2 * Copyright (c) 2008-2010 David Schultz <das@FreeBSD.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
28 * Tests for corner cases in log*().
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
44 #include "test-utils.h"
46 #pragma STDC FENV_ACCESS ON
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.
55 * These are macros instead of functions so that assert provides more
56 * meaningful error messages.
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.
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(((void)(func), fetestexcept(exceptmask) == (excepts))); \
68 #define test(func, x, result, exceptmask, excepts) do { \
69 volatile long double _d = x; \
70 assert(feclearexcept(FE_ALL_EXCEPT) == 0); \
71 assert(fpequal((func)(_d), (result))); \
72 assert(((void)(func), fetestexcept(exceptmask) == (excepts))); \
75 #define test_tol(func, z, result, tol) do { \
76 volatile long double _d = z; \
77 debug(" testing %6s(%15La) ~= % .36Le\n", #func, _d, result); \
78 assert(fpequal_tol((func)(_d), (result), (tol), CS_BOTH)); \
81 /* Test all the functions that compute log(x). */
82 #define testall0(x, result, exceptmask, excepts) do { \
83 test(log, x, result, exceptmask, excepts); \
84 test(logf, x, result, exceptmask, excepts); \
85 test(logl, x, result, exceptmask, excepts); \
86 test(log2, x, result, exceptmask, excepts); \
87 test(log2f, x, result, exceptmask, excepts); \
88 test(log2l, x, result, exceptmask, excepts); \
89 test(log10, x, result, exceptmask, excepts); \
90 test(log10f, x, result, exceptmask, excepts); \
91 test(log10l, x, result, exceptmask, excepts); \
94 /* Test all the functions that compute log(1+x). */
95 #define testall1(x, result, exceptmask, excepts) do { \
96 test(log1p, x, result, exceptmask, excepts); \
97 test(log1pf, x, result, exceptmask, excepts); \
98 test(log1pl, x, result, exceptmask, excepts); \
102 run_generic_tests(void)
105 /* log(1) == 0, no exceptions raised */
106 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0);
107 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0);
108 testall1(-0.0, -0.0, ALL_STD_EXCEPT, 0);
110 /* log(NaN) == NaN, no exceptions raised */
111 testall0(NAN, NAN, ALL_STD_EXCEPT, 0);
112 testall1(NAN, NAN, ALL_STD_EXCEPT, 0);
114 /* log(Inf) == Inf, no exceptions raised */
115 testall0(INFINITY, INFINITY, ALL_STD_EXCEPT, 0);
116 testall1(INFINITY, INFINITY, ALL_STD_EXCEPT, 0);
118 /* log(x) == NaN for x < 0, invalid exception raised */
119 testall0(-INFINITY, NAN, ALL_STD_EXCEPT, FE_INVALID);
120 testall1(-INFINITY, NAN, ALL_STD_EXCEPT, FE_INVALID);
121 testall0(-1.0, NAN, ALL_STD_EXCEPT, FE_INVALID);
122 testall1(-1.5, NAN, ALL_STD_EXCEPT, FE_INVALID);
124 /* log(0) == -Inf, divide-by-zero exception */
125 testall0(0.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO);
126 testall0(-0.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO);
127 testall1(-1.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO);
136 * We should insist that log2() return exactly the correct
137 * result and not raise an inexact exception for powers of 2.
139 feclearexcept(FE_ALL_EXCEPT);
140 for (i = FLT_MIN_EXP - FLT_MANT_DIG; i < FLT_MAX_EXP; i++) {
141 assert(log2f(ldexpf(1.0, i)) == i);
142 assert(fetestexcept(ALL_STD_EXCEPT) == 0);
144 for (i = DBL_MIN_EXP - DBL_MANT_DIG; i < DBL_MAX_EXP; i++) {
145 assert(log2(ldexp(1.0, i)) == i);
146 assert(fetestexcept(ALL_STD_EXCEPT) == 0);
148 for (i = LDBL_MIN_EXP - LDBL_MANT_DIG; i < LDBL_MAX_EXP; i++) {
149 assert(log2l(ldexpl(1.0, i)) == i);
151 /* XXX This test does not pass yet. */
152 assert(fetestexcept(ALL_STD_EXCEPT) == 0);
158 run_roundingmode_tests(void)
162 * Corner cases in other rounding modes.
