bug#11913: Unusual Emacs 24.1 arithmetic error (abs) on i386 machine

[Eli Zaretskii <eliz@gnu.org>]

> From: Rob Browning <rlb@defaultvalue.org>
> Cc: Glenn Morris <rgm@gnu.org>,  11913@debbugs.gnu.org
> Date: Fri, 13 Jul 2012 14:02:16 -0500
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > Do we even understand how this error happens?  There's nothing even
> > close to a reference to 'abs' on that line of cal-hebrew.el in my copy
> > of Emacs 24.1.
> 
> Right.  While I'm not extremely knowledgeable about the process, since
> that string is associated with Qarith_error (in data.c), I assumed it
> was probably some code deeper down raising the exception (from either
> data.c or floatfns.c).  Given the fact that it only happens on i386, I
> also wondered if x87 issues might be involved -- but the fact that it
> only happens on *this* i386 machine (and a couple of others) suggests
> the software versions matter.

Does that 386 machine have an x87 co-processor?  If not, what provides
the floating-point emulation -- the kernel?

If you compile a trivial C program that calls 'fabs' on that machine,
does it work as expected, or does it bomb?