[Mlir-commits] [mlir] [mlir][gpu] Add `gpu.subgroup_uniform` op (PR #157743)

[Jianhui Li]

Jianhui-Li wrote:

> > Just to get a sense of how people are feeling, how would folks feel if this thing was called `gpu.as_subgroup_uniform` or `gpu.make_subgroup_uniform`?
> 
> `gpu.subgroup_assume_uniform`?

I was thinking gpu.assume_uniform with subgroup as attribute. 

assume_ prefix indicates that the op works as a compiler hint. Subgroup_ prefix implies that it is a subgroup operation, and the lane is cooperating with Neighbour lanes.
>From the motivation example @krzysz00 shared: "[thread ID x] / [subgroup size]", the value can be uniform across workgroup, or cluster, if the example uses workgroup size or cluster size.  So why not treat subgroup as an attribute, instead of part of the name?  

https://github.com/llvm/llvm-project/pull/157743