exponential_test.c revision 251241 
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: head/tools/regression/lib/msun/test-exponential.c 251241 2013-06-02 04:30:03Z das $");
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	test(exp2l, x, result, exceptmask, excepts);			\
75} while (0)
76
77/* Test all the functions that compute b^x - 1. */
78#define	testall1(x, result, exceptmask, excepts)	do {		\
79	test(expm1, x, result, exceptmask, excepts);			\
80	test(expm1f, x, result, exceptmask, excepts);			\
81} while (0)
82
83void
84run_generic_tests(void)
85{
86
87	/* exp(0) == 1, no exceptions raised */
88	testall0(0.0, 1.0, ALL_STD_EXCEPT, 0);
89	testall1(0.0, 0.0, ALL_STD_EXCEPT, 0);
90	testall0(-0.0, 1.0, ALL_STD_EXCEPT, 0);
91	testall1(-0.0, -0.0, ALL_STD_EXCEPT, 0);
92
93	/* exp(NaN) == NaN, no exceptions raised */
94	testall0(NAN, NAN, ALL_STD_EXCEPT, 0);
95	testall1(NAN, NAN, ALL_STD_EXCEPT, 0);
96
97	/* exp(Inf) == Inf, no exceptions raised */
98	testall0(INFINITY, INFINITY, ALL_STD_EXCEPT, 0);
99	testall1(INFINITY, INFINITY, ALL_STD_EXCEPT, 0);
100
101	/* exp(-Inf) == 0, no exceptions raised */
102	testall0(-INFINITY, 0.0, ALL_STD_EXCEPT, 0);
103	testall1(-INFINITY, -1.0, ALL_STD_EXCEPT, 0);
104
105	/* exp(big) == Inf, overflow exception */
106	testall0(50000.0, INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_OVERFLOW);
107	testall1(50000.0, INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_OVERFLOW);
108
109	/* exp(small) == 0, underflow and inexact exceptions */
110	testall0(-50000.0, 0.0, ALL_STD_EXCEPT, FE_UNDERFLOW | FE_INEXACT);
111	testall1(-50000.0, -1.0, ALL_STD_EXCEPT, FE_INEXACT);
112}
113
114void
115run_exp2_tests(void)
116{
117	int i;
118
119	/*
120	 * We should insist that exp2() return exactly the correct
121	 * result and not raise an inexact exception for integer
122	 * arguments.
123	 */
124	feclearexcept(FE_ALL_EXCEPT);
125	for (i = FLT_MIN_EXP - FLT_MANT_DIG; i < FLT_MAX_EXP; i++) {
126		assert(exp2f(i) == ldexpf(1.0, i));
127		assert(fetestexcept(ALL_STD_EXCEPT) == 0);
128	}
129	for (i = DBL_MIN_EXP - DBL_MANT_DIG; i < DBL_MAX_EXP; i++) {
130		assert(exp2(i) == ldexp(1.0, i));
131		assert(fetestexcept(ALL_STD_EXCEPT) == 0);
132	}
133	for (i = LDBL_MIN_EXP - LDBL_MANT_DIG; i < LDBL_MAX_EXP; i++) {
134		assert(exp2l(i) == ldexpl(1.0, i));
135		assert(fetestexcept(ALL_STD_EXCEPT) == 0);
136	}
137}
138
139int
140main(int argc, char *argv[])
141{
142
143	printf("1..3\n");
144
145	run_generic_tests();
146	printf("ok 1 - exponential\n");
147
148#ifdef __i386__
149	fpsetprec(FP_PE);
150	run_generic_tests();
151#endif
152	printf("ok 2 - exponential\n");
153
154	run_exp2_tests();
155	printf("ok 3 - exponential\n");
156
157	return (0);
158}
159