Extend the undef ^ undef idiom once more. No testcase: I can't figure out how to actually trigger the codepath in question at the moment, but it might get exposed in the future.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137781 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp
index cfff9c0..89e55a4 100644
--- a/lib/Analysis/InstructionSimplify.cpp
+++ b/lib/Analysis/InstructionSimplify.cpp
@@ -1348,6 +1348,11 @@
std::swap(Op0, Op1);
}
+ // A ^ A = 0
+ // Do this first so that we catch the undef ^ undef "idiom".
+ if (Op0 == Op1)
+ return Constant::getNullValue(Op0->getType());
+
// A ^ undef -> undef
if (match(Op1, m_Undef()))
return Op1;
@@ -1356,10 +1361,6 @@
if (match(Op1, m_Zero()))
return Op0;
- // A ^ A = 0
- if (Op0 == Op1)
- return Constant::getNullValue(Op0->getType());
-
// A ^ ~A = ~A ^ A = -1
if (match(Op0, m_Not(m_Specific(Op1))) ||
match(Op1, m_Not(m_Specific(Op0))))