[llvm] SelectionDAG: Support FMINIMUMNUM and FMINIMUM in combineMinNumMaxNumImpl (PR #137449)

[Matt Arsenault via llvm-commits]

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@@ -11907,7 +11907,16 @@ static bool isLegalToCombineMinNumMaxNum(SelectionDAG &DAG, SDValue LHS,
   if (!VT.isFloatingPoint())
     return false;
 
-  return Flags.hasNoSignedZeros() &&
+  bool hasMinMaxOpc = (TLI.isOperationLegalOrCustom(ISD::FMINNUM, VT) &&
+                       TLI.isOperationLegalOrCustom(ISD::FMAXNUM, VT)) ||
+                      (TLI.isOperationLegalOrCustom(ISD::FMINNUM_IEEE, VT) &&
+                       TLI.isOperationLegalOrCustom(ISD::FMAXNUM_IEEE, VT)) ||
+                      (TLI.isOperationLegalOrCustom(ISD::FMINIMUM, VT) &&
+                       TLI.isOperationLegalOrCustom(ISD::FMAXIMUM, VT)) ||
+                      (TLI.isOperationLegalOrCustom(ISD::FMINIMUMNUM, VT) &&
+                       TLI.isOperationLegalOrCustom(ISD::FMAXIMUMNUM, VT));
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arsenm wrote:

Can you move this to a separate helper function 

https://github.com/llvm/llvm-project/pull/137449