#include <math.h> int
ilogb (double x); int
ilogbf (float x); int
ilogbl (long double x); double
logb (double x); float
logbf (float x);
DESCRIPTION
ilogb (,);
ilogbf ();
and
ilogbl ();
return
Fa x Ns 's exponent
in integer format.
ilogb ();
returns
INT_MAX
ilogb ();
returns
FP_ILOGBNAN
and
ilogb (0);
returns
FP_ILOGB0
logb (x);
and
logbf (x);
return
Fa x Ns 's exponent
in floating-point format with the same precision as
Fa x .
logb ();
returns +, and
logb (0);
returns - with a division by zero exception.
The
ilogb (,);
ilogbf (,);
ilogbl (,);
logb ();
and
logbf ();
routines conform to
St -isoC-99 .
logb ();
and
logbf ();
implement the logb function recommended by
St -ieee754 .
HISTORY
The
logb ();
function appeared in
BSD 4.3
The
ilogb ();
function appeared in
Fx 1.1.5 .
The
ilogbf ();
and
logbf ();
functions appeared in
Fx 2.0 .
The
ilogbl ();
function appeared in
Fx 5.4 .