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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/tint/lang/hlsl/writer/ast_printer/ast_printer.h"
#include <algorithm>
#include <cmath>
#include <functional>
#include <iomanip>
#include <set>
#include <utility>
#include <vector>
#include "src/tint/lang/core/constant/splat.h"
#include "src/tint/lang/core/constant/value.h"
#include "src/tint/lang/core/fluent_types.h"
#include "src/tint/lang/core/type/array.h"
#include "src/tint/lang/core/type/atomic.h"
#include "src/tint/lang/core/type/depth_multisampled_texture.h"
#include "src/tint/lang/core/type/depth_texture.h"
#include "src/tint/lang/core/type/multisampled_texture.h"
#include "src/tint/lang/core/type/sampled_texture.h"
#include "src/tint/lang/core/type/storage_texture.h"
#include "src/tint/lang/core/type/texture_dimension.h"
#include "src/tint/lang/hlsl/writer/ast_raise/calculate_array_length.h"
#include "src/tint/lang/hlsl/writer/ast_raise/decompose_memory_access.h"
#include "src/tint/lang/hlsl/writer/ast_raise/localize_struct_array_assignment.h"
#include "src/tint/lang/hlsl/writer/ast_raise/num_workgroups_from_uniform.h"
#include "src/tint/lang/hlsl/writer/ast_raise/remove_continue_in_switch.h"
#include "src/tint/lang/hlsl/writer/ast_raise/truncate_interstage_variables.h"
#include "src/tint/lang/wgsl/ast/call_statement.h"
#include "src/tint/lang/wgsl/ast/id_attribute.h"
#include "src/tint/lang/wgsl/ast/internal_attribute.h"
#include "src/tint/lang/wgsl/ast/interpolate_attribute.h"
#include "src/tint/lang/wgsl/ast/transform/add_empty_entry_point.h"
#include "src/tint/lang/wgsl/ast/transform/array_length_from_uniform.h"
#include "src/tint/lang/wgsl/ast/transform/binding_remapper.h"
#include "src/tint/lang/wgsl/ast/transform/builtin_polyfill.h"
#include "src/tint/lang/wgsl/ast/transform/canonicalize_entry_point_io.h"
#include "src/tint/lang/wgsl/ast/transform/demote_to_helper.h"
#include "src/tint/lang/wgsl/ast/transform/direct_variable_access.h"
#include "src/tint/lang/wgsl/ast/transform/disable_uniformity_analysis.h"
#include "src/tint/lang/wgsl/ast/transform/expand_compound_assignment.h"
#include "src/tint/lang/wgsl/ast/transform/manager.h"
#include "src/tint/lang/wgsl/ast/transform/multiplanar_external_texture.h"
#include "src/tint/lang/wgsl/ast/transform/promote_initializers_to_let.h"
#include "src/tint/lang/wgsl/ast/transform/promote_side_effects_to_decl.h"
#include "src/tint/lang/wgsl/ast/transform/remove_phonies.h"
#include "src/tint/lang/wgsl/ast/transform/robustness.h"
#include "src/tint/lang/wgsl/ast/transform/simplify_pointers.h"
#include "src/tint/lang/wgsl/ast/transform/unshadow.h"
#include "src/tint/lang/wgsl/ast/transform/vectorize_scalar_matrix_initializers.h"
#include "src/tint/lang/wgsl/ast/transform/zero_init_workgroup_memory.h"
#include "src/tint/lang/wgsl/ast/variable_decl_statement.h"
#include "src/tint/lang/wgsl/helpers/append_vector.h"
#include "src/tint/lang/wgsl/helpers/check_supported_extensions.h"
#include "src/tint/lang/wgsl/sem/block_statement.h"
#include "src/tint/lang/wgsl/sem/call.h"
#include "src/tint/lang/wgsl/sem/function.h"
#include "src/tint/lang/wgsl/sem/member_accessor_expression.h"
#include "src/tint/lang/wgsl/sem/module.h"
#include "src/tint/lang/wgsl/sem/statement.h"
#include "src/tint/lang/wgsl/sem/struct.h"
#include "src/tint/lang/wgsl/sem/switch_statement.h"
#include "src/tint/lang/wgsl/sem/value_constructor.h"
#include "src/tint/lang/wgsl/sem/value_conversion.h"
#include "src/tint/lang/wgsl/sem/variable.h"
#include "src/tint/utils/containers/map.h"
#include "src/tint/utils/ice/ice.h"
#include "src/tint/utils/macros/compiler.h"
#include "src/tint/utils/macros/defer.h"
#include "src/tint/utils/macros/scoped_assignment.h"
#include "src/tint/utils/rtti/switch.h"
#include "src/tint/utils/strconv/float_to_string.h"
#include "src/tint/utils/text/string.h"
#include "src/tint/utils/text/string_stream.h"
using namespace tint::core::number_suffixes; // NOLINT
using namespace tint::core::fluent_types; // NOLINT
namespace tint::hlsl::writer {
namespace {
const char kTempNamePrefix[] = "tint_tmp";
const char* image_format_to_rwtexture_type(core::TexelFormat image_format) {
switch (image_format) {
case core::TexelFormat::kBgra8Unorm:
case core::TexelFormat::kRgba8Unorm:
case core::TexelFormat::kRgba8Snorm:
case core::TexelFormat::kRgba16Float:
case core::TexelFormat::kR32Float:
case core::TexelFormat::kRg32Float:
case core::TexelFormat::kRgba32Float:
return "float4";
case core::TexelFormat::kRgba8Uint:
case core::TexelFormat::kRgba16Uint:
case core::TexelFormat::kR32Uint:
case core::TexelFormat::kRg32Uint:
case core::TexelFormat::kRgba32Uint:
return "uint4";
case core::TexelFormat::kRgba8Sint:
case core::TexelFormat::kRgba16Sint:
case core::TexelFormat::kR32Sint:
case core::TexelFormat::kRg32Sint:
case core::TexelFormat::kRgba32Sint:
return "int4";
default:
return nullptr;
}
}
void PrintF32(StringStream& out, float value) {
if (std::isinf(value)) {
out << "0.0f " << (value >= 0 ? "/* inf */" : "/* -inf */");
} else if (std::isnan(value)) {
out << "0.0f /* nan */";
} else {
out << tint::writer::FloatToString(value) << "f";
}
}
void PrintF16(StringStream& out, float value) {
if (std::isinf(value)) {
out << "0.0h " << (value >= 0 ? "/* inf */" : "/* -inf */");
} else if (std::isnan(value)) {
out << "0.0h /* nan */";
} else {
out << tint::writer::FloatToString(value) << "h";
}
}
// 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, BindingPoint bp) : reg(r), binding_point(bp) {}
const char reg;
BindingPoint const binding_point;
};
StringStream& operator<<(StringStream& s, const RegisterAndSpace& rs) {
s << " : register(" << rs.reg << rs.binding_point.binding;
// Omit the space if it's 0, as it's the default.
// SM 5.0 doesn't support spaces, so we don't emit them if group is 0 for better compatibility.
if (rs.binding_point.group == 0) {
s << ")";
} else {
s << ", space" << rs.binding_point.group << ")";
}
return s;
}
} // namespace
SanitizedResult::SanitizedResult() = default;
SanitizedResult::~SanitizedResult() = default;
SanitizedResult::SanitizedResult(SanitizedResult&&) = default;
SanitizedResult Sanitize(const Program* in, const Options& options) {
ast::transform::Manager manager;
ast::transform::DataMap data;
manager.Add<ast::transform::DisableUniformityAnalysis>();
// ExpandCompoundAssignment must come before BuiltinPolyfill
manager.Add<ast::transform::ExpandCompoundAssignment>();
manager.Add<ast::transform::Unshadow>(); // Must come before DirectVariableAccess
// LocalizeStructArrayAssignment must come after:
// * SimplifyPointers, because it assumes assignment to arrays in structs are
// done directly, not indirectly.
// TODO(crbug.com/tint/1340): See if we can get rid of the duplicate
// SimplifyPointers transform. Can't do it right now because
// LocalizeStructArrayAssignment introduces pointers.
manager.Add<ast::transform::SimplifyPointers>();
manager.Add<LocalizeStructArrayAssignment>();
manager.Add<ast::transform::PromoteSideEffectsToDecl>();
if (!options.disable_robustness) {
// Robustness must come after PromoteSideEffectsToDecl
// Robustness must come before BuiltinPolyfill and CanonicalizeEntryPointIO
manager.Add<ast::transform::Robustness>();
ast::transform::Robustness::Config config = {};
config.bindings_ignored = std::unordered_set<BindingPoint>(
options.binding_points_ignored_in_robustness_transform.cbegin(),
options.binding_points_ignored_in_robustness_transform.cend());
// Direct3D guarantees to return zero for any resource that is accessed out of bounds, and
// according to the description of the assembly store_uav_typed, out of bounds addressing
// means nothing gets written to memory.
config.texture_action = ast::transform::Robustness::Action::kIgnore;
data.Add<ast::transform::Robustness::Config>(config);
}
// Note: it is more efficient for MultiplanarExternalTexture to come after Robustness
data.Add<ast::transform::MultiplanarExternalTexture::NewBindingPoints>(
options.external_texture_options.bindings_map);
manager.Add<ast::transform::MultiplanarExternalTexture>();
// BindingRemapper must come after MultiplanarExternalTexture
manager.Add<ast::transform::BindingRemapper>();
data.Add<ast::transform::BindingRemapper::Remappings>(
options.binding_remapper_options.binding_points,
options.binding_remapper_options.access_controls,
options.binding_remapper_options.allow_collisions);
{ // Builtin polyfills
ast::transform::BuiltinPolyfill::Builtins polyfills;
polyfills.acosh = ast::transform::BuiltinPolyfill::Level::kFull;
polyfills.asinh = true;
polyfills.atanh = ast::transform::BuiltinPolyfill::Level::kFull;
polyfills.bitshift_modulo = true;
polyfills.clamp_int = true;
// TODO(crbug.com/tint/1449): Some of these can map to HLSL's `firstbitlow`
// and `firstbithigh`.
polyfills.conv_f32_to_iu32 = true;
polyfills.count_leading_zeros = true;
polyfills.count_trailing_zeros = true;
polyfills.extract_bits = ast::transform::BuiltinPolyfill::Level::kFull;
polyfills.first_leading_bit = true;
polyfills.first_trailing_bit = true;
polyfills.insert_bits = ast::transform::BuiltinPolyfill::Level::kFull;
polyfills.int_div_mod = true;
polyfills.precise_float_mod = true;
polyfills.reflect_vec2_f32 = options.polyfill_reflect_vec2_f32;
polyfills.texture_sample_base_clamp_to_edge_2d_f32 = true;
polyfills.workgroup_uniform_load = true;
data.Add<ast::transform::BuiltinPolyfill::Config>(polyfills);
manager.Add<ast::transform::BuiltinPolyfill>(); // Must come before DirectVariableAccess
}
manager.Add<ast::transform::DirectVariableAccess>();
if (!options.disable_workgroup_init) {
// ZeroInitWorkgroupMemory must come before CanonicalizeEntryPointIO as
// ZeroInitWorkgroupMemory may inject new builtin parameters.
manager.Add<ast::transform::ZeroInitWorkgroupMemory>();
}
// CanonicalizeEntryPointIO must come after Robustness
manager.Add<ast::transform::CanonicalizeEntryPointIO>();
if (options.truncate_interstage_variables) {
// When interstage_locations is empty, it means there's no user-defined interstage variables
// being used in the next stage. Still, HLSL compiler register mismatch could happen, if
// there's builtin inputs used in the next stage. So we still run
// TruncateInterstageVariables transform.
// TruncateInterstageVariables itself will skip when interstage_locations matches exactly
// with the current stage output.
// Build the config for internal TruncateInterstageVariables transform.
TruncateInterstageVariables::Config truncate_interstage_variables_cfg;
truncate_interstage_variables_cfg.interstage_locations =
std::move(options.interstage_locations);
manager.Add<TruncateInterstageVariables>();
data.Add<TruncateInterstageVariables::Config>(std::move(truncate_interstage_variables_cfg));
}
// 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<NumWorkgroupsFromUniform>();
manager.Add<ast::transform::VectorizeScalarMatrixInitializers>();
manager.Add<ast::transform::SimplifyPointers>();
manager.Add<ast::transform::RemovePhonies>();
// Build the config for the internal ArrayLengthFromUniform transform.
auto& array_length_from_uniform = options.array_length_from_uniform;
ast::transform::ArrayLengthFromUniform::Config array_length_from_uniform_cfg(
array_length_from_uniform.ubo_binding);
array_length_from_uniform_cfg.bindpoint_to_size_index =
array_length_from_uniform.bindpoint_to_size_index;
// DemoteToHelper must come after CanonicalizeEntryPointIO, PromoteSideEffectsToDecl, and
// ExpandCompoundAssignment.
// TODO(crbug.com/tint/1752): This is only necessary when FXC is being used.
manager.Add<ast::transform::DemoteToHelper>();
// ArrayLengthFromUniform must come after SimplifyPointers as it assumes that the form of the
// array length argument is &var.array.
manager.Add<ast::transform::ArrayLengthFromUniform>();
data.Add<ast::transform::ArrayLengthFromUniform::Config>(
std::move(array_length_from_uniform_cfg));
// DecomposeMemoryAccess must come after:
// * SimplifyPointers, as we cannot take the address of calls to
// DecomposeMemoryAccess::Intrinsic and 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<DecomposeMemoryAccess>();
// CalculateArrayLength must come after DecomposeMemoryAccess, as
// DecomposeMemoryAccess special-cases the arrayLength() intrinsic, which
// will be transformed by CalculateArrayLength
manager.Add<CalculateArrayLength>();
manager.Add<ast::transform::PromoteInitializersToLet>();
manager.Add<RemoveContinueInSwitch>();
manager.Add<ast::transform::AddEmptyEntryPoint>();
data.Add<ast::transform::CanonicalizeEntryPointIO::Config>(
ast::transform::CanonicalizeEntryPointIO::ShaderStyle::kHlsl);
data.Add<NumWorkgroupsFromUniform::Config>(options.root_constant_binding_point);
SanitizedResult result;
ast::transform::DataMap outputs;
result.program = manager.Run(in, data, outputs);
if (auto* res = outputs.Get<ast::transform::ArrayLengthFromUniform::Result>()) {
result.used_array_length_from_uniform_indices = std::move(res->used_size_indices);
}
return result;
}
ASTPrinter::ASTPrinter(const Program* program) : builder_(ProgramBuilder::Wrap(program)) {}
ASTPrinter::~ASTPrinter() = default;
bool ASTPrinter::Generate() {
if (!tint::writer::CheckSupportedExtensions(
"HLSL", builder_.AST(), diagnostics_,
Vector{
wgsl::Extension::kChromiumDisableUniformityAnalysis,
wgsl::Extension::kChromiumExperimentalDp4A,
wgsl::Extension::kChromiumExperimentalFullPtrParameters,
wgsl::Extension::kChromiumExperimentalPushConstant,
wgsl::Extension::kChromiumExperimentalReadWriteStorageTexture,
wgsl::Extension::kChromiumExperimentalSubgroups,
wgsl::Extension::kF16,
wgsl::Extension::kChromiumInternalDualSourceBlending,
})) {
return false;
}
const tint::TypeInfo* last_kind = nullptr;
size_t last_padding_line = 0;
auto* mod = builder_.Sem().Module();
for (auto* decl : mod->DependencyOrderedDeclarations()) {
if (decl->IsAnyOf<ast::Alias, ast::DiagnosticDirective, ast::Enable, ast::ConstAssert>()) {
continue; // These are not emitted.
