math: raise flags in log2l.c on <= 0 arguments, and fix volatile

[musl] / src / complex / cpow.c

#include "libm.h"

/* pow(z, c) = exp(c log(z)), See C99 G.6.4.1 */

double complex cpow(double complex z, double complex c)
{
        return cexp(c * clog(z));
}