2 files changed, 46 insertions, 21 deletions

diff --git a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
index 24af7c463f4..7de2c1cc8d5 100644
--- a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
@@ -1037,3 +1037,40 @@ Value *llvm::emitFWrite(Value *Ptr, Value *Size, Value *File, IRBuilder<> &B,
     CI->setCallingConv(Fn->getCallingConv());
   return CI;
 }
+
+Value *llvm::emitMalloc(Value *Num, 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, Num, "malloc");
+
+  if (const Function *F = dyn_cast<Function>(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);
+  inferLibFuncAttributes(*M->getFunction("calloc"), TLI);
+  CallInst *CI = B.CreateCall(Calloc, {Num, Size}, "calloc");
+
+  if (const auto *F = dyn_cast<Function>(Calloc->stripPointerCasts()))
+    CI->setCallingConv(F->getCallingConv());
+
+  return CI;
+}
diff --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
index 6c68b88adc6..e65ecc55c83 100644
--- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -811,27 +811,6 @@ Value *LibCallSimplifier::optimizeMemMove(CallInst *CI, IRBuilder<> &B) {
   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<Function>(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 @@ Value *LibCallSimplifier::optimizeMemSet(CallInst *CI, IRBuilder<> &B) {
   return CI->getArgOperand(0);
 }
 
+Value *LibCallSimplifier::optimizeRealloc(CallInst *CI, IRBuilder<> &B) {
+  if (isa<ConstantPointerNull>(CI->getArgOperand(0)))
+    return emitMalloc(CI->getArgOperand(1), B, DL, TLI);
+
+  return nullptr;
+}
+
 //===----------------------------------------------------------------------===//
 // Math Library Optimizations
 //===----------------------------------------------------------------------===//
@@ -2080,6 +2066,8 @@ Value *LibCallSimplifier::optimizeStringMemoryLibCall(CallInst *CI,
       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: