From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 31370 invoked by alias); 18 Sep 2014 10:26:44 -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 31358 invoked by uid 89); 18 Sep 2014 10:26:43 -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_00,SPF_PASS autolearn=ham version=3.3.2 X-HELO: service87.mimecast.com Received: from service87.mimecast.com (HELO service87.mimecast.com) (91.220.42.44) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 18 Sep 2014 10:26:42 +0000 Received: from cam-owa1.Emea.Arm.com (fw-tnat.cambridge.arm.com [217.140.96.21]) by service87.mimecast.com; Thu, 18 Sep 2014 11:26:40 +0100 Received: from localhost ([10.1.255.212]) by cam-owa1.Emea.Arm.com with Microsoft SMTPSVC(6.0.3790.3959); Thu, 18 Sep 2014 11:26:39 +0100 From: Richard Sandiford To: gcc-patches@gcc.gnu.org Mail-Followup-To: gcc-patches@gcc.gnu.org, richard.sandiford@arm.com Subject: [PATCH 5/5] Remove CANNOT_CHANGE_MODE_CLASS workaround in i386.c References: <87ppetnsxd.fsf@e105548-lin.cambridge.arm.com> Date: Thu, 18 Sep 2014 10:26:00 -0000 In-Reply-To: <87ppetnsxd.fsf@e105548-lin.cambridge.arm.com> (Richard Sandiford's message of "Thu, 18 Sep 2014 11:07:10 +0100") Message-ID: <874mw5ns0x.fsf@e105548-lin.cambridge.arm.com> User-Agent: Gnus/5.130012 (Ma Gnus v0.12) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 X-MC-Unique: 114091811264002901 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable X-SW-Source: 2014-09/txt/msg01450.txt.bz2 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 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D --- 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; } =20 return false;