xref: /freebsd/lib/libc/gen/erand48.c (revision 8d20be1e22095c27faf8fe8b2f0d089739cc742e)
1 /*
2  * Copyright (c) 1993 Martin Birgmeier
3  * All rights reserved.
4  *
5  * You may redistribute unmodified or modified versions of this source
6  * code provided that the above copyright notice and this and the
7  * following conditions are retained.
8  *
9  * This software is provided ``as is'', and comes with no warranties
10  * of any kind. I shall in no event be liable for anything that happens
11  * to anyone/anything when using this software.
12  */
13 
14 #include <sys/cdefs.h>
15 __FBSDID("$FreeBSD$");
16 
17 #include "rand48.h"
18 
19 double
20 erand48(unsigned short xseed[3])
21 {
22 	_dorand48(xseed);
23 	return ldexp((double) xseed[0], -48) +
24 	       ldexp((double) xseed[1], -32) +
25 	       ldexp((double) xseed[2], -16);
26 }
27