Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753520AbYKRWyT (ORCPT ); Tue, 18 Nov 2008 17:54:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751035AbYKRWyG (ORCPT ); Tue, 18 Nov 2008 17:54:06 -0500 Received: from mx1.redhat.com ([66.187.233.31]:60692 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751483AbYKRWyF (ORCPT ); Tue, 18 Nov 2008 17:54:05 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: Roland McGrath To: Ingo Molnar X-Fcc: ~/Mail/linus Cc: Jan Beulich , heukelum@fastmail.fm, Andi Kleen , Thomas Gleixner , Alexander van Heukelum , Glauber Costa , LKML , Nick Piggin , "H. Peter Anvin" Subject: Re: [RFC,v2] x86_64: save_args out of line In-Reply-To: Ingo Molnar's message of Tuesday, 18 November 2008 16:00:24 +0100 <20081118150024.GD30358@elte.hu> 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> X-Shopping-List: (1) Cinematic atypical money (2) Ominous winters (3) Paradoxical organs (4) Symbolical hamster-lip pronunciations Message-Id: <20081118225336.60FFA1544EB@magilla.localdomain> Date: Tue, 18 Nov 2008 14:53:36 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1021 Lines: 23 > but that's the exception. Most of the annotations could be > auto-generated. Not really. An implicit .cfi_undefined can be auto-generated for an unannotated instruction with an output register. An implicit .cfi_register can be auto-generated for an unannotated register-to-register move. An implicit .cfi_same_value can be auto-generated when you can tell a register is being written with the register or stack slot tha the current CFI state says holds the caller's value of that register. Beyond that, it gets into either assumptions or hairy analysis of how stack slots are being used and so forth. I don't think auto-generation is very a useful angle to take for this any time soon. Explicit (but simple) macros in the assembly is what I favor. Thanks, Roland -- 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/