[llvm] PatternMatch: migrate to CmpPredicate (PR #118534)

[Ramkumar Ramachandra via llvm-commits]

artagnon wrote:

> > This is going to have a sizable compile-time impact, but again, I'm not sure we can help it.
> 
> Can you share what the compile-time impact is?
> 
> We could just provide two overloads in PatternMatch. There isn't really a need to migrate _everything_ to CmpPredicate if it's not free, I expect only a small fraction of code will actually care about samesign (the bits interacting with implied conditions).

Okay, I was wrong, and it's essentially free.

https://llvm-compile-time-tracker.com/compare.php?from=c7babfa6a375d1094cf5e5d7ce4b36b2b9a6b717&to=61823cdd5e86b8ae0c45da03ce6d8faf32b86038&stat=instructions:u

https://github.com/llvm/llvm-project/pull/118534