In InstCombiner::visitOr, make sure we reverse the operand swap used for checking for or-of-xor operations after those checks; a later check expects that any constant will be in Op1. PR12234.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152884 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 1 deletions

diff --git a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index cc8f5bf43e..1165660f40 100644
--- a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -1929,8 +1929,11 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
       }
 
   // Canonicalize xor to the RHS.
-  if (match(Op0, m_Xor(m_Value(), m_Value())))
+  bool SwappedForXor = false;
+  if (match(Op0, m_Xor(m_Value(), m_Value()))) {
     std::swap(Op0, Op1);
+    SwappedForXor = true;
+  }
 
   // A | ( A ^ B) -> A |  B
   // A | (~A ^ B) -> A | ~B
@@ -1961,6 +1964,9 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
         return BinaryOperator::CreateOr(Not, Op0);
       }
 
+  if (SwappedForXor)
+    std::swap(Op0, Op1);
+
   if (ICmpInst *RHS = dyn_cast<ICmpInst>(I.getOperand(1)))
     if (ICmpInst *LHS = dyn_cast<ICmpInst>(I.getOperand(0)))
       if (Value *Res = FoldOrOfICmps(LHS, RHS))