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 24 namespace art { 25 26 /** 27 * Optimization pass performing dead code elimination (removal of 28 * unused variables/instructions) on the SSA form. 29 */ 30 class HDeadCodeElimination : public HOptimization { 31 public: 32 HDeadCodeElimination(HGraph* graph, OptimizingCompilerStats* stats, const char* name) 33 : HOptimization(graph, name, stats) {} 34 35 void Run() OVERRIDE; 36 static constexpr const char* kDeadCodeEliminationPassName = "dead_code_elimination"; 37 38 private: 39 void MaybeRecordDeadBlock(HBasicBlock* block); 40 void MaybeRecordSimplifyIf(); 41 bool RemoveDeadBlocks(); 42 void RemoveDeadInstructions(); 43 bool SimplifyAlwaysThrows(); 44 bool SimplifyIfs(); 45 void ConnectSuccessiveBlocks(); 46 47 DISALLOW_COPY_AND_ASSIGN(HDeadCodeElimination); 48 }; 49 50 } // namespace art 51 52 #endif // ART_COMPILER_OPTIMIZING_DEAD_CODE_ELIMINATION_H_ 53
