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Diffstat (limited to 'third_party/rust/naga/src/back/msl/mod.rs')
| -rw-r--r-- | third_party/rust/naga/src/back/msl/mod.rs | 497 |
1 files changed, 497 insertions, 0 deletions
diff --git a/third_party/rust/naga/src/back/msl/mod.rs b/third_party/rust/naga/src/back/msl/mod.rs new file mode 100644 index 0000000000..a8ed2dd0d5 --- /dev/null +++ b/third_party/rust/naga/src/back/msl/mod.rs @@ -0,0 +1,497 @@ +/*! +Backend for [MSL][msl] (Metal Shading Language). + +## Binding model + +Metal's bindings are flat per resource. Since there isn't an obvious mapping +from SPIR-V's descriptor sets, we require a separate mapping provided in the options. +This mapping may have one or more resource end points for each descriptor set + index +pair. + +## Entry points + +Even though MSL and our IR appear to be similar in that the entry points in both can +accept arguments and return values, the restrictions are different. +MSL allows the varyings to be either in separate arguments, or inside a single +`[[stage_in]]` struct. We gather input varyings and form this artificial structure. +We also add all the (non-Private) globals into the arguments. + +At the beginning of the entry point, we assign the local constants and re-compose +the arguments as they are declared on IR side, so that the rest of the logic can +pretend that MSL doesn't have all the restrictions it has. + +For the result type, if it's a structure, we re-compose it with a temporary value +holding the result. + +[msl]: https://developer.apple.com/metal/Metal-Shading-Language-Specification.pdf +*/ + +use crate::{arena::Handle, proc::index, valid::ModuleInfo}; +use std::{ + fmt::{Error as FmtError, Write}, + ops, +}; + +mod keywords; +pub mod sampler; +mod writer; + +pub use writer::Writer; + +pub type Slot = u8; +pub type InlineSamplerIndex = u8; + +#[derive(Clone, Debug, PartialEq, Eq, Hash)] +#[cfg_attr(feature = "serialize", derive(serde::Serialize))] +#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))] +pub enum BindSamplerTarget { + Resource(Slot), + Inline(InlineSamplerIndex), +} + +#[derive(Clone, Debug, Default, PartialEq, Eq, Hash)] +#[cfg_attr(feature = "serialize", derive(serde::Serialize))] +#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))] +#[cfg_attr(any(feature = "serialize", feature = "deserialize"), serde(default))] +pub struct BindTarget { + pub buffer: Option<Slot>, + pub texture: Option<Slot>, + pub sampler: Option<BindSamplerTarget>, + /// If the binding is an unsized binding array, this overrides the size. + pub binding_array_size: Option<u32>, + pub mutable: bool, +} + +// Using `BTreeMap` instead of `HashMap` so that we can hash itself. +pub type BindingMap = std::collections::BTreeMap<crate::ResourceBinding, BindTarget>; + +#[derive(Clone, Debug, Default, Hash, Eq, PartialEq)] +#[cfg_attr(feature = "serialize", derive(serde::Serialize))] +#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))] +#[cfg_attr(any(feature = "serialize", feature = "deserialize"), serde(default))] +pub struct PerStageResources { + pub resources: BindingMap, + + pub push_constant_buffer: Option<Slot>, + + /// The slot of a buffer that contains an array of `u32`, + /// one for the size of each bound buffer that contains a runtime array, + /// in order of [`crate::GlobalVariable`] declarations. + pub sizes_buffer: Option<Slot>, +} + +#[derive(Clone, Debug, Default, Hash, Eq, PartialEq)] +#[cfg_attr(feature = "serialize", derive(serde::Serialize))] +#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))] +#[cfg_attr(any(feature = "serialize", feature = "deserialize"), serde(default))] +pub struct PerStageMap { + pub vs: PerStageResources, + pub fs: PerStageResources, + pub cs: PerStageResources, +} + +impl ops::Index<crate::ShaderStage> for PerStageMap { + type Output = PerStageResources; + fn index(&self, stage: crate::ShaderStage) -> &PerStageResources { + match stage { + crate::ShaderStage::Vertex => &self.vs, + crate::ShaderStage::Fragment => &self.fs, + crate::ShaderStage::Compute => &self.cs, + } + } +} + +enum ResolvedBinding { + BuiltIn(crate::BuiltIn), + Attribute(u32), + Color(u32), + User { + prefix: &'static str, + index: u32, + interpolation: Option<ResolvedInterpolation>, + }, + Resource(BindTarget), +} + +#[derive(Copy, Clone)] +enum ResolvedInterpolation { + CenterPerspective, + CenterNoPerspective, + CentroidPerspective, + CentroidNoPerspective, + SamplePerspective, + SampleNoPerspective, + Flat, +} + +// Note: some of these should be removed in favor of proper IR validation. + +#[derive(Debug, thiserror::Error)] +pub enum Error { + #[error(transparent)] + Format(#[from] FmtError), + #[error("bind target {0:?} is empty")] + UnimplementedBindTarget(BindTarget), + #[error("composing of {0:?} is not implemented yet")] + UnsupportedCompose(Handle<crate::Type>), + #[error("operation {0:?} is not implemented yet")] + UnsupportedBinaryOp(crate::BinaryOperator), + #[error("standard function '{0}' is not implemented yet")] + UnsupportedCall(String), + #[error("feature '{0}' is not implemented yet")] + FeatureNotImplemented(String), + #[error("module is not valid")] + Validation, + #[error("BuiltIn {0:?} is not supported")] + UnsupportedBuiltIn(crate::BuiltIn), + #[error("capability {0:?} is not supported")] + CapabilityNotSupported(crate::valid::Capabilities), + #[error("address space {0:?} is not supported for target MSL version")] + UnsupportedAddressSpace(crate::AddressSpace), + #[error("attribute '{0}' is not supported for target MSL version")] + UnsupportedAttribute(String), +} + +#[derive(Clone, Debug, PartialEq, thiserror::Error)] +#[cfg_attr(feature = "serialize", derive(serde::Serialize))] +#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))] +pub enum EntryPointError { + #[error("mapping of {0:?} is missing")] + MissingBinding(crate::ResourceBinding), + #[error("mapping for push constants is missing")] + MissingPushConstants, + #[error("mapping for sizes buffer is missing")] + MissingSizesBuffer, +} + +/// Points in the MSL code where we might emit a pipeline input or output. +/// +/// Note that, even though vertex shaders' outputs are always fragment +/// shaders' inputs, we still need to distinguish `VertexOutput` and +/// `FragmentInput`, since there are certain differences in the way +/// [`ResolvedBinding`s] are represented on either side. +/// +/// [`ResolvedBinding`s]: ResolvedBinding +#[derive(Clone, Copy, Debug)] +enum LocationMode { + /// Input to the vertex shader. + VertexInput, + + /// Output from the vertex shader. + VertexOutput, + + /// Input to the fragment shader. + FragmentInput, + + /// Output from the fragment shader. + FragmentOutput, + + /// Compute shader input or output. + Uniform, +} + +#[derive(Clone, Debug, Hash, PartialEq, Eq)] +#[cfg_attr(feature = "serialize", derive(serde::Serialize))] +#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))] +pub struct Options { + /// (Major, Minor) target version of the Metal Shading Language. + pub lang_version: (u8, u8), + /// Map of per-stage resources to slots. + pub per_stage_map: PerStageMap, + /// Samplers to be inlined into the code. + pub inline_samplers: Vec<sampler::InlineSampler>, + /// Make it possible to link different stages via SPIRV-Cross. + pub spirv_cross_compatibility: bool, + /// Don't panic on missing bindings, instead generate invalid MSL. + pub fake_missing_bindings: bool, + /// Bounds checking policies. + #[cfg_attr(feature = "deserialize", serde(default))] + pub bounds_check_policies: index::BoundsCheckPolicies, +} + +impl Default for Options { + fn default() -> Self { + Options { + lang_version: (2, 0), + per_stage_map: PerStageMap::default(), + inline_samplers: Vec::new(), + spirv_cross_compatibility: false, + fake_missing_bindings: true, + bounds_check_policies: index::BoundsCheckPolicies::default(), + } + } +} + +/// A subset of options that are meant to be changed per pipeline. +#[derive(Debug, Default, Clone, PartialEq, Eq, Hash)] +#[cfg_attr(feature = "serialize", derive(serde::Serialize))] +#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))] +pub struct PipelineOptions { + /// Allow `BuiltIn::PointSize` in the vertex shader. + /// + /// Metal doesn't like this for non-point primitive topologies. + pub allow_point_size: bool, +} + +impl Options { + fn resolve_local_binding( + &self, + binding: &crate::Binding, + mode: LocationMode, + ) -> Result<ResolvedBinding, Error> { + match *binding { + crate::Binding::BuiltIn(mut built_in) => { + if let crate::BuiltIn::Position { ref mut invariant } = built_in { + if *invariant && self.lang_version < (2, 1) { + return Err(Error::UnsupportedAttribute("invariant".to_string())); + } + + // The 'invariant' attribute may only appear on vertex + // shader outputs, not fragment shader inputs. + if !matches!(mode, LocationMode::VertexOutput) { + *invariant = false; + } + } + + Ok(ResolvedBinding::BuiltIn(built_in)) + } + crate::Binding::Location { + location, + interpolation, + sampling, + } => match mode { + LocationMode::VertexInput => Ok(ResolvedBinding::Attribute(location)), + LocationMode::FragmentOutput => Ok(ResolvedBinding::Color(location)), + LocationMode::VertexOutput | LocationMode::FragmentInput => { + Ok(ResolvedBinding::User { + prefix: if self.spirv_cross_compatibility { + "locn" + } else { + "loc" + }, + index: location, + interpolation: { + // unwrap: The verifier ensures that vertex shader outputs and fragment + // shader inputs always have fully specified interpolation, and that + // sampling is `None` only for Flat interpolation. + let interpolation = interpolation.unwrap(); + let sampling = sampling.unwrap_or(crate::Sampling::Center); + Some(ResolvedInterpolation::from_binding(interpolation, sampling)) + }, + }) + } + LocationMode::Uniform => { + log::error!( + "Unexpected Binding::Location({}) for the Uniform mode", + location + ); + Err(Error::Validation) + } + }, + } + } + + fn resolve_resource_binding( + &self, + stage: crate::ShaderStage, + res_binding: &crate::ResourceBinding, + ) -> Result<ResolvedBinding, EntryPointError> { + match self.per_stage_map[stage].resources.get(res_binding) { + Some(target) => Ok(ResolvedBinding::Resource(target.clone())), + None if self.fake_missing_bindings => Ok(ResolvedBinding::User { + prefix: "fake", + index: 0, + interpolation: None, + }), + None => Err(EntryPointError::MissingBinding(res_binding.clone())), + } + } + + const fn resolve_push_constants( + &self, + stage: crate::ShaderStage, + ) -> Result<ResolvedBinding, EntryPointError> { + let slot = match stage { + crate::ShaderStage::Vertex => self.per_stage_map.vs.push_constant_buffer, + crate::ShaderStage::Fragment => self.per_stage_map.fs.push_constant_buffer, + crate::ShaderStage::Compute => self.per_stage_map.cs.push_constant_buffer, + }; + match slot { + Some(slot) => Ok(ResolvedBinding::Resource(BindTarget { + buffer: Some(slot), + texture: None, + sampler: None, + binding_array_size: None, + mutable: false, + })), + None if self.fake_missing_bindings => Ok(ResolvedBinding::User { + prefix: "fake", + index: 0, + interpolation: None, + }), + None => Err(EntryPointError::MissingPushConstants), + } + } + + fn resolve_sizes_buffer( + &self, + stage: crate::ShaderStage, + ) -> Result<ResolvedBinding, EntryPointError> { + let slot = self.per_stage_map[stage].sizes_buffer; + match slot { + Some(slot) => Ok(ResolvedBinding::Resource(BindTarget { + buffer: Some(slot), + texture: None, + sampler: None, + binding_array_size: None, + mutable: false, + })), + None if self.fake_missing_bindings => Ok(ResolvedBinding::User { + prefix: "fake", + index: 0, + interpolation: None, + }), + None => Err(EntryPointError::MissingSizesBuffer), + } + } +} + +impl ResolvedBinding { + fn as_inline_sampler<'a>(&self, options: &'a Options) -> Option<&'a sampler::InlineSampler> { + match *self { + Self::Resource(BindTarget { + sampler: Some(BindSamplerTarget::Inline(index)), + .. + }) => Some(&options.inline_samplers[index as usize]), + _ => None, + } + } + + const fn as_bind_target(&self) -> Option<&BindTarget> { + match *self { + Self::Resource(ref target) => Some(target), + _ => None, + } + } + + fn try_fmt<W: Write>(&self, out: &mut W) -> Result<(), Error> { + write!