Index: include/llvm/Transforms/Utils/BuildLibCalls.h =================================================================== --- include/llvm/Transforms/Utils/BuildLibCalls.h +++ include/llvm/Transforms/Utils/BuildLibCalls.h @@ -120,6 +120,14 @@ /// Size is an 'intptr_t', and File is a pointer to FILE. Value *emitFWrite(Value *Ptr, Value *Size, Value *File, IRBuilder<> &B, const DataLayout &DL, const TargetLibraryInfo *TLI); + + /// Emit a call to the malloc function. + Value *emitMalloc(Value *Len, IRBuilder<> &B, const DataLayout &DL, + const TargetLibraryInfo *TLI); + + /// Emit a call to the calloc function. + Value *emitCalloc(Value *Num, Value *Size, const AttributeList &Attrs, + IRBuilder<> &B, const TargetLibraryInfo &TLI); } #endif Index: include/llvm/Transforms/Utils/SimplifyLibCalls.h =================================================================== --- include/llvm/Transforms/Utils/SimplifyLibCalls.h +++ include/llvm/Transforms/Utils/SimplifyLibCalls.h @@ -124,6 +124,7 @@ Value *optimizeMemCpy(CallInst *CI, IRBuilder<> &B); Value *optimizeMemMove(CallInst *CI, IRBuilder<> &B); Value *optimizeMemSet(CallInst *CI, IRBuilder<> &B); + Value *optimizeRealloc(CallInst *CI, IRBuilder<> &B); Value *optimizeWcslen(CallInst *CI, IRBuilder<> &B); // Wrapper for all String/Memory Library Call Optimizations Value *optimizeStringMemoryLibCall(CallInst *CI, IRBuilder<> &B); Index: lib/Transforms/Utils/BuildLibCalls.cpp =================================================================== --- lib/Transforms/Utils/BuildLibCalls.cpp +++ lib/Transforms/Utils/BuildLibCalls.cpp @@ -1037,3 +1037,39 @@ CI->setCallingConv(Fn->getCallingConv()); return CI; } + +Value *llvm::emitMalloc(Value *Len, IRBuilder<> &B, const DataLayout &DL, + const TargetLibraryInfo *TLI) { + if (!TLI->has(LibFunc_malloc)) + return nullptr; + + Module *M = B.GetInsertBlock()->getModule(); + LLVMContext &Context = B.GetInsertBlock()->getContext(); + Value *Malloc = M->getOrInsertFunction("malloc", B.getInt8PtrTy(), + DL.getIntPtrType(Context)); + inferLibFuncAttributes(*M->getFunction("malloc"), *TLI); + CallInst *CI = B.CreateCall(Malloc, Len, "malloc"); + + if (const Function *F = dyn_cast(Malloc->stripPointerCasts())) + CI->setCallingConv(F->getCallingConv()); + + return CI; +} + +Value *llvm::emitCalloc(Value *Num, Value *Size, const AttributeList &Attrs, + IRBuilder<> &B, const TargetLibraryInfo &TLI) { + if (!TLI->has(LibFunc_calloc) + return nullptr; + + Module *M = B.GetInsertBlock()->getModule(); + const DataLayout &DL = M->getDataLayout(); + IntegerType *PtrType = DL.getIntPtrType((B.GetInsertBlock()->getContext())); + Value *Calloc = M->getOrInsertFunction("calloc", Attrs, B.getInt8PtrTy(), + PtrType, PtrType); + CallInst *CI = B.CreateCall(Calloc, {Num, Size}, "calloc"); + + if (const auto *F = dyn_cast(Calloc->stripPointerCasts())) + CI->setCallingConv(F->getCallingConv()); + + return CI; +} Index: lib/Transforms/Utils/SimplifyLibCalls.cpp =================================================================== --- lib/Transforms/Utils/SimplifyLibCalls.cpp +++ lib/Transforms/Utils/SimplifyLibCalls.cpp @@ -811,27 +811,6 @@ return CI->getArgOperand(0); } -// TODO: Does this belong in BuildLibCalls or should all of those similar -// functions be moved here? -static Value *emitCalloc(Value *Num, Value *Size, const AttributeList &Attrs, - IRBuilder<> &B, const TargetLibraryInfo &TLI) { - LibFunc Func; - if (!TLI.getLibFunc("calloc", Func) || !TLI.has(Func)) - return nullptr; - - Module *M = B.GetInsertBlock()->getModule(); - const DataLayout &DL = M->getDataLayout(); - IntegerType *PtrType = DL.getIntPtrType((B.GetInsertBlock()->getContext())); - Value *Calloc = M->getOrInsertFunction("calloc", Attrs, B.getInt8PtrTy(), - PtrType, PtrType); - CallInst *CI = B.CreateCall(Calloc, { Num, Size }, "calloc"); - - if (const auto *F = dyn_cast(Calloc->stripPointerCasts())) - CI->setCallingConv(F->getCallingConv()); - - return CI; -} - /// Fold memset[_chk](malloc(n), 0, n) --> calloc(1, n). static Value *foldMallocMemset(CallInst *Memset, IRBuilder<> &B, const TargetLibraryInfo &TLI) { @@ -889,6 +868,13 @@ return CI->getArgOperand(0); } +Value *LibCallSimplifier::optimizeRealloc(CallInst *CI, IRBuilder<> &B) { + if (isa(CI->getArgOperand(0))) + return emitMalloc(CI->getArgOperand(1), B, DL, TLI); + + return nullptr; +} + //===----------------------------------------------------------------------===// // Math Library Optimizations //===----------------------------------------------------------------------===// @@ -2080,6 +2066,8 @@ return optimizeMemMove(CI, Builder); case LibFunc_memset: return optimizeMemSet(CI, Builder); + case LibFunc_realloc: + return optimizeRealloc(CI, Builder); case LibFunc_wcslen: return optimizeWcslen(CI, Builder); default: Index: test/Transforms/InstCombine/realloc.ll =================================================================== --- /dev/null +++ test/Transforms/InstCombine/realloc.ll @@ -0,0 +1,24 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt < %s -instcombine -S | FileCheck %s + +declare i8* @realloc(i8*, i64) #1 +declare noalias i8* @malloc(i64) #1 + + +define i8* @realloc_null_ptr() #0 { +; CHECK-LABEL: @realloc_null_ptr( +; CHECK-NEXT: [[MALLOC:%.*]] = call i8* @malloc(i64 100) +; CHECK-NEXT: ret i8* [[MALLOC]] +; + %malloc = call i8* @malloc(i64 100) + ret i8* %malloc +} + +define i8* @realloc_unknown_ptr(i8* %ptr) #0 { +; CHECK-LABEL: @realloc_unknown_ptr( +; CHECK-NEXT: [[CALL:%.*]] = call i8* @realloc(i8* [[PTR:%.*]], i64 100) +; CHECK-NEXT: ret i8* [[CALL]] +; + %call = call i8* @realloc(i8* %ptr, i64 100) #2 + ret i8* %call +}