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 2, or (at your option)
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, write to the Free Software Foundation,
16 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
18 /* Written by Bruno Haible <bruno@clisp.org>, 2007. */
27 #define ASSERT(expr) if (!(expr)) abort ();
29 /* The Compaq (ex-DEC) C 6.4 compiler chokes on the expression 0.0 / 0.0. */
34 static double zero = 0.0;
38 # define NaN() (0.0 / 0.0)
45 ASSERT (!isnan (3.141));
46 ASSERT (!isnan (3.141e30));
47 ASSERT (!isnan (3.141e-30));
48 ASSERT (!isnan (-2.718));
49 ASSERT (!isnan (-2.718e30));
50 ASSERT (!isnan (-2.718e-30));
51 /* Infinite values. */
52 ASSERT (!isnan (1.0 / 0.0));
53 ASSERT (!isnan (-1.0 / 0.0));
55 ASSERT (isnan (NaN ()));
56 #if defined DBL_EXPBIT0_WORD && defined DBL_EXPBIT0_BIT
60 ((sizeof (double) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
61 typedef union { double value; unsigned int word[NWORDS]; } memory_double;
64 # if DBL_EXPBIT0_BIT > 0
65 m.word[DBL_EXPBIT0_WORD] ^= (unsigned int) 1 << (DBL_EXPBIT0_BIT - 1);
67 m.word[DBL_EXPBIT0_WORD + (DBL_EXPBIT0_WORD < NWORDS / 2 ? 1 : - 1)]
68 ^= (unsigned int) 1 << (sizeof (unsigned int) * CHAR_BIT - 1);
70 m.word[DBL_EXPBIT0_WORD + (DBL_EXPBIT0_WORD < NWORDS / 2 ? 1 : - 1)]
71 |= (unsigned int) 1 << DBL_EXPBIT0_BIT;
72 ASSERT (isnan (m.value));