blob: 32b4d94ae284555150e68fa9e40c86de47925fef [file] [log] [blame]
/// Copyright 2021 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/glsl/generator_impl.h"
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <set>
#include <utility>
#include <vector>
#include "src/ast/call_statement.h"
#include "src/ast/fallthrough_statement.h"
#include "src/ast/internal_decoration.h"
#include "src/ast/interpolate_decoration.h"
#include "src/ast/override_decoration.h"
#include "src/ast/variable_decl_statement.h"
#include "src/debug.h"
#include "src/sem/array.h"
#include "src/sem/atomic_type.h"
#include "src/sem/block_statement.h"
#include "src/sem/call.h"
#include "src/sem/depth_multisampled_texture_type.h"
#include "src/sem/depth_texture_type.h"
#include "src/sem/function.h"
#include "src/sem/member_accessor_expression.h"
#include "src/sem/multisampled_texture_type.h"
#include "src/sem/sampled_texture_type.h"
#include "src/sem/statement.h"
#include "src/sem/storage_texture_type.h"
#include "src/sem/struct.h"
#include "src/sem/type_constructor.h"
#include "src/sem/type_conversion.h"
#include "src/sem/variable.h"
#include "src/transform/calculate_array_length.h"
#include "src/transform/glsl.h"
#include "src/utils/defer.h"
#include "src/utils/get_or_create.h"
#include "src/utils/scoped_assignment.h"
#include "src/writer/append_vector.h"
#include "src/writer/float_to_string.h"
namespace {
bool IsRelational(tint::ast::BinaryOp op) {
return op == tint::ast::BinaryOp::kEqual ||
op == tint::ast::BinaryOp::kNotEqual ||
op == tint::ast::BinaryOp::kLessThan ||
op == tint::ast::BinaryOp::kGreaterThan ||
op == tint::ast::BinaryOp::kLessThanEqual ||
op == tint::ast::BinaryOp::kGreaterThanEqual;
}
} // namespace
namespace tint {
namespace writer {
namespace glsl {
namespace {
const char kTempNamePrefix[] = "tint_tmp";
const char kSpecConstantPrefix[] = "WGSL_SPEC_CONSTANT_";
bool last_is_break_or_fallthrough(const ast::BlockStatement* stmts) {
return IsAnyOf<ast::BreakStatement, ast::FallthroughStatement>(stmts->Last());
}
} // namespace
GeneratorImpl::GeneratorImpl(const Program* program) : TextGenerator(program) {}
GeneratorImpl::~GeneratorImpl() = default;
bool GeneratorImpl::Generate() {
if (!builder_.HasTransformApplied<transform::Glsl>()) {
diagnostics_.add_error(
diag::System::Writer,
"GLSL writer requires the transform::Glsl sanitizer to have been "
"applied to the input program");
return false;
}
const TypeInfo* last_kind = nullptr;
size_t last_padding_line = 0;
line() << "#version 310 es";
line() << "precision mediump float;";
auto helpers_insertion_point = current_buffer_->lines.size();
line();
for (auto* decl : builder_.AST().GlobalDeclarations()) {
if (decl->Is<ast::Alias>()) {
continue; // Ignore aliases.
}
// Emit a new line between declarations if the type of declaration has
// changed, or we're about to emit a function
auto* kind = &decl->TypeInfo();
if (current_buffer_->lines.size() != last_padding_line) {
if (last_kind && (last_kind != kind || decl->Is<ast::Function>())) {
line();
last_padding_line = current_buffer_->lines.size();
}
}
last_kind = kind;
if (auto* global = decl->As<ast::Variable>()) {
if (!EmitGlobalVariable(global)) {
return false;
}
} else if (auto* str = decl->As<ast::Struct>()) {
if (!str->IsBlockDecorated()) {
if (!EmitStructType(current_buffer_, builder_.Sem().Get(str))) {
return false;
}
}
} else if (auto* func = decl->As<ast::Function>()) {
if (func->IsEntryPoint()) {
if (!EmitEntryPointFunction(func)) {
return false;
}
} else {
if (!EmitFunction(func)) {
return false;
}
}
} else {
TINT_ICE(Writer, diagnostics_)
<< "unhandled module-scope declaration: " << decl->TypeInfo().name;
return false;
}
}
if (!helpers_.lines.empty()) {
current_buffer_->Insert("", helpers_insertion_point++, 0);
current_buffer_->Insert(helpers_, helpers_insertion_point++, 0);
}
return true;
}
bool GeneratorImpl::EmitIndexAccessor(
std::ostream& out,
const ast::IndexAccessorExpression* expr) {
if (!EmitExpression(out, expr->object)) {
return false;
}
out << "[";
if (!EmitExpression(out, expr->index)) {
return false;
}
out << "]";
return true;
}
bool GeneratorImpl::EmitBitcast(std::ostream& out,
const ast::BitcastExpression* expr) {
auto* src_type = TypeOf(expr->expr);
auto* dst_type = TypeOf(expr);
if (!dst_type->is_integer_scalar_or_vector() &&
!dst_type->is_float_scalar_or_vector()) {
diagnostics_.add_error(
diag::System::Writer,
"Unable to do bitcast to type " + dst_type->type_name());
return false;
}
if (src_type == dst_type) {
return EmitExpression(out, expr->expr);
}
if (src_type->is_float_scalar_or_vector() &&
dst_type->is_signed_scalar_or_vector()) {
out << "floatBitsToInt";
} else if (src_type->is_float_scalar_or_vector() &&
dst_type->is_unsigned_scalar_or_vector()) {
out << "floatBitsToUint";
} else if (src_type->is_signed_scalar_or_vector() &&
dst_type->is_float_scalar_or_vector()) {
out << "intBitsToFloat";
} else if (src_type->is_unsigned_scalar_or_vector() &&
dst_type->is_float_scalar_or_vector()) {
out << "uintBitsToFloat";
} else {
if (!EmitType(out, dst_type, ast::StorageClass::kNone,
ast::Access::kReadWrite, "")) {
return false;
}
}
out << "(";
if (!EmitExpression(out, expr->expr)) {
return false;
}
out << ")";
return true;
}
bool GeneratorImpl::EmitAssign(const ast::AssignmentStatement* stmt) {
auto out = line();
if (!EmitExpression(out, stmt->lhs)) {
return false;
}
out << " = ";
if (!EmitExpression(out, stmt->rhs)) {
return false;
}
out << ";";
return true;
}
bool GeneratorImpl::EmitVectorRelational(std::ostream& out,
const ast::BinaryExpression* expr) {
switch (expr->op) {
case ast::BinaryOp::kEqual:
out << "equal";
break;
case ast::BinaryOp::kNotEqual:
out << "notEqual";
break;
case ast::BinaryOp::kLessThan:
out << "lessThan";
break;
case ast::BinaryOp::kGreaterThan:
out << "greaterThan";
break;
case ast::BinaryOp::kLessThanEqual:
out << "lessThanEqual";
break;
case ast::BinaryOp::kGreaterThanEqual:
out << "greaterThanEqual";
break;
default:
break;
}
out << "(";
if (!EmitExpression(out, expr->lhs)) {
return false;
}
out << ", ";
if (!EmitExpression(out, expr->rhs)) {
return false;
}
out << ")";
return true;
}
bool GeneratorImpl::EmitBinary(std::ostream& out,
const ast::BinaryExpression* expr) {
if (IsRelational(expr->op) && !TypeOf(expr->lhs)->UnwrapRef()->is_scalar()) {
return EmitVectorRelational(out, expr);
}
if (expr->op == ast::BinaryOp::kLogicalAnd ||
expr->op == ast::BinaryOp::kLogicalOr) {
auto name = UniqueIdentifier(kTempNamePrefix);
{
auto pre = line();
pre << "bool " << name << " = ";
if (!EmitExpression(pre, expr->lhs)) {
return false;
}
pre << ";";
}
if (expr->op == ast::BinaryOp::kLogicalOr) {
line() << "if (!" << name << ") {";
} else {
line() << "if (" << name << ") {";
}
{
ScopedIndent si(this);
auto pre = line();
pre << name << " = ";
if (!EmitExpression(pre, expr->rhs)) {
return false;
}
pre << ";";
}
line() << "}";
out << "(" << name << ")";
return true;
}
out << "(";
if (!EmitExpression(out, expr->lhs)) {
return false;
}
out << " ";
switch (expr->op) {
case ast::BinaryOp::kAnd:
out << "&";
break;
case ast::BinaryOp::kOr:
out << "|";
break;
case ast::BinaryOp::kXor:
out << "^";
break;
case ast::BinaryOp::kLogicalAnd:
case ast::BinaryOp::kLogicalOr: {
// These are both handled above.
