[Mlir-commits] [mlir] [mlir][test] Make SME e2e tests require an emulator (PR #86489)

[Cullen Rhodes]

c-rhodes wrote:

> > No lines is better than 3
> This does not seem like a useful comment IMO.

Apologies, that wasn't helpful.

> 
> A nice error message at configuration time is much better than a compile time failure, which is itself much better than a link-time failure, which itself is much better than a runtime test failure!

I agree, hard to argue with that, failing early is a good thing.

> > I've seen setups in the past for example where emulation is enabled opaquely via binfmt_misc on Linux.
> 
> That seems like a valid use-case, @banach-space how do you see this supported? Also: what about someone who has the actual HW in the future?

You've touched on a further issue, if we had done this for SVE we wouldn't have been able to run the integration tests on hardware without removing it. However, we don't all have access to hardware at the same time, at what point do we decide this can be removed?

Lit has constraints [1] which are the typically used for situations like this. The `REQUIRES` constraint can be used to specify target but as far as I'm aware it doesn't support specific target features. It would be nice if the integration tests could have something like:

```
// REQUIRES: target=aarch64 features=sme
```

where `config.available_features` is filled in via host features or supported emulator features.

[1] https://llvm.org/docs/TestingGuide.html#constraining-test-execution



https://github.com/llvm/llvm-project/pull/86489