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      1  1.10   kamil /*	$NetBSD: _rand48.c,v 1.10 2020/02/23 09:53:42 kamil Exp $	*/
      2   1.4   perry 
      3   1.1  brezak /*
      4   1.1  brezak  * Copyright (c) 1993 Martin Birgmeier
      5   1.1  brezak  * All rights reserved.
      6   1.1  brezak  *
      7   1.1  brezak  * You may redistribute unmodified or modified versions of this source
      8   1.1  brezak  * code provided that the above copyright notice and this and the
      9   1.1  brezak  * following conditions are retained.
     10   1.1  brezak  *
     11   1.1  brezak  * This software is provided ``as is'', and comes with no warranties
     12   1.1  brezak  * of any kind. I shall in no event be liable for anything that happens
     13   1.1  brezak  * to anyone/anything when using this software.
     14   1.1  brezak  */
     15   1.1  brezak 
     16   1.7   lukem #include <sys/cdefs.h>
     17   1.7   lukem #if defined(LIBC_SCCS) && !defined(lint)
     18  1.10   kamil __RCSID("$NetBSD: _rand48.c,v 1.10 2020/02/23 09:53:42 kamil Exp $");
     19   1.7   lukem #endif /* LIBC_SCCS and not lint */
     20   1.7   lukem 
     21   1.5   lukem #include <assert.h>
     22   1.5   lukem 
     23   1.1  brezak #include "rand48.h"
     24   1.1  brezak 
     25   1.3     jtc unsigned short __rand48_seed[3] = {
     26   1.1  brezak 	RAND48_SEED_0,
     27   1.1  brezak 	RAND48_SEED_1,
     28   1.1  brezak 	RAND48_SEED_2
     29   1.1  brezak };
     30   1.3     jtc unsigned short __rand48_mult[3] = {
     31   1.1  brezak 	RAND48_MULT_0,
     32   1.1  brezak 	RAND48_MULT_1,
     33   1.1  brezak 	RAND48_MULT_2
     34   1.1  brezak };
     35   1.3     jtc unsigned short __rand48_add = RAND48_ADD;
     36   1.1  brezak 
     37   1.1  brezak void
     38   1.2     jtc __dorand48(unsigned short xseed[3])
     39   1.1  brezak {
     40   1.1  brezak 	unsigned long accu;
     41   1.1  brezak 	unsigned short temp[2];
     42   1.5   lukem 
     43   1.5   lukem 	_DIAGASSERT(xseed != NULL);
     44   1.1  brezak 
     45   1.8   kamil 	accu = (unsigned long) __rand48_mult[0] * (unsigned long) xseed[0];
     46   1.8   kamil 	accu += (unsigned long) __rand48_add;
     47   1.1  brezak 	temp[0] = (unsigned short) accu;	/* lower 16 bits */
     48   1.1  brezak 	accu >>= sizeof(unsigned short) * 8;
     49   1.8   kamil 	accu += (unsigned long) __rand48_mult[0] * (unsigned long) xseed[1];
     50   1.8   kamil 	accu += (unsigned long) __rand48_mult[1] * (unsigned long) xseed[0];
     51   1.1  brezak 	temp[1] = (unsigned short) accu;	/* middle 16 bits */
     52   1.1  brezak 	accu >>= sizeof(unsigned short) * 8;
     53  1.10   kamil 	accu += (unsigned long) __rand48_mult[0] * (unsigned long) xseed[2];
     54  1.10   kamil 	accu += (unsigned long) __rand48_mult[1] * (unsigned long) xseed[1];
     55  1.10   kamil 	accu += (unsigned long) __rand48_mult[2] * (unsigned long) xseed[0];
     56   1.1  brezak 	xseed[0] = temp[0];
     57   1.1  brezak 	xseed[1] = temp[1];
     58   1.1  brezak 	xseed[2] = (unsigned short) accu;
     59   1.1  brezak }
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