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// Copyright 2020 The Tint Authors. //
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "src/writer/spirv/builder.h"
#include <limits>
#include <sstream>
#include <utility>
#include "spirv/unified1/spirv.h"
#include "src/ast/array_accessor_expression.h"
#include "src/ast/as_expression.h"
#include "src/ast/assignment_statement.h"
#include "src/ast/binary_expression.h"
#include "src/ast/binding_decoration.h"
#include "src/ast/bool_literal.h"
#include "src/ast/builtin_decoration.h"
#include "src/ast/call_expression.h"
#include "src/ast/case_statement.h"
#include "src/ast/cast_expression.h"
#include "src/ast/constructor_expression.h"
#include "src/ast/decorated_variable.h"
#include "src/ast/else_statement.h"
#include "src/ast/float_literal.h"
#include "src/ast/identifier_expression.h"
#include "src/ast/if_statement.h"
#include "src/ast/intrinsic.h"
#include "src/ast/location_decoration.h"
#include "src/ast/loop_statement.h"
#include "src/ast/member_accessor_expression.h"
#include "src/ast/null_literal.h"
#include "src/ast/return_statement.h"
#include "src/ast/scalar_constructor_expression.h"
#include "src/ast/set_decoration.h"
#include "src/ast/sint_literal.h"
#include "src/ast/struct.h"
#include "src/ast/struct_member.h"
#include "src/ast/struct_member_offset_decoration.h"
#include "src/ast/switch_statement.h"
#include "src/ast/type/array_type.h"
#include "src/ast/type/matrix_type.h"
#include "src/ast/type/pointer_type.h"
#include "src/ast/type/struct_type.h"
#include "src/ast/type/u32_type.h"
#include "src/ast/type/vector_type.h"
#include "src/ast/type_constructor_expression.h"
#include "src/ast/uint_literal.h"
#include "src/ast/unary_op_expression.h"
#include "src/ast/variable_decl_statement.h"
namespace tint {
namespace writer {
namespace spirv {
namespace {
uint32_t size_of(const InstructionList& instructions) {
uint32_t size = 0;
for (const auto& inst : instructions)
size += inst.word_length();
return size;
}
uint32_t pipeline_stage_to_execution_model(ast::PipelineStage stage) {
SpvExecutionModel model = SpvExecutionModelVertex;
switch (stage) {
case ast::PipelineStage::kFragment:
model = SpvExecutionModelFragment;
break;
case ast::PipelineStage::kVertex:
model = SpvExecutionModelVertex;
break;
case ast::PipelineStage::kCompute:
model = SpvExecutionModelGLCompute;
break;
case ast::PipelineStage::kNone:
model = SpvExecutionModelMax;
break;
}
return model;
}
bool LastIsFallthrough(const ast::StatementList& stmts) {
return !stmts.empty() && stmts.back()->IsFallthrough();
}
// A terminator is anything which will case a SPIR-V terminator to be emitted.
// This means things like breaks, fallthroughs and continues which all emit an
// OpBranch or return for the OpReturn emission.
bool LastIsTerminator(const ast::StatementList& stmts) {
if (stmts.empty()) {
return false;
}
auto* last = stmts.back().get();
return last->IsBreak() || last->IsContinue() || last->IsReturn() ||
last->IsKill() || last->IsFallthrough();
}
uint32_t IndexFromName(char name) {
switch (name) {
case 'x':
case 'r':
return 0;
case 'y':
case 'g':
return 1;
case 'z':
case 'b':
return 2;
case 'w':
case 'a':
return 3;
}
return std::numeric_limits<uint32_t>::max();
}
} // namespace
Builder::AccessorInfo::AccessorInfo() : source_id(0), source_type(nullptr) {}
Builder::AccessorInfo::~AccessorInfo() {}
Builder::Builder(ast::Module* mod) : mod_(mod), scope_stack_({}) {}
Builder::~Builder() = default;
bool Builder::Build() {
push_capability(SpvCapabilityShader);
// TODO(dneto): Stop using the Vulkan memory model. crbug.com/tint/63
push_capability(SpvCapabilityVulkanMemoryModel);
push_preamble(spv::Op::OpExtension,
{Operand::String("SPV_KHR_vulkan_memory_model")});
for (const auto& imp : mod_->imports()) {
GenerateImport(imp.get());
}
push_preamble(spv::Op::OpMemoryModel,
{Operand::Int(SpvAddressingModelLogical),
Operand::Int(SpvMemoryModelVulkanKHR)});
for (const auto& var : mod_->global_variables()) {
if (!GenerateGlobalVariable(var.get())) {
return false;
}
}
for (const auto& func : mod_->functions()) {
if (!GenerateFunction(func.get())) {
return false;
}
}
// Note, the entry points must be generated after the functions as they need
// to be able to lookup the function information based on the name.
for (const auto& ep : mod_->entry_points()) {
if (!GenerateEntryPoint(ep.get())) {
return false;
}
}
for (const auto& ep : mod_->entry_points()) {
if (!GenerateExecutionModes(ep.get())) {
return false;
}
}
return true;
}
Operand Builder::result_op() {
return Operand::Int(next_id());
}
uint32_t Builder::total_size() const {
// The 5 covers the magic, version, generator, id bound and reserved.
uint32_t size = 5;
size += size_of(capabilities_);
size += size_of(preamble_);
size += size_of(debug_);
size += size_of(annotations_);
size += size_of(types_);
for (const auto& func : functions_) {
size += func.word_length();
}
return size;
}
void Builder::iterate(std::function<void(const Instruction&)> cb) const {
for (const auto& inst : capabilities_) {
cb(inst);
}
for (const auto& inst : preamble_) {
cb(inst);
}
for (const auto& inst : debug_) {
cb(inst);
}
for (const auto& inst : annotations_) {
cb(inst);
}
for (const auto& inst : types_) {
cb(inst);
}
for (const auto& func : functions_) {
func.iterate(cb);
}
}
void Builder::push_capability(uint32_t cap) {
capabilities_.push_back(
Instruction{spv::Op::OpCapability, {Operand::Int(cap)}});
}
void Builder::GenerateLabel(uint32_t id) {
push_function_inst(spv::Op::OpLabel, {Operand::Int(id)});
current_label_id_ = id;
}
uint32_t Builder::GenerateU32Literal(uint32_t val) {
ast::type::U32Type u32;
ast::SintLiteral lit(&u32, val);
return GenerateLiteralIfNeeded(&lit);
}
bool Builder::GenerateAssignStatement(ast::AssignmentStatement* assign) {
auto lhs_id = GenerateExpression(assign->lhs());
if (lhs_id == 0) {
return false;
}
auto rhs_id = GenerateExpression(assign->rhs());
if (rhs_id == 0) {
return false;
}
// If the thing we're assigning is a pointer then we must load it first.
rhs_id = GenerateLoadIfNeeded(assign->rhs()->result_type(), rhs_id);
GenerateStore(lhs_id, rhs_id);
return true;
}
bool Builder::GenerateBreakStatement(ast::BreakStatement*) {
if (merge_stack_.empty()) {
error_ = "Attempted to break without a merge block";
return false;
}
push_function_inst(spv::Op::OpBranch, {Operand::Int(merge_stack_.back())});
return true;
}
bool Builder::GenerateContinueStatement(ast::ContinueStatement*) {
if (continue_stack_.empty()) {
error_ = "Attempted to continue without a continue block";
return false;
}
push_function_inst(spv::Op::OpBranch, {Operand::Int(continue_stack_.back())});
return true;
}
// TODO(dsinclair): This is generating an OpKill but the semantics of kill
// haven't been defined for WGSL yet. So, this may need to change.
