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/* Copyright (C) 1995, 1996, 2001 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu <mailto:drepper@gnu.ai.mit.edu>>, August 1995.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, write to the Free

   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA

   02111-1307 USA.  */

#include <errno.h>

#include <stdlib.h>

#include <limits.h>

#include <stdint.h>

#include <sys/types.h>

/* Global state for non-reentrant functions.  */

struct drand48_data __libc_drand48_data;

int

__drand48_iterate (unsigned short int xsubi[3], struct drand48_data *buffer)

{

  uint64_t X;

  uint64_t result;

  /* Initialize buffer, if not yet done.  */

  if (unlikely(!buffer->__init))

    {

      buffer->__a = 0x5deece66dull;

      buffer->__c = 0xb;

      buffer->__init = 1;

    }

  /* Do the real work.  We choose a data type which contains at least

     48 bits.  Because we compute the modulus it does not care how

     many bits really are computed.  */

  X = (uint64_t) xsubi[2] << 32 | (uint32_t) xsubi[1] << 16 | xsubi[0];

  result = X * buffer->__a + buffer->__c;

  xsubi[0] = result & 0xffff;

  xsubi[1] = (result >> 16) & 0xffff;

  xsubi[2] = (result >> 32) & 0xffff;

  return 0;

}