From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists.gentoo.org ([140.105.134.102] helo=robin.gentoo.org) by nuthatch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1FycgP-0006Nr-5w for garchives@archives.gentoo.org; Thu, 06 Jul 2006 22:50:53 +0000 Received: from robin.gentoo.org (localhost [127.0.0.1]) by robin.gentoo.org (8.13.7/8.13.6) with SMTP id k66MnGuI027102; Thu, 6 Jul 2006 22:49:16 GMT Received: from smtp0.libero.it (smtp0.libero.it [193.70.192.33]) by robin.gentoo.org (8.13.7/8.13.6) with ESMTP id k66MkAqt009201 for ; Thu, 6 Jul 2006 22:46:10 GMT Received: from localhost (172.16.1.19) by smtp0.libero.it (7.0.027-DD01) id 44A365590088857A for gentoo-dev@lists.gentoo.org; Fri, 7 Jul 2006 00:46:10 +0200 Received: from smtp0.libero.it ([172.16.1.204]) by localhost (asav13.libero.it [193.70.192.96]) (amavisd-new, port 10024) with ESMTP id 06698-05 for ; Fri, 7 Jul 2006 00:46:10 +0200 (CEST) Received: from [192.168.0.6] (adsl-ull-62-62.44-151.net24.it [151.44.62.62]) by smtp0.libero.it (Postfix) with ESMTP id BBCB8333891 for ; Fri, 7 Jul 2006 00:46:09 +0200 (MEST) Message-ID: <44AD92AF.305@gentoo.org> Date: Fri, 07 Jul 2006 00:46:07 +0200 From: Luca Barbato User-Agent: Thunderbird 1.5.0.4 (X11/20060603) Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-dev@gentoo.org Reply-to: gentoo-dev@lists.gentoo.org MIME-Version: 1.0 To: gentoo-dev@lists.gentoo.org Subject: Re: [gentoo-dev] Replacing cpu-feature USE flags References: <200607061252.33028@enterprise.flameeyes.is-a-geek.org> In-Reply-To: <200607061252.33028@enterprise.flameeyes.is-a-geek.org> X-Enigmail-Version: 0.94.0.0 Content-Type: text/plain; charset=UTF-8 X-Scanned: with antispam and antivirus automated system at libero.it Content-Transfer-Encoding: quoted-printable X-MIME-Autoconverted: from 8bit to quoted-printable by robin.gentoo.org id k66MnGw7027102 X-Archives-Salt: 6e9652f8-a82d-406e-901b-705d59170941 X-Archives-Hash: 8e90a4e0aaa99a54779b6c7db95e1696 Diego 'Flameeyes' Petten=C3=B2 wrote: [summary:provide a way to enable simd features by extracting them from the ones supported by the cflags selected and the compiler] Pros: - automagic : you just carefully select your cflags and your apps will have all the simd goodness you may dream/want/expect. - less useflags around - simpler life when building stages (given we gut cpuinfo checks in configures) Cons: - assumes gcc - per ebuild cflags feat isn't ready yet - makes less simple to have certain corner case Alternatives: - as PPC we provide a default cflags & use tuned per certain cpu families using profiles, amd64 could provide a nocona profile that bans 3dnow* useflags. - have simdflags as use_expand to keep them on a single place and improve the description - as before but provide an eclass that uses flameeyes infrastructure to warn about possible mismatch between what the cflags could do and what you expect to obtain eg: -mcpu=3Dnocona use 3dnow would issue a warning and disable it - as the one before again but with a var to decide if follow the use or the gcc check. lu --=20 Luca Barbato Gentoo/linux Gentoo/PPC http://dev.gentoo.org/~lu_zero --=20 gentoo-dev@gentoo.org mailing list