// https://github.com/gpuweb/gpuweb/issues/676
bool Builder::GenerateKillStatement(ast::KillStatement*) {
push_function_inst(spv::Op::OpKill, {});
return true;
}
bool Builder::GenerateEntryPoint(ast::EntryPoint* ep) {
auto name = ep->name();
if (name.empty()) {
name = ep->function_name();
}
const auto id = id_for_entry_point(ep);
if (id == 0) {
return false;
}
auto stage = pipeline_stage_to_execution_model(ep->stage());
if (stage == SpvExecutionModelMax) {
error_ = "Unknown pipeline stage provided";
return false;
}
OperandList operands = {Operand::Int(stage), Operand::Int(id),
Operand::String(name)};
auto* func = func_name_to_func_[ep->function_name()];
if (func == nullptr) {
error_ = "processing an entry point when the function has not been seen.";
return false;
}
for (const auto* var : func->referenced_module_variables()) {
// For SPIR-V 1.3 we only output Input/output variables. If we update to
// SPIR-V 1.4 or later this should be all variables.
if (var->storage_class() != ast::StorageClass::kInput &&
var->storage_class() != ast::StorageClass::kOutput) {
continue;
}
uint32_t var_id;
if (!scope_stack_.get(var->name(), &var_id)) {
error_ = "unable to find ID for global variable: " + var->name();
return false;
}
operands.push_back(Operand::Int(var_id));
}
push_preamble(spv::Op::OpEntryPoint, operands);
return true;
}
bool Builder::GenerateExecutionModes(ast::EntryPoint* ep) {
const auto id = id_for_entry_point(ep);
if (id == 0) {
return false;
}
// WGSL fragment shader origin is upper left
if (ep->stage() == ast::PipelineStage::kFragment) {
push_preamble(
spv::Op::OpExecutionMode,
{Operand::Int(id), Operand::Int(SpvExecutionModeOriginUpperLeft)});
} else if (ep->stage() == ast::PipelineStage::kCompute) {
// TODO(dsinclair): Support LocalSize other then (1, 1, 1)
push_preamble(spv::Op::OpExecutionMode,
{Operand::Int(id), Operand::Int(SpvExecutionModeLocalSize),
Operand::Int(1), Operand::Int(1), Operand::Int(1)});
}
return true;
}
uint32_t Builder::GenerateExpression(ast::Expression* expr) {
if (expr->IsArrayAccessor()) {
return GenerateAccessorExpression(expr->AsArrayAccessor());
}
if (expr->IsAs()) {
return GenerateAsExpression(expr->AsAs());
}
if (expr->IsBinary()) {
return GenerateBinaryExpression(expr->AsBinary());
}
if (expr->IsCall()) {
return GenerateCallExpression(expr->AsCall());
}
if (expr->IsCast()) {
return GenerateCastExpression(expr->AsCast());
}
if (expr->IsConstructor()) {
return GenerateConstructorExpression(expr->AsConstructor(), false);
}
if (expr->IsIdentifier()) {
return GenerateIdentifierExpression(expr->AsIdentifier());
}
if (expr->IsMemberAccessor()) {
return GenerateAccessorExpression(expr->AsMemberAccessor());
}
if (expr->IsUnaryOp()) {
return GenerateUnaryOpExpression(expr->AsUnaryOp());
}
error_ = "unknown expression type: " + expr->str();
return 0;
}
bool Builder::GenerateFunction(ast::Function* func) {
uint32_t func_type_id = GenerateFunctionTypeIfNeeded(func);
if (func_type_id == 0) {
return false;
}
auto func_op = result_op();
auto func_id = func_op.to_i();
push_debug(spv::Op::OpName,
{Operand::Int(func_id), Operand::String(func->name())});
auto ret_id = GenerateTypeIfNeeded(func->return_type());
if (ret_id == 0) {
return false;
}
scope_stack_.push_scope();
auto definition_inst = Instruction{
spv::Op::OpFunction,
{Operand::Int(ret_id), func_op, Operand::Int(SpvFunctionControlMaskNone),
Operand::Int(func_type_id)}};
InstructionList params;
for (const auto& param : func->params()) {
auto param_op = result_op();
auto param_id = param_op.to_i();
auto param_type_id = GenerateTypeIfNeeded(param->type());
if (param_type_id == 0) {
return false;
}
push_debug(spv::Op::OpName,
{Operand::Int(param_id), Operand::String(param->name())});
params.push_back(Instruction{spv::Op::OpFunctionParameter,
{Operand::Int(param_type_id), param_op}});
scope_stack_.set(param->name(), param_id);
}
push_function(Function{definition_inst, result_op(), std::move(params)});
for (const auto& stmt : func->body()) {
if (!GenerateStatement(stmt.get())) {
return false;
}
}
scope_stack_.pop_scope();
func_name_to_id_[func->name()] = func_id;
func_name_to_func_[func->name()] = func;
return true;
}
uint32_t Builder::GenerateFunctionTypeIfNeeded(ast::Function* func) {
auto val = type_name_to_id_.find(func->type_name());
if (val != type_name_to_id_.end()) {
return val->second;
}
auto func_op = result_op();
auto func_type_id = func_op.to_i();
auto ret_id = GenerateTypeIfNeeded(func->return_type());
if (ret_id == 0) {
return 0;
}
OperandList ops = {func_op, Operand::Int(ret_id)};
for (const auto& param : func->params()) {
auto param_type_id = GenerateTypeIfNeeded(param->type());
if (param_type_id == 0) {
return 0;
}
ops.push_back(Operand::Int(param_type_id));
}
push_type(spv::Op::OpTypeFunction, std::move(ops));
type_name_to_id_[func->type_name()] = func_type_id;
return func_type_id;
}
bool Builder::GenerateFunctionVariable(ast::Variable* var) {
uint32_t init_id = 0;
if (var->has_constructor()) {
init_id = GenerateExpression(var->constructor());
if (init_id == 0) {
return false;
}
}
if (var->is_const()) {
if (!var->has_constructor()) {
error_ = "missing constructor for constant";
return false;
}
scope_stack_.set(var->name(), init_id);
spirv_id_to_variable_[init_id] = var;
return true;
}
auto result = result_op();
auto var_id = result.to_i();
auto sc = ast::StorageClass::kFunction;
ast::type::PointerType pt(var->type(), sc);
auto type_id = GenerateTypeIfNeeded(&pt);
if (type_id == 0) {
return false;
}
push_debug(spv::Op::OpName,
{Operand::Int(var_id), Operand::String(var->name())});
// TODO(dsinclair) We could detect if the constructor is fully const and emit
// an initializer value for the variable instead of doing the OpLoad.
ast::NullLiteral nl(var->type()->UnwrapPtrIfNeeded());
auto null_id = GenerateLiteralIfNeeded(&nl);
if (null_id == 0) {
return 0;
}
push_function_var({Operand::Int(type_id), result,
Operand::Int(ConvertStorageClass(sc)),
Operand::Int(null_id)});
if (var->has_constructor()) {
init_id = GenerateLoadIfNeeded(var->constructor()->result_type(), init_id);
GenerateStore(var_id, init_id);
}
scope_stack_.set(var->name(), var_id);
spirv_id_to_variable_[var_id] = var;
return true;
}
void Builder::GenerateStore(uint32_t to, uint32_t from) {
push_function_inst(spv::Op::OpStore, {Operand::Int(to), Operand::Int(from)});
}
bool Builder::GenerateGlobalVariable(ast::Variable* var) {
uint32_t init_id = 0;
if (var->has_constructor()) {
if (!var->constructor()->IsConstructor()) {
error_ = "scalar constructor expected";
return false;
}
init_id = GenerateConstructorExpression(var->constructor()->AsConstructor(),
true);
if (init_id == 0) {
return false;
}
}
if (var->is_const()) {
if (!var->has_constructor()) {
error_ = "missing constructor for constant";
return false;
}
scope_stack_.set_global(var->name(), init_id);
spirv_id_to_variable_[init_id] = var;
return true;
}
auto result = result_op();
auto var_id = result.to_i();
auto sc = var->storage_class() == ast::StorageClass::kNone
? ast::StorageClass::kPrivate
: var->storage_class();
ast::type::PointerType pt(var->type(), sc);
auto type_id = GenerateTypeIfNeeded(&pt);
if (type_id == 0) {
return false;
}
push_debug(spv::Op::OpName,
{Operand::Int(var_id), Operand::String(var->name())});
OperandList ops = {Operand::Int(type_id), result,
Operand::Int(ConvertStorageClass(sc))};
if (var->has_constructor()) {
ops.push_back(Operand::Int(init_id));
} else {
// If we don't have a constructor and we're an Output or Private variable
// then WGSL requires an initializer.
