Merging upstream version 1.71.1+dfsg1.

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

43 files changed, 2179 insertions, 725 deletions

diff --git a/library/portable-simd/.github/workflows/ci.yml b/library/portable-simd/.github/workflows/ci.yml
index d50dfa1be..acd47a3da 100644
--- a/library/portable-simd/.github/workflows/ci.yml
+++ b/library/portable-simd/.github/workflows/ci.yml
@@ -241,6 +241,10 @@ jobs:
           - "--features std"
           - "--features generic_const_exprs"
           - "--features std --features generic_const_exprs"
+          - "--features all_lane_counts"
+          - "--features all_lane_counts --features std"
+          - "--features all_lane_counts --features generic_const_exprs"
+          - "--features all_lane_counts --features std --features generic_const_exprs"
 
     steps:
       - uses: actions/checkout@v2
diff --git a/library/portable-simd/README.md b/library/portable-simd/README.md
index db0af2da6..e8ac600de 100644
--- a/library/portable-simd/README.md
+++ b/library/portable-simd/README.md
@@ -24,19 +24,10 @@ or by setting up `rustup default nightly` or else with `cargo +nightly {build,te
 ```bash
 cargo new hellosimd
 ```
-to create a new crate. Edit `hellosimd/Cargo.toml` to be 
-```toml
-[package]
-name = "hellosimd"
-version = "0.1.0"
-edition = "2018"
-[dependencies]
-core_simd = { git = "https://github.com/rust-lang/portable-simd" }
-```
-
-and finally write this in `src/main.rs`:
+to create a new crate. Finally write this in `src/main.rs`:
 ```rust
-use core_simd::*;
+#![feature(portable_simd)]
+use std::simd::f32x4;
 fn main() {
     let a = f32x4::splat(10.0);
     let b = f32x4::from_array([1.0, 2.0, 3.0, 4.0]);
@@ -44,24 +35,23 @@ fn main() {
 }
 ```
 
-Explanation: We import all the bindings from the crate with the first line. Then, we construct our SIMD vectors with methods like `splat` or `from_array`. Finally, we can use operators on them like `+` and the appropriate SIMD instructions will be carried out. When we run `cargo run` you should get `[11.0, 12.0, 13.0, 14.0]`.
-
-## Code Organization
+Explanation: We construct our SIMD vectors with methods like `splat` or `from_array`. Next, we can use operators like `+` on them, and the appropriate SIMD instructions will be carried out. When we run `cargo run` you should get `[11.0, 12.0, 13.0, 14.0]`.
 
-Currently the crate is organized so that each element type is a file, and then the 64-bit, 128-bit, 256-bit, and 512-bit vectors using those types are contained in said file.
+## Supported vectors
 
-All types are then exported as a single, flat module.
+Currently, vectors may have up to 64 elements, but aliases are provided only up to 512-bit vectors.
 
 Depending on the size of the primitive type, the number of lanes the vector will have varies. For example, 128-bit vectors have four `f32` lanes and two `f64` lanes.
 
 The supported element types are as follows:
 * **Floating Point:** `f32`, `f64`
-* **Signed Integers:** `i8`, `i16`, `i32`, `i64`, `i128`, `isize`
-* **Unsigned Integers:** `u8`, `u16`, `u32`, `u64`, `u128`, `usize`
-* **Masks:** `mask8`, `mask16`, `mask32`, `mask64`, `mask128`, `masksize`
+* **Signed Integers:** `i8`, `i16`, `i32`, `i64`, `isize` (`i128` excluded)
+* **Unsigned Integers:** `u8`, `u16`, `u32`, `u64`, `usize` (`u128` excluded)
+* **Pointers:** `*const T` and `*mut T` (zero-sized metadata only)
+* **Masks:** 8-bit, 16-bit, 32-bit, 64-bit, and `usize`-sized masks
 
-Floating point, signed integers, and unsigned integers are the [primitive types](https://doc.rust-lang.org/core/primitive/index.html) you're already used to.
-The `mask` types are "truthy" values, but they use the number of bits in their name instead of just 1 bit like a normal `bool` uses.
+Floating point, signed integers, unsigned integers, and pointers are the [primitive types](https://doc.rust-lang.org/core/primitive/index.html) you're already used to.
+The mask types have elements that are "truthy" values, like `bool`, but have an unspecified layout because different architectures prefer different layouts for mask types.
 
 [simd-guide]: ./beginners-guide.md
 [zulip-project-portable-simd]: https://rust-lang.zulipchat.com/#narrow/stream/257879-project-portable-simd
diff --git a/library/portable-simd/crates/core_simd/Cargo.toml b/library/portable-simd/crates/core_simd/Cargo.toml
index 8a29cf156..d1a3a515a 100644
--- a/library/portable-simd/crates/core_simd/Cargo.toml
+++ b/library/portable-simd/crates/core_simd/Cargo.toml
@@ -13,12 +13,11 @@ default = ["as_crate"]
 as_crate = []
 std = []
 generic_const_exprs = []
+all_lane_counts = []
 
-[target.'cfg(target_arch = "wasm32")'.dev-dependencies.wasm-bindgen]
-version = "0.2"
-
-[dev-dependencies.wasm-bindgen-test]
-version = "0.3"
+[target.'cfg(target_arch = "wasm32")'.dev-dependencies]
+wasm-bindgen = "0.2"
+wasm-bindgen-test = "0.3"
 
 [dev-dependencies.proptest]
 version = "0.10"
diff --git a/library/portable-simd/crates/core_simd/examples/README.md b/library/portable-simd/crates/core_simd/examples/README.md
new file mode 100644
index 000000000..82747f1b5
--- /dev/null
+++ b/library/portable-simd/crates/core_simd/examples/README.md
@@ -0,0 +1,13 @@
+### `stdsimd` examples
+
+This crate is a port of example uses of `stdsimd`, mostly taken from the `packed_simd` crate.
+
+The examples contain, as in the case of `dot_product.rs`, multiple ways of solving the problem, in order to show idiomatic uses of SIMD and iteration of performance designs.
+
+Run the tests with the command 
+
+```
+cargo run --example dot_product
+```
+
+and verify the code for `dot_product.rs` on your machine.
diff --git a/library/portable-simd/crates/core_simd/examples/dot_product.rs b/library/portable-simd/crates/core_simd/examples/dot_product.rs
new file mode 100644
index 000000000..391f08f55
--- /dev/null
+++ b/library/portable-simd/crates/core_simd/examples/dot_product.rs
@@ -0,0 +1,169 @@
+// Code taken from the `packed_simd` crate
+// Run this code with `cargo test --example dot_product`
+//use std::iter::zip;
+
+#![feature(array_chunks)]
+#![feature(slice_as_chunks)]
+// Add these imports to use the stdsimd library
+#![feature(portable_simd)]
+use core_simd::simd::*;
+
+// This is your barebones dot product implementation:
+// Take 2 vectors, multiply them element wise and *then*
+// go along the resulting array and add up the result.
+// In the next example we will see if there
+//  is any difference to adding and multiplying in tandem.
+pub fn dot_prod_scalar_0(a: &[f32], b: &[f32]) -> f32 {
+    assert_eq!(a.len(), b.len());
+
+    a.iter().zip(b.iter()).map(|(a, b)| a * b).sum()
+}
+
+// When dealing with SIMD, it is very important to think about the amount
+// of data movement and when it happens. We're going over simple computation examples here, and yet
+// it is not trivial to understand what may or may not contribute to performance
+// changes. Eventually, you will need tools to inspect the generated assembly and confirm your
+// hypothesis and benchmarks - we will mention them later on.
+// With the use of `fold`, we're doing a multiplication,
+// and then adding it to the sum, one element from both vectors at a time.
+pub fn dot_prod_scalar_1(a: &[f32], b: &[f32]) -> f32 {
+    assert_eq!(a.len(), b.len());
+    a.iter()
+        .zip(b.iter())
+        .fold(0.0, |a, zipped| a + zipped.0 * zipped.1)
+}
+
+// We now move on to the SIMD implementations: notice the following constructs:
+// `array_chunks::<4>`: mapping this over the vector will let use construct SIMD vectors
+// `f32x4::from_array`: construct the SIMD vector from a slice
+// `(a * b).reduce_sum()`: Multiply both f32x4 vectors together, and then reduce them.
+// This approach essentially uses SIMD to produce a vector of length N/4 of all the products,
+// and then add those with `sum()`. This is suboptimal.
+// TODO: ASCII diagrams
+pub fn dot_prod_simd_0(a: &[f32], b: &[f32]) -> f32 {
+    assert_eq!(a.len(), b.len());
+    // TODO handle remainder when a.len() % 4 != 0
+    a.array_chunks::<4>()
+        .map(|&a| f32x4::from_array(a))
+        .zip(b.array_chunks::<4>().map(|&b| f32x4::from_array(b)))
+        .map(|(a, b)| (a * b).reduce_sum())
+        .sum()
+}
+
+// There's some simple ways to improve the previous code:
+// 1. Make a `zero` `f32x4` SIMD vector that we will be accumulating into
+// So that there is only one `sum()` reduction when the last `f32x4` has been processed
+// 2. Exploit Fused Multiply Add so that the multiplication, addition and sinking into the reduciton
+// happen in the same step.
+// If the arrays are large, minimizing the data shuffling will lead to great perf.
+// If the arrays are small, handling the remainder elements when the length isn't a multiple of 4
+// Can become a problem.
+pub fn dot_prod_simd_1(a: &[f32], b: &[f32]) -> f32 {
+    assert_eq!(a.len(), b.len());
+    // TODO handle remainder when a.len() % 4 != 0
+    a.array_chunks::<4>()
+        .map(|&a| f32x4::from_array(a))
+        .zip(b.array_chunks::<4>().map(|&b| f32x4::from_array(b)))
+        .fold(f32x4::splat(0.0), |acc, zipped| acc + zipped.0 * zipped.1)
+        .reduce_sum()
+}
+
+// A lot of knowledgeable use of SIMD comes from knowing specific instructions that are
+// available - let's try to use the `mul_add` instruction, which is the fused-multiply-add we were looking for.
+use std_float::StdFloat;
+pub fn dot_prod_simd_2(a: &[f32], b: &[f32]) -> f32 {
+    assert_eq!(a.len(), b.len());
+    // TODO handle remainder when a.len() % 4 != 0
+    let mut res = f32x4::splat(0.0);
+    a.array_chunks::<4>()
+        .map(|&a| f32x4::from_array(a))
+        .zip(b.array_chunks::<4>().map(|&b| f32x4::from_array(b)))
+        .for_each(|(a, b)| {
+            res = a.mul_add(b, res);
+        });
+    res.reduce_sum()
+}
+
+// Finally, we will write the same operation but handling the loop remainder.
+const LANES: usize = 4;
+pub fn dot_prod_simd_3(a: &[f32], b: &[f32]) -> f32 {
+    assert_eq!(a.len(), b.len());
+
+    let (a_extra, a_chunks) = a.as_rchunks();
+    let (b_extra, b_chunks) = b.as_rchunks();
+
+    // These are always true, but for emphasis:
+    assert_eq!(a_chunks.len(), b_chunks.len());
+    assert_eq!(a_extra.len(), b_extra.len());
+
+    let mut sums = [0.0; LANES];
+    for ((x, y), d) in std::iter::zip(a_extra, b_extra).zip(&mut sums) {
+        *d = x * y;
+    }
+
+    let mut sums = f32x4::from_array(sums);
+    std::iter::zip(a_chunks, b_chunks).for_each(|(x, y)| {
+        sums += f32x4::from_array(*x) * f32x4::from_array(*y);
+    });
+
+    sums.reduce_sum()
+}
+
+// Finally, we present an iterator version for handling remainders in a scalar fashion at the end of the loop.
+// Unfortunately, this is allocating 1 `XMM` register on the order of `~len(a)` - we'll see how we can get around it in the
+// next example.
+pub fn dot_prod_simd_4(a: &[f32], b: &[f32]) -> f32 {
+    let mut sum = a
+        .array_chunks::<4>()
+        .map(|&a| f32x4::from_array(a))
+        .zip(b.array_chunks::<4>().map(|&b| f32x4::from_array(b)))
+        .map(|(a, b)| a * b)
+        .fold(f32x4::splat(0.0), std::ops::Add::add)
+        .reduce_sum();
+    let remain = a.len() - (a.len() % 4);
+    sum += a[remain..]
+        .iter()
+        .zip(&b[remain..])
+        .map(|(a, b)| a * b)
+        .sum::<f32>();
+    sum
+}
+
+// This version allocates a single `XMM` register for accumulation, and the folds don't allocate on top of that.
+// Notice the the use of `mul_add`, which can do a multiply and an add operation ber iteration.
+pub fn dot_prod_simd_5(a: &[f32], b: &[f32]) -> f32 {
+    a.array_chunks::<4>()
+        .map(|&a| f32x4::from_array(a))
+        .zip(b.array_chunks::<4>().map(|&b| f32x4::from_array(b)))
+        .fold(f32x4::splat(0.), |acc, (a, b)| a.mul_add(b, acc))
+        .reduce_sum()
+}
+
+fn main() {
+    // Empty main to make cargo happy
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn smoke_test() {
+        use super::*;
+        let a: Vec<f32> = vec![1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0];
+        let b: Vec<f32> = vec![-8.0, -7.0, -6.0, -5.0, 4.0, 3.0, 2.0, 1.0];
+        let x: Vec<f32> = [0.5; 1003].to_vec();
+        let y: Vec<f32> = [2.0; 1003].to_vec();
+
+        // Basic check
+        assert_eq!(0.0, dot_prod_scalar_0(&a, &b));
+        assert_eq!(0.0, dot_prod_scalar_1(&a, &b));
+        assert_eq!(0.0, dot_prod_simd_0(&a, &b));
+        assert_eq!(0.0, dot_prod_simd_1(&a, &b));
+        assert_eq!(0.0, dot_prod_simd_2(&a, &b));
+        assert_eq!(0.0, dot_prod_simd_3(&a, &b));
+        assert_eq!(0.0, dot_prod_simd_4(&a, &b));
+        assert_eq!(0.0, dot_prod_simd_5(&a, &b));
+
+        // We can handle vectors that are non-multiples of 4
+        assert_eq!(1003.0, dot_prod_simd_3(&x, &y));
+    }
+}
diff --git a/library/portable-simd/crates/core_simd/src/alias.rs b/library/portable-simd/crates/core_simd/src/alias.rs
new file mode 100644
index 000000000..23f121c46
--- /dev/null
+++ b/library/portable-simd/crates/core_simd/src/alias.rs
@@ -0,0 +1,227 @@
+macro_rules! number {
+    { 1 } => { "one" };
+    { 2 } => { "two" };
+    { 4 } => { "four" };
+    { 8 } => { "eight" };
+    { $x:literal } => { stringify!($x) };
+}
+
+macro_rules! plural {
+    { 1 } => { "" };
+    { $x:literal } => { "s" };
+}
+
+macro_rules! alias {
+    {
+        $(
+            $element_ty:ty = {
+                $($alias:ident $num_elements:tt)*
+            }
+        )*
+    } => {
+        $(
+            $(
+            #[doc = concat!("A SIMD vector with ", number!($num_elements), " element", plural!($num_elements), " of type [`", stringify!($element_ty), "`].")]
+            #[allow(non_camel_case_types)]
+            pub type $alias = $crate::simd::Simd<$element_ty, $num_elements>;
+            )*
+        )*
+    }
+}
+
+macro_rules! mask_alias {
+    {
+        $(
+            $element_ty:ty : $size:literal = {
+                $($alias:ident $num_elements:tt)*
+            }
+        )*
+    } => {
+        $(
+            $(
+            #[doc = concat!("A SIMD mask with ", number!($num_elements), " element", plural!($num_elements), " for vectors with ", $size, " element types.")]
+            ///
+            #[doc = concat!(
+                "The layout of this type is unspecified, and may change between platforms and/or Rust versions, and code should not assume that it is equivalent to `[",
+                stringify!($element_ty), "; ", $num_elements, "]`."
+            )]
+            #[allow(non_camel_case_types)]
+            pub type $alias = $crate::simd::Mask<$element_ty, $num_elements>;
+            )*
+        )*
+    }
+}
+
+alias! {
+    i8 = {
+        i8x1 1
+        i8x2 2
+        i8x4 4
+        i8x8 8
+        i8x16 16
+        i8x32 32
+        i8x64 64
+    }
+
+    i16 = {
+        i16x1 1
+        i16x2 2
+        i16x4 4
+        i16x8 8
+        i16x16 16
+        i16x32 32
+        i16x64 64
+    }
+
+    i32 = {
+        i32x1 1
+        i32x2 2
+        i32x4 4
+        i32x8 8
+        i32x16 16
+        i32x32 32
+        i32x64 64
+    }
+
+    i64 = {
+        i64x1 1
+        i64x2 2
+        i64x4 4
+        i64x8 8
+        i64x16 16
+        i64x32 32
+        i64x64 64
+    }
+
+    isize = {
+        isizex1 1
+        isizex2 2
+        isizex4 4
+        isizex8 8
+        isizex16 16
+        isizex32 32
+        isizex64 64
+    }
+
+    u8 = {
+        u8x1 1
+        u8x2 2
+        u8x4 4
+        u8x8 8
+        u8x16 16
+        u8x32 32
+        u8x64 64
+    }
+
+    u16 = {
+        u16x1 1
+        u16x2 2
+        u16x4 4
+        u16x8 8
+        u16x16 16
+        u16x32 32
+        u16x64 64
+    }
+
+    u32 = {
+        u32x1 1
+        u32x2 2
+        u32x4 4
+        u32x8 8
+        u32x16 16
+        u32x32 32
+        u32x64 64
+    }
+
+    u64 = {
+        u64x1 1
+        u64x2 2
+        u64x4 4
+        u64x8 8
+        u64x16 16
+        u64x32 32
+        u64x64 64
+    }
+
+    usize = {
+        usizex1 1
+        usizex2 2
+        usizex4 4
+        usizex8 8
+        usizex16 16
+        usizex32 32
+        usizex64 64
+    }
+
+    f32 = {
+        f32x1 1
+        f32x2 2
+        f32x4 4
+        f32x8 8
+        f32x16 16
+        f32x32 32
+        f32x64 64
+    }
+
+    f64 = {
+        f64x1 1
+        f64x2 2
+        f64x4 4
+        f64x8 8
+        f64x16 16
+        f64x32 32
+        f64x64 64
+    }
+}
+
+mask_alias! {
+    i8 : "8-bit" = {
+        mask8x1 1
+        mask8x2 2
+        mask8x4 4
+        mask8x8 8
+        mask8x16 16
+        mask8x32 32
+        mask8x64 64
+    }
+
+    i16 : "16-bit" = {
+        mask16x1 1
+        mask16x2 2
+        mask16x4 4
+        mask16x8 8
+        mask16x16 16
+        mask16x32 32
+        mask16x64 64
+    }
+
+    i32 : "32-bit" = {
+        mask32x1 1
+        mask32x2 2
+        mask32x4 4
+        mask32x8 8
+        mask32x16 16
+        mask32x32 32
+        mask32x64 64
+    }
+
+    i64 : "64-bit" = {
+        mask64x1 1
+        mask64x2 2
+        mask64x4 4
+        mask64x8 8
+        mask64x16 16
+        mask64x32 32
+        mask64x64 64
+    }
+
+    isize : "pointer-sized" = {
+        masksizex1 1
+        masksizex2 2
+        masksizex4 4
+        masksizex8 8
+        masksizex16 16
+        masksizex32 32
+        masksizex64 64
+    }
+}
diff --git a/library/portable-simd/crates/core_simd/src/cast.rs b/library/portable-simd/crates/core_simd/src/cast.rs
new file mode 100644
index 000000000..65a3f845f
--- /dev/null
+++ b/library/portable-simd/crates/core_simd/src/cast.rs
@@ -0,0 +1,55 @@
+use crate::simd::SimdElement;
+
+/// Supporting trait for `Simd::cast`.  Typically doesn't need to be used directly.
+///
+/// # Safety
+/// Implementing this trait asserts that the type is a valid vector element for the `simd_cast` or
+/// `simd_as` intrinsics.
+pub unsafe trait SimdCast: SimdElement {}
+
+// Safety: primitive number types can be cast to other primitive number types
+unsafe impl SimdCast for i8 {}
+// Safety: primitive number types can be cast to other primitive number types
+unsafe impl SimdCast for i16 {}
+// Safety: primitive number types can be cast to other primitive number types
+unsafe impl SimdCast for i32 {}
+// Safety: primitive number types can be cast to other primitive number types
+unsafe impl SimdCast for i64 {}
+// Safety: primitive number types can be cast to other primitive number types
+unsafe impl SimdCast for isize {}
+// Safety: primitive number types can be cast to other primitive number types
+unsafe impl SimdCast for u8 {}
+// Safety: primitive number types can be cast to other primitive number types
+unsafe impl SimdCast for u16 {}
+// Safety: primitive number types can be cast to other primitive number types
+unsafe impl SimdCast for u32 {}
+// Safety: primitive number types can be cast to other primitive number types
+unsafe impl SimdCast for u64 {}
+// Safety: primitive number types can be cast to other primitive number types
+unsafe impl SimdCast for usize {}
+// Safety: primitive number types can be cast to other primitive number types
+unsafe impl SimdCast for f32 {}
+// Safety: primitive number types can be cast to other primitive number types
+unsafe impl SimdCast for f64 {}
+
+/// Supporting trait for `Simd::cast_ptr`.  Typically doesn't need to be used directly.
+///
+/// # Safety
+/// Implementing this trait asserts that the type is a valid vector element for the `simd_cast_ptr`
+/// intrinsic.
+pub unsafe trait SimdCastPtr<T> {}
+
+// Safety: pointers can be cast to other pointer types
+unsafe impl<T, U> SimdCastPtr<T> for *const U
+where
+    U: core::ptr::Pointee,
+    T: core::ptr::Pointee<Metadata = U::Metadata>,
+{
+}
+// Safety: pointers can be cast to other pointer types
+unsafe impl<T, U> SimdCastPtr<T> for *mut U
+where
+    U: core::ptr::Pointee,
+    T: core::ptr::Pointee<Metadata = U::Metadata>,
+{
+}
diff --git a/library/portable-simd/crates/core_simd/src/elements.rs b/library/portable-simd/crates/core_simd/src/elements.rs
index 701eb66b2..dc7f52a4d 100644
--- a/library/portable-simd/crates/core_simd/src/elements.rs
+++ b/library/portable-simd/crates/core_simd/src/elements.rs
@@ -1,11 +1,15 @@
+mod const_ptr;
 mod float;
 mod int;
+mod mut_ptr;
 mod uint;
 
