/*
  test_mpf_pi precision(10-) output-flag(0-1)

  Compile:
    gcc -I/usr/local/include -L/usr/local/lib -Wall -O3 -o test_mpf_pi test_mpf_pi.c mpf_pi.c -lgmp
*/

#include <stdio.h>
#include <sys/times.h>
#include <unistd.h>
#include <gmp.h>

#define LOG_2_10 3.32192809488736234787031942949

void mpf_pi (mpf_t rop);

int main (int argc, char *argv[]) {
  int error = 0, output = 1;
  unsigned long int prec10 = 100;
  mpf_t pi;
  struct tms t_buf;
  clock_t start, stop;

  switch (argc) {
  case 3:
    error |= sscanf (argv[2], "%d", &output) != 1;
  case 2:
    error |= sscanf (argv[1], "%lu", &prec10) != 1;
    if (prec10 < 10) {
      prec10 = 10;
    }
    break;
  default:
    error = 1;
  }

  if (error) {
    printf ("usage: %s precision(10-) output-flag(0-1)\n", argv[0]);
    return error;
  }

  mpf_init2 (pi, (int) ((double) (2 + prec10) * LOG_2_10) + 1);

  stop = times (&t_buf);
  while ((start = times (&t_buf)) == stop);
  mpf_pi (pi);
  stop = times (&t_buf);
  printf ("%.3f sec.\n", (double) (stop - start) / (double) sysconf (_SC_CLK_TCK));
  if (output) {
    gmp_printf ("%.*Ff\n", prec10, pi);
    stop = times (&t_buf);
    printf ("%.3f sec.\n", (double) (stop - start) / (double) sysconf (_SC_CLK_TCK));
  }

  mpf_clear (pi);

  return 0;
}