TINT_UNREACHABLE(Writer, diagnostics_);
return false;
}
case ast::BinaryOp::kEqual:
out << "==";
break;
case ast::BinaryOp::kNotEqual:
out << "!=";
break;
case ast::BinaryOp::kLessThan:
out << "<";
break;
case ast::BinaryOp::kGreaterThan:
out << ">";
break;
case ast::BinaryOp::kLessThanEqual:
out << "<=";
break;
case ast::BinaryOp::kGreaterThanEqual:
out << ">=";
break;
case ast::BinaryOp::kShiftLeft:
out << "<<";
break;
case ast::BinaryOp::kShiftRight:
// TODO(dsinclair): MSL is based on C++14, and >> in C++14 has
// implementation-defined behaviour for negative LHS. We may have to
// generate extra code to implement WGSL-specified behaviour for negative
// LHS.
out << R"(>>)";
break;
case ast::BinaryOp::kAdd:
out << "+";
break;
case ast::BinaryOp::kSubtract:
out << "-";
break;
case ast::BinaryOp::kMultiply:
out << "*";
break;
case ast::BinaryOp::kDivide:
out << "/";
break;
case ast::BinaryOp::kModulo:
out << "%";
break;
case ast::BinaryOp::kNone:
diagnostics_.add_error(diag::System::Writer,
"missing binary operation type");
return false;
}
out << " ";
if (!EmitExpression(out, expr->rhs)) {
return false;
}
out << ")";
return true;
}
bool GeneratorImpl::EmitStatements(const ast::StatementList& stmts) {
for (auto* s : stmts) {
if (!EmitStatement(s)) {
return false;
}
}
return true;
}
bool GeneratorImpl::EmitStatementsWithIndent(const ast::StatementList& stmts) {
ScopedIndent si(this);
return EmitStatements(stmts);
}
bool GeneratorImpl::EmitBlock(const ast::BlockStatement* stmt) {
line() << "{";
if (!EmitStatementsWithIndent(stmt->statements)) {
return false;
}
line() << "}";
return true;
}
bool GeneratorImpl::EmitBreak(const ast::BreakStatement*) {
line() << "break;";
return true;
}
bool GeneratorImpl::EmitCall(std::ostream& out,
const ast::CallExpression* expr) {
auto* call = builder_.Sem().Get(expr);
auto* target = call->Target();
if (auto* func = target->As<sem::Function>()) {
return EmitFunctionCall(out, call, func);
}
if (auto* intrinsic = target->As<sem::Intrinsic>()) {
return EmitIntrinsicCall(out, call, intrinsic);
}
if (auto* cast = target->As<sem::TypeConversion>()) {
return EmitTypeConversion(out, call, cast);
}
if (auto* ctor = target->As<sem::TypeConstructor>()) {
return EmitTypeConstructor(out, call, ctor);
}
TINT_ICE(Writer, diagnostics_)
<< "unhandled call target: " << target->TypeInfo().name;
return false;
}
bool GeneratorImpl::EmitFunctionCall(std::ostream& out,
const sem::Call* call,
const sem::Function* func) {
const auto& args = call->Arguments();
auto* decl = call->Declaration();
auto* ident = decl->target.name;
auto name = builder_.Symbols().NameFor(ident->symbol);
auto caller_sym = ident->symbol;
if (ast::HasDecoration<transform::CalculateArrayLength::BufferSizeIntrinsic>(
func->Declaration()->decorations)) {
// Special function generated by the CalculateArrayLength transform for
// calling X.GetDimensions(Y)
if (!EmitExpression(out, args[0]->Declaration())) {
return false;
}
out << ".GetDimensions(";
if (!EmitExpression(out, args[1]->Declaration())) {
return false;
}
out << ")";
return true;
}
out << name << "(";
bool first = true;
for (auto* arg : args) {
if (!first) {
out << ", ";
}
first = false;
if (!EmitExpression(out, arg->Declaration())) {
return false;
}
}
out << ")";
return true;
}
bool GeneratorImpl::EmitIntrinsicCall(std::ostream& out,
const sem::Call* call,
const sem::Intrinsic* intrinsic) {
auto* expr = call->Declaration();
if (intrinsic->IsTexture()) {
return EmitTextureCall(out, expr, intrinsic);
}
if (intrinsic->Type() == sem::IntrinsicType::kSelect) {
return EmitSelectCall(out, expr);
}
if (intrinsic->Type() == sem::IntrinsicType::kDot) {
return EmitDotCall(out, expr, intrinsic);
}
if (intrinsic->Type() == sem::IntrinsicType::kModf) {
return EmitModfCall(out, expr, intrinsic);
}
if (intrinsic->Type() == sem::IntrinsicType::kFrexp) {
return EmitFrexpCall(out, expr, intrinsic);
}
if (intrinsic->Type() == sem::IntrinsicType::kIsNormal) {
return EmitIsNormalCall(out, expr, intrinsic);
}
if (intrinsic->Type() == sem::IntrinsicType::kIgnore) {
return EmitExpression(out, expr->args[0]); // [DEPRECATED]
}
if (intrinsic->IsDataPacking()) {
return EmitDataPackingCall(out, expr, intrinsic);
}
if (intrinsic->IsDataUnpacking()) {
return EmitDataUnpackingCall(out, expr, intrinsic);
}
if (intrinsic->IsBarrier()) {
return EmitBarrierCall(out, intrinsic);
}
if (intrinsic->IsAtomic()) {
return EmitWorkgroupAtomicCall(out, expr, intrinsic);
}
auto name = generate_builtin_name(intrinsic);
if (name.empty()) {
return false;
}
out << name << "(";
bool first = true;
for (auto* arg : call->Arguments()) {
if (!first) {
out << ", ";
}
first = false;
if (!EmitExpression(out, arg->Declaration())) {
return false;
}
}
out << ")";
return true;
}
bool GeneratorImpl::EmitTypeConversion(std::ostream& out,
const sem::Call* call,
const sem::TypeConversion* conv) {
if (!EmitType(out, conv->Target(), ast::StorageClass::kNone,
ast::Access::kReadWrite, "")) {
return false;
}
out << "(";
if (!EmitExpression(out, call->Arguments()[0]->Declaration())) {
return false;
}
out << ")";
return true;
}
bool GeneratorImpl::EmitTypeConstructor(std::ostream& out,
const sem::Call* call,
const sem::TypeConstructor* ctor) {
auto* type = ctor->ReturnType();
// If the type constructor is empty then we need to construct with the zero
// value for all components.
