exponential_test.c revision 294243 
1/*-
2 * Copyright (c) 2008 David Schultz <das@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27/*
28 * Tests for corner cases in exp*().
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD: stable/10/lib/msun/tests/exponential_test.c 294243 2016-01-18 03:55:40Z ngie $");
33
34#include <assert.h>
35#include <fenv.h>
36#include <float.h>
37#include <math.h>
38#include <stdio.h>
39
40#ifdef __i386__
41#include <ieeefp.h>
42#endif
43
44#include "test-utils.h"
45
46#pragma STDC FENV_ACCESS ON
47
48/*
49 * Test that a function returns the correct value and sets the
50 * exception flags correctly. The exceptmask specifies which
51 * exceptions we should check. We need to be lenient for several
52 * reasoons, but mainly because on some architectures it's impossible
53 * to raise FE_OVERFLOW without raising FE_INEXACT.
54 *
55 * These are macros instead of functions so that assert provides more
56 * meaningful error messages.
57 *
58 * XXX The volatile here is to avoid gcc's bogus constant folding and work
59 *     around the lack of support for the FENV_ACCESS pragma.
60 */
61#define	test(func, x, result, exceptmask, excepts)	do {		\
62	volatile long double _d = x;					\
63	assert(feclearexcept(FE_ALL_EXCEPT) == 0);			\
64	assert(fpequal((func)(_d), (result)));				 \
65	assert(((void)(func), fetestexcept(exceptmask) == (excepts)));	\
66} while (0)
67
68/* Test all the functions that compute b^x. */
69#define	_testall0(x, result, exceptmask, excepts)	do {		\
70	test(exp, x, result, exceptmask, excepts);			\
71	test(expf, x, result, exceptmask, excepts);			\
72	test(exp2, x, result, exceptmask, excepts);			\
73	test(exp2f, x, result, exceptmask, excepts);			\
74} while (0)
75
76/* Skip over exp2l on platforms that don't support it. */
77#if LDBL_PREC == 53
78#define	testall0	_testall0
79#else
80#define	testall0(x, result, exceptmask, excepts)	do {		\
81	_testall0(x, result, exceptmask, excepts); 			\
82	test(exp2l, x, result, exceptmask, excepts);			\
83} while (0)
84#endif
85
86/* Test all the functions that compute b^x - 1. */
87#define	testall1(x, result, exceptmask, excepts)	do {		\
88	test(expm1, x, result, exceptmask, excepts);			\
89	test(expm1f, x, result, exceptmask, excepts);			\
90} while (0)
91
92void
93run_generic_tests(void)
94{
95
96	/* exp(0) == 1, no exceptions raised */
97	testall0(0.0, 1.0, ALL_STD_EXCEPT, 0);
98	testall1(0.0, 0.0, ALL_STD_EXCEPT, 0);
99	testall0(-0.0, 1.0, ALL_STD_EXCEPT, 0);
100	testall1(-0.0, -0.0, ALL_STD_EXCEPT, 0);
101
102	/* exp(NaN) == NaN, no exceptions raised */
103	testall0(NAN, NAN, ALL_STD_EXCEPT, 0);
104	testall1(NAN, NAN, ALL_STD_EXCEPT, 0);
105
106	/* exp(Inf) == Inf, no exceptions raised */
107	testall0(INFINITY, INFINITY, ALL_STD_EXCEPT, 0);
108	testall1(INFINITY, INFINITY, ALL_STD_EXCEPT, 0);
109
110	/* exp(-Inf) == 0, no exceptions raised */
111	testall0(-INFINITY, 0.0, ALL_STD_EXCEPT, 0);
112	testall1(-INFINITY, -1.0, ALL_STD_EXCEPT, 0);
113
114#if !defined(__i386__)
115	/* exp(big) == Inf, overflow exception */
116	testall0(50000.0, INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_OVERFLOW);
117	testall1(50000.0, INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_OVERFLOW);
118
119	/* exp(small) == 0, underflow and inexact exceptions */
120	testall0(-50000.0, 0.0, ALL_STD_EXCEPT, FE_UNDERFLOW | FE_INEXACT);
121#endif
122	testall1(-50000.0, -1.0, ALL_STD_EXCEPT, FE_INEXACT);
123}
124
125void
126run_exp2_tests(void)
127{
128	int i;
129
130	/*
131	 * We should insist that exp2() return exactly the correct
132	 * result and not raise an inexact exception for integer
133	 * arguments.
134	 */
135	feclearexcept(FE_ALL_EXCEPT);
136	for (i = FLT_MIN_EXP - FLT_MANT_DIG; i < FLT_MAX_EXP; i++) {
137		assert(exp2f(i) == ldexpf(1.0, i));
138		assert(fetestexcept(ALL_STD_EXCEPT) == 0);
139	}
140	for (i = DBL_MIN_EXP - DBL_MANT_DIG; i < DBL_MAX_EXP; i++) {
141		assert(exp2(i) == ldexp(1.0, i));
142		assert(fetestexcept(ALL_STD_EXCEPT) == 0);
143	}
144	for (i = LDBL_MIN_EXP - LDBL_MANT_DIG; i < LDBL_MAX_EXP; i++) {
145		assert(exp2l(i) == ldexpl(1.0, i));
146		assert(fetestexcept(ALL_STD_EXCEPT) == 0);
147	}
148}
149
150int
151main(int argc, char *argv[])
152{
153
154	printf("1..3\n");
155
156	run_generic_tests();
157	printf("ok 1 - exponential\n");
158
159#ifdef __i386__
160	fpsetprec(FP_PE);
161	run_generic_tests();
162#endif
163	printf("ok 2 - exponential\n");
164
165	run_exp2_tests();
166	printf("ok 3 - exponential\n");
167
168	return (0);
169}
170