}
// 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;
bool ok = Switch(
decl,
[&](const ast::Variable* global) { //
return EmitGlobalVariable(global);
},
[&](const ast::Struct* str) {
auto* ty = builder_.Sem().Get(str);
auto address_space_uses = ty->AddressSpaceUsage();
if (address_space_uses.size() !=
(address_space_uses.count(core::AddressSpace::kStorage) +
address_space_uses.count(core::AddressSpace::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.
return EmitStructType(current_buffer_, ty);
}
return true;
},
[&](const ast::Function* func) {
if (func->IsEntryPoint()) {
return EmitEntryPointFunction(func);
}
return EmitFunction(func);
},
[&](Default) {
TINT_ICE() << "unhandled module-scope declaration: " << decl->TypeInfo().name;
return false;
});
if (!ok) {
return false;
}
}
if (!helpers_.lines.empty()) {
current_buffer_->Insert(helpers_, 0, 0);
}
return true;
}
bool ASTPrinter::EmitDynamicVectorAssignment(const ast::AssignmentStatement* stmt,
const core::type::Vector* vec) {
auto name = tint::GetOrCreate(dynamic_vector_write_, vec, [&]() -> std::string {
std::string fn;
{
StringStream ss;
if (!EmitType(ss, vec, tint::core::AddressSpace::kUndefined, core::Access::kUndefined,
"")) {
return "";
}
fn = UniqueIdentifier("set_" + ss.str());
}
{
auto out = Line(&helpers_);
out << "void " << fn << "(inout ";
if (!EmitTypeAndName(out, vec, core::AddressSpace::kUndefined, core::Access::kUndefined,
"vec")) {
return "";
}
out << ", int idx, ";
if (!EmitTypeAndName(out, vec->type(), core::AddressSpace::kUndefined,
core::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() << "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::IndexAccessorExpression>();
auto out = Line();
out << name << "(";
if (!EmitExpression(out, ast_access_expr->object)) {
return false;
}
out << ", ";
if (!EmitExpression(out, ast_access_expr->index)) {
return false;
}
out << ", ";
if (!EmitExpression(out, stmt->rhs)) {
return false;
}
out << ");";
return true;
}
bool ASTPrinter::EmitDynamicMatrixVectorAssignment(const ast::AssignmentStatement* stmt,
const core::type::Matrix* mat) {
auto name = tint::GetOrCreate(dynamic_matrix_vector_write_, mat, [&]() -> std::string {
std::string fn;
{
StringStream ss;
if (!EmitType(ss, mat, tint::core::AddressSpace::kUndefined, core::Access::kUndefined,
"")) {
return "";
}
fn = UniqueIdentifier("set_vector_" + ss.str());
}
{
auto out = Line(&helpers_);
out << "void " << fn << "(inout ";
if (!EmitTypeAndName(out, mat, core::AddressSpace::kUndefined, core::Access::kUndefined,
"mat")) {
return "";
}
out << ", int col, ";
if (!EmitTypeAndName(out, mat->ColumnType(), core::AddressSpace::kUndefined,
core::Access::kUndefined, "val")) {
return "";
}
out << ") {";
}
{
ScopedIndent si(&helpers_);
Line(&helpers_) << "switch (col) {";
{
ScopedIndent si2(&helpers_);
for (uint32_t i = 0; i < mat->columns(); ++i) {
Line(&helpers_) << "case " << i << ": mat[" << i << "] = val; break;";
}
}
Line(&helpers_) << "}";
}
Line(&helpers_) << "}";
Line(&helpers_);
return fn;
});
if (name.empty()) {
return false;
}
auto* ast_access_expr = stmt->lhs->As<ast::IndexAccessorExpression>();
auto out = Line();
out << name << "(";
if (!EmitExpression(out, ast_access_expr->object)) {
return false;
}
out << ", ";
if (!EmitExpression(out, ast_access_expr->index)) {
return false;
}
out << ", ";
if (!EmitExpression(out, stmt->rhs)) {
return false;
}
out << ");";
return true;
}
bool ASTPrinter::EmitDynamicMatrixScalarAssignment(const ast::AssignmentStatement* stmt,
const core::type::Matrix* mat) {
auto* lhs_row_access = stmt->lhs->As<ast::IndexAccessorExpression>();
auto* lhs_col_access = lhs_row_access->object->As<ast::IndexAccessorExpression>();
auto name = tint::GetOrCreate(dynamic_matrix_scalar_write_, mat, [&]() -> std::string {
std::string fn;
{
StringStream ss;
if (!EmitType(ss, mat, tint::core::AddressSpace::kUndefined, core::Access::kUndefined,
"")) {
return "";
}
fn = UniqueIdentifier("set_scalar_" + ss.str());
}
{
auto out = Line(&helpers_);
out << "void " << fn << "(inout ";
if (!EmitTypeAndName(out, mat, core::AddressSpace::kUndefined, core::Access::kUndefined,
"mat")) {
return "";
}
out << ", int col, int row, ";
if (!EmitTypeAndName(out, mat->type(), core::AddressSpace::kUndefined,
core::Access::kUndefined, "val")) {
return "";
}
out << ") {";
}
{
ScopedIndent si(&helpers_);
Line(&helpers_) << "switch (col) {";
{
ScopedIndent si2(&helpers_);
for (uint32_t i = 0; i < mat->columns(); ++i) {
Line(&helpers_) << "case " << i << ":";
{
auto vec_name = "mat[" + std::to_string(i) + "]";
ScopedIndent si3(&helpers_);
{
auto out = Line(&helpers_);
switch (mat->rows()) {
case 2:
out << vec_name
<< " = (row.xx == int2(0, 1)) ? val.xx : " << vec_name
<< ";";
break;
case 3:
out << vec_name
<< " = (row.xxx == int3(0, 1, 2)) ? val.xxx : " << vec_name
<< ";";
break;
case 4:
out << vec_name
<< " = (row.xxxx == int4(0, 1, 2, 3)) ? val.xxxx : "
<< vec_name << ";";
break;
default: {
auto* vec = TypeOf(lhs_row_access->object)
->UnwrapRef()
->As<core::type::Vector>();
TINT_UNREACHABLE() << "invalid vector size " << vec->Width();
break;
}
}
}
Line(&helpers_) << "break;";
}
}
}
Line(&helpers_) << "}";
}
Line(&helpers_) << "}";
Line(&helpers_);
return fn;
});
if (name.empty()) {
return false;
}
auto out = Line();
out << name << "(";
if (!EmitExpression(out, lhs_col_access->object)) {
return false;
}
out << ", ";
if (!EmitExpression(out, lhs_col_access->index)) {
return false;
}
out << ", ";
if (!EmitExpression(out, lhs_row_access->index)) {
return false;
}
out << ", ";
if (!EmitExpression(out, stmt->rhs)) {
return false;
}
out << ");";
return true;
}
bool ASTPrinter::EmitIndexAccessor(StringStream& out, const ast::IndexAccessorExpression* expr) {
if (!EmitExpression(out, expr->object)) {
return false;
}
out << "[";
if (!EmitExpression(out, expr->index)) {
return false;
}
out << "]";
return true;
}
bool ASTPrinter::EmitBitcast(StringStream& out, const ast::BitcastExpression* expr) {
auto* dst_type = TypeOf(expr)->UnwrapRef();
auto* src_type = TypeOf(expr->expr)->UnwrapRef();
auto* src_el_type = src_type->DeepestElement();
auto* dst_el_type = dst_type->DeepestElement();
if (!dst_el_type->is_integer_scalar() && !dst_el_type->is_float_scalar()) {
diagnostics_.add_error(diag::System::Writer,
"Unable to do bitcast to type " + dst_el_type->FriendlyName());
return false;
}
// Handle identity bitcast.
if (src_type == dst_type) {
return EmitExpression(out, expr->expr);
}
// Handle the f16 types using polyfill functions
if (src_el_type->Is<core::type::F16>() || dst_el_type->Is<core::type::F16>()) {
auto f16_bitcast_polyfill = [&]() {
if (src_el_type->Is<core::type::F16>()) {
// Source type must be vec2<f16> or vec4<f16>, since type f16 and vec3<f16> can only
// have identity bitcast.
auto* src_vec = src_type->As<core::type::Vector>();
TINT_ASSERT(src_vec);
TINT_ASSERT(((src_vec->Width() == 2u) || (src_vec->Width() == 4u)));
// Bitcast f16 types to others by converting the given f16 value to f32 and call
// f32tof16 to get the bits. This should be safe, because the convertion is precise
// for finite and infinite f16 value as they are exactly representable by f32, and
// WGSL spec allow any result if f16 value is NaN.
return tint::GetOrCreate(
bitcast_funcs_, BinaryType{{src_type, dst_type}}, [&]() -> std::string {
TextBuffer b;
TINT_DEFER(helpers_.Append(b));
auto fn_name = UniqueIdentifier(std::string("tint_bitcast_from_f16"));
{
auto decl = Line(&b);
if (!EmitTypeAndName(decl, dst_type, core::AddressSpace::kUndefined,
core::Access::kUndefined, fn_name)) {
return "";
}
{
ScopedParen sp(decl);
if (!EmitTypeAndName(decl, src_type, core::AddressSpace::kUndefined,
core::Access::kUndefined, "src")) {
return "";
}
}
decl << " {";
}
{
ScopedIndent si(&b);
{
Line(&b) << "uint" << src_vec->Width() << " r = f32tof16(float"
<< src_vec->Width() << "(src));";
{
auto s = Line(&b);
s << "return as";
if (!EmitType(s, dst_el_type, core::AddressSpace::kUndefined,
core::Access::kReadWrite, "")) {
return "";
}
s << "(";
switch (src_vec->Width()) {
case 2: {
s << "uint((r.x & 0xffff) | ((r.y & 0xffff) << 16))";
break;
}
case 4: {
s << "uint2((r.x & 0xffff) | ((r.y & 0xffff) << 16), "
"(r.z & 0xffff) | ((r.w & 0xffff) << 16))";
break;
}
}
s << ");";
}
}
}
Line(&b) << "}";
Line(&b);
return fn_name;
});
} else {
// Destination type must be vec2<f16> or vec4<f16>.
auto* dst_vec = dst_type->As<core::type::Vector>();
TINT_ASSERT((dst_vec && ((dst_vec->Width() == 2u) || (dst_vec->Width() == 4u)) &&
dst_el_type->Is<core::type::F16>()));
// Source type must be f32/i32/u32 or vec2<f32/i32/u32>.
auto* src_vec = src_type->As<core::type::Vector>();
TINT_ASSERT(
(src_type->IsAnyOf<core::type::I32, core::type::U32, core::type::F32>() ||
(src_vec && src_vec->Width() == 2u &&
src_el_type->IsAnyOf<core::type::I32, core::type::U32, core::type::F32>())));
std::string src_type_suffix = (src_vec ? "2" : "");
// Bitcast other types to f16 types by reinterpreting their bits as f16 using
// f16tof32, and convert the result f32 to f16. This should be safe, because the
// convertion is precise for finite and infinite f16 result value as they are
// exactly representable by f32, and WGSL spec allow any result if f16 result value
// would be NaN.
return tint::GetOrCreate(
bitcast_funcs_, BinaryType{{src_type, dst_type}}, [&]() -> std::string {
TextBuffer b;
TINT_DEFER(helpers_.Append(b));
auto fn_name = UniqueIdentifier(std::string("tint_bitcast_to_f16"));
{
auto decl = Line(&b);
if (!EmitTypeAndName(decl, dst_type, core::AddressSpace::kUndefined,
core::Access::kUndefined, fn_name)) {
return "";
}
{
ScopedParen sp(decl);
if (!EmitTypeAndName(decl, src_type, core::AddressSpace::kUndefined,
core::Access::kUndefined, "src")) {
return "";
}
}
decl << " {";
}
{
ScopedIndent si(&b);
{
// Convert the source to uint for f16tof32.
Line(&b) << "uint" << src_type_suffix << " v = asuint(src);";
// Reinterprete the low 16 bits and high 16 bits
Line(&b) << "float" << src_type_suffix
<< " t_low = f16tof32(v & 0xffff);";
Line(&b) << "float" << src_type_suffix
<< " t_high = f16tof32((v >> 16) & 0xffff);";
// Construct the result f16 vector
{
auto s = Line(&b);
s << "return ";
if (!EmitType(s, dst_type, core::AddressSpace::kUndefined,
core::Access::kReadWrite, "")) {
return "";
}
s << "(";
switch (dst_vec->Width()) {
case 2: {
s << "t_low.x, t_high.x";
break;
}
case 4: {
s << "t_low.x, t_high.x, t_low.y, t_high.y";
break;
}
}
s << ");";
}
}
}
Line(&b) << "}";
Line(&b);
return fn_name;
});
}
};
// Get or create the polyfill
auto fn = f16_bitcast_polyfill();
if (fn.empty()) {
return false;
}
// Call the polyfill
out << fn;
{
ScopedParen sp(out);
if (!EmitExpression(out, expr->expr)) {
return false;
}
}
return true;
}
// Otherwise, bitcasting between non-f16 types.
TINT_ASSERT((!src_el_type->Is<core::type::F16>() && !dst_el_type->Is<core::type::F16>()));
out << "as";
if (!EmitType(out, dst_el_type, core::AddressSpace::kUndefined, core::Access::kReadWrite, "")) {
return false;
}
out << "(";
if (!EmitExpression(out, expr->expr)) {
return false;
}
out << ")";
return true;
}
bool ASTPrinter::EmitAssign(const ast::AssignmentStatement* stmt) {
if (auto* lhs_access = stmt->lhs->As<ast::IndexAccessorExpression>()) {
// BUG(crbug.com/tint/1333): work around assignment of scalar to matrices
// with at least one dynamic index
if (auto* lhs_sub_access = lhs_access->object->As<ast::IndexAccessorExpression>()) {
if (auto* mat = TypeOf(lhs_sub_access->object)->UnwrapRef()->As<core::type::Matrix>()) {
auto* rhs_row_idx_sem = builder_.Sem().GetVal(lhs_access->index);
auto* rhs_col_idx_sem = builder_.Sem().GetVal(lhs_sub_access->index);
if (!rhs_row_idx_sem->ConstantValue() || !rhs_col_idx_sem->ConstantValue()) {
return EmitDynamicMatrixScalarAssignment(stmt, mat);
}
}
}
// BUG(crbug.com/tint/1333): work around assignment of vector to matrices
// with dynamic indices
const auto* lhs_access_type = TypeOf(lhs_access->object)->UnwrapRef();
if (auto* mat = lhs_access_type->As<core::type::Matrix>()) {
auto* lhs_index_sem = builder_.Sem().GetVal(lhs_access->index);
if (!lhs_index_sem->ConstantValue()) {
return EmitDynamicMatrixVectorAssignment(stmt, mat);
}
}
// BUG(crbug.com/tint/534): work around assignment to vectors with dynamic
// indices
if (auto* vec = lhs_access_type->As<core::type::Vector>()) {
auto* rhs_sem = builder_.Sem().GetVal(lhs_access->index);
if (!rhs_sem->ConstantValue()) {
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 ASTPrinter::EmitBinary(StringStream& out, const ast::BinaryExpression* expr) {
if (expr->op == core::BinaryOp::kLogicalAnd || expr->op == core::BinaryOp::kLogicalOr) {
auto name = UniqueIdentifier(kTempNamePrefix);
{
auto pre = Line();
pre << "bool " << name << " = ";
if (!EmitExpression(pre, expr->lhs)) {
return false;
}
pre << ";";
}
if (expr->op == core::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 == core::BinaryOp::kMultiply &&
((lhs_type->Is<core::type::Vector>() && rhs_type->Is<core::type::Matrix>()) ||
(lhs_type->Is<core::type::Matrix>() && rhs_type->Is<core::type::Vector>()) ||
(lhs_type->Is<core::type::Matrix>() && rhs_type->Is<core::type::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;
}
ScopedParen sp(out);
if (!EmitExpression(out, expr->lhs)) {
return false;
}
out << " ";
switch (expr->op) {
case core::BinaryOp::kAnd:
out << "&";
break;
case core::BinaryOp::kOr:
out << "|";
break;
case core::BinaryOp::kXor:
out << "^";
break;
case core::BinaryOp::kLogicalAnd:
case core::BinaryOp::kLogicalOr: {
// These are both handled above.
