[llvm] Adding support in llvm-exegesis for Aarch64 for handling FPR64/128, PPR16 and ZPR128 reg class. (PR #127564)

[Sjoerd Meijer via llvm-commits]

sjoerdmeijer wrote:

About the warning, yes, it will produce a result, but:
- the warning is annoying,
- and for some instructions it might actually influence results.

> Can you add a test, and maybe fix the existing one for ADDXrr?

Yep, we definitely need some tests. 

https://github.com/llvm/llvm-project/pull/127564