From mboxrd@z Thu Jan  1 00:00:00 1970
From: ludovic.courtes@inria.fr (Ludovic =?utf-8?Q?Court=C3=A8s?=)
Subject: Re: fftw runtime cpu detection
Date: Fri, 06 Apr 2018 17:09:21 +0200
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	<87sh883gko.fsf@gnu.org> <20180406150232.GU105827@pe06.us.cray.com>
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In-Reply-To: <20180406150232.GU105827@pe06.us.cray.com> (Eric Bavier's message
	of "Fri, 6 Apr 2018 10:02:32 -0500")
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To: Eric Bavier <bavier@cray.com>
Cc: guix-devel@gnu.org

Eric Bavier <bavier@cray.com> skribis:

> On Fri, Apr 06, 2018 at 10:05:43AM +0200, Ludovic Court=C3=A8s wrote:
>> Hello Eric,
>>=20
>> Eric Bavier <bavier@cray.com> skribis:
>>=20
>> > I recently discovered that the FFTW library can do runtime cpu
>> > detection.  In order to do this, the package needs to be configured to
>> > build SIMD "codelets", like how our 'fftw-avx' currently does.  Then,
>> > based on the instruction support detected at runtime, make those
>> > kernels available to the fftw "planner" for execution.
>>=20
>> That=E2=80=99s really good news!  Thanks for testing it.
>>=20
>> The patch LGTM.  Can you confirm that the planner won=E2=80=99t ever try=
 to use
>> the AVX2 codelets, for instance when running the test suite on an x86_64
>> box that lacks AVX2?
>
> Yes, I've successfully run 'make check' on an sse2-only machine where
> '--enable-avx' and '--enable-avx2' where configured.  I'll check on an
> i686 machine tonight.

OK.

>> If that=E2=80=99s the case, I=E2=80=99d be in favor of pushing this patc=
h to core-updates.
>
> Great.  I'll do some more testing.  Should I send a finalized patch to
> guix-patches when it's ready?

If Marius has no objections, I think you could push it directly to
core-updates.

Thank you,
Ludo=E2=80=99.