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// Copyright (C) 2015-2025 Jonathan Müller and foonathan/memory contributors
// SPDX-License-Identifier: Zlib
#include <foonathan/memory/detail/ilog2.hpp>
#include <doctest/doctest.h>
using namespace foonathan::memory;
using namespace detail;
TEST_CASE("detail::ilog2()")
{
// Check everything up to 2^16.
for (std::size_t i = 0; i != 16; ++i)
{
auto power = 1u << i;
auto next_power = 2 * power;
for (auto x = power; x != next_power; ++x)
CHECK(ilog2(x) == i);
}
// Check some higher values.
CHECK(ilog2(std::uint64_t(1) << 32) == 32);
CHECK(ilog2((std::uint64_t(1) << 32) + 44) == 32);
CHECK(ilog2((std::uint64_t(1) << 32) + 2048) == 32);
CHECK(ilog2(std::uint64_t(1) << 48) == 48);
CHECK(ilog2((std::uint64_t(1) << 48) + 44) == 48);
CHECK(ilog2((std::uint64_t(1) << 48) + 2048) == 48);
CHECK(ilog2(std::uint64_t(1) << 63) == 63);
CHECK(ilog2((std::uint64_t(1) << 63) + 44) == 63);
CHECK(ilog2((std::uint64_t(1) << 63) + 2063) == 63);
}
TEST_CASE("detail::ilog2_ceil()")
{
// Check everything up to 2^16.
for (std::size_t i = 0; i != 16; ++i)
{
auto power = 1u << i;
CHECK(ilog2_ceil(power) == i);
auto next_power = 2 * power;
for (auto x = power + 1; x != next_power; ++x)
CHECK(ilog2_ceil(x) == i + 1);
}
// Check some higher values.
CHECK(ilog2_ceil(std::uint64_t(1) << 32) == 32);
CHECK(ilog2_ceil((std::uint64_t(1) << 32) + 44) == 33);
CHECK(ilog2_ceil((std::uint64_t(1) << 32) + 2048) == 33);
CHECK(ilog2_ceil(std::uint64_t(1) << 48) == 48);
CHECK(ilog2_ceil((std::uint64_t(1) << 48) + 44) == 49);
CHECK(ilog2_ceil((std::uint64_t(1) << 48) + 2048) == 49);
CHECK(ilog2_ceil(std::uint64_t(1) << 63) == 63);
CHECK(ilog2_ceil((std::uint64_t(1) << 63) + 44) == 64);
CHECK(ilog2_ceil((std::uint64_t(1) << 63) + 2063) == 64);
}
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