),
+            },
+            crate::Expression::AtomicResult { ty, .. } => TypeResolution::Handle(ty),
+            crate::Expression::WorkGroupUniformLoadResult { ty } => TypeResolution::Handle(ty),
+            crate::Expression::Select { accept, .. } => past(accept)?.clone(),
+            crate::Expression::Derivative { expr, .. } => past(expr)?.clone(),
+            crate::Expression::Relational { fun, argument } => match fun {
+                crate::RelationalFunction::All | crate::RelationalFunction::Any => {
+                    TypeResolution::Value(Ti::Scalar(crate::Scalar::BOOL))
+                }
+                crate::RelationalFunction::IsNan | crate::RelationalFunction::IsInf => {
+                    match *past(argument)?.inner_with(types) {
+                        Ti::Scalar { .. } => TypeResolution::Value(Ti::Scalar(crate::Scalar::BOOL)),
+                        Ti::Vector { size, .. } => TypeResolution::Value(Ti::Vector {
+                            scalar: crate::Scalar::BOOL,
+                            size,
+                        }),
+                        ref other => {
+                            return Err(ResolveError::IncompatibleOperands(format!(
+                                "{fun:?}({other:?})"
+                            )))
+                        }
+                    }
+                }
+            },
+            crate::Expression::Math {
+                fun,
+                arg,
+                arg1,
+                arg2: _,
+                arg3: _,
+            } => {
+                use crate::MathFunction as Mf;
+                let res_arg = past(arg)?;
+                match fun {
+                    // comparison
+                    Mf::Abs |
+                    Mf::Min |
+                    Mf::Max |
+                    Mf::Clamp |
+                    Mf::Saturate |
+                    // trigonometry
+                    Mf::Cos |
+                    Mf::Cosh |
+                    Mf::Sin |
+                    Mf::Sinh |
+                    Mf::Tan |
+                    Mf::Tanh |
+                    Mf::Acos |
+                    Mf::Asin |
+                    Mf::Atan |
+                    Mf::Atan2 |
+                    Mf::Asinh |
+                    Mf::Acosh |
+                    Mf::Atanh |
+                    Mf::Radians |
+                    Mf::Degrees |
+                    // decomposition
+                    Mf::Ceil |
+                    Mf::Floor |
+                    Mf::Round |
+                    Mf::Fract |
+                    Mf::Trunc |
+                    Mf::Ldexp |
+                    // exponent
+                    Mf::Exp |
+                    Mf::Exp2 |
+                    Mf::Log |
+                    Mf::Log2 |
+                    Mf::Pow => res_arg.clone(),
+                    Mf::Modf | Mf::Frexp => {
+                        let (size, width) = match res_arg.inner_with(types) {
+                            &Ti::Scalar(crate::Scalar {
+                                kind: crate::ScalarKind::Float,
+                                width,
+                            }) => (None, width),
+                            &Ti::Vector {
+                                scalar: crate::Scalar {
+                                    kind: crate::ScalarKind::Float,
+                                    width,
+                                },
+                                size,
+                            } => (Some(size), width),
+                            ref other =>
+                                return Err(ResolveError::IncompatibleOperands(format!("{fun:?}({other:?}, _)")))
+                        };
+                        let result = self
+                        .special_types
+                        .predeclared_types
+                        .get(&if fun == Mf::Modf {
+                            crate::PredeclaredType::ModfResult { size, width }
+                    } else {
+                            crate::PredeclaredType::FrexpResult { size, width }
+                    })
+                        .ok_or(ResolveError::MissingSpecialType)?;
+                        TypeResolution::Handle(*result)
+                    },
+                    // geometry
+                    Mf::Dot => match *res_arg.inner_with(types) {
+                        Ti::Vector {
+                            size: _,
+                            scalar,
+                        } => TypeResolution::Value(Ti::Scalar(scalar)),
+                        ref other =>
+                            return Err(ResolveError::IncompatibleOperands(
+                                format!("{fun:?}({other:?}, _)")
+                            )),
+                    },
+                    Mf::Outer => {
+                        let arg1 = arg1.ok_or_else(|| ResolveError::IncompatibleOperands(
+                            format!("{fun:?}(_, None)")
+                        ))?;
+                        match (res_arg.inner_with(types), past(arg1)?.inner_with(types)) {
+                            (
+                                &Ti::Vector { size: columns, scalar },
+                                &Ti::Vector{ size: rows, .. }
+                            ) => TypeResolution::Value(Ti::Matrix {
+                                columns,
+                                rows,
+                                scalar,
+                            }),
+                            (left, right) =>
+                                return Err(ResolveError::IncompatibleOperands(
+                                    format!("{fun:?}({left:?}, {right:?})")
+                                )),
+                        }
+                    },
+                    Mf::Cross => res_arg.clone(),
+                    Mf::Distance |
+                    Mf::Length => match *res_arg.inner_with(types) {
+                        Ti::Scalar(scalar) |
+                        Ti::Vector {scalar,size:_} => TypeResolution::Value(Ti::Scalar(scalar)),
+                        ref other => return Err(ResolveError::IncompatibleOperands(
+                                format!("{fun:?}({other:?})")
+                            )),
+                    },
+                    Mf::Normalize |
+                    Mf::FaceForward |
+                    Mf::Reflect |
+                    Mf::Refract => res_arg.clone(),
+                    // computational
+                    Mf::Sign |
+                    Mf::Fma |
+                    Mf::Mix |
+                    Mf::Step |
+                    Mf::SmoothStep |
+                    Mf::Sqrt |
+                    Mf::InverseSqrt => res_arg.clone(),
+                    Mf::Transpose => match *res_arg.inner_with(types) {
+                        Ti::Matrix {
+                            columns,
+                            rows,
+                            scalar,
+                        } => TypeResolution::Value(Ti::Matrix {
+                            columns: rows,
+                            rows: columns,
+                            scalar,
+                        }),
+                        ref other => return Err(ResolveError::IncompatibleOperands(
+                            format!("{fun:?}({other:?})")
+                        )),
+                    },
+                    Mf::Inverse => match *res_arg.inner_with(types) {
+                        Ti::Matrix {
+                            columns,
+                            rows,
+                            scalar,
+                        } if columns == rows => TypeResolution::Value(Ti::Matrix {
+                            columns,
+                            rows,
+                            scalar,
+                        }),
+                        ref other => return Err(ResolveError::IncompatibleOperands(
+                            format!("{fun:?}({other:?})")
+                        )),
+                    },
+                    Mf::Determinant => match *res_arg.inner_with(types) {
+                        Ti::Matrix {
+                            scalar,
+                            ..
+                        } => TypeResolution::Value(Ti::Scalar(scalar)),
+                        ref other => return Err(ResolveError::IncompatibleOperands(
+                            format!("{fun:?}({other:?})")
+                        )),
+                    },
+                    // bits
+                    Mf::CountTrailingZeros |
+                    Mf::CountLeadingZeros |
+                    Mf::CountOneBits |
+                    Mf::ReverseBits |
+                    Mf::ExtractBits |
+                    Mf::InsertBits |
+                    Mf::FindLsb |
+                    Mf::FindMsb => match *res_arg.inner_with(types)  {
+                        Ti::Scalar(scalar @ crate::Scalar {
+                            kind: crate::ScalarKind::Sint | crate::ScalarKind::Uint,
+                            ..
+                        }) => TypeResolution::Value(Ti::Scalar(scalar)),
+                        Ti::Vector {
+                            size,
+                            scalar: scalar @ crate::Scalar {
+                                kind: crate::ScalarKind::Sint | crate::ScalarKind::Uint,
+                                ..
+                            }
+                        } => TypeResolution::Value(Ti::Vector { size, scalar }),
+                        ref other => return Err(ResolveError::IncompatibleOperands(
+                                format!("{fun:?}({other:?})")
+                            )),
+                    },
+                    // data packing
+                    Mf::Pack4x8snorm |
+                    Mf::Pack4x8unorm |
+                    Mf::Pack2x16snorm |
+                    Mf::Pack2x16unorm |
+                    Mf::Pack2x16float => TypeResolution::Value(Ti::Scalar(crate::Scalar::U32)),
+                    // data unpacking
+                    Mf::Unpack4x8snorm |
+                    Mf::Unpack4x8unorm => TypeResolution::Value(Ti::Vector {
+                        size: crate::VectorSize::Quad,
+                        scalar: crate::Scalar::F32
+                    }),
+                    Mf::Unpack2x16snorm |
+                    Mf::Unpack2x16unorm |
+                    Mf::Unpack2x16float => TypeResolution::Value(Ti::Vector {
+                        size: crate::VectorSize::Bi,
+                        scalar: crate::Scalar::F32
+                    }),
+                }
+            }
+            crate::Expression::As {
+                expr,
+                kind,
+                convert,
+            } => match *past(expr)?.inner_with(types) {
+                Ti::Scalar(crate::Scalar { width, .. }) => {
+                    TypeResolution::Value(Ti::Scalar(crate::Scalar {
+                        kind,
+                        width: convert.unwrap_or(width),
+                    }))
+                }
+                Ti::Vector {
+                    size,
+                    scalar: crate::Scalar { kind: _, width },
+                } => TypeResolution::Value(Ti::Vector {
+                    size,
+                    scalar: crate::Scalar {
+                        kind,
+                        width: convert.unwrap_or(width),
+                    },
+                }),
+                Ti::Matrix {
+                    columns,
+                    rows,
+                    mut scalar,
+                } => {
+                    if let Some(width) = convert {
+                        scalar.width = width;
+                    }
+                    TypeResolution::Value(Ti::Matrix {
+                        columns,
+                        rows,
+                        scalar,
+                    })
+                }
+                ref other => {
+                    return Err(ResolveError::IncompatibleOperands(format!(
+                        "{other:?} as {kind:?}"
+                    )))
+                }
+            },
+            crate::Expression::CallResult(function) => {
+                let result = self.functions[function]
+                    .result
+                    .as_ref()
+                    .ok_or(ResolveError::FunctionReturnsVoid)?;
+                TypeResolution::Handle(result.ty)
+            }
+            crate::Expression::ArrayLength(_) => {
+                TypeResolution::Value(Ti::Scalar(crate::Scalar::U32))
+            }
+            crate::Expression::RayQueryProceedResult => {
+                TypeResolution::Value(Ti::Scalar(crate::Scalar::BOOL))
+            }
+            crate::Expression::RayQueryGetIntersection { .. } => {
+                let result = self
+                    .special_types
+                    .ray_intersection
+                    .ok_or(ResolveError::MissingSpecialType)?;
+                TypeResolution::Handle(result)
+            }
+        })
+    }
+}
+
+#[test]
+fn test_error_size() {
+    use std::mem::size_of;
+    assert_eq!(size_of::<ResolveError>(), 32);
+}
diff --git a/third_party/rust/naga/src/span.rs b/third_party/rust/naga/src/span.rs
new file mode 100644
index 0000000000..53246b25d6
--- /dev/null
+++ b/third_party/rust/naga/src/span.rs
@@ -0,0 +1,501 @@
+use crate::{Arena, Handle, UniqueArena};
+use std::{error::Error, fmt, ops::Range};
+
+/// A source code span, used for error reporting.
+#[derive(Clone, Copy, Debug, PartialEq, Default)]
+#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
+pub struct Span {
+    start: u32,
+    end: u32,
+}
+
+impl Span {
+    pub const UNDEFINED: Self = Self { start: 0, end: 0 };
+    /// Creates a new `Span` from a range of byte indices
+    ///
+    /// Note: end is exclusive, it doesn't belong to the `Span`
+    pub const fn new(start: u32, end: u32) -> Self {
+        Span { start, end }
+    }
+
+    /// Returns a new `Span` starting at `self` and ending at `other`
+    pub const fn until(&self, other: &Self) -> Self {
+        Span {
+            start: self.start,
+            end: other.end,
+        }
+    }
+
+    /// Modifies `self` to contain the smallest `Span` possible that
+    /// contains both `self` and `other`
+    pub fn subsume(&mut self, other: Self) {
+        *self = if !self.is_defined() {
+            // self isn't defined so use other
+            other
+        } else if !other.is_defined() {
+            // other isn't defined so don't try to subsume
+            *self
+        } else {
+            // Both self and other are defined so calculate the span that contains them both
+            Span {
+                start: self.start.min(other.start),
+                end: self.end.max(other.end),
+            }
+        }
+    }
+
+    /// Returns the smallest `Span` possible that contains all the `Span`s
+    /// defined in the `from` iterator
+    pub fn total_span<T: Iterator<Item = Self>>(from: T) -> Self {
+        let mut span: Self = Default::default();
+        for other in from {
+            span.subsume(other);
+        }
+        span
+    }
+
+    /// Converts `self` to a range if the span is not unknown
+    pub fn to_range(self) -> Option<Range<usize>> {
+        if self.is_defined() {
+            Some(self.start as usize..self.end as usize)
+        } else {
+            None
+        }
+    }
+
+    /// Check whether `self` was defined or is a default/unknown span
+    pub fn is_defined(&self) -> bool {
+        *self != Self::default()
+    }
+
+    /// Return a [`SourceLocation`] for this span in the provided source.
+    pub fn location(&self, source: &str) -> SourceLocation {
+        let prefix = &source[..self.start as usize];
+        let line_number = prefix.matches('\n').count() as u32 + 1;
+        let line_start = prefix.rfind('\n').map(|pos| pos + 1).unwrap_or(0);
+        let line_position = source[line_start..self.start as usize].chars().count() as u32 + 1;
+
+        SourceLocation {
+            line_number,
+            line_position,
+            offset: self.start,
+            length: self.end - self.start,
+        }
+    }
+}
+
+impl From<Range<usize>> for Span {
+    fn from(range: Range<usize>) -> Self {
+        Span {
+            start: range.start as u32,
+            end: range.end as u32,
+        }
+    }
+}
+
+impl std::ops::Index<Span> for str {
+    type Output = str;
+
+    #[inline]
+    fn index(&self, span: Span) -> &str {
+        &self[span.start as usize..span.end as usize]
+    }
+}
+
+/// A human-readable representation for a span, tailored for text source.
+///
+/// Corresponds to the positional members of [`GPUCompilationMessage`][gcm] from
+/// the WebGPU specification, except that `offset` and `length` are in bytes
+/// (UTF-8 code units), instead of UTF-16 code units.
+///
+/// [gcm]: https://www.w3.org/TR/webgpu/#gpucompilationmessage
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+pub struct SourceLocation {
+    /// 1-based line number.
+    pub line_number: u32,
+    /// 1-based column of the start of this span
+    pub line_position: u32,
+    /// 0-based Offset in code units (in bytes) of the start of the span.
+    pub offset: u32,
+    /// Length in code units (in bytes) of the span.
+    pub length: u32,
+}
+
+/// A source code span together with "context", a user-readable description of what part of the error it refers to.
+pub type SpanContext = (Span, String);
+
+/// Wrapper class for [`Error`], augmenting it with a list of [`SpanContext`]s.
+#[derive(Debug, Clone)]
+pub struct WithSpan<E> {
+    inner: E,
+    spans: Vec<SpanContext>,
+}
+
+impl<E> fmt::Display for WithSpan<E>
+where
+    E: fmt::Display,
+{
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> std::fmt::Result {
+        self.inner.fmt(f)
+    }
+}
+
+#[cfg(test)]
+impl<E> PartialEq for WithSpan<E>
+where
+    E: PartialEq,
+{
+    fn eq(&self, other: &Self) -> bool {
+        self.inner.eq(&other.inner)
+    }
+}
+
+impl<E> Error for WithSpan<E>
+where
+    E: Error,
+{
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
+        self.inner.source()
+    }
+}
+
+impl<E> WithSpan<E> {
+    /// Create a new [`WithSpan`] from an [`Error`], containing no spans.
+    pub const fn new(inner: E) -> Self {
+        Self {
+            inner,
+            spans: Vec::new(),
+        }
+    }
+
+    /// Reverse of [`Self::new`], discards span information and returns an inner error.
+    #[allow(clippy::missing_const_for_fn)] // ignore due to requirement of #![feature(const_precise_live_drops)]
+    pub fn into_inner(self) -> E {
+        self.inner
+    }
+
+    pub const fn as_inner(&self) -> &E {
+        &self.inner
+    }
+
+    /// Iterator over stored [`SpanContext`]s.
+    pub fn spans(&self) -> impl ExactSizeIterator<Item = &SpanContext> {
+        self.spans.iter()
+    }
+
+    /// Add a new span with description.
+    pub fn with_span<S>(mut self, span: Span, description: S) -> Self
+    where
+        S: ToString,
+    {
+        if span.is_defined() {
+            self.spans.push((span, description.to_string()));
+        }
+        self
+    }
+
+    /// Add a [`SpanContext`].
+    pub fn with_context(self, span_context: SpanContext) -> Self {
+        let (span, description) = span_context;
+        self.with_span(span, description)
+    }
+
+    /// Add a [`Handle`] from either [`Arena`] or [`UniqueArena`], borrowing its span information from there
+    /// and annotating with a type and the handle representation.
+    pub(crate) fn with_handle<T, A: SpanProvider<T>>(self, handle: Handle<T>, arena: &A) -> Self {
+        self.with_context(arena.get_span_context(handle))
+    }
+
+    /// Convert inner error using [`From`].
+    pub fn into_other<E2>(self) -> WithSpan<E2>
+    where
+        E2: From<E>,
+    {
+        WithSpan {
+            inner: self.inner.into(),
+            spans: self.spans,
+        }
+    }
+
+    /// Convert inner error into another type. Joins span information contained in `self`
+    /// with what is returned from `func`.
+    pub fn and_then<F, E2>(self, func: F) -> WithSpan<E2>
+    where
+        F: FnOnce(E) -> WithSpan<E2>,
+    {
+        let mut res = func(self.inner);
+        res.spans.extend(self.spans);
+        res
+    }
+
+    /// Return a [`SourceLocation`] for our first span, if we have one.
+    pub fn location(&self, source: &str) -> Option<SourceLocation> {
+        if self.spans.is_empty() {
+            return None;
+        }
+
+        Some(self.spans[0].0.location(source))
+    }
+
+    fn diagnostic(&self) -> codespan_reporting::diagnostic::Diagnostic<()>
+    where
+        E: Error,
+    {
+        use codespan_reporting::diagnostic::{Diagnostic, Label};
+        let diagnostic = Diagnostic::error()
+            .with_message(self.inner.to_string())
+            .with_labels(
+                self.spans()
+                    .map(|&(span, ref desc)| {
+                        Label::primary((), span.to_range().unwrap()).with_message(desc.to_owned())
+                    })
+                    .collect(),
+            )
+            .with_notes({
+                let mut notes = Vec::new();
+                let mut source: &dyn Error = &self.inner;
+                while let Some(next) = Error::source(source) {
+                    notes.push(next.to_string());
+                    source = next;
+                }
+                notes
+            });
+        diagnostic
+    }
+
+    /// Emits a summary of the error to standard error stream.
+    pub fn emit_to_stderr(&self, source: &str)
+    where
+        E: Error,
+    {
+        self.emit_to_stderr_with_path(source, "wgsl")
+    }
+
+    /// Emits a summary of the error to standard error stream.
+    pub fn emit_to_stderr_with_path(&self, source: &str, path: &str)
+    where
+        E: Error,
+    {
+        use codespan_reporting::{files, term};
+        use term::termcolor::{ColorChoice, StandardStream};
+
+        let files = files::SimpleFile::new(path, source);
+        let config = term::Config::default();
+        let writer = StandardStream::stderr(ColorChoice::Auto);
+        term::emit(&mut writer.lock(), &config, &files, &self.diagnostic())
+            .expect("cannot write error");
+    }
+
+    /// Emits a summary of the error to a string.
+    pub fn emit_to_string(&self, source: &str) -> String
+    where
+        E: Error,
+    {
+        self.emit_to_string_with_path(source, "wgsl")
+    }
+
+    /// Emits a summary of the error to a string.
+    pub fn emit_to_string_with_path(&self, source: &str, path: &str) -> String
+    where
+        E: Error,
+    {
+        use codespan_reporting::{files, term};
+        use term::termcolor::NoColor;
+
+        let files = files::SimpleFile::new(path, source);
+        let config = codespan_reporting::term::Config::default();
+        let mut writer = NoColor::new(Vec::new());
+        term::emit(&mut writer, &config, &files, &self.diagnostic()).expect("cannot write error");
+        String::from_utf8(writer.into_inner()).unwrap()
+    }
+}
+
+/// Convenience trait for [`Error`] to be able to apply spans to anything.
+pub(crate) trait AddSpan: Sized {
+    type Output;
+    /// See [`WithSpan::new`].
+    fn with_span(self) -> Self::Output;
+    /// See [`WithSpan::with_span`].
+    fn with_span_static(self, span: Span, description: &'static str) -> Self::Output;
+    /// See [`WithSpan::with_context`].
+    fn with_span_context(self, span_context: SpanContext) -> Self::Output;
+    /// See [`WithSpan::with_handle`].
+    fn with_span_handle<T, A: SpanProvider<T>>(self, handle: Handle<T>, arena: &A) -> Self::Output;
+}
+
+/// Trait abstracting over getting a span from an [`Arena`] or a [`UniqueArena`].
+pub(crate) trait SpanProvider<T> {
+    fn get_span(&self, handle: Handle<T>) -> Span;
+    fn get_span_context(&self, handle: Handle<T>) -> SpanContext {
+        match self.get_span(handle) {
+            x if !x.is_defined() => (Default::default(), "".to_string()),
+            known => (
+                known,
+                format!("{} {:?}", std::any::type_name::<T>(), handle),
+            ),
+        }
+    }
+}
+
+impl<T> SpanProvider<T> for Arena<T> {
+    fn get_span(&self, handle: Handle<T>) -> Span {
+        self.get_span(handle)
+    }
+}
+
+impl<T> SpanProvider<T> for UniqueArena<T> {
+    fn get_span(&self, handle: Handle<T>) -> Span {
+        self.get_span(handle)
+    }
+}
+
+impl<E> AddSpan for E
+where
+    E: Error,
+{
+    type Output = WithSpan<Self>;
+    fn with_span(self) -> WithSpan<Self> {
+        WithSpan::new(self)
+    }
+
+    fn with_span_static(self, span: Span, description: &'static str) -> WithSpan<Self> {
+        WithSpan::new(self).with_span(span, description)
+    }
+
+    fn with_span_context(self, span_context: SpanContext) -> WithSpan<Self> {
+        WithSpan::new(self).with_context(span_context)
+    }
+
+    fn with_span_handle<T, A: SpanProvider<T>>(
+        self,
+        handle: Handle<T>,
+        arena: &A,
+    ) -> WithSpan<Self> {
+        WithSpan::new(self).with_handle(handle, arena)
+    }
+}
+
+/// Convenience trait for [`Result`], adding a [`MapErrWithSpan::map_err_inner`]
+/// mapping to [`WithSpan::and_then`].
+pub trait MapErrWithSpan<E, E2>: Sized {
+    type Output: Sized;
+    fn map_err_inner<F, E3>(self, func: F) -> Self::Output
+    where
+        F: FnOnce(E) -> WithSpan<E3>,
+        E2: From<E3>;
+}
+
+impl<T, E, E2> MapErrWithSpan<E, E2> for Result<T, WithSpan<E>> {
+    type Output = Result<T, WithSpan<E2>>;
+    fn map_err_inner<F, E3>(self, func: F) -> Result<T, WithSpan<E2>>
+    where
+        F: FnOnce(E) -> WithSpan<E3>,
+        E2: From<E3>,
+    {
+        self.map_err(|e| e.and_then(func).into_other::<E2>())
+    }
+}
+
+#[test]
+fn span_location() {
+    let source = "12\n45\n\n89\n";
+    assert_eq!(
+        Span { start: 0, end: 1 }.location(source),
+        SourceLocation {
+            line_number: 1,
+            line_position: 1,
+            offset: 0,
+            length: 1
+        }
+    );
+    assert_eq!(
+        Span { start: 1, end: 2 }.location(source),
+        SourceLocation {
+            line_number: 1,
+            line_position: 2,
+            offset: 1,
+            length: 1
+        }
+    );
+    assert_eq!(
+        Span { start: 2, end: 3 }.location(source),
+        SourceLocation {
+            line_number: 1,
+            line_position: 3,
+            offset: 2,
+            length: 1
+        }
+    );
+    assert_eq!(
+        Span { start: 3, end: 5 }.location(source),
+        SourceLocation {
+            line_number: 2,
+            line_position: 1,
+            offset: 3,
+            length: 2
+        }
+    );
+    assert_eq!(
+        Span { start: 4, end: 6 }.location(source),
+        SourceLocation {
+            line_number: 2,
+            line_position: 2,
+            offset: 4,
+            length: 2
+        }
+    );
+    assert_eq!(
+        Span { start: 5, end: 6 }.location(source),
+        SourceLocation {
+            line_number: 2,
+            line_position: 3,
+            offset: 5,
+            length: 1
+        }
+    );
+    assert_eq!(
+        Span { start: 6, end: 7 }.location(source),
+        SourceLocation {
+            line_number: 3,
+            line_position: 1,
+            offset: 6,
+            length: 1
+        }
+    );
+    assert_eq!(
+        Span { start: 7, end: 8 }.location(source),
+        SourceLocation {
+            line_number: 4,
+            line_position: 1,
+            offset: 7,
+            length: 1
+        }
+    );
+    assert_eq!(
+        Span { start: 8, end: 9 }.location(source),
+        SourceLocation {
+            line_number: 4,
+            line_position: 2,
+            offset: 8,
+            length: 1
+        }
+    );
+    assert_eq!(
+        Span { start: 9, end: 10 }.location(source),
+        SourceLocation {
+            line_number: 4,
+            line_position: 3,
+            offset: 9,
+            length: 1
+        }
+    );
+    assert_eq!(
+        Span { start: 10, end: 11 }.location(source),
+        SourceLocation {
+            line_number: 5,
+            line_position: 1,
+            offset: 10,
+            length: 1
+        }
+    );
+}
diff --git a/third_party/rust/naga/src/valid/analyzer.rs b/third_party/rust/naga/src/valid/analyzer.rs
new file mode 100644
index 0000000000..df6fc5e9b0
--- /dev/null
+++ b/third_party/rust/naga/src/valid/analyzer.rs
@@ -0,0 +1,1281 @@
+/*! Module analyzer.
+
+Figures out the following properties:
+  - control flow uniformity
+  - texture/sampler pairs
+  - expression reference counts
+!*/
+
+use super::{ExpressionError, FunctionError, ModuleInfo, ShaderStages, ValidationFlags};
+use crate::span::{AddSpan as _, WithSpan};
+use crate::{
+    arena::{Arena, Handle},
+    proc::{ResolveContext, TypeResolution},
+};
+use std::ops;
+
+pub type NonUniformResult = Option<Handle<crate::Expression>>;
+
+// Remove this once we update our uniformity analysis and
+// add support for the `derivative_uniformity` diagnostic
+const DISABLE_UNIFORMITY_REQ_FOR_FRAGMENT_STAGE: bool = true;
+
+bitflags::bitflags! {
+    /// Kinds of expressions that require uniform control flow.
+    #[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+    #[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+    #[derive(Clone, Copy, Debug, Eq, PartialEq)]
+    pub struct UniformityRequirements: u8 {
+        const WORK_GROUP_BARRIER = 0x1;
+        const DERIVATIVE = if DISABLE_UNIFORMITY_REQ_FOR_FRAGMENT_STAGE { 0 } else { 0x2 };
+        const IMPLICIT_LEVEL = if DISABLE_UNIFORMITY_REQ_FOR_FRAGMENT_STAGE { 0 } else { 0x4 };
+    }
+}
+
+/// Uniform control flow characteristics.
+#[derive(Clone, Debug)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+#[cfg_attr(test, derive(PartialEq))]
+pub struct Uniformity {
+    /// A child expression with non-uniform result.
+    ///
+    /// This means, when the relevant invocations are scheduled on a compute unit,
+    /// they have to use vector registers to store an individual value
+    /// per invocation.
+    ///
+    /// Whenever the control flow is conditioned on such value,
+    /// the hardware needs to keep track of the mask of invocations,
+    /// and process all branches of the control flow.
+    ///
+    /// Any operations that depend on non-uniform results also produce non-uniform.
+    pub non_uniform_result: NonUniformResult,
+    /// If this expression requires uniform control flow, store the reason here.
+    pub requirements: UniformityRequirements,
+}
+
+impl Uniformity {
+    const fn new() -> Self {
+        Uniformity {
+            non_uniform_result: None,
+            requirements: UniformityRequirements::empty(),
+        }
+    }
+}
+
+bitflags::bitflags! {
+    #[derive(Clone, Copy, Debug, PartialEq)]
+    struct ExitFlags: u8 {
+        /// Control flow may return from the function, which makes all the
+        /// subsequent statements within the current function (only!)
+        /// to be executed in a non-uniform control flow.
+        const MAY_RETURN = 0x1;
+        /// Control flow may be killed. Anything after `Statement::Kill` is
+        /// considered inside non-uniform context.
+        const MAY_KILL = 0x2;
+    }
+}
+
+/// Uniformity characteristics of a function.
+#[cfg_attr(test, derive(Debug, PartialEq))]
+struct FunctionUniformity {
+    result: Uniformity,
+    exit: ExitFlags,
+}
+
+impl ops::BitOr for FunctionUniformity {
+    type Output = Self;
+    fn bitor(self, other: Self) -> Self {
+        FunctionUniformity {
+            result: Uniformity {
+                non_uniform_result: self
+                    .result
+                    .non_uniform_result
+                    .or(other.result.non_uniform_result),
+                requirements: self.result.requirements | other.result.requirements,
+            },
+            exit: self.exit | other.exit,
+        }
+    }
+}
+
+impl FunctionUniformity {
+    const fn new() -> Self {
+        FunctionUniformity {
+            result: Uniformity::new(),
+            exit: ExitFlags::empty(),
+        }
+    }
+
+    /// Returns a disruptor based on the stored exit flags, if any.
+    const fn exit_disruptor(&self) -> Option<UniformityDisruptor> {
+        if self.exit.contains(ExitFlags::MAY_RETURN) {
+            Some(UniformityDisruptor::Return)
+        } else if self.exit.contains(ExitFlags::MAY_KILL) {
+            Some(UniformityDisruptor::Discard)
+        } else {
+            None
+        }
+    }
+}
+
+bitflags::bitflags! {
+    /// Indicates how a global variable is used.
+    #[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+    #[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+    #[derive(Clone, Copy, Debug, Eq, PartialEq)]
+    pub struct GlobalUse: u8 {
+        /// Data will be read from the variable.
+        const READ = 0x1;
+        /// Data will be written to the variable.
+        const WRITE = 0x2;
+        /// The information about the data is queried.
+        const QUERY = 0x4;
+    }
+}
+
+#[derive(Clone, Debug, Eq, Hash, PartialEq)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub struct SamplingKey {
+    pub image: Handle<crate::GlobalVariable>,
+    pub sampler: Handle<crate::GlobalVariable>,
+}
+
+#[derive(Clone, Debug)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub struct ExpressionInfo {
+    pub uniformity: Uniformity,
+    pub ref_count: usize,
+    assignable_global: Option<Handle<crate::GlobalVariable>>,
+    pub ty: TypeResolution,
+}
+
+impl ExpressionInfo {
+    const fn new() -> Self {
+        ExpressionInfo {
+            uniformity: Uniformity::new(),
+            ref_count: 0,
+            assignable_global: None,
+            // this doesn't matter at this point, will be overwritten
+            ty: TypeResolution::Value(crate::TypeInner::Scalar(crate::Scalar {
+                kind: crate::ScalarKind::Bool,
+                width: 0,
+            })),
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+enum GlobalOrArgument {
+    Global(Handle<crate::GlobalVariable>),
+    Argument(u32),
+}
+
+impl GlobalOrArgument {
+    fn from_expression(
+        expression_arena: &Arena<crate::Expression>,
+        expression: Handle<crate::Expression>,
+    ) -> Result<GlobalOrArgument, ExpressionError> {
+        Ok(match expression_arena[expression] {
+            crate::Expression::GlobalVariable(var) => GlobalOrArgument::Global(var),
+            crate::Expression::FunctionArgument(i) => GlobalOrArgument::Argument(i),
+            crate::Expression::Access { base, .. }
+            | crate::Expression::AccessIndex { base, .. } => match expression_arena[base] {
+                crate::Expression::GlobalVariable(var) => GlobalOrArgument::Global(var),
+                _ => return Err(ExpressionError::ExpectedGlobalOrArgument),
+            },
+            _ => return Err(ExpressionError::ExpectedGlobalOrArgument),
+        })
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+struct Sampling {
+    image: GlobalOrArgument,
+    sampler: GlobalOrArgument,
+}
+
+#[derive(Debug)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub struct FunctionInfo {
+    /// Validation flags.
+    #[allow(dead_code)]
+    flags: ValidationFlags,
+    /// Set of shader stages where calling this function is valid.
+    pub available_stages: ShaderStages,
+    /// Uniformity characteristics.
+    pub uniformity: Uniformity,
+    /// Function may kill the invocation.
+    pub may_kill: bool,
+
+    /// All pairs of (texture, sampler) globals that may be used together in
+    /// sampling operations by this function and its callees. This includes
+    /// pairings that arise when this function passes textures and samplers as
+    /// arguments to its callees.
+    ///
+    /// This table does not include uses of textures and samplers passed as
+    /// arguments to this function itself, since we do not know which globals
+    /// those will be. However, this table *is* exhaustive when computed for an
+    /// entry point function: entry points never receive textures or samplers as
+    /// arguments, so all an entry point's sampling can be reported in terms of
+    /// globals.
+    ///
+    /// The GLSL back end uses this table to construct reflection info that
+    /// clients need to construct texture-combined sampler values.
+    pub sampling_set: crate::FastHashSet<SamplingKey>,
+
+    /// How this function and its callees use this module's globals.
