xref: /minix3/lib/libc/stdlib/erand48.c (revision 2fe8fb192fe7e8720e3e7a77f928da545e872a6a)
1*2fe8fb19SBen Gras /*	$NetBSD: erand48.c,v 1.9 2006/03/22 20:52:16 drochner Exp $	*/
2*2fe8fb19SBen Gras 
3*2fe8fb19SBen Gras /*
4*2fe8fb19SBen Gras  * Copyright (c) 1993 Martin Birgmeier
5*2fe8fb19SBen Gras  * All rights reserved.
6*2fe8fb19SBen Gras  *
7*2fe8fb19SBen Gras  * You may redistribute unmodified or modified versions of this source
8*2fe8fb19SBen Gras  * code provided that the above copyright notice and this and the
9*2fe8fb19SBen Gras  * following conditions are retained.
10*2fe8fb19SBen Gras  *
11*2fe8fb19SBen Gras  * This software is provided ``as is'', and comes with no warranties
12*2fe8fb19SBen Gras  * of any kind. I shall in no event be liable for anything that happens
13*2fe8fb19SBen Gras  * to anyone/anything when using this software.
14*2fe8fb19SBen Gras  */
15*2fe8fb19SBen Gras 
16*2fe8fb19SBen Gras #include <sys/cdefs.h>
17*2fe8fb19SBen Gras #if defined(LIBC_SCCS) && !defined(lint)
18*2fe8fb19SBen Gras __RCSID("$NetBSD: erand48.c,v 1.9 2006/03/22 20:52:16 drochner Exp $");
19*2fe8fb19SBen Gras #endif /* LIBC_SCCS and not lint */
20*2fe8fb19SBen Gras 
21*2fe8fb19SBen Gras #include "namespace.h"
22*2fe8fb19SBen Gras 
23*2fe8fb19SBen Gras #include <assert.h>
24*2fe8fb19SBen Gras #include <math.h>
25*2fe8fb19SBen Gras 
26*2fe8fb19SBen Gras #include "rand48.h"
27*2fe8fb19SBen Gras 
28*2fe8fb19SBen Gras #ifdef __weak_alias
__weak_alias(erand48,_erand48)29*2fe8fb19SBen Gras __weak_alias(erand48,_erand48)
30*2fe8fb19SBen Gras #endif
31*2fe8fb19SBen Gras 
32*2fe8fb19SBen Gras double
33*2fe8fb19SBen Gras erand48(unsigned short xseed[3])
34*2fe8fb19SBen Gras {
35*2fe8fb19SBen Gras 
36*2fe8fb19SBen Gras 	_DIAGASSERT(xseed != NULL);
37*2fe8fb19SBen Gras 
38*2fe8fb19SBen Gras 	__dorand48(xseed);
39*2fe8fb19SBen Gras 	return ldexp((double) xseed[0], -48) +
40*2fe8fb19SBen Gras 	       ldexp((double) xseed[1], -32) +
41*2fe8fb19SBen Gras 	       ldexp((double) xseed[2], -16);
42*2fe8fb19SBen Gras }
43