[ksh93-integration-discuss] "negative NaN" ?

[Glenn Fowler]

another exception for NaN is
        signbit(NaN)==0
        signbit(-NaN)==1
so there is a negative NaN
NaN also has unused "payload" bits -- but its not clear
how the standard those

I'll check libast/sfio/sfvprintf() to make sure it uses
signbit(NaN) (where available) to render NaN values

I'll also look at using fpclassify() as a fallback to
the related <math.h> is*() macros

-- Glenn Fowler -- AT&T Research, Florham Park NJ --