[llvm] r176289 - Don't add an attribute that already exists and don't remove an attribute that doesn't exist.

[Bill Wendling]

Author: void
Date: Thu Feb 28 13:17:40 2013
New Revision: 176289

URL: http://llvm.org/viewvc/llvm-project?rev=176289&view=rev
Log:
Don't add an attribute that already exists and don't remove an attribute that doesn't exist.

Modified:
    llvm/trunk/lib/IR/Attributes.cpp

Modified: llvm/trunk/lib/IR/Attributes.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Attributes.cpp?rev=176289&r1=176288&r2=176289&view=diff
==============================================================================
--- llvm/trunk/lib/IR/Attributes.cpp (original)
+++ llvm/trunk/lib/IR/Attributes.cpp Thu Feb 28 13:17:40 2013
@@ -645,6 +645,7 @@ AttributeSet AttributeSet::get(LLVMConte
 
 AttributeSet AttributeSet::addAttribute(LLVMContext &C, unsigned Idx,
                                         Attribute::AttrKind Attr) const {
+  if (hasAttribute(Idx, Attr)) return *this;
   return addAttributes(C, Idx, AttributeSet::get(C, Idx, Attr));
 }
 
@@ -699,6 +700,7 @@ AttributeSet AttributeSet::addAttributes
 
 AttributeSet AttributeSet::removeAttribute(LLVMContext &C, unsigned Idx,
                                            Attribute::AttrKind Attr) const {
+  if (!hasAttribute(Idx, Attr)) return *this;
   return removeAttributes(C, Idx, AttributeSet::get(C, Idx, Attr));
 }