include/llvm/Transforms/Utils/SimplifyIndVar.h

   1 //===-- llvm/Transforms/Utils/SimplifyIndVar.h - Indvar Utils ---*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file defines in interface for induction variable simplification. It does
  10 // not define any actual pass or policy, but provides a single function to
  11 // simplify a loop's induction variables based on ScalarEvolution.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #ifndef LLVM_TRANSFORMS_UTILS_SIMPLIFYINDVAR_H
  16 #define LLVM_TRANSFORMS_UTILS_SIMPLIFYINDVAR_H
  17
  18 #include "llvm/IR/ValueHandle.h"
  19
  20 namespace llvm {
  21
  22 class CastInst;
  23 class DominatorTree;
  24 class Loop;
  25 class LoopInfo;
  26 class PHINode;
  27 class ScalarEvolution;
  28 class SCEVExpander;
  29
  30 /// Interface for visiting interesting IV users that are recognized but not
  31 /// simplified by this utility.
  32 class IVVisitor {
  33 protected:
  34   const DominatorTree *DT = nullptr;
  35
  36   virtual void anchor();
  37
  38 public:
  39   IVVisitor() = default;
  40   virtual ~IVVisitor() = default;
  41
  42   const DominatorTree *getDomTree() const { return DT; }
  43   virtual void visitCast(CastInst *Cast) = 0;
  44 };
  45
  46 /// simplifyUsersOfIV - Simplify instructions that use this induction variable
  47 /// by using ScalarEvolution to analyze the IV's recurrence.
  48 bool simplifyUsersOfIV(PHINode *CurrIV, ScalarEvolution *SE, DominatorTree *DT,
  49                        LoopInfo *LI, SmallVectorImpl<WeakTrackingVH> &Dead,
  50                        SCEVExpander &Rewriter, IVVisitor *V = nullptr);
  51
  52 /// SimplifyLoopIVs - Simplify users of induction variables within this
  53 /// loop. This does not actually change or add IVs.
  54 bool simplifyLoopIVs(Loop *L, ScalarEvolution *SE, DominatorTree *DT,
  55                      LoopInfo *LI, SmallVectorImpl<WeakTrackingVH> &Dead);
  56
  57 } // end namespace llvm
  58
  59 #endif // LLVM_TRANSFORMS_UTILS_SIMPLIFYINDVAR_H