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From: ludo@gnu.org (Ludovic =?utf-8?Q?Court=C3=A8s?=)
Subject: Re: Optionally using more advanced CPU features
Date: Mon, 04 Sep 2017 16:50:25 +0200
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In-Reply-To: <19eb4906-44d1-723b-94ba-9ab86dfbedf5@uq.edu.au> (Ben Woodcroft's
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To: Ben Woodcroft <b.woodcroft@uq.edu.au>
Cc: guix-devel <guix-devel@gnu.org>

Hi Ben,

Ben Woodcroft <b.woodcroft@uq.edu.au> skribis:

> Anyway, to move forward I created a repo so that package recipes can
> be modified to use a GCC that has been optimised for a particular
> architecture. I put it out there so that it is more than just a patch
> on this ML, but I'd be happy to incorporate it into Guix proper if
> that is desired.
> https://github.com/wwood/cpu-specific-guix
>
> For instance, to build DIAMOND optimised for sandybridge:
>
> GUILE_LOAD_PATH=3D/path/to/cpu-specific-guix:$GUILE_LOAD_PATH\ |guix
> build -e '(begin (use-modules (cpu-specific-guix) (gnu packages
> bioinformatics))\ (cpu-specific-package diamond "sandybridge"))'|

That=E2=80=99s a neat hack!

It=E2=80=99s a bit of a sledgehammer, in that we could achieve this without
rebuilding GCC, I think.  For instance, we could create a =E2=80=98gcc=E2=
=80=99 wrapper
that automatically passes =E2=80=9C-march=3Dfoo=E2=80=9D on the command lin=
e of the real
=E2=80=98gcc=E2=80=99, no?

Thanks for sharing!

Ludo=E2=80=99.