Re: I think - it's a bug...

["David C. Hoos" <david.c.hoos.sr@ada95.com>]

There are two problems, viz.

   1.  When z is essentially equal to b but (say) 1 lsb greater,
         then z/b is greater than 1.0, causing a negative argument
         to sqrt.

   2.   The problem with commenting out the put_line statement I
         believe to be a documented case where the NT C runtime
         can leave the FPU in a bad state.

----- Original Message ----- 
From: "Wes Groleau" <wesgroleau@despammed.com>
Newsgroups: comp.lang.ada
To: <comp.lang.ada@ada.eu.org>
Sent: Monday, March 11, 2002 8:53 AM
Subject: Re: I think - it's a bug...


> 
> > This is not a bug.  The problem comes about by not being aware of
> > the nature of floating point representation in computers.
> 
> Unless I misunderstood the original post, there IS a bug.
> 
> If commenting out this
> 
> > >       put_line (float'image(1.0-(z/b)));
> 
> causes this to stop raising an exception
> 
> > >       rr:=-a*sqrt((1.0-(z/b)**2))+a+r;
> 
> then I think there must be a bug in the optimizer.
> 
> But it should be sent to report@gnat.com and not to comp.lang.ada
> 
> -- 
> Wes Groleau
> http://freepages.rootsweb.com/~wgroleau
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