 mod sealed {
     pub trait Sealed {}
 }
 
+pub use const_ptr::*;
 pub use float::*;
 pub use int::*;
+pub use mut_ptr::*;
 pub use uint::*;
diff --git a/library/portable-simd/crates/core_simd/src/elements/const_ptr.rs b/library/portable-simd/crates/core_simd/src/elements/const_ptr.rs
new file mode 100644
index 000000000..0ef9802b5
--- /dev/null
+++ b/library/portable-simd/crates/core_simd/src/elements/const_ptr.rs
@@ -0,0 +1,141 @@
+use super::sealed::Sealed;
+use crate::simd::{intrinsics, LaneCount, Mask, Simd, SimdPartialEq, SupportedLaneCount};
+
+/// Operations on SIMD vectors of constant pointers.
+pub trait SimdConstPtr: Copy + Sealed {
+    /// Vector of `usize` with the same number of lanes.
+    type Usize;
+
+    /// Vector of `isize` with the same number of lanes.
+    type Isize;
+
+    /// Vector of mutable pointers to the same type.
+    type MutPtr;
+
+    /// Mask type used for manipulating this SIMD vector type.
+    type Mask;
+
+    /// Returns `true` for each lane that is null.
+    fn is_null(self) -> Self::Mask;
+
+    /// Changes constness without changing the type.
+    ///
+    /// Equivalent to calling [`pointer::cast_mut`] on each lane.
+    fn cast_mut(self) -> Self::MutPtr;
+
+    /// Gets the "address" portion of the pointer.
+    ///
+    /// This method discards pointer semantic metadata, so the result cannot be
+    /// directly cast into a valid pointer.
+    ///
+    /// This method semantically discards *provenance* and
+    /// *address-space* information. To properly restore that information, use [`Self::with_addr`].
+    ///
+    /// Equivalent to calling [`pointer::addr`] on each lane.
+    fn addr(self) -> Self::Usize;
+
+    /// Creates a new pointer with the given address.
+    ///
+    /// This performs the same operation as a cast, but copies the *address-space* and
+    /// *provenance* of `self` to the new pointer.
+    ///
+    /// Equivalent to calling [`pointer::with_addr`] on each lane.
+    fn with_addr(self, addr: Self::Usize) -> Self;
+
+    /// Gets the "address" portion of the pointer, and "exposes" the provenance part for future use
+    /// in [`Self::from_exposed_addr`].
+    fn expose_addr(self) -> Self::Usize;
+
+    /// Convert an address back to a pointer, picking up a previously "exposed" provenance.
+    ///
+    /// Equivalent to calling [`core::ptr::from_exposed_addr`] on each lane.
+    fn from_exposed_addr(addr: Self::Usize) -> Self;
+
+    /// Calculates the offset from a pointer using wrapping arithmetic.
+    ///
+    /// Equivalent to calling [`pointer::wrapping_offset`] on each lane.
+    fn wrapping_offset(self, offset: Self::Isize) -> Self;
+
+    /// Calculates the offset from a pointer using wrapping arithmetic.
+    ///
+    /// Equivalent to calling [`pointer::wrapping_add`] on each lane.
+    fn wrapping_add(self, count: Self::Usize) -> Self;
+
+    /// Calculates the offset from a pointer using wrapping arithmetic.
+    ///
+    /// Equivalent to calling [`pointer::wrapping_sub`] on each lane.
+    fn wrapping_sub(self, count: Self::Usize) -> Self;
+}
+
+impl<T, const LANES: usize> Sealed for Simd<*const T, LANES> where
+    LaneCount<LANES>: SupportedLaneCount
+{
+}
+
+impl<T, const LANES: usize> SimdConstPtr for Simd<*const T, LANES>
+where
+    LaneCount<LANES>: SupportedLaneCount,
+{
+    type Usize = Simd<usize, LANES>;
+    type Isize = Simd<isize, LANES>;
+    type MutPtr = Simd<*mut T, LANES>;
+    type Mask = Mask<isize, LANES>;
+
+    #[inline]
+    fn is_null(self) -> Self::Mask {
+        Simd::splat(core::ptr::null()).simd_eq(self)
+    }
+
+    #[inline]
+    fn cast_mut(self) -> Self::MutPtr {
+        self.cast_ptr()
+    }
+
+    #[inline]
+    fn addr(self) -> Self::Usize {
+        // FIXME(strict_provenance_magic): I am magic and should be a compiler intrinsic.
+        // SAFETY: Pointer-to-integer transmutes are valid (if you are okay with losing the
+        // provenance).
+        unsafe { core::mem::transmute_copy(&self) }
+    }
+
+    #[inline]
+    fn with_addr(self, addr: Self::Usize) -> Self {
+        // FIXME(strict_provenance_magic): I am magic and should be a compiler intrinsic.
+        //
+        // In the mean-time, this operation is defined to be "as if" it was
+        // a wrapping_offset, so we can emulate it as such. This should properly
+        // restore pointer provenance even under today's compiler.
+        self.cast_ptr::<*const u8>()
+            .wrapping_offset(addr.cast::<isize>() - self.addr().cast::<isize>())
+            .cast_ptr()
+    }
+
+    #[inline]
+    fn expose_addr(self) -> Self::Usize {
+        // Safety: `self` is a pointer vector
+        unsafe { intrinsics::simd_expose_addr(self) }
+    }
+
+    #[inline]
+    fn from_exposed_addr(addr: Self::Usize) -> Self {
+        // Safety: `self` is a pointer vector
+        unsafe { intrinsics::simd_from_exposed_addr(addr) }
+    }
+
+    #[inline]
+    fn wrapping_offset(self, count: Self::Isize) -> Self {
+        // Safety: simd_arith_offset takes a vector of pointers and a vector of offsets
+        unsafe { intrinsics::simd_arith_offset(self, count) }
+    }
+
+    #[inline]
+    fn wrapping_add(self, count: Self::Usize) -> Self {
+        self.wrapping_offset(count.cast())
+    }
+
+    #[inline]
+    fn wrapping_sub(self, count: Self::Usize) -> Self {
+        self.wrapping_offset(-count.cast::<isize>())
+    }
+}
diff --git a/library/portable-simd/crates/core_simd/src/elements/mut_ptr.rs b/library/portable-simd/crates/core_simd/src/elements/mut_ptr.rs
new file mode 100644
index 000000000..d87986b4a
--- /dev/null
+++ b/library/portable-simd/crates/core_simd/src/elements/mut_ptr.rs
@@ -0,0 +1,136 @@
+use super::sealed::Sealed;
+use crate::simd::{intrinsics, LaneCount, Mask, Simd, SimdPartialEq, SupportedLaneCount};
+
+/// Operations on SIMD vectors of mutable pointers.
+pub trait SimdMutPtr: Copy + Sealed {
+    /// Vector of `usize` with the same number of lanes.
+    type Usize;
+
+    /// Vector of `isize` with the same number of lanes.
+    type Isize;
+
+    /// Vector of constant pointers to the same type.
+    type ConstPtr;
+
+    /// Mask type used for manipulating this SIMD vector type.
+    type Mask;
+
+    /// Returns `true` for each lane that is null.
+    fn is_null(self) -> Self::Mask;
+
+    /// Changes constness without changing the type.
+    ///
+    /// Equivalent to calling [`pointer::cast_const`] on each lane.
+    fn cast_const(self) -> Self::ConstPtr;
+
+    /// Gets the "address" portion of the pointer.
+    ///
+    /// This method discards pointer semantic metadata, so the result cannot be
+    /// directly cast into a valid pointer.
+    ///
+    /// Equivalent to calling [`pointer::addr`] on each lane.
+    fn addr(self) -> Self::Usize;
+
+    /// Creates a new pointer with the given address.
+    ///
+    /// This performs the same operation as a cast, but copies the *address-space* and
+    /// *provenance* of `self` to the new pointer.
+    ///
+    /// Equivalent to calling [`pointer::with_addr`] on each lane.
+    fn with_addr(self, addr: Self::Usize) -> Self;
+
+    /// Gets the "address" portion of the pointer, and "exposes" the provenance part for future use
+    /// in [`Self::from_exposed_addr`].
+    fn expose_addr(self) -> Self::Usize;
+
+    /// Convert an address back to a pointer, picking up a previously "exposed" provenance.
+    ///
+    /// Equivalent to calling [`core::ptr::from_exposed_addr_mut`] on each lane.
+    fn from_exposed_addr(addr: Self::Usize) -> Self;
+
+    /// Calculates the offset from a pointer using wrapping arithmetic.
+    ///
+    /// Equivalent to calling [`pointer::wrapping_offset`] on each lane.
+    fn wrapping_offset(self, offset: Self::Isize) -> Self;
+
+    /// Calculates the offset from a pointer using wrapping arithmetic.
+    ///
+    /// Equivalent to calling [`pointer::wrapping_add`] on each lane.
+    fn wrapping_add(self, count: Self::Usize) -> Self;
+
+    /// Calculates the offset from a pointer using wrapping arithmetic.
+    ///
+    /// Equivalent to calling [`pointer::wrapping_sub`] on each lane.
+    fn wrapping_sub(self, count: Self::Usize) -> Self;
+}
+
+impl<T, const LANES: usize> Sealed for Simd<*mut T, LANES> where LaneCount<LANES>: SupportedLaneCount
+{}
+
+impl<T, const LANES: usize> SimdMutPtr for Simd<*mut T, LANES>
+where
+    LaneCount<LANES>: SupportedLaneCount,
+{
+    type Usize = Simd<usize, LANES>;
+    type Isize = Simd<isize, LANES>;
+    type ConstPtr = Simd<*const T, LANES>;
+    type Mask = Mask<isize, LANES>;
+
+    #[inline]
+    fn is_null(self) -> Self::Mask {
+        Simd::splat(core::ptr::null_mut()).simd_eq(self)
+    }
+
+    #[inline]
+    fn cast_const(self) -> Self::ConstPtr {
+        self.cast_ptr()
+    }
+
+    #[inline]
+    fn addr(self) -> Self::Usize {
+        // FIXME(strict_provenance_magic): I am magic and should be a compiler intrinsic.
+        // SAFETY: Pointer-to-integer transmutes are valid (if you are okay with losing the
+        // provenance).
+        unsafe { core::mem::transmute_copy(&self) }
+    }
+
+    #[inline]
+    fn with_addr(self, addr: Self::Usize) -> Self {
+        // FIXME(strict_provenance_magic): I am magic and should be a compiler intrinsic.
+        //
+        // In the mean-time, this operation is defined to be "as if" it was
+        // a wrapping_offset, so we can emulate it as such. This should properly
+        // restore pointer provenance even under today's compiler.
+        self.cast_ptr::<*mut u8>()
+            .wrapping_offset(addr.cast::<isize>() - self.addr().cast::<isize>())
+            .cast_ptr()
+    }
+
+    #[inline]
+    fn expose_addr(self) -> Self::Usize {
+        // Safety: `self` is a pointer vector
+        unsafe { intrinsics::simd_expose_addr(self) }
+    }
+
+    #[inline]
+    fn from_exposed_addr(addr: Self::Usize) -> Self {
+        // Safety: `self` is a pointer vector
+        unsafe { intrinsics::simd_from_exposed_addr(addr) }
+    }
+
+    #[inline]
+    fn wrapping_offset(self, count: Self::Isize) -> Self {
+        // Safety: simd_arith_offset takes a vector of pointers and a vector of offsets
+        unsafe { intrinsics::simd_arith_offset(self, count) }
+    }
+
+    #[inline]
+    fn wrapping_add(self, count: Self::Usize) -> Self {
+        self.wrapping_offset(count.cast())
+    }
+
+    #[inline]
+    fn wrapping_sub(self, count: Self::Usize) -> Self {
+        self.wrapping_offset(-count.cast::<isize>())
+    }
+}
diff --git a/library/portable-simd/crates/core_simd/src/eq.rs b/library/portable-simd/crates/core_simd/src/eq.rs
index c7111f720..80763c072 100644
--- a/library/portable-simd/crates/core_simd/src/eq.rs
+++ b/library/portable-simd/crates/core_simd/src/eq.rs
@@ -1,4 +1,6 @@
-use crate::simd::{intrinsics, LaneCount, Mask, Simd, SimdElement, SupportedLaneCount};
+use crate::simd::{
+    intrinsics, LaneCount, Mask, Simd, SimdConstPtr, SimdElement, SimdMutPtr, SupportedLaneCount,
+};
 
 /// Parallel `PartialEq`.
 pub trait SimdPartialEq {
@@ -71,3 +73,37 @@ macro_rules! impl_mask {
 }
 
 impl_mask! { i8, i16, i32, i64, isize }
+
+impl<T, const LANES: usize> SimdPartialEq for Simd<*const T, LANES>
+where
+    LaneCount<LANES>: SupportedLaneCount,
+{
+    type Mask = Mask<isize, LANES>;
+
+    #[inline]
+    fn simd_eq(self, other: Self) -> Self::Mask {
+        self.addr().simd_eq(other.addr())
+    }
+
+    #[inline]
+    fn simd_ne(self, other: Self) -> Self::Mask {
+        self.addr().simd_ne(other.addr())
+    }
+}
+
+impl<T, const LANES: usize> SimdPartialEq for Simd<*mut T, LANES>
+where
+    LaneCount<LANES>: SupportedLaneCount,
+{
+    type Mask = Mask<isize, LANES>;
+
+    #[inline]
+    fn simd_eq(self, other: Self) -> Self::Mask {
+        self.addr().simd_eq(other.addr())
+    }
+
+    #[inline]
+    fn simd_ne(self, other: Self) -> Self::Mask {
+        self.addr().simd_ne(other.addr())
+    }
+}
diff --git a/library/portable-simd/crates/core_simd/src/fmt.rs b/library/portable-simd/crates/core_simd/src/fmt.rs
index dbd9839c4..b7317969c 100644
--- a/library/portable-simd/crates/core_simd/src/fmt.rs
+++ b/library/portable-simd/crates/core_simd/src/fmt.rs
@@ -1,39 +1,21 @@
 use crate::simd::{LaneCount, Simd, SimdElement, SupportedLaneCount};
 use core::fmt;
 
-macro_rules! impl_fmt_trait {
-    { $($trait:ident,)* } => {
-        $(
-            impl<T, const LANES: usize> fmt::$trait for Simd<T, LANES>
-            where
-                LaneCount<LANES>: SupportedLaneCount,
-                T: SimdElement + fmt::$trait,
-            {
-                fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-                    #[repr(transparent)]
-                    struct Wrapper<'a, T: fmt::$trait>(&'a T);
-
-                    impl<T: fmt::$trait> fmt::Debug for Wrapper<'_, T> {
-                        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-                            self.0.fmt(f)
-                        }
-                    }
-
-                    f.debug_list()
-                        .entries(self.as_array().iter().map(|x| Wrapper(x)))
-                        .finish()
-                }
-            }
-        )*
+impl<T, const LANES: usize> fmt::Debug for Simd<T, LANES>
+where
+    LaneCount<LANES>: SupportedLaneCount,
+    T: SimdElement + fmt::Debug,
+{
+    /// A `Simd<T, N>` has a debug format like the one for `[T]`:
+    /// ```
+    /// # #![feature(portable_simd)]
+    /// # #[cfg(feature = "as_crate")] use core_simd::simd::Simd;
+    /// # #[cfg(not(feature = "as_crate"))] use core::simd::Simd;
+    /// let floats = Simd::<f32, 4>::splat(-1.0);
+    /// assert_eq!(format!("{:?}", [-1.0; 4]), format!("{:?}", floats));
+    /// ```
+    #[inline]
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        <[T] as fmt::Debug>::fmt(self.as_array(), f)
     }
 }
-
-impl_fmt_trait! {
-    Debug,
-    Binary,
-    LowerExp,
-    UpperExp,
-    Octal,
-    LowerHex,
-    UpperHex,
-}
diff --git a/library/portable-simd/crates/core_simd/src/intrinsics.rs b/library/portable-simd/crates/core_simd/src/intrinsics.rs
index 704e6ed01..dd6698e2b 100644
--- a/library/portable-simd/crates/core_simd/src/intrinsics.rs
+++ b/library/portable-simd/crates/core_simd/src/intrinsics.rs
@@ -61,9 +61,6 @@ extern "platform-intrinsic" {
     /// xor
     pub(crate) fn simd_xor<T>(x: T, y: T) -> T;
 
-    /// getelementptr (without inbounds)
-    pub(crate) fn simd_arith_offset<T, U>(ptrs: T, offsets: U) -> T;
-
     /// fptoui/fptosi/uitofp/sitofp
     /// casting floats to integers is truncating, so it is safe to convert values like e.g. 1.5
     /// but the truncated value must fit in the target type or the result is poison.
@@ -150,4 +147,17 @@ extern "platform-intrinsic" {
     pub(crate) fn simd_select<M, T>(m: M, yes: T, no: T) -> T;
     #[allow(unused)]
     pub(crate) fn simd_select_bitmask<M, T>(m: M, yes: T, no: T) -> T;
+
+    /// getelementptr (without inbounds)
+    /// equivalent to wrapping_offset
+    pub(crate) fn simd_arith_offset<T, U>(ptr: T, offset: U) -> T;
+
+    /// equivalent to `T as U` semantics, specifically for pointers
+    pub(crate) fn simd_cast_ptr<T, U>(ptr: T) -> U;
+
+    /// expose a pointer as an address
+    pub(crate) fn simd_expose_addr<T, U>(ptr: T) -> U;
+
+    /// convert an exposed address back to a pointer
+    pub(crate) fn simd_from_exposed_addr<T, U>(addr: T) -> U;
 }
diff --git a/library/portable-simd/crates/core_simd/src/lane_count.rs b/library/portable-simd/crates/core_simd/src/lane_count.rs
index 63723e2ec..2b91eb9e8 100644
--- a/library/portable-simd/crates/core_simd/src/lane_count.rs
+++ b/library/portable-simd/crates/core_simd/src/lane_count.rs
@@ -23,24 +23,20 @@ pub trait SupportedLaneCount: Sealed {
 
 impl<const LANES: usize> Sealed for LaneCount<LANES> {}
 
-impl SupportedLaneCount for LaneCount<1> {
-    type BitMask = [u8; 1];
-}
-impl SupportedLaneCount for LaneCount<2> {
-    type BitMask = [u8; 1];
-}
-impl SupportedLaneCount for LaneCount<4> {
-    type BitMask = [u8; 1];
-}
-impl SupportedLaneCount for LaneCount<8> {
-    type BitMask = [u8; 1];
-}
-impl SupportedLaneCount for LaneCount<16> {
-    type BitMask = [u8; 2];
-}
-impl SupportedLaneCount for LaneCount<32> {
-    type BitMask = [u8; 4];
-}
-impl SupportedLaneCount for LaneCount<64> {
-    type BitMask = [u8; 8];
+macro_rules! supported_lane_count {
+    ($($lanes:literal),+) => {
+        $(
+            impl SupportedLaneCount for LaneCount<$lanes> {
+                type BitMask = [u8; ($lanes + 7) / 8];
+            }
+        )+
+    };
 }
+
+supported_lane_count!(1, 2, 4, 8, 16, 32, 64);
+#[cfg(feature = "all_lane_counts")]
+supported_lane_count!(
+    3, 5, 6, 7, 9, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30,
+    31, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55,
+    56, 57, 58, 59, 60, 61, 62, 63
+);
diff --git a/library/portable-simd/crates/core_simd/src/lib.rs b/library/portable-simd/crates/core_simd/src/lib.rs
index 715f258f6..e5307de21 100644
--- a/library/portable-simd/crates/core_simd/src/lib.rs
+++ b/library/portable-simd/crates/core_simd/src/lib.rs
@@ -1,5 +1,8 @@
 #![no_std]
 #![feature(
+    const_refs_to_cell,
+    const_maybe_uninit_as_mut_ptr,
+    const_mut_refs,
     convert_float_to_int,
     decl_macro,
     intra_doc_pointers,
@@ -7,7 +10,9 @@
     repr_simd,
     simd_ffi,
     staged_api,
-    stdsimd
+    stdsimd,
+    strict_provenance,
+    ptr_metadata
 )]
 #![cfg_attr(feature = "generic_const_exprs", feature(generic_const_exprs))]
 #![cfg_attr(feature = "generic_const_exprs", allow(incomplete_features))]
@@ -19,4 +24,3 @@
 #[path = "mod.rs"]
 mod core_simd;
 pub use self::core_simd::simd;
-pub use simd::*;
diff --git a/library/portable-simd/crates/core_simd/src/masks.rs b/library/portable-simd/crates/core_simd/src/masks.rs
index c36c336d8..e0f3c7bee 100644
--- a/library/portable-simd/crates/core_simd/src/masks.rs
+++ b/library/portable-simd/crates/core_simd/src/masks.rs
@@ -55,6 +55,7 @@ pub unsafe trait MaskElement: SimdElement + Sealed {}
 macro_rules! impl_element {
     { $ty:ty } => {
         impl Sealed for $ty {
+            #[inline]
             fn valid<const LANES: usize>(value: Simd<Self, LANES>) -> bool
             where
                 LaneCount<LANES>: SupportedLaneCount,
@@ -62,6 +63,7 @@ macro_rules! impl_element {
                 (value.simd_eq(Simd::splat(0 as _)) | value.simd_eq(Simd::splat(-1 as _))).all()
             }
 
