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dawn / tint / 2423df3e048507cd6352a2297d1eaa36087e7e7e / . / src / writer / hlsl / generator_impl.cc
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/// Copyright 2020 The Tint Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "src/writer/hlsl/generator_impl.h"
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <set>
#include <utility>
#include <vector>
#include "src/ast/call_statement.h"
#include "src/ast/fallthrough_statement.h"
#include "src/ast/internal_decoration.h"
#include "src/ast/interpolate_decoration.h"
#include "src/ast/override_decoration.h"
#include "src/ast/variable_decl_statement.h"
#include "src/debug.h"
#include "src/sem/array.h"
#include "src/sem/atomic_type.h"
#include "src/sem/block_statement.h"
#include "src/sem/call.h"
#include "src/sem/depth_multisampled_texture_type.h"
#include "src/sem/depth_texture_type.h"
#include "src/sem/function.h"
#include "src/sem/member_accessor_expression.h"
#include "src/sem/multisampled_texture_type.h"
#include "src/sem/sampled_texture_type.h"
#include "src/sem/statement.h"
#include "src/sem/storage_texture_type.h"
#include "src/sem/struct.h"
#include "src/sem/variable.h"
#include "src/transform/add_empty_entry_point.h"
#include "src/transform/calculate_array_length.h"
#include "src/transform/canonicalize_entry_point_io.h"
#include "src/transform/decompose_memory_access.h"
#include "src/transform/external_texture_transform.h"
#include "src/transform/fold_trivial_single_use_lets.h"
#include "src/transform/inline_pointer_lets.h"
#include "src/transform/loop_to_for_loop.h"
#include "src/transform/manager.h"
#include "src/transform/num_workgroups_from_uniform.h"
#include "src/transform/pad_array_elements.h"
#include "src/transform/promote_initializers_to_const_var.h"
#include "src/transform/remove_phonies.h"
#include "src/transform/simplify.h"
#include "src/transform/zero_init_workgroup_memory.h"
#include "src/utils/defer.h"
#include "src/utils/get_or_create.h"
#include "src/utils/scoped_assignment.h"
#include "src/writer/append_vector.h"
#include "src/writer/float_to_string.h"
namespace tint {
namespace writer {
namespace hlsl {
namespace {
const char kTempNamePrefix[] = "tint_tmp";
const char kSpecConstantPrefix[] = "WGSL_SPEC_CONSTANT_";
const char* image_format_to_rwtexture_type(ast::ImageFormat image_format) {
switch (image_format) {
case ast::ImageFormat::kRgba8Unorm:
case ast::ImageFormat::kRgba8Snorm:
case ast::ImageFormat::kRgba16Float:
case ast::ImageFormat::kR32Float:
case ast::ImageFormat::kRg32Float:
case ast::ImageFormat::kRgba32Float:
return "float4";
case ast::ImageFormat::kRgba8Uint:
case ast::ImageFormat::kRgba16Uint:
case ast::ImageFormat::kR32Uint:
case ast::ImageFormat::kRg32Uint:
case ast::ImageFormat::kRgba32Uint:
return "uint4";
case ast::ImageFormat::kRgba8Sint:
case ast::ImageFormat::kRgba16Sint:
case ast::ImageFormat::kR32Sint:
case ast::ImageFormat::kRg32Sint:
case ast::ImageFormat::kRgba32Sint:
return "int4";
default:
return nullptr;
}
}
// Helper for writing " : register(RX, spaceY)", where R is the register, X is
// the binding point binding value, and Y is the binding point group value.
struct RegisterAndSpace {
RegisterAndSpace(char r, ast::VariableBindingPoint bp)
: reg(r), binding_point(bp) {}
const char reg;
ast::VariableBindingPoint const binding_point;
};
std::ostream& operator<<(std::ostream& s, const RegisterAndSpace& rs) {
s << " : register(" << rs.reg << rs.binding_point.binding->value << ", space"
<< rs.binding_point.group->value << ")";
return s;
}
} // namespace
SanitizedResult Sanitize(const Program* in,
sem::BindingPoint root_constant_binding_point,
bool disable_workgroup_init) {
transform::Manager manager;
transform::DataMap data;
// Attempt to convert `loop`s into for-loops. This is to try and massage the
// output into something that will not cause FXC to choke or misbehave.
manager.Add<transform::FoldTrivialSingleUseLets>();
manager.Add<transform::LoopToForLoop>();
if (!disable_workgroup_init) {
// ZeroInitWorkgroupMemory must come before CanonicalizeEntryPointIO as
// ZeroInitWorkgroupMemory may inject new builtin parameters.
manager.Add<transform::ZeroInitWorkgroupMemory>();
}
manager.Add<transform::CanonicalizeEntryPointIO>();
// NumWorkgroupsFromUniform must come after CanonicalizeEntryPointIO, as it
// assumes that num_workgroups builtins only appear as struct members and are
// only accessed directly via member accessors.
manager.Add<transform::NumWorkgroupsFromUniform>();
manager.Add<transform::InlinePointerLets>();
// Simplify cleans up messy `*(&(expr))` expressions from InlinePointerLets.
manager.Add<transform::Simplify>();
manager.Add<transform::RemovePhonies>();
// DecomposeMemoryAccess must come after:
// * InlinePointerLets, as we cannot take the address of calls to
// DecomposeMemoryAccess::Intrinsic.
// * Simplify, as we need to fold away the address-of and dereferences of
// `*(&(intrinsic_load()))` expressions.
// * RemovePhonies, as phonies can be assigned a pointer to a
// non-constructible buffer, or dynamic array, which DMA cannot cope with.
manager.Add<transform::DecomposeMemoryAccess>();
// CalculateArrayLength must come after DecomposeMemoryAccess, as
// DecomposeMemoryAccess special-cases the arrayLength() intrinsic, which
// will be transformed by CalculateArrayLength
manager.Add<transform::CalculateArrayLength>();
manager.Add<transform::ExternalTextureTransform>();
manager.Add<transform::PromoteInitializersToConstVar>();
manager.Add<transform::PadArrayElements>();
manager.Add<transform::AddEmptyEntryPoint>();
data.Add<transform::CanonicalizeEntryPointIO::Config>(
transform::CanonicalizeEntryPointIO::ShaderStyle::kHlsl);
data.Add<transform::NumWorkgroupsFromUniform::Config>(
root_constant_binding_point);
SanitizedResult result;
result.program = std::move(manager.Run(in, data).program);
return result;
}
GeneratorImpl::GeneratorImpl(const Program* program) : TextGenerator(program) {}
GeneratorImpl::~GeneratorImpl() = default;
bool GeneratorImpl::Generate() {
const TypeInfo* last_kind = nullptr;
size_t last_padding_line = 0;
for (auto* decl : builder_.AST().GlobalDeclarations()) {
if (decl->Is<ast::Alias>()) {
continue; // Ignore aliases.
}
// Emit a new line between declarations if the type of declaration has
// changed, or we're about to emit a function
auto* kind = &decl->TypeInfo();
if (current_buffer_->lines.size() != last_padding_line) {
if (last_kind && (last_kind != kind || decl->Is<ast::Function>())) {
line();
last_padding_line = current_buffer_->lines.size();
}
}
last_kind = kind;
if (auto* global = decl->As<ast::Variable>()) {
if (!EmitGlobalVariable(global)) {
return false;
}
} else if (auto* str = decl->As<ast::Struct>()) {
auto* ty = builder_.Sem().Get(str);
auto storage_class_uses = ty->StorageClassUsage();
if (storage_class_uses.size() !=
(storage_class_uses.count(ast::StorageClass::kStorage) +
storage_class_uses.count(ast::StorageClass::kUniform))) {
// The structure is used as something other than a storage buffer or
// uniform buffer, so it needs to be emitted.
// Storage buffer are read and written to via a ByteAddressBuffer
// instead of true structure.
// Structures used as uniform buffer are read from an array of vectors
// instead of true structure.
if (!EmitStructType(current_buffer_, ty)) {
return false;
}
}
} else if (auto* func = decl->As<ast::Function>()) {
if (func->IsEntryPoint()) {
if (!EmitEntryPointFunction(func)) {
return false;
}
} else {
if (!EmitFunction(func)) {
return false;
}
}
} else {
TINT_ICE(Writer, diagnostics_)
<< "unhandled module-scope declaration: " << decl->TypeInfo().name;
return false;
}
}
if (!helpers_.lines.empty()) {
current_buffer_->Insert(helpers_, 0, 0);
}
return true;
}
bool GeneratorImpl::EmitDynamicVectorAssignment(
const ast::AssignmentStatement* stmt,
const sem::Vector* vec) {
auto name =
utils::GetOrCreate(dynamic_vector_write_, vec, [&]() -> std::string {
std::string fn;
{
std::ostringstream ss;
if (!EmitType(ss, vec, tint::ast::StorageClass::kInvalid,
ast::Access::kUndefined, "")) {
return "";
}
fn = UniqueIdentifier("set_" + ss.str());
}
{
auto out = line(&helpers_);
out << "void " << fn << "(inout ";
if (!EmitTypeAndName(out, vec, ast::StorageClass::kInvalid,
ast::Access::kUndefined, "vec")) {
return "";
}
out << ", int idx, ";
if (!EmitTypeAndName(out, vec->type(), ast::StorageClass::kInvalid,
ast::Access::kUndefined, "val")) {
return "";
}
out << ") {";
}
{
ScopedIndent si(&helpers_);
auto out = line(&helpers_);
switch (vec->Width()) {
case 2:
out << "vec = (idx.xx == int2(0, 1)) ? val.xx : vec;";
break;
case 3:
out << "vec = (idx.xxx == int3(0, 1, 2)) ? val.xxx : vec;";
break;
case 4:
out << "vec = (idx.xxxx == int4(0, 1, 2, 3)) ? val.xxxx : vec;";
break;
default:
TINT_UNREACHABLE(Writer, builder_.Diagnostics())
<< "invalid vector size " << vec->Width();
break;
}
}
line(&helpers_) << "}";
line(&helpers_);
return fn;
});
if (name.empty()) {
return false;
}
auto* ast_access_expr = stmt->lhs->As<ast::ArrayAccessorExpression>();
auto out = line();
out << name << "(";
if (!EmitExpression(out, ast_access_expr->array)) {
return false;
}
out << ", ";
if (!EmitExpression(out, ast_access_expr->index)) {
return false;
}
out << ", ";
if (!EmitExpression(out, stmt->rhs)) {
return false;
}
out << ");";
return true;
}
bool GeneratorImpl::EmitArrayAccessor(
std::ostream& out,
const ast::ArrayAccessorExpression* expr) {
if (!EmitExpression(out, expr->array)) {
return false;
}
out << "[";
if (!EmitExpression(out, expr->index)) {
return false;
}
out << "]";
return true;
}
bool GeneratorImpl::EmitBitcast(std::ostream& out,
const ast::BitcastExpression* expr) {
auto* type = TypeOf(expr);
if (auto* vec = type->UnwrapRef()->As<sem::Vector>()) {
type = vec->type();
}
if (!type->is_integer_scalar() && !type->is_float_scalar()) {
diagnostics_.add_error(diag::System::Writer,
"Unable to do bitcast to type " + type->type_name());
return false;
}
out << "as";
if (!EmitType(out, type, ast::StorageClass::kNone, ast::Access::kReadWrite,
"")) {
return false;
}
out << "(";
if (!EmitExpression(out, expr->expr)) {
return false;
}
out << ")";
return true;
}
bool GeneratorImpl::EmitAssign(const ast::AssignmentStatement* stmt) {
if (auto* idx = stmt->lhs->As<ast::ArrayAccessorExpression>()) {
if (auto* vec = TypeOf(idx->array)->UnwrapRef()->As<sem::Vector>()) {
auto* rhs_sem = builder_.Sem().Get(idx->index);
if (!rhs_sem->ConstantValue().IsValid()) {
return EmitDynamicVectorAssignment(stmt, vec);
}
}
}
auto out = line();
if (!EmitExpression(out, stmt->lhs)) {
return false;
}
out << " = ";
if (!EmitExpression(out, stmt->rhs)) {
return false;
}
out << ";";
return true;
}
bool GeneratorImpl::EmitBinary(std::ostream& out,
const ast::BinaryExpression* expr) {
if (expr->op == ast::BinaryOp::kLogicalAnd ||
expr->op == ast::BinaryOp::kLogicalOr) {
auto name = UniqueIdentifier(kTempNamePrefix);
{
auto pre = line();
pre << "bool " << name << " = ";
if (!EmitExpression(pre, expr->lhs)) {
return false;
}
pre << ";";
}
if (expr->op == ast::BinaryOp::kLogicalOr) {
line() << "if (!" << name << ") {";
} else {
line() << "if (" << name << ") {";
}
{
ScopedIndent si(this);
auto pre = line();
pre << name << " = ";
if (!EmitExpression(pre, expr->rhs)) {
return false;
}
pre << ";";
}
line() << "}";
out << "(" << name << ")";
return true;
}
auto* lhs_type = TypeOf(expr->lhs)->UnwrapRef();
auto* rhs_type = TypeOf(expr->rhs)->UnwrapRef();
// Multiplying by a matrix requires the use of `mul` in order to get the
// type of multiply we desire.
if (expr->op == ast::BinaryOp::kMultiply &&
((lhs_type->Is<sem::Vector>() && rhs_type->Is<sem::Matrix>()) ||
(lhs_type->Is<sem::Matrix>() && rhs_type->Is<sem::Vector>()) ||
(lhs_type->Is<sem::Matrix>() && rhs_type->Is<sem::Matrix>()))) {
// Matrices are transposed, so swap LHS and RHS.
out << "mul(";
if (!EmitExpression(out, expr->rhs)) {
return false;
}
out << ", ";
if (!EmitExpression(out, expr->lhs)) {
return false;
}
out << ")";
return true;
}
out << "(";
TINT_DEFER(out << ")");
if (!EmitExpression(out, expr->lhs)) {
return false;
}
out << " ";
switch (expr->op) {
case ast::BinaryOp::kAnd:
out << "&";
break;
case ast::BinaryOp::kOr:
out << "|";
break;
case ast::BinaryOp::kXor:
out << "^";
break;
case ast::BinaryOp::kLogicalAnd:
case ast::BinaryOp::kLogicalOr: {
// These are both handled above.
