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 21 namespace llvm { 22 23 class CastInst; 24 class DominatorTree; 25 class Loop; 26 class LoopInfo; 27 class PHINode; 28 class ScalarEvolution; 29 class SCEVExpander; 30 31 /// Interface for visiting interesting IV users that are recognized but not 32 /// simplified by this utility. 33 class IVVisitor { 34 protected: 35 const DominatorTree *DT = nullptr; 36 37 virtual void anchor(); 38 39 public: 40 IVVisitor() = default; 41 virtual ~IVVisitor() = default; 42 43 const DominatorTree *getDomTree() const { return DT; } 44 virtual void visitCast(CastInst *Cast) = 0; 45 }; 46 47 /// simplifyUsersOfIV - Simplify instructions that use this induction variable 48 /// by using ScalarEvolution to analyze the IV's recurrence. 49 bool simplifyUsersOfIV(PHINode *CurrIV, ScalarEvolution *SE, DominatorTree *DT, 50 LoopInfo *LI, SmallVectorImpl<WeakTrackingVH> &Dead, 51 SCEVExpander &Rewriter, IVVisitor *V = nullptr); 52 53 /// SimplifyLoopIVs - Simplify users of induction variables within this 54 /// loop. This does not actually change or add IVs. 55 bool simplifyLoopIVs(Loop *L, ScalarEvolution *SE, DominatorTree *DT, 56 LoopInfo *LI, SmallVectorImpl<WeakTrackingVH> &Dead); 57 58 } // end namespace llvm 59 60 #endif // LLVM_TRANSFORMS_UTILS_SIMPLIFYINDVAR_H 61
