2 * Copyright (c) 2008-2010 David Schultz <das@FreeBSD.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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
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12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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28 * Tests for corner cases in log*().
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
44 #define ALL_STD_EXCEPT (FE_DIVBYZERO | FE_INEXACT | FE_INVALID | \
45 FE_OVERFLOW | FE_UNDERFLOW)
47 #pragma STDC FENV_ACCESS ON
50 * Test that a function returns the correct value and sets the
51 * exception flags correctly. The exceptmask specifies which
52 * exceptions we should check. We need to be lenient for several
53 * reasoons, but mainly because on some architectures it's impossible
54 * to raise FE_OVERFLOW without raising FE_INEXACT.
56 * These are macros instead of functions so that assert provides more
57 * meaningful error messages.
59 * XXX The volatile here is to avoid gcc's bogus constant folding and work
60 * around the lack of support for the FENV_ACCESS pragma.
62 #define test(func, x, result, exceptmask, excepts) do { \
63 volatile long double _d = x; \
64 assert(feclearexcept(FE_ALL_EXCEPT) == 0); \
65 assert(fpequal((func)(_d), (result))); \
66 assert(((func), fetestexcept(exceptmask) == (excepts))); \
69 /* Test all the functions that compute log(x). */
70 #define testall0(x, result, exceptmask, excepts) do { \
71 test(log, x, result, exceptmask, excepts); \
72 test(logf, x, result, exceptmask, excepts); \
73 test(log2, x, result, exceptmask, excepts); \
74 test(log2f, x, result, exceptmask, excepts); \
75 test(log10, x, result, exceptmask, excepts); \
76 test(log10f, x, result, exceptmask, excepts); \
79 /* Test all the functions that compute log(1+x). */
80 #define testall1(x, result, exceptmask, excepts) do { \
81 test(log1p, x, result, exceptmask, excepts); \
82 test(log1pf, x, result, exceptmask, excepts); \
86 * Determine whether x and y are equal, with two special rules:
91 fpequal(long double x, long double y)
93 return ((x == y && !signbit(x) == !signbit(y)) || isnan(x) && isnan(y));
97 run_generic_tests(void)
100 /* exp(1) == 0, no exceptions raised */
101 testall0(1.0, 0.0, ALL_STD_EXCEPT, 0);
102 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0);
103 testall1(-0.0, -0.0, ALL_STD_EXCEPT, 0);
105 /* log(NaN) == NaN, no exceptions raised */
106 testall0(NAN, NAN, ALL_STD_EXCEPT, 0);
107 testall1(NAN, NAN, ALL_STD_EXCEPT, 0);
109 /* log(Inf) == Inf, no exceptions raised */
110 testall0(INFINITY, INFINITY, ALL_STD_EXCEPT, 0);
111 testall1(INFINITY, INFINITY, ALL_STD_EXCEPT, 0);
113 /* log(x) == NaN for x < 0, invalid exception raised */
114 testall0(-INFINITY, NAN, ALL_STD_EXCEPT, FE_INVALID);
115 testall1(-INFINITY, NAN, ALL_STD_EXCEPT, FE_INVALID);
116 testall0(-1.0, NAN, ALL_STD_EXCEPT, FE_INVALID);
117 testall1(-1.5, NAN, ALL_STD_EXCEPT, FE_INVALID);
119 /* log(0) == -Inf, divide-by-zero exception */
120 testall0(0.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO);
121 testall0(-0.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO);
122 testall1(-1.0, -INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_DIVBYZERO);
131 * We should insist that log2() return exactly the correct
132 * result and not raise an inexact exception for powers of 2.
134 feclearexcept(FE_ALL_EXCEPT);
135 for (i = FLT_MIN_EXP - FLT_MANT_DIG; i < FLT_MAX_EXP; i++) {
136 assert(log2f(ldexpf(1.0, i)) == i);
137 assert(fetestexcept(ALL_STD_EXCEPT) == 0);
139 for (i = DBL_MIN_EXP - DBL_MANT_DIG; i < DBL_MAX_EXP; i++) {
140 assert(log2(ldexp(1.0, i)) == i);
141 assert(fetestexcept(ALL_STD_EXCEPT) == 0);
146 main(int argc, char *argv[])
152 printf("ok 1 - logarithm\n");
155 printf("ok 2 - logarithm\n");