[llvm] TargetInstrInfo: make getOperandLatency return optional (NFC) (PR #73769)

[Ramkumar Ramachandra via llvm-commits]

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@@ -155,22 +155,21 @@ unsigned PPCInstrInfo::getInstrLatency(const InstrItineraryData *ItinData,
     if (!MO.isReg() || !MO.isDef() || MO.isImplicit())
       continue;
 
-    int Cycle = ItinData->getOperandCycle(DefClass, i);
-    if (Cycle < 0)
+    std::optional<unsigned> Cycle = ItinData->getOperandCycle(DefClass, i);
+    if (!Cycle)
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artagnon wrote:

I personally don't like `.has_value()`.

https://github.com/llvm/llvm-project/pull/73769