+            #[inline]
             fn eq(self, other: Self) -> bool { self == other }
 
             const TRUE: Self = -1;
@@ -83,8 +85,10 @@ impl_element! { isize }
 ///
 /// Masks represent boolean inclusion/exclusion on a per-lane basis.
 ///
-/// The layout of this type is unspecified.
-#[repr(transparent)]
+/// The layout of this type is unspecified, and may change between platforms
+/// and/or Rust versions, and code should not assume that it is equivalent to
+/// `[T; LANES]`.
+#[cfg_attr(not(doc), repr(transparent))] // work around https://github.com/rust-lang/rust/issues/90435
 pub struct Mask<T, const LANES: usize>(mask_impl::Mask<T, LANES>)
 where
     T: MaskElement,
@@ -102,6 +106,7 @@ where
     T: MaskElement,
     LaneCount<LANES>: SupportedLaneCount,
 {
+    #[inline]
     fn clone(&self) -> Self {
         *self
     }
@@ -113,11 +118,13 @@ where
     LaneCount<LANES>: SupportedLaneCount,
 {
     /// Construct a mask by setting all lanes to the given value.
+    #[inline]
     pub fn splat(value: bool) -> Self {
         Self(mask_impl::Mask::splat(value))
     }
 
     /// Converts an array of bools to a SIMD mask.
+    #[inline]
     pub fn from_array(array: [bool; LANES]) -> Self {
         // SAFETY: Rust's bool has a layout of 1 byte (u8) with a value of
         //     true:    0b_0000_0001
@@ -134,6 +141,7 @@ where
     }
 
     /// Converts a SIMD mask to an array of bools.
+    #[inline]
     pub fn to_array(self) -> [bool; LANES] {
         // This follows mostly the same logic as from_array.
         // SAFETY: Rust's bool has a layout of 1 byte (u8) with a value of
@@ -261,6 +269,7 @@ where
     T: MaskElement,
     LaneCount<LANES>: SupportedLaneCount,
 {
+    #[inline]
     fn from(array: [bool; LANES]) -> Self {
         Self::from_array(array)
     }
@@ -271,6 +280,7 @@ where
     T: MaskElement,
     LaneCount<LANES>: SupportedLaneCount,
 {
+    #[inline]
     fn from(vector: Mask<T, LANES>) -> Self {
         vector.to_array()
     }
@@ -520,60 +530,6 @@ where
     }
 }
 
-/// A mask for SIMD vectors with eight elements of 8 bits.
-pub type mask8x8 = Mask<i8, 8>;
-
-/// A mask for SIMD vectors with 16 elements of 8 bits.
-pub type mask8x16 = Mask<i8, 16>;
-
-/// A mask for SIMD vectors with 32 elements of 8 bits.
-pub type mask8x32 = Mask<i8, 32>;
-
-/// A mask for SIMD vectors with 64 elements of 8 bits.
-pub type mask8x64 = Mask<i8, 64>;
-
-/// A mask for SIMD vectors with four elements of 16 bits.
-pub type mask16x4 = Mask<i16, 4>;
-
-/// A mask for SIMD vectors with eight elements of 16 bits.
-pub type mask16x8 = Mask<i16, 8>;
-
-/// A mask for SIMD vectors with 16 elements of 16 bits.
-pub type mask16x16 = Mask<i16, 16>;
-
-/// A mask for SIMD vectors with 32 elements of 16 bits.
-pub type mask16x32 = Mask<i16, 32>;
-
-/// A mask for SIMD vectors with two elements of 32 bits.
-pub type mask32x2 = Mask<i32, 2>;
-
-/// A mask for SIMD vectors with four elements of 32 bits.
-pub type mask32x4 = Mask<i32, 4>;
-
-/// A mask for SIMD vectors with eight elements of 32 bits.
-pub type mask32x8 = Mask<i32, 8>;
-
-/// A mask for SIMD vectors with 16 elements of 32 bits.
-pub type mask32x16 = Mask<i32, 16>;
-
-/// A mask for SIMD vectors with two elements of 64 bits.
-pub type mask64x2 = Mask<i64, 2>;
-
-/// A mask for SIMD vectors with four elements of 64 bits.
-pub type mask64x4 = Mask<i64, 4>;
-
-/// A mask for SIMD vectors with eight elements of 64 bits.
-pub type mask64x8 = Mask<i64, 8>;
-
-/// A mask for SIMD vectors with two elements of pointer width.
-pub type masksizex2 = Mask<isize, 2>;
-
-/// A mask for SIMD vectors with four elements of pointer width.
-pub type masksizex4 = Mask<isize, 4>;
-
-/// A mask for SIMD vectors with eight elements of pointer width.
-pub type masksizex8 = Mask<isize, 8>;
-
 macro_rules! impl_from {
     { $from:ty  => $($to:ty),* } => {
         $(
@@ -581,6 +537,7 @@ macro_rules! impl_from {
         where
             LaneCount<LANES>: SupportedLaneCount,
         {
+            #[inline]
             fn from(value: Mask<$from, LANES>) -> Self {
                 value.cast()
             }
diff --git a/library/portable-simd/crates/core_simd/src/masks/bitmask.rs b/library/portable-simd/crates/core_simd/src/masks/bitmask.rs
index 365ecc0a3..20465ba9b 100644
--- a/library/portable-simd/crates/core_simd/src/masks/bitmask.rs
+++ b/library/portable-simd/crates/core_simd/src/masks/bitmask.rs
@@ -26,6 +26,7 @@ where
     T: MaskElement,
     LaneCount<LANES>: SupportedLaneCount,
 {
+    #[inline]
     fn clone(&self) -> Self {
         *self
     }
@@ -36,6 +37,7 @@ where
     T: MaskElement,
     LaneCount<LANES>: SupportedLaneCount,
 {
+    #[inline]
     fn eq(&self, other: &Self) -> bool {
         self.0.as_ref() == other.0.as_ref()
     }
@@ -46,6 +48,7 @@ where
     T: MaskElement,
     LaneCount<LANES>: SupportedLaneCount,
 {
+    #[inline]
     fn partial_cmp(&self, other: &Self) -> Option<core::cmp::Ordering> {
         self.0.as_ref().partial_cmp(other.0.as_ref())
     }
@@ -63,6 +66,7 @@ where
     T: MaskElement,
     LaneCount<LANES>: SupportedLaneCount,
 {
+    #[inline]
     fn cmp(&self, other: &Self) -> core::cmp::Ordering {
         self.0.as_ref().cmp(other.0.as_ref())
     }
diff --git a/library/portable-simd/crates/core_simd/src/masks/full_masks.rs b/library/portable-simd/crates/core_simd/src/masks/full_masks.rs
index b5ba198e5..1d13c45b8 100644
--- a/library/portable-simd/crates/core_simd/src/masks/full_masks.rs
+++ b/library/portable-simd/crates/core_simd/src/masks/full_masks.rs
@@ -37,6 +37,7 @@ where
     T: MaskElement + PartialEq,
     LaneCount<LANES>: SupportedLaneCount,
 {
+    #[inline]
     fn eq(&self, other: &Self) -> bool {
         self.0.eq(&other.0)
     }
@@ -47,6 +48,7 @@ where
     T: MaskElement + PartialOrd,
     LaneCount<LANES>: SupportedLaneCount,
 {
+    #[inline]
     fn partial_cmp(&self, other: &Self) -> Option<core::cmp::Ordering> {
         self.0.partial_cmp(&other.0)
     }
@@ -64,6 +66,7 @@ where
     T: MaskElement + Ord,
     LaneCount<LANES>: SupportedLaneCount,
 {
+    #[inline]
     fn cmp(&self, other: &Self) -> core::cmp::Ordering {
         self.0.cmp(&other.0)
     }
@@ -262,6 +265,7 @@ where
     T: MaskElement,
     LaneCount<LANES>: SupportedLaneCount,
 {
+    #[inline]
     fn from(value: Mask<T, LANES>) -> Self {
         value.0
     }
diff --git a/library/portable-simd/crates/core_simd/src/masks/to_bitmask.rs b/library/portable-simd/crates/core_simd/src/masks/to_bitmask.rs
index 2235f016c..fc7d6b781 100644
--- a/library/portable-simd/crates/core_simd/src/masks/to_bitmask.rs
+++ b/library/portable-simd/crates/core_simd/src/masks/to_bitmask.rs
@@ -48,10 +48,12 @@ macro_rules! impl_integer_intrinsic {
         impl<T: MaskElement> ToBitMask for Mask<T, $lanes> {
             type BitMask = $int;
 
+            #[inline]
             fn to_bitmask(self) -> $int {
                 self.0.to_bitmask_integer()
             }
 
+            #[inline]
             fn from_bitmask(bitmask: $int) -> Self {
                 Self(mask_impl::Mask::from_bitmask_integer(bitmask))
             }
@@ -83,10 +85,12 @@ where
 {
     const BYTES: usize = bitmask_len(LANES);
 
+    #[inline]
     fn to_bitmask_array(self) -> [u8; Self::BYTES] {
         self.0.to_bitmask_array()
     }
 
+    #[inline]
     fn from_bitmask_array(bitmask: [u8; Self::BYTES]) -> Self {
         Mask(mask_impl::Mask::from_bitmask_array(bitmask))
     }
diff --git a/library/portable-simd/crates/core_simd/src/mod.rs b/library/portable-simd/crates/core_simd/src/mod.rs
index b472aa3ab..35c659b7a 100644
--- a/library/portable-simd/crates/core_simd/src/mod.rs
+++ b/library/portable-simd/crates/core_simd/src/mod.rs
@@ -6,6 +6,8 @@ pub(crate) mod intrinsics;
 #[cfg(feature = "generic_const_exprs")]
 mod to_bytes;
 
+mod alias;
+mod cast;
 mod elements;
 mod eq;
 mod fmt;
@@ -15,6 +17,7 @@ mod masks;
 mod ops;
 mod ord;
 mod select;
+mod swizzle_dyn;
 mod vector;
 mod vendor;
 
@@ -22,11 +25,14 @@ mod vendor;
 pub mod simd {
     pub(crate) use crate::core_simd::intrinsics;
 
+    pub use crate::core_simd::alias::*;
+    pub use crate::core_simd::cast::*;
     pub use crate::core_simd::elements::*;
     pub use crate::core_simd::eq::*;
     pub use crate::core_simd::lane_count::{LaneCount, SupportedLaneCount};
     pub use crate::core_simd::masks::*;
     pub use crate::core_simd::ord::*;
     pub use crate::core_simd::swizzle::*;
+    pub use crate::core_simd::swizzle_dyn::*;
     pub use crate::core_simd::vector::*;
 }
diff --git a/library/portable-simd/crates/core_simd/src/ops/deref.rs b/library/portable-simd/crates/core_simd/src/ops/deref.rs
index 9883a74c9..302bf148b 100644
--- a/library/portable-simd/crates/core_simd/src/ops/deref.rs
+++ b/library/portable-simd/crates/core_simd/src/ops/deref.rs
@@ -71,7 +71,7 @@ macro_rules! deref_ops {
 
                 #[inline]
                 #[must_use = "operator returns a new vector without mutating the inputs"]
-                fn $call(self, rhs: &$simd) -> Self::Output {
+                fn $call(self, rhs: &'rhs $simd) -> Self::Output {
                     (*self).$call(*rhs)
                 }
             }
diff --git a/library/portable-simd/crates/core_simd/src/ord.rs b/library/portable-simd/crates/core_simd/src/ord.rs
index 9a87bc2e3..1ae9cd061 100644
--- a/library/portable-simd/crates/core_simd/src/ord.rs
+++ b/library/portable-simd/crates/core_simd/src/ord.rs
@@ -1,4 +1,6 @@
-use crate::simd::{intrinsics, LaneCount, Mask, Simd, SimdPartialEq, SupportedLaneCount};
+use crate::simd::{
+    intrinsics, LaneCount, Mask, Simd, SimdConstPtr, SimdMutPtr, SimdPartialEq, SupportedLaneCount,
+};
 
 /// Parallel `PartialOrd`.
 pub trait SimdPartialOrd: SimdPartialEq {
@@ -211,3 +213,101 @@ macro_rules! impl_mask {
 }
 
 impl_mask! { i8, i16, i32, i64, isize }
+
+impl<T, const LANES: usize> SimdPartialOrd for Simd<*const T, LANES>
+where
+    LaneCount<LANES>: SupportedLaneCount,
+{
+    #[inline]
+    fn simd_lt(self, other: Self) -> Self::Mask {
+        self.addr().simd_lt(other.addr())
+    }
+
+    #[inline]
+    fn simd_le(self, other: Self) -> Self::Mask {
+        self.addr().simd_le(other.addr())
+    }
+
+    #[inline]
+    fn simd_gt(self, other: Self) -> Self::Mask {
+        self.addr().simd_gt(other.addr())
+    }
+
+    #[inline]
+    fn simd_ge(self, other: Self) -> Self::Mask {
+        self.addr().simd_ge(other.addr())
+    }
+}
+
+impl<T, const LANES: usize> SimdOrd for Simd<*const T, LANES>
+where
+    LaneCount<LANES>: SupportedLaneCount,
+{
+    #[inline]
+    fn simd_max(self, other: Self) -> Self {
+        self.simd_lt(other).select(other, self)
+    }
+
+    #[inline]
+    fn simd_min(self, other: Self) -> Self {
+        self.simd_gt(other).select(other, self)
+    }
+
+    #[inline]
+    fn simd_clamp(self, min: Self, max: Self) -> Self {
+        assert!(
+            min.simd_le(max).all(),
+            "each lane in `min` must be less than or equal to the corresponding lane in `max`",
+        );
+        self.simd_max(min).simd_min(max)
+    }
+}
+
+impl<T, const LANES: usize> SimdPartialOrd for Simd<*mut T, LANES>
+where
+    LaneCount<LANES>: SupportedLaneCount,
+{
+    #[inline]
+    fn simd_lt(self, other: Self) -> Self::Mask {
+        self.addr().simd_lt(other.addr())
+    }
+
+    #[inline]
+    fn simd_le(self, other: Self) -> Self::Mask {
+        self.addr().simd_le(other.addr())
+    }
+
+    #[inline]
+    fn simd_gt(self, other: Self) -> Self::Mask {
+        self.addr().simd_gt(other.addr())
+    }
+
+    #[inline]
+    fn simd_ge(self, other: Self) -> Self::Mask {
+        self.addr().simd_ge(other.addr())
+    }
+}
+
+impl<T, const LANES: usize> SimdOrd for Simd<*mut T, LANES>
+where
+    LaneCount<LANES>: SupportedLaneCount,
+{
+    #[inline]
+    fn simd_max(self, other: Self) -> Self {
+        self.simd_lt(other).select(other, self)
+    }
+
+    #[inline]
+    fn simd_min(self, other: Self) -> Self {
+        self.simd_gt(other).select(other, self)
+    }
+
+    #[inline]
+    fn simd_clamp(self, min: Self, max: Self) -> Self {
+        assert!(
+            min.simd_le(max).all(),
+            "each lane in `min` must be less than or equal to the corresponding lane in `max`",
+        );
+        self.simd_max(min).simd_min(max)
+    }
+}
diff --git a/library/portable-simd/crates/core_simd/src/swizzle.rs b/library/portable-simd/crates/core_simd/src/swizzle.rs
index 22999d249..68f20516c 100644
--- a/library/portable-simd/crates/core_simd/src/swizzle.rs
+++ b/library/portable-simd/crates/core_simd/src/swizzle.rs
@@ -265,16 +265,13 @@ where
 
     /// Interleave two vectors.
     ///
-    /// Produces two vectors with lanes taken alternately from `self` and `other`.
+    /// The resulting vectors contain lanes taken alternatively from `self` and `other`, first
+    /// filling the first result, and then the second.
     ///
-    /// The first result contains the first `LANES / 2` lanes from `self` and `other`,
-    /// alternating, starting with the first lane of `self`.
-    ///
-    /// The second result contains the last `LANES / 2` lanes from `self` and `other`,
-    /// alternating, starting with the lane `LANES / 2` from the start of `self`.
+    /// The reverse of this operation is [`Simd::deinterleave`].
     ///
     /// ```
-    /// #![feature(portable_simd)]
+    /// # #![feature(portable_simd)]
     /// # use core::simd::Simd;
     /// let a = Simd::from_array([0, 1, 2, 3]);
     /// let b = Simd::from_array([4, 5, 6, 7]);
@@ -285,29 +282,17 @@ where
     #[inline]
     #[must_use = "method returns a new vector and does not mutate the original inputs"]
     pub fn interleave(self, other: Self) -> (Self, Self) {
-        const fn lo<const LANES: usize>() -> [Which; LANES] {
-            let mut idx = [Which::First(0); LANES];
-            let mut i = 0;
-            while i < LANES {
-                let offset = i / 2;
-                idx[i] = if i % 2 == 0 {
-                    Which::First(offset)
-                } else {
-                    Which::Second(offset)
-                };
-                i += 1;
-            }
-            idx
-        }
-        const fn hi<const LANES: usize>() -> [Which; LANES] {
+        const fn interleave<const LANES: usize>(high: bool) -> [Which; LANES] {
             let mut idx = [Which::First(0); LANES];
             let mut i = 0;
             while i < LANES {
-                let offset = (LANES + i) / 2;
-                idx[i] = if i % 2 == 0 {
-                    Which::First(offset)
+                // Treat the source as a concatenated vector
+                let dst_index = if high { i + LANES } else { i };
+                let src_index = dst_index / 2 + (dst_index % 2) * LANES;
+                idx[i] = if src_index < LANES {
+                    Which::First(src_index)
                 } else {
-                    Which::Second(offset)
+                    Which::Second(src_index % LANES)
                 };
                 i += 1;
             }
@@ -318,11 +303,11 @@ where
         struct Hi;
 
         impl<const LANES: usize> Swizzle2<LANES, LANES> for Lo {
-            const INDEX: [Which; LANES] = lo::<LANES>();
+            const INDEX: [Which; LANES] = interleave::<LANES>(false);
         }
 
         impl<const LANES: usize> Swizzle2<LANES, LANES> for Hi {
-            const INDEX: [Which; LANES] = hi::<LANES>();
+            const INDEX: [Which; LANES] = interleave::<LANES>(true);
         }
 
         (Lo::swizzle2(self, other), Hi::swizzle2(self, other))
@@ -336,8 +321,10 @@ where
     /// The second result takes every other lane of `self` and then `other`, starting with
     /// the second lane.
     ///
+    /// The reverse of this operation is [`Simd::interleave`].
+    ///
     /// ```
-    /// #![feature(portable_simd)]
+    /// # #![feature(portable_simd)]
     /// # use core::simd::Simd;
     /// let a = Simd::from_array([0, 4, 1, 5]);
     /// let b = Simd::from_array([2, 6, 3, 7]);
@@ -348,22 +335,17 @@ where
     #[inline]
     #[must_use = "method returns a new vector and does not mutate the original inputs"]
     pub fn deinterleave(self, other: Self) -> (Self, Self) {
-        const fn even<const LANES: usize>() -> [Which; LANES] {
-            let mut idx = [Which::First(0); LANES];
-            let mut i = 0;
-            while i < LANES / 2 {
-                idx[i] = Which::First(2 * i);
-                idx[i + LANES / 2] = Which::Second(2 * i);
-                i += 1;
-            }
-            idx
-        }
-        const fn odd<const LANES: usize>() -> [Which; LANES] {
+        const fn deinterleave<const LANES: usize>(second: bool) -> [Which; LANES] {
             let mut idx = [Which::First(0); LANES];
             let mut i = 0;
-            while i < LANES / 2 {
-                idx[i] = Which::First(2 * i + 1);
-                idx[i + LANES / 2] = Which::Second(2 * i + 1);
+            while i < LANES {
+                // Treat the source as a concatenated vector
+                let src_index = i * 2 + second as usize;
+                idx[i] = if src_index < LANES {
+                    Which::First(src_index)
+                } else {
+                    Which::Second(src_index % LANES)
+                };
                 i += 1;
             }
             idx
@@ -373,11 +355,11 @@ where
         struct Odd;
 
         impl<const LANES: usize> Swizzle2<LANES, LANES> for Even {
-            const INDEX: [Which; LANES] = even::<LANES>();
+            const INDEX: [Which; LANES] = deinterleave::<LANES>(false);
         }
 
         impl<const LANES: usize> Swizzle2<LANES, LANES> for Odd {
-            const INDEX: [Which; LANES] = odd::<LANES>();
+            const INDEX: [Which; LANES] = deinterleave::<LANES>(true);
         }
 
