Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1032440AbXEHWEx (ORCPT ); Tue, 8 May 2007 18:04:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934472AbXEHWEt (ORCPT ); Tue, 8 May 2007 18:04:49 -0400 Received: from gw.goop.org ([64.81.55.164]:49736 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934468AbXEHWEr (ORCPT ); Tue, 8 May 2007 18:04:47 -0400 Message-ID: <4640F3FD.80001@goop.org> Date: Tue, 08 May 2007 15:04:45 -0700 From: Jeremy Fitzhardinge User-Agent: Thunderbird 1.5.0.10 (X11/20070302) MIME-Version: 1.0 To: David Rientjes CC: Randy Dunlap , Andrew Morton , Paul Sokolovsky , linux-kernel@vger.kernel.org, Andi Kleen Subject: Re: [RFC/PATCH] doc: volatile considered evil References: <516386418.20070501080839@gmail.com> <20070430235642.e576e917.akpm@linux-foundation.org> <20070508121404.17bd97a6.randy.dunlap@oracle.com> <4640E98B.4030107@goop.org> <4640ED7D.708@goop.org> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1267 Lines: 31 David Rientjes wrote: > Now if all such output operands are to specify that the input operands > were "modified", 'volatile' is required to ensure the side-effects are > preserved or, otherwise, gcc is free optimize the entire asm construct > away since it appears to be unused. > Yup. >> Yeah, they're completely different. They're not even analogous, really, >> which was my point. People confer more meaning to "asm volatile" than >> it actually has, because of the analogy with volatile variables/types. >> They would have been better off with something like "asm static", which >> isn't much more meaningful, but at least it doesn't mislead the reader >> into thinking it has anything to do with the other volatile. >> >> > > You're point about reordering "asm volatile" constructs differs depending > on -mvolatile-asm-stop or -mno-volatile-asm-stop, however. > Erm, that seems to be ia64 specific, and I have no idea what adding a "stop bit" implies. Can you set even or odd parity too? J - 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/