+    ///
+    /// This is indexed by `Handle<GlobalVariable>` indices. However,
+    /// `FunctionInfo` implements `std::ops::Index<Handle<GlobalVariable>>`,
+    /// so you can simply index this struct with a global handle to retrieve
+    /// its usage information.
+    global_uses: Box<[GlobalUse]>,
+
+    /// Information about each expression in this function's body.
+    ///
+    /// This is indexed by `Handle<Expression>` indices. However, `FunctionInfo`
+    /// implements `std::ops::Index<Handle<Expression>>`, so you can simply
+    /// index this struct with an expression handle to retrieve its
+    /// `ExpressionInfo`.
+    expressions: Box<[ExpressionInfo]>,
+
+    /// All (texture, sampler) pairs that may be used together in sampling
+    /// operations by this function and its callees, whether they are accessed
+    /// as globals or passed as arguments.
+    ///
+    /// Participants are represented by [`GlobalVariable`] handles whenever
+    /// possible, and otherwise by indices of this function's arguments.
+    ///
+    /// When analyzing a function call, we combine this data about the callee
+    /// with the actual arguments being passed to produce the callers' own
+    /// `sampling_set` and `sampling` tables.
+    ///
+    /// [`GlobalVariable`]: crate::GlobalVariable
+    sampling: crate::FastHashSet<Sampling>,
+
+    /// Indicates that the function is using dual source blending.
+    pub dual_source_blending: bool,
+}
+
+impl FunctionInfo {
+    pub const fn global_variable_count(&self) -> usize {
+        self.global_uses.len()
+    }
+    pub const fn expression_count(&self) -> usize {
+        self.expressions.len()
+    }
+    pub fn dominates_global_use(&self, other: &Self) -> bool {
+        for (self_global_uses, other_global_uses) in
+            self.global_uses.iter().zip(other.global_uses.iter())
+        {
+            if !self_global_uses.contains(*other_global_uses) {
+                return false;
+            }
+        }
+        true
+    }
+}
+
+impl ops::Index<Handle<crate::GlobalVariable>> for FunctionInfo {
+    type Output = GlobalUse;
+    fn index(&self, handle: Handle<crate::GlobalVariable>) -> &GlobalUse {
+        &self.global_uses[handle.index()]
+    }
+}
+
+impl ops::Index<Handle<crate::Expression>> for FunctionInfo {
+    type Output = ExpressionInfo;
+    fn index(&self, handle: Handle<crate::Expression>) -> &ExpressionInfo {
+        &self.expressions[handle.index()]
+    }
+}
+
+/// Disruptor of the uniform control flow.
+#[derive(Clone, Copy, Debug, thiserror::Error)]
+#[cfg_attr(test, derive(PartialEq))]
+pub enum UniformityDisruptor {
+    #[error("Expression {0:?} produced non-uniform result, and control flow depends on it")]
+    Expression(Handle<crate::Expression>),
+    #[error("There is a Return earlier in the control flow of the function")]
+    Return,
+    #[error("There is a Discard earlier in the entry point across all called functions")]
+    Discard,
+}
+
+impl FunctionInfo {
+    /// Adds a value-type reference to an expression.
+    #[must_use]
+    fn add_ref_impl(
+        &mut self,
+        handle: Handle<crate::Expression>,
+        global_use: GlobalUse,
+    ) -> NonUniformResult {
+        let info = &mut self.expressions[handle.index()];
+        info.ref_count += 1;
+        // mark the used global as read
+        if let Some(global) = info.assignable_global {
+            self.global_uses[global.index()] |= global_use;
+        }
+        info.uniformity.non_uniform_result
+    }
+
+    /// Adds a value-type reference to an expression.
+    #[must_use]
+    fn add_ref(&mut self, handle: Handle<crate::Expression>) -> NonUniformResult {
+        self.add_ref_impl(handle, GlobalUse::READ)
+    }
+
+    /// Adds a potentially assignable reference to an expression.
+    /// These are destinations for `Store` and `ImageStore` statements,
+    /// which can transit through `Access` and `AccessIndex`.
+    #[must_use]
+    fn add_assignable_ref(
+        &mut self,
+        handle: Handle<crate::Expression>,
+        assignable_global: &mut Option<Handle<crate::GlobalVariable>>,
+    ) -> NonUniformResult {
+        let info = &mut self.expressions[handle.index()];
+        info.ref_count += 1;
+        // propagate the assignable global up the chain, till it either hits
+        // a value-type expression, or the assignment statement.
+        if let Some(global) = info.assignable_global {
+            if let Some(_old) = assignable_global.replace(global) {
+                unreachable!()
+            }
+        }
+        info.uniformity.non_uniform_result
+    }
+
+    /// Inherit information from a called function.
+    fn process_call(
+        &mut self,
+        callee: &Self,
+        arguments: &[Handle<crate::Expression>],
+        expression_arena: &Arena<crate::Expression>,
+    ) -> Result<FunctionUniformity, WithSpan<FunctionError>> {
+        self.sampling_set
+            .extend(callee.sampling_set.iter().cloned());
+        for sampling in callee.sampling.iter() {
+            // If the callee was passed the texture or sampler as an argument,
+            // we may now be able to determine which globals those referred to.
+            let image_storage = match sampling.image {
+                GlobalOrArgument::Global(var) => GlobalOrArgument::Global(var),
+                GlobalOrArgument::Argument(i) => {
+                    let handle = arguments[i as usize];
+                    GlobalOrArgument::from_expression(expression_arena, handle).map_err(
+                        |source| {
+                            FunctionError::Expression { handle, source }
+                                .with_span_handle(handle, expression_arena)
+                        },
+                    )?
+                }
+            };
+
+            let sampler_storage = match sampling.sampler {
+                GlobalOrArgument::Global(var) => GlobalOrArgument::Global(var),
+                GlobalOrArgument::Argument(i) => {
+                    let handle = arguments[i as usize];
+                    GlobalOrArgument::from_expression(expression_arena, handle).map_err(
+                        |source| {
+                            FunctionError::Expression { handle, source }
+                                .with_span_handle(handle, expression_arena)
+                        },
+                    )?
+                }
+            };
+
+            // If we've managed to pin both the image and sampler down to
+            // specific globals, record that in our `sampling_set`. Otherwise,
+            // record as much as we do know in our own `sampling` table, for our
+            // callers to sort out.
+            match (image_storage, sampler_storage) {
+                (GlobalOrArgument::Global(image), GlobalOrArgument::Global(sampler)) => {
+                    self.sampling_set.insert(SamplingKey { image, sampler });
+                }
+                (image, sampler) => {
+                    self.sampling.insert(Sampling { image, sampler });
+                }
+            }
+        }
+
+        // Inherit global use from our callees.
+        for (mine, other) in self.global_uses.iter_mut().zip(callee.global_uses.iter()) {
+            *mine |= *other;
+        }
+
+        Ok(FunctionUniformity {
+            result: callee.uniformity.clone(),
+            exit: if callee.may_kill {
+                ExitFlags::MAY_KILL
+            } else {
+                ExitFlags::empty()
+            },
+        })
+    }
+
+    /// Compute the [`ExpressionInfo`] for `handle`.
+    ///
+    /// Replace the dummy entry in [`self.expressions`] for `handle`
+    /// with a real `ExpressionInfo` value describing that expression.
+    ///
+    /// This function is called as part of a forward sweep through the
+    /// arena, so we can assume that all earlier expressions in the
+    /// arena already have valid info. Since expressions only depend
+    /// on earlier expressions, this includes all our subexpressions.
+    ///
+    /// Adjust the reference counts on all expressions we use.
+    ///
+    /// Also populate the [`sampling_set`], [`sampling`] and
+    /// [`global_uses`] fields of `self`.
+    ///
+    /// [`self.expressions`]: FunctionInfo::expressions
+    /// [`sampling_set`]: FunctionInfo::sampling_set
+    /// [`sampling`]: FunctionInfo::sampling
+    /// [`global_uses`]: FunctionInfo::global_uses
+    #[allow(clippy::or_fun_call)]
+    fn process_expression(
+        &mut self,
+        handle: Handle<crate::Expression>,
+        expression_arena: &Arena<crate::Expression>,
+        other_functions: &[FunctionInfo],
+        resolve_context: &ResolveContext,
+        capabilities: super::Capabilities,
+    ) -> Result<(), ExpressionError> {
+        use crate::{Expression as E, SampleLevel as Sl};
+
+        let expression = &expression_arena[handle];
+        let mut assignable_global = None;
+        let uniformity = match *expression {
+            E::Access { base, index } => {
+                let base_ty = self[base].ty.inner_with(resolve_context.types);
+
+                // build up the caps needed if this is indexed non-uniformly
+                let mut needed_caps = super::Capabilities::empty();
+                let is_binding_array = match *base_ty {
+                    crate::TypeInner::BindingArray {
+                        base: array_element_ty_handle,
+                        ..
+                    } => {
+                        // these are nasty aliases, but these idents are too long and break rustfmt
+                        let ub_st = super::Capabilities::UNIFORM_BUFFER_AND_STORAGE_TEXTURE_ARRAY_NON_UNIFORM_INDEXING;
+                        let st_sb = super::Capabilities::SAMPLED_TEXTURE_AND_STORAGE_BUFFER_ARRAY_NON_UNIFORM_INDEXING;
+                        let sampler = super::Capabilities::SAMPLER_NON_UNIFORM_INDEXING;
+
+                        // We're a binding array, so lets use the type of _what_ we are array of to determine if we can non-uniformly index it.
+                        let array_element_ty =
+                            &resolve_context.types[array_element_ty_handle].inner;
+
+                        needed_caps |= match *array_element_ty {
+                            // If we're an image, use the appropriate limit.
+                            crate::TypeInner::Image { class, .. } => match class {
+                                crate::ImageClass::Storage { .. } => ub_st,
+                                _ => st_sb,
+                            },
+                            crate::TypeInner::Sampler { .. } => sampler,
+                            // If we're anything but an image, assume we're a buffer and use the address space.
+                            _ => {
+                                if let E::GlobalVariable(global_handle) = expression_arena[base] {
+                                    let global = &resolve_context.global_vars[global_handle];
+                                    match global.space {
+                                        crate::AddressSpace::Uniform => ub_st,
+                                        crate::AddressSpace::Storage { .. } => st_sb,
+                                        _ => unreachable!(),
+                                    }
+                                } else {
+                                    unreachable!()
+                                }
+                            }
+                        };
+
+                        true
+                    }
+                    _ => false,
+                };
+
+                if self[index].uniformity.non_uniform_result.is_some()
+                    && !capabilities.contains(needed_caps)
+                    && is_binding_array
+                {
+                    return Err(ExpressionError::MissingCapabilities(needed_caps));
+                }
+
+                Uniformity {
+                    non_uniform_result: self
+                        .add_assignable_ref(base, &mut assignable_global)
+                        .or(self.add_ref(index)),
+                    requirements: UniformityRequirements::empty(),
+                }
+            }
+            E::AccessIndex { base, .. } => Uniformity {
+                non_uniform_result: self.add_assignable_ref(base, &mut assignable_global),
+                requirements: UniformityRequirements::empty(),
+            },
+            // always uniform
+            E::Splat { size: _, value } => Uniformity {
+                non_uniform_result: self.add_ref(value),
+                requirements: UniformityRequirements::empty(),
+            },
+            E::Swizzle { vector, .. } => Uniformity {
+                non_uniform_result: self.add_ref(vector),
+                requirements: UniformityRequirements::empty(),
+            },
+            E::Literal(_) | E::Constant(_) | E::ZeroValue(_) => Uniformity::new(),
+            E::Compose { ref components, .. } => {
+                let non_uniform_result = components
+                    .iter()
+                    .fold(None, |nur, &comp| nur.or(self.add_ref(comp)));
+                Uniformity {
+                    non_uniform_result,
+                    requirements: UniformityRequirements::empty(),
+                }
+            }
+            // depends on the builtin or interpolation
+            E::FunctionArgument(index) => {
+                let arg = &resolve_context.arguments[index as usize];
+                let uniform = match arg.binding {
+                    Some(crate::Binding::BuiltIn(built_in)) => match built_in {
+                        // per-polygon built-ins are uniform
+                        crate::BuiltIn::FrontFacing
+                        // per-work-group built-ins are uniform
+                        | crate::BuiltIn::WorkGroupId
+                        | crate::BuiltIn::WorkGroupSize
+                        | crate::BuiltIn::NumWorkGroups => true,
+                        _ => false,
+                    },
+                    // only flat inputs are uniform
+                    Some(crate::Binding::Location {
+                        interpolation: Some(crate::Interpolation::Flat),
+                        ..
+                    }) => true,
+                    _ => false,
+                };
+                Uniformity {
+                    non_uniform_result: if uniform { None } else { Some(handle) },
+                    requirements: UniformityRequirements::empty(),
+                }
+            }
+            // depends on the address space
+            E::GlobalVariable(gh) => {
+                use crate::AddressSpace as As;
+                assignable_global = Some(gh);
+                let var = &resolve_context.global_vars[gh];
+                let uniform = match var.space {
+                    // local data is non-uniform
+                    As::Function | As::Private => false,
+                    // workgroup memory is exclusively accessed by the group
+                    As::WorkGroup => true,
+                    // uniform data
+                    As::Uniform | As::PushConstant => true,
+                    // storage data is only uniform when read-only
+                    As::Storage { access } => !access.contains(crate::StorageAccess::STORE),
+                    As::Handle => false,
+                };
+                Uniformity {
+                    non_uniform_result: if uniform { None } else { Some(handle) },
+                    requirements: UniformityRequirements::empty(),
+                }
+            }
+            E::LocalVariable(_) => Uniformity {
+                non_uniform_result: Some(handle),
+                requirements: UniformityRequirements::empty(),
+            },
+            E::Load { pointer } => Uniformity {
+                non_uniform_result: self.add_ref(pointer),
+                requirements: UniformityRequirements::empty(),
+            },
+            E::ImageSample {
+                image,
+                sampler,
+                gather: _,
+                coordinate,
+                array_index,
+                offset: _,
+                level,
+                depth_ref,
+            } => {
+                let image_storage = GlobalOrArgument::from_expression(expression_arena, image)?;
+                let sampler_storage = GlobalOrArgument::from_expression(expression_arena, sampler)?;
+
+                match (image_storage, sampler_storage) {
+                    (GlobalOrArgument::Global(image), GlobalOrArgument::Global(sampler)) => {
+                        self.sampling_set.insert(SamplingKey { image, sampler });
+                    }
+                    _ => {
+                        self.sampling.insert(Sampling {
+                            image: image_storage,
+                            sampler: sampler_storage,
+                        });
+                    }
+                }
+
+                // "nur" == "Non-Uniform Result"
+                let array_nur = array_index.and_then(|h| self.add_ref(h));
+                let level_nur = match level {
+                    Sl::Auto | Sl::Zero => None,
+                    Sl::Exact(h) | Sl::Bias(h) => self.add_ref(h),
+                    Sl::Gradient { x, y } => self.add_ref(x).or(self.add_ref(y)),
+                };
+                let dref_nur = depth_ref.and_then(|h| self.add_ref(h));
+                Uniformity {
+                    non_uniform_result: self
+                        .add_ref(image)
+                        .or(self.add_ref(sampler))
+                        .or(self.add_ref(coordinate))
+                        .or(array_nur)
+                        .or(level_nur)
+                        .or(dref_nur),
+                    requirements: if level.implicit_derivatives() {
+                        UniformityRequirements::IMPLICIT_LEVEL
+                    } else {
+                        UniformityRequirements::empty()
+                    },
+                }
+            }
+            E::ImageLoad {
+                image,
+                coordinate,
+                array_index,
+                sample,
+                level,
+            } => {
+                let array_nur = array_index.and_then(|h| self.add_ref(h));
+                let sample_nur = sample.and_then(|h| self.add_ref(h));
+                let level_nur = level.and_then(|h| self.add_ref(h));
+                Uniformity {
+                    non_uniform_result: self
+                        .add_ref(image)
+                        .or(self.add_ref(coordinate))
+                        .or(array_nur)
+                        .or(sample_nur)
+                        .or(level_nur),
+                    requirements: UniformityRequirements::empty(),
+                }
+            }
+            E::ImageQuery { image, query } => {
+                let query_nur = match query {
+                    crate::ImageQuery::Size { level: Some(h) } => self.add_ref(h),
+                    _ => None,
+                };
+                Uniformity {
+                    non_uniform_result: self.add_ref_impl(image, GlobalUse::QUERY).or(query_nur),
+                    requirements: UniformityRequirements::empty(),
+                }
+            }
+            E::Unary { expr, .. } => Uniformity {
+                non_uniform_result: self.add_ref(expr),
+                requirements: UniformityRequirements::empty(),
+            },
+            E::Binary { left, right, .. } => Uniformity {
+                non_uniform_result: self.add_ref(left).or(self.add_ref(right)),
+                requirements: UniformityRequirements::empty(),
+            },
+            E::Select {
+                condition,
+                accept,
+                reject,
+            } => Uniformity {
+                non_uniform_result: self
+                    .add_ref(condition)
+                    .or(self.add_ref(accept))
+                    .or(self.add_ref(reject)),
+                requirements: UniformityRequirements::empty(),
+            },
+            // explicit derivatives require uniform
+            E::Derivative { expr, .. } => Uniformity {
+                //Note: taking a derivative of a uniform doesn't make it non-uniform
+                non_uniform_result: self.add_ref(expr),
+                requirements: UniformityRequirements::DERIVATIVE,
+            },
+            E::Relational { argument, .. } => Uniformity {
+                non_uniform_result: self.add_ref(argument),
+                requirements: UniformityRequirements::empty(),
+            },
+            E::Math {
+                fun: _,
+                arg,
+                arg1,
+                arg2,
+                arg3,
+            } => {
+                let arg1_nur = arg1.and_then(|h| self.add_ref(h));
+                let arg2_nur = arg2.and_then(|h| self.add_ref(h));
+                let arg3_nur = arg3.and_then(|h| self.add_ref(h));
+                Uniformity {
+                    non_uniform_result: self.add_ref(arg).or(arg1_nur).or(arg2_nur).or(arg3_nur),
+                    requirements: UniformityRequirements::empty(),
+                }
+            }
+            E::As { expr, .. } => Uniformity {
+                non_uniform_result: self.add_ref(expr),
+                requirements: UniformityRequirements::empty(),
+            },
+            E::CallResult(function) => other_functions[function.index()].uniformity.clone(),
+            E::AtomicResult { .. } | E::RayQueryProceedResult => Uniformity {
+                non_uniform_result: Some(handle),
+                requirements: UniformityRequirements::empty(),
+            },
+            E::WorkGroupUniformLoadResult { .. } => Uniformity {
+                // The result of WorkGroupUniformLoad is always uniform by definition
+                non_uniform_result: None,
+                // The call is what cares about uniformity, not the expression
+                // This expression is never emitted, so this requirement should never be used anyway?
+                requirements: UniformityRequirements::empty(),
+            },
+            E::ArrayLength(expr) => Uniformity {
+                non_uniform_result: self.add_ref_impl(expr, GlobalUse::QUERY),
+                requirements: UniformityRequirements::empty(),
+            },
+            E::RayQueryGetIntersection {
+                query,
+                committed: _,
+            } => Uniformity {
+                non_uniform_result: self.add_ref(query),
+                requirements: UniformityRequirements::empty(),
+            },
+        };
+
+        let ty = resolve_context.resolve(expression, |h| Ok(&self[h].ty))?;
+        self.expressions[handle.index()] = ExpressionInfo {
+            uniformity,
+            ref_count: 0,
+            assignable_global,
+            ty,
+        };
+        Ok(())
+    }
+
+    /// Analyzes the uniformity requirements of a block (as a sequence of statements).
+    /// Returns the uniformity characteristics at the *function* level, i.e.
+    /// whether or not the function requires to be called in uniform control flow,
+    /// and whether the produced result is not disrupting the control flow.
+    ///
+    /// The parent control flow is uniform if `disruptor.is_none()`.
+    ///
+    /// Returns a `NonUniformControlFlow` error if any of the expressions in the block
+    /// require uniformity, but the current flow is non-uniform.
+    #[allow(clippy::or_fun_call)]
+    fn process_block(
+        &mut self,
+        statements: &crate::Block,
+        other_functions: &[FunctionInfo],
+        mut disruptor: Option<UniformityDisruptor>,
+        expression_arena: &Arena<crate::Expression>,
+    ) -> Result<FunctionUniformity, WithSpan<FunctionError>> {
+        use crate::Statement as S;
+
+        let mut combined_uniformity = FunctionUniformity::new();
+        for statement in statements {
+            let uniformity = match *statement {
+                S::Emit(ref range) => {
+                    let mut requirements = UniformityRequirements::empty();
+                    for expr in range.clone() {
+                        let req = self.expressions[expr.index()].uniformity.requirements;
+                        if self
+                            .flags
+                            .contains(super::ValidationFlags::CONTROL_FLOW_UNIFORMITY)
+                            && !req.is_empty()
+                        {
+                            if let Some(cause) = disruptor {
+                                return Err(FunctionError::NonUniformControlFlow(req, expr, cause)
+                                    .with_span_handle(expr, expression_arena));
+                            }
+                        }
+                        requirements |= req;
+                    }
+                    FunctionUniformity {
+                        result: Uniformity {
+                            non_uniform_result: None,
+                            requirements,
+                        },
+                        exit: ExitFlags::empty(),
+                    }
+                }
+                S::Break | S::Continue => FunctionUniformity::new(),
+                S::Kill => FunctionUniformity {
+                    result: Uniformity::new(),
+                    exit: if disruptor.is_some() {
+                        ExitFlags::MAY_KILL
+                    } else {
+                        ExitFlags::empty()
+                    },
+                },
+                S::Barrier(_) => FunctionUniformity {
+                    result: Uniformity {
+                        non_uniform_result: None,
+                        requirements: UniformityRequirements::WORK_GROUP_BARRIER,
+                    },
+                    exit: ExitFlags::empty(),
+                },
+                S::WorkGroupUniformLoad { pointer, .. } => {
+                    let _condition_nur = self.add_ref(pointer);
+
+                    // Don't check that this call occurs in uniform control flow until Naga implements WGSL's standard
+                    // uniformity analysis (https://github.com/gfx-rs/naga/issues/1744).
+                    // The uniformity analysis Naga uses now is less accurate than the one in the WGSL standard,
+                    // causing Naga to reject correct uses of `workgroupUniformLoad` in some interesting programs.
+
+                    /*
+                    if self
+                        .flags
+                        .contains(super::ValidationFlags::CONTROL_FLOW_UNIFORMITY)
+                    {
+                        let condition_nur = self.add_ref(pointer);
+                        let this_disruptor =
+                            disruptor.or(condition_nur.map(UniformityDisruptor::Expression));
+                        if let Some(cause) = this_disruptor {
+                            return Err(FunctionError::NonUniformWorkgroupUniformLoad(cause)
+                                .with_span_static(*span, "WorkGroupUniformLoad"));
+                        }
+                    } */
+                    FunctionUniformity {
+                        result: Uniformity {
+                            non_uniform_result: None,
+                            requirements: UniformityRequirements::WORK_GROUP_BARRIER,
+                        },
+                        exit: ExitFlags::empty(),
+                    }
+                }
+                S::Block(ref b) => {
+                    self.process_block(b, other_functions, disruptor, expression_arena)?
+                }
+                S::If {
+                    condition,
+                    ref accept,
+                    ref reject,
+                } => {
+                    let condition_nur = self.add_ref(condition);
+                    let branch_disruptor =
+                        disruptor.or(condition_nur.map(UniformityDisruptor::Expression));
+                    let accept_uniformity = self.process_block(
+                        accept,
+                        other_functions,
+                        branch_disruptor,
+                        expression_arena,
+                    )?;
+                    let reject_uniformity = self.process_block(
+                        reject,
+                        other_functions,
+                        branch_disruptor,
+                        expression_arena,
+                    )?;
+                    accept_uniformity | reject_uniformity
+                }
+                S::Switch {
+                    selector,
+                    ref cases,
+                } => {
+                    let selector_nur = self.add_ref(selector);
+                    let branch_disruptor =
+                        disruptor.or(selector_nur.map(UniformityDisruptor::Expression));
+                    let mut uniformity = FunctionUniformity::new();
+                    let mut case_disruptor = branch_disruptor;
+                    for case in cases.iter() {
+                        let case_uniformity = self.process_block(
+                            &case.body,
+                            other_functions,
+                            case_disruptor,
+                            expression_arena,
+                        )?;
+                        case_disruptor = if case.fall_through {
+                            case_disruptor.or(case_uniformity.exit_disruptor())
+                        } else {
+                            branch_disruptor
+                        };
+                        uniformity = uniformity | case_uniformity;
+                    }
+                    uniformity
+                }
+                S::Loop {
+                    ref body,
+                    ref continuing,
+                    break_if,
+                } => {
+                    let body_uniformity =
+                        self.process_block(body, other_functions, disruptor, expression_arena)?;
+                    let continuing_disruptor = disruptor.or(body_uniformity.exit_disruptor());
+                    let continuing_uniformity = self.process_block(
+                        continuing,
+                        other_functions,
+                        continuing_disruptor,
+                        expression_arena,
+                    )?;
+                    if let Some(expr) = break_if {
+                        let _ = self.add_ref(expr);
+                    }
+                    body_uniformity | continuing_uniformity
+                }
+                S::Return { value } => FunctionUniformity {
+                    result: Uniformity {
+                        non_uniform_result: value.and_then(|expr| self.add_ref(expr)),
+                        requirements: UniformityRequirements::empty(),
+                    },
+                    exit: if disruptor.is_some() {
+                        ExitFlags::MAY_RETURN
+                    } else {
+                        ExitFlags::empty()
+                    },
+                },
+                // Here and below, the used expressions are already emitted,
+                // and their results do not affect the function return value,
+                // so we can ignore their non-uniformity.
+                S::Store { pointer, value } => {
+                    let _ = self.add_ref_impl(pointer, GlobalUse::WRITE);
+                    let _ = self.add_ref(value);
+                    FunctionUniformity::new()
+                }
+                S::ImageStore {
+                    image,
+                    coordinate,
+                    array_index,
+                    value,
+                } => {
+                    let _ = self.add_ref_impl(image, GlobalUse::WRITE);
+                    if let Some(expr) = array_index {
+                        let _ = self.add_ref(expr);
+                    }
+                    let _ = self.add_ref(coordinate);
+                    let _ = self.add_ref(value);
+                    FunctionUniformity::new()
+                }
+                S::Call {
+                    function,
+                    ref arguments,
+                    result: _,
+                } => {
+                    for &argument in arguments {
+                        let _ = self.add_ref(argument);
+                    }
+                    let info = &other_functions[function.index()];
+                    //Note: the result is validated by the Validator, not here
+                    self.process_call(info, arguments, expression_arena)?
+                }
+                S::Atomic {
+                    pointer,
+                    ref fun,
+                    value,
+                    result: _,
+                } => {
+                    let _ = self.add_ref_impl(pointer, GlobalUse::WRITE);
+                    let _ = self.add_ref(value);
+                    if let crate::AtomicFunction::Exchange { compare: Some(cmp) } = *fun {
+                        let _ = self.add_ref(cmp);
+                    }
+                    FunctionUniformity::new()
+                }
+                S::RayQuery { query, ref fun } => {
+                    let _ = self.add_ref(query);
+                    if let crate::RayQueryFunction::Initialize {
+                        acceleration_structure,
+                        descriptor,
+                    } = *fun
+                    {
+                        let _ = self.add_ref(acceleration_structure);
+                        let _ = self.add_ref(descriptor);
+                    }
+                    FunctionUniformity::new()
+                }
+            };
+
+            disruptor = disruptor.or(uniformity.exit_disruptor());
+            combined_uniformity = combined_uniformity | uniformity;
+        }
+        Ok(combined_uniformity)
+    }
+}
+
+impl ModuleInfo {
+    /// Populates `self.const_expression_types`
+    pub(super) fn process_const_expression(
+        &mut self,
+        handle: Handle<crate::Expression>,
+        resolve_context: &ResolveContext,
+        gctx: crate::proc::GlobalCtx,
+    ) -> Result<(), super::ConstExpressionError> {
+        self.const_expression_types[handle.index()] =
+            resolve_context.resolve(&gctx.const_expressions[handle], |h| Ok(&self[h]))?;
+        Ok(())
+    }
+
+    /// Builds the `FunctionInfo` based on the function, and validates the
+    /// uniform control flow if required by the expressions of this function.
