/*- * Copyright (c) 2008-2010 David Schultz * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * Tests for corner cases in log*(). */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #ifdef __i386__ #include #endif #include "test-utils.h" #pragma STDC FENV_ACCESS ON /* * Test that a function returns the correct value and sets the * exception flags correctly. The exceptmask specifies which * exceptions we should check. We need to be lenient for several * reasoons, but mainly because on some architectures it's impossible * to raise FE_OVERFLOW without raising FE_INEXACT. * * These are macros instead of functions so that assert provides more * meaningful error messages. * * XXX The volatile here is to avoid gcc's bogus constant folding and work * around the lack of support for the FENV_ACCESS pragma. */ #define test(func, x, result, exceptmask, excepts) do { \ volatile long double _d = x; \ assert(feclearexcept(FE_ALL_EXCEPT) == 0); \ assert(fpequal((func)(_d), (result))); \ assert(((void)(func), fetestexcept(exceptmask) == (excepts))); \ } while (0) #define test(func, x, result, exceptmask, excepts) do { \ volatile long double _d = x; \ assert(feclearexcept(FE_ALL_EXCEPT) == 0); \ assert(fpequal((func)(_d), (result))); \ assert(((void)(func), fetestexcept(exceptmask) == (excepts))); \ } while (0) #define test_tol(func, z, result, tol) do { \ volatile long double _d = z; \ debug(" testing %6s(%15La) ~= % .36Le\n", #func, _d, result); \ assert(fpequal_tol((func)(_d), (result), (tol), CS_BOTH)); \ } while (0) /* Test all the functions that compute log(x). */ #define testall0(x, result, exceptmask, excepts) do { \ test(log, x, result, exceptmask, excepts); \ test(logf, x, result, exceptmask, excepts); \ test(logl, x, result, exceptmask, excepts); \ test(log2, x, result, exceptmask, excepts); \ test(log2f, x, result, exceptmask, excepts); \ test(log2l, x, result, exceptmask, excepts); \ test(log10, x, result, exceptmask, excepts); \ test(log10f, x, result, exceptmask, excepts); \ test(log10l, x, result, exceptmask, excepts); \ } while (0) /* Test all the functions that compute log(1+x). */ #define testall1(x, result, exceptmask, excepts) do { \ test(log1p, x, result, exceptmask, excepts); \ test(log1pf, x, result, exceptmask, excepts); \ test(log1pl, x, result, exceptmask, excepts); \ } while (0) void run_generic_tests(void) { /* log(1) == 0, no exceptions raised */ testall0(1.0, 0.0, ALL_STD_EXCEPT, 0); testall1(0.0, 0.0, ALL_STD_EXCEPT, 0); testall1(-0.0, -0.0, ALL_STD_EXCEPT, 0); /* log(NaN) == NaN, no exceptions raised */ testall0(NAN, NAN, ALL_STD_EXCEPT, 0); testall1(NAN, NAN, ALL_STD_EXCEPT, 0); /* log(Inf) == Inf, no exceptions raised */ testall0(INFINITY, INFINITY, ALL_STD_EXCEPT, 0); testall1(INFINITY, INFINITY, ALL_STD_EXCEPT, 0); /* log(x) == NaN for x < 0, invalid exception raised */ testall0(-INFINITY, NAN, ALL_STD_EXCEPT, FE_INVALID); testall1(-INFINITY, NAN, ALL_STD_EXCEPT, FE_INVALID); testall0(-1.0, NAN, ALL_STD_EXCEPT, FE_INVALID); testall1(-1.5, NAN, ALL_STD_EXCEPT, FE_INVALID); /* log(0) == -Inf, divide-by-zero exception */ testall0(0.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO); testall0(-0.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO); testall1(-1.