if (call->Arguments().empty()) {
return EmitZeroValue(out, type);
}
// For single-value vector initializers, swizzle the scalar to the right
// vector dimension using .x
const bool is_single_value_vector_init =
type->is_scalar_vector() && call->Arguments().size() == 1 &&
call->Arguments()[0]->Type()->UnwrapRef()->is_scalar();
auto it = structure_builders_.find(As<sem::Struct>(type));
if (it != structure_builders_.end()) {
out << it->second << "(";
} else {
if (!EmitType(out, type, ast::StorageClass::kNone, ast::Access::kReadWrite,
"")) {
return false;
}
out << "(";
}
if (is_single_value_vector_init) {
out << "(";
}
bool first = true;
for (auto* arg : call->Arguments()) {
if (!first) {
out << ", ";
}
first = false;
if (!EmitExpression(out, arg->Declaration())) {
return false;
}
}
if (is_single_value_vector_init) {
out << ")." << std::string(type->As<sem::Vector>()->Width(), 'x');
}
out << ")";
return true;
}
bool GeneratorImpl::EmitWorkgroupAtomicCall(std::ostream& out,
const ast::CallExpression* expr,
const sem::Intrinsic* intrinsic) {
std::string result = UniqueIdentifier("atomic_result");
if (!intrinsic->ReturnType()->Is<sem::Void>()) {
auto pre = line();
if (!EmitTypeAndName(pre, intrinsic->ReturnType(), ast::StorageClass::kNone,
ast::Access::kUndefined, result)) {
return false;
}
pre << " = ";
if (!EmitZeroValue(pre, intrinsic->ReturnType())) {
return false;
}
pre << ";";
}
auto call = [&](const char* name) {
auto pre = line();
pre << name;
{
ScopedParen sp(pre);
for (size_t i = 0; i < expr->args.size(); i++) {
auto* arg = expr->args[i];
if (i > 0) {
pre << ", ";
}
if (!EmitExpression(pre, arg)) {
return false;
}
}
pre << ", " << result;
}
pre << ";";
out << result;
return true;
};
switch (intrinsic->Type()) {
case sem::IntrinsicType::kAtomicLoad: {
// GLSL does not have an InterlockedLoad, so we emulate it with
// InterlockedOr using 0 as the OR value
auto pre = line();
pre << "InterlockedOr";
{
ScopedParen sp(pre);
if (!EmitExpression(pre, expr->args[0])) {
return false;
}
pre << ", 0, " << result;
}
pre << ";";
out << result;
return true;
}
case sem::IntrinsicType::kAtomicStore: {
// GLSL does not have an InterlockedStore, so we emulate it with
// InterlockedExchange and discard the returned value
{ // T result = 0;
auto pre = line();
auto* value_ty = intrinsic->Parameters()[1]->Type();
if (!EmitTypeAndName(pre, value_ty, ast::StorageClass::kNone,
ast::Access::kUndefined, result)) {
return false;
}
pre << " = ";
if (!EmitZeroValue(pre, value_ty)) {
return false;
}
pre << ";";
}
out << "InterlockedExchange";
{
ScopedParen sp(out);
if (!EmitExpression(out, expr->args[0])) {
return false;
}
out << ", ";
if (!EmitExpression(out, expr->args[1])) {
return false;
}
out << ", " << result;
}
return true;
}
case sem::IntrinsicType::kAtomicCompareExchangeWeak: {
auto* dest = expr->args[0];
auto* compare_value = expr->args[1];
auto* value = expr->args[2];
std::string compare = UniqueIdentifier("atomic_compare_value");
{ // T compare_value = <compare_value>;
auto pre = line();
if (!EmitTypeAndName(pre, TypeOf(compare_value),
ast::StorageClass::kNone, ast::Access::kUndefined,
compare)) {
return false;
}
pre << " = ";
if (!EmitExpression(pre, compare_value)) {
return false;
}
pre << ";";
}
{ // InterlockedCompareExchange(dst, compare, value, result.x);
auto pre = line();
pre << "InterlockedCompareExchange";
{
ScopedParen sp(pre);
if (!EmitExpression(pre, dest)) {
return false;
}
pre << ", " << compare << ", ";
if (!EmitExpression(pre, value)) {
return false;
}
pre << ", " << result << ".x";
}
pre << ";";
}
{ // result.y = result.x == compare;
line() << result << ".y = " << result << ".x == " << compare << ";";
}
out << result;
return true;
}
case sem::IntrinsicType::kAtomicAdd:
case sem::IntrinsicType::kAtomicSub:
return call("InterlockedAdd");
case sem::IntrinsicType::kAtomicMax:
return call("InterlockedMax");
case sem::IntrinsicType::kAtomicMin:
return call("InterlockedMin");
case sem::IntrinsicType::kAtomicAnd:
return call("InterlockedAnd");
case sem::IntrinsicType::kAtomicOr:
return call("InterlockedOr");
case sem::IntrinsicType::kAtomicXor:
return call("InterlockedXor");
case sem::IntrinsicType::kAtomicExchange:
return call("InterlockedExchange");
default:
break;
}
TINT_UNREACHABLE(Writer, diagnostics_)
<< "unsupported atomic intrinsic: " << intrinsic->Type();
return false;
}
bool GeneratorImpl::EmitSelectCall(std::ostream& out,
const ast::CallExpression* expr) {
auto* expr_false = expr->args[0];
auto* expr_true = expr->args[1];
auto* expr_cond = expr->args[2];
ScopedParen paren(out);
if (!EmitExpression(out, expr_cond)) {
return false;
}
out << " ? ";
if (!EmitExpression(out, expr_true)) {
return false;
}
out << " : ";
if (!EmitExpression(out, expr_false)) {
return false;
}
return true;
}
bool GeneratorImpl::EmitDotCall(std::ostream& out,
const ast::CallExpression* expr,
const sem::Intrinsic* intrinsic) {
auto* vec_ty = intrinsic->Parameters()[0]->Type()->As<sem::Vector>();
std::string fn = "dot";
if (vec_ty->type()->is_integer_scalar()) {
// GLSL does not have a builtin for dot() with integer vector types.
// Generate the helper function if it hasn't been created already
fn = utils::GetOrCreate(int_dot_funcs_, vec_ty, [&]() -> std::string {
TextBuffer b;
TINT_DEFER(helpers_.Append(b));
auto fn_name = UniqueIdentifier("tint_int_dot");
std::string v;
{
std::stringstream s;
if (!EmitType(s, vec_ty->type(), ast::StorageClass::kNone,
ast::Access::kRead, "")) {
return "";
}
v = s.str();
}
{ // (u)int tint_int_dot([i|u]vecN a, [i|u]vecN b) {
auto l = line(&b);
if (!EmitType(l, vec_ty->type(), ast::StorageClass::kNone,
ast::Access::kRead, "")) {
return "";
}
l << " " << fn_name << "(";
if (!EmitType(l, vec_ty, ast::StorageClass::kNone, ast::Access::kRead,
"")) {
return "";
}
l << " a, ";
if (!EmitType(l, vec_ty, ast::StorageClass::kNone, ast::Access::kRead,
"")) {
return "";
}
l << " b) {";
}
{
auto l = line(&b);
l << " return ";
for (uint32_t i = 0; i < vec_ty->Width(); i++) {
if (i > 0) {
l << " + ";
}
l << "a[" << i << "]*b[" << i << "]";
}
l << ";";
}
line(&b) << "}";
return fn_name;
});
if (fn.empty()) {
return false;
}
}
out << fn << "(";
if (!EmitExpression(out, expr->args[0])) {
return false;
}
out << ", ";
if (!EmitExpression(out, expr->args[1])) {
return false;
}
out << ")";
return true;
}
bool GeneratorImpl::EmitModfCall(std::ostream& out,
const ast::CallExpression* expr,
const sem::Intrinsic* intrinsic) {
if (expr->args.size() == 1) {
return CallIntrinsicHelper(
out, expr, intrinsic,
[&](TextBuffer* b, const std::vector<std::string>& params) {
auto* ty = intrinsic->Parameters()[0]->Type();
auto in = params[0];
std::string width;
if (auto* vec = ty->As<sem::Vector>()) {
width = std::to_string(vec->Width());
}
// Emit the builtin return type unique to this overload. This does not
// exist in the AST, so it will not be generated in Generate().
if (!EmitStructType(&helpers_,
intrinsic->ReturnType()->As<sem::Struct>())) {
return false;
}
line(b) << "float" << width << " whole;";
line(b) << "float" << width << " fract = modf(" << in << ", whole);";
{
auto l = line(b);
if (!EmitType(l, intrinsic->ReturnType(), ast::StorageClass::kNone,
ast::Access::kUndefined, "")) {
return false;
}
l << " result = {fract, whole};";
}
line(b) << "return result;";
return true;
});
}
// DEPRECATED
out << "modf";
ScopedParen sp(out);
if (!EmitExpression(out, expr->args[0])) {
return false;
}
out << ", ";
if (!EmitExpression(out, expr->args[1])) {
return false;
}
return true;
}
bool GeneratorImpl::EmitFrexpCall(std::ostream& out,
const ast::CallExpression* expr,
const sem::Intrinsic* intrinsic) {
if (expr->args.size() == 1) {
return CallIntrinsicHelper(
out, expr, intrinsic,
[&](TextBuffer* b, const std::vector<std::string>& params) {
auto* ty = intrinsic->Parameters()[0]->Type();
auto in = params[0];
std::string width;
if (auto* vec = ty->As<sem::Vector>()) {
width = std::to_string(vec->Width());
}
// Emit the builtin return type unique to this overload. This does not
// exist in the AST, so it will not be generated in Generate().
if (!EmitStructType(&helpers_,
intrinsic->ReturnType()->As<sem::Struct>())) {
return false;
}
line(b) << "float" << width << " exp;";
line(b) << "float" << width << " sig = frexp(" << in << ", exp);";
{
auto l = line(b);
if (!EmitType(l, intrinsic->ReturnType(), ast::StorageClass::kNone,
ast::Access::kUndefined, "")) {
return false;
}
l << " result = {sig, int" << width << "(exp)};";
}
line(b) << "return result;";
return true;
});
}
// DEPRECATED
// Exponent is an integer in WGSL, but HLSL wants a float.
// We need to make the call with a temporary float, and then cast.
return CallIntrinsicHelper(
out, expr, intrinsic,
[&](TextBuffer* b, const std::vector<std::string>& params) {
auto* significand_ty = intrinsic->Parameters()[0]->Type();
auto significand = params[0];
auto* exponent_ty = intrinsic->Parameters()[1]->Type();
auto exponent = params[1];
std::string width;
if (auto* vec = significand_ty->As<sem::Vector>()) {
width = std::to_string(vec->Width());
}
// Exponent is an integer, which HLSL does not have an overload for.
