[llvm] [AMDGPU][GlobalIsel] Introduce isRegType to check for legal types, instead of checking bit width. (PR #68189)

[Jay Foad via llvm-commits]

https://github.com/jayfoad commented:

I've just taken a fresh look at this. I do have a couple of concerns:

1. It introduces yet another list of supported register classes, which will need to be updated whenever we add a new one. But maybe that is unavoidable.
2. It looks like `isRegisterClassType` will not be super fast, especially since it has to construct all the pointer types on every call.

https://github.com/llvm/llvm-project/pull/68189