ladybird/Tests/AK/TestIntegerMath.cpp
Zaggy1024 bbd8a218a5 AK: Prevent overflow of the min when clamping unsigned values to signed
Also, add some tests for the cases that were broken before.
2024-06-24 12:41:32 -06:00

134 lines
4.7 KiB
C++

/*
* Copyright (c) 2022, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibTest/TestCase.h>
#include <AK/IntegralMath.h>
#include <initializer_list>
TEST_CASE(pow)
{
EXPECT_EQ(AK::pow<u64>(0, 0), 1ull);
EXPECT_EQ(AK::pow<u64>(10, 0), 1ull);
EXPECT_EQ(AK::pow<u64>(10, 1), 10ull);
EXPECT_EQ(AK::pow<u64>(10, 2), 100ull);
EXPECT_EQ(AK::pow<u64>(10, 3), 1'000ull);
EXPECT_EQ(AK::pow<u64>(10, 4), 10'000ull);
EXPECT_EQ(AK::pow<u64>(10, 5), 100'000ull);
EXPECT_EQ(AK::pow<u64>(10, 6), 1'000'000ull);
}
TEST_CASE(is_power_of)
{
EXPECT(!AK::is_power_of<0>(10ull));
// We don't have enough context to know if the input was from 0^0
EXPECT(!AK::is_power_of<0>(1ull));
EXPECT(!AK::is_power_of<1>(10ull));
EXPECT(!AK::is_power_of<1>(0ull));
constexpr auto check_prime = []<u64 prime>(u64 limit, u64 init = 0) {
for (u64 power = init; power < limit; ++power)
EXPECT(AK::is_power_of<prime>(AK::pow(prime, power)));
};
// Limits calculated as floor( log_{prime}(2^64) ) to prevent overflows.
check_prime.operator()<0>(42, 1);
check_prime.operator()<1>(36);
check_prime.operator()<2>(64);
check_prime.operator()<3>(40);
check_prime.operator()<5>(27);
check_prime.operator()<7>(20);
check_prime.operator()<11>(18);
check_prime.operator()<97>(9);
check_prime.operator()<257>(7);
}
TEST_CASE(exp2)
{
EXPECT_EQ(AK::exp2<u64>(0), 1ull);
EXPECT_EQ(AK::exp2<u64>(1), 2ull);
EXPECT_EQ(AK::exp2<i8>(6), 64);
EXPECT_EQ(AK::exp2<u8>(7), 128);
EXPECT_EQ(AK::exp2<u16>(9), 512);
EXPECT_EQ(AK::exp2<i16>(14), 16384);
EXPECT_EQ(AK::exp2<u16>(15), 32768);
EXPECT_EQ(AK::exp2<u32>(17), 131072u);
EXPECT_EQ(AK::exp2<i32>(30), 1073741824);
EXPECT_EQ(AK::exp2<u32>(31), 2147483648);
EXPECT_EQ(AK::exp2<i64>(32), 4294967296);
EXPECT_EQ(AK::exp2<u64>(33), 8589934592ull);
EXPECT_EQ(AK::exp2<i64>(62), 4611686018427387904);
EXPECT_EQ(AK::exp2<u64>(63), 9223372036854775808ull);
}
TEST_CASE(log2)
{
EXPECT_EQ(AK::log2<u64>(0), 0ull);
EXPECT_EQ(AK::log2<u64>(1), 0ull);
EXPECT_EQ(AK::log2<i8>(64), 6);
EXPECT_EQ(AK::log2<u8>(128), 7);
EXPECT_EQ(AK::log2<u16>(512), 9);
EXPECT_EQ(AK::log2<i16>(16384), 14);
EXPECT_EQ(AK::log2<u16>(32768), 15);
EXPECT_EQ(AK::log2<i32>(131072), 17);
EXPECT_EQ(AK::log2<i32>(1073741824), 30);
EXPECT_EQ(AK::log2<u32>(2147483648), 31u);
EXPECT_EQ(AK::log2<i64>(4294967296), 32);
EXPECT_EQ(AK::log2<i64>(8589934592), 33);
EXPECT_EQ(AK::log2<i64>(4611686018427387904), 62);
EXPECT_EQ(AK::log2<u64>(9223372036854775808ull), 63ull);
}
TEST_CASE(ceil_log2)
{
EXPECT_EQ(AK::ceil_log2<u64>(0), 0ull);
EXPECT_EQ(AK::ceil_log2<u64>(1), 0ull);
EXPECT_EQ(AK::ceil_log2<u8>(2), 1);
EXPECT_EQ(AK::ceil_log2<u8>(3), 2);
EXPECT_EQ(AK::ceil_log2<u8>(6), 3);
EXPECT_EQ(AK::ceil_log2<i8>(96), 7);
EXPECT_EQ(AK::ceil_log2<i8>(127), 7);
EXPECT_EQ(AK::ceil_log2<u8>(128), 7);
EXPECT_EQ(AK::ceil_log2<u8>(255), 8);
EXPECT_EQ(AK::ceil_log2<i16>(256), 8);
EXPECT_EQ(AK::ceil_log2<i16>(257), 9);
EXPECT_EQ(AK::ceil_log2<i16>(384), 9);
EXPECT_EQ(AK::ceil_log2<i16>(24576), 15);
EXPECT_EQ(AK::ceil_log2<i16>(32767), 15);
EXPECT_EQ(AK::ceil_log2<i32>(32768), 15);
EXPECT_EQ(AK::ceil_log2<i32>(32769), 16);
EXPECT_EQ(AK::ceil_log2<i32>(98304), 17);
EXPECT_EQ(AK::ceil_log2<i32>(1610612736), 31);
EXPECT_EQ(AK::ceil_log2<i32>(2147483647), 31);
EXPECT_EQ(AK::ceil_log2<u32>(2147483648), 31u);
EXPECT_EQ(AK::ceil_log2<u32>(2147483649), 32u);
EXPECT_EQ(AK::ceil_log2<u32>(3221225472), 32u);
EXPECT_EQ(AK::ceil_log2<u32>(4294967295), 32u);
EXPECT_EQ(AK::ceil_log2<i64>(4294967296), 32);
EXPECT_EQ(AK::ceil_log2<i64>(4294967297), 33);
EXPECT_EQ(AK::ceil_log2<i64>(9223372036854775807), 63ll);
EXPECT_EQ(AK::ceil_log2<u64>(9223372036854775808ull), 63ull);
EXPECT_EQ(AK::ceil_log2<u64>(9223372036854775809ull), 64ull);
EXPECT_EQ(AK::ceil_log2<u64>(13835058055282163712ull), 64ull);
EXPECT_EQ(AK::ceil_log2<u64>(18446744073709551615ull), 64ull);
}
TEST_CASE(clamp_to)
{
EXPECT_EQ((AK::clamp_to<i32>(1000000u)), 1000000);
EXPECT_EQ((AK::clamp_to<i32>(NumericLimits<u64>::max())), NumericLimits<i32>::max());
EXPECT_EQ((AK::clamp_to<u32>(-10)), 0u);
EXPECT_EQ((AK::clamp_to<u32>(10)), 10u);
EXPECT_EQ((AK::clamp_to<i32>(NumericLimits<i64>::min())), NumericLimits<i32>::min());
EXPECT_EQ((AK::clamp_to<i32>(NumericLimits<i64>::max())), NumericLimits<i32>::max());
EXPECT_EQ(AK::clamp_to<i64>(-9223372036854775808.0), NumericLimits<i64>::min());
EXPECT_EQ(AK::clamp_to<i64>(9223372036854775807.0), NumericLimits<i64>::max());
}