TINT_UNREACHABLE(Writer, diagnostics_);
return false;
}
case ast::BinaryOp::kEqual:
out << "==";
break;
case ast::BinaryOp::kNotEqual:
out << "!=";
break;
case ast::BinaryOp::kLessThan:
out << "<";
break;
case ast::BinaryOp::kGreaterThan:
out << ">";
break;
case ast::BinaryOp::kLessThanEqual:
out << "<=";
break;
case ast::BinaryOp::kGreaterThanEqual:
out << ">=";
break;
case ast::BinaryOp::kShiftLeft:
out << "<<";
break;
case ast::BinaryOp::kShiftRight:
// TODO(dsinclair): MSL is based on C++14, and >> in C++14 has
// implementation-defined behaviour for negative LHS. We may have to
// generate extra code to implement WGSL-specified behaviour for negative
// LHS.
out << R"(>>)";
break;
case ast::BinaryOp::kAdd:
out << "+";
break;
case ast::BinaryOp::kSubtract:
out << "-";
break;
case ast::BinaryOp::kMultiply:
out << "*";
break;
case ast::BinaryOp::kDivide:
out << "/";
if (auto val = program_->Sem().Get(expr->rhs)->ConstantValue()) {
// Integer divide by zero is a DXC compile error, and undefined behavior
// in WGSL. Replace the 0 with 1.
if (val.Type()->Is<sem::I32>() && val.Elements()[0].i32 == 0) {
out << " 1";
return true;
}
if (val.Type()->Is<sem::U32>() && val.Elements()[0].u32 == 0u) {
out << " 1u";
return true;
}
}
break;
case ast::BinaryOp::kModulo:
out << "%";
break;
case ast::BinaryOp::kNone:
diagnostics_.add_error(diag::System::Writer,
"missing binary operation type");
return false;
}
out << " ";
if (!EmitExpression(out, expr->rhs)) {
return false;
}
return true;
}
bool GeneratorImpl::EmitStatements(const ast::StatementList& stmts) {
for (auto* s : stmts) {
if (!EmitStatement(s)) {
return false;
}
}
return true;
}
bool GeneratorImpl::EmitStatementsWithIndent(const ast::StatementList& stmts) {
ScopedIndent si(this);
return EmitStatements(stmts);
}
bool GeneratorImpl::EmitBlock(const ast::BlockStatement* stmt) {
line() << "{";
if (!EmitStatementsWithIndent(stmt->statements)) {
return false;
}
line() << "}";
return true;
}
bool GeneratorImpl::EmitBreak(const ast::BreakStatement*) {
line() << "break;";
return true;
}
bool GeneratorImpl::EmitCall(std::ostream& out,
const ast::CallExpression* expr) {
const auto& args = expr->args;
auto* ident = expr->func;
auto* call = builder_.Sem().Get(expr);
auto* target = call->Target();
if (auto* func = target->As<sem::Function>()) {
if (ast::HasDecoration<
transform::CalculateArrayLength::BufferSizeIntrinsic>(
func->Declaration()->decorations)) {
// Special function generated by the CalculateArrayLength transform for
// calling X.GetDimensions(Y)
if (!EmitExpression(out, args[0])) {
return false;
}
out << ".GetDimensions(";
if (!EmitExpression(out, args[1])) {
return false;
}
out << ")";
return true;
}
if (auto* intrinsic =
ast::GetDecoration<transform::DecomposeMemoryAccess::Intrinsic>(
func->Declaration()->decorations)) {
switch (intrinsic->storage_class) {
case ast::StorageClass::kUniform:
return EmitUniformBufferAccess(out, expr, intrinsic);
case ast::StorageClass::kStorage:
return EmitStorageBufferAccess(out, expr, intrinsic);
default:
TINT_UNREACHABLE(Writer, diagnostics_)
<< "unsupported DecomposeMemoryAccess::Intrinsic storage class:"
<< intrinsic->storage_class;
return false;
}
}
}
if (auto* intrinsic = call->Target()->As<sem::Intrinsic>()) {
if (intrinsic->IsTexture()) {
return EmitTextureCall(out, expr, intrinsic);
} else if (intrinsic->Type() == sem::IntrinsicType::kSelect) {
return EmitSelectCall(out, expr);
} else if (intrinsic->Type() == sem::IntrinsicType::kModf) {
return EmitModfCall(out, expr, intrinsic);
} else if (intrinsic->Type() == sem::IntrinsicType::kFrexp) {
return EmitFrexpCall(out, expr, intrinsic);
} else if (intrinsic->Type() == sem::IntrinsicType::kIsNormal) {
return EmitIsNormalCall(out, expr, intrinsic);
} else if (intrinsic->Type() == sem::IntrinsicType::kIgnore) {
return EmitExpression(out, expr->args[0]); // [DEPRECATED]
} else if (intrinsic->IsDataPacking()) {
return EmitDataPackingCall(out, expr, intrinsic);
} else if (intrinsic->IsDataUnpacking()) {
return EmitDataUnpackingCall(out, expr, intrinsic);
} else if (intrinsic->IsBarrier()) {
return EmitBarrierCall(out, intrinsic);
} else if (intrinsic->IsAtomic()) {
return EmitWorkgroupAtomicCall(out, expr, intrinsic);
}
auto name = generate_builtin_name(intrinsic);
if (name.empty()) {
return false;
}
out << name << "(";
bool first = true;
for (auto* arg : args) {
if (!first) {
out << ", ";
}
first = false;
if (!EmitExpression(out, arg)) {
return false;
}
}
out << ")";
return true;
}
auto name = builder_.Symbols().NameFor(ident->symbol);
auto caller_sym = ident->symbol;
auto* func = builder_.AST().Functions().Find(ident->symbol);
if (func == nullptr) {
diagnostics_.add_error(diag::System::Writer,
"Unable to find function: " +
builder_.Symbols().NameFor(ident->symbol));
return false;
}
out << name << "(";
bool first = true;
for (auto* arg : args) {
if (!first) {
out << ", ";
}
first = false;
if (!EmitExpression(out, arg)) {
return false;
}
}
out << ")";
return true;
}
bool GeneratorImpl::EmitUniformBufferAccess(
std::ostream& out,
const ast::CallExpression* expr,
const transform::DecomposeMemoryAccess::Intrinsic* intrinsic) {
const auto& args = expr->args;
auto* offset_arg = builder_.Sem().Get(args[1]);
uint32_t scalar_offset_value = 0;
std::string scalar_offset_expr;
// If true, use scalar_offset_value, otherwise use scalar_offset_expr
bool scalar_offset_constant = false;
if (auto val = offset_arg->ConstantValue()) {
TINT_ASSERT(Writer, val.Type()->Is<sem::U32>());
scalar_offset_value = val.Elements()[0].u32;
scalar_offset_value /= 4; // bytes -> scalar index
scalar_offset_constant = true;
}
if (!scalar_offset_constant) {
// UBO offset not compile-time known.
// Calculate the scalar offset into a temporary.
scalar_offset_expr = UniqueIdentifier("scalar_offset");
auto pre = line();
pre << "const uint " << scalar_offset_expr << " = (";
if (!EmitExpression(pre, args[1])) { // offset
return false;
}
pre << ") / 4;";
}
using Op = transform::DecomposeMemoryAccess::Intrinsic::Op;
using DataType = transform::DecomposeMemoryAccess::Intrinsic::DataType;
switch (intrinsic->op) {
case Op::kLoad: {
auto cast = [&](const char* to, auto&& load) {
out << to << "(";
auto result = load();
out << ")";
return result;
};
auto load_scalar = [&]() {
if (!EmitExpression(out, args[0])) { // buffer
return false;
}
if (scalar_offset_constant) {
char swizzle[] = {'x', 'y', 'z', 'w'};
out << "[" << (scalar_offset_value / 4) << "]."
