From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1M9mNM-0003Qb-M6 for garchives@archives.gentoo.org; Thu, 28 May 2009 20:38:56 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 722DBE0747; Thu, 28 May 2009 20:38:55 +0000 (UTC) Received: from smtpout.karoo.kcom.com (smtpout.karoo.kcom.com [212.50.160.34]) by pigeon.gentoo.org (Postfix) with ESMTP id 354F5E0747 for ; Thu, 28 May 2009 20:38:55 +0000 (UTC) X-IronPort-AV: E=Sophos;i="4.41,267,1241391600"; d="scan'208";a="102675612" Received: from unknown (HELO compaq.stroller.uk.eu.org) ([213.152.39.90]) by smtpout.karoo.kcom.com with ESMTP; 28 May 2009 21:38:54 +0100 Received: from [192.168.1.71] (unknown [192.168.1.71]) by compaq.stroller.uk.eu.org (Postfix) with ESMTP id 9FF49137CA0 for ; Thu, 28 May 2009 21:38:50 +0100 (BST) Message-Id: <10C63527-EC84-4039-B922-5579447DB9D7@stellar.eclipse.co.uk> From: Stroller To: gentoo-user@lists.gentoo.org In-Reply-To: Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org Mime-Version: 1.0 (Apple Message framework v935.3) Subject: Re: [gentoo-user] USE="mmx mmxext sse sse2 ssse3 3dnow 3dnowext" Date: Thu, 28 May 2009 21:38:52 +0100 References: <4E38BD16-0410-4A31-839C-290364A8D735@stellar.eclipse.co.uk> <208DD9E9-EDD3-4E85-A8DE-6B08B08EDCEA@stellar.eclipse.co.uk> <20090527130041.214f5aa9@ilievnet.com> <20090528131735.10e3b3ce@ilievnet.com> <9837B633-4DCD-47E2-9A88-442A0FE750BC@stellar.eclipse.co.uk> <047506CD-647D-472E-A96B-96C278C31F51@stellar.eclipse.co.uk> X-Mailer: Apple Mail (2.935.3) X-Archives-Salt: caa35eaa-ad88-4b3a-aba3-416e541f373f X-Archives-Hash: 1a97465a84e19fb4c2930bff964f8ea1 On 28 May 2009, at 21:27, Ward Poelmans wrote: > On Thu, May 28, 2009 at 22:19, Stroller > wrote: >> What's the difference between supporting the "certain set of >> instructions" >> with "-march=" and doing so with USEs? >> >> Or doesn't "-march=" support additional "certain sets of >> instructions". What >> does it do, then? > > The difference is that with the USE flag, you enable the use of > assembly code in the source of mplayer that makes use of the "certain > set of instructions". The -march option enables the use of the > "certain set of instructions" when gcc is optimizing and so gcc will > use the "certain set of instructions" when it converts the source code > into assembly code. Right. That's what I was surmising in the post (28 May 2009 20:13:57 BST) you previously replied to. Stroller.