// We need to cast from a float.
line(b) << "float" << width << " float_exp;";
line(b) << "float" << width << " significand = frexp(" << significand
<< ", float_exp);";
{
auto l = line(b);
l << exponent << " = ";
if (!EmitType(l, exponent_ty->UnwrapPtr(), ast::StorageClass::kNone,
ast::Access::kUndefined, "")) {
return false;
}
l << "(float_exp);";
}
line(b) << "return significand;";
return true;
});
}
bool GeneratorImpl::EmitIsNormalCall(std::ostream& out,
const ast::CallExpression* expr,
const sem::Intrinsic* intrinsic) {
// GLSL doesn't have a isNormal intrinsic, we need to emulate
return CallIntrinsicHelper(
out, expr, intrinsic,
[&](TextBuffer* b, const std::vector<std::string>& params) {
auto* input_ty = intrinsic->Parameters()[0]->Type();
std::string width;
if (auto* vec = input_ty->As<sem::Vector>()) {
width = std::to_string(vec->Width());
}
constexpr auto* kExponentMask = "0x7f80000";
constexpr auto* kMinNormalExponent = "0x0080000";
constexpr auto* kMaxNormalExponent = "0x7f00000";
line(b) << "uint" << width << " exponent = asuint(" << params[0]
<< ") & " << kExponentMask << ";";
line(b) << "uint" << width << " clamped = "
<< "clamp(exponent, " << kMinNormalExponent << ", "
<< kMaxNormalExponent << ");";
line(b) << "return clamped == exponent;";
return true;
});
}
bool GeneratorImpl::EmitDataPackingCall(std::ostream& out,
const ast::CallExpression* expr,
const sem::Intrinsic* intrinsic) {
return CallIntrinsicHelper(
out, expr, intrinsic,
[&](TextBuffer* b, const std::vector<std::string>& params) {
uint32_t dims = 2;
bool is_signed = false;
uint32_t scale = 65535;
if (intrinsic->Type() == sem::IntrinsicType::kPack4x8snorm ||
intrinsic->Type() == sem::IntrinsicType::kPack4x8unorm) {
dims = 4;
scale = 255;
}
if (intrinsic->Type() == sem::IntrinsicType::kPack4x8snorm ||
intrinsic->Type() == sem::IntrinsicType::kPack2x16snorm) {
is_signed = true;
scale = (scale - 1) / 2;
}
switch (intrinsic->Type()) {
case sem::IntrinsicType::kPack4x8snorm:
case sem::IntrinsicType::kPack4x8unorm:
case sem::IntrinsicType::kPack2x16snorm:
case sem::IntrinsicType::kPack2x16unorm: {
{
auto l = line(b);
l << (is_signed ? "" : "u") << "int" << dims
<< " i = " << (is_signed ? "" : "u") << "int" << dims
<< "(round(clamp(" << params[0] << ", "
<< (is_signed ? "-1.0" : "0.0") << ", 1.0) * " << scale
<< ".0))";
if (is_signed) {
l << " & " << (dims == 4 ? "0xff" : "0xffff");
}
l << ";";
}
{
auto l = line(b);
l << "return ";
if (is_signed) {
l << "asuint";
}
l << "(i.x | i.y << " << (32 / dims);
if (dims == 4) {
l << " | i.z << 16 | i.w << 24";
}
l << ");";
}
break;
}
case sem::IntrinsicType::kPack2x16float: {
line(b) << "uint2 i = f32tof16(" << params[0] << ");";
line(b) << "return i.x | (i.y << 16);";
break;
}
default:
diagnostics_.add_error(
diag::System::Writer,
"Internal error: unhandled data packing intrinsic");
return false;
}
return true;
});
}
bool GeneratorImpl::EmitDataUnpackingCall(std::ostream& out,
const ast::CallExpression* expr,
const sem::Intrinsic* intrinsic) {
return CallIntrinsicHelper(
out, expr, intrinsic,
[&](TextBuffer* b, const std::vector<std::string>& params) {
uint32_t dims = 2;
bool is_signed = false;
uint32_t scale = 65535;
if (intrinsic->Type() == sem::IntrinsicType::kUnpack4x8snorm ||
intrinsic->Type() == sem::IntrinsicType::kUnpack4x8unorm) {
dims = 4;
scale = 255;
}
if (intrinsic->Type() == sem::IntrinsicType::kUnpack4x8snorm ||
intrinsic->Type() == sem::IntrinsicType::kUnpack2x16snorm) {
is_signed = true;
scale = (scale - 1) / 2;
}
switch (intrinsic->Type()) {
case sem::IntrinsicType::kUnpack4x8snorm:
case sem::IntrinsicType::kUnpack2x16snorm: {
line(b) << "int j = int(" << params[0] << ");";
{ // Perform sign extension on the converted values.
auto l = line(b);
l << "int" << dims << " i = int" << dims << "(";
if (dims == 2) {
l << "j << 16, j) >> 16";
} else {
l << "j << 24, j << 16, j << 8, j) >> 24";
}
l << ";";
}
line(b) << "return clamp(float" << dims << "(i) / " << scale
<< ".0, " << (is_signed ? "-1.0" : "0.0") << ", 1.0);";
break;
}
case sem::IntrinsicType::kUnpack4x8unorm:
case sem::IntrinsicType::kUnpack2x16unorm: {
line(b) << "uint j = " << params[0] << ";";
{
auto l = line(b);
l << "uint" << dims << " i = uint" << dims << "(";
l << "j & " << (dims == 2 ? "0xffff" : "0xff") << ", ";
if (dims == 4) {
l << "(j >> " << (32 / dims)
<< ") & 0xff, (j >> 16) & 0xff, j >> 24";
} else {
l << "j >> " << (32 / dims);
}
l << ");";
}
line(b) << "return float" << dims << "(i) / " << scale << ".0;";
break;
}
case sem::IntrinsicType::kUnpack2x16float:
line(b) << "uint i = " << params[0] << ";";
line(b) << "return f16tof32(uint2(i & 0xffff, i >> 16));";
break;
default:
diagnostics_.add_error(
diag::System::Writer,
"Internal error: unhandled data packing intrinsic");
return false;
}
return true;
});
}
bool GeneratorImpl::EmitBarrierCall(std::ostream& out,
const sem::Intrinsic* intrinsic) {
// TODO(crbug.com/tint/661): Combine sequential barriers to a single
// instruction.
if (intrinsic->Type() == sem::IntrinsicType::kWorkgroupBarrier) {
out << "GroupMemoryBarrierWithGroupSync()";
} else if (intrinsic->Type() == sem::IntrinsicType::kStorageBarrier) {
out << "DeviceMemoryBarrierWithGroupSync()";
} else {
TINT_UNREACHABLE(Writer, diagnostics_)
<< "unexpected barrier intrinsic type " << sem::str(intrinsic->Type());
return false;
}
return true;
}
bool GeneratorImpl::EmitTextureCall(std::ostream& out,
const ast::CallExpression* expr,
const sem::Intrinsic* intrinsic) {
using Usage = sem::ParameterUsage;
auto& signature = intrinsic->Signature();
auto arguments = expr->args;
// Returns the argument with the given usage
auto arg = [&](Usage usage) {
int idx = signature.IndexOf(usage);
return (idx >= 0) ? arguments[idx] : nullptr;
};
auto* texture = arg(Usage::kTexture);
if (!texture) {
TINT_ICE(Writer, diagnostics_) << "missing texture argument";
return false;
}
auto* texture_type = TypeOf(texture)->UnwrapRef()->As<sem::Texture>();
switch (intrinsic->Type()) {
case sem::IntrinsicType::kTextureDimensions: {
out << "textureSize(";
if (!EmitExpression(out, texture)) {
return false;
}
auto* level_arg = arg(Usage::kLevel);
if (level_arg) {
if (!EmitExpression(out, level_arg)) {
return false;
}
}
out << ")";
return true;
}
// TODO(senorblanco): determine if this works for array textures
case sem::IntrinsicType::kTextureNumLayers:
case sem::IntrinsicType::kTextureNumLevels: {
out << "textureQueryLevels(";
if (!EmitExpression(out, texture)) {
return false;
}
out << ");";
return true;
}
case sem::IntrinsicType::kTextureNumSamples: {
out << "textureSamples(";
if (!EmitExpression(out, texture)) {
return false;
}
out << ");";
return true;
}
default:
break;
}
// If pack_level_in_coords is true, then the mip level will be appended as the
// last value of the coordinates argument. If the WGSL intrinsic overload does
// not have a level parameter and pack_level_in_coords is true, then a zero
// mip level will be inserted.
bool pack_level_in_coords = false;
uint32_t glsl_ret_width = 4u;
switch (intrinsic->Type()) {
case sem::IntrinsicType::kTextureSample:
case sem::IntrinsicType::kTextureSampleBias:
out << "texture(";
break;
case sem::IntrinsicType::kTextureSampleLevel:
out << "textureLod(";
break;
case sem::IntrinsicType::kTextureSampleGrad:
out << "textureGrad(";
break;
case sem::IntrinsicType::kTextureSampleCompare:
out << "texture(";
glsl_ret_width = 1;
break;
case sem::IntrinsicType::kTextureSampleCompareLevel:
out << "texture(";
glsl_ret_width = 1;
break;
case sem::IntrinsicType::kTextureLoad:
out << "texelFetch(";
// Multisampled textures do not support mip-levels.
