1  /* Test mpfr_get_d_2exp.
       2  
       3  Copyright 1999-2023 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  #include <float.h>
      24  
      25  #include "mpfr-test.h"
      26  
      27  
      28  /* Check that hardware rounding doesn't make mpfr_get_d_2exp return a value
      29     outside its defined range. */
      30  static void
      31  check_round (void)
      32  {
      33    static const unsigned long data[] = { 1, 32, 53, 54, 64, 128, 256, 512 };
      34    mpfr_t  f;
      35    double  got;
      36    long    got_exp;
      37    int     i, rnd_mode, neg;
      38  
      39    mpfr_init2 (f, 1024L);
      40  
      41    RND_LOOP (rnd_mode)
      42      {
      43        for (i = 0; i < (int) numberof (data); i++)
      44          {
      45            mpfr_set_ui (f, 1L, MPFR_RNDZ);
      46            mpfr_mul_2ui (f, f, data[i], MPFR_RNDZ);
      47            mpfr_sub_ui (f, f, 1L, MPFR_RNDZ);
      48  
      49            for (neg = 0; neg <= 1; neg++)
      50              {
      51                got = mpfr_get_d_2exp (&got_exp, f, (mpfr_rnd_t) rnd_mode);
      52  
      53                if (neg == 0
      54                    ? (got < 0.5 || got >= 1.0)
      55                    : (got <= -1.0 || got > -0.5))
      56                  {
      57                    printf  ("mpfr_get_d_2exp wrong on 2**%lu-1\n", data[i]);
      58                    printf  ("result out of range, expect 0.5 <= got < 1.0\n");
      59                    printf  ("   rnd_mode = %d\n", rnd_mode);
      60                    printf  ("   data[i]  = %lu\n", data[i]);
      61                    printf  ("   f    ");
      62                    mpfr_out_str (stdout, 2, 0, f, MPFR_RNDN);
      63                    printf  ("\n");
      64                    d_trace ("   got  ", got);
      65                    printf  ("   got exp  %ld\n", got_exp);
      66                    exit(1);
      67                  }
      68  
      69                mpfr_neg (f, f, MPFR_RNDZ);
      70              }
      71          }
      72      }
      73  
      74    mpfr_clear (f);
      75  }
      76  
      77  
      78  static void
      79  check_inf_nan (void)
      80  {
      81  #if !defined(MPFR_ERRDIVZERO)
      82    mpfr_t  x;
      83    double  d;
      84    long    exp;
      85  
      86    mpfr_init2 (x, 123);
      87  
      88    mpfr_set_inf (x, 1);
      89    d = mpfr_get_d_2exp (&exp, x, MPFR_RNDZ);
      90    MPFR_ASSERTN (d > 0);
      91    MPFR_ASSERTN (DOUBLE_ISINF (d));
      92  
      93    mpfr_set_inf (x, -1);
      94    d = mpfr_get_d_2exp (&exp, x, MPFR_RNDZ);
      95    MPFR_ASSERTN (d < 0);
      96    MPFR_ASSERTN (DOUBLE_ISINF (d));
      97  
      98    mpfr_set_nan (x);
      99    d = mpfr_get_d_2exp (&exp, x, MPFR_RNDZ);
     100    MPFR_ASSERTN (DOUBLE_ISNAN (d));
     101  
     102    mpfr_clear (x);
     103  #endif
     104  }
     105  
     106  
     107  int
     108  main (void)
     109  {
     110    tests_start_mpfr ();
     111    mpfr_test_init ();
     112  
     113    check_round ();
     114    check_inf_nan ();
     115  
     116    tests_end_mpfr ();
     117    return 0;
     118  }