include/llvm/Transforms/Scalar/MemCpyOptimizer.h

   1 //===- MemCpyOptimizer.h - memcpy optimization ------------------*- 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 pass performs various transformations related to eliminating memcpy
  10 // calls, or transforming sets of stores into memset's.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef LLVM_TRANSFORMS_SCALAR_MEMCPYOPTIMIZER_H
  15 #define LLVM_TRANSFORMS_SCALAR_MEMCPYOPTIMIZER_H
  16
  17 #include "llvm/Analysis/AliasAnalysis.h"
  18 #include "llvm/IR/BasicBlock.h"
  19 #include "llvm/IR/CallSite.h"
  20 #include "llvm/IR/PassManager.h"
  21 #include <cstdint>
  22 #include <functional>
  23
  24 namespace llvm {
  25
  26 class AssumptionCache;
  27 class CallInst;
  28 class DominatorTree;
  29 class Function;
  30 class Instruction;
  31 class MemCpyInst;
  32 class MemMoveInst;
  33 class MemoryDependenceResults;
  34 class MemSetInst;
  35 class StoreInst;
  36 class TargetLibraryInfo;
  37 class Value;
  38
  39 class MemCpyOptPass : public PassInfoMixin<MemCpyOptPass> {
  40   MemoryDependenceResults *MD = nullptr;
  41   TargetLibraryInfo *TLI = nullptr;
  42   std::function<AliasAnalysis &()> LookupAliasAnalysis;
  43   std::function<AssumptionCache &()> LookupAssumptionCache;
  44   std::function<DominatorTree &()> LookupDomTree;
  45
  46 public:
  47   MemCpyOptPass() = default;
  48
  49   PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
  50
  51   // Glue for the old PM.
  52   bool runImpl(Function &F, MemoryDependenceResults *MD_,
  53                TargetLibraryInfo *TLI_,
  54                std::function<AliasAnalysis &()> LookupAliasAnalysis_,
  55                std::function<AssumptionCache &()> LookupAssumptionCache_,
  56                std::function<DominatorTree &()> LookupDomTree_);
  57
  58 private:
  59   // Helper functions
  60   bool processStore(StoreInst *SI, BasicBlock::iterator &BBI);
  61   bool processMemSet(MemSetInst *SI, BasicBlock::iterator &BBI);
  62   bool processMemCpy(MemCpyInst *M);
  63   bool processMemMove(MemMoveInst *M);
  64   bool performCallSlotOptzn(Instruction *cpy, Value *cpyDst, Value *cpySrc,
  65                             uint64_t cpyLen, unsigned cpyAlign, CallInst *C);
  66   bool processMemCpyMemCpyDependence(MemCpyInst *M, MemCpyInst *MDep);
  67   bool processMemSetMemCpyDependence(MemCpyInst *M, MemSetInst *MDep);
  68   bool performMemCpyToMemSetOptzn(MemCpyInst *M, MemSetInst *MDep);
  69   bool processByValArgument(CallSite CS, unsigned ArgNo);
  70   Instruction *tryMergingIntoMemset(Instruction *I, Value *StartPtr,
  71                                     Value *ByteVal);
  72
  73   bool iterateOnFunction(Function &F);
  74 };
  75
  76 } // end namespace llvm
  77
  78 #endif // LLVM_TRANSFORMS_SCALAR_MEMCPYOPTIMIZER_H