Re: crash building in groff

["Michael L. Hitch" <mhitch%lightning.msu.montana.edu@localhost>]

On Fri, 9 Jan 2009, Brad Parker wrote:

> Turns out the crash in groff is due to some problem with hypot()
> in the arc object creation code.  (what a pain to find!)
>
> If I make the c++ hypot() return 1.0 all is good.
>
> I'll try and figure out why.

  That sounds like it may be a problem in hypot() attempting to return
a "quiet" NaN, but the vax doesn't have a real NaN of any type, and
someone decided to use a "reserved operand" for that, which would result 
in an illegal instruction trap.

  One possible fix or work-around would be to have the trap handler
recognize the reserved operand and do something else (other than
signal SIGILL to the process).

--
Michael L. Hitch                        mhitch%montana.edu@localhost
Computer Consultant
Information Technology Center
Montana State University        Bozeman, MT     USA