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO); } void run_log2_tests(void) { int i; /* * We should insist that log2() return exactly the correct * result and not raise an inexact exception for powers of 2. */ assert(feclearexcept(FE_ALL_EXCEPT) == 0); for (i = FLT_MIN_EXP - FLT_MANT_DIG; i < FLT_MAX_EXP; i++) { assert(log2f(ldexpf(1.0, i)) == i); assert(fetestexcept(ALL_STD_EXCEPT) == 0); } for (i = DBL_MIN_EXP - DBL_MANT_DIG; i < DBL_MAX_EXP; i++) { assert(log2(ldexp(1.0, i)) == i); assert(fetestexcept(ALL_STD_EXCEPT) == 0); } for (i = LDBL_MIN_EXP - LDBL_MANT_DIG; i < LDBL_MAX_EXP; i++) { assert(log2l(ldexpl(1.0, i)) == i); #if 0 /* XXX This test does not pass yet. */ assert(fetestexcept(ALL_STD_EXCEPT) == 0); #endif } } void run_roundingmode_tests(void) { /* * Corner cases in other rounding modes. */ fesetround(FE_DOWNWARD); /* These are still positive per IEEE 754R */ #if 0 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0); #else /* logl, log2l, and log10l don't pass yet. */ test(log, 1.0, 0.0, ALL_STD_EXCEPT, 0); test(logf, 1.0, 0.0, ALL_STD_EXCEPT, 0); test(log2, 1.0, 0.0, ALL_STD_EXCEPT, 0); test(log2f, 1.0, 0.0, ALL_STD_EXCEPT, 0); test(log10, 1.0, 0.0, ALL_STD_EXCEPT, 0); test(log10f, 1.0, 0.0, ALL_STD_EXCEPT, 0); #endif testall1(0.0, 0.0, ALL_STD_EXCEPT, 0); fesetround(FE_TOWARDZERO); testall0(1.0, 0.0, ALL_STD_EXCEPT, 0); testall1(0.0, 0.0, ALL_STD_EXCEPT, 0); fesetround(FE_UPWARD); testall0(1.0, 0.0, ALL_STD_EXCEPT, 0); testall1(0.0, 0.0, ALL_STD_EXCEPT, 0); /* log1p(-0.0) == -0.0 even when rounding upwards */ testall1(-0.0, -0.0, ALL_STD_EXCEPT, 0); fesetround(FE_TONEAREST); } void run_accuracy_tests(void) { static const struct { float x; long double log2x; long double logex; long double log10x; } tests[] = { { 0x1p-120 + 0x1p-140, -1.19999998624139449158861798943319717e2L, -8.31776607135195754708796206665656732e1L, -3.61235990655024477716980559136055915e1L, }, { 1.0 - 0x1p-20, -1.37586186296463416424364914705656460e-6L, -9.53674771153890007250243736279163253e-7L, -4.14175690642480911859354110516159131e-7L, }, { 1.0 + 0x1p-20, 1.37586055084113820105668028340371476e-6L, 9.53673861659188233908415514963336144e-7L, 4.14175295653950611453333571759200697e-7L }, { 19.75, 4.30378074817710292442728634194115348e0L, 2.98315349134713087533848129856505779e0L, 1.29556709996247903756734359702926363e0L }, { 19.75 * 0x1p100, 1.043037807481771029244272863419411534e2L, 7.229787154734166181706169344438271459e1L, 3.139856666636059855894123306947856631e1L }, }; int i; for (i = 0; i < sizeof(tests) / sizeof(tests[0]); i++) { test_tol(log2, tests[i].x, tests[i].log2x, DBL_ULP()); test_tol(log2f, tests[i].x, tests[i].log2x, FLT_ULP()); test_tol(log2l, tests[i].x, tests[i].log2x, LDBL_ULP()); test_tol(log, tests[i].x, tests[i].logex, DBL_ULP()); test_tol(logf, tests[i].x, tests[i].logex, FLT_ULP()); test_tol(logl, tests[i].x, tests[i].logex, LDBL_ULP()); test_tol(log10, tests[i].x, tests[i].log10x, DBL_ULP()); test_tol(log10f, tests[i].x, tests[i].log10x, FLT_ULP()); test_tol(log10l, tests[i].x, tests[i].log10x, LDBL_ULP()); if (tests[i].x >= 0.5) { test_tol(log1p, tests[i].x - 1, tests[i].logex, DBL_ULP()); test_tol(log1pf, tests[i].x - 1, tests[i].logex, FLT_ULP()); test_tol(log1pl, tests[i].x - 1, tests[i].logex, LDBL_ULP()); } } } void run_log1p_accuracy_tests(void) { test_tol(log1pf, 0x0.333333p0F, 1.82321546859847114303367992804596800640e-1L, FLT_ULP()); test_tol(log1p, 0x0.3333333333333p0, 1.82321556793954589204283870982629267635e-1L, DBL_ULP()); test_tol(log1pl, 0x0.33333333333333332p0L, 1.82321556793954626202683007050468762914e-1L, LDBL_ULP()); test_tol(log1pf, -0x0.333333p0F, -2.23143536413048672940940199918017467652e-1L, FLT_ULP()); test_tol(log1p, -0x0.3333333333333p0, -2.23143551314209700255143859052009022937e-1L, DBL_ULP()); test_tol(log1pl, -0x0.33333333333333332p0L, -2.23143551314209755752742563153765697950e-1L, LDBL_ULP()); } int main(int argc, char *argv[]) { printf("1..5\n"); run_generic_tests(); printf("ok 1 - logarithm\n"); run_log2_tests(); printf("ok 2 - logarithm\n"); run_roundingmode_tests(); printf("ok 3 - logarithm\n"); run_accuracy_tests(); printf("ok 4 - logarithm\n"); run_log1p_accuracy_tests(); printf("ok 5 - logarithm\n"); return (0); }