163 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++17, c++2010 11#include <algorithm>12#include <cassert>13#include <cstddef>14#include <deque>15#include <iterator>16#include <list>17#include <vector>18 19#include <benchmark/benchmark.h>20#include "../../GenerateInput.h"21 22int main(int argc, char** argv) {23 // Benchmark ranges::contains_subrange where we never find the needle, which is the24 // worst case.25 {26 auto bm = []<class Container>(std::string name) {27 benchmark::RegisterBenchmark(28 name,29 [](auto& st) {30 std::size_t const size = st.range(0);31 using ValueType = typename Container::value_type;32 ValueType x = Generate<ValueType>::random();33 ValueType y = random_different_from({x});34 Container haystack(size, x);35 std::size_t n = size / 10; // needle size is 10% of the haystack, but we'll never find it36 assert(n > 0);37 Container needle(n, y);38 39 for ([[maybe_unused]] auto _ : st) {40 benchmark::DoNotOptimize(haystack);41 benchmark::DoNotOptimize(needle);42 auto result = std::ranges::contains_subrange(haystack, needle);43 benchmark::DoNotOptimize(result);44 }45 })46 ->Arg(16)47 ->Arg(32)48 ->Arg(50) // non power-of-two49 ->Arg(8192)50 ->Arg(1 << 20);51 };52 bm.operator()<std::vector<int>>("rng::contains_subrange(vector<int>) (process all)");53 bm.operator()<std::deque<int>>("rng::contains_subrange(deque<int>) (process all)");54 bm.operator()<std::list<int>>("rng::contains_subrange(list<int>) (process all)");55 }56 57 // Benchmark ranges::contains_subrange where we intersperse "near matches" inside the haystack.58 {59 auto bm = []<class Container>(std::string name) {60 benchmark::RegisterBenchmark(61 name,62 [](auto& st) {63 std::size_t const size = st.range(0);64 using ValueType = typename Container::value_type;65 ValueType x = Generate<ValueType>::random();66 ValueType y = random_different_from({x});67 Container haystack(size, x);68 std::size_t n = size / 10; // needle size is 10% of the haystack, but we'll never find it69 assert(n > 0);70 Container needle(n, y);71 72 // intersperse near-matches inside the haystack73 {74 auto first = haystack.begin();75 for (int i = 0; i != 10; ++i) {76 first = std::copy_n(needle.begin(), n - 1, first);77 ++first; // this causes the subsequence not to match because it has length n-178 }79 }80 81 for ([[maybe_unused]] auto _ : st) {82 benchmark::DoNotOptimize(haystack);83 benchmark::DoNotOptimize(needle);84 auto result = std::ranges::contains_subrange(haystack, needle);85 benchmark::DoNotOptimize(result);86 }87 })88 ->Arg(1000) // non power-of-two89 ->Arg(1024)90 ->Arg(8192);91 };92 bm.operator()<std::vector<int>>("rng::contains_subrange(vector<int>) (near matches)");93 bm.operator()<std::deque<int>>("rng::contains_subrange(deque<int>) (near matches)");94 bm.operator()<std::list<int>>("rng::contains_subrange(list<int>) (near matches)");95 }96 97 // Special case: the two ranges are the same length (and they are equal, which is the worst case).98 {99 auto bm = []<class Container>(std::string name) {100 benchmark::RegisterBenchmark(101 name,102 [](auto& st) {103 std::size_t const size = st.range(0);104 using ValueType = typename Container::value_type;105 ValueType x = Generate<ValueType>::random();106 Container haystack(size, x);107 Container needle(size, x);108 109 for ([[maybe_unused]] auto _ : st) {110 benchmark::DoNotOptimize(haystack);111 benchmark::DoNotOptimize(needle);112 auto result = std::ranges::contains_subrange(haystack, needle);113 benchmark::DoNotOptimize(result);114 }115 })116 ->Arg(16)117 ->Arg(32)118 ->Arg(50) // non power-of-two119 ->Arg(8192)120 ->Arg(1 << 20);121 };122 bm.operator()<std::vector<int>>("rng::contains_subrange(vector<int>) (same length)");123 bm.operator()<std::deque<int>>("rng::contains_subrange(deque<int>) (same length)");124 bm.operator()<std::list<int>>("rng::contains_subrange(list<int>) (same length)");125 }126 127 // Special case: the needle contains a single element (which we never find, i.e. the worst case).128 {129 auto bm = []<class Container>(std::string name) {130 benchmark::RegisterBenchmark(131 name,132 [](auto& st) {133 std::size_t const size = st.range(0);134 using ValueType = typename Container::value_type;135 ValueType x = Generate<ValueType>::random();136 ValueType y = random_different_from({x});137 Container haystack(size, x);138 Container needle(1, y);139 140 for ([[maybe_unused]] auto _ : st) {141 benchmark::DoNotOptimize(haystack);142 benchmark::DoNotOptimize(needle);143 auto result = std::ranges::contains_subrange(haystack, needle);144 benchmark::DoNotOptimize(result);145 }146 })147 ->Arg(16)148 ->Arg(32)149 ->Arg(50) // non power-of-two150 ->Arg(8192)151 ->Arg(1 << 20);152 };153 bm.operator()<std::vector<int>>("rng::contains_subrange(vector<int>) (single element)");154 bm.operator()<std::deque<int>>("rng::contains_subrange(deque<int>) (single element)");155 bm.operator()<std::list<int>>("rng::contains_subrange(list<int>) (single element)");156 }157 158 benchmark::Initialize(&argc, argv);159 benchmark::RunSpecifiedBenchmarks();160 benchmark::Shutdown();161 return 0;162}163