1 /* 2 * Copyright (c) 2021-2023 Huawei Device Co., Ltd. 3 * Licensed under the Apache License, Version 2.0 (the "License"); 4 * you may not use this file except in compliance with the License. 5 * You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software 10 * distributed under the License is distributed on an "AS IS" BASIS, 11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 * See the License for the specific language governing permissions and 13 * limitations under the License. 14 */ 15 #ifndef COMPILER_OPTIMIZER_ANALYSIS_COUNTABLE_LOOP_PARSER_H 16 #define COMPILER_OPTIMIZER_ANALYSIS_COUNTABLE_LOOP_PARSER_H 17 18 #include "optimizer/ir/inst.h" 19 20 namespace panda::compiler { 21 class Loop; 22 23 /** 24 * Example of code 25 * --------------- 26 * for (init(a); if_imm(compare(a,test)); update(a)) {...} 27 */ 28 struct CountableLoopInfo { 29 Inst *ifImm; 30 Inst *init; 31 Inst *test; 32 Inst *update; 33 Inst *index; 34 uint64_t constStep; 35 ConditionCode normalizedCc; // cc between `update` and `test` 36 bool isInc; 37 }; 38 39 /// Helper class to check if loop is countable and to get its parameters 40 class CountableLoopParser { 41 public: CountableLoopParser(const Loop & loop)42 explicit CountableLoopParser(const Loop &loop) : loop_(loop) {} 43 44 NO_MOVE_SEMANTIC(CountableLoopParser); 45 NO_COPY_SEMANTIC(CountableLoopParser); 46 ~CountableLoopParser() = default; 47 48 std::optional<CountableLoopInfo> Parse(); 49 static bool HasPreHeaderCompare(Loop *loop, const CountableLoopInfo &loopInfo); 50 static std::optional<uint64_t> GetLoopIterations(const CountableLoopInfo &loopInfo); 51 52 private: 53 bool IsInstIncOrDec(Inst *inst); 54 bool SetUpdateAndTestInputs(); 55 void SetIndexAndConstStep(); 56 void SetNormalizedConditionCode(); 57 bool IsConditionCodeAcceptable(); 58 BasicBlock *FindLoopExitBlock(); 59 bool CheckParsingLoopCorrectness(); 60 bool TryProcessBackEdge(); 61 62 private: 63 const Loop &loop_; 64 CountableLoopInfo loopInfo_ {}; 65 bool isHeadLoopExit_ = false; 66 }; 67 } // namespace panda::compiler 68 69 #endif // COMPILER_OPTIMIZER_ANALYSIS_COUNTABLE_LOOP_PARSER_H 70