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

[Nikita Popov via llvm-commits]

nikic 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).

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