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/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;
}