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/* $NetBSD: _rand48.c,v 1.7 2005/06/12 05:21:27 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 <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: _rand48.c,v 1.7 2005/06/12 05:21:27 lukem Exp $");
#endif /* LIBC_SCCS and not lint */
#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;
}
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