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/*!
Helpers for the hlsl backend
Important note about `Expression::ImageQuery`/`Expression::ArrayLength` and hlsl backend:
Due to implementation of `GetDimensions` function in hlsl (<https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-to-getdimensions>)
backend can't work with it as an expression.
Instead, it generates a unique wrapped function per `Expression::ImageQuery`, based on texture info and query function.
See `WrappedImageQuery` struct that represents a unique function and will be generated before writing all statements and expressions.
This allowed to works with `Expression::ImageQuery` as expression and write wrapped function.
For example:
```wgsl
let dim_1d = textureDimensions(image_1d);
```
```hlsl
int NagaDimensions1D(Texture1D<float4>)
{
uint4 ret;
image_1d.GetDimensions(ret.x);
return ret.x;
}
int dim_1d = NagaDimensions1D(image_1d);
```
*/
use super::{
super::FunctionCtx,
writer::{EXTRACT_BITS_FUNCTION, INSERT_BITS_FUNCTION},
BackendResult,
};
use crate::{arena::Handle, proc::NameKey};
use std::fmt::Write;
#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
pub(super) struct WrappedArrayLength {
pub(super) writable: bool,
}
#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
pub(super) struct WrappedImageQuery {
pub(super) dim: crate::ImageDimension,
pub(super) arrayed: bool,
pub(super) class: crate::ImageClass,
pub(super) query: ImageQuery,
}
#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
pub(super) struct WrappedConstructor {
pub(super) ty: Handle<crate::Type>,
}
#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
pub(super) struct WrappedStructMatrixAccess {
pub(super) ty: Handle<crate::Type>,
pub(super) index: u32,
}
#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
pub(super) struct WrappedMatCx2 {
pub(super) columns: crate::VectorSize,
}
#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
pub(super) struct WrappedMath {
pub(super) fun: crate::MathFunction,
pub(super) scalar: crate::Scalar,
pub(super) components: Option<u32>,
}
#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
pub(super) struct WrappedZeroValue {
pub(super) ty: Handle<crate::Type>,
}
/// HLSL backend requires its own `ImageQuery` enum.
///
/// It is used inside `WrappedImageQuery` and should be unique per ImageQuery function.
/// IR version can't be unique per function, because it's store mipmap level as an expression.
///
/// For example:
/// ```wgsl
/// let dim_cube_array_lod = textureDimensions(image_cube_array, 1);
/// let dim_cube_array_lod2 = textureDimensions(image_cube_array, 1);
/// ```
///
/// ```ir
/// ImageQuery {
/// image: [1],
/// query: Size {
/// level: Some(
/// [1],
/// ),
/// },
/// },
/// ImageQuery {
/// image: [1],
/// query: Size {
/// level: Some(
/// [2],
/// ),
/// },
/// },
/// ```
///
/// HLSL should generate only 1 function for this case.
#[derive(Clone, Copy, Debug, Hash, Eq, Ord, PartialEq, PartialOrd)]
pub(super) enum ImageQuery {
Size,
SizeLevel,
NumLevels,
NumLayers,
NumSamples,
}
impl From<crate::ImageQuery> for ImageQuery {
fn from(q: crate::ImageQuery) -> Self {
use crate::ImageQuery as Iq;
match q {
Iq::Size { level: Some(_) } => ImageQuery::SizeLevel,
Iq::Size { level: None } => ImageQuery::Size,
Iq::NumLevels => ImageQuery::NumLevels,
Iq::NumLayers => ImageQuery::NumLayers,
Iq::NumSamples => ImageQuery::NumSamples,
}
}
}
impl<'a, W: Write> super::Writer<'a, W> {
pub(super) fn write_image_type(
&mut self,
dim: crate::ImageDimension,
arrayed: bool,
class: crate::ImageClass,
) -> BackendResult {
let access_str = match class {
crate::ImageClass::Storage { .. } => "RW",
_ => "",
};
let dim_str = dim.to_hlsl_str();
let arrayed_str = if arrayed { "Array" } else { "" };
write!(self.out, "{access_str}Texture{dim_str}{arrayed_str}")?;
match class {
crate::ImageClass::Depth { multi } => {
let multi_str = if multi { "MS" } else { "" };
write!(self.out, "{multi_str}<float>")?
}
crate::ImageClass::Sampled { kind, multi } => {
let multi_str = if multi { "MS" } else { "" };
let scalar_kind_str = crate::Scalar { kind, width: 4 }.to_hlsl_str()?;
write!(self.out, "{multi_str}<{scalar_kind_str}4>")?
}
crate::ImageClass::Storage { format, .. } => {
let storage_format_str = format.to_hlsl_str();
write!(self.out, "<{storage_format_str}>")?
}
}
Ok(())
}
pub(super) fn write_wrapped_array_length_function_name(
&mut self,
query: WrappedArrayLength,
) -> BackendResult {
let access_str = if query.writable { "RW" } else { "" };
write!(self.out, "NagaBufferLength{access_str}",)?;
Ok(())
}
/// Helper function that write wrapped function for `Expression::ArrayLength`
///
pub(super) fn write_wrapped_array_length_function(
&mut self,
wal: WrappedArrayLength,
) -> BackendResult {
use crate::back::INDENT;
const ARGUMENT_VARIABLE_NAME: &str = "buffer";
const RETURN_VARIABLE_NAME: &str = "ret";
// Write function return type and name
write!(self.out, "uint ")?;
self.write_wrapped_array_length_function_name(wal)?;
// Write function parameters
write!(self.out, "(")?;
let access_str = if wal.writable { "RW" } else { "" };
writeln!(
self.out,
"{access_str}ByteAddressBuffer {ARGUMENT_VARIABLE_NAME})"
)?;
// Write function body
writeln!(self.out, "{{")?;
// Write `GetDimensions` function.