+    pub(super) fn process_function(
+        &self,
+        fun: &crate::Function,
+        module: &crate::Module,
+        flags: ValidationFlags,
+        capabilities: super::Capabilities,
+    ) -> Result<FunctionInfo, WithSpan<FunctionError>> {
+        let mut info = FunctionInfo {
+            flags,
+            available_stages: ShaderStages::all(),
+            uniformity: Uniformity::new(),
+            may_kill: false,
+            sampling_set: crate::FastHashSet::default(),
+            global_uses: vec![GlobalUse::empty(); module.global_variables.len()].into_boxed_slice(),
+            expressions: vec![ExpressionInfo::new(); fun.expressions.len()].into_boxed_slice(),
+            sampling: crate::FastHashSet::default(),
+            dual_source_blending: false,
+        };
+        let resolve_context =
+            ResolveContext::with_locals(module, &fun.local_variables, &fun.arguments);
+
+        for (handle, _) in fun.expressions.iter() {
+            if let Err(source) = info.process_expression(
+                handle,
+                &fun.expressions,
+                &self.functions,
+                &resolve_context,
+                capabilities,
+            ) {
+                return Err(FunctionError::Expression { handle, source }
+                    .with_span_handle(handle, &fun.expressions));
+            }
+        }
+
+        for (_, expr) in fun.local_variables.iter() {
+            if let Some(init) = expr.init {
+                let _ = info.add_ref(init);
+            }
+        }
+
+        let uniformity = info.process_block(&fun.body, &self.functions, None, &fun.expressions)?;
+        info.uniformity = uniformity.result;
+        info.may_kill = uniformity.exit.contains(ExitFlags::MAY_KILL);
+
+        Ok(info)
+    }
+
+    pub fn get_entry_point(&self, index: usize) -> &FunctionInfo {
+        &self.entry_points[index]
+    }
+}
+
+#[test]
+fn uniform_control_flow() {
+    use crate::{Expression as E, Statement as S};
+
+    let mut type_arena = crate::UniqueArena::new();
+    let ty = type_arena.insert(
+        crate::Type {
+            name: None,
+            inner: crate::TypeInner::Vector {
+                size: crate::VectorSize::Bi,
+                scalar: crate::Scalar::F32,
+            },
+        },
+        Default::default(),
+    );
+    let mut global_var_arena = Arena::new();
+    let non_uniform_global = global_var_arena.append(
+        crate::GlobalVariable {
+            name: None,
+            init: None,
+            ty,
+            space: crate::AddressSpace::Handle,
+            binding: None,
+        },
+        Default::default(),
+    );
+    let uniform_global = global_var_arena.append(
+        crate::GlobalVariable {
+            name: None,
+            init: None,
+            ty,
+            binding: None,
+            space: crate::AddressSpace::Uniform,
+        },
+        Default::default(),
+    );
+
+    let mut expressions = Arena::new();
+    // checks the uniform control flow
+    let constant_expr = expressions.append(E::Literal(crate::Literal::U32(0)), Default::default());
+    // checks the non-uniform control flow
+    let derivative_expr = expressions.append(
+        E::Derivative {
+            axis: crate::DerivativeAxis::X,
+            ctrl: crate::DerivativeControl::None,
+            expr: constant_expr,
+        },
+        Default::default(),
+    );
+    let emit_range_constant_derivative = expressions.range_from(0);
+    let non_uniform_global_expr =
+        expressions.append(E::GlobalVariable(non_uniform_global), Default::default());
+    let uniform_global_expr =
+        expressions.append(E::GlobalVariable(uniform_global), Default::default());
+    let emit_range_globals = expressions.range_from(2);
+
+    // checks the QUERY flag
+    let query_expr = expressions.append(E::ArrayLength(uniform_global_expr), Default::default());
+    // checks the transitive WRITE flag
+    let access_expr = expressions.append(
+        E::AccessIndex {
+            base: non_uniform_global_expr,
+            index: 1,
+        },
+        Default::default(),
+    );
+    let emit_range_query_access_globals = expressions.range_from(2);
+
+    let mut info = FunctionInfo {
+        flags: ValidationFlags::all(),
+        available_stages: ShaderStages::all(),
+        uniformity: Uniformity::new(),
+        may_kill: false,
+        sampling_set: crate::FastHashSet::default(),
+        global_uses: vec![GlobalUse::empty(); global_var_arena.len()].into_boxed_slice(),
+        expressions: vec![ExpressionInfo::new(); expressions.len()].into_boxed_slice(),
+        sampling: crate::FastHashSet::default(),
+        dual_source_blending: false,
+    };
+    let resolve_context = ResolveContext {
+        constants: &Arena::new(),
+        types: &type_arena,
+        special_types: &crate::SpecialTypes::default(),
+        global_vars: &global_var_arena,
+        local_vars: &Arena::new(),
+        functions: &Arena::new(),
+        arguments: &[],
+    };
+    for (handle, _) in expressions.iter() {
+        info.process_expression(
+            handle,
+            &expressions,
+            &[],
+            &resolve_context,
+            super::Capabilities::empty(),
+        )
+        .unwrap();
+    }
+    assert_eq!(info[non_uniform_global_expr].ref_count, 1);
+    assert_eq!(info[uniform_global_expr].ref_count, 1);
+    assert_eq!(info[query_expr].ref_count, 0);
+    assert_eq!(info[access_expr].ref_count, 0);
+    assert_eq!(info[non_uniform_global], GlobalUse::empty());
+    assert_eq!(info[uniform_global], GlobalUse::QUERY);
+
+    let stmt_emit1 = S::Emit(emit_range_globals.clone());
+    let stmt_if_uniform = S::If {
+        condition: uniform_global_expr,
+        accept: crate::Block::new(),
+        reject: vec![
+            S::Emit(emit_range_constant_derivative.clone()),
+            S::Store {
+                pointer: constant_expr,
+                value: derivative_expr,
+            },
+        ]
+        .into(),
+    };
+    assert_eq!(
+        info.process_block(
+            &vec![stmt_emit1, stmt_if_uniform].into(),
+            &[],
+            None,
+            &expressions
+        ),
+        Ok(FunctionUniformity {
+            result: Uniformity {
+                non_uniform_result: None,
+                requirements: UniformityRequirements::DERIVATIVE,
+            },
+            exit: ExitFlags::empty(),
+        }),
+    );
+    assert_eq!(info[constant_expr].ref_count, 2);
+    assert_eq!(info[uniform_global], GlobalUse::READ | GlobalUse::QUERY);
+
+    let stmt_emit2 = S::Emit(emit_range_globals.clone());
+    let stmt_if_non_uniform = S::If {
+        condition: non_uniform_global_expr,
+        accept: vec![
+            S::Emit(emit_range_constant_derivative),
+            S::Store {
+                pointer: constant_expr,
+                value: derivative_expr,
+            },
+        ]
+        .into(),
+        reject: crate::Block::new(),
+    };
+    {
+        let block_info = info.process_block(
+            &vec![stmt_emit2, stmt_if_non_uniform].into(),
+            &[],
+            None,
+            &expressions,
+        );
+        if DISABLE_UNIFORMITY_REQ_FOR_FRAGMENT_STAGE {
+            assert_eq!(info[derivative_expr].ref_count, 2);
+        } else {
+            assert_eq!(
+                block_info,
+                Err(FunctionError::NonUniformControlFlow(
+                    UniformityRequirements::DERIVATIVE,
+                    derivative_expr,
+                    UniformityDisruptor::Expression(non_uniform_global_expr)
+                )
+                .with_span()),
+            );
+            assert_eq!(info[derivative_expr].ref_count, 1);
+        }
+    }
+    assert_eq!(info[non_uniform_global], GlobalUse::READ);
+
+    let stmt_emit3 = S::Emit(emit_range_globals);
+    let stmt_return_non_uniform = S::Return {
+        value: Some(non_uniform_global_expr),
+    };
+    assert_eq!(
+        info.process_block(
+            &vec![stmt_emit3, stmt_return_non_uniform].into(),
+            &[],
+            Some(UniformityDisruptor::Return),
+            &expressions
+        ),
+        Ok(FunctionUniformity {
+            result: Uniformity {
+                non_uniform_result: Some(non_uniform_global_expr),
+                requirements: UniformityRequirements::empty(),
+            },
+            exit: ExitFlags::MAY_RETURN,
+        }),
+    );
+    assert_eq!(info[non_uniform_global_expr].ref_count, 3);
+
+    // Check that uniformity requirements reach through a pointer
+    let stmt_emit4 = S::Emit(emit_range_query_access_globals);
+    let stmt_assign = S::Store {
+        pointer: access_expr,
+        value: query_expr,
+    };
+    let stmt_return_pointer = S::Return {
+        value: Some(access_expr),
+    };
+    let stmt_kill = S::Kill;
+    assert_eq!(
+        info.process_block(
+            &vec![stmt_emit4, stmt_assign, stmt_kill, stmt_return_pointer].into(),
+            &[],
+            Some(UniformityDisruptor::Discard),
+            &expressions
+        ),
+        Ok(FunctionUniformity {
+            result: Uniformity {
+                non_uniform_result: Some(non_uniform_global_expr),
+                requirements: UniformityRequirements::empty(),
+            },
+            exit: ExitFlags::all(),
+        }),
+    );
+    assert_eq!(info[non_uniform_global], GlobalUse::READ | GlobalUse::WRITE);
+}
diff --git a/third_party/rust/naga/src/valid/compose.rs b/third_party/rust/naga/src/valid/compose.rs
new file mode 100644
index 0000000000..c21e98c6f2
--- /dev/null
+++ b/third_party/rust/naga/src/valid/compose.rs
@@ -0,0 +1,128 @@
+use crate::proc::TypeResolution;
+
+use crate::arena::Handle;
+
+#[derive(Clone, Debug, thiserror::Error)]
+#[cfg_attr(test, derive(PartialEq))]
+pub enum ComposeError {
+    #[error("Composing of type {0:?} can't be done")]
+    Type(Handle<crate::Type>),
+    #[error("Composing expects {expected} components but {given} were given")]
+    ComponentCount { given: u32, expected: u32 },
+    #[error("Composing {index}'s component type is not expected")]
+    ComponentType { index: u32 },
+}
+
+pub fn validate_compose(
+    self_ty_handle: Handle<crate::Type>,
+    gctx: crate::proc::GlobalCtx,
+    component_resolutions: impl ExactSizeIterator<Item = TypeResolution>,
+) -> Result<(), ComposeError> {
+    use crate::TypeInner as Ti;
+
+    match gctx.types[self_ty_handle].inner {
+        // vectors are composed from scalars or other vectors
+        Ti::Vector { size, scalar } => {
+            let mut total = 0;
+            for (index, comp_res) in component_resolutions.enumerate() {
+                total += match *comp_res.inner_with(gctx.types) {
+                    Ti::Scalar(comp_scalar) if comp_scalar == scalar => 1,
+                    Ti::Vector {
+                        size: comp_size,
+                        scalar: comp_scalar,
+                    } if comp_scalar == scalar => comp_size as u32,
+                    ref other => {
+                        log::error!(
+                            "Vector component[{}] type {:?}, building {:?}",
+                            index,
+                            other,
+                            scalar
+                        );
+                        return Err(ComposeError::ComponentType {
+                            index: index as u32,
+                        });
+                    }
+                };
+            }
+            if size as u32 != total {
+                return Err(ComposeError::ComponentCount {
+                    expected: size as u32,
+                    given: total,
+                });
+            }
+        }
+        // matrix are composed from column vectors
+        Ti::Matrix {
+            columns,
+            rows,
+            scalar,
+        } => {
+            let inner = Ti::Vector { size: rows, scalar };
+            if columns as usize != component_resolutions.len() {
+                return Err(ComposeError::ComponentCount {
+                    expected: columns as u32,
+                    given: component_resolutions.len() as u32,
+                });
+            }
+            for (index, comp_res) in component_resolutions.enumerate() {
+                if comp_res.inner_with(gctx.types) != &inner {
+                    log::error!("Matrix component[{}] type {:?}", index, comp_res);
+                    return Err(ComposeError::ComponentType {
+                        index: index as u32,
+                    });
+                }
+            }
+        }
+        Ti::Array {
+            base,
+            size: crate::ArraySize::Constant(count),
+            stride: _,
+        } => {
+            if count.get() as usize != component_resolutions.len() {
+                return Err(ComposeError::ComponentCount {
+                    expected: count.get(),
+                    given: component_resolutions.len() as u32,
+                });
+            }
+            for (index, comp_res) in component_resolutions.enumerate() {
+                let base_inner = &gctx.types[base].inner;
+                let comp_res_inner = comp_res.inner_with(gctx.types);
+                // We don't support arrays of pointers, but it seems best not to
+                // embed that assumption here, so use `TypeInner::equivalent`.
+                if !base_inner.equivalent(comp_res_inner, gctx.types) {
+                    log::error!("Array component[{}] type {:?}", index, comp_res);
+                    return Err(ComposeError::ComponentType {
+                        index: index as u32,
+                    });
+                }
+            }
+        }
+        Ti::Struct { ref members, .. } => {
+            if members.len() != component_resolutions.len() {
+                return Err(ComposeError::ComponentCount {
+                    given: component_resolutions.len() as u32,
+                    expected: members.len() as u32,
+                });
+            }
+            for (index, (member, comp_res)) in members.iter().zip(component_resolutions).enumerate()
+            {
+                let member_inner = &gctx.types[member.ty].inner;
+                let comp_res_inner = comp_res.inner_with(gctx.types);
+                // We don't support pointers in structs, but it seems best not to embed
+                // that assumption here, so use `TypeInner::equivalent`.
+                if !comp_res_inner.equivalent(member_inner, gctx.types) {
+                    log::error!("Struct component[{}] type {:?}", index, comp_res);
+                    return Err(ComposeError::ComponentType {
+                        index: index as u32,
+                    });
+                }
+            }
+        }
+        ref other => {
+            log::error!("Composing of {:?}", other);
+            return Err(ComposeError::Type(self_ty_handle));
+        }
+    }
+
+    Ok(())
+}
diff --git a/third_party/rust/naga/src/valid/expression.rs b/third_party/rust/naga/src/valid/expression.rs
new file mode 100644
index 0000000000..c82d60f062
--- /dev/null
+++ b/third_party/rust/naga/src/valid/expression.rs
@@ -0,0 +1,1797 @@
+use super::{
+    compose::validate_compose, validate_atomic_compare_exchange_struct, FunctionInfo, ModuleInfo,
+    ShaderStages, TypeFlags,
+};
+use crate::arena::UniqueArena;
+
+use crate::{
+    arena::Handle,
+    proc::{IndexableLengthError, ResolveError},
+};
+
+#[derive(Clone, Debug, thiserror::Error)]
+#[cfg_attr(test, derive(PartialEq))]
+pub enum ExpressionError {
+    #[error("Doesn't exist")]
+    DoesntExist,
+    #[error("Used by a statement before it was introduced into the scope by any of the dominating blocks")]
+    NotInScope,
+    #[error("Base type {0:?} is not compatible with this expression")]
+    InvalidBaseType(Handle<crate::Expression>),
+    #[error("Accessing with index {0:?} can't be done")]
+    InvalidIndexType(Handle<crate::Expression>),
+    #[error("Accessing {0:?} via a negative index is invalid")]
+    NegativeIndex(Handle<crate::Expression>),
+    #[error("Accessing index {1} is out of {0:?} bounds")]
+    IndexOutOfBounds(Handle<crate::Expression>, u32),
+    #[error("The expression {0:?} may only be indexed by a constant")]
+    IndexMustBeConstant(Handle<crate::Expression>),
+    #[error("Function argument {0:?} doesn't exist")]
+    FunctionArgumentDoesntExist(u32),
+    #[error("Loading of {0:?} can't be done")]
+    InvalidPointerType(Handle<crate::Expression>),
+    #[error("Array length of {0:?} can't be done")]
+    InvalidArrayType(Handle<crate::Expression>),
+    #[error("Get intersection of {0:?} can't be done")]
+    InvalidRayQueryType(Handle<crate::Expression>),
+    #[error("Splatting {0:?} can't be done")]
+    InvalidSplatType(Handle<crate::Expression>),
+    #[error("Swizzling {0:?} can't be done")]
+    InvalidVectorType(Handle<crate::Expression>),
+    #[error("Swizzle component {0:?} is outside of vector size {1:?}")]
+    InvalidSwizzleComponent(crate::SwizzleComponent, crate::VectorSize),
+    #[error(transparent)]
+    Compose(#[from] super::ComposeError),
+    #[error(transparent)]
+    IndexableLength(#[from] IndexableLengthError),
+    #[error("Operation {0:?} can't work with {1:?}")]
+    InvalidUnaryOperandType(crate::UnaryOperator, Handle<crate::Expression>),
+    #[error("Operation {0:?} can't work with {1:?} and {2:?}")]
+    InvalidBinaryOperandTypes(
+        crate::BinaryOperator,
+        Handle<crate::Expression>,
+        Handle<crate::Expression>,
+    ),
+    #[error("Selecting is not possible")]
+    InvalidSelectTypes,
+    #[error("Relational argument {0:?} is not a boolean vector")]
+    InvalidBooleanVector(Handle<crate::Expression>),
+    #[error("Relational argument {0:?} is not a float")]
+    InvalidFloatArgument(Handle<crate::Expression>),
+    #[error("Type resolution failed")]
+    Type(#[from] ResolveError),
+    #[error("Not a global variable")]
+    ExpectedGlobalVariable,
+    #[error("Not a global variable or a function argument")]
+    ExpectedGlobalOrArgument,
+    #[error("Needs to be an binding array instead of {0:?}")]
+    ExpectedBindingArrayType(Handle<crate::Type>),
+    #[error("Needs to be an image instead of {0:?}")]
+    ExpectedImageType(Handle<crate::Type>),
+    #[error("Needs to be an image instead of {0:?}")]
+    ExpectedSamplerType(Handle<crate::Type>),
+    #[error("Unable to operate on image class {0:?}")]
+    InvalidImageClass(crate::ImageClass),
+    #[error("Derivatives can only be taken from scalar and vector floats")]
+    InvalidDerivative,
+    #[error("Image array index parameter is misplaced")]
+    InvalidImageArrayIndex,
+    #[error("Inappropriate sample or level-of-detail index for texel access")]
+    InvalidImageOtherIndex,
+    #[error("Image array index type of {0:?} is not an integer scalar")]
+    InvalidImageArrayIndexType(Handle<crate::Expression>),
+    #[error("Image sample or level-of-detail index's type of {0:?} is not an integer scalar")]
+    InvalidImageOtherIndexType(Handle<crate::Expression>),
+    #[error("Image coordinate type of {1:?} does not match dimension {0:?}")]
+    InvalidImageCoordinateType(crate::ImageDimension, Handle<crate::Expression>),
+    #[error("Comparison sampling mismatch: image has class {image:?}, but the sampler is comparison={sampler}, and the reference was provided={has_ref}")]
+    ComparisonSamplingMismatch {
+        image: crate::ImageClass,
+        sampler: bool,
+        has_ref: bool,
+    },
+    #[error("Sample offset constant {1:?} doesn't match the image dimension {0:?}")]
+    InvalidSampleOffset(crate::ImageDimension, Handle<crate::Expression>),
+    #[error("Depth reference {0:?} is not a scalar float")]
+    InvalidDepthReference(Handle<crate::Expression>),
+    #[error("Depth sample level can only be Auto or Zero")]
+    InvalidDepthSampleLevel,
+    #[error("Gather level can only be Zero")]
+    InvalidGatherLevel,
+    #[error("Gather component {0:?} doesn't exist in the image")]
+    InvalidGatherComponent(crate::SwizzleComponent),
+    #[error("Gather can't be done for image dimension {0:?}")]
+    InvalidGatherDimension(crate::ImageDimension),
+    #[error("Sample level (exact) type {0:?} is not a scalar float")]
+    InvalidSampleLevelExactType(Handle<crate::Expression>),
+    #[error("Sample level (bias) type {0:?} is not a scalar float")]
+    InvalidSampleLevelBiasType(Handle<crate::Expression>),
+    #[error("Sample level (gradient) of {1:?} doesn't match the image dimension {0:?}")]
+    InvalidSampleLevelGradientType(crate::ImageDimension, Handle<crate::Expression>),
+    #[error("Unable to cast")]
+    InvalidCastArgument,
+    #[error("Invalid argument count for {0:?}")]
+    WrongArgumentCount(crate::MathFunction),
+    #[error("Argument [{1}] to {0:?} as expression {2:?} has an invalid type.")]
+    InvalidArgumentType(crate::MathFunction, u32, Handle<crate::Expression>),
+    #[error("Atomic result type can't be {0:?}")]
+    InvalidAtomicResultType(Handle<crate::Type>),
+    #[error(
+        "workgroupUniformLoad result type can't be {0:?}. It can only be a constructible type."
+    )]
+    InvalidWorkGroupUniformLoadResultType(Handle<crate::Type>),
+    #[error("Shader requires capability {0:?}")]
+    MissingCapabilities(super::Capabilities),
+    #[error(transparent)]
+    Literal(#[from] LiteralError),
+}
+
+#[derive(Clone, Debug, thiserror::Error)]
+pub enum ConstExpressionError {
+    #[error("The expression is not a constant expression")]
+    NonConst,
+    #[error(transparent)]
+    Compose(#[from] super::ComposeError),
+    #[error("Splatting {0:?} can't be done")]
+    InvalidSplatType(Handle<crate::Expression>),
+    #[error("Type resolution failed")]
+    Type(#[from] ResolveError),
+    #[error(transparent)]
+    Literal(#[from] LiteralError),
+    #[error(transparent)]
+    Width(#[from] super::r#type::WidthError),
+}
+
+#[derive(Clone, Debug, thiserror::Error)]
+#[cfg_attr(test, derive(PartialEq))]
+pub enum LiteralError {
+    #[error("Float literal is NaN")]
+    NaN,
+    #[error("Float literal is infinite")]
+    Infinity,
+    #[error(transparent)]
+    Width(#[from] super::r#type::WidthError),
+}
+
+struct ExpressionTypeResolver<'a> {
+    root: Handle<crate::Expression>,
+    types: &'a UniqueArena<crate::Type>,
+    info: &'a FunctionInfo,
+}
+
+impl<'a> std::ops::Index<Handle<crate::Expression>> for ExpressionTypeResolver<'a> {
+    type Output = crate::TypeInner;
+
+    #[allow(clippy::panic)]
+    fn index(&self, handle: Handle<crate::Expression>) -> &Self::Output {
+        if handle < self.root {
+            self.info[handle].ty.inner_with(self.types)
+        } else {
+            // `Validator::validate_module_handles` should have caught this.
+            panic!(
+                "Depends on {:?}, which has not been processed yet",
+                self.root
+            )
+        }
+    }
+}
+
+impl super::Validator {
+    pub(super) fn validate_const_expression(
+        &self,
+        handle: Handle<crate::Expression>,
+        gctx: crate::proc::GlobalCtx,
+        mod_info: &ModuleInfo,
+    ) -> Result<(), ConstExpressionError> {
+        use crate::Expression as E;
+
+        match gctx.const_expressions[handle] {
+            E::Literal(literal) => {
+                self.validate_literal(literal)?;
+            }
+            E::Constant(_) | E::ZeroValue(_) => {}
+            E::Compose { ref components, ty } => {
+                validate_compose(
+                    ty,
+                    gctx,
+                    components.iter().map(|&handle| mod_info[handle].clone()),
+                )?;
+            }
+            E::Splat { value, .. } => match *mod_info[value].inner_with(gctx.types) {
+                crate::TypeInner::Scalar { .. } => {}
+                _ => return Err(super::ConstExpressionError::InvalidSplatType(value)),
+            },
+            _ => return Err(super::ConstExpressionError::NonConst),
+        }
+
+        Ok(())
+    }
+
+    pub(super) fn validate_expression(
+        &self,
+        root: Handle<crate::Expression>,
+        expression: &crate::Expression,
+        function: &crate::Function,
+        module: &crate::Module,
+        info: &FunctionInfo,
+        mod_info: &ModuleInfo,
+    ) -> Result<ShaderStages, ExpressionError> {
+        use crate::{Expression as E, Scalar as Sc, ScalarKind as Sk, TypeInner as Ti};
+
+        let resolver = ExpressionTypeResolver {
+            root,
+            types: &module.types,
+            info,
+        };
+
+        let stages = match *expression {
+            E::Access { base, index } => {
+                let base_type = &resolver[base];
+                // See the documentation for `Expression::Access`.
+                let dynamic_indexing_restricted = match *base_type {
+                    Ti::Vector { .. } => false,
+                    Ti::Matrix { .. } | Ti::Array { .. } => true,
+                    Ti::Pointer { .. }
+                    | Ti::ValuePointer { size: Some(_), .. }
+                    | Ti::BindingArray { .. } => false,
+                    ref other => {
+                        log::error!("Indexing of {:?}", other);
+                        return Err(ExpressionError::InvalidBaseType(base));
+                    }
+                };
+                match resolver[index] {
+                    //TODO: only allow one of these
+                    Ti::Scalar(Sc {
+                        kind: Sk::Sint | Sk::Uint,
+                        ..
+                    }) => {}
+                    ref other => {
+                        log::error!("Indexing by {:?}", other);
+                        return Err(ExpressionError::InvalidIndexType(index));
+                    }
+                }
+                if dynamic_indexing_restricted
+                    && function.expressions[index].is_dynamic_index(module)
+                {
+                    return Err(ExpressionError::IndexMustBeConstant(base));
+                }
+
+                // If we know both the length and the index, we can do the
+                // bounds check now.
+                if let crate::proc::IndexableLength::Known(known_length) =
+                    base_type.indexable_length(module)?
+                {
+                    match module
+                        .to_ctx()
+                        .eval_expr_to_u32_from(index, &function.expressions)
+                    {
+                        Ok(value) => {
+                            if value >= known_length {
+                                return Err(ExpressionError::IndexOutOfBounds(base, value));
+                            }
+                        }
+                        Err(crate::proc::U32EvalError::Negative) => {
+                            return Err(ExpressionError::NegativeIndex(base))
+                        }
+                        Err(crate::proc::U32EvalError::NonConst) => {}
+                    }
+                }
+
+                ShaderStages::all()
+            }
+            E::AccessIndex { base, index } => {
+                fn resolve_index_limit(
+                    module: &crate::Module,
+                    top: Handle<crate::Expression>,
+                    ty: &crate::TypeInner,
+                    top_level: bool,
+                ) -> Result<u32, ExpressionError> {
+                    let limit = match *ty {
+                        Ti::Vector { size, .. }
+                        | Ti::ValuePointer {
+                            size: Some(size), ..
+                        } => size as u32,
+                        Ti::Matrix { columns, .. } => columns as u32,
+                        Ti::Array {
+                            size: crate::ArraySize::Constant(len),
+                            ..
+                        } => len.get(),
+                        Ti::Array { .. } | Ti::BindingArray { .. } => u32::MAX, // can't statically know, but need run-time checks
+                        Ti::Pointer { base, .. } if top_level => {
+                            resolve_index_limit(module, top, &module.types[base].inner, false)?
+                        }
+                        Ti::Struct { ref members, .. } => members.len() as u32,
+                        ref other => {
+                            log::error!("Indexing of {:?}", other);
+                            return Err(ExpressionError::InvalidBaseType(top));
+                        }
+                    };
+                    Ok(limit)
+                }
+
+                let limit = resolve_index_limit(module, base, &resolver[base], true)?;
+                if index >= limit {
+                    return Err(ExpressionError::IndexOutOfBounds(base, limit));
+                }
+                ShaderStages::all()
+            }
+            E::Splat { size: _, value } => match resolver[value] {
+                Ti::Scalar { .. } => ShaderStages::all(),
+                ref other => {
+                    log::error!("Splat scalar type {:?}", other);
+                    return Err(ExpressionError::InvalidSplatType(value));
+                }
+            },
+            E::Swizzle {
+                size,
+                vector,
+                pattern,
+            } => {
+                let vec_size = match resolver[vector] {
+                    Ti::Vector { size: vec_size, .. } => vec_size,
+                    ref other => {
+                        log::error!("Swizzle vector type {:?}", other);
+                        return Err(ExpressionError::InvalidVectorType(vector));
+                    }
+                };
+                for &sc in pattern[..size as usize].iter() {
+                    if sc as u8 >= vec_size as u8 {
+                        return Err(ExpressionError::InvalidSwizzleComponent(sc, vec_size));
+                    }
+                }
+                ShaderStages::all()
+            }
+            E::Literal(literal) => {
+                self.validate_literal(literal)?;
+                ShaderStages::all()
+            }
+            E::Constant(_) | E::ZeroValue(_) => ShaderStages::all(),
+            E::Compose { ref components, ty } => {
+                validate_compose(
+                    ty,
+                    module.to_ctx(),
+                    components.iter().map(|&handle| info[handle].ty.clone()),
+                )?;
+                ShaderStages::all()
+            }
+            E::FunctionArgument(index) => {
+                if index >= function.arguments.len() as u32 {
+                    return Err(ExpressionError::FunctionArgumentDoesntExist(index));
+                }
+                ShaderStages::all()
+            }
+            E::GlobalVariable(_handle) => ShaderStages::all(),
+            E::LocalVariable(_handle) => ShaderStages::all(),
+            E::Load { pointer } => {
+                match resolver[pointer] {
+                    Ti::Pointer { base, .. }
+                        if self.types[base.index()]
+                            .flags
+                            .contains(TypeFlags::SIZED | TypeFlags::DATA) => {}
+                    Ti::ValuePointer { .. } => {}
+                    ref other => {
+                        log::error!("Loading {:?}", other);
+                        return Err(ExpressionError::InvalidPointerType(pointer));
+                    }
+                }
+                ShaderStages::all()
+            }
+            E::ImageSample {
+                image,
+                sampler,
+                gather,
+                coordinate,
+                array_index,
+                offset,
+                level,
+                depth_ref,
+            } => {
+                // check the validity of expressions
+                let image_ty = Self::global_var_ty(module, function, image)?;
+                let sampler_ty = Self::global_var_ty(module, function, sampler)?;
+
+                let comparison = match module.types[sampler_ty].inner {
+                    Ti::Sampler { comparison } => comparison,
+                    _ => return Err(ExpressionError::ExpectedSamplerType(sampler_ty)),
+                };
+
+                let (class, dim) = match module.types[image_ty].inner {
+                    Ti::Image {
+                        class,
+                        arrayed,
+                        dim,
+                    } => {
+                        // check the array property
+                        if arrayed != array_index.is_some() {
+                            return Err(ExpressionError::InvalidImageArrayIndex);
+                        }
+                        if let Some(expr) = array_index {
+                            match resolver[expr] {
+                                Ti::Scalar(Sc {
+                                    kind: Sk::Sint | Sk::Uint,
+                                    ..
+                                }) => {}
+                                _ => return Err(ExpressionError::InvalidImageArrayIndexType(expr)),
+                            }
+                        }
+                        (class, dim)
+                    }
+                    _ => return Err(ExpressionError::ExpectedImageType(image_ty)),
+                };
+
+                // check sampling and comparison properties
+                let image_depth = match class {
+                    crate::ImageClass::Sampled {
+                        kind: crate::ScalarKind::Float,
+                        multi: false,
+                    } => false,
+                    crate::ImageClass::Sampled {
+                        kind: crate::ScalarKind::Uint | crate::ScalarKind::Sint,
+                        multi: false,
+                    } if gather.is_some() => false,
+                    crate::ImageClass::Depth { multi: false } => true,
+                    _ => return Err(ExpressionError::InvalidImageClass(class)),
+                };
+                if comparison != depth_ref.is_some() || (comparison && !image_depth) {
+                    return Err(ExpressionError::ComparisonSamplingMismatch {
+                        image: class,
+                        sampler: comparison,
+                        has_ref: depth_ref.is_some(),
+                    });
+                }
+
+                // check texture coordinates type
+                let num_components = match dim {
+                    crate::ImageDimension::D1 => 1,
+                    crate::ImageDimension::D2 => 2,
+                    crate::ImageDimension::D3 | crate::ImageDimension::Cube => 3,
+                };
+                match resolver[coordinate] {
+                    Ti::Scalar(Sc {
+                        kind: Sk::Float, ..
+                    }) if num_components == 1 => {}
+                    Ti::Vector {
+                        size,
+                        scalar:
+                            Sc {
+                                kind: Sk::Float, ..
+                            },
+                    } if size as u32 == num_components => {}
+                    _ => return Err(ExpressionError::InvalidImageCoordinateType(dim, coordinate)),
+                }
+
+                // check constant offset
+                if let Some(const_expr) = offset {
+                    match *mod_info[const_expr].inner_with(&module.types) {
+                        Ti::Scalar(Sc { kind: Sk::Sint, .. }) if num_components == 1 => {}
+                        Ti::Vector {
+                            size,
+                            scalar: Sc { kind: Sk::Sint, .. },
+                        } if size as u32 == num_components => {}
+                        _ => {
+                            return Err(ExpressionError::InvalidSampleOffset(dim, const_expr));
+                        }
+                    }
+                }
+
+                // check depth reference type
+                if let Some(expr) = depth_ref {
+                    match resolver[expr] {
+                        Ti::Scalar(Sc {
+                            kind: Sk::Float, ..
+                        }) => {}
+                        _ => return Err(ExpressionError::InvalidDepthReference(expr)),
+                    }
+                    match level {
+                        crate::SampleLevel::Auto | crate::SampleLevel::Zero => {}
+                        _ => return Err(ExpressionError::InvalidDepthSampleLevel),
+                    }
+                }
+
+                if let Some(component) = gather {
+                    match dim {
+                        crate::ImageDimension::D2 | crate::ImageDimension::Cube => {}
+                        crate::ImageDimension::D1 | crate::ImageDimension::D3 => {
+                            return Err(ExpressionError::InvalidGatherDimension(dim))
+                        }
+                    };
+                    let max_component = match class {
+                        crate::ImageClass::Depth { .. } => crate::SwizzleComponent::X,
+                        _ => crate::SwizzleComponent::W,
+                    };
+                    if component > max_component {
+                        return Err(ExpressionError::InvalidGatherComponent(component));
+                    }
+                    match level {
+                        crate::SampleLevel::Zero => {}
+                        _ => return Err(ExpressionError::InvalidGatherLevel),
+                    }
+                }
+
+                // check level properties
+                match level {
+                    crate::SampleLevel::Auto => ShaderStages::FRAGMENT,
+                    crate::SampleLevel::Zero => ShaderStages::all(),
+                    crate::SampleLevel::Exact(expr) => {
+                        match resolver[expr] {
+                            Ti::Scalar(Sc {
+                                kind: Sk::Float, ..
+                            }) => {}
+                            _ => return Err(ExpressionError::InvalidSampleLevelExactType(expr)),
+                        }
+                        ShaderStages::all()
+                    }
+                    crate::SampleLevel::Bias(expr) => {
+                        match resolver[expr] {
+                            Ti::Scalar(Sc {
+                                kind: Sk::Float, ..
+                            }) => {}
+                            _ => return Err(ExpressionError::InvalidSampleLevelBiasType(expr)),
+                        }
+                        ShaderStages::FRAGMENT
+                    }
+                    crate::SampleLevel::Gradient { x, y } => {
+                        match resolver[x] {
+                            Ti::Scalar(Sc {
+                                kind: Sk::Float, ..
+                            }) if num_components == 1 => {}
+                            Ti::Vector {
+                                size,
+                                scalar:
+                                    Sc {
+                                        kind: Sk::Float, ..
+                                    },
+                            } if size as u32 == num_components => {}
+                            _ => {
+                                return Err(ExpressionError::InvalidSampleLevelGradientType(dim, x))
+                            }
+                        }
+                        match resolver[y] {
+                            Ti::Scalar(Sc {
+                                kind: Sk::Float, ..
+                            }) if num_components == 1 => {}
+                            Ti::Vector {
+                                size,
+                                scalar:
+                                    Sc {
+                                        kind: Sk::Float, ..
+                                    },
+                            } if size as u32 == num_components => {}
+                            _ => {
+                                return Err(ExpressionError::InvalidSampleLevelGradientType(dim, y))
+                            }
+                        }
+                        ShaderStages::all()
+                    }
+                }
+            }
+            E::ImageLoad {
+                image,
+                coordinate,
+                array_index,
+                sample,
+                level,
+            } => {
+                let ty = Self::global_var_ty(module, function, image)?;
+                match module.types[ty].inner {
+                    Ti::Image {
+                        class,
+                        arrayed,
+                        dim,
+                    } => {
+                        match resolver[coordinate].image_storage_coordinates() {
+                            Some(coord_dim) if coord_dim == dim => {}
+                            _ => {
+                                return Err(ExpressionError::InvalidImageCoordinateType(
+                                    dim, coordinate,
+                                ))
+                            }
+                        };
+                        if arrayed != array_index.is_some() {
+                            return Err(ExpressionError::InvalidImageArrayIndex);
+                        }
+                        if let Some(expr) = array_index {
+                            match resolver[expr] {
+                                Ti::Scalar(Sc {
+                                    kind: Sk::Sint | Sk::Uint,
+                                    width: _,
+                                }) => {}
+                                _ => return Err(ExpressionError::InvalidImageArrayIndexType(expr)),
+                            }
+                        }
+
+                        match (sample, class.is_multisampled()) {
+                            (None, false) => {}
+                            (Some(sample), true) => {
+                                if resolver[sample].scalar_kind() != Some(Sk::Sint) {
+                                    return Err(ExpressionError::InvalidImageOtherIndexType(
+                                        sample,
+                                    ));
+                                }
+                            }
+                            _ => {
+                                return Err(ExpressionError::InvalidImageOtherIndex);
+                            }
+                        }
+
+                        match (level, class.is_mipmapped()) {
+                            (None, false) => {}
+                            (Some(level), true) => {
+                                if resolver[level].scalar_kind() != Some(Sk::Sint) {
+                                    return Err(ExpressionError::InvalidImageOtherIndexType(level));
+                                }
+                            }
+                            _ => {
+                                return Err(ExpressionError::InvalidImageOtherIndex);
+                            }
+                        }
+                    }
+                    _ => return Err(ExpressionError::ExpectedImageType(ty)),
+                }
+                ShaderStages::all()
+            }
+            E::ImageQuery { image, query } => {
+                let ty = Self::global_var_ty(module, function, image)?;
+                match module.types[ty].inner {
+                    Ti::Image { class, arrayed, .. } => {
+                        let good = match query {
+                            crate::ImageQuery::NumLayers => arrayed,
+                            crate::ImageQuery::Size { level: None } => true,
+                            crate::ImageQuery::Size { level: Some(_) }
+                            | crate::ImageQuery::NumLevels => class.is_mipmapped(),
+                            crate::ImageQuery::NumSamples => class.is_multisampled(),
+                        };
+                        if !good {
+                            return Err(ExpressionError::InvalidImageClass(class));
+                        }
+                    }
+                    _ => return Err(ExpressionError::ExpectedImageType(ty)),
+                }
+                ShaderStages::all()
+            }
+            E::Unary { op, expr } => {
+                use crate::UnaryOperator as Uo;
+                let inner = &resolver[expr];
+                match (op, inner.scalar_kind()) {
+                    (Uo::Negate, Some(Sk::Float | Sk::Sint))
+                    | (Uo::LogicalNot, Some(Sk::Bool))
+                    | (Uo::BitwiseNot, Some(Sk::Sint | Sk::Uint)) => {}
+                    other => {
+                        log::error!("Op {:?} kind {:?}", op, other);
+                        return Err(ExpressionError::InvalidUnaryOperandType(op, expr));
+                    }
+                }
+                ShaderStages::all()
+            }
+            E::Binary { op, left, right } => {
+                use crate::BinaryOperator as Bo;
+                let left_inner = &resolver[left];
+                let right_inner = &resolver[right];
+                let good = match op {
+                    Bo::Add | Bo::Subtract => match *left_inner {
+                        Ti::Scalar(scalar) | Ti::Vector { scalar, .. } => match scalar.kind {
+                            Sk::Uint | Sk::Sint | Sk::Float => left_inner == right_inner,
+                            Sk::Bool | Sk::AbstractInt | Sk::AbstractFloat => false,
+                        },
+                        Ti::Matrix { .. } => left_inner == right_inner,
+                        _ => false,
+                    },
+                    Bo::Divide | Bo::Modulo => match *left_inner {
+                        Ti::Scalar(scalar) | Ti::Vector { scalar, .. } => match scalar.kind {
+                            Sk::Uint | Sk::Sint | Sk::Float => left_inner == right_inner,
+                            Sk::Bool | Sk::AbstractInt | Sk::AbstractFloat => false,
+                        },
+                        _ => false,
+                    },
+                    Bo::Multiply => {
+                        let kind_allowed = match left_inner.scalar_kind() {
+                            Some(Sk::Uint | Sk::Sint | Sk::Float) => true,
+                            Some(Sk::Bool | Sk::AbstractInt | Sk::AbstractFloat) | None => false,
+                        };
+                        let types_match = match (left_inner, right_inner) {
+                            // Straight scalar and mixed scalar/vector.
