1 /* Test of signbit() substitute.
2 Copyright (C) 2007-2023 Free Software Foundation, Inc.
3
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation, either version 3 of the License, or
7 (at your option) any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <https://www.gnu.org/licenses/>. */
16
17 /* Written by Bruno Haible <bruno@clisp.org>, 2007. */
18
19 #include <config.h>
20
21 #include <math.h>
22
23 /* signbit must be a macro. */
24 #ifndef signbit
25 # error missing declaration
26 #endif
27
28 #include <float.h>
29 #include <limits.h>
30
31 #include "minus-zero.h"
32 #include "infinity.h"
33 #include "macros.h"
34
35 float zerof = 0.0f;
36 double zerod = 0.0;
37 long double zerol = 0.0L;
38
39 static void
40 test_signbitf ()
41 {
42 /* Finite values. */
43 ASSERT (!signbit (3.141f));
44 ASSERT (!signbit (3.141e30f));
45 ASSERT (!signbit (3.141e-30f));
46 ASSERT (signbit (-2.718f));
47 ASSERT (signbit (-2.718e30f));
48 ASSERT (signbit (-2.718e-30f));
49 /* Zeros. */
50 ASSERT (!signbit (0.0f));
51 if (1.0f / minus_zerof < 0)
52 ASSERT (signbit (minus_zerof));
53 else
54 ASSERT (!signbit (minus_zerof));
55 /* Infinite values. */
56 ASSERT (!signbit (Infinityf ()));
57 ASSERT (signbit (- Infinityf ()));
58 /* Quiet NaN. */
59 (void) signbit (zerof / zerof);
60 #if defined FLT_EXPBIT0_WORD && defined FLT_EXPBIT0_BIT
61 /* Signalling NaN. */
62 {
63 #define NWORDS \
64 ((sizeof (float) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
65 typedef union { float value; unsigned int word[NWORDS]; } memory_float;
66 memory_float m;
67 m.value = zerof / zerof;
68 # if FLT_EXPBIT0_BIT > 0
69 m.word[FLT_EXPBIT0_WORD] ^= (unsigned int) 1 << (FLT_EXPBIT0_BIT - 1);
70 # else
71 m.word[FLT_EXPBIT0_WORD + (FLT_EXPBIT0_WORD < NWORDS / 2 ? 1 : - 1)]
72 ^= (unsigned int) 1 << (sizeof (unsigned int) * CHAR_BIT - 1);
73 # endif
74 if (FLT_EXPBIT0_WORD < NWORDS / 2)
75 m.word[FLT_EXPBIT0_WORD + 1] |= (unsigned int) 1 << FLT_EXPBIT0_BIT;
76 else
77 m.word[0] |= (unsigned int) 1;
78 (void) signbit (m.value);
79 #undef NWORDS
80 }
81 #endif
82 }
83
84 static void
85 test_signbitd ()
86 {
87 /* Finite values. */
88 ASSERT (!signbit (3.141));
89 ASSERT (!signbit (3.141e30));
90 ASSERT (!signbit (3.141e-30));
91 ASSERT (signbit (-2.718));
92 ASSERT (signbit (-2.718e30));
93 ASSERT (signbit (-2.718e-30));
94 /* Zeros. */
95 ASSERT (!signbit (0.0));
96 if (1.0 / minus_zerod < 0)
97 ASSERT (signbit (minus_zerod));
98 else
99 ASSERT (!signbit (minus_zerod));
100 /* Infinite values. */
101 ASSERT (!signbit (Infinityd ()));
102 ASSERT (signbit (- Infinityd ()));
103 /* Quiet NaN. */
104 (void) signbit (zerod / zerod);
105 #if defined DBL_EXPBIT0_WORD && defined DBL_EXPBIT0_BIT
106 /* Signalling NaN. */
107 {
108 #define NWORDS \
109 ((sizeof (double) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
110 typedef union { double value; unsigned int word[NWORDS]; } memory_double;
111 memory_double m;
112 m.value = zerod / zerod;
113 # if DBL_EXPBIT0_BIT > 0
114 m.word[DBL_EXPBIT0_WORD] ^= (unsigned int) 1 << (DBL_EXPBIT0_BIT - 1);
115 # else
116 m.word[DBL_EXPBIT0_WORD + (DBL_EXPBIT0_WORD < NWORDS / 2 ? 1 : - 1)]
117 ^= (unsigned int) 1 << (sizeof (unsigned int) * CHAR_BIT - 1);
118 # endif
119 m.word[DBL_EXPBIT0_WORD + (DBL_EXPBIT0_WORD < NWORDS / 2 ? 1 : - 1)]
120 |= (unsigned int) 1 << DBL_EXPBIT0_BIT;
121 (void) signbit (m.value);
122 #undef NWORDS
123 }
124 #endif
125 }
126
127 static void
128 test_signbitl ()
129 {
130 /* Finite values. */
131 ASSERT (!signbit (3.141L));
132 ASSERT (!signbit (3.141e30L));
133 ASSERT (!signbit (3.141e-30L));
134 ASSERT (signbit (-2.718L));
135 ASSERT (signbit (-2.718e30L));
136 ASSERT (signbit (-2.718e-30L));
137 /* Zeros. */
138 ASSERT (!signbit (0.0L));
139 if (1.0L / minus_zerol < 0)
140 ASSERT (signbit (minus_zerol));
141 else
142 ASSERT (!signbit (minus_zerol));
143 /* Infinite values. */
144 ASSERT (!signbit (Infinityl ()));
145 ASSERT (signbit (- Infinityl ()));
146 /* Quiet NaN. */
147 (void) signbit (zerol / zerol);
148 #if defined LDBL_EXPBIT0_WORD && defined LDBL_EXPBIT0_BIT
149 /* Signalling NaN. */
150 {
151 #define NWORDS \
152 ((sizeof (long double) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
153 typedef union { long double value; unsigned int word[NWORDS]; } memory_long_double;
154
155 #if defined __powerpc__ && LDBL_MANT_DIG == 106
156 /* This is PowerPC "double double", a pair of two doubles. Inf and Nan are
157 represented as the corresponding 64-bit IEEE values in the first double;
158 the second is ignored. Manipulate only the first double. */
159 #undef NWORDS
160 #define NWORDS \
161 ((sizeof (double) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
162 #endif
163
164 memory_long_double m;
165 m.value = zerol / zerol;
166 # if LDBL_EXPBIT0_BIT > 0
167 m.word[LDBL_EXPBIT0_WORD] ^= (unsigned int) 1 << (LDBL_EXPBIT0_BIT - 1);
168 # else
169 m.word[LDBL_EXPBIT0_WORD + (LDBL_EXPBIT0_WORD < NWORDS / 2 ? 1 : - 1)]
170 ^= (unsigned int) 1 << (sizeof (unsigned int) * CHAR_BIT - 1);
171 # endif
172 m.word[LDBL_EXPBIT0_WORD + (LDBL_EXPBIT0_WORD < NWORDS / 2 ? 1 : - 1)]
173 |= (unsigned int) 1 << LDBL_EXPBIT0_BIT;
174 (void) signbit (m.value);
175 #undef NWORDS
176 }
177 #endif
178 }
179
180 int
181 main ()
182 {
183 test_signbitf ();
184 test_signbitd ();
185 test_signbitl ();
186 return 0;
187 }