InstCombineWorklist.h revision 309124
1228753Smm//===- InstCombineWorklist.h - Worklist for InstCombine pass ----*- C++ -*-===// 2228753Smm// 3228753Smm// The LLVM Compiler Infrastructure 4228753Smm// 5228753Smm// This file is distributed under the University of Illinois Open Source 6228753Smm// License. See LICENSE.TXT for details. 7228753Smm// 8228753Smm//===----------------------------------------------------------------------===// 9228753Smm 10228753Smm#ifndef LLVM_TRANSFORMS_INSTCOMBINE_INSTCOMBINEWORKLIST_H 11228753Smm#define LLVM_TRANSFORMS_INSTCOMBINE_INSTCOMBINEWORKLIST_H 12228753Smm 13228753Smm#include "llvm/ADT/DenseMap.h" 14228753Smm#include "llvm/ADT/STLExtras.h" 15228753Smm#include "llvm/ADT/SmallVector.h" 16228753Smm#include "llvm/IR/Instruction.h" 17228753Smm#include "llvm/Support/Compiler.h" 18228753Smm#include "llvm/Support/Debug.h" 19228753Smm#include "llvm/Support/raw_ostream.h" 20228753Smm 21228753Smm#define DEBUG_TYPE "instcombine" 22228753Smm 23228753Smmnamespace llvm { 24228753Smm 25228753Smm/// InstCombineWorklist - This is the worklist management logic for 26228753Smm/// InstCombine. 27228753Smmclass InstCombineWorklist { 28228753Smm SmallVector<Instruction*, 256> Worklist; 29228753Smm DenseMap<Instruction*, unsigned> WorklistMap; 30228753Smm 31228753Smm void operator=(const InstCombineWorklist&RHS) = delete; 32228753Smm InstCombineWorklist(const InstCombineWorklist&) = delete; 33228753Smmpublic: 34228753Smm InstCombineWorklist() {} 35228753Smm 36228753Smm InstCombineWorklist(InstCombineWorklist &&Arg) 37228753Smm : Worklist(std::move(Arg.Worklist)), 38228753Smm WorklistMap(std::move(Arg.WorklistMap)) {} 39228753Smm InstCombineWorklist &operator=(InstCombineWorklist &&RHS) { 40228753Smm Worklist = std::move(RHS.Worklist); 41228753Smm WorklistMap = std::move(RHS.WorklistMap); 42228753Smm return *this; 43228753Smm } 44228753Smm 45228753Smm bool isEmpty() const { return Worklist.empty(); } 46228753Smm 47228753Smm /// Add - Add the specified instruction to the worklist if it isn't already 48228753Smm /// in it. 49228753Smm void Add(Instruction *I) { 50228753Smm if (WorklistMap.insert(std::make_pair(I, Worklist.size())).second) { 51228753Smm DEBUG(dbgs() << "IC: ADD: " << *I << '\n'); 52228753Smm Worklist.push_back(I); 53228753Smm } 54228753Smm } 55228753Smm 56228753Smm void AddValue(Value *V) { 57228753Smm if (Instruction *I = dyn_cast<Instruction>(V)) 58228753Smm Add(I); 59228753Smm } 60228753Smm 61228753Smm /// AddInitialGroup - Add the specified batch of stuff in reverse order. 62228753Smm /// which should only be done when the worklist is empty and when the group 63228753Smm /// has no duplicates. 64228753Smm void AddInitialGroup(ArrayRef<Instruction *> List) { 65228753Smm assert(Worklist.empty() && "Worklist must be empty to add initial group"); 66228753Smm Worklist.reserve(List.size()+16); 67228753Smm WorklistMap.reserve(List.size()); 68228753Smm DEBUG(dbgs() << "IC: ADDING: " << List.size() << " instrs to worklist\n"); 69228753Smm unsigned Idx = 0; 70228753Smm for (Instruction *I : reverse(List)) { 71228753Smm WorklistMap.insert(std::make_pair(I, Idx++)); 72228753Smm Worklist.push_back(I); 73228753Smm } 74228753Smm } 75228753Smm 76228753Smm // Remove - remove I from the worklist if it exists. 77228753Smm void Remove(Instruction *I) { 78228753Smm DenseMap<Instruction*, unsigned>::iterator It = WorklistMap.find(I); 79228753Smm if (It == WorklistMap.end()) return; // Not in worklist. 80228753Smm 81228753Smm // Don't bother moving everything down, just null out the slot. 82228753Smm Worklist[It->second] = nullptr; 83228753Smm 84228753Smm 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