xref: /freebsd/lib/msun/tests/exponential_test.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
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 
90 static void
91 run_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  */
129 ATF_TC_WITHOUT_HEAD(exp2f);
130 ATF_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 
139 ATF_TC_WITHOUT_HEAD(exp2);
140 ATF_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 
149 ATF_TC_WITHOUT_HEAD(exp2l);
150 ATF_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 
159 ATF_TC_WITHOUT_HEAD(generic);
160 ATF_TC_BODY(generic, tc)
161 {
162 	run_generic_tests();
163 }
164 
165 #ifdef __i386__
166 ATF_TC_WITHOUT_HEAD(generic_fp_pe);
167 ATF_TC_BODY(generic_fp_pe, tc)
168 {
169 	fpsetprec(FP_PE);
170 	run_generic_tests();
171 }
172 #endif
173 
174 ATF_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