Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762898AbYF3VDE (ORCPT ); Mon, 30 Jun 2008 17:03:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753739AbYF3VCx (ORCPT ); Mon, 30 Jun 2008 17:02:53 -0400 Received: from mx1.redhat.com ([66.187.233.31]:60808 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752364AbYF3VCw (ORCPT ); Mon, 30 Jun 2008 17:02:52 -0400 Message-ID: <4869497B.5040100@redhat.com> Date: Mon, 30 Jun 2008 18:00:43 -0300 From: Glauber Costa Organization: Red Hat User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: Andi Kleen CC: linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@elte.hu, x86@kernel.org Subject: Re: [PATCH 17/39] clobber rbx in putuser_64.S References: <1214602486-17080-1-git-send-email-gcosta@redhat.com> <1214602486-17080-3-git-send-email-gcosta@redhat.com> <1214602486-17080-4-git-send-email-gcosta@redhat.com> <1214602486-17080-5-git-send-email-gcosta@redhat.com> <1214602486-17080-6-git-send-email-gcosta@redhat.com> <1214602486-17080-7-git-send-email-gcosta@redhat.com> <1214602486-17080-8-git-send-email-gcosta@redhat.com> <1214602486-17080-9-git-send-email-gcosta@redhat.com> <1214602486-17080-10-git-send-email-gcosta@redhat.com> <1214602486-17080-11-git-send-email-gcosta@redhat.com> <1214602486-17080-12-git-send-email-gcosta@redhat.com> <1214602486-17080-13-git-send-email-gcosta@redhat.com> <1214602486-17080-14-git-send-email-gcosta@redhat.com> <1214602486-17080-15-git-send-email-gcosta@redhat.com> <1214602486-17080-16-git-send-email-gcosta@redhat.com> <1214602486-17080-17-git-send-email-gcosta@redhat.com> <1214602486-17080-18-git-send-email-gcosta@redhat.com> <87abh5pxl6.fsf@basil.nowhere.org> In-Reply-To: <87abh5pxl6.fsf@basil.nowhere.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 899 Lines: 26 Andi Kleen wrote: > Glauber Costa writes: > >> Instead of clobbering r8, clobber rbx, which is the i386 way. > > Note rbx is callee saved on 64bit, so using that one means > the surrounding function always has to save explicitely. > Not the case with r8. > > There's a reason it is the way it is. > > -Andi Right. Thanks for pointing this out. However, r8 is not available for i386. We could use %ax, but it holds part of the data for the call itself. But for this case, I think we can come up with a macro that selects the appropriate register for each of them. Should be easy to do now that the code is merged. Many thanks. -- 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/