/*
 *  call-seq:
 *     Math.log2(numeric)    => float
 *  
 *  Returns the base 2 logarithm of <i>numeric</i>.
 */

static VALUE
math_log2(VALUE obj, VALUE x)
{
    double d;

    Need_Float(x);
    errno = 0;
    d = log2(RFLOAT_VALUE(x));
    if (errno) {
        rb_sys_fail("log2");
    }
    return DOUBLE2NUM(d);
}