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 79