From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14138 invoked by alias); 20 Sep 2011 07:56:57 -0000 Received: (qmail 14128 invoked by uid 22791); 20 Sep 2011 07:56:56 -0000 X-SWARE-Spam-Status: No, hits=-2.4 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED,DKIM_VALID,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW X-Spam-Check-By: sourceware.org Received: from mail-wy0-f175.google.com (HELO mail-wy0-f175.google.com) (74.125.82.175) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 20 Sep 2011 07:56:39 +0000 Received: by wyh5 with SMTP id 5so249048wyh.20 for ; Tue, 20 Sep 2011 00:56:37 -0700 (PDT) Received: by 10.227.55.5 with SMTP id s5mr508265wbg.92.1316505397916; Tue, 20 Sep 2011 00:56:37 -0700 (PDT) Received: from yakj.usersys.redhat.com (93-34-188-71.ip51.fastwebnet.it. [93.34.188.71]) by mx.google.com with ESMTPS id p2sm1045803wbo.17.2011.09.20.00.56.36 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 20 Sep 2011 00:56:36 -0700 (PDT) Message-ID: <4E784734.10300@gnu.org> Date: Tue, 20 Sep 2011 07:56:00 -0000 From: Paolo Bonzini User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:6.0.2) Gecko/20110906 Thunderbird/6.0.2 MIME-Version: 1.0 To: "gcc@gcc.gnu.org" CC: Richard Henderson Subject: Re: should sync builtins be full optimization barriers? References: <4E7225AF.3060800@redhat.com> <4E722733.3010003@gnu.org> In-Reply-To: <4E722733.3010003@gnu.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org X-SW-Source: 2011-09/txt/msg00194.txt.bz2 On 09/15/2011 06:26 PM, Paolo Bonzini wrote: > >> There's no reference to a GCC bug report about this in the thread. >> Did the folks over at the libdispatch project never think to file one? > > I asked them to attach a preprocessed testcase somewhere, but they > haven't done so yet. :( They now attached it, and the bug turns out to be a missing parenthesis in an #ifdef. This made libdispatch compile the xchg as an asm rather than a sync builtin. And of course the asm was wrong. Apparently, Apple people on the mailing list were looking at the Apple trunk, but the reporter was obviously compiling from the public trunk. Paolo