From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262423AbTDUVcz (ORCPT ); Mon, 21 Apr 2003 17:32:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262426AbTDUVcy (ORCPT ); Mon, 21 Apr 2003 17:32:54 -0400 Received: from cpe-24-221-190-179.ca.sprintbbd.net ([24.221.190.179]:41933 "EHLO myware.akkadia.org") by vger.kernel.org with ESMTP id S262423AbTDUVcN (ORCPT ); Mon, 21 Apr 2003 17:32:13 -0400 Message-ID: <3EA4660A.6000506@redhat.com> Date: Mon, 21 Apr 2003 14:43:38 -0700 From: Ulrich Drepper Organization: Red Hat, Inc. User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4b) Gecko/20030420 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Linus Torvalds CC: Andi Kleen , linux-kernel@vger.kernel.org Subject: Re: [PATCH] Runtime memory barrier patching References: In-Reply-To: X-Enigmail-Version: 0.74.1.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Linus Torvalds wrote: > They may _work_ for intel, but quite frankly they suck for most Intel (and > probably non-intel too) CPU's. Using prefixes tends to almost always mess > up the instruction decoders on most CPU's out there. Indeed, using prefixes is terrible. This is what is used in gas: {0x90}; /* nop */ static const char f32_2[] = {0x89,0xf6}; /* movl %esi,%esi */ static const char f32_3[] = {0x8d,0x76,0x00}; /* leal 0(%esi),%esi */ static const char f32_4[] = {0x8d,0x74,0x26,0x00}; /* leal 0(%esi,1),%esi */ static const char f32_5[] = {0x90, /* nop */ 0x8d,0x74,0x26,0x00}; /* leal 0(%esi,1),%esi */ static const char f32_6[] = {0x8d,0xb6,0x00,0x00,0x00,0x00}; /* leal 0L(%esi),%esi */ static const char f32_7[] = {0x8d,0xb4,0x26,0x00,0x00,0x00,0x00}; /* leal 0L(%esi,1),%esi */ static const char f32_8[] = {0x90, /* nop */ 0x8d,0xb4,0x26,0x00,0x00,0x00,0x00}; /* leal 0L(%esi,1),%esi */ static const char f32_9[] = {0x89,0xf6, /* movl %esi,%esi */ 0x8d,0xbc,0x27,0x00,0x00,0x00,0x00}; /* leal 0L(%edi,1),%edi */ static const char f32_10[] = {0x8d,0x76,0x00, /* leal 0(%esi),%esi */ 0x8d,0xbc,0x27,0x00,0x00,0x00,0x00}; /* leal 0L(%edi,1),%edi */ static const char f32_11[] = {0x8d,0x74,0x26,0x00, /* leal 0(%esi,1),%esi */ 0x8d,0xbc,0x27,0x00,0x00,0x00,0x00}; /* leal 0L(%edi,1),%edi */ static const char f32_12[] = {0x8d,0xb6,0x00,0x00,0x00,0x00, /* leal 0L(%esi),%esi */ 0x8d,0xbf,0x00,0x00,0x00,0x00}; /* leal 0L(%edi),%edi */ static const char f32_13[] = {0x8d,0xb6,0x00,0x00,0x00,0x00, /* leal 0L(%esi),%esi */ 0x8d,0xbc,0x27,0x00,0x00,0x00,0x00}; /* leal 0L(%edi,1),%edi */ static const char f32_14[] = {0x8d,0xb4,0x26,0x00,0x00,0x00,0x00, /* leal 0L(%esi,1),%esi */ 0x8d,0xbc,0x27,0x00,0x00,0x00,0x00}; /* leal 0L(%edi,1),%edi */ static const char f32_15[] = {0xeb,0x0d,0x90,0x90,0x90,0x90,0x90, /* jmp .+15; lotsa nops */ 0x90,0x90,0x90,0x90,0x90,0x90,0x90,0x90}; - -- - --------------. ,-. 444 Castro Street Ulrich Drepper \ ,-----------------' \ Mountain View, CA 94041 USA Red Hat `--' drepper at redhat.com `--------------------------- -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (GNU/Linux) iD8DBQE+pGYK2ijCOnn/RHQRArJ7AJ4gT4Di95o6wYonrmb+OGvNlbHvvQCfcohZ nICs/UdZHeqwGs6Y4QJhhAA= =JZN7 -----END PGP SIGNATURE-----