1 files changed, 3 insertions, 1 deletions
diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
index fed239eae3..c199f301a9 100644
--- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
@@ -733,8 +733,10 @@ struct VISIBILITY_HIDDEN StrToOpt : public LibCallOptimization {
       return 0;
 
     Value *EndPtr = CI->getOperand(2);
-    if (isa<ConstantPointerNull>(EndPtr))
+    if (isa<ConstantPointerNull>(EndPtr)) {
+      CI->setOnlyReadsMemory();
       CI->addAttribute(1, Attribute::NoCapture);
+    }
 
     return 0;
   }