ack/lang/cem/libcc.ansi/pure/math/log10.c

/*
 * (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
 */
/* $Id$ */

#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;
}