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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/reader/spirv/parser_impl.h"
#include <algorithm>
#include <limits>
#include <locale>
#include <utility>
#include "source/opt/build_module.h"
#include "src/ast/bitcast_expression.h"
#include "src/ast/disable_validation_decoration.h"
#include "src/ast/interpolate_decoration.h"
#include "src/ast/override_decoration.h"
#include "src/ast/struct_block_decoration.h"
#include "src/ast/type_name.h"
#include "src/ast/unary_op_expression.h"
#include "src/reader/spirv/function.h"
#include "src/sem/depth_texture_type.h"
#include "src/sem/multisampled_texture_type.h"
#include "src/sem/sampled_texture_type.h"
#include "src/utils/unique_vector.h"
namespace tint {
namespace reader {
namespace spirv {
namespace {
// Input SPIR-V needs only to conform to Vulkan 1.1 requirements.
// The combination of the SPIR-V reader and the semantics of WGSL
// tighten up the code so that the output of the SPIR-V *writer*
// will satisfy SPV_ENV_WEBGPU_0 validation.
const spv_target_env kInputEnv = SPV_ENV_VULKAN_1_1;
// A FunctionTraverser is used to compute an ordering of functions in the
// module such that callees precede callers.
class FunctionTraverser {
public:
explicit FunctionTraverser(const spvtools::opt::Module& module)
: module_(module) {}
// @returns the functions in the modules such that callees precede callers.
std::vector<const spvtools::opt::Function*> TopologicallyOrderedFunctions() {
visited_.clear();
ordered_.clear();
id_to_func_.clear();
for (const auto& f : module_) {
id_to_func_[f.result_id()] = &f;
}
for (const auto& f : module_) {
Visit(f);
}
return ordered_;
}
private:
void Visit(const spvtools::opt::Function& f) {
if (visited_.count(&f)) {
return;
}
visited_.insert(&f);
for (const auto& bb : f) {
for (const auto& inst : bb) {
if (inst.opcode() != SpvOpFunctionCall) {
continue;
}
const auto* callee = id_to_func_[inst.GetSingleWordInOperand(0)];
if (callee) {
Visit(*callee);
}
}
}
ordered_.push_back(&f);
}
const spvtools::opt::Module& module_;
std::unordered_set<const spvtools::opt::Function*> visited_;
std::unordered_map<uint32_t, const spvtools::opt::Function*> id_to_func_;
std::vector<const spvtools::opt::Function*> ordered_;
};
// Returns true if the opcode operates as if its operands are signed integral.
bool AssumesSignedOperands(SpvOp opcode) {
switch (opcode) {
case SpvOpSNegate:
case SpvOpSDiv:
case SpvOpSRem:
case SpvOpSMod:
case SpvOpSLessThan:
case SpvOpSLessThanEqual:
case SpvOpSGreaterThan:
case SpvOpSGreaterThanEqual:
case SpvOpConvertSToF:
return true;
default:
break;
}
return false;
}
// Returns true if the GLSL extended instruction expects operands to be signed.
// @param extended_opcode GLSL.std.450 opcode
// @returns true if all operands must be signed integral type
bool AssumesSignedOperands(GLSLstd450 extended_opcode) {
switch (extended_opcode) {
case GLSLstd450SAbs:
case GLSLstd450SSign:
case GLSLstd450SMin:
case GLSLstd450SMax:
case GLSLstd450SClamp:
return true;
default:
break;
}
return false;
}
// Returns true if the opcode operates as if its operands are unsigned integral.
bool AssumesUnsignedOperands(SpvOp opcode) {
switch (opcode) {
case SpvOpUDiv:
case SpvOpUMod:
case SpvOpULessThan:
case SpvOpULessThanEqual:
case SpvOpUGreaterThan:
case SpvOpUGreaterThanEqual:
case SpvOpConvertUToF:
return true;
default:
break;
}
return false;
}
// Returns true if the GLSL extended instruction expects operands to be
// unsigned.
// @param extended_opcode GLSL.std.450 opcode
// @returns true if all operands must be unsigned integral type
bool AssumesUnsignedOperands(GLSLstd450 extended_opcode) {
switch (extended_opcode) {
case GLSLstd450UMin:
case GLSLstd450UMax:
case GLSLstd450UClamp:
return true;
default:
break;
}
return false;
}
// Returns true if the corresponding WGSL operation requires
// the signedness of the second operand to match the signedness of the
// first operand, and it's not one of the OpU* or OpS* instructions.
// (Those are handled via MakeOperand.)
bool AssumesSecondOperandSignednessMatchesFirstOperand(SpvOp opcode) {
switch (opcode) {
// All the OpI* integer binary operations.
case SpvOpIAdd:
case SpvOpISub:
case SpvOpIMul:
case SpvOpIEqual:
case SpvOpINotEqual:
// All the bitwise integer binary operations.
case SpvOpBitwiseAnd:
case SpvOpBitwiseOr:
case SpvOpBitwiseXor:
return true;
default:
break;
}
return false;
}
// Returns true if the corresponding WGSL operation requires
// the signedness of the result to match the signedness of the first operand.
bool AssumesResultSignednessMatchesFirstOperand(SpvOp opcode) {
switch (opcode) {
case SpvOpNot:
case SpvOpSNegate:
case SpvOpBitCount:
case SpvOpBitReverse:
case SpvOpSDiv:
case SpvOpSMod:
case SpvOpSRem:
case SpvOpIAdd:
case SpvOpISub:
case SpvOpIMul:
case SpvOpBitwiseAnd:
case SpvOpBitwiseOr:
case SpvOpBitwiseXor:
case SpvOpShiftLeftLogical:
case SpvOpShiftRightLogical:
case SpvOpShiftRightArithmetic:
return true;
default:
break;
}
return false;
}
// Returns true if the extended instruction requires the signedness of the
// result to match the signedness of the first operand to the operation.
// @param extended_opcode GLSL.std.450 opcode
// @returns true if the result type must match the first operand type.
bool AssumesResultSignednessMatchesFirstOperand(GLSLstd450 extended_opcode) {
switch (extended_opcode) {
case GLSLstd450SAbs:
case GLSLstd450SSign:
case GLSLstd450SMin:
case GLSLstd450SMax:
case GLSLstd450SClamp:
case GLSLstd450UMin:
case GLSLstd450UMax:
case GLSLstd450UClamp:
// TODO(dneto): FindSMsb?
// TODO(dneto): FindUMsb?
return true;
default:
break;
}
return false;
}
// @param a SPIR-V decoration
// @return true when the given decoration is a pipeline decoration other than a
// bulitin variable.
bool IsPipelineDecoration(const Decoration& deco) {
if (deco.size() < 1) {
return false;
}
switch (deco[0]) {
case SpvDecorationLocation:
case SpvDecorationFlat:
case SpvDecorationNoPerspective:
case SpvDecorationCentroid:
case SpvDecorationSample:
return true;
default:
break;
}
return false;
}
} // namespace
TypedExpression::TypedExpression() = default;
TypedExpression::TypedExpression(const TypedExpression&) = default;
TypedExpression& TypedExpression::operator=(const TypedExpression&) = default;
TypedExpression::TypedExpression(const Type* type_in, ast::Expression* expr_in)
: type(type_in), expr(expr_in) {}
ParserImpl::ParserImpl(const std::vector<uint32_t>& spv_binary)
: Reader(),
spv_binary_(spv_binary),
fail_stream_(&success_, &errors_),
namer_(fail_stream_),
enum_converter_(fail_stream_),
tools_context_(kInputEnv) {
// Create a message consumer to propagate error messages from SPIRV-Tools
// out as our own failures.
message_consumer_ = [this](spv_message_level_t level, const char* /*source*/,
const spv_position_t& position,
const char* message) {
switch (level) {
// Ignore info and warning message.
case SPV_MSG_WARNING:
case SPV_MSG_INFO:
break;
// Otherwise, propagate the error.
default:
// For binary validation errors, we only have the instruction
// number. It's not text, so there is no column number.
this->Fail() << "line:" << position.index << ": " << message;
}
};
}
ParserImpl::~ParserImpl() = default;
bool ParserImpl::Parse() {
// Set up use of SPIRV-Tools utilities.
spvtools::SpirvTools spv_tools(kInputEnv);
// Error messages from SPIRV-Tools are forwarded as failures, including
// setting |success_| to false.
spv_tools.SetMessageConsumer(message_consumer_);
if (!success_) {
return false;
}
// Only consider modules valid for Vulkan 1.0. On failure, the message
// consumer will set the error status.
if (!spv_tools.Validate(spv_binary_)) {
success_ = false;
return false;
}
if (!BuildInternalModule()) {
return false;
}
if (!ParseInternalModule()) {
return false;
}
return success_;
}
Program ParserImpl::program() {
// TODO(dneto): Should we clear out spv_binary_ here, to reduce
// memory usage?
return tint::Program(std::move(builder_));
}
const Type* ParserImpl::ConvertType(uint32_t type_id, PtrAs ptr_as) {
if (!success_) {
return nullptr;
}
if (type_mgr_ == nullptr) {
Fail() << "ConvertType called when the internal module has not been built";
return nullptr;
}
auto* spirv_type = type_mgr_->GetType(type_id);
if (spirv_type == nullptr) {
Fail() << "ID is not a SPIR-V type: " << type_id;
return nullptr;
}
auto maybe_generate_alias = [this, type_id,
spirv_type](const Type* type) -> const Type* {
if (type != nullptr) {
return MaybeGenerateAlias(type_id, spirv_type, type);
}
return type;
};
switch (spirv_type->kind()) {
case spvtools::opt::analysis::Type::kVoid:
return maybe_generate_alias(ty_.Void());
case spvtools::opt::analysis::Type::kBool:
return maybe_generate_alias(ty_.Bool());
case spvtools::opt::analysis::Type::kInteger:
return maybe_generate_alias(ConvertType(spirv_type->AsInteger()));
case spvtools::opt::analysis::Type::kFloat:
return maybe_generate_alias(ConvertType(spirv_type->AsFloat()));
case spvtools::opt::analysis::Type::kVector:
return maybe_generate_alias(ConvertType(spirv_type->AsVector()));
case spvtools::opt::analysis::Type::kMatrix:
return maybe_generate_alias(ConvertType(spirv_type->AsMatrix()));
case spvtools::opt::analysis::Type::kRuntimeArray:
return maybe_generate_alias(ConvertType(spirv_type->AsRuntimeArray()));
case spvtools::opt::analysis::Type::kArray:
return maybe_generate_alias(ConvertType(spirv_type->AsArray()));
case spvtools::opt::analysis::Type::kStruct:
return maybe_generate_alias(ConvertType(type_id, spirv_type->AsStruct()));
case spvtools::opt::analysis::Type::kPointer:
return maybe_generate_alias(
ConvertType(type_id, ptr_as, spirv_type->AsPointer()));
case spvtools::opt::analysis::Type::kFunction:
// Tint doesn't have a Function type.