+                            (&Ti::Scalar(scalar1), &Ti::Scalar(scalar2))
+                            | (
+                                &Ti::Vector {
+                                    scalar: scalar1, ..
+                                },
+                                &Ti::Scalar(scalar2),
+                            )
+                            | (
+                                &Ti::Scalar(scalar1),
+                                &Ti::Vector {
+                                    scalar: scalar2, ..
+                                },
+                            ) => scalar1 == scalar2,
+                            // Scalar/matrix.
+                            (
+                                &Ti::Scalar(Sc {
+                                    kind: Sk::Float, ..
+                                }),
+                                &Ti::Matrix { .. },
+                            )
+                            | (
+                                &Ti::Matrix { .. },
+                                &Ti::Scalar(Sc {
+                                    kind: Sk::Float, ..
+                                }),
+                            ) => true,
+                            // Vector/vector.
+                            (
+                                &Ti::Vector {
+                                    size: size1,
+                                    scalar: scalar1,
+                                },
+                                &Ti::Vector {
+                                    size: size2,
+                                    scalar: scalar2,
+                                },
+                            ) => scalar1 == scalar2 && size1 == size2,
+                            // Matrix * vector.
+                            (
+                                &Ti::Matrix { columns, .. },
+                                &Ti::Vector {
+                                    size,
+                                    scalar:
+                                        Sc {
+                                            kind: Sk::Float, ..
+                                        },
+                                },
+                            ) => columns == size,
+                            // Vector * matrix.
+                            (
+                                &Ti::Vector {
+                                    size,
+                                    scalar:
+                                        Sc {
+                                            kind: Sk::Float, ..
+                                        },
+                                },
+                                &Ti::Matrix { rows, .. },
+                            ) => size == rows,
+                            (&Ti::Matrix { columns, .. }, &Ti::Matrix { rows, .. }) => {
+                                columns == rows
+                            }
+                            _ => false,
+                        };
+                        let left_width = left_inner.scalar_width().unwrap_or(0);
+                        let right_width = right_inner.scalar_width().unwrap_or(0);
+                        kind_allowed && types_match && left_width == right_width
+                    }
+                    Bo::Equal | Bo::NotEqual => left_inner.is_sized() && left_inner == right_inner,
+                    Bo::Less | Bo::LessEqual | Bo::Greater | Bo::GreaterEqual => {
+                        match *left_inner {
+                            Ti::Scalar(scalar) | Ti::Vector { scalar, .. } => match scalar.kind {
+                                Sk::Uint | Sk::Sint | Sk::Float => left_inner == right_inner,
+                                Sk::Bool | Sk::AbstractInt | Sk::AbstractFloat => false,
+                            },
+                            ref other => {
+                                log::error!("Op {:?} left type {:?}", op, other);
+                                false
+                            }
+                        }
+                    }
+                    Bo::LogicalAnd | Bo::LogicalOr => match *left_inner {
+                        Ti::Scalar(Sc { kind: Sk::Bool, .. })
+                        | Ti::Vector {
+                            scalar: Sc { kind: Sk::Bool, .. },
+                            ..
+                        } => left_inner == right_inner,
+                        ref other => {
+                            log::error!("Op {:?} left type {:?}", op, other);
+                            false
+                        }
+                    },
+                    Bo::And | Bo::InclusiveOr => match *left_inner {
+                        Ti::Scalar(scalar) | Ti::Vector { scalar, .. } => match scalar.kind {
+                            Sk::Bool | Sk::Sint | Sk::Uint => left_inner == right_inner,
+                            Sk::Float | Sk::AbstractInt | Sk::AbstractFloat => false,
+                        },
+                        ref other => {
+                            log::error!("Op {:?} left type {:?}", op, other);
+                            false
+                        }
+                    },
+                    Bo::ExclusiveOr => match *left_inner {
+                        Ti::Scalar(scalar) | Ti::Vector { scalar, .. } => match scalar.kind {
+                            Sk::Sint | Sk::Uint => left_inner == right_inner,
+                            Sk::Bool | Sk::Float | Sk::AbstractInt | Sk::AbstractFloat => false,
+                        },
+                        ref other => {
+                            log::error!("Op {:?} left type {:?}", op, other);
+                            false
+                        }
+                    },
+                    Bo::ShiftLeft | Bo::ShiftRight => {
+                        let (base_size, base_scalar) = match *left_inner {
+                            Ti::Scalar(scalar) => (Ok(None), scalar),
+                            Ti::Vector { size, scalar } => (Ok(Some(size)), scalar),
+                            ref other => {
+                                log::error!("Op {:?} base type {:?}", op, other);
+                                (Err(()), Sc::BOOL)
+                            }
+                        };
+                        let shift_size = match *right_inner {
+                            Ti::Scalar(Sc { kind: Sk::Uint, .. }) => Ok(None),
+                            Ti::Vector {
+                                size,
+                                scalar: Sc { kind: Sk::Uint, .. },
+                            } => Ok(Some(size)),
+                            ref other => {
+                                log::error!("Op {:?} shift type {:?}", op, other);
+                                Err(())
+                            }
+                        };
+                        match base_scalar.kind {
+                            Sk::Sint | Sk::Uint => base_size.is_ok() && base_size == shift_size,
+                            Sk::Float | Sk::AbstractInt | Sk::AbstractFloat | Sk::Bool => false,
+                        }
+                    }
+                };
+                if !good {
+                    log::error!(
+                        "Left: {:?} of type {:?}",
+                        function.expressions[left],
+                        left_inner
+                    );
+                    log::error!(
+                        "Right: {:?} of type {:?}",
+                        function.expressions[right],
+                        right_inner
+                    );
+                    return Err(ExpressionError::InvalidBinaryOperandTypes(op, left, right));
+                }
+                ShaderStages::all()
+            }
+            E::Select {
+                condition,
+                accept,
+                reject,
+            } => {
+                let accept_inner = &resolver[accept];
+                let reject_inner = &resolver[reject];
+                let condition_good = match resolver[condition] {
+                    Ti::Scalar(Sc {
+                        kind: Sk::Bool,
+                        width: _,
+                    }) => {
+                        // When `condition` is a single boolean, `accept` and
+                        // `reject` can be vectors or scalars.
+                        match *accept_inner {
+                            Ti::Scalar { .. } | Ti::Vector { .. } => true,
+                            _ => false,
+                        }
+                    }
+                    Ti::Vector {
+                        size,
+                        scalar:
+                            Sc {
+                                kind: Sk::Bool,
+                                width: _,
+                            },
+                    } => match *accept_inner {
+                        Ti::Vector {
+                            size: other_size, ..
+                        } => size == other_size,
+                        _ => false,
+                    },
+                    _ => false,
+                };
+                if !condition_good || accept_inner != reject_inner {
+                    return Err(ExpressionError::InvalidSelectTypes);
+                }
+                ShaderStages::all()
+            }
+            E::Derivative { expr, .. } => {
+                match resolver[expr] {
+                    Ti::Scalar(Sc {
+                        kind: Sk::Float, ..
+                    })
+                    | Ti::Vector {
+                        scalar:
+                            Sc {
+                                kind: Sk::Float, ..
+                            },
+                        ..
+                    } => {}
+                    _ => return Err(ExpressionError::InvalidDerivative),
+                }
+                ShaderStages::FRAGMENT
+            }
+            E::Relational { fun, argument } => {
+                use crate::RelationalFunction as Rf;
+                let argument_inner = &resolver[argument];
+                match fun {
+                    Rf::All | Rf::Any => match *argument_inner {
+                        Ti::Vector {
+                            scalar: Sc { kind: Sk::Bool, .. },
+                            ..
+                        } => {}
+                        ref other => {
+                            log::error!("All/Any of type {:?}", other);
+                            return Err(ExpressionError::InvalidBooleanVector(argument));
+                        }
+                    },
+                    Rf::IsNan | Rf::IsInf => match *argument_inner {
+                        Ti::Scalar(scalar) | Ti::Vector { scalar, .. }
+                            if scalar.kind == Sk::Float => {}
+                        ref other => {
+                            log::error!("Float test of type {:?}", other);
+                            return Err(ExpressionError::InvalidFloatArgument(argument));
+                        }
+                    },
+                }
+                ShaderStages::all()
+            }
+            E::Math {
+                fun,
+                arg,
+                arg1,
+                arg2,
+                arg3,
+            } => {
+                use crate::MathFunction as Mf;
+
+                let resolve = |arg| &resolver[arg];
+                let arg_ty = resolve(arg);
+                let arg1_ty = arg1.map(resolve);
+                let arg2_ty = arg2.map(resolve);
+                let arg3_ty = arg3.map(resolve);
+                match fun {
+                    Mf::Abs => {
+                        if arg1_ty.is_some() || arg2_ty.is_some() || arg3_ty.is_some() {
+                            return Err(ExpressionError::WrongArgumentCount(fun));
+                        }
+                        let good = match *arg_ty {
+                            Ti::Scalar(scalar) | Ti::Vector { scalar, .. } => {
+                                scalar.kind != Sk::Bool
+                            }
+                            _ => false,
+                        };
+                        if !good {
+                            return Err(ExpressionError::InvalidArgumentType(fun, 0, arg));
+                        }
+                    }
+                    Mf::Min | Mf::Max => {
+                        let arg1_ty = match (arg1_ty, arg2_ty, arg3_ty) {
+                            (Some(ty1), None, None) => ty1,
+                            _ => return Err(ExpressionError::WrongArgumentCount(fun)),
+                        };
+                        let good = match *arg_ty {
+                            Ti::Scalar(scalar) | Ti::Vector { scalar, .. } => {
+                                scalar.kind != Sk::Bool
+                            }
+                            _ => false,
+                        };
+                        if !good {
+                            return Err(ExpressionError::InvalidArgumentType(fun, 0, arg));
+                        }
+                        if arg1_ty != arg_ty {
+                            return Err(ExpressionError::InvalidArgumentType(
+                                fun,
+                                1,
+                                arg1.unwrap(),
+                            ));
+                        }
+                    }
+                    Mf::Clamp => {
+                        let (arg1_ty, arg2_ty) = match (arg1_ty, arg2_ty, arg3_ty) {
+                            (Some(ty1), Some(ty2), None) => (ty1, ty2),
+                            _ => return Err(ExpressionError::WrongArgumentCount(fun)),
+                        };
+                        let good = match *arg_ty {
+                            Ti::Scalar(scalar) | Ti::Vector { scalar, .. } => {
+                                scalar.kind != Sk::Bool
+                            }
+                            _ => false,
+                        };
+                        if !good {
+                            return Err(ExpressionError::InvalidArgumentType(fun, 0, arg));
+                        }
+                        if arg1_ty != arg_ty {
+                            return Err(ExpressionError::InvalidArgumentType(
+                                fun,
+                                1,
+                                arg1.unwrap(),
+                            ));
+                        }
+                        if arg2_ty != arg_ty {
+                            return Err(ExpressionError::InvalidArgumentType(
+                                fun,
+                                2,
+                                arg2.unwrap(),
+                            ));
+                        }
+                    }
+                    Mf::Saturate
+                    | Mf::Cos
+                    | Mf::Cosh
+                    | Mf::Sin
+                    | Mf::Sinh
+                    | Mf::Tan
+                    | Mf::Tanh
+                    | Mf::Acos
+                    | Mf::Asin
+                    | Mf::Atan
+                    | Mf::Asinh
+                    | Mf::Acosh
+                    | Mf::Atanh
+                    | Mf::Radians
+                    | Mf::Degrees
+                    | Mf::Ceil
+                    | Mf::Floor
+                    | Mf::Round
+                    | Mf::Fract
+                    | Mf::Trunc
+                    | Mf::Exp
+                    | Mf::Exp2
+                    | Mf::Log
+                    | Mf::Log2
+                    | Mf::Length
+                    | Mf::Sqrt
+                    | Mf::InverseSqrt => {
+                        if arg1_ty.is_some() || arg2_ty.is_some() || arg3_ty.is_some() {
+                            return Err(ExpressionError::WrongArgumentCount(fun));
+                        }
+                        match *arg_ty {
+                            Ti::Scalar(scalar) | Ti::Vector { scalar, .. }
+                                if scalar.kind == Sk::Float => {}
+                            _ => return Err(ExpressionError::InvalidArgumentType(fun, 0, arg)),
+                        }
+                    }
+                    Mf::Sign => {
+                        if arg1_ty.is_some() || arg2_ty.is_some() || arg3_ty.is_some() {
+                            return Err(ExpressionError::WrongArgumentCount(fun));
+                        }
+                        match *arg_ty {
+                            Ti::Scalar(Sc {
+                                kind: Sk::Float | Sk::Sint,
+                                ..
+                            })
+                            | Ti::Vector {
+                                scalar:
+                                    Sc {
+                                        kind: Sk::Float | Sk::Sint,
+                                        ..
+                                    },
+                                ..
+                            } => {}
+                            _ => return Err(ExpressionError::InvalidArgumentType(fun, 0, arg)),
+                        }
+                    }
+                    Mf::Atan2 | Mf::Pow | Mf::Distance | Mf::Step => {
+                        let arg1_ty = match (arg1_ty, arg2_ty, arg3_ty) {
+                            (Some(ty1), None, None) => ty1,
+                            _ => return Err(ExpressionError::WrongArgumentCount(fun)),
+                        };
+                        match *arg_ty {
+                            Ti::Scalar(scalar) | Ti::Vector { scalar, .. }
+                                if scalar.kind == Sk::Float => {}
+                            _ => return Err(ExpressionError::InvalidArgumentType(fun, 0, arg)),
+                        }
+                        if arg1_ty != arg_ty {
+                            return Err(ExpressionError::InvalidArgumentType(
+                                fun,
+                                1,
+                                arg1.unwrap(),
+                            ));
+                        }
+                    }
+                    Mf::Modf | Mf::Frexp => {
+                        if arg1_ty.is_some() || arg2_ty.is_some() || arg3_ty.is_some() {
+                            return Err(ExpressionError::WrongArgumentCount(fun));
+                        }
+                        if !matches!(*arg_ty,
+                                     Ti::Scalar(scalar) | Ti::Vector { scalar, .. }
+                                     if scalar.kind == Sk::Float)
+                        {
+                            return Err(ExpressionError::InvalidArgumentType(fun, 1, arg));
+                        }
+                    }
+                    Mf::Ldexp => {
+                        let arg1_ty = match (arg1_ty, arg2_ty, arg3_ty) {
+                            (Some(ty1), None, None) => ty1,
+                            _ => return Err(ExpressionError::WrongArgumentCount(fun)),
+                        };
+                        let size0 = match *arg_ty {
+                            Ti::Scalar(Sc {
+                                kind: Sk::Float, ..
+                            }) => None,
+                            Ti::Vector {
+                                scalar:
+                                    Sc {
+                                        kind: Sk::Float, ..
+                                    },
+                                size,
+                            } => Some(size),
+                            _ => {
+                                return Err(ExpressionError::InvalidArgumentType(fun, 0, arg));
+                            }
+                        };
+                        let good = match *arg1_ty {
+                            Ti::Scalar(Sc { kind: Sk::Sint, .. }) if size0.is_none() => true,
+                            Ti::Vector {
+                                size,
+                                scalar: Sc { kind: Sk::Sint, .. },
+                            } if Some(size) == size0 => true,
+                            _ => false,
+                        };
+                        if !good {
+                            return Err(ExpressionError::InvalidArgumentType(
+                                fun,
+                                1,
+                                arg1.unwrap(),
+                            ));
+                        }
+                    }
+                    Mf::Dot => {
+                        let arg1_ty = match (arg1_ty, arg2_ty, arg3_ty) {
+                            (Some(ty1), None, None) => ty1,
+                            _ => return Err(ExpressionError::WrongArgumentCount(fun)),
+                        };
+                        match *arg_ty {
+                            Ti::Vector {
+                                scalar:
+                                    Sc {
+                                        kind: Sk::Float | Sk::Sint | Sk::Uint,
+                                        ..
+                                    },
+                                ..
+                            } => {}
+                            _ => return Err(ExpressionError::InvalidArgumentType(fun, 0, arg)),
+                        }
+                        if arg1_ty != arg_ty {
+                            return Err(ExpressionError::InvalidArgumentType(
+                                fun,
+                                1,
+                                arg1.unwrap(),
+                            ));
+                        }
+                    }
+                    Mf::Outer | Mf::Cross | Mf::Reflect => {
+                        let arg1_ty = match (arg1_ty, arg2_ty, arg3_ty) {
+                            (Some(ty1), None, None) => ty1,
+                            _ => return Err(ExpressionError::WrongArgumentCount(fun)),
+                        };
+                        match *arg_ty {
+                            Ti::Vector {
+                                scalar:
+                                    Sc {
+                                        kind: Sk::Float, ..
+                                    },
+                                ..
+                            } => {}
+                            _ => return Err(ExpressionError::InvalidArgumentType(fun, 0, arg)),
+                        }
+                        if arg1_ty != arg_ty {
+                            return Err(ExpressionError::InvalidArgumentType(
+                                fun,
+                                1,
+                                arg1.unwrap(),
+                            ));
+                        }
+                    }
+                    Mf::Refract => {
+                        let (arg1_ty, arg2_ty) = match (arg1_ty, arg2_ty, arg3_ty) {
+                            (Some(ty1), Some(ty2), None) => (ty1, ty2),
+                            _ => return Err(ExpressionError::WrongArgumentCount(fun)),
+                        };
+
+                        match *arg_ty {
+                            Ti::Vector {
+                                scalar:
+                                    Sc {
+                                        kind: Sk::Float, ..
+                                    },
+                                ..
+                            } => {}
+                            _ => return Err(ExpressionError::InvalidArgumentType(fun, 0, arg)),
+                        }
+
+                        if arg1_ty != arg_ty {
+                            return Err(ExpressionError::InvalidArgumentType(
+                                fun,
+                                1,
+                                arg1.unwrap(),
+                            ));
+                        }
+
+                        match (arg_ty, arg2_ty) {
+                            (
+                                &Ti::Vector {
+                                    scalar:
+                                        Sc {
+                                            width: vector_width,
+                                            ..
+                                        },
+                                    ..
+                                },
+                                &Ti::Scalar(Sc {
+                                    width: scalar_width,
+                                    kind: Sk::Float,
+                                }),
+                            ) if vector_width == scalar_width => {}
+                            _ => {
+                                return Err(ExpressionError::InvalidArgumentType(
+                                    fun,
+                                    2,
+                                    arg2.unwrap(),
+                                ))
+                            }
+                        }
+                    }
+                    Mf::Normalize => {
+                        if arg1_ty.is_some() || arg2_ty.is_some() || arg3_ty.is_some() {
+                            return Err(ExpressionError::WrongArgumentCount(fun));
+                        }
+                        match *arg_ty {
+                            Ti::Vector {
+                                scalar:
+                                    Sc {
+                                        kind: Sk::Float, ..
+                                    },
+                                ..
+                            } => {}
+                            _ => return Err(ExpressionError::InvalidArgumentType(fun, 0, arg)),
+                        }
+                    }
+                    Mf::FaceForward | Mf::Fma | Mf::SmoothStep => {
+                        let (arg1_ty, arg2_ty) = match (arg1_ty, arg2_ty, arg3_ty) {
+                            (Some(ty1), Some(ty2), None) => (ty1, ty2),
+                            _ => return Err(ExpressionError::WrongArgumentCount(fun)),
+                        };
+                        match *arg_ty {
+                            Ti::Scalar(Sc {
+                                kind: Sk::Float, ..
+                            })
+                            | Ti::Vector {
+                                scalar:
+                                    Sc {
+                                        kind: Sk::Float, ..
+                                    },
+                                ..
+                            } => {}
+                            _ => return Err(ExpressionError::InvalidArgumentType(fun, 0, arg)),
+                        }
+                        if arg1_ty != arg_ty {
+                            return Err(ExpressionError::InvalidArgumentType(
+                                fun,
+                                1,
+                                arg1.unwrap(),
+                            ));
+                        }
+                        if arg2_ty != arg_ty {
+                            return Err(ExpressionError::InvalidArgumentType(
+                                fun,
+                                2,
+                                arg2.unwrap(),
+                            ));
+                        }
+                    }
+                    Mf::Mix => {
+                        let (arg1_ty, arg2_ty) = match (arg1_ty, arg2_ty, arg3_ty) {
+                            (Some(ty1), Some(ty2), None) => (ty1, ty2),
+                            _ => return Err(ExpressionError::WrongArgumentCount(fun)),
+                        };
+                        let arg_width = match *arg_ty {
+                            Ti::Scalar(Sc {
+                                kind: Sk::Float,
+                                width,
+                            })
+                            | Ti::Vector {
+                                scalar:
+                                    Sc {
+                                        kind: Sk::Float,
+                                        width,
+                                    },
+                                ..
+                            } => width,
+                            _ => return Err(ExpressionError::InvalidArgumentType(fun, 0, arg)),
+                        };
+                        if arg1_ty != arg_ty {
+                            return Err(ExpressionError::InvalidArgumentType(
+                                fun,
+                                1,
+                                arg1.unwrap(),
+                            ));
+                        }
+                        // the last argument can always be a scalar
+                        match *arg2_ty {
+                            Ti::Scalar(Sc {
+                                kind: Sk::Float,
+                                width,
+                            }) if width == arg_width => {}
+                            _ if arg2_ty == arg_ty => {}
+                            _ => {
+                                return Err(ExpressionError::InvalidArgumentType(
+                                    fun,
+                                    2,
+                                    arg2.unwrap(),
+                                ));
+                            }
+                        }
+                    }
+                    Mf::Inverse | Mf::Determinant => {
+                        if arg1_ty.is_some() || arg2_ty.is_some() || arg3_ty.is_some() {
+                            return Err(ExpressionError::WrongArgumentCount(fun));
+                        }
+                        let good = match *arg_ty {
+                            Ti::Matrix { columns, rows, .. } => columns == rows,
+                            _ => false,
+                        };
+                        if !good {
+                            return Err(ExpressionError::InvalidArgumentType(fun, 0, arg));
+                        }
+                    }
+                    Mf::Transpose => {
+                        if arg1_ty.is_some() || arg2_ty.is_some() || arg3_ty.is_some() {
+                            return Err(ExpressionError::WrongArgumentCount(fun));
+                        }
+                        match *arg_ty {
+                            Ti::Matrix { .. } => {}
+                            _ => return Err(ExpressionError::InvalidArgumentType(fun, 0, arg)),
+                        }
+                    }
+                    Mf::CountTrailingZeros
+                    | Mf::CountLeadingZeros
+                    | Mf::CountOneBits
+                    | Mf::ReverseBits
+                    | Mf::FindLsb
+                    | Mf::FindMsb => {
+                        if arg1_ty.is_some() || arg2_ty.is_some() || arg3_ty.is_some() {
+                            return Err(ExpressionError::WrongArgumentCount(fun));
+                        }
+                        match *arg_ty {
+                            Ti::Scalar(Sc {
+                                kind: Sk::Sint | Sk::Uint,
+                                ..
+                            })
+                            | Ti::Vector {
+                                scalar:
+                                    Sc {
+                                        kind: Sk::Sint | Sk::Uint,
+                                        ..
+                                    },
+                                ..
+                            } => {}
+                            _ => return Err(ExpressionError::InvalidArgumentType(fun, 0, arg)),
+                        }
+                    }
+                    Mf::InsertBits => {
+                        let (arg1_ty, arg2_ty, arg3_ty) = match (arg1_ty, arg2_ty, arg3_ty) {
+                            (Some(ty1), Some(ty2), Some(ty3)) => (ty1, ty2, ty3),
+                            _ => return Err(ExpressionError::WrongArgumentCount(fun)),
+                        };
+                        match *arg_ty {
+                            Ti::Scalar(Sc {
+                                kind: Sk::Sint | Sk::Uint,
+                                ..
+                            })
+                            | Ti::Vector {
+                                scalar:
+                                    Sc {
+                                        kind: Sk::Sint | Sk::Uint,
+                                        ..
+                                    },
+                                ..
+                            } => {}
+                            _ => return Err(ExpressionError::InvalidArgumentType(fun, 0, arg)),
+                        }
+                        if arg1_ty != arg_ty {
+                            return Err(ExpressionError::InvalidArgumentType(
+                                fun,
+                                1,
+                                arg1.unwrap(),
+                            ));
+                        }
+                        match *arg2_ty {
+                            Ti::Scalar(Sc { kind: Sk::Uint, .. }) => {}
+                            _ => {
+                                return Err(ExpressionError::InvalidArgumentType(
+                                    fun,
+                                    2,
+                                    arg2.unwrap(),
+                                ))
+                            }
+                        }
+                        match *arg3_ty {
+                            Ti::Scalar(Sc { kind: Sk::Uint, .. }) => {}
+                            _ => {
+                                return Err(ExpressionError::InvalidArgumentType(
+                                    fun,
+                                    2,
+                                    arg3.unwrap(),
+                                ))
+                            }
+                        }
+                    }
+                    Mf::ExtractBits => {
+                        let (arg1_ty, arg2_ty) = match (arg1_ty, arg2_ty, arg3_ty) {
+                            (Some(ty1), Some(ty2), None) => (ty1, ty2),
+                            _ => return Err(ExpressionError::WrongArgumentCount(fun)),
+                        };
+                        match *arg_ty {
+                            Ti::Scalar(Sc {
+                                kind: Sk::Sint | Sk::Uint,
+                                ..
+                            })
+                            | Ti::Vector {
+                                scalar:
+                                    Sc {
+                                        kind: Sk::Sint | Sk::Uint,
+                                        ..
+                                    },
+                                ..
+                            } => {}
+                            _ => return Err(ExpressionError::InvalidArgumentType(fun, 0, arg)),
+                        }
+                        match *arg1_ty {
+                            Ti::Scalar(Sc { kind: Sk::Uint, .. }) => {}
+                            _ => {
+                                return Err(ExpressionError::InvalidArgumentType(
+                                    fun,
+                                    2,
+                                    arg1.unwrap(),
+                                ))
+                            }
+                        }
+                        match *arg2_ty {
+                            Ti::Scalar(Sc { kind: Sk::Uint, .. }) => {}
+                            _ => {
+                                return Err(ExpressionError::InvalidArgumentType(
+                                    fun,
+                                    2,
+                                    arg2.unwrap(),
+                                ))
+                            }
+                        }
+                    }
+                    Mf::Pack2x16unorm | Mf::Pack2x16snorm | Mf::Pack2x16float => {
+                        if arg1_ty.is_some() || arg2_ty.is_some() || arg3_ty.is_some() {
+                            return Err(ExpressionError::WrongArgumentCount(fun));
+                        }
+                        match *arg_ty {
+                            Ti::Vector {
+                                size: crate::VectorSize::Bi,
+                                scalar:
+                                    Sc {
+                                        kind: Sk::Float, ..
+                                    },
+                            } => {}
+                            _ => return Err(ExpressionError::InvalidArgumentType(fun, 0, arg)),
+                        }
+                    }
+                    Mf::Pack4x8snorm | Mf::Pack4x8unorm => {
+                        if arg1_ty.is_some() || arg2_ty.is_some() || arg3_ty.is_some() {
+                            return Err(ExpressionError::WrongArgumentCount(fun));
+                        }
+                        match *arg_ty {
+                            Ti::Vector {
+                                size: crate::VectorSize::Quad,
+                                scalar:
+                                    Sc {
+                                        kind: Sk::Float, ..
+                                    },
+                            } => {}
+                            _ => return Err(ExpressionError::InvalidArgumentType(fun, 0, arg)),
+                        }
+                    }
+                    Mf::Unpack2x16float
+                    | Mf::Unpack2x16snorm
+                    | Mf::Unpack2x16unorm
+                    | Mf::Unpack4x8snorm
+                    | Mf::Unpack4x8unorm => {
+                        if arg1_ty.is_some() || arg2_ty.is_some() || arg3_ty.is_some() {
+                            return Err(ExpressionError::WrongArgumentCount(fun));
+                        }
+                        match *arg_ty {
+                            Ti::Scalar(Sc { kind: Sk::Uint, .. }) => {}
+                            _ => return Err(ExpressionError::InvalidArgumentType(fun, 0, arg)),
+                        }
+                    }
+                }
+                ShaderStages::all()
+            }
+            E::As {
+                expr,
+                kind,
+                convert,
+            } => {
+                let mut base_scalar = match resolver[expr] {
+                    crate::TypeInner::Scalar(scalar) | crate::TypeInner::Vector { scalar, .. } => {
+                        scalar
+                    }
+                    crate::TypeInner::Matrix { scalar, .. } => scalar,
+                    _ => return Err(ExpressionError::InvalidCastArgument),
+                };
+                base_scalar.kind = kind;
+                if let Some(width) = convert {
+                    base_scalar.width = width;
+                }
+                if self.check_width(base_scalar).is_err() {
+                    return Err(ExpressionError::InvalidCastArgument);
+                }
+                ShaderStages::all()
+            }
+            E::CallResult(function) => mod_info.functions[function.index()].available_stages,
+            E::AtomicResult { ty, comparison } => {
+                let scalar_predicate = |ty: &crate::TypeInner| match ty {
+                    &crate::TypeInner::Scalar(
+                        scalar @ Sc {
+                            kind: crate::ScalarKind::Uint | crate::ScalarKind::Sint,
+                            ..
+                        },
+                    ) => self.check_width(scalar).is_ok(),
+                    _ => false,
+                };
+                let good = match &module.types[ty].inner {
+                    ty if !comparison => scalar_predicate(ty),
+                    &crate::TypeInner::Struct { ref members, .. } if comparison => {
+                        validate_atomic_compare_exchange_struct(
+                            &module.types,
+                            members,
+                            scalar_predicate,
+                        )
+                    }
+                    _ => false,
+                };
+                if !good {
+                    return Err(ExpressionError::InvalidAtomicResultType(ty));
+                }
+                ShaderStages::all()
+            }
+            E::WorkGroupUniformLoadResult { ty } => {
+                if self.types[ty.index()]
+                    .flags
+                    // Sized | Constructible is exactly the types currently supported by
+                    // WorkGroupUniformLoad
+                    .contains(TypeFlags::SIZED | TypeFlags::CONSTRUCTIBLE)
+                {
+                    ShaderStages::COMPUTE
+                } else {
+                    return Err(ExpressionError::InvalidWorkGroupUniformLoadResultType(ty));
+                }
+            }
+            E::ArrayLength(expr) => match resolver[expr] {
+                Ti::Pointer { base, .. } => {
+                    let base_ty = &resolver.types[base];
+                    if let Ti::Array {
+                        size: crate::ArraySize::Dynamic,
+                        ..
