suyu/src/shader_recompiler/ir_opt/dead_code_elimination_pass.cpp

25 lines
876 B
C++

// SPDX-FileCopyrightText: Copyright 2021 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#include "shader_recompiler/frontend/ir/basic_block.h"
#include "shader_recompiler/frontend/ir/value.h"
#include "shader_recompiler/ir_opt/passes.h"
namespace Shader::Optimization {
void DeadCodeEliminationPass(IR::Program& program) {
// We iterate over the instructions in reverse order.
// This is because removing an instruction reduces the number of uses for earlier instructions.
for (IR::Block* const block : program.post_order_blocks) {
auto it{block->end()};
while (it != block->begin()) {
--it;
if (!it->HasUses() && !it->MayHaveSideEffects()) {
it->Invalidate();
it = block->Instructions().erase(it);
}
}
}
}
} // namespace Shader::Optimization