[Mlir-commits] [mlir] [mlir] [XeGPU] Add XeGPU workgroup to subgroup pass (PR #139477)

[Adam Siemieniuk]

adam-smnk wrote:

A more general question about the design here.

If I read it correctly, the whole distribution logic is currently driven purely by `create_nd_tdesc` distribution and the other ops just follow. In general all these ops (and tests) more or less expect to be accompanied by `create_nd_tdesc` because we don't support distributing `tensor_desc` coming from, for example, function args.
However, this falls apart for `dpas` that operates on vectors highlighting the limitation of this approach. The distribution right now does nothing if it is just `xegpu.dpas` op on its own.

Since each op is self contained thanks to the layout attr, I'd expect each op to be distributed individually and by the end of the conversion unrealized_casts will cancel out and/or necessary layout conversions would be materialized. The latter probably being a todo for later.

https://github.com/llvm/llvm-project/pull/139477