/*
 * Calculate 'machine epsilon'
 *
 * To compile: 
 *
 *      make macheps
 *
 *    or
 *
 *      gcc -O0 macheps.c -o macheps
 *
 *    or
 *
 *      clang -O0 macheps.c -o macheps
 */
 
 #include <stdio.h>
 
 int main(void)
 {
     double x = 1.;
     int i = 0;
     
     while (x + 1. > 1.)
     {
         x /= 2;
         i += 1;
     }
     
     printf("Machine epsilon:     %g\n", x);
     printf("Number of divisions: %d\n", i);
     
     return 0;
 }