1 //===- InstCombineWorklist.h - Worklist for InstCombine pass ----*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef LLVM_TRANSFORMS_INSTCOMBINE_INSTCOMBINEWORKLIST_H 11 #define LLVM_TRANSFORMS_INSTCOMBINE_INSTCOMBINEWORKLIST_H 12 13 #include "llvm/ADT/DenseMap.h" 14 #include "llvm/ADT/STLExtras.h" 15 #include "llvm/ADT/SmallVector.h" 16 #include "llvm/IR/Instruction.h" 17 #include "llvm/Support/Compiler.h" 18 #include "llvm/Support/Debug.h" 19 #include "llvm/Support/raw_ostream.h" 20 21 #define DEBUG_TYPE "instcombine" 22 23 namespace llvm { 24 25 /// InstCombineWorklist - This is the worklist management logic for 26 /// InstCombine. 27 class InstCombineWorklist { 28 SmallVector<Instruction*, 256> Worklist; 29 DenseMap<Instruction*, unsigned> WorklistMap; 30 31 void operator=(const InstCombineWorklist&RHS) = delete; 32 InstCombineWorklist(const InstCombineWorklist&) = delete; 33 public: 34 InstCombineWorklist() {} 35 36 InstCombineWorklist(InstCombineWorklist &&Arg) 37 : Worklist(std::move(Arg.Worklist)), 38 WorklistMap(std::move(Arg.WorklistMap)) {} 39 InstCombineWorklist &operator=(InstCombineWorklist &&RHS) { 40 Worklist = std::move(RHS.Worklist); 41 WorklistMap = std::move(RHS.WorklistMap); 42 return *this; 43 } 44 45 bool isEmpty() const { return Worklist.empty(); } 46 47 /// Add - Add the specified instruction to the worklist if it isn't already 48 /// in it. 49 void Add(Instruction *I) { 50 if (WorklistMap.insert(std::make_pair(I, Worklist.size())).second) { 51 DEBUG(dbgs() << "IC: ADD: " << *I << '\n'); 52 Worklist.push_back(I); 53 } 54 } 55 56 void AddValue(Value *V) { 57 if (Instruction *I = dyn_cast<Instruction>(V)) 58 Add(I); 59 } 60 61 /// AddInitialGroup - Add the specified batch of stuff in reverse order. 62 /// which should only be done when the worklist is empty and when the group 63 /// has no duplicates. 64 void AddInitialGroup(ArrayRef<Instruction *> List) { 65 assert(Worklist.empty() && "Worklist must be empty to add initial group"); 66 Worklist.reserve(List.size()+16); 67 WorklistMap.reserve(List.size()); 68 DEBUG(dbgs() << "IC: ADDING: " << List.size() << " instrs to worklist\n"); 69 unsigned Idx = 0; 70 for (Instruction *I : reverse(List)) { 71 WorklistMap.insert(std::make_pair(I, Idx++)); 72 Worklist.push_back(I); 73 } 74 } 75 76 // Remove - remove I from the worklist if it exists. 77 void Remove(Instruction *I) { 78 DenseMap<Instruction*, unsigned>::iterator It = WorklistMap.find(I); 79 if (It == WorklistMap.end()) return; // Not in worklist. 80 81 // Don't bother moving everything down, just null out the slot. 82 Worklist[It->second] = nullptr; 83 84 WorklistMap.erase(It); 85 } 86 87 Instruction *RemoveOne() { 88 Instruction *I = Worklist.pop_back_val(); 89 WorklistMap.erase(I); 90 return I; 91 } 92 93 /// AddUsersToWorkList - When an instruction is simplified, add all users of 94 /// the instruction to the work lists because they might get more simplified 95 /// now. 96 /// 97 void AddUsersToWorkList(Instruction &I) { 98 for (User *U : I.users()) 99 Add(cast<Instruction>(U)); 100 } 101 102 103 /// Zap - check that the worklist is empty and nuke the backing store for 104 /// the map if it is large. 105 void Zap() { 106 assert(WorklistMap.empty() && "Worklist empty, but map not?"); 107 108 // Do an explicit clear, this shrinks the map if needed. 109 WorklistMap.clear(); 110 } 111 }; 112 113 } // end namespace llvm. 114 115 #undef DEBUG_TYPE 116 117 #endif 118
