Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932100AbXACVuP (ORCPT ); Wed, 3 Jan 2007 16:50:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751048AbXACVuP (ORCPT ); Wed, 3 Jan 2007 16:50:15 -0500 Received: from ug-out-1314.google.com ([66.249.92.173]:24529 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751112AbXACVuM (ORCPT ); Wed, 3 Jan 2007 16:50:12 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=googlemail.com; h=received:from:to:subject:date:user-agent:cc:references:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:message-id; b=GqhIoJbVJlvY4SBwO5m/PyJTvXC0BLOXcKZo6cBvKnjMD1X3AXWN51ibuBeFpeZbe9zKDgaOSt3DkJ/MvrGk97CRiDVL5EeonyxGJ3NDUp4U1d8EGH+Zd3HSiefatf+Cu6HeppnXNKUW/c0rPQwNeHhcBrial+WspuHfuAR6F28= From: Denis Vlasenko To: Linus Torvalds Subject: Re: kernel + gcc 4.1 = several problems Date: Wed, 3 Jan 2007 22:48:38 +0100 User-Agent: KMail/1.8.2 Cc: Grzegorz Kulewski , Alan , Mikael Pettersson , s0348365@sms.ed.ac.uk, 76306.1226@compuserve.com, akpm@osdl.org, bunk@stusta.de, greg@kroah.com, linux-kernel@vger.kernel.org, yanmin_zhang@linux.intel.com References: <200701030212.l032CDXe015365@harpo.it.uu.se> <200701032047.02941.vda.linux@googlemail.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200701032248.38653.vda.linux@googlemail.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 798 Lines: 20 On Wednesday 03 January 2007 21:38, Linus Torvalds wrote: > On Wed, 3 Jan 2007, Denis Vlasenko wrote: > > > > Why CPU people do not internally convert cmov into jmp,mov pair? > ... > It really all boils down to: there's simply no real reason to use cmov. > It's not horrible either, so go ahead and use it if you want to, but don't > expect your code to really magically run any faster. IOW: yet another slot in instruction opcode matrix and thousands of transistors in instruction decoders are wasted because of this "clever invention", eh? -- vda - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/