if (!texture_type->Is<sem::MultisampledTexture>()) {
pack_level_in_coords = true;
}
break;
case sem::IntrinsicType::kTextureStore:
out << "imageStore(";
break;
default:
diagnostics_.add_error(
diag::System::Writer,
"Internal compiler error: Unhandled texture intrinsic '" +
std::string(intrinsic->str()) + "'");
return false;
}
if (!EmitExpression(out, texture))
return false;
out << ", ";
auto* param_coords = arg(Usage::kCoords);
if (!param_coords) {
TINT_ICE(Writer, diagnostics_) << "missing coords argument";
return false;
}
auto emit_vector_appended_with_i32_zero = [&](const ast::Expression* vector) {
auto* i32 = builder_.create<sem::I32>();
auto* zero = builder_.Expr(0);
auto* stmt = builder_.Sem().Get(vector)->Stmt();
builder_.Sem().Add(zero, builder_.create<sem::Expression>(zero, i32, stmt,
sem::Constant{}));
auto* packed = AppendVector(&builder_, vector, zero);
return EmitExpression(out, packed->Declaration());
};
auto emit_vector_appended_with_level = [&](const ast::Expression* vector) {
if (auto* level = arg(Usage::kLevel)) {
auto* packed = AppendVector(&builder_, vector, level);
return EmitExpression(out, packed->Declaration());
}
return emit_vector_appended_with_i32_zero(vector);
};
if (auto* array_index = arg(Usage::kArrayIndex)) {
// Array index needs to be appended to the coordinates.
auto* packed = AppendVector(&builder_, param_coords, array_index);
if (pack_level_in_coords) {
// Then mip level needs to be appended to the coordinates.
if (!emit_vector_appended_with_level(packed->Declaration())) {
return false;
}
} else {
if (!EmitExpression(out, packed->Declaration())) {
return false;
}
}
} else if (pack_level_in_coords) {
// Mip level needs to be appended to the coordinates.
if (!emit_vector_appended_with_level(param_coords)) {
return false;
}
} else {
if (!EmitExpression(out, param_coords)) {
return false;
}
}
for (auto usage :
{Usage::kDepthRef, Usage::kBias, Usage::kLevel, Usage::kDdx, Usage::kDdy,
Usage::kSampleIndex, Usage::kOffset, Usage::kValue}) {
if (usage == Usage::kLevel && pack_level_in_coords) {
continue; // mip level already packed in coordinates.
}
if (auto* e = arg(usage)) {
out << ", ";
if (!EmitExpression(out, e)) {
return false;
}
}
}
out << ")";
// If the intrinsic return type does not match the number of elements of the
// GLSL intrinsic, we need to swizzle the expression to generate the correct
// number of components.
uint32_t wgsl_ret_width = 1;
if (auto* vec = intrinsic->ReturnType()->As<sem::Vector>()) {
wgsl_ret_width = vec->Width();
}
if (wgsl_ret_width < glsl_ret_width) {
out << ".";
for (uint32_t i = 0; i < wgsl_ret_width; i++) {
out << "xyz"[i];
}
}
if (wgsl_ret_width > glsl_ret_width) {
TINT_ICE(Writer, diagnostics_)
<< "WGSL return width (" << wgsl_ret_width
<< ") is wider than GLSL return width (" << glsl_ret_width << ") for "
<< intrinsic->Type();
return false;
}
return true;
}
std::string GeneratorImpl::generate_builtin_name(
const sem::Intrinsic* intrinsic) {
switch (intrinsic->Type()) {
case sem::IntrinsicType::kAbs:
case sem::IntrinsicType::kAcos:
case sem::IntrinsicType::kAll:
case sem::IntrinsicType::kAny:
case sem::IntrinsicType::kAsin:
case sem::IntrinsicType::kAtan:
case sem::IntrinsicType::kCeil:
case sem::IntrinsicType::kClamp:
case sem::IntrinsicType::kCos:
case sem::IntrinsicType::kCosh:
case sem::IntrinsicType::kCross:
case sem::IntrinsicType::kDeterminant:
case sem::IntrinsicType::kDistance:
case sem::IntrinsicType::kDot:
case sem::IntrinsicType::kExp:
case sem::IntrinsicType::kExp2:
case sem::IntrinsicType::kFloor:
case sem::IntrinsicType::kFrexp:
case sem::IntrinsicType::kLdexp:
case sem::IntrinsicType::kLength:
case sem::IntrinsicType::kLog:
case sem::IntrinsicType::kLog2:
case sem::IntrinsicType::kMax:
case sem::IntrinsicType::kMin:
case sem::IntrinsicType::kModf:
case sem::IntrinsicType::kNormalize:
case sem::IntrinsicType::kPow:
case sem::IntrinsicType::kReflect:
case sem::IntrinsicType::kRefract:
case sem::IntrinsicType::kRound:
case sem::IntrinsicType::kSign:
case sem::IntrinsicType::kSin:
case sem::IntrinsicType::kSinh:
case sem::IntrinsicType::kSqrt:
case sem::IntrinsicType::kStep:
case sem::IntrinsicType::kTan:
case sem::IntrinsicType::kTanh:
case sem::IntrinsicType::kTranspose:
case sem::IntrinsicType::kTrunc:
return intrinsic->str();
case sem::IntrinsicType::kAtan2:
return "atan";
case sem::IntrinsicType::kCountOneBits:
return "countbits";
case sem::IntrinsicType::kDpdx:
return "ddx";
case sem::IntrinsicType::kDpdxCoarse:
return "ddx_coarse";
case sem::IntrinsicType::kDpdxFine:
return "ddx_fine";
case sem::IntrinsicType::kDpdy:
return "ddy";
case sem::IntrinsicType::kDpdyCoarse:
return "ddy_coarse";
case sem::IntrinsicType::kDpdyFine:
return "ddy_fine";
case sem::IntrinsicType::kFaceForward:
return "faceforward";
case sem::IntrinsicType::kFract:
return "frac";
case sem::IntrinsicType::kFma:
return "mad";
case sem::IntrinsicType::kFwidth:
case sem::IntrinsicType::kFwidthCoarse:
case sem::IntrinsicType::kFwidthFine:
return "fwidth";
case sem::IntrinsicType::kInverseSqrt:
return "rsqrt";
case sem::IntrinsicType::kIsFinite:
return "isfinite";
case sem::IntrinsicType::kIsInf:
return "isinf";
case sem::IntrinsicType::kIsNan:
return "isnan";
case sem::IntrinsicType::kMix:
return "mix";
case sem::IntrinsicType::kReverseBits:
return "reversebits";
case sem::IntrinsicType::kSmoothStep:
return "smoothstep";
default:
diagnostics_.add_error(
diag::System::Writer,
"Unknown builtin method: " + std::string(intrinsic->str()));
}
return "";
}
bool GeneratorImpl::EmitCase(const ast::CaseStatement* stmt) {
if (stmt->IsDefault()) {
line() << "default: {";
} else {
for (auto* selector : stmt->selectors) {
auto out = line();
out << "case ";
if (!EmitLiteral(out, selector)) {
return false;
}
out << ":";
if (selector == stmt->selectors.back()) {
out << " {";
}
}
}
{
ScopedIndent si(this);
if (!EmitStatements(stmt->body->statements)) {
return false;
}
if (!last_is_break_or_fallthrough(stmt->body)) {
line() << "break;";
}
}
line() << "}";
return true;
}
bool GeneratorImpl::EmitContinue(const ast::ContinueStatement*) {
if (!emit_continuing_()) {
return false;
}
line() << "continue;";
return true;
}
bool GeneratorImpl::EmitDiscard(const ast::DiscardStatement*) {
// TODO(dsinclair): Verify this is correct when the discard semantics are
// defined for WGSL (https://github.com/gpuweb/gpuweb/issues/361)
line() << "discard;";
return true;
}
bool GeneratorImpl::EmitExpression(std::ostream& out,
const ast::Expression* expr) {
if (auto* a = expr->As<ast::IndexAccessorExpression>()) {
return EmitIndexAccessor(out, a);
}
if (auto* b = expr->As<ast::BinaryExpression>()) {
return EmitBinary(out, b);
}
if (auto* b = expr->As<ast::BitcastExpression>()) {
return EmitBitcast(out, b);
}
if (auto* c = expr->As<ast::CallExpression>()) {
return EmitCall(out, c);
}
if (auto* i = expr->As<ast::IdentifierExpression>()) {
return EmitIdentifier(out, i);
}
if (auto* l = expr->As<ast::LiteralExpression>()) {
return EmitLiteral(out, l);
}
if (auto* m = expr->As<ast::MemberAccessorExpression>()) {
return EmitMemberAccessor(out, m);
}
if (auto* u = expr->As<ast::UnaryOpExpression>()) {
return EmitUnaryOp(out, u);
}
diagnostics_.add_error(
diag::System::Writer,
"unknown expression type: " + std::string(expr->TypeInfo().name));
return false;
}
bool GeneratorImpl::EmitIdentifier(std::ostream& out,
const ast::IdentifierExpression* expr) {
out << builder_.Symbols().NameFor(expr->symbol);
return true;
}
bool GeneratorImpl::EmitIf(const ast::IfStatement* stmt) {
{
auto out = line();
out << "if (";
if (!EmitExpression(out, stmt->condition)) {
return false;
}
out << ") {";
}
if (!EmitStatementsWithIndent(stmt->body->statements)) {
return false;
}
for (auto* e : stmt->else_statements) {
if (e->condition) {
line() << "} else {";
increment_indent();
{
auto out = line();
out << "if (";
if (!EmitExpression(out, e->condition)) {
return false;
}
out << ") {";
}
} else {
line() << "} else {";
}
if (!EmitStatementsWithIndent(e->body->statements)) {
return false;
}
}
line() << "}";
for (auto* e : stmt->else_statements) {
if (e->condition) {
decrement_indent();
line() << "}";
}
}
return true;
}
bool GeneratorImpl::EmitFunction(const ast::Function* func) {
auto* sem = builder_.Sem().Get(func);
if (ast::HasDecoration<ast::InternalDecoration>(func->decorations)) {
// An internal function. Do not emit.