+                    } = base_ty.inner
+                    {
+                        ShaderStages::all()
+                    } else {
+                        return Err(ExpressionError::InvalidArrayType(expr));
+                    }
+                }
+                ref other => {
+                    log::error!("Array length of {:?}", other);
+                    return Err(ExpressionError::InvalidArrayType(expr));
+                }
+            },
+            E::RayQueryProceedResult => ShaderStages::all(),
+            E::RayQueryGetIntersection {
+                query,
+                committed: _,
+            } => match resolver[query] {
+                Ti::Pointer {
+                    base,
+                    space: crate::AddressSpace::Function,
+                } => match resolver.types[base].inner {
+                    Ti::RayQuery => ShaderStages::all(),
+                    ref other => {
+                        log::error!("Intersection result of a pointer to {:?}", other);
+                        return Err(ExpressionError::InvalidRayQueryType(query));
+                    }
+                },
+                ref other => {
+                    log::error!("Intersection result of {:?}", other);
+                    return Err(ExpressionError::InvalidRayQueryType(query));
+                }
+            },
+        };
+        Ok(stages)
+    }
+
+    fn global_var_ty(
+        module: &crate::Module,
+        function: &crate::Function,
+        expr: Handle<crate::Expression>,
+    ) -> Result<Handle<crate::Type>, ExpressionError> {
+        use crate::Expression as Ex;
+
+        match function.expressions[expr] {
+            Ex::GlobalVariable(var_handle) => Ok(module.global_variables[var_handle].ty),
+            Ex::FunctionArgument(i) => Ok(function.arguments[i as usize].ty),
+            Ex::Access { base, .. } | Ex::AccessIndex { base, .. } => {
+                match function.expressions[base] {
+                    Ex::GlobalVariable(var_handle) => {
+                        let array_ty = module.global_variables[var_handle].ty;
+
+                        match module.types[array_ty].inner {
+                            crate::TypeInner::BindingArray { base, .. } => Ok(base),
+                            _ => Err(ExpressionError::ExpectedBindingArrayType(array_ty)),
+                        }
+                    }
+                    _ => Err(ExpressionError::ExpectedGlobalVariable),
+                }
+            }
+            _ => Err(ExpressionError::ExpectedGlobalVariable),
+        }
+    }
+
+    pub fn validate_literal(&self, literal: crate::Literal) -> Result<(), LiteralError> {
+        self.check_width(literal.scalar())?;
+        check_literal_value(literal)?;
+
+        Ok(())
+    }
+}
+
+pub fn check_literal_value(literal: crate::Literal) -> Result<(), LiteralError> {
+    let is_nan = match literal {
+        crate::Literal::F64(v) => v.is_nan(),
+        crate::Literal::F32(v) => v.is_nan(),
+        _ => false,
+    };
+    if is_nan {
+        return Err(LiteralError::NaN);
+    }
+
+    let is_infinite = match literal {
+        crate::Literal::F64(v) => v.is_infinite(),
+        crate::Literal::F32(v) => v.is_infinite(),
+        _ => false,
+    };
+    if is_infinite {
+        return Err(LiteralError::Infinity);
+    }
+
+    Ok(())
+}
+
+#[cfg(all(test, feature = "validate"))]
+/// Validate a module containing the given expression, expecting an error.
+fn validate_with_expression(
+    expr: crate::Expression,
+    caps: super::Capabilities,
+) -> Result<ModuleInfo, crate::span::WithSpan<super::ValidationError>> {
+    use crate::span::Span;
+
+    let mut function = crate::Function::default();
+    function.expressions.append(expr, Span::default());
+    function.body.push(
+        crate::Statement::Emit(function.expressions.range_from(0)),
+        Span::default(),
+    );
+
+    let mut module = crate::Module::default();
+    module.functions.append(function, Span::default());
+
+    let mut validator = super::Validator::new(super::ValidationFlags::EXPRESSIONS, caps);
+
+    validator.validate(&module)
+}
+
+#[cfg(all(test, feature = "validate"))]
+/// Validate a module containing the given constant expression, expecting an error.
+fn validate_with_const_expression(
+    expr: crate::Expression,
+    caps: super::Capabilities,
+) -> Result<ModuleInfo, crate::span::WithSpan<super::ValidationError>> {
+    use crate::span::Span;
+
+    let mut module = crate::Module::default();
+    module.const_expressions.append(expr, Span::default());
+
+    let mut validator = super::Validator::new(super::ValidationFlags::CONSTANTS, caps);
+
+    validator.validate(&module)
+}
+
+/// Using F64 in a function's expression arena is forbidden.
+#[cfg(feature = "validate")]
+#[test]
+fn f64_runtime_literals() {
+    let result = validate_with_expression(
+        crate::Expression::Literal(crate::Literal::F64(0.57721_56649)),
+        super::Capabilities::default(),
+    );
+    let error = result.unwrap_err().into_inner();
+    assert!(matches!(
+        error,
+        crate::valid::ValidationError::Function {
+            source: super::FunctionError::Expression {
+                source: super::ExpressionError::Literal(super::LiteralError::Width(
+                    super::r#type::WidthError::MissingCapability {
+                        name: "f64",
+                        flag: "FLOAT64",
+                    }
+                ),),
+                ..
+            },
+            ..
+        }
+    ));
+
+    let result = validate_with_expression(
+        crate::Expression::Literal(crate::Literal::F64(0.57721_56649)),
+        super::Capabilities::default() | super::Capabilities::FLOAT64,
+    );
+    assert!(result.is_ok());
+}
+
+/// Using F64 in a module's constant expression arena is forbidden.
+#[cfg(feature = "validate")]
+#[test]
+fn f64_const_literals() {
+    let result = validate_with_const_expression(
+        crate::Expression::Literal(crate::Literal::F64(0.57721_56649)),
+        super::Capabilities::default(),
+    );
+    let error = result.unwrap_err().into_inner();
+    assert!(matches!(
+        error,
+        crate::valid::ValidationError::ConstExpression {
+            source: super::ConstExpressionError::Literal(super::LiteralError::Width(
+                super::r#type::WidthError::MissingCapability {
+                    name: "f64",
+                    flag: "FLOAT64",
+                }
+            )),
+            ..
+        }
+    ));
+
+    let result = validate_with_const_expression(
+        crate::Expression::Literal(crate::Literal::F64(0.57721_56649)),
+        super::Capabilities::default() | super::Capabilities::FLOAT64,
+    );
+    assert!(result.is_ok());
+}
+
+/// Using I64 in a function's expression arena is forbidden.
+#[cfg(feature = "validate")]
+#[test]
+fn i64_runtime_literals() {
+    let result = validate_with_expression(
+        crate::Expression::Literal(crate::Literal::I64(1729)),
+        // There is no capability that enables this.
+        super::Capabilities::all(),
+    );
+    let error = result.unwrap_err().into_inner();
+    assert!(matches!(
+        error,
+        crate::valid::ValidationError::Function {
+            source: super::FunctionError::Expression {
+                source: super::ExpressionError::Literal(super::LiteralError::Width(
+                    super::r#type::WidthError::Unsupported64Bit
+                ),),
+                ..
+            },
+            ..
+        }
+    ));
+}
+
+/// Using I64 in a module's constant expression arena is forbidden.
+#[cfg(feature = "validate")]
+#[test]
+fn i64_const_literals() {
+    let result = validate_with_const_expression(
+        crate::Expression::Literal(crate::Literal::I64(1729)),
+        // There is no capability that enables this.
+        super::Capabilities::all(),
+    );
+    let error = result.unwrap_err().into_inner();
+    assert!(matches!(
+        error,
+        crate::valid::ValidationError::ConstExpression {
+            source: super::ConstExpressionError::Literal(super::LiteralError::Width(
+                super::r#type::WidthError::Unsupported64Bit,
+            ),),
+            ..
+        }
+    ));
+}
diff --git a/third_party/rust/naga/src/valid/function.rs b/third_party/rust/naga/src/valid/function.rs
new file mode 100644
index 0000000000..f0ca22cbda
--- /dev/null
+++ b/third_party/rust/naga/src/valid/function.rs
@@ -0,0 +1,1056 @@
+use crate::arena::Handle;
+use crate::arena::{Arena, UniqueArena};
+
+use super::validate_atomic_compare_exchange_struct;
+
+use super::{
+    analyzer::{UniformityDisruptor, UniformityRequirements},
+    ExpressionError, FunctionInfo, ModuleInfo,
+};
+use crate::span::WithSpan;
+use crate::span::{AddSpan as _, MapErrWithSpan as _};
+
+use bit_set::BitSet;
+
+#[derive(Clone, Debug, thiserror::Error)]
+#[cfg_attr(test, derive(PartialEq))]
+pub enum CallError {
+    #[error("Argument {index} expression is invalid")]
+    Argument {
+        index: usize,
+        source: ExpressionError,
+    },
+    #[error("Result expression {0:?} has already been introduced earlier")]
+    ResultAlreadyInScope(Handle<crate::Expression>),
+    #[error("Result value is invalid")]
+    ResultValue(#[source] ExpressionError),
+    #[error("Requires {required} arguments, but {seen} are provided")]
+    ArgumentCount { required: usize, seen: usize },
+    #[error("Argument {index} value {seen_expression:?} doesn't match the type {required:?}")]
+    ArgumentType {
+        index: usize,
+        required: Handle<crate::Type>,
+        seen_expression: Handle<crate::Expression>,
+    },
+    #[error("The emitted expression doesn't match the call")]
+    ExpressionMismatch(Option<Handle<crate::Expression>>),
+}
+
+#[derive(Clone, Debug, thiserror::Error)]
+#[cfg_attr(test, derive(PartialEq))]
+pub enum AtomicError {
+    #[error("Pointer {0:?} to atomic is invalid.")]
+    InvalidPointer(Handle<crate::Expression>),
+    #[error("Operand {0:?} has invalid type.")]
+    InvalidOperand(Handle<crate::Expression>),
+    #[error("Result type for {0:?} doesn't match the statement")]
+    ResultTypeMismatch(Handle<crate::Expression>),
+}
+
+#[derive(Clone, Debug, thiserror::Error)]
+#[cfg_attr(test, derive(PartialEq))]
+pub enum LocalVariableError {
+    #[error("Local variable has a type {0:?} that can't be stored in a local variable.")]
+    InvalidType(Handle<crate::Type>),
+    #[error("Initializer doesn't match the variable type")]
+    InitializerType,
+    #[error("Initializer is not const")]
+    NonConstInitializer,
+}
+
+#[derive(Clone, Debug, thiserror::Error)]
+#[cfg_attr(test, derive(PartialEq))]
+pub enum FunctionError {
+    #[error("Expression {handle:?} is invalid")]
+    Expression {
+        handle: Handle<crate::Expression>,
+        source: ExpressionError,
+    },
+    #[error("Expression {0:?} can't be introduced - it's already in scope")]
+    ExpressionAlreadyInScope(Handle<crate::Expression>),
+    #[error("Local variable {handle:?} '{name}' is invalid")]
+    LocalVariable {
+        handle: Handle<crate::LocalVariable>,
+        name: String,
+        source: LocalVariableError,
+    },
+    #[error("Argument '{name}' at index {index} has a type that can't be passed into functions.")]
+    InvalidArgumentType { index: usize, name: String },
+    #[error("The function's given return type cannot be returned from functions")]
+    NonConstructibleReturnType,
+    #[error("Argument '{name}' at index {index} is a pointer of space {space:?}, which can't be passed into functions.")]
+    InvalidArgumentPointerSpace {
+        index: usize,
+        name: String,
+        space: crate::AddressSpace,
+    },
+    #[error("There are instructions after `return`/`break`/`continue`")]
+    InstructionsAfterReturn,
+    #[error("The `break` is used outside of a `loop` or `switch` context")]
+    BreakOutsideOfLoopOrSwitch,
+    #[error("The `continue` is used outside of a `loop` context")]
+    ContinueOutsideOfLoop,
+    #[error("The `return` is called within a `continuing` block")]
+    InvalidReturnSpot,
+    #[error("The `return` value {0:?} does not match the function return value")]
+    InvalidReturnType(Option<Handle<crate::Expression>>),
+    #[error("The `if` condition {0:?} is not a boolean scalar")]
+    InvalidIfType(Handle<crate::Expression>),
+    #[error("The `switch` value {0:?} is not an integer scalar")]
+    InvalidSwitchType(Handle<crate::Expression>),
+    #[error("Multiple `switch` cases for {0:?} are present")]
+    ConflictingSwitchCase(crate::SwitchValue),
+    #[error("The `switch` contains cases with conflicting types")]
+    ConflictingCaseType,
+    #[error("The `switch` is missing a `default` case")]
+    MissingDefaultCase,
+    #[error("Multiple `default` cases are present")]
+    MultipleDefaultCases,
+    #[error("The last `switch` case contains a `fallthrough`")]
+    LastCaseFallTrough,
+    #[error("The pointer {0:?} doesn't relate to a valid destination for a store")]
+    InvalidStorePointer(Handle<crate::Expression>),
+    #[error("The value {0:?} can not be stored")]
+    InvalidStoreValue(Handle<crate::Expression>),
+    #[error("The type of {value:?} doesn't match the type stored in {pointer:?}")]
+    InvalidStoreTypes {
+        pointer: Handle<crate::Expression>,
+        value: Handle<crate::Expression>,
+    },
+    #[error("Image store parameters are invalid")]
+    InvalidImageStore(#[source] ExpressionError),
+    #[error("Call to {function:?} is invalid")]
+    InvalidCall {
+        function: Handle<crate::Function>,
+        #[source]
+        error: CallError,
+    },
+    #[error("Atomic operation is invalid")]
+    InvalidAtomic(#[from] AtomicError),
+    #[error("Ray Query {0:?} is not a local variable")]
+    InvalidRayQueryExpression(Handle<crate::Expression>),
+    #[error("Acceleration structure {0:?} is not a matching expression")]
+    InvalidAccelerationStructure(Handle<crate::Expression>),
+    #[error("Ray descriptor {0:?} is not a matching expression")]
+    InvalidRayDescriptor(Handle<crate::Expression>),
+    #[error("Ray Query {0:?} does not have a matching type")]
+    InvalidRayQueryType(Handle<crate::Type>),
+    #[error(
+        "Required uniformity of control flow for {0:?} in {1:?} is not fulfilled because of {2:?}"
+    )]
+    NonUniformControlFlow(
+        UniformityRequirements,
+        Handle<crate::Expression>,
+        UniformityDisruptor,
+    ),
+    #[error("Functions that are not entry points cannot have `@location` or `@builtin` attributes on their arguments: \"{name}\" has attributes")]
+    PipelineInputRegularFunction { name: String },
+    #[error("Functions that are not entry points cannot have `@location` or `@builtin` attributes on their return value types")]
+    PipelineOutputRegularFunction,
+    #[error("Required uniformity for WorkGroupUniformLoad is not fulfilled because of {0:?}")]
+    // The actual load statement will be "pointed to" by the span
+    NonUniformWorkgroupUniformLoad(UniformityDisruptor),
+    // This is only possible with a misbehaving frontend
+    #[error("The expression {0:?} for a WorkGroupUniformLoad isn't a WorkgroupUniformLoadResult")]
+    WorkgroupUniformLoadExpressionMismatch(Handle<crate::Expression>),
+    #[error("The expression {0:?} is not valid as a WorkGroupUniformLoad argument. It should be a Pointer in Workgroup address space")]
+    WorkgroupUniformLoadInvalidPointer(Handle<crate::Expression>),
+}
+
+bitflags::bitflags! {
+    #[repr(transparent)]
+    #[derive(Clone, Copy)]
+    struct ControlFlowAbility: u8 {
+        /// The control can return out of this block.
+        const RETURN = 0x1;
+        /// The control can break.
+        const BREAK = 0x2;
+        /// The control can continue.
+        const CONTINUE = 0x4;
+    }
+}
+
+struct BlockInfo {
+    stages: super::ShaderStages,
+    finished: bool,
+}
+
+struct BlockContext<'a> {
+    abilities: ControlFlowAbility,
+    info: &'a FunctionInfo,
+    expressions: &'a Arena<crate::Expression>,
+    types: &'a UniqueArena<crate::Type>,
+    local_vars: &'a Arena<crate::LocalVariable>,
+    global_vars: &'a Arena<crate::GlobalVariable>,
+    functions: &'a Arena<crate::Function>,
+    special_types: &'a crate::SpecialTypes,
+    prev_infos: &'a [FunctionInfo],
+    return_type: Option<Handle<crate::Type>>,
+}
+
+impl<'a> BlockContext<'a> {
+    fn new(
+        fun: &'a crate::Function,
+        module: &'a crate::Module,
+        info: &'a FunctionInfo,
+        prev_infos: &'a [FunctionInfo],
+    ) -> Self {
+        Self {
+            abilities: ControlFlowAbility::RETURN,
+            info,
+            expressions: &fun.expressions,
+            types: &module.types,
+            local_vars: &fun.local_variables,
+            global_vars: &module.global_variables,
+            functions: &module.functions,
+            special_types: &module.special_types,
+            prev_infos,
+            return_type: fun.result.as_ref().map(|fr| fr.ty),
+        }
+    }
+
+    const fn with_abilities(&self, abilities: ControlFlowAbility) -> Self {
+        BlockContext { abilities, ..*self }
+    }
+
+    fn get_expression(&self, handle: Handle<crate::Expression>) -> &'a crate::Expression {
+        &self.expressions[handle]
+    }
+
+    fn resolve_type_impl(
+        &self,
+        handle: Handle<crate::Expression>,
+        valid_expressions: &BitSet,
+    ) -> Result<&crate::TypeInner, WithSpan<ExpressionError>> {
+        if handle.index() >= self.expressions.len() {
+            Err(ExpressionError::DoesntExist.with_span())
+        } else if !valid_expressions.contains(handle.index()) {
+            Err(ExpressionError::NotInScope.with_span_handle(handle, self.expressions))
+        } else {
+            Ok(self.info[handle].ty.inner_with(self.types))
+        }
+    }
+
+    fn resolve_type(
+        &self,
+        handle: Handle<crate::Expression>,
+        valid_expressions: &BitSet,
+    ) -> Result<&crate::TypeInner, WithSpan<FunctionError>> {
+        self.resolve_type_impl(handle, valid_expressions)
+            .map_err_inner(|source| FunctionError::Expression { handle, source }.with_span())
+    }
+
+    fn resolve_pointer_type(
+        &self,
+        handle: Handle<crate::Expression>,
+    ) -> Result<&crate::TypeInner, FunctionError> {
+        if handle.index() >= self.expressions.len() {
+            Err(FunctionError::Expression {
+                handle,
+                source: ExpressionError::DoesntExist,
+            })
+        } else {
+            Ok(self.info[handle].ty.inner_with(self.types))
+        }
+    }
+}
+
+impl super::Validator {
+    fn validate_call(
+        &mut self,
+        function: Handle<crate::Function>,
+        arguments: &[Handle<crate::Expression>],
+        result: Option<Handle<crate::Expression>>,
+        context: &BlockContext,
+    ) -> Result<super::ShaderStages, WithSpan<CallError>> {
+        let fun = &context.functions[function];
+        if fun.arguments.len() != arguments.len() {
+            return Err(CallError::ArgumentCount {
+                required: fun.arguments.len(),
+                seen: arguments.len(),
+            }
+            .with_span());
+        }
+        for (index, (arg, &expr)) in fun.arguments.iter().zip(arguments).enumerate() {
+            let ty = context
+                .resolve_type_impl(expr, &self.valid_expression_set)
+                .map_err_inner(|source| {
+                    CallError::Argument { index, source }
+                        .with_span_handle(expr, context.expressions)
+                })?;
+            let arg_inner = &context.types[arg.ty].inner;
+            if !ty.equivalent(arg_inner, context.types) {
+                return Err(CallError::ArgumentType {
+                    index,
+                    required: arg.ty,
+                    seen_expression: expr,
+                }
+                .with_span_handle(expr, context.expressions));
+            }
+        }
+
+        if let Some(expr) = result {
+            if self.valid_expression_set.insert(expr.index()) {
+                self.valid_expression_list.push(expr);
+            } else {
+                return Err(CallError::ResultAlreadyInScope(expr)
+                    .with_span_handle(expr, context.expressions));
+            }
+            match context.expressions[expr] {
+                crate::Expression::CallResult(callee)
+                    if fun.result.is_some() && callee == function => {}
+                _ => {
+                    return Err(CallError::ExpressionMismatch(result)
+                        .with_span_handle(expr, context.expressions))
+                }
+            }
+        } else if fun.result.is_some() {
+            return Err(CallError::ExpressionMismatch(result).with_span());
+        }
+
+        let callee_info = &context.prev_infos[function.index()];
+        Ok(callee_info.available_stages)
+    }
+
+    fn emit_expression(
+        &mut self,
+        handle: Handle<crate::Expression>,
+        context: &BlockContext,
+    ) -> Result<(), WithSpan<FunctionError>> {
+        if self.valid_expression_set.insert(handle.index()) {
+            self.valid_expression_list.push(handle);
+            Ok(())
+        } else {
+            Err(FunctionError::ExpressionAlreadyInScope(handle)
+                .with_span_handle(handle, context.expressions))
+        }
+    }
+
+    fn validate_atomic(
+        &mut self,
+        pointer: Handle<crate::Expression>,
+        fun: &crate::AtomicFunction,
+        value: Handle<crate::Expression>,
+        result: Handle<crate::Expression>,
+        context: &BlockContext,
+    ) -> Result<(), WithSpan<FunctionError>> {
+        let pointer_inner = context.resolve_type(pointer, &self.valid_expression_set)?;
+        let ptr_scalar = match *pointer_inner {
+            crate::TypeInner::Pointer { base, .. } => match context.types[base].inner {
+                crate::TypeInner::Atomic(scalar) => scalar,
+                ref other => {
+                    log::error!("Atomic pointer to type {:?}", other);
+                    return Err(AtomicError::InvalidPointer(pointer)
+                        .with_span_handle(pointer, context.expressions)
+                        .into_other());
+                }
+            },
+            ref other => {
+                log::error!("Atomic on type {:?}", other);
+                return Err(AtomicError::InvalidPointer(pointer)
+                    .with_span_handle(pointer, context.expressions)
+                    .into_other());
+            }
+        };
+
+        let value_inner = context.resolve_type(value, &self.valid_expression_set)?;
+        match *value_inner {
+            crate::TypeInner::Scalar(scalar) if scalar == ptr_scalar => {}
+            ref other => {
+                log::error!("Atomic operand type {:?}", other);
+                return Err(AtomicError::InvalidOperand(value)
+                    .with_span_handle(value, context.expressions)
+                    .into_other());
+            }
+        }
+
+        if let crate::AtomicFunction::Exchange { compare: Some(cmp) } = *fun {
+            if context.resolve_type(cmp, &self.valid_expression_set)? != value_inner {
+                log::error!("Atomic exchange comparison has a different type from the value");
+                return Err(AtomicError::InvalidOperand(cmp)
+                    .with_span_handle(cmp, context.expressions)
+                    .into_other());
+            }
+        }
+
+        self.emit_expression(result, context)?;
+        match context.expressions[result] {
+            crate::Expression::AtomicResult { ty, comparison }
+                if {
+                    let scalar_predicate =
+                        |ty: &crate::TypeInner| *ty == crate::TypeInner::Scalar(ptr_scalar);
+                    match &context.types[ty].inner {
+                        ty if !comparison => scalar_predicate(ty),
+                        &crate::TypeInner::Struct { ref members, .. } if comparison => {
+                            validate_atomic_compare_exchange_struct(
+                                context.types,
+                                members,
+                                scalar_predicate,
+                            )
+                        }
+                        _ => false,
+                    }
+                } => {}
+            _ => {
+                return Err(AtomicError::ResultTypeMismatch(result)
+                    .with_span_handle(result, context.expressions)
+                    .into_other())
+            }
+        }
+        Ok(())
+    }
+
+    fn validate_block_impl(
+        &mut self,
+        statements: &crate::Block,
+        context: &BlockContext,
+    ) -> Result<BlockInfo, WithSpan<FunctionError>> {
+        use crate::{AddressSpace, Statement as S, TypeInner as Ti};
+        let mut finished = false;
+        let mut stages = super::ShaderStages::all();
+        for (statement, &span) in statements.span_iter() {
+            if finished {
+                return Err(FunctionError::InstructionsAfterReturn
+                    .with_span_static(span, "instructions after return"));
+            }
+            match *statement {
+                S::Emit(ref range) => {
+                    for handle in range.clone() {
+                        self.emit_expression(handle, context)?;
+                    }
+                }
+                S::Block(ref block) => {
+                    let info = self.validate_block(block, context)?;
+                    stages &= info.stages;
+                    finished = info.finished;
+                }
+                S::If {
+                    condition,
+                    ref accept,
+                    ref reject,
+                } => {
+                    match *context.resolve_type(condition, &self.valid_expression_set)? {
+                        Ti::Scalar(crate::Scalar {
+                            kind: crate::ScalarKind::Bool,
+                            width: _,
+                        }) => {}
+                        _ => {
+                            return Err(FunctionError::InvalidIfType(condition)
+                                .with_span_handle(condition, context.expressions))
+                        }
+                    }
+                    stages &= self.validate_block(accept, context)?.stages;
+                    stages &= self.validate_block(reject, context)?.stages;
+                }
+                S::Switch {
+                    selector,
+                    ref cases,
+                } => {
+                    let uint = match context
+                        .resolve_type(selector, &self.valid_expression_set)?
+                        .scalar_kind()
+                    {
+                        Some(crate::ScalarKind::Uint) => true,
+                        Some(crate::ScalarKind::Sint) => false,
+                        _ => {
+                            return Err(FunctionError::InvalidSwitchType(selector)
+                                .with_span_handle(selector, context.expressions))
+                        }
+                    };
+                    self.switch_values.clear();
+                    for case in cases {
+                        match case.value {
+                            crate::SwitchValue::I32(_) if !uint => {}
+                            crate::SwitchValue::U32(_) if uint => {}
+                            crate::SwitchValue::Default => {}
+                            _ => {
+                                return Err(FunctionError::ConflictingCaseType.with_span_static(
+                                    case.body
+                                        .span_iter()
+                                        .next()
+                                        .map_or(Default::default(), |(_, s)| *s),
+                                    "conflicting switch arm here",
+                                ));
+                            }
+                        };
+                        if !self.switch_values.insert(case.value) {
+                            return Err(match case.value {
+                                crate::SwitchValue::Default => FunctionError::MultipleDefaultCases
+                                    .with_span_static(
+                                        case.body
+                                            .span_iter()
+                                            .next()
+                                            .map_or(Default::default(), |(_, s)| *s),
+                                        "duplicated switch arm here",
+                                    ),
+                                _ => FunctionError::ConflictingSwitchCase(case.value)
+                                    .with_span_static(
+                                        case.body
+                                            .span_iter()
+                                            .next()
+                                            .map_or(Default::default(), |(_, s)| *s),
+                                        "conflicting switch arm here",
+                                    ),
+                            });
+                        }
+                    }
+                    if !self.switch_values.contains(&crate::SwitchValue::Default) {
+                        return Err(FunctionError::MissingDefaultCase
+                            .with_span_static(span, "missing default case"));
+                    }
+                    if let Some(case) = cases.last() {
+                        if case.fall_through {
+                            return Err(FunctionError::LastCaseFallTrough.with_span_static(
+                                case.body
+                                    .span_iter()
+                                    .next()
+                                    .map_or(Default::default(), |(_, s)| *s),
+                                "bad switch arm here",
+                            ));
+                        }
+                    }
+                    let pass_through_abilities = context.abilities
+                        & (ControlFlowAbility::RETURN | ControlFlowAbility::CONTINUE);
+                    let sub_context =
+                        context.with_abilities(pass_through_abilities | ControlFlowAbility::BREAK);
+                    for case in cases {
+                        stages &= self.validate_block(&case.body, &sub_context)?.stages;
+                    }
+                }
+                S::Loop {
+                    ref body,
+                    ref continuing,
+                    break_if,
+                } => {
+                    // special handling for block scoping is needed here,
+                    // because the continuing{} block inherits the scope
+                    let base_expression_count = self.valid_expression_list.len();
+                    let pass_through_abilities = context.abilities & ControlFlowAbility::RETURN;
+                    stages &= self
+                        .validate_block_impl(
+                            body,
+                            &context.with_abilities(
+                                pass_through_abilities
+                                    | ControlFlowAbility::BREAK
+                                    | ControlFlowAbility::CONTINUE,
+                            ),
+                        )?
+                        .stages;
+                    stages &= self
+                        .validate_block_impl(
+                            continuing,
+                            &context.with_abilities(ControlFlowAbility::empty()),
+                        )?
+                        .stages;
+
+                    if let Some(condition) = break_if {
+                        match *context.resolve_type(condition, &self.valid_expression_set)? {
+                            Ti::Scalar(crate::Scalar {
+                                kind: crate::ScalarKind::Bool,
+                                width: _,
+                            }) => {}
+                            _ => {
+                                return Err(FunctionError::InvalidIfType(condition)
+                                    .with_span_handle(condition, context.expressions))
+                            }
+                        }
+                    }
+
+                    for handle in self.valid_expression_list.drain(base_expression_count..) {
+                        self.valid_expression_set.remove(handle.index());
+                    }
+                }
+                S::Break => {
+                    if !context.abilities.contains(ControlFlowAbility::BREAK) {
+                        return Err(FunctionError::BreakOutsideOfLoopOrSwitch
+                            .with_span_static(span, "invalid break"));
+                    }
+                    finished = true;
+                }
+                S::Continue => {
+                    if !context.abilities.contains(ControlFlowAbility::CONTINUE) {
+                        return Err(FunctionError::ContinueOutsideOfLoop
+                            .with_span_static(span, "invalid continue"));
+                    }
+                    finished = true;
+                }
+                S::Return { value } => {
+                    if !context.abilities.contains(ControlFlowAbility::RETURN) {
+                        return Err(FunctionError::InvalidReturnSpot
+                            .with_span_static(span, "invalid return"));
+                    }
+                    let value_ty = value
+                        .map(|expr| context.resolve_type(expr, &self.valid_expression_set))
+                        .transpose()?;
+                    let expected_ty = context.return_type.map(|ty| &context.types[ty].inner);
+                    // We can't return pointers, but it seems best not to embed that
+                    // assumption here, so use `TypeInner::equivalent` for comparison.
+                    let okay = match (value_ty, expected_ty) {
+                        (None, None) => true,
+                        (Some(value_inner), Some(expected_inner)) => {
+                            value_inner.equivalent(expected_inner, context.types)
+                        }
+                        (_, _) => false,
+                    };
+
+                    if !okay {
+                        log::error!(
+                            "Returning {:?} where {:?} is expected",
+                            value_ty,
+                            expected_ty
+                        );
+                        if let Some(handle) = value {
+                            return Err(FunctionError::InvalidReturnType(value)
+                                .with_span_handle(handle, context.expressions));
+                        } else {
+                            return Err(FunctionError::InvalidReturnType(value)
+                                .with_span_static(span, "invalid return"));
+                        }
+                    }
+                    finished = true;
+                }
+                S::Kill => {
+                    stages &= super::ShaderStages::FRAGMENT;
+                    finished = true;
+                }
+                S::Barrier(_) => {
+                    stages &= super::ShaderStages::COMPUTE;
+                }
+                S::Store { pointer, value } => {
+                    let mut current = pointer;
+                    loop {
+                        let _ = context
+                            .resolve_pointer_type(current)
+                            .map_err(|e| e.with_span())?;
+                        match context.expressions[current] {
+                            crate::Expression::Access { base, .. }
+                            | crate::Expression::AccessIndex { base, .. } => current = base,
+                            crate::Expression::LocalVariable(_)
+                            | crate::Expression::GlobalVariable(_)
+                            | crate::Expression::FunctionArgument(_) => break,
+                            _ => {
+                                return Err(FunctionError::InvalidStorePointer(current)
+                                    .with_span_handle(pointer, context.expressions))
+                            }
+                        }
+                    }
+
+                    let value_ty = context.resolve_type(value, &self.valid_expression_set)?;
+                    match *value_ty {
+                        Ti::Image { .. } | Ti::Sampler { .. } => {
+                            return Err(FunctionError::InvalidStoreValue(value)
+                                .with_span_handle(value, context.expressions));
+                        }
+                        _ => {}
+                    }
+
+                    let pointer_ty = context
+                        .resolve_pointer_type(pointer)
+                        .map_err(|e| e.with_span())?;
+
+                    let good = match *pointer_ty {
+                        Ti::Pointer { base, space: _ } => match context.types[base].inner {
+                            Ti::Atomic(scalar) => *value_ty == Ti::Scalar(scalar),
+                            ref other => value_ty == other,
+                        },
+                        Ti::ValuePointer {
+                            size: Some(size),
+                            scalar,
+                            space: _,
+                        } => *value_ty == Ti::Vector { size, scalar },
+                        Ti::ValuePointer {
+                            size: None,
+                            scalar,
+                            space: _,
+                        } => *value_ty == Ti::Scalar(scalar),
+                        _ => false,
+                    };
+                    if !good {
+                        return Err(FunctionError::InvalidStoreTypes { pointer, value }
+                            .with_span()
+                            .with_handle(pointer, context.expressions)
+                            .with_handle(value, context.expressions));
+                    }
+
+                    if let Some(space) = pointer_ty.pointer_space() {
+                        if !space.access().contains(crate::StorageAccess::STORE) {
+                            return Err(FunctionError::InvalidStorePointer(pointer)
+                                .with_span_static(
+                                    context.expressions.get_span(pointer),
+                                    "writing to this location is not permitted",
+                                ));
+                        }
+                    }
+                }
+                S::ImageStore {
+                    image,
+                    coordinate,
+                    array_index,
+                    value,
+                } => {
+                    //Note: this code uses a lot of `FunctionError::InvalidImageStore`,
+                    // and could probably be refactored.
+                    let var = match *context.get_expression(image) {
+                        crate::Expression::GlobalVariable(var_handle) => {
+                            &context.global_vars[var_handle]
+                        }
+                        // We're looking at a binding index situation, so punch through the index and look at the global behind it.
+                        crate::Expression::Access { base, .. }
+                        | crate::Expression::AccessIndex { base, .. } => {
+                            match *context.get_expression(base) {
+                                crate::Expression::GlobalVariable(var_handle) => {
+                                    &context.global_vars[var_handle]
+                                }
+                                _ => {
+                                    return Err(FunctionError::InvalidImageStore(
+                                        ExpressionError::ExpectedGlobalVariable,
+                                    )
+                                    .with_span_handle(image, context.expressions))
+                                }
+                            }
+                        }
+                        _ => {
+                            return Err(FunctionError::InvalidImageStore(
+                                ExpressionError::ExpectedGlobalVariable,
+                            )
+                            .with_span_handle(image, context.expressions))
+                        }
+                    };
+
+                    // Punch through a binding array to get the underlying type
+                    let global_ty = match context.types[var.ty].inner {
+                        Ti::BindingArray { base, .. } => &context.types[base].inner,
+                        ref inner => inner,
+                    };
+
+                    let value_ty = match *global_ty {
+                        Ti::Image {
+                            class,
+                            arrayed,
+                            dim,
+                        } => {
+                            match context
+                                .resolve_type(coordinate, &self.valid_expression_set)?
