Tests the sign.
#include <math.h> int signbit (x) real-floating x;
The signbit macro determines whether the sign of its argument value is negative. NaNs, zeros, and infinities have a sign bit.
| x | Specifies the value to be tested. |
The signbit macro returns a nonzero value if the sign of its argument value is negative.
class, _class, finite, isnan, or unordered Subroutines, fpclassify Subroutine, isfinite Subroutine, isinf Subroutine, isnormal Subroutine, and lldiv Subroutine in AIX 5L Version 5.2 Technical Reference: Base Operating System and Extensions Volume 1.
math.h in AIX 5L Version 5.2 Files Reference.