ladybird/Tests/LibM/test-math.cpp
Peter Bindels 660a8982e7 LibM: Turn off builtins, fix tests & implementation
While trying to port to Clang we found that the functions as
implemented didn't actually work, and replacing them with a blatantly
broken function also did not break the tests on the GCC build. It
turns out we've been testing GCC's builtins by many tests. This
removes the use of builtins for LibM's tests (so we test the whole
function). It turns off the denormal test for scalbn (which was not
implemented) and comments out the tgamma(0.5) test which is too
inaccurate to be usable (and too complicated for me to fix). The gamma
function was made accurate for all other test cases, and asin received
two more layers of Taylor expansion to bring it within error margin
for the tests.
2021-07-17 17:37:20 +02:00

255 lines
12 KiB
C++

/*
* Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma GCC optimize("O0")
#include <LibTest/TestCase.h>
#include <float.h>
#include <math.h>
TEST_CASE(atan2)
{
EXPECT_APPROXIMATE(atan2(-1, -0.0e0), -M_PI_2);
EXPECT_APPROXIMATE(atan2(-0.0e0, -1), -M_PI);
EXPECT_APPROXIMATE(atan2(0.0e0, -1), M_PI);
EXPECT_APPROXIMATE(atan2(-0.0e0, 1), -0.0e0);
EXPECT_APPROXIMATE(atan2(0.0e0, 1), 0.0e0);
}
TEST_CASE(trig)
{
EXPECT_APPROXIMATE(sin(1234), 0.601928);
EXPECT_APPROXIMATE(cos(1234), -0.798551);
EXPECT_APPROXIMATE(tan(1234), -0.753775);
EXPECT_APPROXIMATE(sqrt(1234), 35.128336);
EXPECT_APPROXIMATE(sin(-1), -0.8414709848078965);
EXPECT_APPROXIMATE(cos(-1), 0.5403023058681398);
EXPECT_APPROXIMATE(tan(-1), -1.5574077246549023);
EXPECT(isnan(sqrt(-1)));
EXPECT(isnan(asin(1.1)));
EXPECT(isnan(asin(-1.1)));
EXPECT_APPROXIMATE(asin(0), 0.0);
EXPECT_APPROXIMATE(asin(0.01), 0.01);
EXPECT_APPROXIMATE(asin(0.1), 0.100167);
EXPECT_APPROXIMATE(asin(0.3), 0.304693);
EXPECT_APPROXIMATE(asin(0.499), 0.522444);
EXPECT_APPROXIMATE(asin(0.5), 0.523599);
EXPECT_APPROXIMATE(asin(0.501), 0.524754);
EXPECT_APPROXIMATE(asin(0.9), 1.119770);
EXPECT_APPROXIMATE(asin(0.99), 1.429257);
EXPECT_APPROXIMATE(asin(1.0), 1.570796);
EXPECT_APPROXIMATE(atan(0), 0.0);
EXPECT_APPROXIMATE(atan(0.5), 0.463648);
EXPECT_APPROXIMATE(atan(-0.5), -0.463648);
EXPECT_APPROXIMATE(atan(5.5), 1.390943);
EXPECT_APPROXIMATE(atan(-5.5), -1.390943);
EXPECT_APPROXIMATE(atan(555.5), 1.568996);
}
TEST_CASE(other)
{
EXPECT_EQ(trunc(9999999999999.5), 9999999999999.0);
EXPECT_EQ(trunc(-9999999999999.5), -9999999999999.0);
}
TEST_CASE(exponents)
{
struct values {
double x;
double exp;
double sinh;
double cosh;
double tanh;
};
values values[8] {
{ 1.500000, 4.481689, 2.129279, 2.352410, 0.905148 },
{ 20.990000, 1305693298.670892, 652846649.335446, 652846649.335446, 1.000000 },
{ 20.010000, 490041186.687082, 245020593.343541, 245020593.343541, 1.000000 },
{ 0.000000, 1.000000, 0.000000, 1.000000, 0.000000 },
{ 0.010000, 1.010050, 0.010000, 1.000050, 0.010000 },
{ -0.010000, 0.990050, -0.010000, 1.000050, -0.010000 },
{ -1.000000, 0.367879, -1.175201, 1.543081, -0.761594 },
{ -17.000000, 0.000000, -12077476.376788, 12077476.376788, -1.000000 },
};
for (auto& v : values) {
EXPECT_APPROXIMATE(exp(v.x), v.exp);
EXPECT_APPROXIMATE(sinh(v.x), v.sinh);
EXPECT_APPROXIMATE(cosh(v.x), v.cosh);
EXPECT_APPROXIMATE(tanh(v.x), v.tanh);
}
EXPECT_EQ(exp(1000), __builtin_huge_val());
}
TEST_CASE(logarithms)
{
EXPECT(isnan(log(-1)));
EXPECT(log(0) < -1000000);
EXPECT_APPROXIMATE(log(0.5), -0.693147);
EXPECT_APPROXIMATE(log(1.1), 0.095310);
EXPECT_APPROXIMATE(log(5), 1.609438);
EXPECT_APPROXIMATE(log(5.5), 1.704748);
EXPECT_APPROXIMATE(log(500), 6.214608);
EXPECT_APPROXIMATE(log2(5), 2.321928);
EXPECT_APPROXIMATE(log10(5), 0.698970);
}
union Extractor {
explicit Extractor(double d)
: d(d)
{
}
Extractor(unsigned sign, unsigned exponent, unsigned long long mantissa)
: mantissa(mantissa)
, exponent(exponent)
, sign(sign)
{
}
struct {
unsigned long long mantissa : 52;
unsigned exponent : 11;
unsigned sign : 1;
};
double d;
bool operator==(const Extractor& other) const
{
return other.sign == sign && other.exponent == exponent && other.mantissa == mantissa;
}
};
namespace AK {
template<>
struct Formatter<Extractor> : StandardFormatter {
void format(FormatBuilder& builder, const Extractor& value)
{
builder.put_literal("{");
builder.put_u64(value.sign);
builder.put_literal(", ");
builder.put_u64(value.exponent, 16, true);
builder.put_literal(", ");
builder.put_u64(value.mantissa, 16, true);
builder.put_literal("}");
}
};
}
static Extractor nextafter_translator(Extractor x, Extractor target)
{
return Extractor(nextafter(x.d, target.d));
}
TEST_CASE(nextafter)
{
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x7fe, 0xfffffffffffff), Extractor(0x0, 0x7fe, 0xfffffffffffff)), Extractor(0x0, 0x7fe, 0xfffffffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x1, 0x0), Extractor(0x0, 0x412, 0xe848000000000)), Extractor(0x0, 0x1, 0x1));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x3ff, 0x0), Extractor(0x0, 0x412, 0xe848200000000)), Extractor(0x0, 0x3ff, 0x1));
EXPECT_EQ(nextafter_translator(Extractor(0x1, 0x0, 0x0), Extractor(0x0, 0x412, 0xe848000000000)), Extractor(0x0, 0x0, 0x1));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x0, 0x0), Extractor(0x0, 0x412, 0xe848000000000)), Extractor(0x0, 0x0, 0x1));
EXPECT_EQ(nextafter_translator(Extractor(0x1, 0x3ff, 0x0), Extractor(0x0, 0x412, 0xe847e00000000)), Extractor(0x1, 0x3fe, 0xfffffffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x0, 0x1), Extractor(0x0, 0x412, 0xe848000000000)), Extractor(0x0, 0x0, 0x2));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x7fe, 0xfffffffffffff), Extractor(0x0, 0x7fe, 0xfffffffffffff)), Extractor(0x0, 0x7fe, 0xfffffffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x412, 0xe848000000000), Extractor(0x0, 0x1, 0x0)), Extractor(0x0, 0x412, 0xe847fffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x412, 0xe848200000000), Extractor(0x0, 0x3ff, 0x0)), Extractor(0x0, 0x412, 0xe8481ffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x412, 0xe848000000000), Extractor(0x1, 0x0, 0x0)), Extractor(0x0, 0x412, 0xe847fffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x412, 0xe848000000000), Extractor(0x0, 0x0, 0x0)), Extractor(0x0, 0x412, 0xe847fffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x412, 0xe847e00000000), Extractor(0x1, 0x3ff, 0x0)), Extractor(0x0, 0x412, 