1/* Test mpfr_get_d_2exp.
2
3Copyright 1999-2023 Free Software Foundation, Inc.
4Contributed by the AriC and Caramba projects, INRIA.
5
6This file is part of the GNU MPFR Library.
7
8The GNU MPFR Library is free software; you can redistribute it and/or modify
9it under the terms of the GNU Lesser General Public License as published by
10the Free Software Foundation; either version 3 of the License, or (at your
11option) any later version.
12
13The GNU MPFR Library is distributed in the hope that it will be useful, but
14WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
16License for more details.
17
18You should have received a copy of the GNU Lesser General Public License
19along with the GNU MPFR Library; see the file COPYING.LESSER.  If not, see
20https://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
2151 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. */
30static void
31check_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
78static void
79check_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
107int
108main (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}
119