         (Even::swizzle2(self, other), Odd::swizzle2(self, other))
diff --git a/library/portable-simd/crates/core_simd/src/swizzle_dyn.rs b/library/portable-simd/crates/core_simd/src/swizzle_dyn.rs
new file mode 100644
index 000000000..6065d6459
--- /dev/null
+++ b/library/portable-simd/crates/core_simd/src/swizzle_dyn.rs
@@ -0,0 +1,157 @@
+use crate::simd::{LaneCount, Simd, SupportedLaneCount};
+use core::mem;
+
+impl<const N: usize> Simd<u8, N>
+where
+    LaneCount<N>: SupportedLaneCount,
+{
+    /// Swizzle a vector of bytes according to the index vector.
+    /// Indices within range select the appropriate byte.
+    /// Indices "out of bounds" instead select 0.
+    ///
+    /// Note that the current implementation is selected during build-time
+    /// of the standard library, so `cargo build -Zbuild-std` may be necessary
+    /// to unlock better performance, especially for larger vectors.
+    /// A planned compiler improvement will enable using `#[target_feature]` instead.
+    #[inline]
+    pub fn swizzle_dyn(self, idxs: Simd<u8, N>) -> Self {
+        #![allow(unused_imports, unused_unsafe)]
+        #[cfg(target_arch = "aarch64")]
+        use core::arch::aarch64::{uint8x8_t, vqtbl1q_u8, vtbl1_u8};
+        #[cfg(all(target_arch = "arm", target_feature = "v7", target_feature = "neon"))]
+        use core::arch::arm::{uint8x8_t, vtbl1_u8};
+        #[cfg(target_arch = "wasm32")]
+        use core::arch::wasm32 as wasm;
+        #[cfg(target_arch = "x86")]
+        use core::arch::x86;
+        #[cfg(target_arch = "x86_64")]
+        use core::arch::x86_64 as x86;
+        // SAFETY: Intrinsics covered by cfg
+        unsafe {
+            match N {
+                #[cfg(target_feature = "neon")]
+                8 => transize(vtbl1_u8, self, idxs),
+                #[cfg(target_feature = "ssse3")]
+                16 => transize(x86::_mm_shuffle_epi8, self, idxs),
+                #[cfg(target_feature = "simd128")]
+                16 => transize(wasm::i8x16_swizzle, self, idxs),
+                #[cfg(all(target_arch = "aarch64", target_feature = "neon"))]
+                16 => transize(vqtbl1q_u8, self, idxs),
+                #[cfg(all(target_feature = "avx2", not(target_feature = "avx512vbmi")))]
+                32 => transize_raw(avx2_pshufb, self, idxs),
+                #[cfg(target_feature = "avx512vl,avx512vbmi")]
+                32 => transize(x86::_mm256_permutexvar_epi8, self, idxs),
+                // Notable absence: avx512bw shuffle
+                // If avx512bw is available, odds of avx512vbmi are good
+                // FIXME: initial AVX512VBMI variant didn't actually pass muster
+                // #[cfg(target_feature = "avx512vbmi")]
+                // 64 => transize(x86::_mm512_permutexvar_epi8, self, idxs),
+                _ => {
+                    let mut array = [0; N];
+                    for (i, k) in idxs.to_array().into_iter().enumerate() {
+                        if (k as usize) < N {
+                            array[i] = self[k as usize];
+                        };
+                    }
+                    array.into()
+                }
+            }
+        }
+    }
+}
+
+/// "vpshufb like it was meant to be" on AVX2
+///
+/// # Safety
+/// This requires AVX2 to work
+#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+#[target_feature(enable = "avx2")]
+#[allow(unused)]
+#[inline]
+#[allow(clippy::let_and_return)]
+unsafe fn avx2_pshufb(bytes: Simd<u8, 32>, idxs: Simd<u8, 32>) -> Simd<u8, 32> {
+    use crate::simd::SimdPartialOrd;
+    #[cfg(target_arch = "x86")]
+    use core::arch::x86;
+    #[cfg(target_arch = "x86_64")]
+    use core::arch::x86_64 as x86;
+    use x86::_mm256_permute2x128_si256 as avx2_cross_shuffle;
+    use x86::_mm256_shuffle_epi8 as avx2_half_pshufb;
+    let mid = Simd::splat(16u8);
+    let high = mid + mid;
+    // SAFETY: Caller promised AVX2
+    unsafe {
+        // This is ordering sensitive, and LLVM will order these how you put them.
+        // Most AVX2 impls use ~5 "ports", and only 1 or 2 are capable of permutes.
+        // But the "compose" step will lower to ops that can also use at least 1 other port.
+        // So this tries to break up permutes so composition flows through "open" ports.
+        // Comparative benches should be done on multiple AVX2 CPUs before reordering this
+
+        let hihi = avx2_cross_shuffle::<0x11>(bytes.into(), bytes.into());
+        let hi_shuf = Simd::from(avx2_half_pshufb(
+            hihi,        // duplicate the vector's top half
+            idxs.into(), // so that using only 4 bits of an index still picks bytes 16-31
+        ));
+        // A zero-fill during the compose step gives the "all-Neon-like" OOB-is-0 semantics
+        let compose = idxs.simd_lt(high).select(hi_shuf, Simd::splat(0));
+        let lolo = avx2_cross_shuffle::<0x00>(bytes.into(), bytes.into());
+        let lo_shuf = Simd::from(avx2_half_pshufb(lolo, idxs.into()));
+        // Repeat, then pick indices < 16, overwriting indices 0-15 from previous compose step
+        let compose = idxs.simd_lt(mid).select(lo_shuf, compose);
+        compose
+    }
+}
+
+/// This sets up a call to an architecture-specific function, and in doing so
+/// it persuades rustc that everything is the correct size. Which it is.
+/// This would not be needed if one could convince Rust that, by matching on N,
+/// N is that value, and thus it would be valid to substitute e.g. 16.
+///
+/// # Safety
+/// The correctness of this function hinges on the sizes agreeing in actuality.
+#[allow(dead_code)]
+#[inline(always)]
+unsafe fn transize<T, const N: usize>(
+    f: unsafe fn(T, T) -> T,
+    bytes: Simd<u8, N>,
+    idxs: Simd<u8, N>,
+) -> Simd<u8, N>
+where
+    LaneCount<N>: SupportedLaneCount,
+{
+    let idxs = zeroing_idxs(idxs);
+    // SAFETY: Same obligation to use this function as to use mem::transmute_copy.
+    unsafe { mem::transmute_copy(&f(mem::transmute_copy(&bytes), mem::transmute_copy(&idxs))) }
+}
+
+/// Make indices that yield 0 for this architecture
+#[inline(always)]
+fn zeroing_idxs<const N: usize>(idxs: Simd<u8, N>) -> Simd<u8, N>
+where
+    LaneCount<N>: SupportedLaneCount,
+{
+    // On x86, make sure the top bit is set.
+    #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+    let idxs = {
+        use crate::simd::SimdPartialOrd;
+        idxs.simd_lt(Simd::splat(N as u8))
+            .select(idxs, Simd::splat(u8::MAX))
+    };
+    // Simply do nothing on most architectures.
+    idxs
+}
+
+/// As transize but no implicit call to `zeroing_idxs`.
+#[allow(dead_code)]
+#[inline(always)]
+unsafe fn transize_raw<T, const N: usize>(
+    f: unsafe fn(T, T) -> T,
+    bytes: Simd<u8, N>,
+    idxs: Simd<u8, N>,
+) -> Simd<u8, N>
+where
+    LaneCount<N>: SupportedLaneCount,
+{
+    // SAFETY: Same obligation to use this function as to use mem::transmute_copy.
+    unsafe { mem::transmute_copy(&f(mem::transmute_copy(&bytes), mem::transmute_copy(&idxs))) }
+}
diff --git a/library/portable-simd/crates/core_simd/src/vector.rs b/library/portable-simd/crates/core_simd/src/vector.rs
index d52d1ac4d..3809cc961 100644
--- a/library/portable-simd/crates/core_simd/src/vector.rs
+++ b/library/portable-simd/crates/core_simd/src/vector.rs
@@ -1,60 +1,63 @@
-mod float;
-mod int;
-mod uint;
-
-pub use float::*;
-pub use int::*;
-pub use uint::*;
-
-// Vectors of pointers are not for public use at the current time.
-pub(crate) mod ptr;
-
 use crate::simd::{
-    intrinsics, LaneCount, Mask, MaskElement, SimdPartialOrd, SupportedLaneCount, Swizzle,
+    intrinsics, LaneCount, Mask, MaskElement, SimdCast, SimdCastPtr, SimdConstPtr, SimdMutPtr,
+    SimdPartialOrd, SupportedLaneCount, Swizzle,
 };
+use core::convert::{TryFrom, TryInto};
 
-/// A SIMD vector of `LANES` elements of type `T`. `Simd<T, N>` has the same shape as [`[T; N]`](array), but operates like `T`.
+/// A SIMD vector with the shape of `[T; N]` but the operations of `T`.
 ///
-/// Two vectors of the same type and length will, by convention, support the operators (+, *, etc.) that `T` does.
-/// These take the lanes at each index on the left-hand side and right-hand side, perform the operation,
-/// and return the result in the same lane in a vector of equal size. For a given operator, this is equivalent to zipping
-/// the two arrays together and mapping the operator over each lane.
+/// `Simd<T, N>` supports the operators (+, *, etc.) that `T` does in "elementwise" fashion.
+/// These take the element at each index from the left-hand side and right-hand side,
+/// perform the operation, then return the result in the same index in a vector of equal size.
+/// However, `Simd` differs from normal iteration and normal arrays:
+/// - `Simd<T, N>` executes `N` operations in a single step with no `break`s
+/// - `Simd<T, N>` can have an alignment greater than `T`, for better mechanical sympathy
+///
+/// By always imposing these constraints on `Simd`, it is easier to compile elementwise operations
+/// into machine instructions that can themselves be executed in parallel.
 ///
 /// ```rust
-/// # #![feature(array_zip, portable_simd)]
+/// # #![feature(portable_simd)]
 /// # use core::simd::{Simd};
-/// let a0: [i32; 4] = [-2, 0, 2, 4];
-/// let a1 = [10, 9, 8, 7];
-/// let zm_add = a0.zip(a1).map(|(lhs, rhs)| lhs + rhs);
-/// let zm_mul = a0.zip(a1).map(|(lhs, rhs)| lhs * rhs);
+/// # use core::array;
+/// let a: [i32; 4] = [-2, 0, 2, 4];
+/// let b = [10, 9, 8, 7];
+/// let sum = array::from_fn(|i| a[i] + b[i]);
+/// let prod = array::from_fn(|i| a[i] * b[i]);
 ///
 /// // `Simd<T, N>` implements `From<[T; N]>`
-/// let (v0, v1) = (Simd::from(a0), Simd::from(a1));
+/// let (v, w) = (Simd::from(a), Simd::from(b));
 /// // Which means arrays implement `Into<Simd<T, N>>`.
-/// assert_eq!(v0 + v1, zm_add.into());
-/// assert_eq!(v0 * v1, zm_mul.into());
+/// assert_eq!(v + w, sum.into());
+/// assert_eq!(v * w, prod.into());
 /// ```
 ///
-/// `Simd` with integers has the quirk that these operations are also inherently wrapping, as if `T` was [`Wrapping<T>`].
+///
+/// `Simd` with integer elements treats operators as wrapping, as if `T` was [`Wrapping<T>`].
 /// Thus, `Simd` does not implement `wrapping_add`, because that is the default behavior.
 /// This means there is no warning on overflows, even in "debug" builds.
 /// For most applications where `Simd` is appropriate, it is "not a bug" to wrap,
 /// and even "debug builds" are unlikely to tolerate the loss of performance.
 /// You may want to consider using explicitly checked arithmetic if such is required.
-/// Division by zero still causes a panic, so you may want to consider using floating point numbers if that is unacceptable.
+/// Division by zero on integers still causes a panic, so
+/// you may want to consider using `f32` or `f64` if that is unacceptable.
 ///
 /// [`Wrapping<T>`]: core::num::Wrapping
 ///
 /// # Layout
-/// `Simd<T, N>` has a layout similar to `[T; N]` (identical "shapes"), but with a greater alignment.
+/// `Simd<T, N>` has a layout similar to `[T; N]` (identical "shapes"), with a greater alignment.
 /// `[T; N]` is aligned to `T`, but `Simd<T, N>` will have an alignment based on both `T` and `N`.
-/// It is thus sound to [`transmute`] `Simd<T, N>` to `[T; N]`, and will typically optimize to zero cost,
-/// but the reverse transmutation is more likely to require a copy the compiler cannot simply elide.
+/// Thus it is sound to [`transmute`] `Simd<T, N>` to `[T; N]` and should optimize to "zero cost",
+/// but the reverse transmutation may require a copy the compiler cannot simply elide.
 ///
 /// # ABI "Features"
-/// Due to Rust's safety guarantees, `Simd<T, N>` is currently passed to and from functions via memory, not SIMD registers,
-/// except as an optimization. `#[inline]` hints are recommended on functions that accept `Simd<T, N>` or return it.
-/// The need for this may be corrected in the future.
+/// Due to Rust's safety guarantees, `Simd<T, N>` is currently passed and returned via memory,
+/// not SIMD registers, except as an optimization. Using `#[inline]` on functions that accept
+/// `Simd<T, N>` or return it is recommended, at the cost of code generation time, as
+/// inlining SIMD-using functions can omit a large function prolog or epilog and thus
+/// improve both speed and code size. The need for this may be corrected in the future.
+///
+/// Using `#[inline(always)]` still requires additional care.
 ///
 /// # Safe SIMD with Unsafe Rust
 ///
@@ -65,18 +68,22 @@ use crate::simd::{
 /// Thus, when using `unsafe` Rust to read and write `Simd<T, N>` through [raw pointers], it is a good idea to first try with
 /// [`read_unaligned`] and [`write_unaligned`]. This is because:
 /// - [`read`] and [`write`] require full alignment (in this case, `Simd<T, N>`'s alignment)
-/// - the likely source for reading or destination for writing `Simd<T, N>` is [`[T]`](slice) and similar types, aligned to `T`
-/// - combining these actions would violate the `unsafe` contract and explode the program into a puff of **undefined behavior**
-/// - the compiler can implicitly adjust layouts to make unaligned reads or writes fully aligned if it sees the optimization
-/// - most contemporary processors suffer no performance penalty for "unaligned" reads and writes that are aligned at runtime
+/// - `Simd<T, N>` is often read from or written to [`[T]`](slice) and other types aligned to `T`
+/// - combining these actions violates the `unsafe` contract and explodes the program into
+///   a puff of **undefined behavior**
+/// - the compiler can implicitly adjust layouts to make unaligned reads or writes fully aligned
+///   if it sees the optimization
+/// - most contemporary processors with "aligned" and "unaligned" read and write instructions
+///   exhibit no performance difference if the "unaligned" variant is aligned at runtime
 ///
-/// By imposing less obligations, unaligned functions are less likely to make the program unsound,
+/// Less obligations mean unaligned reads and writes are less likely to make the program unsound,
 /// and may be just as fast as stricter alternatives.
-/// When trying to guarantee alignment, [`[T]::as_simd`][as_simd] is an option for converting `[T]` to `[Simd<T, N>]`,
-/// and allows soundly operating on an aligned SIMD body, but it may cost more time when handling the scalar head and tail.
-/// If these are not sufficient, then it is most ideal to design data structures to be already aligned
-/// to the `Simd<T, N>` you wish to use before using `unsafe` Rust to read or write.
-/// More conventional ways to compensate for these facts, like materializing `Simd` to or from an array first,
+/// When trying to guarantee alignment, [`[T]::as_simd`][as_simd] is an option for
+/// converting `[T]` to `[Simd<T, N>]`, and allows soundly operating on an aligned SIMD body,
+/// but it may cost more time when handling the scalar head and tail.
+/// If these are not enough, it is most ideal to design data structures to be already aligned
+/// to `mem::align_of::<Simd<T, N>>()` before using `unsafe` Rust to read or write.
+/// Other ways to compensate for these facts, like materializing `Simd` to or from an array first,
 /// are handled by safe methods like [`Simd::from_array`] and [`Simd::from_slice`].
 ///
 /// [`transmute`]: core::mem::transmute
@@ -86,21 +93,26 @@ use crate::simd::{
 /// [`read`]: pointer::read
 /// [`write`]: pointer::write
 /// [as_simd]: slice::as_simd
+//
+// NOTE: Accessing the inner array directly in any way (e.g. by using the `.0` field syntax) or
+// directly constructing an instance of the type (i.e. `let vector = Simd(array)`) should be
+// avoided, as it will likely become illegal on `#[repr(simd)]` structs in the future. It also
+// causes rustc to emit illegal LLVM IR in some cases.
 #[repr(simd)]
-pub struct Simd<T, const LANES: usize>([T; LANES])
+pub struct Simd<T, const N: usize>([T; N])
 where
-    T: SimdElement,
-    LaneCount<LANES>: SupportedLaneCount;
+    LaneCount<N>: SupportedLaneCount,
+    T: SimdElement;
 
-impl<T, const LANES: usize> Simd<T, LANES>
+impl<T, const N: usize> Simd<T, N>
 where
-    LaneCount<LANES>: SupportedLaneCount,
+    LaneCount<N>: SupportedLaneCount,
     T: SimdElement,
 {
-    /// Number of lanes in this vector.
-    pub const LANES: usize = LANES;
+    /// Number of elements in this vector.
+    pub const LANES: usize = N;
 
-    /// Returns the number of lanes in this SIMD vector.
+    /// Returns the number of elements in this SIMD vector.
     ///
     /// # Examples
     ///
@@ -111,10 +123,10 @@ where
     /// assert_eq!(v.lanes(), 4);
     /// ```
     pub const fn lanes(&self) -> usize {
-        LANES
+        Self::LANES
     }
 
-    /// Constructs a new SIMD vector with all lanes set to the given value.
+    /// Constructs a new SIMD vector with all elements set to the given value.
     ///
     /// # Examples
     ///
@@ -125,11 +137,11 @@ where
     /// assert_eq!(v.as_array(), &[8, 8, 8, 8]);
     /// ```
     pub fn splat(value: T) -> Self {
-        // This is preferred over `[value; LANES]`, since it's explicitly a splat:
+        // This is preferred over `[value; N]`, since it's explicitly a splat:
         // https://github.com/rust-lang/rust/issues/97804
         struct Splat;
-        impl<const LANES: usize> Swizzle<1, LANES> for Splat {
-            const INDEX: [usize; LANES] = [0; LANES];
+        impl<const N: usize> Swizzle<1, N> for Splat {
+            const INDEX: [usize; N] = [0; N];
         }
         Splat::swizzle(Simd::<T, 1>::from([value]))
     }
@@ -144,32 +156,100 @@ where
     /// let v: u64x4 = Simd::from_array([0, 1, 2, 3]);
     /// assert_eq!(v.as_array(), &[0, 1, 2, 3]);
     /// ```
-    pub const fn as_array(&self) -> &[T; LANES] {
-        &self.0
+    pub const fn as_array(&self) -> &[T; N] {
+        // SAFETY: `Simd<T, N>` is just an overaligned `[T; N]` with
+        // potential padding at the end, so pointer casting to a
+        // `&[T; N]` is safe.
+        //
+        // NOTE: This deliberately doesn't just use `&self.0`, see the comment
+        // on the struct definition for details.
+        unsafe { &*(self as *const Self as *const [T; N]) }
     }
 
