From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750829AbVKKPti (ORCPT ); Fri, 11 Nov 2005 10:49:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750830AbVKKPti (ORCPT ); Fri, 11 Nov 2005 10:49:38 -0500 Received: from public.id2-vpn.continvity.gns.novell.com ([195.33.99.129]:4622 "EHLO emea1-mh.id2.novell.com") by vger.kernel.org with ESMTP id S1750829AbVKKPth (ORCPT ); Fri, 11 Nov 2005 10:49:37 -0500 Message-Id: <4374CBE9.76F0.0078.0@novell.com> X-Mailer: Novell GroupWise Internet Agent 7.0 Date: Fri, 11 Nov 2005 16:50:49 +0100 From: "Jan Beulich" To: "Andi Kleen" Cc: , Subject: Re: [PATCH] x86-64: adjust ia32entry.S References: <4370AFF0.76F0.0078.0@novell.com> <4370C36D.76F0.0078.0@novell.com> <43722D73.76F0.0078.0@novell.com> <200511111634.44871.ak@suse.de> In-Reply-To: <200511111634.44871.ak@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >>> Andi Kleen 11.11.05 16:34:44 >>> >On Wednesday 09 November 2005 17:10, Jan Beulich wrote: >> IA32 compatibility entry points needlessly played with extended >> registers. Additionally, frame unwind information was still incorrect >> for ia32_ptregs_common (sorry, my fault). > >What do you mean with needlessly played? That it didn't initialize >all on the stack frame? That was more a feature than a bug. >Did it cause you problems? It saved and restored R12-R15, even though these registers have no meaning (and are architecturally undefined) when coming from/going to 32-bit mode. Problems? No, except that without the extra loads (stores don't matter that much I believe) performance is better... >In general I'm weary of making the asm macros more complex >(adding more arguments etc.) Please keep it simple. Then ignore this, perhaps with the exception of the unwind info adjustment. Jan