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 <cstddef>
13#include <deque>
14#include <iterator>
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_is_sorted = [](auto first, auto last) { return std::is_sorted(first, last); };
24 auto std_is_sorted_pred = [](auto first, auto last) {
25 return std::is_sorted(first, last, [](auto x, auto y) {
26 benchmark::DoNotOptimize(x);
27 benchmark::DoNotOptimize(y);
28 return x < y;
29 });
30 };
31 auto ranges_is_sorted_pred = [](auto first, auto last) {
32 return std::ranges::is_sorted(first, last, [](auto x, auto y) {
33 benchmark::DoNotOptimize(x);
34 benchmark::DoNotOptimize(y);
35 return x < y;
36 });
37 };
38
39 // Benchmark {std,ranges}::is_sorted on a sorted sequence (the worst case).
40 {
41 auto bm = []<class Container>(std::string name, auto is_sorted) {
42 benchmark::RegisterBenchmark(
43 name,
44 [is_sorted](auto& st) {
45 std::size_t const size = st.range(0);
46 using ValueType = typename Container::value_type;
47 std::vector<ValueType> data;
48 std::generate_n(std::back_inserter(data), size, [] { return Generate<ValueType>::random(); });
49 std::sort(data.begin(), data.end());
50
51 Container c(data.begin(), data.end());
52
53 for ([[maybe_unused]] auto _ : st) {
54 benchmark::DoNotOptimize(c);
55 auto result = is_sorted(c.begin(), c.end());
56 benchmark::DoNotOptimize(result);
57 }
58 })
59 ->Arg(8)
60 ->Arg(1024)
61 ->Arg(8192);
62 };
63 bm.operator()<std::vector<int>>(name: "std::is_sorted(vector<int>)", is_sorted: std_is_sorted);
64 bm.operator()<std::deque<int>>(name: "std::is_sorted(deque<int>)", is_sorted: std_is_sorted);
65 bm.operator()<std::list<int>>(name: "std::is_sorted(list<int>)", is_sorted: std_is_sorted);
66 bm.operator()<std::vector<int>>("rng::is_sorted(vector<int>)", std::ranges::is_sorted);
67 bm.operator()<std::deque<int>>("rng::is_sorted(deque<int>)", std::ranges::is_sorted);
68 bm.operator()<std::list<int>>("rng::is_sorted(list<int>)", std::ranges::is_sorted);
69
70 bm.operator()<std::vector<int>>(name: "std::is_sorted(vector<int>, pred)", is_sorted: std_is_sorted_pred);
71 bm.operator()<std::deque<int>>(name: "std::is_sorted(deque<int>, pred)", is_sorted: std_is_sorted_pred);
72 bm.operator()<std::list<int>>(name: "std::is_sorted(list<int>, pred)", is_sorted: std_is_sorted_pred);
73 bm.operator()<std::vector<int>>(name: "rng::is_sorted(vector<int>, pred)", is_sorted: ranges_is_sorted_pred);
74 bm.operator()<std::deque<int>>(name: "rng::is_sorted(deque<int>, pred)", is_sorted: ranges_is_sorted_pred);
75 bm.operator()<std::list<int>>(name: "rng::is_sorted(list<int>, pred)", is_sorted: ranges_is_sorted_pred);
76 }
77
78 benchmark::Initialize(&argc, argv);
79 benchmark::RunSpecifiedBenchmarks();
80 benchmark::Shutdown();
81 return 0;
82}
83

source code of libcxx/test/benchmarks/algorithms/sorting/is_sorted.bench.cpp