+                                .image_storage_coordinates()
+                            {
+                                Some(coord_dim) if coord_dim == dim => {}
+                                _ => {
+                                    return Err(FunctionError::InvalidImageStore(
+                                        ExpressionError::InvalidImageCoordinateType(
+                                            dim, coordinate,
+                                        ),
+                                    )
+                                    .with_span_handle(coordinate, context.expressions));
+                                }
+                            };
+                            if arrayed != array_index.is_some() {
+                                return Err(FunctionError::InvalidImageStore(
+                                    ExpressionError::InvalidImageArrayIndex,
+                                )
+                                .with_span_handle(coordinate, context.expressions));
+                            }
+                            if let Some(expr) = array_index {
+                                match *context.resolve_type(expr, &self.valid_expression_set)? {
+                                    Ti::Scalar(crate::Scalar {
+                                        kind: crate::ScalarKind::Sint | crate::ScalarKind::Uint,
+                                        width: _,
+                                    }) => {}
+                                    _ => {
+                                        return Err(FunctionError::InvalidImageStore(
+                                            ExpressionError::InvalidImageArrayIndexType(expr),
+                                        )
+                                        .with_span_handle(expr, context.expressions));
+                                    }
+                                }
+                            }
+                            match class {
+                                crate::ImageClass::Storage { format, .. } => {
+                                    crate::TypeInner::Vector {
+                                        size: crate::VectorSize::Quad,
+                                        scalar: crate::Scalar {
+                                            kind: format.into(),
+                                            width: 4,
+                                        },
+                                    }
+                                }
+                                _ => {
+                                    return Err(FunctionError::InvalidImageStore(
+                                        ExpressionError::InvalidImageClass(class),
+                                    )
+                                    .with_span_handle(image, context.expressions));
+                                }
+                            }
+                        }
+                        _ => {
+                            return Err(FunctionError::InvalidImageStore(
+                                ExpressionError::ExpectedImageType(var.ty),
+                            )
+                            .with_span()
+                            .with_handle(var.ty, context.types)
+                            .with_handle(image, context.expressions))
+                        }
+                    };
+
+                    if *context.resolve_type(value, &self.valid_expression_set)? != value_ty {
+                        return Err(FunctionError::InvalidStoreValue(value)
+                            .with_span_handle(value, context.expressions));
+                    }
+                }
+                S::Call {
+                    function,
+                    ref arguments,
+                    result,
+                } => match self.validate_call(function, arguments, result, context) {
+                    Ok(callee_stages) => stages &= callee_stages,
+                    Err(error) => {
+                        return Err(error.and_then(|error| {
+                            FunctionError::InvalidCall { function, error }
+                                .with_span_static(span, "invalid function call")
+                        }))
+                    }
+                },
+                S::Atomic {
+                    pointer,
+                    ref fun,
+                    value,
+                    result,
+                } => {
+                    self.validate_atomic(pointer, fun, value, result, context)?;
+                }
+                S::WorkGroupUniformLoad { pointer, result } => {
+                    stages &= super::ShaderStages::COMPUTE;
+                    let pointer_inner =
+                        context.resolve_type(pointer, &self.valid_expression_set)?;
+                    match *pointer_inner {
+                        Ti::Pointer {
+                            space: AddressSpace::WorkGroup,
+                            ..
+                        } => {}
+                        Ti::ValuePointer {
+                            space: AddressSpace::WorkGroup,
+                            ..
+                        } => {}
+                        _ => {
+                            return Err(FunctionError::WorkgroupUniformLoadInvalidPointer(pointer)
+                                .with_span_static(span, "WorkGroupUniformLoad"))
+                        }
+                    }
+                    self.emit_expression(result, context)?;
+                    let ty = match &context.expressions[result] {
+                        &crate::Expression::WorkGroupUniformLoadResult { ty } => ty,
+                        _ => {
+                            return Err(FunctionError::WorkgroupUniformLoadExpressionMismatch(
+                                result,
+                            )
+                            .with_span_static(span, "WorkGroupUniformLoad"));
+                        }
+                    };
+                    let expected_pointer_inner = Ti::Pointer {
+                        base: ty,
+                        space: AddressSpace::WorkGroup,
+                    };
+                    if !expected_pointer_inner.equivalent(pointer_inner, context.types) {
+                        return Err(FunctionError::WorkgroupUniformLoadInvalidPointer(pointer)
+                            .with_span_static(span, "WorkGroupUniformLoad"));
+                    }
+                }
+                S::RayQuery { query, ref fun } => {
+                    let query_var = match *context.get_expression(query) {
+                        crate::Expression::LocalVariable(var) => &context.local_vars[var],
+                        ref other => {
+                            log::error!("Unexpected ray query expression {other:?}");
+                            return Err(FunctionError::InvalidRayQueryExpression(query)
+                                .with_span_static(span, "invalid query expression"));
+                        }
+                    };
+                    match context.types[query_var.ty].inner {
+                        Ti::RayQuery => {}
+                        ref other => {
+                            log::error!("Unexpected ray query type {other:?}");
+                            return Err(FunctionError::InvalidRayQueryType(query_var.ty)
+                                .with_span_static(span, "invalid query type"));
+                        }
+                    }
+                    match *fun {
+                        crate::RayQueryFunction::Initialize {
+                            acceleration_structure,
+                            descriptor,
+                        } => {
+                            match *context
+                                .resolve_type(acceleration_structure, &self.valid_expression_set)?
+                            {
+                                Ti::AccelerationStructure => {}
+                                _ => {
+                                    return Err(FunctionError::InvalidAccelerationStructure(
+                                        acceleration_structure,
+                                    )
+                                    .with_span_static(span, "invalid acceleration structure"))
+                                }
+                            }
+                            let desc_ty_given =
+                                context.resolve_type(descriptor, &self.valid_expression_set)?;
+                            let desc_ty_expected = context
+                                .special_types
+                                .ray_desc
+                                .map(|handle| &context.types[handle].inner);
+                            if Some(desc_ty_given) != desc_ty_expected {
+                                return Err(FunctionError::InvalidRayDescriptor(descriptor)
+                                    .with_span_static(span, "invalid ray descriptor"));
+                            }
+                        }
+                        crate::RayQueryFunction::Proceed { result } => {
+                            self.emit_expression(result, context)?;
+                        }
+                        crate::RayQueryFunction::Terminate => {}
+                    }
+                }
+            }
+        }
+        Ok(BlockInfo { stages, finished })
+    }
+
+    fn validate_block(
+        &mut self,
+        statements: &crate::Block,
+        context: &BlockContext,
+    ) -> Result<BlockInfo, WithSpan<FunctionError>> {
+        let base_expression_count = self.valid_expression_list.len();
+        let info = self.validate_block_impl(statements, context)?;
+        for handle in self.valid_expression_list.drain(base_expression_count..) {
+            self.valid_expression_set.remove(handle.index());
+        }
+        Ok(info)
+    }
+
+    fn validate_local_var(
+        &self,
+        var: &crate::LocalVariable,
+        gctx: crate::proc::GlobalCtx,
+        fun_info: &FunctionInfo,
+        expression_constness: &crate::proc::ExpressionConstnessTracker,
+    ) -> Result<(), LocalVariableError> {
+        log::debug!("var {:?}", var);
+        let type_info = self
+            .types
+            .get(var.ty.index())
+            .ok_or(LocalVariableError::InvalidType(var.ty))?;
+        if !type_info.flags.contains(super::TypeFlags::CONSTRUCTIBLE) {
+            return Err(LocalVariableError::InvalidType(var.ty));
+        }
+
+        if let Some(init) = var.init {
+            let decl_ty = &gctx.types[var.ty].inner;
+            let init_ty = fun_info[init].ty.inner_with(gctx.types);
+            if !decl_ty.equivalent(init_ty, gctx.types) {
+                return Err(LocalVariableError::InitializerType);
+            }
+
+            if !expression_constness.is_const(init) {
+                return Err(LocalVariableError::NonConstInitializer);
+            }
+        }
+
+        Ok(())
+    }
+
+    pub(super) fn validate_function(
+        &mut self,
+        fun: &crate::Function,
+        module: &crate::Module,
+        mod_info: &ModuleInfo,
+        entry_point: bool,
+    ) -> Result<FunctionInfo, WithSpan<FunctionError>> {
+        let mut info = mod_info.process_function(fun, module, self.flags, self.capabilities)?;
+
+        let expression_constness =
+            crate::proc::ExpressionConstnessTracker::from_arena(&fun.expressions);
+
+        for (var_handle, var) in fun.local_variables.iter() {
+            self.validate_local_var(var, module.to_ctx(), &info, &expression_constness)
+                .map_err(|source| {
+                    FunctionError::LocalVariable {
+                        handle: var_handle,
+                        name: var.name.clone().unwrap_or_default(),
+                        source,
+                    }
+                    .with_span_handle(var.ty, &module.types)
+                    .with_handle(var_handle, &fun.local_variables)
+                })?;
+        }
+
+        for (index, argument) in fun.arguments.iter().enumerate() {
+            match module.types[argument.ty].inner.pointer_space() {
+                Some(crate::AddressSpace::Private | crate::AddressSpace::Function) | None => {}
+                Some(other) => {
+                    return Err(FunctionError::InvalidArgumentPointerSpace {
+                        index,
+                        name: argument.name.clone().unwrap_or_default(),
+                        space: other,
+                    }
+                    .with_span_handle(argument.ty, &module.types))
+                }
+            }
+            // Check for the least informative error last.
+            if !self.types[argument.ty.index()]
+                .flags
+                .contains(super::TypeFlags::ARGUMENT)
+            {
+                return Err(FunctionError::InvalidArgumentType {
+                    index,
+                    name: argument.name.clone().unwrap_or_default(),
+                }
+                .with_span_handle(argument.ty, &module.types));
+            }
+
+            if !entry_point && argument.binding.is_some() {
+                return Err(FunctionError::PipelineInputRegularFunction {
+                    name: argument.name.clone().unwrap_or_default(),
+                }
+                .with_span_handle(argument.ty, &module.types));
+            }
+        }
+
+        if let Some(ref result) = fun.result {
+            if !self.types[result.ty.index()]
+                .flags
+                .contains(super::TypeFlags::CONSTRUCTIBLE)
+            {
+                return Err(FunctionError::NonConstructibleReturnType
+                    .with_span_handle(result.ty, &module.types));
+            }
+
+            if !entry_point && result.binding.is_some() {
+                return Err(FunctionError::PipelineOutputRegularFunction
+                    .with_span_handle(result.ty, &module.types));
+            }
+        }
+
+        self.valid_expression_set.clear();
+        self.valid_expression_list.clear();
+        for (handle, expr) in fun.expressions.iter() {
+            if expr.needs_pre_emit() {
+                self.valid_expression_set.insert(handle.index());
+            }
+            if self.flags.contains(super::ValidationFlags::EXPRESSIONS) {
+                match self.validate_expression(handle, expr, fun, module, &info, mod_info) {
+                    Ok(stages) => info.available_stages &= stages,
+                    Err(source) => {
+                        return Err(FunctionError::Expression { handle, source }
+                            .with_span_handle(handle, &fun.expressions))
+                    }
+                }
+            }
+        }
+
+        if self.flags.contains(super::ValidationFlags::BLOCKS) {
+            let stages = self
+                .validate_block(
+                    &fun.body,
+                    &BlockContext::new(fun, module, &info, &mod_info.functions),
+                )?
+                .stages;
+            info.available_stages &= stages;
+        }
+        Ok(info)
+    }
+}
diff --git a/third_party/rust/naga/src/valid/handles.rs b/third_party/rust/naga/src/valid/handles.rs
new file mode 100644
index 0000000000..e482f293bb
--- /dev/null
+++ b/third_party/rust/naga/src/valid/handles.rs
@@ -0,0 +1,699 @@
+//! Implementation of `Validator::validate_module_handles`.
+
+use crate::{
+    arena::{BadHandle, BadRangeError},
+    Handle,
+};
+
+use crate::{Arena, UniqueArena};
+
+use super::ValidationError;
+
+use std::{convert::TryInto, hash::Hash, num::NonZeroU32};
+
+impl super::Validator {
+    /// Validates that all handles within `module` are:
+    ///
+    /// * Valid, in the sense that they contain indices within each arena structure inside the
+    /// [`crate::Module`] type.
+    /// * No arena contents contain any items that have forward dependencies; that is, the value
+    ///     associated with a handle only may contain references to handles in the same arena that
+    ///     were constructed before it.
+    ///
+    /// By validating the above conditions, we free up subsequent logic to assume that handle
+    /// accesses are infallible.
+    ///
+    /// # Errors
+    ///
+    /// Errors returned by this method are intentionally sparse, for simplicity of implementation.
+    /// It is expected that only buggy frontends or fuzzers should ever emit IR that fails this
+    /// validation pass.
+    pub(super) fn validate_module_handles(module: &crate::Module) -> Result<(), ValidationError> {
+        let &crate::Module {
+            ref constants,
+            ref entry_points,
+            ref functions,
+            ref global_variables,
+            ref types,
+            ref special_types,
+            ref const_expressions,
+        } = module;
+
+        // NOTE: Types being first is important. All other forms of validation depend on this.
+        for (this_handle, ty) in types.iter() {
+            match ty.inner {
+                crate::TypeInner::Scalar { .. }
+                | crate::TypeInner::Vector { .. }
+                | crate::TypeInner::Matrix { .. }
+                | crate::TypeInner::ValuePointer { .. }
+                | crate::TypeInner::Atomic { .. }
+                | crate::TypeInner::Image { .. }
+                | crate::TypeInner::Sampler { .. }
+                | crate::TypeInner::AccelerationStructure
+                | crate::TypeInner::RayQuery => (),
+                crate::TypeInner::Pointer { base, space: _ } => {
+                    this_handle.check_dep(base)?;
+                }
+                crate::TypeInner::Array { base, .. }
+                | crate::TypeInner::BindingArray { base, .. } => {
+                    this_handle.check_dep(base)?;
+                }
+                crate::TypeInner::Struct {
+                    ref members,
+                    span: _,
+                } => {
+                    this_handle.check_dep_iter(members.iter().map(|m| m.ty))?;
+                }
+            }
+        }
+
+        for handle_and_expr in const_expressions.iter() {
+            Self::validate_const_expression_handles(handle_and_expr, constants, types)?;
+        }
+
+        let validate_type = |handle| Self::validate_type_handle(handle, types);
+        let validate_const_expr =
+            |handle| Self::validate_expression_handle(handle, const_expressions);
+
+        for (_handle, constant) in constants.iter() {
+            let &crate::Constant {
+                name: _,
+                r#override: _,
+                ty,
+                init,
+            } = constant;
+            validate_type(ty)?;
+            validate_const_expr(init)?;
+        }
+
+        for (_handle, global_variable) in global_variables.iter() {
+            let &crate::GlobalVariable {
+                name: _,
+                space: _,
+                binding: _,
+                ty,
+                init,
+            } = global_variable;
+            validate_type(ty)?;
+            if let Some(init_expr) = init {
+                validate_const_expr(init_expr)?;
+            }
+        }
+
+        let validate_function = |function_handle, function: &_| -> Result<_, InvalidHandleError> {
+            let &crate::Function {
+                name: _,
+                ref arguments,
+                ref result,
+                ref local_variables,
+                ref expressions,
+                ref named_expressions,
+                ref body,
+            } = function;
+
+            for arg in arguments.iter() {
+                let &crate::FunctionArgument {
+                    name: _,
+                    ty,
+                    binding: _,
+                } = arg;
+                validate_type(ty)?;
+            }
+
+            if let &Some(crate::FunctionResult { ty, binding: _ }) = result {
+                validate_type(ty)?;
+            }
+
+            for (_handle, local_variable) in local_variables.iter() {
+                let &crate::LocalVariable { name: _, ty, init } = local_variable;
+                validate_type(ty)?;
+                if let Some(init) = init {
+                    Self::validate_expression_handle(init, expressions)?;
+                }
+            }
+
+            for handle in named_expressions.keys().copied() {
+                Self::validate_expression_handle(handle, expressions)?;
+            }
+
+            for handle_and_expr in expressions.iter() {
+                Self::validate_expression_handles(
+                    handle_and_expr,
+                    constants,
+                    const_expressions,
+                    types,
+                    local_variables,
+                    global_variables,
+                    functions,
+                    function_handle,
+                )?;
+            }
+
+            Self::validate_block_handles(body, expressions, functions)?;
+
+            Ok(())
+        };
+
+        for entry_point in entry_points.iter() {
+            validate_function(None, &entry_point.function)?;
+        }
+
+        for (function_handle, function) in functions.iter() {
+            validate_function(Some(function_handle), function)?;
+        }
+
+        if let Some(ty) = special_types.ray_desc {
+            validate_type(ty)?;
+        }
+        if let Some(ty) = special_types.ray_intersection {
+            validate_type(ty)?;
+        }
+
+        Ok(())
+    }
+
+    fn validate_type_handle(
+        handle: Handle<crate::Type>,
+        types: &UniqueArena<crate::Type>,
+    ) -> Result<(), InvalidHandleError> {
+        handle.check_valid_for_uniq(types).map(|_| ())
+    }
+
+    fn validate_constant_handle(
+        handle: Handle<crate::Constant>,
+        constants: &Arena<crate::Constant>,
+    ) -> Result<(), InvalidHandleError> {
+        handle.check_valid_for(constants).map(|_| ())
+    }
+
+    fn validate_expression_handle(
+        handle: Handle<crate::Expression>,
+        expressions: &Arena<crate::Expression>,
+    ) -> Result<(), InvalidHandleError> {
+        handle.check_valid_for(expressions).map(|_| ())
+    }
+
+    fn validate_function_handle(
+        handle: Handle<crate::Function>,
+        functions: &Arena<crate::Function>,
+    ) -> Result<(), InvalidHandleError> {
+        handle.check_valid_for(functions).map(|_| ())
+    }
+
+    fn validate_const_expression_handles(
+        (handle, expression): (Handle<crate::Expression>, &crate::Expression),
+        constants: &Arena<crate::Constant>,
+        types: &UniqueArena<crate::Type>,
+    ) -> Result<(), InvalidHandleError> {
+        let validate_constant = |handle| Self::validate_constant_handle(handle, constants);
+        let validate_type = |handle| Self::validate_type_handle(handle, types);
+
+        match *expression {
+            crate::Expression::Literal(_) => {}
+            crate::Expression::Constant(constant) => {
+                validate_constant(constant)?;
+                handle.check_dep(constants[constant].init)?;
+            }
+            crate::Expression::ZeroValue(ty) => {
+                validate_type(ty)?;
+            }
+            crate::Expression::Compose { ty, ref components } => {
+                validate_type(ty)?;
+                handle.check_dep_iter(components.iter().copied())?;
+            }
+            _ => {}
+        }
+        Ok(())
+    }
+
+    #[allow(clippy::too_many_arguments)]
+    fn validate_expression_handles(
+        (handle, expression): (Handle<crate::Expression>, &crate::Expression),
+        constants: &Arena<crate::Constant>,
+        const_expressions: &Arena<crate::Expression>,
+        types: &UniqueArena<crate::Type>,
+        local_variables: &Arena<crate::LocalVariable>,
+        global_variables: &Arena<crate::GlobalVariable>,
+        functions: &Arena<crate::Function>,
+        // The handle of the current function or `None` if it's an entry point
+        current_function: Option<Handle<crate::Function>>,
+    ) -> Result<(), InvalidHandleError> {
+        let validate_constant = |handle| Self::validate_constant_handle(handle, constants);
+        let validate_const_expr =
+            |handle| Self::validate_expression_handle(handle, const_expressions);
+        let validate_type = |handle| Self::validate_type_handle(handle, types);
+
+        match *expression {
+            crate::Expression::Access { base, index } => {
+                handle.check_dep(base)?.check_dep(index)?;
+            }
+            crate::Expression::AccessIndex { base, .. } => {
+                handle.check_dep(base)?;
+            }
+            crate::Expression::Splat { value, .. } => {
+                handle.check_dep(value)?;
+            }
+            crate::Expression::Swizzle { vector, .. } => {
+                handle.check_dep(vector)?;
+            }
+            crate::Expression::Literal(_) => {}
+            crate::Expression::Constant(constant) => {
+                validate_constant(constant)?;
+            }
+            crate::Expression::ZeroValue(ty) => {
+                validate_type(ty)?;
+            }
+            crate::Expression::Compose { ty, ref components } => {
+                validate_type(ty)?;
+                handle.check_dep_iter(components.iter().copied())?;
+            }
+            crate::Expression::FunctionArgument(_arg_idx) => (),
+            crate::Expression::GlobalVariable(global_variable) => {
+                global_variable.check_valid_for(global_variables)?;
+            }
+            crate::Expression::LocalVariable(local_variable) => {
+                local_variable.check_valid_for(local_variables)?;
+            }
+            crate::Expression::Load { pointer } => {
+                handle.check_dep(pointer)?;
+            }
+            crate::Expression::ImageSample {
+                image,
+                sampler,
+                gather: _,
+                coordinate,
+                array_index,
+                offset,
+                level,
+                depth_ref,
+            } => {
+                if let Some(offset) = offset {
+                    validate_const_expr(offset)?;
+                }
+
+                handle
+                    .check_dep(image)?
+                    .check_dep(sampler)?
+                    .check_dep(coordinate)?
+                    .check_dep_opt(array_index)?;
+
+                match level {
+                    crate::SampleLevel::Auto | crate::SampleLevel::Zero => (),
+                    crate::SampleLevel::Exact(expr) => {
+                        handle.check_dep(expr)?;
+                    }
+                    crate::SampleLevel::Bias(expr) => {
+                        handle.check_dep(expr)?;
+                    }
+                    crate::SampleLevel::Gradient { x, y } => {
+                        handle.check_dep(x)?.check_dep(y)?;
+                    }
+                };
+
+                handle.check_dep_opt(depth_ref)?;
+            }
+            crate::Expression::ImageLoad {
+                image,
+                coordinate,
+                array_index,
+                sample,
+                level,
+            } => {
+                handle
+                    .check_dep(image)?
+                    .check_dep(coordinate)?
+                    .check_dep_opt(array_index)?
+                    .check_dep_opt(sample)?
+                    .check_dep_opt(level)?;
+            }
+            crate::Expression::ImageQuery { image, query } => {
+                handle.check_dep(image)?;
+                match query {
+                    crate::ImageQuery::Size { level } => {
+                        handle.check_dep_opt(level)?;
+                    }
+                    crate::ImageQuery::NumLevels
+                    | crate::ImageQuery::NumLayers
+                    | crate::ImageQuery::NumSamples => (),
+                };
+            }
+            crate::Expression::Unary {
+                op: _,
+                expr: operand,
+            } => {
+                handle.check_dep(operand)?;
+            }
+            crate::Expression::Binary { op: _, left, right } => {
+                handle.check_dep(left)?.check_dep(right)?;
+            }
+            crate::Expression::Select {
+                condition,
+                accept,
+                reject,
+            } => {
+                handle
+                    .check_dep(condition)?
+                    .check_dep(accept)?
+                    .check_dep(reject)?;
+            }
+            crate::Expression::Derivative { expr: argument, .. } => {
+                handle.check_dep(argument)?;
+            }
+            crate::Expression::Relational { fun: _, argument } => {
+                handle.check_dep(argument)?;
+            }
+            crate::Expression::Math {
+                fun: _,
+                arg,
+                arg1,
+                arg2,
+                arg3,
+            } => {
+                handle
+                    .check_dep(arg)?
+                    .check_dep_opt(arg1)?
+                    .check_dep_opt(arg2)?
+                    .check_dep_opt(arg3)?;
+            }
+            crate::Expression::As {
+                expr: input,
+                kind: _,
+                convert: _,
+            } => {
+                handle.check_dep(input)?;
+            }
+            crate::Expression::CallResult(function) => {
+                Self::validate_function_handle(function, functions)?;
+                if let Some(handle) = current_function {
+                    handle.check_dep(function)?;
+                }
+            }
+            crate::Expression::AtomicResult { .. }
+            | crate::Expression::RayQueryProceedResult
+            | crate::Expression::WorkGroupUniformLoadResult { .. } => (),
+            crate::Expression::ArrayLength(array) => {
+                handle.check_dep(array)?;
+            }
+            crate::Expression::RayQueryGetIntersection {
+                query,
+                committed: _,
+            } => {
+                handle.check_dep(query)?;
+            }
+        }
+        Ok(())
+    }
+
+    fn validate_block_handles(
+        block: &crate::Block,
+        expressions: &Arena<crate::Expression>,
+        functions: &Arena<crate::Function>,
+    ) -> Result<(), InvalidHandleError> {
+        let validate_block = |block| Self::validate_block_handles(block, expressions, functions);
+        let validate_expr = |handle| Self::validate_expression_handle(handle, expressions);
+        let validate_expr_opt = |handle_opt| {
+            if let Some(handle) = handle_opt {
+                validate_expr(handle)?;
+            }
+            Ok(())
+        };
+
+        block.iter().try_for_each(|stmt| match *stmt {
+            crate::Statement::Emit(ref expr_range) => {
+                expr_range.check_valid_for(expressions)?;
+                Ok(())
+            }
+            crate::Statement::Block(ref block) => {
+                validate_block(block)?;
+                Ok(())
+            }
+            crate::Statement::If {
+                condition,
+                ref accept,
+                ref reject,
+            } => {
+                validate_expr(condition)?;
+                validate_block(accept)?;
+                validate_block(reject)?;
+                Ok(())
+            }
+            crate::Statement::Switch {
+                selector,
+                ref cases,
+            } => {
+                validate_expr(selector)?;
+                for &crate::SwitchCase {
+                    value: _,
+                    ref body,
+                    fall_through: _,
+                } in cases
+                {
+                    validate_block(body)?;
+                }
+                Ok(())
+            }
+            crate::Statement::Loop {
+                ref body,
+                ref continuing,
+                break_if,
+            } => {
+                validate_block(body)?;
+                validate_block(continuing)?;
+                validate_expr_opt(break_if)?;
+                Ok(())
+            }
+            crate::Statement::Return { value } => validate_expr_opt(value),
+            crate::Statement::Store { pointer, value } => {
+                validate_expr(pointer)?;
+                validate_expr(value)?;
+                Ok(())
+            }
+            crate::Statement::ImageStore {
+                image,
+                coordinate,
+                array_index,
+                value,
+            } => {
+                validate_expr(image)?;
+                validate_expr(coordinate)?;
+                validate_expr_opt(array_index)?;
+                validate_expr(value)?;
+                Ok(())
+            }
+            crate::Statement::Atomic {
+                pointer,
+                fun,
+                value,
+                result,
+            } => {
+                validate_expr(pointer)?;
+                match fun {
+                    crate::AtomicFunction::Add
+                    | crate::AtomicFunction::Subtract
+                    | crate::AtomicFunction::And
+                    | crate::AtomicFunction::ExclusiveOr
+                    | crate::AtomicFunction::InclusiveOr
+                    | crate::AtomicFunction::Min
+                    | crate::AtomicFunction::Max => (),
+                    crate::AtomicFunction::Exchange { compare } => validate_expr_opt(compare)?,
+                };
+                validate_expr(value)?;
+                validate_expr(result)?;
+                Ok(())
+            }
+            crate::Statement::WorkGroupUniformLoad { pointer, result } => {
+                validate_expr(pointer)?;
+                validate_expr(result)?;
+                Ok(())
+            }
+            crate::Statement::Call {
+                function,
+                ref arguments,
+                result,
+            } => {
+                Self::validate_function_handle(function, functions)?;
+                for arg in arguments.iter().copied() {
+                    validate_expr(arg)?;
+                }
+                validate_expr_opt(result)?;
+                Ok(())
+            }
+            crate::Statement::RayQuery { query, ref fun } => {
+                validate_expr(query)?;
+                match *fun {
+                    crate::RayQueryFunction::Initialize {
+                        acceleration_structure,
+                        descriptor,
+                    } => {
+                        validate_expr(acceleration_structure)?;
+                        validate_expr(descriptor)?;
+                    }
+                    crate::RayQueryFunction::Proceed { result } => {
+                        validate_expr(result)?;
+                    }
+                    crate::RayQueryFunction::Terminate => {}
+                }
+                Ok(())
+            }
+            crate::Statement::Break
+            | crate::Statement::Continue
+            | crate::Statement::Kill
+            | crate::Statement::Barrier(_) => Ok(()),
+        })
+    }
+}
+
+impl From<BadHandle> for ValidationError {
+    fn from(source: BadHandle) -> Self {
+        Self::InvalidHandle(source.into())
+    }
+}
+
+impl From<FwdDepError> for ValidationError {
+    fn from(source: FwdDepError) -> Self {
+        Self::InvalidHandle(source.into())
+    }
+}
+
+impl From<BadRangeError> for ValidationError {
+    fn from(source: BadRangeError) -> Self {
+        Self::InvalidHandle(source.into())
+    }
+}
+
+#[derive(Clone, Debug, thiserror::Error)]
+pub enum InvalidHandleError {
+    #[error(transparent)]
+    BadHandle(#[from] BadHandle),
+    #[error(transparent)]
+    ForwardDependency(#[from] FwdDepError),
+    #[error(transparent)]
+    BadRange(#[from] BadRangeError),
+}
+
+#[derive(Clone, Debug, thiserror::Error)]
+#[error(
+    "{subject:?} of kind {subject_kind:?} depends on {depends_on:?} of kind {depends_on_kind}, \
+    which has not been processed yet"
+)]
+pub struct FwdDepError {
+    // This error is used for many `Handle` types, but there's no point in making this generic, so
+    // we just flatten them all to `Handle<()>` here.
+    subject: Handle<()>,
+    subject_kind: &'static str,
+    depends_on: Handle<()>,
+    depends_on_kind: &'static str,
+}
+
+impl<T> Handle<T> {
+    /// Check that `self` is valid within `arena` using [`Arena::check_contains_handle`].
+    pub(self) fn check_valid_for(self, arena: &Arena<T>) -> Result<(), InvalidHandleError> {
+        arena.check_contains_handle(self)?;
+        Ok(())
+    }
+
+    /// Check that `self` is valid within `arena` using [`UniqueArena::check_contains_handle`].
+    pub(self) fn check_valid_for_uniq(
+        self,
+        arena: &UniqueArena<T>,
+    ) -> Result<(), InvalidHandleError>
+    where
+        T: Eq + Hash,
+    {
+        arena.check_contains_handle(self)?;
+        Ok(())
+    }
+
+    /// Check that `depends_on` was constructed before `self` by comparing handle indices.
+    ///
+    /// If `self` is a valid handle (i.e., it has been validated using [`Self::check_valid_for`])
+    /// and this function returns [`Ok`], then it may be assumed that `depends_on` is also valid.
+    /// In [`naga`](crate)'s current arena-based implementation, this is useful for validating
+    /// recursive definitions of arena-based values in linear time.
+    ///
+    /// # Errors
+    ///
+    /// If `depends_on`'s handle is from the same [`Arena`] as `self'`s, but not constructed earlier
+    /// than `self`'s, this function returns an error.
+    pub(self) fn check_dep(self, depends_on: Self) -> Result<Self, FwdDepError> {
+        if depends_on < self {
+            Ok(self)
+        } else {
+            let erase_handle_type = |handle: Handle<_>| {
+                Handle::new(NonZeroU32::new((handle.index() + 1).try_into().unwrap()).unwrap())
+            };
+            Err(FwdDepError {
+                subject: erase_handle_type(self),
+                subject_kind: std::any::type_name::<T>(),
+                depends_on: erase_handle_type(depends_on),
+                depends_on_kind: std::any::type_name::<T>(),
+            })
+        }
+    }
+
+    /// Like [`Self::check_dep`], except for [`Option`]al handle values.
+    pub(self) fn check_dep_opt(self, depends_on: Option<Self>) -> Result<Self, FwdDepError> {
+        self.check_dep_iter(depends_on.into_iter())
+    }
+
+    /// Like [`Self::check_dep`], except for [`Iterator`]s over handle values.
+    pub(self) fn check_dep_iter(
+        self,
+        depends_on: impl Iterator<Item = Self>,
+    ) -> Result<Self, FwdDepError> {
+        for handle in depends_on {
+            self.check_dep(handle)?;
+        }
+        Ok(self)
+    }
+}
+
+impl<T> crate::arena::Range<T> {
+    pub(self) fn check_valid_for(&self, arena: &Arena<T>) -> Result<(), BadRangeError> {
+        arena.check_contains_range(self)
+    }
+}
+
+#[test]
+fn constant_deps() {
+    use crate::{Constant, Expression, Literal, Span, Type, TypeInner};
+
+    let nowhere = Span::default();
+
+    let mut types = UniqueArena::new();
+    let mut const_exprs = Arena::new();
+    let mut fun_exprs = Arena::new();
+    let mut constants = Arena::new();
+
+    let i32_handle = types.insert(
+        Type {
+            name: None,
+            inner: TypeInner::Scalar(crate::Scalar::I32),
+        },
+        nowhere,
+    );
+
+    // Construct a self-referential constant by misusing a handle to
+    // fun_exprs as a constant initializer.
