#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <sys/resource.h>

#define NITERS 10000000

float finps[NITERS], foutps[NITERS];
double dinps[NITERS], doutps[NITERS];

int main ()
{
  struct rusage start_float_ru, end_float_ru;
  struct rusage start_double_ru, end_double_ru;
  int i;

  for (i = 0; i < NITERS; i++)
    dinps[i] = drand48() + 1e-6;
  for (i = 0; i < NITERS; i++)
    finps[i] = (float) (dinps[i]);

  getrusage (RUSAGE_SELF, &start_float_ru);
  for (i = 0; i < NITERS; i++)
    foutps[i] = expf (finps[i]);
  getrusage (RUSAGE_SELF, &end_float_ru);

  getrusage (RUSAGE_SELF, &start_double_ru);
  for (i = 0; i < NITERS; i++)
    doutps[i] = exp (dinps[i]);
  getrusage (RUSAGE_SELF, &end_double_ru);

  double fisum = 0;
  for (i = 0; i < NITERS; i++)
    fisum += finps[i];

  double disum = 0;
  for (i = 0; i < NITERS; i++)
    disum += dinps[i];

  double fosum = 0;
  for (i = 0; i < NITERS; i++)
    fosum += foutps[i];

  double dosum = 0;
  for (i = 0; i < NITERS; i++)
    dosum += doutps[i];

  printf ("fisum = %g, disum = %g\n", fisum, disum);
  printf ("fosum = %g, dosum = %g\n", fosum, dosum);

  printf ("float (expf) user time: %g sec\n",
	  ((double)(end_float_ru.ru_utime.tv_sec
		    - start_float_ru.ru_utime.tv_sec)
	   +(double)(end_float_ru.ru_utime.tv_usec
		     - start_float_ru.ru_utime.tv_usec) / 1.e6));
  printf ("double (exp) user time: %g sec\n",
	  ((double)(end_double_ru.ru_utime.tv_sec
		    - start_double_ru.ru_utime.tv_sec)
	   +(double)(end_double_ru.ru_utime.tv_usec
		     - start_double_ru.ru_utime.tv_usec) / 1.e6));

  return 0;
}