Line data    Source code

       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             : public:
      32       13317 :   InstCombineWorklist() = default;
      33             : 
      34        1324 :   InstCombineWorklist(InstCombineWorklist &&) = default;
      35             :   InstCombineWorklist &operator=(InstCombineWorklist &&) = default;
      36             : 
      37    28533011 :   bool isEmpty() const { return Worklist.empty(); }
      38             : 
      39             :   /// Add - Add the specified instruction to the worklist if it isn't already
      40             :   /// in it.
      41     1218418 :   void Add(Instruction *I) {
      42     1218418 :     if (WorklistMap.insert(std::make_pair(I, Worklist.size())).second) {
      43             :       LLVM_DEBUG(dbgs() << "IC: ADD: " << *I << '\n');
      44      834222 :       Worklist.push_back(I);
      45             :     }
      46     1218418 :   }
      47             : 
      48             :   void AddValue(Value *V) {
      49             :     if (Instruction *I = dyn_cast<Instruction>(V))
      50          21 :       Add(I);
      51             :   }
      52             : 
      53             :   /// AddInitialGroup - Add the specified batch of stuff in reverse order.
      54             :   /// which should only be done when the worklist is empty and when the group
      55             :   /// has no duplicates.
      56      334019 :   void AddInitialGroup(ArrayRef<Instruction *> List) {
      57             :     assert(Worklist.empty() && "Worklist must be empty to add initial group");
      58      334019 :     Worklist.reserve(List.size()+16);
      59      334019 :     WorklistMap.reserve(List.size());
      60             :     LLVM_DEBUG(dbgs() << "IC: ADDING: " << List.size()
      61             :                       << " instrs to worklist\n");
      62             :     unsigned Idx = 0;
      63    27698789 :     for (Instruction *I : reverse(List)) {
      64    27364770 :       WorklistMap.insert(std::make_pair(I, Idx++));
      65    27364770 :       Worklist.push_back(I);
      66             :     }
      67      334019 :   }
      68             : 
      69             :   // Remove - remove I from the worklist if it exists.
      70      245317 :   void Remove(Instruction *I) {
      71      245317 :     DenseMap<Instruction*, unsigned>::iterator It = WorklistMap.find(I);
      72      245317 :     if (It == WorklistMap.end()) return; // Not in worklist.
      73             : 
      74             :     // Don't bother moving everything down, just null out the slot.
      75       27032 :     Worklist[It->second] = nullptr;
      76             : 
      77             :     WorklistMap.erase(It);
      78             :   }
      79             : 
      80    28198992 :   Instruction *RemoveOne() {
      81    28198992 :     Instruction *I = Worklist.pop_back_val();
      82    28198992 :     WorklistMap.erase(I);
      83    28198992 :     return I;
      84             :   }
      85             : 
      86             :   /// AddUsersToWorkList - When an instruction is simplified, add all users of
      87             :   /// the instruction to the work lists because they might get more simplified
      88             :   /// now.
      89             :   ///
      90      436479 :   void AddUsersToWorkList(Instruction &I) {
      91      826633 :     for (User *U : I.users())
      92      390154 :       Add(cast<Instruction>(U));
      93      436479 :   }
      94             : 
      95             : 
      96             :   /// Zap - check that the worklist is empty and nuke the backing store for
      97             :   /// the map if it is large.
      98             :   void Zap() {
      99             :     assert(WorklistMap.empty() && "Worklist empty, but map not?");
     100             : 
     101             :     // Do an explicit clear, this shrinks the map if needed.
     102      334019 :     WorklistMap.clear();
     103             :   }
     104             : };
     105             : 
     106             : } // end namespace llvm.
     107             : 
     108             : #undef DEBUG_TYPE
     109             : 
     110             : #endif