TINT_UNREACHABLE();
return false;
}
case core::BinaryOp::kEqual:
out << "==";
break;
case core::BinaryOp::kNotEqual:
out << "!=";
break;
case core::BinaryOp::kLessThan:
out << "<";
break;
case core::BinaryOp::kGreaterThan:
out << ">";
break;
case core::BinaryOp::kLessThanEqual:
out << "<=";
break;
case core::BinaryOp::kGreaterThanEqual:
out << ">=";
break;
case core::BinaryOp::kShiftLeft:
out << "<<";
break;
case core::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 core::BinaryOp::kAdd:
out << "+";
break;
case core::BinaryOp::kSubtract:
out << "-";
break;
case core::BinaryOp::kMultiply:
out << "*";
break;
case core::BinaryOp::kDivide:
out << "/";
break;
case core::BinaryOp::kModulo:
out << "%";
break;
}
out << " ";
if (!EmitExpression(out, expr->rhs)) {
return false;
}
return true;
}
bool ASTPrinter::EmitStatements(VectorRef<const ast::Statement*> stmts) {
for (auto* s : stmts) {
if (!EmitStatement(s)) {
return false;
}
}
return true;
}
bool ASTPrinter::EmitStatementsWithIndent(VectorRef<const ast::Statement*> stmts) {
ScopedIndent si(this);
return EmitStatements(stmts);
}
bool ASTPrinter::EmitBlock(const ast::BlockStatement* stmt) {
Line() << "{";
if (!EmitStatementsWithIndent(stmt->statements)) {
return false;
}
Line() << "}";
return true;
}
bool ASTPrinter::EmitBreak(const ast::BreakStatement*) {
Line() << "break;";
return true;
}
bool ASTPrinter::EmitBreakIf(const ast::BreakIfStatement* b) {
auto out = Line();
out << "if (";
if (!EmitExpression(out, b->condition)) {
return false;
}
out << ") { break; }";
return true;
}
bool ASTPrinter::EmitCall(StringStream& out, const ast::CallExpression* expr) {
auto* call = builder_.Sem().Get<sem::Call>(expr);
auto* target = call->Target();
return Switch(
target, //
[&](const sem::Function* func) { return EmitFunctionCall(out, call, func); },
[&](const sem::Builtin* builtin) { return EmitBuiltinCall(out, call, builtin); },
[&](const sem::ValueConversion* conv) { return EmitValueConversion(out, call, conv); },
[&](const sem::ValueConstructor* ctor) { return EmitValueConstructor(out, call, ctor); },
[&](Default) {
TINT_ICE() << "unhandled call target: " << target->TypeInfo().name;
return false;
});
}
bool ASTPrinter::EmitFunctionCall(StringStream& out,
const sem::Call* call,
const sem::Function* func) {
auto* expr = call->Declaration();
if (ast::HasAttribute<CalculateArrayLength::BufferSizeIntrinsic>(
func->Declaration()->attributes)) {
// Special function generated by the CalculateArrayLength transform for
// calling X.GetDimensions(Y)
if (!EmitExpression(out, call->Arguments()[0]->Declaration())) {
return false;
}
out << ".GetDimensions(";
if (!EmitExpression(out, call->Arguments()[1]->Declaration())) {
return false;
}
out << ")";
return true;
}
if (auto* intrinsic =
ast::GetAttribute<DecomposeMemoryAccess::Intrinsic>(func->Declaration()->attributes)) {
switch (intrinsic->address_space) {
case core::AddressSpace::kUniform:
return EmitUniformBufferAccess(out, expr, intrinsic);
case core::AddressSpace::kStorage:
if (!intrinsic->IsAtomic()) {
return EmitStorageBufferAccess(out, expr, intrinsic);
}
break;
default:
TINT_UNREACHABLE() << "unsupported DecomposeMemoryAccess::Intrinsic address space:"
<< intrinsic->address_space;
return false;
}
}
if (auto* wave_intrinsic =
ast::GetAttribute<ast::transform::CanonicalizeEntryPointIO::HLSLWaveIntrinsic>(
func->Declaration()->attributes)) {
switch (wave_intrinsic->op) {
case ast::transform::CanonicalizeEntryPointIO::HLSLWaveIntrinsic::Op::kWaveGetLaneCount:
out << "WaveGetLaneCount()";
return true;
case ast::transform::CanonicalizeEntryPointIO::HLSLWaveIntrinsic::Op::kWaveGetLaneIndex:
out << "WaveGetLaneIndex()";
return true;
}
}
out << func->Declaration()->name->symbol.Name() << "(";
bool first = true;
for (auto* arg : call->Arguments()) {
if (!first) {
out << ", ";
}
first = false;
if (!EmitExpression(out, arg->Declaration())) {
return false;
}
}
out << ")";
return true;
}
bool ASTPrinter::EmitBuiltinCall(StringStream& out,
const sem::Call* call,
const sem::Builtin* builtin) {
const auto type = builtin->Type();
auto* expr = call->Declaration();
if (builtin->IsTexture()) {
return EmitTextureCall(out, call, builtin);
}
if (type == core::Function::kSelect) {
return EmitSelectCall(out, expr);
}
if (type == core::Function::kModf) {
return EmitModfCall(out, expr, builtin);
}
if (type == core::Function::kFrexp) {
return EmitFrexpCall(out, expr, builtin);
}
if (type == core::Function::kDegrees) {
return EmitDegreesCall(out, expr, builtin);
}
if (type == core::Function::kRadians) {
return EmitRadiansCall(out, expr, builtin);
}
if (type == core::Function::kSign) {
return EmitSignCall(out, call, builtin);
}
if (type == core::Function::kQuantizeToF16) {
return EmitQuantizeToF16Call(out, expr, builtin);
}
if (type == core::Function::kTrunc) {
return EmitTruncCall(out, expr, builtin);
}
if (builtin->IsDataPacking()) {
return EmitDataPackingCall(out, expr, builtin);
}
if (builtin->IsDataUnpacking()) {
return EmitDataUnpackingCall(out, expr, builtin);
}
if (builtin->IsBarrier()) {
return EmitBarrierCall(out, builtin);
}
if (builtin->IsAtomic()) {
return EmitWorkgroupAtomicCall(out, expr, builtin);
}
if (builtin->IsDP4a()) {
return EmitDP4aCall(out, expr, builtin);
}
if (builtin->IsSubgroup()) {
if (builtin->Type() == core::Function::kSubgroupBroadcast) {
// Fall through the regular path.
} else {
return EmitSubgroupCall(out, expr, builtin);
}
}
auto name = generate_builtin_name(builtin);
if (name.empty()) {
return false;
}
// Handle single argument builtins that only accept and return uint (not int overload). We need
// to explicitly cast the return value (we also cast the arg for good measure). See
// crbug.com/tint/1550
if (type == core::Function::kCountOneBits || type == core::Function::kReverseBits) {
auto* arg = call->Arguments()[0];
if (arg->Type()->UnwrapRef()->is_signed_integer_scalar_or_vector()) {
out << "asint(" << name << "(asuint(";
if (!EmitExpression(out, arg->Declaration())) {
return false;
}
out << ")))";
return true;
}
}
out << name << "(";
bool first = true;
for (auto* arg : call->Arguments()) {
if (!first) {
out << ", ";
}
first = false;
if (!EmitExpression(out, arg->Declaration())) {
return false;
}
}
out << ")";
return true;
}
bool ASTPrinter::EmitValueConversion(StringStream& out,
const sem::Call* call,
const sem::ValueConversion* conv) {
if (!EmitType(out, conv->Target(), core::AddressSpace::kUndefined, core::Access::kReadWrite,
"")) {
return false;
}
out << "(";
if (!EmitExpression(out, call->Arguments()[0]->Declaration())) {
return false;
}
out << ")";
return true;
}
bool ASTPrinter::EmitValueConstructor(StringStream& out,
const sem::Call* call,
const sem::ValueConstructor* ctor) {
auto* type = call->Type();
// If the value constructor arguments are empty then we need to construct with the zero value
// for all components.
if (call->Arguments().IsEmpty()) {
return EmitZeroValue(out, type);
}
// Single parameter matrix initializers must be identity initializer.
// It could also be conversions between f16 and f32 matrix when f16 is properly supported.
if (type->Is<core::type::Matrix>() && call->Arguments().Length() == 1) {
if (!ctor->Parameters()[0]->Type()->UnwrapRef()->is_float_matrix()) {
TINT_UNREACHABLE()
<< "found a single-parameter matrix initializer that is not identity initializer";
return false;
}
}
bool brackets = type->IsAnyOf<core::type::Array, core::type::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() && call->Arguments().Length() == 1 &&
ctor->Parameters()[0]->Type()->Is<core::type::Scalar>();
if (brackets) {
out << "{";
} else {
if (!EmitType(out, type, core::AddressSpace::kUndefined, core::Access::kReadWrite, "")) {
return false;
}
out << "(";
}
if (is_single_value_vector_init) {
out << "(";
}
bool first = true;
for (auto* e : call->Arguments()) {
if (!first) {
out << ", ";
}
first = false;
if (!EmitExpression(out, e->Declaration())) {
return false;
}
}
if (is_single_value_vector_init) {
out << ")." << std::string(type->As<core::type::Vector>()->Width(), 'x');
}
out << (brackets ? "}" : ")");
return true;
}
bool ASTPrinter::EmitUniformBufferAccess(StringStream& out,
const ast::CallExpression* expr,
const DecomposeMemoryAccess::Intrinsic* intrinsic) {
auto const buffer = intrinsic->Buffer()->identifier->symbol.Name();
auto* const offset = expr->args[0];
// offset in bytes
uint32_t scalar_offset_bytes = 0;
// offset in uint (4 bytes)
uint32_t scalar_offset_index = 0;
// expression to calculate offset in bytes
std::string scalar_offset_bytes_expr;
// expression to calculate offset in uint, by dividing scalar_offset_bytes_expr by 4
std::string scalar_offset_index_expr;
// expression to calculate offset in uint, independently
std::string scalar_offset_index_unified_expr;
// If true, use scalar_offset_index, otherwise use scalar_offset_index_expr
bool scalar_offset_constant = false;
if (auto* val = builder_.Sem().GetVal(offset)->ConstantValue()) {
TINT_ASSERT(val->Type()->Is<core::type::U32>());
scalar_offset_bytes = static_cast<uint32_t>(val->ValueAs<AInt>());
scalar_offset_index = scalar_offset_bytes / 4; // bytes -> scalar index
scalar_offset_constant = true;
}
// If true, scalar_offset_bytes or scalar_offset_bytes_expr should be used, otherwise only use
// scalar_offset_index or scalar_offset_index_unified_expr. Currently only loading f16 scalar
// require using offset in bytes.
const bool need_offset_in_bytes =
intrinsic->type == DecomposeMemoryAccess::Intrinsic::DataType::kF16;
if (!scalar_offset_constant) {
// UBO offset not compile-time known.
// Calculate the scalar offset into a temporary.
if (need_offset_in_bytes) {
scalar_offset_bytes_expr = UniqueIdentifier("scalar_offset_bytes");
scalar_offset_index_expr = UniqueIdentifier("scalar_offset_index");
{
auto pre = Line();
pre << "const uint " << scalar_offset_bytes_expr << " = (";
if (!EmitExpression(pre, offset)) {
return false;
}
pre << ");";
}
Line() << "const uint " << scalar_offset_index_expr << " = " << scalar_offset_bytes_expr
<< " / 4;";
} else {
scalar_offset_index_unified_expr = UniqueIdentifier("scalar_offset");
auto pre = Line();
pre << "const uint " << scalar_offset_index_unified_expr << " = (";
if (!EmitExpression(pre, offset)) {
return false;
}
pre << ") / 4;";
}
}
const char swizzle[] = {'x', 'y', 'z', 'w'};
using Op = DecomposeMemoryAccess::Intrinsic::Op;
using DataType = 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_u32_to = [&](StringStream& target) {
target << buffer;
if (scalar_offset_constant) {
target << "[" << (scalar_offset_index / 4) << "]."
<< swizzle[scalar_offset_index & 3];
} else {
target << "[" << scalar_offset_index_unified_expr << " / 4]["
<< scalar_offset_index_unified_expr << " % 4]";
}
return true;
};
auto load_u32 = [&] { return load_u32_to(out); };
// Has a minimum alignment of 8 bytes, so is either .xy or .zw
auto load_vec2_u32_to = [&](StringStream& target) {
if (scalar_offset_constant) {
target << buffer << "[" << (scalar_offset_index / 4) << "]"
<< ((scalar_offset_index & 2) == 0 ? ".xy" : ".zw");
} else {
std::string ubo_load = UniqueIdentifier("ubo_load");
{
auto pre = Line();
pre << "uint4 " << ubo_load << " = " << buffer << "["
<< scalar_offset_index_unified_expr << " / 4];";
}
target << "((" << scalar_offset_index_unified_expr << " & 2) ? " << ubo_load
<< ".zw : " << ubo_load << ".xy)";
}
return true;
};
auto load_vec2_u32 = [&] { return load_vec2_u32_to(out); };
// vec4 has a minimum alignment of 16 bytes, easiest case
auto load_vec4_u32 = [&] {
out << buffer;
if (scalar_offset_constant) {
out << "[" << (scalar_offset_index / 4) << "]";
} else {
out << "[" << scalar_offset_index_unified_expr << " / 4]";
}
return true;
};
// vec3 has a minimum alignment of 16 bytes, so is just a .xyz swizzle
auto load_vec3_u32 = [&] {
if (!load_vec4_u32()) {
return false;
}
out << ".xyz";
return true;
};
auto load_scalar_f16 = [&] {
// offset bytes = 4k, ((buffer[index].x) & 0xFFFF)
// offset bytes = 4k+2, ((buffer[index].x >> 16) & 0xFFFF)
out << "float16_t(f16tof32(((" << buffer;
if (scalar_offset_constant) {
out << "[" << (scalar_offset_index / 4) << "]."