// We need to convert the result type and parameter types.
// But the SPIR-V defines those before defining the function
// type. No further work is required here.
return nullptr;
case spvtools::opt::analysis::Type::kSampler:
case spvtools::opt::analysis::Type::kSampledImage:
case spvtools::opt::analysis::Type::kImage:
// Fake it for sampler and texture types. These are handled in an
// entirely different way.
return maybe_generate_alias(ty_.Void());
default:
break;
}
Fail() << "unknown SPIR-V type with ID " << type_id << ": "
<< def_use_mgr_->GetDef(type_id)->PrettyPrint();
return nullptr;
}
DecorationList ParserImpl::GetDecorationsFor(uint32_t id) const {
DecorationList result;
const auto& decorations = deco_mgr_->GetDecorationsFor(id, true);
for (const auto* inst : decorations) {
if (inst->opcode() != SpvOpDecorate) {
continue;
}
// Example: OpDecorate %struct_id Block
// Example: OpDecorate %array_ty ArrayStride 16
std::vector<uint32_t> inst_as_words;
inst->ToBinaryWithoutAttachedDebugInsts(&inst_as_words);
Decoration d(inst_as_words.begin() + 2, inst_as_words.end());
result.push_back(d);
}
return result;
}
DecorationList ParserImpl::GetDecorationsForMember(
uint32_t id,
uint32_t member_index) const {
DecorationList result;
const auto& decorations = deco_mgr_->GetDecorationsFor(id, true);
for (const auto* inst : decorations) {
if ((inst->opcode() != SpvOpMemberDecorate) ||
(inst->GetSingleWordInOperand(1) != member_index)) {
continue;
}
// Example: OpMemberDecorate %struct_id 2 Offset 24
std::vector<uint32_t> inst_as_words;
inst->ToBinaryWithoutAttachedDebugInsts(&inst_as_words);
Decoration d(inst_as_words.begin() + 3, inst_as_words.end());
result.push_back(d);
}
return result;
}
std::string ParserImpl::ShowType(uint32_t type_id) {
if (def_use_mgr_) {
const auto* type_inst = def_use_mgr_->GetDef(type_id);
if (type_inst) {
return type_inst->PrettyPrint();
}
}
return "SPIR-V type " + std::to_string(type_id);
}
ast::DecorationList ParserImpl::ConvertMemberDecoration(
uint32_t struct_type_id,
uint32_t member_index,
const Type* member_ty,
const Decoration& decoration) {
if (decoration.empty()) {
Fail() << "malformed SPIR-V decoration: it's empty";
return {};
}
switch (decoration[0]) {
case SpvDecorationOffset:
if (decoration.size() != 2) {
Fail()
<< "malformed Offset decoration: expected 1 literal operand, has "
<< decoration.size() - 1 << ": member " << member_index << " of "
<< ShowType(struct_type_id);
return {};
}
return {
create<ast::StructMemberOffsetDecoration>(Source{}, decoration[1]),
};
case SpvDecorationNonReadable:
// WGSL doesn't have a member decoration for this. Silently drop it.
return {};
case SpvDecorationNonWritable:
// WGSL doesn't have a member decoration for this.
return {};
case SpvDecorationColMajor:
// WGSL only supports column major matrices.
return {};
case SpvDecorationRelaxedPrecision:
// WGSL doesn't support relaxed precision.
return {};
case SpvDecorationRowMajor:
Fail() << "WGSL does not support row-major matrices: can't "
"translate member "
<< member_index << " of " << ShowType(struct_type_id);
return {};
case SpvDecorationMatrixStride: {
if (decoration.size() != 2) {
Fail() << "malformed MatrixStride decoration: expected 1 literal "
"operand, has "
<< decoration.size() - 1 << ": member " << member_index << " of "
<< ShowType(struct_type_id);
return {};
}
uint32_t stride = decoration[1];
auto* ty = member_ty->UnwrapAlias();
while (auto* arr = ty->As<Array>()) {
ty = arr->type->UnwrapAlias();
}
auto* mat = ty->As<Matrix>();
if (!mat) {
Fail() << "MatrixStride cannot be applied to type " << ty->String();
return {};
}
uint32_t natural_stride = (mat->rows == 2) ? 8 : 16;
if (stride == natural_stride) {
return {}; // Decoration matches the natural stride for the matrix
}
if (!member_ty->Is<Matrix>()) {
Fail() << "custom matrix strides not currently supported on array of "
"matrices";
return {};
}
return {
create<ast::StrideDecoration>(Source{}, decoration[1]),
builder_.ASTNodes().Create<ast::DisableValidationDecoration>(
builder_.ID(), ast::DisabledValidation::kIgnoreStrideDecoration),
};
}
default:
// TODO(dneto): Support the remaining member decorations.
break;
}
Fail() << "unhandled member decoration: " << decoration[0] << " on member "
<< member_index << " of " << ShowType(struct_type_id);
return {};
}
bool ParserImpl::BuildInternalModule() {
if (!success_) {
return false;
}
const spv_context& context = tools_context_.CContext();
ir_context_ = spvtools::BuildModule(context->target_env, context->consumer,
spv_binary_.data(), spv_binary_.size());
if (!ir_context_) {
return Fail() << "internal error: couldn't build the internal "
"representation of the module";
}
module_ = ir_context_->module();
def_use_mgr_ = ir_context_->get_def_use_mgr();
constant_mgr_ = ir_context_->get_constant_mgr();
type_mgr_ = ir_context_->get_type_mgr();
deco_mgr_ = ir_context_->get_decoration_mgr();
topologically_ordered_functions_ =
FunctionTraverser(*module_).TopologicallyOrderedFunctions();
return success_;
}
void ParserImpl::ResetInternalModule() {
ir_context_.reset(nullptr);
module_ = nullptr;
def_use_mgr_ = nullptr;
constant_mgr_ = nullptr;
type_mgr_ = nullptr;
deco_mgr_ = nullptr;
glsl_std_450_imports_.clear();
}
bool ParserImpl::ParseInternalModule() {
if (!success_) {
return false;
}
RegisterLineNumbers();
if (!ParseInternalModuleExceptFunctions()) {
return false;
}
if (!EmitFunctions()) {
return false;
}
return success_;
}
void ParserImpl::RegisterLineNumbers() {
Source::Location instruction_number{};
// Has there been an OpLine since the last OpNoLine or start of the module?
bool in_op_line_scope = false;
// The source location provided by the most recent OpLine instruction.
Source::Location op_line_source{};
const bool run_on_debug_insts = true;
module_->ForEachInst(
[this, &in_op_line_scope, &op_line_source,
&instruction_number](const spvtools::opt::Instruction* inst) {
++instruction_number.line;
switch (inst->opcode()) {
case SpvOpLine:
in_op_line_scope = true;
// TODO(dneto): This ignores the File ID (operand 0), since the Tint
// Source concept doesn't represent that.
op_line_source.line = inst->GetSingleWordInOperand(1);
op_line_source.column = inst->GetSingleWordInOperand(2);
break;
case SpvOpNoLine:
in_op_line_scope = false;
break;
default:
break;
}
this->inst_source_[inst] =
in_op_line_scope ? op_line_source : instruction_number;
},
run_on_debug_insts);
}
Source ParserImpl::GetSourceForResultIdForTest(uint32_t id) const {
return GetSourceForInst(def_use_mgr_->GetDef(id));
}
Source ParserImpl::GetSourceForInst(
const spvtools::opt::Instruction* inst) const {
auto where = inst_source_.find(inst);
if (where == inst_source_.end()) {
return {};
}
return Source{where->second};
}
bool ParserImpl::ParseInternalModuleExceptFunctions() {
if (!success_) {
return false;
}
if (!RegisterExtendedInstructionImports()) {
return false;
}
if (!RegisterUserAndStructMemberNames()) {
return false;
}
if (!RegisterWorkgroupSizeBuiltin()) {
return false;
}
if (!RegisterEntryPoints()) {
return false;
}
if (!RegisterHandleUsage()) {
return false;
}
if (!RegisterTypes()) {
return false;
}
if (!RejectInvalidPointerRoots()) {
return false;
}
if (!EmitScalarSpecConstants()) {
return false;
}
if (!EmitModuleScopeVariables()) {
return false;
}
return success_;
}
bool ParserImpl::RegisterExtendedInstructionImports() {
for (const spvtools::opt::Instruction& import : module_->ext_inst_imports()) {
std::string name(
reinterpret_cast<const char*>(import.GetInOperand(0).words.data()));
// TODO(dneto): Handle other extended instruction sets when needed.
if (name == "GLSL.std.450") {
glsl_std_450_imports_.insert(import.result_id());
} else if (name.find("NonSemantic.") == 0) {
ignored_imports_.insert(import.result_id());
} else {
return Fail() << "Unrecognized extended instruction set: " << name;
}
}
return true;
}
bool ParserImpl::IsGlslExtendedInstruction(
const spvtools::opt::Instruction& inst) const {
return (inst.opcode() == SpvOpExtInst) &&
(glsl_std_450_imports_.count(inst.GetSingleWordInOperand(0)) > 0);
}
bool ParserImpl::IsIgnoredExtendedInstruction(
const spvtools::opt::Instruction& inst) const {
return (inst.opcode() == SpvOpExtInst) &&
(ignored_imports_.count(inst.GetSingleWordInOperand(0)) > 0);
}
bool ParserImpl::RegisterUserAndStructMemberNames() {
if (!success_) {
return false;
}
// Register entry point names. An entry point name is the point of contact
// between the API and the shader. It has the highest priority for
// preservation, so register it first.
for (const spvtools::opt::Instruction& entry_point :
module_->entry_points()) {
const uint32_t function_id = entry_point.GetSingleWordInOperand(1);
const std::string name = entry_point.GetInOperand(2).AsString();
// This translator requires the entry point to be a valid WGSL identifier.
