Small code change to improve performance
in my last patch, suggested by Argyrios.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173182 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaExprObjC.cpp b/lib/Sema/SemaExprObjC.cpp
index 87da440..7f0c832 100644
--- a/lib/Sema/SemaExprObjC.cpp
+++ b/lib/Sema/SemaExprObjC.cpp
@@ -2485,8 +2485,12 @@
                                       MultiExprArg Args) {
   if (!Receiver)
     return ExprError();
-  IdentifierInfo *SelectorId = &Context.Idents.get("respondsToSelector");
-  if (Sel == Context.Selectors.getUnarySelector(SelectorId))
+  
+  if (RespondsToSelectorSel.isNull()) {
+    IdentifierInfo *SelectorId = &Context.Idents.get("respondsToSelector");
+    RespondsToSelectorSel = Context.Selectors.getUnarySelector(SelectorId);
+  }
+  if (Sel == RespondsToSelectorSel)
     RemoveSelectorFromWarningCache(*this, Args[0]);
     
   return BuildInstanceMessage(Receiver, Receiver->getType(),