From mboxrd@z Thu Jan  1 00:00:00 1970
From: ludo@gnu.org (Ludovic =?utf-8?Q?Court=C3=A8s?=)
Subject: Re: Qt
Date: Thu, 10 Oct 2013 15:09:09 +0200
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References: <20131008190520.GA31264@debian> <87mwmjxym7.fsf@gnu.org>
	<20131010125952.GA32470@debian.bordeaux.inria.fr>
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To: Andreas Enge <andreas@enge.fr>
Cc: guix-devel@gnu.org

Andreas Enge <andreas@enge.fr> skribis:

> On Tue, Oct 08, 2013 at 11:05:04PM +0200, Ludovic Court=C3=A8s wrote:
>> Andreas Enge <andreas@enge.fr> skribis:
>> > Also, the build uses
>> > sse/sse2/... instructions according to what is available on the
>> > processor; we might wish to disable all or at least the most advanced
>> > of them in the long run.
>> If it=E2=80=99s a matter of adding the right configure flag, I=E2=80=99d=
 do it before
>> it bites.
>
> The following will leave out any special instructions, as far as I can se=
e:
> +                              "-no-sse2"
> +                              "-no-sse3"
> +                              "-no-ssse3"
> +                              "-no-sse4.1"
> +                              "-no-sse4.2"
> +                              "-no-avx"
> +                              "-no-avx2"
> +                              "-no-neon"
> +                              "-no-mips_dsp"
> +                              "-no-mips_dspr2"))))
>
> I do not know how much this slows down qt applications. According to wiki=
pedia,
> sse2 arrived in 2001. So one could argue that adding it would exclude alm=
ost
> no machines.

Yes, you may be right for SSE2 (especially considering the fact that
this kind of software is typically used on fairly recent machines.)

Ludo=E2=80=99.