89 lines · cpp
1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9// UNSUPPORTED: c++03, c++11, c++14, c++1710 11#include <algorithm>12#include <cassert>13#include <cstddef>14#include <deque>15#include <list>16#include <string>17#include <vector>18 19#include <benchmark/benchmark.h>20#include "../../GenerateInput.h"21 22int main(int argc, char** argv) {23 auto std_search_n = [](auto first, auto last, auto n, auto const& value) {24 return std::search_n(first, last, n, value);25 };26 auto std_search_n_pred = [](auto first, auto last, auto n, auto const& value) {27 return std::search_n(first, last, n, value, [](auto x, auto y) {28 benchmark::DoNotOptimize(x);29 benchmark::DoNotOptimize(y);30 return x == y;31 });32 };33 auto ranges_search_n_pred = [](auto first, auto last, auto n, auto const& value) {34 return std::ranges::search_n(first, last, n, value, [](auto x, auto y) {35 benchmark::DoNotOptimize(x);36 benchmark::DoNotOptimize(y);37 return x == y;38 });39 };40 41 // Benchmark {std,ranges}::search_n where the needle is never found (worst case).42 {43 auto bm = []<class Container>(std::string name, auto search_n) {44 benchmark::RegisterBenchmark(45 name,46 [search_n](auto& st) {47 std::size_t const size = st.range(0);48 using ValueType = typename Container::value_type;49 ValueType x = Generate<ValueType>::random();50 ValueType y = random_different_from({x});51 Container haystack(size, x);52 std::size_t n = size / 10; // needle size is 10% of the haystack53 54 for ([[maybe_unused]] auto _ : st) {55 benchmark::DoNotOptimize(haystack);56 benchmark::DoNotOptimize(n);57 benchmark::DoNotOptimize(y);58 auto result = search_n(haystack.begin(), haystack.end(), n, y);59 benchmark::DoNotOptimize(result);60 }61 })62 ->Arg(1000) // non power-of-two63 ->Arg(1024)64 ->Arg(8192)65 ->Arg(1 << 20);66 };67 // {std,ranges}::search_n68 bm.operator()<std::vector<int>>("std::search_n(vector<int>) (no match)", std_search_n);69 bm.operator()<std::deque<int>>("std::search_n(deque<int>) (no match)", std_search_n);70 bm.operator()<std::list<int>>("std::search_n(list<int>) (no match)", std_search_n);71 bm.operator()<std::vector<int>>("rng::search_n(vector<int>) (no match)", std::ranges::search_n);72 bm.operator()<std::deque<int>>("rng::search_n(deque<int>) (no match)", std::ranges::search_n);73 bm.operator()<std::list<int>>("rng::search_n(list<int>) (no match)", std::ranges::search_n);74 75 // {std,ranges}::search_n(pred)76 bm.operator()<std::vector<int>>("std::search_n(vector<int>, pred) (no match)", std_search_n_pred);77 bm.operator()<std::deque<int>>("std::search_n(deque<int>, pred) (no match)", std_search_n_pred);78 bm.operator()<std::list<int>>("std::search_n(list<int>, pred) (no match)", std_search_n_pred);79 bm.operator()<std::vector<int>>("rng::search_n(vector<int>, pred) (no match)", ranges_search_n_pred);80 bm.operator()<std::deque<int>>("rng::search_n(deque<int>, pred) (no match)", ranges_search_n_pred);81 bm.operator()<std::list<int>>("rng::search_n(list<int>, pred) (no match)", ranges_search_n_pred);82 }83 84 benchmark::Initialize(&argc, argv);85 benchmark::RunSpecifiedBenchmarks();86 benchmark::Shutdown();87 return 0;88}89