gcc/mpfr/tests/tcoth.c

/* Test file for mpfr_coth.

Copyright 2005, 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_coth
#include "tgeneric.c"

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

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

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

  mpfr_set_inf (x, 1);
  mpfr_coth (y, x, GMP_RNDN);
  if (mpfr_cmp_ui (y, 1))
    {
      printf ("Error: coth(Inf) != 1\n");
      exit (1);
    }

  mpfr_set_inf (x, -1);
  mpfr_coth (y, x, GMP_RNDN);
  if (mpfr_cmp_si (y, -1))
    {
      printf ("Error: coth(-Inf) != -1\n");
      exit (1);
    }

  /* cot(+/-0) = +/-0 */
  mpfr_set_ui (x, 0, GMP_RNDN);
  mpfr_coth (y, x, GMP_RNDN);
  if (! (mpfr_zero_p (y) && MPFR_SIGN (y) > 0))
    {
      printf ("Error: coth(+0) != +0\n");
      exit (1);
    }
  mpfr_neg (x, x, GMP_RNDN);
  mpfr_coth (y, x, GMP_RNDN);
  if (! (mpfr_zero_p (y) && MPFR_SIGN (y) < 0))
    {
      printf ("Error: coth(-0) != -0\n");
      exit (1);
    }

  mpfr_clear (x);
  mpfr_clear (y);
}

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

  mpfr_init (x);
  mpfr_init (y);

  /* bug found by Rob (Sisyphus) on 16 Sep 2005 */
  mpfr_set_ui (x, 2, GMP_RNDN);
  mpfr_set_prec (y, 2);
  mpfr_coth (y, x, GMP_RNDN);
  if (mpfr_cmp_ui (y, 1))
    {
      printf ("Error for coth(2), expected 1, got ");
      mpfr_dump (y);
      exit (1);
    }

  mpfr_set_prec (x, 53);
  mpfr_set_prec (y, 53);

  mpfr_set_str (x, "18.368400284838550", 10, GMP_RNDN);
  mpfr_set_str (y, "1.0000000000000002", 10, GMP_RNDN);
  mpfr_coth (x, x, GMP_RNDN);
  if (mpfr_cmp (x, y) != 0)
    {
      printf ("Error for coth(18.368400284838550)\n");
      exit (1);
    }

  mpfr_set_str (x, "18.714973875118520", 10, GMP_RNDN);
  mpfr_coth (x, x, GMP_RNDN);
  if (mpfr_cmp (x, y) != 0)
    {
      printf ("Error for coth(18.714973875118520)\n");
      exit (1);
    }

  mpfr_set_str (x, "18.714973875118524", 10, GMP_RNDN);
  mpfr_coth (x, x, GMP_RNDN);
  if (mpfr_cmp_ui (x, 1) != 0)
    {
      printf ("Error for coth(18.714973875118524)\n");
      exit (1);
    }

  mpfr_clear (x);
  mpfr_clear (y);
}

static void
underflowed_cothinf (void)
{
  mpfr_t x, y;
  int i, inex, rnd, err = 0;
  mp_exp_t old_emin;

  old_emin = mpfr_get_emin ();

  mpfr_init2 (x, 8);
  mpfr_init2 (y, 8);

  for (i = -1; i <= 1; i += 2)
    RND_LOOP (rnd)
      {
        mpfr_set_inf (x, i);
        mpfr_clear_flags ();
        set_emin (2);  /* 1 is not representable. */
        inex = mpfr_coth (x, x, (mp_rnd_t) rnd);
        set_emin (old_emin);
        if (! mpfr_underflow_p ())
          {
            printf ("Error in underflowed_cothinf (i = %d, rnd = %s):\n"
                    "  The underflow flag is not set.\n",
                    i, mpfr_print_rnd_mode ((mp_rnd_t) rnd));
            err = 1;
          }
        mpfr_set_si (y, (i < 0 && rnd == GMP_RNDD) ||
                        (i > 0 && rnd == GMP_RNDU) ? 2 : 0, GMP_RNDN);
        if (i < 0)
          mpfr_neg (y, y, GMP_RNDN);
        if (! (mpfr_equal_p (x, y) &&
               MPFR_MULT_SIGN (MPFR_SIGN (x), MPFR_SIGN (y)) > 0))
          {
            printf ("Error in underflowed_cothinf (i = %d, rnd = %s):\n"
                    "  Got ", i, mpfr_print_rnd_mode ((mp_rnd_t) rnd));
            mpfr_print_binary (x);
            printf (" instead of ");
            mpfr_print_binary (y);
            printf (".\n");
            err = 1;
          }
        if ((rnd == GMP_RNDD ||
             (i > 0 && (rnd == GMP_RNDN || rnd == GMP_RNDZ))) && inex >= 0)
          {
            printf ("Error in underflowed_cothinf (i = %d, rnd = %s):\n"
                    "  The inexact value must be negative.\n",
                    i, mpfr_print_rnd_mode ((mp_rnd_t) rnd));
            err = 1;
          }
        if ((rnd == GMP_RNDU ||
             (i < 0 && (rnd == GMP_RNDN || rnd == GMP_RNDZ))) && inex <= 0)
          {
            printf ("Error in underflowed_cothinf (i = %d, rnd = %s):\n"
                    "  The inexact value must be positive.\n",
                    i, mpfr_print_rnd_mode ((mp_rnd_t) rnd));
            err = 1;
          }
      }

  if (err)
    exit (1);
  mpfr_clear (x);
  mpfr_clear (y);
}

int
main (int argc, char *argv[])
{
  tests_start_mpfr ();

  check_specials ();
  check_bugs ();
  test_generic (2, 200, 10);
  underflowed_cothinf ();

  tests_end_mpfr ();
  return 0;
}