mirror of
https://github.com/KytyPS5/KytyPS5.git
synced 2026-10-20 19:07:01 +02:00
nmzik
52 lines
1.6 KiB
C++
52 lines
1.6 KiB
C++
#include "graphics/shader/recompiler/ir/passes/DeadCodeElimination.h"
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#include <algorithm>
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namespace Libs::Graphics::ShaderRecompiler::IR {
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void RemoveIdentities(const BlockList& blocks) {
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for (auto* block: blocks) {
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auto& instructions = block->Instructions();
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for (auto inst = instructions.begin(); inst != instructions.end();) {
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if (inst->GetOpcode() != ValueOpcode::Identity) {
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inst++;
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continue;
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}
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const auto replacement = inst->Arg(0);
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inst->ReplaceUsesWith(replacement, false);
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inst = instructions.erase(inst);
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}
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}
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}
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void EliminateDeadCode(const BlockList& blocks) {
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std::vector<Inst*> pending;
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for (auto* block: blocks) {
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for (auto& inst: *block) {
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// Retained resource-planning instructions live outside the block list.
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inst.live = inst.MayHaveSideEffects() || std::ranges::any_of(inst.Uses(),
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[](const Use& use) { return use.user->Parent() == nullptr; });
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if (inst.live) pending.push_back(&inst);
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}
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}
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while (!pending.empty()) {
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const auto* inst = pending.back();
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pending.pop_back();
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for (size_t arg = 0; arg < inst->NumArgs(); ++arg) {
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auto* input = inst->Arg(arg).TryInstruction();
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if (input != nullptr && input->Parent() != nullptr && !input->live) {
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input->live = true;
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pending.push_back(input);
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}
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}
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}
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// Unlink every dead operand before freeing nodes in a dead Phi cycle.
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for (auto* block: blocks)
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for (auto& inst: *block)
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if (!inst.live) inst.Invalidate();
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for (auto* block: blocks)
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std::erase_if(block->Instructions(), [](const Inst& inst) { return !inst.live; });
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}
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} // namespace Libs::Graphics::ShaderRecompiler::IR
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