[llvm] [X86][AMX] Checking AMXProgModel in X86LowerTileCopy (PR #94358)

[via llvm-commits]

https://github.com/aengelke commented:

I did my best to look at this, but I'm don't feel really qualified to review AMX. I like the idea (very similar to what I had in mind) and this generally looks good, but I have a few questions/points where I'm unsure.

- Maybe add a short comment explaining the two AMX modes? If there's some documentation elsewhere, I couldn't find it.
- For managed RA, the only sources of AMX values are zero, load and cast intrinsics. Whenever a load/zero(/store) occurs, the mode is set accordingly. Looks good. What about casts from vectors?
- For unmanaged RA, all (?) (non-internal) intrinsics should set the prog model. So there's zero, load, store, and the actual operations. Zero, load, store are handled, ok. But shouldn't any occurrence of the compute intrinsics also set the prog model? (Can they theoretically occur alone?)

https://github.com/llvm/llvm-project/pull/94358