[SYCL][Doc] Add spec to get device index #20007
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Add a proposed extension specification that allows applications to easily get the index of a `device` object and to get a `device` object from its index.
| class device { | ||
| // ... | ||
| int ext_oneapi_to_index() const; | ||
| static device ext_oneapi_from_index(int index); |
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Personally, I think ext_oneapi_from_index(i) is a little unnecessary. It is effectively just a "shorthand" for device::get_devices()[i], but not currently actually shorter:
device::ext_oneapi_from_index(i)
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I agree with this, but it seemed better to add a pair of APIs to convert back and forth between index and device, rather than just adding a single API to do a one-way conversion. In addition, it is a bit wasteful to construct a std::vector if the user just wants a single element from that vector.
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I agree with this, but it seemed better to add a pair of APIs to convert back and forth between index and
device, rather than just adding a single API to do a one-way conversion.
Since the API is already talking about the return value being an index into the vector of devices, I am not personally too much against just having the one-way API added here. It is a minor thing, but it is also an additional API to maintain. I suppose we could maybe just reword it to say "Same as calling device::get_devices()[i]" or something along those lines.
In addition, it is a bit wasteful to construct a
std::vectorif the user just wants a single element from that vector.
That is a good point. I would be tempted to say we would want to do that internally as well, simply to make sure the sets of devices don't suddenly change due to the adapters not making any ordering guarantees, but maybe some implementations could avoid that.
That said, even if we did keep an internal version for book-keeping, the API for get_devices() would return a copy of it, so you are right that it would be wasteful.
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@intel/llvm-gatekeepers please consider merging |
Yes. @intel/llvm-gatekeepers, I think this is ready to mege. |
Add a proposed extension specification that allows applications to easily get the index of a
deviceobject and to get adeviceobject from its index.