ladybird/Tests/AK/TestBuiltinWrappers.cpp
Martin Janiczek d52ffcd830 LibTest: Add more numeric generators
Rename unsigned_int generator to number_u32.
Add generators:
- number_u64
- number_f64
- percentage
2024-01-12 16:42:51 -07:00

104 lines
4 KiB
C++

/*
* Copyright (c) 2018-2020, Nick Johnson <sylvyrfysh@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibTest/TestCase.h>
#include <AK/BuiltinWrappers.h>
#include <AK/Types.h>
using namespace Test::Randomized;
TEST_CASE(wrapped_popcount)
{
EXPECT_EQ(popcount(NumericLimits<u8>::max()), 8);
EXPECT_EQ(popcount(NumericLimits<u16>::max()), 16);
EXPECT_EQ(popcount(NumericLimits<u32>::max()), 32);
EXPECT_EQ(popcount(NumericLimits<u64>::max()), 64);
EXPECT_EQ(popcount(NumericLimits<size_t>::max()), static_cast<int>(8 * sizeof(size_t)));
EXPECT_EQ(popcount(0u), 0);
EXPECT_EQ(popcount(0b01010101ULL), 4);
}
TEST_CASE(wrapped_count_leading_zeroes)
{
EXPECT_EQ(count_leading_zeroes(NumericLimits<u8>::max()), 0);
EXPECT_EQ(count_leading_zeroes(static_cast<u8>(0x20)), 2);
EXPECT_EQ(count_leading_zeroes_safe(static_cast<u8>(0)), 8);
EXPECT_EQ(count_leading_zeroes(NumericLimits<u16>::max()), 0);
EXPECT_EQ(count_leading_zeroes(static_cast<u16>(0x20)), 10);
EXPECT_EQ(count_leading_zeroes_safe(static_cast<u16>(0)), 16);
EXPECT_EQ(count_leading_zeroes(NumericLimits<u32>::max()), 0);
EXPECT_EQ(count_leading_zeroes(static_cast<u32>(0x20)), 26);
EXPECT_EQ(count_leading_zeroes_safe(static_cast<u32>(0)), 32);
EXPECT_EQ(count_leading_zeroes(NumericLimits<u64>::max()), 0);
}
TEST_CASE(wrapped_count_trailing_zeroes)
{
EXPECT_EQ(count_trailing_zeroes(NumericLimits<u8>::max()), 0);
EXPECT_EQ(count_trailing_zeroes(static_cast<u8>(1)), 0);
EXPECT_EQ(count_trailing_zeroes(static_cast<u8>(2)), 1);
EXPECT_EQ(count_trailing_zeroes_safe(static_cast<u8>(0)), 8);
EXPECT_EQ(count_trailing_zeroes(NumericLimits<u16>::max()), 0);
EXPECT_EQ(count_trailing_zeroes(static_cast<u16>(1)), 0);
EXPECT_EQ(count_trailing_zeroes(static_cast<u16>(2)), 1);
EXPECT_EQ(count_trailing_zeroes_safe(static_cast<u16>(0)), 16);
EXPECT_EQ(count_trailing_zeroes(NumericLimits<u32>::max()), 0);
EXPECT_EQ(count_trailing_zeroes(static_cast<u32>(1)), 0);
EXPECT_EQ(count_trailing_zeroes(static_cast<u32>(2)), 1);
EXPECT_EQ(count_trailing_zeroes_safe(static_cast<u32>(0)), 32);
EXPECT_EQ(count_trailing_zeroes(NumericLimits<u64>::max()), 0);
EXPECT_EQ(count_trailing_zeroes(static_cast<u64>(1)), 0);
EXPECT_EQ(count_trailing_zeroes(static_cast<u64>(2)), 1);
}
TEST_CASE(wrapped_count_required_bits)
{
EXPECT_EQ(count_required_bits(0b0u), 1ul);
EXPECT_EQ(count_required_bits(0b1u), 1ul);
EXPECT_EQ(count_required_bits(0b10u), 2ul);
EXPECT_EQ(count_required_bits(0b11u), 2ul);
EXPECT_EQ(count_required_bits(0b100u), 3ul);
EXPECT_EQ(count_required_bits(0b111u), 3ul);
EXPECT_EQ(count_required_bits(0b1000u), 4ul);
EXPECT_EQ(count_required_bits(0b1111u), 4ul);
EXPECT_EQ(count_required_bits(NumericLimits<u32>::max()), sizeof(u32) * 8);
}
RANDOMIZED_TEST_CASE(count_leading_zeroes)
{
// count_leading_zeroes(0b000...0001000...000)
// == count_leading_zeroes(0b000...0001___...___) (where _ is 0 or 1)
GEN(e, Gen::number_u64(0, 63));
auto power_of_two = 1ULL << e;
// We add random one-bits below the leftmost (and only) one-bit.
// This shouldn't change the output of count_leading_zeroes because
// the function should only care about the most significant one.
GEN(below, Gen::number_u64(0, power_of_two - 1));
auto n = power_of_two + below;
EXPECT_EQ(count_leading_zeroes(n), count_leading_zeroes(power_of_two));
}
RANDOMIZED_TEST_CASE(count_required_bits)
{
// count_required_bits(n) == log2(n) + 1
// log2(0) is -infinity, we don't care about that
GEN(n, Gen::number_u32(1, NumericLimits<u32>::max()));
size_t expected = AK::log2(static_cast<double>(n)) + 1;
EXPECT_EQ(count_required_bits(n), expected);
}
RANDOMIZED_TEST_CASE(bit_scan_forward_count_trailing_zeroes)
{
// Behaviour for 0 differs, so we skip it.
GEN(n, Gen::number_u32(1, 1 << 31));
EXPECT_EQ(bit_scan_forward(n), count_trailing_zeroes(n) + 1);
}