From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 53046 invoked by alias); 12 Aug 2015 17:17:00 -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 53033 invoked by uid 89); 12 Aug 2015 17:17:00 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.2 required=5.0 tests=AWL,BAYES_00,KAM_LAZY_DOMAIN_SECURITY,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=no 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; Wed, 12 Aug 2015 17:16:59 +0000 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (Postfix) with ESMTPS id 9A6B6341AEE; Wed, 12 Aug 2015 17:16:58 +0000 (UTC) Received: from localhost.localdomain (ovpn-113-104.phx2.redhat.com [10.3.113.104]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t7CHGvVI006059; Wed, 12 Aug 2015 13:16:57 -0400 Subject: Re: Fix reload1.c warning for some targets To: gcc-patches@gcc.gnu.org, richard.sandiford@arm.com References: <87d1z1kedx.fsf@e105548-lin.cambridge.arm.com> From: Jeff Law Message-ID: <55CB7F88.5040104@redhat.com> Date: Wed, 12 Aug 2015 17:17:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 In-Reply-To: <87d1z1kedx.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: 2015-08/txt/msg00634.txt.bz2 On 08/05/2015 08:18 AM, Richard Sandiford wrote: > Building some targets results in a warning about orig_dup[i] potentially > being used uninitialised. I think the warning is fair, since it isn't > obvious that the reog_data-based loop bound remains unchanged between: > > for (i = 0; i < recog_data.n_dups; i++) > orig_dup[i] = *recog_data.dup_loc[i]; > > and: > > for (i = 0; i < recog_data.n_dups; i++) > *recog_data.dup_loc[i] = orig_dup[i]; > > Tested on x86_64-linux-gnu. OK to install? > > Thanks, > Richard > > gcc/ > * reload1.c (elimination_costs_in_insn): Make it obvious to the > compiler that the n_dups and n_operands loop bounds are invariant. So thinking more about this, I think the best way forward is to: 1. Create a new BZ with the false positive extracted from c#4. 2. Install your patch and close 55035. I'll take care of #1, you can handle #2. jeff