Re: Geometry test on NetBSD (was Re: [HACKERS] RC1?)

At 1:15 AM -0500 11/20/02, Tom Lane wrote:
>Bruce Momjian <pgman@candle.pha.pa.us> writes:
>>  Tom, can you clarify why -0 is valid.
>
>The IEEE spec absolutely thinks that -0 and +0 are distinct entities.
>I don't remember why, at one in the morning ... but if you insist I'm
>sure that plenty sufficient numerical-analysis reasons can be produced.
>The guys who wrote that spec knew what they were doing (that's why it's
>been adopted so universally).

It's so that 1/(1/-infinity) == -infinity.  There are probably other 
reasons as well.

I'm just guessing here, but it's possible NetBSD acquired the bug by 
trying to be functional on non-IEEE hardware.  I hope that whoever 
found the problem (I don't see that in this thread) filed a bug 
report with NetBSD.
-- 
The opinions expressed in this message are mine,
not those of Caltech, JPL, NASA, or the US Government.
Henry.B.Hotz@jpl.nasa.gov, or hbhotz@oxy.edu