<< swizzle[scalar_offset_index & 3];
// WGSL spec ensure little endian memory layout.
if (scalar_offset_bytes % 4 == 0) {
out << ") & 0xFFFF)";
} else {
out << " >> 16) & 0xFFFF)";
}
} else {
out << "[" << scalar_offset_index_expr << " / 4][" << scalar_offset_index_expr
<< " % 4] >> (" << scalar_offset_bytes_expr
<< " % 4 == 0 ? 0 : 16)) & 0xFFFF)";
}
out << "))";
return true;
};
auto load_vec2_f16 = [&] {
// vec2<f16> is aligned to 4 bytes
// Preclude code load the vec2<f16> data as a uint:
// uint ubo_load = buffer[id0][id1];
// Loading code convert it to vec2<f16>:
// vector<float16_t, 2>(float16_t(f16tof32(ubo_load & 0xFFFF)),
// float16_t(f16tof32(ubo_load >> 16)))
std::string ubo_load = UniqueIdentifier("ubo_load");
{
auto pre = Line();
// Load the 4 bytes f16 vector as an uint
pre << "uint " << ubo_load << " = ";
if (!load_u32_to(pre)) {
return false;
}
pre << ";";
}
out << "vector<float16_t, 2>(float16_t(f16tof32(" << ubo_load
<< " & 0xFFFF)), float16_t(f16tof32(" << ubo_load << " >> 16)))";
return true;
};
auto load_vec3_f16 = [&] {
// vec3<f16> is aligned to 8 bytes
// Preclude code load the vec3<f16> data as uint2 and convert its elements to
// float16_t:
// uint2 ubo_load = buffer[id0].xy;
// /* The low 8 bits of two uint are the x and z elements of vec3<f16> */
// vector<float16_t> ubo_load_xz = vector<float16_t, 2>(f16tof32(ubo_load &
// 0xFFFF));
// /* The high 8 bits of first uint is the y element of vec3<f16> */
// float16_t ubo_load_y = f16tof32(ubo_load[0] >> 16);
// Loading code convert it to vec3<f16>:
// vector<float16_t, 3>(ubo_load_xz[0], ubo_load_y, ubo_load_xz[1])
std::string ubo_load = UniqueIdentifier("ubo_load");
std::string ubo_load_xz = UniqueIdentifier(ubo_load + "_xz");
std::string ubo_load_y = UniqueIdentifier(ubo_load + "_y");
{
auto pre = Line();
// Load the 8 bytes uint2 with the f16 vector at lower 6 bytes
pre << "uint2 " << ubo_load << " = ";
if (!load_vec2_u32_to(pre)) {
return false;
}
pre << ";";
}
{
auto pre = Line();
pre << "vector<float16_t, 2> " << ubo_load_xz
<< " = vector<float16_t, 2>(f16tof32(" << ubo_load << " & 0xFFFF));";
}
{
auto pre = Line();
pre << "float16_t " << ubo_load_y << " = f16tof32(" << ubo_load
<< "[0] >> 16);";
}
out << "vector<float16_t, 3>(" << ubo_load_xz << "[0], " << ubo_load_y << ", "
<< ubo_load_xz << "[1])";
return true;
};
auto load_vec4_f16 = [&] {
// vec4<f16> is aligned to 8 bytes
// Preclude code load the vec4<f16> data as uint2 and convert its elements to
// float16_t:
// uint2 ubo_load = buffer[id0].xy;
// /* The low 8 bits of two uint are the x and z elements of vec4<f16> */
// vector<float16_t> ubo_load_xz = vector<float16_t, 2>(f16tof32(ubo_load &
// 0xFFFF));
// /* The high 8 bits of two uint are the y and w elements of vec4<f16> */
// vector<float16_t, 2> ubo_load_yw = vector<float16_t, 2>(f16tof32(ubo_load >>
// 16));
// Loading code convert it to vec4<f16>:
// vector<float16_t, 4>(ubo_load_xz[0], ubo_load_yw[0], ubo_load_xz[1],
// ubo_load_yw[1])
std::string ubo_load = UniqueIdentifier("ubo_load");
std::string ubo_load_xz = UniqueIdentifier(ubo_load + "_xz");
std::string ubo_load_yw = UniqueIdentifier(ubo_load + "_yw");
{
auto pre = Line();
// Load the 8 bytes f16 vector as an uint2
pre << "uint2 " << ubo_load << " = ";
if (!load_vec2_u32_to(pre)) {
return false;
}
pre << ";";
}
{
auto pre = Line();
pre << "vector<float16_t, 2> " << ubo_load_xz
<< " = vector<float16_t, 2>(f16tof32(" << ubo_load << " & 0xFFFF));";
}
{
auto pre = Line();
pre << "vector<float16_t, 2> " << ubo_load_yw
<< " = vector<float16_t, 2>(f16tof32(" << ubo_load << " >> 16));";
}
out << "vector<float16_t, 4>(" << ubo_load_xz << "[0], " << ubo_load_yw << "[0], "
<< ubo_load_xz << "[1], " << ubo_load_yw << "[1])";
return true;
};
switch (intrinsic->type) {
case DataType::kU32:
return load_u32();
case DataType::kF32:
return cast("asfloat", load_u32);
case DataType::kI32:
return cast("asint", load_u32);
case DataType::kF16:
return load_scalar_f16();
case DataType::kVec2U32:
return load_vec2_u32();
case DataType::kVec2F32:
return cast("asfloat", load_vec2_u32);
case DataType::kVec2I32:
return cast("asint", load_vec2_u32);
case DataType::kVec2F16:
return load_vec2_f16();
case DataType::kVec3U32:
return load_vec3_u32();
case DataType::kVec3F32:
return cast("asfloat", load_vec3_u32);
case DataType::kVec3I32:
return cast("asint", load_vec3_u32);
case DataType::kVec3F16:
return load_vec3_f16();
case DataType::kVec4U32:
return load_vec4_u32();
case DataType::kVec4F32:
return cast("asfloat", load_vec4_u32);
case DataType::kVec4I32:
return cast("asint", load_vec4_u32);
case DataType::kVec4F16:
return load_vec4_f16();
}
TINT_UNREACHABLE() << "unsupported DecomposeMemoryAccess::Intrinsic::DataType: "
<< static_cast<int>(intrinsic->type);
return false;
}
default:
break;
}
TINT_UNREACHABLE() << "unsupported DecomposeMemoryAccess::Intrinsic::Op: "
<< static_cast<int>(intrinsic->op);
return false;
}
bool ASTPrinter::EmitStorageBufferAccess(StringStream& out,
const ast::CallExpression* expr,
const DecomposeMemoryAccess::Intrinsic* intrinsic) {
auto const buffer = intrinsic->Buffer()->identifier->symbol.Name();
auto* const offset = expr->args[0];
auto* const value = expr->args.Length() > 1 ? expr->args[1] : nullptr;
using Op = DecomposeMemoryAccess::Intrinsic::Op;
using DataType = DecomposeMemoryAccess::Intrinsic::DataType;
switch (intrinsic->op) {
case Op::kLoad: {
auto load = [&](const char* cast, int n) {
if (cast) {
out << cast << "(";
}
out << buffer << ".Load";
if (n > 1) {
out << n;
}
ScopedParen sp(out);
if (!EmitExpression(out, offset)) {
return false;
}
if (cast) {
out << ")";
}
return true;
};
// Templated load used for f16 types, requires SM6.2 or higher and DXC
// Used by loading f16 types, e.g. for f16 type, set type parameter to "float16_t"
// to emit `buffer.Load<float16_t>(offset)`.
auto templated_load = [&](const char* type) {
out << buffer << ".Load<" << type << ">"; // templated load
ScopedParen sp(out);
if (!EmitExpression(out, offset)) {
return false;
}
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::kF16:
return templated_load("float16_t");
case DataType::kVec2U32:
return load(nullptr, 2);
case DataType::kVec2F32:
return load("asfloat", 2);
case DataType::kVec2I32:
return load("asint", 2);
case DataType::kVec2F16:
return templated_load("vector<float16_t, 2> ");
case DataType::kVec3U32:
return load(nullptr, 3);
case DataType::kVec3F32:
return load("asfloat", 3);
case DataType::kVec3I32:
return load("asint", 3);
case DataType::kVec3F16:
return templated_load("vector<float16_t, 3> ");
case DataType::kVec4U32:
return load(nullptr, 4);
case DataType::kVec4F32:
return load("asfloat", 4);
case DataType::kVec4I32:
return load("asint", 4);
case DataType::kVec4F16:
return templated_load("vector<float16_t, 4> ");
}
TINT_UNREACHABLE() << "unsupported DecomposeMemoryAccess::Intrinsic::DataType: "
<< static_cast<int>(intrinsic->type);
return false;
}
case Op::kStore: {
auto store = [&](int n) {
out << buffer << ".Store";
if (n > 1) {
out << n;
}
ScopedParen sp1(out);
if (!EmitExpression(out, offset)) {
return false;
}
out << ", asuint";
ScopedParen sp2(out);
if (!EmitTextureOrStorageBufferCallArgExpression(out, value)) {
return false;
}
return true;
};
// Templated stored used for f16 types, requires SM6.2 or higher and DXC
// Used by storing f16 types, e.g. for f16 type, set type parameter to "float16_t"
// to emit `buffer.Store<float16_t>(offset)`.
auto templated_store = [&](const char* type) {
out << buffer << ".Store<" << type << ">"; // templated store
ScopedParen sp1(out);
if (!EmitExpression(out, offset)) {
return false;
}
out << ", ";
if (!EmitExpression(out, 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::kF16:
return templated_store("float16_t");
case DataType::kVec2U32:
return store(2);
case DataType::kVec2F32:
return store(2);
case DataType::kVec2I32:
return store(2);
case DataType::kVec2F16:
return templated_store("vector<float16_t, 2> ");
case DataType::kVec3U32:
return store(3);
case DataType::kVec3F32:
return store(3);
case DataType::kVec3I32:
return store(3);
case DataType::kVec3F16:
return templated_store("vector<float16_t, 3> ");
case DataType::kVec4U32:
return store(4);
case DataType::kVec4F32:
return store(4);
case DataType::kVec4I32:
return store(4);
case DataType::kVec4F16:
return templated_store("vector<float16_t, 4> ");
}
TINT_UNREACHABLE() << "unsupported DecomposeMemoryAccess::Intrinsic::DataType: "
<< static_cast<int>(intrinsic->type);
return false;
}
default:
// Break out to error case below
// Note that atomic intrinsics are generated as functions.
break;
}
TINT_UNREACHABLE() << "unsupported DecomposeMemoryAccess::Intrinsic::Op: "
<< static_cast<int>(intrinsic->op);
return false;
}
bool ASTPrinter::EmitStorageAtomicIntrinsic(const ast::Function* func,
const DecomposeMemoryAccess::Intrinsic* intrinsic) {
using Op = DecomposeMemoryAccess::Intrinsic::Op;
const sem::Function* sem_func = builder_.Sem().Get(func);
auto* result_ty = sem_func->ReturnType();
const auto name = func->name->symbol.Name();
auto& buf = *current_buffer_;
auto const buffer = intrinsic->Buffer()->identifier->symbol.Name();
auto rmw = [&](const char* hlsl) -> bool {
{
auto fn = Line(&buf);
if (!EmitTypeAndName(fn, result_ty, core::AddressSpace::kUndefined,
core::Access::kUndefined, name)) {
return false;
}
fn << "(uint offset, ";
if (!EmitTypeAndName(fn, result_ty, core::AddressSpace::kUndefined,
core::Access::kUndefined, "value")) {
return false;
}
fn << ") {";
}
buf.IncrementIndent();
TINT_DEFER({
buf.DecrementIndent();
Line(&buf) << "}";
Line(&buf);
});
{
auto l = Line(&buf);
if (!EmitTypeAndName(l, result_ty, core::AddressSpace::kUndefined,
core::Access::kUndefined, "original_value")) {
return false;
}
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 true;
};
switch (intrinsic->op) {
case Op::kAtomicAdd:
return rmw("InterlockedAdd");
case Op::kAtomicSub:
// Use add with the operand negated.
return rmw("InterlockedAdd");
case Op::kAtomicMax:
return rmw("InterlockedMax");
case Op::kAtomicMin:
return rmw("InterlockedMin");
case Op::kAtomicAnd:
return rmw("InterlockedAnd");
case Op::kAtomicOr:
return rmw("InterlockedOr");
case Op::kAtomicXor:
return rmw("InterlockedXor");
case Op::kAtomicExchange:
return rmw("InterlockedExchange");
case Op::kAtomicLoad: {
// HLSL does not have an InterlockedLoad, so we emulate it with
// InterlockedOr using 0 as the OR value
{
auto fn = Line(&buf);
if (!EmitTypeAndName(fn, result_ty, core::AddressSpace::kUndefined,
core::Access::kUndefined, name)) {
return false;
}
fn << "(uint offset) {";
}
buf.IncrementIndent();
TINT_DEFER({
buf.DecrementIndent();
Line(&buf) << "}";
Line(&buf);
});
{
auto l = Line(&buf);
if (!EmitTypeAndName(l, result_ty, core::AddressSpace::kUndefined,
core::Access::kUndefined, "value")) {
return false;
}
l << " = 0;";
}
Line(&buf) << buffer << ".InterlockedOr(offset, 0, value);";
Line(&buf) << "return value;";
return true;
}
case Op::kAtomicStore: {
auto* const value_ty = sem_func->Parameters()[1]->Type()->UnwrapRef();
// HLSL does not have an InterlockedStore, so we emulate it with
// InterlockedExchange and discard the returned value
{
auto fn = Line(&buf);
fn << "void " << name << "(uint offset, ";
if (!EmitTypeAndName(fn, value_ty, core::AddressSpace::kUndefined,
core::Access::kUndefined, "value")) {
return false;
}
fn << ") {";
}
buf.IncrementIndent();
TINT_DEFER({
buf.DecrementIndent();
Line(&buf) << "}";
Line(&buf);
});
{
auto l = Line(&buf);
if (!EmitTypeAndName(l, value_ty, core::AddressSpace::kUndefined,
core::Access::kUndefined, "ignored")) {
return false;
}
l << ";";
}
Line(&buf) << buffer << ".InterlockedExchange(offset, value, ignored);";
return true;
}
case Op::kAtomicCompareExchangeWeak: {
if (!EmitStructType(&helpers_, result_ty->As<core::type::Struct>())) {
return false;
}
auto* const value_ty = sem_func->Parameters()[1]->Type()->UnwrapRef();
// NOTE: We don't need to emit the return type struct here as DecomposeMemoryAccess
// already added it to the AST, and it should have already been emitted by now.
