From owner-cvs-all@FreeBSD.ORG Tue Aug 15 13:14:57 2006 Return-Path: X-Original-To: cvs-all@freebsd.org Delivered-To: cvs-all@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 63B4F16A4DD; Tue, 15 Aug 2006 13:14:57 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from server.baldwin.cx (66-23-211-162.clients.speedfactory.net [66.23.211.162]) by mx1.FreeBSD.org (Postfix) with ESMTP id 9CF7843D46; Tue, 15 Aug 2006 13:14:56 +0000 (GMT) (envelope-from jhb@freebsd.org) Received: from zion.baldwin.cx (zion.baldwin.cx [192.168.0.7]) (authenticated bits=0) by server.baldwin.cx (8.13.6/8.13.6) with ESMTP id k7FDEp8i027268; Tue, 15 Aug 2006 09:14:54 -0400 (EDT) (envelope-from jhb@freebsd.org) From: John Baldwin To: David Xu Date: Tue, 15 Aug 2006 09:13:51 -0400 User-Agent: KMail/1.9.1 References: <200608151245.k7FCjpJo077372@repoman.freebsd.org> In-Reply-To: <200608151245.k7FCjpJo077372@repoman.freebsd.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200608150913.52419.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-2.0.2 (server.baldwin.cx [192.168.0.1]); Tue, 15 Aug 2006 09:14:54 -0400 (EDT) X-Virus-Scanned: ClamAV 0.88.3/1662/Tue Aug 15 04:29:25 2006 on server.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-4.4 required=4.2 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.1.3 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on server.baldwin.cx Cc: cvs-src@freebsd.org, src-committers@freebsd.org, cvs-all@freebsd.org Subject: Re: cvs commit: src/sys/amd64/amd64 support.S X-BeenThere: cvs-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: CVS commit messages for the entire tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 15 Aug 2006 13:14:57 -0000 On Tuesday 15 August 2006 08:45, David Xu wrote: > davidxu 2006-08-15 12:45:51 UTC > > FreeBSD src repository > > Modified files: > sys/amd64/amd64 support.S > Log: > Because fuword on AMD64 returns 64bit long integer -1 on fault, clear > entire %rax to zero instead of only clearing %eax, otherwise it will > leave garbage data in upper 32 bits. Are you sure that 'xorl %eax,%eax' doesn't actually clear all 64 bits? This practice of just using xorl rather than xorq is all over the place in the amd64 code, and I think I've even seen gcc generate it, so I'm guessing that the xorl actually is a xorq. -- John Baldwin