if (var->storage_class() == ast::StorageClass::kPrivate ||
var->storage_class() == ast::StorageClass::kNone ||
var->storage_class() == ast::StorageClass::kOutput) {
ast::NullLiteral nl(var->type()->UnwrapPtrIfNeeded());
init_id = GenerateLiteralIfNeeded(&nl);
if (init_id == 0) {
return 0;
}
ops.push_back(Operand::Int(init_id));
}
}
push_type(spv::Op::OpVariable, std::move(ops));
if (var->IsDecorated()) {
for (const auto& deco : var->AsDecorated()->decorations()) {
if (deco->IsBuiltin()) {
push_annot(spv::Op::OpDecorate,
{Operand::Int(var_id), Operand::Int(SpvDecorationBuiltIn),
Operand::Int(ConvertBuiltin(deco->AsBuiltin()->value()))});
} else if (deco->IsLocation()) {
push_annot(spv::Op::OpDecorate,
{Operand::Int(var_id), Operand::Int(SpvDecorationLocation),
Operand::Int(deco->AsLocation()->value())});
} else if (deco->IsBinding()) {
push_annot(spv::Op::OpDecorate,
{Operand::Int(var_id), Operand::Int(SpvDecorationBinding),
Operand::Int(deco->AsBinding()->value())});
} else if (deco->IsSet()) {
push_annot(
spv::Op::OpDecorate,
{Operand::Int(var_id), Operand::Int(SpvDecorationDescriptorSet),
Operand::Int(deco->AsSet()->value())});
} else {
error_ = "unknown decoration";
return false;
}
}
}
scope_stack_.set_global(var->name(), var_id);
spirv_id_to_variable_[var_id] = var;
return true;
}
bool Builder::GenerateArrayAccessor(ast::ArrayAccessorExpression* expr,
AccessorInfo* info) {
auto idx_id = GenerateExpression(expr->idx_expr());
if (idx_id == 0) {
return 0;
}
idx_id = GenerateLoadIfNeeded(expr->idx_expr()->result_type(), idx_id);
// If the source is a pointer we access chain into it.
if (info->source_type->IsPointer()) {
info->access_chain_indices.push_back(idx_id);
info->source_type = expr->result_type();
return true;
}
auto result_type_id = GenerateTypeIfNeeded(expr->result_type());
if (result_type_id == 0) {
return false;
}
// We don't have a pointer, so we have to extract value from the vector
auto extract = result_op();
auto extract_id = extract.to_i();
push_function_inst(spv::Op::OpVectorExtractDynamic,
{Operand::Int(result_type_id), extract,
Operand::Int(info->source_id), Operand::Int(idx_id)});
info->source_id = extract_id;
info->source_type = expr->result_type();
return true;
}
bool Builder::GenerateMemberAccessor(ast::MemberAccessorExpression* expr,
AccessorInfo* info) {
auto* data_type = expr->structure()
->result_type()
->UnwrapPtrIfNeeded()
->UnwrapAliasesIfNeeded();
// If the data_type is a structure we're accessing a member, if it's a
// vector we're accessing a swizzle.
if (data_type->IsStruct()) {
if (!info->source_type->IsPointer()) {
error_ =
"Attempting to access a struct member on a non-pointer. Something is "
"wrong";
return false;
}
auto* strct = data_type->AsStruct()->impl();
auto name = expr->member()->name();
uint32_t i = 0;
for (; i < strct->members().size(); ++i) {
const auto& member = strct->members()[i];
if (member->name() == name) {
break;
}
}
auto idx_id = GenerateU32Literal(i);
if (idx_id == 0) {
return 0;
}
info->access_chain_indices.push_back(idx_id);
info->source_type = expr->result_type();
return true;
}
if (!data_type->IsVector()) {
error_ = "Member accessor without a struct or vector. Something is wrong";
return false;
}
auto swiz = expr->member()->name();
// Single element swizzle is either an access chain or a composite extract
if (swiz.size() == 1) {
auto val = IndexFromName(swiz[0]);
if (val == std::numeric_limits<uint32_t>::max()) {
error_ = "invalid swizzle name: " + swiz;
return false;
}
if (info->source_type->IsPointer()) {
auto idx_id = GenerateU32Literal(val);
if (idx_id == 0) {
return 0;
}
info->access_chain_indices.push_back(idx_id);
} else {
auto result_type_id = GenerateTypeIfNeeded(expr->result_type());
if (result_type_id == 0) {
return 0;
}
auto extract = result_op();
auto extract_id = extract.to_i();
push_function_inst(spv::Op::OpCompositeExtract,
{Operand::Int(result_type_id), extract,
Operand::Int(info->source_id), Operand::Int(val)});
info->source_id = extract_id;
info->source_type = expr->result_type();
}
return true;
}
// Store the type away as it may change if we run the access chain
auto* incoming_type = info->source_type;
// Multi-item extract is a VectorShuffle. We have to emit any existing access
// chain data, then load the access chain and shuffle that.
if (!info->access_chain_indices.empty()) {
auto result_type_id = GenerateTypeIfNeeded(info->source_type);
if (result_type_id == 0) {
return 0;
}
auto extract = result_op();
auto extract_id = extract.to_i();
OperandList ops = {Operand::Int(result_type_id), extract,
Operand::Int(info->source_id)};
for (auto id : info->access_chain_indices) {
ops.push_back(Operand::Int(id));
}
push_function_inst(spv::Op::OpAccessChain, ops);
info->source_id = GenerateLoadIfNeeded(expr->result_type(), extract_id);
info->source_type = expr->result_type()->UnwrapPtrIfNeeded();
info->access_chain_indices.clear();
}
auto result_type_id = GenerateTypeIfNeeded(expr->result_type());
if (result_type_id == 0) {
return false;
}
auto vec_id = GenerateLoadIfNeeded(incoming_type, info->source_id);
auto result = result_op();
auto result_id = result.to_i();
OperandList ops = {Operand::Int(result_type_id), result, Operand::Int(vec_id),
Operand::Int(vec_id)};
for (uint32_t i = 0; i < swiz.size(); ++i) {
auto val = IndexFromName(swiz[i]);
if (val == std::numeric_limits<uint32_t>::max()) {
error_ = "invalid swizzle name: " + swiz;
return false;
}
ops.push_back(Operand::Int(val));
}
push_function_inst(spv::Op::OpVectorShuffle, ops);
info->source_id = result_id;
info->source_type = expr->result_type();
return true;
}
uint32_t Builder::GenerateAccessorExpression(ast::Expression* expr) {
assert(expr->IsArrayAccessor() || expr->IsMemberAccessor());
// Gather a list of all the member and array accessors that are in this chain.
// The list is built in reverse order as that's the order we need to access
// the chain.