return true;
}
{
auto out = line();
auto name = builder_.Symbols().NameFor(func->symbol);
if (!EmitType(out, sem->ReturnType(), ast::StorageClass::kNone,
ast::Access::kReadWrite, "")) {
return false;
}
out << " " << name << "(";
bool first = true;
for (auto* v : sem->Parameters()) {
if (!first) {
out << ", ";
}
first = false;
auto const* type = v->Type();
if (auto* ptr = type->As<sem::Pointer>()) {
// Transform pointer parameters in to `inout` parameters.
// The WGSL spec is highly restrictive in what can be passed in pointer
// parameters, which allows for this transformation. See:
// https://gpuweb.github.io/gpuweb/wgsl/#function-restriction
out << "inout ";
type = ptr->StoreType();
}
// Note: WGSL only allows for StorageClass::kNone on parameters, however
// the sanitizer transforms generates load / store functions for storage
// or uniform buffers. These functions have a buffer parameter with
// StorageClass::kStorage or StorageClass::kUniform. This is required to
// correctly translate the parameter to a [RW]ByteAddressBuffer for
// storage buffers and a uint4[N] for uniform buffers.
if (!EmitTypeAndName(
out, type, v->StorageClass(), v->Access(),
builder_.Symbols().NameFor(v->Declaration()->symbol))) {
return false;
}
}
out << ") {";
}
if (!EmitStatementsWithIndent(func->body->statements)) {
return false;
}
line() << "}";
return true;
}
bool GeneratorImpl::EmitGlobalVariable(const ast::Variable* global) {
if (global->is_const) {
return EmitProgramConstVariable(global);
}
auto* sem = builder_.Sem().Get(global);
switch (sem->StorageClass()) {
case ast::StorageClass::kUniform:
return EmitUniformVariable(sem);
case ast::StorageClass::kStorage:
return EmitStorageVariable(sem);
case ast::StorageClass::kUniformConstant:
return EmitHandleVariable(sem);
case ast::StorageClass::kPrivate:
return EmitPrivateVariable(sem);
case ast::StorageClass::kWorkgroup:
return EmitWorkgroupVariable(sem);
default:
break;
}
TINT_ICE(Writer, diagnostics_)
<< "unhandled storage class " << sem->StorageClass();
return false;
}
bool GeneratorImpl::EmitUniformVariable(const sem::Variable* var) {
auto* decl = var->Declaration();
auto* type = var->Type()->UnwrapRef();
auto* str = type->As<sem::Struct>();
if (!str) {
TINT_ICE(Writer, builder_.Diagnostics())
<< "storage variable must be of struct type";
return false;
}
ast::VariableBindingPoint bp = decl->BindingPoint();
line() << "layout (binding = " << bp.binding->value << ") uniform "
<< UniqueIdentifier(StructName(str)) << " {";
EmitStructMembers(current_buffer_, str);
auto name = builder_.Symbols().NameFor(decl->symbol);
line() << "} " << name << ";";
return true;
}
bool GeneratorImpl::EmitStorageVariable(const sem::Variable* var) {
auto* decl = var->Declaration();
auto* type = var->Type()->UnwrapRef();
auto* str = type->As<sem::Struct>();
if (!str) {
TINT_ICE(Writer, builder_.Diagnostics())
<< "storage variable must be of struct type";
return false;
}
ast::VariableBindingPoint bp = decl->BindingPoint();
line() << "layout (binding = " << bp.binding->value << ") buffer "
<< UniqueIdentifier(StructName(str)) << " {";
EmitStructMembers(current_buffer_, str);
auto name = builder_.Symbols().NameFor(decl->symbol);
line() << "} " << name << ";";
return true;
}
bool GeneratorImpl::EmitHandleVariable(const sem::Variable* var) {
auto* decl = var->Declaration();
auto out = line();
auto name = builder_.Symbols().NameFor(decl->symbol);
auto* type = var->Type()->UnwrapRef();
if (type->As<sem::Sampler>()) {
// GLSL ignores Sampler variables.
return true;
}
if (!EmitTypeAndName(out, type, var->StorageClass(), var->Access(), name)) {
return false;
}
out << ";";
return true;
}
bool GeneratorImpl::EmitPrivateVariable(const sem::Variable* var) {
auto* decl = var->Declaration();
auto out = line();
auto name = builder_.Symbols().NameFor(decl->symbol);
auto* type = var->Type()->UnwrapRef();
if (!EmitTypeAndName(out, type, var->StorageClass(), var->Access(), name)) {
return false;
}
out << " = ";
if (auto* constructor = decl->constructor) {
if (!EmitExpression(out, constructor)) {
return false;
}
} else {
if (!EmitZeroValue(out, var->Type()->UnwrapRef())) {
return false;
}
}
out << ";";
return true;
}
bool GeneratorImpl::EmitWorkgroupVariable(const sem::Variable* var) {
auto* decl = var->Declaration();
auto out = line();
out << "groupshared ";
auto name = builder_.Symbols().NameFor(decl->symbol);
auto* type = var->Type()->UnwrapRef();
if (!EmitTypeAndName(out, type, var->StorageClass(), var->Access(), name)) {
return false;
}
if (auto* constructor = decl->constructor) {
out << " = ";
if (!EmitExpression(out, constructor)) {
return false;
}
}
out << ";";
return true;
}
sem::Type* GeneratorImpl::builtin_type(ast::Builtin builtin) {
switch (builtin) {
case ast::Builtin::kPosition: {
auto* f32 = builder_.create<sem::F32>();
return builder_.create<sem::Vector>(f32, 4);
}
case ast::Builtin::kVertexIndex:
case ast::Builtin::kInstanceIndex: {
return builder_.create<sem::I32>();
}
case ast::Builtin::kFrontFacing: {
return builder_.create<sem::Bool>();
}
case ast::Builtin::kFragDepth: {
return builder_.create<sem::F32>();
}
case ast::Builtin::kLocalInvocationId:
case ast::Builtin::kGlobalInvocationId:
case ast::Builtin::kWorkgroupId: {
auto* u32 = builder_.create<sem::U32>();
return builder_.create<sem::Vector>(u32, 3);
}
case ast::Builtin::kSampleIndex: {
return builder_.create<sem::I32>();
}
case ast::Builtin::kSampleMask:
default:
return nullptr;
}
}
const char* GeneratorImpl::builtin_to_string(ast::Builtin builtin,
ast::PipelineStage stage) {
switch (builtin) {
case ast::Builtin::kPosition:
switch (stage) {
case ast::PipelineStage::kVertex:
return "gl_Position";
case ast::PipelineStage::kFragment:
return "gl_FragCoord";
default:
TINT_ICE(Writer, builder_.Diagnostics())
<< "position builtin unexpected in this pipeline stage";
return "";
}
case ast::Builtin::kVertexIndex:
return "gl_VertexID";
case ast::Builtin::kInstanceIndex:
return "gl_InstanceID";
case ast::Builtin::kFrontFacing:
return "gl_FrontFacing";
case ast::Builtin::kFragDepth:
return "gl_FragDepth";
case ast::Builtin::kLocalInvocationId:
return "gl_LocalInvocationID";
case ast::Builtin::kLocalInvocationIndex:
return "gl_LocalInvocationIndex";
case ast::Builtin::kGlobalInvocationId:
return "gl_GlobalInvocationID";
case ast::Builtin::kWorkgroupId:
return "gl_WorkGroupID";
case ast::Builtin::kSampleIndex:
return "gl_SampleID";
case ast::Builtin::kSampleMask:
// FIXME: is this always available?