// Allowing otherwise leads to difficulties in that the programmer needs
// to get a mapping from their original entry point name to the WGSL name,
// and we don't have a good mechanism for that.
if (!IsValidIdentifier(name)) {
return Fail() << "entry point name is not a valid WGSL identifier: "
<< name;
}
// SPIR-V allows a single function to be the implementation for more
// than one entry point. In the common case, it's one-to-one, and we should
// try to name the function after the entry point. Otherwise, give the
// function a name automatically derived from the entry point name.
namer_.SuggestSanitizedName(function_id, name);
// There is another many-to-one relationship to take care of: In SPIR-V
// the same name can be used for multiple entry points, provided they are
// for different shader stages. Take action now to ensure we can use the
// entry point name later on, and not have it taken for another identifier
// by an accidental collision with a derived name made for a different ID.
if (!namer_.IsRegistered(name)) {
// The entry point name is "unoccupied" becase an earlier entry point
// grabbed the slot for the function that implements both entry points.
// Register this new entry point's name, to avoid accidental collisions
// with a future generated ID.
if (!namer_.RegisterWithoutId(name)) {
return false;
}
}
}
// Register names from OpName and OpMemberName
for (const auto& inst : module_->debugs2()) {
switch (inst.opcode()) {
case SpvOpName: {
const auto name = inst.GetInOperand(1).AsString();
if (!name.empty()) {
namer_.SuggestSanitizedName(inst.GetSingleWordInOperand(0), name);
}
break;
}
case SpvOpMemberName: {
const auto name = inst.GetInOperand(2).AsString();
if (!name.empty()) {
namer_.SuggestSanitizedMemberName(inst.GetSingleWordInOperand(0),
inst.GetSingleWordInOperand(1),
name);
}
break;
}
default:
break;
}
}
// Fill in struct member names, and disambiguate them.
for (const auto* type_inst : module_->GetTypes()) {
if (type_inst->opcode() == SpvOpTypeStruct) {
namer_.ResolveMemberNamesForStruct(type_inst->result_id(),
type_inst->NumInOperands());
}
}
return true;
}
bool ParserImpl::IsValidIdentifier(const std::string& str) {
if (str.empty()) {
return false;
}
std::locale c_locale("C");
if (!std::isalpha(str[0], c_locale)) {
return false;
}
for (const char& ch : str) {
if ((ch != '_') && !std::isalnum(ch, c_locale)) {
return false;
}
}
return true;
}
bool ParserImpl::RegisterWorkgroupSizeBuiltin() {
WorkgroupSizeInfo& info = workgroup_size_builtin_;
for (const spvtools::opt::Instruction& inst : module_->annotations()) {
if (inst.opcode() != SpvOpDecorate) {
continue;
}
if (inst.GetSingleWordInOperand(1) != SpvDecorationBuiltIn) {
continue;
}
if (inst.GetSingleWordInOperand(2) != SpvBuiltInWorkgroupSize) {
continue;
}
info.id = inst.GetSingleWordInOperand(0);
}
if (info.id == 0) {
return true;
}
// Gather the values.
const spvtools::opt::Instruction* composite_def =
def_use_mgr_->GetDef(info.id);
if (!composite_def) {
return Fail() << "Invalid WorkgroupSize builtin value";
}
// SPIR-V validation checks that the result is a 3-element vector of 32-bit
// integer scalars (signed or unsigned). Rely on validation to check the
// type. In theory the instruction could be OpConstantNull and still
// pass validation, but that would be non-sensical. Be a little more
// stringent here and check for specific opcodes. WGSL does not support
// const-expr yet, so avoid supporting OpSpecConstantOp here.
// TODO(dneto): See https://github.com/gpuweb/gpuweb/issues/1272 for WGSL
// const_expr proposals.
if ((composite_def->opcode() != SpvOpSpecConstantComposite &&
composite_def->opcode() != SpvOpConstantComposite)) {
return Fail() << "Invalid WorkgroupSize builtin. Expected 3-element "
"OpSpecConstantComposite or OpConstantComposite: "
<< composite_def->PrettyPrint();
}
info.type_id = composite_def->type_id();
// Extract the component type from the vector type.
info.component_type_id =
def_use_mgr_->GetDef(info.type_id)->GetSingleWordInOperand(0);
/// Sets the ID and value of the index'th member of the composite constant.
/// Returns false and emits a diagnostic on error.
auto set_param = [this, composite_def](uint32_t* id_ptr, uint32_t* value_ptr,
int index) -> bool {
const auto id = composite_def->GetSingleWordInOperand(index);
const auto* def = def_use_mgr_->GetDef(id);
if (!def ||
(def->opcode() != SpvOpSpecConstant &&
def->opcode() != SpvOpConstant) ||
(def->NumInOperands() != 1)) {
return Fail() << "invalid component " << index << " of workgroupsize "
<< (def ? def->PrettyPrint()
: std::string("no definition"));
}
*id_ptr = id;
// Use the default value of a spec constant.
*value_ptr = def->GetSingleWordInOperand(0);
return true;
};
return set_param(&info.x_id, &info.x_value, 0) &&
set_param(&info.y_id, &info.y_value, 1) &&
set_param(&info.z_id, &info.z_value, 2);
}
bool ParserImpl::RegisterEntryPoints() {
// Mapping from entry point ID to GridSize computed from LocalSize
// decorations.
std::unordered_map<uint32_t, GridSize> local_size;
for (const spvtools::opt::Instruction& inst : module_->execution_modes()) {
auto mode = static_cast<SpvExecutionMode>(inst.GetSingleWordInOperand(1));
if (mode == SpvExecutionModeLocalSize) {
if (inst.NumInOperands() != 5) {
// This won't even get past SPIR-V binary parsing.
return Fail() << "invalid LocalSize execution mode: "
<< inst.PrettyPrint();
}
uint32_t function_id = inst.GetSingleWordInOperand(0);
local_size[function_id] = GridSize{inst.GetSingleWordInOperand(2),
inst.GetSingleWordInOperand(3),
inst.GetSingleWordInOperand(4)};
}
}
for (const spvtools::opt::Instruction& entry_point :
module_->entry_points()) {
const auto stage = SpvExecutionModel(entry_point.GetSingleWordInOperand(0));
const uint32_t function_id = entry_point.GetSingleWordInOperand(1);
const std::string ep_name = entry_point.GetOperand(2).AsString();
if (!IsValidIdentifier(ep_name)) {
return Fail() << "entry point name is not a valid WGSL identifier: "
<< ep_name;
}
bool owns_inner_implementation = false;
std::string inner_implementation_name;
auto where = function_to_ep_info_.find(function_id);
if (where == function_to_ep_info_.end()) {
// If this is the first entry point to have function_id as its
// implementation, then this entry point is responsible for generating
// the inner implementation.
owns_inner_implementation = true;
inner_implementation_name = namer_.MakeDerivedName(ep_name);
} else {
// Reuse the inner implementation owned by the first entry point.
inner_implementation_name = where->second[0].inner_name;
}
TINT_ASSERT(Reader, !inner_implementation_name.empty());
TINT_ASSERT(Reader, ep_name != inner_implementation_name);
tint::UniqueVector<uint32_t> inputs;
tint::UniqueVector<uint32_t> outputs;
for (unsigned iarg = 3; iarg < entry_point.NumInOperands(); iarg++) {
const uint32_t var_id = entry_point.GetSingleWordInOperand(iarg);
if (const auto* var_inst = def_use_mgr_->GetDef(var_id)) {
switch (SpvStorageClass(var_inst->GetSingleWordInOperand(0))) {
case SpvStorageClassInput:
inputs.add(var_id);
break;
case SpvStorageClassOutput:
outputs.add(var_id);
break;
default:
break;
}
}
}
// Save the lists, in ID-sorted order.
std::vector<uint32_t> sorted_inputs(inputs.begin(), inputs.end());
std::sort(sorted_inputs.begin(), sorted_inputs.end());
std::vector<uint32_t> sorted_outputs(outputs.begin(), outputs.end());
std::sort(sorted_inputs.begin(), sorted_inputs.end());
const auto ast_stage = enum_converter_.ToPipelineStage(stage);
GridSize wgsize;
if (ast_stage == ast::PipelineStage::kCompute) {
if (workgroup_size_builtin_.id) {
// Store the default values.
// WGSL allows specializing these, but this code doesn't support that
// yet. https://github.com/gpuweb/gpuweb/issues/1442
wgsize = GridSize{workgroup_size_builtin_.x_value,
workgroup_size_builtin_.y_value,
workgroup_size_builtin_.z_value};
} else {
// Use the LocalSize execution mode. This is the second choice.
auto where_local_size = local_size.find(function_id);
if (where_local_size != local_size.end()) {
wgsize = where_local_size->second;
}
}
}
function_to_ep_info_[function_id].emplace_back(
ep_name, ast_stage, owns_inner_implementation,
inner_implementation_name, std::move(sorted_inputs),
std::move(sorted_outputs), wgsize);
}
// The enum conversion could have failed, so return the existing status value.
return success_;
}
const Type* ParserImpl::ConvertType(
const spvtools::opt::analysis::Integer* int_ty) {
if (int_ty->width() == 32) {
return int_ty->IsSigned() ? static_cast<const Type*>(ty_.I32())
: static_cast<const Type*>(ty_.U32());
}
Fail() << "unhandled integer width: " << int_ty->width();
return nullptr;
}
const Type* ParserImpl::ConvertType(
const spvtools::opt::analysis::Float* float_ty) {
if (float_ty->width() == 32) {
return ty_.F32();
}
Fail() << "unhandled float width: " << float_ty->width();
return nullptr;
}
const Type* ParserImpl::ConvertType(
const spvtools::opt::analysis::Vector* vec_ty) {
const auto num_elem = vec_ty->element_count();
auto* ast_elem_ty = ConvertType(type_mgr_->GetId(vec_ty->element_type()));
if (ast_elem_ty == nullptr) {
return ast_elem_ty;
}
return ty_.Vector(ast_elem_ty, num_elem);
}
const Type* ParserImpl::ConvertType(
const spvtools::opt::analysis::Matrix* mat_ty) {
const auto* vec_ty = mat_ty->element_type()->AsVector();
const auto* scalar_ty = vec_ty->element_type();
const auto num_rows = vec_ty->element_count();
const auto num_columns = mat_ty->element_count();
auto* ast_scalar_ty = ConvertType(type_mgr_->GetId(scalar_ty));
if (ast_scalar_ty == nullptr) {
return nullptr;
}
return ty_.Matrix(ast_scalar_ty, num_columns, num_rows);
}
const Type* ParserImpl::ConvertType(
const spvtools::opt::analysis::RuntimeArray* rtarr_ty) {
auto* ast_elem_ty = ConvertType(type_mgr_->GetId(rtarr_ty->element_type()));
if (ast_elem_ty == nullptr) {
return nullptr;
}
uint32_t array_stride = 0;
if (!ParseArrayDecorations(rtarr_ty, &array_stride)) {
return nullptr;
}
return ty_.Array(ast_elem_ty, 0, array_stride);
}
const Type* ParserImpl::ConvertType(
const spvtools::opt::analysis::Array* arr_ty) {
const auto elem_type_id = type_mgr_->GetId(arr_ty->element_type());
auto* ast_elem_ty = ConvertType(elem_type_id);
if (ast_elem_ty == nullptr) {
return nullptr;
}
const auto& length_info = arr_ty->length_info();
if (length_info.words.empty()) {
// The internal representation is invalid. The discriminant vector
// is mal-formed.