164 fesetround(FE_DOWNWARD);
165 /* These are still positive per IEEE 754R */
167 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0);
169 /* logl, log2l, and log10l don't pass yet. */
170 test(log, 1.0, 0.0, ALL_STD_EXCEPT, 0);
171 test(logf, 1.0, 0.0, ALL_STD_EXCEPT, 0);
172 test(log2, 1.0, 0.0, ALL_STD_EXCEPT, 0);
173 test(log2f, 1.0, 0.0, ALL_STD_EXCEPT, 0);
174 test(log10, 1.0, 0.0, ALL_STD_EXCEPT, 0);
175 test(log10f, 1.0, 0.0, ALL_STD_EXCEPT, 0);
177 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0);
178 fesetround(FE_TOWARDZERO);
179 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0);
180 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0);
182 fesetround(FE_UPWARD);
183 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0);
184 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0);
185 /* log1p(-0.0) == -0.0 even when rounding upwards */
186 testall1(-0.0, -0.0, ALL_STD_EXCEPT, 0);
188 fesetround(FE_TONEAREST);
192 run_accuracy_tests(void)
194 static const struct {
200 { 0x1p-120 + 0x1p-140,
201 -1.19999998624139449158861798943319717e2L,
202 -8.31776607135195754708796206665656732e1L,
203 -3.61235990655024477716980559136055915e1L,
206 -1.37586186296463416424364914705656460e-6L,
207 -9.53674771153890007250243736279163253e-7L,
208 -4.14175690642480911859354110516159131e-7L, },
210 1.37586055084113820105668028340371476e-6L,
211 9.53673861659188233908415514963336144e-7L,
212 4.14175295653950611453333571759200697e-7L },
214 4.30378074817710292442728634194115348e0L,
215 2.98315349134713087533848129856505779e0L,
216 1.29556709996247903756734359702926363e0L },
218 1.043037807481771029244272863419411534e2L,
219 7.229787154734166181706169344438271459e1L,
220 3.139856666636059855894123306947856631e1L },
224 for (i = 0; i < sizeof(tests) / sizeof(tests[0]); i++) {
225 test_tol(log2, tests[i].x, tests[i].log2x, DBL_ULP());
226 test_tol(log2f, tests[i].x, tests[i].log2x, FLT_ULP());
227 test_tol(log2l, tests[i].x, tests[i].log2x, LDBL_ULP());
228 test_tol(log, tests[i].x, tests[i].logex, DBL_ULP());
229 test_tol(logf, tests[i].x, tests[i].logex, FLT_ULP());
230 test_tol(logl, tests[i].x, tests[i].logex, LDBL_ULP());
231 test_tol(log10, tests[i].x, tests[i].log10x, DBL_ULP());
232 test_tol(log10f, tests[i].x, tests[i].log10x, FLT_ULP());
233 test_tol(log10l, tests[i].x, tests[i].log10x, LDBL_ULP());
234 if (tests[i].x >= 0.5) {
235 test_tol(log1p, tests[i].x - 1, tests[i].logex,
237 test_tol(log1pf, tests[i].x - 1, tests[i].logex,
239 test_tol(log1pl, tests[i].x - 1, tests[i].logex,
246 run_log1p_accuracy_tests(void)
249 test_tol(log1pf, 0x0.333333p0F,
250 1.82321546859847114303367992804596800640e-1L, FLT_ULP());
251 test_tol(log1p, 0x0.3333333333333p0,
252 1.82321556793954589204283870982629267635e-1L, DBL_ULP());
253 test_tol(log1pl, 0x0.33333333333333332p0L,
254 1.82321556793954626202683007050468762914e-1L, LDBL_ULP());
256 test_tol(log1pf, -0x0.333333p0F,
257 -2.23143536413048672940940199918017467652e-1L, FLT_ULP());
258 test_tol(log1p, -0x0.3333333333333p0,
259 -2.23143551314209700255143859052009022937e-1L, DBL_ULP());
260 test_tol(log1pl, -0x0.33333333333333332p0L,
261 -2.23143551314209755752742563153765697950e-1L, LDBL_ULP());
265 main(int argc, char *argv[])
271 printf("ok 1 - logarithm\n");
274 printf("ok 2 - logarithm\n");
276 run_roundingmode_tests();
277 printf("ok 3 - logarithm\n");
279 run_accuracy_tests();
280 printf("ok 4 - logarithm\n");
282 run_log1p_accuracy_tests();
283 printf("ok 5 - logarithm\n");