return "gl_SampleMask";
default:
return "";
}
}
std::string GeneratorImpl::interpolation_to_modifiers(
ast::InterpolationType type,
ast::InterpolationSampling sampling) const {
std::string modifiers;
switch (type) {
case ast::InterpolationType::kPerspective:
modifiers += "linear ";
break;
case ast::InterpolationType::kLinear:
modifiers += "noperspective ";
break;
case ast::InterpolationType::kFlat:
modifiers += "nointerpolation ";
break;
}
switch (sampling) {
case ast::InterpolationSampling::kCentroid:
modifiers += "centroid ";
break;
case ast::InterpolationSampling::kSample:
modifiers += "sample ";
break;
case ast::InterpolationSampling::kCenter:
case ast::InterpolationSampling::kNone:
break;
}
return modifiers;
}
bool GeneratorImpl::EmitEntryPointFunction(const ast::Function* func) {
auto* func_sem = builder_.Sem().Get(func);
{
auto out = line();
if (func->PipelineStage() == ast::PipelineStage::kCompute) {
// Emit the layout(local_size) attributes.
auto wgsize = func_sem->WorkgroupSize();
out << "layout(";
for (int i = 0; i < 3; i++) {
if (i > 0) {
out << ", ";
}
out << "local_size_" << (i == 0 ? "x" : i == 1 ? "y" : "z") << " = ";
if (wgsize[i].overridable_const) {
auto* global = builder_.Sem().Get<sem::GlobalVariable>(
wgsize[i].overridable_const);
if (!global->IsOverridable()) {
TINT_ICE(Writer, builder_.Diagnostics())
<< "expected a pipeline-overridable constant";
}
out << kSpecConstantPrefix << global->ConstantId();
} else {
out << std::to_string(wgsize[i].value);
}
}
out << ") in;" << std::endl;
}
out << func->return_type->FriendlyName(builder_.Symbols());
out << " " << builder_.Symbols().NameFor(func->symbol) << "(";
bool first = true;
// Emit entry point parameters.
for (auto* var : func->params) {
auto* sem = builder_.Sem().Get(var);
auto* type = sem->Type();
if (!type->Is<sem::Struct>()) {
// ICE likely indicates that the CanonicalizeEntryPointIO transform was
// not run, or a builtin parameter was added after it was run.
TINT_ICE(Writer, diagnostics_)
<< "Unsupported non-struct entry point parameter";
}
if (!first) {
out << ", ";
}
first = false;
if (!EmitTypeAndName(out, type, sem->StorageClass(), sem->Access(),
builder_.Symbols().NameFor(var->symbol))) {
return false;
}
}
out << ") {";
}
{
ScopedIndent si(this);
if (!EmitStatements(func->body->statements)) {
return false;
}
if (!Is<ast::ReturnStatement>(func->body->Last())) {
ast::ReturnStatement ret(ProgramID(), Source{});
if (!EmitStatement(&ret)) {
return false;
}
}
}
line() << "}";
auto out = line();
// Declare entry point input variables
for (auto* var : func->params) {
auto* sem = builder_.Sem().Get(var);
auto* str = sem->Type()->As<sem::Struct>();
for (auto* member : str->Members()) {
if (ast::HasDecoration<ast::BuiltinDecoration>(
member->Declaration()->decorations)) {
continue;
}
if (!EmitTypeAndName(
out, member->Type(), ast::StorageClass::kInput,
ast::Access::kReadWrite,
builder_.Symbols().NameFor(member->Declaration()->symbol))) {
return false;
}
out << ";" << std::endl;
}
}
// Declare entry point output variables
auto* return_type = func_sem->ReturnType()->As<sem::Struct>();
if (return_type) {
for (auto* member : return_type->Members()) {
if (ast::HasDecoration<ast::BuiltinDecoration>(
member->Declaration()->decorations)) {
continue;
}
if (!EmitTypeAndName(
out, member->Type(), ast::StorageClass::kOutput,
ast::Access::kReadWrite,
builder_.Symbols().NameFor(member->Declaration()->symbol))) {
return false;
}
out << ";" << std::endl;
}
}
// Create a main() function which calls the entry point.
out << "void main() {" << std::endl;
std::string printed_name;
for (auto* var : func->params) {
out << " ";
auto* sem = builder_.Sem().Get(var);
if (!EmitTypeAndName(out, sem->Type(), sem->StorageClass(), sem->Access(),
"inputs")) {
return false;
}
out << ";" << std::endl;
auto* type = sem->Type();
auto* str = type->As<sem::Struct>();
for (auto* member : str->Members()) {
std::string name =
builder_.Symbols().NameFor(member->Declaration()->symbol);
out << " inputs." << name << " = ";
if (auto* builtin = ast::GetDecoration<ast::BuiltinDecoration>(
member->Declaration()->decorations)) {
if (builtin_type(builtin->builtin) != member->Type()) {
if (!EmitType(out, member->Type(), ast::StorageClass::kNone,
ast::Access::kReadWrite, "")) {
return false;
}
out << "(";
out << builtin_to_string(builtin->builtin, func->PipelineStage());
out << ")";
} else {
out << builtin_to_string(builtin->builtin, func->PipelineStage());
}
} else {
out << name;
}
out << ";" << std::endl;
}
}
out << " ";
if (return_type) {
out << return_type->FriendlyName(builder_.Symbols()) << " "
<< "outputs;" << std::endl;
out << " outputs = ";
}
out << builder_.Symbols().NameFor(func->symbol);
if (func->params.empty()) {
out << "()";
} else {
out << "(inputs)";
}
out << ";" << std::endl;
auto* str = func_sem->ReturnType()->As<sem::Struct>();
if (str) {
for (auto* member : str->Members()) {
std::string name =
builder_.Symbols().NameFor(member->Declaration()->symbol);
out << " ";
if (auto* builtin = ast::GetDecoration<ast::BuiltinDecoration>(
member->Declaration()->decorations)) {
out << builtin_to_string(builtin->builtin, func->PipelineStage());
} else {
out << name;
}
out << " = outputs." << name << ";" << std::endl;
}
}
if (func->PipelineStage() == ast::PipelineStage::kVertex) {
out << " gl_Position.y = -gl_Position.y;" << std::endl;
}
out << "}" << std::endl << std::endl;
return true;
}
bool GeneratorImpl::EmitLiteral(std::ostream& out,
const ast::LiteralExpression* lit) {
if (auto* l = lit->As<ast::BoolLiteralExpression>()) {
out << (l->value ? "true" : "false");
} else if (auto* fl = lit->As<ast::FloatLiteralExpression>()) {
if (std::isinf(fl->value)) {
out << (fl->value >= 0 ? "uintBitsToFloat(0x7f800000u)"
: "uintBitsToFloat(0xff800000u)");
} else if (std::isnan(fl->value)) {
out << "uintBitsToFloat(0x7fc00000u)";
} else {
out << FloatToString(fl->value) << "f";
}
} else if (auto* sl = lit->As<ast::SintLiteralExpression>()) {
out << sl->value;
} else if (auto* ul = lit->As<ast::UintLiteralExpression>()) {
out << ul->value << "u";
} else {
diagnostics_.add_error(diag::System::Writer, "unknown literal type");
return false;
}
return true;
}
bool GeneratorImpl::EmitZeroValue(std::ostream& out, const sem::Type* type) {
if (type->Is<sem::Bool>()) {
out << "false";
} else if (type->Is<sem::F32>()) {
out << "0.0f";
} else if (type->Is<sem::I32>()) {
out << "0";
} else if (type->Is<sem::U32>()) {
out << "0u";
} else if (auto* vec = type->As<sem::Vector>()) {
if (!EmitType(out, type, ast::StorageClass::kNone, ast::Access::kReadWrite,
"")) {
return false;
}
ScopedParen sp(out);
for (uint32_t i = 0; i < vec->Width(); i++) {
if (i != 0) {
out << ", ";
}
if (!EmitZeroValue(out, vec->type())) {
return false;
}
}
} else if (auto* mat = type->As<sem::Matrix>()) {
if (!EmitType(out, type, ast::StorageClass::kNone, ast::Access::kReadWrite,
"")) {
return false;
}
ScopedParen sp(out);
for (uint32_t i = 0; i < (mat->rows() * mat->columns()); i++) {
if (i != 0) {
out << ", ";
}
if (!EmitZeroValue(out, mat->type())) {
return false;
}
}
} else if (auto* str = type->As<sem::Struct>()) {
if (!EmitType(out, type, ast::StorageClass::kNone, ast::Access::kUndefined,
"")) {
return false;
}
bool first = true;
out << "(";
for (auto* member : str->Members()) {
if (!first) {
out << ", ";
} else {
first = false;
}
EmitZeroValue(out, member->Type());
}
out << ")";
} else if (auto* array = type->As<sem::Array>()) {
if (!EmitType(out, type, ast::StorageClass::kNone, ast::Access::kUndefined,
"")) {
return false;
}
out << "(";
for (uint32_t i = 0; i < array->Count(); i++) {
if (i != 0) {
out << ", ";
}
EmitZeroValue(out, array->ElemType());
}
out << ")";
} else {
diagnostics_.add_error(
diag::System::Writer,
"Invalid type for zero emission: " + type->type_name());
return false;
}
return true;
}
bool GeneratorImpl::EmitLoop(const ast::LoopStatement* stmt) {
auto emit_continuing = [this, stmt]() {
if (stmt->continuing && !stmt->continuing->Empty()) {
if (!EmitBlock(stmt->continuing)) {
return false;
}
}
return true;
};
TINT_SCOPED_ASSIGNMENT(emit_continuing_, emit_continuing);
line() << "while (true) {";
{
ScopedIndent si(this);
if (!EmitStatements(stmt->body->statements)) {
return false;
}
if (!emit_continuing()) {
return false;
}
}
line() << "}";
return true;
}
bool GeneratorImpl::EmitForLoop(const ast::ForLoopStatement* stmt) {
// Nest a for loop with a new block. In HLSL the initializer scope is not
// nested by the for-loop, so we may get variable redefinitions.
