regex.c:2601
static void
insert_op_2(op, there, current_end, num_1, num_2)
     int op;
     char *there, *current_end;
     int num_1, num_2;
{
  register char *pfrom = current_end;		/* Copy from here...  */
  register char *pto = current_end + 5;		/* ...to here.  */

  while (pfrom != there)			       
    *--pto = *--pfrom;

  there[0] = (char)op;
  STORE_NUMBER(there + 1, num_1);
  STORE_NUMBER(there + 3, num_2);
}
