repeat ... until control flow in c language

repeatuntil.c

#include <stdio.h>
#define __repeat__ do
#define __until__(COND) while(!(COND))

int isPrime(int n) {

    if( n == 0 || n == 1 ) return 0;
    if( n == 2 || n == 3 ) return 1;    

    int i = 2, 
        prime = 1;

    while((i*i) <= n && prime) {

          prime = ((n % i) != 0);
          i++;
    } 

    return prime;
}

int main(int argc, char const *argv[])
{
	
    int num, 

        i, 

        j;

    num = 1000;

    i = 2;

    j = 0;

    __repeat__ {

       if( isPrime( i ) ) { 

       	  j++; 

       	  printf("%d ", i);
       }	  

       i++;  

    } __until__( j == num );

    return 0;
}