From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933202Ab2AFLKS (ORCPT ); Fri, 6 Jan 2012 06:10:18 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:58293 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933119Ab2AFLKO (ORCPT ); Fri, 6 Jan 2012 06:10:14 -0500 Date: Fri, 6 Jan 2012 12:08:12 +0100 From: Ingo Molnar To: Andi Kleen Cc: "H. Peter Anvin" , Jan Beulich , tglx@linutronix.de, linux-kernel@vger.kernel.org Subject: Re: x86-64: memset()/memcpy() not fully standards compliant Message-ID: <20120106110812.GA24369@elte.hu> References: <4F05BBFE020000780006A983@nat28.tlf.novell.com> <20120105182846.GQ11715@one.firstfloor.org> <4F0630CC.7050001@zytor.com> <20120106014748.GS11715@one.firstfloor.org> <4F06566B.8080708@zytor.com> <20120106094922.GU11715@one.firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120106094922.GU11715@one.firstfloor.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Andi Kleen wrote: > You would slow a critical fast path operation down for > something that never happens?!? There were big differences > between strings and the unrolled loop for several. AFAICS Jan's approach speeds up memset(), so what you say is 100% pure nonsense. Thanks, Ingo