<< swizzle[scalar_offset_value & 3];
} else {
out << "[" << scalar_offset_expr << " / 4][" << scalar_offset_expr
<< " % 4]";
}
return true;
};
// Has a minimum alignment of 8 bytes, so is either .xy or .zw
auto load_vec2 = [&] {
if (scalar_offset_constant) {
if (!EmitExpression(out, args[0])) { // buffer
return false;
}
out << "[" << (scalar_offset_value / 4) << "]";
out << ((scalar_offset_value & 2) == 0 ? ".xy" : ".zw");
} else {
std::string ubo_load = UniqueIdentifier("ubo_load");
{
auto pre = line();
pre << "uint4 " << ubo_load << " = ";
if (!EmitExpression(pre, args[0])) { // buffer
return false;
}
pre << "[" << scalar_offset_expr << " / 4];";
}
out << "((" << scalar_offset_expr << " & 2) ? " << ubo_load
<< ".zw : " << ubo_load << ".xy)";
}
return true;
};
// vec4 has a minimum alignment of 16 bytes, easiest case
auto load_vec4 = [&] {
if (!EmitExpression(out, args[0])) { // buffer
return false;
}
if (scalar_offset_constant) {
out << "[" << (scalar_offset_value / 4) << "]";
} else {
out << "[" << scalar_offset_expr << " / 4]";
}
return true;
};
// vec3 has a minimum alignment of 16 bytes, so is just a .xyz swizzle
auto load_vec3 = [&] {
if (!load_vec4()) {
return false;
}
out << ".xyz";
return true;
};
switch (intrinsic->type) {
case DataType::kU32:
return load_scalar();
case DataType::kF32:
return cast("asfloat", load_scalar);
case DataType::kI32:
return cast("asint", load_scalar);
case DataType::kVec2U32:
return load_vec2();
case DataType::kVec2F32:
return cast("asfloat", load_vec2);
case DataType::kVec2I32:
return cast("asint", load_vec2);
case DataType::kVec3U32:
return load_vec3();
case DataType::kVec3F32:
return cast("asfloat", load_vec3);
case DataType::kVec3I32:
return cast("asint", load_vec3);
case DataType::kVec4U32:
return load_vec4();
case DataType::kVec4F32:
return cast("asfloat", load_vec4);
case DataType::kVec4I32:
return cast("asint", load_vec4);
}
TINT_UNREACHABLE(Writer, diagnostics_)
<< "unsupported DecomposeMemoryAccess::Intrinsic::DataType: "
<< static_cast<int>(intrinsic->type);
return false;
}
default:
break;
}
TINT_UNREACHABLE(Writer, diagnostics_)
<< "unsupported DecomposeMemoryAccess::Intrinsic::Op: "
<< static_cast<int>(intrinsic->op);
return false;
}
bool GeneratorImpl::EmitStorageBufferAccess(
std::ostream& out,
const ast::CallExpression* expr,
const transform::DecomposeMemoryAccess::Intrinsic* intrinsic) {
const auto& args = expr->args;
using Op = transform::DecomposeMemoryAccess::Intrinsic::Op;
using DataType = transform::DecomposeMemoryAccess::Intrinsic::DataType;
switch (intrinsic->op) {
case Op::kLoad: {
auto load = [&](const char* cast, int n) {
if (cast) {
out << cast << "(";
}
if (!EmitExpression(out, args[0])) { // buffer
return false;
}
out << ".Load";
if (n > 1) {
out << n;
}
ScopedParen sp(out);
if (!EmitExpression(out, args[1])) { // offset
return false;
}
if (cast) {
out << ")";
}
return true;
};
switch (intrinsic->type) {
case DataType::kU32:
return load(nullptr, 1);
case DataType::kF32:
return load("asfloat", 1);
case DataType::kI32:
return load("asint", 1);
case DataType::kVec2U32:
return load(nullptr, 2);
case DataType::kVec2F32:
return load("asfloat", 2);
case DataType::kVec2I32:
return load("asint", 2);
case DataType::kVec3U32:
return load(nullptr, 3);
case DataType::kVec3F32:
return load("asfloat", 3);
case DataType::kVec3I32:
return load("asint", 3);
case DataType::kVec4U32:
return load(nullptr, 4);
case DataType::kVec4F32:
return load("asfloat", 4);
case DataType::kVec4I32:
return load("asint", 4);
}
TINT_UNREACHABLE(Writer, diagnostics_)
<< "unsupported DecomposeMemoryAccess::Intrinsic::DataType: "
<< static_cast<int>(intrinsic->type);
return false;
}
case Op::kStore: {
auto store = [&](int n) {
if (!EmitExpression(out, args[0])) { // buffer
return false;
}
out << ".Store";
if (n > 1) {
out << n;
}
ScopedParen sp1(out);
if (!EmitExpression(out, args[1])) { // offset
return false;
}
out << ", asuint";
ScopedParen sp2(out);
if (!EmitExpression(out, args[2])) { // value
return false;
}
return true;
};
switch (intrinsic->type) {
case DataType::kU32:
return store(1);
case DataType::kF32:
return store(1);
case DataType::kI32:
return store(1);
case DataType::kVec2U32:
return store(2);
case DataType::kVec2F32:
return store(2);
case DataType::kVec2I32:
return store(2);
case DataType::kVec3U32:
return store(3);
case DataType::kVec3F32:
return store(3);
case DataType::kVec3I32:
return store(3);
case DataType::kVec4U32:
return store(4);
case DataType::kVec4F32:
return store(4);
case DataType::kVec4I32:
return store(4);
}
TINT_UNREACHABLE(Writer, diagnostics_)
<< "unsupported DecomposeMemoryAccess::Intrinsic::DataType: "
<< static_cast<int>(intrinsic->type);
return false;
}
case Op::kAtomicLoad:
case Op::kAtomicStore:
case Op::kAtomicAdd:
case Op::kAtomicSub:
case Op::kAtomicMax:
case Op::kAtomicMin:
case Op::kAtomicAnd:
case Op::kAtomicOr:
case Op::kAtomicXor:
case Op::kAtomicExchange:
case Op::kAtomicCompareExchangeWeak:
return EmitStorageAtomicCall(out, expr, intrinsic);
}
TINT_UNREACHABLE(Writer, diagnostics_)
<< "unsupported DecomposeMemoryAccess::Intrinsic::Op: "
<< static_cast<int>(intrinsic->op);
return false;
}
bool GeneratorImpl::EmitStorageAtomicCall(
std::ostream& out,
const ast::CallExpression* expr,
const transform::DecomposeMemoryAccess::Intrinsic* intrinsic) {
using Op = transform::DecomposeMemoryAccess::Intrinsic::Op;
auto* result_ty = TypeOf(expr);
auto& buf = helpers_;
// generate_helper() generates a helper function that translates the
// DecomposeMemoryAccess::Intrinsic call into the corresponding HLSL
// atomic intrinsic function.
auto generate_helper = [&]() -> std::string {
auto rmw = [&](const char* wgsl, const char* hlsl) -> std::string {
auto name = UniqueIdentifier(wgsl);
{
auto fn = line(&buf);
if (!EmitTypeAndName(fn, result_ty, ast::StorageClass::kNone,
ast::Access::kUndefined, name)) {
return "";
}
fn << "(RWByteAddressBuffer buffer, uint offset, ";
if (!EmitTypeAndName(fn, result_ty, ast::StorageClass::kNone,
ast::Access::kUndefined, "value")) {
return "";
}
fn << ") {";
}
buf.IncrementIndent();
TINT_DEFER({
buf.DecrementIndent();
line(&buf) << "}";
line(&buf);
});
{
auto l = line(&buf);
if (!EmitTypeAndName(l, result_ty, ast::StorageClass::kNone,
ast::Access::kUndefined, "original_value")) {
return "";
}
l << " = 0;";
}
{
auto l = line(&buf);
l << "buffer." << hlsl << "(offset, ";
if (intrinsic->op == Op::kAtomicSub) {
l << "-";
}
l << "value, original_value);";
}
line(&buf) << "return original_value;";
return name;
};
switch (intrinsic->op) {
case Op::kAtomicAdd:
return rmw("atomicAdd", "InterlockedAdd");
case Op::kAtomicSub:
// Use add with the operand negated.
return rmw("atomicSub", "InterlockedAdd");
case Op::kAtomicMax:
return rmw("atomicMax", "InterlockedMax");
case Op::kAtomicMin:
return rmw("atomicMin", "InterlockedMin");
case Op::kAtomicAnd:
return rmw("atomicAnd", "InterlockedAnd");
case Op::kAtomicOr:
return rmw("atomicOr", "InterlockedOr");
case Op::kAtomicXor:
return rmw("atomicXor", "InterlockedXor");
case Op::kAtomicExchange:
return rmw("atomicExchange", "InterlockedExchange");
case Op::kAtomicLoad: {
// HLSL does not have an InterlockedLoad, so we emulate it with
// InterlockedOr using 0 as the OR value
auto name = UniqueIdentifier("atomicLoad");
{
auto fn = line(&buf);
if (!EmitTypeAndName(fn, result_ty, ast::StorageClass::kNone,
ast::Access::kUndefined, name)) {
return "";
}
fn << "(RWByteAddressBuffer buffer, uint offset) {";
}
buf.IncrementIndent();
TINT_DEFER({
buf.DecrementIndent();
line(&buf) << "}";
line(&buf);
});
{
auto l = line(&buf);
if (!EmitTypeAndName(l, result_ty, ast::StorageClass::kNone,
ast::Access::kUndefined, "value")) {
return "";
}
l << " = 0;";
}
line(&buf) << "buffer.InterlockedOr(offset, 0, value);";
line(&buf) << "return value;";
return name;
}
case Op::kAtomicStore: {
// HLSL does not have an InterlockedStore, so we emulate it with
// InterlockedExchange and discard the returned value
auto* value_ty = TypeOf(expr->args[2])->UnwrapRef();
auto name = UniqueIdentifier("atomicStore");
{
auto fn = line(&buf);
fn << "void " << name << "(RWByteAddressBuffer buffer, uint offset, ";
if (!EmitTypeAndName(fn, value_ty, ast::StorageClass::kNone,
ast::Access::kUndefined, "value")) {
return "";
}
fn << ") {";
}
buf.IncrementIndent();
TINT_DEFER({
buf.DecrementIndent();
line(&buf) << "}";
line(&buf);
});
{
auto l = line(&buf);
if (!EmitTypeAndName(l, value_ty, ast::StorageClass::kNone,
ast::Access::kUndefined, "ignored")) {
return "";
}
l << ";";
}
line(&buf) << "buffer.InterlockedExchange(offset, value, ignored);";
return name;
}
case Op::kAtomicCompareExchangeWeak: {
auto* value_ty = TypeOf(expr->args[2])->UnwrapRef();
auto name = UniqueIdentifier("atomicCompareExchangeWeak");
{
auto fn = line(&buf);
if (!EmitTypeAndName(fn, result_ty, ast::StorageClass::kNone,
ast::Access::kUndefined, name)) {
return "";
}
fn << "(RWByteAddressBuffer buffer, uint offset, ";
if (!EmitTypeAndName(fn, value_ty, ast::StorageClass::kNone,
ast::Access::kUndefined, "compare")) {
return "";
}
fn << ", ";
if (!EmitTypeAndName(fn, value_ty, ast::StorageClass::kNone,
ast::Access::kUndefined, "value")) {
return "";
}
fn << ") {";
}
buf.IncrementIndent();
TINT_DEFER({
buf.DecrementIndent();
line(&buf) << "}";
line(&buf);
});
{ // T result = {0, 0};
auto l = line(&buf);
if (!EmitTypeAndName(l, result_ty, ast::StorageClass::kNone,
ast::Access::kUndefined, "result")) {
return "";
}
l << " = {0, 0};";
}
line(&buf) << "buffer.InterlockedCompareExchange(offset, compare, "
"value, result.x);";
line(&buf) << "result.y = result.x == compare;";
line(&buf) << "return result;";
return name;
}
default:
break;
}
TINT_UNREACHABLE(Writer, diagnostics_)
<< "unsupported atomic DecomposeMemoryAccess::Intrinsic::Op: "
<< static_cast<int>(intrinsic->op);
return "";
};
auto func = utils::GetOrCreate(dma_intrinsics_,
DMAIntrinsic{intrinsic->op, intrinsic->type},
generate_helper);
if (func.empty()) {
return false;
}
out << func;
{
ScopedParen sp(out);
bool first = true;
for (auto* arg : expr->args) {
if (!first) {
out << ", ";
}
first = false;
if (!EmitExpression(out, arg)) {
return false;
}
}
}
return true;
}
bool GeneratorImpl::EmitWorkgroupAtomicCall(std::ostream& out,
const ast::CallExpression* expr,
const sem::Intrinsic* intrinsic) {
std::string result = UniqueIdentifier("atomic_result");
if (!intrinsic->ReturnType()->Is<sem::Void>()) {
auto pre = line();
if (!EmitTypeAndName(pre, intrinsic->ReturnType(), ast::StorageClass::kNone,
ast::Access::kUndefined, result)) {
return false;
}
pre << " = ";
if (!EmitZeroValue(pre, intrinsic->ReturnType())) {
return false;
}
pre << ";";
}
auto call = [&](const char* name) {
auto pre = line();
pre << name;
{
ScopedParen sp(pre);
for (size_t i = 0; i < expr->args.size(); i++) {
auto* arg = expr->args[i];
if (i > 0) {
pre << ", ";
}
if (i == 1 && intrinsic->Type() == sem::IntrinsicType::kAtomicSub) {
// Sub uses InterlockedAdd with the operand negated.
