Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753971AbYKSAId (ORCPT ); Tue, 18 Nov 2008 19:08:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752817AbYKSAIR (ORCPT ); Tue, 18 Nov 2008 19:08:17 -0500 Received: from gw.goop.org ([64.81.55.164]:49450 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752770AbYKSAIQ (ORCPT ); Tue, 18 Nov 2008 19:08:16 -0500 Message-ID: <492358ED.5090904@goop.org> Date: Tue, 18 Nov 2008 16:08:13 -0800 From: Jeremy Fitzhardinge User-Agent: Thunderbird 2.0.0.17 (X11/20081009) MIME-Version: 1.0 To: "H. Peter Anvin" CC: Andi Kleen , Roland McGrath , Ingo Molnar , Jan Beulich , heukelum@fastmail.fm, Thomas Gleixner , Alexander van Heukelum , Glauber Costa , LKML , Nick Piggin Subject: Re: [RFC,v2] x86_64: save_args out of line References: <1226845741-12470-2-git-send-email-heukelum@fastmail.fm> <20081117175232.GA13766@mailshack.com> <49228648.76E4.0078.0@novell.com> <20081118111633.GA21036@mailshack.com> <4922C863.76E4.0078.0@novell.com> <20081118140349.GC23479@elte.hu> <4922E4D4.76E4.0078.0@novell.com> <20081118150024.GD30358@elte.hu> <20081118225336.60FFA1544EB@magilla.localdomain> <20081118233552.GP6703@one.firstfloor.org> <49235178.2050108@goop.org> <49235347.7010005@zytor.com> In-Reply-To: <49235347.7010005@zytor.com> X-Enigmail-Version: 0.95.6 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: 1391 Lines: 35 H. Peter Anvin wrote: > Jeremy Fitzhardinge wrote: >> >> Not really. At the moment we have two parallel assembly languages >> which say different things about the same instructions. In practice, >> almost nobody understands the cfi parts, so they just get ignored >> while the x86 instructions change around them, leaving them either >> stale or missing. >> >> If we had a sensible macro layer which emits both instructions and >> cfi annotations, it at least means that people who write plain x86 >> instructions will simply get no annotations, and people who bother to >> learn the (clearly and fully documented) macros will get the best of >> both. >> > > I think that it would be nice to have macros for the most commonly > annotatable instructions, e.g. push, and stack pointer movement. Just > compactifying the code should improve readability, if perhaps not > writability. Yes. Something that obviously relates to both the instruction and the semantic intent of the annotation: add_sp, sub_sp, save_reg, etc. And at least that will eliminate the differently-signed(!) constant for stack movement. J > > -hpa -- 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/