1/*	$OpenBSD: drand48.c,v 1.7 2015/09/14 13:30:17 guenther Exp $ */
2/*
3 * Copyright (c) 1993 Martin Birgmeier
4 * All rights reserved.
5 *
6 * You may redistribute unmodified or modified versions of this source
7 * code provided that the above copyright notice and this and the
8 * following conditions are retained.
9 *
10 * This software is provided ``as is'', and comes with no warranties
11 * of any kind. I shall in no event be liable for anything that happens
12 * to anyone/anything when using this software.
13 */
14
15#include <math.h>
16#include "rand48.h"
17
18double
19drand48(void)
20{
21	if (__rand48_deterministic == 0) {
22		unsigned short rseed[3];
23
24		arc4random_buf(rseed, sizeof rseed);
25		return ldexp((double) rseed[0], -48) +
26		       ldexp((double) rseed[1], -32) +
27		       ldexp((double) rseed[2], -16);
28	}
29	return erand48(__rand48_seed);
30}
31