1//===---- MemCpyOptimizer.h - memcpy optimization ---------------*- 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 pass performs various transformations related to eliminating memcpy
11// calls, or transforming sets of stores into memset's.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_TRANSFORMS_SCALAR_MEMCPYOPTIMIZER_H
16#define LLVM_TRANSFORMS_SCALAR_MEMCPYOPTIMIZER_H
17
18#include "llvm/ADT/STLExtras.h"
19#include "llvm/Analysis/AliasAnalysis.h"
20#include "llvm/Analysis/AssumptionCache.h"
21#include "llvm/Analysis/GlobalsModRef.h"
22#include "llvm/Analysis/MemoryDependenceAnalysis.h"
23#include "llvm/Analysis/TargetLibraryInfo.h"
24#include "llvm/IR/Dominators.h"
25#include "llvm/IR/Function.h"
26#include "llvm/IR/Instructions.h"
27#include "llvm/IR/IntrinsicInst.h"
28#include "llvm/IR/PassManager.h"
29
30namespace llvm {
31
32class MemCpyOptPass : public PassInfoMixin<MemCpyOptPass> {
33  MemoryDependenceResults *MD = nullptr;
34  TargetLibraryInfo *TLI = nullptr;
35  std::function<AliasAnalysis &()> LookupAliasAnalysis;
36  std::function<AssumptionCache &()> LookupAssumptionCache;
37  std::function<DominatorTree &()> LookupDomTree;
38
39public:
40  MemCpyOptPass() {}
41  PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
42  // Glue for the old PM.
43  bool runImpl(Function &F, MemoryDependenceResults *MD_,
44               TargetLibraryInfo *TLI_,
45               std::function<AliasAnalysis &()> LookupAliasAnalysis_,
46               std::function<AssumptionCache &()> LookupAssumptionCache_,
47               std::function<DominatorTree &()> LookupDomTree_);
48
49private:
50  // Helper functions
51  bool processStore(StoreInst *SI, BasicBlock::iterator &BBI);
52  bool processMemSet(MemSetInst *SI, BasicBlock::iterator &BBI);
53  bool processMemCpy(MemCpyInst *M);
54  bool processMemMove(MemMoveInst *M);
55  bool performCallSlotOptzn(Instruction *cpy, Value *cpyDst, Value *cpySrc,
56                            uint64_t cpyLen, unsigned cpyAlign, CallInst *C);
57  bool processMemCpyMemCpyDependence(MemCpyInst *M, MemCpyInst *MDep);
58  bool processMemSetMemCpyDependence(MemCpyInst *M, MemSetInst *MDep);
59  bool performMemCpyToMemSetOptzn(MemCpyInst *M, MemSetInst *MDep);
60  bool processByValArgument(CallSite CS, unsigned ArgNo);
61  Instruction *tryMergingIntoMemset(Instruction *I, Value *StartPtr,
62                                    Value *ByteVal);
63
64  bool iterateOnFunction(Function &F);
65};
66}
67
68#endif // LLVM_TRANSFORMS_SCALAR_MEMCPYOPTIMIZER_H
69