pre << "-";
}
if (!EmitExpression(pre, arg)) {
return false;
}
}
pre << ", " << result;
}
pre << ";";
out << result;
return true;
};
switch (intrinsic->Type()) {
case sem::IntrinsicType::kAtomicLoad: {
// HLSL does not have an InterlockedLoad, so we emulate it with
// InterlockedOr using 0 as the OR value
auto pre = line();
pre << "InterlockedOr";
{
ScopedParen sp(pre);
if (!EmitExpression(pre, expr->args[0])) {
return false;
}
pre << ", 0, " << result;
}
pre << ";";
out << result;
return true;
}
case sem::IntrinsicType::kAtomicStore: {
// HLSL does not have an InterlockedStore, so we emulate it with
// InterlockedExchange and discard the returned value
{ // T result = 0;
auto pre = line();
auto* value_ty = intrinsic->Parameters()[1]->Type()->UnwrapRef();
if (!EmitTypeAndName(pre, value_ty, ast::StorageClass::kNone,
ast::Access::kUndefined, result)) {
return false;
}
pre << " = ";
if (!EmitZeroValue(pre, value_ty)) {
return false;
}
pre << ";";
}
out << "InterlockedExchange";
{
ScopedParen sp(out);
if (!EmitExpression(out, expr->args[0])) {
return false;
}
out << ", ";
if (!EmitExpression(out, expr->args[1])) {
return false;
}
out << ", " << result;
}
return true;
}
case sem::IntrinsicType::kAtomicCompareExchangeWeak: {
auto* dest = expr->args[0];
auto* compare_value = expr->args[1];
auto* value = expr->args[2];
std::string compare = UniqueIdentifier("atomic_compare_value");
{ // T compare_value = <compare_value>;
auto pre = line();
if (!EmitTypeAndName(pre, TypeOf(compare_value),
ast::StorageClass::kNone, ast::Access::kUndefined,
compare)) {
return false;
}
pre << " = ";
if (!EmitExpression(pre, compare_value)) {
return false;
}
pre << ";";
}
{ // InterlockedCompareExchange(dst, compare, value, result.x);
auto pre = line();
pre << "InterlockedCompareExchange";
{
ScopedParen sp(pre);
if (!EmitExpression(pre, dest)) {
return false;
}
pre << ", " << compare << ", ";
if (!EmitExpression(pre, value)) {
return false;
}
pre << ", " << result << ".x";
}
pre << ";";
}
{ // result.y = result.x == compare;
line() << result << ".y = " << result << ".x == " << compare << ";";
}
out << result;
return true;
}
case sem::IntrinsicType::kAtomicAdd:
case sem::IntrinsicType::kAtomicSub:
return call("InterlockedAdd");
case sem::IntrinsicType::kAtomicMax:
return call("InterlockedMax");
case sem::IntrinsicType::kAtomicMin:
return call("InterlockedMin");
case sem::IntrinsicType::kAtomicAnd:
return call("InterlockedAnd");
case sem::IntrinsicType::kAtomicOr:
return call("InterlockedOr");
case sem::IntrinsicType::kAtomicXor:
return call("InterlockedXor");
case sem::IntrinsicType::kAtomicExchange:
return call("InterlockedExchange");
default:
break;
}
TINT_UNREACHABLE(Writer, diagnostics_)
<< "unsupported atomic intrinsic: " << intrinsic->Type();
return false;
}
bool GeneratorImpl::EmitSelectCall(std::ostream& out,
const ast::CallExpression* expr) {
auto* expr_false = expr->args[0];
auto* expr_true = expr->args[1];
auto* expr_cond = expr->args[2];
ScopedParen paren(out);
if (!EmitExpression(out, expr_cond)) {
return false;
}
out << " ? ";
if (!EmitExpression(out, expr_true)) {
return false;
}
out << " : ";
if (!EmitExpression(out, expr_false)) {
return false;
}
return true;
}
bool GeneratorImpl::EmitModfCall(std::ostream& out,
const ast::CallExpression* expr,
const sem::Intrinsic* intrinsic) {
return CallIntrinsicHelper(
out, expr, intrinsic,
[&](TextBuffer* b, const std::vector<std::string>& params) {
auto* ty = intrinsic->Parameters()[0]->Type();
auto in = params[0];
std::string width;
if (auto* vec = ty->As<sem::Vector>()) {
width = std::to_string(vec->Width());
}
// Emit the builtin return type unique to this overload. This does not
// exist in the AST, so it will not be generated in Generate().
if (!EmitStructType(&helpers_,
intrinsic->ReturnType()->As<sem::Struct>())) {
return false;
}
line(b) << "float" << width << " whole;";
line(b) << "float" << width << " fract = modf(" << in << ", whole);";
{
auto l = line(b);
if (!EmitType(l, intrinsic->ReturnType(), ast::StorageClass::kNone,
ast::Access::kUndefined, "")) {
return false;
}
l << " result = {fract, whole};";
}
line(b) << "return result;";
return true;
});
}
bool GeneratorImpl::EmitFrexpCall(std::ostream& out,
const ast::CallExpression* expr,
const sem::Intrinsic* intrinsic) {
return CallIntrinsicHelper(
out, expr, intrinsic,
[&](TextBuffer* b, const std::vector<std::string>& params) {
auto* ty = intrinsic->Parameters()[0]->Type();
auto in = params[0];
std::string width;
if (auto* vec = ty->As<sem::Vector>()) {
width = std::to_string(vec->Width());
}
// Emit the builtin return type unique to this overload. This does not
// exist in the AST, so it will not be generated in Generate().
if (!EmitStructType(&helpers_,
intrinsic->ReturnType()->As<sem::Struct>())) {
return false;
}
line(b) << "float" << width << " exp;";
line(b) << "float" << width << " sig = frexp(" << in << ", exp);";
{
auto l = line(b);
if (!EmitType(l, intrinsic->ReturnType(), ast::StorageClass::kNone,
ast::Access::kUndefined, "")) {
return false;
}
l << " result = {sig, int" << width << "(exp)};";
}
line(b) << "return result;";
return true;
});
}
bool GeneratorImpl::EmitIsNormalCall(std::ostream& out,
const ast::CallExpression* expr,
const sem::Intrinsic* intrinsic) {
// HLSL doesn't have a isNormal intrinsic, we need to emulate
return CallIntrinsicHelper(
out, expr, intrinsic,
[&](TextBuffer* b, const std::vector<std::string>& params) {
auto* input_ty = intrinsic->Parameters()[0]->Type();
std::string width;
if (auto* vec = input_ty->As<sem::Vector>()) {
width = std::to_string(vec->Width());
}
constexpr auto* kExponentMask = "0x7f80000";
constexpr auto* kMinNormalExponent = "0x0080000";
constexpr auto* kMaxNormalExponent = "0x7f00000";
line(b) << "uint" << width << " exponent = asuint(" << params[0]
<< ") & " << kExponentMask << ";";
line(b) << "uint" << width << " clamped = "
<< "clamp(exponent, " << kMinNormalExponent << ", "
<< kMaxNormalExponent << ");";
line(b) << "return clamped == exponent;";
return true;
});
}
bool GeneratorImpl::EmitDataPackingCall(std::ostream& out,
const ast::CallExpression* expr,
const sem::Intrinsic* intrinsic) {
return CallIntrinsicHelper(
out, expr, intrinsic,
[&](TextBuffer* b, const std::vector<std::string>& params) {
uint32_t dims = 2;
bool is_signed = false;
uint32_t scale = 65535;
if (intrinsic->Type() == sem::IntrinsicType::kPack4x8snorm ||
intrinsic->Type() == sem::IntrinsicType::kPack4x8unorm) {
dims = 4;
scale = 255;
}
if (intrinsic->Type() == sem::IntrinsicType::kPack4x8snorm ||
intrinsic->Type() == sem::IntrinsicType::kPack2x16snorm) {
is_signed = true;
scale = (scale - 1) / 2;
}
switch (intrinsic->Type()) {
case sem::IntrinsicType::kPack4x8snorm:
case sem::IntrinsicType::kPack4x8unorm:
case sem::IntrinsicType::kPack2x16snorm:
case sem::IntrinsicType::kPack2x16unorm: {
{
auto l = line(b);
l << (is_signed ? "" : "u") << "int" << dims
<< " i = " << (is_signed ? "" : "u") << "int" << dims
<< "(round(clamp(" << params[0] << ", "
<< (is_signed ? "-1.0" : "0.0") << ", 1.0) * " << scale
<< ".0))";
if (is_signed) {
l << " & " << (dims == 4 ? "0xff" : "0xffff");
}
l << ";";
}
{
auto l = line(b);
l << "return ";
if (is_signed) {
l << "asuint";
}
l << "(i.x | i.y << " << (32 / dims);
if (dims == 4) {
l << " | i.z << 16 | i.w << 24";
}
l << ");";
}
break;
}
case sem::IntrinsicType::kPack2x16float: {
line(b) << "uint2 i = f32tof16(" << params[0] << ");";
line(b) << "return i.x | (i.y << 16);";
break;
}
default:
diagnostics_.add_error(
diag::System::Writer,
"Internal error: unhandled data packing intrinsic");
return false;
}
return true;
});
}
bool GeneratorImpl::EmitDataUnpackingCall(std::ostream& out,
const ast::CallExpression* expr,
const sem::Intrinsic* intrinsic) {
return CallIntrinsicHelper(
out, expr, intrinsic,
[&](TextBuffer* b, const std::vector<std::string>& params) {
uint32_t dims = 2;
bool is_signed = false;
uint32_t scale = 65535;
if (intrinsic->Type() == sem::IntrinsicType::kUnpack4x8snorm ||
intrinsic->Type() == sem::IntrinsicType::kUnpack4x8unorm) {
dims = 4;
scale = 255;
}
if (intrinsic->Type() == sem::IntrinsicType::kUnpack4x8snorm ||
intrinsic->Type() == sem::IntrinsicType::kUnpack2x16snorm) {
is_signed = true;
scale = (scale - 1) / 2;
}
switch (intrinsic->Type()) {
case sem::IntrinsicType::kUnpack4x8snorm:
case sem::IntrinsicType::kUnpack2x16snorm: {
line(b) << "int j = int(" << params[0] << ");";
{ // Perform sign extension on the converted values.
auto l = line(b);
l << "int" << dims << " i = int" << dims << "(";
if (dims == 2) {
l << "j << 16, j) >> 16";
} else {
l << "j << 24, j << 16, j << 8, j) >> 24";
}
l << ";";
}
line(b) << "return clamp(float" << dims << "(i) / " << scale
<< ".0, " << (is_signed ? "-1.0" : "0.0") << ", 1.0);";
break;
}
case sem::IntrinsicType::kUnpack4x8unorm:
case sem::IntrinsicType::kUnpack2x16unorm: {
line(b) << "uint j = " << params[0] << ";";
{
auto l = line(b);
l << "uint" << dims << " i = uint" << dims << "(";
l << "j & " << (dims == 2 ? "0xffff" : "0xff") << ", ";
if (dims == 4) {
l << "(j >> " << (32 / dims)
<< ") & 0xff, (j >> 16) & 0xff, j >> 24";
} else {
l << "j >> " << (32 / dims);
}
l << ");";
}
line(b) << "return float" << dims << "(i) / " << scale << ".0;";
break;
}
case sem::IntrinsicType::kUnpack2x16float:
line(b) << "uint i = " << params[0] << ";";
line(b) << "return f16tof32(uint2(i & 0xffff, i >> 16));";
break;
default:
diagnostics_.add_error(
diag::System::Writer,
"Internal error: unhandled data packing intrinsic");
return false;
}
return true;
});
}
bool GeneratorImpl::EmitBarrierCall(std::ostream& out,
const sem::Intrinsic* intrinsic) {
// TODO(crbug.com/tint/661): Combine sequential barriers to a single
// instruction.
if (intrinsic->Type() == sem::IntrinsicType::kWorkgroupBarrier) {
out << "GroupMemoryBarrierWithGroupSync()";
} else if (intrinsic->Type() == sem::IntrinsicType::kStorageBarrier) {
out << "DeviceMemoryBarrierWithGroupSync()";
} else {
TINT_UNREACHABLE(Writer, diagnostics_)
<< "unexpected barrier intrinsic type " << sem::str(intrinsic->Type());
return false;
}
return true;
}
bool GeneratorImpl::EmitTextureCall(std::ostream& out,
const ast::CallExpression* expr,
const sem::Intrinsic* intrinsic) {
using Usage = sem::ParameterUsage;
auto& signature = intrinsic->Signature();
auto arguments = expr->args;
// Returns the argument with the given usage
auto arg = [&](Usage usage) {
int idx = signature.IndexOf(usage);
return (idx >= 0) ? arguments[idx] : nullptr;
};
auto* texture = arg(Usage::kTexture);
if (!texture) {
TINT_ICE(Writer, diagnostics_) << "missing texture argument";
return false;
}
auto* texture_type = TypeOf(texture)->UnwrapRef()->As<sem::Texture>();
switch (intrinsic->Type()) {
case sem::IntrinsicType::kTextureDimensions:
case sem::IntrinsicType::kTextureNumLayers:
case sem::IntrinsicType::kTextureNumLevels:
case sem::IntrinsicType::kTextureNumSamples: {
// All of these intrinsics use the GetDimensions() method on the texture
bool is_ms = texture_type->IsAnyOf<sem::MultisampledTexture,
sem::DepthMultisampledTexture>();
int num_dimensions = 0;
std::string swizzle;
switch (intrinsic->Type()) {
case sem::IntrinsicType::kTextureDimensions:
switch (texture_type->dim()) {
case ast::TextureDimension::kNone:
TINT_ICE(Writer, diagnostics_) << "texture dimension is kNone";
return false;
case ast::TextureDimension::k1d:
num_dimensions = 1;
break;
case ast::TextureDimension::k2d:
num_dimensions = is_ms ? 3 : 2;
swizzle = is_ms ? ".xy" : "";
break;
case ast::TextureDimension::k2dArray:
num_dimensions = is_ms ? 4 : 3;
swizzle = ".xy";
break;
case ast::TextureDimension::k3d:
num_dimensions = 3;
break;
case ast::TextureDimension::kCube:
num_dimensions = 2;
break;
case ast::TextureDimension::kCubeArray:
num_dimensions = 3;
swizzle = ".xy";
break;
}
break;
case sem::IntrinsicType::kTextureNumLayers:
switch (texture_type->dim()) {
default:
TINT_ICE(Writer, diagnostics_)
<< "texture dimension is not arrayed";
return false;
case ast::TextureDimension::k2dArray:
num_dimensions = is_ms ? 4 : 3;
swizzle = ".z";
break;
case ast::TextureDimension::kCubeArray:
num_dimensions = 3;
swizzle = ".z";
break;
}
break;
case sem::IntrinsicType::kTextureNumLevels:
switch (texture_type->dim()) {
default:
TINT_ICE(Writer, diagnostics_)
<< "texture dimension does not support mips";
return false;
case ast::TextureDimension::k1d:
num_dimensions = 2;
swizzle = ".y";
break;
case ast::TextureDimension::k2d:
case ast::TextureDimension::kCube:
num_dimensions = 3;
swizzle = ".z";
break;
case ast::TextureDimension::k2dArray:
case ast::TextureDimension::k3d:
case ast::TextureDimension::kCubeArray:
num_dimensions = 4;
swizzle = ".w";
break;
}
break;
case sem::IntrinsicType::kTextureNumSamples:
switch (texture_type->dim()) {
default:
TINT_ICE(Writer, diagnostics_)
<< "texture dimension does not support multisampling";
return false;
case ast::TextureDimension::k2d:
num_dimensions = 3;
swizzle = ".z";
break;
case ast::TextureDimension::k2dArray:
num_dimensions = 4;
swizzle = ".w";
break;
}
break;
default:
TINT_ICE(Writer, diagnostics_) << "unexpected intrinsic";
return false;
}
auto* level_arg = arg(Usage::kLevel);
if (level_arg) {
// `NumberOfLevels` is a non-optional argument if `MipLevel` was passed.
