Re: Packaging BLIS

[ludovic.courtes@inria.fr (Ludovic Courtès)]

Dave Love <fx@gnu.org> skribis:

> ludovic.courtes@inria.fr (Ludovic Courtès) writes:
>
>> That caught my attention so I packaged BLIS:
>>
>>   https://git.savannah.gnu.org/cgit/guix.git/commit/?id=5a7deb117424ff4d430b771b50e534cf065c0ba1
>>
>> There are several “flavors” of BLIS, so you can always rebuild your
>> favorite program with:
>>
>>   --with-input=openblas=blis-haswell
>>
>> and similar (or even ‘--with-graft=blis=blis-haswell’ where applicable).
>
> I'm not aware of an advantage of BLIS over OpenBLAS except for KNL (and
> maybe Skylake Xeon, if that's covered).  My interest was specifically
> for avx512.  (BLIS is documented as basically a research effort, which I
> think explains the way it's built.)

OK, I haven’t done any benchmarking yet.

>> Hopefully the issue you linked to above will be fixed in future versions
>> of BLIS, at which point we can probably provide a single “blis” package.
>>
>> Ludo’.
>
> I still think it's important to be able to select the BLAS at run time
> with dynamic linking.  I suppose the trick I used for rpm will work
> similarly, though I'm not sure how ld.so behaves in Guix.

ld.so does not honor /etc/ld.so.{conf,cache}, but apart from that it
works as usual.

HTH,
Ludo’.