From owner-freebsd-hackers Sat May 8 3:40: 8 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from herring.nlsystems.com (nlsys.demon.co.uk [158.152.125.33]) by hub.freebsd.org (Postfix) with ESMTP id 9530E1508C; Sat, 8 May 1999 03:39:55 -0700 (PDT) (envelope-from dfr@nlsystems.com) Received: from localhost (dfr@localhost) by herring.nlsystems.com (8.9.3/8.8.8) with ESMTP id LAA50156; Sat, 8 May 1999 11:40:10 +0100 (BST) (envelope-from dfr@nlsystems.com) Date: Sat, 8 May 1999 11:40:09 +0100 (BST) From: Doug Rabson To: Brian Feldman Cc: eagle , John-Mark Gurney , Lee Cremeans , hackers@FreeBSD.ORG, multimedia@FreeBSD.ORG Subject: Re: G200 GLX and SIGFPU In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Sat, 8 May 1999, Brian Feldman wrote: > On Sat, 8 May 1999, eagle wrote: > > > > > > > On Sat, 8 May 1999, Doug Rabson wrote: > > > > > > This should be done by the GL implementation. At Microsoft, we used to > > > save/restore the fp flags on entry to Direct3D so that we could force the > > > correct mode for our maths to work properly. We had all sorts of trouble > > > before doing that (stupid exceptions enabled, people changing fp > > > precision etc). > > > > > > I think in current versions of D3D, there is an api which you can call to > > > say 'I agree not to touch the fp flags' which improves performance > > > slightly. Mesa should be doing something similar, IMHO. > > > > > That was my next question shouldn't this be done in the port of MESA since > > thats whats throwing the sigfpe, disabling it in flightgear wouldn't help > > the problem at all.. > > What about switching to __BETTER_BDE_NPXCW__? It looks like __BETTER_BDE_NPXCW__ would mask OVF, DIV0 and INV which I think is a better default. Is there some reason other than inertia for not changing to __BETTER_BDE_NPXCW__? I still think Mesa should deal with the flags itself (and save/restore them) otherwise it can get hosed by a stupid application changing to 23bit precision or something similar. -- Doug Rabson Mail: dfr@nlsystems.com Nonlinear Systems Ltd. Phone: +44 181 442 9037 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message