[llvm] [ARM] Have custom lowering for ucmp and scmp (PR #149315)

[via llvm-commits]

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@@ -1628,6 +1634,10 @@ bool ARMTargetLowering::useSoftFloat() const {
   return Subtarget->useSoftFloat();
 }
 
+bool ARMTargetLowering::shouldExpandCmpUsingSelects(EVT VT) const {
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AZero13 wrote:

Actually mve generates better code than the custom lowering, hence why it is enabled there, but when it is not, then yes the cost modeling this best matches what we are doing for that. 

https://github.com/llvm/llvm-project/pull/149315