t_acos.c revision 1.6 
1/* $NetBSD: t_acos.c,v 1.6 2014/03/02 22:40:45 dsl Exp $ */
2
3/*-
4 * Copyright (c) 2011 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jukka Ruohonen.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include <atf-c.h>
33#include <math.h>
34#include <fenv.h>
35
36/*
37 * Check result of fn(arg) is correct within the bounds.
38 * Should be ok to do the checks using 'double' for 'float' functions.
39 */
40#define T_LIBM_CHECK(subtest, fn, arg, expect, epsilon) do { \
41	double r = fn(arg); \
42	double e = fabs(r - expect); \
43	if (e > epsilon) \
44		atf_tc_fail_nonfatal( \
45		    "subtest %zu: " #fn "(%g) is %g not %g (error %g > %g), roundmode %x", \
46		    subtest, arg, r, expect, e, epsilon, fegetround()); \
47    } while (0)
48
49/* Check that the result of fn(arg) is NaN */
50#ifndef __vax__
51#define T_LIBM_CHECK_NAN(subtest, fn, arg) do { \
52	double r = fn(arg); \
53	if (!isnan(r)) \
54		atf_tc_fail_nonfatal("subtest %zu: " #fn "(%g) is %g not NaN", \
55		    subtest, arg, r); \
56    } while (0)
57#else
58/* vax doesn't support NaN */
59#define T_LIBM_CHECK_NAN(subtest, fn, arg) (void)(arg)
60#endif
61
62#define AFT_LIBM_TEST(name, description) \
63ATF_TC(name); \
64ATF_TC_HEAD(name, tc) { atf_tc_set_md_var(tc, "descr", description); } \
65ATF_TC_BODY(name, tc)
66
67/*
68 * acos(3) and acosf(3)
69 */
70
71AFT_LIBM_TEST(acos_nan, "Test acos/acosf(x) == NaN, x = NaN, +/-Inf, ![-1..1]")
72{
73	static const double x[] = {
74	    -1.000000001, 1.000000001,
75	    -1.0000001, 1.0000001,
76	    -1.1, 1.1,
77	    0.0L / 0.0L,  /* NAN */
78	    -1.0L / 0.0L, /* -Inf */
79	    +1.0L / 0.0L, /* +Inf */
80	};
81	size_t i;
82
83	for (i = 0; i < __arraycount(x); i++) {
84		T_LIBM_CHECK_NAN(i, acos, x[i]);
85		if (i < 2)
86			/* Values are too small for float */
87			continue;
88		T_LIBM_CHECK_NAN(i, acosf, x[i]);
89	}
90}
91
92AFT_LIBM_TEST(acos_inrange, "Test acos/acosf(x) for some valid values")
93{
94	static const struct {
95		double x;
96		double y;
97	} values[] = {
98		{ -1,    M_PI,              },
99		{ -0.99, 3.000053180265366, },
100		{ -0.5,  2.094395102393195, },
101		{ -0.1,  1.670963747956456, },
102		{  0,    M_PI / 2,          },
103		{  0.1,  1.470628905633337, },
104		{  0.5,  1.047197551196598, },
105		{  0.99, 0.141539473324427, },
106	};
107	size_t i;
108
109	/*
110	 * Note that acos(x) might be calculated as atan2(sqrt(1-x*x),x).
111	 * This means that acos(-1) is atan2(+0,-1), if the sign is wrong
112	 * the value will be -M_PI (atan2(-0,-1)) not M_PI.
113	 */
114
115	for (i = 0; i < __arraycount(values); i++) {
116		T_LIBM_CHECK(i, acos, values[i].x, values[i].y, 1.0e-15);
117		T_LIBM_CHECK(i, acosf, values[i].x, values[i].y, 1.0e-5);
118	}
119}
120
121AFT_LIBM_TEST(acos_one_pos, "Test acos(1.0) == +0.0")
122{
123#ifndef __vax__
124	const double y = acos(1.0);
125
126	if (fabs(y) > 0.0 || signbit(y) != 0)
127		atf_tc_fail_nonfatal("acos(1.0) != +0.0");
128#endif
129}
130
131AFT_LIBM_TEST(acosf_one_pos, "Test acosf(1.0) == +0.0")
132{
133#ifndef __vax__
134	const float y = acosf(1.0);
135
136	if (fabsf(y) > 0.0 || signbit(y) != 0)
137		atf_tc_fail_nonfatal("acosf(1.0) != +0.0");
138#endif
139}
140
141ATF_TP_ADD_TCS(tp)
142{
143
144	ATF_TP_ADD_TC(tp, acos_nan);
145	ATF_TP_ADD_TC(tp, acos_inrange);
146	ATF_TP_ADD_TC(tp, acos_one_pos);
147	ATF_TP_ADD_TC(tp, acosf_one_pos);
148
149	return atf_no_error();
150}
151