Fail() << "internal error: Array length info is invalid";
return nullptr;
}
if (length_info.words[0] !=
spvtools::opt::analysis::Array::LengthInfo::kConstant) {
Fail() << "Array type " << type_mgr_->GetId(arr_ty)
<< " length is a specialization constant";
return nullptr;
}
const auto* constant = constant_mgr_->FindDeclaredConstant(length_info.id);
if (constant == nullptr) {
Fail() << "Array type " << type_mgr_->GetId(arr_ty) << " length ID "
<< length_info.id << " does not name an OpConstant";
return nullptr;
}
const uint64_t num_elem = constant->GetZeroExtendedValue();
// For now, limit to only 32bits.
if (num_elem > std::numeric_limits<uint32_t>::max()) {
Fail() << "Array type " << type_mgr_->GetId(arr_ty)
<< " has too many elements (more than can fit in 32 bits): "
<< num_elem;
return nullptr;
}
uint32_t array_stride = 0;
if (!ParseArrayDecorations(arr_ty, &array_stride)) {
return nullptr;
}
if (remap_buffer_block_type_.count(elem_type_id)) {
remap_buffer_block_type_.insert(type_mgr_->GetId(arr_ty));
}
return ty_.Array(ast_elem_ty, static_cast<uint32_t>(num_elem), array_stride);
}
bool ParserImpl::ParseArrayDecorations(
const spvtools::opt::analysis::Type* spv_type,
uint32_t* array_stride) {
bool has_array_stride = false;
const auto type_id = type_mgr_->GetId(spv_type);
for (auto& decoration : this->GetDecorationsFor(type_id)) {
if (decoration.size() == 2 && decoration[0] == SpvDecorationArrayStride) {
const auto stride = decoration[1];
if (stride == 0) {
return Fail() << "invalid array type ID " << type_id
<< ": ArrayStride can't be 0";
}
if (has_array_stride) {
return Fail() << "invalid array type ID " << type_id
<< ": multiple ArrayStride decorations";
}
has_array_stride = true;
*array_stride = stride;
} else {
return Fail() << "invalid array type ID " << type_id
<< ": unknown decoration "
<< (decoration.empty() ? "(empty)"
: std::to_string(decoration[0]))
<< " with " << decoration.size() << " total words";
}
}
return true;
}
const Type* ParserImpl::ConvertType(
uint32_t type_id,
const spvtools::opt::analysis::Struct* struct_ty) {
// Compute the struct decoration.
auto struct_decorations = this->GetDecorationsFor(type_id);
bool is_block_decorated = false;
if (struct_decorations.size() == 1) {
const auto decoration = struct_decorations[0][0];
if (decoration == SpvDecorationBlock) {
is_block_decorated = true;
} else if (decoration == SpvDecorationBufferBlock) {
is_block_decorated = true;
remap_buffer_block_type_.insert(type_id);
} else {
Fail() << "struct with ID " << type_id
<< " has unrecognized decoration: " << int(decoration);
}
} else if (struct_decorations.size() > 1) {
Fail() << "can't handle a struct with more than one decoration: struct "
<< type_id << " has " << struct_decorations.size();
return nullptr;
}
// Compute members
ast::StructMemberList ast_members;
const auto members = struct_ty->element_types();
if (members.empty()) {
Fail() << "WGSL does not support empty structures. can't convert type: "
<< def_use_mgr_->GetDef(type_id)->PrettyPrint();
return nullptr;
}
TypeList ast_member_types;
unsigned num_non_writable_members = 0;
for (uint32_t member_index = 0; member_index < members.size();
++member_index) {
const auto member_type_id = type_mgr_->GetId(members[member_index]);
auto* ast_member_ty = ConvertType(member_type_id);
if (ast_member_ty == nullptr) {
// Already emitted diagnostics.
return nullptr;
}
ast_member_types.emplace_back(ast_member_ty);
// Scan member for built-in decorations. Some vertex built-ins are handled
// specially, and should not generate a structure member.
bool create_ast_member = true;
for (auto& decoration : GetDecorationsForMember(type_id, member_index)) {
if (decoration.empty()) {
Fail() << "malformed SPIR-V decoration: it's empty";
return nullptr;
}
if ((decoration[0] == SpvDecorationBuiltIn) && (decoration.size() > 1)) {
switch (decoration[1]) {
case SpvBuiltInPosition:
// Record this built-in variable specially.
builtin_position_.struct_type_id = type_id;
builtin_position_.position_member_index = member_index;
builtin_position_.position_member_type_id = member_type_id;
create_ast_member = false; // Not part of the WGSL structure.
break;
case SpvBuiltInPointSize: // not supported in WGSL, but ignore
builtin_position_.pointsize_member_index = member_index;
create_ast_member = false; // Not part of the WGSL structure.
break;
case SpvBuiltInClipDistance: // not supported in WGSL
case SpvBuiltInCullDistance: // not supported in WGSL
create_ast_member = false; // Not part of the WGSL structure.
break;
default:
Fail() << "unrecognized builtin " << decoration[1];
return nullptr;
}
}
}
if (!create_ast_member) {
// This member is decorated as a built-in, and is handled specially.
continue;
}
bool is_non_writable = false;
ast::DecorationList ast_member_decorations;
for (auto& decoration : GetDecorationsForMember(type_id, member_index)) {
if (IsPipelineDecoration(decoration)) {
// IO decorations are handled when emitting the entry point.
continue;
} else if (decoration[0] == SpvDecorationNonWritable) {
// WGSL doesn't represent individual members as non-writable. Instead,
// apply the ReadOnly access control to the containing struct if all
// the members are non-writable.
is_non_writable = true;
} else {
auto decos = ConvertMemberDecoration(type_id, member_index,
ast_member_ty, decoration);
for (auto* deco : decos) {
ast_member_decorations.emplace_back(deco);
}
if (!success_) {
return nullptr;
}
}
}
if (is_non_writable) {
// Count a member as non-writable only once, no matter how many
// NonWritable decorations are applied to it.
++num_non_writable_members;
}
const auto member_name = namer_.GetMemberName(type_id, member_index);
auto* ast_struct_member = create<ast::StructMember>(
Source{}, builder_.Symbols().Register(member_name),
ast_member_ty->Build(builder_), std::move(ast_member_decorations));
ast_members.push_back(ast_struct_member);
}
if (ast_members.empty()) {
// All members were likely built-ins. Don't generate an empty AST structure.
return nullptr;
}
namer_.SuggestSanitizedName(type_id, "S");
auto name = namer_.GetName(type_id);
// Now make the struct.
auto sym = builder_.Symbols().Register(name);
ast::DecorationList ast_struct_decorations;
if (is_block_decorated && struct_types_for_buffers_.count(type_id)) {
ast_struct_decorations.emplace_back(
create<ast::StructBlockDecoration>(Source{}));
}
auto* ast_struct = create<ast::Struct>(Source{}, sym, std::move(ast_members),
std::move(ast_struct_decorations));
if (num_non_writable_members == members.size()) {
read_only_struct_types_.insert(ast_struct->name());
}
AddTypeDecl(sym, ast_struct);
const auto* result = ty_.Struct(sym, std::move(ast_member_types));
struct_id_for_symbol_[sym] = type_id;
return result;
}
void ParserImpl::AddTypeDecl(Symbol name, ast::TypeDecl* decl) {
auto iter = declared_types_.insert(name);
if (iter.second) {
builder_.AST().AddTypeDecl(decl);
}
}
const Type* ParserImpl::ConvertType(uint32_t type_id,
PtrAs ptr_as,
const spvtools::opt::analysis::Pointer*) {
const auto* inst = def_use_mgr_->GetDef(type_id);
const auto pointee_type_id = inst->GetSingleWordInOperand(1);
const auto storage_class = SpvStorageClass(inst->GetSingleWordInOperand(0));
if (pointee_type_id == builtin_position_.struct_type_id) {
builtin_position_.pointer_type_id = type_id;
// Pipeline IO builtins map to private variables.
builtin_position_.storage_class = SpvStorageClassPrivate;
return nullptr;
}
auto* ast_elem_ty = ConvertType(pointee_type_id, PtrAs::Ptr);
if (ast_elem_ty == nullptr) {
Fail() << "SPIR-V pointer type with ID " << type_id
<< " has invalid pointee type " << pointee_type_id;
return nullptr;
}
auto ast_storage_class = enum_converter_.ToStorageClass(storage_class);
if (ast_storage_class == ast::StorageClass::kInvalid) {
Fail() << "SPIR-V pointer type with ID " << type_id
<< " has invalid storage class "
<< static_cast<uint32_t>(storage_class);
return nullptr;
}
if (ast_storage_class == ast::StorageClass::kUniform &&
remap_buffer_block_type_.count(pointee_type_id)) {
ast_storage_class = ast::StorageClass::kStorage;
remap_buffer_block_type_.insert(type_id);
}
// Pipeline input and output variables map to private variables.
if (ast_storage_class == ast::StorageClass::kInput ||
ast_storage_class == ast::StorageClass::kOutput) {
ast_storage_class = ast::StorageClass::kPrivate;
}
switch (ptr_as) {
case PtrAs::Ref:
return ty_.Reference(ast_elem_ty, ast_storage_class);
case PtrAs::Ptr:
return ty_.Pointer(ast_elem_ty, ast_storage_class);
}
Fail() << "invalid value for ptr_as: " << static_cast<int>(ptr_as);
return nullptr;
}
bool ParserImpl::RegisterTypes() {
if (!success_) {
return false;
}
// First record the structure types that should have a `block` decoration
// in WGSL. In particular, exclude user-defined pipeline IO in a
// block-decorated struct.
