Teach simplify libcall to transform __strcpy_chk to __memcpy_chk to enable optimizations down stream.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99282 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
index 22f3628..058cd3c 100644
--- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
@@ -49,10 +49,13 @@
Function *Caller;
const TargetData *TD;
LLVMContext* Context;
+ bool OptChkCall; // True if it's optimizing a *_chk libcall.
public:
- LibCallOptimization() { }
+ LibCallOptimization() : OptChkCall(false) { }
virtual ~LibCallOptimization() {}
+ void setOptChkCall(bool c) { OptChkCall = c; }
+
/// CallOptimizer - This pure virtual method is implemented by base classes to
/// do various optimizations. If this returns null then no transformation was
/// performed. If it returns CI, then it transformed the call and CI is to be
@@ -352,8 +355,10 @@
struct StrCpyOpt : public LibCallOptimization {
virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
// Verify the "strcpy" function prototype.
+ unsigned NumParams = OptChkCall ? 3 : 2;
const FunctionType *FT = Callee->getFunctionType();
- if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
+ if (FT->getNumParams() != NumParams ||
+ FT->getReturnType() != FT->getParamType(0) ||
FT->getParamType(0) != FT->getParamType(1) ||
FT->getParamType(0) != Type::getInt8PtrTy(*Context))
return 0;
@@ -371,8 +376,13 @@
// We have enough information to now generate the memcpy call to do the
// concatenation for us. Make a memcpy to copy the nul byte with align = 1.
- EmitMemCpy(Dst, Src,
- ConstantInt::get(TD->getIntPtrType(*Context), Len), 1, B, TD);
+ if (OptChkCall)
+ EmitMemCpyChk(Dst, Src,
+ ConstantInt::get(TD->getIntPtrType(*Context), Len),
+ CI->getOperand(3), B, TD);
+ else
+ EmitMemCpy(Dst, Src,
+ ConstantInt::get(TD->getIntPtrType(*Context), Len), 1, B, TD);
return Dst;
}
};
@@ -1162,7 +1172,8 @@
StringMap<LibCallOptimization*> Optimizations;
// String and Memory LibCall Optimizations
StrCatOpt StrCat; StrNCatOpt StrNCat; StrChrOpt StrChr; StrCmpOpt StrCmp;
- StrNCmpOpt StrNCmp; StrCpyOpt StrCpy; StrNCpyOpt StrNCpy; StrLenOpt StrLen;
+ StrNCmpOpt StrNCmp; StrCpyOpt StrCpy; StrCpyOpt StrCpyChk;
+ StrNCpyOpt StrNCpy; StrLenOpt StrLen;
StrToOpt StrTo; StrStrOpt StrStr;
MemCmpOpt MemCmp; MemCpyOpt MemCpy; MemMoveOpt MemMove; MemSetOpt MemSet;
// Math Library Optimizations
@@ -1228,6 +1239,10 @@
Optimizations["memmove"] = &MemMove;
Optimizations["memset"] = &MemSet;
+ // _chk variants of String and Memory LibCall Optimizations.
+ StrCpyChk.setOptChkCall(true);
+ Optimizations["__strcpy_chk"] = &StrCpyChk;
+
// Math Library Optimizations
Optimizations["powf"] = &Pow;
Optimizations["pow"] = &Pow;
diff --git a/lib/Transforms/Utils/BuildLibCalls.cpp b/lib/Transforms/Utils/BuildLibCalls.cpp
index 2e6edfa..0afccf4 100644
--- a/lib/Transforms/Utils/BuildLibCalls.cpp
+++ b/lib/Transforms/Utils/BuildLibCalls.cpp
@@ -108,7 +108,7 @@
/// EmitMemCpy - Emit a call to the memcpy function to the builder. This always
-/// expects that the size has type 'intptr_t' and Dst/Src are pointers.
+/// expects that Len has type 'intptr_t' and Dst/Src are pointers.
Value *llvm::EmitMemCpy(Value *Dst, Value *Src, Value *Len,
unsigned Align, IRBuilder<> &B, const TargetData *TD) {
Module *M = B.GetInsertBlock()->getParent()->getParent();
@@ -120,6 +120,30 @@
ConstantInt::get(B.getInt32Ty(), Align));
}
+/// EmitMemCpyChk - Emit a call to the __memcpy_chk function to the builder.
+/// This expects that the Len and ObjSize have type 'intptr_t' and Dst/Src
+/// are pointers.
+Value *llvm::EmitMemCpyChk(Value *Dst, Value *Src, Value *Len, Value *ObjSize,
+ IRBuilder<> &B, const TargetData *TD) {
+ Module *M = B.GetInsertBlock()->getParent()->getParent();
+ AttributeWithIndex AWI;
+ AWI = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
+ LLVMContext &Context = B.GetInsertBlock()->getContext();
+ Value *MemCpy = M->getOrInsertFunction("__memcpy_chk",
+ AttrListPtr::get(&AWI, 1),
+ B.getInt8PtrTy(),
+ B.getInt8PtrTy(),
+ B.getInt8PtrTy(),
+ TD->getIntPtrType(Context),
+ TD->getIntPtrType(Context), NULL);
+ Dst = CastToCStr(Dst, B);
+ Src = CastToCStr(Src, B);
+ CallInst *CI = B.CreateCall4(MemCpy, Dst, Src, Len, ObjSize);
+ if (const Function *F = dyn_cast<Function>(MemCpy->stripPointerCasts()))
+ CI->setCallingConv(F->getCallingConv());
+ return CI;
+}
+
/// EmitMemMove - Emit a call to the memmove function to the builder. This
/// always expects that the size has type 'intptr_t' and Dst/Src are pointers.
Value *llvm::EmitMemMove(Value *Dst, Value *Src, Value *Len,