     /// Returns a mutable array reference containing the entire SIMD vector.
-    pub fn as_mut_array(&mut self) -> &mut [T; LANES] {
-        &mut self.0
+    pub fn as_mut_array(&mut self) -> &mut [T; N] {
+        // SAFETY: `Simd<T, N>` is just an overaligned `[T; N]` with
+        // potential padding at the end, so pointer casting to a
+        // `&mut [T; N]` is safe.
+        //
+        // NOTE: This deliberately doesn't just use `&mut self.0`, see the comment
+        // on the struct definition for details.
+        unsafe { &mut *(self as *mut Self as *mut [T; N]) }
+    }
+
+    /// Load a vector from an array of `T`.
+    ///
+    /// This function is necessary since `repr(simd)` has padding for non-power-of-2 vectors (at the time of writing).
+    /// With padding, `read_unaligned` will read past the end of an array of N elements.
+    ///
+    /// # Safety
+    /// Reading `ptr` must be safe, as if by `<*const [T; N]>::read_unaligned`.
+    const unsafe fn load(ptr: *const [T; N]) -> Self {
+        // There are potentially simpler ways to write this function, but this should result in
+        // LLVM `load <N x T>`
+
+        let mut tmp = core::mem::MaybeUninit::<Self>::uninit();
+        // SAFETY: `Simd<T, N>` always contains `N` elements of type `T`.  It may have padding
+        // which does not need to be initialized.  The safety of reading `ptr` is ensured by the
+        // caller.
+        unsafe {
+            core::ptr::copy_nonoverlapping(ptr, tmp.as_mut_ptr().cast(), 1);
+            tmp.assume_init()
+        }
+    }
+
+    /// Store a vector to an array of `T`.
+    ///
+    /// See `load` as to why this function is necessary.
+    ///
+    /// # Safety
+    /// Writing to `ptr` must be safe, as if by `<*mut [T; N]>::write_unaligned`.
+    const unsafe fn store(self, ptr: *mut [T; N]) {
+        // There are potentially simpler ways to write this function, but this should result in
+        // LLVM `store <N x T>`
+
+        // Creating a temporary helps LLVM turn the memcpy into a store.
+        let tmp = self;
+        // SAFETY: `Simd<T, N>` always contains `N` elements of type `T`.  The safety of writing
+        // `ptr` is ensured by the caller.
+        unsafe { core::ptr::copy_nonoverlapping(tmp.as_array(), ptr, 1) }
     }
 
     /// Converts an array to a SIMD vector.
-    pub const fn from_array(array: [T; LANES]) -> Self {
-        Self(array)
+    pub const fn from_array(array: [T; N]) -> Self {
+        // SAFETY: `&array` is safe to read.
+        //
+        // FIXME: We currently use a pointer load instead of `transmute_copy` because `repr(simd)`
+        // results in padding for non-power-of-2 vectors (so vectors are larger than arrays).
+        //
+        // NOTE: This deliberately doesn't just use `Self(array)`, see the comment
+        // on the struct definition for details.
+        unsafe { Self::load(&array) }
     }
 
     /// Converts a SIMD vector to an array.
-    pub const fn to_array(self) -> [T; LANES] {
-        self.0
+    pub const fn to_array(self) -> [T; N] {
+        let mut tmp = core::mem::MaybeUninit::uninit();
+        // SAFETY: writing to `tmp` is safe and initializes it.
+        //
+        // FIXME: We currently use a pointer store instead of `transmute_copy` because `repr(simd)`
+        // results in padding for non-power-of-2 vectors (so vectors are larger than arrays).
+        //
+        // NOTE: This deliberately doesn't just use `self.0`, see the comment
+        // on the struct definition for details.
+        unsafe {
+            self.store(tmp.as_mut_ptr());
+            tmp.assume_init()
+        }
     }
 
-    /// Converts a slice to a SIMD vector containing `slice[..LANES]`.
+    /// Converts a slice to a SIMD vector containing `slice[..N]`.
     ///
     /// # Panics
     ///
-    /// Panics if the slice's length is less than the vector's `Simd::LANES`.
+    /// Panics if the slice's length is less than the vector's `Simd::N`.
     ///
-    /// # Examples
+    /// # Example
     ///
     /// ```
     /// # #![feature(portable_simd)]
@@ -180,22 +260,49 @@ where
     /// ```
     #[must_use]
     pub const fn from_slice(slice: &[T]) -> Self {
-        assert!(slice.len() >= LANES, "slice length must be at least the number of lanes");
-        let mut array = [slice[0]; LANES];
-        let mut i = 0;
-        while i < LANES {
-            array[i] = slice[i];
-            i += 1;
-        }
-        Self(array)
+        assert!(
+            slice.len() >= Self::LANES,
+            "slice length must be at least the number of elements"
+        );
+        // SAFETY: We just checked that the slice contains
+        // at least `N` elements.
+        unsafe { Self::load(slice.as_ptr().cast()) }
+    }
+
+    /// Writes a SIMD vector to the first `N` elements of a slice.
+    ///
+    /// # Panics
+    ///
+    /// Panics if the slice's length is less than the vector's `Simd::N`.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # #![feature(portable_simd)]
+    /// # #[cfg(feature = "as_crate")] use core_simd::simd;
+    /// # #[cfg(not(feature = "as_crate"))] use core::simd;
+    /// # use simd::u32x4;
+    /// let mut dest = vec![0; 6];
+    /// let v = u32x4::from_array([1, 2, 3, 4]);
+    /// v.copy_to_slice(&mut dest);
+    /// assert_eq!(&dest, &[1, 2, 3, 4, 0, 0]);
+    /// ```
+    pub fn copy_to_slice(self, slice: &mut [T]) {
+        assert!(
+            slice.len() >= Self::LANES,
+            "slice length must be at least the number of elements"
+        );
+        // SAFETY: We just checked that the slice contains
+        // at least `N` elements.
+        unsafe { self.store(slice.as_mut_ptr().cast()) }
     }
 
-    /// Performs lanewise conversion of a SIMD vector's elements to another SIMD-valid type.
+    /// Performs elementwise conversion of a SIMD vector's elements to another SIMD-valid type.
     ///
-    /// This follows the semantics of Rust's `as` conversion for casting
-    /// integers to unsigned integers (interpreting as the other type, so `-1` to `MAX`),
-    /// and from floats to integers (truncating, or saturating at the limits) for each lane,
-    /// or vice versa.
+    /// This follows the semantics of Rust's `as` conversion for casting integers between
+    /// signed and unsigned (interpreting integers as 2s complement, so `-1` to `U::MAX` and
+    /// `1 << (U::BITS -1)` becoming `I::MIN` ), and from floats to integers (truncating,
+    /// or saturating at the limits) for each element.
     ///
     /// # Examples
     /// ```
@@ -215,11 +322,26 @@ where
     /// ```
     #[must_use]
     #[inline]
-    pub fn cast<U: SimdElement>(self) -> Simd<U, LANES> {
-        // Safety: The input argument is a vector of a valid SIMD element type.
+    pub fn cast<U: SimdCast>(self) -> Simd<U, N>
+    where
+        T: SimdCast,
+    {
+        // Safety: supported types are guaranteed by SimdCast
         unsafe { intrinsics::simd_as(self) }
     }
 
+    /// Casts a vector of pointers to another pointer type.
+    #[must_use]
+    #[inline]
+    pub fn cast_ptr<U>(self) -> Simd<U, N>
+    where
+        T: SimdCastPtr<U>,
+        U: SimdElement,
+    {
+        // Safety: supported types are guaranteed by SimdCastPtr
+        unsafe { intrinsics::simd_cast_ptr(self) }
+    }
+
     /// Rounds toward zero and converts to the same-width integer type, assuming that
     /// the value is finite and fits in that type.
     ///
@@ -235,90 +357,90 @@ where
     ///
     /// [cast]: Simd::cast
     #[inline]
-    pub unsafe fn to_int_unchecked<I>(self) -> Simd<I, LANES>
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
+    pub unsafe fn to_int_unchecked<I>(self) -> Simd<I, N>
     where
-        T: core::convert::FloatToInt<I>,
-        I: SimdElement,
+        T: core::convert::FloatToInt<I> + SimdCast,
+        I: SimdCast,
     {
-        // Safety: `self` is a vector, and `FloatToInt` ensures the type can be casted to
-        // an integer.
+        // Safety: supported types are guaranteed by SimdCast, the caller is responsible for the extra invariants
         unsafe { intrinsics::simd_cast(self) }
     }
 
     /// Reads from potentially discontiguous indices in `slice` to construct a SIMD vector.
-    /// If an index is out-of-bounds, the lane is instead selected from the `or` vector.
+    /// If an index is out-of-bounds, the element is instead selected from the `or` vector.
     ///
     /// # Examples
     /// ```
     /// # #![feature(portable_simd)]
     /// # use core::simd::Simd;
     /// let vec: Vec<i32> = vec![10, 11, 12, 13, 14, 15, 16, 17, 18];
-    /// let idxs = Simd::from_array([9, 3, 0, 5]);
+    /// let idxs = Simd::from_array([9, 3, 0, 5]);  // Note the index that is out-of-bounds
     /// let alt = Simd::from_array([-5, -4, -3, -2]);
     ///
-    /// let result = Simd::gather_or(&vec, idxs, alt); // Note the lane that is out-of-bounds.
+    /// let result = Simd::gather_or(&vec, idxs, alt);
     /// assert_eq!(result, Simd::from_array([-5, 13, 10, 15]));
     /// ```
     #[must_use]
     #[inline]
-    pub fn gather_or(slice: &[T], idxs: Simd<usize, LANES>, or: Self) -> Self {
+    pub fn gather_or(slice: &[T], idxs: Simd<usize, N>, or: Self) -> Self {
         Self::gather_select(slice, Mask::splat(true), idxs, or)
     }
 
-    /// Reads from potentially discontiguous indices in `slice` to construct a SIMD vector.
-    /// If an index is out-of-bounds, the lane is set to the default value for the type.
+    /// Reads from indices in `slice` to construct a SIMD vector.
+    /// If an index is out-of-bounds, the element is set to the default given by `T: Default`.
     ///
     /// # Examples
     /// ```
     /// # #![feature(portable_simd)]
     /// # use core::simd::Simd;
     /// let vec: Vec<i32> = vec![10, 11, 12, 13, 14, 15, 16, 17, 18];
-    /// let idxs = Simd::from_array([9, 3, 0, 5]);
+    /// let idxs = Simd::from_array([9, 3, 0, 5]);  // Note the index that is out-of-bounds
     ///
-    /// let result = Simd::gather_or_default(&vec, idxs); // Note the lane that is out-of-bounds.
+    /// let result = Simd::gather_or_default(&vec, idxs);
     /// assert_eq!(result, Simd::from_array([0, 13, 10, 15]));
     /// ```
     #[must_use]
     #[inline]
-    pub fn gather_or_default(slice: &[T], idxs: Simd<usize, LANES>) -> Self
+    pub fn gather_or_default(slice: &[T], idxs: Simd<usize, N>) -> Self
     where
         T: Default,
     {
         Self::gather_or(slice, idxs, Self::splat(T::default()))
     }
 
-    /// Reads from potentially discontiguous indices in `slice` to construct a SIMD vector.
-    /// The mask `enable`s all `true` lanes and disables all `false` lanes.
-    /// If an index is disabled or is out-of-bounds, the lane is selected from the `or` vector.
+    /// Reads from indices in `slice` to construct a SIMD vector.
+    /// The mask `enable`s all `true` indices and disables all `false` indices.
+    /// If an index is disabled or is out-of-bounds, the element is selected from the `or` vector.
     ///
     /// # Examples
     /// ```
     /// # #![feature(portable_simd)]
     /// # use core::simd::{Simd, Mask};
     /// let vec: Vec<i32> = vec![10, 11, 12, 13, 14, 15, 16, 17, 18];
-    /// let idxs = Simd::from_array([9, 3, 0, 5]);
+    /// let idxs = Simd::from_array([9, 3, 0, 5]); // Includes an out-of-bounds index
     /// let alt = Simd::from_array([-5, -4, -3, -2]);
-    /// let enable = Mask::from_array([true, true, true, false]); // Note the mask of the last lane.
+    /// let enable = Mask::from_array([true, true, true, false]); // Includes a masked element
     ///
-    /// let result = Simd::gather_select(&vec, enable, idxs, alt); // Note the lane that is out-of-bounds.
+    /// let result = Simd::gather_select(&vec, enable, idxs, alt);
     /// assert_eq!(result, Simd::from_array([-5, 13, 10, -2]));
     /// ```
     #[must_use]
     #[inline]
     pub fn gather_select(
         slice: &[T],
-        enable: Mask<isize, LANES>,
-        idxs: Simd<usize, LANES>,
+        enable: Mask<isize, N>,
+        idxs: Simd<usize, N>,
         or: Self,
     ) -> Self {
-        let enable: Mask<isize, LANES> = enable & idxs.simd_lt(Simd::splat(slice.len()));
-        // Safety: We have masked-off out-of-bounds lanes.
+        let enable: Mask<isize, N> = enable & idxs.simd_lt(Simd::splat(slice.len()));
+        // Safety: We have masked-off out-of-bounds indices.
         unsafe { Self::gather_select_unchecked(slice, enable, idxs, or) }
     }
 
-    /// Reads from potentially discontiguous indices in `slice` to construct a SIMD vector.
-    /// The mask `enable`s all `true` lanes and disables all `false` lanes.
-    /// If an index is disabled, the lane is selected from the `or` vector.
+    /// Reads from indices in `slice` to construct a SIMD vector.
+    /// The mask `enable`s all `true` indices and disables all `false` indices.
+    /// If an index is disabled, the element is selected from the `or` vector.
     ///
     /// # Safety
     ///
@@ -332,57 +454,123 @@ where
     /// # #[cfg(not(feature = "as_crate"))] use core::simd;
     /// # use simd::{Simd, SimdPartialOrd, Mask};
     /// let vec: Vec<i32> = vec![10, 11, 12, 13, 14, 15, 16, 17, 18];
-    /// let idxs = Simd::from_array([9, 3, 0, 5]);
+    /// let idxs = Simd::from_array([9, 3, 0, 5]); // Includes an out-of-bounds index
     /// let alt = Simd::from_array([-5, -4, -3, -2]);
-    /// let enable = Mask::from_array([true, true, true, false]); // Note the final mask lane.
+    /// let enable = Mask::from_array([true, true, true, false]); // Includes a masked element
     /// // If this mask was used to gather, it would be unsound. Let's fix that.
     /// let enable = enable & idxs.simd_lt(Simd::splat(vec.len()));
     ///
-    /// // We have masked the OOB lane, so it's safe to gather now.
+    /// // The out-of-bounds index has been masked, so it's safe to gather now.
     /// let result = unsafe { Simd::gather_select_unchecked(&vec, enable, idxs, alt) };
     /// assert_eq!(result, Simd::from_array([-5, 13, 10, -2]));
     /// ```
     /// [undefined behavior]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html
     #[must_use]
     #[inline]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub unsafe fn gather_select_unchecked(
         slice: &[T],
-        enable: Mask<isize, LANES>,
-        idxs: Simd<usize, LANES>,
+        enable: Mask<isize, N>,
+        idxs: Simd<usize, N>,
         or: Self,
     ) -> Self {
-        let base_ptr = crate::simd::ptr::SimdConstPtr::splat(slice.as_ptr());
+        let base_ptr = Simd::<*const T, N>::splat(slice.as_ptr());
         // Ferris forgive me, I have done pointer arithmetic here.
         let ptrs = base_ptr.wrapping_add(idxs);
-        // Safety: The ptrs have been bounds-masked to prevent memory-unsafe reads insha'allah
-        unsafe { intrinsics::simd_gather(or, ptrs, enable.to_int()) }
+        // Safety: The caller is responsible for determining the indices are okay to read
+        unsafe { Self::gather_select_ptr(ptrs, enable, or) }
+    }
+
+    /// Read elementwise from pointers into a SIMD vector.
+    ///
+    /// # Safety
+    ///
+    /// Each read must satisfy the same conditions as [`core::ptr::read`].
+    ///
+    /// # Example
+    /// ```
+    /// # #![feature(portable_simd)]
+    /// # #[cfg(feature = "as_crate")] use core_simd::simd;
+    /// # #[cfg(not(feature = "as_crate"))] use core::simd;
+    /// # use simd::{Simd, SimdConstPtr};
+    /// let values = [6, 2, 4, 9];
+    /// let offsets = Simd::from_array([1, 0, 0, 3]);
+    /// let source = Simd::splat(values.as_ptr()).wrapping_add(offsets);
+    /// let gathered = unsafe { Simd::gather_ptr(source) };
+    /// assert_eq!(gathered, Simd::from_array([2, 6, 6, 9]));
+    /// ```
+    #[must_use]
+    #[inline]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
+    pub unsafe fn gather_ptr(source: Simd<*const T, N>) -> Self
+    where
+        T: Default,
+    {
+        // TODO: add an intrinsic that doesn't use a passthru vector, and remove the T: Default bound
+        // Safety: The caller is responsible for upholding all invariants
+        unsafe { Self::gather_select_ptr(source, Mask::splat(true), Self::default()) }
+    }
+
+    /// Conditionally read elementwise from pointers into a SIMD vector.
+    /// The mask `enable`s all `true` pointers and disables all `false` pointers.
+    /// If a pointer is disabled, the element is selected from the `or` vector,
+    /// and no read is performed.
+    ///
+    /// # Safety
+    ///
+    /// Enabled elements must satisfy the same conditions as [`core::ptr::read`].
+    ///
+    /// # Example
+    /// ```
+    /// # #![feature(portable_simd)]
+    /// # #[cfg(feature = "as_crate")] use core_simd::simd;
+    /// # #[cfg(not(feature = "as_crate"))] use core::simd;
+    /// # use simd::{Mask, Simd, SimdConstPtr};
+    /// let values = [6, 2, 4, 9];
+    /// let enable = Mask::from_array([true, true, false, true]);
+    /// let offsets = Simd::from_array([1, 0, 0, 3]);
+    /// let source = Simd::splat(values.as_ptr()).wrapping_add(offsets);
+    /// let gathered = unsafe { Simd::gather_select_ptr(source, enable, Simd::splat(0)) };
+    /// assert_eq!(gathered, Simd::from_array([2, 6, 0, 9]));
+    /// ```
+    #[must_use]
+    #[inline]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
+    pub unsafe fn gather_select_ptr(
+        source: Simd<*const T, N>,
+        enable: Mask<isize, N>,
+        or: Self,
+    ) -> Self {
+        // Safety: The caller is responsible for upholding all invariants
+        unsafe { intrinsics::simd_gather(or, source, enable.to_int()) }
     }
 
     /// Writes the values in a SIMD vector to potentially discontiguous indices in `slice`.
-    /// If two lanes in the scattered vector would write to the same index
-    /// only the last lane is guaranteed to actually be written.
+    /// If an index is out-of-bounds, the write is suppressed without panicking.
+    /// If two elements in the scattered vector would write to the same index
+    /// only the last element is guaranteed to actually be written.
     ///
     /// # Examples
     /// ```
     /// # #![feature(portable_simd)]
     /// # use core::simd::Simd;
     /// let mut vec: Vec<i32> = vec![10, 11, 12, 13, 14, 15, 16, 17, 18];
-    /// let idxs = Simd::from_array([9, 3, 0, 0]);
+    /// let idxs = Simd::from_array([9, 3, 0, 0]); // Note the duplicate index.
     /// let vals = Simd::from_array([-27, 82, -41, 124]);
     ///
-    /// vals.scatter(&mut vec, idxs); // index 0 receives two writes.
+    /// vals.scatter(&mut vec, idxs); // two logical writes means the last wins.
     /// assert_eq!(vec, vec![124, 11, 12, 82, 14, 15, 16, 17, 18]);
     /// ```
     #[inline]
-    pub fn scatter(self, slice: &mut [T], idxs: Simd<usize, LANES>) {
+    pub fn scatter(self, slice: &mut [T], idxs: Simd<usize, N>) {
         self.scatter_select(slice, Mask::splat(true), idxs)
     }
 
-    /// Writes the values in a SIMD vector to multiple potentially discontiguous indices in `slice`.
-    /// The mask `enable`s all `true` lanes and disables all `false` lanes.
-    /// If an enabled index is out-of-bounds, the lane is not written.
-    /// If two enabled lanes in the scattered vector would write to the same index,
-    /// only the last lane is guaranteed to actually be written.
+    /// Writes values from a SIMD vector to multiple potentially discontiguous indices in `slice`.
+    /// The mask `enable`s all `true` indices and disables all `false` indices.
+    /// If an enabled index is out-of-bounds, the write is suppressed without panicking.
+    /// If two enabled elements in the scattered vector would write to the same index,
+    /// only the last element is guaranteed to actually be written.
     ///
     /// # Examples
     /// ```
@@ -391,29 +579,24 @@ where
     /// # #[cfg(not(feature = "as_crate"))] use core::simd;
     /// # use simd::{Simd, Mask};
     /// let mut vec: Vec<i32> = vec![10, 11, 12, 13, 14, 15, 16, 17, 18];
-    /// let idxs = Simd::from_array([9, 3, 0, 0]);
+    /// let idxs = Simd::from_array([9, 3, 0, 0]); // Includes an out-of-bounds index
     /// let vals = Simd::from_array([-27, 82, -41, 124]);
-    /// let enable = Mask::from_array([true, true, true, false]); // Note the mask of the last lane.
+    /// let enable = Mask::from_array([true, true, true, false]); // Includes a masked element
     ///
-    /// vals.scatter_select(&mut vec, enable, idxs); // index 0's second write is masked, thus omitted.
+    /// vals.scatter_select(&mut vec, enable, idxs); // The last write is masked, thus omitted.
     /// assert_eq!(vec, vec![-41, 11, 12, 82, 14, 15, 16, 17, 18]);
     /// ```
     #[inline]
-    pub fn scatter_select(
-        self,
-        slice: &mut [T],
-        enable: Mask<isize, LANES>,
-        idxs: Simd<usize, LANES>,
-    ) {
-        let enable: Mask<isize, LANES> = enable & idxs.simd_lt(Simd::splat(slice.len()));
-        // Safety: We have masked-off out-of-bounds lanes.
+    pub fn scatter_select(self, slice: &mut [T], enable: Mask<isize, N>, idxs: Simd<usize, N>) {
+        let enable: Mask<isize, N> = enable & idxs.simd_lt(Simd::splat(slice.len()));
+        // Safety: We have masked-off out-of-bounds indices.
         unsafe { self.scatter_select_unchecked(slice, enable, idxs) }
     }
 
-    /// Writes the values in a SIMD vector to multiple potentially discontiguous indices in `slice`.
-    /// The mask `enable`s all `true` lanes and disables all `false` lanes.
-    /// If two enabled lanes in the scattered vector would write to the same index,
-    /// only the last lane is guaranteed to actually be written.
+    /// Writes values from a SIMD vector to multiple potentially discontiguous indices in `slice`.
+    /// The mask `enable`s all `true` indices and disables all `false` indices.
+    /// If two enabled elements in the scattered vector would write to the same index,
+    /// only the last element is guaranteed to actually be written.
     ///
     /// # Safety
     ///
@@ -429,22 +612,23 @@ where
     /// let mut vec: Vec<i32> = vec![10, 11, 12, 13, 14, 15, 16, 17, 18];
     /// let idxs = Simd::from_array([9, 3, 0, 0]);
     /// let vals = Simd::from_array([-27, 82, -41, 124]);
-    /// let enable = Mask::from_array([true, true, true, false]); // Note the mask of the last lane.
+    /// let enable = Mask::from_array([true, true, true, false]); // Masks the final index
     /// // If this mask was used to scatter, it would be unsound. Let's fix that.
     /// let enable = enable & idxs.simd_lt(Simd::splat(vec.len()));
     ///
-    /// // We have masked the OOB lane, so it's safe to scatter now.
+    /// // We have masked the OOB index, so it's safe to scatter now.
     /// unsafe { vals.scatter_select_unchecked(&mut vec, enable, idxs); }
-    /// // index 0's second write is masked, thus was omitted.
+    /// // The second write to index 0 was masked, thus omitted.
     /// assert_eq!(vec, vec![-41, 11, 12, 82, 14, 15, 16, 17, 18]);
     /// ```
     /// [undefined behavior]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html
     #[inline]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub unsafe fn scatter_select_unchecked(
         self,
         slice: &mut [T],
-        enable: Mask<isize, LANES>,
-        idxs: Simd<usize, LANES>,
+        enable: Mask<isize, N>,
+        idxs: Simd<usize, N>,
     ) {
         // Safety: This block works with *mut T derived from &mut 'a [T],
         // which means it is delicate in Rust's borrowing model, circa 2021:
@@ -458,36 +642,89 @@ where
         // 3. &mut [T] which will become our base ptr.
         unsafe {
             // Now Entering ☢️ *mut T Zone
-            let base_ptr = crate::simd::ptr::SimdMutPtr::splat(slice.as_mut_ptr());
+            let base_ptr = Simd::<*mut T, N>::splat(slice.as_mut_ptr());
             // Ferris forgive me, I have done pointer arithmetic here.
             let ptrs = base_ptr.wrapping_add(idxs);
             // The ptrs have been bounds-masked to prevent memory-unsafe writes insha'allah
-            intrinsics::simd_scatter(self, ptrs, enable.to_int())
+            self.scatter_select_ptr(ptrs, enable);
             // Cleared ☢️ *mut T Zone
         }
     }
+
+    /// Write pointers elementwise into a SIMD vector.
+    ///
+    /// # Safety
+    ///
+    /// Each write must satisfy the same conditions as [`core::ptr::write`].
+    ///
+    /// # Example
+    /// ```
+    /// # #![feature(portable_simd)]
+    /// # #[cfg(feature = "as_crate")] use core_simd::simd;
+    /// # #[cfg(not(feature = "as_crate"))] use core::simd;
+    /// # use simd::{Simd, SimdMutPtr};
+    /// let mut values = [0; 4];
+    /// let offset = Simd::from_array([3, 2, 1, 0]);
+    /// let ptrs = Simd::splat(values.as_mut_ptr()).wrapping_add(offset);
+    /// unsafe { Simd::from_array([6, 3, 5, 7]).scatter_ptr(ptrs); }
+    /// assert_eq!(values, [7, 5, 3, 6]);
+    /// ```
+    #[inline]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
+    pub unsafe fn scatter_ptr(self, dest: Simd<*mut T, N>) {
+        // Safety: The caller is responsible for upholding all invariants
+        unsafe { self.scatter_select_ptr(dest, Mask::splat(true)) }
+    }
+
+    /// Conditionally write pointers elementwise into a SIMD vector.
+    /// The mask `enable`s all `true` pointers and disables all `false` pointers.
+    /// If a pointer is disabled, the write to its pointee is skipped.
+    ///
+    /// # Safety
+    ///
+    /// Enabled pointers must satisfy the same conditions as [`core::ptr::write`].
+    ///
+    /// # Example
+    /// ```
+    /// # #![feature(portable_simd)]
+    /// # #[cfg(feature = "as_crate")] use core_simd::simd;
+    /// # #[cfg(not(feature = "as_crate"))] use core::simd;
+    /// # use simd::{Mask, Simd, SimdMutPtr};
+    /// let mut values = [0; 4];
+    /// let offset = Simd::from_array([3, 2, 1, 0]);
+    /// let ptrs = Simd::splat(values.as_mut_ptr()).wrapping_add(offset);
+    /// let enable = Mask::from_array([true, true, false, false]);
+    /// unsafe { Simd::from_array([6, 3, 5, 7]).scatter_select_ptr(ptrs, enable); }
+    /// assert_eq!(values, [0, 0, 3, 6]);
+    /// ```
+    #[inline]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
+    pub unsafe fn scatter_select_ptr(self, dest: Simd<*mut T, N>, enable: Mask<isize, N>) {
+        // Safety: The caller is responsible for upholding all invariants
+        unsafe { intrinsics::simd_scatter(self, dest, enable.to_int()) }
+    }
 }
 
-impl<T, const LANES: usize> Copy for Simd<T, LANES>
+impl<T, const N: usize> Copy for Simd<T, N>
 where
+    LaneCount<N>: SupportedLaneCount,
     T: SimdElement,
-    LaneCount<LANES>: SupportedLaneCount,
 {
 }
 
-impl<T, const LANES: usize> Clone for Simd<T, LANES>
+impl<T, const N: usize> Clone for Simd<T, N>
 where
+    LaneCount<N>: SupportedLaneCount,
     T: SimdElement,
-    LaneCount<LANES>: SupportedLaneCount,
 {
     fn clone(&self) -> Self {
         *self
     }
 }
 
-impl<T, const LANES: usize> Default for Simd<T, LANES>
+impl<T, const N: usize> Default for Simd<T, N>
 where
-    LaneCount<LANES>: SupportedLaneCount,
+    LaneCount<N>: SupportedLaneCount,
     T: SimdElement + Default,
 {
     #[inline]
@@ -496,20 +733,20 @@ where
     }
 }
 
-impl<T, const LANES: usize> PartialEq for Simd<T, LANES>
+impl<T, const N: usize> PartialEq for Simd<T, N>
 where
-    LaneCount<LANES>: SupportedLaneCount,
+    LaneCount<N>: SupportedLaneCount,
     T: SimdElement + PartialEq,
 {
     #[inline]
     fn eq(&self, other: &Self) -> bool {
         // Safety: All SIMD vectors are SimdPartialEq, and the comparison produces a valid mask.
         let mask = unsafe {
-            let tfvec: Simd<<T as SimdElement>::Mask, LANES> = intrinsics::simd_eq(*self, *other);
+            let tfvec: Simd<<T as SimdElement>::Mask, N> = intrinsics::simd_eq(*self, *other);
             Mask::from_int_unchecked(tfvec)
         };
 
-        // Two vectors are equal if all lanes tested true for vertical equality.
+        // Two vectors are equal if all elements are equal when compared elementwise
         mask.all()
     }
 
@@ -518,18 +755,18 @@ where
     fn ne(&self, other: &Self) -> bool {
         // Safety: All SIMD vectors are SimdPartialEq, and the comparison produces a valid mask.
         let mask = unsafe {
-            let tfvec: Simd<<T as SimdElement>::Mask, LANES> = intrinsics::simd_ne(*self, *other);
+            let tfvec: Simd<<T as SimdElement>::Mask, N> = intrinsics::simd_ne(*self, *other);
             Mask::from_int_unchecked(tfvec)
         };
 
-        // Two vectors are non-equal if any lane tested true for vertical non-equality.
+        // Two vectors are non-equal if any elements are non-equal when compared elementwise
         mask.any()
     }
 }
 
-impl<T, const LANES: usize> PartialOrd for Simd<T, LANES>
+impl<T, const N: usize> PartialOrd for Simd<T, N>
 where
-    LaneCount<LANES>: SupportedLaneCount,
+    LaneCount<N>: SupportedLaneCount,
     T: SimdElement + PartialOrd,
 {
     #[inline]
@@ -539,16 +776,16 @@ where
     }
 }
 
-impl<T, const LANES: usize> Eq for Simd<T, LANES>
+impl<T, const N: usize> Eq for Simd<T, N>
 where
-    LaneCount<LANES>: SupportedLaneCount,
+    LaneCount<N>: SupportedLaneCount,
     T: SimdElement + Eq,
 {
 }
 
-impl<T, const LANES: usize> Ord for Simd<T, LANES>
+impl<T, const N: usize> Ord for Simd<T, N>
 where
-    LaneCount<LANES>: SupportedLaneCount,
+    LaneCount<N>: SupportedLaneCount,
     T: SimdElement + Ord,
 {
     #[inline]
@@ -558,9 +795,9 @@ where
     }
 }
 
-impl<T, const LANES: usize> core::hash::Hash for Simd<T, LANES>
+impl<T, const N: usize> core::hash::Hash for Simd<T, N>
 where
-    LaneCount<LANES>: SupportedLaneCount,
+    LaneCount<N>: SupportedLaneCount,
     T: SimdElement + core::hash::Hash,
 {
     #[inline]
@@ -573,72 +810,96 @@ where
 }
 
 // array references
-impl<T, const LANES: usize> AsRef<[T; LANES]> for Simd<T, LANES>
+impl<T, const N: usize> AsRef<[T; N]> for Simd<T, N>
 where
-    LaneCount<LANES>: SupportedLaneCount,
+    LaneCount<N>: SupportedLaneCount,
     T: SimdElement,
 {
     #[inline]
-    fn as_ref(&self) -> &[T; LANES] {
-        &self.0
+    fn as_ref(&self) -> &[T; N] {
+        self.as_array()
     }
 }
 
-impl<T, const LANES: usize> AsMut<[T; LANES]> for Simd<T, LANES>
+impl<T, const N: usize> AsMut<[T; N]> for Simd<T, N>
 where
-    LaneCount<LANES>: SupportedLaneCount,
+    LaneCount<N>: SupportedLaneCount,
     T: SimdElement,
 {
     #[inline]
-    fn as_mut(&mut self) -> &mut [T; LANES] {
-        &mut self.0
+    fn as_mut(&mut self) -> &mut [T; N] {
+        self.as_mut_array()
     }
 }
 
 // slice references
-impl<T, const LANES: usize> AsRef<[T]> for Simd<T, LANES>
+impl<T, const N: usize> AsRef<[T]> for Simd<T, N>
 where
-    LaneCount<LANES>: SupportedLaneCount,
+    LaneCount<N>: SupportedLaneCount,
     T: SimdElement,
 {
     #[inline]
     fn as_ref(&self) -> &[T] {
-        &self.0
+        self.as_array()
     }
 }
 
-impl<T, const LANES: usize> AsMut<[T]> for Simd<T, LANES>
+impl<T, const N: usize> AsMut<[T]> for Simd<T, N>
 where
-    LaneCount<LANES>: SupportedLaneCount,
+    LaneCount<N>: SupportedLaneCount,
     T: SimdElement,
 {
     #[inline]
     fn as_mut(&mut self) -> &mut [T] {
-        &mut self.0
+        self.as_mut_array()
     }
 }
 
 // vector/array conversion
-impl<T, const LANES: usize> From<[T; LANES]> for Simd<T, LANES>
+impl<T, const N: usize> From<[T; N]> for Simd<T, N>
 where
-    LaneCount<LANES>: SupportedLaneCount,
+    LaneCount<N>: SupportedLaneCount,
     T: SimdElement,
 {
-    fn from(array: [T; LANES]) -> Self {
-        Self(array)
+    fn from(array: [T; N]) -> Self {
+        Self::from_array(array)
     }
 }
 
-impl<T, const LANES: usize> From<Simd<T, LANES>> for [T; LANES]
+impl<T, const N: usize> From<Simd<T, N>> for [T; N]
 where
-    LaneCount<LANES>: SupportedLaneCount,
+    LaneCount<N>: SupportedLaneCount,
     T: SimdElement,
 {
-    fn from(vector: Simd<T, LANES>) -> Self {
+    fn from(vector: Simd<T, N>) -> Self {
         vector.to_array()
     }
 }
 
+impl<T, const N: usize> TryFrom<&[T]> for Simd<T, N>
+where
+    LaneCount<N>: SupportedLaneCount,
+    T: SimdElement,
+{
+    type Error = core::array::TryFromSliceError;
+
+    fn try_from(slice: &[T]) -> Result<Self, core::array::TryFromSliceError> {
+        Ok(Self::from_array(slice.try_into()?))
+    }
+}
+
+impl<T, const N: usize> TryFrom<&mut [T]> for Simd<T, N>
+where
+    LaneCount<N>: SupportedLaneCount,
+    T: SimdElement,
+{
+    type Error = core::array::TryFromSliceError;
+
+    fn try_from(slice: &mut [T]) -> Result<Self, core::array::TryFromSliceError> {
+        Ok(Self::from_array(slice.try_into()?))
+    }
+}
+
 mod sealed {
     pub trait Sealed {}
 }
@@ -740,3 +1001,27 @@ impl Sealed for f64 {}
 unsafe impl SimdElement for f64 {
     type Mask = i64;
 }
+
+impl<T> Sealed for *const T {}
+
+// Safety: (thin) const pointers are valid SIMD element types, and are supported by this API
+//
+// Fat pointers may be supported in the future.
+unsafe impl<T> SimdElement for *const T
+where
+    T: core::ptr::Pointee<Metadata = ()>,
+{
+    type Mask = isize;
+}
+
+impl<T> Sealed for *mut T {}
+
+// Safety: (thin) mut pointers are valid SIMD element types, and are supported by this API
+//
+// Fat pointers may be supported in the future.
+unsafe impl<T> SimdElement for *mut T
+where
+    T: core::ptr::Pointee<Metadata = ()>,
+{
+    type Mask = isize;
+}
diff --git a/library/portable-simd/crates/core_simd/src/vector/float.rs b/library/portable-simd/crates/core_simd/src/vector/float.rs
deleted file mode 100644
index f836c99b1..000000000
--- a/library/portable-simd/crates/core_simd/src/vector/float.rs
+++ /dev/null
@@ -1,24 +0,0 @@
-#![allow(non_camel_case_types)]
-
-use crate::simd::Simd;
-
-/// A 64-bit SIMD vector with two elements of type `f32`.
-pub type f32x2 = Simd<f32, 2>;
-
-/// A 128-bit SIMD vector with four elements of type `f32`.
-pub type f32x4 = Simd<f32, 4>;
-
-/// A 256-bit SIMD vector with eight elements of type `f32`.
-pub type f32x8 = Simd<f32, 8>;
-
-/// A 512-bit SIMD vector with 16 elements of type `f32`.
-pub type f32x16 = Simd<f32, 16>;
-
-/// A 128-bit SIMD vector with two elements of type `f64`.
-pub type f64x2 = Simd<f64, 2>;
-
-/// A 256-bit SIMD vector with four elements of type `f64`.
-pub type f64x4 = Simd<f64, 4>;
-
-/// A 512-bit SIMD vector with eight elements of type `f64`.
-pub type f64x8 = Simd<f64, 8>;
diff --git a/library/portable-simd/crates/core_simd/src/vector/int.rs b/library/portable-simd/crates/core_simd/src/vector/int.rs
deleted file mode 100644
index 20e56c7dc..000000000
--- a/library/portable-simd/crates/core_simd/src/vector/int.rs
+++ /dev/null
@@ -1,63 +0,0 @@
-#![allow(non_camel_case_types)]
-
-use crate::simd::Simd;
-
-/// A SIMD vector with two elements of type `isize`.
-pub type isizex2 = Simd<isize, 2>;
-
-/// A SIMD vector with four elements of type `isize`.
-pub type isizex4 = Simd<isize, 4>;
-
-/// A SIMD vector with eight elements of type `isize`.
-pub type isizex8 = Simd<isize, 8>;
-
-/// A 32-bit SIMD vector with two elements of type `i16`.
-pub type i16x2 = Simd<i16, 2>;
-
-/// A 64-bit SIMD vector with four elements of type `i16`.
-pub type i16x4 = Simd<i16, 4>;
-
-/// A 128-bit SIMD vector with eight elements of type `i16`.
-pub type i16x8 = Simd<i16, 8>;
-
-/// A 256-bit SIMD vector with 16 elements of type `i16`.
-pub type i16x16 = Simd<i16, 16>;
-
-/// A 512-bit SIMD vector with 32 elements of type `i16`.
-pub type i16x32 = Simd<i16, 32>;
-
-/// A 64-bit SIMD vector with two elements of type `i32`.
-pub type i32x2 = Simd<i32, 2>;
-
-/// A 128-bit SIMD vector with four elements of type `i32`.
-pub type i32x4 = Simd<i32, 4>;
-
-/// A 256-bit SIMD vector with eight elements of type `i32`.
-pub type i32x8 = Simd<i32, 8>;
-
-/// A 512-bit SIMD vector with 16 elements of type `i32`.
-pub type i32x16 = Simd<i32, 16>;
-
-/// A 128-bit SIMD vector with two elements of type `i64`.
-pub type i64x2 = Simd<i64, 2>;
-
-/// A 256-bit SIMD vector with four elements of type `i64`.
-pub type i64x4 = Simd<i64, 4>;
-
-/// A 512-bit SIMD vector with eight elements of type `i64`.
-pub type i64x8 = Simd<i64, 8>;
-
-/// A 32-bit SIMD vector with four elements of type `i8`.
-pub type i8x4 = Simd<i8, 4>;
-
-/// A 64-bit SIMD vector with eight elements of type `i8`.
-pub type i8x8 = Simd<i8, 8>;
-
-/// A 128-bit SIMD vector with 16 elements of type `i8`.
-pub type i8x16 = Simd<i8, 16>;
-
-/// A 256-bit SIMD vector with 32 elements of type `i8`.
-pub type i8x32 = Simd<i8, 32>;
-
-/// A 512-bit SIMD vector with 64 elements of type `i8`.
-pub type i8x64 = Simd<i8, 64>;
diff --git a/library/portable-simd/crates/core_simd/src/vector/ptr.rs b/library/portable-simd/crates/core_simd/src/vector/ptr.rs
deleted file mode 100644
index fa756344d..000000000
--- a/library/portable-simd/crates/core_simd/src/vector/ptr.rs
+++ /dev/null
@@ -1,51 +0,0 @@
-//! Private implementation details of public gather/scatter APIs.
-use crate::simd::intrinsics;
-use crate::simd::{LaneCount, Simd, SupportedLaneCount};
-
-/// A vector of *const T.
-#[derive(Debug, Copy, Clone)]
-#[repr(simd)]
-pub(crate) struct SimdConstPtr<T, const LANES: usize>([*const T; LANES]);
-
-impl<T, const LANES: usize> SimdConstPtr<T, LANES>
-where
-    LaneCount<LANES>: SupportedLaneCount,
-    T: Sized,
-{
-    #[inline]
-    #[must_use]
-    pub fn splat(ptr: *const T) -> Self {
-        Self([ptr; LANES])
-    }
-
-    #[inline]
-    #[must_use]
-    pub fn wrapping_add(self, addend: Simd<usize, LANES>) -> Self {
-        // Safety: this intrinsic doesn't have a precondition
-        unsafe { intrinsics::simd_arith_offset(self, addend) }
-    }
-}
-
-/// A vector of *mut T. Be very careful around potential aliasing.
-#[derive(Debug, Copy, Clone)]
-#[repr(simd)]
-pub(crate) struct SimdMutPtr<T, const LANES: usize>([*mut T; LANES]);
-
-impl<T, const LANES: usize> SimdMutPtr<T, LANES>
-where
-    LaneCount<LANES>: SupportedLaneCount,
-    T: Sized,
-{
-    #[inline]
-    #[must_use]
-    pub fn splat(ptr: *mut T) -> Self {
-        Self([ptr; LANES])
-    }
-
-    #[inline]
-    #[must_use]
-    pub fn wrapping_add(self, addend: Simd<usize, LANES>) -> Self {
-        // Safety: this intrinsic doesn't have a precondition
-        unsafe { intrinsics::simd_arith_offset(self, addend) }
-    }
-}
diff --git a/library/portable-simd/crates/core_simd/src/vector/uint.rs b/library/portable-simd/crates/core_simd/src/vector/uint.rs
deleted file mode 100644
index b4a69c443..000000000
--- a/library/portable-simd/crates/core_simd/src/vector/uint.rs
+++ /dev/null
@@ -1,63 +0,0 @@
-#![allow(non_camel_case_types)]
-
-use crate::simd::Simd;
-
-/// A SIMD vector with two elements of type `usize`.
-pub type usizex2 = Simd<usize, 2>;
-
-/// A SIMD vector with four elements of type `usize`.
-pub type usizex4 = Simd<usize, 4>;
-
-/// A SIMD vector with eight elements of type `usize`.
-pub type usizex8 = Simd<usize, 8>;
-
-/// A 32-bit SIMD vector with two elements of type `u16`.
-pub type u16x2 = Simd<u16, 2>;
-
-/// A 64-bit SIMD vector with four elements of type `u16`.
-pub type u16x4 = Simd<u16, 4>;
-
-/// A 128-bit SIMD vector with eight elements of type `u16`.
-pub type u16x8 = Simd<u16, 8>;
-
-/// A 256-bit SIMD vector with 16 elements of type `u16`.
-pub type u16x16 = Simd<u16, 16>;
-
-/// A 512-bit SIMD vector with 32 elements of type `u16`.
-pub type u16x32 = Simd<u16, 32>;
-
-/// A 64-bit SIMD vector with two elements of type `u32`.
-pub type u32x2 = Simd<u32, 2>;
-
-/// A 128-bit SIMD vector with four elements of type `u32`.
-pub type u32x4 = Simd<u32, 4>;
-
-/// A 256-bit SIMD vector with eight elements of type `u32`.
-pub type u32x8 = Simd<u32, 8>;
-
-/// A 512-bit SIMD vector with 16 elements of type `u32`.
-pub type u32x16 = Simd<u32, 16>;
-
-/// A 128-bit SIMD vector with two elements of type `u64`.
-pub type u64x2 = Simd<u64, 2>;
-
-/// A 256-bit SIMD vector with four elements of type `u64`.
-pub type u64x4 = Simd<u64, 4>;
-
-/// A 512-bit SIMD vector with eight elements of type `u64`.
-pub type u64x8 = Simd<u64, 8>;
-
-/// A 32-bit SIMD vector with four elements of type `u8`.
-pub type u8x4 = Simd<u8, 4>;
-
-/// A 64-bit SIMD vector with eight elements of type `u8`.
-pub type u8x8 = Simd<u8, 8>;
-
-/// A 128-bit SIMD vector with 16 elements of type `u8`.
-pub type u8x16 = Simd<u8, 16>;
-
-/// A 256-bit SIMD vector with 32 elements of type `u8`.
-pub type u8x32 = Simd<u8, 32>;
-
-/// A 512-bit SIMD vector with 64 elements of type `u8`.
-pub type u8x64 = Simd<u8, 64>;
diff --git a/library/portable-simd/crates/core_simd/tests/autoderef.rs b/library/portable-simd/crates/core_simd/tests/autoderef.rs
index 9359da16e..3181826ef 100644
--- a/library/portable-simd/crates/core_simd/tests/autoderef.rs
+++ b/library/portable-simd/crates/core_simd/tests/autoderef.rs
@@ -1,6 +1,6 @@
 // Test that we handle all our "auto-deref" cases correctly.
 #![feature(portable_simd)]
-use core_simd::f32x4;
+use core_simd::simd::f32x4;
 
