From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 117241 invoked by alias); 15 Jan 2016 16:35:01 -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 117174 invoked by uid 89); 15 Jan 2016 16:35:00 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy=Hx-languages-length:875 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, 15 Jan 2016 16:34:59 +0000 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (Postfix) with ESMTPS id 31FC68F872 for ; Fri, 15 Jan 2016 16:34:58 +0000 (UTC) Received: from slagheap.utah.redhat.com ([10.3.113.15]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u0FGYvbx007611; Fri, 15 Jan 2016 11:34:57 -0500 Subject: Re: IRA fix for 47992 To: Bernd Schmidt , GCC Patches References: <5698F757.1080709@redhat.com> From: Jeff Law Message-ID: <56991FB1.4010108@redhat.com> Date: Fri, 15 Jan 2016 16:35:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.0 MIME-Version: 1.0 In-Reply-To: <5698F757.1080709@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2016-01/txt/msg01095.txt.bz2 On 01/15/2016 06:42 AM, Bernd Schmidt wrote: > This is a report of a crash in IRA. If you debug it with a sufficiently > old compiler, you'll find that we manage to delete some basic blocks > from within IRA. Later on, reload calls alter_reg for all unallocated > pseudos, including one that only occurs in the deleted blocks. reload > does not notice it is unused, because REG_N_REFS is still 3. We crash in > an IRA callback because the pseudo has no allocno. > > Fixed as below. A similar patch cures the problem in gcc-4.6. Adding a > testcase seems pointless - the crashing code was derived from an > existing Fortran testcase with exotic options, and the whole thing only > ever triggered in one gcc version AFAICT. Current gcc can't trigger it > because it's not using reload on x86_64. > > Bootstrapped and tested on x86_64-linux, ok? OK. jeff