for (const auto& type_or_value : module_->types_values()) {
if (type_or_value.opcode() != SpvOpVariable) {
continue;
}
const auto& var = type_or_value;
const auto spirv_storage_class =
SpvStorageClass(var.GetSingleWordInOperand(0));
if ((spirv_storage_class != SpvStorageClassStorageBuffer) &&
(spirv_storage_class != SpvStorageClassUniform)) {
continue;
}
const auto* ptr_type = def_use_mgr_->GetDef(var.type_id());
if (ptr_type->opcode() != SpvOpTypePointer) {
return Fail() << "OpVariable type expected to be a pointer: "
<< var.PrettyPrint();
}
const auto* store_type =
def_use_mgr_->GetDef(ptr_type->GetSingleWordInOperand(1));
if (store_type->opcode() == SpvOpTypeStruct) {
struct_types_for_buffers_.insert(store_type->result_id());
} else {
Fail() << "WGSL does not support arrays of buffers: "
<< var.PrettyPrint();
}
}
// Now convert each type.
for (auto& type_or_const : module_->types_values()) {
const auto* type = type_mgr_->GetType(type_or_const.result_id());
if (type == nullptr) {
continue;
}
ConvertType(type_or_const.result_id());
}
// Manufacture a type for the gl_Position variable if we have to.
if ((builtin_position_.struct_type_id != 0) &&
(builtin_position_.position_member_pointer_type_id == 0)) {
builtin_position_.position_member_pointer_type_id =
type_mgr_->FindPointerToType(builtin_position_.position_member_type_id,
builtin_position_.storage_class);
ConvertType(builtin_position_.position_member_pointer_type_id);
}
return success_;
}
bool ParserImpl::RejectInvalidPointerRoots() {
if (!success_) {
return false;
}
for (auto& inst : module_->types_values()) {
if (const auto* result_type = type_mgr_->GetType(inst.type_id())) {
if (result_type->AsPointer()) {
switch (inst.opcode()) {
case SpvOpVariable:
// This is the only valid case.
break;
case SpvOpUndef:
return Fail() << "undef pointer is not valid: "
<< inst.PrettyPrint();
case SpvOpConstantNull:
return Fail() << "null pointer is not valid: "
<< inst.PrettyPrint();
default:
return Fail() << "module-scope pointer is not valid: "
<< inst.PrettyPrint();
}
}
}
}
return success();
}
bool ParserImpl::EmitScalarSpecConstants() {
if (!success_) {
return false;
}
// Generate a module-scope const declaration for each instruction
// that is OpSpecConstantTrue, OpSpecConstantFalse, or OpSpecConstant.
for (auto& inst : module_->types_values()) {
// These will be populated for a valid scalar spec constant.
const Type* ast_type = nullptr;
ast::ScalarConstructorExpression* ast_expr = nullptr;
switch (inst.opcode()) {
case SpvOpSpecConstantTrue:
case SpvOpSpecConstantFalse: {
ast_type = ConvertType(inst.type_id());
ast_expr = create<ast::ScalarConstructorExpression>(
Source{}, create<ast::BoolLiteral>(
Source{}, inst.opcode() == SpvOpSpecConstantTrue));
break;
}
case SpvOpSpecConstant: {
ast_type = ConvertType(inst.type_id());
const uint32_t literal_value = inst.GetSingleWordInOperand(0);
if (ast_type->Is<I32>()) {
ast_expr = create<ast::ScalarConstructorExpression>(
Source{}, create<ast::SintLiteral>(
Source{}, static_cast<int32_t>(literal_value)));
} else if (ast_type->Is<U32>()) {
ast_expr = create<ast::ScalarConstructorExpression>(
Source{}, create<ast::UintLiteral>(
Source{}, static_cast<uint32_t>(literal_value)));
} else if (ast_type->Is<F32>()) {
float float_value;
// Copy the bits so we can read them as a float.
std::memcpy(&float_value, &literal_value, sizeof(float_value));
ast_expr = create<ast::ScalarConstructorExpression>(
Source{}, create<ast::FloatLiteral>(Source{}, float_value));
} else {
return Fail() << " invalid result type for OpSpecConstant "
<< inst.PrettyPrint();
}
break;
}
default:
break;
}
if (ast_type && ast_expr) {
ast::DecorationList spec_id_decos;
for (const auto& deco : GetDecorationsFor(inst.result_id())) {
if ((deco.size() == 2) && (deco[0] == SpvDecorationSpecId)) {
const uint32_t id = deco[1];
if (id > 65535) {
return Fail() << "SpecId too large. WGSL override IDs must be "
"between 0 and 65535: ID %"
<< inst.result_id() << " has SpecId " << id;
}
auto* cid = create<ast::OverrideDecoration>(Source{}, id);
spec_id_decos.push_back(cid);
break;
}
}
auto* ast_var =
MakeVariable(inst.result_id(), ast::StorageClass::kNone, ast_type,
true, ast_expr, std::move(spec_id_decos));
if (ast_var) {
builder_.AST().AddGlobalVariable(ast_var);
scalar_spec_constants_.insert(inst.result_id());
}
}
}
return success_;
}
const Type* ParserImpl::MaybeGenerateAlias(
uint32_t type_id,
const spvtools::opt::analysis::Type* type,
const Type* ast_type) {
if (!success_) {
return nullptr;
}
// We only care about arrays, and runtime arrays.
switch (type->kind()) {
case spvtools::opt::analysis::Type::kRuntimeArray:
// Runtime arrays are always decorated with ArrayStride so always get a
// type alias.
namer_.SuggestSanitizedName(type_id, "RTArr");
break;
case spvtools::opt::analysis::Type::kArray:
// Only make a type aliase for arrays with decorations.
if (GetDecorationsFor(type_id).empty()) {
return ast_type;
}
namer_.SuggestSanitizedName(type_id, "Arr");
break;
default:
// Ignore constants, and any other types.
return ast_type;
}
auto* ast_underlying_type = ast_type;
if (ast_underlying_type == nullptr) {
Fail() << "internal error: no type registered for SPIR-V ID: " << type_id;
return nullptr;
}
const auto name = namer_.GetName(type_id);
const auto sym = builder_.Symbols().Register(name);
auto* ast_alias_type =
builder_.ty.alias(sym, ast_underlying_type->Build(builder_));
// Record this new alias as the AST type for this SPIR-V ID.
AddTypeDecl(sym, ast_alias_type);
return ty_.Alias(sym, ast_underlying_type);
}
bool ParserImpl::EmitModuleScopeVariables() {
if (!success_) {
return false;
}
for (const auto& type_or_value : module_->types_values()) {
if (type_or_value.opcode() != SpvOpVariable) {
continue;
}
const auto& var = type_or_value;
const auto spirv_storage_class =
SpvStorageClass(var.GetSingleWordInOperand(0));
uint32_t type_id = var.type_id();
if ((type_id == builtin_position_.pointer_type_id) &&
((spirv_storage_class == SpvStorageClassInput) ||
(spirv_storage_class == SpvStorageClassOutput))) {
// Skip emitting gl_PerVertex.
builtin_position_.per_vertex_var_id = var.result_id();
builtin_position_.per_vertex_var_init_id =
var.NumInOperands() > 1 ? var.GetSingleWordInOperand(1) : 0u;
continue;
}
switch (enum_converter_.ToStorageClass(spirv_storage_class)) {
case ast::StorageClass::kNone:
case ast::StorageClass::kInput:
case ast::StorageClass::kOutput:
case ast::StorageClass::kUniform:
case ast::StorageClass::kUniformConstant:
case ast::StorageClass::kStorage:
case ast::StorageClass::kImage:
case ast::StorageClass::kWorkgroup:
case ast::StorageClass::kPrivate:
break;
default:
return Fail() << "invalid SPIR-V storage class "
<< int(spirv_storage_class)
<< " for module scope variable: " << var.PrettyPrint();
}
if (!success_) {
return false;
}
const Type* ast_type = nullptr;
if (spirv_storage_class == SpvStorageClassUniformConstant) {
// These are opaque handles: samplers or textures
ast_type = GetTypeForHandleVar(var);
if (!ast_type) {
return false;
}
} else {
ast_type = ConvertType(type_id);
if (ast_type == nullptr) {
return Fail() << "internal error: failed to register Tint AST type for "
"SPIR-V type with ID: "
<< var.type_id();
}
if (!ast_type->Is<Pointer>()) {
return Fail() << "variable with ID " << var.result_id()
<< " has non-pointer type " << var.type_id();
}
}
auto* ast_store_type = ast_type->As<Pointer>()->type;
auto ast_storage_class = ast_type->As<Pointer>()->storage_class;
ast::Expression* ast_constructor = nullptr;
if (var.NumInOperands() > 1) {
// SPIR-V initializers are always constants.
// (OpenCL also allows the ID of an OpVariable, but we don't handle that
// here.)
ast_constructor =
MakeConstantExpression(var.GetSingleWordInOperand(1)).expr;
}
auto* ast_var =
MakeVariable(var.result_id(), ast_storage_class, ast_store_type, false,
ast_constructor, ast::DecorationList{});
// TODO(dneto): initializers (a.k.a. constructor expression)
if (ast_var) {
builder_.AST().AddGlobalVariable(ast_var);
}
}
// Emit gl_Position instead of gl_PerVertex
if (builtin_position_.per_vertex_var_id) {
// Make sure the variable has a name.
namer_.SuggestSanitizedName(builtin_position_.per_vertex_var_id,
"gl_Position");
ast::Expression* ast_constructor = nullptr;
if (builtin_position_.per_vertex_var_init_id) {
// The initializer is complex.
