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 * $FreeBSD: src/tools/regression/lib/msun/test-logarithm.c,v 1.3 2011/10/15 05:28:13 das Exp $
27 */
28
29 /*
30 * Tests for corner cases in log*().
31 */
32
33 #include <assert.h>
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 #define ALL_STD_EXCEPT (FE_DIVBYZERO | FE_INEXACT | FE_INVALID | \
44 FE_OVERFLOW | FE_UNDERFLOW)
45
46 #pragma STDC FENV_ACCESS ON
47
48 /*
49 * Test that a function returns the correct value and sets the
50 * exception flags correctly. The exceptmask specifies which
51 * exceptions we should check. We need to be lenient for several
52 * reasoons, but mainly because on some architectures it's impossible
53 * to raise FE_OVERFLOW without raising FE_INEXACT.
54 *
55 * These are macros instead of functions so that assert provides more
56 * meaningful error messages.
57 *
58 * XXX The volatile here is to avoid gcc's bogus constant folding and work
59 * around the lack of support for the FENV_ACCESS pragma.
60 */
61 #define test(func, x, result, exceptmask, excepts) do { \
62 volatile long double _d = x; \
63 assert(feclearexcept(FE_ALL_EXCEPT) == 0); \
64 assert(fpequal((func)(_d), (result))); \
65 assert(((func), fetestexcept(exceptmask) == (excepts))); \
66 } while (0)
67
68 /* Test all the functions that compute log(x). */
69 #define testall0(x, result, exceptmask, excepts) do { \
70 test(log, x, result, exceptmask, excepts); \
71 test(logf, x, result, exceptmask, excepts); \
72 test(log2, x, result, exceptmask, excepts); \
73 test(log2f, x, result, exceptmask, excepts); \
74 test(log10, x, result, exceptmask, excepts); \
75 test(log10f, x, result, exceptmask, excepts); \
76 } while (0)
77
78 /* Test all the functions that compute log(1+x). */
79 #define testall1(x, result, exceptmask, excepts) do { \
80 test(log1p, x, result, exceptmask, excepts); \
81 test(log1pf, x, result, exceptmask, excepts); \
82 } while (0)
83
84 /*
85 * Determine whether x and y are equal, with two special rules:
86 * +0.0 != -0.0
87 * NaN == NaN
88 */
89 int
fpequal(long double x,long double y)90 fpequal(long double x, long double y)
91 {
92 return ((x == y && !signbit(x) == !signbit(y)) || isnan(x) && isnan(y));
93 }
94
95 void
run_generic_tests(void)96 run_generic_tests(void)
97 {
98
99 /* log(1) == 0, no exceptions raised */
100 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0);
101 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0);
102 testall1(-0.0, -0.0, ALL_STD_EXCEPT, 0);
103
104 /* log(NaN) == NaN, no exceptions raised */
105 testall0(NAN, NAN, ALL_STD_EXCEPT, 0);
106 testall1(NAN, NAN, ALL_STD_EXCEPT, 0);
107
108 /* log(Inf) == Inf, no exceptions raised */
109 testall0(INFINITY, INFINITY, ALL_STD_EXCEPT, 0);
110 testall1(INFINITY, INFINITY, ALL_STD_EXCEPT, 0);
111
112 /* log(x) == NaN for x < 0, invalid exception raised */
113 testall0(-INFINITY, NAN, ALL_STD_EXCEPT, FE_INVALID);
114 testall1(-INFINITY, NAN, ALL_STD_EXCEPT, FE_INVALID);
115 testall0(-1.0, NAN, ALL_STD_EXCEPT, FE_INVALID);
116 testall1(-1.5, NAN, ALL_STD_EXCEPT, FE_INVALID);
117
118 /* log(0) == -Inf, divide-by-zero exception */
119 testall0(0.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO);
120 testall0(-0.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO);
121 testall1(-1.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO);
122 }
123
124 void
run_log2_tests(void)125 run_log2_tests(void)
126 {
127 int i;
128
129 /*
130 * We should insist that log2() return exactly the correct
131 * result and not raise an inexact exception for powers of 2.
132 */
133 feclearexcept(FE_ALL_EXCEPT);
134 for (i = FLT_MIN_EXP - FLT_MANT_DIG; i < FLT_MAX_EXP; i++) {
135 assert(log2f(ldexpf(1.0, i)) == i);
136 assert(fetestexcept(ALL_STD_EXCEPT) == 0);
137 }
138 for (i = DBL_MIN_EXP - DBL_MANT_DIG; i < DBL_MAX_EXP; i++) {
139 assert(log2(ldexp(1.0, i)) == i);
140 assert(fetestexcept(ALL_STD_EXCEPT) == 0);
141 }
142 }
143
144 void
run_roundingmode_tests(void)145 run_roundingmode_tests(void)
146 {
147
148 /*
149 * Corner cases in other rounding modes.
150 */
151 fesetround(FE_DOWNWARD);
152 /* These are still positive per IEEE 754R */
153 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0);
154 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0);
155 fesetround(FE_TOWARDZERO);
156 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0);
157 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0);
158
159 fesetround(FE_UPWARD);
160 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0);
161 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0);
162 /* log1p(-0.0) == -0.0 even when rounding upwards */
163 testall1(-0.0, -0.0, ALL_STD_EXCEPT, 0);
164
165 fesetround(FE_TONEAREST);
166 }
167
168 int
main(int argc,char * argv[])169 main(int argc, char *argv[])
170 {
171
172 printf("1..3\n");
173
174 run_generic_tests();
175 printf("ok 1 - logarithm\n");
176
177 run_log2_tests();
178 printf("ok 2 - logarithm\n");
179
180 run_roundingmode_tests();
181 printf("ok 3 - logarithm\n");
182
183 return (0);
184 }
185