Don't add an attribute that already exists and don't remove an attribute that doesn't exist.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176289 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 0 deletions

diff --git a/lib/IR/Attributes.cpp b/lib/IR/Attributes.cpp
index 6eb51f0edc..ed2bf05e90 100644
--- a/lib/IR/Attributes.cpp
+++ b/lib/IR/Attributes.cpp
@@ -645,6 +645,7 @@ AttributeSet AttributeSet::get(LLVMContext &C, ArrayRef<AttributeSet> Attrs) {
 
 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(LLVMContext &C, unsigned Idx,
 
 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));
 }