[llvm] [AMDGPU][TargetLowering] Allow forming overflow op if it is legal (PR #156266)

[Matt Arsenault via llvm-commits]

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@@ -9788,7 +9788,8 @@ SDValue TargetLowering::expandABD(SDNode *N, SelectionDAG &DAG) const {
   // flag if the (scalar) type is illegal as this is more likely to legalize
   // cleanly:
   // abdu(lhs, rhs) -> sub(xor(sub(lhs, rhs), uof(lhs, rhs)), uof(lhs, rhs))
-  if (!IsSigned && VT.isScalarInteger() && !isTypeLegal(VT)) {
+  if (!IsSigned && (isOperationLegal(ISD::USUBO, VT) ||
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arsenm wrote:

This is an unrelated change? 

https://github.com/llvm/llvm-project/pull/156266