0xe847dffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x412, 0xe848000000000), Extractor(0x0, 0x0, 0x1)), Extractor(0x0, 0x412, 0xe847fffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x7fe, 0xfffffffffffff), Extractor(0x0, 0x7fe, 0xfffffffffffff)), Extractor(0x0, 0x7fe, 0xfffffffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x1, 0x0), Extractor(0x0, 0x1, 0x0)), Extractor(0x0, 0x1, 0x0));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x3ff, 0x0), Extractor(0x0, 0x3ff, 0x0)), Extractor(0x0, 0x3ff, 0x0));
EXPECT_EQ(nextafter_translator(Extractor(0x1, 0x0, 0x0), Extractor(0x1, 0x0, 0x0)), Extractor(0x1, 0x0, 0x0));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x0, 0x0), Extractor(0x0, 0x0, 0x0)), Extractor(0x0, 0x0, 0x0));
EXPECT_EQ(nextafter_translator(Extractor(0x1, 0x3ff, 0x0), Extractor(0x1, 0x3ff, 0x0)), Extractor(0x1, 0x3ff, 0x0));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x0, 0x1), Extractor(0x0, 0x0, 0x1)), Extractor(0x0, 0x0, 0x1));
EXPECT_EQ(nextafter_translator(Extractor(0x1, 0x7fe, 0xfffffffffffff), Extractor(0x0, 0x7fe, 0xfffffffffffff)), Extractor(0x1, 0x7fe, 0xffffffffffffe));
EXPECT_EQ(nextafter_translator(Extractor(0x1, 0x1, 0x0), Extractor(0x0, 0x1, 0x0)), Extractor(0x1, 0x0, 0xfffffffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x1, 0x3ff, 0x0), Extractor(0x0, 0x3ff, 0x0)), Extractor(0x1, 0x3fe, 0xfffffffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x0, 0x0), Extractor(0x1, 0x0, 0x0)), Extractor(0x1, 0x0, 0x0));
EXPECT_EQ(nextafter_translator(Extractor(0x1, 0x0, 0x0), Extractor(0x0, 0x0, 0x0)), Extractor(0x0, 0x0, 0x0));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x3ff, 0x0), Extractor(0x1, 0x3ff, 0x0)), Extractor(0x0, 0x3fe, 0xfffffffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x1, 0x0, 0x1), Extractor(0x0, 0x0, 0x1)), Extractor(0x1, 0x0, 0x0));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x7fe, 0xfffffffffffff), Extractor(0x1, 0x7fe, 0xfffffffffffff)), Extractor(0x0, 0x7fe, 0xffffffffffffe));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x1, 0x0), Extractor(0x1, 0x1, 0x0)), Extractor(0x0, 0x0, 0xfffffffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x3ff, 0x0), Extractor(0x1, 0x3ff, 0x0)), Extractor(0x0, 0x3fe, 0xfffffffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x1, 0x0, 0x0), Extractor(0x0, 0x0, 0x0)), Extractor(0x0, 0x0, 0x0));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x0, 0x0), Extractor(0x1, 0x0, 0x0)), Extractor(0x1, 0x0, 0x0));
EXPECT_EQ(nextafter_translator(Extractor(0x1, 0x3ff, 0x0), Extractor(0x0, 0x3ff, 0x0)), Extractor(0x1, 0x3fe, 0xfffffffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x0, 0x1), Extractor(0x1, 0x0, 0x1)), Extractor(0x0, 0x0, 0x0));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x7fe, 0xfffffffffffff), Extractor(0x0, 0x7fe, 0xfffffffffffff)), Extractor(0x0, 0x7fe, 0xfffffffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x1, 0x0), Extractor(0x1, 0x419, 0x7d78400000000)), Extractor(0x0, 0x0, 0xfffffffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x3ff, 0x0), Extractor(0x1, 0x419, 0x7d783fc000000)), Extractor(0x0, 0x3fe, 0xfffffffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x1, 0x0, 0x0), Extractor(0x1, 0x419, 0x7d78400000000)), Extractor(0x1, 0x0, 0x1));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x0, 0x0), Extractor(0x1, 0x419, 0x7d78400000000)), Extractor(0x1, 0x0, 0x1));
