Initial commit of OpenSPARC T2 design and verification files.

[OpenSPARC-T2-DV] / verif / env / common / vera / niu_ippktgen / C / wrapper / pgrand.c

#include <stdio.h>

#define N 25
#define M 7

unsigned int rand();        /* returns a random integer */
void init( unsigned int );     /* initialize the generator */


/* return a random float >= 0 and < 1 */
#define rand_float          ((double)rand() / 4294967296.0)


static unsigned int x[N];         /* the 25 seeds */

static unsigned int mag01[2];
static int randk;
void setpgSeed( unsigned int seed )
{
  int k;

  x[0] = (seed|1) & 0xffffffff;
  for (k=1; k<N; k++)
     x[k] = (69069 * x[k-1]) & 0xffffffff;
  mag01[0]= 0x0;
  mag01[1]= 0x8ebfd028;  /* "magic" vector */
  randk  = 0;
}


unsigned int pgrand()
  {
  unsigned int y;
  unsigned int retval;
  int kk;


  if (randk==N)
     {
     for (kk=0; kk < N-M; kk++)
        x[kk] = x[kk+M] ^ (x[kk] >> 1) ^ mag01[x[kk] & 1];

     for (; kk < N; kk++)
        x[kk] = x[kk+(M-N)] ^ (x[kk] >> 1) ^ mag01[x[kk] & 1];

     randk=0;
     }
  y = x[randk++];
  y ^= (y << 7) & 0x2b5b2500;
  y ^= (y << 15) & 0xdb8b0000;
  y &= 0xffffffff;     /* you may delete this line if word size = 32 */
  y ^= (y >> 16);

  retval = y;
  return (retval);
}