diff --git a/lib/Target/X86/SSEDomainFix.cpp b/lib/Target/X86/SSEDomainFix.cpp
index fe4e35329c6..be17515184a 100644
--- a/lib/Target/X86/SSEDomainFix.cpp
+++ b/lib/Target/X86/SSEDomainFix.cpp
@@ -261,6 +261,8 @@ void SSEDomainFixPass::Collapse(DomainValue *dv, unsigned domain) {
 bool SSEDomainFixPass::Merge(DomainValue *A, DomainValue *B) {
   assert(!A->collapsed() && "Cannot merge into collapsed");
   assert(!B->collapsed() && "Cannot merge from collapsed");
+	if (A == B)
+    return true;
   if (!A->compat(B->Mask))
     return false;
   A->Mask &= B->Mask;