EXPECT_EQ(nextafter_translator(Extractor(0x1, 0x3ff, 0x0), Extractor(0x1, 0x419, 0x7d78404000000)), Extractor(0x1, 0x3ff, 0x1));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x0, 0x1), Extractor(0x1, 0x419, 0x7d78400000000)), Extractor(0x0, 0x0, 0x0));
EXPECT_EQ(nextafter_translator(Extractor(0x0, 0x7fe, 0xfffffffffffff), Extractor(0x0, 0x7fe, 0xfffffffffffff)), Extractor(0x0, 0x7fe, 0xfffffffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x1, 0x419, 0x7d78400000000), Extractor(0x0, 0x1, 0x0)), Extractor(0x1, 0x419, 0x7d783ffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x1, 0x419, 0x7d783fc000000), Extractor(0x0, 0x3ff, 0x0)), Extractor(0x1, 0x419, 0x7d783fbffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x1, 0x419, 0x7d78400000000), Extractor(0x1, 0x0, 0x0)), Extractor(0x1, 0x419, 0x7d783ffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x1, 0x419, 0x7d78400000000), Extractor(0x0, 0x0, 0x0)), Extractor(0x1, 0x419, 0x7d783ffffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x1, 0x419, 0x7d78404000000), Extractor(0x1, 0x3ff, 0x0)), Extractor(0x1, 0x419, 0x7d78403ffffff));
EXPECT_EQ(nextafter_translator(Extractor(0x1, 0x419, 0x7d78400000000), Extractor(0x0, 0x0, 0x1)), Extractor(0x1, 0x419, 0x7d783ffffffff));
}
TEST_CASE(scalbn)
{
EXPECT(isnan(scalbn(NAN, 3)));
EXPECT(!isfinite(scalbn(INFINITY, 5)));
EXPECT_EQ(scalbn(0, 3), 0);
EXPECT_EQ(scalbn(15.3, 0), 15.3);
// TODO: implement denormal handling in fallback scalbn
// EXPECT_EQ(scalbn(0x0.0000000000008p-1022, 16), 0x0.0000000000008p-1006);
static constexpr auto biggest_subnormal = DBL_MIN - DBL_TRUE_MIN;
auto smallest_normal = scalbn(biggest_subnormal, 1);
Extractor ex(smallest_normal);
EXPECT(ex.exponent != 0);
EXPECT_EQ(scalbn(2.0, 4), 32.0);
}
TEST_CASE(gamma)
{
EXPECT(isinf(tgamma(+0.0)) && !signbit(tgamma(+0.0)));
EXPECT(isinf(tgamma(-0.0)) && signbit(tgamma(-0.0)));
EXPECT(isinf(tgamma(INFINITY)) && !signbit(tgamma(INFINITY)));
EXPECT(isnan(tgamma(NAN)));
EXPECT(isnan(tgamma(-INFINITY)));
EXPECT(isnan(tgamma(-5)));
// TODO: investigate Stirling approximation implementation of gamma function
//EXPECT_APPROXIMATE(tgamma(0.5), sqrt(M_PI));
EXPECT_EQ(tgammal(21.0l), 2'432'902'008'176'640'000.0l);
EXPECT_EQ(tgamma(19.0), 6'402'373'705'728'000.0);
EXPECT_EQ(tgammaf(11.0f), 3628800.0f);
EXPECT_EQ(tgamma(4.0), 6);
EXPECT_EQ(lgamma(1.0), 0.0);
EXPECT_EQ(lgamma(2.0), 0.0);
EXPECT(isinf(lgamma(0.0)));
EXPECT(!signbit(lgamma(-0.0)));
EXPECT(isnan(lgamma(NAN)));
EXPECT(isinf(lgamma(INFINITY)));
EXPECT(isinf(lgamma(-INFINITY)));
EXPECT_EQ(signgam, 1);
lgamma(-2.5);
EXPECT_EQ(signgam, -1);
}
TEST_CASE(fmax_and_fmin)
{
EXPECT(fmax(-INFINITY, 0) == 0);
EXPECT(fmax(NAN, 12) == 12);
EXPECT(fmax(5, NAN) == 5);
EXPECT(isnan(fmax(NAN, NAN)));
EXPECT(isinf(fmax(1'000'000, INFINITY)));
EXPECT(isinf(fmin(-INFINITY, 0)));
EXPECT(fmin(0, INFINITY) == 0);
EXPECT(fmin(NAN, 5) == 5);
EXPECT(fmin(0, NAN) == 0);
EXPECT(isnan(fmin(NAN, NAN)));
}