From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262792AbUBZNkH (ORCPT ); Thu, 26 Feb 2004 08:40:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262800AbUBZNkH (ORCPT ); Thu, 26 Feb 2004 08:40:07 -0500 Received: from uslink-66.173.43-133.uslink.net ([66.173.43.133]:6532 "EHLO dingdong.cryptoapps.com") by vger.kernel.org with ESMTP id S262792AbUBZNkA (ORCPT ); Thu, 26 Feb 2004 08:40:00 -0500 Date: Thu, 26 Feb 2004 05:39:59 -0800 From: Chris Wedgwood To: "Nakajima, Jun" Cc: richard.brunner@amd.com, linux-kernel@vger.kernel.org Subject: Re: Intel vs AMD64 Message-ID: <20040226133959.GA19254@dingdong.cryptoapps.com> References: <7F740D512C7C1046AB53446D37200173EA28A5@scsmsx402.sc.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7F740D512C7C1046AB53446D37200173EA28A5@scsmsx402.sc.intel.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 25, 2004 at 09:32:08PM -0800, Nakajima, Jun wrote: > Yes, "implementation specific" is one of the differences between > IA-32e and AMD64, i.e. that behavior is architecturally defined on > AMD64, but on IA-32e (as I posted): > Near branch with 66H prefix: > As documented in PRM the behavior is implementation specific and > should avoid using 66H prefix on near branches. Not that it really matters that much --- but I'm curious to know why Intel made this decision? It seems really dumb to make such differences when Intel is already sorely lagging behind their competitor here, I would think given the circumstances Intel would try to be as compatible as possible on all fronts. I'd almost be nervous about getting an IA-32e CPU right now given that the AMD64 chips work just fine, have had lots of testing and there is plenty of code out there which is *known* to work reliably.