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