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 * $FreeBSD: src/tools/regression/lib/msun/test-logarithm.c,v 1.3 2011/10/15 05:28:13 das Exp $ 27 */ 28 29 /* 30 * Tests for corner cases in log*(). 31 */ 32 33 #include <assert.h> 34 #include <fenv.h> 35 #include <float.h> 36 #include <math.h> 37 #include <stdio.h> 38 39 #ifdef __i386__ 40 #include <ieeefp.h> 41 #endif 42 43 #define ALL_STD_EXCEPT (FE_DIVBYZERO | FE_INEXACT | FE_INVALID | \ 44 FE_OVERFLOW | FE_UNDERFLOW) 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(((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 84 /* 85 * Determine whether x and y are equal, with two special rules: 86 * +0.0 != -0.0 87 * NaN == NaN 88 */ 89 int 90 fpequal(long double x, long double y) 91 { 92 return ((x == y && !signbit(x) == !signbit(y)) || isnan(x) && isnan(y)); 93 } 94 95 void 96 run_generic_tests(void) 97 { 98 99 /* log(1) == 0, no exceptions raised */ 100 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0); 101 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0); 102 testall1(-0.0, -0.0, ALL_STD_EXCEPT, 0); 103 104 /* log(NaN) == NaN, no exceptions raised */ 105 testall0(NAN, NAN, ALL_STD_EXCEPT, 0); 106 testall1(NAN, NAN, ALL_STD_EXCEPT, 0); 107 108 /* log(Inf) == Inf, no exceptions raised */ 109 testall0(INFINITY, INFINITY, ALL_STD_EXCEPT, 0); 110 testall1(INFINITY, INFINITY, ALL_STD_EXCEPT, 0); 111 112 /* log(x) == NaN for x < 0, invalid exception raised */ 113 testall0(-INFINITY, NAN, ALL_STD_EXCEPT, FE_INVALID); 114 testall1(-INFINITY, NAN, ALL_STD_EXCEPT, FE_INVALID); 115 testall0(-1.0, NAN, ALL_STD_EXCEPT, FE_INVALID); 116 testall1(-1.5, NAN, ALL_STD_EXCEPT, FE_INVALID); 117 118 /* log(0) == -Inf, divide-by-zero exception */ 119 testall0(0.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO); 120 testall0(-0.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO); 121 testall1(-1.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO); 122 } 123 124 void 125 run_log2_tests(void) 126 { 127 int i; 128 129 /* 130 * We should insist that log2() return exactly the correct 131 * result and not raise an inexact exception for powers of 2. 132 */ 133 feclearexcept(FE_ALL_EXCEPT); 134 for (i = FLT_MIN_EXP - FLT_MANT_DIG; i < FLT_MAX_EXP; i++) { 135 assert(log2f(ldexpf(1.0, i)) == i); 136 assert(fetestexcept(ALL_STD_EXCEPT) == 0); 137 } 138 for (i = DBL_MIN_EXP - DBL_MANT_DIG; i < DBL_MAX_EXP; i++) { 139 assert(log2(ldexp(1.0, i)) == i); 140 assert(fetestexcept(ALL_STD_EXCEPT) == 0); 141 } 142 } 143 144 void 145 run_roundingmode_tests(void) 146 { 147 148 /* 149 * Corner cases in other rounding modes. 150 */ 151 fesetround(FE_DOWNWARD); 152 /* These are still positive per IEEE 754R */ 153 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0); 154 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0); 155 fesetround(FE_TOWARDZERO); 156 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0); 157 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0); 158 159 fesetround(FE_UPWARD); 160 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0); 161 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0); 162 /* log1p(-0.0) == -0.0 even when rounding upwards */ 163 testall1(-0.0, -0.0, ALL_STD_EXCEPT, 0); 164 165 fesetround(FE_TONEAREST); 166 } 167 168 int 169 main(int argc, char *argv[]) 170 { 171 172 printf("1..3\n"); 173 174 run_generic_tests(); 175 printf("ok 1 - logarithm\n"); 176 177 run_log2_tests(); 178 printf("ok 2 - logarithm\n"); 179 180 run_roundingmode_tests(); 181 printf("ok 3 - logarithm\n"); 182 183 return (0); 184 } 185