From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932490AbVHYC1G (ORCPT ); Wed, 24 Aug 2005 22:27:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932491AbVHYC1G (ORCPT ); Wed, 24 Aug 2005 22:27:06 -0400 Received: from mail1.webmaster.com ([216.152.64.168]:55313 "EHLO mail1.webmaster.com") by vger.kernel.org with ESMTP id S932490AbVHYC1F (ORCPT ); Wed, 24 Aug 2005 22:27:05 -0400 From: "David Schwartz" To: "linux-os \(Dick Johnson\)" , "Andy Isaacson" Cc: "moreau francis" , Subject: RE: question on memory barrier Date: Wed, 24 Aug 2005 19:25:51 -0700 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.6604 (9.0.2911.0) Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2670 In-Reply-To: X-Authenticated-Sender: joelkatz@webmaster.com X-Spam-Processed: mail1.webmaster.com, Wed, 24 Aug 2005 19:23:52 -0700 (not processed: message from trusted or authenticated source) X-MDRemoteIP: 206.171.168.138 X-Return-Path: davids@webmaster.com X-MDaemon-Deliver-To: linux-kernel@vger.kernel.org Reply-To: davids@webmaster.com X-MDAV-Processed: mail1.webmaster.com, Wed, 24 Aug 2005 19:23:57 -0700 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > Wrong. Reference: > > http://www.phy.duke.edu/~rgb/General/c_book/c_book/chapter8/sequen > ce_points.html > > Cheers, > Dick Johnson That discussion is wrong. The form of the argument is simply invalid. Just because an optimization could break things in some cases doesn’t mean the compiler can’t ever make the optimization. It just can’t make the optimization in the case that breaks things. And by “things” I mean things that are defined in the standard that would be broken, not things outside of it. DS