From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id F0558385840E for ; Tue, 21 Mar 2023 23:31:40 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org F0558385840E Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1679441500; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=yQru3cibU66Z4NPeNIHs+clpXO25A7ORsbwphVpKa5g=; b=MlcXqp8PjnX10EOkMQkOB7PmNfUcyjJKb8Isn+anXai3gLeMirPbQEZ+cgBvpHwvuttjbM Wj1Y/wG29pYaH+u6uPCLhE0F2W4HNKRlxc6S98yGtWgZapIOJO724qtUEKyx9135h6xicx 2aTd+/U1CcyVwPoemut3YmECe83PHeE= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-136-g8ptgKZtMomaRkik1XW7Cw-1; Tue, 21 Mar 2023 19:31:39 -0400 X-MC-Unique: g8ptgKZtMomaRkik1XW7Cw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id F0570100DEAF; Tue, 21 Mar 2023 23:31:38 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.39.192.16]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B3AB62166B29; Tue, 21 Mar 2023 23:31:38 +0000 (UTC) Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.17.1/8.17.1) with ESMTPS id 32LNVZRM224644 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Wed, 22 Mar 2023 00:31:36 +0100 Received: (from jakub@localhost) by tucnak.zalov.cz (8.17.1/8.17.1/Submit) id 32LNVZRe223587; Wed, 22 Mar 2023 00:31:35 +0100 Date: Wed, 22 Mar 2023 00:31:34 +0100 From: Jakub Jelinek To: Jeff Law Cc: Qing Zhao , "gcc-patches@gcc.gnu.org" Subject: Re: Should -ffp-contract=off the default on GCC? Message-ID: Reply-To: Jakub Jelinek References: <87384938-FDB1-487B-8B03-7787996435B2@comcast.net> <7C6B7ED7-7AA4-47EF-8E44-E3AD81BF3E29@oracle.com> <4a670847-9728-e0cb-46f3-d476839f7cd4@gmail.com> <9787B47E-9800-47B1-B98D-60430257C4E5@oracle.com> <9a05445f-320d-08ca-7ca6-42c1ec44a1bf@gmail.com> MIME-Version: 1.0 In-Reply-To: <9a05445f-320d-08ca-7ca6-42c1ec44a1bf@gmail.com> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Spam-Status: No, score=-3.3 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Tue, Mar 21, 2023 at 05:28:52PM -0600, Jeff Law via Gcc-patches wrote: > On 3/21/23 13:12, Jakub Jelinek wrote: > > On Tue, Mar 21, 2023 at 07:01:36PM +0000, Qing Zhao via Gcc-patches wrote: > > > In addition to this, Standards have been changed from time to time. > > > > So, the user needs to know the standard they are compiling for. > > > > Anyway, talking again about contractions, it isn't anything new in the > > standard, C99 had those too. > And I think Qing is asking if adding a warning in the manual about how fp > contractions can cause unpredictability in FP results is appropriate in the > fp-contract section. > > I think that would be a fine addition to the manual. Depending on how it is worded, probably yes. Jakub