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/param.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_CHECK_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 #define test_tol(func, z, result, tol) do { \
67 volatile long double _d = z; \
68 debug(" testing %6s(%15La) ~= % .36Le\n", #func, _d, result); \
69 CHECK_FPEQUAL_TOL((func)(_d), (result), (tol), CS_BOTH); \
70 } while (0)
71
72 /* Test all the functions that compute log(x). */
73 #define testall0(x, result, exceptmask, excepts) do { \
74 test(log, x, result, exceptmask, excepts); \
75 test(logf, x, result, exceptmask, excepts); \
76 test(logl, x, result, exceptmask, excepts); \
77 test(log2, x, result, exceptmask, excepts); \
78 test(log2f, x, result, exceptmask, excepts); \
79 test(log2l, x, result, exceptmask, excepts); \
80 test(log10, x, result, exceptmask, excepts); \
81 test(log10f, x, result, exceptmask, excepts); \
82 test(log10l, x, result, exceptmask, excepts); \
83 } while (0)
84
85 /* Test all the functions that compute log(1+x). */
86 #define testall1(x, result, exceptmask, excepts) do { \
87 test(log1p, x, result, exceptmask, excepts); \
88 test(log1pf, x, result, exceptmask, excepts); \
89 test(log1pl, x, result, exceptmask, excepts); \
90 } while (0)
91
92 ATF_TC_WITHOUT_HEAD(generic_tests);
ATF_TC_BODY(generic_tests,tc)93 ATF_TC_BODY(generic_tests, tc)
94 {
95
96 /* log(1) == 0, no exceptions raised */
97 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0);
98 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0);
99 testall1(-0.0, -0.0, ALL_STD_EXCEPT, 0);
100
101 /* log(NaN) == NaN, no exceptions raised */
102 testall0(NAN, NAN, ALL_STD_EXCEPT, 0);
103 testall1(NAN, NAN, ALL_STD_EXCEPT, 0);
104
105 /* log(Inf) == Inf, no exceptions raised */
106 testall0(INFINITY, INFINITY, ALL_STD_EXCEPT, 0);
107 testall1(INFINITY, INFINITY, ALL_STD_EXCEPT, 0);
108
109 /* log(x) == NaN for x < 0, invalid exception raised */
110 testall0(-INFINITY, NAN, ALL_STD_EXCEPT, FE_INVALID);
111 testall1(-INFINITY, NAN, ALL_STD_EXCEPT, FE_INVALID);
112 testall0(-1.0, NAN, ALL_STD_EXCEPT, FE_INVALID);
113 testall1(-1.5, NAN, ALL_STD_EXCEPT, FE_INVALID);
114
115 /* log(0) == -Inf, divide-by-zero exception */
116 testall0(0.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO);
117 testall0(-0.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO);
118 testall1(-1.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO);
119 }
120
121 ATF_TC_WITHOUT_HEAD(log2_tests);
ATF_TC_BODY(log2_tests,tc)122 ATF_TC_BODY(log2_tests, tc)
123 {
124 unsigned i;
125
126 /*
127 * We should insist that log2() return exactly the correct
128 * result and not raise an inexact exception for powers of 2.
129 */
130 ATF_REQUIRE_EQ(0, feclearexcept(FE_ALL_EXCEPT));
131 for (i = FLT_MIN_EXP - FLT_MANT_DIG; i < FLT_MAX_EXP; i++) {
132 ATF_CHECK_EQ(i, log2f(ldexpf(1.0, i)));
133 CHECK_FP_EXCEPTIONS(0, ALL_STD_EXCEPT);
134 }
135 for (i = DBL_MIN_EXP - DBL_MANT_DIG; i < DBL_MAX_EXP; i++) {
136 ATF_CHECK_EQ(i, log2(ldexp(1.0, i)));
137 CHECK_FP_EXCEPTIONS(0, ALL_STD_EXCEPT);
138 }
139 for (i = LDBL_MIN_EXP - LDBL_MANT_DIG; i < LDBL_MAX_EXP; i++) {
140 ATF_CHECK_EQ(i, log2l(ldexpl(1.0, i)));
141 CHECK_FP_EXCEPTIONS(0, ALL_STD_EXCEPT);
142 }
143 }
144
145 ATF_TC_WITHOUT_HEAD(roundingmode_tests);
ATF_TC_BODY(roundingmode_tests,tc)146 ATF_TC_BODY(roundingmode_tests, tc)
147 {
148
149 /*
150 * Corner cases in other rounding modes.
