xref: /openbsd-src/regress/lib/libm/msun/exponential_test.c (revision 4e1ee0786f11cc571bd0be17d38e46f635c719fc)
1 /*	$OpenBSD: exponential_test.c,v 1.2 2021/10/22 18:07:01 mbuhl Exp $	*/
2 /*-
3  * Copyright (c) 2008 David Schultz <das@FreeBSD.org>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include "macros.h"
29 
30 /*
31  * Tests for corner cases in exp*().
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include <fenv.h>
38 #include <float.h>
39 #include <math.h>
40 #include <stdio.h>
41 
42 #ifdef __i386__
43 #include <ieeefp.h>
44 #endif
45 
46 #include "test-utils.h"
47 
48 #pragma STDC FENV_ACCESS ON
49 
50 /*
51  * Test that a function returns the correct value and sets the
52  * exception flags correctly. The exceptmask specifies which
53  * exceptions we should check. We need to be lenient for several
54  * reasoons, but mainly because on some architectures it's impossible
55  * to raise FE_OVERFLOW without raising FE_INEXACT.
56  *
57  * These are macros instead of functions so that assert provides more
58  * meaningful error messages.
59  *
60  * XXX The volatile here is to avoid gcc's bogus constant folding and work
61  *     around the lack of support for the FENV_ACCESS pragma.
62  */
63 #define	test(func, x, result, exceptmask, excepts)	do {		\
64 	volatile long double _d = x;					\
65 	ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));		\
66 	CHECK_FPEQUAL((func)(_d), (result));			\
67 	CHECK_FP_EXCEPTIONS_MSG(excepts, exceptmask, "for %s(%s)",	\
68 	    #func, #x);							\
69 } while (0)
70 
71 /* Test all the functions that compute b^x. */
72 #define	_testall0(x, result, exceptmask, excepts)	do {		\
73 	test(exp, x, result, exceptmask, excepts);			\
74 	test(expf, x, result, exceptmask, excepts);			\
75 	test(exp2, x, result, exceptmask, excepts);			\
76 	test(exp2f, x, result, exceptmask, excepts);			\
77 } while (0)
78 
79 /* Skip over exp2l on platforms that don't support it. */
80 #if LDBL_PREC == 53
81 #define	testall0	_testall0
82 #else
83 #define	testall0(x, result, exceptmask, excepts)	do {		\
84 	_testall0(x, result, exceptmask, excepts); 			\
85 	test(exp2l, x, result, exceptmask, excepts);			\
86 } while (0)
87 #endif
88 
89 /* Test all the functions that compute b^x - 1. */
90 #define	testall1(x, result, exceptmask, excepts)	do {		\
91 	test(expm1, x, result, exceptmask, excepts);			\
92 	test(expm1f, x, result, exceptmask, excepts);			\
93 } while (0)
94 
95 static void
96 run_generic_tests(void)
97 {
98 
99 	/* exp(0) == 1, no exceptions raised */
100 	testall0(0.0, 1.0, ALL_STD_EXCEPT, 0);
101 	testall1(0.0, 0.0, ALL_STD_EXCEPT, 0);
102 	testall0(-0.0, 1.0, ALL_STD_EXCEPT, 0);
103 	testall1(-0.0, -0.0, ALL_STD_EXCEPT, 0);
104 
105 	/* exp(NaN) == NaN, no exceptions raised */
106 	testall0(NAN, NAN, ALL_STD_EXCEPT, 0);
107 	testall1(NAN, NAN, ALL_STD_EXCEPT, 0);
108 
109 	/* exp(Inf) == Inf, no exceptions raised */
110 	testall0(INFINITY, INFINITY, ALL_STD_EXCEPT, 0);
111 	testall1(INFINITY, INFINITY, ALL_STD_EXCEPT, 0);
112 
113 	/* exp(-Inf) == 0, no exceptions raised */
114 	testall0(-INFINITY, 0.0, ALL_STD_EXCEPT, 0);
115 	testall1(-INFINITY, -1.0, ALL_STD_EXCEPT, 0);
116 
117 #if !defined(__i386__)
118 	/* exp(big) == Inf, overflow exception */
119 	testall0(50000.0, INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_OVERFLOW);
120 	testall1(50000.0, INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_OVERFLOW);
121 
122 	/* exp(small) == 0, underflow and inexact exceptions */
123 	testall0(-50000.0, 0.0, ALL_STD_EXCEPT, FE_UNDERFLOW | FE_INEXACT);
124 #endif
125 	testall1(-50000.0, -1.0, ALL_STD_EXCEPT, FE_INEXACT);
126 }
127 
128 
129 /*
130  * We should insist that exp2() return exactly the correct
131  * result and not raise an inexact exception for integer
132  * arguments.
133  */
134 ATF_TC_WITHOUT_HEAD(exp2f);
135 ATF_TC_BODY(exp2f, tc)
136 {
137 	int i;
138 	ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));
139 	for (i = FLT_MIN_EXP - FLT_MANT_DIG; i < FLT_MAX_EXP; i++) {
140 		ATF_CHECK_EQ(exp2f(i), ldexpf(1.0, i));
141 		CHECK_FP_EXCEPTIONS(0, ALL_STD_EXCEPT);
142 	}
143 }
144 
145 ATF_TC_WITHOUT_HEAD(exp2);
146 ATF_TC_BODY(exp2, tc)
147 {
148 	int i;
149 	ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));
150 	for (i = DBL_MIN_EXP - DBL_MANT_DIG; i < DBL_MAX_EXP; i++) {
151 		ATF_CHECK_EQ(exp2(i), ldexp(1.0, i));
152 		CHECK_FP_EXCEPTIONS(0, ALL_STD_EXCEPT);
153 	}
154 }
155 
156 ATF_TC_WITHOUT_HEAD(exp2l);
157 ATF_TC_BODY(exp2l, tc)
158 {
159 	int i;
160 	ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));
161 	for (i = LDBL_MIN_EXP - LDBL_MANT_DIG; i < LDBL_MAX_EXP; i++) {
162 		ATF_CHECK_EQ(exp2l(i), ldexpl(1.0, i));
163 		CHECK_FP_EXCEPTIONS(0, ALL_STD_EXCEPT);
164 	}
165 }
166 
167 ATF_TC_WITHOUT_HEAD(generic);
168 ATF_TC_BODY(generic, tc)
169 {
170 	run_generic_tests();
171 }
172 
173 #ifndef __OpenBSD__
174 #ifdef __i386__
175 ATF_TC_WITHOUT_HEAD(generic_fp_pe);
176 ATF_TC_BODY(generic_fp_pe, tc)
177 {
178 	fpsetprec(FP_PE);
179 	run_generic_tests();
180 }
181 #endif
182 #endif
183 
184 ATF_TP_ADD_TCS(tp)
185 {
186 	ATF_TP_ADD_TC(tp, generic);
187 #ifndef __OpenBSD__
188 #ifdef __i386__
189 	ATF_TP_ADD_TC(tp, generic_fp_pe);
190 #endif
191 #endif
192 	ATF_TP_ADD_TC(tp, exp2);
193 	ATF_TP_ADD_TC(tp, exp2f);
194 	ATF_TP_ADD_TC(tp, exp2l);
195 
196 	return (atf_no_error());
197 }
198