[llvm] Remove unnecessary add instructions in ctlz.i8 (PR #77615)

[Leon Clark via llvm-commits]

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@@ -3062,6 +3068,25 @@ static bool isCttzOpc(unsigned Opc) {
   return Opc == ISD::CTTZ || Opc == ISD::CTTZ_ZERO_UNDEF;
 }
 
+void AMDGPUTargetLowering::replaceCTLZResults(
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PeddleSpam wrote:

I thought it might be confusing since we already have a `LowerCTLZ_CTTZ` function. Other backends use the "replaceXResults" convention which seemed appropriate. Or we could split the difference and call it `lowerCTLZResults`.

https://github.com/llvm/llvm-project/pull/77615