151 */
152 fesetround(FE_DOWNWARD);
153 /* These are still positive per IEEE 754R */
154 #if 0
155 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0);
156 #else
157 /* logl, log2l, and log10l don't pass yet. */
158 test(log, 1.0, 0.0, ALL_STD_EXCEPT, 0);
159 test(logf, 1.0, 0.0, ALL_STD_EXCEPT, 0);
160 test(log2, 1.0, 0.0, ALL_STD_EXCEPT, 0);
161 test(log2f, 1.0, 0.0, ALL_STD_EXCEPT, 0);
162 test(log10, 1.0, 0.0, ALL_STD_EXCEPT, 0);
163 test(log10f, 1.0, 0.0, ALL_STD_EXCEPT, 0);
164 #endif
165 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0);
166 fesetround(FE_TOWARDZERO);
167 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0);
168 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0);
169
170 fesetround(FE_UPWARD);
171 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0);
172 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0);
173 /* log1p(-0.0) == -0.0 even when rounding upwards */
174 testall1(-0.0, -0.0, ALL_STD_EXCEPT, 0);
175
176 fesetround(FE_TONEAREST);
177 }
178
179 ATF_TC_WITHOUT_HEAD(accuracy_tests);
ATF_TC_BODY(accuracy_tests,tc)180 ATF_TC_BODY(accuracy_tests, tc)
181 {
182 static const struct {
183 float x;
184 long double log2x;
185 long double logex;
186 long double log10x;
187 } tests[] = {
188 { 0x1p-120 + 0x1p-140,
189 -1.19999998624139449158861798943319717e2L,
190 -8.31776607135195754708796206665656732e1L,
191 -3.61235990655024477716980559136055915e1L,
192 },
193 { 1.0 - 0x1p-20,
194 -1.37586186296463416424364914705656460e-6L,
195 -9.53674771153890007250243736279163253e-7L,
196 -4.14175690642480911859354110516159131e-7L, },
197 { 1.0 + 0x1p-20,
198 1.37586055084113820105668028340371476e-6L,
199 9.53673861659188233908415514963336144e-7L,
200 4.14175295653950611453333571759200697e-7L },
201 { 19.75,
202 4.30378074817710292442728634194115348e0L,
203 2.98315349134713087533848129856505779e0L,
204 1.29556709996247903756734359702926363e0L },
205 { 19.75 * 0x1p100,
206 1.043037807481771029244272863419411534e2L,
207 72.29787154734166181706169344438271459357255439172762452L,
208 3.139856666636059855894123306947856631e1L },
209 };
210 unsigned i;
211
212 long double log1p_ldbl_ulp = LDBL_ULP();
213 #if LDBL_MANT_DIG > 64
214 /*
215 * On ld128 platforms the log1p() implementation provides less accuracy,
216 * but does still match the ld80 precision. Use the ld80 LDBL_ULP()
217 * value for now to avoid losing test coverage for the other functions.
218 * Reported as https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=253984
219 */
220 log1p_ldbl_ulp = ldexpl(1.0, 1 - 64);
221 #endif
222
223 for (i = 0; i < nitems(tests); i++) {
224 test_tol(log2, tests[i].x, tests[i].log2x, DBL_ULP());
225 test_tol(log2f, tests[i].x, tests[i].log2x, FLT_ULP());
226 test_tol(log2l, tests[i].x, tests[i].log2x, LDBL_ULP());
227 test_tol(log, tests[i].x, tests[i].logex, DBL_ULP());
228 test_tol(logf, tests[i].x, tests[i].logex, FLT_ULP());
229 test_tol(logl, tests[i].x, tests[i].logex, LDBL_ULP());
230 test_tol(log10, tests[i].x, tests[i].log10x, DBL_ULP());
231 test_tol(log10f, tests[i].x, tests[i].log10x, FLT_ULP());
232 test_tol(log10l, tests[i].x, tests[i].log10x, LDBL_ULP());
233 if (tests[i].x >= 0.5) {
234 test_tol(log1p, tests[i].x - 1, tests[i].logex,
235 DBL_ULP());
236 test_tol(log1pf, tests[i].x - 1, tests[i].logex,
237 FLT_ULP());
238 test_tol(log1pl, tests[i].x - 1, tests[i].logex,
239 log1p_ldbl_ulp);
240 }
241 }
242 }
243
244 ATF_TC_WITHOUT_HEAD(log1p_accuracy_tests);
ATF_TC_BODY(log1p_accuracy_tests,tc)245 ATF_TC_BODY(log1p_accuracy_tests, tc)
246 {
247 #if LDBL_MANT_DIG > 64
248 if (atf_tc_get_config_var_as_bool_wd(tc, "ci", false))
249 atf_tc_expect_fail("https://bugs.freebsd.org/253984");
250 #endif
251
252 test_tol(log1pf, 0x0.333333p0F,
253 1.82321546859847114303367992804596800640e-1L, FLT_ULP());
254 test_tol(log1p, 0x0.3333333333333p0,
255 1.82321556793954589204283870982629267635e-1L, DBL_ULP());
256 test_tol(log1pl, 0x0.33333333333333332p0L,
257 1.82321556793954626202683007050468762914e-1L, LDBL_ULP());
258
259 test_tol(log1pf, -0x0.333333p0F,
260 -2.23143536413048672940940199918017467652e-1L, FLT_ULP());
261 test_tol(log1p, -0x0.3333333333333p0,
262 -2.23143551314209700255143859052009022937e-1L, DBL_ULP());
263 test_tol(log1pl, -0x0.33333333333333332p0L,
264 -2.23143551314209755752742563153765697950e-1L, LDBL_ULP());
265 }
266
ATF_TP_ADD_TCS(tp)267 ATF_TP_ADD_TCS(tp)
268 {
269
270 ATF_TP_ADD_TC(tp, generic_tests);
271 ATF_TP_ADD_TC(tp, log2_tests);
272 ATF_TP_ADD_TC(tp, roundingmode_tests);
273 ATF_TP_ADD_TC(tp, accuracy_tests);
274 ATF_TP_ADD_TC(tp, log1p_accuracy_tests);
275
276 return (atf_no_error());
277 }
278