line() << "{";
increment_indent();
TINT_DEFER({
decrement_indent();
line() << "}";
});
TextBuffer init_buf;
if (auto* init = stmt->initializer) {
TINT_SCOPED_ASSIGNMENT(current_buffer_, &init_buf);
if (!EmitStatement(init)) {
return false;
}
}
TextBuffer cond_pre;
std::stringstream cond_buf;
if (auto* cond = stmt->condition) {
TINT_SCOPED_ASSIGNMENT(current_buffer_, &cond_pre);
if (!EmitExpression(cond_buf, cond)) {
return false;
}
}
TextBuffer cont_buf;
if (auto* cont = stmt->continuing) {
TINT_SCOPED_ASSIGNMENT(current_buffer_, &cont_buf);
if (!EmitStatement(cont)) {
return false;
}
}
// If the for-loop has a multi-statement conditional and / or continuing, then
// we cannot emit this as a regular for-loop in HLSL. Instead we need to
// generate a `while(true)` loop.
bool emit_as_loop = cond_pre.lines.size() > 0 || cont_buf.lines.size() > 1;
// If the for-loop has multi-statement initializer, or is going to be emitted
// as a `while(true)` loop, then declare the initializer statement(s) before
// the loop.
if (init_buf.lines.size() > 1 || (stmt->initializer && emit_as_loop)) {
current_buffer_->Append(init_buf);
init_buf.lines.clear(); // Don't emit the initializer again in the 'for'
}
if (emit_as_loop) {
auto emit_continuing = [&]() {
current_buffer_->Append(cont_buf);
return true;
};
TINT_SCOPED_ASSIGNMENT(emit_continuing_, emit_continuing);
line() << "while (true) {";
increment_indent();
TINT_DEFER({
decrement_indent();
line() << "}";
});
if (stmt->condition) {
current_buffer_->Append(cond_pre);
line() << "if (!(" << cond_buf.str() << ")) { break; }";
}
if (!EmitStatements(stmt->body->statements)) {
return false;
}
if (!emit_continuing()) {
return false;
}
} else {
// For-loop can be generated.
{
auto out = line();
out << "for";
{
ScopedParen sp(out);
if (!init_buf.lines.empty()) {
out << init_buf.lines[0].content << " ";
} else {
out << "; ";
}
out << cond_buf.str() << "; ";
if (!cont_buf.lines.empty()) {
out << TrimSuffix(cont_buf.lines[0].content, ";");
}
}
out << " {";
}
{
auto emit_continuing = [] { return true; };
TINT_SCOPED_ASSIGNMENT(emit_continuing_, emit_continuing);
if (!EmitStatementsWithIndent(stmt->body->statements)) {
return false;
}
}
line() << "}";
}
return true;
}
bool GeneratorImpl::EmitMemberAccessor(
std::ostream& out,
const ast::MemberAccessorExpression* expr) {
if (!EmitExpression(out, expr->structure)) {
return false;
}
out << ".";
// Swizzles output the name directly
if (builder_.Sem().Get(expr)->Is<sem::Swizzle>()) {
out << builder_.Symbols().NameFor(expr->member->symbol);
} else if (!EmitExpression(out, expr->member)) {
return false;
}
return true;
}
bool GeneratorImpl::EmitReturn(const ast::ReturnStatement* stmt) {
if (stmt->value) {
auto out = line();
out << "return ";
if (!EmitExpression(out, stmt->value)) {
return false;
}
out << ";";
} else {
line() << "return;";
}
return true;
}
bool GeneratorImpl::EmitStatement(const ast::Statement* stmt) {
if (auto* a = stmt->As<ast::AssignmentStatement>()) {
return EmitAssign(a);
}
if (auto* b = stmt->As<ast::BlockStatement>()) {
return EmitBlock(b);
}
if (auto* b = stmt->As<ast::BreakStatement>()) {
return EmitBreak(b);
}
if (auto* c = stmt->As<ast::CallStatement>()) {
auto out = line();
if (!EmitCall(out, c->expr)) {
return false;
}
out << ";";
return true;
}
if (auto* c = stmt->As<ast::ContinueStatement>()) {
return EmitContinue(c);
}
if (auto* d = stmt->As<ast::DiscardStatement>()) {
return EmitDiscard(d);
}
if (stmt->As<ast::FallthroughStatement>()) {
line() << "/* fallthrough */";
return true;
}
if (auto* i = stmt->As<ast::IfStatement>()) {
return EmitIf(i);
}
if (auto* l = stmt->As<ast::LoopStatement>()) {
return EmitLoop(l);
}
if (auto* l = stmt->As<ast::ForLoopStatement>()) {
return EmitForLoop(l);
}
if (auto* r = stmt->As<ast::ReturnStatement>()) {
return EmitReturn(r);
}
if (auto* s = stmt->As<ast::SwitchStatement>()) {
return EmitSwitch(s);
}
if (auto* v = stmt->As<ast::VariableDeclStatement>()) {
return EmitVariable(v->variable);
}
diagnostics_.add_error(
diag::System::Writer,
"unknown statement type: " + std::string(stmt->TypeInfo().name));
return false;
}
bool GeneratorImpl::EmitSwitch(const ast::SwitchStatement* stmt) {
{ // switch(expr) {
auto out = line();
out << "switch(";
if (!EmitExpression(out, stmt->condition)) {
return false;
}
out << ") {";
}
{
ScopedIndent si(this);
for (auto* s : stmt->body) {
if (!EmitCase(s)) {
return false;
}
}
}
line() << "}";
return true;
}
bool GeneratorImpl::EmitType(std::ostream& out,
const sem::Type* type,
ast::StorageClass storage_class,
ast::Access access,
const std::string& name,
bool* name_printed /* = nullptr */) {
if (name_printed) {
*name_printed = false;
}
switch (storage_class) {
case ast::StorageClass::kInput: {
out << "in ";
break;
}
case ast::StorageClass::kOutput: {
out << "out ";
break;
}
case ast::StorageClass::kUniform: {
out << "uniform ";
break;
}
default:
break;
}
if (auto* ary = type->As<sem::Array>()) {
const sem::Type* base_type = ary;
std::vector<uint32_t> sizes;
while (auto* arr = base_type->As<sem::Array>()) {
sizes.push_back(arr->Count());
base_type = arr->ElemType();
}
if (!EmitType(out, base_type, storage_class, access, "")) {
return false;
}
if (!name.empty()) {
out << " " << name;
if (name_printed) {
*name_printed = true;
}
}
for (uint32_t size : sizes) {
if (size > 0) {
out << "[" << size << "]";
} else {
out << "[]";
}
}
} else if (type->Is<sem::Bool>()) {
out << "bool";
} else if (type->Is<sem::F32>()) {
out << "float";
} else if (type->Is<sem::I32>()) {
out << "int";
} else if (auto* mat = type->As<sem::Matrix>()) {
TINT_ASSERT(Writer, mat->type()->Is<sem::F32>());
out << "mat" << mat->columns();
if (mat->rows() != mat->columns()) {
out << "x" << mat->rows();
}
} else if (type->Is<sem::Pointer>()) {
TINT_ICE(Writer, diagnostics_)
<< "Attempting to emit pointer type. These should have been removed "
"with the InlinePointerLets transform";
return false;
} else if (type->Is<sem::Sampler>()) {
return false;
} else if (auto* str = type->As<sem::Struct>()) {
out << StructName(str);
} else if (auto* tex = type->As<sem::Texture>()) {