1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef ART_COMPILER_OPTIMIZING_DEAD_CODE_ELIMINATION_H_
18#define ART_COMPILER_OPTIMIZING_DEAD_CODE_ELIMINATION_H_
19
20#include "nodes.h"
21#include "optimization.h"
22#include "optimizing_compiler_stats.h"
23
24namespace art {
25
26/**
27 * Optimization pass performing dead code elimination (removal of
28 * unused variables/instructions) on the SSA form.
29 */
30class HDeadCodeElimination : public HOptimization {
31 public:
32  HDeadCodeElimination(HGraph* graph,
33                       OptimizingCompilerStats* stats = nullptr,
34                       const char* name = kInitialDeadCodeEliminationPassName)
35      : HOptimization(graph, name, stats) {}
36
37  void Run() OVERRIDE;
38
39  static constexpr const char* kInitialDeadCodeEliminationPassName = "dead_code_elimination";
40  static constexpr const char* kFinalDeadCodeEliminationPassName = "dead_code_elimination_final";
41
42 private:
43  void MaybeRecordDeadBlock(HBasicBlock* block);
44  void RemoveDeadBlocks();
45  void RemoveDeadInstructions();
46
47  DISALLOW_COPY_AND_ASSIGN(HDeadCodeElimination);
48};
49
50}  // namespace art
51
52#endif  // ART_COMPILER_OPTIMIZING_DEAD_CODE_ELIMINATION_H_
53