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/*-
* Copyright (c) 2008-2010 David Schultz <das@FreeBSD.org>
* 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <assert.h>
#include <fenv.h>
#include <float.h>
#include <math.h>
#include <stdio.h>
#ifdef __i386__
#include <ieeefp.h>
#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.
*/
feclearexcept(FE_ALL_EXCEPT);
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);
}
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