Don't remove the memcpy when call slot substitution fails.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51848 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/lib/Transforms/Scalar/MemCpyOptimizer.cpp
index 22a00ba..c599928 100644
--- a/lib/Transforms/Scalar/MemCpyOptimizer.cpp
+++ b/lib/Transforms/Scalar/MemCpyOptimizer.cpp
@@ -580,14 +580,19 @@
return false;
// All the checks have passed, so do the transformation.
+ bool changedArgument = false;
for (unsigned i = 0; i < CS.arg_size(); ++i)
if (CS.getArgument(i) == cpySrc) {
if (cpySrc->getType() != cpyDest->getType())
cpyDest = CastInst::CreatePointerCast(cpyDest, cpySrc->getType(),
cpyDest->getName(), C);
+ changedArgument = true;
CS.setArgument(i, cpyDest);
}
+ if (!changedArgument)
+ return false;
+
// Drop any cached information about the call, because we may have changed
// its dependence information by changing its parameter.
MemoryDependenceAnalysis& MD = getAnalysis<MemoryDependenceAnalysis>();