int
     ilogb(double x);

     int
     ilogbl(long double x);

     int
     ilogbf(float x);

DESCRIPTION

     The ilogb() functions return the exponent of x as a signed integer value.

SPECIAL VALUES

     ilogb(+-0) returns FP_ILOGB0.

     ilogb(+-infinity) returns INT_MAX.

     ilogb(x) returns FP_ILOGBNAN if x is a NaN.

     A range error may occur if x is 0, +-infinity, or a nan.

     The special return values FP_ILOGB0 and FP_ILOGBNAN are defined in
     math.h, and may differ between platforms.  INT_MAX is defined in lim-
     its.h.

SEE ALSO

     math(3)

STANDARDS

     The ilogb() functions conform to ISO/IEC 9899:1999(E).

BSD                              July 22, 2003                             BSD