[mlir][XeGPU] Add optional layout attribute to LoadGather StoreScatter ops (#163414)
As [suggested
here](https://github.com/llvm/llvm-project/pull/163071#discussion_r2427229637)
the PR adds an optional layout attribute for `LoadGather` and
`StoreScatter` ops.
For the load-op the attribute describes the layout of the result (ex
`layout_result_0`), and for store-op it describes the layout for the
vector-to-store operand (ex `layout_operand_0`).
The PR also reworks `propagate-layout` pass to consider perm layout
attributes and back-propagate them accordingly.
The helper utility function `getDistributeLayoutAttr` is reworked to
return either `layout_operand/result_0` or `layout` for load/store ops
(denepding on which one is set). After an offline discussion decided
that the overall utilities layouts API is confusing since it tries to
mix permament and temporary layouts. Would need to change it in the
future.
---------
Signed-off-by: dchigarev <dmitry.chigarev@intel.com>
llvm-project
6c563dc6 - [mlir][XeGPU] Add optional layout attribute to LoadGather StoreScatter ops (#163414)
