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); 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); 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); 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); 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); 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 } 266 267 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