| // 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/transform/spirv.h" |
| |
| #include <string> |
| #include <utility> |
| |
| #include "src/ast/variable.h" |
| #include "src/program_builder.h" |
| #include "src/semantic/expression.h" |
| #include "src/semantic/variable.h" |
| |
| namespace tint { |
| namespace transform { |
| |
| Spirv::Spirv() = default; |
| Spirv::~Spirv() = default; |
| |
| Transform::Output Spirv::Run(const Program* in) { |
| ProgramBuilder out; |
| CloneContext ctx(&out, in); |
| HandleSampleMaskBuiltins(ctx); |
| ctx.Clone(); |
| return Output{Program(std::move(out))}; |
| } |
| |
| void Spirv::HandleSampleMaskBuiltins(CloneContext& ctx) const { |
| // Find global variables decorated with [[builtin(sample_mask_{in,out})]] and |
| // change their type from `u32` to `array<u32, 1>`, as required by Vulkan. |
| // |
| // Before: |
| // ``` |
| // [[builtin(sample_mask_out)]] var<out> mask_out : u32; |
| // fn main() -> void { |
| // mask_out = 1u; |
| // } |
| // ``` |
| // After: |
| // ``` |
| // [[builtin(sample_mask_out)]] var<out> mask_out : array<u32, 1>; |
| // fn main() -> void { |
| // mask_out[0] = 1u; |
| // } |
| // ``` |
| |
| for (auto* var : ctx.src->AST().GlobalVariables()) { |
| for (auto* deco : var->decorations()) { |
| if (auto* builtin = deco->As<ast::BuiltinDecoration>()) { |
| if (builtin->value() != ast::Builtin::kSampleMaskIn && |
| builtin->value() != ast::Builtin::kSampleMaskOut) { |
| continue; |
| } |
| |
| // Use the same name as the old variable. |
| std::string var_name = ctx.src->Symbols().NameFor(var->symbol()); |
| // Use `array<u32, 1>` for the new variable. |
| auto* type = ctx.dst->ty.array(ctx.dst->ty.u32(), 1u); |
| // Create the new variable. |
| auto* var_arr = ctx.dst->Var(var->source(), var_name, type, |
| var->declared_storage_class(), nullptr, |
| ctx.Clone(var->decorations())); |
| // Replace the variable with the arrayed version. |
| ctx.Replace(var, var_arr); |
| |
| // Replace all uses of the old variable with `var_arr[0]`. |
| for (auto* user : ctx.src->Sem().Get(var)->Users()) { |
| auto* new_ident = ctx.dst->IndexAccessor( |
| ctx.dst->Expr(var_arr->symbol()), ctx.dst->Expr(0)); |
| ctx.Replace<ast::Expression>(user->Declaration(), new_ident); |
| } |
| } |
| } |
| } |
| } |
| |
| } // namespace transform |
| } // namespace tint |