[SelectionDAG] ISD::XOR has the same non-zero detection as ISD::SUB

[AZero13]

If X != Y, then X ^ Y != 0

[llvmbot]

@llvm/pr-subscribers-backend-x86

@llvm/pr-subscribers-llvm-selectiondag

Author: AZero13 (AZero13)

Changes

If X != Y, then X ^ Y != 0

---

Full diff: https://github.com/llvm/llvm-project/pull/146980.diff

1 Files Affected:

• (modified) llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp (+1-1)

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 6df21b624137f..4e9cebb881deb 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -6016,7 +6016,7 @@ bool SelectionDAG::isKnownNeverZero(SDValue Op, unsigned Depth) const {
         return true;
     // TODO: There are a lot more cases we can prove for add.
     break;
-
+  case ISD::XOR:
   case ISD::SUB: {
     if (isNullConstant(Op.getOperand(0)))
       return isKnownNeverZero(Op.getOperand(1), Depth + 1);

[topperc]

Your second commit doesn't seem to change any tests?