std::vector<ast::Expression*> accessors;
ast::Expression* source = expr;
while (true) {
if (source->IsArrayAccessor()) {
accessors.insert(accessors.begin(), source);
source = source->AsArrayAccessor()->array();
} else if (source->IsMemberAccessor()) {
accessors.insert(accessors.begin(), source);
source = source->AsMemberAccessor()->structure();
} else {
break;
}
}
AccessorInfo info;
info.source_id = GenerateExpression(source);
if (info.source_id == 0) {
return 0;
}
info.source_type = source->result_type();
std::vector<uint32_t> access_chain_indices;
for (auto* accessor : accessors) {
if (accessor->IsArrayAccessor()) {
if (!GenerateArrayAccessor(accessor->AsArrayAccessor(), &info)) {
return 0;
}
} else if (accessor->IsMemberAccessor()) {
if (!GenerateMemberAccessor(accessor->AsMemberAccessor(), &info)) {
return 0;
}
} else {
error_ = "invalid accessor in list: " + accessor->str();
return 0;
}
}
if (!info.access_chain_indices.empty()) {
auto result_type_id = GenerateTypeIfNeeded(expr->result_type());
if (result_type_id == 0) {
return 0;
}
auto result = result_op();
auto result_id = result.to_i();
OperandList ops = {Operand::Int(result_type_id), result,
Operand::Int(info.source_id)};
for (auto id : info.access_chain_indices) {
ops.push_back(Operand::Int(id));
}
push_function_inst(spv::Op::OpAccessChain, ops);
info.source_id = result_id;
}
return info.source_id;
}
uint32_t Builder::GenerateIdentifierExpression(
ast::IdentifierExpression* expr) {
uint32_t val = 0;
if (expr->has_path()) {
auto* imp = mod_->FindImportByName(expr->path());
if (imp == nullptr) {
error_ = "unable to find import for " + expr->path();
return 0;
}
val = imp->GetIdForMethod(expr->name());
if (val == 0) {
error_ = "unable to lookup: " + expr->name() + " in " + expr->path();
}
return val;
}
if (scope_stack_.get(expr->name(), &val)) {
return val;
}
error_ = "unable to find name for identifier: " + expr->name();
return 0;
}
uint32_t Builder::GenerateLoadIfNeeded(ast::type::Type* type, uint32_t id) {
if (!type->IsPointer()) {
return id;
}
auto type_id = GenerateTypeIfNeeded(type->UnwrapPtrIfNeeded());
auto result = result_op();
auto result_id = result.to_i();
push_function_inst(spv::Op::OpLoad,
{Operand::Int(type_id), result, Operand::Int(id)});
return result_id;
}
uint32_t Builder::GenerateUnaryOpExpression(ast::UnaryOpExpression* expr) {
auto result = result_op();
auto result_id = result.to_i();
auto val_id = GenerateExpression(expr->expr());
if (val_id == 0) {
return 0;
}
auto type_id = GenerateTypeIfNeeded(expr->result_type());
if (type_id == 0) {
return 0;
}
spv::Op op = spv::Op::OpNop;
if (expr->op() == ast::UnaryOp::kNegation) {
if (expr->result_type()->is_float_scalar_or_vector()) {
op = spv::Op::OpFNegate;
} else {
op = spv::Op::OpSNegate;
}
} else if (expr->op() == ast::UnaryOp::kNot) {
op = spv::Op::OpNot;
}
if (op == spv::Op::OpNop) {
error_ = "invalid unary op type";
return 0;
}
push_function_inst(op, {Operand::Int(type_id), result, Operand::Int(val_id)});
return result_id;
}
void Builder::GenerateImport(ast::Import* imp) {
auto result = result_op();
auto id = result.to_i();
push_preamble(spv::Op::OpExtInstImport,
{result, Operand::String(imp->path())});
import_name_to_id_[imp->name()] = id;
}
uint32_t Builder::GenerateConstructorExpression(
ast::ConstructorExpression* expr,
bool is_global_init) {
if (expr->IsScalarConstructor()) {
return GenerateLiteralIfNeeded(expr->AsScalarConstructor()->literal());
}
if (expr->IsTypeConstructor()) {
return GenerateTypeConstructorExpression(expr->AsTypeConstructor(),
is_global_init);
}
error_ = "unknown constructor expression";
return 0;
}
uint32_t Builder::GenerateTypeConstructorExpression(
ast::TypeConstructorExpression* init,
bool is_global_init) {
auto type_id = GenerateTypeIfNeeded(init->type());
if (type_id == 0) {
return 0;
}
// Generate the zero initializer if there are no values provided.
if (init->values().empty()) {
ast::NullLiteral nl(init->type()->UnwrapPtrIfNeeded());
return GenerateLiteralIfNeeded(&nl);
}
auto* result_type = init->type()->UnwrapPtrIfNeeded();
if (result_type->IsVector()) {
result_type = result_type->AsVector()->type();
} else if (result_type->IsArray()) {
result_type = result_type->AsArray()->type();
} else if (result_type->IsMatrix()) {
result_type = result_type->AsMatrix()->type();
}
std::ostringstream out;
out << "__const";
OperandList ops;
bool constructor_is_const = true;
for (const auto& e : init->values()) {
if (!e->IsConstructor()) {
if (is_global_init) {
error_ = "constructor must be a constant expression";
return 0;
}
constructor_is_const = false;
}
}
bool result_is_constant_composite = constructor_is_const;
bool result_is_spec_composite = false;
for (const auto& e : init->values()) {
uint32_t id = 0;
if (constructor_is_const) {
id = GenerateConstructorExpression(e->AsConstructor(), is_global_init);
} else {
id = GenerateExpression(e.get());
id = GenerateLoadIfNeeded(e->result_type(), id);
}
if (id == 0) {
return 0;
}
auto* value_type = e->result_type()->UnwrapPtrIfNeeded();
// When handling vectors as the values there a few cases to take into
// consideration:
// 1. Module scoped vec3<f32>(vec2<f32>(1, 2), 3) -> OpSpecConstantOp
// 2. Function scoped vec3<f32>(vec2<f32>(1, 2), 3) -> OpCompositeExtract
// 3. Either array<vec3<f32>, 1>(vec3<f32>(1, 2, 3)) -> use the ID.
if (value_type->IsVector()) {
auto* vec = value_type->AsVector();
auto* vec_type = vec->type();
// If the value we want is the same as what we have, use it directly.
// This maps to case 3.
if (result_type == value_type) {
out << "_" << id;
ops.push_back(Operand::Int(id));
} else if (!is_global_init) {
// A non-global initializer. Case 2.
auto value_type_id = GenerateTypeIfNeeded(vec_type);
if (value_type_id == 0) {
return 0;
}
for (uint32_t i = 0; i < vec->size(); ++i) {
auto extract = result_op();
auto extract_id = extract.to_i();
push_function_inst(spv::Op::OpCompositeExtract,
{Operand::Int(value_type_id), extract,
Operand::Int(id), Operand::Int(i)});
out << "_" << extract_id;
ops.push_back(Operand::Int(extract_id));
// We no longer have a constant composite, but have to do a
// composite construction as these calls are inside a function.
result_is_constant_composite = false;
}
} else {
// A global initializer, must use OpSpecConstantOp. Case 1.
auto value_type_id = GenerateTypeIfNeeded(vec_type);
if (value_type_id == 0) {
return 0;
}
for (uint32_t i = 0; i < vec->size(); ++i) {
auto extract = result_op();
auto extract_id = extract.to_i();
auto idx_id = GenerateU32Literal(i);
if (idx_id == 0) {
return 0;
}
push_type(spv::Op::OpSpecConstantOp,
{Operand::Int(value_type_id), extract,
Operand::Int(SpvOpCompositeExtract), Operand::Int(id),
Operand::Int(idx_id)});
out << "_" << extract_id;
ops.push_back(Operand::Int(extract_id));
result_is_spec_composite = true;
}
}
} else {
out << "_" << id;
ops.push_back(Operand::Int(id));
}
}
auto str = out.str();
auto val = const_to_id_.find(str);
if (val != const_to_id_.end()) {
return val->second;
}
auto result = result_op();
ops.insert(ops.begin(), result);
ops.insert(ops.begin(), Operand::Int(type_id));
const_to_id_[str] = result.to_i();
if (result_is_spec_composite) {
push_type(spv::Op::OpSpecConstantComposite, ops);
} else if (result_is_constant_composite) {
push_type(spv::Op::OpConstantComposite, ops);
} else {
push_function_inst(spv::Op::OpCompositeConstruct, ops);
}
return result.to_i();
}
uint32_t Builder::GenerateLiteralIfNeeded(ast::Literal* lit) {
auto type_id = GenerateTypeIfNeeded(lit->type());
if (type_id == 0) {
return 0;
}
auto name = lit->name();
auto val = const_to_id_.find(name);
if (val != const_to_id_.end()) {
return val->second;
}
auto result = result_op();
auto result_id = result.to_i();
if (lit->IsBool()) {
if (lit->AsBool()->IsTrue()) {
push_type(spv::Op::OpConstantTrue, {Operand::Int(type_id), result});
} else {
push_type(spv::Op::OpConstantFalse, {Operand::Int(type_id), result});
}
} else if (lit->IsSint()) {
push_type(spv::Op::OpConstant, {Operand::Int(type_id), result,
Operand::Int(lit->AsSint()->value())});
} else if (lit->IsUint()) {
push_type(spv::Op::OpConstant, {Operand::Int(type_id), result,
Operand::Int(lit->AsUint()->value())});
} else if (lit->IsFloat()) {
push_type(spv::Op::OpConstant, {Operand::Int(type_id), result,
Operand::Float(lit->AsFloat()->value())});
} else if (lit->IsNull()) {
push_type(spv::Op::OpConstantNull, {Operand::Int(type_id), result});
} else {
error_ = "unknown literal type";
return 0;
}
const_to_id_[name] = result_id;
return result_id;
}
uint32_t Builder::GenerateShortCircuitBinaryExpression(
ast::BinaryExpression* expr) {
auto lhs_id = GenerateExpression(expr->lhs());
if (lhs_id == 0) {
return false;
}
lhs_id = GenerateLoadIfNeeded(expr->lhs()->result_type(), lhs_id);
auto original_label_id = current_label_id_;
auto type_id = GenerateTypeIfNeeded(expr->result_type());
if (type_id == 0) {
return 0;
}
auto merge_block = result_op();
auto merge_block_id = merge_block.to_i();
auto block = result_op();
auto block_id = block.to_i();
auto true_block_id = block_id;
auto false_block_id = merge_block_id;
// For a logical or we want to only check the RHS if the LHS is failed.
