1 /* Test file for mpfr_nextabove, mpfr_nextbelow, mpfr_nexttoward.
2
3 Copyright 2003-2023 Free Software Foundation, Inc.
4 Contributed by the AriC and Caramba projects, INRIA.
5
6 This file is part of the GNU MPFR Library.
7
8 The GNU MPFR Library is free software; you can redistribute it and/or modify
9 it under the terms of the GNU Lesser General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or (at your
11 option) any later version.
12
13 The GNU MPFR Library is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
16 License for more details.
17
18 You should have received a copy of the GNU Lesser General Public License
19 along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see
20 https://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
21 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
22
23 #include "mpfr-test.h"
24
25 /* Generic tests for mpfr_nextabove and mpfr_nextbelow */
26 static void
27 generic_abovebelow (void)
28 {
29 int i;
30
31 for (i = 0; i < 20000; i++)
32 {
33 mpfr_t x, y, z, t;
34 mpfr_prec_t prec;
35 int neg, below;
36
37 prec = (randlimb () % 300) + MPFR_PREC_MIN;
38 mpfr_inits2 (prec, x, y, z, (mpfr_ptr) 0);
39 mpfr_init2 (t, 3);
40
41 /* special tests (executed once is enough) */
42 if (i == 0)
43 {
44 mpfr_set_nan (x);
45 mpfr_nextabove (x);
46 MPFR_ASSERTN(mpfr_nan_p (x));
47 mpfr_nextbelow (x);
48 MPFR_ASSERTN(mpfr_nan_p (x));
49 mpfr_nexttoward (x, y);
50 MPFR_ASSERTN(mpfr_nan_p (x));
51 mpfr_set_ui (y, 1, MPFR_RNDN);
52 mpfr_nexttoward (y, x);
53 MPFR_ASSERTN(mpfr_nan_p (y));
54 mpfr_set_ui (x, 1, MPFR_RNDN);
55 mpfr_set_ui (y, 1, MPFR_RNDN);
56 mpfr_nexttoward (x, y);
57 MPFR_ASSERTN(mpfr_cmp_ui (x, 1) == 0);
58 }
59
60 do
61 mpfr_urandomb (x, RANDS);
62 while (mpfr_cmp_ui (x, 0) == 0);
63 neg = RAND_BOOL ();
64 if (neg)
65 mpfr_neg (x, x, MPFR_RNDN);
66 mpfr_set (y, x, MPFR_RNDN);
67 below = RAND_BOOL ();
68 if (below)
69 mpfr_nextbelow (y);
70 else
71 mpfr_nextabove (y);
72 mpfr_set_si (t, below ? -5 : 5, MPFR_RNDN);
73 mpfr_mul_2si (t, t, (mpfr_get_exp) (x) - prec - 3, MPFR_RNDN);
74 /* t = (1/2 + 1/8) ulp(x) */
75 mpfr_add (z, x, t, MPFR_RNDN);
76 if (!mpfr_number_p (y) || mpfr_cmp (y, z) != 0)
77 {
78 printf ("Error in mpfr_next%s for\n",
79 below ? "below" : "above");
80 mpfr_out_str (stdout, 2, 0, x, MPFR_RNDN);
81 printf (", got\n");
82 mpfr_out_str (stdout, 2, 0, y, MPFR_RNDN);
83 printf (" instead of\n");
84 mpfr_out_str (stdout, 2, 0, z, MPFR_RNDN);
85 printf ("\n");
86 exit (1);
87 }
88 mpfr_clears (x, y, z, t, (mpfr_ptr) 0);
89 }
90 }
91
92 static void
93 inverse_test (void)
94 {
95 static const char *tests[] = { "0", "1", "2", "3.1", "Inf" };
96 int i, neg, below;
97 mpfr_prec_t prec;
98
99 for (i = 0; i < numberof (tests); i++)
100 for (neg = 0; neg <= 1; neg++)
101 for (below = 0; below <= 1; below++)
102 for (prec = MPFR_PREC_MIN; prec < 200; prec += 3)
103 {
104 mpfr_t x, y;
105 int sign;
106
107 mpfr_inits2 (prec, x, y, (mpfr_ptr) 0);
108 mpfr_set_str (x, tests[i], 10, MPFR_RNDN);
109 if (neg)
110 mpfr_neg (x, x, MPFR_RNDN);
111 mpfr_set (y, x, MPFR_RNDN);
112 if (below)
113 mpfr_nextbelow (y);
114 else
115 mpfr_nextabove (y);
116 sign = MPFR_SIGN (y);
117 if (!(neg == below && mpfr_inf_p (x))) /* then x = y */
118 {
119 if (mpfr_cmp (x, y) == 0)
120 {
121 printf ("Error in inverse_test for %s, neg = %d,"
122 " below = %d, prec = %d: x = y", tests[i],
123 neg, below, (int) prec);
124 printf ("\nx = ");
125 mpfr_out_str (stdout, 2, 0, x, MPFR_RNDN);
126 printf ("\ny = ");
127 mpfr_out_str (stdout, 2, 0, y, MPFR_RNDN);
128 printf ("\n");
129 exit (1);
130 }
131 mpfr_nexttoward (y, x);
132 if (mpfr_cmp_ui (y, 0) == 0 && MPFR_SIGN (y) != sign)
133 {
134 printf ("Sign error in inverse_test for %s, neg = %d,"
135 " below = %d, prec = %d\n", tests[i], neg,
136 below, (int) prec);
137 mpfr_out_str (stdout, 2, 0, y, MPFR_RNDN);
138 printf ("\n");
139 exit (1);
140 }
141 }
142 if (mpfr_cmp (x, y) != 0)
143 {
144 printf ("Error in inverse_test for %s, neg = %d, below = %d,"
145 " prec = %d", tests[i], neg, below, (int) prec);
146 printf ("\nx = ");
147 mpfr_out_str (stdout, 2, 0, x, MPFR_RNDN);
148 printf ("\ny = ");
149 mpfr_out_str (stdout, 2, 0, y, MPFR_RNDN);
150 printf ("\n");
151 exit (1);
152 }
153 mpfr_clears (x, y, (mpfr_ptr) 0);
154 }
155 }
156
157 int
158 main (void)
159 {
160 tests_start_mpfr ();
161 generic_abovebelow ();
162 inverse_test ();
163 tests_end_mpfr ();
164 return 0;
165 }