// Increment the number of dimensions for the temporary vector to
// accommodate this.
num_dimensions++;
// If the swizzle was empty, the expression will evaluate to the whole
// vector. As we've grown the vector by one element, we now need to
// swizzle to keep the result expression equivalent.
if (swizzle.empty()) {
static constexpr const char* swizzles[] = {"", ".x", ".xy", ".xyz"};
swizzle = swizzles[num_dimensions - 1];
}
}
if (num_dimensions > 4) {
TINT_ICE(Writer, diagnostics_)
<< "Texture query intrinsic temporary vector has " << num_dimensions
<< " dimensions";
return false;
}
// Declare a variable to hold the queried texture info
auto dims = UniqueIdentifier(kTempNamePrefix);
if (num_dimensions == 1) {
line() << "int " << dims << ";";
} else {
line() << "int" << num_dimensions << " " << dims << ";";
}
{ // texture.GetDimensions(...)
auto pre = line();
if (!EmitExpression(pre, texture)) {
return false;
}
pre << ".GetDimensions(";
if (level_arg) {
if (!EmitExpression(pre, level_arg)) {
return false;
}
pre << ", ";
} else if (intrinsic->Type() == sem::IntrinsicType::kTextureNumLevels) {
pre << "0, ";
}
if (num_dimensions == 1) {
pre << dims;
} else {
static constexpr char xyzw[] = {'x', 'y', 'z', 'w'};
if (num_dimensions < 0 || num_dimensions > 4) {
TINT_ICE(Writer, diagnostics_)
<< "vector dimensions are " << num_dimensions;
return false;
}
for (int i = 0; i < num_dimensions; i++) {
if (i > 0) {
pre << ", ";
}
pre << dims << "." << xyzw[i];
}
}
pre << ");";
}
// The out parameters of the GetDimensions() call is now in temporary
// `dims` variable. This may be packed with other data, so the final
// expression may require a swizzle.
out << dims << swizzle;
return true;
}
default:
break;
}
if (!EmitExpression(out, texture))
return false;
// If pack_level_in_coords is true, then the mip level will be appended as the
// last value of the coordinates argument. If the WGSL intrinsic overload does
// not have a level parameter and pack_level_in_coords is true, then a zero
// mip level will be inserted.
bool pack_level_in_coords = false;
uint32_t hlsl_ret_width = 4u;
switch (intrinsic->Type()) {
case sem::IntrinsicType::kTextureSample:
out << ".Sample(";
break;
case sem::IntrinsicType::kTextureSampleBias:
out << ".SampleBias(";
break;
case sem::IntrinsicType::kTextureSampleLevel:
out << ".SampleLevel(";
break;
case sem::IntrinsicType::kTextureSampleGrad:
out << ".SampleGrad(";
break;
case sem::IntrinsicType::kTextureSampleCompare:
out << ".SampleCmp(";
hlsl_ret_width = 1;
break;
case sem::IntrinsicType::kTextureSampleCompareLevel:
out << ".SampleCmpLevelZero(";
hlsl_ret_width = 1;
break;
case sem::IntrinsicType::kTextureLoad:
out << ".Load(";
// Multisampled textures do not support mip-levels.
if (!texture_type->Is<sem::MultisampledTexture>()) {
pack_level_in_coords = true;
}
break;
case sem::IntrinsicType::kTextureStore:
out << "[";
break;
default:
diagnostics_.add_error(
diag::System::Writer,
"Internal compiler error: Unhandled texture intrinsic '" +
std::string(intrinsic->str()) + "'");
return false;
}
if (auto* sampler = arg(Usage::kSampler)) {
if (!EmitExpression(out, sampler))
return false;
out << ", ";
}
auto* param_coords = arg(Usage::kCoords);
if (!param_coords) {
TINT_ICE(Writer, diagnostics_) << "missing coords argument";
return false;
}
auto emit_vector_appended_with_i32_zero = [&](const ast::Expression* vector) {
auto* i32 = builder_.create<sem::I32>();
auto* zero = builder_.Expr(0);
auto* stmt = builder_.Sem().Get(vector)->Stmt();
builder_.Sem().Add(zero, builder_.create<sem::Expression>(zero, i32, stmt,
sem::Constant{}));
auto* packed = AppendVector(&builder_, vector, zero);
return EmitExpression(out, packed);
};
auto emit_vector_appended_with_level = [&](const ast::Expression* vector) {
if (auto* level = arg(Usage::kLevel)) {
auto* packed = AppendVector(&builder_, vector, level);
return EmitExpression(out, packed);
}
return emit_vector_appended_with_i32_zero(vector);
};
if (auto* array_index = arg(Usage::kArrayIndex)) {
// Array index needs to be appended to the coordinates.
auto* packed = AppendVector(&builder_, param_coords, array_index);
if (pack_level_in_coords) {
// Then mip level needs to be appended to the coordinates.
if (!emit_vector_appended_with_level(packed)) {
return false;
}
} else {
if (!EmitExpression(out, packed)) {
return false;
}
}
} else if (pack_level_in_coords) {
// Mip level needs to be appended to the coordinates.
if (!emit_vector_appended_with_level(param_coords)) {
return false;
}
} else {
if (!EmitExpression(out, param_coords)) {
return false;
}
}
for (auto usage : {Usage::kDepthRef, Usage::kBias, Usage::kLevel, Usage::kDdx,
Usage::kDdy, Usage::kSampleIndex, Usage::kOffset}) {
if (usage == Usage::kLevel && pack_level_in_coords) {
continue; // mip level already packed in coordinates.
}
if (auto* e = arg(usage)) {
out << ", ";
if (!EmitExpression(out, e)) {
return false;
}
}
}
if (intrinsic->Type() == sem::IntrinsicType::kTextureStore) {
out << "] = ";
if (!EmitExpression(out, arg(Usage::kValue))) {
return false;
}
} else {
out << ")";
// If the intrinsic return type does not match the number of elements of the
// HLSL intrinsic, we need to swizzle the expression to generate the correct
// number of components.
uint32_t wgsl_ret_width = 1;
if (auto* vec = intrinsic->ReturnType()->As<sem::Vector>()) {
wgsl_ret_width = vec->Width();
}
if (wgsl_ret_width < hlsl_ret_width) {
out << ".";
for (uint32_t i = 0; i < wgsl_ret_width; i++) {
out << "xyz"[i];
}
}
if (wgsl_ret_width > hlsl_ret_width) {
TINT_ICE(Writer, diagnostics_)
<< "WGSL return width (" << wgsl_ret_width
<< ") is wider than HLSL return width (" << hlsl_ret_width << ") for "
<< intrinsic->Type();
return false;
}
}
return true;
}
std::string GeneratorImpl::generate_builtin_name(
const sem::Intrinsic* intrinsic) {
switch (intrinsic->Type()) {
case sem::IntrinsicType::kAbs:
case sem::IntrinsicType::kAcos:
case sem::IntrinsicType::kAll:
case sem::IntrinsicType::kAny:
case sem::IntrinsicType::kAsin:
case sem::IntrinsicType::kAtan:
case sem::IntrinsicType::kAtan2:
case sem::IntrinsicType::kCeil:
case sem::IntrinsicType::kClamp:
case sem::IntrinsicType::kCos:
case sem::IntrinsicType::kCosh:
case sem::IntrinsicType::kCross:
case sem::IntrinsicType::kDeterminant:
case sem::IntrinsicType::kDistance:
case sem::IntrinsicType::kDot:
case sem::IntrinsicType::kExp:
case sem::IntrinsicType::kExp2:
case sem::IntrinsicType::kFloor:
case sem::IntrinsicType::kFrexp:
case sem::IntrinsicType::kLdexp:
case sem::IntrinsicType::kLength:
case sem::IntrinsicType::kLog:
case sem::IntrinsicType::kLog2:
case sem::IntrinsicType::kMax:
case sem::IntrinsicType::kMin:
case sem::IntrinsicType::kModf:
case sem::IntrinsicType::kNormalize:
case sem::IntrinsicType::kPow:
case sem::IntrinsicType::kReflect:
case sem::IntrinsicType::kRefract:
case sem::IntrinsicType::kRound:
case sem::IntrinsicType::kSign:
case sem::IntrinsicType::kSin:
case sem::IntrinsicType::kSinh:
case sem::IntrinsicType::kSqrt:
case sem::IntrinsicType::kStep:
case sem::IntrinsicType::kTan:
case sem::IntrinsicType::kTanh:
case sem::IntrinsicType::kTranspose:
case sem::IntrinsicType::kTrunc:
return intrinsic->str();
case sem::IntrinsicType::kCountOneBits:
return "countbits";
case sem::IntrinsicType::kDpdx:
return "ddx";
case sem::IntrinsicType::kDpdxCoarse:
return "ddx_coarse";
case sem::IntrinsicType::kDpdxFine:
return "ddx_fine";
case sem::IntrinsicType::kDpdy:
return "ddy";
case sem::IntrinsicType::kDpdyCoarse:
return "ddy_coarse";
case sem::IntrinsicType::kDpdyFine:
return "ddy_fine";
case sem::IntrinsicType::kFaceForward:
return "faceforward";
case sem::IntrinsicType::kFract:
return "frac";
case sem::IntrinsicType::kFma:
return "mad";
case sem::IntrinsicType::kFwidth:
case sem::IntrinsicType::kFwidthCoarse:
case sem::IntrinsicType::kFwidthFine:
return "fwidth";
case sem::IntrinsicType::kInverseSqrt:
return "rsqrt";
case sem::IntrinsicType::kIsFinite:
return "isfinite";
case sem::IntrinsicType::kIsInf:
return "isinf";
case sem::IntrinsicType::kIsNan:
return "isnan";
case sem::IntrinsicType::kMix:
return "lerp";
case sem::IntrinsicType::kReverseBits:
return "reversebits";
case sem::IntrinsicType::kSmoothStep:
return "smoothstep";
default:
diagnostics_.add_error(
diag::System::Writer,
"Unknown builtin method: " + std::string(intrinsic->str()));
}
return "";
}
bool GeneratorImpl::EmitCase(const ast::SwitchStatement* s, size_t case_idx) {
auto* stmt = s->body[case_idx];
if (stmt->IsDefault()) {
line() << "default: {";
} else {
for (auto* selector : stmt->selectors) {
auto out = line();
out << "case ";
if (!EmitLiteral(out, selector)) {
return false;
}
out << ":";
if (selector == stmt->selectors.back()) {
out << " {";
}
}
}
increment_indent();
TINT_DEFER({
decrement_indent();
line() << "}";
});
// Emit the case statement
if (!EmitStatements(stmt->body->statements)) {
return false;
}
// Inline all fallthrough case statements. FXC cannot handle fallthroughs.
