1  /* tsgn -- Test for the sign of a floating point number.
       2  
       3  Copyright 2003, 2006-2023 Free Software Foundation, Inc.
       4  Contributed by the AriC and Caramba projects, INRIA.
       5  
       6  This file is part of the GNU MPFR Library.
       7  
       8  The GNU MPFR Library is free software; you can redistribute it and/or modify
       9  it under the terms of the GNU Lesser General Public License as published by
      10  the Free Software Foundation; either version 3 of the License, or (at your
      11  option) any later version.
      12  
      13  The GNU MPFR Library is distributed in the hope that it will be useful, but
      14  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
      15  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
      16  License for more details.
      17  
      18  You should have received a copy of the GNU Lesser General Public License
      19  along with the GNU MPFR Library; see the file COPYING.LESSER.  If not, see
      20  https://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
      21  51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
      22  
      23  #define MPFR_TESTS_TSGN 1
      24  #include "mpfr-test.h"
      25  
      26  static void
      27  mpfr_sgn_test (mpfr_srcptr x, int res)
      28  {
      29    mpfr_exp_t old_emin, old_emax, e;
      30    mpfr_flags_t flags;
      31    int i, v;
      32  
      33    old_emin = mpfr_get_emin ();
      34    old_emax = mpfr_get_emax ();
      35  
      36    for (i = 0; i <= 1; i++)
      37      {
      38        if (i != 0)
      39          {
      40            e = MPFR_IS_SINGULAR (x) ? MPFR_EMIN_MIN : mpfr_get_exp (x);
      41            set_emin (e);
      42            set_emax (e);
      43          }
      44  
      45        for (flags = 0; flags <= MPFR_FLAGS_ALL; flags++)
      46          {
      47            __gmpfr_flags = flags;
      48            v = (mpfr_sgn) (x);
      49            MPFR_ASSERTN (__gmpfr_flags == flags);
      50            if (VSIGN (v) != res)
      51              {
      52                printf ("mpfr_sgn function error (got %d) for ", v);
      53                mpfr_dump (x);
      54                exit (1);
      55              }
      56            v = mpfr_sgn (x);
      57            MPFR_ASSERTN (__gmpfr_flags == flags);
      58            if (VSIGN (v) != res)
      59              {
      60                printf ("mpfr_sgn macro error (got %d) for ", v);
      61                mpfr_dump (x);
      62                exit (1);
      63              }
      64          }
      65      }
      66  
      67    set_emin (old_emin);
      68    set_emax (old_emax);
      69  }
      70  
      71  static void
      72  check_special (void)
      73  {
      74    mpfr_t x;
      75    int i;
      76  
      77    mpfr_init (x);
      78  
      79    for (i = 1; i >= -1; i -= 2)
      80      {
      81        mpfr_set_zero (x, i);
      82        mpfr_sgn_test (x, 0);
      83        mpfr_set_inf (x, i);
      84        mpfr_sgn_test (x, i);
      85        mpfr_set_si (x, i, MPFR_RNDN);
      86        mpfr_sgn_test (x, i);
      87      }
      88  
      89    MPFR_SET_NAN (x);
      90  
      91    mpfr_clear_flags ();
      92    if ((mpfr_sgn) (x) != 0 || !mpfr_erangeflag_p ())
      93      {
      94        printf ("Sgn error for NaN.\n");
      95        exit (1);
      96      }
      97  
      98    mpfr_clear_flags ();
      99    if (mpfr_sgn (x) != 0 || !mpfr_erangeflag_p ())
     100      {
     101        printf ("Sgn error for NaN.\n");
     102        exit (1);
     103      }
     104  
     105    mpfr_clear (x);
     106  }
     107  
     108  static void
     109  check_sgn(void)
     110  {
     111    mpfr_t x;
     112    int i, s1, s2;
     113  
     114    mpfr_init(x);
     115    for(i = 0 ; i < 100 ; i++)
     116      {
     117        mpfr_urandomb (x, RANDS);
     118        if (i&1)
     119          {
     120            MPFR_SET_POS(x);
     121            s2 = 1;
     122          }
     123        else
     124          {
     125            MPFR_SET_NEG(x);
     126            s2 = -1;
     127          }
     128        s1 = mpfr_sgn(x);
     129        if (s1 < -1 || s1 > 1)
     130          {
     131            printf("Error for sgn: out of range.\n");
     132            goto lexit;
     133          }
     134        else if (MPFR_IS_NAN(x) || MPFR_IS_ZERO(x))
     135          {
     136            if (s1 != 0)
     137              {
     138                printf("Error for sgn: Nan or Zero should return 0.\n");
     139                goto lexit;
     140              }
     141          }
     142        else if (s1 != s2)
     143          {
     144            printf("Error for sgn. Return %d instead of %d.\n", s1, s2);
     145            goto lexit;
     146          }
     147      }
     148    mpfr_clear(x);
     149    return;
     150  
     151   lexit:
     152    mpfr_clear(x);
     153    exit(1);
     154  }
     155  
     156  int
     157  main (int argc, char *argv[])
     158  {
     159    tests_start_mpfr ();
     160  
     161    check_special ();
     162    check_sgn ();
     163  
     164    tests_end_mpfr ();
     165    return 0;
     166  }