[llvm] [AArch64] Lower disjoint_or+not to eon. (PR #147279)

[Paul Walker via llvm-commits]

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@@ -1254,6 +1254,16 @@ def fminnum_nnan : PatFrag<(ops node:$Rn, node:$Rm),
   return N->getFlags().hasNoNaNs();
   }]>;
 
+// Match disjoint or nodes.
+def or_disjoint : PatFrag<(ops node:$lhs, node:$rhs),
+                          (or node:$lhs, node:$rhs), [{
+  return N->getFlags().hasDisjoint();
+}]> {
+  let GISelPredicateCode = [{
+    return mi_match(MI, MRI, m_GDisjointOr(m_Reg(), m_Reg()));
+  }];
+}
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paulwalker-arm wrote:

The change is well contained but what do you think to the idea of adding `xor_like` to TargetSelectionDAG.td? That way any patterns that don't specifically require `xor` can be easily ported. 

https://github.com/llvm/llvm-project/pull/147279