1 /* Test of signbit() substitute.
2 Copyright (C) 2007, 2008 Free Software Foundation, Inc.
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.
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.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
17 /* Written by Bruno Haible <bruno@clisp.org>, 2007. */
28 #define ASSERT(expr) \
33 fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
42 long double zerol = 0.0L;
44 /* HP cc on HP-UX 10.20 has a bug with the constant expression -0.0f.
45 So we use -zerof instead. */
47 /* HP cc on HP-UX 10.20 has a bug with the constant expression -0.0.
48 So we use -zerod instead. */
50 /* On HP-UX 10.20, negating 0.0L does not yield -0.0L.
51 So we use minus_zerol instead. */
52 long double minus_zerol = -LDBL_MIN * LDBL_MIN;
58 ASSERT (!signbit (3.141f));
59 ASSERT (!signbit (3.141e30f));
60 ASSERT (!signbit (3.141e-30f));
61 ASSERT (signbit (-2.718f));
62 ASSERT (signbit (-2.718e30f));
63 ASSERT (signbit (-2.718e-30f));
65 ASSERT (!signbit (0.0f));
66 if (1.0f / -zerof < 0)
67 ASSERT (signbit (-zerof));
69 ASSERT (!signbit (-zerof));
70 /* Infinite values. */
71 ASSERT (!signbit (1.0f / 0.0f));
72 ASSERT (signbit (-1.0f / 0.0f));
74 (void) signbit (zerof / zerof);
75 #if defined FLT_EXPBIT0_WORD && defined FLT_EXPBIT0_BIT
79 ((sizeof (float) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
80 typedef union { float value; unsigned int word[NWORDS]; } memory_float;
82 m.value = zerof / zerof;
83 # if FLT_EXPBIT0_BIT > 0
84 m.word[FLT_EXPBIT0_WORD] ^= (unsigned int) 1 << (FLT_EXPBIT0_BIT - 1);
86 m.word[FLT_EXPBIT0_WORD + (FLT_EXPBIT0_WORD < NWORDS / 2 ? 1 : - 1)]
87 ^= (unsigned int) 1 << (sizeof (unsigned int) * CHAR_BIT - 1);
89 if (FLT_EXPBIT0_WORD < NWORDS / 2)
90 m.word[FLT_EXPBIT0_WORD + 1] |= (unsigned int) 1 << FLT_EXPBIT0_BIT;
92 m.word[0] |= (unsigned int) 1;
93 (void) signbit (m.value);
103 ASSERT (!signbit (3.141));
104 ASSERT (!signbit (3.141e30));
105 ASSERT (!signbit (3.141e-30));
106 ASSERT (signbit (-2.718));
107 ASSERT (signbit (-2.718e30));
108 ASSERT (signbit (-2.718e-30));
110 ASSERT (!signbit (0.0));
111 if (1.0 / -zerod < 0)
112 ASSERT (signbit (-zerod));
114 ASSERT (!signbit (-zerod));
115 /* Infinite values. */
116 ASSERT (!signbit (1.0 / 0.0));
117 ASSERT (signbit (-1.0 / 0.0));
119 (void) signbit (zerod / zerod);
120 #if defined DBL_EXPBIT0_WORD && defined DBL_EXPBIT0_BIT
121 /* Signalling NaN. */
124 ((sizeof (double) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
125 typedef union { double value; unsigned int word[NWORDS]; } memory_double;
127 m.value = zerod / zerod;
128 # if DBL_EXPBIT0_BIT > 0
129 m.word[DBL_EXPBIT0_WORD] ^= (unsigned int) 1 << (DBL_EXPBIT0_BIT - 1);
131 m.word[DBL_EXPBIT0_WORD + (DBL_EXPBIT0_WORD < NWORDS / 2 ? 1 : - 1)]
132 ^= (unsigned int) 1 << (sizeof (unsigned int) * CHAR_BIT - 1);
134 m.word[DBL_EXPBIT0_WORD + (DBL_EXPBIT0_WORD < NWORDS / 2 ? 1 : - 1)]
135 |= (unsigned int) 1 << DBL_EXPBIT0_BIT;
136 (void) signbit (m.value);
146 ASSERT (!signbit (3.141L));
147 ASSERT (!signbit (3.141e30L));
148 ASSERT (!signbit (3.141e-30L));
149 ASSERT (signbit (-2.718L));
150 ASSERT (signbit (-2.718e30L));
151 ASSERT (signbit (-2.718e-30L));
153 ASSERT (!signbit (0.0L));
154 if (1.0L / minus_zerol < 0)
155 ASSERT (signbit (minus_zerol));
157 ASSERT (!signbit (minus_zerol));
158 /* Infinite values. */
159 ASSERT (!signbit (1.0L / 0.0L));
160 ASSERT (signbit (-1.0L / 0.0L));
162 (void) signbit (zerol / zerol);
163 #if defined LDBL_EXPBIT0_WORD && defined LDBL_EXPBIT0_BIT
164 /* Signalling NaN. */
167 ((sizeof (long double) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
168 typedef union { long double value; unsigned int word[NWORDS]; } memory_long_double;
169 memory_long_double m;
170 m.value = zerol / zerol;
171 # if LDBL_EXPBIT0_BIT > 0
172 m.word[LDBL_EXPBIT0_WORD] ^= (unsigned int) 1 << (LDBL_EXPBIT0_BIT - 1);
174 m.word[LDBL_EXPBIT0_WORD + (LDBL_EXPBIT0_WORD < NWORDS / 2 ? 1 : - 1)]
175 ^= (unsigned int) 1 << (sizeof (unsigned int) * CHAR_BIT - 1);
177 m.word[LDBL_EXPBIT0_WORD + (LDBL_EXPBIT0_WORD < NWORDS / 2 ? 1 : - 1)]
178 |= (unsigned int) 1 << LDBL_EXPBIT0_BIT;
179 (void) signbit (m.value);