1 /*-
2 * Copyright (c) 2008-2010 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 log*().
29 */
30
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD: stable/9/tools/regression/lib/msun/test-logarithm.c 216222 2010-12-06 00:02:49Z 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 #define ALL_STD_EXCEPT (FE_DIVBYZERO | FE_INEXACT | FE_INVALID | \
45 FE_OVERFLOW | FE_UNDERFLOW)
46
47 #pragma STDC FENV_ACCESS ON
48
49 /*
50 * Test that a function returns the correct value and sets the
51 * exception flags correctly. The exceptmask specifies which
52 * exceptions we should check. We need to be lenient for several
53 * reasoons, but mainly because on some architectures it's impossible
54 * to raise FE_OVERFLOW without raising FE_INEXACT.
55 *
56 * These are macros instead of functions so that assert provides more
57 * meaningful error messages.
58 *
59 * XXX The volatile here is to avoid gcc's bogus constant folding and work
60 * around the lack of support for the FENV_ACCESS pragma.
61 */
62 #define test(func, x, result, exceptmask, excepts) do { \
63 volatile long double _d = x; \
64 assert(feclearexcept(FE_ALL_EXCEPT) == 0); \
65 assert(fpequal((func)(_d), (result))); \
66 assert(((func), fetestexcept(exceptmask) == (excepts))); \
67 } while (0)
68
69 /* Test all the functions that compute log(x). */
70 #define testall0(x, result, exceptmask, excepts) do { \
71 test(log, x, result, exceptmask, excepts); \
72 test(logf, x, result, exceptmask, excepts); \
73 test(log2, x, result, exceptmask, excepts); \
74 test(log2f, x, result, exceptmask, excepts); \
75 test(log10, x, result, exceptmask, excepts); \
76 test(log10f, x, result, exceptmask, excepts); \
77 } while (0)
78
79 /* Test all the functions that compute log(1+x). */
80 #define testall1(x, result, exceptmask, excepts) do { \
81 test(log1p, x, result, exceptmask, excepts); \
82 test(log1pf, x, result, exceptmask, excepts); \
83 } while (0)
84
85 /*
86 * Determine whether x and y are equal, with two special rules:
87 * +0.0 != -0.0
88 * NaN == NaN
89 */
90 int
fpequal(long double x,long double y)91 fpequal(long double x, long double y)
92 {
93 return ((x == y && !signbit(x) == !signbit(y)) || isnan(x) && isnan(y));
94 }
95
96 void
run_generic_tests(void)97 run_generic_tests(void)
98 {
99
100 /* exp(1) == 0, no exceptions raised */
101 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0);
102 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0);
103 testall1(-0.0, -0.0, ALL_STD_EXCEPT, 0);
104
105 /* log(NaN) == NaN, no exceptions raised */
106 testall0(NAN, NAN, ALL_STD_EXCEPT, 0);
107 testall1(NAN, NAN, ALL_STD_EXCEPT, 0);
108
109 /* log(Inf) == Inf, no exceptions raised */
110 testall0(INFINITY, INFINITY, ALL_STD_EXCEPT, 0);
111 testall1(INFINITY, INFINITY, ALL_STD_EXCEPT, 0);
112
113 /* log(x) == NaN for x < 0, invalid exception raised */
114 testall0(-INFINITY, NAN, ALL_STD_EXCEPT, FE_INVALID);
115 testall1(-INFINITY, NAN, ALL_STD_EXCEPT, FE_INVALID);
116 testall0(-1.0, NAN, ALL_STD_EXCEPT, FE_INVALID);
117 testall1(-1.5, NAN, ALL_STD_EXCEPT, FE_INVALID);
118
119 /* log(0) == -Inf, divide-by-zero exception */
120 testall0(0.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO);
121 testall0(-0.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO);
122 testall1(-1.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO);
123 }
124
125 void
run_log2_tests(void)126 run_log2_tests(void)
127 {
128 int i;
129
130 /*
131 * We should insist that log2() return exactly the correct
132 * result and not raise an inexact exception for powers of 2.
133 */
134 feclearexcept(FE_ALL_EXCEPT);
135 for (i = FLT_MIN_EXP - FLT_MANT_DIG; i < FLT_MAX_EXP; i++) {
136 assert(log2f(ldexpf(1.0, i)) == i);
137 assert(fetestexcept(ALL_STD_EXCEPT) == 0);
138 }
139 for (i = DBL_MIN_EXP - DBL_MANT_DIG; i < DBL_MAX_EXP; i++) {
140 assert(log2(ldexp(1.0, i)) == i);
141 assert(fetestexcept(ALL_STD_EXCEPT) == 0);
142 }
143 }
144
145 int
main(int argc,char * argv[])146 main(int argc, char *argv[])
147 {
148
149 printf("1..2\n");
150
151 run_generic_tests();
152 printf("ok 1 - logarithm\n");
153
154 run_log2_tests();
155 printf("ok 2 - logarithm\n");
156
157 return (0);
158 }
159