From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 31404 invoked by alias); 21 Jul 2011 16:12:53 -0000 Received: (qmail 31394 invoked by uid 22791); 21 Jul 2011 16:12:52 -0000 X-SWARE-Spam-Status: No, hits=-6.8 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD,SPF_HELO_PASS 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; Thu, 21 Jul 2011 16:12:38 +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 p6LGCVYT028544 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 21 Jul 2011 12:12:31 -0400 Received: from anchor.twiddle.net (vpn-226-71.phx2.redhat.com [10.3.226.71]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id p6LGCVSV028056; Thu, 21 Jul 2011 12:12:31 -0400 Message-ID: <4E284FEE.7080804@redhat.com> Date: Thu, 21 Jul 2011 16:23:00 -0000 From: Richard Henderson User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.18) Gecko/20110621 Fedora/3.1.11-1.fc15 Thunderbird/3.1.11 MIME-Version: 1.0 To: Richard Guenther CC: "Joseph S. Myers" , gcc-patches@gcc.gnu.org Subject: Re: [PATCH] Fix PR49715, (float)unsigned -> (float)signed References: <4E284374.6090304@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: 2011-07/txt/msg01800.txt.bz2 On 07/21/2011 08:47 AM, Richard Guenther wrote: > Hm, of course some targets define unsigned float expanders just do > do the complicated stuff manually (which is why I didn't look > at the conversion optabs). Unfortunately, there's no way to tell optabs.c not to widen conversions all the way into software-only fp modes. This has forced backends to replicate the fallback logic. > I assume that if a target can do > an unsigned -> float conversion it can also to a signed -> float > conversion of the same source mode (probably a safe assumption?). That's an assumption that's borne out in the md files. r~