Tighten a ARM dag combine condition to avoid an identity transformation, which
ends up introducing a cycle in the DAG.

rdar://10196296


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140733 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 9f31385..54f8aaa 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -7344,7 +7344,7 @@
   //   movne   r0, y
   /// FIXME: Turn this into a target neutral optimization?
   SDValue Res;
-  if (CC == ARMCC::NE && FalseVal == RHS) {
+  if (CC == ARMCC::NE && FalseVal == RHS && FalseVal != LHS) {
     Res = DAG.getNode(ARMISD::CMOV, dl, VT, LHS, TrueVal, ARMcc,
                       N->getOperand(3), Cmp);
   } else if (CC == ARMCC::EQ && TrueVal == RHS) {