writeln!(self.out, "{INDENT}uint {RETURN_VARIABLE_NAME};")?;
writeln!(
self.out,
"{INDENT}{ARGUMENT_VARIABLE_NAME}.GetDimensions({RETURN_VARIABLE_NAME});"
)?;
// Write return value
writeln!(self.out, "{INDENT}return {RETURN_VARIABLE_NAME};")?;
// End of function body
writeln!(self.out, "}}")?;
// Write extra new line
writeln!(self.out)?;
Ok(())
}
pub(super) fn write_wrapped_image_query_function_name(
&mut self,
query: WrappedImageQuery,
) -> BackendResult {
let dim_str = query.dim.to_hlsl_str();
let class_str = match query.class {
crate::ImageClass::Sampled { multi: true, .. } => "MS",
crate::ImageClass::Depth { multi: true } => "DepthMS",
crate::ImageClass::Depth { multi: false } => "Depth",
crate::ImageClass::Sampled { multi: false, .. } => "",
crate::ImageClass::Storage { .. } => "RW",
};
let arrayed_str = if query.arrayed { "Array" } else { "" };
let query_str = match query.query {
ImageQuery::Size => "Dimensions",
ImageQuery::SizeLevel => "MipDimensions",
ImageQuery::NumLevels => "NumLevels",
ImageQuery::NumLayers => "NumLayers",
ImageQuery::NumSamples => "NumSamples",
};
write!(self.out, "Naga{class_str}{query_str}{dim_str}{arrayed_str}")?;
Ok(())
}
/// Helper function that write wrapped function for `Expression::ImageQuery`
///
pub(super) fn write_wrapped_image_query_function(
&mut self,
module: &crate::Module,
wiq: WrappedImageQuery,
expr_handle: Handle<crate::Expression>,
func_ctx: &FunctionCtx,
) -> BackendResult {
use crate::{
back::{COMPONENTS, INDENT},
ImageDimension as IDim,
};
const ARGUMENT_VARIABLE_NAME: &str = "tex";
const RETURN_VARIABLE_NAME: &str = "ret";
const MIP_LEVEL_PARAM: &str = "mip_level";
// Write function return type and name
let ret_ty = func_ctx.resolve_type(expr_handle, &module.types);
self.write_value_type(module, ret_ty)?;
write!(self.out, " ")?;
self.write_wrapped_image_query_function_name(wiq)?;
// Write function parameters
write!(self.out, "(")?;
// Texture always first parameter
self.write_image_type(wiq.dim, wiq.arrayed, wiq.class)?;
write!(self.out, " {ARGUMENT_VARIABLE_NAME}")?;
// Mipmap is a second parameter if exists
if let ImageQuery::SizeLevel = wiq.query {
write!(self.out, ", uint {MIP_LEVEL_PARAM}")?;
}
writeln!(self.out, ")")?;
// Write function body
writeln!(self.out, "{{")?;
let array_coords = usize::from(wiq.arrayed);
// extra parameter is the mip level count or the sample count
let extra_coords = match wiq.class {
crate::ImageClass::Storage { .. } => 0,
crate::ImageClass::Sampled { .. } | crate::ImageClass::Depth { .. } => 1,
};
// GetDimensions Overloaded Methods
let (ret_swizzle, number_of_params) = match wiq.query {
ImageQuery::Size | ImageQuery::SizeLevel => {
let ret = match wiq.dim {
IDim::D1 => "x",
IDim::D2 => "xy",
IDim::D3 => "xyz",
IDim::Cube => "xy",
};
(ret, ret.len() + array_coords + extra_coords)
}
ImageQuery::NumLevels | ImageQuery::NumSamples | ImageQuery::NumLayers => {
if wiq.arrayed || wiq.dim == IDim::D3 {
("w", 4)
} else {
("z", 3)
}
}
};
// Write `GetDimensions` function.
writeln!(self.out, "{INDENT}uint4 {RETURN_VARIABLE_NAME};")?;
write!(self.out, "{INDENT}{ARGUMENT_VARIABLE_NAME}.GetDimensions(")?;
match wiq.query {
ImageQuery::SizeLevel => {
write!(self.out, "{MIP_LEVEL_PARAM}, ")?;
}
_ => match wiq.class {
crate::ImageClass::Sampled { multi: true, .. }
| crate::ImageClass::Depth { multi: true }
| crate::ImageClass::Storage { .. } => {}
_ => {
// Write zero mipmap level for supported types
write!(self.out, "0, ")?;
}
},
}
for component in COMPONENTS[..number_of_params - 1].iter() {
write!(self.out, "{RETURN_VARIABLE_NAME}.{component}, ")?;
}
// write last parameter without comma and space for last parameter
write!(
self.out,
"{}.{}",
RETURN_VARIABLE_NAME,
COMPONENTS[number_of_params - 1]
)?;
writeln!(self.out, ");")?;
// Write return value
writeln!(
self.out,
"{INDENT}return {RETURN_VARIABLE_NAME}.{ret_swizzle};"
)?;
// End of function body
writeln!(self.out, "}}")?;
// Write extra new line
writeln!(self.out)?;
Ok(())
}
pub(super) fn write_wrapped_constructor_function_name(
&mut self,
module: &crate::Module,
constructor: WrappedConstructor,
) -> BackendResult {
let name = crate::TypeInner::hlsl_type_id(constructor.ty, module.to_ctx(), &self.names)?;
write!(self.out, "Construct{name}")?;
Ok(())
}
/// Helper function that write wrapped function for `Expression::Compose` for structures.