if (expr->IsLogicalOr()) {
std::swap(true_block_id, false_block_id);
}
push_function_inst(spv::Op::OpSelectionMerge,
{Operand::Int(merge_block_id),
Operand::Int(SpvSelectionControlMaskNone)});
push_function_inst(spv::Op::OpBranchConditional,
{Operand::Int(lhs_id), Operand::Int(true_block_id),
Operand::Int(false_block_id)});
// Output block to check the RHS
GenerateLabel(block_id);
auto rhs_id = GenerateExpression(expr->rhs());
if (rhs_id == 0) {
return 0;
}
rhs_id = GenerateLoadIfNeeded(expr->rhs()->result_type(), rhs_id);
push_function_inst(spv::Op::OpBranch, {Operand::Int(merge_block_id)});
// Output the merge block
GenerateLabel(merge_block_id);
auto result = result_op();
auto result_id = result.to_i();
push_function_inst(spv::Op::OpPhi,
{Operand::Int(type_id), result, Operand::Int(lhs_id),
Operand::Int(original_label_id), Operand::Int(rhs_id),
Operand::Int(block_id)});
return result_id;
}
uint32_t Builder::GenerateBinaryExpression(ast::BinaryExpression* expr) {
// There is special logic for short circuiting operators.
if (expr->IsLogicalAnd() || expr->IsLogicalOr()) {
return GenerateShortCircuitBinaryExpression(expr);
}
auto lhs_id = GenerateExpression(expr->lhs());
if (lhs_id == 0) {
return 0;
}
lhs_id = GenerateLoadIfNeeded(expr->lhs()->result_type(), lhs_id);
auto rhs_id = GenerateExpression(expr->rhs());
if (rhs_id == 0) {
return 0;
}
rhs_id = GenerateLoadIfNeeded(expr->rhs()->result_type(), rhs_id);
auto result = result_op();
auto result_id = result.to_i();
auto type_id = GenerateTypeIfNeeded(expr->result_type());
if (type_id == 0) {
return 0;
}
// Handle int and float and the vectors of those types. Other types
// should have been rejected by validation.
auto* lhs_type = expr->lhs()->result_type()->UnwrapPtrIfNeeded();
auto* rhs_type = expr->rhs()->result_type()->UnwrapPtrIfNeeded();
bool lhs_is_float_or_vec = lhs_type->is_float_scalar_or_vector();
bool lhs_is_unsigned = lhs_type->is_unsigned_scalar_or_vector();
spv::Op op = spv::Op::OpNop;
if (expr->IsAnd()) {
op = spv::Op::OpBitwiseAnd;
} else if (expr->IsAdd()) {
op = lhs_is_float_or_vec ? spv::Op::OpFAdd : spv::Op::OpIAdd;
} else if (expr->IsDivide()) {
if (lhs_is_float_or_vec) {
op = spv::Op::OpFDiv;
} else if (lhs_is_unsigned) {
op = spv::Op::OpUDiv;
} else {
op = spv::Op::OpSDiv;
}
} else if (expr->IsEqual()) {
op = lhs_is_float_or_vec ? spv::Op::OpFOrdEqual : spv::Op::OpIEqual;
} else if (expr->IsGreaterThan()) {
if (lhs_is_float_or_vec) {
op = spv::Op::OpFOrdGreaterThan;
} else if (lhs_is_unsigned) {
op = spv::Op::OpUGreaterThan;
} else {
op = spv::Op::OpSGreaterThan;
}
} else if (expr->IsGreaterThanEqual()) {
if (lhs_is_float_or_vec) {
op = spv::Op::OpFOrdGreaterThanEqual;
} else if (lhs_is_unsigned) {
op = spv::Op::OpUGreaterThanEqual;
} else {
op = spv::Op::OpSGreaterThanEqual;
}
} else if (expr->IsLessThan()) {
if (lhs_is_float_or_vec) {
op = spv::Op::OpFOrdLessThan;
} else if (lhs_is_unsigned) {
op = spv::Op::OpULessThan;
} else {
op = spv::Op::OpSLessThan;
}
} else if (expr->IsLessThanEqual()) {
if (lhs_is_float_or_vec) {
op = spv::Op::OpFOrdLessThanEqual;
} else if (lhs_is_unsigned) {
op = spv::Op::OpULessThanEqual;
} else {
op = spv::Op::OpSLessThanEqual;
}
} else if (expr->IsModulo()) {
if (lhs_is_float_or_vec) {
op = spv::Op::OpFMod;
} else if (lhs_is_unsigned) {
op = spv::Op::OpUMod;
} else {
op = spv::Op::OpSMod;
}
} else if (expr->IsMultiply()) {
if (lhs_type->is_integer_scalar_or_vector()) {
// If the left hand side is an integer then this _has_ to be OpIMul as
// there there is no other integer multiplication.
