| // 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/tint/transform/fold_constants.h" |
| |
| #include <unordered_map> |
| #include <utility> |
| #include <vector> |
| |
| #include "src/tint/program_builder.h" |
| #include "src/tint/sem/call.h" |
| #include "src/tint/sem/expression.h" |
| #include "src/tint/sem/type_constructor.h" |
| #include "src/tint/sem/type_conversion.h" |
| |
| TINT_INSTANTIATE_TYPEINFO(tint::transform::FoldConstants); |
| |
| namespace tint::transform { |
| |
| FoldConstants::FoldConstants() = default; |
| |
| FoldConstants::~FoldConstants() = default; |
| |
| void FoldConstants::Run(CloneContext& ctx, const DataMap&, DataMap&) const { |
| ctx.ReplaceAll([&](const ast::Expression* expr) -> const ast::Expression* { |
| auto* call = ctx.src->Sem().Get<sem::Call>(expr); |
| if (!call) { |
| return nullptr; |
| } |
| |
| auto value = call->ConstantValue(); |
| if (!value.IsValid()) { |
| return nullptr; |
| } |
| |
| auto* ty = call->Type(); |
| |
| if (!call->Target()->IsAnyOf<sem::TypeConversion, sem::TypeConstructor>()) { |
| return nullptr; |
| } |
| |
| // If original ctor expression had no init values, don't replace the |
| // expression |
| if (call->Arguments().empty()) { |
| return nullptr; |
| } |
| |
| if (auto* vec = ty->As<sem::Vector>()) { |
| uint32_t vec_size = static_cast<uint32_t>(vec->Width()); |
| |
| // We'd like to construct the new vector with the same number of |
| // constructor args that the original node had, but after folding |
| // constants, cases like the following are problematic: |
| // |
| // vec3<f32> = vec3<f32>(vec2<f32>, 1.0) // vec_size=3, ctor_size=2 |
| // |
| // In this case, creating a vec3 with 2 args is invalid, so we should |
| // create it with 3. So what we do is construct with vec_size args, |
| // except if the original vector was single-value initialized, in |
| // which case, we only construct with one arg again. |
| uint32_t ctor_size = (call->Arguments().size() == 1) ? 1 : vec_size; |
| |
| ast::ExpressionList ctors; |
| for (uint32_t i = 0; i < ctor_size; ++i) { |
| value.WithScalarAt( |
| i, [&](auto&& s) { ctors.emplace_back(ctx.dst->Expr(s)); }); |
| } |
| |
| auto* el_ty = CreateASTTypeFor(ctx, vec->type()); |
| return ctx.dst->vec(el_ty, vec_size, ctors); |
| } |
| |
| if (ty->is_scalar()) { |
| return value.WithScalarAt(0, |
| [&](auto&& s) -> const ast::LiteralExpression* { |
| return ctx.dst->Expr(s); |
| }); |
| } |
| |
| return nullptr; |
| }); |
| |
| ctx.Clone(); |
| } |
| |
| } // namespace tint::transform |