From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 109013 invoked by alias); 13 Oct 2016 10:37:45 -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 108947 invoked by uid 89); 13 Oct 2016 10:37:44 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.3 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy=Hx-languages-length:2112, Location 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 ESMTP; Thu, 13 Oct 2016 10:37:42 +0000 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6503B4E33C; Thu, 13 Oct 2016 10:37:41 +0000 (UTC) Received: from tucnak.zalov.cz (ovpn-116-44.ams2.redhat.com [10.36.116.44]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u9DAbdps012054 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 13 Oct 2016 06:37:40 -0400 Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.15.2/8.15.2) with ESMTP id u9DAbbRm023528; Thu, 13 Oct 2016 12:37:37 +0200 Received: (from jakub@localhost) by tucnak.zalov.cz (8.15.2/8.15.2/Submit) id u9DAbZBT023527; Thu, 13 Oct 2016 12:37:35 +0200 Date: Thu, 13 Oct 2016 10:37:00 -0000 From: Jakub Jelinek To: Richard Biener Cc: Eric Botcazou , GCC Patches Subject: Re: [patch] Fix GC issue triggered by arithmetic overflow checking Message-ID: <20161013103735.GD7282@tucnak.redhat.com> Reply-To: Jakub Jelinek References: <1863165.r8qPLI7fxq@polaris> <2004625.PcKOVMIpSq@polaris> <1624828.Cq9Sk6vVoa@polaris> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-IsSubscribed: yes X-SW-Source: 2016-10/txt/msg01008.txt.bz2 On Thu, Oct 13, 2016 at 12:19:53PM +0200, Richard Biener wrote: > > (note 6350 6349 6351 (var_location temp (nil)) NOTE_INSN_VAR_LOCATION) > > (note 6351 6350 6352 (var_location temp$low (mem/c:DI (plus:SI (reg/f:SI 30 > > %fp) > > (const_int -112 [0xffffffffffffff90])) [10 MEM[(struct cpp_num > > *)&result + 8B]+0 S8 A64])) NOTE_INSN_VAR_LOCATION) > > (note 6352 6351 6353 (var_location temp$8 (nil)) NOTE_INSN_VAR_LOCATION) > > [...] > > (code_label 2091 6355 2092 79 912 "" [1 uses]) > > (note 2092 2091 5271 79 [bb 79] NOTE_INSN_BASIC_BLOCK) > > > > is interpreted differently from: > > > > (note 6350 6349 6351 (var_location temp (nil)) NOTE_INSN_VAR_LOCATION) > > (note 6351 6350 6352 (var_location temp$8 (nil)) NOTE_INSN_VAR_LOCATION) > > (note 6352 6351 6353 (var_location temp$low (mem/c:DI (plus:SI (reg/f:SI 30 > > %fp) > > (const_int -112 [0xffffffffffffff90])) [10 MEM[(struct cpp_num > > *)&result + 8B]+0 S8 A64])) NOTE_INSN_VAR_LOCATION) > > [...] > > (note 2092 2091 5271 79 [bb 79] NOTE_INSN_BASIC_BLOCK) > > > > @@ -32608,6 +32608,17 @@ > > .uleb128 0x8 > > .byte 0x93 ! DW_OP_piece > > .uleb128 0x8 > > + .uaword .LLVL592-.LLtext0 ! Location list begin address > > (*.LLLST153) > > + .uaword .LLVL597-.LLtext0 ! Location list end address > > (*.LLLST153) > > + .uahalf 0x9 ! Location expression size > > + .byte 0x93 ! DW_OP_piece > > + .uleb128 0x8 > > + .byte 0x8e ! DW_OP_breg30 > > + .sleb128 -112 > > + .byte 0x93 ! DW_OP_piece > > + .uleb128 0x8 > > + .byte 0x93 ! DW_OP_piece > > + .uleb128 0x8 > > .uaword .LLVL695-.LLtext0 ! Location list begin address > > (*.LLLST153) > > .uaword .LLVL696-.LLtext0 ! Location list end address > > (*.LLLST153) > > .uahalf 0xe ! Location expression size > > > > probably because the non-null location comes last in the second case. > > Definitely looks like a bug to me. Can you open a PR for this so it doesn't get > lost? I guess it depends on whether temp$8 and temp$low overlap or not. If they overlap, then the different orders of course matter and should matter. Jakub