const auto* init =
def_use_mgr_->GetDef(builtin_position_.per_vertex_var_init_id);
switch (init->opcode()) {
case SpvOpConstantComposite:
case SpvOpSpecConstantComposite:
ast_constructor = MakeConstantExpression(
init->GetSingleWordInOperand(
builtin_position_.position_member_index))
.expr;
break;
default:
return Fail() << "gl_PerVertex initializer too complex. only "
"OpCompositeConstruct and OpSpecConstantComposite "
"are supported: "
<< init->PrettyPrint();
}
}
auto* ast_var = MakeVariable(
builtin_position_.per_vertex_var_id,
enum_converter_.ToStorageClass(builtin_position_.storage_class),
ConvertType(builtin_position_.position_member_type_id), false,
ast_constructor, {});
builder_.AST().AddGlobalVariable(ast_var);
}
return success_;
}
// @param var_id SPIR-V id of an OpVariable, assumed to be pointer
// to an array
// @returns the IntConstant for the size of the array, or nullptr
const spvtools::opt::analysis::IntConstant* ParserImpl::GetArraySize(
uint32_t var_id) {
auto* var = def_use_mgr_->GetDef(var_id);
if (!var || var->opcode() != SpvOpVariable) {
return nullptr;
}
auto* ptr_type = def_use_mgr_->GetDef(var->type_id());
if (!ptr_type || ptr_type->opcode() != SpvOpTypePointer) {
return nullptr;
}
auto* array_type = def_use_mgr_->GetDef(ptr_type->GetSingleWordInOperand(1));
if (!array_type || array_type->opcode() != SpvOpTypeArray) {
return nullptr;
}
auto* size = constant_mgr_->FindDeclaredConstant(
array_type->GetSingleWordInOperand(1));
if (!size) {
return nullptr;
}
return size->AsIntConstant();
}
ast::Variable* ParserImpl::MakeVariable(uint32_t id,
ast::StorageClass sc,
const Type* storage_type,
bool is_const,
ast::Expression* constructor,
ast::DecorationList decorations) {
if (storage_type == nullptr) {
Fail() << "internal error: can't make ast::Variable for null type";
return nullptr;
}
ast::Access access = ast::Access::kUndefined;
if (sc == ast::StorageClass::kStorage) {
bool read_only = false;
if (auto* tn = storage_type->As<Named>()) {
read_only = read_only_struct_types_.count(tn->name) > 0;
}
// Apply the access(read) or access(read_write) modifier.
access = read_only ? ast::Access::kRead : ast::Access::kReadWrite;
}
// Handle variables (textures and samplers) are always in the handle
// storage class, so we don't mention the storage class.
if (sc == ast::StorageClass::kUniformConstant) {
sc = ast::StorageClass::kNone;
}
if (!ConvertDecorationsForVariable(id, &storage_type, &decorations,
sc != ast::StorageClass::kPrivate)) {
return nullptr;
}
std::string name = namer_.Name(id);
// Note: we're constructing the variable here with the *storage* type,
// regardless of whether this is a `let` or `var` declaration.
// `var` declarations will have a resolved type of ref<storage>, but at the
// AST level both `var` and `let` are declared with the same type.
return create<ast::Variable>(Source{}, builder_.Symbols().Register(name), sc,
access, storage_type->Build(builder_), is_const,
constructor, decorations);
}
bool ParserImpl::ConvertDecorationsForVariable(uint32_t id,
const Type** store_type,
ast::DecorationList* decorations,
bool transfer_pipeline_io) {
DecorationList non_builtin_pipeline_decorations;
for (auto& deco : GetDecorationsFor(id)) {
if (deco.empty()) {
return Fail() << "malformed decoration on ID " << id << ": it is empty";
}
if (deco[0] == SpvDecorationBuiltIn) {
if (deco.size() == 1) {
return Fail() << "malformed BuiltIn decoration on ID " << id
<< ": has no operand";
}
const auto spv_builtin = static_cast<SpvBuiltIn>(deco[1]);
switch (spv_builtin) {
case SpvBuiltInPointSize:
special_builtins_[id] = spv_builtin;
return false; // This is not an error
case SpvBuiltInSampleId:
case SpvBuiltInVertexIndex:
case SpvBuiltInInstanceIndex:
case SpvBuiltInLocalInvocationId:
case SpvBuiltInLocalInvocationIndex:
case SpvBuiltInGlobalInvocationId:
case SpvBuiltInWorkgroupId:
case SpvBuiltInNumWorkgroups:
// The SPIR-V variable may signed (because GLSL requires signed for
// some of these), but WGSL requires unsigned. Handle specially
// so we always perform the conversion at load and store.
special_builtins_[id] = spv_builtin;
if (auto* forced_type = UnsignedTypeFor(*store_type)) {
// Requires conversion and special handling in code generation.
if (transfer_pipeline_io) {
*store_type = forced_type;
}
}
break;
case SpvBuiltInSampleMask: {
// In SPIR-V this is used for both input and output variable.
// The SPIR-V variable has store type of array of integer scalar,
// either signed or unsigned.
// WGSL requires the store type to be u32.
auto* size = GetArraySize(id);
if (!size || size->GetZeroExtendedValue() != 1) {
Fail() << "WGSL supports a sample mask of at most 32 bits. "
"SampleMask must be an array of 1 element.";
}
special_builtins_[id] = spv_builtin;
if (transfer_pipeline_io) {
*store_type = ty_.U32();
}
break;
}
default:
break;
}
auto ast_builtin = enum_converter_.ToBuiltin(spv_builtin);
if (ast_builtin == ast::Builtin::kNone) {
// A diagnostic has already been emitted.
return false;
}
if (transfer_pipeline_io) {
decorations->emplace_back(
create<ast::BuiltinDecoration>(Source{}, ast_builtin));
}
}
if (transfer_pipeline_io && IsPipelineDecoration(deco)) {
non_builtin_pipeline_decorations.push_back(deco);
}
if (deco[0] == SpvDecorationDescriptorSet) {
if (deco.size() == 1) {
return Fail() << "malformed DescriptorSet decoration on ID " << id
<< ": has no operand";
}
decorations->emplace_back(
create<ast::GroupDecoration>(Source{}, deco[1]));
}
if (deco[0] == SpvDecorationBinding) {
if (deco.size() == 1) {
return Fail() << "malformed Binding decoration on ID " << id
<< ": has no operand";
}
decorations->emplace_back(
create<ast::BindingDecoration>(Source{}, deco[1]));
}
}
if (transfer_pipeline_io) {
if (!ConvertPipelineDecorations(
*store_type, non_builtin_pipeline_decorations, decorations)) {
return false;
}
}
return success();
}
DecorationList ParserImpl::GetMemberPipelineDecorations(
const Struct& struct_type,
int member_index) {
// Yes, I could have used std::copy_if or std::copy_if.
DecorationList result;
for (const auto& deco : GetDecorationsForMember(
struct_id_for_symbol_[struct_type.name], member_index)) {
if (IsPipelineDecoration(deco)) {
result.emplace_back(deco);
}
}
return result;
}
ast::Decoration* ParserImpl::SetLocation(ast::DecorationList* decos,
ast::Decoration* replacement) {
if (!replacement) {
return nullptr;
}
for (auto*& deco : *decos) {
if (deco->Is<ast::LocationDecoration>()) {
// Replace this location decoration with the replacement.
// The old one doesn't leak because it's kept in the builder's AST node
// list.
ast::Decoration* result = nullptr;
result = deco;
deco = replacement;
return result; // Assume there is only one such decoration.
}
}
// The list didn't have a location. Add it.
decos->push_back(replacement);
return nullptr;
}
bool ParserImpl::ConvertPipelineDecorations(const Type* store_type,
const DecorationList& decorations,
ast::DecorationList* ast_decos) {
bool has_interpolate_no_perspective = false;
bool has_interpolate_sampling_centroid = false;
bool has_interpolate_sampling_sample = false;
for (const auto& deco : decorations) {
TINT_ASSERT(Reader, deco.size() > 0);
switch (deco[0]) {
case SpvDecorationLocation:
if (deco.size() != 2) {
return Fail() << "malformed Location decoration on ID requires one "
"literal operand";
}
SetLocation(ast_decos,
create<ast::LocationDecoration>(Source{}, deco[1]));
break;
case SpvDecorationFlat:
// In WGSL, integral types are always flat, and so the decoration
// is never specified.
if (!store_type->IsIntegerScalarOrVector()) {
ast_decos->emplace_back(create<ast::InterpolateDecoration>(
Source{}, ast::InterpolationType::kFlat,
ast::InterpolationSampling::kNone));
// Only one interpolate attribute is allowed.
return true;
}
break;
case SpvDecorationNoPerspective:
if (store_type->IsIntegerScalarOrVector()) {
// This doesn't capture the array or struct case.
return Fail() << "NoPerspective is invalid on integral IO";
}
has_interpolate_no_perspective = true;
break;
case SpvDecorationCentroid:
if (store_type->IsIntegerScalarOrVector()) {
// This doesn't capture the array or struct case.
return Fail()
<< "Centroid interpolation sampling is invalid on integral IO";
}
has_interpolate_sampling_centroid = true;
break;
case SpvDecorationSample:
if (store_type->IsIntegerScalarOrVector()) {
// This doesn't capture the array or struct case.
return Fail()
<< "Sample interpolation sampling is invalid on integral IO";
}
has_interpolate_sampling_sample = true;
break;
default:
break;
}
}
// Apply non-integral interpolation.
if (has_interpolate_no_perspective || has_interpolate_sampling_centroid ||
has_interpolate_sampling_sample) {
const ast::InterpolationType type =
has_interpolate_no_perspective ? ast::InterpolationType::kLinear
: ast::InterpolationType::kPerspective;
const ast::InterpolationSampling sampling =
has_interpolate_sampling_centroid
? ast::InterpolationSampling::kCentroid
: (has_interpolate_sampling_sample
? ast::InterpolationSampling::kSample
: ast::InterpolationSampling::
kNone /* Center is the default */);
if (type == ast::InterpolationType::kPerspective &&
sampling == ast::InterpolationSampling::kNone) {
// This is the default. Don't add a decoration.
