github.com/aergoio/aergo@v1.3.1/libtool/src/gmp-6.1.2/tests/mpf/t-get_d.c (about)

     1  /* Test mpf_get_d and mpf_set_d.
     2  
     3  Copyright 1996, 1999-2001, 2009 Free Software Foundation, Inc.
     4  
     5  This file is part of the GNU MP Library test suite.
     6  
     7  The GNU MP Library test suite is free software; you can redistribute it
     8  and/or modify it under the terms of the GNU General Public License as
     9  published by the Free Software Foundation; either version 3 of the License,
    10  or (at your option) any later version.
    11  
    12  The GNU MP Library test suite is distributed in the hope that it will be
    13  useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
    14  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
    15  Public License for more details.
    16  
    17  You should have received a copy of the GNU General Public License along with
    18  the GNU MP Library test suite.  If not, see https://www.gnu.org/licenses/.  */
    19  
    20  #include <stdio.h>
    21  #include <stdlib.h>
    22  #include "gmp.h"
    23  #include "tests.h"
    24  
    25  #if defined (__vax) || defined (__vax__)
    26  #define LOW_BOUND 1e-38
    27  #define HIGH_BOUND 8e37
    28  #endif
    29  
    30  #if defined (_CRAY) && ! defined (_CRAYIEEE)
    31  /* The range varies mysteriously between Cray version.  On an SV1,
    32     the range seem to be 1e-600..1e603, but a cfp (non-ieee) T90
    33     has a much smaller range of 1e-240..1e240.  */
    34  #define LOW_BOUND 1e-240
    35  #define HIGH_BOUND 1e240
    36  #endif
    37  
    38  #if ! defined (LOW_BOUND)
    39  #define LOW_BOUND 1e-300
    40  #define HIGH_BOUND 1e300
    41  #endif
    42  
    43  void
    44  test_denorms (int prc)
    45  {
    46  #ifdef _GMP_IEEE_FLOATS
    47    double d1, d2;
    48    mpf_t f;
    49    int i;
    50  
    51    mpf_set_default_prec (prc);
    52  
    53    mpf_init (f);
    54  
    55    d1 = 1.9;
    56    for (i = 0; i < 820; i++)
    57      {
    58        mpf_set_d (f, d1);
    59        d2 = mpf_get_d (f);
    60        if (d1 != d2)
    61          abort ();
    62        d1 *= 0.4;
    63      }
    64  
    65    mpf_clear (f);
    66  #endif
    67  }
    68  
    69  int
    70  main (int argc, char **argv)
    71  {
    72    double d, e, r;
    73    mpf_t u, v;
    74  
    75    tests_start ();
    76    mpf_init (u);
    77    mpf_init (v);
    78  
    79    mpf_set_d (u, LOW_BOUND);
    80    for (d = 2.0 * LOW_BOUND; d < HIGH_BOUND; d *= 1.01)
    81      {
    82        mpf_set_d (v, d);
    83        if (mpf_cmp (u, v) >= 0)
    84  	abort ();
    85        e = mpf_get_d (v);
    86        r = e/d;
    87        if (r < 0.99999999999999 || r > 1.00000000000001)
    88  	{
    89  	  fprintf (stderr, "should be one ulp from 1: %.16f\n", r);
    90  	  abort ();
    91  	}
    92        mpf_set (u, v);
    93      }
    94  
    95    mpf_clear (u);
    96    mpf_clear (v);
    97  
    98    test_denorms (10);
    99    test_denorms (32);
   100    test_denorms (64);
   101    test_denorms (100);
   102    test_denorms (200);
   103  
   104    tests_end ();
   105    exit (0);
   106  }