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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 <cassert>
#include <cstddef>
#include <deque>
#include <list>
#include <string>
#include <vector>
#include <benchmark/benchmark.h>
#include "../../GenerateInput.h"
int main(int argc, char** argv) {
auto std_search_n = [](auto first, auto last, auto n, auto const& value) {
return std::search_n(first, last, n, value);
};
auto std_search_n_pred = [](auto first, auto last, auto n, auto const& value) {
return std::search_n(first, last, n, value, [](auto x, auto y) {
benchmark::DoNotOptimize(x);
benchmark::DoNotOptimize(y);
return x == y;
});
};
auto ranges_search_n_pred = [](auto first, auto last, auto n, auto const& value) {
return std::ranges::search_n(first, last, n, value, [](auto x, auto y) {
benchmark::DoNotOptimize(x);
benchmark::DoNotOptimize(y);
return x == y;
});
};
// Benchmark {std,ranges}::search_n where the needle is never found (worst case).
{
auto bm = []<class Container>(std::string name, auto search_n) {
benchmark::RegisterBenchmark(
name,
[search_n](auto& st) {
std::size_t const size = st.range(0);
using ValueType = typename Container::value_type;
ValueType x = Generate<ValueType>::random();
ValueType y = random_different_from({x});
Container haystack(size, x);
std::size_t n = size / 10; // needle size is 10% of the haystack
for ([[maybe_unused]] auto _ : st) {
benchmark::DoNotOptimize(haystack);
benchmark::DoNotOptimize(n);
benchmark::DoNotOptimize(y);
auto result = search_n(haystack.begin(), haystack.end(), n, y);
benchmark::DoNotOptimize(result);
}
})
->Arg(1000) // non power-of-two
->Arg(1024)
->Arg(8192)
->Arg(1 << 20);
};
// {std,ranges}::search_n
bm.operator()<std::vector<int>>("std::search_n(vector<int>) (no match)", std_search_n);
bm.operator()<std::deque<int>>("std::search_n(deque<int>) (no match)", std_search_n);
bm.operator()<std::list<int>>("std::search_n(list<int>) (no match)", std_search_n);
bm.operator()<std::vector<int>>("rng::search_n(vector<int>) (no match)", std::ranges::search_n);
bm.operator()<std::deque<int>>("rng::search_n(deque<int>) (no match)", std::ranges::search_n);
bm.operator()<std::list<int>>("rng::search_n(list<int>) (no match)", std::ranges::search_n);
// {std,ranges}::search_n(pred)
bm.operator()<std::vector<int>>("std::search_n(vector<int>, pred) (no match)", std_search_n_pred);
bm.operator()<std::deque<int>>("std::search_n(deque<int>, pred) (no match)", std_search_n_pred);
bm.operator()<std::list<int>>("std::search_n(list<int>, pred) (no match)", std_search_n_pred);
bm.operator()<std::vector<int>>("rng::search_n(vector<int>, pred) (no match)", ranges_search_n_pred);
bm.operator()<std::deque<int>>("rng::search_n(deque<int>, pred) (no match)", ranges_search_n_pred);
bm.operator()<std::list<int>>("rng::search_n(list<int>, pred) (no match)", ranges_search_n_pred);
}
benchmark::Initialize(&argc, argv);
benchmark::RunSpecifiedBenchmarks();
benchmark::Shutdown();
return 0;
}
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