Thread: The new 'isinf.c' function in port.

Hi Marc,

I was looking at the new 'isinf.c' function in the src/backend/port directory.
I have a question about the inclusion of cases for FP_SNAN and FP_QNAN.

    Does the 'isinf' function mean "not finite" or "is infinity"?

If it is to mean "not finite", then (IMHO) then checking for FP_SNAN and
FP_QNAN is appropiate.  If it is to mean "is infinity", then the function
should only be checking (again, IHMO) for FP_NINF and FP_PINF.

--
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On Thu, 5 Feb 1998, Billy G. Allie wrote:

> Hi Marc,
>
> I was looking at the new 'isinf.c' function in the src/backend/port directory.
> I have a question about the inclusion of cases for FP_SNAN and FP_QNAN.
>
>     Does the 'isinf' function mean "not finite" or "is infinity"?
>
> If it is to mean "not finite", then (IMHO) then checking for FP_SNAN and
> FP_QNAN is appropiate.  If it is to mean "is infinity", then the function
> should only be checking (again, IHMO) for FP_NINF and FP_PINF.

    Good question...

    From FreeBSD's man page:

The isninf() function returns 1 if the number is ``infinity'', otherwise
0.

    In my defence, those functions were just pulled in from the
various ports themselves...I believe you are correct about removing
FP_SNAN/FP_QNAN...