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/*
* Copyright (c) 1994 The University of Utah and
* the Computer Systems Laboratory (CSL). All rights reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
* IS" CONDITION. THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
* ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* CSL requests users of this software to return to csl-dist@cs.utah.edu any
* improvements that they make and grant CSL redistribution rights.
*/
#include <stdlib.h>
static unsigned seed[2];
int
rand(void)
{
seed[0] += 0xa859c317;
seed[0] += (seed[1] << 13) | (seed[1] >> 19);
seed[1] += seed[0];
return seed[0] & 0x7FFFFFFF;
}
void
srand(unsigned new_seed)
{
seed[0] = seed[1] = new_seed;
}
#if 0 /* test code */
#define CYCLES 100000000
void main(int argc, char **argv)
{
unsigned orig_seed = atol(argv[1]);
int i;
srand(orig_seed);
for(i = 0; i < CYCLES; i++)
{
int r = rand();
/*printf("%08x\n", r);*/
if ((seed[0] == orig_seed) && (seed[1] == orig_seed))
{
printf("repeates after %d cycles\n", i);
exit(0);
}
}
printf("still not repeating after %d cycles\n", CYCLES);
}
#endif
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