} else {
ast_decos->emplace_back(
create<ast::InterpolateDecoration>(type, sampling));
}
}
return success();
}
bool ParserImpl::CanMakeConstantExpression(uint32_t id) {
if ((id == workgroup_size_builtin_.id) ||
(id == workgroup_size_builtin_.x_id) ||
(id == workgroup_size_builtin_.y_id) ||
(id == workgroup_size_builtin_.z_id)) {
return true;
}
const auto* inst = def_use_mgr_->GetDef(id);
if (!inst) {
return false;
}
if (inst->opcode() == SpvOpUndef) {
return true;
}
return nullptr != constant_mgr_->FindDeclaredConstant(id);
}
TypedExpression ParserImpl::MakeConstantExpression(uint32_t id) {
if (!success_) {
return {};
}
// Handle the special cases for workgroup sizing.
if (id == workgroup_size_builtin_.id) {
auto x = MakeConstantExpression(workgroup_size_builtin_.x_id);
auto y = MakeConstantExpression(workgroup_size_builtin_.y_id);
auto z = MakeConstantExpression(workgroup_size_builtin_.z_id);
auto* ast_type = ty_.Vector(x.type, 3);
return {ast_type, create<ast::TypeConstructorExpression>(
Source{}, ast_type->Build(builder_),
ast::ExpressionList{x.expr, y.expr, z.expr})};
} else if (id == workgroup_size_builtin_.x_id) {
return MakeConstantExpressionForSpirvConstant(
Source{}, ConvertType(workgroup_size_builtin_.component_type_id),
constant_mgr_->GetConstant(
type_mgr_->GetType(workgroup_size_builtin_.component_type_id),
{workgroup_size_builtin_.x_value}));
} else if (id == workgroup_size_builtin_.y_id) {
return MakeConstantExpressionForSpirvConstant(
Source{}, ConvertType(workgroup_size_builtin_.component_type_id),
constant_mgr_->GetConstant(
type_mgr_->GetType(workgroup_size_builtin_.component_type_id),
{workgroup_size_builtin_.y_value}));
} else if (id == workgroup_size_builtin_.z_id) {
return MakeConstantExpressionForSpirvConstant(
Source{}, ConvertType(workgroup_size_builtin_.component_type_id),
constant_mgr_->GetConstant(
type_mgr_->GetType(workgroup_size_builtin_.component_type_id),
{workgroup_size_builtin_.z_value}));
}
// Handle the general case where a constant is already registered
// with the SPIR-V optimizer's analysis framework.
const auto* inst = def_use_mgr_->GetDef(id);
if (inst == nullptr) {
Fail() << "ID " << id << " is not a registered instruction";
return {};
}
auto* original_ast_type = ConvertType(inst->type_id());
if (original_ast_type == nullptr) {
return {};
}
if (inst->opcode() == SpvOpUndef) {
// Remap undef to null.
return {original_ast_type, MakeNullValue(original_ast_type)};
}
// TODO(dneto): Handle spec constants too?
const auto* spirv_const = constant_mgr_->FindDeclaredConstant(id);
if (spirv_const == nullptr) {
Fail() << "ID " << id << " is not a constant";
return {};
}
auto source = GetSourceForInst(inst);
return MakeConstantExpressionForSpirvConstant(source, original_ast_type,
spirv_const);
}
TypedExpression ParserImpl::MakeConstantExpressionForSpirvConstant(
Source source,
const Type* original_ast_type,
const spvtools::opt::analysis::Constant* spirv_const) {
auto* ast_type = original_ast_type->UnwrapAlias();
// TODO(dneto): Note: NullConstant for int, uint, float map to a regular 0.
// So canonicalization should map that way too.
// Currently "null<type>" is missing from the WGSL parser.
// See https://bugs.chromium.org/p/tint/issues/detail?id=34
if (ast_type->Is<U32>()) {
return {ty_.U32(), create<ast::ScalarConstructorExpression>(
Source{}, create<ast::UintLiteral>(
source, spirv_const->GetU32()))};
}
if (ast_type->Is<I32>()) {
return {ty_.I32(), create<ast::ScalarConstructorExpression>(
Source{}, create<ast::SintLiteral>(
source, spirv_const->GetS32()))};
}
if (ast_type->Is<F32>()) {
return {ty_.F32(), create<ast::ScalarConstructorExpression>(
Source{}, create<ast::FloatLiteral>(
source, spirv_const->GetFloat()))};
}
if (ast_type->Is<Bool>()) {
const bool value = spirv_const->AsNullConstant()
? false
: spirv_const->AsBoolConstant()->value();
return {ty_.Bool(), create<ast::ScalarConstructorExpression>(
Source{}, create<ast::BoolLiteral>(source, value))};
}
auto* spirv_composite_const = spirv_const->AsCompositeConstant();
if (spirv_composite_const != nullptr) {
// Handle vector, matrix, array, and struct
// TODO(dneto): Handle the spirv_composite_const->IsZero() case specially.
// See https://github.com/gpuweb/gpuweb/issues/685
// Generate a composite from explicit components.
ast::ExpressionList ast_components;
for (const auto* component : spirv_composite_const->GetComponents()) {
auto* def = constant_mgr_->GetDefiningInstruction(component);
if (def == nullptr) {
Fail() << "internal error: SPIR-V constant doesn't have defining "
"instruction";
return {};
}
auto ast_component = MakeConstantExpression(def->result_id());
if (!success_) {
// We've already emitted a diagnostic.
return {};
}
ast_components.emplace_back(ast_component.expr);
}
return {original_ast_type, create<ast::TypeConstructorExpression>(
Source{}, original_ast_type->Build(builder_),
std::move(ast_components))};
}
if (spirv_const->AsNullConstant()) {
return {original_ast_type, MakeNullValue(original_ast_type)};
}
Fail() << "Unhandled constant type ";
return {};
}
ast::Expression* ParserImpl::MakeNullValue(const Type* type) {
// TODO(dneto): Use the no-operands constructor syntax when it becomes
// available in Tint.
// https://github.com/gpuweb/gpuweb/issues/685
// https://bugs.chromium.org/p/tint/issues/detail?id=34
if (!type) {
Fail() << "trying to create null value for a null type";
return nullptr;
}
auto* original_type = type;
type = type->UnwrapAlias();
if (type->Is<Bool>()) {
return create<ast::ScalarConstructorExpression>(
Source{}, create<ast::BoolLiteral>(Source{}, false));
}
if (type->Is<U32>()) {
return create<ast::ScalarConstructorExpression>(
Source{}, create<ast::UintLiteral>(Source{}, 0u));
}
if (type->Is<I32>()) {
return create<ast::ScalarConstructorExpression>(
Source{}, create<ast::SintLiteral>(Source{}, 0));
}
if (type->Is<F32>()) {
return create<ast::ScalarConstructorExpression>(
Source{}, create<ast::FloatLiteral>(Source{}, 0.0f));
}
if (type->Is<Alias>()) {
// TODO(amaiorano): No type constructor for TypeName (yet?)
ast::ExpressionList ast_components;
return create<ast::TypeConstructorExpression>(
Source{}, original_type->Build(builder_), std::move(ast_components));
}
if (auto* vec_ty = type->As<Vector>()) {
ast::ExpressionList ast_components;
for (size_t i = 0; i < vec_ty->size; ++i) {
ast_components.emplace_back(MakeNullValue(vec_ty->type));
}
return create<ast::TypeConstructorExpression>(
Source{}, type->Build(builder_), std::move(ast_components));
}
if (auto* mat_ty = type->As<Matrix>()) {
// Matrix components are columns
auto* column_ty = ty_.Vector(mat_ty->type, mat_ty->rows);
ast::ExpressionList ast_components;
for (size_t i = 0; i < mat_ty->columns; ++i) {
ast_components.emplace_back(MakeNullValue(column_ty));
}
return create<ast::TypeConstructorExpression>(
Source{}, type->Build(builder_), std::move(ast_components));
}
if (auto* arr_ty = type->As<Array>()) {
ast::ExpressionList ast_components;
for (size_t i = 0; i < arr_ty->size; ++i) {
ast_components.emplace_back(MakeNullValue(arr_ty->type));
}
return create<ast::TypeConstructorExpression>(
Source{}, original_type->Build(builder_), std::move(ast_components));
}
if (auto* struct_ty = type->As<Struct>()) {
ast::ExpressionList ast_components;
for (auto* member : struct_ty->members) {
ast_components.emplace_back(MakeNullValue(member));
}
return create<ast::TypeConstructorExpression>(
Source{}, original_type->Build(builder_), std::move(ast_components));
}
Fail() << "can't make null value for type: " << type->TypeInfo().name;
return nullptr;
}
TypedExpression ParserImpl::MakeNullExpression(const Type* type) {
return {type, MakeNullValue(type)};
}
const Type* ParserImpl::UnsignedTypeFor(const Type* type) {
if (type->Is<I32>()) {
return ty_.U32();
}
if (auto* v = type->As<Vector>()) {
if (v->type->Is<I32>()) {
return ty_.Vector(ty_.U32(), v->size);
}
}
return {};
}
const Type* ParserImpl::SignedTypeFor(const Type* type) {
if (type->Is<U32>()) {
return ty_.I32();
}
if (auto* v = type->As<Vector>()) {
if (v->type->Is<U32>()) {
return ty_.Vector(ty_.I32(), v->size);
}
}
return {};
}
TypedExpression ParserImpl::RectifyOperandSignedness(
const spvtools::opt::Instruction& inst,
TypedExpression&& expr) {
bool requires_signed = false;
bool requires_unsigned = false;
if (IsGlslExtendedInstruction(inst)) {
const auto extended_opcode =
static_cast<GLSLstd450>(inst.GetSingleWordInOperand(1));
requires_signed = AssumesSignedOperands(extended_opcode);
requires_unsigned = AssumesUnsignedOperands(extended_opcode);
} else {
const auto opcode = inst.opcode();
requires_signed = AssumesSignedOperands(opcode);
requires_unsigned = AssumesUnsignedOperands(opcode);
}
if (!requires_signed && !requires_unsigned) {
// No conversion is required, assuming our tables are complete.
return std::move(expr);
}
if (!expr) {
Fail() << "internal error: RectifyOperandSignedness given a null expr\n";
return {};
}
auto* type = expr.type;
if (!type) {
Fail() << "internal error: unmapped type for: " << builder_.str(expr.expr)
<< "\n";
return {};
}
if (requires_unsigned) {
if (auto* unsigned_ty = UnsignedTypeFor(type)) {
// Conversion is required.
return {unsigned_ty,
create<ast::BitcastExpression>(
Source{}, unsigned_ty->Build(builder_), expr.expr)};
}
} else if (requires_signed) {
if (auto* signed_ty = SignedTypeFor(type)) {
// Conversion is required.
return {signed_ty, create<ast::BitcastExpression>(
Source{}, signed_ty->Build(builder_), expr.expr)};
}
}
// We should not reach here.
return std::move(expr);
}
TypedExpression ParserImpl::RectifySecondOperandSignedness(
const spvtools::opt::Instruction& inst,
const Type* first_operand_type,
TypedExpression&& second_operand_expr) {
if ((first_operand_type != second_operand_expr.type) &&
AssumesSecondOperandSignednessMatchesFirstOperand(inst.opcode())) {
// Conversion is required.
return {first_operand_type,
create<ast::BitcastExpression>(Source{},
first_operand_type->Build(builder_),
second_operand_expr.expr)};
}
// No conversion necessary.
