From owner-freebsd-arch Mon Jan 7 13:48:59 2002 Delivered-To: freebsd-arch@freebsd.org Received: from mail12.speakeasy.net (mail12.speakeasy.net [216.254.0.212]) by hub.freebsd.org (Postfix) with ESMTP id 080CA37B41A for ; Mon, 7 Jan 2002 13:48:56 -0800 (PST) Received: (qmail 13709 invoked from network); 7 Jan 2002 21:48:52 -0000 Received: from unknown (HELO laptop.baldwin.cx) ([64.81.54.73]) (envelope-sender ) by mail12.speakeasy.net (qmail-ldap-1.03) with SMTP for ; 7 Jan 2002 21:48:52 -0000 Message-ID: X-Mailer: XFMail 1.4.0 on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: <15418.5641.919327.356015@caddis.yogotech.com> Date: Mon, 07 Jan 2002 13:48:17 -0800 (PST) From: John Baldwin To: Nate Williams Subject: Re: Request for review: getcontext, setcontext, etc Cc: arch@freebsd.org, Dan Eischen Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On 07-Jan-02 Nate Williams wrote: >> > Also, forgive my ignorance, but why are we using fnsave instead of >> > fsave? From my reading of the x86 manuals, it would seem that there is >> > the possibility of getting bogus FPU results with fnsave (vs. fsave) >> > since by using fsave, we give the FPU a chance to finish up the current >> > FPU operations before we save the state? I could see where they might >> > be a race where we might end up storing intermediate results of the FPU >> > in some instances. >> > >> > Or, is there something else I'm missing? (The reason I ask is that the >> > JDK uses fsave to be 'safe', but maybe it's not buying us anything other >> > than warm fuzzies. :) >> >> I don't know :-) That's what it was using when John Birrell was >> maintaining libc_r. I can always change it... > > How about it John? Why the use of 'fnsave' when storing FPU context > vs. using fsave? Hmm, wrong John. You want jb@ I believe. :) > Nate -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message