Add test plan for sycl_ext_oneapi_composite_device

[AlexeySachkov]

No description provided.

[maarquitos14]

Should we also check for device::get_devices()?

[AlexeySachkov]

I think that this is related to #865 (comment) - CTS is currently launches tests for a single selected device and I'm hesitant to move too away from that. device::get_devices() is not limited by a backend or platform and it may pull in some unwanted things from the environment which are unrelated to one device/platform you are trying to test.

Current wording allows to test devices other than the selected one, but it still limits the list to devices which belong to the same platform taken from the selected device.

A good implementation should probably ensure that it supports all the functionality (support here may mean some reasonable fallback and no unexpected crashes or undocumented exceptions) for all backends and platforms which are reported by it, but I don't think that we should expand testing to all the available platforms and backends right now and just for this extension test.

[maarquitos14]

I know https://github.com/gmlueck/llvm/blob/1f1712ed025c76a30ca251c97175685a59bf58bb/sycl/doc/extensions/proposed/sycl_ext_oneapi_composite_device.asciidoc#impact-to-the-oneapi_device_selector section just impacts Intel's implementation, but I wonder if similar mechanisms might exist for other implementations, and if there's a generic way to test this for any given SYCL implementation. To be specific: composite devices should only be returned if all their components are in the list of root devices returned from device::get_devices(), so if there's a way to only select some of the components --like Intel's implementation has with ONEAPI_DEVICE_SELECTOR--, then CTS should maybe test it.

[AlexeySachkov]

I know https://github.com/gmlueck/llvm/blob/1f1712ed025c76a30ca251c97175685a59bf58bb/sycl/doc/extensions/proposed/sycl_ext_oneapi_composite_device.asciidoc#impact-to-the-oneapi_device_selector section just impacts Intel's implementation, but I wonder if similar mechanisms might exist for other implementations, and if there's a generic way to test this for any given SYCL implementation. To be specific: composite devices should only be returned if all their components are in the list of root devices returned from device::get_devices(), so if there's a way to only select some of the components --like Intel's implementation has with ONEAPI_DEVICE_SELECTOR--, then CTS should maybe test it.

ONEAPI_DEVICE_SELECTOR isn't really a part of the language, so I would say that interaction of the extension with it should be tested by the implementation, and not by CTS

[keryell]

Interesting.