/****************************************************************************
 *
 * $Source: /usr/local/cvsroot/gccsdk/unixlib/source/stdlib/_rand48.c,v $
 * $Date: 2003/01/21 17:54:22 $
 * $Revision: 1.3 $
 * $State: Exp $
 * $Author: admin $
 *
 ***************************************************************************/

/*
 * 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 "rand48.h"
#include <pthread.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];

  PTHREAD_UNSAFE

  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;
}
