1 /* Test of isnan() substitute.
2 Copyright (C) 2007 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. */
27 #define ASSERT(expr) \
32 fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
38 /* The Compaq (ex-DEC) C 6.4 compiler chokes on the expression 0.0 / 0.0. */
43 static double zero = 0.0;
47 # define NaN() (0.0 / 0.0)
54 ASSERT (!isnan (3.141));
55 ASSERT (!isnan (3.141e30));
56 ASSERT (!isnan (3.141e-30));
57 ASSERT (!isnan (-2.718));
58 ASSERT (!isnan (-2.718e30));
59 ASSERT (!isnan (-2.718e-30));
60 ASSERT (!isnan (0.0));
61 ASSERT (!isnan (-0.0));
62 /* Infinite values. */
63 ASSERT (!isnan (1.0 / 0.0));
64 ASSERT (!isnan (-1.0 / 0.0));
66 ASSERT (isnan (NaN ()));
67 #if defined DBL_EXPBIT0_WORD && defined DBL_EXPBIT0_BIT
71 ((sizeof (double) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
72 typedef union { double value; unsigned int word[NWORDS]; } memory_double;
75 # if DBL_EXPBIT0_BIT > 0
76 m.word[DBL_EXPBIT0_WORD] ^= (unsigned int) 1 << (DBL_EXPBIT0_BIT - 1);
78 m.word[DBL_EXPBIT0_WORD + (DBL_EXPBIT0_WORD < NWORDS / 2 ? 1 : - 1)]
79 ^= (unsigned int) 1 << (sizeof (unsigned int) * CHAR_BIT - 1);
81 m.word[DBL_EXPBIT0_WORD + (DBL_EXPBIT0_WORD < NWORDS / 2 ? 1 : - 1)]
82 |= (unsigned int) 1 << DBL_EXPBIT0_BIT;
83 ASSERT (isnan (m.value));