{
auto fn = Line(&buf);
if (!EmitTypeAndName(fn, result_ty, core::AddressSpace::kUndefined,
core::Access::kUndefined, name)) {
return false;
}
fn << "(uint offset, ";
if (!EmitTypeAndName(fn, value_ty, core::AddressSpace::kUndefined,
core::Access::kUndefined, "compare")) {
return false;
}
fn << ", ";
if (!EmitTypeAndName(fn, value_ty, core::AddressSpace::kUndefined,
core::Access::kUndefined, "value")) {
return false;
}
fn << ") {";
}
buf.IncrementIndent();
TINT_DEFER({
buf.DecrementIndent();
Line(&buf) << "}";
Line(&buf);
});
{ // T result = {0};
auto l = Line(&buf);
if (!EmitTypeAndName(l, result_ty, core::AddressSpace::kUndefined,
core::Access::kUndefined, "result")) {
return false;
}
l << "=";
if (!EmitZeroValue(l, result_ty)) {
return false;
}
l << ";";
}
Line(&buf) << buffer
<< ".InterlockedCompareExchange(offset, compare, value, result.old_value);";
Line(&buf) << "result.exchanged = result.old_value == compare;";
Line(&buf) << "return result;";
return true;
}
default:
break;
}
TINT_UNREACHABLE() << "unsupported atomic DecomposeMemoryAccess::Intrinsic::Op: "
<< static_cast<int>(intrinsic->op);
return false;
}
bool ASTPrinter::EmitWorkgroupAtomicCall(StringStream& out,
const ast::CallExpression* expr,
const sem::Builtin* builtin) {
std::string result = UniqueIdentifier("atomic_result");
if (!builtin->ReturnType()->Is<core::type::Void>()) {
auto pre = Line();
if (!EmitTypeAndName(pre, builtin->ReturnType(), core::AddressSpace::kUndefined,
core::Access::kUndefined, result)) {
return false;
}
pre << " = ";
if (!EmitZeroValue(pre, builtin->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.Length(); i++) {
auto* arg = expr->args[i];
if (i > 0) {
pre << ", ";
}
if (i == 1 && builtin->Type() == core::Function::kAtomicSub) {
// Sub uses InterlockedAdd with the operand negated.
pre << "-";
}
if (!EmitExpression(pre, arg)) {
return false;
}
}
pre << ", " << result;
}
pre << ";";
out << result;
return true;
};
switch (builtin->Type()) {
case core::Function::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 core::Function::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 = builtin->Parameters()[1]->Type()->UnwrapRef();
if (!EmitTypeAndName(pre, value_ty, core::AddressSpace::kUndefined,
core::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 core::Function::kAtomicCompareExchangeWeak: {
if (!EmitStructType(&helpers_, builtin->ReturnType()->As<core::type::Struct>())) {
return false;
}
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)->UnwrapRef(),
core::AddressSpace::kUndefined, core::Access::kUndefined,
compare)) {
return false;
}
pre << " = ";
if (!EmitExpression(pre, compare_value)) {
return false;
}
pre << ";";
}
{ // InterlockedCompareExchange(dst, compare, value, result.old_value);
auto pre = Line();
pre << "InterlockedCompareExchange";
{
ScopedParen sp(pre);
if (!EmitExpression(pre, dest)) {
return false;
}
pre << ", " << compare << ", ";
if (!EmitExpression(pre, value)) {
return false;
}
pre << ", " << result << ".old_value";
}
pre << ";";
}
// result.exchanged = result.old_value == compare;
Line() << result << ".exchanged = " << result << ".old_value == " << compare << ";";
out << result;
return true;
}
case core::Function::kAtomicAdd:
case core::Function::kAtomicSub:
return call("InterlockedAdd");
case core::Function::kAtomicMax:
return call("InterlockedMax");
case core::Function::kAtomicMin:
return call("InterlockedMin");
case core::Function::kAtomicAnd:
return call("InterlockedAnd");
case core::Function::kAtomicOr:
return call("InterlockedOr");
case core::Function::kAtomicXor:
return call("InterlockedXor");
case core::Function::kAtomicExchange:
return call("InterlockedExchange");
default:
break;
}
TINT_UNREACHABLE() << "unsupported atomic builtin: " << builtin->Type();
return false;
}
bool ASTPrinter::EmitSelectCall(StringStream& 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 ASTPrinter::EmitModfCall(StringStream& out,
const ast::CallExpression* expr,
const sem::Builtin* builtin) {
return CallBuiltinHelper(
out, expr, builtin, [&](TextBuffer* b, const std::vector<std::string>& params) {
auto* ty = builtin->Parameters()[0]->Type();
auto in = params[0];
std::string width;
if (auto* vec = ty->As<core::type::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_, builtin->ReturnType()->As<core::type::Struct>())) {
return false;
}
{
auto l = Line(b);
if (!EmitType(l, builtin->ReturnType(), core::AddressSpace::kUndefined,
core::Access::kUndefined, "")) {
return false;
}
l << " result;";
}
Line(b) << "result.fract = modf(" << params[0] << ", result.whole);";
Line(b) << "return result;";
return true;
});
}
bool ASTPrinter::EmitFrexpCall(StringStream& out,
const ast::CallExpression* expr,
const sem::Builtin* builtin) {
return CallBuiltinHelper(
out, expr, builtin, [&](TextBuffer* b, const std::vector<std::string>& params) {
auto* ty = builtin->Parameters()[0]->Type();
auto in = params[0];
std::string width;
if (auto* vec = ty->As<core::type::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_, builtin->ReturnType()->As<core::type::Struct>())) {
return false;
}
std::string member_type;
if (Is<core::type::F16>(ty->DeepestElement())) {
member_type = width.empty() ? "float16_t" : ("vector<float16_t, " + width + ">");
} else {
member_type = "float" + width;
}
Line(b) << member_type << " exp;";
Line(b) << member_type << " fract = sign(" << in << ") * frexp(" << in << ", exp);";
{
auto l = Line(b);
if (!EmitType(l, builtin->ReturnType(), core::AddressSpace::kUndefined,
core::Access::kUndefined, "")) {
return false;
}
l << " result = {fract, int" << width << "(exp)};";
}
Line(b) << "return result;";
return true;
});
}
bool ASTPrinter::EmitDegreesCall(StringStream& out,
const ast::CallExpression* expr,
const sem::Builtin* builtin) {
return CallBuiltinHelper(out, expr, builtin,
[&](TextBuffer* b, const std::vector<std::string>& params) {
Line(b) << "return " << params[0] << " * " << std::setprecision(20)
<< sem::kRadToDeg << ";";
return true;
});
}
bool ASTPrinter::EmitRadiansCall(StringStream& out,
const ast::CallExpression* expr,
const sem::Builtin* builtin) {
return CallBuiltinHelper(out, expr, builtin,
[&](TextBuffer* b, const std::vector<std::string>& params) {
Line(b) << "return " << params[0] << " * " << std::setprecision(20)
<< sem::kDegToRad << ";";
return true;
});
}
// The HLSL `sign` method always returns an `int` result (scalar or vector). In WGSL the result is
// expected to be the same type as the argument. This injects a cast to the expected WGSL result
// type after the call to `sign`.
bool ASTPrinter::EmitSignCall(StringStream& out, const sem::Call* call, const sem::Builtin*) {
auto* arg = call->Arguments()[0];
if (!EmitType(out, arg->Type(), core::AddressSpace::kUndefined, core::Access::kReadWrite, "")) {
return false;
}
out << "(sign(";
if (!EmitExpression(out, arg->Declaration())) {
return false;
}
out << "))";
return true;
}
bool ASTPrinter::EmitQuantizeToF16Call(StringStream& out,
const ast::CallExpression* expr,
const sem::Builtin* builtin) {
// Cast to f16 and back
std::string width;
if (auto* vec = builtin->ReturnType()->As<core::type::Vector>()) {
width = std::to_string(vec->Width());
}
out << "f16tof32(f32tof16"
<< "(";
if (!EmitExpression(out, expr->args[0])) {
return false;
}
out << "))";
return true;
}
bool ASTPrinter::EmitTruncCall(StringStream& out,
const ast::CallExpression* expr,
const sem::Builtin* builtin) {
// HLSL's trunc is broken for very large/small float values.
// See crbug.com/tint/1883
return CallBuiltinHelper( //
out, expr, builtin, [&](TextBuffer* b, const std::vector<std::string>& params) {
// value < 0 ? ceil(value) : floor(value)
Line(b) << "return " << params[0] << " < 0 ? ceil(" << params[0] << ") : floor("
<< params[0] << ");";
return true;
});
}
bool ASTPrinter::EmitDataPackingCall(StringStream& out,
const ast::CallExpression* expr,
const sem::Builtin* builtin) {
return CallBuiltinHelper(
out, expr, builtin, [&](TextBuffer* b, const std::vector<std::string>& params) {
uint32_t dims = 2;
bool is_signed = false;
uint32_t scale = 65535;
if (builtin->Type() == core::Function::kPack4X8Snorm ||
builtin->Type() == core::Function::kPack4X8Unorm) {
dims = 4;
scale = 255;
}
if (builtin->Type() == core::Function::kPack4X8Snorm ||
builtin->Type() == core::Function::kPack2X16Snorm) {
is_signed = true;
scale = (scale - 1) / 2;
}
switch (builtin->Type()) {
case core::Function::kPack4X8Snorm:
case core::Function::kPack4X8Unorm:
case core::Function::kPack2X16Snorm:
case core::Function::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 core::Function::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 builtin");
return false;
}
return true;
});
}
bool ASTPrinter::EmitDataUnpackingCall(StringStream& out,
const ast::CallExpression* expr,
const sem::Builtin* builtin) {
return CallBuiltinHelper(
out, expr, builtin, [&](TextBuffer* b, const std::vector<std::string>& params) {
uint32_t dims = 2;
bool is_signed = false;
uint32_t scale = 65535;
if (builtin->Type() == core::Function::kUnpack4X8Snorm ||
builtin->Type() == core::Function::kUnpack4X8Unorm) {
dims = 4;
scale = 255;
}
if (builtin->Type() == core::Function::kUnpack4X8Snorm ||
builtin->Type() == core::Function::kUnpack2X16Snorm) {
is_signed = true;
scale = (scale - 1) / 2;
}
switch (builtin->Type()) {
case core::Function::kUnpack4X8Snorm:
case core::Function::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 core::Function::kUnpack4X8Unorm:
case core::Function::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 core::Function::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 builtin");
return false;
}
return true;
});
}
bool ASTPrinter::EmitDP4aCall(StringStream& out,
const ast::CallExpression* expr,
const sem::Builtin* builtin) {
// TODO(crbug.com/tint/1497): support the polyfill version of DP4a functions.
return CallBuiltinHelper(
out, expr, builtin, [&](TextBuffer* b, const std::vector<std::string>& params) {
std::string functionName;
switch (builtin->Type()) {
case core::Function::kDot4I8Packed:
Line(b) << "int accumulator = 0;";
functionName = "dot4add_i8packed";
break;
case core::Function::kDot4U8Packed:
Line(b) << "uint accumulator = 0u;";
functionName = "dot4add_u8packed";
break;
default:
diagnostics_.add_error(diag::System::Writer,
"Internal error: unhandled DP4a builtin");
return false;
}
Line(b) << "return " << functionName << "(" << params[0] << ", " << params[1]
<< ", accumulator);";
return true;
});
}
bool ASTPrinter::EmitBarrierCall(StringStream& out, const sem::Builtin* builtin) {
// TODO(crbug.com/tint/661): Combine sequential barriers to a single
// instruction.
if (builtin->Type() == core::Function::kWorkgroupBarrier) {
out << "GroupMemoryBarrierWithGroupSync()";
} else if (builtin->Type() == core::Function::kStorageBarrier) {
out << "DeviceMemoryBarrierWithGroupSync()";
} else if (builtin->Type() == core::Function::kTextureBarrier) {
out << "DeviceMemoryBarrierWithGroupSync()";
} else {
TINT_UNREACHABLE() << "unexpected barrier builtin type " << core::str(builtin->Type());
return false;
}
return true;
}
bool ASTPrinter::EmitSubgroupCall(StringStream& out,
[[maybe_unused]] const ast::CallExpression* expr,
const sem::Builtin* builtin) {
if (builtin->Type() == core::Function::kSubgroupBallot) {
out << "WaveActiveBallot(true)";
} else {
// subgroupBroadcast is already handled in the regular builtin flow.
TINT_UNREACHABLE() << "unexpected subgroup builtin type " << core::str(builtin->Type());
return false;
}
return true;
}
bool ASTPrinter::EmitTextureOrStorageBufferCallArgExpression(StringStream& out,
const ast::Expression* expr) {
// TODO(crbug.com/tint/1976): Workaround DXC bug that fails to compile texture/storage function
// calls with signed integer splatted constants. DXC fails to convert the coord arg, for e.g.
// `0.xxx`, from a vector of 64-bit ints to a vector of 32-bit ints to match the texture load
// parameter type. We work around this for now by explicitly casting the splatted constant to
// the right type, for e.g. `int3(0.xxx)`.
bool emitted_cast = false;
if (auto* sem = builder_.Sem().GetVal(expr)) {
if (auto* constant = sem->ConstantValue()) {
if (auto* splat = constant->As<core::constant::Splat>()) {
if (splat->Type()->is_signed_integer_vector()) {
if (!EmitType(out, constant->Type(), core::AddressSpace::kUndefined,
core::Access::kUndefined, "")) {
return false;
}
out << "(";
emitted_cast = true;
}
}
}
}
if (!EmitExpression(out, expr)) {
return false;
}
if (emitted_cast) {
out << ")";
}
return true;
}
bool ASTPrinter::EmitTextureCall(StringStream& out,
const sem::Call* call,
const sem::Builtin* builtin) {
using Usage = core::ParameterUsage;
auto& signature = builtin->Signature();
auto* expr = call->Declaration();
auto arguments = expr->args;
// Returns the argument with the given usage
auto arg = [&](Usage usage) {
int idx = signature.IndexOf(usage);
return (idx >= 0) ? arguments[static_cast<size_t>(idx)] : nullptr;
};
auto* texture = arg(Usage::kTexture);
if (TINT_UNLIKELY(!texture)) {
TINT_ICE() << "missing texture argument";
return false;
}
auto* texture_type = TypeOf(texture)->UnwrapRef()->As<core::type::Texture>();
switch (builtin->Type()) {
case core::Function::kTextureDimensions:
case core::Function::kTextureNumLayers:
case core::Function::kTextureNumLevels:
case core::Function::kTextureNumSamples: {
// All of these builtins use the GetDimensions() method on the texture
bool is_ms = texture_type->IsAnyOf<core::type::MultisampledTexture,
core::type::DepthMultisampledTexture>();
int num_dimensions = 0;
std::string swizzle;
switch (builtin->Type()) {
case core::Function::kTextureDimensions:
switch (texture_type->dim()) {
case core::type::TextureDimension::kNone:
TINT_ICE() << "texture dimension is kNone";
return false;
case core::type::TextureDimension::k1d:
num_dimensions = 1;
break;
case core::type::TextureDimension::k2d:
num_dimensions = is_ms ? 3 : 2;
swizzle = is_ms ? ".xy" : "";
break;
case core::type::TextureDimension::k2dArray:
num_dimensions = is_ms ? 4 : 3;
swizzle = ".xy";
break;
case core::type::TextureDimension::k3d:
num_dimensions = 3;
break;
case core::type::TextureDimension::kCube:
num_dimensions = 2;
break;
case core::type::TextureDimension::kCubeArray:
num_dimensions = 3;
swizzle = ".xy";
break;
}
break;
case core::Function::kTextureNumLayers:
switch (texture_type->dim()) {
default:
TINT_ICE() << "texture dimension is not arrayed";
return false;
case core::type::TextureDimension::k2dArray:
num_dimensions = is_ms ? 4 : 3;
swizzle = ".z";
break;
case core::type::TextureDimension::kCubeArray:
num_dimensions = 3;
swizzle = ".z";
break;
}
break;
case core::Function::kTextureNumLevels:
switch (texture_type->dim()) {
default:
TINT_ICE() << "texture dimension does not support mips";
return false;
case core::type::TextureDimension::k1d:
num_dimensions = 2;
swizzle = ".y";
break;
case core::type::TextureDimension::k2d:
case core::type::TextureDimension::kCube:
num_dimensions = 3;
swizzle = ".z";
break;
case core::type::TextureDimension::k2dArray:
case core::type::TextureDimension::k3d:
case core::type::TextureDimension::kCubeArray:
num_dimensions = 4;
swizzle = ".w";
break;
}
break;
case core::Function::kTextureNumSamples:
switch (texture_type->dim()) {
default:
TINT_ICE() << "texture dimension does not support multisampling";
return false;
case core::type::TextureDimension::k2d:
num_dimensions = 3;
swizzle = ".z";
break;
case core::type::TextureDimension::k2dArray:
num_dimensions = 4;
swizzle = ".w";
break;
}
break;
default:
TINT_ICE() << "unexpected builtin";
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 (TINT_UNLIKELY(num_dimensions > 4)) {
TINT_ICE() << "Texture query builtin 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() << "uint " << dims << ";";
} else {
Line() << "uint" << 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 (builtin->Type() == core::Function::kTextureNumLevels) {
pre << "0, ";
}
if (num_dimensions == 1) {
pre << dims;
} else {
static constexpr char xyzw[] = {'x', 'y', 'z', 'w'};
if (TINT_UNLIKELY(num_dimensions < 0 || num_dimensions > 4)) {
TINT_ICE() << "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 builtin 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 (builtin->Type()) {
case core::Function::kTextureSample:
out << ".Sample(";
break;
case core::Function::kTextureSampleBias:
out << ".SampleBias(";
break;
case core::Function::kTextureSampleLevel:
out << ".SampleLevel(";
break;
case core::Function::kTextureSampleGrad:
out << ".SampleGrad(";
break;
case core::Function::kTextureSampleCompare:
out << ".SampleCmp(";
hlsl_ret_width = 1;
break;
case core::Function::kTextureSampleCompareLevel:
out << ".SampleCmpLevelZero(";
hlsl_ret_width = 1;
break;
case core::Function::kTextureLoad:
out << ".Load(";
// Multisampled textures do not support mip-levels.
