From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tobias Geerinckx-Rice Subject: Re: [PATCH 2/2] gnu: icecat: Use libjpeg-turbo instead of bundled libjpeg. Date: Mon, 28 Nov 2016 00:15:01 +0100 Message-ID: References: <20161127201707.3789-1-me@tobias.gr> <20161127201707.3789-2-me@tobias.gr> <20161127205618.GC27187@jasmine> <20161127214119.GB30774@jasmine> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="PaeXSxMHK9mwWLi7rHR9GCeeiuIcdNjtx" Return-path: Received: from eggs.gnu.org ([2001:4830:134:3::10]:32855) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cB8fo-0001bH-Am for guix-devel@gnu.org; Sun, 27 Nov 2016 18:15:53 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cB8fl-0003wp-5R for guix-devel@gnu.org; Sun, 27 Nov 2016 18:15:52 -0500 Received: from relay9-d.mail.gandi.net ([217.70.183.199]:41690) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cB8fk-0003wS-RU for guix-devel@gnu.org; Sun, 27 Nov 2016 18:15:49 -0500 In-Reply-To: <20161127214119.GB30774@jasmine> List-Id: "Development of GNU Guix and the GNU System distribution." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org Sender: "Guix-devel" To: leo@famulari.name Cc: guix-devel@gnu.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --PaeXSxMHK9mwWLi7rHR9GCeeiuIcdNjtx Content-Type: multipart/mixed; boundary="7jKehBM92JsDxlwxlH4Qt8TbSB9MIxoi3"; protected-headers="v1" From: Tobias Geerinckx-Rice To: leo@famulari.name Cc: guix-devel@gnu.org, andreas@enge.fr Message-ID: Subject: Re: [PATCH 2/2] gnu: icecat: Use libjpeg-turbo instead of bundled libjpeg. References: <20161127201707.3789-1-me@tobias.gr> <20161127201707.3789-2-me@tobias.gr> <20161127205618.GC27187@jasmine> <20161127214119.GB30774@jasmine> In-Reply-To: <20161127214119.GB30774@jasmine> --7jKehBM92JsDxlwxlH4Qt8TbSB9MIxoi3 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Andreas, Leo, Thanks for the feedback! On 27/11/16 22:41, Leo Famulari wrote: > I'm not sure, but the comment seems to indicate that we don't want to > use it: >=20 > ;; According to > ;; http://sourceforge.net/projects/libjpeg-turbo/ , > ;; "libjpeg-turbo is a derivative of libjpeg that > ;; uses MMX, SSE, SSE2, and NEON SIMD instructions > ;; to accelerate baseline JPEG compression/ > ;; decompression", so we had better not use it There seems to be some misunderstanding here. Sorry if it wasn't clear: this (libjpeg-turbo) was *already* bundled and used by icecat, as the =E2=80=98media/libjpeg=E2=80=99 (sic) that this patch removes. You'll fin= d the same SIMD code there. For the quote above is missing: > ;; Fails with "libjpeg-turbo JCS_EXTENSIONS required". Translation: icecat wouldn't build with Guix's =E2=80=98libjpeg=E2=80=99 = even if we'd want that. And we don't. This isn't some dodgy go-faster fork of IJG's =E2=80=98real= =E2=80=99 libjpeg. It's intended as a sane alternative to the IJG library, albeit one that doesn't implement every recent extension. It detects CPU features at runtime =E2=80=94 although they're the status quo now, as And= reas notes =E2=80=94 and falls back to other algorithms that might still be fa= ster. Dang it. I thought I wrote good (description)s. :-( Kind regards, T G-R-turbo --7jKehBM92JsDxlwxlH4Qt8TbSB9MIxoi3-- --PaeXSxMHK9mwWLi7rHR9GCeeiuIcdNjtx Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEqBAEBCgAUBQJYO2j9DRxtZUB0b2JpYXMuZ3IACgkQkczbm0hUG5k2QwgAgknQ 5yHVh2I5qh+jQm4TgPwUdkvFmo1DjWrDnki2AjzCXT71YHf7KWE/6jA7piJccsWA 5FPdoGpRfox58Xas75fDUV2V48WnCMbV4y+uIR6eZ6FmMp3TnkrZOd1p4hfsDZ7E 610LQ7/eDNDiWA5gYHscIYr9Rb3yLBR58eHE/GU7yJpziYLGZ2m/lJLByfCQ6Do4 4mhFcbDwtWT5hCysc8R/NTg1dp9RQ25+7YKl2+NmsPVBm72LskIaw7pKxnU5pyiv wg2W/BW6YCCRndjrF8kpHJ5HOwIRnuZZTA/dypgww5DOigJJExm5TJPUM+/DERj8 BEbVYoVv2iDLUXjNgQ== =3wS6 -----END PGP SIGNATURE----- --PaeXSxMHK9mwWLi7rHR9GCeeiuIcdNjtx--