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
test_denorms(int prc)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
main(int argc,char ** argv)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 }
107