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#include <fenv.h>
33#include <float.h>
34#include <math.h>
35#include <stdio.h>
36
37#ifdef __i386__
38#include <ieeefp.h>
39#endif
40
41#include "test-utils.h"
42
43#pragma STDC FENV_ACCESS ON
44
45/*
46 * Test that a function returns the correct value and sets the
47 * exception flags correctly. The exceptmask specifies which
48 * exceptions we should check. We need to be lenient for several
49 * reasoons, but mainly because on some architectures it's impossible
50 * to raise FE_OVERFLOW without raising FE_INEXACT.
51 *
52 * These are macros instead of functions so that assert provides more
53 * meaningful error messages.
54 *
55 * XXX The volatile here is to avoid gcc's bogus constant folding and work
56 *     around the lack of support for the FENV_ACCESS pragma.
57 */
58#define	test(func, x, result, exceptmask, excepts)	do {		\
59	volatile long double _d = x;					\
60	ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));		\
61	CHECK_FPEQUAL((func)(_d), (result));			\
62	CHECK_FP_EXCEPTIONS_MSG(excepts, exceptmask, "for %s(%s)",	\
63	    #func, #x);							\
64} while (0)
65
66/* Test all the functions that compute b^x. */
67#define	_testall0(x, result, exceptmask, excepts)	do {		\
68	test(exp, x, result, exceptmask, excepts);			\
69	test(expf, x, result, exceptmask, excepts);			\
70	test(exp2, x, result, exceptmask, excepts);			\
71	test(exp2f, x, result, exceptmask, excepts);			\
72} while (0)
73
74/* Skip over exp2l on platforms that don't support it. */
75#if LDBL_PREC == 53
76#define	testall0	_testall0
77#else
78#define	testall0(x, result, exceptmask, excepts)	do {		\
79	_testall0(x, result, exceptmask, excepts); 			\
80	test(exp2l, x, result, exceptmask, excepts);			\
81} while (0)
82#endif
83
84/* Test all the functions that compute b^x - 1. */
85#define	testall1(x, result, exceptmask, excepts)	do {		\
86	test(expm1, x, result, exceptmask, excepts);			\
87	test(expm1f, x, result, exceptmask, excepts);			\
88} while (0)
89
90static void
91run_generic_tests(void)
92{
93
94	/* exp(0) == 1, no exceptions raised */
95	testall0(0.0, 1.0, ALL_STD_EXCEPT, 0);
96	testall1(0.0, 0.0, ALL_STD_EXCEPT, 0);
97	testall0(-0.0, 1.0, ALL_STD_EXCEPT, 0);
98	testall1(-0.0, -0.0, ALL_STD_EXCEPT, 0);
99
100	/* exp(NaN) == NaN, no exceptions raised */
101	testall0(NAN, NAN, ALL_STD_EXCEPT, 0);
102	testall1(NAN, NAN, ALL_STD_EXCEPT, 0);
103
104	/* exp(Inf) == Inf, no exceptions raised */
105	testall0(INFINITY, INFINITY, ALL_STD_EXCEPT, 0);
106	testall1(INFINITY, INFINITY, ALL_STD_EXCEPT, 0);
107
108	/* exp(-Inf) == 0, no exceptions raised */
109	testall0(-INFINITY, 0.0, ALL_STD_EXCEPT, 0);
110	testall1(-INFINITY, -1.0, ALL_STD_EXCEPT, 0);
111
112#if !defined(__i386__)
113	/* exp(big) == Inf, overflow exception */
114	testall0(50000.0, INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_OVERFLOW);
115	testall1(50000.0, INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_OVERFLOW);
116
117	/* exp(small) == 0, underflow and inexact exceptions */
118	testall0(-50000.0, 0.0, ALL_STD_EXCEPT, FE_UNDERFLOW | FE_INEXACT);
119#endif
120	testall1(-50000.0, -1.0, ALL_STD_EXCEPT, FE_INEXACT);
121}
122
123
124/*
125 * We should insist that exp2() return exactly the correct
126 * result and not raise an inexact exception for integer
127 * arguments.
128 */
129ATF_TC_WITHOUT_HEAD(exp2f);
130ATF_TC_BODY(exp2f, tc)
131{
132	ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));
133	for (int i = FLT_MIN_EXP - FLT_MANT_DIG; i < FLT_MAX_EXP; i++) {
134		ATF_CHECK_EQ(exp2f(i), ldexpf(1.0, i));
135		CHECK_FP_EXCEPTIONS(0, ALL_STD_EXCEPT);
136	}
137}
138
139ATF_TC_WITHOUT_HEAD(exp2);
140ATF_TC_BODY(exp2, tc)
141{
142	ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));
143	for (int i = DBL_MIN_EXP - DBL_MANT_DIG; i < DBL_MAX_EXP; i++) {
144		ATF_CHECK_EQ(exp2(i), ldexp(1.0, i));
145		CHECK_FP_EXCEPTIONS(0, ALL_STD_EXCEPT);
146	}
147}
148
149ATF_TC_WITHOUT_HEAD(exp2l);
150ATF_TC_BODY(exp2l, tc)
151{
152	ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));
153	for (int i = LDBL_MIN_EXP - LDBL_MANT_DIG; i < LDBL_MAX_EXP; i++) {
154		ATF_CHECK_EQ(exp2l(i), ldexpl(1.0, i));
155		CHECK_FP_EXCEPTIONS(0, ALL_STD_EXCEPT);
156	}
157}
158
159ATF_TC_WITHOUT_HEAD(generic);
160ATF_TC_BODY(generic, tc)
161{
162	run_generic_tests();
163}
164
165#ifdef __i386__
166ATF_TC_WITHOUT_HEAD(generic_fp_pe);
167ATF_TC_BODY(generic_fp_pe, tc)
168{
169	fpsetprec(FP_PE);
170	run_generic_tests();
171}
172#endif
173
174ATF_TP_ADD_TCS(tp)
175{
176	ATF_TP_ADD_TC(tp, generic);
177#ifdef __i386__
178	ATF_TP_ADD_TC(tp, generic_fp_pe);
179#endif
180	ATF_TP_ADD_TC(tp, exp2);
181	ATF_TP_ADD_TC(tp, exp2f);
182	ATF_TP_ADD_TC(tp, exp2l);
183
184	return (atf_no_error());
185}
186