if (!texture_type->Is<core::type::MultisampledTexture>()) {
pack_level_in_coords = true;
}
break;
case core::Function::kTextureGather:
out << ".Gather";
if (builtin->Parameters()[0]->Usage() == core::ParameterUsage::kComponent) {
switch (call->Arguments()[0]->ConstantValue()->ValueAs<AInt>()) {
case 0:
out << "Red";
break;
case 1:
out << "Green";
break;
case 2:
out << "Blue";
break;
case 3:
out << "Alpha";
break;
}
}
out << "(";
break;
case core::Function::kTextureGatherCompare:
out << ".GatherCmp(";
break;
case core::Function::kTextureStore:
out << "[";
break;
default:
diagnostics_.add_error(diag::System::Writer,
"Internal compiler error: Unhandled texture builtin '" +
std::string(builtin->str()) + "'");
return false;
}
if (auto* sampler = arg(Usage::kSampler)) {
if (!EmitExpression(out, sampler)) {
return false;
}
out << ", ";
}
auto* param_coords = arg(Usage::kCoords);
if (TINT_UNLIKELY(!param_coords)) {
TINT_ICE() << "missing coords argument";
return false;
}
auto emit_vector_appended_with_i32_zero = [&](const ast::Expression* vector) {
auto* i32 = builder_.create<core::type::I32>();
auto* zero = builder_.Expr(0_i);
auto* stmt = builder_.Sem().Get(vector)->Stmt();
builder_.Sem().Add(zero, builder_.create<sem::ValueExpression>(
zero, i32, core::EvaluationStage::kRuntime, stmt,
/* constant_value */ nullptr,
/* has_side_effects */ false));
auto* packed = tint::writer::AppendVector(&builder_, vector, zero);
return EmitExpression(out, packed->Declaration());
};
auto emit_vector_appended_with_level = [&](const ast::Expression* vector) {
if (auto* level = arg(Usage::kLevel)) {
auto* packed = tint::writer::AppendVector(&builder_, vector, level);
return EmitExpression(out, packed->Declaration());
}
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 = tint::writer::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->Declaration())) {
return false;
}
} else {
if (!EmitExpression(out, packed->Declaration())) {
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 (builtin->Type() == core::Function::kTextureStore) {
// param_coords is an index expression, not a function arg
if (!EmitExpression(out, param_coords)) {
return false;
}
} else if (!EmitTextureOrStorageBufferCallArgExpression(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 (!EmitTextureOrStorageBufferCallArgExpression(out, e)) {
return false;
}
}
}
if (builtin->Type() == core::Function::kTextureStore) {
out << "] = ";
if (!EmitExpression(out, arg(Usage::kValue))) {
return false;
}
} else {
out << ")";
// If the builtin return type does not match the number of elements of the
// HLSL builtin, we need to swizzle the expression to generate the correct
// number of components.
uint32_t wgsl_ret_width = 1;
if (auto* vec = builtin->ReturnType()->As<core::type::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 (TINT_UNLIKELY(wgsl_ret_width > hlsl_ret_width)) {
TINT_ICE() << "WGSL return width (" << wgsl_ret_width
<< ") is wider than HLSL return width (" << hlsl_ret_width << ") for "
<< builtin->Type();
return false;
}
}
return true;
}
std::string ASTPrinter::generate_builtin_name(const sem::Builtin* builtin) {
switch (builtin->Type()) {
case core::Function::kAbs:
case core::Function::kAcos:
case core::Function::kAll:
case core::Function::kAny:
case core::Function::kAsin:
case core::Function::kAtan:
case core::Function::kAtan2:
case core::Function::kCeil:
case core::Function::kClamp:
case core::Function::kCos:
case core::Function::kCosh:
case core::Function::kCross:
case core::Function::kDeterminant:
case core::Function::kDistance:
case core::Function::kDot:
case core::Function::kExp:
case core::Function::kExp2:
case core::Function::kFloor:
case core::Function::kFrexp:
case core::Function::kLdexp:
case core::Function::kLength:
case core::Function::kLog:
case core::Function::kLog2:
case core::Function::kMax:
case core::Function::kMin:
case core::Function::kModf:
case core::Function::kNormalize:
case core::Function::kPow:
case core::Function::kReflect:
case core::Function::kRefract:
case core::Function::kRound:
case core::Function::kSaturate:
case core::Function::kSin:
case core::Function::kSinh:
case core::Function::kSqrt:
case core::Function::kStep:
case core::Function::kTan:
case core::Function::kTanh:
case core::Function::kTranspose:
return builtin->str();
case core::Function::kCountOneBits: // uint
return "countbits";
case core::Function::kDpdx:
return "ddx";
case core::Function::kDpdxCoarse:
return "ddx_coarse";
case core::Function::kDpdxFine:
return "ddx_fine";
case core::Function::kDpdy:
return "ddy";
case core::Function::kDpdyCoarse:
return "ddy_coarse";
case core::Function::kDpdyFine:
return "ddy_fine";
case core::Function::kFaceForward:
return "faceforward";
case core::Function::kFract:
return "frac";
case core::Function::kFma:
return "mad";
case core::Function::kFwidth:
case core::Function::kFwidthCoarse:
case core::Function::kFwidthFine:
return "fwidth";
case core::Function::kInverseSqrt:
return "rsqrt";
case core::Function::kMix:
return "lerp";
case core::Function::kReverseBits: // uint
return "reversebits";
case core::Function::kSmoothstep:
return "smoothstep";
case core::Function::kSubgroupBroadcast:
return "WaveReadLaneAt";
default:
diagnostics_.add_error(diag::System::Writer,
"Unknown builtin method: " + std::string(builtin->str()));
}
return "";
}
bool ASTPrinter::EmitCase(const ast::SwitchStatement* s, size_t case_idx) {
auto* stmt = s->body[case_idx];
auto* sem = builder_.Sem().Get<sem::CaseStatement>(stmt);
for (auto* selector : sem->Selectors()) {
auto out = Line();
if (selector->IsDefault()) {
out << "default";
} else {
out << "case ";
if (!EmitConstant(out, selector->Value(), /* is_variable_initializer */ false)) {
return false;
}
}
out << ":";
if (selector == sem->Selectors().back()) {
out << " {";
}
}
IncrementIndent();
TINT_DEFER({
DecrementIndent();
Line() << "}";
});
// Emit the case statement
if (!EmitStatements(stmt->body->statements)) {
return false;
}
if (!tint::IsAnyOf<ast::BreakStatement>(stmt->body->Last())) {
Line() << "break;";
}
return true;
}
bool ASTPrinter::EmitContinue(const ast::ContinueStatement*) {
if (!emit_continuing_ || !emit_continuing_()) {
return false;
}
Line() << "continue;";
return true;
}
bool ASTPrinter::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 ASTPrinter::EmitExpression(StringStream& out, const ast::Expression* expr) {
if (auto* sem = builder_.Sem().GetVal(expr)) {
if (auto* constant = sem->ConstantValue()) {
bool is_variable_initializer = false;
if (auto* stmt = sem->Stmt()) {
if (auto* decl = As<ast::VariableDeclStatement>(stmt->Declaration())) {
is_variable_initializer = decl->variable->initializer == expr;
}
}
return EmitConstant(out, constant, is_variable_initializer);
}
}
return Switch(
expr, //
[&](const ast::IndexAccessorExpression* a) { return EmitIndexAccessor(out, a); },
[&](const ast::BinaryExpression* b) { return EmitBinary(out, b); },
[&](const ast::BitcastExpression* b) { return EmitBitcast(out, b); },
[&](const ast::CallExpression* c) { return EmitCall(out, c); },
[&](const ast::IdentifierExpression* i) { return EmitIdentifier(out, i); },
[&](const ast::LiteralExpression* l) { return EmitLiteral(out, l); },
[&](const ast::MemberAccessorExpression* m) { return EmitMemberAccessor(out, m); },
[&](const ast::UnaryOpExpression* u) { return EmitUnaryOp(out, u); },
[&](Default) {
diagnostics_.add_error(diag::System::Writer, "unknown expression type: " +
std::string(expr->TypeInfo().name));
return false;
});
}
bool ASTPrinter::EmitIdentifier(StringStream& out, const ast::IdentifierExpression* expr) {
out << expr->identifier->symbol.Name();
return true;
}
bool ASTPrinter::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;
}
if (stmt->else_statement) {
Line() << "} else {";
if (auto* block = stmt->else_statement->As<ast::BlockStatement>()) {
if (!EmitStatementsWithIndent(block->statements)) {
return false;
}
} else {
if (!EmitStatementsWithIndent(Vector{stmt->else_statement})) {
return false;
}
}
}
Line() << "}";
return true;
}
bool ASTPrinter::EmitFunction(const ast::Function* func) {
auto* sem = builder_.Sem().Get(func);
// Emit storage atomic helpers
if (auto* intrinsic = ast::GetAttribute<DecomposeMemoryAccess::Intrinsic>(func->attributes)) {
if (intrinsic->address_space == core::AddressSpace::kStorage && intrinsic->IsAtomic()) {
if (!EmitStorageAtomicIntrinsic(func, intrinsic)) {
return false;
}
}
return true;
}
if (ast::HasAttribute<ast::InternalAttribute>(func->attributes)) {
// An internal function. Do not emit.
return true;
}
{
auto out = Line();
auto name = func->name->symbol.Name();
// If the function returns an array, then we need to declare a typedef for
// this.
if (sem->ReturnType()->Is<core::type::Array>()) {
auto typedef_name = UniqueIdentifier(name + "_ret");
auto pre = Line();
pre << "typedef ";
if (!EmitTypeAndName(pre, sem->ReturnType(), core::AddressSpace::kUndefined,
core::Access::kReadWrite, typedef_name)) {
return false;
}
pre << ";";
out << typedef_name;
} else {
if (!EmitType(out, sem->ReturnType(), core::AddressSpace::kUndefined,
core::Access::kReadWrite, "")) {
return false;
}
}
out << " " << name << "(";
bool first = true;
for (auto* v : sem->Parameters()) {
if (!first) {
out << ", ";
}
first = false;
auto const* type = v->Type();
auto address_space = core::AddressSpace::kUndefined;
auto access = core::Access::kUndefined;
if (auto* ptr = type->As<core::type::Pointer>()) {
type = ptr->StoreType();
switch (ptr->AddressSpace()) {
case core::AddressSpace::kStorage:
case core::AddressSpace::kUniform:
// Not allowed by WGSL, but is used by certain transforms (e.g. DMA) to pass
// storage buffers and uniform buffers down into transform-generated
// functions. In this situation we want to generate the parameter without an
// 'inout', using the address space and access from the pointer.
address_space = ptr->AddressSpace();
access = ptr->Access();
break;
default:
// Transform regular WGSL pointer parameters in to `inout` parameters.
out << "inout ";
}
}
// Note: WGSL only allows for AddressSpace::kUndefined on parameters, however
// the sanitizer transforms generates load / store functions for storage
// or uniform buffers. These functions have a buffer parameter with
// AddressSpace::kStorage or AddressSpace::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, address_space, access,
v->Declaration()->name->symbol.Name())) {
return false;
}
}
out << ") {";
}
if (sem->DiscardStatement() && !sem->ReturnType()->Is<core::type::Void>()) {
// BUG(crbug.com/tint/1081): work around non-void functions with discard
// failing compilation sometimes
if (!EmitFunctionBodyWithDiscard(func)) {
return false;
}
} else {
if (!EmitStatementsWithIndent(func->body->statements)) {
return false;
}
}
Line() << "}";
return true;
}
bool ASTPrinter::EmitFunctionBodyWithDiscard(const ast::Function* func) {
// FXC sometimes fails to compile functions that discard with 'Not all control
// paths return a value'. We work around this by wrapping the function body
// within an "if (true) { <body> } return <default return type obj>;" so that
// there is always an (unused) return statement.
auto* sem = builder_.Sem().Get(func);
TINT_ASSERT(sem->DiscardStatement() && !sem->ReturnType()->Is<core::type::Void>());
ScopedIndent si(this);
Line() << "if (true) {";
if (!EmitStatementsWithIndent(func->body->statements)) {
return false;
}
Line() << "}";
// Return an unused result that matches the type of the return value
auto name = builder_.Symbols().New("unused").Name();
{
auto out = Line();
if (!EmitTypeAndName(out, sem->ReturnType(), core::AddressSpace::kUndefined,
core::Access::kReadWrite, name)) {
return false;
}
out << ";";
}
Line() << "return " << name << ";";
return true;
}
bool ASTPrinter::EmitGlobalVariable(const ast::Variable* global) {
return Switch(
global, //
[&](const ast::Var* var) {
auto* sem = builder_.Sem().Get(global);
switch (sem->AddressSpace()) {
case core::AddressSpace::kUniform:
return EmitUniformVariable(var, sem);
case core::AddressSpace::kStorage:
return EmitStorageVariable(var, sem);
case core::AddressSpace::kHandle:
return EmitHandleVariable(var, sem);
case core::AddressSpace::kPrivate:
return EmitPrivateVariable(sem);
case core::AddressSpace::kWorkgroup:
return EmitWorkgroupVariable(sem);
case core::AddressSpace::kPushConstant:
diagnostics_.add_error(
diag::System::Writer,
"unhandled address space " + tint::ToString(sem->AddressSpace()));
return false;
default: {
TINT_ICE() << "unhandled address space " << sem->AddressSpace();
return false;
}
}
},
[&](const ast::Override*) {
// Override is removed with SubstituteOverride
diagnostics_.add_error(diag::System::Writer,
"override-expressions should have been removed with the "
"SubstituteOverride transform");
return false;
},
[&](const ast::Const*) {
return true; // Constants are embedded at their use
},
[&](Default) {
TINT_ICE() << "unhandled global variable type " << global->TypeInfo().name;
return false;
});
}
bool ASTPrinter::EmitUniformVariable(const ast::Var* var, const sem::Variable* sem) {
auto binding_point = *sem->As<sem::GlobalVariable>()->BindingPoint();
auto* type = sem->Type()->UnwrapRef();
auto name = var->name->symbol.Name();
Line() << "cbuffer cbuffer_" << name << RegisterAndSpace('b', binding_point) << " {";
{
ScopedIndent si(this);
auto out = Line();
if (!EmitTypeAndName(out, type, core::AddressSpace::kUniform, sem->Access(), name)) {
return false;
}
out << ";";
}
Line() << "};";
return true;
}
bool ASTPrinter::EmitStorageVariable(const ast::Var* var, const sem::Variable* sem) {
auto* type = sem->Type()->UnwrapRef();
auto out = Line();
if (!EmitTypeAndName(out, type, core::AddressSpace::kStorage, sem->Access(),
var->name->symbol.Name())) {
return false;
}
auto* global_sem = sem->As<sem::GlobalVariable>();
out << RegisterAndSpace(sem->Access() == core::Access::kRead ? 't' : 'u',
*global_sem->BindingPoint())
<< ";";
return true;
}
bool ASTPrinter::EmitHandleVariable(const ast::Var* var, const sem::Variable* sem) {
auto* unwrapped_type = sem->Type()->UnwrapRef();
auto out = Line();
auto name = var->name->symbol.Name();
auto* type = sem->Type()->UnwrapRef();
if (!EmitTypeAndName(out, type, sem->AddressSpace(), sem->Access(), name)) {
return false;
}
const char* register_space = nullptr;
if (unwrapped_type->Is<core::type::Texture>()) {
register_space = "t";
if (auto* st = unwrapped_type->As<core::type::StorageTexture>();
st && st->access() != core::Access::kRead) {
register_space = "u";
}
} else if (unwrapped_type->Is<core::type::Sampler>()) {
register_space = "s";
}
if (register_space) {
auto bp = sem->As<sem::GlobalVariable>()->BindingPoint();
out << " : register(" << register_space << bp->binding;
// Omit the space if it's 0, as it's the default.
