From 3548068c22f809e5bc64b83d2c3622018469256c Mon Sep 17 00:00:00 2001
From: Fariborz Jahanian <fjahanian@apple.com>
Date: Tue, 22 Jan 2013 19:05:17 +0000
Subject: [PATCH] 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
---
 include/clang/Sema/Sema.h | 3 +++
 lib/Sema/SemaExprObjC.cpp | 8 ++++++--
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h
index a3402782a9..20d3db625a 100644
--- a/include/clang/Sema/Sema.h
+++ b/include/clang/Sema/Sema.h
@@ -575,6 +575,9 @@ public:
   /// \brief id<NSCopying> type.
   QualType QIDNSCopying;
 
+  /// \brief will hold 'respondsToSelector:'
+  Selector RespondsToSelectorSel;
+  
   /// A flag to remember whether the implicit forms of operator new and delete
   /// have been declared.
   bool GlobalNewDeleteDeclared;
diff --git a/lib/Sema/SemaExprObjC.cpp b/lib/Sema/SemaExprObjC.cpp
index 87da440191..7f0c832575 100644
--- a/lib/Sema/SemaExprObjC.cpp
+++ b/lib/Sema/SemaExprObjC.cpp
@@ -2485,8 +2485,12 @@ ExprResult Sema::ActOnInstanceMessage(Scope *S,
                                       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(),