#include <stdio.h>

#define useregister 0

double MachEps2() // definitly wrong coded ;-)

{
      double eps;

      eps=0.5;
      while ((1.0 + eps) != 1.0) {
        eps=0.5*eps;
      }
      return 2.0*eps;
}

double MachEps()

{
#if useregister == 1
      register 
      double eps,EinsPlusEps;
#else
      double eps,EinsPlusEps;
#endif

      eps=0.5;
      EinsPlusEps=1.5;
      while (EinsPlusEps != 1.0) {
        eps=0.5*eps;
        EinsPlusEps=1.0+eps;
      }
      return 2.0*eps;
}

void main() 

{
      double deps;
      float  feps;

      deps = MachEps();
      feps = (float) deps;

      printf("\n\n%s%14.7E\n\n","MachEsp  (double precision) = ",deps);
      printf(    "%s%14.7E\n\n","MachEsp  (single precision) = ",feps);

      deps = MachEps2();
      feps = (float) deps;

      printf("\n\n%s%14.7E\n\n","MachEps2 (double precision) = ",deps);
      printf(    "%s%14.7E\n\n","MachEps2 (single precision) = ",feps);
}