From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 32214 invoked by alias); 19 Sep 2014 17:54:05 -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 32203 invoked by uid 89); 19 Sep 2014 17:54:05 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.1 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=ham 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, 19 Sep 2014 17:54:03 +0000 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s8JHrvmZ007138 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 19 Sep 2014 13:53:57 -0400 Received: from stumpy.slc.redhat.com (ovpn-113-30.phx2.redhat.com [10.3.113.30]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s8JHrvCx032475; Fri, 19 Sep 2014 13:53:57 -0400 Message-ID: <541C6DB5.8010006@redhat.com> Date: Fri, 19 Sep 2014 17:54:00 -0000 From: Jeff Law User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.0 MIME-Version: 1.0 To: gcc-patches@gcc.gnu.org, richard.sandiford@arm.com Subject: Re: [PATCH 5/5] Remove CANNOT_CHANGE_MODE_CLASS workaround in i386.c References: <87ppetnsxd.fsf@e105548-lin.cambridge.arm.com> <874mw5ns0x.fsf@e105548-lin.cambridge.arm.com> In-Reply-To: <874mw5ns0x.fsf@e105548-lin.cambridge.arm.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2014-09/txt/msg01667.txt.bz2 On 09/18/14 04:26, Richard Sandiford wrote: > Patch 4 should make it possible to relax i386'a CANNOT_CHANGE_MODE_CLASS, > solving the missed optimisation that triggered the original thread. > > > gcc/ > * config/i386/i386.c (ix86_cannot_change_mode_class): Remove > GET_MODE_SIZE (to) < GET_MODE_SIZE (from) test. > > Index: gcc/config/i386/i386.c > =================================================================== > --- gcc/config/i386/i386.c 2014-09-15 09:48:11.310438531 +0100 > +++ gcc/config/i386/i386.c 2014-09-15 09:48:11.310438531 +0100 > @@ -37526,13 +37526,6 @@ ix86_cannot_change_mode_class (enum mach > the vec_dupv4hi pattern. */ > if (GET_MODE_SIZE (from) < 4) > return true; > - > - /* Vector registers do not support subreg with nonzero offsets, which > - are otherwise valid for integer registers. Since we can't see > - whether we have a nonzero offset from here, prohibit all > - nonparadoxical subregs changing size. */ > - if (GET_MODE_SIZE (to) < GET_MODE_SIZE (from)) > - return true; > } > > return false; > OK. jeff