source: trunk/minix/lib/math/log10.c@ 20

/*
 * (c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
 * See the copyright notice in the ACK home directory, in the file "Copyright".
 *
 * Author: Ceriel J.H. Jacobs
 */
/* $Header: /cvsup/minix/src/lib/math/log10.c,v 1.1.1.1 2005/04/21 14:56:26 beng Exp $ */

#include        <math.h>
#include        <errno.h>
#include        "localmath.h"

double
log10(double x)
{
        if (__IsNan(x)) {
                errno = EDOM;
                return x;
        }
        if (x < 0) {
                errno = EDOM;
                return -HUGE_VAL;
        }
        else if (x == 0) {
                errno = ERANGE;
                return -HUGE_VAL;
        }

        return log(x) / M_LN10;
}