mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-21 11:13:30 +00:00
47 lines
1.3 KiB
C
47 lines
1.3 KiB
C
/*
|
|
* 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"
|
|
|
|
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];
|
|
|
|
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;
|
|
}
|