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-impl.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  }