From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 13632 invoked by alias); 9 Nov 2010 01:37:50 -0000 Received: (qmail 13624 invoked by uid 22791); 9 Nov 2010 01:37:49 -0000 X-SWARE-Spam-Status: No, hits=-5.9 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI,SPF_HELO_PASS,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 09 Nov 2010 01:37:40 +0000 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id oA91ZuY8012306 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Mon, 8 Nov 2010 20:35:56 -0500 Received: from anchor.twiddle.home (ovpn-113-46.phx2.redhat.com [10.3.113.46]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id oA91Zqxc021763; Mon, 8 Nov 2010 20:35:52 -0500 Message-ID: <4CD8A578.1020301@redhat.com> Date: Tue, 09 Nov 2010 01:41:00 -0000 From: Richard Henderson User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.12) Gecko/20101027 Fedora/3.1.6-1.fc14 Thunderbird/3.1.6 MIME-Version: 1.0 To: "Joseph S. Myers" CC: Steve Ellcey , Richard Guenther , gcc-patches@gcc.gnu.org, sterling@tensilica.com, rdsandiford@googlemail.com Subject: Re: -mfused-madd vs -ffp-contract deprication? References: <201011081911.oA8JBqS23929@lucas.cup.hp.com> <4CD84DCB.5080806@redhat.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-IsSubscribed: yes 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 X-SW-Source: 2010-11/txt/msg00830.txt.bz2 On 11/08/2010 02:58 PM, Joseph S. Myers wrote: > : > Existing target options may sometimes be ambiguous as to whether they are > meant to disable instructions that might not be available, or to disable > automatic conversion It's currently used in: xtensa i386 s390 rs6000 mips ia64 Given that MIPS doesn't implement true FMA, MIPS probably should match the (plus (mult a b) c) pattern unconditionally (modulo ISA) and be done with it. The rest of the targets either have the instructions in the base ISA (xtensa, s390, rs6000, ia64) or additionally have some other macro that controls availability (i386). So, if we fix MIPS all remaining users will only control contraction. Only xtensa has not been converted to the named fma patterns, though many still contain additional (plus (mult)) patterns for FUSED_MADD. Given that we have a pass that performs that operation at the tree level, it would seem that all we need to do is delete the obsolete patterns. r~