fn write_wrapped_constructor_function(
&mut self,
module: &crate::Module,
constructor: WrappedConstructor,
) -> BackendResult {
use crate::back::INDENT;
const ARGUMENT_VARIABLE_NAME: &str = "arg";
const RETURN_VARIABLE_NAME: &str = "ret";
// Write function return type and name
if let crate::TypeInner::Array { base, size, .. } = module.types[constructor.ty].inner {
write!(self.out, "typedef ")?;
self.write_type(module, constructor.ty)?;
write!(self.out, " ret_")?;
self.write_wrapped_constructor_function_name(module, constructor)?;
self.write_array_size(module, base, size)?;
writeln!(self.out, ";")?;
write!(self.out, "ret_")?;
self.write_wrapped_constructor_function_name(module, constructor)?;
} else {
self.write_type(module, constructor.ty)?;
}
write!(self.out, " ")?;
self.write_wrapped_constructor_function_name(module, constructor)?;
// Write function parameters
write!(self.out, "(")?;
let mut write_arg = |i, ty| -> BackendResult {
if i != 0 {
write!(self.out, ", ")?;
}
self.write_type(module, ty)?;
write!(self.out, " {ARGUMENT_VARIABLE_NAME}{i}")?;
if let crate::TypeInner::Array { base, size, .. } = module.types[ty].inner {
self.write_array_size(module, base, size)?;
}
Ok(())
};
match module.types[constructor.ty].inner {
crate::TypeInner::Struct { ref members, .. } => {
for (i, member) in members.iter().enumerate() {
write_arg(i, member.ty)?;
}
}
crate::TypeInner::Array {
base,
size: crate::ArraySize::Constant(size),
..
} => {
for i in 0..size.get() as usize {
write_arg(i, base)?;
}
}
_ => unreachable!(),
};
write!(self.out, ")")?;
// Write function body
writeln!(self.out, " {{")?;
match module.types[constructor.ty].inner {
crate::TypeInner::Struct { ref members, .. } => {
let struct_name = &self.names[&NameKey::Type(constructor.ty)];
writeln!(
self.out,
"{INDENT}{struct_name} {RETURN_VARIABLE_NAME} = ({struct_name})0;"
)?;
for (i, member) in members.iter().enumerate() {
let field_name = &self.names[&NameKey::StructMember(constructor.ty, i as u32)];
match module.types[member.ty].inner {
crate::TypeInner::Matrix {
columns,
rows: crate::VectorSize::Bi,
..
} if member.binding.is_none() => {
for j in 0..columns as u8 {
writeln!(
self.out,
"{INDENT}{RETURN_VARIABLE_NAME}.{field_name}_{j} = {ARGUMENT_VARIABLE_NAME}{i}[{j}];"
)?;
}
}
ref other => {
// We cast arrays of native HLSL `floatCx2`s to arrays of `matCx2`s
// (where the inner matrix is represented by a struct with C `float2` members).
// See the module-level block comment in mod.rs for details.
if let Some(super::writer::MatrixType {
columns,
rows: crate::VectorSize::Bi,
width: 4,
}) = super::writer::get_inner_matrix_data(module, member.ty)
{
write!(
self.out,
"{}{}.{} = (__mat{}x2",
INDENT, RETURN_VARIABLE_NAME, field_name, columns as u8
)?;
if let crate::TypeInner::Array { base, size, .. } = *other {
self.write_array_size(module, base, size)?;
}
writeln!(self.out, "){ARGUMENT_VARIABLE_NAME}{i};",)?;
} else {
writeln!(
self.out,
"{INDENT}{RETURN_VARIABLE_NAME}.{field_name} = {ARGUMENT_VARIABLE_NAME}{i};",
)?;
}
}
}
}
}
crate::TypeInner::Array {
base,
size: crate::ArraySize::Constant(size),
..
} => {
write!(self.out, "{INDENT}")?;
self.write_type(module, base)?;
write!(self.out, " {RETURN_VARIABLE_NAME}")?;
self.write_array_size(module, base, crate::ArraySize::Constant(size))?;
write!(self.out, " = {{ ")?;
for i in 0..size.get() {
if i != 0 {
write!(self.out, ", ")?;
}
write!(self.out, "{ARGUMENT_VARIABLE_NAME}{i}")?;
}
writeln!(self.out, " }};",)?;
}
_ => unreachable!(),
}
// Write return value
writeln!(self.out, "{INDENT}return {RETURN_VARIABLE_NAME};")?;
// End of function body
writeln!(self.out, "}}")?;
// Write extra new line
writeln!(self.out)?;
Ok(())
}
pub(super) fn write_wrapped_struct_matrix_get_function_name(
&mut self,
access: WrappedStructMatrixAccess,
) -> BackendResult {
let name = &self.names[&NameKey::Type(access.ty)];
let field_name = &self.names[&NameKey::StructMember(access.ty, access.index)];
write!(self.out, "GetMat{field_name}On{name}")?;
Ok(())
}
/// Writes a function used to get a matCx2 from within a structure.
