From owner-cvs-all Thu May 23 7:10:24 2002 Delivered-To: cvs-all@freebsd.org Received: from 12-234-96-171.client.attbi.com (12-234-96-171.client.attbi.com [12.234.96.171]) by hub.freebsd.org (Postfix) with ESMTP id C21BD37B407; Thu, 23 May 2002 07:10:18 -0700 (PDT) Received: by 12-234-96-171.client.attbi.com (Postfix, from userid 1000) id 85B45A900; Thu, 23 May 2002 07:08:14 -0700 (PDT) Date: Thu, 23 May 2002 07:08:14 -0700 From: Jonathan Mini To: John Baldwin Cc: Peter Jeremy , cvs-all@FreeBSD.org, cvs-committers@FreeBSD.org Subject: Re: cvs commit: src/sys/kern kern_mutex.c Message-ID: <20020523070814.Q25907@stylus.haikugeek.com> Mail-Followup-To: John Baldwin , Peter Jeremy , cvs-all@FreeBSD.org, cvs-committers@FreeBSD.org References: <20020523161537.A10471@gsmx07.alcatel.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: ; from jhb@FreeBSD.org on Thu, May 23, 2002 at 09:43:22AM -0400 Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG John Baldwin [jhb@FreeBSD.org] wrote : > In Intel's documentation they said that all current look-alikes worked as > well. It's the opcode for 'rep mov'. I am curious if some implementations > trash %ecx, and if we are paranoid we could always clobber %ecx in the > constraints. [ ... ] The rep prefix doesn't modify any registers. You do need to make sure that %ecx was zero when you dispatch a rep mov (unles you're dispatching a rep mov $0, %ecx), or you'll get an infinite loop. -- Jonathan Mini http://www.haikugeek.com "He who is not aware of his ignorance will be only misled by his knowledge." -- Richard Whatley To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message