// simple C program to demmonstate loop unriolling
#include <stdio.h>
#define VEC_LEN 10

int main(void) {
  int i, n = VEC_LEN; 
  int x[VEC_LEN];

  // original loop
  for (i=0; i < n; i++) {
     x[i] = 2*i; 
  }

  // unrolled loop
  for (i=0; i+1 < n; i+=2) {
     x[i] = 2*i; 
     x[i+1] = 2*(i+1); 
  }

  // print to see if unrolled loop gave expected result
  printf("expecting sequence 0, 2, ..., %d:\n\t", 2*(n-1));  
  for (i=0; i < n; i++) {
     printf(" %3d", x[i]); 
  }
  printf("\n");

  return 0;
}