pub(super) fn write_wrapped_struct_matrix_get_function(
&mut self,
module: &crate::Module,
access: WrappedStructMatrixAccess,
) -> BackendResult {
use crate::back::INDENT;
const STRUCT_ARGUMENT_VARIABLE_NAME: &str = "obj";
// Write function return type and name
let member = match module.types[access.ty].inner {
crate::TypeInner::Struct { ref members, .. } => &members[access.index as usize],
_ => unreachable!(),
};
let ret_ty = &module.types[member.ty].inner;
self.write_value_type(module, ret_ty)?;
write!(self.out, " ")?;
self.write_wrapped_struct_matrix_get_function_name(access)?;
// Write function parameters
write!(self.out, "(")?;
let struct_name = &self.names[&NameKey::Type(access.ty)];
write!(self.out, "{struct_name} {STRUCT_ARGUMENT_VARIABLE_NAME}")?;
// Write function body
writeln!(self.out, ") {{")?;
// Write return value
write!(self.out, "{INDENT}return ")?;
self.write_value_type(module, ret_ty)?;
write!(self.out, "(")?;
let field_name = &self.names[&NameKey::StructMember(access.ty, access.index)];
match module.types[member.ty].inner {
crate::TypeInner::Matrix { columns, .. } => {
for i in 0..columns as u8 {
if i != 0 {
write!(self.out, ", ")?;
}
write!(self.out, "{STRUCT_ARGUMENT_VARIABLE_NAME}.{field_name}_{i}")?;
}
}
_ => unreachable!(),
}
writeln!(self.out, ");")?;
// End of function body
writeln!(self.out, "}}")?;
// Write extra new line
writeln!(self.out)?;
Ok(())
}
pub(super) fn write_wrapped_struct_matrix_set_function_name(
&mut self,
access: WrappedStructMatrixAccess,
) -> BackendResult {
let name = &self.names[&NameKey::Type(access.ty)];
let field_name = &self.names[&NameKey::StructMember(access.ty, access.index)];
write!(self.out, "SetMat{field_name}On{name}")?;
Ok(())
}
/// Writes a function used to set a matCx2 from within a structure.
pub(super) fn write_wrapped_struct_matrix_set_function(
&mut self,
module: &crate::Module,
access: WrappedStructMatrixAccess,
) -> BackendResult {
use crate::back::INDENT;
const STRUCT_ARGUMENT_VARIABLE_NAME: &str = "obj";
const MATRIX_ARGUMENT_VARIABLE_NAME: &str = "mat";
// Write function return type and name
write!(self.out, "void ")?;
self.write_wrapped_struct_matrix_set_function_name(access)?;
// Write function parameters
write!(self.out, "(")?;
let struct_name = &self.names[&NameKey::Type(access.ty)];
write!(self.out, "{struct_name} {STRUCT_ARGUMENT_VARIABLE_NAME}, ")?;
let member = match module.types[access.ty].inner {
crate::TypeInner::Struct { ref members, .. } => &members[access.index as usize],
_ => unreachable!(),
};
self.write_type(module, member.ty)?;
write!(self.out, " {MATRIX_ARGUMENT_VARIABLE_NAME}")?;
// Write function body
writeln!(self.out, ") {{")?;
let field_name = &self.names[&NameKey::StructMember(access.ty, access.index)];
match module.types[member.ty].inner {
crate::TypeInner::Matrix { columns, .. } => {
for i in 0..columns as u8 {
writeln!(
self.out,
"{INDENT}{STRUCT_ARGUMENT_VARIABLE_NAME}.{field_name}_{i} = {MATRIX_ARGUMENT_VARIABLE_NAME}[{i}];"
)?;
}
}
_ => unreachable!(),
}
// End of function body
writeln!(self.out, "}}")?;
// Write extra new line
writeln!(self.out)?;
Ok(())
}
pub(super) fn write_wrapped_struct_matrix_set_vec_function_name(
&mut self,
access: WrappedStructMatrixAccess,
) -> BackendResult {
let name = &self.names[&NameKey::Type(access.ty)];
let field_name = &self.names[&NameKey::StructMember(access.ty, access.index)];
write!(self.out, "SetMatVec{field_name}On{name}")?;
Ok(())
}
/// Writes a function used to set a vec2 on a matCx2 from within a structure.
pub(super) fn write_wrapped_struct_matrix_set_vec_function(
&mut self,
module: &crate::Module,
access: WrappedStructMatrixAccess,
) -> BackendResult {
use crate::back::INDENT;
const STRUCT_ARGUMENT_VARIABLE_NAME: &str = "obj";
const VECTOR_ARGUMENT_VARIABLE_NAME: &str = "vec";
const MATRIX_INDEX_ARGUMENT_VARIABLE_NAME: &str = "mat_idx";
// Write function return type and name
write!(self.out, "void ")?;
self.write_wrapped_struct_matrix_set_vec_function_name(access)?;
// Write function parameters
write!(self.out, "(")?;
let struct_name = &self.names[&NameKey::Type(access.ty)];
write!(self.out, "{struct_name} {STRUCT_ARGUMENT_VARIABLE_NAME}, ")?;
let member = match module.types[access.ty].inner {
crate::TypeInner::Struct { ref members, .. } => &members[access.index as usize],
_ => unreachable!(),
};
let vec_ty = match module.types[member.ty].inner {
crate::TypeInner::Matrix { rows, scalar, .. } => {
crate::TypeInner::Vector { size: rows, scalar }
}
_ => unreachable!(),
};
self.write_value_type(module, &vec_ty)?;
write!(
self.out,
" {VECTOR_ARGUMENT_VARIABLE_NAME}, uint {MATRIX_INDEX_ARGUMENT_VARIABLE_NAME}"
)?;
// Write function body
writeln!(self.out, ") {{")?;
writeln!(
self.out,
"{INDENT}switch({MATRIX_INDEX_ARGUMENT_VARIABLE_NAME}) {{"
)?;
let field_name = &self.names[&NameKey::StructMember(access.ty, access.index)];
match module.types[member.ty].inner {
crate::TypeInner::Matrix { columns, .. } => {
for i in 0..columns as u8 {
writeln!(
self.out,
"{INDENT}case {i}: {{ {STRUCT_ARGUMENT_VARIABLE_NAME}.{field_name}_{i} = {VECTOR_ARGUMENT_VARIABLE_NAME}; break; }}"
)?;
}
}
_ => unreachable!(),
}
writeln!(self.out, "{INDENT}}}")?;
// End of function body
writeln!(self.out, "}}")?;
// Write extra new line
writeln!(self.out)?;
Ok(())
}
pub(super) fn write_wrapped_struct_matrix_set_scalar_function_name(
&mut self,
access: WrappedStructMatrixAccess,
) -> BackendResult {
let name = &self.names[&NameKey::Type(access.ty)];
let field_name = &self.names[&NameKey::StructMember(access.ty, access.index)];
write!(self.out, "SetMatScalar{field_name}On{name}")?;
Ok(())
}
/// Writes a function used to set a float on a matCx2 from within a structure.
