1 /* Test file for mpfr_atanu.
2
3 Copyright 2021-2023 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 #define TEST_FUNCTION mpfr_atanu
26 #define ULONG_ARG2
27 #include "tgeneric.c"
28
29 static void
30 check_underflow (void)
31 {
32 mpfr_t x, y;
33 mpfr_exp_t emin = mpfr_get_emin ();
34
35 set_emin (mpfr_get_emin_min ());
36
37 mpfr_init2 (x, MPFR_PREC_MIN);
38 mpfr_init2 (y, MPFR_PREC_MIN);
39 mpfr_set_ui_2exp (x, 1, mpfr_get_emin_min () - 1, MPFR_RNDN);
40 /* atanu(x,1) = atan(x)/(2*pi) will underflow */
41 mpfr_atanu (y, x, 1, MPFR_RNDN);
42 MPFR_ASSERTN(mpfr_zero_p (y) && mpfr_signbit (y) == 0);
43 mpfr_atanu (y, x, 1, MPFR_RNDZ);
44 MPFR_ASSERTN(mpfr_zero_p (y) && mpfr_signbit (y) == 0);
45 mpfr_atanu (y, x, 1, MPFR_RNDU);
46 MPFR_ASSERTN(mpfr_cmp_ui_2exp (y, 1, mpfr_get_emin_min () - 1) == 0);
47 mpfr_clear (x);
48 mpfr_clear (y);
49
50 set_emin (emin);
51 }
52
53 int
54 main (void)
55 {
56 mpfr_t x, y;
57 int r, inex;
58 unsigned long u;
59
60 tests_start_mpfr ();
61
62 check_underflow ();
63
64 mpfr_init (x);
65 mpfr_init (y);
66
67 /* check singular cases */
68 MPFR_SET_NAN(x);
69 mpfr_atanu (y, x, 1, MPFR_RNDN);
70 if (mpfr_nan_p (y) == 0)
71 {
72 printf ("Error: atanu (NaN, 1) != NaN\n");
73 exit (1);
74 }
75
76 mpfr_set_inf (x, 1);
77 mpfr_atanu (y, x, 1, MPFR_RNDN);
78 if (mpfr_cmp_ui_2exp (y, 1, -2) != 0)
79 {
80 printf ("Error: atanu (+Inf, 1) != 1/4\n");
81 printf ("got: "); mpfr_dump (y);
82 exit (1);
83 }
84
85 mpfr_set_inf (x, -1);
86 mpfr_atanu (y, x, 1, MPFR_RNDN);
87 if (mpfr_cmp_si_2exp (y, -1, -2) != 0)
88 {
89 printf ("Error: atanu (-Inf, 1) != -1/4\n");
90 exit (1);
91 }
92
93 /* atanu (+0,u) = +0 */
94 mpfr_set_ui (x, 0, MPFR_RNDN);
95 mpfr_atanu (y, x, 1, MPFR_RNDN);
96 if (MPFR_NOTZERO (y) || MPFR_IS_NEG (y))
97 {
98 printf ("Error: atanu(+0,1) != +0\n");
99 exit (1);
100 }
101
102 /* atanu (-0,u) = -0 */
103 mpfr_set_ui (x, 0, MPFR_RNDN);
104 mpfr_neg (x, x, MPFR_RNDN);
105 mpfr_atanu (y, x, 1, MPFR_RNDN);
106 if (MPFR_NOTZERO (y) || MPFR_IS_POS (y))
107 {
108 printf ("Error: atanu(-0,1) != -0\n");
109 exit (1);
110 }
111
112 /* atanu (1,u) = u/8 */
113 for (u = 1; u < 100; u++)
114 RND_LOOP (r)
115 {
116 mpfr_set_ui (x, 1, MPFR_RNDN); /* exact */
117 mpfr_atanu (y, x, u, (mpfr_rnd_t) r);
118 inex = mpfr_set_ui (x, u, MPFR_RNDN);
119 MPFR_ASSERTN(inex == 0);
120 inex = mpfr_div_ui (x, x, 8, (mpfr_rnd_t) r);
121 if ((r != MPFR_RNDF || inex == 0) && !mpfr_equal_p (x, y))
122 {
123 printf ("Error: atanu(1,u) != u/8 for u=%lu and rnd=%s\n",
124 u, mpfr_print_rnd_mode ((mpfr_rnd_t) r));
125 printf ("got: "); mpfr_dump (y);
126 exit (1);
127 }
128 }
129
130 /* atanu (-1,u) = -u/8 */
131 for (u = 1; u < 100; u++)
132 RND_LOOP (r)
133 {
134 mpfr_set_si (x, -1, MPFR_RNDN); /* exact */
135 mpfr_atanu (y, x, u, (mpfr_rnd_t) r);
136 inex = mpfr_set_ui (x, u, MPFR_RNDN);
137 MPFR_ASSERTN(inex == 0);
138 inex = mpfr_div_si (x, x, -8, (mpfr_rnd_t) r);
139 if ((r != MPFR_RNDF || inex == 0) && !mpfr_equal_p (x, y))
140 {
141 printf ("Error: atanu(-1,u) != -u/8 for u=%lu and rnd=%s\n",
142 u, mpfr_print_rnd_mode ((mpfr_rnd_t) r));
143 printf ("got: "); mpfr_dump (y);
144 exit (1);
145 }
146 }
147
148 /* case u=0 */
149 mpfr_set_ui (x, 1, MPFR_RNDN);
150 mpfr_atanu (y, x, 0, MPFR_RNDN);
151 if (MPFR_NOTZERO (y) || MPFR_IS_NEG (y))
152 {
153 printf ("Error: atanu(1,0) != +0\n");
154 printf ("got "); mpfr_dump (y);
155 exit (1);
156 }
157 mpfr_set_si (x, -1, MPFR_RNDN);
158 mpfr_atanu (y, x, 0, MPFR_RNDN);
159 if (MPFR_NOTZERO (y) || MPFR_IS_POS (y))
160 {
161 printf ("Error: atanu(-1,0) != -0\n");
162 printf ("got "); mpfr_dump (y);
163 exit (1);
164 }
165
166 test_generic (MPFR_PREC_MIN, 100, 100);
167
168 mpfr_clear (x);
169 mpfr_clear (y);
170
171 tests_end_mpfr ();
172 return 0;
173 }