1/*	$OpenBSD: ldexp_test.c,v 1.1 2017/10/15 12:15:30 visa Exp $	*/
2
3/*
4 * Copyright (c) 2017 Visa Hankala
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19#include <assert.h>
20#include <math.h>
21
22int
23main(int argc, char *argv[])
24{
25	double f;
26
27	/*
28	 * Test that the result has the correct sign.
29	 * Assumes IEEE 754 double-precision arithmetics.
30	 */
31
32	assert(ldexp(1.0, -1022) > 0.0); /* IEEE 754 minimum normal positive */
33	assert(ldexp(1.0, -1023) > 0.0); /* subnormal positive */
34	assert(ldexp(1.0, -1024) > 0.0); /* subnormal positive */
35	assert(ldexp(1.0, -1074) > 0.0); /* minimum subnormal positive */
36	assert(ldexp(1.0, -1075) >= 0.0); /* zero */
37	assert(ldexp(ldexp(1.0, -1022), -53) >= 0.0); /* zero */
38
39	assert(ldexp(1.0, 1023) > 0.0);	/* normal positive */
40
41	f = ldexp(1.0, 1024);		/* infinite positive */
42	assert(isinf(f));
43	assert(!signbit(f));
44
45	f = ldexp(ldexp(1.0, 1023), 1);	/* infinite positive */
46	assert(isinf(f));
47	assert(!signbit(f));
48
49	assert(ldexp(-1.0, -1022) < 0.0); /* IEEE 754 maximum normal negative */
50	assert(ldexp(-1.0, -1023) < 0.0); /* subnormal negative */
51	assert(ldexp(-1.0, -1024) < 0.0); /* subnormal negative */
52	assert(ldexp(-1.0, -1074) < 0.0); /* maximum subnormal negative */
53	assert(ldexp(-1.0, -1075) <= 0.0); /* zero */
54	assert(ldexp(ldexp(-1.0, -1022), -53) <= 0.0); /* zero */
55
56	assert(ldexp(-1.0, 1023) < 0.0); /* normal negative */
57
58	f = ldexp(-1.0, 1024);		/* infinite negative */
59	assert(isinf(f));
60	assert(signbit(f));
61
62	f = ldexp(ldexp(-1.0, 1023), 1); /* infinite negative */
63	assert(isinf(f));
64	assert(signbit(f));
65
66	f = ldexp(NAN, 0);
67	assert(isnan(f));
68	assert(!signbit(f));
69
70	f = ldexp(-NAN, 0);
71	assert(isnan(f));
72	assert(signbit(f));
73
74	return 0;
75}
76