pub(super) fn write_wrapped_struct_matrix_set_scalar_function(
&mut self,
module: &crate::Module,
access: WrappedStructMatrixAccess,
) -> BackendResult {
use crate::back::INDENT;
const STRUCT_ARGUMENT_VARIABLE_NAME: &str = "obj";
const SCALAR_ARGUMENT_VARIABLE_NAME: &str = "scalar";
const MATRIX_INDEX_ARGUMENT_VARIABLE_NAME: &str = "mat_idx";
const VECTOR_INDEX_ARGUMENT_VARIABLE_NAME: &str = "vec_idx";
// Write function return type and name
write!(self.out, "void ")?;
self.write_wrapped_struct_matrix_set_scalar_function_name(access)?;
// Write function parameters
write!(self.out, "(")?;
let struct_name = &self.names[&NameKey::Type(access.ty)];
write!(self.out, "{struct_name} {STRUCT_ARGUMENT_VARIABLE_NAME}, ")?;
let member = match module.types[access.ty].inner {
crate::TypeInner::Struct { ref members, .. } => &members[access.index as usize],
_ => unreachable!(),
};
let scalar_ty = match module.types[member.ty].inner {
crate::TypeInner::Matrix { scalar, .. } => crate::TypeInner::Scalar(scalar),
_ => unreachable!(),
};
self.write_value_type(module, &scalar_ty)?;
write!(
self.out,
" {SCALAR_ARGUMENT_VARIABLE_NAME}, uint {MATRIX_INDEX_ARGUMENT_VARIABLE_NAME}, uint {VECTOR_INDEX_ARGUMENT_VARIABLE_NAME}"
)?;
// Write function body
writeln!(self.out, ") {{")?;
writeln!(
self.out,
"{INDENT}switch({MATRIX_INDEX_ARGUMENT_VARIABLE_NAME}) {{"
)?;
let field_name = &self.names[&NameKey::StructMember(access.ty, access.index)];
match module.types[member.ty].inner {
crate::TypeInner::Matrix { columns, .. } => {
for i in 0..columns as u8 {
writeln!(
self.out,
"{INDENT}case {i}: {{ {STRUCT_ARGUMENT_VARIABLE_NAME}.{field_name}_{i}[{VECTOR_INDEX_ARGUMENT_VARIABLE_NAME}] = {SCALAR_ARGUMENT_VARIABLE_NAME}; break; }}"
)?;
}
}
_ => unreachable!(),
}
writeln!(self.out, "{INDENT}}}")?;
// End of function body
writeln!(self.out, "}}")?;
// Write extra new line
writeln!(self.out)?;
Ok(())
}
/// Write functions to create special types.
pub(super) fn write_special_functions(&mut self, module: &crate::Module) -> BackendResult {
for (type_key, struct_ty) in module.special_types.predeclared_types.iter() {
match type_key {
&crate::PredeclaredType::ModfResult { size, width }
| &crate::PredeclaredType::FrexpResult { size, width } => {
let arg_type_name_owner;
let arg_type_name = if let Some(size) = size {
arg_type_name_owner = format!(
"{}{}",
if width == 8 { "double" } else { "float" },
size as u8
);
&arg_type_name_owner
} else if width == 8 {
"double"
} else {
"float"
};
let (defined_func_name, called_func_name, second_field_name, sign_multiplier) =
if matches!(type_key, &crate::PredeclaredType::ModfResult { .. }) {
(super::writer::MODF_FUNCTION, "modf", "whole", "")
} else {
(
super::writer::FREXP_FUNCTION,
"frexp",
"exp_",
"sign(arg) * ",
)
};
let struct_name = &self.names[&NameKey::Type(*struct_ty)];
writeln!(
self.out,
"{struct_name} {defined_func_name}({arg_type_name} arg) {{
{arg_type_name} other;
{struct_name} result;
result.fract = {sign_multiplier}{called_func_name}(arg, other);
result.{second_field_name} = other;
return result;
}}"
)?;
writeln!(self.out)?;
}
&crate::PredeclaredType::AtomicCompareExchangeWeakResult { .. } => {}
}
}
Ok(())
}
/// Helper function that writes compose wrapped functions
pub(super) fn write_wrapped_compose_functions(
&mut self,
module: &crate::Module,
expressions: &crate::Arena<crate::Expression>,
) -> BackendResult {
for (handle, _) in expressions.iter() {
if let crate::Expression::Compose { ty, .. } = expressions[handle] {
match module.types[ty].inner {
crate::TypeInner::Struct { .. } | crate::TypeInner::Array { .. } => {
let constructor = WrappedConstructor { ty };
if self.wrapped.constructors.insert(constructor) {
self.write_wrapped_constructor_function(module, constructor)?;
}
}
_ => {}
};
}
}
Ok(())
}
// TODO: we could merge this with iteration in write_wrapped_compose_functions...
