xref: /freebsd/lib/msun/tests/exponential_test.c (revision f7c32ed617858bcd22f8d1b03199099d50125721)
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("$FreeBSD$");
33 
34 #include <fenv.h>
35 #include <float.h>
36 #include <math.h>
37 #include <stdio.h>
38 
39 #ifdef __i386__
40 #include <ieeefp.h>
41 #endif
42 
43 #include "test-utils.h"
44 
45 #pragma STDC FENV_ACCESS ON
46 
47 /*
48  * Test that a function returns the correct value and sets the
49  * exception flags correctly. The exceptmask specifies which
50  * exceptions we should check. We need to be lenient for several
51  * reasoons, but mainly because on some architectures it's impossible
52  * to raise FE_OVERFLOW without raising FE_INEXACT.
53  *
54  * These are macros instead of functions so that assert provides more
55  * meaningful error messages.
56  *
57  * XXX The volatile here is to avoid gcc's bogus constant folding and work
58  *     around the lack of support for the FENV_ACCESS pragma.
59  */
60 #define	test(func, x, result, exceptmask, excepts)	do {		\
61 	volatile long double _d = x;					\
62 	ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));		\
63 	CHECK_FPEQUAL((func)(_d), (result));			\
64 	CHECK_FP_EXCEPTIONS_MSG(excepts, exceptmask, "for %s(%s)",	\
65 	    #func, #x);							\
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 
92 static void
93 run_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 
125 
126 /*
127  * We should insist that exp2() return exactly the correct
128  * result and not raise an inexact exception for integer
129  * arguments.
130  */
131 ATF_TC_WITHOUT_HEAD(exp2f);
132 ATF_TC_BODY(exp2f, tc)
133 {
134 	ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));
135 	for (int i = FLT_MIN_EXP - FLT_MANT_DIG; i < FLT_MAX_EXP; i++) {
136 		ATF_CHECK_EQ(exp2f(i), ldexpf(1.0, i));
137 		CHECK_FP_EXCEPTIONS(0, ALL_STD_EXCEPT);
138 	}
139 }
140 
141 ATF_TC_WITHOUT_HEAD(exp2);
142 ATF_TC_BODY(exp2, tc)
143 {
144 	ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));
145 	for (int i = DBL_MIN_EXP - DBL_MANT_DIG; i < DBL_MAX_EXP; i++) {
146 		ATF_CHECK_EQ(exp2(i), ldexp(1.0, i));
147 		CHECK_FP_EXCEPTIONS(0, ALL_STD_EXCEPT);
148 	}
149 }
150 
151 ATF_TC_WITHOUT_HEAD(exp2l);
152 ATF_TC_BODY(exp2l, tc)
153 {
154 	ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));
155 	for (int i = LDBL_MIN_EXP - LDBL_MANT_DIG; i < LDBL_MAX_EXP; i++) {
156 		ATF_CHECK_EQ(exp2l(i), ldexpl(1.0, i));
157 		CHECK_FP_EXCEPTIONS(0, ALL_STD_EXCEPT);
158 	}
159 }
160 
161 ATF_TC_WITHOUT_HEAD(generic);
162 ATF_TC_BODY(generic, tc)
163 {
164 	run_generic_tests();
165 }
166 
167 #ifdef __i386__
168 ATF_TC_WITHOUT_HEAD(generic_fp_pe);
169 ATF_TC_BODY(generic_fp_pe, tc)
170 {
171 	fpsetprec(FP_PE);
172 	run_generic_tests();
173 }
174 #endif
175 
176 ATF_TP_ADD_TCS(tp)
177 {
178 	ATF_TP_ADD_TC(tp, generic);
179 #ifdef __i386__
180 	ATF_TP_ADD_TC(tp, generic_fp_pe);
181 #endif
182 	ATF_TP_ADD_TC(tp, exp2);
183 	ATF_TP_ADD_TC(tp, exp2f);
184 	ATF_TP_ADD_TC(tp, exp2l);
185 
186 	return (atf_no_error());
187 }
188