+    let fun_expr = fun_exprs.append(Expression::Literal(Literal::I32(42)), nowhere);
+    let self_referential_const = constants.append(
+        Constant {
+            name: None,
+            r#override: crate::Override::None,
+            ty: i32_handle,
+            init: fun_expr,
+        },
+        nowhere,
+    );
+    let _self_referential_expr =
+        const_exprs.append(Expression::Constant(self_referential_const), nowhere);
+
+    for handle_and_expr in const_exprs.iter() {
+        assert!(super::Validator::validate_const_expression_handles(
+            handle_and_expr,
+            &constants,
+            &types,
+        )
+        .is_err());
+    }
+}
diff --git a/third_party/rust/naga/src/valid/interface.rs b/third_party/rust/naga/src/valid/interface.rs
new file mode 100644
index 0000000000..84c8b09ddb
--- /dev/null
+++ b/third_party/rust/naga/src/valid/interface.rs
@@ -0,0 +1,709 @@
+use super::{
+    analyzer::{FunctionInfo, GlobalUse},
+    Capabilities, Disalignment, FunctionError, ModuleInfo,
+};
+use crate::arena::{Handle, UniqueArena};
+
+use crate::span::{AddSpan as _, MapErrWithSpan as _, SpanProvider as _, WithSpan};
+use bit_set::BitSet;
+
+const MAX_WORKGROUP_SIZE: u32 = 0x4000;
+
+#[derive(Clone, Debug, thiserror::Error)]
+pub enum GlobalVariableError {
+    #[error("Usage isn't compatible with address space {0:?}")]
+    InvalidUsage(crate::AddressSpace),
+    #[error("Type isn't compatible with address space {0:?}")]
+    InvalidType(crate::AddressSpace),
+    #[error("Type flags {seen:?} do not meet the required {required:?}")]
+    MissingTypeFlags {
+        required: super::TypeFlags,
+        seen: super::TypeFlags,
+    },
+    #[error("Capability {0:?} is not supported")]
+    UnsupportedCapability(Capabilities),
+    #[error("Binding decoration is missing or not applicable")]
+    InvalidBinding,
+    #[error("Alignment requirements for address space {0:?} are not met by {1:?}")]
+    Alignment(
+        crate::AddressSpace,
+        Handle<crate::Type>,
+        #[source] Disalignment,
+    ),
+    #[error("Initializer doesn't match the variable type")]
+    InitializerType,
+    #[error("Initializer can't be used with address space {0:?}")]
+    InitializerNotAllowed(crate::AddressSpace),
+    #[error("Storage address space doesn't support write-only access")]
+    StorageAddressSpaceWriteOnlyNotSupported,
+}
+
+#[derive(Clone, Debug, thiserror::Error)]
+pub enum VaryingError {
+    #[error("The type {0:?} does not match the varying")]
+    InvalidType(Handle<crate::Type>),
+    #[error("The type {0:?} cannot be used for user-defined entry point inputs or outputs")]
+    NotIOShareableType(Handle<crate::Type>),
+    #[error("Interpolation is not valid")]
+    InvalidInterpolation,
+    #[error("Interpolation must be specified on vertex shader outputs and fragment shader inputs")]
+    MissingInterpolation,
+    #[error("Built-in {0:?} is not available at this stage")]
+    InvalidBuiltInStage(crate::BuiltIn),
+    #[error("Built-in type for {0:?} is invalid")]
+    InvalidBuiltInType(crate::BuiltIn),
+    #[error("Entry point arguments and return values must all have bindings")]
+    MissingBinding,
+    #[error("Struct member {0} is missing a binding")]
+    MemberMissingBinding(u32),
+    #[error("Multiple bindings at location {location} are present")]
+    BindingCollision { location: u32 },
+    #[error("Built-in {0:?} is present more than once")]
+    DuplicateBuiltIn(crate::BuiltIn),
+    #[error("Capability {0:?} is not supported")]
+    UnsupportedCapability(Capabilities),
+    #[error("The attribute {0:?} is only valid as an output for stage {1:?}")]
+    InvalidInputAttributeInStage(&'static str, crate::ShaderStage),
+    #[error("The attribute {0:?} is not valid for stage {1:?}")]
+    InvalidAttributeInStage(&'static str, crate::ShaderStage),
+    #[error(
+        "The location index {location} cannot be used together with the attribute {attribute:?}"
+    )]
+    InvalidLocationAttributeCombination {
+        location: u32,
+        attribute: &'static str,
+    },
+}
+
+#[derive(Clone, Debug, thiserror::Error)]
+pub enum EntryPointError {
+    #[error("Multiple conflicting entry points")]
+    Conflict,
+    #[error("Vertex shaders must return a `@builtin(position)` output value")]
+    MissingVertexOutputPosition,
+    #[error("Early depth test is not applicable")]
+    UnexpectedEarlyDepthTest,
+    #[error("Workgroup size is not applicable")]
+    UnexpectedWorkgroupSize,
+    #[error("Workgroup size is out of range")]
+    OutOfRangeWorkgroupSize,
+    #[error("Uses operations forbidden at this stage")]
+    ForbiddenStageOperations,
+    #[error("Global variable {0:?} is used incorrectly as {1:?}")]
+    InvalidGlobalUsage(Handle<crate::GlobalVariable>, GlobalUse),
+    #[error("More than 1 push constant variable is used")]
+    MoreThanOnePushConstantUsed,
+    #[error("Bindings for {0:?} conflict with other resource")]
+    BindingCollision(Handle<crate::GlobalVariable>),
+    #[error("Argument {0} varying error")]
+    Argument(u32, #[source] VaryingError),
+    #[error(transparent)]
+    Result(#[from] VaryingError),
+    #[error("Location {location} interpolation of an integer has to be flat")]
+    InvalidIntegerInterpolation { location: u32 },
+    #[error(transparent)]
+    Function(#[from] FunctionError),
+    #[error(
+        "Invalid locations {location_mask:?} are set while dual source blending. Only location 0 may be set."
+    )]
+    InvalidLocationsWhileDualSourceBlending { location_mask: BitSet },
+}
+
+fn storage_usage(access: crate::StorageAccess) -> GlobalUse {
+    let mut storage_usage = GlobalUse::QUERY;
+    if access.contains(crate::StorageAccess::LOAD) {
+        storage_usage |= GlobalUse::READ;
+    }
+    if access.contains(crate::StorageAccess::STORE) {
+        storage_usage |= GlobalUse::WRITE;
+    }
+    storage_usage
+}
+
+struct VaryingContext<'a> {
+    stage: crate::ShaderStage,
+    output: bool,
+    second_blend_source: bool,
+    types: &'a UniqueArena<crate::Type>,
+    type_info: &'a Vec<super::r#type::TypeInfo>,
+    location_mask: &'a mut BitSet,
+    built_ins: &'a mut crate::FastHashSet<crate::BuiltIn>,
+    capabilities: Capabilities,
+    flags: super::ValidationFlags,
+}
+
+impl VaryingContext<'_> {
+    fn validate_impl(
+        &mut self,
+        ty: Handle<crate::Type>,
+        binding: &crate::Binding,
+    ) -> Result<(), VaryingError> {
+        use crate::{BuiltIn as Bi, ShaderStage as St, TypeInner as Ti, VectorSize as Vs};
+
+        let ty_inner = &self.types[ty].inner;
+        match *binding {
+            crate::Binding::BuiltIn(built_in) => {
+                // Ignore the `invariant` field for the sake of duplicate checks,
+                // but use the original in error messages.
+                let canonical = if let crate::BuiltIn::Position { .. } = built_in {
+                    crate::BuiltIn::Position { invariant: false }
+                } else {
+                    built_in
+                };
+
+                if self.built_ins.contains(&canonical) {
+                    return Err(VaryingError::DuplicateBuiltIn(built_in));
+                }
+                self.built_ins.insert(canonical);
+
+                let required = match built_in {
+                    Bi::ClipDistance => Capabilities::CLIP_DISTANCE,
+                    Bi::CullDistance => Capabilities::CULL_DISTANCE,
+                    Bi::PrimitiveIndex => Capabilities::PRIMITIVE_INDEX,
+                    Bi::ViewIndex => Capabilities::MULTIVIEW,
+                    Bi::SampleIndex => Capabilities::MULTISAMPLED_SHADING,
+                    _ => Capabilities::empty(),
+                };
+                if !self.capabilities.contains(required) {
+                    return Err(VaryingError::UnsupportedCapability(required));
+                }
+
+                let (visible, type_good) = match built_in {
+                    Bi::BaseInstance | Bi::BaseVertex | Bi::InstanceIndex | Bi::VertexIndex => (
+                        self.stage == St::Vertex && !self.output,
+                        *ty_inner == Ti::Scalar(crate::Scalar::U32),
+                    ),
+                    Bi::ClipDistance | Bi::CullDistance => (
+                        self.stage == St::Vertex && self.output,
+                        match *ty_inner {
+                            Ti::Array { base, .. } => {
+                                self.types[base].inner == Ti::Scalar(crate::Scalar::F32)
+                            }
+                            _ => false,
+                        },
+                    ),
+                    Bi::PointSize => (
+                        self.stage == St::Vertex && self.output,
+                        *ty_inner == Ti::Scalar(crate::Scalar::F32),
+                    ),
+                    Bi::PointCoord => (
+                        self.stage == St::Fragment && !self.output,
+                        *ty_inner
+                            == Ti::Vector {
+                                size: Vs::Bi,
+                                scalar: crate::Scalar::F32,
+                            },
+                    ),
+                    Bi::Position { .. } => (
+                        match self.stage {
+                            St::Vertex => self.output,
+                            St::Fragment => !self.output,
+                            St::Compute => false,
+                        },
+                        *ty_inner
+                            == Ti::Vector {
+                                size: Vs::Quad,
+                                scalar: crate::Scalar::F32,
+                            },
+                    ),
+                    Bi::ViewIndex => (
+                        match self.stage {
+                            St::Vertex | St::Fragment => !self.output,
+                            St::Compute => false,
+                        },
+                        *ty_inner == Ti::Scalar(crate::Scalar::I32),
+                    ),
+                    Bi::FragDepth => (
+                        self.stage == St::Fragment && self.output,
+                        *ty_inner == Ti::Scalar(crate::Scalar::F32),
+                    ),
+                    Bi::FrontFacing => (
+                        self.stage == St::Fragment && !self.output,
+                        *ty_inner == Ti::Scalar(crate::Scalar::BOOL),
+                    ),
+                    Bi::PrimitiveIndex => (
+                        self.stage == St::Fragment && !self.output,
+                        *ty_inner == Ti::Scalar(crate::Scalar::U32),
+                    ),
+                    Bi::SampleIndex => (
+                        self.stage == St::Fragment && !self.output,
+                        *ty_inner == Ti::Scalar(crate::Scalar::U32),
+                    ),
+                    Bi::SampleMask => (
+                        self.stage == St::Fragment,
+                        *ty_inner == Ti::Scalar(crate::Scalar::U32),
+                    ),
+                    Bi::LocalInvocationIndex => (
+                        self.stage == St::Compute && !self.output,
+                        *ty_inner == Ti::Scalar(crate::Scalar::U32),
+                    ),
+                    Bi::GlobalInvocationId
+                    | Bi::LocalInvocationId
+                    | Bi::WorkGroupId
+                    | Bi::WorkGroupSize
+                    | Bi::NumWorkGroups => (
+                        self.stage == St::Compute && !self.output,
+                        *ty_inner
+                            == Ti::Vector {
+                                size: Vs::Tri,
+                                scalar: crate::Scalar::U32,
+                            },
+                    ),
+                };
+
+                if !visible {
+                    return Err(VaryingError::InvalidBuiltInStage(built_in));
+                }
+                if !type_good {
+                    log::warn!("Wrong builtin type: {:?}", ty_inner);
+                    return Err(VaryingError::InvalidBuiltInType(built_in));
+                }
+            }
+            crate::Binding::Location {
+                location,
+                interpolation,
+                sampling,
+                second_blend_source,
+            } => {
+                // Only IO-shareable types may be stored in locations.
+                if !self.type_info[ty.index()]
+                    .flags
+                    .contains(super::TypeFlags::IO_SHAREABLE)
+                {
+                    return Err(VaryingError::NotIOShareableType(ty));
+                }
+
+                if second_blend_source {
+                    if !self
+                        .capabilities
+                        .contains(Capabilities::DUAL_SOURCE_BLENDING)
+                    {
+                        return Err(VaryingError::UnsupportedCapability(
+                            Capabilities::DUAL_SOURCE_BLENDING,
+                        ));
+                    }
+                    if self.stage != crate::ShaderStage::Fragment {
+                        return Err(VaryingError::InvalidAttributeInStage(
+                            "second_blend_source",
+                            self.stage,
+                        ));
+                    }
+                    if !self.output {
+                        return Err(VaryingError::InvalidInputAttributeInStage(
+                            "second_blend_source",
+                            self.stage,
+                        ));
+                    }
+                    if location != 0 {
+                        return Err(VaryingError::InvalidLocationAttributeCombination {
+                            location,
+                            attribute: "second_blend_source",
+                        });
+                    }
+
+                    self.second_blend_source = true;
+                } else if !self.location_mask.insert(location as usize) {
+                    if self.flags.contains(super::ValidationFlags::BINDINGS) {
+                        return Err(VaryingError::BindingCollision { location });
+                    }
+                }
+
+                let needs_interpolation = match self.stage {
+                    crate::ShaderStage::Vertex => self.output,
+                    crate::ShaderStage::Fragment => !self.output,
+                    crate::ShaderStage::Compute => false,
+                };
+
+                // It doesn't make sense to specify a sampling when `interpolation` is `Flat`, but
+                // SPIR-V and GLSL both explicitly tolerate such combinations of decorators /
+                // qualifiers, so we won't complain about that here.
+                let _ = sampling;
+
+                let required = match sampling {
+                    Some(crate::Sampling::Sample) => Capabilities::MULTISAMPLED_SHADING,
+                    _ => Capabilities::empty(),
+                };
+                if !self.capabilities.contains(required) {
+                    return Err(VaryingError::UnsupportedCapability(required));
+                }
+
+                match ty_inner.scalar_kind() {
+                    Some(crate::ScalarKind::Float) => {
+                        if needs_interpolation && interpolation.is_none() {
+                            return Err(VaryingError::MissingInterpolation);
+                        }
+                    }
+                    Some(_) => {
+                        if needs_interpolation && interpolation != Some(crate::Interpolation::Flat)
+                        {
+                            return Err(VaryingError::InvalidInterpolation);
+                        }
+                    }
+                    None => return Err(VaryingError::InvalidType(ty)),
+                }
+            }
+        }
+
+        Ok(())
+    }
+
+    fn validate(
+        &mut self,
+        ty: Handle<crate::Type>,
+        binding: Option<&crate::Binding>,
+    ) -> Result<(), WithSpan<VaryingError>> {
+        let span_context = self.types.get_span_context(ty);
+        match binding {
+            Some(binding) => self
+                .validate_impl(ty, binding)
+                .map_err(|e| e.with_span_context(span_context)),
+            None => {
+                match self.types[ty].inner {
+                    crate::TypeInner::Struct { ref members, .. } => {
+                        for (index, member) in members.iter().enumerate() {
+                            let span_context = self.types.get_span_context(ty);
+                            match member.binding {
+                                None => {
+                                    if self.flags.contains(super::ValidationFlags::BINDINGS) {
+                                        return Err(VaryingError::MemberMissingBinding(
+                                            index as u32,
+                                        )
+                                        .with_span_context(span_context));
+                                    }
+                                }
+                                Some(ref binding) => self
+                                    .validate_impl(member.ty, binding)
+                                    .map_err(|e| e.with_span_context(span_context))?,
+                            }
+                        }
+                    }
+                    _ => {
+                        if self.flags.contains(super::ValidationFlags::BINDINGS) {
+                            return Err(VaryingError::MissingBinding.with_span());
+                        }
+                    }
+                }
+                Ok(())
+            }
+        }
+    }
+}
+
+impl super::Validator {
+    pub(super) fn validate_global_var(
+        &self,
+        var: &crate::GlobalVariable,
+        gctx: crate::proc::GlobalCtx,
+        mod_info: &ModuleInfo,
+    ) -> Result<(), GlobalVariableError> {
+        use super::TypeFlags;
+
+        log::debug!("var {:?}", var);
+        let inner_ty = match gctx.types[var.ty].inner {
+            // A binding array is (mostly) supposed to behave the same as a
+            // series of individually bound resources, so we can (mostly)
+            // validate a `binding_array<T>` as if it were just a plain `T`.
+            crate::TypeInner::BindingArray { base, .. } => match var.space {
+                crate::AddressSpace::Storage { .. }
+                | crate::AddressSpace::Uniform
+                | crate::AddressSpace::Handle => base,
+                _ => return Err(GlobalVariableError::InvalidUsage(var.space)),
+            },
+            _ => var.ty,
+        };
+        let type_info = &self.types[inner_ty.index()];
+
+        let (required_type_flags, is_resource) = match var.space {
+            crate::AddressSpace::Function => {
+                return Err(GlobalVariableError::InvalidUsage(var.space))
+            }
+            crate::AddressSpace::Storage { access } => {
+                if let Err((ty_handle, disalignment)) = type_info.storage_layout {
+                    if self.flags.contains(super::ValidationFlags::STRUCT_LAYOUTS) {
+                        return Err(GlobalVariableError::Alignment(
+                            var.space,
+                            ty_handle,
+                            disalignment,
+                        ));
+                    }
+                }
+                if access == crate::StorageAccess::STORE {
+                    return Err(GlobalVariableError::StorageAddressSpaceWriteOnlyNotSupported);
+                }
+                (TypeFlags::DATA | TypeFlags::HOST_SHAREABLE, true)
+            }
+            crate::AddressSpace::Uniform => {
+                if let Err((ty_handle, disalignment)) = type_info.uniform_layout {
+                    if self.flags.contains(super::ValidationFlags::STRUCT_LAYOUTS) {
+                        return Err(GlobalVariableError::Alignment(
+                            var.space,
+                            ty_handle,
+                            disalignment,
+                        ));
+                    }
+                }
+                (
+                    TypeFlags::DATA
+                        | TypeFlags::COPY
+                        | TypeFlags::SIZED
+                        | TypeFlags::HOST_SHAREABLE,
+                    true,
+                )
+            }
+            crate::AddressSpace::Handle => {
+                match gctx.types[inner_ty].inner {
+                    crate::TypeInner::Image { class, .. } => match class {
+                        crate::ImageClass::Storage {
+                            format:
+                                crate::StorageFormat::R16Unorm
+                                | crate::StorageFormat::R16Snorm
+                                | crate::StorageFormat::Rg16Unorm
+                                | crate::StorageFormat::Rg16Snorm
+                                | crate::StorageFormat::Rgba16Unorm
+                                | crate::StorageFormat::Rgba16Snorm,
+                            ..
+                        } => {
+                            if !self
+                                .capabilities
+                                .contains(Capabilities::STORAGE_TEXTURE_16BIT_NORM_FORMATS)
+                            {
+                                return Err(GlobalVariableError::UnsupportedCapability(
+                                    Capabilities::STORAGE_TEXTURE_16BIT_NORM_FORMATS,
+                                ));
+                            }
+                        }
+                        _ => {}
+                    },
+                    crate::TypeInner::Sampler { .. }
+                    | crate::TypeInner::AccelerationStructure
+                    | crate::TypeInner::RayQuery => {}
+                    _ => {
+                        return Err(GlobalVariableError::InvalidType(var.space));
+                    }
+                }
+
+                (TypeFlags::empty(), true)
+            }
+            crate::AddressSpace::Private => (TypeFlags::CONSTRUCTIBLE, false),
+            crate::AddressSpace::WorkGroup => (TypeFlags::DATA | TypeFlags::SIZED, false),
+            crate::AddressSpace::PushConstant => {
+                if !self.capabilities.contains(Capabilities::PUSH_CONSTANT) {
+                    return Err(GlobalVariableError::UnsupportedCapability(
+                        Capabilities::PUSH_CONSTANT,
+                    ));
+                }
+                (
+                    TypeFlags::DATA
+                        | TypeFlags::COPY
+                        | TypeFlags::HOST_SHAREABLE
+                        | TypeFlags::SIZED,
+                    false,
+                )
+            }
+        };
+
+        if !type_info.flags.contains(required_type_flags) {
+            return Err(GlobalVariableError::MissingTypeFlags {
+                seen: type_info.flags,
+                required: required_type_flags,
+            });
+        }
+
+        if is_resource != var.binding.is_some() {
+            if self.flags.contains(super::ValidationFlags::BINDINGS) {
+                return Err(GlobalVariableError::InvalidBinding);
+            }
+        }
+
+        if let Some(init) = var.init {
+            match var.space {
+                crate::AddressSpace::Private | crate::AddressSpace::Function => {}
+                _ => {
+                    return Err(GlobalVariableError::InitializerNotAllowed(var.space));
+                }
+            }
+
+            let decl_ty = &gctx.types[var.ty].inner;
+            let init_ty = mod_info[init].inner_with(gctx.types);
+            if !decl_ty.equivalent(init_ty, gctx.types) {
+                return Err(GlobalVariableError::InitializerType);
+            }
+        }
+
+        Ok(())
+    }
+
+    pub(super) fn validate_entry_point(
+        &mut self,
+        ep: &crate::EntryPoint,
+        module: &crate::Module,
+        mod_info: &ModuleInfo,
+    ) -> Result<FunctionInfo, WithSpan<EntryPointError>> {
+        if ep.early_depth_test.is_some() {
+            let required = Capabilities::EARLY_DEPTH_TEST;
+            if !self.capabilities.contains(required) {
+                return Err(
+                    EntryPointError::Result(VaryingError::UnsupportedCapability(required))
+                        .with_span(),
+                );
+            }
+
+            if ep.stage != crate::ShaderStage::Fragment {
+                return Err(EntryPointError::UnexpectedEarlyDepthTest.with_span());
+            }
+        }
+
+        if ep.stage == crate::ShaderStage::Compute {
+            if ep
+                .workgroup_size
+                .iter()
+                .any(|&s| s == 0 || s > MAX_WORKGROUP_SIZE)
+            {
+                return Err(EntryPointError::OutOfRangeWorkgroupSize.with_span());
+            }
+        } else if ep.workgroup_size != [0; 3] {
+            return Err(EntryPointError::UnexpectedWorkgroupSize.with_span());
+        }
+
+        let mut info = self
+            .validate_function(&ep.function, module, mod_info, true)
+            .map_err(WithSpan::into_other)?;
+
+        {
+            use super::ShaderStages;
+
+            let stage_bit = match ep.stage {
+                crate::ShaderStage::Vertex => ShaderStages::VERTEX,
+                crate::ShaderStage::Fragment => ShaderStages::FRAGMENT,
+                crate::ShaderStage::Compute => ShaderStages::COMPUTE,
+            };
+
+            if !info.available_stages.contains(stage_bit) {
+                return Err(EntryPointError::ForbiddenStageOperations.with_span());
+            }
+        }
+
+        self.location_mask.clear();
+        let mut argument_built_ins = crate::FastHashSet::default();
+        // TODO: add span info to function arguments
+        for (index, fa) in ep.function.arguments.iter().enumerate() {
+            let mut ctx = VaryingContext {
+                stage: ep.stage,
+                output: false,
+                second_blend_source: false,
+                types: &module.types,
+                type_info: &self.types,
+                location_mask: &mut self.location_mask,
+                built_ins: &mut argument_built_ins,
+                capabilities: self.capabilities,
+                flags: self.flags,
+            };
+            ctx.validate(fa.ty, fa.binding.as_ref())
+                .map_err_inner(|e| EntryPointError::Argument(index as u32, e).with_span())?;
+        }
+
+        self.location_mask.clear();
+        if let Some(ref fr) = ep.function.result {
+            let mut result_built_ins = crate::FastHashSet::default();
+            let mut ctx = VaryingContext {
+                stage: ep.stage,
+                output: true,
+                second_blend_source: false,
+                types: &module.types,
+                type_info: &self.types,
+                location_mask: &mut self.location_mask,
+                built_ins: &mut result_built_ins,
+                capabilities: self.capabilities,
+                flags: self.flags,
+            };
+            ctx.validate(fr.ty, fr.binding.as_ref())
+                .map_err_inner(|e| EntryPointError::Result(e).with_span())?;
+            if ctx.second_blend_source {
+                // Only the first location may be used when dual source blending
+                if ctx.location_mask.len() == 1 && ctx.location_mask.contains(0) {
+                    info.dual_source_blending = true;
+                } else {
+                    return Err(EntryPointError::InvalidLocationsWhileDualSourceBlending {
+                        location_mask: self.location_mask.clone(),
+                    }
+                    .with_span());
+                }
+            }
+
+            if ep.stage == crate::ShaderStage::Vertex
+                && !result_built_ins.contains(&crate::BuiltIn::Position { invariant: false })
+            {
+                return Err(EntryPointError::MissingVertexOutputPosition.with_span());
+            }
+        } else if ep.stage == crate::ShaderStage::Vertex {
+            return Err(EntryPointError::MissingVertexOutputPosition.with_span());
+        }
+
+        {
+            let used_push_constants = module
+                .global_variables
+                .iter()
+                .filter(|&(_, var)| var.space == crate::AddressSpace::PushConstant)
+                .map(|(handle, _)| handle)
+                .filter(|&handle| !info[handle].is_empty());
+            // Check if there is more than one push constant, and error if so.
+            // Use a loop for when returning multiple errors is supported.
+            #[allow(clippy::never_loop)]
+            for handle in used_push_constants.skip(1) {
+                return Err(EntryPointError::MoreThanOnePushConstantUsed
+                    .with_span_handle(handle, &module.global_variables));
+            }
+        }
+
+        self.ep_resource_bindings.clear();
+        for (var_handle, var) in module.global_variables.iter() {
+            let usage = info[var_handle];
+            if usage.is_empty() {
+                continue;
+            }
+
+            let allowed_usage = match var.space {
+                crate::AddressSpace::Function => unreachable!(),
+                crate::AddressSpace::Uniform => GlobalUse::READ | GlobalUse::QUERY,
+                crate::AddressSpace::Storage { access } => storage_usage(access),
+                crate::AddressSpace::Handle => match module.types[var.ty].inner {
+                    crate::TypeInner::BindingArray { base, .. } => match module.types[base].inner {
+                        crate::TypeInner::Image {
+                            class: crate::ImageClass::Storage { access, .. },
+                            ..
+                        } => storage_usage(access),
+                        _ => GlobalUse::READ | GlobalUse::QUERY,
+                    },
+                    crate::TypeInner::Image {
+                        class: crate::ImageClass::Storage { access, .. },
+                        ..
+                    } => storage_usage(access),
+                    _ => GlobalUse::READ | GlobalUse::QUERY,
+                },
+                crate::AddressSpace::Private | crate::AddressSpace::WorkGroup => GlobalUse::all(),
+                crate::AddressSpace::PushConstant => GlobalUse::READ,
+            };
+            if !allowed_usage.contains(usage) {
+                log::warn!("\tUsage error for: {:?}", var);
+                log::warn!(
+                    "\tAllowed usage: {:?}, requested: {:?}",
+                    allowed_usage,
+                    usage
+                );
+                return Err(EntryPointError::InvalidGlobalUsage(var_handle, usage)
+                    .with_span_handle(var_handle, &module.global_variables));
+            }
+
+            if let Some(ref bind) = var.binding {
+                if !self.ep_resource_bindings.insert(bind.clone()) {
+                    if self.flags.contains(super::ValidationFlags::BINDINGS) {
+                        return Err(EntryPointError::BindingCollision(var_handle)
+                            .with_span_handle(var_handle, &module.global_variables));
+                    }
+                }
+            }
+        }
+
+        Ok(info)
+    }
+}
diff --git a/third_party/rust/naga/src/valid/mod.rs b/third_party/rust/naga/src/valid/mod.rs
new file mode 100644
index 0000000000..388495a3ac
--- /dev/null
+++ b/third_party/rust/naga/src/valid/mod.rs
@@ -0,0 +1,477 @@
+/*!
+Shader validator.
+*/
+
+mod analyzer;
+mod compose;
+mod expression;
+mod function;
+mod handles;
+mod interface;
+mod r#type;
+
+use crate::{
+    arena::Handle,
+    proc::{LayoutError, Layouter, TypeResolution},
+    FastHashSet,
+};
+use bit_set::BitSet;
+use std::ops;
+
+//TODO: analyze the model at the same time as we validate it,
+// merge the corresponding matches over expressions and statements.
+
+use crate::span::{AddSpan as _, WithSpan};
+pub use analyzer::{ExpressionInfo, FunctionInfo, GlobalUse, Uniformity, UniformityRequirements};
+pub use compose::ComposeError;
+pub use expression::{check_literal_value, LiteralError};
+pub use expression::{ConstExpressionError, ExpressionError};
+pub use function::{CallError, FunctionError, LocalVariableError};
+pub use interface::{EntryPointError, GlobalVariableError, VaryingError};
+pub use r#type::{Disalignment, TypeError, TypeFlags};
+
+use self::handles::InvalidHandleError;
+
+bitflags::bitflags! {
+    /// Validation flags.
+    ///
+    /// If you are working with trusted shaders, then you may be able
+    /// to save some time by skipping validation.
+    ///
+    /// If you do not perform full validation, invalid shaders may
+    /// cause Naga to panic. If you do perform full validation and
+    /// [`Validator::validate`] returns `Ok`, then Naga promises that
+    /// code generation will either succeed or return an error; it
+    /// should never panic.
+    ///
+    /// The default value for `ValidationFlags` is
+    /// `ValidationFlags::all()`.
+    #[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+    #[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+    #[derive(Clone, Copy, Debug, Eq, PartialEq)]
+    pub struct ValidationFlags: u8 {
+        /// Expressions.
+        const EXPRESSIONS = 0x1;
+        /// Statements and blocks of them.
+        const BLOCKS = 0x2;
+        /// Uniformity of control flow for operations that require it.
+        const CONTROL_FLOW_UNIFORMITY = 0x4;
+        /// Host-shareable structure layouts.
+        const STRUCT_LAYOUTS = 0x8;
+        /// Constants.
+        const CONSTANTS = 0x10;
+        /// Group, binding, and location attributes.
+        const BINDINGS = 0x20;
+    }
+}
+
+impl Default for ValidationFlags {
+    fn default() -> Self {
+        Self::all()
+    }
+}
+
+bitflags::bitflags! {
+    /// Allowed IR capabilities.
+    #[must_use]
+    #[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+    #[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+    #[derive(Clone, Copy, Debug, Eq, PartialEq)]
+    pub struct Capabilities: u16 {
+        /// Support for [`AddressSpace:PushConstant`].
+        const PUSH_CONSTANT = 0x1;
+        /// Float values with width = 8.
+        const FLOAT64 = 0x2;
+        /// Support for [`Builtin:PrimitiveIndex`].
+        const PRIMITIVE_INDEX = 0x4;
+        /// Support for non-uniform indexing of sampled textures and storage buffer arrays.
+        const SAMPLED_TEXTURE_AND_STORAGE_BUFFER_ARRAY_NON_UNIFORM_INDEXING = 0x8;
+        /// Support for non-uniform indexing of uniform buffers and storage texture arrays.
+        const UNIFORM_BUFFER_AND_STORAGE_TEXTURE_ARRAY_NON_UNIFORM_INDEXING = 0x10;
+        /// Support for non-uniform indexing of samplers.
+        const SAMPLER_NON_UNIFORM_INDEXING = 0x20;
+        /// Support for [`Builtin::ClipDistance`].
+        const CLIP_DISTANCE = 0x40;
+        /// Support for [`Builtin::CullDistance`].
+        const CULL_DISTANCE = 0x80;
+        /// Support for 16-bit normalized storage texture formats.
+        const STORAGE_TEXTURE_16BIT_NORM_FORMATS = 0x100;
+        /// Support for [`BuiltIn::ViewIndex`].
+        const MULTIVIEW = 0x200;
+        /// Support for `early_depth_test`.
+        const EARLY_DEPTH_TEST = 0x400;
+        /// Support for [`Builtin::SampleIndex`] and [`Sampling::Sample`].
+        const MULTISAMPLED_SHADING = 0x800;
+        /// Support for ray queries and acceleration structures.
+        const RAY_QUERY = 0x1000;
+        /// Support for generating two sources for blending from fragment shaders.
+        const DUAL_SOURCE_BLENDING = 0x2000;
+        /// Support for arrayed cube textures.
+        const CUBE_ARRAY_TEXTURES = 0x4000;
+    }
+}
+
+impl Default for Capabilities {
+    fn default() -> Self {
+        Self::MULTISAMPLED_SHADING | Self::CUBE_ARRAY_TEXTURES
+    }
+}
+
+bitflags::bitflags! {
+    /// Validation flags.
+    #[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+    #[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+    #[derive(Clone, Copy, Debug, Eq, PartialEq)]
+    pub struct ShaderStages: u8 {
+        const VERTEX = 0x1;
+        const FRAGMENT = 0x2;
+        const COMPUTE = 0x4;
+    }
+}
+
+#[derive(Debug)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub struct ModuleInfo {
+    type_flags: Vec<TypeFlags>,
+    functions: Vec<FunctionInfo>,
+    entry_points: Vec<FunctionInfo>,
+    const_expression_types: Box<[TypeResolution]>,
+}
+
+impl ops::Index<Handle<crate::Type>> for ModuleInfo {
+    type Output = TypeFlags;
+    fn index(&self, handle: Handle<crate::Type>) -> &Self::Output {
+        &self.type_flags[handle.index()]
+    }
+}
+
+impl ops::Index<Handle<crate::Function>> for ModuleInfo {
+    type Output = FunctionInfo;
+    fn index(&self, handle: Handle<crate::Function>) -> &Self::Output {
+        &self.functions[handle.index()]
+    }
+}
+
+impl ops::Index<Handle<crate::Expression>> for ModuleInfo {
+    type Output = TypeResolution;
+    fn index(&self, handle: Handle<crate::Expression>) -> &Self::Output {
+        &self.const_expression_types[handle.index()]
+    }
+}
+
+#[derive(Debug)]
+pub struct Validator {
+    flags: ValidationFlags,
+    capabilities: Capabilities,
+    types: Vec<r#type::TypeInfo>,
+    layouter: Layouter,
+    location_mask: BitSet,
+    ep_resource_bindings: FastHashSet<crate::ResourceBinding>,
+    #[allow(dead_code)]
+    switch_values: FastHashSet<crate::SwitchValue>,
+    valid_expression_list: Vec<Handle<crate::Expression>>,
+    valid_expression_set: BitSet,
+}
+
+#[derive(Clone, Debug, thiserror::Error)]
+pub enum ConstantError {
+    #[error("The type doesn't match the constant")]
+    InvalidType,
+    #[error("The type is not constructible")]
+    NonConstructibleType,
+}
+
+#[derive(Clone, Debug, thiserror::Error)]
+pub enum ValidationError {
+    #[error(transparent)]
+    InvalidHandle(#[from] InvalidHandleError),
+    #[error(transparent)]
+    Layouter(#[from] LayoutError),
+    #[error("Type {handle:?} '{name}' is invalid")]
+    Type {
+        handle: Handle<crate::Type>,
+        name: String,
+        source: TypeError,
+    },
+    #[error("Constant expression {handle:?} is invalid")]
+    ConstExpression {
+        handle: Handle<crate::Expression>,
+        source: ConstExpressionError,
+    },
+    #[error("Constant {handle:?} '{name}' is invalid")]
+    Constant {
+        handle: Handle<crate::Constant>,
+        name: String,
+        source: ConstantError,
+    },
+    #[error("Global variable {handle:?} '{name}' is invalid")]
+    GlobalVariable {
+        handle: Handle<crate::GlobalVariable>,
+        name: String,
+        source: GlobalVariableError,
+    },
+    #[error("Function {handle:?} '{name}' is invalid")]
+    Function {
+        handle: Handle<crate::Function>,
+        name: String,
+        source: FunctionError,
+    },
+    #[error("Entry point {name} at {stage:?} is invalid")]
+    EntryPoint {
+        stage: crate::ShaderStage,
+        name: String,
+        source: EntryPointError,
+    },
+    #[error("Module is corrupted")]
+    Corrupted,
+}
+
+impl crate::TypeInner {
+    const fn is_sized(&self) -> bool {
+        match *self {
+            Self::Scalar { .. }
+            | Self::Vector { .. }
+            | Self::Matrix { .. }
+            | Self::Array {
+                size: crate::ArraySize::Constant(_),
+                ..
