From owner-cvs-all Fri Mar 10 13:47:43 2000 Delivered-To: cvs-all@freebsd.org Received: from knight.cons.org (knight.cons.org [194.233.237.86]) by hub.freebsd.org (Postfix) with ESMTP id 9376A37BC6C; Fri, 10 Mar 2000 13:47:33 -0800 (PST) (envelope-from cracauer@knight.cons.org) Received: (from cracauer@localhost) by knight.cons.org (8.9.3/8.9.3) id WAA20754; Fri, 10 Mar 2000 22:47:27 +0100 (CET) Date: Fri, 10 Mar 2000 22:47:26 +0100 From: Martin Cracauer To: Alfred Perlstein Cc: Garrett Wollman , Doug Rabson , Martin Cracauer , cvs-committers@FreeBSD.ORG, cvs-all@FreeBSD.ORG Subject: Re: cvs commit: src/sys/i386/include npx.h Message-ID: <20000310224726.B20522@cons.org> References: <200003101756.JAA90710@freefall.freebsd.org> <20000310133936.B14279@fw.wintelcom.net> <200003102122.QAA18594@khavrinen.lcs.mit.edu> <20000310140843.C14279@fw.wintelcom.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0i In-Reply-To: <20000310140843.C14279@fw.wintelcom.net>; from bright@wintelcom.net on Fri, Mar 10, 2000 at 02:08:43PM -0800 Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In <20000310140843.C14279@fw.wintelcom.net>, Alfred Perlstein wrote: > * Garrett Wollman [000310 13:58] wrote: > > < said: > > > > > Is there any reason for doing this other than so we can emulate > > > linux's bog^H^H^H nifty ability to divide by zero? > > > > The fact that the IEEE standard says this is the default state. > > I haven't had the time to test this, but integer divide by zero is > still trapped? And you're right, using fp on solaris/irix doesn't > bomb out when doing / 0, but does for integer math. Integer math is not affected by the FPU mask (Although the exceptions thown is SIGFPE). You can't mask it, the only thing you can do is to longjump out of a SIGFPE signal handler. Yes, out of the major Unix derivates we were the last to default to trap (Solaris, Linux, NetBSD, OpenBSD...). Again, you can't clearly claime that IEEE754 is the holy thing since we violate it otherwise due to C89 restrictions. Martin -- %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Martin Cracauer http://www.cons.org/cracauer/ Tel.: (private) +4940 5221829 Fax.: (private) +4940 5228536 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message