From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 12751 invoked by alias); 13 Oct 2016 10:16:20 -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 12264 invoked by uid 89); 13 Oct 2016 10:16:15 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.8 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE,SPF_PASS autolearn=ham version=3.3.2 spammy=outcome, uleb128, sleb128, 0x9 X-HELO: smtp.eu.adacore.com Received: from mel.act-europe.fr (HELO smtp.eu.adacore.com) (194.98.77.210) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 13 Oct 2016 10:16:14 +0000 Received: from localhost (localhost [127.0.0.1]) by filtered-smtp.eu.adacore.com (Postfix) with ESMTP id 45909812DD; Thu, 13 Oct 2016 12:16:12 +0200 (CEST) Received: from smtp.eu.adacore.com ([127.0.0.1]) by localhost (smtp.eu.adacore.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 29eXgsEORR6R; Thu, 13 Oct 2016 12:16:12 +0200 (CEST) Received: from polaris.localnet (bon31-6-88-161-99-133.fbx.proxad.net [88.161.99.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.eu.adacore.com (Postfix) with ESMTPSA id 2285A812D8; Thu, 13 Oct 2016 12:16:12 +0200 (CEST) From: Eric Botcazou To: Richard Biener Cc: gcc-patches@gcc.gnu.org Subject: Re: [patch] Fix GC issue triggered by arithmetic overflow checking Date: Thu, 13 Oct 2016 10:16:00 -0000 Message-ID: <1624828.Cq9Sk6vVoa@polaris> User-Agent: KMail/4.14.10 (Linux/3.16.7-42-desktop; KDE/4.14.9; x86_64; ; ) In-Reply-To: References: <1863165.r8qPLI7fxq@polaris> <2004625.PcKOVMIpSq@polaris> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-SW-Source: 2016-10/txt/msg01000.txt.bz2 > Yes. But that's not the only source for DECL_UID differences. Btw, > I see lots of FOR_EACH_HASH_TABLE_ELEMENT in var-tracking.c > but they don't look like their outcome is supposed to be dependent on > element ordering. This leads to NOTE_INSN_VAR_LOCATION notes emitted in a different order, which are then interpreted by dwarf2out_var_location. In particular: (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. -- Eric Botcazou