(out, " [[")?; + match *self { + Self::BuiltIn(built_in) => { + use crate::BuiltIn as Bi; + let name = match built_in { + Bi::Position { invariant: false } => "position", + Bi::Position { invariant: true } => "position, invariant", + // vertex + Bi::BaseInstance => "base_instance", + Bi::BaseVertex => "base_vertex", + Bi::ClipDistance => "clip_distance", + Bi::InstanceIndex => "instance_id", + Bi::PointSize => "point_size", + Bi::VertexIndex => "vertex_id", + // fragment + Bi::FragDepth => "depth(any)", + Bi::FrontFacing => "front_facing", + Bi::PrimitiveIndex => "primitive_id", + Bi::SampleIndex => "sample_id", + Bi::SampleMask => "sample_mask", + // compute + Bi::GlobalInvocationId => "thread_position_in_grid", + Bi::LocalInvocationId => "thread_position_in_threadgroup", + Bi::LocalInvocationIndex => "thread_index_in_threadgroup", + Bi::WorkGroupId => "threadgroup_position_in_grid", + Bi::WorkGroupSize => "dispatch_threads_per_threadgroup", + Bi::NumWorkGroups => "threadgroups_per_grid", + Bi::CullDistance | Bi::ViewIndex => { + return Err(Error::UnsupportedBuiltIn(built_in)) + } + }; + write!(out, "{}", name)?; + } + Self::Attribute(index) => write!(out, "attribute({})", index)?, + Self::Color(index) => write!(out, "color({})", index)?, + Self::User { + prefix, + index, + interpolation, + } => { + write!(out, "user({}{})", prefix, index)?; + if let Some(interpolation) = interpolation { + write!(out, ", ")?; + interpolation.try_fmt(out)?; + } + } + Self::Resource(ref target) => { + if let Some(id) = target.buffer { + write!(out, "buffer({})", id)?; + } else if let Some(id) = target.texture { + write!(out, "texture({})", id)?; + } else if let Some(BindSamplerTarget::Resource(id)) = target.sampler { + write!(out, "sampler({})", id)?; + } else { + return Err(Error::UnimplementedBindTarget(target.clone())); + } + } + } + write!(out, "]]")?; + Ok(()) + } +} + +impl ResolvedInterpolation { + const fn from_binding(interpolation: crate::Interpolation, sampling: crate::Sampling) -> Self { + use crate::Interpolation as I; + use crate::Sampling as S; + + match (interpolation, sampling) { + (I::Perspective, S::Center) => Self::CenterPerspective, + (I::Perspective, S::Centroid) => Self::CentroidPerspective, + (I::Perspective, S::Sample) => Self::SamplePerspective, + (I::Linear, S::Center) => Self::CenterNoPerspective, + (I::Linear, S::Centroid) => Self::CentroidNoPerspective, + (I::Linear, S::Sample) => Self::SampleNoPerspective, + (I::Flat, _) => Self::Flat, + } + } + + fn try_fmt<W: Write>(self, out: &mut W) -> Result<(), Error> { + let identifier = match self { + Self::CenterPerspective => "center_perspective", + Self::CenterNoPerspective => "center_no_perspective", + Self::CentroidPerspective => "centroid_perspective", + Self::CentroidNoPerspective => "centroid_no_perspective", + Self::SamplePerspective => "sample_perspective", + Self::SampleNoPerspective => "sample_no_perspective", + Self::Flat => "flat", + }; + out.write_str(identifier)?; + Ok(()) + } +} + +/// Information about a translated module that is required +/// for the use of the result. +pub struct TranslationInfo { + /// Mapping of the entry point names. Each item in the array + /// corresponds to an entry point index. + /// + ///Note: Some entry points may fail translation because of missing bindings. + pub entry_point_names: Vec<Result<String, EntryPointError>>, +} + +pub fn write_string( + module: &crate::Module, + info: &ModuleInfo, + options: &Options, + pipeline_options: &PipelineOptions, +) -> Result<(String, TranslationInfo), Error> { + let mut w = writer::Writer::new(String::new()); + let info = w.write(module, info, options, pipeline_options)?; + Ok((w.finish(), info)) +} + +#[test] +fn test_error_size() { + use std::mem::size_of; + assert_eq!(size_of::<Error>(), 32); +} |