aboutsummaryrefslogblamecommitdiff
path: root/src/shader_recompiler/ir_opt/dead_code_elimination_pass.cpp
blob: 1bd8afd6f6b0d6a9c3a55b9dceba706636377e2b (plain) (tree)
1
2
3
4
5
6
7
8
9
10
                                                               
 
                                                      
                                                

                                            
                                                    
                                                                                                   





                                                              
             


                                   
// 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