src/llvm/include/llvm/Transforms/Utils/SimplifyIndVar.h

   1 //===-- llvm/Transforms/Utils/SimplifyIndVar.h - Indvar Utils ---*- 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 // This file defines in interface for induction variable simplification. It does
  11 // not define any actual pass or policy, but provides a single function to
  12 // simplify a loop's induction variables based on ScalarEvolution.
  13 //
  14 //===----------------------------------------------------------------------===//
  15
  16 #ifndef LLVM_TRANSFORMS_UTILS_SIMPLIFYINDVAR_H
  17 #define LLVM_TRANSFORMS_UTILS_SIMPLIFYINDVAR_H
  18
  19 #include "llvm/IR/ValueHandle.h"
  20 #include "llvm/Support/CommandLine.h"
  21
  22 namespace llvm {
  23
  24 class CastInst;
  25 class DominatorTree;
  26 class IVUsers;
  27 class Loop;
  28 class LPPassManager;
  29 class PHINode;
  30 class ScalarEvolution;
  31
  32 /// Interface for visiting interesting IV users that are recognized but not
  33 /// simplified by this utility.
  34 class IVVisitor {
  35 protected:
  36   const DominatorTree *DT;
  37   bool ShouldSplitOverflowIntrinsics;
  38
  39   virtual void anchor();
  40
  41 public:
  42   IVVisitor(): DT(nullptr), ShouldSplitOverflowIntrinsics(false) {}
  43   virtual ~IVVisitor() {}
  44
  45   const DominatorTree *getDomTree() const { return DT; }
  46
  47   bool shouldSplitOverflowInstrinsics() const {
  48     return ShouldSplitOverflowIntrinsics;
  49   }
  50   void setSplitOverflowIntrinsics() {
  51     ShouldSplitOverflowIntrinsics = true;
  52     assert(DT && "Splitting overflow intrinsics requires a DomTree.");
  53   }
  54
  55   virtual void visitCast(CastInst *Cast) = 0;
  56 };
  57
  58 /// simplifyUsersOfIV - Simplify instructions that use this induction variable
  59 /// by using ScalarEvolution to analyze the IV's recurrence.
  60 bool simplifyUsersOfIV(PHINode *CurrIV, ScalarEvolution *SE, LPPassManager *LPM,
  61                        SmallVectorImpl<WeakVH> &Dead, IVVisitor *V = nullptr);
  62
  63 /// SimplifyLoopIVs - Simplify users of induction variables within this
  64 /// loop. This does not actually change or add IVs.
  65 bool simplifyLoopIVs(Loop *L, ScalarEvolution *SE, LPPassManager *LPM,
  66                      SmallVectorImpl<WeakVH> &Dead);
  67
  68 } // namespace llvm
  69
  70 #endif