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

     1  /* Test mpz_set_d and mpz_init_set_d.
     2  
     3  Copyright 2000-2003, 2006 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 "gmp-impl.h"
    24  #include "tests.h"
    25  
    26  
    27  void
    28  check_data (void)
    29  {
    30    static const struct {
    31      double     d;
    32      mp_size_t  want_size;
    33      mp_limb_t  want_data[2];
    34    } data[] = {
    35  
    36      {  0.0,  0 },
    37      {  1.0,  1, { 1 } },
    38      { -1.0, -1, { 1 } },
    39  
    40      {  123.0,  1, { 123 } },
    41      { -123.0, -1, { 123 } },
    42  
    43      { 1e-1, 0, { 0 } },
    44      { -1e-1, 0, { 0 } },
    45      { 2.328306436538696e-10, 0, { 0 } },
    46      { -2.328306436538696e-10, 0, { 0 } },
    47      { 5.421010862427522e-20, 0, { 0 } },
    48      { -5.421010862427522e-20, 0, { 0 } },
    49      { 2.938735877055719e-39, 0, { 0 } },
    50      { -2.938735877055719e-39, 0, { 0 } },
    51    };
    52  
    53    mpz_t  z;
    54    int    i;
    55  
    56    for (i = 0; i < numberof (data); i++)
    57      {
    58        mpz_init (z);
    59        mpz_set_d (z, data[i].d);
    60        MPZ_CHECK_FORMAT (z);
    61        if (z->_mp_size != data[i].want_size
    62            || refmpn_cmp_allowzero (z->_mp_d, data[i].want_data,
    63                                     ABS (data[i].want_size)) != 0)
    64          {
    65            printf ("mpz_set_d wrong on data[%d]\n", i);
    66          bad:
    67            d_trace   ("  d  ", data[i].d);
    68            printf    ("  got  size %ld\n", (long) z->_mp_size);
    69            printf    ("  want size %ld\n", (long) data[i].want_size);
    70            mpn_trace ("  got  z", z->_mp_d, z->_mp_size);
    71            mpn_trace ("  want z", data[i].want_data, data[i].want_size);
    72            abort();
    73          }
    74        mpz_clear (z);
    75  
    76        mpz_init_set_d (z, data[i].d);
    77        MPZ_CHECK_FORMAT (z);
    78        if (z->_mp_size != data[i].want_size
    79            || refmpn_cmp_allowzero (z->_mp_d, data[i].want_data,
    80                                     ABS (data[i].want_size)) != 0)
    81          {
    82            printf ("mpz_init_set_d wrong on data[%d]\n", i);
    83            goto bad;
    84          }
    85        mpz_clear (z);
    86      }
    87  }
    88  
    89  /* Try mpz_set_d on values 2^i+1, while such a value fits a double. */
    90  void
    91  check_2n_plus_1 (void)
    92  {
    93    volatile double  p, d, diff;
    94    mpz_t  want, got;
    95    int    i;
    96  
    97    mpz_init (want);
    98    mpz_init (got);
    99  
   100    p = 1.0;
   101    mpz_set_ui (want, 2L);  /* gives 3 on first step */
   102  
   103    for (i = 1; i < 500; i++)
   104      {
   105        mpz_mul_2exp (want, want, 1L);
   106        mpz_sub_ui (want, want, 1L);   /* want = 2^i+1 */
   107  
   108        p *= 2.0;  /* p = 2^i */
   109        d = p + 1.0;
   110        diff = d - p;
   111        if (diff != 1.0)
   112          break;   /* rounding occurred, stop now */
   113  
   114        mpz_set_d (got, d);
   115        MPZ_CHECK_FORMAT (got);
   116        if (mpz_cmp (got, want) != 0)
   117          {
   118            printf ("mpz_set_d wrong on 2^%d+1\n", i);
   119            d_trace   ("  d ", d);
   120            mpz_trace ("  got  ", got);
   121            mpz_trace ("  want ", want);
   122            abort ();
   123          }
   124      }
   125  
   126    mpz_clear (want);
   127    mpz_clear (got);
   128  }
   129  
   130  int
   131  main (void)
   132  {
   133    tests_start ();
   134  
   135    check_data ();
   136    check_2n_plus_1 ();
   137  
   138    tests_end ();
   139    exit (0);
   140  }