//
/// Helper function that writes zero value wrapped functions
pub(super) fn write_wrapped_zero_value_functions(
&mut self,
module: &crate::Module,
expressions: &crate::Arena<crate::Expression>,
) -> BackendResult {
for (handle, _) in expressions.iter() {
if let crate::Expression::ZeroValue(ty) = expressions[handle] {
let zero_value = WrappedZeroValue { ty };
if self.wrapped.zero_values.insert(zero_value) {
self.write_wrapped_zero_value_function(module, zero_value)?;
}
}
}
Ok(())
}
pub(super) fn write_wrapped_math_functions(
&mut self,
module: &crate::Module,
func_ctx: &FunctionCtx,
) -> BackendResult {
for (_, expression) in func_ctx.expressions.iter() {
if let crate::Expression::Math {
fun,
arg,
arg1: _arg1,
arg2: _arg2,
arg3: _arg3,
} = *expression
{
match fun {
crate::MathFunction::ExtractBits => {
// The behavior of our extractBits polyfill is undefined if offset + count > bit_width. We need
// to first sanitize the offset and count first. If we don't do this, we will get out-of-spec
// values if the extracted range is not within the bit width.
//
// This encodes the exact formula specified by the wgsl spec:
//
// w = sizeof(x) * 8
// o = min(offset, w)
// c = min(count, w - o)
//
// bitfieldExtract(x, o, c)
let arg_ty = func_ctx.resolve_type(arg, &module.types);
let scalar = arg_ty.scalar().unwrap();
let components = arg_ty.components();
let wrapped = WrappedMath {
fun,
scalar,
components,
};
if !self.wrapped.math.insert(wrapped) {
continue;
}
// Write return type
self.write_value_type(module, arg_ty)?;
let scalar_width: u8 = scalar.width * 8;
// Write function name and parameters
writeln!(self.out, " {EXTRACT_BITS_FUNCTION}(")?;
write!(self.out, " ")?;
self.write_value_type(module, arg_ty)?;
writeln!(self.out, " e,")?;
writeln!(self.out, " uint offset,")?;
writeln!(self.out, " uint count")?;
writeln!(self.out, ") {{")?;
// Write function body
writeln!(self.out, " uint w = {scalar_width};")?;
writeln!(self.out, " uint o = min(offset, w);")?;
writeln!(self.out, " uint c = min(count, w - o);")?;
writeln!(
self.out,
" return (c == 0 ? 0 : (e << (w - c - o)) >> (w - c));"
)?;
// End of function body
writeln!(self.out, "}}")?;
}
crate::MathFunction::InsertBits => {
// The behavior of our insertBits polyfill has the same constraints as the extractBits polyfill.
let arg_ty = func_ctx.resolve_type(arg, &module.types);
let scalar = arg_ty.scalar().unwrap();
let components = arg_ty.components();
let wrapped = WrappedMath {
fun,
scalar,
components,
};
if !self.wrapped.math.insert(wrapped) {
continue;
}
// Write return type
self.write_value_type(module, arg_ty)?;
let scalar_width: u8 = scalar.width * 8;
let scalar_max: u64 = match scalar.width {
1 => 0xFF,
2 => 0xFFFF,
4 => 0xFFFFFFFF,
8 => 0xFFFFFFFFFFFFFFFF,
_ => unreachable!(),
};
// Write function name and parameters
writeln!(self.out, " {INSERT_BITS_FUNCTION}(")?;
write!(self.out, " ")?;
self.write_value_type(module, arg_ty)?;
writeln!(self.out, " e,")?;
write!(self.out, " ")?;
self.write_value_type(module, arg_ty)?;
writeln!(self.out, " newbits,")?;
writeln!(self.out, " uint offset,")?;
writeln!(self.out, " uint count")?;
writeln!(self.out, ") {{")?;
// Write function body
writeln!(self.out, " uint w = {scalar_width}u;")?;
writeln!(self.out, " uint o = min(offset, w);")?;
writeln!(self.out, " uint c = min(count, w - o);")?;
// The `u` suffix on the literals is _extremely_ important. Otherwise it will use
// i32 shifting instead of the intended u32 shifting.