return std::move(second_operand_expr);
}
const Type* ParserImpl::ForcedResultType(const spvtools::opt::Instruction& inst,
const Type* first_operand_type) {
const auto opcode = inst.opcode();
if (AssumesResultSignednessMatchesFirstOperand(opcode)) {
return first_operand_type;
}
if (IsGlslExtendedInstruction(inst)) {
const auto extended_opcode =
static_cast<GLSLstd450>(inst.GetSingleWordInOperand(1));
if (AssumesResultSignednessMatchesFirstOperand(extended_opcode)) {
return first_operand_type;
}
}
return nullptr;
}
const Type* ParserImpl::GetSignedIntMatchingShape(const Type* other) {
if (other == nullptr) {
Fail() << "no type provided";
}
if (other->Is<F32>() || other->Is<U32>() || other->Is<I32>()) {
return ty_.I32();
}
if (auto* vec_ty = other->As<Vector>()) {
return ty_.Vector(ty_.I32(), vec_ty->size);
}
Fail() << "required numeric scalar or vector, but got "
<< other->TypeInfo().name;
return nullptr;
}
const Type* ParserImpl::GetUnsignedIntMatchingShape(const Type* other) {
if (other == nullptr) {
Fail() << "no type provided";
return nullptr;
}
if (other->Is<F32>() || other->Is<U32>() || other->Is<I32>()) {
return ty_.U32();
}
if (auto* vec_ty = other->As<Vector>()) {
return ty_.Vector(ty_.U32(), vec_ty->size);
}
Fail() << "required numeric scalar or vector, but got "
<< other->TypeInfo().name;
return nullptr;
}
TypedExpression ParserImpl::RectifyForcedResultType(
TypedExpression expr,
const spvtools::opt::Instruction& inst,
const Type* first_operand_type) {
auto* forced_result_ty = ForcedResultType(inst, first_operand_type);
if ((!forced_result_ty) || (forced_result_ty == expr.type)) {
return expr;
}
return {expr.type, create<ast::BitcastExpression>(
Source{}, expr.type->Build(builder_), expr.expr)};
}
TypedExpression ParserImpl::AsUnsigned(TypedExpression expr) {
if (expr.type && expr.type->IsSignedScalarOrVector()) {
auto* new_type = GetUnsignedIntMatchingShape(expr.type);
return {new_type, create<ast::BitcastExpression>(
Source{}, new_type->Build(builder_), expr.expr)};
}
return expr;
}
TypedExpression ParserImpl::AsSigned(TypedExpression expr) {
if (expr.type && expr.type->IsUnsignedScalarOrVector()) {
auto* new_type = GetSignedIntMatchingShape(expr.type);
return {new_type, create<ast::BitcastExpression>(
Source{}, new_type->Build(builder_), expr.expr)};
}
return expr;
}
bool ParserImpl::EmitFunctions() {
if (!success_) {
return false;
}
for (const auto* f : topologically_ordered_functions_) {
if (!success_) {
return false;
}
auto id = f->result_id();
auto it = function_to_ep_info_.find(id);
if (it == function_to_ep_info_.end()) {
FunctionEmitter emitter(this, *f, nullptr);
success_ = emitter.Emit();
} else {
for (const auto& ep : it->second) {
FunctionEmitter emitter(this, *f, &ep);
success_ = emitter.Emit();
if (!success_) {
return false;
}
}
}
}
return success_;
}
const spvtools::opt::Instruction*
ParserImpl::GetMemoryObjectDeclarationForHandle(uint32_t id,
bool follow_image) {
auto saved_id = id;
auto local_fail = [this, saved_id, id,
follow_image]() -> const spvtools::opt::Instruction* {
const auto* inst = def_use_mgr_->GetDef(id);
Fail() << "Could not find memory object declaration for the "
<< (follow_image ? "image" : "sampler") << " underlying id " << id
<< " (from original id " << saved_id << ") "
<< (inst ? inst->PrettyPrint() : std::string());
return nullptr;
};
auto& memo_table =
(follow_image ? mem_obj_decl_image_ : mem_obj_decl_sampler_);
// Use a visited set to defend against bad input which might have long
// chains or even loops.
std::unordered_set<uint32_t> visited;
// Trace backward in the SSA data flow until we hit a memory object
// declaration.
while (true) {
auto where = memo_table.find(id);
if (where != memo_table.end()) {
return where->second;
}
// Protect against loops.
auto visited_iter = visited.find(id);
if (visited_iter != visited.end()) {
// We've hit a loop. Mark all the visited nodes
// as dead ends.
for (auto iter : visited) {
memo_table[iter] = nullptr;
}
return nullptr;
}
visited.insert(id);
const auto* inst = def_use_mgr_->GetDef(id);
if (inst == nullptr) {
return local_fail();
}
switch (inst->opcode()) {
case SpvOpFunctionParameter:
case SpvOpVariable:
// We found the memory object declaration.
// Remember it as the answer for the whole path.
for (auto iter : visited) {
memo_table[iter] = inst;
}
return inst;
case SpvOpLoad:
// Follow the pointer being loaded
id = inst->GetSingleWordInOperand(0);
break;
case SpvOpCopyObject:
// Follow the object being copied.
id = inst->GetSingleWordInOperand(0);
break;
case SpvOpAccessChain:
case SpvOpInBoundsAccessChain:
case SpvOpPtrAccessChain:
case SpvOpInBoundsPtrAccessChain:
// Follow the base pointer.
id = inst->GetSingleWordInOperand(0);
break;
case SpvOpSampledImage:
// Follow the image or the sampler, depending on the follow_image
// parameter.
id = inst->GetSingleWordInOperand(follow_image ? 0 : 1);
break;
case SpvOpImage:
// Follow the sampled image
id = inst->GetSingleWordInOperand(0);
break;
default:
// Can't trace further.
// Remember it as the answer for the whole path.
for (auto iter : visited) {
memo_table[iter] = nullptr;
}
return nullptr;
}
}
}
const spvtools::opt::Instruction*
ParserImpl::GetSpirvTypeForHandleMemoryObjectDeclaration(
const spvtools::opt::Instruction& var) {
if (!success()) {
return nullptr;
}
// The WGSL handle type is determined by looking at information from
// several sources:
// - the usage of the handle by image access instructions
// - the SPIR-V type declaration
// Each source does not have enough information to completely determine
// the result.
// Messages are phrased in terms of images and samplers because those
// are the only SPIR-V handles supported by WGSL.
// Get the SPIR-V handle type.
const auto* ptr_type = def_use_mgr_->GetDef(var.type_id());
if (!ptr_type || (ptr_type->opcode() != SpvOpTypePointer)) {
Fail() << "Invalid type for variable or function parameter "
<< var.PrettyPrint();
return nullptr;
}
const auto* raw_handle_type =
def_use_mgr_->GetDef(ptr_type->GetSingleWordInOperand(1));
if (!raw_handle_type) {
Fail() << "Invalid pointer type for variable or function parameter "
<< var.PrettyPrint();
return nullptr;
}
switch (raw_handle_type->opcode()) {
case SpvOpTypeSampler:
case SpvOpTypeImage:
// The expected cases.
break;
case SpvOpTypeArray:
case SpvOpTypeRuntimeArray:
Fail()
<< "arrays of textures or samplers are not supported in WGSL; can't "
"translate variable or function parameter: "
<< var.PrettyPrint();
return nullptr;
case SpvOpTypeSampledImage:
Fail() << "WGSL does not support combined image-samplers: "
<< var.PrettyPrint();
return nullptr;
default:
Fail() << "invalid type for image or sampler variable or function "
"parameter: "
<< var.PrettyPrint();
return nullptr;
}
return raw_handle_type;
}
const Pointer* ParserImpl::GetTypeForHandleVar(
const spvtools::opt::Instruction& var) {
auto where = handle_type_.find(&var);
if (where != handle_type_.end()) {
return where->second;
}
const spvtools::opt::Instruction* raw_handle_type =
GetSpirvTypeForHandleMemoryObjectDeclaration(var);
if (!raw_handle_type) {
return nullptr;
}
// The variable could be a sampler or image.
// Where possible, determine which one it is from the usage inferred
// for the variable.
Usage usage = handle_usage_[&var];
if (!usage.IsValid()) {
Fail() << "Invalid sampler or texture usage for variable "
<< var.PrettyPrint() << "\n"
<< usage;
return nullptr;
}
// Infer a handle type, if usage didn't already tell us.
if (!usage.IsComplete()) {
// In SPIR-V you could statically reference a texture or sampler without
// using it in a way that gives us a clue on how to declare it. Look inside
// the store type to infer a usage.
if (raw_handle_type->opcode() == SpvOpTypeSampler) {
usage.AddSampler();
} else {
// It's a texture.
if (raw_handle_type->NumInOperands() != 7) {
Fail() << "invalid SPIR-V image type: expected 7 operands: "
<< raw_handle_type->PrettyPrint();
return nullptr;
}
const auto sampled_param = raw_handle_type->GetSingleWordInOperand(5);
const auto format_param = raw_handle_type->GetSingleWordInOperand(6);
// Only storage images have a format.
if ((format_param != SpvImageFormatUnknown) ||
sampled_param == 2 /* without sampler */) {
// Get NonWritable and NonReadable attributes of the variable.
bool is_nonwritable = false;
bool is_nonreadable = false;
for (const auto& deco : GetDecorationsFor(var.result_id())) {
if (deco.size() != 1) {
continue;
}
if (deco[0] == SpvDecorationNonWritable) {
is_nonwritable = true;
}
if (deco[0] == SpvDecorationNonReadable) {
is_nonreadable = true;
}
}
if (is_nonwritable && is_nonreadable) {
Fail() << "storage image variable is both NonWritable and NonReadable"
<< var.PrettyPrint();
}
if (!is_nonwritable && !is_nonreadable) {
Fail()
<< "storage image variable is neither NonWritable nor NonReadable"
<< var.PrettyPrint();
}
// Let's make it one of the storage textures.
if (is_nonwritable) {
usage.AddStorageReadTexture();
} else {
usage.AddStorageWriteTexture();
}
} else {
usage.AddSampledTexture();
}
}
if (!usage.IsComplete()) {
Fail()
<< "internal error: should have inferred a complete handle type. got "
<< usage.to_str();
return nullptr;
}
}
// Construct the Tint handle type.
const Type* ast_store_type = nullptr;
if (usage.IsSampler()) {
ast_store_type = ty_.Sampler(usage.IsComparisonSampler()
? ast::SamplerKind::kComparisonSampler
: ast::SamplerKind::kSampler);
} else if (usage.IsTexture()) {
const spvtools::opt::analysis::Image* image_type =
type_mgr_->GetType(raw_handle_type->result_id())->AsImage();