while (tint::Is<ast::FallthroughStatement>(stmt->body->Last())) {
case_idx++;
stmt = s->body[case_idx];
// Generate each fallthrough case statement in a new block. This is done to
// prevent symbol collision of variables declared in these cases statements.
if (!EmitBlock(stmt->body)) {
return false;
}
}
if (!tint::IsAnyOf<ast::BreakStatement, ast::FallthroughStatement>(
stmt->body->Last())) {
line() << "break;";
}
return true;
}
bool GeneratorImpl::EmitConstructor(std::ostream& out,
const ast::ConstructorExpression* expr) {
if (auto* scalar = expr->As<ast::ScalarConstructorExpression>()) {
return EmitScalarConstructor(out, scalar);
}
return EmitTypeConstructor(out, expr->As<ast::TypeConstructorExpression>());
}
bool GeneratorImpl::EmitScalarConstructor(
std::ostream& out,
const ast::ScalarConstructorExpression* expr) {
return EmitLiteral(out, expr->literal);
}
bool GeneratorImpl::EmitTypeConstructor(
std::ostream& out,
const ast::TypeConstructorExpression* expr) {
auto* type = TypeOf(expr)->UnwrapRef();
// If the type constructor is empty then we need to construct with the zero
// value for all components.
if (expr->values.empty()) {
return EmitZeroValue(out, type);
}
bool brackets = type->IsAnyOf<sem::Array, sem::Struct>();
// For single-value vector initializers, swizzle the scalar to the right
// vector dimension using .x
const bool is_single_value_vector_init =
type->is_scalar_vector() && expr->values.size() == 1 &&
TypeOf(expr->values[0])->UnwrapRef()->is_scalar();
auto it = structure_builders_.find(As<sem::Struct>(type));
if (it != structure_builders_.end()) {
out << it->second << "(";
brackets = false;
} else if (brackets) {
out << "{";
} else {
if (!EmitType(out, type, ast::StorageClass::kNone, ast::Access::kReadWrite,
"")) {
return false;
}
out << "(";
}
if (is_single_value_vector_init) {
out << "(";
}
bool first = true;
for (auto* e : expr->values) {
if (!first) {
out << ", ";
}
first = false;
if (!EmitExpression(out, e)) {
return false;
}
}
if (is_single_value_vector_init) {
out << ")." << std::string(type->As<sem::Vector>()->Width(), 'x');
}
out << (brackets ? "}" : ")");
return true;
}
bool GeneratorImpl::EmitContinue(const ast::ContinueStatement*) {
if (!emit_continuing_()) {
return false;
}
line() << "continue;";
return true;
}
bool GeneratorImpl::EmitDiscard(const ast::DiscardStatement*) {
// TODO(dsinclair): Verify this is correct when the discard semantics are
// defined for WGSL (https://github.com/gpuweb/gpuweb/issues/361)
line() << "discard;";
return true;
}
bool GeneratorImpl::EmitExpression(std::ostream& out,
const ast::Expression* expr) {
if (auto* a = expr->As<ast::ArrayAccessorExpression>()) {
return EmitArrayAccessor(out, a);
}
if (auto* b = expr->As<ast::BinaryExpression>()) {
return EmitBinary(out, b);
}
if (auto* b = expr->As<ast::BitcastExpression>()) {
return EmitBitcast(out, b);
}
if (auto* c = expr->As<ast::CallExpression>()) {
return EmitCall(out, c);
}
if (auto* c = expr->As<ast::ConstructorExpression>()) {
return EmitConstructor(out, c);
}
if (auto* i = expr->As<ast::IdentifierExpression>()) {
return EmitIdentifier(out, i);
}
if (auto* m = expr->As<ast::MemberAccessorExpression>()) {
return EmitMemberAccessor(out, m);
}
if (auto* u = expr->As<ast::UnaryOpExpression>()) {
return EmitUnaryOp(out, u);
}
diagnostics_.add_error(
diag::System::Writer,
"unknown expression type: " + std::string(expr->TypeInfo().name));
return false;
}
bool GeneratorImpl::EmitIdentifier(std::ostream& out,
const ast::IdentifierExpression* expr) {
out << builder_.Symbols().NameFor(expr->symbol);
return true;
}
bool GeneratorImpl::EmitIf(const ast::IfStatement* stmt) {
{
auto out = line();
out << "if (";
if (!EmitExpression(out, stmt->condition)) {
return false;
}
out << ") {";
}
if (!EmitStatementsWithIndent(stmt->body->statements)) {
return false;
}
for (auto* e : stmt->else_statements) {
if (e->condition) {
line() << "} else {";
increment_indent();
{
auto out = line();
out << "if (";
if (!EmitExpression(out, e->condition)) {
return false;
}
out << ") {";
}
} else {
line() << "} else {";
}
if (!EmitStatementsWithIndent(e->body->statements)) {
return false;
}
}
line() << "}";
for (auto* e : stmt->else_statements) {
if (e->condition) {
decrement_indent();
line() << "}";
}
}
return true;
}
bool GeneratorImpl::EmitFunction(const ast::Function* func) {
auto* sem = builder_.Sem().Get(func);
if (ast::HasDecoration<ast::InternalDecoration>(func->decorations)) {
// An internal function. Do not emit.
return true;
}
{
auto out = line();
auto name = builder_.Symbols().NameFor(func->symbol);
// If the function returns an array, then we need to declare a typedef for
// this.
if (sem->ReturnType()->Is<sem::Array>()) {
auto typedef_name = UniqueIdentifier(name + "_ret");
auto pre = line();
pre << "typedef ";
if (!EmitTypeAndName(pre, sem->ReturnType(), ast::StorageClass::kNone,
ast::Access::kReadWrite, typedef_name)) {
return false;
}
pre << ";";
out << typedef_name;
} else {
if (!EmitType(out, sem->ReturnType(), ast::StorageClass::kNone,
ast::Access::kReadWrite, "")) {
return false;
}
}
out << " " << name << "(";
bool first = true;
for (auto* v : sem->Parameters()) {
if (!first) {
out << ", ";
}
first = false;
auto const* type = v->Type();
if (auto* ptr = type->As<sem::Pointer>()) {
// Transform pointer parameters in to `inout` parameters.
// The WGSL spec is highly restrictive in what can be passed in pointer
// parameters, which allows for this transformation. See:
// https://gpuweb.github.io/gpuweb/wgsl/#function-restriction
out << "inout ";
type = ptr->StoreType();
}
// Note: WGSL only allows for StorageClass::kNone on parameters, however
// the sanitizer transforms generates load / store functions for storage
// or uniform buffers. These functions have a buffer parameter with
// StorageClass::kStorage or StorageClass::kUniform. This is required to
// correctly translate the parameter to a [RW]ByteAddressBuffer for
// storage buffers and a uint4[N] for uniform buffers.
if (!EmitTypeAndName(
out, type, v->StorageClass(), v->Access(),
builder_.Symbols().NameFor(v->Declaration()->symbol))) {
return false;
}
}
out << ") {";
}
if (!EmitStatementsWithIndent(func->body->statements)) {
return false;
}
line() << "}";
return true;
}
bool GeneratorImpl::EmitGlobalVariable(const ast::Variable* global) {
if (global->is_const) {
return EmitProgramConstVariable(global);
}
auto* sem = builder_.Sem().Get(global);
switch (sem->StorageClass()) {
case ast::StorageClass::kUniform:
return EmitUniformVariable(sem);
case ast::StorageClass::kStorage:
return EmitStorageVariable(sem);
case ast::StorageClass::kUniformConstant:
return EmitHandleVariable(sem);
case ast::StorageClass::kPrivate:
return EmitPrivateVariable(sem);
case ast::StorageClass::kWorkgroup:
return EmitWorkgroupVariable(sem);
default:
break;
}
TINT_ICE(Writer, diagnostics_)
<< "unhandled storage class " << sem->StorageClass();
return false;
}
bool GeneratorImpl::EmitUniformVariable(const sem::Variable* var) {
auto* decl = var->Declaration();
auto binding_point = decl->BindingPoint();
auto* type = var->Type()->UnwrapRef();
auto* str = type->As<sem::Struct>();
if (!str) {
// https://www.w3.org/TR/WGSL/#module-scope-variables
TINT_ICE(Writer, diagnostics_)
<< "variables with uniform storage must be structure";
}
auto name = builder_.Symbols().NameFor(decl->symbol);
line() << "cbuffer cbuffer_" << name << RegisterAndSpace('b', binding_point)
<< " {";
{
ScopedIndent si(this);
auto out = line();
if (!EmitTypeAndName(out, type, ast::StorageClass::kUniform, var->Access(),
name)) {
return false;
}
out << ";";
}
line() << "};";
return true;
}
bool GeneratorImpl::EmitStorageVariable(const sem::Variable* var) {
auto* decl = var->Declaration();
auto* type = var->Type()->UnwrapRef();
auto out = line();
if (!EmitTypeAndName(out, type, ast::StorageClass::kStorage, var->Access(),
builder_.Symbols().NameFor(decl->symbol))) {
return false;
}
out << RegisterAndSpace(var->Access() == ast::Access::kRead ? 't' : 'u',
decl->BindingPoint())
<< ";";
return true;
}
bool GeneratorImpl::EmitHandleVariable(const sem::Variable* var) {
auto* decl = var->Declaration();
auto* unwrapped_type = var->Type()->UnwrapRef();
auto out = line();
auto name = builder_.Symbols().NameFor(decl->symbol);
auto* type = var->Type()->UnwrapRef();
if (!EmitTypeAndName(out, type, var->StorageClass(), var->Access(), name)) {
return false;
}
const char* register_space = nullptr;
if (unwrapped_type->Is<sem::Texture>()) {
register_space = "t";
if (unwrapped_type->Is<sem::StorageTexture>()) {
register_space = "u";
}
} else if (unwrapped_type->Is<sem::Sampler>()) {
register_space = "s";
}
if (register_space) {
auto bp = decl->BindingPoint();
out << " : register(" << register_space << bp.binding->value << ", space"
<< bp.group->value << ")";
}
out << ";";
return true;
}
bool GeneratorImpl::EmitPrivateVariable(const sem::Variable* var) {
auto* decl = var->Declaration();
auto out = line();
out << "static ";
auto name = builder_.Symbols().NameFor(decl->symbol);
auto* type = var->Type()->UnwrapRef();
if (!EmitTypeAndName(out, type, var->StorageClass(), var->Access(), name)) {
return false;
}
out << " = ";
if (auto* constructor = decl->constructor) {
if (!EmitExpression(out, constructor)) {
return false;
}
} else {
if (!EmitZeroValue(out, var->Type()->UnwrapRef())) {
return false;
}
}
out << ";";
return true;
}
bool GeneratorImpl::EmitWorkgroupVariable(const sem::Variable* var) {
auto* decl = var->Declaration();
auto out = line();
out << "groupshared ";
auto name = builder_.Symbols().NameFor(decl->symbol);
auto* type = var->Type()->UnwrapRef();
if (!EmitTypeAndName(out, type, var->StorageClass(), var->Access(), name)) {
return false;
}
if (auto* constructor = decl->constructor) {
out << " = ";
if (!EmitExpression(out, constructor)) {
return false;
}
}
out << ";";
return true;
}
std::string GeneratorImpl::builtin_to_attribute(ast::Builtin builtin) const {
switch (builtin) {
case ast::Builtin::kPosition:
return "SV_Position";
case ast::Builtin::kVertexIndex:
return "SV_VertexID";
case ast::Builtin::kInstanceIndex:
return "SV_InstanceID";
case ast::Builtin::kFrontFacing:
return "SV_IsFrontFace";
case ast::Builtin::kFragDepth:
return "SV_Depth";
case ast::Builtin::kLocalInvocationId:
return "SV_GroupThreadID";
case ast::Builtin::kLocalInvocationIndex:
return "SV_GroupIndex";
case ast::Builtin::kGlobalInvocationId:
return "SV_DispatchThreadID";
case ast::Builtin::kWorkgroupId:
return "SV_GroupID";
case ast::Builtin::kSampleIndex:
return "SV_SampleIndex";
case ast::Builtin::kSampleMask:
return "SV_Coverage";
default:
break;
}
return "";
}
std::string GeneratorImpl::interpolation_to_modifiers(
ast::InterpolationType type,
ast::InterpolationSampling sampling) const {
std::string modifiers;
switch (type) {
case ast::InterpolationType::kPerspective:
modifiers += "linear ";
break;
case ast::InterpolationType::kLinear:
modifiers += "noperspective ";
break;
case ast::InterpolationType::kFlat:
modifiers += "nointerpolation ";
break;
}
switch (sampling) {
case ast::InterpolationSampling::kCentroid:
modifiers += "centroid ";
break;
case ast::InterpolationSampling::kSample:
modifiers += "sample ";
break;
case ast::InterpolationSampling::kCenter:
case ast::InterpolationSampling::kNone:
break;
}
return modifiers;
}
bool GeneratorImpl::EmitEntryPointFunction(const ast::Function* func) {
auto* func_sem = builder_.Sem().Get(func);
{
auto out = line();
if (func->PipelineStage() == ast::PipelineStage::kCompute) {
// Emit the workgroup_size attribute.
auto wgsize = func_sem->WorkgroupSize();
out << "[numthreads(";
for (int i = 0; i < 3; i++) {
if (i > 0) {
out << ", ";
}
if (wgsize[i].overridable_const) {
auto* global = builder_.Sem().Get<sem::GlobalVariable>(
wgsize[i].overridable_const);
if (!global->IsPipelineConstant()) {
TINT_ICE(Writer, builder_.Diagnostics())
<< "expected a pipeline-overridable constant";
}
out << kSpecConstantPrefix << global->ConstantId();
} else {
out << std::to_string(wgsize[i].value);
}
}
out << ")]" << std::endl;
}
out << func->return_type->FriendlyName(builder_.Symbols());
out << " " << builder_.Symbols().NameFor(func->symbol) << "(";
bool first = true;
// Emit entry point parameters.
for (auto* var : func->params) {
auto* sem = builder_.Sem().Get(var);
auto* type = sem->Type();
if (!type->Is<sem::Struct>()) {
// ICE likely indicates that the CanonicalizeEntryPointIO transform was
// not run, or a builtin parameter was added after it was run.
