[BACK]Return to _rand48.c CVS log [TXT][DIR] Up to [cvs.NetBSD.org] / src / lib / libc / stdlib

File: [cvs.NetBSD.org] / src / lib / libc / stdlib / _rand48.c (download)

Revision 1.6, Mon Sep 20 04:39:35 1999 UTC (20 years, 5 months ago) by lukem
Branch: MAIN
CVS Tags: wrstuden-devbsize-base, wrstuden-devbsize-19991221, wrstuden-devbsize, netbsd-3-base, netbsd-3-1-RELEASE, netbsd-3-1-RC4, netbsd-3-1-RC3, netbsd-3-1-RC2, netbsd-3-1-RC1, netbsd-3-1-1-RELEASE, netbsd-3-1, netbsd-3-0-RELEASE, netbsd-3-0-RC6, netbsd-3-0-RC5, netbsd-3-0-RC4, netbsd-3-0-RC3, netbsd-3-0-RC2, netbsd-3-0-RC1, netbsd-3-0-3-RELEASE, netbsd-3-0-2-RELEASE, netbsd-3-0-1-RELEASE, netbsd-3-0, netbsd-3, netbsd-2-base, netbsd-2-1-RELEASE, netbsd-2-1-RC6, netbsd-2-1-RC5, netbsd-2-1-RC4, netbsd-2-1-RC3, netbsd-2-1-RC2, netbsd-2-1-RC1, netbsd-2-1, netbsd-2-0-base, netbsd-2-0-RELEASE, netbsd-2-0-RC5, netbsd-2-0-RC4, netbsd-2-0-RC3, netbsd-2-0-RC2, netbsd-2-0-RC1, netbsd-2-0-3-RELEASE, netbsd-2-0-2-RELEASE, netbsd-2-0-1-RELEASE, netbsd-2-0, netbsd-2, netbsd-1-6-base, netbsd-1-6-RELEASE, netbsd-1-6-RC3, netbsd-1-6-RC2, netbsd-1-6-RC1, netbsd-1-6-PATCH002-RELEASE, netbsd-1-6-PATCH002-RC4, netbsd-1-6-PATCH002-RC3, netbsd-1-6-PATCH002-RC2, netbsd-1-6-PATCH002-RC1, netbsd-1-6-PATCH002, netbsd-1-6-PATCH001-RELEASE, netbsd-1-6-PATCH001-RC3, netbsd-1-6-PATCH001-RC2, netbsd-1-6-PATCH001-RC1, netbsd-1-6-PATCH001, netbsd-1-6, netbsd-1-5-base, netbsd-1-5-RELEASE, netbsd-1-5-PATCH003, netbsd-1-5-PATCH002, netbsd-1-5-PATCH001, netbsd-1-5-BETA2, netbsd-1-5-BETA, netbsd-1-5-ALPHA2, netbsd-1-5, nathanw_sa_end, nathanw_sa_before_merge, nathanw_sa_base, nathanw_sa, minoura-xpg4dl-base, minoura-xpg4dl, fvdl_fs64_base, comdex-fall-1999-base, comdex-fall-1999
Changes since 1.5: +1 -5 lines

back out the #ifdef _DIAGNOSTIC argument checks; too many people complained.
_DIAGASSERT() is still retained.

/*	$NetBSD: _rand48.c,v 1.6 1999/09/20 04:39:35 lukem Exp $	*/

/*
 * Copyright (c) 1993 Martin Birgmeier
 * All rights reserved.
 *
 * You may redistribute unmodified or modified versions of this source
 * code provided that the above copyright notice and this and the
 * following conditions are retained.
 *
 * This software is provided ``as is'', and comes with no warranties
 * of any kind. I shall in no event be liable for anything that happens
 * to anyone/anything when using this software.
 */

#include <assert.h>

#include "rand48.h"

unsigned short __rand48_seed[3] = {
	RAND48_SEED_0,
	RAND48_SEED_1,
	RAND48_SEED_2
};
unsigned short __rand48_mult[3] = {
	RAND48_MULT_0,
	RAND48_MULT_1,
	RAND48_MULT_2
};
unsigned short __rand48_add = RAND48_ADD;

void
__dorand48(unsigned short xseed[3])
{
	unsigned long accu;
	unsigned short temp[2];

	_DIAGASSERT(xseed != NULL);

	accu = (unsigned long) __rand48_mult[0] * (unsigned long) xseed[0] +
	 (unsigned long) __rand48_add;
	temp[0] = (unsigned short) accu;	/* lower 16 bits */
	accu >>= sizeof(unsigned short) * 8;
	accu += (unsigned long) __rand48_mult[0] * (unsigned long) xseed[1] +
	 (unsigned long) __rand48_mult[1] * (unsigned long) xseed[0];
	temp[1] = (unsigned short) accu;	/* middle 16 bits */
	accu >>= sizeof(unsigned short) * 8;
	accu += __rand48_mult[0] * xseed[2] + __rand48_mult[1] * xseed[1] + __rand48_mult[2] * xseed[0];
	xseed[0] = temp[0];
	xseed[1] = temp[1];
	xseed[2] = (unsigned short) accu;
}