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// SPDX-FileCopyrightText: 2006-2025 Knut Reinert & Freie Universität Berlin
// SPDX-FileCopyrightText: 2016-2025 Knut Reinert & MPI für molekulare Genetik
// SPDX-License-Identifier: BSD-3-Clause
#include <benchmark/benchmark.h>
#include <bit>
#include <cstdlib>
template <typename size_type>
static void is_power_of_two_popcount(benchmark::State & state)
{
std::srand(0);
size_type n = 0;
for (auto _ : state)
{
n = std::rand();
if constexpr (std::is_same_v<size_type, unsigned long long>)
{
bool result = __builtin_popcountll(n) == 1;
benchmark::DoNotOptimize(result);
}
else if constexpr (std::is_same_v<size_type, unsigned long>)
{
bool result = __builtin_popcountl(n) == 1;
benchmark::DoNotOptimize(result);
}
else if constexpr (std::is_same_v<size_type, unsigned>)
{
bool result = __builtin_popcount(n) == 1;
benchmark::DoNotOptimize(result);
}
else
static_assert(std::is_same_v<size_type, void>, "FAILED");
}
}
BENCHMARK_TEMPLATE(is_power_of_two_popcount, unsigned);
BENCHMARK_TEMPLATE(is_power_of_two_popcount, unsigned long);
BENCHMARK_TEMPLATE(is_power_of_two_popcount, unsigned long long);
static void is_power_of_two_arithmetic(benchmark::State & state)
{
std::srand(0);
size_t n = 0;
for (auto _ : state)
{
n = std::rand();
bool result = n > 0 && (n & (n - 1)) == 0;
benchmark::DoNotOptimize(result);
}
}
BENCHMARK(is_power_of_two_arithmetic);
static void is_power_of_two_std(benchmark::State & state)
{
std::srand(0);
size_t n = 0;
for (auto _ : state)
{
n = std::rand();
bool result = std::has_single_bit(n);
benchmark::DoNotOptimize(result);
}
}
BENCHMARK(is_power_of_two_std);
static void next_power_of_two_std(benchmark::State & state)
{
std::srand(0);
size_t n = 0;
for (auto _ : state)
{
n = std::rand();
bool result = std::bit_ceil(n);
benchmark::DoNotOptimize(result);
}
}
BENCHMARK(next_power_of_two_std);
BENCHMARK_MAIN();
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