// SM 5.0 doesn't support spaces, so we don't emit them if group is 0 for better
// compatibility.
if (bp->group == 0) {
out << ")";
} else {
out << ", space" << bp->group << ")";
}
}
out << ";";
return true;
}
bool ASTPrinter::EmitPrivateVariable(const sem::Variable* var) {
auto* decl = var->Declaration();
auto out = Line();
out << "static ";
auto name = decl->name->symbol.Name();
auto* type = var->Type()->UnwrapRef();
if (!EmitTypeAndName(out, type, var->AddressSpace(), var->Access(), name)) {
return false;
}
out << " = ";
if (auto* initializer = decl->initializer) {
if (!EmitExpression(out, initializer)) {
return false;
}
} else {
if (!EmitZeroValue(out, var->Type()->UnwrapRef())) {
return false;
}
}
out << ";";
return true;
}
bool ASTPrinter::EmitWorkgroupVariable(const sem::Variable* var) {
auto* decl = var->Declaration();
auto out = Line();
out << "groupshared ";
auto name = decl->name->symbol.Name();
auto* type = var->Type()->UnwrapRef();
if (!EmitTypeAndName(out, type, var->AddressSpace(), var->Access(), name)) {
return false;
}
if (auto* initializer = decl->initializer) {
out << " = ";
if (!EmitExpression(out, initializer)) {
return false;
}
}
out << ";";
return true;
}
std::string ASTPrinter::builtin_to_attribute(core::BuiltinValue builtin) const {
switch (builtin) {
case core::BuiltinValue::kPosition:
return "SV_Position";
case core::BuiltinValue::kVertexIndex:
return "SV_VertexID";
case core::BuiltinValue::kInstanceIndex:
return "SV_InstanceID";
case core::BuiltinValue::kFrontFacing:
return "SV_IsFrontFace";
case core::BuiltinValue::kFragDepth:
return "SV_Depth";
case core::BuiltinValue::kLocalInvocationId:
return "SV_GroupThreadID";
case core::BuiltinValue::kLocalInvocationIndex:
return "SV_GroupIndex";
case core::BuiltinValue::kGlobalInvocationId:
return "SV_DispatchThreadID";
case core::BuiltinValue::kWorkgroupId:
return "SV_GroupID";
case core::BuiltinValue::kSampleIndex:
return "SV_SampleIndex";
case core::BuiltinValue::kSampleMask:
return "SV_Coverage";
default:
break;
}
return "";
}
std::string ASTPrinter::interpolation_to_modifiers(core::InterpolationType type,
core::InterpolationSampling sampling) const {
std::string modifiers;
switch (type) {
case core::InterpolationType::kPerspective:
modifiers += "linear ";
break;
case core::InterpolationType::kLinear:
modifiers += "noperspective ";
break;
case core::InterpolationType::kFlat:
modifiers += "nointerpolation ";
break;
case core::InterpolationType::kUndefined:
break;
}
switch (sampling) {
case core::InterpolationSampling::kCentroid:
modifiers += "centroid ";
break;
case core::InterpolationSampling::kSample:
modifiers += "sample ";
break;
case core::InterpolationSampling::kCenter:
case core::InterpolationSampling::kUndefined:
break;
}
return modifiers;
}
bool ASTPrinter::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 (size_t i = 0; i < 3; i++) {
if (i > 0) {
out << ", ";
}
if (!wgsize[i].has_value()) {
diagnostics_.add_error(
diag::System::Writer,
"override-expressions should have been removed with the SubstituteOverride "
"transform");
return false;
}
out << std::to_string(wgsize[i].value());
}
out << ")]" << std::endl;
}
if (!EmitTypeAndName(out, func_sem->ReturnType(), core::AddressSpace::kUndefined,
core::Access::kUndefined, func->name->symbol.Name())) {
return false;
}
out << "(";
bool first = true;
// Emit entry point parameters.
for (auto* var : func->params) {
auto* sem = builder_.Sem().Get(var);
auto* type = sem->Type();
if (TINT_UNLIKELY(!type->Is<core::type::Struct>())) {
// ICE likely indicates that the CanonicalizeEntryPointIO transform was
// not run, or a builtin parameter was added after it was run.
TINT_ICE() << "Unsupported non-struct entry point parameter";
}
if (!first) {
out << ", ";
}
first = false;
if (!EmitTypeAndName(out, type, sem->AddressSpace(), sem->Access(),
var->name->symbol.Name())) {
return false;
}
}
out << ") {";
}
{
ScopedIndent si(this);
if (!EmitStatements(func->body->statements)) {
return false;
}
if (!Is<ast::ReturnStatement>(func->body->Last())) {
ast::ReturnStatement ret(GenerationID(), ast::NodeID{}, Source{});
if (!EmitStatement(&ret)) {
return false;
}
}
}
Line() << "}";
return true;
}
bool ASTPrinter::EmitConstant(StringStream& out,
const core::constant::Value* constant,
bool is_variable_initializer) {
return Switch(
constant->Type(), //
[&](const core::type::Bool*) {
out << (constant->ValueAs<AInt>() ? "true" : "false");
return true;
},
[&](const core::type::F32*) {
PrintF32(out, constant->ValueAs<f32>());
return true;
},
[&](const core::type::F16*) {
// emit a f16 scalar with explicit float16_t type declaration.
out << "float16_t(";
PrintF16(out, constant->ValueAs<f16>());
out << ")";
return true;
},
[&](const core::type::I32*) {
out << constant->ValueAs<AInt>();
return true;
},
[&](const core::type::U32*) {
out << constant->ValueAs<AInt>() << "u";
return true;
},
[&](const core::type::Vector* v) {
if (auto* splat = constant->As<core::constant::Splat>()) {
{
ScopedParen sp(out);
if (!EmitConstant(out, splat->el, is_variable_initializer)) {
return false;
}
}
out << ".";
for (size_t i = 0; i < v->Width(); i++) {
out << "x";
}
return true;
}
if (!EmitType(out, v, core::AddressSpace::kUndefined, core::Access::kUndefined, "")) {
return false;
}
ScopedParen sp(out);
for (size_t i = 0; i < v->Width(); i++) {
if (i > 0) {
out << ", ";
}
if (!EmitConstant(out, constant->Index(i), is_variable_initializer)) {
return false;
}
}
return true;
},
[&](const core::type::Matrix* m) {
if (!EmitType(out, m, core::AddressSpace::kUndefined, core::Access::kUndefined, "")) {
return false;
}
ScopedParen sp(out);
for (size_t i = 0; i < m->columns(); i++) {
if (i > 0) {
out << ", ";
}
if (!EmitConstant(out, constant->Index(i), is_variable_initializer)) {
return false;
}
}
return true;
},
[&](const core::type::Array* a) {
if (constant->AllZero()) {
out << "(";
if (!EmitType(out, a, core::AddressSpace::kUndefined, core::Access::kUndefined,
"")) {
return false;
}
out << ")0";
return true;
}
out << "{";
TINT_DEFER(out << "}");
auto count = a->ConstantCount();
if (!count) {
diagnostics_.add_error(diag::System::Writer,
core::type::Array::kErrExpectedConstantCount);
return false;
}
for (size_t i = 0; i < count; i++) {
if (i > 0) {
out << ", ";
}
if (!EmitConstant(out, constant->Index(i), is_variable_initializer)) {
return false;
}
}
return true;
},
[&](const core::type::Struct* s) {
if (!EmitStructType(&helpers_, s)) {
return false;
}
if (constant->AllZero()) {
out << "(" << StructName(s) << ")0";
return true;
}
auto emit_member_values = [&](StringStream& o) {
o << "{";
for (size_t i = 0; i < s->Members().Length(); i++) {
if (i > 0) {
o << ", ";
}
if (!EmitConstant(o, constant->Index(i), is_variable_initializer)) {
return false;
}
}
o << "}";
return true;
};
if (is_variable_initializer) {
if (!emit_member_values(out)) {
return false;
}
} else {
// HLSL requires structure initializers to be assigned directly to a variable.
auto name = UniqueIdentifier("c");
{
auto decl = Line();
decl << "const " << StructName(s) << " " << name << " = ";
if (!emit_member_values(decl)) {
return false;
}
decl << ";";
}
out << name;
}
return true;
},
[&](Default) {
diagnostics_.add_error(diag::System::Writer,
"unhandled constant type: " + constant->Type()->FriendlyName());
return false;
});
}
bool ASTPrinter::EmitLiteral(StringStream& out, const ast::LiteralExpression* lit) {
return Switch(
lit,
[&](const ast::BoolLiteralExpression* l) {
out << (l->value ? "true" : "false");
return true;
},
[&](const ast::FloatLiteralExpression* l) {
if (l->suffix == ast::FloatLiteralExpression::Suffix::kH) {
// Emit f16 literal with explicit float16_t type declaration.
out << "float16_t(";
PrintF16(out, static_cast<float>(l->value));
out << ")";
}
PrintF32(out, static_cast<float>(l->value));
return true;
},
[&](const ast::IntLiteralExpression* i) {
out << i->value;
switch (i->suffix) {
case ast::IntLiteralExpression::Suffix::kNone:
case ast::IntLiteralExpression::Suffix::kI:
return true;
case ast::IntLiteralExpression::Suffix::kU:
out << "u";
return true;
}
diagnostics_.add_error(diag::System::Writer, "unknown integer literal suffix type");
return false;
},
[&](Default) {
diagnostics_.add_error(diag::System::Writer, "unknown literal type");
return false;
});
}
bool ASTPrinter::EmitValue(StringStream& out, const core::type::Type* type, int value) {
return Switch(
type,
[&](const core::type::Bool*) {
out << (value == 0 ? "false" : "true");
return true;
},
[&](const core::type::F32*) {
out << value << ".0f";
return true;
},
[&](const core::type::F16*) {
out << "float16_t(" << value << ".0h)";
return true;
},
[&](const core::type::I32*) {
out << value;
return true;
},
[&](const core::type::U32*) {
out << value << "u";
return true;
},
[&](const core::type::Vector* vec) {
if (!EmitType(out, type, core::AddressSpace::kUndefined, core::Access::kReadWrite,
"")) {
return false;
}
ScopedParen sp(out);
for (uint32_t i = 0; i < vec->Width(); i++) {
if (i != 0) {
out << ", ";
}
if (!EmitValue(out, vec->type(), value)) {
return false;
}
}
return true;
},
[&](const core::type::Matrix* mat) {
if (!EmitType(out, type, core::AddressSpace::kUndefined, core::Access::kReadWrite,
"")) {
return false;
}
ScopedParen sp(out);
for (uint32_t i = 0; i < (mat->rows() * mat->columns()); i++) {
if (i != 0) {
out << ", ";
}
if (!EmitValue(out, mat->type(), value)) {
return false;
}
}
return true;
},
[&](const core::type::Struct*) {
out << "(";
TINT_DEFER(out << ")" << value);
return EmitType(out, type, core::AddressSpace::kUndefined, core::Access::kUndefined,
"");
},
[&](const core::type::Array*) {
out << "(";
TINT_DEFER(out << ")" << value);
return EmitType(out, type, core::AddressSpace::kUndefined, core::Access::kUndefined,
"");
},
[&](Default) {
diagnostics_.add_error(diag::System::Writer,
"Invalid type for value emission: " + type->FriendlyName());
return false;
});
}
bool ASTPrinter::EmitZeroValue(StringStream& out, const core::type::Type* type) {
return EmitValue(out, type, 0);
}
bool ASTPrinter::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 ASTPrinter::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() << "{";
IncrementIndent();
TINT_DEFER({
DecrementIndent();
Line() << "}";
});
TextBuffer init_buf;
if (auto* init = stmt->initializer) {
TINT_SCOPED_ASSIGNMENT(current_buffer_, &init_buf);
if (!EmitStatement(init)) {
return false;
}
}
TextBuffer cond_pre;
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) {";
IncrementIndent();
TINT_DEFER({
DecrementIndent();
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 << tint::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 ASTPrinter::EmitWhile(const ast::WhileStatement* stmt) {
TextBuffer cond_pre;
StringStream cond_buf;
{
auto* cond = stmt->condition;
TINT_SCOPED_ASSIGNMENT(current_buffer_, &cond_pre);
if (!EmitExpression(cond_buf, cond)) {
return false;
}
}
auto emit_continuing = [&] { return true; };
TINT_SCOPED_ASSIGNMENT(emit_continuing_, emit_continuing);
// If the while has a multi-statement conditional, then we cannot emit this
// as a regular while in HLSL. Instead we need to generate a `while(true)` loop.
bool emit_as_loop = cond_pre.lines.size() > 0;
if (emit_as_loop) {
Line() << "while (true) {";
IncrementIndent();
TINT_DEFER({
DecrementIndent();
Line() << "}";
});
current_buffer_->Append(cond_pre);
Line() << "if (!(" << cond_buf.str() << ")) { break; }";
if (!EmitStatements(stmt->body->statements)) {
return false;
}
} else {
// While can be generated.
