[bug#49096] [PATCH] gnu: petsc: Link against OpenBLAS rather than LAPACK.

[Ludovic Courtès]

Hi,

Efraim Flashner <efraim@flashner.co.il> skribis:

> On Fri, Jun 18, 2021 at 06:12:04PM +0200, Ludovic Courtès wrote:

[...]

>> Usually there’s no reason to depend on the reference (“Netlib”) BLAS/LAPACK
>> implementations because they perform poorly.  This change is one way to
>> bring consistency here.
>> 
>> Thoughts?
>> 
>> Ludo’.
>
> It sounds reasonable to me.

Cool, thanks for taking a look.

> As long as you're open to thoughts, perhaps we want to have a discussion
> (in a new thread) about renaming the input labels for lapack/openblas so
> it's easier to do 'guix build foo
> --with-inputs=blas=openblas-tuned-for-my-machine'

We’ve very much interested in that.  However, input labels don’t have a
role here since ‘--with-input’ matches packages by name.

So most likely, we’d (1) use OpenBLAS by default everywhere instead of
netlib blas/lapack, and (2) you’d use:

  --with-input=openblas=openblas-tuned

WDYT?

Ludo’.