#include        <stdio.h>
#include        <fenv.h>

#pragma STDC FENV_ACCESS ON

double my_op(double x, double y);

int main(int argc, char *argv[])
{
  double a, b, x, y;
  int old_fp_mode, status1, status2, status3;

  x = 7.1;  y = 1.0/5.0;

  old_fp_mode = fegetround();
  status1 = fesetround(FE_DOWNWARD);
  a = my_op(x, y);
  status2 = fesetround(FE_UPWARD);
  b = my_op(x, y);
  status3 = fesetround(old_fp_mode);

  /* All status values should be zero */
  printf("Status values are: %d, %d, %d\n", 
         status1, status2, status3);
  printf("Difference is %g\n", b-a);
}