diff --git a/lib/Analysis/LibCallSemantics.cpp b/lib/Analysis/LibCallSemantics.cpp
index 01fe730..e0060c3 100644
--- a/lib/Analysis/LibCallSemantics.cpp
+++ b/lib/Analysis/LibCallSemantics.cpp
@@ -57,9 +57,6 @@
   }
   
   // Look up this function in the string map.
-  const char *ValueName = F->getNameStart();
-  StringMap<const LibCallFunctionInfo*>::iterator I =
-    Map->find(StringRef(ValueName, F->getNameLen()));
-  return I != Map->end() ? I->second : 0;
+  return Map->lookup(F->getName());
 }