writeln!(
self.out,
" uint mask = (({scalar_max}u >> ({scalar_width}u - c)) << o);"
)?;
writeln!(
self.out,
" return (c == 0 ? e : ((e & ~mask) | ((newbits << o) & mask)));"
)?;
// End of function body
writeln!(self.out, "}}")?;
}
_ => {}
}
}
}
Ok(())
}
/// Helper function that writes various wrapped functions
pub(super) fn write_wrapped_functions(
&mut self,
module: &crate::Module,
func_ctx: &FunctionCtx,
) -> BackendResult {
self.write_wrapped_math_functions(module, func_ctx)?;
self.write_wrapped_compose_functions(module, func_ctx.expressions)?;
self.write_wrapped_zero_value_functions(module, func_ctx.expressions)?;
for (handle, _) in func_ctx.expressions.iter() {
match func_ctx.expressions[handle] {
crate::Expression::ArrayLength(expr) => {
let global_expr = match func_ctx.expressions[expr] {
crate::Expression::GlobalVariable(_) => expr,
crate::Expression::AccessIndex { base, index: _ } => base,
ref other => unreachable!("Array length of {:?}", other),
};
let global_var = match func_ctx.expressions[global_expr] {
crate::Expression::GlobalVariable(var_handle) => {
&module.global_variables[var_handle]
}
ref other => {
return Err(super::Error::Unimplemented(format!(
"Array length of base {other:?}"
)))
}
};
let storage_access = match global_var.space {
crate::AddressSpace::Storage { access } => access,
_ => crate::StorageAccess::default(),
};
let wal = WrappedArrayLength {
writable: storage_access.contains(crate::StorageAccess::STORE),
};
if self.wrapped.array_lengths.insert(wal) {
self.write_wrapped_array_length_function(wal)?;
}
}
crate::Expression::ImageQuery { image, query } => {
let wiq = match *func_ctx.resolve_type(image, &module.types) {
crate::TypeInner::Image {
dim,
arrayed,
class,
} => WrappedImageQuery {
dim,
arrayed,
class,
query: query.into(),
},
_ => unreachable!("we only query images"),
};
if self.wrapped.image_queries.insert(wiq) {
self.write_wrapped_image_query_function(module, wiq, handle, func_ctx)?;
}
}
// Write `WrappedConstructor` for structs that are loaded from `AddressSpace::Storage`
// since they will later be used by the fn `write_storage_load`
crate::Expression::Load { pointer } => {
let pointer_space = func_ctx
.resolve_type(pointer, &module.types)
.pointer_space();
if let Some(crate::AddressSpace::Storage { .. }) = pointer_space {
if let Some(ty) = func_ctx.info[handle].ty.handle() {
write_wrapped_constructor(self, ty, module)?;
}
}
fn write_wrapped_constructor<W: Write>(
writer: &mut super::Writer<'_, W>,
ty: Handle<crate::Type>,
module: &crate::Module,
) -> BackendResult {
match module.types[ty].inner {
crate::TypeInner::Struct { ref members, .. } => {
for member in members {
write_wrapped_constructor(writer, member.ty, module)?;
}
let constructor = WrappedConstructor { ty };
if writer.wrapped.constructors.insert(constructor) {
writer
.write_wrapped_constructor_function(module, constructor)?;
}
}
crate::TypeInner::Array { base, .. } => {
write_wrapped_constructor(writer, base, module)?;
let constructor = WrappedConstructor { ty };
if writer.wrapped.constructors.insert(constructor) {
writer
.write_wrapped_constructor_function(module, constructor)?;
}
}
_ => {}
};
Ok(())
}
}
// We treat matrices of the form `matCx2` as a sequence of C `vec2`s
// (see top level module docs for details).
//
// The functions injected here are required to get the matrix accesses working.
crate::Expression::AccessIndex { base, index } => {
let base_ty_res = &func_ctx.info[base].ty;
let mut resolved = base_ty_res.inner_with(&module.types);
let base_ty_handle = match *resolved {
crate::TypeInner::Pointer { base, .. } => {
resolved = &module.types[base].inner;
Some(base)
}
_ => base_ty_res.handle(),
};
if let crate::TypeInner::Struct { ref members, .. } = *resolved {
let member = &members[index as usize];
match module.types[member.ty].inner {
crate::TypeInner::Matrix {
rows: crate::VectorSize::Bi,
..
} if member.binding.is_none() => {
let ty = base_ty_handle.unwrap();
let access = WrappedStructMatrixAccess { ty, index };
if self.wrapped.struct_matrix_access.insert(access) {
self.write_wrapped_struct_matrix_get_function(module, access)?;
self.write_wrapped_struct_matrix_set_function(module, access)?;
self.write_wrapped_struct_matrix_set_vec_function(
module, access,
)?;
self.write_wrapped_struct_matrix_set_scalar_function(
module, access,
)?;
}
}
_ => {}
}
}
}
_ => {}
};
}
Ok(())
}
pub(super) fn write_texture_coordinates(
&mut self,
kind: &str,
coordinate: Handle<crate::Expression>,
array_index: Option<Handle<crate::Expression>>,
mip_level: Option<Handle<crate::Expression>>,
module: &crate::Module,
func_ctx: &FunctionCtx,
) -> BackendResult {
// HLSL expects the array index to be merged with the coordinate
let extra = array_index.is_some() as usize + (mip_level.is_some()) as usize;
if extra == 0 {
self.write_expr(module, coordinate, func_ctx)?;
} else {
let num_coords = match *func_ctx.resolve_type(coordinate, &module.types) {
crate::TypeInner::Scalar { .. } => 1,
