/* $Id: pb-trig-dir.c 47490 2011-11-10 17:07:08Z vinc17/ypig $ */

#include <stdio.h>
#include <stdlib.h>
#include <gmp.h>
#include <mpfr.h>

static const mp_rnd_t rnd[3] = { MPFR_RNDD, MPFR_RNDN, MPFR_RNDU };

int main (int argc, char *argv[])
{
  mpfr_t x, s, c;
  int prec, i;

  if (argc != 3)
    {
      fprintf (stderr, "Usage: pb-trig-dir <x> <prec>\n");
      exit (EXIT_FAILURE);
    }

  prec = atoi (argv[2]);
  if (prec < MPFR_PREC_MIN || prec > MPFR_PREC_MAX)
    {
      fprintf (stderr, "pb-trig-dir: incorrect precision %d\n", prec);
      exit (EXIT_FAILURE);
    }

  mpfr_inits2 (prec, x, s, c, (void *) 0);

  if (mpfr_set_str (x, argv[1], 0, MPFR_RNDN))
    {
      fprintf (stderr, "pb-trig-dir: bad value x (%s)\n", argv[1]);
      exit (EXIT_FAILURE);
    }

  printf ("Lower bound, value using MPFR_RNDN, upper bound:\n");
  for (i = 0; i < 3; i++)
    {
      mpfr_sin_cos (s, c, x, rnd[i]);
      mpfr_hypot (x, s, c, rnd[i]);
      mpfr_out_str (stdout, 10, 0, x, rnd[i]);
      putchar ('\n');
    }

  mpfr_clears (x, s, c, (void *) 0);
  return 0;
}

/*
  The result seems to be always exactly 1. Try x >= 1e200000 to see the
  slow down (only for the first rounding mode, because of cached pi).
*/