ilogb(3) [osf1 man page]

ilogb(3)						     Library Functions Manual							  ilogb(3)

NAME

       ilogb - Returns an unbiased exponent

LIBRARY

       Math Library (libm.a)

SYNOPSIS

       #include <math.h>

       int ilogb  (double x); int ilogbf (float  x); int ilogbl  (long double x);

STANDARDS

       Interfaces documented on this reference page conform to industry standards as follows:

       ilogb():  XPG4-UNIX

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

DESCRIPTION

       The  ilogb(),  ilogbf(),  and  ilogbl() functions return the integral part of the base r  logarithm of (|x|) as a signed integral value for
       non-zero x, where r is the radix of the machine's floating point arithmetic.

       The following table describes function behavior in response to exceptional arguments:

       ---------------------------------------------------------------------
       Function 		    Exceptional Argument   Routine Behavior
       ---------------------------------------------------------------------
       ilogb(), ilogbf() ilogbl()   |x| = infinity	   INT_MAX
       ilogb(), ilogbf() ilogbl()   x = 0, NaN		   INT_MIN
       ---------------------------------------------------------------------
       delim off

																	  ilogb(3)

ILOGB(3)						   BSD Library Functions Manual 						  ILOGB(3)

NAME

     ilogb, ilogbf, ilogbl, logb, logbf, logbl -- extract exponent

LIBRARY

     Math Library (libm, -lm)

SYNOPSIS

     #include <math.h>

     int
     ilogb(double x);

     int
     ilogbf(float x);

     int
     ilogbl(long double x);

     double
     logb(double x);

     float
     logbf(float x);

     long double
     logbl(long double x);

DESCRIPTION

     ilogb(), ilogbf() and ilogbl() return x's exponent in integer format.  ilogb(+-infinity) returns INT_MAX, ilogb(+-NaN) returns FP_ILOGBNAN,
     and ilogb(0) returns FP_ILOGB0.

     logb(x), logbf(x), and logbl(x) return x's exponent in floating-point format with the same precision as x.  logb(+-infinity) returns +infin-
     ity, and logb(0) returns -infinity with a division by zero exception.

SEE ALSO

     frexp(3), ieee(3), math(3), scalbn(3)

STANDARDS

     The ilogb(), ilogbf(), ilogbl(), logb(), logbf(), and logbl() routines conform to ISO/IEC 9899:1999 (``ISO C99'').  The latter three imple-
     ment the logb function recommended by IEEE Std 754-1985.

HISTORY

     Function	First Appeared In
     logb()	4.3BSD
     ilogb()	FreeBSD 1.1.5
     ilogbf()	FreeBSD 2.0
     logbf()	FreeBSD 2.0
     ilogbl()	FreeBSD 5.4
     logbl()	FreeBSD 8.0

BSD
								 December 16, 2007							       BSD