op = spv::Op::OpIMul;
} else if (lhs_type->is_float_scalar() && rhs_type->is_float_scalar()) {
// Float scalars multiply with OpFMul
op = spv::Op::OpFMul;
} else if (lhs_type->is_float_vector() && rhs_type->is_float_vector()) {
// Float vectors must be validated to be the same size and then use OpFMul
op = spv::Op::OpFMul;
} else if (lhs_type->is_float_scalar() && rhs_type->is_float_vector()) {
// Scalar * Vector we need to flip lhs and rhs types
// because OpVectorTimesScalar expects <vector>, <scalar>
std::swap(lhs_id, rhs_id);
op = spv::Op::OpVectorTimesScalar;
} else if (lhs_type->is_float_vector() && rhs_type->is_float_scalar()) {
// float vector * scalar
op = spv::Op::OpVectorTimesScalar;
} else if (lhs_type->is_float_scalar() && rhs_type->is_float_matrix()) {
// Scalar * Matrix we need to flip lhs and rhs types because
// OpMatrixTimesScalar expects <matrix>, <scalar>
std::swap(lhs_id, rhs_id);
op = spv::Op::OpMatrixTimesScalar;
} else if (lhs_type->is_float_matrix() && rhs_type->is_float_scalar()) {
// float matrix * scalar
op = spv::Op::OpMatrixTimesScalar;
} else if (lhs_type->is_float_vector() && rhs_type->is_float_matrix()) {
// float vector * matrix
op = spv::Op::OpVectorTimesMatrix;
} else if (lhs_type->is_float_matrix() && rhs_type->is_float_vector()) {
// float matrix * vector
op = spv::Op::OpMatrixTimesVector;
} else if (lhs_type->is_float_matrix() && rhs_type->is_float_matrix()) {
// float matrix * matrix
op = spv::Op::OpMatrixTimesMatrix;
} else {
return 0;
}
} else if (expr->IsNotEqual()) {
op = lhs_is_float_or_vec ? spv::Op::OpFOrdNotEqual : spv::Op::OpINotEqual;
} else if (expr->IsOr()) {
op = spv::Op::OpBitwiseOr;
} else if (expr->IsShiftLeft()) {
op = spv::Op::OpShiftLeftLogical;
} else if (expr->IsShiftRight()) {
// TODO(dsinclair): This depends on the type of the LHS if it's a
// OpShiftRightLogical or OpShiftRightArithmetic
// http://crbug.com/tint/84
op = spv::Op::OpShiftRightLogical;
} else if (expr->IsSubtract()) {
op = lhs_is_float_or_vec ? spv::Op::OpFSub : spv::Op::OpISub;
} else if (expr->IsXor()) {
op = spv::Op::OpBitwiseXor;
} else {
error_ = "unknown binary expression";
return 0;
}
push_function_inst(op, {Operand::Int(type_id), result, Operand::Int(lhs_id),
Operand::Int(rhs_id)});
return result_id;
}
uint32_t Builder::GenerateCallExpression(ast::CallExpression* expr) {
if (!expr->func()->IsIdentifier()) {
error_ = "invalid function name";
return 0;
}
auto* ident = expr->func()->AsIdentifier();
if (!ident->has_path() && ast::intrinsic::IsIntrinsic(ident->name())) {
return GenerateIntrinsic(ident->name(), expr);
}
auto type_id = GenerateTypeIfNeeded(expr->func()->result_type());
if (type_id == 0) {
return 0;
}
auto result = result_op();
auto result_id = result.to_i();
spv::Op op = spv::Op::OpNop;
OperandList ops = {Operand::Int(type_id), result};
// Handle regular function calls
if (!ident->has_path()) {
auto func_id = func_name_to_id_[ident->name()];
if (func_id == 0) {
error_ = "unable to find called function: " + ident->name();
return 0;
}
ops.push_back(Operand::Int(func_id));
op = spv::Op::OpFunctionCall;
} else {
// Imported function call
auto set_iter = import_name_to_id_.find(ident->path());
if (set_iter == import_name_to_id_.end()) {
error_ = "unknown import " + ident->path();
return 0;
}
auto set_id = set_iter->second;
auto* imp = mod_->FindImportByName(ident->path());
if (imp == nullptr) {
error_ = "unknown import " + ident->path();
return 0;
}
auto inst_id = imp->GetIdForMethod(ident->name());
if (inst_id == 0) {
error_ = "unknown method " + ident->name();
return 0;
}
ops.push_back(Operand::Int(set_id));
ops.push_back(Operand::Int(inst_id));
op = spv::Op::OpExtInst;
}
for (const auto& param : expr->params()) {
auto id = GenerateExpression(param.get());
if (id == 0) {
return 0;
}
id = GenerateLoadIfNeeded(param->result_type(), id);
ops.push_back(Operand::Int(id));
}
push_function_inst(op, std::move(ops));
return result_id;
}
uint32_t Builder::GenerateIntrinsic(const std::string& name,
ast::CallExpression* call) {
auto result = result_op();
auto result_id = result.to_i();
auto result_type_id = GenerateTypeIfNeeded(call->result_type());
if (result_type_id == 0) {
return 0;
}
OperandList params = {Operand::Int(result_type_id), result};
for (const auto& p : call->params()) {
auto val_id = GenerateExpression(p.get());
if (val_id == 0) {
return 0;
}
val_id = GenerateLoadIfNeeded(p->result_type(), val_id);
params.push_back(Operand::Int(val_id));
}
if (ast::intrinsic::IsFineDerivative(name) ||
ast::intrinsic::IsCoarseDerivative(name)) {
push_capability(SpvCapabilityDerivativeControl);
}
spv::Op op = spv::Op::OpNop;
if (name == "any") {
op = spv::Op::OpAny;
} else if (name == "all") {
op = spv::Op::OpAll;
} else if (name == "dot") {
op = spv::Op::OpDot;
} else if (name == "dpdx") {
op = spv::Op::OpDPdx;
} else if (name == "dpdx_coarse") {
op = spv::Op::OpDPdxCoarse;
} else if (name == "dpdx_fine") {
op = spv::Op::OpDPdxFine;
} else if (name == "dpdy") {
op = spv::Op::OpDPdy;
} else if (name == "dpdy_coarse") {
op = spv::Op::OpDPdyCoarse;
} else if (name == "dpdy_fine") {
op = spv::Op::OpDPdyFine;
} else if (name == "fwidth") {
op = spv::Op::OpFwidth;
} else if (name == "fwidth_coarse") {
op = spv::Op::OpFwidthCoarse;
} else if (name == "fwidth_fine") {
op = spv::Op::OpFwidthFine;
} else if (name == "is_inf") {
op = spv::Op::OpIsInf;
} else if (name == "is_nan") {
op = spv::Op::OpIsNan;
} else if (name == "outer_product") {
op = spv::Op::OpOuterProduct;
}
if (op == spv::Op::OpNop) {
error_ = "unable to determine operator for: " + name;
return 0;
}
push_function_inst(op, params);
return result_id;
}
uint32_t Builder::GenerateAsExpression(ast::AsExpression* as) {
auto result = result_op();
auto result_id = result.to_i();
auto result_type_id = GenerateTypeIfNeeded(as->result_type());
if (result_type_id == 0) {
return 0;
}
auto val_id = GenerateExpression(as->expr());
if (val_id == 0) {
return 0;
}
val_id = GenerateLoadIfNeeded(as->expr()->result_type(), val_id);
// Bitcast does not allow same types, just emit a CopyObject
auto* to_type = as->result_type()->UnwrapPtrIfNeeded();
auto* from_type = as->expr()->result_type()->UnwrapPtrIfNeeded();
if (to_type->type_name() == from_type->type_name()) {
push_function_inst(spv::Op::OpCopyObject, {Operand::Int(result_type_id),
result, Operand::Int(val_id)});
return result_id;
}
push_function_inst(spv::Op::OpBitcast, {Operand::Int(result_type_id), result,
Operand::Int(val_id)});
return result_id;
}
uint32_t Builder::GenerateCastExpression(ast::CastExpression* cast) {
auto result = result_op();
auto result_id = result.to_i();
auto result_type_id = GenerateTypeIfNeeded(cast->result_type());
if (result_type_id == 0) {
return 0;
}
auto val_id = GenerateExpression(cast->expr());
if (val_id == 0) {
return 0;
}
val_id = GenerateLoadIfNeeded(cast->expr()->result_type(), val_id);
auto* to_type = cast->result_type()->UnwrapPtrIfNeeded();
auto* from_type = cast->expr()->result_type()->UnwrapPtrIfNeeded();
spv::Op op = spv::Op::OpNop;
if ((from_type->IsI32() && to_type->IsF32()) ||
(from_type->is_signed_integer_vector() && to_type->is_float_vector())) {
op = spv::Op::OpConvertSToF;
} else if ((from_type->IsU32() && to_type->IsF32()) ||
(from_type->is_unsigned_integer_vector() &&
to_type->is_float_vector())) {
op = spv::Op::OpConvertUToF;
} else if ((from_type->IsF32() && to_type->IsI32()) ||
(from_type->is_float_vector() &&
to_type->is_signed_integer_vector())) {
op = spv::Op::OpConvertFToS;
} else if ((from_type->IsF32() && to_type->IsU32()) ||
(from_type->is_float_vector() &&
to_type->is_unsigned_integer_vector())) {
op = spv::Op::OpConvertFToU;
} else if ((from_type->IsU32() && to_type->IsU32()) ||
(from_type->IsI32() && to_type->IsI32()) ||
(from_type->IsF32() && to_type->IsF32()) ||
(from_type->is_unsigned_integer_vector() &&
to_type->is_unsigned_integer_vector()) ||
(from_type->is_signed_integer_vector() &&
to_type->is_signed_integer_vector()) ||
(from_type->is_float_vector() && to_type->is_float_vector())) {
op = spv::Op::OpCopyObject;
} else if ((from_type->IsI32() && to_type->IsU32()) ||
(from_type->IsU32() && to_type->IsI32()) ||
(from_type->is_signed_integer_vector() &&
to_type->is_unsigned_integer_vector()) ||
(from_type->is_unsigned_integer_vector() &&
to_type->is_integer_scalar_or_vector())) {
op = spv::Op::OpBitcast;
}
if (op == spv::Op::OpNop) {
error_ = "unable to determine conversion type for cast, from: " +
from_type->type_name() + " to: " + to_type->type_name();
return 0;
}
push_function_inst(
op, {Operand::Int(result_type_id), result, Operand::Int(val_id)});
return result_id;
}
bool Builder::GenerateConditionalBlock(
ast::Expression* cond,
const ast::StatementList& true_body,
size_t cur_else_idx,
const ast::ElseStatementList& else_stmts) {
auto cond_id = GenerateExpression(cond);
if (cond_id == 0) {
return false;
}
auto merge_block = result_op();
auto merge_block_id = merge_block.to_i();
push_function_inst(spv::Op::OpSelectionMerge,
{Operand::Int(merge_block_id),
Operand::Int(SpvSelectionControlMaskNone)});
auto true_block = result_op();
auto true_block_id = true_block.to_i();
// if there are no more else statements we branch on false to the merge block
// otherwise we branch to the false block
auto false_block_id =
cur_else_idx < else_stmts.size() ? next_id() : merge_block_id;
push_function_inst(spv::Op::OpBranchConditional,
{Operand::Int(cond_id), Operand::Int(true_block_id),
Operand::Int(false_block_id)});
// Output true block
GenerateLabel(true_block_id);
if (!GenerateStatementList(true_body)) {
return false;
}
// We only branch if the last element of the body didn't already branch.
