NAME

ilogb − Returns an unbiased exponent

SYNOPSIS

#include <math.h>
int ilogb(
        double x ); int ilogbf(
        float x ); int ilogbl(
        long double x );

LIBRARY

Math Library (libm)

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: