[llvm] [AMDGPU] Account for existing SDWA selections (PR #123221)

[Jeffrey Byrnes via llvm-commits]

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@@ -1285,10 +1374,12 @@ bool SIPeepholeSDWA::run(MachineFunction &MF) {
 
       for (const auto &OperandPair : SDWAOperands) {
         const auto &Operand = OperandPair.second;
-        MachineInstr *PotentialMI = Operand->potentialToConvert(TII, ST, &PotentialMatches);
-        if (PotentialMI && isConvertibleToSDWA(*PotentialMI, ST, TII)) {
+        MachineInstr *PotentialMI =
+            Operand->potentialToConvert(TII, ST, &PotentialMatches);
+
+        if (PotentialMI && isConvertibleToSDWA(*PotentialMI, ST, TII) &&
+            Operand->canCombineSelections(*PotentialMI, TII))
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jrbyrnes wrote:

Think this is redundant if we're already checking from `Operand->potentialToConvert` above

https://github.com/llvm/llvm-project/pull/123221