| //===-- llvm/Transforms/Utils/SimplifyIndVar.h - Indvar Utils ---*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file defines in interface for induction variable simplification. It does |
| // not define any actual pass or policy, but provides a single function to |
| // simplify a loop's induction variables based on ScalarEvolution. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_TRANSFORMS_UTILS_SIMPLIFYINDVAR_H |
| #define LLVM_TRANSFORMS_UTILS_SIMPLIFYINDVAR_H |
| |
| #include "llvm/Analysis/ScalarEvolutionExpressions.h" |
| #include "llvm/IR/ConstantRange.h" |
| #include "llvm/IR/ValueHandle.h" |
| |
| namespace llvm { |
| |
| class CastInst; |
| class DominatorTree; |
| class Loop; |
| class LoopInfo; |
| class PHINode; |
| class ScalarEvolution; |
| class SCEVExpander; |
| class TargetTransformInfo; |
| |
| /// Interface for visiting interesting IV users that are recognized but not |
| /// simplified by this utility. |
| class IVVisitor { |
| protected: |
| const DominatorTree *DT = nullptr; |
| |
| virtual void anchor(); |
| |
| public: |
| IVVisitor() = default; |
| virtual ~IVVisitor() = default; |
| |
| const DominatorTree *getDomTree() const { return DT; } |
| virtual void visitCast(CastInst *Cast) = 0; |
| }; |
| |
| /// simplifyUsersOfIV - Simplify instructions that use this induction variable |
| /// by using ScalarEvolution to analyze the IV's recurrence. |
| bool simplifyUsersOfIV(PHINode *CurrIV, ScalarEvolution *SE, DominatorTree *DT, |
| LoopInfo *LI, const TargetTransformInfo *TTI, |
| SmallVectorImpl<WeakTrackingVH> &Dead, |
| SCEVExpander &Rewriter, IVVisitor *V = nullptr); |
| |
| /// SimplifyLoopIVs - Simplify users of induction variables within this |
| /// loop. This does not actually change or add IVs. |
| bool simplifyLoopIVs(Loop *L, ScalarEvolution *SE, DominatorTree *DT, |
| LoopInfo *LI, const TargetTransformInfo *TTI, |
| SmallVectorImpl<WeakTrackingVH> &Dead); |
| |
| /// Collect information about induction variables that are used by sign/zero |
| /// extend operations. This information is recorded by CollectExtend and provides |
| /// the input to WidenIV. |
| struct WideIVInfo { |
| PHINode *NarrowIV = nullptr; |
| |
| // Widest integer type created [sz]ext |
| Type *WidestNativeType = nullptr; |
| |
| // Was a sext user seen before a zext? |
| bool IsSigned = false; |
| }; |
| |
| /// Widen Induction Variables - Extend the width of an IV to cover its |
| /// widest uses. |
| PHINode *createWideIV(const WideIVInfo &WI, |
| LoopInfo *LI, ScalarEvolution *SE, SCEVExpander &Rewriter, |
| DominatorTree *DT, SmallVectorImpl<WeakTrackingVH> &DeadInsts, |
| unsigned &NumElimExt, unsigned &NumWidened, |
| bool HasGuards, bool UsePostIncrementRanges); |
| |
| } // end namespace llvm |
| |
| #endif // LLVM_TRANSFORMS_UTILS_SIMPLIFYINDVAR_H |