 #[cfg(target_arch = "wasm32")]
 use wasm_bindgen_test::*;
diff --git a/library/portable-simd/crates/core_simd/tests/mask_ops_impl/mask_macros.rs b/library/portable-simd/crates/core_simd/tests/mask_ops_impl/mask_macros.rs
index 795f9e27c..faafa5fa5 100644
--- a/library/portable-simd/crates/core_simd/tests/mask_ops_impl/mask_macros.rs
+++ b/library/portable-simd/crates/core_simd/tests/mask_ops_impl/mask_macros.rs
@@ -2,7 +2,7 @@ macro_rules! mask_tests {
     { $vector:ident, $lanes:literal } => {
         #[cfg(test)]
         mod $vector {
-            use core_simd::$vector as Vector;
+            use core_simd::simd::$vector as Vector;
             const LANES: usize = $lanes;
 
             #[cfg(target_arch = "wasm32")]
diff --git a/library/portable-simd/crates/core_simd/tests/masks.rs b/library/portable-simd/crates/core_simd/tests/masks.rs
index 673d0db93..9f8bad1c3 100644
--- a/library/portable-simd/crates/core_simd/tests/masks.rs
+++ b/library/portable-simd/crates/core_simd/tests/masks.rs
@@ -13,11 +13,13 @@ macro_rules! test_mask_api {
             #[cfg(target_arch = "wasm32")]
             use wasm_bindgen_test::*;
 
+            use core_simd::simd::Mask;
+
             #[test]
             #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
             fn set_and_test() {
                 let values = [true, false, false, true, false, false, true, false];
-                let mut mask = core_simd::Mask::<$type, 8>::splat(false);
+                let mut mask = Mask::<$type, 8>::splat(false);
                 for (lane, value) in values.iter().copied().enumerate() {
                     mask.set(lane, value);
                 }
@@ -29,7 +31,7 @@ macro_rules! test_mask_api {
             #[test]
             #[should_panic]
             fn set_invalid_lane() {
-                let mut mask = core_simd::Mask::<$type, 8>::splat(false);
+                let mut mask = Mask::<$type, 8>::splat(false);
                 mask.set(8, true);
                 let _ = mask;
             }
@@ -37,24 +39,24 @@ macro_rules! test_mask_api {
             #[test]
             #[should_panic]
             fn test_invalid_lane() {
-                let mask = core_simd::Mask::<$type, 8>::splat(false);
+                let mask = Mask::<$type, 8>::splat(false);
                 let _ = mask.test(8);
             }
 
             #[test]
             fn any() {
-                assert!(!core_simd::Mask::<$type, 8>::splat(false).any());
-                assert!(core_simd::Mask::<$type, 8>::splat(true).any());
-                let mut v = core_simd::Mask::<$type, 8>::splat(false);
+                assert!(!Mask::<$type, 8>::splat(false).any());
+                assert!(Mask::<$type, 8>::splat(true).any());
+                let mut v = Mask::<$type, 8>::splat(false);
                 v.set(2, true);
                 assert!(v.any());
             }
 
             #[test]
             fn all() {
-                assert!(!core_simd::Mask::<$type, 8>::splat(false).all());
-                assert!(core_simd::Mask::<$type, 8>::splat(true).all());
-                let mut v = core_simd::Mask::<$type, 8>::splat(false);
+                assert!(!Mask::<$type, 8>::splat(false).all());
+                assert!(Mask::<$type, 8>::splat(true).all());
+                let mut v = Mask::<$type, 8>::splat(false);
                 v.set(2, true);
                 assert!(!v.all());
             }
@@ -62,57 +64,57 @@ macro_rules! test_mask_api {
             #[test]
             fn roundtrip_int_conversion() {
                 let values = [true, false, false, true, false, false, true, false];
-                let mask = core_simd::Mask::<$type, 8>::from_array(values);
+                let mask = Mask::<$type, 8>::from_array(values);
                 let int = mask.to_int();
                 assert_eq!(int.to_array(), [-1, 0, 0, -1, 0, 0, -1, 0]);
-                assert_eq!(core_simd::Mask::<$type, 8>::from_int(int), mask);
+                assert_eq!(Mask::<$type, 8>::from_int(int), mask);
             }
 
             #[test]
             fn roundtrip_bitmask_conversion() {
-                use core_simd::ToBitMask;
+                use core_simd::simd::ToBitMask;
                 let values = [
                     true, false, false, true, false, false, true, false,
                     true, true, false, false, false, false, false, true,
                 ];
-                let mask = core_simd::Mask::<$type, 16>::from_array(values);
+                let mask = Mask::<$type, 16>::from_array(values);
                 let bitmask = mask.to_bitmask();
                 assert_eq!(bitmask, 0b1000001101001001);
-                assert_eq!(core_simd::Mask::<$type, 16>::from_bitmask(bitmask), mask);
+                assert_eq!(Mask::<$type, 16>::from_bitmask(bitmask), mask);
             }
 
             #[test]
             fn roundtrip_bitmask_conversion_short() {
-                use core_simd::ToBitMask;
+                use core_simd::simd::ToBitMask;
 
                 let values = [
                     false, false, false, true,
                 ];
-                let mask = core_simd::Mask::<$type, 4>::from_array(values);
+                let mask = Mask::<$type, 4>::from_array(values);
                 let bitmask = mask.to_bitmask();
                 assert_eq!(bitmask, 0b1000);
-                assert_eq!(core_simd::Mask::<$type, 4>::from_bitmask(bitmask), mask);
+                assert_eq!(Mask::<$type, 4>::from_bitmask(bitmask), mask);
 
                 let values = [true, false];
-                let mask = core_simd::Mask::<$type, 2>::from_array(values);
+                let mask = Mask::<$type, 2>::from_array(values);
                 let bitmask = mask.to_bitmask();
                 assert_eq!(bitmask, 0b01);
-                assert_eq!(core_simd::Mask::<$type, 2>::from_bitmask(bitmask), mask);
+                assert_eq!(Mask::<$type, 2>::from_bitmask(bitmask), mask);
             }
 
             #[test]
             fn cast() {
-                fn cast_impl<T: core_simd::MaskElement>()
+                fn cast_impl<T: core_simd::simd::MaskElement>()
                 where
-                    core_simd::Mask<$type, 8>: Into<core_simd::Mask<T, 8>>,
+                    Mask<$type, 8>: Into<Mask<T, 8>>,
                 {
                     let values = [true, false, false, true, false, false, true, false];
-                    let mask = core_simd::Mask::<$type, 8>::from_array(values);
+                    let mask = Mask::<$type, 8>::from_array(values);
 
                     let cast_mask = mask.cast::<T>();
                     assert_eq!(values, cast_mask.to_array());
 
-                    let into_mask: core_simd::Mask<T, 8> = mask.into();
+                    let into_mask: Mask<T, 8> = mask.into();
                     assert_eq!(values, into_mask.to_array());
                 }
 
@@ -126,15 +128,15 @@ macro_rules! test_mask_api {
             #[cfg(feature = "generic_const_exprs")]
             #[test]
             fn roundtrip_bitmask_array_conversion() {
-                use core_simd::ToBitMaskArray;
+                use core_simd::simd::ToBitMaskArray;
                 let values = [
                     true, false, false, true, false, false, true, false,
                     true, true, false, false, false, false, false, true,
                 ];
-                let mask = core_simd::Mask::<$type, 16>::from_array(values);
+                let mask = Mask::<$type, 16>::from_array(values);
                 let bitmask = mask.to_bitmask_array();
                 assert_eq!(bitmask, [0b01001001, 0b10000011]);
-                assert_eq!(core_simd::Mask::<$type, 16>::from_bitmask_array(bitmask), mask);
+                assert_eq!(Mask::<$type, 16>::from_bitmask_array(bitmask), mask);
             }
         }
     }
@@ -150,9 +152,10 @@ mod mask_api {
 
 #[test]
 fn convert() {
+    use core_simd::simd::Mask;
     let values = [true, false, false, true, false, false, true, false];
     assert_eq!(
-        core_simd::Mask::<i8, 8>::from_array(values),
-        core_simd::Mask::<i32, 8>::from_array(values).into()
+        Mask::<i8, 8>::from_array(values),
+        Mask::<i32, 8>::from_array(values).into()
     );
 }
diff --git a/library/portable-simd/crates/core_simd/tests/ops_macros.rs b/library/portable-simd/crates/core_simd/tests/ops_macros.rs
index f759394d0..3a02f3f01 100644
--- a/library/portable-simd/crates/core_simd/tests/ops_macros.rs
+++ b/library/portable-simd/crates/core_simd/tests/ops_macros.rs
@@ -7,7 +7,7 @@ macro_rules! impl_unary_op_test {
         test_helpers::test_lanes! {
             fn $fn<const LANES: usize>() {
                 test_helpers::test_unary_elementwise(
-                    &<core_simd::Simd<$scalar, LANES> as core::ops::$trait>::$fn,
+                    &<core_simd::simd::Simd<$scalar, LANES> as core::ops::$trait>::$fn,
                     &$scalar_fn,
                     &|_| true,
                 );
@@ -27,7 +27,7 @@ macro_rules! impl_binary_op_test {
     { $scalar:ty, $trait:ident :: $fn:ident, $trait_assign:ident :: $fn_assign:ident, $scalar_fn:expr } => {
         mod $fn {
             use super::*;
-            use core_simd::Simd;
+            use core_simd::simd::Simd;
 
             test_helpers::test_lanes! {
                 fn normal<const LANES: usize>() {
@@ -64,7 +64,7 @@ macro_rules! impl_binary_checked_op_test {
     { $scalar:ty, $trait:ident :: $fn:ident, $trait_assign:ident :: $fn_assign:ident, $scalar_fn:expr, $check_fn:expr } => {
         mod $fn {
             use super::*;
-            use core_simd::Simd;
+            use core_simd::simd::Simd;
 
             test_helpers::test_lanes! {
                 fn normal<const LANES: usize>() {
@@ -173,7 +173,7 @@ macro_rules! impl_signed_tests {
     { $scalar:tt } => {
         mod $scalar {
             use core_simd::simd::SimdInt;
-            type Vector<const LANES: usize> = core_simd::Simd<Scalar, LANES>;
+            type Vector<const LANES: usize> = core_simd::simd::Simd<Scalar, LANES>;
             type Scalar = $scalar;
 
             impl_common_integer_tests! { Vector, Scalar }
@@ -314,7 +314,7 @@ macro_rules! impl_unsigned_tests {
     { $scalar:tt } => {
         mod $scalar {
             use core_simd::simd::SimdUint;
-            type Vector<const LANES: usize> = core_simd::Simd<Scalar, LANES>;
+            type Vector<const LANES: usize> = core_simd::simd::Simd<Scalar, LANES>;
             type Scalar = $scalar;
 
             impl_common_integer_tests! { Vector, Scalar }
@@ -348,8 +348,8 @@ macro_rules! impl_unsigned_tests {
 macro_rules! impl_float_tests {
     { $scalar:tt, $int_scalar:tt } => {
         mod $scalar {
-            use core_simd::SimdFloat;
-            type Vector<const LANES: usize> = core_simd::Simd<Scalar, LANES>;
+            use core_simd::simd::SimdFloat;
+            type Vector<const LANES: usize> = core_simd::simd::Simd<Scalar, LANES>;
             type Scalar = $scalar;
 
             impl_unary_op_test!(Scalar, Neg::neg);
diff --git a/library/portable-simd/crates/core_simd/tests/pointers.rs b/library/portable-simd/crates/core_simd/tests/pointers.rs
new file mode 100644
index 000000000..0ae8f83b8
--- /dev/null
+++ b/library/portable-simd/crates/core_simd/tests/pointers.rs
@@ -0,0 +1,111 @@
+#![feature(portable_simd, strict_provenance)]
+
+use core_simd::simd::{Simd, SimdConstPtr, SimdMutPtr};
+
+macro_rules! common_tests {
+    { $constness:ident } => {
+        test_helpers::test_lanes! {
+            fn is_null<const LANES: usize>() {
+                test_helpers::test_unary_mask_elementwise(
+                    &Simd::<*$constness u32, LANES>::is_null,
+                    &<*$constness u32>::is_null,
+                    &|_| true,
+                );
+            }
+
+            fn addr<const LANES: usize>() {
+                test_helpers::test_unary_elementwise(
+                    &Simd::<*$constness u32, LANES>::addr,
+                    &<*$constness u32>::addr,
+                    &|_| true,
+                );
+            }
+
+            fn with_addr<const LANES: usize>() {
+                test_helpers::test_binary_elementwise(
+                    &Simd::<*$constness u32, LANES>::with_addr,
+                    &<*$constness u32>::with_addr,
+                    &|_, _| true,
+                );
+            }
+
+            fn expose_addr<const LANES: usize>() {
+                test_helpers::test_unary_elementwise(
+                    &Simd::<*$constness u32, LANES>::expose_addr,
+                    &<*$constness u32>::expose_addr,
+                    &|_| true,
+                );
+            }
+
+            fn wrapping_offset<const LANES: usize>() {
+                test_helpers::test_binary_elementwise(
+                    &Simd::<*$constness u32, LANES>::wrapping_offset,
+                    &<*$constness u32>::wrapping_offset,
+                    &|_, _| true,
+                );
+            }
+
+            fn wrapping_add<const LANES: usize>() {
+                test_helpers::test_binary_elementwise(
+                    &Simd::<*$constness u32, LANES>::wrapping_add,
+                    &<*$constness u32>::wrapping_add,
+                    &|_, _| true,
+                );
+            }
+
+            fn wrapping_sub<const LANES: usize>() {
+                test_helpers::test_binary_elementwise(
+                    &Simd::<*$constness u32, LANES>::wrapping_sub,
+                    &<*$constness u32>::wrapping_sub,
+                    &|_, _| true,
+                );
+            }
+        }
+    }
+}
+
+mod const_ptr {
+    use super::*;
+    common_tests! { const }
+
+    test_helpers::test_lanes! {
+        fn cast_mut<const LANES: usize>() {
+            test_helpers::test_unary_elementwise(
+                &Simd::<*const u32, LANES>::cast_mut,
+                &<*const u32>::cast_mut,
+                &|_| true,
+            );
+        }
+
+        fn from_exposed_addr<const LANES: usize>() {
+            test_helpers::test_unary_elementwise(
+                &Simd::<*const u32, LANES>::from_exposed_addr,
+                &core::ptr::from_exposed_addr::<u32>,
+                &|_| true,
+            );
+        }
+    }
+}
+
+mod mut_ptr {
+    use super::*;
+    common_tests! { mut }
+
+    test_helpers::test_lanes! {
+        fn cast_const<const LANES: usize>() {
+            test_helpers::test_unary_elementwise(
+                &Simd::<*mut u32, LANES>::cast_const,
+                &<*mut u32>::cast_const,
+                &|_| true,
+            );
+        }
+
+        fn from_exposed_addr<const LANES: usize>() {
+            test_helpers::test_unary_elementwise(
+                &Simd::<*mut u32, LANES>::from_exposed_addr,
+                &core::ptr::from_exposed_addr_mut::<u32>,
+                &|_| true,
+            );
+        }
+    }
+}
diff --git a/library/portable-simd/crates/core_simd/tests/round.rs b/library/portable-simd/crates/core_simd/tests/round.rs
index 484fd5bf4..8b9638ad4 100644
--- a/library/portable-simd/crates/core_simd/tests/round.rs
+++ b/library/portable-simd/crates/core_simd/tests/round.rs
@@ -5,7 +5,7 @@ macro_rules! float_rounding_test {
         mod $scalar {
             use std_float::StdFloat;
 
-            type Vector<const LANES: usize> = core_simd::Simd<$scalar, LANES>;
+            type Vector<const LANES: usize> = core_simd::simd::Simd<$scalar, LANES>;
             type Scalar = $scalar;
             type IntScalar = $int_scalar;
 
diff --git a/library/portable-simd/crates/core_simd/tests/swizzle.rs b/library/portable-simd/crates/core_simd/tests/swizzle.rs
index 51c63611a..8cd7c33e8 100644
--- a/library/portable-simd/crates/core_simd/tests/swizzle.rs
+++ b/library/portable-simd/crates/core_simd/tests/swizzle.rs
@@ -1,5 +1,5 @@
 #![feature(portable_simd)]
-use core_simd::{Simd, Swizzle};
+use core_simd::simd::{Simd, Swizzle};
 