if (!LastIsTerminator(true_body)) {
push_function_inst(spv::Op::OpBranch, {Operand::Int(merge_block_id)});
}
// Start the false block if needed
if (false_block_id != merge_block_id) {
GenerateLabel(false_block_id);
auto* else_stmt = else_stmts[cur_else_idx].get();
// Handle the else case by just outputting the statements.
if (!else_stmt->HasCondition()) {
if (!GenerateStatementList(else_stmt->body())) {
return false;
}
} else {
if (!GenerateConditionalBlock(else_stmt->condition(), else_stmt->body(),
cur_else_idx + 1, else_stmts)) {
return false;
}
}
if (!LastIsTerminator(else_stmt->body())) {
push_function_inst(spv::Op::OpBranch, {Operand::Int(merge_block_id)});
}
}
// Output the merge block
GenerateLabel(merge_block_id);
return true;
}
bool Builder::GenerateIfStatement(ast::IfStatement* stmt) {
if (!GenerateConditionalBlock(stmt->condition(), stmt->body(), 0,
stmt->else_statements())) {
return false;
}
return true;
}
bool Builder::GenerateSwitchStatement(ast::SwitchStatement* stmt) {
auto merge_block = result_op();
auto merge_block_id = merge_block.to_i();
merge_stack_.push_back(merge_block_id);
auto cond_id = GenerateExpression(stmt->condition());
if (cond_id == 0) {
return false;
}
cond_id = GenerateLoadIfNeeded(stmt->condition()->result_type(), cond_id);
auto default_block = result_op();
auto default_block_id = default_block.to_i();
OperandList params = {Operand::Int(cond_id), Operand::Int(default_block_id)};
std::vector<uint32_t> case_ids;
for (const auto& item : stmt->body()) {
if (item->IsDefault()) {
case_ids.push_back(default_block_id);
continue;
}
auto block = result_op();
auto block_id = block.to_i();
case_ids.push_back(block_id);
for (const auto& selector : item->selectors()) {
if (!selector->IsSint()) {
error_ = "expected integer literal for switch case label";
return false;
}
params.push_back(Operand::Int(selector->AsSint()->value()));
params.push_back(Operand::Int(block_id));
}
}
push_function_inst(spv::Op::OpSelectionMerge,
{Operand::Int(merge_block_id),
Operand::Int(SpvSelectionControlMaskNone)});
push_function_inst(spv::Op::OpSwitch, params);
bool generated_default = false;
auto& body = stmt->body();
// We output the case statements in order they were entered in the original
// source. Each fallthrough goes to the next case entry, so is a forward
// branch, otherwise the branch is to the merge block which comes after
// the switch statement.
for (uint32_t i = 0; i < body.size(); i++) {
auto& item = body[i];
if (item->IsDefault()) {
generated_default = true;
}
GenerateLabel(case_ids[i]);
if (!GenerateStatementList(item->body())) {
return false;
}
if (LastIsFallthrough(item->body())) {
if (i == (body.size() - 1)) {
error_ = "fallthrough of last case statement is disallowed";
return false;
}
push_function_inst(spv::Op::OpBranch, {Operand::Int(case_ids[i + 1])});
} else if (!LastIsTerminator(item->body())) {
push_function_inst(spv::Op::OpBranch, {Operand::Int(merge_block_id)});
}
}
if (!generated_default) {
GenerateLabel(default_block_id);
push_function_inst(spv::Op::OpBranch, {Operand::Int(merge_block_id)});
}
merge_stack_.pop_back();
GenerateLabel(merge_block_id);
return true;
}
bool Builder::GenerateReturnStatement(ast::ReturnStatement* stmt) {
if (stmt->has_value()) {
auto val_id = GenerateExpression(stmt->value());
if (val_id == 0) {
return false;
}
push_function_inst(spv::Op::OpReturnValue, {Operand::Int(val_id)});
} else {
push_function_inst(spv::Op::OpReturn, {});
}
return true;
}
bool Builder::GenerateLoopStatement(ast::LoopStatement* stmt) {
auto loop_header = result_op();
auto loop_header_id = loop_header.to_i();
push_function_inst(spv::Op::OpBranch, {Operand::Int(loop_header_id)});
GenerateLabel(loop_header_id);
auto merge_block = result_op();
auto merge_block_id = merge_block.to_i();
auto continue_block = result_op();
auto continue_block_id = continue_block.to_i();
auto body_block = result_op();
auto body_block_id = body_block.to_i();
push_function_inst(
spv::Op::OpLoopMerge,
{Operand::Int(merge_block_id), Operand::Int(continue_block_id),
Operand::Int(SpvLoopControlMaskNone)});
continue_stack_.push_back(continue_block_id);
merge_stack_.push_back(merge_block_id);
push_function_inst(spv::Op::OpBranch, {Operand::Int(body_block_id)});
GenerateLabel(body_block_id);
if (!GenerateStatementList(stmt->body())) {
return false;
}
// We only branch if the last element of the body didn't already branch.
if (!LastIsTerminator(stmt->body())) {
push_function_inst(spv::Op::OpBranch, {Operand::Int(continue_block_id)});
}
GenerateLabel(continue_block_id);
if (!GenerateStatementList(stmt->continuing())) {
return false;
}
push_function_inst(spv::Op::OpBranch, {Operand::Int(loop_header_id)});
merge_stack_.pop_back();
continue_stack_.pop_back();
GenerateLabel(merge_block_id);
return true;
}
bool Builder::GenerateStatementList(const ast::StatementList& list) {
for (const auto& inst : list) {
if (!GenerateStatement(inst.get())) {
return false;
}
}
return true;
}
bool Builder::GenerateStatement(ast::Statement* stmt) {
if (stmt->IsAssign()) {
return GenerateAssignStatement(stmt->AsAssign());
}
if (stmt->IsBreak()) {
return GenerateBreakStatement(stmt->AsBreak());
}
if (stmt->IsContinue()) {
return GenerateContinueStatement(stmt->AsContinue());
}
if (stmt->IsFallthrough()) {
// Do nothing here, the fallthrough gets handled by the switch code.