TINT_ICE(Writer, diagnostics_)
<< "Unsupported non-struct entry point parameter";
}
if (!first) {
out << ", ";
}
first = false;
if (!EmitTypeAndName(out, type, sem->StorageClass(), sem->Access(),
builder_.Symbols().NameFor(var->symbol))) {
return false;
}
}
out << ") {";
}
{
ScopedIndent si(this);
if (!EmitStatements(func->body->statements)) {
return false;
}
if (!Is<ast::ReturnStatement>(func->body->Last())) {
ast::ReturnStatement ret(ProgramID(), Source{});
if (!EmitStatement(&ret)) {
return false;
}
}
}
line() << "}";
return true;
}
bool GeneratorImpl::EmitLiteral(std::ostream& out, const ast::Literal* lit) {
if (auto* l = lit->As<ast::BoolLiteral>()) {
out << (l->value ? "true" : "false");
} else if (auto* fl = lit->As<ast::FloatLiteral>()) {
if (std::isinf(fl->value)) {
out << (fl->value >= 0 ? "asfloat(0x7f800000u)" : "asfloat(0xff800000u)");
} else if (std::isnan(fl->value)) {
out << "asfloat(0x7fc00000u)";
} else {
out << FloatToString(fl->value) << "f";
}
} else if (auto* sl = lit->As<ast::SintLiteral>()) {
out << sl->value;
} else if (auto* ul = lit->As<ast::UintLiteral>()) {
out << ul->value << "u";
} else {
diagnostics_.add_error(diag::System::Writer, "unknown literal type");
return false;
}
return true;
}
bool GeneratorImpl::EmitZeroValue(std::ostream& out, const sem::Type* type) {
if (type->Is<sem::Bool>()) {
out << "false";
} else if (type->Is<sem::F32>()) {
out << "0.0f";
} else if (type->Is<sem::I32>()) {
out << "0";
} else if (type->Is<sem::U32>()) {
out << "0u";
} else if (auto* vec = type->As<sem::Vector>()) {
if (!EmitType(out, type, ast::StorageClass::kNone, ast::Access::kReadWrite,
"")) {
return false;
}
ScopedParen sp(out);
for (uint32_t i = 0; i < vec->Width(); i++) {
if (i != 0) {
out << ", ";
}
if (!EmitZeroValue(out, vec->type())) {
return false;
}
}
} else if (auto* mat = type->As<sem::Matrix>()) {
if (!EmitType(out, type, ast::StorageClass::kNone, ast::Access::kReadWrite,
"")) {
return false;
}
ScopedParen sp(out);
for (uint32_t i = 0; i < (mat->rows() * mat->columns()); i++) {
if (i != 0) {
out << ", ";
}
if (!EmitZeroValue(out, mat->type())) {
return false;
}
}
} else if (type->IsAnyOf<sem::Struct, sem::Array>()) {
out << "(";
if (!EmitType(out, type, ast::StorageClass::kNone, ast::Access::kUndefined,
"")) {
return false;
}
out << ")0";
} else {
diagnostics_.add_error(
diag::System::Writer,
"Invalid type for zero emission: " + type->type_name());
return false;
}
return true;
}
bool GeneratorImpl::EmitLoop(const ast::LoopStatement* stmt) {
auto emit_continuing = [this, stmt]() {
if (stmt->continuing && !stmt->continuing->Empty()) {
if (!EmitBlock(stmt->continuing)) {
return false;
}
}
return true;
};
TINT_SCOPED_ASSIGNMENT(emit_continuing_, emit_continuing);
line() << "while (true) {";
{
ScopedIndent si(this);
if (!EmitStatements(stmt->body->statements)) {
return false;
}
if (!emit_continuing()) {
return false;
}
}
line() << "}";
return true;
}
bool GeneratorImpl::EmitForLoop(const ast::ForLoopStatement* stmt) {
// Nest a for loop with a new block. In HLSL the initializer scope is not
// nested by the for-loop, so we may get variable redefinitions.
line() << "{";
increment_indent();
TINT_DEFER({
decrement_indent();
line() << "}";
});
TextBuffer init_buf;
if (auto* init = stmt->initializer) {
TINT_SCOPED_ASSIGNMENT(current_buffer_, &init_buf);
if (!EmitStatement(init)) {
return false;
}
}
TextBuffer cond_pre;
std::stringstream cond_buf;
if (auto* cond = stmt->condition) {
TINT_SCOPED_ASSIGNMENT(current_buffer_, &cond_pre);
if (!EmitExpression(cond_buf, cond)) {
return false;
}
}
TextBuffer cont_buf;
if (auto* cont = stmt->continuing) {
TINT_SCOPED_ASSIGNMENT(current_buffer_, &cont_buf);
if (!EmitStatement(cont)) {
return false;
}
}
// If the for-loop has a multi-statement conditional and / or continuing, then
// we cannot emit this as a regular for-loop in HLSL. Instead we need to
// generate a `while(true)` loop.
bool emit_as_loop = cond_pre.lines.size() > 0 || cont_buf.lines.size() > 1;
// If the for-loop has multi-statement initializer, or is going to be emitted
// as a `while(true)` loop, then declare the initializer statement(s) before
// the loop.
if (init_buf.lines.size() > 1 || (stmt->initializer && emit_as_loop)) {
current_buffer_->Append(init_buf);
init_buf.lines.clear(); // Don't emit the initializer again in the 'for'
}
if (emit_as_loop) {
auto emit_continuing = [&]() {
current_buffer_->Append(cont_buf);
return true;
};
TINT_SCOPED_ASSIGNMENT(emit_continuing_, emit_continuing);
line() << "while (true) {";
increment_indent();
TINT_DEFER({
decrement_indent();
line() << "}";
});
if (stmt->condition) {
current_buffer_->Append(cond_pre);
line() << "if (!(" << cond_buf.str() << ")) { break; }";
}
if (!EmitStatements(stmt->body->statements)) {
return false;
}
if (!emit_continuing()) {
return false;
}
} else {
// For-loop can be generated.
{
auto out = line();
out << "for";
{
ScopedParen sp(out);
if (!init_buf.lines.empty()) {
out << init_buf.lines[0].content << " ";
} else {
out << "; ";
}
out << cond_buf.str() << "; ";
if (!cont_buf.lines.empty()) {
out << TrimSuffix(cont_buf.lines[0].content, ";");
}
}
out << " {";
}
{
auto emit_continuing = [] { return true; };
TINT_SCOPED_ASSIGNMENT(emit_continuing_, emit_continuing);
if (!EmitStatementsWithIndent(stmt->body->statements)) {
return false;
}
}
line() << "}";
}
return true;
}
bool GeneratorImpl::EmitMemberAccessor(
std::ostream& out,
const ast::MemberAccessorExpression* expr) {
if (!EmitExpression(out, expr->structure)) {
return false;
}
out << ".";
// Swizzles output the name directly
if (builder_.Sem().Get(expr)->Is<sem::Swizzle>()) {
out << builder_.Symbols().NameFor(expr->member->symbol);
} else if (!EmitExpression(out, expr->member)) {
return false;
}
return true;
}
bool GeneratorImpl::EmitReturn(const ast::ReturnStatement* stmt) {
if (stmt->value) {
auto out = line();
out << "return ";
if (!EmitExpression(out, stmt->value)) {
return false;
}
out << ";";
} else {
line() << "return;";
}
return true;
}
bool GeneratorImpl::EmitStatement(const ast::Statement* stmt) {
if (auto* a = stmt->As<ast::AssignmentStatement>()) {
return EmitAssign(a);
}
if (auto* b = stmt->As<ast::BlockStatement>()) {
return EmitBlock(b);
}
if (auto* b = stmt->As<ast::BreakStatement>()) {
return EmitBreak(b);
}
if (auto* c = stmt->As<ast::CallStatement>()) {
auto out = line();
if (!EmitCall(out, c->expr)) {
return false;
}
out << ";";
return true;
}
if (auto* c = stmt->As<ast::ContinueStatement>()) {
return EmitContinue(c);
}
if (auto* d = stmt->As<ast::DiscardStatement>()) {
return EmitDiscard(d);
}
if (stmt->As<ast::FallthroughStatement>()) {
line() << "/* fallthrough */";
return true;
}
if (auto* i = stmt->As<ast::IfStatement>()) {
return EmitIf(i);
}
if (auto* l = stmt->As<ast::LoopStatement>()) {
return EmitLoop(l);
}
if (auto* l = stmt->As<ast::ForLoopStatement>()) {
return EmitForLoop(l);
}
if (auto* r = stmt->As<ast::ReturnStatement>()) {
return EmitReturn(r);
}
if (auto* s = stmt->As<ast::SwitchStatement>()) {
return EmitSwitch(s);
}
if (auto* v = stmt->As<ast::VariableDeclStatement>()) {
return EmitVariable(v->variable);
}
diagnostics_.add_error(
diag::System::Writer,
"unknown statement type: " + std::string(stmt->TypeInfo().name));
return false;
}
bool GeneratorImpl::EmitSwitch(const ast::SwitchStatement* stmt) {
{ // switch(expr) {
auto out = line();
out << "switch(";
if (!EmitExpression(out, stmt->condition)) {
return false;
}
out << ") {";
}
{
ScopedIndent si(this);
for (size_t i = 0; i < stmt->body.size(); i++) {
if (!EmitCase(stmt, i)) {
return false;
}
}
}
line() << "}";
return true;
}
bool GeneratorImpl::EmitType(std::ostream& out,
const sem::Type* type,
ast::StorageClass storage_class,
ast::Access access,
const std::string& name,
bool* name_printed /* = nullptr */) {
if (name_printed) {
*name_printed = false;
}
switch (storage_class) {
case ast::StorageClass::kStorage:
if (access != ast::Access::kRead) {
out << "RW";
}
out << "ByteAddressBuffer";
return true;
case ast::StorageClass::kUniform: {
auto* str = type->As<sem::Struct>();
if (!str) {
// https://www.w3.org/TR/WGSL/#module-scope-variables
TINT_ICE(Writer, diagnostics_)
<< "variables with uniform storage must be structure";
}
auto array_length = (str->Size() + 15) / 16;
out << "uint4 " << name << "[" << array_length << "]";
if (name_printed) {
*name_printed = true;
}
return true;
}
default:
break;
}
if (auto* ary = type->As<sem::Array>()) {
const sem::Type* base_type = ary;
std::vector<uint32_t> sizes;
while (auto* arr = base_type->As<sem::Array>()) {
if (arr->IsRuntimeSized()) {
TINT_ICE(Writer, diagnostics_)
<< "Runtime arrays may only exist in storage buffers, which should "
"have been transformed into a ByteAddressBuffer";
return false;
}
sizes.push_back(arr->Count());
base_type = arr->ElemType();
}
if (!EmitType(out, base_type, storage_class, access, "")) {
return false;
}
if (!name.empty()) {
out << " " << name;
if (name_printed) {
*name_printed = true;
}
}
for (uint32_t size : sizes) {
out << "[" << size << "]";
}
} else if (type->Is<sem::Bool>()) {
out << "bool";
} else if (type->Is<sem::F32>()) {
out << "float";
} else if (type->Is<sem::I32>()) {
out << "int";
} else if (auto* mat = type->As<sem::Matrix>()) {
if (!EmitType(out, mat->type(), storage_class, access, "")) {
return false;
}
// Note: HLSL's matrices are declared as <type>NxM, where N is the number of
// rows and M is the number of columns. Despite HLSL's matrices being
// column-major by default, the index operator and constructors actually
// operate on row-vectors, where as WGSL operates on column vectors.
