/* Test file for mpfr_tan.

Copyright 2001, 2002, 2003, 2004, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
Contributed by the Arenaire and Cacao projects, INRIA.

This file is part of the GNU MPFR Library.

The GNU MPFR Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or (at your
option) any later version.

The GNU MPFR Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
License for more details.

You should have received a copy of the GNU Lesser General Public License
along with the GNU MPFR Library; see the file COPYING.LIB.  If not, write to
the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
MA 02110-1301, USA. */

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

#include "mpfr-test.h"

#define TEST_FUNCTION mpfr_tan
#define REDUCE_EMAX 262143 /* otherwise arg. reduction is too expensive */
#include "tgeneric.c"

static void
check_nans (void)
{
  mpfr_t  x, y;

  mpfr_init2 (x, 123L);
  mpfr_init2 (y, 123L);

  mpfr_set_nan (x);
  mpfr_tan (y, x, GMP_RNDN);
  if (! mpfr_nan_p (y))
    {
      printf ("Error: tan(NaN) != NaN\n");
      exit (1);
    }

  mpfr_set_inf (x, 1);
  mpfr_tan (y, x, GMP_RNDN);
  if (! mpfr_nan_p (y))
    {
      printf ("Error: tan(Inf) != NaN\n");
      exit (1);
    }

  mpfr_set_inf (x, -1);
  mpfr_tan (y, x, GMP_RNDN);
  if (! mpfr_nan_p (y))
    {
      printf ("Error: tan(-Inf) != NaN\n");
      exit (1);
    }

  /* exercise recomputation */
  mpfr_set_prec (x, 14);
  mpfr_set_str_binary (x, "0.10100000101010E0");
  mpfr_set_prec (y, 24);
  mpfr_tan (y, x, GMP_RNDU);
  mpfr_set_prec (x, 24);
  mpfr_set_str_binary (x, "101110011011001100100001E-24");
  MPFR_ASSERTN(mpfr_cmp (x, y) == 0);

  /* Compute ~Pi/2 to check overflow */
  mpfr_set_prec (x, 20000);
  mpfr_const_pi (x, GMP_RNDD);
  mpfr_div_2ui (x, x, 1, GMP_RNDN);
  mpfr_set_prec (y, 24);
  mpfr_tan (y, x, GMP_RNDN);
  if (mpfr_cmp_str (y, "0.100011101101011000100011E20001", 2, GMP_RNDN))
    {
      printf("Error computing tan(~Pi/2)\n");
      mpfr_dump (y);
      exit (1);
    }

  /* bug found by Kaveh Ghazi on 13 Jul 2007 */
  mpfr_set_prec (x, 53);
  mpfr_set_prec (y, 53);
  mpfr_set_str_binary (x, "0.10011100110111000001000010110100101000000000000000000E34");
  mpfr_tan (y, x, GMP_RNDN);
  mpfr_set_str_binary (x, "0.1000010011001010001000010100000110100111000011010101E41");
  MPFR_ASSERTN(mpfr_cmp (x, y) == 0);

  mpfr_clear (x);
  mpfr_clear (y);
}

int
main (int argc, char *argv[])
{
  mpfr_t x;
  unsigned int i;
  unsigned int prec[10] = {14, 15, 19, 22, 23, 24, 25, 40, 41, 52};
  unsigned int prec2[10] = {4, 5, 6, 19, 70, 95, 100, 106, 107, 108};

  tests_start_mpfr ();

  check_nans ();

  mpfr_init (x);

  mpfr_set_prec (x, 2);
  mpfr_set_str (x, "0.5", 10, GMP_RNDN);
  mpfr_tan (x, x, GMP_RNDD);
  if (mpfr_cmp_ui_2exp(x, 1, -1))
    {
      printf ("mpfr_tan(0.5, GMP_RNDD) failed\n"
              "expected 0.5, got");
      mpfr_print_binary(x);
      putchar('\n');
      exit (1);
    }

  /* check that tan(3*Pi/4) ~ -1 */
  for (i=0; i<10; i++)
    {
      mpfr_set_prec (x, prec[i]);
      mpfr_const_pi (x, GMP_RNDN);
      mpfr_mul_ui (x, x, 3, GMP_RNDN);
      mpfr_div_ui (x, x, 4, GMP_RNDN);
      mpfr_tan (x, x, GMP_RNDN);
      if (mpfr_cmp_si (x, -1))
        {
          printf ("tan(3*Pi/4) fails for prec=%u\n", prec[i]);
          exit (1);
        }
    }

  /* check that tan(7*Pi/4) ~ -1 */
  for (i=0; i<10; i++)
    {
      mpfr_set_prec (x, prec2[i]);
      mpfr_const_pi (x, GMP_RNDN);
      mpfr_mul_ui (x, x, 7, GMP_RNDN);
      mpfr_div_ui (x, x, 4, GMP_RNDN);
      mpfr_tan (x, x, GMP_RNDN);
      if (mpfr_cmp_si (x, -1))
        {
          printf ("tan(3*Pi/4) fails for prec=%u\n", prec2[i]);
          exit (1);
        }
    }

  mpfr_clear (x);

  test_generic (2, 100, 10);

  data_check ("data/tan", mpfr_tan, "mpfr_tan");
  bad_cases (mpfr_tan, mpfr_atan, "mpfr_tan", 256, -256, 255, 4, 128, 800, 40);

  tests_end_mpfr ();
  return 0;
}