return true;
}
if (stmt->IsIf()) {
return GenerateIfStatement(stmt->AsIf());
}
if (stmt->IsKill()) {
return GenerateKillStatement(stmt->AsKill());
}
if (stmt->IsLoop()) {
return GenerateLoopStatement(stmt->AsLoop());
}
if (stmt->IsReturn()) {
return GenerateReturnStatement(stmt->AsReturn());
}
if (stmt->IsSwitch()) {
return GenerateSwitchStatement(stmt->AsSwitch());
}
if (stmt->IsVariableDecl()) {
return GenerateVariableDeclStatement(stmt->AsVariableDecl());
}
error_ = "Unknown statement";
return false;
}
bool Builder::GenerateVariableDeclStatement(ast::VariableDeclStatement* stmt) {
return GenerateFunctionVariable(stmt->variable());
}
uint32_t Builder::GenerateTypeIfNeeded(ast::type::Type* type) {
if (type == nullptr) {
error_ = "attempting to generate type from null type";
return 0;
}
if (type->IsAlias()) {
return GenerateTypeIfNeeded(type->AsAlias()->type());
}
auto val = type_name_to_id_.find(type->type_name());
if (val != type_name_to_id_.end()) {
return val->second;
}
auto result = result_op();
auto id = result.to_i();
if (type->IsArray()) {
if (!GenerateArrayType(type->AsArray(), result)) {
return 0;
}
} else if (type->IsBool()) {
push_type(spv::Op::OpTypeBool, {result});
} else if (type->IsF32()) {
push_type(spv::Op::OpTypeFloat, {result, Operand::Int(32)});
} else if (type->IsI32()) {
push_type(spv::Op::OpTypeInt, {result, Operand::Int(32), Operand::Int(1)});
} else if (type->IsMatrix()) {
if (!GenerateMatrixType(type->AsMatrix(), result)) {
return 0;
}
} else if (type->IsPointer()) {
if (!GeneratePointerType(type->AsPointer(), result)) {
return 0;
}
} else if (type->IsStruct()) {
if (!GenerateStructType(type->AsStruct(), result)) {
return 0;
}
} else if (type->IsU32()) {
push_type(spv::Op::OpTypeInt, {result, Operand::Int(32), Operand::Int(0)});
} else if (type->IsVector()) {
if (!GenerateVectorType(type->AsVector(), result)) {
return 0;
}
} else if (type->IsVoid()) {
push_type(spv::Op::OpTypeVoid, {result});
} else {
error_ = "unable to convert type: " + type->type_name();
return 0;
}
type_name_to_id_[type->type_name()] = id;
return id;
}
bool Builder::GenerateArrayType(ast::type::ArrayType* ary,
const Operand& result) {
auto elem_type = GenerateTypeIfNeeded(ary->type());
if (elem_type == 0) {
return false;
}
auto result_id = result.to_i();
if (ary->IsRuntimeArray()) {
push_type(spv::Op::OpTypeRuntimeArray, {result, Operand::Int(elem_type)});
} else {
auto len_id = GenerateU32Literal(ary->size());
if (len_id == 0) {
return false;
}
push_type(spv::Op::OpTypeArray,
{result, Operand::Int(elem_type), Operand::Int(len_id)});
}
// SPIR-V explicitly requires no array stride if the array contains a struct
// which has a Block decoration.
if (ary->type()->IsStruct() && ary->type()->AsStruct()->IsBlockDecorated()) {
return true;
}
if (ary->has_array_stride()) {
push_annot(spv::Op::OpDecorate,
{Operand::Int(result_id), Operand::Int(SpvDecorationArrayStride),
Operand::Int(ary->array_stride())});
}
return true;
}
bool Builder::GenerateMatrixType(ast::type::MatrixType* mat,
const Operand& result) {
ast::type::VectorType col_type(mat->type(), mat->rows());
auto col_type_id = GenerateTypeIfNeeded(&col_type);
if (has_error()) {
return false;
}
push_type(spv::Op::OpTypeMatrix,
{result, Operand::Int(col_type_id), Operand::Int(mat->columns())});
return true;
}
bool Builder::GeneratePointerType(ast::type::PointerType* ptr,
const Operand& result) {
auto pointee_id = GenerateTypeIfNeeded(ptr->type());
if (pointee_id == 0) {
return false;
}
auto stg_class = ConvertStorageClass(ptr->storage_class());
if (stg_class == SpvStorageClassMax) {
error_ = "invalid storage class for pointer";
return false;
}
push_type(spv::Op::OpTypePointer,
{result, Operand::Int(stg_class), Operand::Int(pointee_id)});
return true;
}
bool Builder::GenerateStructType(ast::type::StructType* struct_type,
const Operand& result) {
auto struct_id = result.to_i();
auto* impl = struct_type->impl();
if (!struct_type->name().empty()) {
push_debug(spv::Op::OpName,
{Operand::Int(struct_id), Operand::String(struct_type->name())});
}
OperandList ops;
ops.push_back(result);
if (impl->decoration() == ast::StructDecoration::kBlock) {
push_annot(spv::Op::OpDecorate,
{Operand::Int(struct_id), Operand::Int(SpvDecorationBlock)});
} else {
if (impl->decoration() != ast::StructDecoration::kNone) {
error_ = "unknown struct decoration";
return false;
}
}
auto& members = impl->members();
for (uint32_t i = 0; i < members.size(); ++i) {
auto mem_id = GenerateStructMember(struct_id, i, members[i].get());
if (mem_id == 0) {
return false;
}
ops.push_back(Operand::Int(mem_id));
}
push_type(spv::Op::OpTypeStruct, std::move(ops));
return true;
}
uint32_t Builder::GenerateStructMember(uint32_t struct_id,
uint32_t idx,
ast::StructMember* member) {
push_debug(spv::Op::OpMemberName, {Operand::Int(struct_id), Operand::Int(idx),
Operand::String(member->name())});
for (const auto& deco : member->decorations()) {
if (deco->IsOffset()) {
push_annot(spv::Op::OpMemberDecorate,
{Operand::Int(struct_id), Operand::Int(idx),
Operand::Int(SpvDecorationOffset),
Operand::Int(deco->AsOffset()->offset())});
} else {
error_ = "unknown struct member decoration";
return 0;
}
}
return GenerateTypeIfNeeded(member->type());
}
bool Builder::GenerateVectorType(ast::type::VectorType* vec,
const Operand& result) {
auto type_id = GenerateTypeIfNeeded(vec->type());
if (has_error()) {
return false;
}
push_type(spv::Op::OpTypeVector,
{result, Operand::Int(type_id), Operand::Int(vec->size())});
return true;
}
SpvStorageClass Builder::ConvertStorageClass(ast::StorageClass klass) const {
switch (klass) {
case ast::StorageClass::kInput:
return SpvStorageClassInput;
case ast::StorageClass::kOutput:
return SpvStorageClassOutput;
case ast::StorageClass::kUniform:
return SpvStorageClassUniform;
case ast::StorageClass::kWorkgroup:
return SpvStorageClassWorkgroup;
case ast::StorageClass::kUniformConstant:
return SpvStorageClassUniformConstant;
case ast::StorageClass::kStorageBuffer:
return SpvStorageClassStorageBuffer;
case ast::StorageClass::kImage:
return SpvStorageClassImage;
case ast::StorageClass::kPrivate:
return SpvStorageClassPrivate;
case ast::StorageClass::kFunction:
return SpvStorageClassFunction;
case ast::StorageClass::kNone:
break;
}
return SpvStorageClassMax;
}
SpvBuiltIn Builder::ConvertBuiltin(ast::Builtin builtin) const {
switch (builtin) {
case ast::Builtin::kPosition:
return SpvBuiltInPosition;
case ast::Builtin::kVertexIdx:
return SpvBuiltInVertexIndex;
case ast::Builtin::kInstanceIdx:
return SpvBuiltInInstanceIndex;
case ast::Builtin::kFrontFacing:
return SpvBuiltInFrontFacing;
case ast::Builtin::kFragCoord:
return SpvBuiltInFragCoord;
case ast::Builtin::kFragDepth:
return SpvBuiltInFragDepth;
case ast::Builtin::kNumWorkgroups:
return SpvBuiltInNumWorkgroups;
case ast::Builtin::kWorkgroupSize:
return SpvBuiltInWorkgroupSize;
case ast::Builtin::kLocalInvocationId:
return SpvBuiltInLocalInvocationId;
case ast::Builtin::kLocalInvocationIdx:
return SpvBuiltInLocalInvocationIndex;
case ast::Builtin::kGlobalInvocationId:
return SpvBuiltInGlobalInvocationId;
case ast::Builtin::kNone:
break;
}
return SpvBuiltInMax;
}
} // namespace spirv
} // namespace writer
} // namespace tint