 #[cfg(target_arch = "wasm32")]
 use wasm_bindgen_test::*;
@@ -60,3 +60,17 @@ fn interleave() {
     assert_eq!(even, a);
     assert_eq!(odd, b);
 }
+
+// portable-simd#298
+#[test]
+#[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+fn interleave_one() {
+    let a = Simd::from_array([0]);
+    let b = Simd::from_array([1]);
+    let (lo, hi) = a.interleave(b);
+    assert_eq!(lo.to_array(), [0]);
+    assert_eq!(hi.to_array(), [1]);
+    let (even, odd) = lo.deinterleave(hi);
+    assert_eq!(even, a);
+    assert_eq!(odd, b);
+}
diff --git a/library/portable-simd/crates/core_simd/tests/swizzle_dyn.rs b/library/portable-simd/crates/core_simd/tests/swizzle_dyn.rs
new file mode 100644
index 000000000..646cd5f33
--- /dev/null
+++ b/library/portable-simd/crates/core_simd/tests/swizzle_dyn.rs
@@ -0,0 +1,74 @@
+#![feature(portable_simd)]
+use core::{fmt, ops::RangeInclusive};
+use proptest;
+use test_helpers::{self, biteq, make_runner, prop_assert_biteq};
+
+fn swizzle_dyn_scalar_ver<const N: usize>(values: [u8; N], idxs: [u8; N]) -> [u8; N] {
+    let mut array = [0; N];
+    for (i, k) in idxs.into_iter().enumerate() {
+        if (k as usize) < N {
+            array[i] = values[k as usize];
+        };
+    }
+    array
+}
+
+test_helpers::test_lanes! {
+    fn swizzle_dyn<const N: usize>() {
+        match_simd_with_fallback(
+            &core_simd::simd::Simd::<u8, N>::swizzle_dyn,
+            &swizzle_dyn_scalar_ver,
+            &|_, _| true,
+        );
+    }
+}
+
+fn match_simd_with_fallback<Scalar, ScalarResult, Vector, VectorResult, const N: usize>(
+    fv: &dyn Fn(Vector, Vector) -> VectorResult,
+    fs: &dyn Fn([Scalar; N], [Scalar; N]) -> [ScalarResult; N],
+    check: &dyn Fn([Scalar; N], [Scalar; N]) -> bool,
+) where
+    Scalar: Copy + fmt::Debug + SwizzleStrategy,
+    ScalarResult: Copy + biteq::BitEq + fmt::Debug + SwizzleStrategy,
+    Vector: Into<[Scalar; N]> + From<[Scalar; N]> + Copy,
+    VectorResult: Into<[ScalarResult; N]> + From<[ScalarResult; N]> + Copy,
+{
+    test_swizzles_2(&|x: [Scalar; N], y: [Scalar; N]| {
+        proptest::prop_assume!(check(x, y));
+        let result_v: [ScalarResult; N] = fv(x.into(), y.into()).into();
+        let result_s: [ScalarResult; N] = fs(x, y);
+        crate::prop_assert_biteq!(result_v, result_s);
+        Ok(())
+    });
+}
+
+fn test_swizzles_2<A: fmt::Debug + SwizzleStrategy, B: fmt::Debug + SwizzleStrategy>(
+    f: &dyn Fn(A, B) -> proptest::test_runner::TestCaseResult,
+) {
+    let mut runner = make_runner();
+    runner
+        .run(
+            &(A::swizzled_strategy(), B::swizzled_strategy()),
+            |(a, b)| f(a, b),
+        )
+        .unwrap();
+}
+
+pub trait SwizzleStrategy {
+    type Strategy: proptest::strategy::Strategy<Value = Self>;
+    fn swizzled_strategy() -> Self::Strategy;
+}
+
+impl SwizzleStrategy for u8 {
+    type Strategy = RangeInclusive<u8>;
+    fn swizzled_strategy() -> Self::Strategy {
+        0..=64
+    }
+}
+
+impl<T: fmt::Debug + SwizzleStrategy, const N: usize> SwizzleStrategy for [T; N] {
+    type Strategy = test_helpers::array::UniformArrayStrategy<T::Strategy, Self>;
+    fn swizzled_strategy() -> Self::Strategy {
+        Self::Strategy::new(T::swizzled_strategy())
+    }
+}
diff --git a/library/portable-simd/crates/core_simd/tests/to_bytes.rs b/library/portable-simd/crates/core_simd/tests/to_bytes.rs
index debb4335e..be0ee4349 100644
--- a/library/portable-simd/crates/core_simd/tests/to_bytes.rs
+++ b/library/portable-simd/crates/core_simd/tests/to_bytes.rs
@@ -2,7 +2,7 @@
 #![allow(incomplete_features)]
 #![cfg(feature = "generic_const_exprs")]
 
-use core_simd::Simd;
+use core_simd::simd::Simd;
 
 #[test]
 fn byte_convert() {
diff --git a/library/portable-simd/crates/core_simd/tests/try_from_slice.rs b/library/portable-simd/crates/core_simd/tests/try_from_slice.rs
new file mode 100644
index 000000000..859e3b94f
--- /dev/null
+++ b/library/portable-simd/crates/core_simd/tests/try_from_slice.rs
@@ -0,0 +1,25 @@
+#![feature(portable_simd)]
+
+#[cfg(target_arch = "wasm32")]
+use wasm_bindgen_test::*;
+
+#[cfg(target_arch = "wasm32")]
+wasm_bindgen_test_configure!(run_in_browser);
+
+use core_simd::simd::i32x4;
+
+#[test]
+#[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+fn try_from_slice() {
+    // Equal length
+    assert_eq!(
+        i32x4::try_from([1, 2, 3, 4].as_slice()).unwrap(),
+        i32x4::from_array([1, 2, 3, 4])
+    );
+
+    // Slice length > vector length
+    assert!(i32x4::try_from([1, 2, 3, 4, 5].as_slice()).is_err());
+
+    // Slice length < vector length
+    assert!(i32x4::try_from([1, 2, 3].as_slice()).is_err());
+}
diff --git a/library/portable-simd/crates/test_helpers/Cargo.toml b/library/portable-simd/crates/test_helpers/Cargo.toml
index a04b0961d..1d2bc8b51 100644
--- a/library/portable-simd/crates/test_helpers/Cargo.toml
+++ b/library/portable-simd/crates/test_helpers/Cargo.toml
@@ -8,3 +8,6 @@ publish = false
 version = "0.10"
 default-features = false
 features = ["alloc"]
+
+[features]
+all_lane_counts = []
diff --git a/library/portable-simd/crates/test_helpers/src/array.rs b/library/portable-simd/crates/test_helpers/src/array.rs
index 5ffc92269..984a42732 100644
--- a/library/portable-simd/crates/test_helpers/src/array.rs
+++ b/library/portable-simd/crates/test_helpers/src/array.rs
@@ -41,6 +41,7 @@ where
 
     fn new_tree(&self, runner: &mut TestRunner) -> NewTree<Self> {
         let tree: [S::Tree; LANES] = unsafe {
+            #[allow(clippy::uninit_assumed_init)]
             let mut tree: [MaybeUninit<S::Tree>; LANES] = MaybeUninit::uninit().assume_init();
             for t in tree.iter_mut() {
                 *t = MaybeUninit::new(self.strategy.new_tree(runner)?)
@@ -60,6 +61,7 @@ impl<T: ValueTree, const LANES: usize> ValueTree for ArrayValueTree<[T; LANES]>
 
     fn current(&self) -> Self::Value {
         unsafe {
+            #[allow(clippy::uninit_assumed_init)]
             let mut value: [MaybeUninit<T::Value>; LANES] = MaybeUninit::uninit().assume_init();
             for (tree_elem, value_elem) in self.tree.iter().zip(value.iter_mut()) {
                 *value_elem = MaybeUninit::new(tree_elem.current());
diff --git a/library/portable-simd/crates/test_helpers/src/biteq.rs b/library/portable-simd/crates/test_helpers/src/biteq.rs
index 00350e224..7d91260d8 100644
--- a/library/portable-simd/crates/test_helpers/src/biteq.rs
+++ b/library/portable-simd/crates/test_helpers/src/biteq.rs
@@ -55,6 +55,26 @@ macro_rules! impl_float_biteq {
 
 impl_float_biteq! { f32, f64 }
 
+impl<T> BitEq for *const T {
+    fn biteq(&self, other: &Self) -> bool {
+        self == other
+    }
+
+    fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+        write!(f, "{:?}", self)
+    }
+}
+
+impl<T> BitEq for *mut T {
+    fn biteq(&self, other: &Self) -> bool {
+        self == other
+    }
+
+    fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+        write!(f, "{:?}", self)
+    }
+}
+
 impl<T: BitEq, const N: usize> BitEq for [T; N] {
     fn biteq(&self, other: &Self) -> bool {
         self.iter()
diff --git a/library/portable-simd/crates/test_helpers/src/lib.rs b/library/portable-simd/crates/test_helpers/src/lib.rs
index 141bee18a..b26cdc311 100644
--- a/library/portable-simd/crates/test_helpers/src/lib.rs
+++ b/library/portable-simd/crates/test_helpers/src/lib.rs
@@ -38,6 +38,28 @@ impl_num! { usize }
 impl_num! { f32 }
 impl_num! { f64 }
 
+impl<T> DefaultStrategy for *const T {
+    type Strategy = proptest::strategy::Map<proptest::num::isize::Any, fn(isize) -> *const T>;
+    fn default_strategy() -> Self::Strategy {
+        fn map<T>(x: isize) -> *const T {
+            x as _
+        }
+        use proptest::strategy::Strategy;
+        proptest::num::isize::ANY.prop_map(map)
+    }
+}
+
+impl<T> DefaultStrategy for *mut T {
+    type Strategy = proptest::strategy::Map<proptest::num::isize::Any, fn(isize) -> *mut T>;
+    fn default_strategy() -> Self::Strategy {
+        fn map<T>(x: isize) -> *mut T {
+            x as _
+        }
+        use proptest::strategy::Strategy;
+        proptest::num::isize::ANY.prop_map(map)
+    }
+}
+
 #[cfg(not(target_arch = "wasm32"))]
 impl DefaultStrategy for u128 {
     type Strategy = proptest::num::u128::Any;
@@ -135,21 +157,21 @@ pub fn test_unary_elementwise<Scalar, ScalarResult, Vector, VectorResult, const
     fs: &dyn Fn(Scalar) -> ScalarResult,
     check: &dyn Fn([Scalar; LANES]) -> bool,
 ) where
-    Scalar: Copy + Default + core::fmt::Debug + DefaultStrategy,
-    ScalarResult: Copy + Default + biteq::BitEq + core::fmt::Debug + DefaultStrategy,
+    Scalar: Copy + core::fmt::Debug + DefaultStrategy,
+    ScalarResult: Copy + biteq::BitEq + core::fmt::Debug + DefaultStrategy,
     Vector: Into<[Scalar; LANES]> + From<[Scalar; LANES]> + Copy,
     VectorResult: Into<[ScalarResult; LANES]> + From<[ScalarResult; LANES]> + Copy,
 {
     test_1(&|x: [Scalar; LANES]| {
         proptest::prop_assume!(check(x));
         let result_1: [ScalarResult; LANES] = fv(x.into()).into();
-        let result_2: [ScalarResult; LANES] = {
-            let mut result = [ScalarResult::default(); LANES];
-            for (i, o) in x.iter().zip(result.iter_mut()) {
-                *o = fs(*i);
-            }
-            result
-        };
+        let result_2: [ScalarResult; LANES] = x
+            .iter()
+            .copied()
+            .map(fs)
+            .collect::<Vec<_>>()
+            .try_into()
+            .unwrap();
         crate::prop_assert_biteq!(result_1, result_2);
         Ok(())
     });
@@ -162,7 +184,7 @@ pub fn test_unary_mask_elementwise<Scalar, Vector, Mask, const LANES: usize>(
     fs: &dyn Fn(Scalar) -> bool,
     check: &dyn Fn([Scalar; LANES]) -> bool,
 ) where
-    Scalar: Copy + Default + core::fmt::Debug + DefaultStrategy,
+    Scalar: Copy + core::fmt::Debug + DefaultStrategy,
     Vector: Into<[Scalar; LANES]> + From<[Scalar; LANES]> + Copy,
     Mask: Into<[bool; LANES]> + From<[bool; LANES]> + Copy,
 {
@@ -196,9 +218,9 @@ pub fn test_binary_elementwise<
     fs: &dyn Fn(Scalar1, Scalar2) -> ScalarResult,
     check: &dyn Fn([Scalar1; LANES], [Scalar2; LANES]) -> bool,
 ) where
-    Scalar1: Copy + Default + core::fmt::Debug + DefaultStrategy,
-    Scalar2: Copy + Default + core::fmt::Debug + DefaultStrategy,
-    ScalarResult: Copy + Default + biteq::BitEq + core::fmt::Debug + DefaultStrategy,
+    Scalar1: Copy + core::fmt::Debug + DefaultStrategy,
+    Scalar2: Copy + core::fmt::Debug + DefaultStrategy,
+    ScalarResult: Copy + biteq::BitEq + core::fmt::Debug + DefaultStrategy,
     Vector1: Into<[Scalar1; LANES]> + From<[Scalar1; LANES]> + Copy,
     Vector2: Into<[Scalar2; LANES]> + From<[Scalar2; LANES]> + Copy,
     VectorResult: Into<[ScalarResult; LANES]> + From<[ScalarResult; LANES]> + Copy,
@@ -206,13 +228,14 @@ pub fn test_binary_elementwise<
     test_2(&|x: [Scalar1; LANES], y: [Scalar2; LANES]| {
         proptest::prop_assume!(check(x, y));
         let result_1: [ScalarResult; LANES] = fv(x.into(), y.into()).into();
-        let result_2: [ScalarResult; LANES] = {
-            let mut result = [ScalarResult::default(); LANES];
-            for ((i1, i2), o) in x.iter().zip(y.iter()).zip(result.iter_mut()) {
-                *o = fs(*i1, *i2);
-            }
-            result
-        };
+        let result_2: [ScalarResult; LANES] = x
+            .iter()
+            .copied()
+            .zip(y.iter().copied())
+            .map(|(x, y)| fs(x, y))
+            .collect::<Vec<_>>()
+            .try_into()
+            .unwrap();
         crate::prop_assert_biteq!(result_1, result_2);
         Ok(())
     });
@@ -333,6 +356,39 @@ pub fn test_ternary_elementwise<
     );
 }
 
+#[doc(hidden)]
+#[macro_export]
+macro_rules! test_lanes_helper {
+    ($($(#[$meta:meta])* $fn_name:ident $lanes:literal;)+) => {
+        $(
+            #[test]
+            $(#[$meta])*
+            fn $fn_name() {
+                implementation::<$lanes>();
+            }
+        )+
+    };
+    (
+        $(#[$meta:meta])+;
+        $($(#[$meta_before:meta])+ $fn_name_before:ident $lanes_before:literal;)*
+        $fn_name:ident $lanes:literal;
+        $($fn_name_rest:ident $lanes_rest:literal;)*
+    ) => {
+        $crate::test_lanes_helper!(
+            $(#[$meta])+;
+            $($(#[$meta_before])+ $fn_name_before $lanes_before;)*
+            $(#[$meta])+ $fn_name $lanes;
+            $($fn_name_rest $lanes_rest;)*
+        );
+    };
+    (
+        $(#[$meta_ignored:meta])+;
+        $($(#[$meta:meta])+ $fn_name:ident $lanes:literal;)+
+    ) => {
+        $crate::test_lanes_helper!($($(#[$meta])+ $fn_name $lanes;)+);
+    };
+}
+
 /// Expand a const-generic test into separate tests for each possible lane count.
 #[macro_export]
 macro_rules! test_lanes {
@@ -345,57 +401,96 @@ macro_rules! test_lanes {
 
                 fn implementation<const $lanes: usize>()
                 where
-                    core_simd::LaneCount<$lanes>: core_simd::SupportedLaneCount,
+                    core_simd::simd::LaneCount<$lanes>: core_simd::simd::SupportedLaneCount,
                 $body
 
                 #[cfg(target_arch = "wasm32")]
                 wasm_bindgen_test::wasm_bindgen_test_configure!(run_in_browser);
 
-                #[test]
-                #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
-                fn lanes_1() {
-                    implementation::<1>();
-                }
-
-                #[test]
-                #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
-                fn lanes_2() {
-                    implementation::<2>();
-                }
-
-                #[test]
-                #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
-                fn lanes_4() {
-                    implementation::<4>();
-                }
+                $crate::test_lanes_helper!(
+                    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)];
+                    lanes_1 1;
+                    lanes_2 2;
+                    lanes_4 4;
+                );
 
-                #[test]
-                #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
                 #[cfg(not(miri))] // Miri intrinsic implementations are uniform and larger tests are sloooow
-                fn lanes_8() {
-                    implementation::<8>();
-                }
-
-                #[test]
-                #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
+                $crate::test_lanes_helper!(
+                    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)];
+                    lanes_8 8;
+                    lanes_16 16;
+                    lanes_32 32;
+                    lanes_64 64;
+                );
+
+                #[cfg(feature = "all_lane_counts")]
+                $crate::test_lanes_helper!(
+                    // test some odd and even non-power-of-2 lengths on miri
+                    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)];
+                    lanes_3 3;
+                    lanes_5 5;
+                    lanes_6 6;
+                );
+
+                #[cfg(feature = "all_lane_counts")]
                 #[cfg(not(miri))] // Miri intrinsic implementations are uniform and larger tests are sloooow
-                fn lanes_16() {
-                    implementation::<16>();
-                }
-
-                #[test]
-                #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
-                #[cfg(not(miri))] // Miri intrinsic implementations are uniform and larger tests are sloooow
-                fn lanes_32() {
-                    implementation::<32>();
-                }
-
-                #[test]
-                #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
-                #[cfg(not(miri))] // Miri intrinsic implementations are uniform and larger tests are sloooow
-                fn lanes_64() {
-                    implementation::<64>();
-                }
+                $crate::test_lanes_helper!(
+                    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)];
+                    lanes_7 7;
+                    lanes_9 9;
+                    lanes_10 10;
+                    lanes_11 11;
+                    lanes_12 12;
+                    lanes_13 13;
+                    lanes_14 14;
+                    lanes_15 15;
+                    lanes_17 17;
+                    lanes_18 18;
+                    lanes_19 19;
+                    lanes_20 20;
+                    lanes_21 21;
+                    lanes_22 22;
+                    lanes_23 23;
+                    lanes_24 24;
+                    lanes_25 25;
+                    lanes_26 26;
+                    lanes_27 27;
+                    lanes_28 28;
+                    lanes_29 29;
+                    lanes_30 30;
+                    lanes_31 31;
+                    lanes_33 33;
+                    lanes_34 34;
+                    lanes_35 35;
+                    lanes_36 36;
+                    lanes_37 37;
+                    lanes_38 38;
+                    lanes_39 39;
+                    lanes_40 40;
+                    lanes_41 41;
+                    lanes_42 42;
+                    lanes_43 43;
+                    lanes_44 44;
+                    lanes_45 45;
+                    lanes_46 46;
+                    lanes_47 47;
+                    lanes_48 48;
+                    lanes_49 49;
+                    lanes_50 50;
+                    lanes_51 51;
+                    lanes_52 52;
+                    lanes_53 53;
+                    lanes_54 54;
+                    lanes_55 55;
+                    lanes_56 56;
+                    lanes_57 57;
+                    lanes_58 58;
+                    lanes_59 59;
+                    lanes_60 60;
+                    lanes_61 61;
+                    lanes_62 62;
+                    lanes_63 63;
+                );
             }
         )*
     }
@@ -413,50 +508,93 @@ macro_rules! test_lanes_panic {
 
                 fn implementation<const $lanes: usize>()
                 where
-                    core_simd::LaneCount<$lanes>: core_simd::SupportedLaneCount,
+                    core_simd::simd::LaneCount<$lanes>: core_simd::simd::SupportedLaneCount,
                 $body
 
-                #[test]
-                #[should_panic]
-                fn lanes_1() {
-                    implementation::<1>();
-                }
-
-                #[test]
-                #[should_panic]
-                fn lanes_2() {
-                    implementation::<2>();
-                }
-
-                #[test]
-                #[should_panic]
-                fn lanes_4() {
-                    implementation::<4>();
-                }
-
-                #[test]
-                #[should_panic]
-                fn lanes_8() {
-                    implementation::<8>();
-                }
+                $crate::test_lanes_helper!(
+                    #[should_panic];
+                    lanes_1 1;
+                    lanes_2 2;
+                    lanes_4 4;
+                );
 
-                #[test]
-                #[should_panic]
-                fn lanes_16() {
-                    implementation::<16>();
-                }
-
-                #[test]
-                #[should_panic]
-                fn lanes_32() {
-                    implementation::<32>();
-                }
-
-                #[test]
-                #[should_panic]
-                fn lanes_64() {
-                    implementation::<64>();
-                }
+                #[cfg(not(miri))] // Miri intrinsic implementations are uniform and larger tests are sloooow
+                $crate::test_lanes_helper!(
+                    #[should_panic];
+                    lanes_8 8;
+                    lanes_16 16;
+                    lanes_32 32;
+                    lanes_64 64;
+                );
+
+                #[cfg(feature = "all_lane_counts")]
+                $crate::test_lanes_helper!(
+                    // test some odd and even non-power-of-2 lengths on miri
+                    #[should_panic];
+                    lanes_3 3;
+                    lanes_5 5;
+                    lanes_6 6;
+                );
+
+                #[cfg(feature = "all_lane_counts")]
+                #[cfg(not(miri))] // Miri intrinsic implementations are uniform and larger tests are sloooow
+                $crate::test_lanes_helper!(
+                    #[should_panic];
+                    lanes_7 7;
+                    lanes_9 9;
+                    lanes_10 10;
+                    lanes_11 11;
+                    lanes_12 12;
+                    lanes_13 13;
+                    lanes_14 14;
+                    lanes_15 15;
+                    lanes_17 17;
+                    lanes_18 18;
+                    lanes_19 19;
+                    lanes_20 20;
+                    lanes_21 21;
+                    lanes_22 22;
+                    lanes_23 23;
+                    lanes_24 24;
+                    lanes_25 25;
+                    lanes_26 26;
+                    lanes_27 27;
+                    lanes_28 28;
+                    lanes_29 29;
+                    lanes_30 30;
+                    lanes_31 31;
+                    lanes_33 33;
+                    lanes_34 34;
+                    lanes_35 35;
+                    lanes_36 36;
+                    lanes_37 37;
+                    lanes_38 38;
+                    lanes_39 39;
+                    lanes_40 40;
+                    lanes_41 41;
+                    lanes_42 42;
+                    lanes_43 43;
+                    lanes_44 44;
+                    lanes_45 45;
+                    lanes_46 46;
+                    lanes_47 47;
+                    lanes_48 48;
+                    lanes_49 49;
+                    lanes_50 50;
+                    lanes_51 51;
+                    lanes_52 52;
+                    lanes_53 53;
+                    lanes_54 54;
+                    lanes_55 55;
+                    lanes_56 56;
+                    lanes_57 57;
+                    lanes_58 58;
+                    lanes_59 59;
+                    lanes_60 60;
+                    lanes_61 61;
+                    lanes_62 62;
+                    lanes_63 63;
+                );
             }
         )*
     }