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 LoopInfo; 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, DominatorTree *DT, 61 LoopInfo *LI, SmallVectorImpl<WeakVH> &Dead, 62 IVVisitor *V = nullptr); 63 64 /// SimplifyLoopIVs - Simplify users of induction variables within this 65 /// loop. This does not actually change or add IVs. 66 bool simplifyLoopIVs(Loop *L, ScalarEvolution *SE, DominatorTree *DT, 67 LoopInfo *LI, SmallVectorImpl<WeakVH> &Dead); 68 69 } // namespace llvm 70 71 #endif 72