crate::TypeInner::Vector { size, .. } => size as usize,
_ => unreachable!(),
};
write!(self.out, "{}{}(", kind, num_coords + extra)?;
self.write_expr(module, coordinate, func_ctx)?;
if let Some(expr) = array_index {
write!(self.out, ", ")?;
self.write_expr(module, expr, func_ctx)?;
}
if let Some(expr) = mip_level {
write!(self.out, ", ")?;
self.write_expr(module, expr, func_ctx)?;
}
write!(self.out, ")")?;
}
Ok(())
}
pub(super) fn write_mat_cx2_typedef_and_functions(
&mut self,
WrappedMatCx2 { columns }: WrappedMatCx2,
) -> BackendResult {
use crate::back::INDENT;
// typedef
write!(self.out, "typedef struct {{ ")?;
for i in 0..columns as u8 {
write!(self.out, "float2 _{i}; ")?;
}
writeln!(self.out, "}} __mat{}x2;", columns as u8)?;
// __get_col_of_mat
writeln!(
self.out,
"float2 __get_col_of_mat{}x2(__mat{}x2 mat, uint idx) {{",
columns as u8, columns as u8
)?;
writeln!(self.out, "{INDENT}switch(idx) {{")?;
for i in 0..columns as u8 {
writeln!(self.out, "{INDENT}case {i}: {{ return mat._{i}; }}")?;
}
writeln!(self.out, "{INDENT}default: {{ return (float2)0; }}")?;
writeln!(self.out, "{INDENT}}}")?;
writeln!(self.out, "}}")?;
// __set_col_of_mat
writeln!(
self.out,
"void __set_col_of_mat{}x2(__mat{}x2 mat, uint idx, float2 value) {{",
columns as u8, columns as u8
)?;
writeln!(self.out, "{INDENT}switch(idx) {{")?;
for i in 0..columns as u8 {
writeln!(self.out, "{INDENT}case {i}: {{ mat._{i} = value; break; }}")?;
}
writeln!(self.out, "{INDENT}}}")?;
writeln!(self.out, "}}")?;
// __set_el_of_mat
writeln!(
self.out,
"void __set_el_of_mat{}x2(__mat{}x2 mat, uint idx, uint vec_idx, float value) {{",
columns as u8, columns as u8
)?;
writeln!(self.out, "{INDENT}switch(idx) {{")?;
for i in 0..columns as u8 {
writeln!(
self.out,
"{INDENT}case {i}: {{ mat._{i}[vec_idx] = value; break; }}"
)?;
}
writeln!(self.out, "{INDENT}}}")?;
writeln!(self.out, "}}")?;
writeln!(self.out)?;
Ok(())
}
pub(super) fn write_all_mat_cx2_typedefs_and_functions(
&mut self,
module: &crate::Module,
) -> BackendResult {
for (handle, _) in module.global_variables.iter() {
let global = &module.global_variables[handle];
if global.space == crate::AddressSpace::Uniform {
if let Some(super::writer::MatrixType {
columns,
rows: crate::VectorSize::Bi,
width: 4,
}) = super::writer::get_inner_matrix_data(module, global.ty)
{
let entry = WrappedMatCx2 { columns };
if self.wrapped.mat_cx2s.insert(entry) {
self.write_mat_cx2_typedef_and_functions(entry)?;
}
}
}
}
for (_, ty) in module.types.iter() {
if let crate::TypeInner::Struct { ref members, .. } = ty.inner {
for member in members.iter() {
if let crate::TypeInner::Array { .. } = module.types[member.ty].inner {
if let Some(super::writer::MatrixType {
columns,
rows: crate::VectorSize::Bi,
width: 4,
}) = super::writer::get_inner_matrix_data(module, member.ty)
{
let entry = WrappedMatCx2 { columns };
if self.wrapped.mat_cx2s.insert(entry) {
self.write_mat_cx2_typedef_and_functions(entry)?;
}
}
}
}
}
}
Ok(())
}
pub(super) fn write_wrapped_zero_value_function_name(
&mut self,
module: &crate::Module,
zero_value: WrappedZeroValue,
) -> BackendResult {
let name = crate::TypeInner::hlsl_type_id(zero_value.ty, module.to_ctx(), &self.names)?;
write!(self.out, "ZeroValue{name}")?;
Ok(())
}
/// Helper function that write wrapped function for `Expression::ZeroValue`
///
/// This is necessary since we might have a member access after the zero value expression, e.g.
/// `.y` (in practice this can come up when consuming SPIRV that's been produced by glslc).
///
/// So we can't just write `(float4)0` since `(float4)0.y` won't parse correctly.
///
/// Parenthesizing the expression like `((float4)0).y` would work... except DXC can't handle
/// cases like:
///
/// ```text
/// tests\out\hlsl\access.hlsl:183:41: error: cannot compile this l-value expression yet
/// t_1.am = (__mat4x2[2])((float4x2[2])0);
/// ^
/// ```
fn write_wrapped_zero_value_function(
&mut self,
module: &crate::Module,
zero_value: WrappedZeroValue,
) -> BackendResult {
use crate::back::INDENT;
const RETURN_VARIABLE_NAME: &str = "ret";
// Write function return type and name
if let crate::TypeInner::Array { base, size, .. } = module.types[zero_value.ty].inner {
write!(self.out, "typedef ")?;
self.write_type(module, zero_value.ty)?;
write!(self.out, " ret_")?;
self.write_wrapped_zero_value_function_name(module, zero_value)?;
self.write_array_size(module, base, size)?;
writeln!(self.out, ";")?;
write!(self.out, "ret_")?;
self.write_wrapped_zero_value_function_name(module, zero_value)?;
} else {
self.write_type(module, zero_value.ty)?;
}
write!(self.out, " ")?;
self.write_wrapped_zero_value_function_name(module, zero_value)?;
// Write function parameters (none) and start function body
writeln!(self.out, "() {{")?;
// Write `ZeroValue` function.
write!(self.out, "{INDENT}return ")?;
self.write_default_init(module, zero_value.ty)?;
writeln!(self.out, ";")?;
// End of function body
writeln!(self.out, "}}")?;
// Write extra new line
writeln!(self.out)?;
Ok(())
}
}