citra/src/shader_recompiler/ir_opt/dead_code_elimination_pass.cpp

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// Copyright 2021 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <ranges>
#include "shader_recompiler/frontend/ir/basic_block.h"
#include "shader_recompiler/frontend/ir/value.h"
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#include "shader_recompiler/ir_opt/passes.h"
namespace Shader::Optimization {
void DeadCodeEliminationPass(IR::Program& program) {
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// 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);
}
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}
}
}
} // namespace Shader::Optimization