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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14, c++17
#include <algorithm>
#include <cstddef>
#include <deque>
#include <iterator>
#include <ranges>
#include <vector>
#include <benchmark/benchmark.h>
int main(int argc, char** argv) {
auto std_distance = [](auto first, auto last) { return std::distance(first, last); };
// {std,ranges}::distance(std::deque)
{
auto bm = [](std::string name, auto distance) {
benchmark::RegisterBenchmark(
name,
[distance](auto& st) {
std::size_t const size = st.range(0);
std::deque<int> c(size, 1);
for ([[maybe_unused]] auto _ : st) {
benchmark::DoNotOptimize(c);
auto result = distance(c.begin(), c.end());
benchmark::DoNotOptimize(result);
}
})
->Arg(50) // non power-of-two
->Arg(1024)
->Arg(4096)
->Arg(8192);
};
bm.operator()("std::distance(deque<int>)", std_distance);
bm.operator()("rng::distance(deque<int>)", std::ranges::distance);
}
// {std,ranges}::distance(std::join_view)
{
auto bm = []<class Container>(std::string name, auto distance, std::size_t seg_size) {
benchmark::RegisterBenchmark(
name,
[distance, seg_size](auto& st) {
std::size_t const size = st.range(0);
std::size_t const segments = (size + seg_size - 1) / seg_size;
Container c(segments);
for (std::size_t i = 0, n = size; i < segments; ++i, n -= seg_size) {
c[i].resize(std::min(seg_size, n));
}
auto view = c | std::views::join;
auto first = view.begin();
auto last = view.end();
for ([[maybe_unused]] auto _ : st) {
benchmark::DoNotOptimize(c);
auto result = distance(first, last);
benchmark::DoNotOptimize(result);
}
})
->Arg(50) // non power-of-two
->Arg(1024)
->Arg(4096)
->Arg(8192);
};
bm.operator()<std::vector<std::vector<int>>>("std::distance(join_view(vector<vector<int>>))", std_distance, 256);
bm.operator()<std::vector<std::vector<int>>>(
"rng::distance(join_view(vector<vector<int>>)", std::ranges::distance, 256);
}
benchmark::Initialize(&argc, argv);
benchmark::RunSpecifiedBenchmarks();
benchmark::Shutdown();
return 0;
}
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