From owner-freebsd-hackers@FreeBSD.ORG Tue Feb 22 10:12:22 2011 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 36B5C106567A for ; Tue, 22 Feb 2011 10:12:22 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from mail.zoral.com.ua (mx0.zoral.com.ua [91.193.166.200]) by mx1.freebsd.org (Postfix) with ESMTP id A2C6E8FC18 for ; Tue, 22 Feb 2011 10:12:21 +0000 (UTC) Received: from deviant.kiev.zoral.com.ua (root@deviant.kiev.zoral.com.ua [10.1.1.148]) by mail.zoral.com.ua (8.14.2/8.14.2) with ESMTP id p1MACG4A084556 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 22 Feb 2011 12:12:16 +0200 (EET) (envelope-from kostikbel@gmail.com) Received: from deviant.kiev.zoral.com.ua (kostik@localhost [127.0.0.1]) by deviant.kiev.zoral.com.ua (8.14.4/8.14.4) with ESMTP id p1MACGKi048553; Tue, 22 Feb 2011 12:12:16 +0200 (EET) (envelope-from kostikbel@gmail.com) Received: (from kostik@localhost) by deviant.kiev.zoral.com.ua (8.14.4/8.14.4/Submit) id p1MACGLt048552; Tue, 22 Feb 2011 12:12:16 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: deviant.kiev.zoral.com.ua: kostik set sender to kostikbel@gmail.com using -f Date: Tue, 22 Feb 2011 12:12:16 +0200 From: Kostik Belousov To: Yuri Message-ID: <20110222101216.GZ78089@deviant.kiev.zoral.com.ua> References: <4D62F267.3000706@rawbw.com> <20110221233817.GA4792@britannica.bec.de> <4D62FC28.9040300@rawbw.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="iiKkCP5ouIvP2yCm" Content-Disposition: inline In-Reply-To: <4D62FC28.9040300@rawbw.com> User-Agent: Mutt/1.4.2.3i X-Spam-Status: No, score=-3.4 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00, DNS_FROM_OPENWHOIS autolearn=no version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on skuns.kiev.zoral.com.ua Cc: freebsd-hackers@freebsd.org Subject: Re: FreeBSD ABI? X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Feb 2011 10:12:22 -0000 --iiKkCP5ouIvP2yCm Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Feb 21, 2011 at 03:58:32PM -0800, Yuri wrote: > On 02/21/2011 15:38, Joerg Sonnenberger wrote: > >That's a major difference. The Linux people decided a while ago that > >stack alignment should be 16 Byte. GCC effectively forces that down > >everyone's throat because until at least GCC 4.2 or 4.3, it can't > >correctly realign the stack and just fails miserable. I would be > >surprised if it was a conscious decision for the Solaris either. > > =20 >=20 > I filed gcc PR asking gcc to revert their behavior back to prescribed by= =20 > documentation: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D47842 The i386 ABI was de-facto changed to require 16-byte stack alignment. The change is reasonable, both due to modern CPU cache behaviour, and to not put a block on the usage of the new CPU features (SSE instructions sets). There was a combination of bugs in gcc/glibc/bsd libc etc that made this not a reliable feature. I think there is no point of moving back to 4-byte alignment. --iiKkCP5ouIvP2yCm Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (FreeBSD) iEYEARECAAYFAk1jjAAACgkQC3+MBN1Mb4gguACg4cYjUsd8KOW6vwkCkF23sQ9O 0KYAn0oJH3NtGICNHgCjw1UqTEB0oAP7 =jqiR -----END PGP SIGNATURE----- --iiKkCP5ouIvP2yCm--