delorie.com/archives/browse.cgi   search  
Mail Archives: djgpp-workers/2003/08/30/13:50:44

Date: Sat, 30 Aug 2003 20:48:54 +0200
From: "Eli Zaretskii" <eliz AT elta DOT co DOT il>
Sender: halo1 AT zahav DOT net DOT il
To: Kbwms AT aol DOT com
Message-Id: <1438-Sat30Aug2003204854+0300-eliz@elta.co.il>
X-Mailer: emacs 21.3.50 (via feedmail 8 I) and Blat ver 1.8.9
CC: djgpp-workers AT delorie DOT com
In-reply-to: <114.2823ab81.2c822fce@aol.com> (Kbwms@aol.com)
Subject: Re: Arithmetic Exceptions in C99
References: <114 DOT 2823ab81 DOT 2c822fce AT aol DOT com>
Reply-To: djgpp-workers AT delorie DOT com
Errors-To: nobody AT delorie DOT com
X-Mailing-List: djgpp-workers AT delorie DOT com
X-Unsubscribes-To: listserv AT delorie DOT com

> From: Kbwms AT aol DOT com
> Date: Sat, 30 Aug 2003 12:50:22 EDT
> 
> Has anyone bothered to look at the source for libm.a to see what they do?
> I see expressions like (x-x)/(x-x) to produce a NaN and turn on the
> floating point invalid exception and "huge + x" (where huge =3D 1.0e30)
> to turn on the floating point inexact exception.  In the log function 
> is "-two54/zero" to turn on the floating point divide-by-zero exception
> and generate -infinity.

All these tricks will trigger SIGFPE unless we force the x87 to
suppress exceptions.

- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019