third_party_spirv-tools/source/opt/eliminate_dead_input_components_pass.h
Greg Fischer 9d1b572884
spirv-opt: (WIP) Eliminate Dead Input Component Pass (#4720)
This adds the --eliminate-dead-input-components pass which currently
removes trailing unused components from input arrays.

Fixes #4532
2022-03-22 20:50:52 -06:00

60 lines
2.1 KiB
C++

// Copyright (c) 2022 The Khronos Group Inc.
// Copyright (c) 2022 LunarG Inc.
//
// 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.
#ifndef SOURCE_OPT_ELIMINATE_DEAD_INPUT_COMPONENTS_H_
#define SOURCE_OPT_ELIMINATE_DEAD_INPUT_COMPONENTS_H_
#include <unordered_map>
#include "source/opt/ir_context.h"
#include "source/opt/module.h"
#include "source/opt/pass.h"
namespace spvtools {
namespace opt {
// See optimizer.hpp for documentation.
class EliminateDeadInputComponentsPass : public Pass {
public:
explicit EliminateDeadInputComponentsPass() {}
const char* name() const override { return "reduce-load-size"; }
Status Process() override;
// Return the mask of preserved Analyses.
IRContext::Analysis GetPreservedAnalyses() override {
return IRContext::kAnalysisDefUse |
IRContext::kAnalysisInstrToBlockMapping |
IRContext::kAnalysisCombinators | IRContext::kAnalysisCFG |
IRContext::kAnalysisDominatorAnalysis |
IRContext::kAnalysisLoopAnalysis | IRContext::kAnalysisNameMap |
IRContext::kAnalysisConstants | IRContext::kAnalysisTypes;
}
private:
// Find the max constant used to index the variable declared by |var|
// through OpAccessChain or OpInBoundsAccessChain. If any non-constant
// indices or non-Op*AccessChain use of |var|, return |original_max|.
unsigned FindMaxIndex(Instruction& var, unsigned original_max);
// Change the length of the array |inst| to |length|
void ChangeArrayLength(Instruction& inst, unsigned length);
};
} // namespace opt
} // namespace spvtools
#endif // SOURCE_OPT_ELIMINATE_DEAD_INPUT_COMPONENTS_H_