[Mlir-commits] [mlir] [mlir][llvm] Add llvm.target_features features attribute (PR #71510)

[Andrzej Warzyński]

banach-space wrote:

@ftynse , thanks for reviewing this 🙏🏻 .

We chatted about this offline and realised that instead of using target attributes at this level, we might be able to control what lowerings to use higher up the stack (in our case that would be in IREE).  That should be sufficient for SME's outer-product instructions that this was originally intended for  - we will basically try to configure tiling/vectorisation in IREE depending on the available target extensions/attributes. 

I still believe that we will need this for things like `vector.gather`  - gathers are supported natively by SVE, but not by streaming SVE (the latter is included with SME). 

My suggestion would be to label this as "in progress/draft" and park it until we:
* take care of various outer-product variants in SME in IREE,
* start looking into `vector.gather` in the context of streaming SVE.

That should help us to identify a suitable motivating example. WDYT?

https://github.com/llvm/llvm-project/pull/71510