xref: /openbsd/lib/libc/stdlib/erand48.c (revision 0fa1c6e6)
1 /*	$OpenBSD: erand48.c,v 1.5 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 
18 double
erand48(unsigned short xseed[3])19 erand48(unsigned short xseed[3])
20 {
21 	__dorand48(xseed);
22 	return ldexp((double) xseed[0], -48) +
23 	       ldexp((double) xseed[1], -32) +
24 	       ldexp((double) xseed[2], -16);
25 }
26 DEF_WEAK(erand48);
27