Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932092AbXACUbG (ORCPT ); Wed, 3 Jan 2007 15:31:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932094AbXACUbF (ORCPT ); Wed, 3 Jan 2007 15:31:05 -0500 Received: from smtp.osdl.org ([65.172.181.25]:47665 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932096AbXACUbE (ORCPT ); Wed, 3 Jan 2007 15:31:04 -0500 Date: Wed, 3 Jan 2007 12:24:56 -0800 (PST) From: Linus Torvalds To: Tim Schmielau cc: l.genoni@oltrelinux.com, 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 Subject: Re: kernel + gcc 4.1 = several problems In-Reply-To: Message-ID: References: <200701030212.l032CDXe015365@harpo.it.uu.se> <20070103102944.09e81786@localhost.localdomain> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 820 Lines: 21 On Wed, 3 Jan 2007, Tim Schmielau wrote: > > Well, on a P4 (which is supposed to be soo bad) I get: Interesting. My P4 gets basically exactly the same timings for the cmov and branch cases. And my Core 2 is consistently faster (something like 15%) for the branch version. Btw, the test-case should be the best possible one for cmov, since there are no data-dependencies except for ALU operations, and everything is totally independent (the actual values have no data dependencies at all, since they are constants). So the critical path issue never show up. Linus - 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/