From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 99286 invoked by alias); 29 Aug 2016 15:40:59 -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 97308 invoked by uid 89); 29 Aug 2016 15:40:58 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE,SPF_PASS,URIBL_RED autolearn=ham version=3.3.2 spammy=versus, Hx-languages-length:1162 X-HELO: relay1.mentorg.com Received: from relay1.mentorg.com (HELO relay1.mentorg.com) (192.94.38.131) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Mon, 29 Aug 2016 15:40:48 +0000 Received: from nat-ies.mentorg.com ([192.94.31.2] helo=SVR-IES-FEM-01.mgc.mentorg.com) by relay1.mentorg.com with esmtp id 1beOg0-0001lV-48 from joseph_myers@mentor.com ; Mon, 29 Aug 2016 08:40:44 -0700 Received: from digraph.polyomino.org.uk (137.202.0.76) by SVR-IES-FEM-01.mgc.mentorg.com (137.202.0.104) with Microsoft SMTP Server id 14.3.224.2; Mon, 29 Aug 2016 16:40:42 +0100 Received: from jsm28 (helo=localhost) by digraph.polyomino.org.uk with local-esmtp (Exim 4.86_2) (envelope-from ) id 1beOfx-0002Zy-8l; Mon, 29 Aug 2016 15:40:41 +0000 Date: Mon, 29 Aug 2016 15:40:00 -0000 From: Joseph Myers To: Marek Polacek CC: Paul Eggert , , Subject: Re: Make max_align_t respect _Float128 In-Reply-To: <20160829132935.GB11131@redhat.com> Message-ID: References: <56e04616-afd7-7fce-f2ba-00304ea5686b@cs.ucla.edu> <20160829132935.GB11131@redhat.com> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" X-SW-Source: 2016-08/txt/msg01973.txt.bz2 On Mon, 29 Aug 2016, Marek Polacek wrote: > On Fri, Aug 26, 2016 at 02:51:38PM -0700, Paul Eggert wrote: > > > Well, the patch could use __SIZEOF_FLOAT128__ just as well as __i386__ > > > (the effect would be an extra union member > > > > s/union/struct/. Though I've always wondered why it is a struct and not a > > union. Maybe change it to union while we're doing an ABI change anyway? > > Yeah, me too. The initial implementation is here > but I don't see any > comments wrt max_align_t being a struct or a union there. I'm not aware of a specific reason for struct versus union (naming via a typedef without a struct tag, so that no identifiers from the tag namespace are used for C and so that the name for linkage purposes in C++ is max_align_t, is deliberate, however). While the chance of any code's ABI being affected by the size of the type should be small, the minimum change is certainly the one that uses __i386__ and so doesn't affect the type at all except in the case where it's necessary to do so. -- Joseph S. Myers joseph@codesourcery.com