Transforms/Scalar/MemCpyOptimizer.h

0001 //===- MemCpyOptimizer.h - memcpy optimization ------------------*- C++ -*-===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008 //
0009 // This pass performs various transformations related to eliminating memcpy
0010 // calls, or transforming sets of stores into memset's.
0011 //
0012 //===----------------------------------------------------------------------===//
0013
0014 #ifndef LLVM_TRANSFORMS_SCALAR_MEMCPYOPTIMIZER_H
0015 #define LLVM_TRANSFORMS_SCALAR_MEMCPYOPTIMIZER_H
0016
0017 #include "llvm/IR/BasicBlock.h"
0018 #include "llvm/IR/PassManager.h"
0019
0020 namespace llvm {
0021
0022 class AAResults;
0023 class AllocaInst;
0024 class BatchAAResults;
0025 class AssumptionCache;
0026 class CallBase;
0027 class CallInst;
0028 class DominatorTree;
0029 class EarliestEscapeAnalysis;
0030 class Function;
0031 class Instruction;
0032 class LoadInst;
0033 class MemCpyInst;
0034 class MemMoveInst;
0035 class MemorySSA;
0036 class MemorySSAUpdater;
0037 class MemSetInst;
0038 class PostDominatorTree;
0039 class StoreInst;
0040 class TargetLibraryInfo;
0041 class TypeSize;
0042 class Value;
0043
0044 class MemCpyOptPass : public PassInfoMixin<MemCpyOptPass> {
0045   TargetLibraryInfo *TLI = nullptr;
0046   AAResults *AA = nullptr;
0047   AssumptionCache *AC = nullptr;
0048   DominatorTree *DT = nullptr;
0049   PostDominatorTree *PDT = nullptr;
0050   MemorySSA *MSSA = nullptr;
0051   MemorySSAUpdater *MSSAU = nullptr;
0052   EarliestEscapeAnalysis *EEA = nullptr;
0053
0054 public:
0055   MemCpyOptPass() = default;
0056
0057   PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
0058
0059   // Glue for the old PM.
0060   bool runImpl(Function &F, TargetLibraryInfo *TLI, AAResults *AA,
0061                AssumptionCache *AC, DominatorTree *DT, PostDominatorTree *PDT,
0062                MemorySSA *MSSA);
0063
0064 private:
0065   // Helper functions
0066   bool processStore(StoreInst *SI, BasicBlock::iterator &BBI);
0067   bool processStoreOfLoad(StoreInst *SI, LoadInst *LI, const DataLayout &DL,
0068                           BasicBlock::iterator &BBI);
0069   bool processMemSet(MemSetInst *SI, BasicBlock::iterator &BBI);
0070   bool processMemCpy(MemCpyInst *M, BasicBlock::iterator &BBI);
0071   bool processMemMove(MemMoveInst *M, BasicBlock::iterator &BBI);
0072   bool performCallSlotOptzn(Instruction *cpyLoad, Instruction *cpyStore,
0073                             Value *cpyDst, Value *cpySrc, TypeSize cpyLen,
0074                             Align cpyAlign, BatchAAResults &BAA,
0075                             std::function<CallInst *()> GetC);
0076   bool processMemCpyMemCpyDependence(MemCpyInst *M, MemCpyInst *MDep,
0077                                      BatchAAResults &BAA);
0078   bool processMemSetMemCpyDependence(MemCpyInst *MemCpy, MemSetInst *MemSet,
0079                                      BatchAAResults &BAA);
0080   bool performMemCpyToMemSetOptzn(MemCpyInst *MemCpy, MemSetInst *MemSet,
0081                                   BatchAAResults &BAA);
0082   bool processByValArgument(CallBase &CB, unsigned ArgNo);
0083   bool processImmutArgument(CallBase &CB, unsigned ArgNo);
0084   Instruction *tryMergingIntoMemset(Instruction *I, Value *StartPtr,
0085                                     Value *ByteVal);
0086   bool moveUp(StoreInst *SI, Instruction *P, const LoadInst *LI);
0087   bool performStackMoveOptzn(Instruction *Load, Instruction *Store,
0088                              AllocaInst *DestAlloca, AllocaInst *SrcAlloca,
0089                              TypeSize Size, BatchAAResults &BAA);
0090   bool isMemMoveMemSetDependency(MemMoveInst *M);
0091
0092   void eraseInstruction(Instruction *I);
0093   bool iterateOnFunction(Function &F);
0094 };
0095
0096 } // end namespace llvm
0097
0098 #endif // LLVM_TRANSFORMS_SCALAR_MEMCPYOPTIMIZER_H