From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262964AbUBZU2N (ORCPT ); Thu, 26 Feb 2004 15:28:13 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262975AbUBZU2L (ORCPT ); Thu, 26 Feb 2004 15:28:11 -0500 Received: from ns.suse.de ([195.135.220.2]:59034 "EHLO Cantor.suse.de") by vger.kernel.org with ESMTP id S262964AbUBZURE (ORCPT ); Thu, 26 Feb 2004 15:17:04 -0500 To: Timothy Miller Cc: "Nakajima, Jun" , richard.brunner@amd.com, linux-kernel@vger.kernel.org Subject: Re: Intel vs AMD64 References: <7F740D512C7C1046AB53446D37200173EA28A5@scsmsx402.sc.intel.com.suse.lists.linux.kernel> <403E4681.20603@techsource.com.suse.lists.linux.kernel> From: Andi Kleen Date: 26 Feb 2004 21:17:00 +0100 In-Reply-To: <403E4681.20603@techsource.com.suse.lists.linux.kernel> Message-ID: User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Timothy Miller writes: > > If these sorts of branches are common enough (and I suspect they are), No they are not at all. Did you really read the descriptions of their semantics in this thread from Richard or Jun? They are completely useless for a 64bit program because they will truncate your 64bit program counter to 16bits. They may make sense in 16bit compat mode with 64K segment, but there there is no incompatibility because this difference only applies to 64bit programs. I doubt anybody has ever used them in a 64bit or even in a 32bit program. > Why did Intel decide to do that? Most likely they didn't plan to, but it happened by accident and is obscure enough to be not worth fixing. I would agree with them that it's not worth fixing. -Andi