From owner-freebsd-toolchain@FreeBSD.ORG Sat Sep 13 18:01:03 2014 Return-Path: Delivered-To: toolchain@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 75071B1A for ; Sat, 13 Sep 2014 18:01:03 +0000 (UTC) Received: from mail-lb0-f177.google.com (mail-lb0-f177.google.com [209.85.217.177]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id E735A669 for ; Sat, 13 Sep 2014 18:01:02 +0000 (UTC) Received: by mail-lb0-f177.google.com with SMTP id l4so2523887lbv.22 for ; Sat, 13 Sep 2014 11:01:00 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:message-id:date:from:user-agent:mime-version:to :cc:subject:references:in-reply-to:content-type; bh=hxPA66QXN17RUmPgd8KisxOlfOdeuu5Ph60kniTIxNA=; b=ZdNb8eD4/MxCGiZX1gy0kX56m1BJnzE1G4GU5DsFaUu61n5zIVuLniP5HzEhk7UjV/ 0ZcOZTqsJm+agszSyM2GKWATeVsgvz58JhXEQMJ5iqTGc85DhJxS507e9ksnHGUFL7CI egBhUjVHN8oUcBjUuDz2bz8GajkenD5cnV/PDAuDbOXeX5e55eSEhbnO8KU71v/7Ezub lgI6+paa9kqO1sp6pNwVLQuXAxhs2b79zH06pAoBR4beZD6qt5cISmOR1OvLVld6Ly+u yMQmF5py69IdZexGJMydDtardBdLlsQpaYA67uJG+bhjeM0cZSWIZZNbP1SHKE0PkFpe n+kA== X-Gm-Message-State: ALoCoQkXadfaL05Oxqj+8KEJ4Myfu6FqvCNhughVJriW9uyV6YRz/wxGjLaDU4XA9aULCVN9BR9B X-Received: by 10.152.9.200 with SMTP id c8mr17684768lab.76.1410631260075; Sat, 13 Sep 2014 11:01:00 -0700 (PDT) Received: from [192.168.1.2] ([89.169.173.68]) by mx.google.com with ESMTPSA id zt1sm2534324lbc.31.2014.09.13.11.00.59 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 13 Sep 2014 11:00:59 -0700 (PDT) Message-ID: <5414865A.6030101@freebsd.org> Date: Sat, 13 Sep 2014 22:00:58 +0400 From: Andrey Chernov User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.1.1 MIME-Version: 1.0 To: Dimitry Andric Subject: Re: clang makes segfaulting code with -march=core2 on i386 References: <54130AD0.8090103@freebsd.org> <54133E1E.9030105@freebsd.org> <54135B24.5040905@freebsd.org> <54135D0B.7060701@freebsd.org> <6FDF432B-8245-4BC7-952B-DFFEEA106D6F@FreeBSD.org> In-Reply-To: <6FDF432B-8245-4BC7-952B-DFFEEA106D6F@FreeBSD.org> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="n7FhQD5bMaQ4uuo5HlHcbDp2tc4Xu1rTK" Cc: toolchain@freebsd.org X-BeenThere: freebsd-toolchain@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Maintenance of FreeBSD's integrated toolchain List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 13 Sep 2014 18:01:03 -0000 This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --n7FhQD5bMaQ4uuo5HlHcbDp2tc4Xu1rTK Content-Type: text/plain; charset=koi8-r Content-Transfer-Encoding: quoted-printable On 13.09.2014 20:45, Dimitry Andric wrote: > After some massaging of gcc's source to disable its built-in segfault > handlers, I get this backtrace: Do you get this with my core or finally able to reproduce it by yourself?= > I think it's most likely this is some type of undefined behavior in gcc= , > which leads to randomly corrupted tree values. Of course, it could als= o > be a clang bug, but I don't see any "64-bit" instructions in there at > all. >=20 > This needs to be investigated further, but it's very hard to understand= > what is going on the guts of gcc's parser. Let alone to reduce this to= > some sort of reproducible test case. By first glance I see a lots of things. It is known that in edge cases gcc preserves more "unused" values than clang. It can be the possible case. I'll try to lower -O level preserving -march=3Dcore2 and see. --=20 http://ache.vniz.net/ --n7FhQD5bMaQ4uuo5HlHcbDp2tc4Xu1rTK Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEcBAEBCAAGBQJUFIZaAAoJEKUckv0MjfbKvDcH/jJIOeC+TalKXt2DFGkKvW3x T9dMEGXISSdt4y5z9/EdKCDtHY5YPu0QOjCaSHLRRfOYiW2cpKoUdw7rjzRyq4Sm q+Ys97X16ttCUaaeh0EpT1oKEyh7OSvv/MA77zAPO/ep3fER6pM7BZmhj5IxZ8N7 x8Zco6birUT7GoXuiRPIExXJnz6ceUou2kF6bEiuTMiV3dU/c18v6TK2O1WMz5hm ZdDY6DoWbNcQi5y13ESs/iTFcxyRut/A0WwllbLfyVXcXi6mmYBPclKgzj9ILHp0 4KegthiD7FWYZ88SPohltLdY57CyY9T0eiPoTsxNGGb4f3BUWGD79ccaWm52neg= =xzzE -----END PGP SIGNATURE----- --n7FhQD5bMaQ4uuo5HlHcbDp2tc4Xu1rTK--