Lower stpcpy_chk when possible.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98274 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/InstCombine/InstCombineCalls.cpp b/lib/Transforms/InstCombine/InstCombineCalls.cpp
index c62155e..43ff58d 100644
--- a/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -838,6 +838,19 @@
// Should be similar to strcpy.
if (Name == "__stpcpy_chk") {
+ ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getOperand(3));
+ if (!SizeCI)
+ return 0;
+ // If a) we don't have any length information, or b) we know this will
+ // fit then just lower to a plain stpcpy. Otherwise we'll keep our
+ // stpcpy_chk call which may fail at runtime if the size is too long.
+ // TODO: It might be nice to get a maximum length out of the possible
+ // string lengths for varying.
+ if (SizeCI->isAllOnesValue() ||
+ SizeCI->getZExtValue() >= GetStringLength(CI->getOperand(2))) {
+ Value *Ret = EmitStpCpy(CI->getOperand(1), CI->getOperand(2), B, TD);
+ return ReplaceInstUsesWith(*CI, Ret);
+ }
return 0;
}
diff --git a/lib/Transforms/Scalar/CodeGenPrepare.cpp b/lib/Transforms/Scalar/CodeGenPrepare.cpp
index f5ccebf..c428d2b 100644
--- a/lib/Transforms/Scalar/CodeGenPrepare.cpp
+++ b/lib/Transforms/Scalar/CodeGenPrepare.cpp
@@ -624,11 +624,6 @@
ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getOperand(3));
if (!SizeCI)
return 0;
- // If a) we don't have any length information, or b) we know this will
- // fit then just lower to a plain strcpy. Otherwise we'll keep our
- // strcpy_chk call which may fail at runtime if the size is too long.
- // TODO: It might be nice to get a maximum length out of the possible
- // string lengths for varying.
if (SizeCI->isAllOnesValue()) {
Value *Ret = EmitStrCpy(CI->getOperand(1), CI->getOperand(2), B, TD);
CI->replaceAllUsesWith(Ret);
@@ -638,8 +633,16 @@
return 0;
}
- // Should be similar to strcpy.
if (Name == "__stpcpy_chk") {
+ ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getOperand(3));
+ if (!SizeCI)
+ return 0;
+ if (SizeCI->isAllOnesValue()) {
+ Value *Ret = EmitStpCpy(CI->getOperand(1), CI->getOperand(2), B, TD);
+ CI->replaceAllUsesWith(Ret);
+ CI->eraseFromParent();
+ return true;
+ }
return 0;
}
diff --git a/lib/Transforms/Utils/BuildLibCalls.cpp b/lib/Transforms/Utils/BuildLibCalls.cpp
index 633aaf4..7f62166 100644
--- a/lib/Transforms/Utils/BuildLibCalls.cpp
+++ b/lib/Transforms/Utils/BuildLibCalls.cpp
@@ -87,6 +87,24 @@
return CI;
}
+/// EmitStpCpy - Emit a call to the stpcpy function to the builder, for the
+/// specified pointer arguments.
+Value *llvm::EmitStpCpy(Value *Dst, Value *Src, IRBuilder<> &B,
+ const TargetData *TD) {
+ Module *M = B.GetInsertBlock()->getParent()->getParent();
+ AttributeWithIndex AWI[2];
+ AWI[0] = AttributeWithIndex::get(2, Attribute::NoCapture);
+ AWI[1] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
+ const Type *I8Ptr = B.getInt8PtrTy();
+ Value *StpCpy = M->getOrInsertFunction("stpcpy", AttrListPtr::get(AWI, 2),
+ I8Ptr, I8Ptr, I8Ptr, NULL);
+ CallInst *CI = B.CreateCall2(StpCpy, CastToCStr(Dst, B), CastToCStr(Src, B),
+ "stpcpy");
+ if (const Function *F = dyn_cast<Function>(StpCpy->stripPointerCasts()))
+ CI->setCallingConv(F->getCallingConv());
+ return CI;
+}
+
/// EmitStrNCpy - Emit a call to the strncpy function to the builder, for the
/// specified pointer arguments.
Value *llvm::EmitStrNCpy(Value *Dst, Value *Src, Value *Len,