[Mlir-commits] [mlir] [mlir][gpu] Add `subgroup_broadcast` op (PR #152808)

[Jakub Kuderski]

kuhar wrote:

> Arbitrary is a synonym for random. https://www.merriam-webster.com/dictionary/arbitrary
> My point is, `any_lane` implies randomness because it doesn't describe which lane to choose. As such, is not a good abstraction.

This is incorrect. In the context of program semantics / formal analysis, arbitrary means non-deterministic, which is different from random because it does not require any specific distribution. The implementation chose any lane, hence the name. Perhaps this framing is not well known by the larger MLIR community and we could pick a different name.

But overall, I think that this does broadcast semantics and not having an extra op for uniform values reduces the maintenance burden. 

https://github.com/llvm/llvm-project/pull/152808