logarithm_test.c revision 251241
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: head/tools/regression/lib/msun/test-logarithm.c 251241 2013-06-02 04:30:03Z das $"); 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/* Test all the functions that compute log(x). */ 69#define testall0(x, result, exceptmask, excepts) do { \ 70 test(log, x, result, exceptmask, excepts); \ 71 test(logf, x, result, exceptmask, excepts); \ 72 test(log2, x, result, exceptmask, excepts); \ 73 test(log2f, x, result, exceptmask, excepts); \ 74 test(log10, x, result, exceptmask, excepts); \ 75 test(log10f, x, result, exceptmask, excepts); \ 76} while (0) 77 78/* Test all the functions that compute log(1+x). */ 79#define testall1(x, result, exceptmask, excepts) do { \ 80 test(log1p, x, result, exceptmask, excepts); \ 81 test(log1pf, x, result, exceptmask, excepts); \ 82} while (0) 83 84void 85run_generic_tests(void) 86{ 87 88 /* log(1) == 0, no exceptions raised */ 89 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0); 90 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0); 91 testall1(-0.0, -0.0, ALL_STD_EXCEPT, 0); 92 93 /* log(NaN) == NaN, no exceptions raised */ 94 testall0(NAN, NAN, ALL_STD_EXCEPT, 0); 95 testall1(NAN, NAN, ALL_STD_EXCEPT, 0); 96 97 /* log(Inf) == Inf, no exceptions raised */ 98 testall0(INFINITY, INFINITY, ALL_STD_EXCEPT, 0); 99 testall1(INFINITY, INFINITY, ALL_STD_EXCEPT, 0); 100 101 /* log(x) == NaN for x < 0, invalid exception raised */ 102 testall0(-INFINITY, NAN, ALL_STD_EXCEPT, FE_INVALID); 103 testall1(-INFINITY, NAN, ALL_STD_EXCEPT, FE_INVALID); 104 testall0(-1.0, NAN, ALL_STD_EXCEPT, FE_INVALID); 105 testall1(-1.5, NAN, ALL_STD_EXCEPT, FE_INVALID); 106 107 /* log(0) == -Inf, divide-by-zero exception */ 108 testall0(0.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO); 109 testall0(-0.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO); 110 testall1(-1.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO); 111} 112 113void 114run_log2_tests(void) 115{ 116 int i; 117 118 /* 119 * We should insist that log2() return exactly the correct 120 * result and not raise an inexact exception for powers of 2. 121 */ 122 feclearexcept(FE_ALL_EXCEPT); 123 for (i = FLT_MIN_EXP - FLT_MANT_DIG; i < FLT_MAX_EXP; i++) { 124 assert(log2f(ldexpf(1.0, i)) == i); 125 assert(fetestexcept(ALL_STD_EXCEPT) == 0); 126 } 127 for (i = DBL_MIN_EXP - DBL_MANT_DIG; i < DBL_MAX_EXP; i++) { 128 assert(log2(ldexp(1.0, i)) == i); 129 assert(fetestexcept(ALL_STD_EXCEPT) == 0); 130 } 131} 132 133void 134run_roundingmode_tests(void) 135{ 136 137 /* 138 * Corner cases in other rounding modes. 139 */ 140 fesetround(FE_DOWNWARD); 141 /* These are still positive per IEEE 754R */ 142 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0); 143 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0); 144 fesetround(FE_TOWARDZERO); 145 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0); 146 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0); 147 148 fesetround(FE_UPWARD); 149 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0); 150 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0); 151 /* log1p(-0.0) == -0.0 even when rounding upwards */ 152 testall1(-0.0, -0.0, ALL_STD_EXCEPT, 0); 153 154 fesetround(FE_TONEAREST); 155} 156 157int 158main(int argc, char *argv[]) 159{ 160 161 printf("1..3\n"); 162 163 run_generic_tests(); 164 printf("ok 1 - logarithm\n"); 165 166 run_log2_tests(); 167 printf("ok 2 - logarithm\n"); 168 169 run_roundingmode_tests(); 170 printf("ok 3 - logarithm\n"); 171 172 return (0); 173} 174