From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764996AbXGWS3v (ORCPT ); Mon, 23 Jul 2007 14:29:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758401AbXGWS3m (ORCPT ); Mon, 23 Jul 2007 14:29:42 -0400 Received: from gw.goop.org ([64.81.55.164]:34832 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758352AbXGWS3l (ORCPT ); Mon, 23 Jul 2007 14:29:41 -0400 Message-ID: <46A4F360.2000905@goop.org> Date: Mon, 23 Jul 2007 11:28:48 -0700 From: Jeremy Fitzhardinge User-Agent: Thunderbird 2.0.0.4 (X11/20070615) MIME-Version: 1.0 To: Satyam Sharma CC: Linux Kernel Mailing List , David Howells , Nick Piggin , Andi Kleen , Andrew Morton , Linus Torvalds Subject: Re: [PATCH 7/8] i386: bitops: Kill needless usage of __asm__ __volatile__ References: <20070723160528.22137.84144.sendpatchset@cselinux1.cse.iitk.ac.in> <20070723160603.22137.16516.sendpatchset@cselinux1.cse.iitk.ac.in> <46A4D612.9050209@goop.org> <46A4E7E3.8090105@goop.org> In-Reply-To: X-Enigmail-Version: 0.95.2 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 Satyam Sharma wrote: > The (3) as I had originally written / meant was that multiple > instructions in a volatile asm would not get _individually_ > interspersed with the rest of the code i.e. be emitted out > _consecutively_. I don't think we need any such guarantees for > the non-atomic variants of those operations, so it's good to > let the compiler have a free hand with what it wants to do, > and optimize/combine multiple bitops as necessary / possible, > which was the original intention. > No, a single asm statement is always emitted in one piece. Gcc doesn't parse the string other than to do %-substitution to insert arguments, so it has no way to meaningfully split it up. J