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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/append_vector.h"
#include <utility>
#include <vector>
#include "src/sem/call.h"
#include "src/sem/expression.h"
#include "src/sem/type_constructor.h"
#include "src/sem/type_conversion.h"
#include "src/utils/transform.h"
namespace tint {
namespace writer {
namespace {
struct VectorConstructorInfo {
const sem::Call* call = nullptr;
const sem::TypeConstructor* ctor = nullptr;
operator bool() const { return call != nullptr; }
};
VectorConstructorInfo AsVectorConstructor(const sem::Expression* expr) {
if (auto* call = expr->As<sem::Call>()) {
if (auto* ctor = call->Target()->As<sem::TypeConstructor>()) {
if (ctor->ReturnType()->Is<sem::Vector>()) {
return {call, ctor};
}
}
}
return {};
}
const sem::Expression* Zero(ProgramBuilder& b,
const sem::Type* ty,
const sem::Statement* stmt) {
const ast::Expression* expr = nullptr;
if (ty->Is<sem::I32>()) {
expr = b.Expr(0);
} else if (ty->Is<sem::U32>()) {
expr = b.Expr(0u);
} else if (ty->Is<sem::F32>()) {
expr = b.Expr(0.0f);
} else if (ty->Is<sem::Bool>()) {
expr = b.Expr(false);
} else {
TINT_UNREACHABLE(Writer, b.Diagnostics())
<< "unsupported vector element type: " << ty->TypeInfo().name;
return nullptr;
}
auto* sem = b.create<sem::Expression>(expr, ty, stmt, sem::Constant{});
b.Sem().Add(expr, sem);
return sem;
}
} // namespace
const sem::Call* AppendVector(ProgramBuilder* b,
const ast::Expression* vector_ast,
const ast::Expression* scalar_ast) {
uint32_t packed_size;
const sem::Type* packed_el_sem_ty;
auto* vector_sem = b->Sem().Get(vector_ast);
auto* scalar_sem = b->Sem().Get(scalar_ast);
auto* vector_ty = vector_sem->Type()->UnwrapRef();
if (auto* vec = vector_ty->As<sem::Vector>()) {
packed_size = vec->Width() + 1;
packed_el_sem_ty = vec->type();
} else {
packed_size = 2;
packed_el_sem_ty = vector_ty;
}
const ast::Type* packed_el_ast_ty = nullptr;
if (packed_el_sem_ty->Is<sem::I32>()) {
packed_el_ast_ty = b->create<ast::I32>();
} else if (packed_el_sem_ty->Is<sem::U32>()) {
packed_el_ast_ty = b->create<ast::U32>();
} else if (packed_el_sem_ty->Is<sem::F32>()) {
packed_el_ast_ty = b->create<ast::F32>();
} else if (packed_el_sem_ty->Is<sem::Bool>()) {
packed_el_ast_ty = b->create<ast::Bool>();
} else {
TINT_UNREACHABLE(Writer, b->Diagnostics())
<< "unsupported vector element type: "
<< packed_el_sem_ty->TypeInfo().name;
}
auto* statement = vector_sem->Stmt();
auto* packed_ast_ty = b->create<ast::Vector>(packed_el_ast_ty, packed_size);
auto* packed_sem_ty = b->create<sem::Vector>(packed_el_sem_ty, packed_size);
// If the coordinates are already passed in a vector constructor, with only
// scalar components supplied, extract the elements into the new vector
// instead of nesting a vector-in-vector.
// If the coordinates are a zero-constructor of the vector, then expand that
// to scalar zeros.
// The other cases for a nested vector constructor are when it is used
// to convert a vector of a different type, e.g. vec2<i32>(vec2<u32>()).
// In that case, preserve the original argument, or you'll get a type error.
std::vector<const sem::Expression*> packed;
if (auto vc = AsVectorConstructor(vector_sem)) {
const auto num_supplied = vc.call->Arguments().size();
if (num_supplied == 0) {
// Zero-value vector constructor. Populate with zeros
for (uint32_t i = 0; i < packed_size - 1; i++) {
auto* zero = Zero(*b, packed_el_sem_ty, statement);
packed.emplace_back(zero);
}
} else if (num_supplied + 1 == packed_size) {
// All vector components were supplied as scalars. Pass them through.
packed = vc.call->Arguments();
}
}
if (packed.empty()) {
// The special cases didn't occur. Use the vector argument as-is.
packed.emplace_back(vector_sem);
}
if (packed_el_sem_ty != scalar_sem->Type()->UnwrapRef()) {
// Cast scalar to the vector element type
auto* scalar_cast_ast = b->Construct(packed_el_ast_ty, scalar_ast);
auto* scalar_cast_target = b->create<sem::TypeConversion>(
packed_el_sem_ty,
b->create<sem::Parameter>(nullptr, 0, scalar_sem->Type()->UnwrapRef(),
ast::StorageClass::kNone,
ast::Access::kUndefined));
auto* scalar_cast_sem =
b->create<sem::Call>(scalar_cast_ast, scalar_cast_target,
std::vector<const sem::Expression*>{scalar_sem},
statement, sem::Constant{});
b->Sem().Add(scalar_cast_ast, scalar_cast_sem);
packed.emplace_back(scalar_cast_sem);
} else {
packed.emplace_back(scalar_sem);
}
auto* constructor_ast = b->Construct(
packed_ast_ty, utils::Transform(packed, [&](const sem::Expression* expr) {
return expr->Declaration();
}));
auto* constructor_target = b->create<sem::TypeConstructor>(
packed_sem_ty,
utils::Transform(packed,
[&](const tint::sem::Expression* arg,
size_t i) -> const sem::Parameter* {
return b->create<sem::Parameter>(
nullptr, i, arg->Type()->UnwrapRef(),
ast::StorageClass::kNone, ast::Access::kUndefined);
}));
auto* constructor_sem = b->create<sem::Call>(
constructor_ast, constructor_target, packed, statement, sem::Constant{});
b->Sem().Add(constructor_ast, constructor_sem);
return constructor_sem;
}
} // namespace writer
} // namespace tint