+            }
+            | Self::Atomic { .. }
+            | Self::Pointer { .. }
+            | Self::ValuePointer { .. }
+            | Self::Struct { .. } => true,
+            Self::Array { .. }
+            | Self::Image { .. }
+            | Self::Sampler { .. }
+            | Self::AccelerationStructure
+            | Self::RayQuery
+            | Self::BindingArray { .. } => false,
+        }
+    }
+
+    /// Return the `ImageDimension` for which `self` is an appropriate coordinate.
+    const fn image_storage_coordinates(&self) -> Option<crate::ImageDimension> {
+        match *self {
+            Self::Scalar(crate::Scalar {
+                kind: crate::ScalarKind::Sint | crate::ScalarKind::Uint,
+                ..
+            }) => Some(crate::ImageDimension::D1),
+            Self::Vector {
+                size: crate::VectorSize::Bi,
+                scalar:
+                    crate::Scalar {
+                        kind: crate::ScalarKind::Sint | crate::ScalarKind::Uint,
+                        ..
+                    },
+            } => Some(crate::ImageDimension::D2),
+            Self::Vector {
+                size: crate::VectorSize::Tri,
+                scalar:
+                    crate::Scalar {
+                        kind: crate::ScalarKind::Sint | crate::ScalarKind::Uint,
+                        ..
+                    },
+            } => Some(crate::ImageDimension::D3),
+            _ => None,
+        }
+    }
+}
+
+impl Validator {
+    /// Construct a new validator instance.
+    pub fn new(flags: ValidationFlags, capabilities: Capabilities) -> Self {
+        Validator {
+            flags,
+            capabilities,
+            types: Vec::new(),
+            layouter: Layouter::default(),
+            location_mask: BitSet::new(),
+            ep_resource_bindings: FastHashSet::default(),
+            switch_values: FastHashSet::default(),
+            valid_expression_list: Vec::new(),
+            valid_expression_set: BitSet::new(),
+        }
+    }
+
+    /// Reset the validator internals
+    pub fn reset(&mut self) {
+        self.types.clear();
+        self.layouter.clear();
+        self.location_mask.clear();
+        self.ep_resource_bindings.clear();
+        self.switch_values.clear();
+        self.valid_expression_list.clear();
+        self.valid_expression_set.clear();
+    }
+
+    fn validate_constant(
+        &self,
+        handle: Handle<crate::Constant>,
+        gctx: crate::proc::GlobalCtx,
+        mod_info: &ModuleInfo,
+    ) -> Result<(), ConstantError> {
+        let con = &gctx.constants[handle];
+
+        let type_info = &self.types[con.ty.index()];
+        if !type_info.flags.contains(TypeFlags::CONSTRUCTIBLE) {
+            return Err(ConstantError::NonConstructibleType);
+        }
+
+        let decl_ty = &gctx.types[con.ty].inner;
+        let init_ty = mod_info[con.init].inner_with(gctx.types);
+        if !decl_ty.equivalent(init_ty, gctx.types) {
+            return Err(ConstantError::InvalidType);
+        }
+
+        Ok(())
+    }
+
+    /// Check the given module to be valid.
+    pub fn validate(
+        &mut self,
+        module: &crate::Module,
+    ) -> Result<ModuleInfo, WithSpan<ValidationError>> {
+        self.reset();
+        self.reset_types(module.types.len());
+
+        Self::validate_module_handles(module).map_err(|e| e.with_span())?;
+
+        self.layouter.update(module.to_ctx()).map_err(|e| {
+            let handle = e.ty;
+            ValidationError::from(e).with_span_handle(handle, &module.types)
+        })?;
+
+        // These should all get overwritten.
+        let placeholder = TypeResolution::Value(crate::TypeInner::Scalar(crate::Scalar {
+            kind: crate::ScalarKind::Bool,
+            width: 0,
+        }));
+
+        let mut mod_info = ModuleInfo {
+            type_flags: Vec::with_capacity(module.types.len()),
+            functions: Vec::with_capacity(module.functions.len()),
+            entry_points: Vec::with_capacity(module.entry_points.len()),
+            const_expression_types: vec![placeholder; module.const_expressions.len()]
+                .into_boxed_slice(),
+        };
+
+        for (handle, ty) in module.types.iter() {
+            let ty_info = self
+                .validate_type(handle, module.to_ctx())
+                .map_err(|source| {
+                    ValidationError::Type {
+                        handle,
+                        name: ty.name.clone().unwrap_or_default(),
+                        source,
+                    }
+                    .with_span_handle(handle, &module.types)
+                })?;
+            mod_info.type_flags.push(ty_info.flags);
+            self.types[handle.index()] = ty_info;
+        }
+
+        {
+            let t = crate::Arena::new();
+            let resolve_context = crate::proc::ResolveContext::with_locals(module, &t, &[]);
+            for (handle, _) in module.const_expressions.iter() {
+                mod_info
+                    .process_const_expression(handle, &resolve_context, module.to_ctx())
+                    .map_err(|source| {
+                        ValidationError::ConstExpression { handle, source }
+                            .with_span_handle(handle, &module.const_expressions)
+                    })?
+            }
+        }
+
+        if self.flags.contains(ValidationFlags::CONSTANTS) {
+            for (handle, _) in module.const_expressions.iter() {
+                self.validate_const_expression(handle, module.to_ctx(), &mod_info)
+                    .map_err(|source| {
+                        ValidationError::ConstExpression { handle, source }
+                            .with_span_handle(handle, &module.const_expressions)
+                    })?
+            }
+
+            for (handle, constant) in module.constants.iter() {
+                self.validate_constant(handle, module.to_ctx(), &mod_info)
+                    .map_err(|source| {
+                        ValidationError::Constant {
+                            handle,
+                            name: constant.name.clone().unwrap_or_default(),
+                            source,
+                        }
+                        .with_span_handle(handle, &module.constants)
+                    })?
+            }
+        }
+
+        for (var_handle, var) in module.global_variables.iter() {
+            self.validate_global_var(var, module.to_ctx(), &mod_info)
+                .map_err(|source| {
+                    ValidationError::GlobalVariable {
+                        handle: var_handle,
+                        name: var.name.clone().unwrap_or_default(),
+                        source,
+                    }
+                    .with_span_handle(var_handle, &module.global_variables)
+                })?;
+        }
+
+        for (handle, fun) in module.functions.iter() {
+            match self.validate_function(fun, module, &mod_info, false) {
+                Ok(info) => mod_info.functions.push(info),
+                Err(error) => {
+                    return Err(error.and_then(|source| {
+                        ValidationError::Function {
+                            handle,
+                            name: fun.name.clone().unwrap_or_default(),
+                            source,
+                        }
+                        .with_span_handle(handle, &module.functions)
+                    }))
+                }
+            }
+        }
+
+        let mut ep_map = FastHashSet::default();
+        for ep in module.entry_points.iter() {
+            if !ep_map.insert((ep.stage, &ep.name)) {
+                return Err(ValidationError::EntryPoint {
+                    stage: ep.stage,
+                    name: ep.name.clone(),
+                    source: EntryPointError::Conflict,
+                }
+                .with_span()); // TODO: keep some EP span information?
+            }
+
+            match self.validate_entry_point(ep, module, &mod_info) {
+                Ok(info) => mod_info.entry_points.push(info),
+                Err(error) => {
+                    return Err(error.and_then(|source| {
+                        ValidationError::EntryPoint {
+                            stage: ep.stage,
+                            name: ep.name.clone(),
+                            source,
+                        }
+                        .with_span()
+                    }));
+                }
+            }
+        }
+
+        Ok(mod_info)
+    }
+}
+
+fn validate_atomic_compare_exchange_struct(
+    types: &crate::UniqueArena<crate::Type>,
+    members: &[crate::StructMember],
+    scalar_predicate: impl FnOnce(&crate::TypeInner) -> bool,
+) -> bool {
+    members.len() == 2
+        && members[0].name.as_deref() == Some("old_value")
+        && scalar_predicate(&types[members[0].ty].inner)
+        && members[1].name.as_deref() == Some("exchanged")
+        && types[members[1].ty].inner == crate::TypeInner::Scalar(crate::Scalar::BOOL)
+}
diff --git a/third_party/rust/naga/src/valid/type.rs b/third_party/rust/naga/src/valid/type.rs
new file mode 100644
index 0000000000..1e3e03fe19
--- /dev/null
+++ b/third_party/rust/naga/src/valid/type.rs
@@ -0,0 +1,643 @@
+use super::Capabilities;
+use crate::{arena::Handle, proc::Alignment};
+
+bitflags::bitflags! {
+    /// Flags associated with [`Type`]s by [`Validator`].
+    ///
+    /// [`Type`]: crate::Type
+    /// [`Validator`]: crate::valid::Validator
+    #[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+    #[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+    #[repr(transparent)]
+    #[derive(Clone, Copy, Debug, Eq, PartialEq)]
+    pub struct TypeFlags: u8 {
+        /// Can be used for data variables.
+        ///
+        /// This flag is required on types of local variables, function
+        /// arguments, array elements, and struct members.
+        ///
+        /// This includes all types except `Image`, `Sampler`,
+        /// and some `Pointer` types.
+        const DATA = 0x1;
+
+        /// The data type has a size known by pipeline creation time.
+        ///
+        /// Unsized types are quite restricted. The only unsized types permitted
+        /// by Naga, other than the non-[`DATA`] types like [`Image`] and
+        /// [`Sampler`], are dynamically-sized [`Array`s], and [`Struct`s] whose
+        /// last members are such arrays. See the documentation for those types
+        /// for details.
+        ///
+        /// [`DATA`]: TypeFlags::DATA
+        /// [`Image`]: crate::Type::Image
+        /// [`Sampler`]: crate::Type::Sampler
+        /// [`Array`]: crate::Type::Array
+        /// [`Struct`]: crate::Type::struct
+        const SIZED = 0x2;
+
+        /// The data can be copied around.
+        const COPY = 0x4;
+
+        /// Can be be used for user-defined IO between pipeline stages.
+        ///
+        /// This covers anything that can be in [`Location`] binding:
+        /// non-bool scalars and vectors, matrices, and structs and
+        /// arrays containing only interface types.
+        const IO_SHAREABLE = 0x8;
+
+        /// Can be used for host-shareable structures.
+        const HOST_SHAREABLE = 0x10;
+
+        /// This type can be passed as a function argument.
+        const ARGUMENT = 0x40;
+
+        /// A WGSL [constructible] type.
+        ///
+        /// The constructible types are scalars, vectors, matrices, fixed-size
+        /// arrays of constructible types, and structs whose members are all
+        /// constructible.
+        ///
+        /// [constructible]: https://gpuweb.github.io/gpuweb/wgsl/#constructible
+        const CONSTRUCTIBLE = 0x80;
+    }
+}
+
+#[derive(Clone, Copy, Debug, thiserror::Error)]
+pub enum Disalignment {
+    #[error("The array stride {stride} is not a multiple of the required alignment {alignment}")]
+    ArrayStride { stride: u32, alignment: Alignment },
+    #[error("The struct span {span}, is not a multiple of the required alignment {alignment}")]
+    StructSpan { span: u32, alignment: Alignment },
+    #[error("The struct member[{index}] offset {offset} is not a multiple of the required alignment {alignment}")]
+    MemberOffset {
+        index: u32,
+        offset: u32,
+        alignment: Alignment,
+    },
+    #[error("The struct member[{index}] offset {offset} must be at least {expected}")]
+    MemberOffsetAfterStruct {
+        index: u32,
+        offset: u32,
+        expected: u32,
+    },
+    #[error("The struct member[{index}] is not statically sized")]
+    UnsizedMember { index: u32 },
+    #[error("The type is not host-shareable")]
+    NonHostShareable,
+}
+
+#[derive(Clone, Debug, thiserror::Error)]
+pub enum TypeError {
+    #[error("Capability {0:?} is required")]
+    MissingCapability(Capabilities),
+    #[error("The {0:?} scalar width {1} is not supported for an atomic")]
+    InvalidAtomicWidth(crate::ScalarKind, crate::Bytes),
+    #[error("Invalid type for pointer target {0:?}")]
+    InvalidPointerBase(Handle<crate::Type>),
+    #[error("Unsized types like {base:?} must be in the `Storage` address space, not `{space:?}`")]
+    InvalidPointerToUnsized {
+        base: Handle<crate::Type>,
+        space: crate::AddressSpace,
+    },
+    #[error("Expected data type, found {0:?}")]
+    InvalidData(Handle<crate::Type>),
+    #[error("Base type {0:?} for the array is invalid")]
+    InvalidArrayBaseType(Handle<crate::Type>),
+    #[error("Matrix elements must always be floating-point types")]
+    MatrixElementNotFloat,
+    #[error("The constant {0:?} is specialized, and cannot be used as an array size")]
+    UnsupportedSpecializedArrayLength(Handle<crate::Constant>),
+    #[error("Array stride {stride} does not match the expected {expected}")]
+    InvalidArrayStride { stride: u32, expected: u32 },
+    #[error("Field '{0}' can't be dynamically-sized, has type {1:?}")]
+    InvalidDynamicArray(String, Handle<crate::Type>),
+    #[error("The base handle {0:?} has to be a struct")]
+    BindingArrayBaseTypeNotStruct(Handle<crate::Type>),
+    #[error("Structure member[{index}] at {offset} overlaps the previous member")]
+    MemberOverlap { index: u32, offset: u32 },
+    #[error(
+        "Structure member[{index}] at {offset} and size {size} crosses the structure boundary of size {span}"
+    )]
+    MemberOutOfBounds {
+        index: u32,
+        offset: u32,
+        size: u32,
+        span: u32,
+    },
+    #[error("Structure types must have at least one member")]
+    EmptyStruct,
+    #[error(transparent)]
+    WidthError(#[from] WidthError),
+}
+
+#[derive(Clone, Debug, thiserror::Error)]
+#[cfg_attr(test, derive(PartialEq))]
+pub enum WidthError {
+    #[error("The {0:?} scalar width {1} is not supported")]
+    Invalid(crate::ScalarKind, crate::Bytes),
+    #[error("Using `{name}` values requires the `naga::valid::Capabilities::{flag}` flag")]
+    MissingCapability {
+        name: &'static str,
+        flag: &'static str,
+    },
+
+    #[error("64-bit integers are not yet supported")]
+    Unsupported64Bit,
+
+    #[error("Abstract types may only appear in constant expressions")]
+    Abstract,
+}
+
+// Only makes sense if `flags.contains(HOST_SHAREABLE)`
+type LayoutCompatibility = Result<Alignment, (Handle<crate::Type>, Disalignment)>;
+
+fn check_member_layout(
+    accum: &mut LayoutCompatibility,
+    member: &crate::StructMember,
+    member_index: u32,
+    member_layout: LayoutCompatibility,
+    parent_handle: Handle<crate::Type>,
+) {
+    *accum = match (*accum, member_layout) {
+        (Ok(cur_alignment), Ok(alignment)) => {
+            if alignment.is_aligned(member.offset) {
+                Ok(cur_alignment.max(alignment))
+            } else {
+                Err((
+                    parent_handle,
+                    Disalignment::MemberOffset {
+                        index: member_index,
+                        offset: member.offset,
+                        alignment,
+                    },
+                ))
+            }
+        }
+        (Err(e), _) | (_, Err(e)) => Err(e),
+    };
+}
+
+/// Determine whether a pointer in `space` can be passed as an argument.
+///
+/// If a pointer in `space` is permitted to be passed as an argument to a
+/// user-defined function, return `TypeFlags::ARGUMENT`. Otherwise, return
+/// `TypeFlags::empty()`.
+///
+/// Pointers passed as arguments to user-defined functions must be in the
+/// `Function` or `Private` address space.
+const fn ptr_space_argument_flag(space: crate::AddressSpace) -> TypeFlags {
+    use crate::AddressSpace as As;
+    match space {
+        As::Function | As::Private => TypeFlags::ARGUMENT,
+        As::Uniform | As::Storage { .. } | As::Handle | As::PushConstant | As::WorkGroup => {
+            TypeFlags::empty()
+        }
+    }
+}
+
+#[derive(Clone, Debug)]
+pub(super) struct TypeInfo {
+    pub flags: TypeFlags,
+    pub uniform_layout: LayoutCompatibility,
+    pub storage_layout: LayoutCompatibility,
+}
+
+impl TypeInfo {
+    const fn dummy() -> Self {
+        TypeInfo {
+            flags: TypeFlags::empty(),
+            uniform_layout: Ok(Alignment::ONE),
+            storage_layout: Ok(Alignment::ONE),
+        }
+    }
+
+    const fn new(flags: TypeFlags, alignment: Alignment) -> Self {
+        TypeInfo {
+            flags,
+            uniform_layout: Ok(alignment),
+            storage_layout: Ok(alignment),
+        }
+    }
+}
+
+impl super::Validator {
+    const fn require_type_capability(&self, capability: Capabilities) -> Result<(), TypeError> {
+        if self.capabilities.contains(capability) {
+            Ok(())
+        } else {
+            Err(TypeError::MissingCapability(capability))
+        }
+    }
+
+    pub(super) const fn check_width(&self, scalar: crate::Scalar) -> Result<(), WidthError> {
+        let good = match scalar.kind {
+            crate::ScalarKind::Bool => scalar.width == crate::BOOL_WIDTH,
+            crate::ScalarKind::Float => {
+                if scalar.width == 8 {
+                    if !self.capabilities.contains(Capabilities::FLOAT64) {
+                        return Err(WidthError::MissingCapability {
+                            name: "f64",
+                            flag: "FLOAT64",
+                        });
+                    }
+                    true
+                } else {
+                    scalar.width == 4
+                }
+            }
+            crate::ScalarKind::Sint | crate::ScalarKind::Uint => {
+                if scalar.width == 8 {
+                    return Err(WidthError::Unsupported64Bit);
+                }
+                scalar.width == 4
+            }
+            crate::ScalarKind::AbstractInt | crate::ScalarKind::AbstractFloat => {
+                return Err(WidthError::Abstract);
+            }
+        };
+        if good {
+            Ok(())
+        } else {
+            Err(WidthError::Invalid(scalar.kind, scalar.width))
+        }
+    }
+
+    pub(super) fn reset_types(&mut self, size: usize) {
+        self.types.clear();
+        self.types.resize(size, TypeInfo::dummy());
+        self.layouter.clear();
+    }
+
+    pub(super) fn validate_type(
+        &self,
+        handle: Handle<crate::Type>,
+        gctx: crate::proc::GlobalCtx,
+    ) -> Result<TypeInfo, TypeError> {
+        use crate::TypeInner as Ti;
+        Ok(match gctx.types[handle].inner {
+            Ti::Scalar(scalar) => {
+                self.check_width(scalar)?;
+                let shareable = if scalar.kind.is_numeric() {
+                    TypeFlags::IO_SHAREABLE | TypeFlags::HOST_SHAREABLE
+                } else {
+                    TypeFlags::empty()
+                };
+                TypeInfo::new(
+                    TypeFlags::DATA
+                        | TypeFlags::SIZED
+                        | TypeFlags::COPY
+                        | TypeFlags::ARGUMENT
+                        | TypeFlags::CONSTRUCTIBLE
+                        | shareable,
+                    Alignment::from_width(scalar.width),
+                )
+            }
+            Ti::Vector { size, scalar } => {
+                self.check_width(scalar)?;
+                let shareable = if scalar.kind.is_numeric() {
+                    TypeFlags::IO_SHAREABLE | TypeFlags::HOST_SHAREABLE
+                } else {
+                    TypeFlags::empty()
+                };
+                TypeInfo::new(
+                    TypeFlags::DATA
+                        | TypeFlags::SIZED
+                        | TypeFlags::COPY
+                        | TypeFlags::HOST_SHAREABLE
+                        | TypeFlags::ARGUMENT
+                        | TypeFlags::CONSTRUCTIBLE
+                        | shareable,
+                    Alignment::from(size) * Alignment::from_width(scalar.width),
+                )
+            }
+            Ti::Matrix {
+                columns: _,
+                rows,
+                scalar,
+            } => {
+                if scalar.kind != crate::ScalarKind::Float {
+                    return Err(TypeError::MatrixElementNotFloat);
+                }
+                self.check_width(scalar)?;
+                TypeInfo::new(
+                    TypeFlags::DATA
+                        | TypeFlags::SIZED
+                        | TypeFlags::COPY
+                        | TypeFlags::HOST_SHAREABLE
+                        | TypeFlags::ARGUMENT
+                        | TypeFlags::CONSTRUCTIBLE,
+                    Alignment::from(rows) * Alignment::from_width(scalar.width),
+                )
+            }
+            Ti::Atomic(crate::Scalar { kind, width }) => {
+                let good = match kind {
+                    crate::ScalarKind::Bool
+                    | crate::ScalarKind::Float
+                    | crate::ScalarKind::AbstractInt
+                    | crate::ScalarKind::AbstractFloat => false,
+                    crate::ScalarKind::Sint | crate::ScalarKind::Uint => width == 4,
+                };
+                if !good {
+                    return Err(TypeError::InvalidAtomicWidth(kind, width));
+                }
+                TypeInfo::new(
+                    TypeFlags::DATA | TypeFlags::SIZED | TypeFlags::HOST_SHAREABLE,
+                    Alignment::from_width(width),
+                )
+            }
+            Ti::Pointer { base, space } => {
+                use crate::AddressSpace as As;
+
+                let base_info = &self.types[base.index()];
+                if !base_info.flags.contains(TypeFlags::DATA) {
+                    return Err(TypeError::InvalidPointerBase(base));
+                }
+
+                // Runtime-sized values can only live in the `Storage` address
+                // space, so it's useless to have a pointer to such a type in
+                // any other space.
+                //
+                // Detecting this problem here prevents the definition of
+                // functions like:
+                //
+                //     fn f(p: ptr<workgroup, UnsizedType>) -> ... { ... }
+                //
+                // which would otherwise be permitted, but uncallable. (They
+                // may also present difficulties in code generation).
+                if !base_info.flags.contains(TypeFlags::SIZED) {
+                    match space {
+                        As::Storage { .. } => {}
+                        _ => {
+                            return Err(TypeError::InvalidPointerToUnsized { base, space });
+                        }
+                    }
+                }
+
+                // `Validator::validate_function` actually checks the address
+                // space of pointer arguments explicitly before checking the
+                // `ARGUMENT` flag, to give better error messages. But it seems
+                // best to set `ARGUMENT` accurately anyway.
+                let argument_flag = ptr_space_argument_flag(space);
+
+                // Pointers cannot be stored in variables, structure members, or
+                // array elements, so we do not mark them as `DATA`.
+                TypeInfo::new(
+                    argument_flag | TypeFlags::SIZED | TypeFlags::COPY,
+                    Alignment::ONE,
+                )
+            }
+            Ti::ValuePointer {
+                size: _,
+                scalar,
+                space,
+            } => {
+                // ValuePointer should be treated the same way as the equivalent
+                // Pointer / Scalar / Vector combination, so each step in those
+                // variants' match arms should have a counterpart here.
+                //
+                // However, some cases are trivial: All our implicit base types
+                // are DATA and SIZED, so we can never return
+                // `InvalidPointerBase` or `InvalidPointerToUnsized`.
+                self.check_width(scalar)?;
+
+                // `Validator::validate_function` actually checks the address
+                // space of pointer arguments explicitly before checking the
+                // `ARGUMENT` flag, to give better error messages. But it seems
+                // best to set `ARGUMENT` accurately anyway.
+                let argument_flag = ptr_space_argument_flag(space);
+
+                // Pointers cannot be stored in variables, structure members, or
+                // array elements, so we do not mark them as `DATA`.
+                TypeInfo::new(
+                    argument_flag | TypeFlags::SIZED | TypeFlags::COPY,
+                    Alignment::ONE,
+                )
+            }
+            Ti::Array { base, size, stride } => {
+                let base_info = &self.types[base.index()];
+                if !base_info.flags.contains(TypeFlags::DATA | TypeFlags::SIZED) {
+                    return Err(TypeError::InvalidArrayBaseType(base));
+                }
+
+                let base_layout = self.layouter[base];
+                let general_alignment = base_layout.alignment;
+                let uniform_layout = match base_info.uniform_layout {
+                    Ok(base_alignment) => {
+                        let alignment = base_alignment
+                            .max(general_alignment)
+                            .max(Alignment::MIN_UNIFORM);
+                        if alignment.is_aligned(stride) {
+                            Ok(alignment)
+                        } else {
+                            Err((handle, Disalignment::ArrayStride { stride, alignment }))
+                        }
+                    }
+                    Err(e) => Err(e),
+                };
+                let storage_layout = match base_info.storage_layout {
+                    Ok(base_alignment) => {
+                        let alignment = base_alignment.max(general_alignment);
+                        if alignment.is_aligned(stride) {
+                            Ok(alignment)
+                        } else {
+                            Err((handle, Disalignment::ArrayStride { stride, alignment }))
+                        }
+                    }
+                    Err(e) => Err(e),
+                };
+
+                let type_info_mask = match size {
+                    crate::ArraySize::Constant(_) => {
+                        TypeFlags::DATA
+                            | TypeFlags::SIZED
+                            | TypeFlags::COPY
+                            | TypeFlags::HOST_SHAREABLE
+                            | TypeFlags::ARGUMENT
+                            | TypeFlags::CONSTRUCTIBLE
+                    }
+                    crate::ArraySize::Dynamic => {
+                        // Non-SIZED types may only appear as the last element of a structure.
+                        // This is enforced by checks for SIZED-ness for all compound types,
+                        // and a special case for structs.
+                        TypeFlags::DATA | TypeFlags::COPY | TypeFlags::HOST_SHAREABLE
+                    }
+                };
+
+                TypeInfo {
+                    flags: base_info.flags & type_info_mask,
+                    uniform_layout,
+                    storage_layout,
+                }
+            }
+            Ti::Struct { ref members, span } => {
+                if members.is_empty() {
+                    return Err(TypeError::EmptyStruct);
+                }
+
+                let mut ti = TypeInfo::new(
+                    TypeFlags::DATA
+                        | TypeFlags::SIZED
+                        | TypeFlags::COPY
+                        | TypeFlags::HOST_SHAREABLE
+                        | TypeFlags::IO_SHAREABLE
+                        | TypeFlags::ARGUMENT
+                        | TypeFlags::CONSTRUCTIBLE,
+                    Alignment::ONE,
+                );
+                ti.uniform_layout = Ok(Alignment::MIN_UNIFORM);
+
+                let mut min_offset = 0;
+
+                let mut prev_struct_data: Option<(u32, u32)> = None;
+
+                for (i, member) in members.iter().enumerate() {
+                    let base_info = &self.types[member.ty.index()];
+                    if !base_info.flags.contains(TypeFlags::DATA) {
+                        return Err(TypeError::InvalidData(member.ty));
+                    }
+                    if !base_info.flags.contains(TypeFlags::HOST_SHAREABLE) {
+                        if ti.uniform_layout.is_ok() {
+                            ti.uniform_layout = Err((member.ty, Disalignment::NonHostShareable));
+                        }
+                        if ti.storage_layout.is_ok() {
+                            ti.storage_layout = Err((member.ty, Disalignment::NonHostShareable));
+                        }
+                    }
+                    ti.flags &= base_info.flags;
+
+                    if member.offset < min_offset {
+                        // HACK: this could be nicer. We want to allow some structures
+                        // to not bother with offsets/alignments if they are never
+                        // used for host sharing.
+                        if member.offset == 0 {
+                            ti.flags.set(TypeFlags::HOST_SHAREABLE, false);
+                        } else {
+                            return Err(TypeError::MemberOverlap {
+                                index: i as u32,
+                                offset: member.offset,
+                            });
+                        }
+                    }
+
+                    let base_size = gctx.types[member.ty].inner.size(gctx);
+                    min_offset = member.offset + base_size;
+                    if min_offset > span {
+                        return Err(TypeError::MemberOutOfBounds {
+                            index: i as u32,
+                            offset: member.offset,
+                            size: base_size,
+                            span,
+                        });
+                    }
+
+                    check_member_layout(
+                        &mut ti.uniform_layout,
+                        member,
+                        i as u32,
+                        base_info.uniform_layout,
+                        handle,
+                    );
+                    check_member_layout(
+                        &mut ti.storage_layout,
+                        member,
+                        i as u32,
+                        base_info.storage_layout,
+                        handle,
+                    );
+
+                    // Validate rule: If a structure member itself has a structure type S,
+                    // then the number of bytes between the start of that member and
+                    // the start of any following member must be at least roundUp(16, SizeOf(S)).
+                    if let Some((span, offset)) = prev_struct_data {
+                        let diff = member.offset - offset;
+                        let min = Alignment::MIN_UNIFORM.round_up(span);
+                        if diff < min {
+                            ti.uniform_layout = Err((
+                                handle,
+                                Disalignment::MemberOffsetAfterStruct {
+                                    index: i as u32,
+                                    offset: member.offset,
+                                    expected: offset + min,
+                                },
+                            ));
+                        }
+                    };
+
+                    prev_struct_data = match gctx.types[member.ty].inner {
+                        crate::TypeInner::Struct { span, .. } => Some((span, member.offset)),
+                        _ => None,
+                    };
+
+                    // The last field may be an unsized array.
+                    if !base_info.flags.contains(TypeFlags::SIZED) {
+                        let is_array = match gctx.types[member.ty].inner {
+                            crate::TypeInner::Array { .. } => true,
+                            _ => false,
+                        };
+                        if !is_array || i + 1 != members.len() {
+                            let name = member.name.clone().unwrap_or_default();
+                            return Err(TypeError::InvalidDynamicArray(name, member.ty));
+                        }
+                        if ti.uniform_layout.is_ok() {
+                            ti.uniform_layout =
+                                Err((handle, Disalignment::UnsizedMember { index: i as u32 }));
+                        }
+                    }
+                }
+
+                let alignment = self.layouter[handle].alignment;
+                if !alignment.is_aligned(span) {
+                    ti.uniform_layout = Err((handle, Disalignment::StructSpan { span, alignment }));
+                    ti.storage_layout = Err((handle, Disalignment::StructSpan { span, alignment }));
+                }
+
+                ti
+            }
+            Ti::Image {
+                dim,
+                arrayed,
+                class: _,
+            } => {
+                if arrayed && matches!(dim, crate::ImageDimension::Cube) {
+                    self.require_type_capability(Capabilities::CUBE_ARRAY_TEXTURES)?;
+                }
+                TypeInfo::new(TypeFlags::ARGUMENT, Alignment::ONE)
+            }
+            Ti::Sampler { .. } => TypeInfo::new(TypeFlags::ARGUMENT, Alignment::ONE),
+            Ti::AccelerationStructure => {
+                self.require_type_capability(Capabilities::RAY_QUERY)?;
+                TypeInfo::new(TypeFlags::ARGUMENT, Alignment::ONE)
+            }
+            Ti::RayQuery => {
+                self.require_type_capability(Capabilities::RAY_QUERY)?;
+                TypeInfo::new(
+                    TypeFlags::DATA | TypeFlags::CONSTRUCTIBLE | TypeFlags::SIZED,
+                    Alignment::ONE,
+                )
+            }
+            Ti::BindingArray { base, size } => {
+                if base >= handle {
+                    return Err(TypeError::InvalidArrayBaseType(base));
+                }
+                let type_info_mask = match size {
+                    crate::ArraySize::Constant(_) => TypeFlags::SIZED | TypeFlags::HOST_SHAREABLE,
+                    crate::ArraySize::Dynamic => {
+                        // Final type is non-sized
+                        TypeFlags::HOST_SHAREABLE
+                    }
+                };
+                let base_info = &self.types[base.index()];
+
+                if base_info.flags.contains(TypeFlags::DATA) {
+                    // Currently Naga only supports binding arrays of structs for non-handle types.
+                    match gctx.types[base].inner {
+                        crate::TypeInner::Struct { .. } => {}
+                        _ => return Err(TypeError::BindingArrayBaseTypeNotStruct(base)),
+                    };
+                }
+
+                TypeInfo::new(base_info.flags & type_info_mask, Alignment::ONE)
+            }
+        })
+    }
+}