From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 130831 invoked by alias); 22 May 2015 18:24:57 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 130800 invoked by uid 89); 22 May 2015 18:24:56 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.4 required=5.0 tests=AWL,BAYES_00,KAM_LAZY_DOMAIN_SECURITY,SPF_HELO_PASS,T_RP_MATCHES_RCVD autolearn=no version=3.3.2 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Fri, 22 May 2015 18:24:56 +0000 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (Postfix) with ESMTPS id 1BA20BAEFD; Fri, 22 May 2015 18:24:55 +0000 (UTC) Received: from anchor.twiddle.net (vpn-227-123.phx2.redhat.com [10.3.227.123]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t4MIOrue003436; Fri, 22 May 2015 14:24:54 -0400 Message-ID: <555F7474.7090107@redhat.com> Date: Fri, 22 May 2015 19:49:00 -0000 From: Richard Henderson User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Jason Merrill , Ramana Radhakrishnan , David Edelsohn CC: "gcc-patches@gcc.gnu.org" , Jim Wilson , Steve Ellcey , Steve Munroe , Torvald Riegel Subject: Re: [RFC / CFT] PR c++/66192 - Remove TARGET_RELAXED_ORDERING and use load acquires. References: <555F1143.4070606@foss.arm.com> <555F11B6.1070001@foss.arm.com> <555F31CF.6060201@redhat.com> <555F3D09.2070700@redhat.com> <555F49FF.1070402@foss.arm.com> <555F6911.6030205@redhat.com> In-Reply-To: <555F6911.6030205@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2015-05/txt/msg02160.txt.bz2 On 05/22/2015 10:36 AM, Jason Merrill wrote: > It also seems unnecessary to load 8 bytes on any target; we could add a > function to optabs.c that returns the smallest mode for which there's atomic > load support? No, while we do use an atomic_load pattern if it exists, we assume that all loads no larger than word_mode are atomic. Thus if the atomic_load doesn't exist, we'll issue a normal move. If we're just trying to load 8 bits, we can do that on *any* target. r~