CLOG2(3) Linux Programmer's Manual CLOG2(3)

clog2, clog2f, clog2l - base-2 logarithm of a complex number

#include <complex.h>
double complex clog2(double complex z);
float complex clog2f(float complex z);
long double complex clog2l(long double complex z);

The call clog2(z) is equivalent to clog(z)/log(2).
The other functions perform the same task for float and long double.
Note that z close to zero will cause an overflow.

These function names are reserved for future use in C99.

Not yet in glibc, as at version 2.19.

cabs(3), cexp(3), clog(3), clog10(3), complex(7)