logarithm_test.c revision 293267
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/10/lib/msun/tests/logarithm_test.c 293267 2016-01-06 20:21:40Z ngie $"); 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#include "test-utils.h" 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(((void)(func), fetestexcept(exceptmask) == (excepts))); \ 66} while (0) 67 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))); \ 73} while (0) 74 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)); \ 79} while (0) 80 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); \ 92} while (0) 93 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); \ 99} while (0) 100 101void 102run_generic_tests(void) 103{ 104 105 /* 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); 109 110 /* log(NaN) == NaN, no exceptions raised */ 111 testall0(NAN, NAN, ALL_STD_EXCEPT, 0); 112 testall1(NAN, NAN, ALL_STD_EXCEPT, 0); 113 114 /* log(Inf) == Inf, no exceptions raised */ 115 testall0(INFINITY, INFINITY, ALL_STD_EXCEPT, 0); 116 testall1(INFINITY, INFINITY, ALL_STD_EXCEPT, 0); 117 118 /* 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); 123 124 /* 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); 128} 129 130void 131run_log2_tests(void) 132{ 133 int i; 134 135 /* 136 * We should insist that log2() return exactly the correct 137 * result and not raise an inexact exception for powers of 2. 138 */ 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); 143 } 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); 147 } 148 for (i = LDBL_MIN_EXP - LDBL_MANT_DIG; i < LDBL_MAX_EXP; i++) { 149 assert(log2l(ldexpl(1.0, i)) == i); 150#if 0 151 /* XXX This test does not pass yet. */ 152 assert(fetestexcept(ALL_STD_EXCEPT) == 0); 153#endif 154 } 155} 156 157void 158run_roundingmode_tests(void) 159{ 160 161 /* 162 * Corner cases in other rounding modes. 163 */ 164 fesetround(FE_DOWNWARD); 165 /* These are still positive per IEEE 754R */ 166#if 0 167 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0); 168#else 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); 176#endif 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); 181 182 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); 187 188 fesetround(FE_TONEAREST); 189} 190 191void 192run_accuracy_tests(void) 193{ 194 static const struct { 195 float x; 196 long double log2x; 197 long double logex; 198 long double log10x; 199 } tests[] = { 200 { 0x1p-120 + 0x1p-140, 201 -1.19999998624139449158861798943319717e2L, 202 -8.31776607135195754708796206665656732e1L, 203 -3.61235990655024477716980559136055915e1L, 204 }, 205 { 1.0 - 0x1p-20, 206 -1.37586186296463416424364914705656460e-6L, 207 -9.53674771153890007250243736279163253e-7L, 208 -4.14175690642480911859354110516159131e-7L, }, 209 { 1.0 + 0x1p-20, 210 1.37586055084113820105668028340371476e-6L, 211 9.53673861659188233908415514963336144e-7L, 212 4.14175295653950611453333571759200697e-7L }, 213 { 19.75, 214 4.30378074817710292442728634194115348e0L, 215 2.98315349134713087533848129856505779e0L, 216 1.29556709996247903756734359702926363e0L }, 217 { 19.75 * 0x1p100, 218 1.043037807481771029244272863419411534e2L, 219 7.229787154734166181706169344438271459e1L, 220 3.139856666636059855894123306947856631e1L }, 221 }; 222 int i; 223 224 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, 236 DBL_ULP()); 237 test_tol(log1pf, tests[i].x - 1, tests[i].logex, 238 FLT_ULP()); 239 test_tol(log1pl, tests[i].x - 1, tests[i].logex, 240 LDBL_ULP()); 241 } 242 } 243} 244 245void 246run_log1p_accuracy_tests(void) 247{ 248 249 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()); 255 256 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()); 262} 263 264int 265main(int argc, char *argv[]) 266{ 267 268 printf("1..5\n"); 269 270 run_generic_tests(); 271 printf("ok 1 - logarithm\n"); 272 273 run_log2_tests(); 274 printf("ok 2 - logarithm\n"); 275 276 run_roundingmode_tests(); 277 printf("ok 3 - logarithm\n"); 278 279 run_accuracy_tests(); 280 printf("ok 4 - logarithm\n"); 281 282 run_log1p_accuracy_tests(); 283 printf("ok 5 - logarithm\n"); 284 285 return (0); 286} 287