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-exception
6//
7//===----------------------------------------------------------------------===//
8
9// UNSUPPORTED: c++03, c++11, c++14, c++17
10
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 = [](auto first1, auto last1, auto first2, auto last2) {
24 return std::search(first1, last1, first2, last2);
25 };
26 auto std_search_pred = [](auto first1, auto last1, auto first2, auto last2) {
27 return std::search(first1, last1, first2, last2, [](auto x, auto y) {
28 benchmark::DoNotOptimize(x);
29 benchmark::DoNotOptimize(y);
30 return x == y;
31 });
32 };
33 auto ranges_search_pred = [](auto first1, auto last1, auto first2, auto last2) {
34 return std::ranges::search(first1, last1, first2, last2, [](auto x, auto y) {
35 benchmark::DoNotOptimize(x);
36 benchmark::DoNotOptimize(y);
37 return x == y;
38 });
39 };
40
41 // Benchmark {std,ranges}::search where the needle is never found (worst case).
42 {
43 auto bm = []<class Container>(std::string name, auto search) {
44 benchmark::RegisterBenchmark(
45 name,
46 [search](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 Container needle(size / 10, y); // needle size is 10% of the haystack
53
54 for ([[maybe_unused]] auto _ : st) {
55 benchmark::DoNotOptimize(haystack);
56 benchmark::DoNotOptimize(needle);
57 auto result = search(haystack.begin(), haystack.end(), needle.begin(), needle.end());
58 benchmark::DoNotOptimize(result);
59 }
60 })
61 ->Arg(1000) // non power-of-two
62 ->Arg(1024)
63 ->Arg(8192)
64 ->Arg(1 << 20);
65 };
66 // {std,ranges}::search
67 bm.operator()<std::vector<int>>(name: "std::search(vector<int>) (no match)", search: std_search);
68 bm.operator()<std::deque<int>>(name: "std::search(deque<int>) (no match)", search: std_search);
69 bm.operator()<std::list<int>>(name: "std::search(list<int>) (no match)", search: std_search);
70 bm.operator()<std::vector<int>>("rng::search(vector<int>) (no match)", std::ranges::search);
71 bm.operator()<std::deque<int>>("rng::search(deque<int>) (no match)", std::ranges::search);
72 bm.operator()<std::list<int>>("rng::search(list<int>) (no match)", std::ranges::search);
73
74 // {std,ranges}::search(pred)
75 bm.operator()<std::vector<int>>(name: "std::search(vector<int>, pred) (no match)", search: std_search_pred);
76 bm.operator()<std::deque<int>>(name: "std::search(deque<int>, pred) (no match)", search: std_search_pred);
77 bm.operator()<std::list<int>>(name: "std::search(list<int>, pred) (no match)", search: std_search_pred);
78 bm.operator()<std::vector<int>>(name: "rng::search(vector<int>, pred) (no match)", search: ranges_search_pred);
79 bm.operator()<std::deque<int>>(name: "rng::search(deque<int>, pred) (no match)", search: ranges_search_pred);
80 bm.operator()<std::list<int>>(name: "rng::search(list<int>, pred) (no match)", search: ranges_search_pred);
81 }
82
83 // Benchmark {std,ranges}::search where we intersperse "near matches" inside the haystack.
84 {
85 auto bm = []<class Container>(std::string name, auto search) {
86 benchmark::RegisterBenchmark(
87 name,
88 [search](auto& st) {
89 std::size_t const size = st.range(0);
90 using ValueType = typename Container::value_type;
91 ValueType x = Generate<ValueType>::random();
92 ValueType y = random_different_from({x});
93 Container haystack(size, x);
94 std::size_t n = size / 10; // needle size is 10% of the haystack
95 assert(n > 0);
96 Container needle(n, y);
97
98 // intersperse near-matches inside the haystack
99 {
100 auto first = haystack.begin();
101 for (int i = 0; i != 10; ++i) {
102 first = std::copy_n(needle.begin(), n - 1, first);
103 ++first; // this causes the subsequence not to match because it has length n-1
104 }
105 }
106
107 for ([[maybe_unused]] auto _ : st) {
108 benchmark::DoNotOptimize(haystack);
109 benchmark::DoNotOptimize(needle);
110 auto result = search(haystack.begin(), haystack.end(), needle.begin(), needle.end());
111 benchmark::DoNotOptimize(result);
112 }
113 })
114 ->Arg(1000) // non power-of-two
115 ->Arg(1024)
116 ->Arg(8192);
117 };
118 // {std,ranges}::search
119 bm.operator()<std::vector<int>>(name: "std::search(vector<int>) (near matches)", search: std_search);
120 bm.operator()<std::deque<int>>(name: "std::search(deque<int>) (near matches)", search: std_search);
121 bm.operator()<std::list<int>>(name: "std::search(list<int>) (near matches)", search: std_search);
122 bm.operator()<std::vector<int>>("rng::search(vector<int>) (near matches)", std::ranges::search);
123 bm.operator()<std::deque<int>>("rng::search(deque<int>) (near matches)", std::ranges::search);
124 bm.operator()<std::list<int>>("rng::search(list<int>) (near matches)", std::ranges::search);
125
126 // {std,ranges}::search(pred)
127 bm.operator()<std::vector<int>>(name: "std::search(vector<int>, pred) (near matches)", search: std_search_pred);
128 bm.operator()<std::deque<int>>(name: "std::search(deque<int>, pred) (near matches)", search: std_search_pred);
129 bm.operator()<std::list<int>>(name: "std::search(list<int>, pred) (near matches)", search: std_search_pred);
130 bm.operator()<std::vector<int>>(name: "rng::search(vector<int>, pred) (near matches)", search: ranges_search_pred);
131 bm.operator()<std::deque<int>>(name: "rng::search(deque<int>, pred) (near matches)", search: ranges_search_pred);
132 bm.operator()<std::list<int>>(name: "rng::search(list<int>, pred) (near matches)", search: ranges_search_pred);
133 }
134
135 // Special case: the two ranges are the same length (and they are equal, which is the worst case).
136 {
137 auto bm = []<class Container>(std::string name, auto search) {
138 benchmark::RegisterBenchmark(
139 name,
140 [search](auto& st) {
141 std::size_t const size = st.range(0);
142 using ValueType = typename Container::value_type;
143 ValueType x = Generate<ValueType>::random();
144 Container haystack(size, x);
145 Container needle(size, x);
146
147 for ([[maybe_unused]] auto _ : st) {
148 benchmark::DoNotOptimize(haystack);
149 benchmark::DoNotOptimize(needle);
150 auto result = search(haystack.begin(), haystack.end(), needle.begin(), needle.end());
151 benchmark::DoNotOptimize(result);
152 }
153 })
154 ->Arg(1000) // non power-of-two
155 ->Arg(1024)
156 ->Arg(8192);
157 };
158 // {std,ranges}::search
159 bm.operator()<std::vector<int>>(name: "std::search(vector<int>) (same length)", search: std_search);
160 bm.operator()<std::deque<int>>(name: "std::search(deque<int>) (same length)", search: std_search);
161 bm.operator()<std::list<int>>(name: "std::search(list<int>) (same length)", search: std_search);
162 bm.operator()<std::vector<int>>("rng::search(vector<int>) (same length)", std::ranges::search);
163 bm.operator()<std::deque<int>>("rng::search(deque<int>) (same length)", std::ranges::search);
164 bm.operator()<std::list<int>>("rng::search(list<int>) (same length)", std::ranges::search);
165
166 // {std,ranges}::search(pred)
167 bm.operator()<std::vector<int>>(name: "std::search(vector<int>, pred) (same length)", search: std_search_pred);
168 bm.operator()<std::deque<int>>(name: "std::search(deque<int>, pred) (same length)", search: std_search_pred);
169 bm.operator()<std::list<int>>(name: "std::search(list<int>, pred) (same length)", search: std_search_pred);
170 bm.operator()<std::vector<int>>(name: "rng::search(vector<int>, pred) (same length)", search: ranges_search_pred);
171 bm.operator()<std::deque<int>>(name: "rng::search(deque<int>, pred) (same length)", search: ranges_search_pred);
172 bm.operator()<std::list<int>>(name: "rng::search(list<int>, pred) (same length)", search: ranges_search_pred);
173 }
174
175 // Special case: the needle contains a single element (which we never find, i.e. the worst case).
176 {
177 auto bm = []<class Container>(std::string name, auto search) {
178 benchmark::RegisterBenchmark(
179 name,
180 [search](auto& st) {
181 std::size_t const size = st.range(0);
182 using ValueType = typename Container::value_type;
183 ValueType x = Generate<ValueType>::random();
184 ValueType y = random_different_from({x});
185 Container haystack(size, x);
186 Container needle(1, y);
187
188 for ([[maybe_unused]] auto _ : st) {
189 benchmark::DoNotOptimize(haystack);
190 benchmark::DoNotOptimize(needle);
191 auto result = search(haystack.begin(), haystack.end(), needle.begin(), needle.end());
192 benchmark::DoNotOptimize(result);
193 }
194 })
195 ->Arg(1000) // non power-of-two
196 ->Arg(1024)
197 ->Arg(8192);
198 };
199 // {std,ranges}::search
200 bm.operator()<std::vector<int>>(name: "std::search(vector<int>) (single element)", search: std_search);
201 bm.operator()<std::deque<int>>(name: "std::search(deque<int>) (single element)", search: std_search);
202 bm.operator()<std::list<int>>(name: "std::search(list<int>) (single element)", search: std_search);
203 bm.operator()<std::vector<int>>("rng::search(vector<int>) (single element)", std::ranges::search);
204 bm.operator()<std::deque<int>>("rng::search(deque<int>) (single element)", std::ranges::search);
205 bm.operator()<std::list<int>>("rng::search(list<int>) (single element)", std::ranges::search);
206
207 // {std,ranges}::search(pred)
208 bm.operator()<std::vector<int>>(name: "std::search(vector<int>, pred) (single element)", search: std_search_pred);
209 bm.operator()<std::deque<int>>(name: "std::search(deque<int>, pred) (single element)", search: std_search_pred);
210 bm.operator()<std::list<int>>(name: "std::search(list<int>, pred) (single element)", search: std_search_pred);
211 bm.operator()<std::vector<int>>(name: "rng::search(vector<int>, pred) (single element)", search: ranges_search_pred);
212 bm.operator()<std::deque<int>>(name: "rng::search(deque<int>, pred) (single element)", search: ranges_search_pred);
213 bm.operator()<std::list<int>>(name: "rng::search(list<int>, pred) (single element)", search: ranges_search_pred);
214 }
215
216 benchmark::Initialize(&argc, argv);
217 benchmark::RunSpecifiedBenchmarks();
218 benchmark::Shutdown();
219 return 0;
220}
221

source code of libcxx/test/benchmarks/algorithms/nonmodifying/search.bench.cpp