{
auto out = Line();
out << "while";
{
ScopedParen sp(out);
out << cond_buf.str();
}
out << " {";
}
if (!EmitStatementsWithIndent(stmt->body->statements)) {
return false;
}
Line() << "}";
}
return true;
}
bool ASTPrinter::EmitMemberAccessor(StringStream& out, const ast::MemberAccessorExpression* expr) {
if (!EmitExpression(out, expr->object)) {
return false;
}
out << ".";
auto* sem = builder_.Sem().Get(expr)->UnwrapLoad();
return Switch(
sem,
[&](const sem::Swizzle*) {
// Swizzles output the name directly
out << expr->member->symbol.Name();
return true;
},
[&](const sem::StructMemberAccess* member_access) {
out << member_access->Member()->Name().Name();
return true;
},
[&](Default) {
TINT_ICE() << "unknown member access type: " << sem->TypeInfo().name;
return false;
});
}
bool ASTPrinter::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 ASTPrinter::EmitStatement(const ast::Statement* stmt) {
return Switch(
stmt,
[&](const ast::AssignmentStatement* a) { //
return EmitAssign(a);
},
[&](const ast::BlockStatement* b) { //
return EmitBlock(b);
},
[&](const ast::BreakStatement* b) { //
return EmitBreak(b);
},
[&](const ast::BreakIfStatement* b) { //
return EmitBreakIf(b);
},
[&](const ast::CallStatement* c) { //
auto out = Line();
if (!EmitCall(out, c->expr)) {
return false;
}
out << ";";
return true;
},
[&](const ast::ContinueStatement* c) { //
return EmitContinue(c);
},
[&](const ast::DiscardStatement* d) { //
return EmitDiscard(d);
},
[&](const ast::IfStatement* i) { //
return EmitIf(i);
},
[&](const ast::LoopStatement* l) { //
return EmitLoop(l);
},
[&](const ast::ForLoopStatement* l) { //
return EmitForLoop(l);
},
[&](const ast::WhileStatement* l) { //
return EmitWhile(l);
},
[&](const ast::ReturnStatement* r) { //
return EmitReturn(r);
},
[&](const ast::SwitchStatement* s) { //
return EmitSwitch(s);
},
[&](const ast::VariableDeclStatement* v) { //
return Switch(
v->variable, //
[&](const ast::Var* var) { return EmitVar(var); },
[&](const ast::Let* let) { return EmitLet(let); },
[&](const ast::Const*) {
return true; // Constants are embedded at their use
},
[&](Default) { //
TINT_ICE() << "unknown variable type: " << v->variable->TypeInfo().name;
return false;
});
},
[&](const ast::ConstAssert*) {
return true; // Not emitted
},
[&](Default) { //
diagnostics_.add_error(diag::System::Writer,
"unknown statement type: " + std::string(stmt->TypeInfo().name));
return false;
});
}
bool ASTPrinter::EmitDefaultOnlySwitch(const ast::SwitchStatement* stmt) {
TINT_ASSERT(stmt->body.Length() == 1 && stmt->body[0]->ContainsDefault());
// FXC fails to compile a switch with just a default case, ignoring the
// default case body. We work around this here by emitting the default case
// without the switch.
// Emit the switch condition as-is if it has side-effects (e.g.
// function call). Note that we can ignore the result of the expression (if any).
if (auto* sem_cond = builder_.Sem().GetVal(stmt->condition); sem_cond->HasSideEffects()) {
auto out = Line();
if (!EmitExpression(out, stmt->condition)) {
return false;
}
out << ";";
}
// Emit "do { <default case body> } while(false);". We use a 'do' loop so
// that break statements work as expected, and make it 'while (false)' in
// case there isn't a break statement.
Line() << "do {";
{
ScopedIndent si(this);
if (!EmitStatements(stmt->body[0]->body->statements)) {
return false;
}
}
Line() << "} while (false);";
return true;
}
bool ASTPrinter::EmitSwitch(const ast::SwitchStatement* stmt) {
// BUG(crbug.com/tint/1188): work around default-only switches
if (stmt->body.Length() == 1 && stmt->body[0]->selectors.Length() == 1 &&
stmt->body[0]->ContainsDefault()) {
return EmitDefaultOnlySwitch(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.Length(); i++) {
if (!EmitCase(stmt, i)) {
return false;
}
}
}
Line() << "}";
return true;
}
bool ASTPrinter::EmitType(StringStream& out,
const core::type::Type* type,
core::AddressSpace address_space,
core::Access access,
const std::string& name,
bool* name_printed /* = nullptr */) {
if (name_printed) {
*name_printed = false;
}
switch (address_space) {
case core::AddressSpace::kStorage:
if (access != core::Access::kRead) {
out << "RW";
}
out << "ByteAddressBuffer";
return true;
case core::AddressSpace::kUniform: {
auto array_length = (type->Size() + 15) / 16;
out << "uint4 " << name << "[" << array_length << "]";
if (name_printed) {
*name_printed = true;
}
return true;
}
default:
break;
}
return Switch(
type,
[&](const core::type::Array* ary) {
const core::type::Type* base_type = ary;
std::vector<uint32_t> sizes;
while (auto* arr = base_type->As<core::type::Array>()) {
if (TINT_UNLIKELY(arr->Count()->Is<core::type::RuntimeArrayCount>())) {
TINT_ICE()
<< "runtime arrays may only exist in storage buffers, which should have "
"been transformed into a ByteAddressBuffer";
return false;
}
const auto count = arr->ConstantCount();
if (!count) {
diagnostics_.add_error(diag::System::Writer,
core::type::Array::kErrExpectedConstantCount);
return false;
}
sizes.push_back(count.value());
base_type = arr->ElemType();
}
if (!EmitType(out, base_type, address_space, access, "")) {
return false;
}
if (!name.empty()) {
out << " " << name;
if (name_printed) {
*name_printed = true;
}
}
for (uint32_t size : sizes) {
out << "[" << size << "]";
}
return true;
},
[&](const core::type::Bool*) {
out << "bool";
return true;
},
[&](const core::type::F32*) {
out << "float";
return true;
},
[&](const core::type::F16*) {
out << "float16_t";
return true;
},
[&](const core::type::I32*) {
out << "int";
return true;
},
[&](const core::type::Matrix* mat) {
if (mat->type()->Is<core::type::F16>()) {
// Use matrix<type, N, M> for f16 matrix
out << "matrix<";
if (!EmitType(out, mat->type(), address_space, access, "")) {
return false;
}
out << ", " << mat->columns() << ", " << mat->rows() << ">";
return true;
}
if (!EmitType(out, mat->type(), address_space, 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
// initializers 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();
return true;
},
[&](const core::type::Pointer*) {
TINT_ICE() << "Attempting to emit pointer type. These should have "
"been removed with the SimplifyPointers transform";
return false;
},
[&](const core::type::Sampler* sampler) {
out << "Sampler";
if (sampler->IsComparison()) {
out << "Comparison";
}
out << "State";
return true;
},
[&](const core::type::Struct* str) {
out << StructName(str);
return true;
},
[&](const core::type::Texture* tex) {
if (TINT_UNLIKELY(tex->Is<core::type::ExternalTexture>())) {
TINT_ICE() << "Multiplanar external texture transform was not run.";
return false;
}
auto* storage = tex->As<core::type::StorageTexture>();
auto* ms = tex->As<core::type::MultisampledTexture>();
auto* depth_ms = tex->As<core::type::DepthMultisampledTexture>();
auto* sampled = tex->As<core::type::SampledTexture>();
if (storage && storage->access() != core::Access::kRead) {
out << "RW";
}
out << "Texture";
switch (tex->dim()) {
case core::type::TextureDimension::k1d:
out << "1D";
break;
case core::type::TextureDimension::k2d:
out << ((ms || depth_ms) ? "2DMS" : "2D");
break;
case core::type::TextureDimension::k2dArray:
out << ((ms || depth_ms) ? "2DMSArray" : "2DArray");
break;
case core::type::TextureDimension::k3d:
out << "3D";
break;
case core::type::TextureDimension::kCube:
out << "Cube";
break;
case core::type::TextureDimension::kCubeArray:
out << "CubeArray";
break;
default:
TINT_UNREACHABLE() << "unexpected TextureDimension " << tex->dim();
return false;
}
if (storage) {
auto* component = image_format_to_rwtexture_type(storage->texel_format());
if (TINT_UNLIKELY(!component)) {
TINT_ICE() << "Unsupported StorageTexture TexelFormat: "
<< static_cast<int>(storage->texel_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<core::type::F32>()) {
out << "float4";
} else if (subtype->Is<core::type::I32>()) {
out << "int4";
} else if (TINT_LIKELY(subtype->Is<core::type::U32>())) {
out << "uint4";
} else {
TINT_ICE() << "Unsupported multisampled texture type";
return false;
}
out << ">";
}
return true;
},
[&](const core::type::U32*) {
out << "uint";
return true;
},
[&](const core::type::Vector* vec) {
auto width = vec->Width();
if (vec->type()->Is<core::type::F32>() && width >= 1 && width <= 4) {
out << "float" << width;
} else if (vec->type()->Is<core::type::I32>() && width >= 1 && width <= 4) {
out << "int" << width;
} else if (vec->type()->Is<core::type::U32>() && width >= 1 && width <= 4) {
out << "uint" << width;
} else if (vec->type()->Is<core::type::Bool>() && width >= 1 && width <= 4) {
out << "bool" << width;
} else {
// For example, use "vector<float16_t, N>" for f16 vector.
out << "vector<";
if (!EmitType(out, vec->type(), address_space, access, "")) {
return false;
}
out << ", " << width << ">";
}
return true;
},
[&](const core::type::Atomic* atomic) {
return EmitType(out, atomic->Type(), address_space, access, name);
},
[&](const core::type::Void*) {
out << "void";
return true;
},
[&](Default) {
diagnostics_.add_error(diag::System::Writer, "unknown type in EmitType");
return false;
});
}
bool ASTPrinter::EmitTypeAndName(StringStream& out,
const core::type::Type* type,
core::AddressSpace address_space,
core::Access access,
const std::string& name) {
bool name_printed = false;
if (!EmitType(out, type, address_space, access, name, &name_printed)) {
return false;
}
if (!name.empty() && !name_printed) {
out << " " << name;
}
return true;
}
bool ASTPrinter::EmitStructType(TextBuffer* b, const core::type::Struct* str) {
auto it = emitted_structs_.emplace(str);
if (!it.second) {
return true;
}
Line(b) << "struct " << StructName(str) << " {";
{
ScopedIndent si(b);
for (auto* mem : str->Members()) {
auto mem_name = mem->Name().Name();
auto* ty = mem->Type();
auto out = Line(b);
std::string pre, post;
auto& attributes = mem->Attributes();
if (auto location = attributes.location) {
auto& pipeline_stage_uses = str->PipelineStageUses();
if (TINT_UNLIKELY(pipeline_stage_uses.size() != 1)) {
TINT_ICE() << "invalid entry point IO struct uses";
}
if (pipeline_stage_uses.count(core::type::PipelineStageUsage::kVertexInput)) {
post += " : TEXCOORD" + std::to_string(location.value());
} else if (pipeline_stage_uses.count(
core::type::PipelineStageUsage::kVertexOutput)) {
post += " : TEXCOORD" + std::to_string(location.value());
} else if (pipeline_stage_uses.count(
core::type::PipelineStageUsage::kFragmentInput)) {
post += " : TEXCOORD" + std::to_string(location.value());
} else if (TINT_LIKELY(pipeline_stage_uses.count(
core::type::PipelineStageUsage::kFragmentOutput))) {
if (auto index = attributes.index) {
post += " : SV_Target" + std::to_string(location.value() + index.value());
} else {
post += " : SV_Target" + std::to_string(location.value());
}
} else {
TINT_ICE() << "invalid use of location attribute";
}
}
if (auto builtin = attributes.builtin) {
auto name = builtin_to_attribute(builtin.value());
if (name.empty()) {
diagnostics_.add_error(diag::System::Writer, "unsupported builtin");
return false;
}
post += " : " + name;
}
if (auto interpolation = attributes.interpolation) {
auto mod = interpolation_to_modifiers(interpolation->type, interpolation->sampling);
if (mod.empty()) {
diagnostics_.add_error(diag::System::Writer, "unsupported interpolation");
return false;
}
pre += mod;
}
if (attributes.invariant) {
// 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 ";
}
out << pre;
if (!EmitTypeAndName(out, ty, core::AddressSpace::kUndefined, core::Access::kReadWrite,
mem_name)) {
return false;
}
out << post << ";";
}
}
Line(b) << "};";
return true;
}
bool ASTPrinter::EmitUnaryOp(StringStream& out, const ast::UnaryOpExpression* expr) {
switch (expr->op) {
case core::UnaryOp::kIndirection:
case core::UnaryOp::kAddressOf:
return EmitExpression(out, expr->expr);
case core::UnaryOp::kComplement:
out << "~";
break;
case core::UnaryOp::kNot:
out << "!";
break;
case core::UnaryOp::kNegation:
out << "-";
break;
}
out << "(";
if (!EmitExpression(out, expr->expr)) {
return false;
}
out << ")";
return true;
}
bool ASTPrinter::EmitVar(const ast::Var* var) {
auto* sem = builder_.Sem().Get(var);
auto* type = sem->Type()->UnwrapRef();
auto out = Line();
if (!EmitTypeAndName(out, type, sem->AddressSpace(), sem->Access(), var->name->symbol.Name())) {
return false;
}
out << " = ";
if (var->initializer) {
if (!EmitExpression(out, var->initializer)) {
return false;
}
} else {
if (!EmitZeroValue(out, type)) {
return false;
}
}
out << ";";
return true;
}
bool ASTPrinter::EmitLet(const ast::Let* let) {
auto* sem = builder_.Sem().Get(let);
auto* type = sem->Type()->UnwrapRef();
auto out = Line();
out << "const ";
if (!EmitTypeAndName(out, type, core::AddressSpace::kUndefined, core::Access::kUndefined,
let->name->symbol.Name())) {
return false;
}
out << " = ";
if (!EmitExpression(out, let->initializer)) {
return false;
}
out << ";";
return true;
}
template <typename F>
bool ASTPrinter::CallBuiltinHelper(StringStream& out,
const ast::CallExpression* call,
const sem::Builtin* builtin,
F&& build) {
// Generate the helper function if it hasn't been created already
auto fn = tint::GetOrCreate(builtins_, builtin, [&]() -> std::string {
TextBuffer b;
TINT_DEFER(helpers_.Append(b));
auto fn_name = UniqueIdentifier(std::string("tint_") + core::str(builtin->Type()));
std::vector<std::string> parameter_names;
{
auto decl = Line(&b);
if (!EmitTypeAndName(decl, builtin->ReturnType(), core::AddressSpace::kUndefined,
core::Access::kUndefined, fn_name)) {
return "";
}
{
ScopedParen sp(decl);
for (auto* param : builtin->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<core::type::Pointer>()) {
decl << "inout ";
ty = ptr->StoreType();
}
if (!EmitTypeAndName(decl, ty, core::AddressSpace::kUndefined,
core::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;
}
std::string ASTPrinter::StructName(const core::type::Struct* s) {
auto name = s->Name().Name();
if (HasPrefix(name, "__")) {
name = tint::GetOrCreate(builtin_struct_names_, s,
[&] { return UniqueIdentifier(name.substr(2)); });
}
return name;
}
std::string ASTPrinter::UniqueIdentifier(const std::string& prefix /* = "" */) {
return builder_.Symbols().New(prefix).Name();
}
} // namespace tint::hlsl::writer