From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 9266 invoked by alias); 24 Feb 2014 09:17:28 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 9247 invoked by uid 89); 24 Feb 2014 09:17:28 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.7 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.2 X-HELO: out3-smtp.messagingengine.com Received: from out3-smtp.messagingengine.com (HELO out3-smtp.messagingengine.com) (66.111.4.27) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Mon, 24 Feb 2014 09:17:26 +0000 Received: from compute4.internal (compute4.nyi.mail.srv.osa [10.202.2.44]) by gateway1.nyi.mail.srv.osa (Postfix) with ESMTP id 0798720C1C for ; Mon, 24 Feb 2014 04:17:21 -0500 (EST) Received: from frontend1 ([10.202.2.160]) by compute4.internal (MEProxy); Mon, 24 Feb 2014 04:17:21 -0500 Received: from [192.168.178.70] (unknown [84.56.3.242]) by mail.messagingengine.com (Postfix) with ESMTPA id 5E547C007AA; Mon, 24 Feb 2014 04:17:20 -0500 (EST) Message-ID: <530B0E1F.8030704@grosser.es> Date: Mon, 24 Feb 2014 09:17:00 -0000 From: Tobias Grosser User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Roman Gareev , gcc-graphite@googlegroups.com CC: GCC Mailing List Subject: Re: asking your advice about bug References: <15de9e2a-10f5-4a5e-8621-3c27bf3ce290@googlegroups.com> <52EF8E94.4010708@grosser.es> <06fe5f6f-1914-49d8-84fe-0e6849e2ee04@googlegroups.com> <52F2344B.1070200@grosser.es> <400c1fca-ab51-48ac-883c-a57c9f742237@googlegroups.com> <52FECDEA.50604@grosser.es> <2dfaa7b0-4a9e-443e-8307-394083fe9777@googlegroups.com> In-Reply-To: <2dfaa7b0-4a9e-443e-8307-394083fe9777@googlegroups.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2014-02/txt/msg00448.txt.bz2 On 02/17/2014 06:50 PM, Roman Gareev wrote: > > > Hi Tobias, > > > thanks for the answer! Hi Roman, sorry for missing this mail. > > I think that the segfault is being caused by NULL arguments being passedto compute_deps > by loop_level_carries_dependences. *This is **causing **an* *assignment of** > NULL values to the following parameters of **compute_deps:* must_raw_no_source, > may_raw_no_source, must_war_no_source, may_war_no_source, > must_waw_no_source, may_waw_no_source. They are being passed to subtract_commutative_associative_deps > and dereferenced in the following statements: > > > *must_raw_no_source = isl_union_map_subtract (*must_raw_no_source, > x_must_raw_no_source); > > > *may_raw_no_source = isl_union_map_subtract (*may_raw_no_source, > x_may_raw_no_source); > > > *must_war_no_source = isl_union_map_subtract (*must_war_no_source, > x_must_war_no_source); > > > *may_war_no_source = isl_union_map_subtract (*may_war_no_source, > x_may_war_no_source); > > > *must_waw_no_source = isl_union_map_subtract (*must_waw_no_source, > x_must_waw_no_source); > > > *may_waw_no_source = isl_union_map_subtract (*may_waw_no_source, > x_may_waw_no_source); > > This is the reason of segfault. (All functions mentioned above are located > in gcc/graphite-dependences.c) > Interesting analysis. > I think that this can be solved by the addition to > subtract_commutative_associative_deps of NULL checking of the following > variables: must_raw_no_source, may_raw_no_source, must_war_no_source, > may_war_no_source, must_waw_no_source, may_waw_no_source. I've implemented > this in the patch, which can be found below. Yes, this would be a 'solution'. However, I am in fact surprised that those variables are NULL at all. Do you have an idea why this is the case? Understanding this would help to understand if the patch you propose is actually the right solution or if it is just hiding a previous bug. Cheers, Tobias