// To simplify everything we use the transpose of the matrices.
// See:
// https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-per-component-math#matrix-ordering
out << mat->columns() << "x" << mat->rows();
} else if (type->Is<sem::Pointer>()) {
TINT_ICE(Writer, diagnostics_)
<< "Attempting to emit pointer type. These should have been removed "
"with the InlinePointerLets transform";
return false;
} else if (auto* sampler = type->As<sem::Sampler>()) {
out << "Sampler";
if (sampler->IsComparison()) {
out << "Comparison";
}
out << "State";
} else if (auto* str = type->As<sem::Struct>()) {
out << StructName(str);
} else if (auto* tex = type->As<sem::Texture>()) {
auto* storage = tex->As<sem::StorageTexture>();
auto* ms = tex->As<sem::MultisampledTexture>();
auto* depth_ms = tex->As<sem::DepthMultisampledTexture>();
auto* sampled = tex->As<sem::SampledTexture>();
if (storage && storage->access() != ast::Access::kRead) {
out << "RW";
}
out << "Texture";
switch (tex->dim()) {
case ast::TextureDimension::k1d:
out << "1D";
break;
case ast::TextureDimension::k2d:
out << ((ms || depth_ms) ? "2DMS" : "2D");
break;
case ast::TextureDimension::k2dArray:
out << ((ms || depth_ms) ? "2DMSArray" : "2DArray");
break;
case ast::TextureDimension::k3d:
out << "3D";
break;
case ast::TextureDimension::kCube:
out << "Cube";
break;
case ast::TextureDimension::kCubeArray:
out << "CubeArray";
break;
default:
TINT_UNREACHABLE(Writer, diagnostics_)
<< "unexpected TextureDimension " << tex->dim();
return false;
}
if (storage) {
auto* component = image_format_to_rwtexture_type(storage->image_format());
if (component == nullptr) {
TINT_ICE(Writer, diagnostics_)
<< "Unsupported StorageTexture ImageFormat: "
<< static_cast<int>(storage->image_format());
return false;
}
out << "<" << component << ">";
} else if (depth_ms) {
out << "<float4>";
} else if (sampled || ms) {
auto* subtype = sampled ? sampled->type() : ms->type();
out << "<";
if (subtype->Is<sem::F32>()) {
out << "float4";
} else if (subtype->Is<sem::I32>()) {
out << "int4";
} else if (subtype->Is<sem::U32>()) {
out << "uint4";
} else {
TINT_ICE(Writer, diagnostics_)
<< "Unsupported multisampled texture type";
return false;
}
out << ">";
}
} else if (type->Is<sem::U32>()) {
out << "uint";
} else if (auto* vec = type->As<sem::Vector>()) {
auto width = vec->Width();
if (vec->type()->Is<sem::F32>() && width >= 1 && width <= 4) {
out << "float" << width;
} else if (vec->type()->Is<sem::I32>() && width >= 1 && width <= 4) {
out << "int" << width;
} else if (vec->type()->Is<sem::U32>() && width >= 1 && width <= 4) {
out << "uint" << width;
} else if (vec->type()->Is<sem::Bool>() && width >= 1 && width <= 4) {
out << "bool" << width;
} else {
out << "vector<";
if (!EmitType(out, vec->type(), storage_class, access, "")) {
return false;
}
out << ", " << width << ">";
}
} else if (auto* atomic = type->As<sem::Atomic>()) {
if (!EmitType(out, atomic->Type(), storage_class, access, name)) {
return false;
}
} else if (type->Is<sem::Void>()) {
out << "void";
} else {
diagnostics_.add_error(diag::System::Writer, "unknown type in EmitType");
return false;
}
return true;
}
bool GeneratorImpl::EmitTypeAndName(std::ostream& out,
const sem::Type* type,
ast::StorageClass storage_class,
ast::Access access,
const std::string& name) {
bool name_printed = false;
if (!EmitType(out, type, storage_class, access, name, &name_printed)) {
return false;
}
if (!name.empty() && !name_printed) {
out << " " << name;
}
return true;
}
bool GeneratorImpl::EmitStructType(TextBuffer* b, const sem::Struct* str) {
line(b) << "struct " << StructName(str) << " {";
{
ScopedIndent si(b);
for (auto* mem : str->Members()) {
auto name = builder_.Symbols().NameFor(mem->Name());
auto* ty = mem->Type();
auto out = line(b);
std::string pre, post;
if (auto* decl = mem->Declaration()) {
for (auto* deco : decl->decorations) {
if (auto* location = deco->As<ast::LocationDecoration>()) {
auto& pipeline_stage_uses = str->PipelineStageUses();
if (pipeline_stage_uses.size() != 1) {
TINT_ICE(Writer, diagnostics_)
<< "invalid entry point IO struct uses";
}
if (pipeline_stage_uses.count(
sem::PipelineStageUsage::kVertexInput)) {
post += " : TEXCOORD" + std::to_string(location->value);
} else if (pipeline_stage_uses.count(
sem::PipelineStageUsage::kVertexOutput)) {
post += " : TEXCOORD" + std::to_string(location->value);
} else if (pipeline_stage_uses.count(
sem::PipelineStageUsage::kFragmentInput)) {
post += " : TEXCOORD" + std::to_string(location->value);
} else if (pipeline_stage_uses.count(
sem::PipelineStageUsage::kFragmentOutput)) {
post += " : SV_Target" + std::to_string(location->value);
} else {
TINT_ICE(Writer, diagnostics_)
<< "invalid use of location decoration";
}
} else if (auto* builtin = deco->As<ast::BuiltinDecoration>()) {
auto attr = builtin_to_attribute(builtin->builtin);
if (attr.empty()) {
diagnostics_.add_error(diag::System::Writer,
"unsupported builtin");
return false;
}
post += " : " + attr;
} else if (auto* interpolate =
deco->As<ast::InterpolateDecoration>()) {
auto mod = interpolation_to_modifiers(interpolate->type,
interpolate->sampling);
if (mod.empty()) {
diagnostics_.add_error(diag::System::Writer,
"unsupported interpolation");
return false;
}
pre += mod;
} else if (deco->Is<ast::InvariantDecoration>()) {
// Note: `precise` is not exactly the same as `invariant`, but is
// stricter and therefore provides the necessary guarantees.
// See discussion here: https://github.com/gpuweb/gpuweb/issues/893
pre += "precise ";
} else if (!deco->IsAnyOf<ast::StructMemberAlignDecoration,
ast::StructMemberOffsetDecoration,
ast::StructMemberSizeDecoration>()) {
TINT_ICE(Writer, diagnostics_)
<< "unhandled struct member attribute: " << deco->Name();
return false;
}
}
}
out << pre;
if (!EmitTypeAndName(out, ty, ast::StorageClass::kNone,
ast::Access::kReadWrite, name)) {
return false;
}
out << post << ";";
}
}
line(b) << "};";
return true;
}
bool GeneratorImpl::EmitUnaryOp(std::ostream& out,
const ast::UnaryOpExpression* expr) {
switch (expr->op) {
case ast::UnaryOp::kIndirection:
case ast::UnaryOp::kAddressOf:
return EmitExpression(out, expr->expr);
case ast::UnaryOp::kComplement:
out << "~";
break;
case ast::UnaryOp::kNot:
out << "!";
break;
case ast::UnaryOp::kNegation:
out << "-";
break;
}
out << "(";
if (!EmitExpression(out, expr->expr)) {
return false;
}
out << ")";
return true;
}
bool GeneratorImpl::EmitVariable(const ast::Variable* var) {
auto* sem = builder_.Sem().Get(var);
auto* type = sem->Type()->UnwrapRef();
// TODO(dsinclair): Handle variable decorations
if (!var->decorations.empty()) {
diagnostics_.add_error(diag::System::Writer,
"Variable decorations are not handled yet");
return false;
}
auto out = line();
if (var->is_const) {
out << "const ";
}
if (!EmitTypeAndName(out, type, sem->StorageClass(), sem->Access(),
builder_.Symbols().NameFor(var->symbol))) {
return false;
}
out << " = ";
if (var->constructor) {
if (!EmitExpression(out, var->constructor)) {
return false;
}
} else {
if (!EmitZeroValue(out, type)) {
return false;
}
}
out << ";";
return true;
}
bool GeneratorImpl::EmitProgramConstVariable(const ast::Variable* var) {
for (auto* d : var->decorations) {
if (!d->Is<ast::OverrideDecoration>()) {
diagnostics_.add_error(diag::System::Writer,
"Decorated const values not valid");
return false;
}
}
if (!var->is_const) {
diagnostics_.add_error(diag::System::Writer, "Expected a const value");
return false;
}
auto* sem = builder_.Sem().Get(var);
auto* type = sem->Type();
auto* global = sem->As<sem::GlobalVariable>();
if (global && global->IsPipelineConstant()) {
auto const_id = global->ConstantId();
line() << "#ifndef " << kSpecConstantPrefix << const_id;
if (var->constructor != nullptr) {
auto out = line();
out << "#define " << kSpecConstantPrefix << const_id << " ";
if (!EmitExpression(out, var->constructor)) {
return false;
}
} else {
line() << "#error spec constant required for constant id " << const_id;
}
line() << "#endif";
{
auto out = line();
out << "static const ";
if (!EmitTypeAndName(out, type, sem->StorageClass(), sem->Access(),
builder_.Symbols().NameFor(var->symbol))) {
return false;
}
out << " = " << kSpecConstantPrefix << const_id << ";";
}
} else {
auto out = line();
out << "static const ";
if (!EmitTypeAndName(out, type, sem->StorageClass(), sem->Access(),
builder_.Symbols().NameFor(var->symbol))) {
return false;
}
out << " = ";
if (!EmitExpression(out, var->constructor)) {
return false;
}
out << ";";
}
return true;
}
template <typename F>
bool GeneratorImpl::CallIntrinsicHelper(std::ostream& out,
const ast::CallExpression* call,
const sem::Intrinsic* intrinsic,
F&& build) {
// Generate the helper function if it hasn't been created already
auto fn = utils::GetOrCreate(intrinsics_, intrinsic, [&]() -> std::string {
TextBuffer b;
TINT_DEFER(helpers_.Append(b));
auto fn_name =
UniqueIdentifier(std::string("tint_") + sem::str(intrinsic->Type()));
std::vector<std::string> parameter_names;
{
auto decl = line(&b);
if (!EmitTypeAndName(decl, intrinsic->ReturnType(),
ast::StorageClass::kNone, ast::Access::kUndefined,
fn_name)) {
return "";
}
{
ScopedParen sp(decl);
for (auto* param : intrinsic->Parameters()) {
if (!parameter_names.empty()) {
decl << ", ";
}
auto param_name = "param_" + std::to_string(parameter_names.size());
const auto* ty = param->Type();
if (auto* ptr = ty->As<sem::Pointer>()) {
decl << "inout ";
ty = ptr->StoreType();
}
if (!EmitTypeAndName(decl, ty, ast::StorageClass::kNone,
ast::Access::kUndefined, param_name)) {
return "";
}
parameter_names.emplace_back(std::move(param_name));
}
}
decl << " {";
}
{
ScopedIndent si(&b);
if (!build(&b, parameter_names)) {
return "";
}
}
line(&b) << "}";
line(&b);
return fn_name;
});
if (fn.empty()) {
return false;
}
// Call the helper
out << fn;
{
ScopedParen sp(out);
bool first = true;
for (auto* arg : call->args) {
if (!first) {
out << ", ";
}
first = false;
if (!EmitExpression(out, arg)) {
return false;
}
}
}
return true;
}
} // namespace hlsl
} // namespace writer
} // namespace tint