From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 112654 invoked by alias); 6 Feb 2018 21:59:44 -0000 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 Received: (qmail 112626 invoked by uid 89); 6 Feb 2018 21:59:43 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=1.8 required=5.0 tests=AWL,BAYES_50,KAM_LAZY_DOMAIN_SECURITY autolearn=no version=3.3.2 spammy=Blog, H*r:rev.sfr.net, aric, LIP X-HELO: joooj.vinc17.net Received: from joooj.vinc17.net (HELO joooj.vinc17.net) (155.133.131.76) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 06 Feb 2018 21:59:42 +0000 Received: from smtp-zira.vinc17.net (128.119.75.86.rev.sfr.net [86.75.119.128]) by joooj.vinc17.net (Postfix) with ESMTPSA id AC7D139C; Tue, 6 Feb 2018 22:59:40 +0100 (CET) Received: by zira.vinc17.org (Postfix, from userid 1000) id 6F3EFC218A6; Tue, 6 Feb 2018 22:59:40 +0100 (CET) Date: Tue, 06 Feb 2018 21:59:00 -0000 From: Vincent Lefevre To: gcc@gcc.gnu.org Subject: Re: GCC 8.0.0 Status Report (2018-01-15), Trunk in Regression and Documentation fixes only mode Message-ID: <20180206215940.GB23233@zira.vinc17.org> Mail-Followup-To: gcc@gcc.gnu.org References: <962d449e-3ab8-f9ad-7a2d-8793ae0188d6@sky.com> <8441a3a4-de80-cf19-f9fe-2251fb9064e2@ubuntu.com> <20180206161438.GA10578@zira.vinc17.org> <20180206162831.GB10578@zira.vinc17.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Mailer-Info: https://www.vinc17.net/mutt/ User-Agent: Mutt/1.9.3+89 (65e1f5c8) vl-105418 (2018-01-21) X-IsSubscribed: yes X-SW-Source: 2018-02/txt/msg00055.txt.bz2 On 2018-02-06 17:34:23 +0000, Joseph Myers wrote: > Use -ffp-contract=off to disable all contraction, or -ffp-contract=on to > disable it between statements (which currently actually disables all > contraction, as the FMA generation doesn't know what was originally a > single source expression). The default in the absence of such -std > options is -ffp-contract=fast (allowing contraction including between > different statements). An environment variable to specify default GCC options would be very useful. It is too easy to forget such an option. Note: In the long term, -std=c99 or -std=c11 is better, as if one day, GCC supports the STDC FP_CONTRACT pragma, contraction could be partly enabled. -- Vincent Lefèvre - Web: 100% accessible validated (X)HTML - Blog: Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)