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#include "test_macros.h"
22
23int main(int argc, char** argv) {
24 auto std_rotate = [](auto first, auto middle, auto last) { return std::rotate(first, middle, last); };
25
26 // Benchmark {std,ranges}::rotate where we rotate various fractions of the range. It is possible to
27 // special-case some of these fractions to cleverly perform swap_ranges.
28 {
29 auto bm = []<class Container>(std::string name, auto rotate, double fraction) {
30 benchmark::RegisterBenchmark(
31 name,
32 [=](auto& st) {
33 std::size_t const size = st.range(0);
34 using ValueType = typename Container::value_type;
35 Container c;
36 std::generate_n(std::back_inserter(c), size, [] { return Generate<ValueType>::random(); });
37
38 auto nth = std::next(c.begin(), static_cast<std::size_t>(size * fraction));
39 for ([[maybe_unused]] auto _ : st) {
40 benchmark::DoNotOptimize(c);
41 auto result = rotate(c.begin(), nth, c.end());
42 benchmark::DoNotOptimize(result);
43 }
44 })
45 ->Arg(32)
46 ->Arg(50) // non power-of-two
47 ->Arg(1024)
48 ->Arg(8192);
49 };
50 bm.operator()<std::vector<int>>("std::rotate(vector<int>) (by 1/4)", std_rotate, 0.25);
51 bm.operator()<std::deque<int>>("std::rotate(deque<int>) (by 1/4)", std_rotate, 0.25);
52 bm.operator()<std::list<int>>("std::rotate(list<int>) (by 1/4)", std_rotate, 0.25);
53 bm.operator()<std::vector<int>>("rng::rotate(vector<int>) (by 1/4)", std::ranges::rotate, 0.25);
54 bm.operator()<std::deque<int>>("rng::rotate(deque<int>) (by 1/4)", std::ranges::rotate, 0.25);
55 bm.operator()<std::list<int>>("rng::rotate(list<int>) (by 1/4)", std::ranges::rotate, 0.25);
56
57 bm.operator()<std::vector<int>>("std::rotate(vector<int>) (by 1/3)", std_rotate, 0.33);
58 bm.operator()<std::deque<int>>("std::rotate(deque<int>) (by 1/3)", std_rotate, 0.33);
59 bm.operator()<std::list<int>>("std::rotate(list<int>) (by 1/3)", std_rotate, 0.33);
60 bm.operator()<std::vector<int>>("rng::rotate(vector<int>) (by 1/3)", std::ranges::rotate, 0.33);
61 bm.operator()<std::deque<int>>("rng::rotate(deque<int>) (by 1/3)", std::ranges::rotate, 0.33);
62 bm.operator()<std::list<int>>("rng::rotate(list<int>) (by 1/3)", std::ranges::rotate, 0.33);
63
64 bm.operator()<std::vector<int>>("std::rotate(vector<int>) (by 1/2)", std_rotate, 0.50);
65 bm.operator()<std::deque<int>>("std::rotate(deque<int>) (by 1/2)", std_rotate, 0.50);
66 bm.operator()<std::list<int>>("std::rotate(list<int>) (by 1/2)", std_rotate, 0.50);
67 bm.operator()<std::vector<int>>("rng::rotate(vector<int>) (by 1/2)", std::ranges::rotate, 0.50);
68 bm.operator()<std::deque<int>>("rng::rotate(deque<int>) (by 1/2)", std::ranges::rotate, 0.50);
69 bm.operator()<std::list<int>>("rng::rotate(list<int>) (by 1/2)", std::ranges::rotate, 0.50);
70
71 bm.operator()<std::vector<bool>>("std::rotate(vector<bool>) (by 1/4)", std_rotate, 0.25);
72 bm.operator()<std::vector<bool>>("std::rotate(vector<bool>) (by 1/3)", std_rotate, 0.33);
73 bm.operator()<std::vector<bool>>("std::rotate(vector<bool>) (by 1/2)", std_rotate, 0.50);
74
75#if TEST_STD_VER >= 23 // vector<bool>::iterator is not std::permutable before C++23
76 bm.operator()<std::vector<bool>>("rng::rotate(vector<bool>) (by 1/4)", std::ranges::rotate, 0.25);
77 bm.operator()<std::vector<bool>>("rng::rotate(vector<bool>) (by 1/3)", std::ranges::rotate, 0.33);
78 bm.operator()<std::vector<bool>>("rng::rotate(vector<bool>) (by 1/2)", std::ranges::rotate, 0.50);
79#endif
80 }
81
82 // Benchmark {std,ranges}::rotate where we rotate a single element from the beginning to the end of the range.
83 {
84 auto bm = []<class Container>(std::string name, auto rotate) {
85 benchmark::RegisterBenchmark(
86 name,
87 [rotate](auto& st) {
88 std::size_t const size = st.range(0);
89 using ValueType = typename Container::value_type;
90 Container c;
91 std::generate_n(std::back_inserter(c), size, [] { return Generate<ValueType>::random(); });
92
93 auto pivot = std::next(c.begin());
94 for ([[maybe_unused]] auto _ : st) {
95 benchmark::DoNotOptimize(c);
96 auto result = rotate(c.begin(), pivot, c.end());
97 benchmark::DoNotOptimize(result);
98 }
99 })
100 ->Arg(32)
101 ->Arg(50) // non power-of-two
102 ->Arg(1024)
103 ->Arg(8192);
104 };
105 bm.operator()<std::vector<int>>("std::rotate(vector<int>) (1 element forward)", std_rotate);
106 bm.operator()<std::deque<int>>("std::rotate(deque<int>) (1 element forward)", std_rotate);
107 bm.operator()<std::list<int>>("std::rotate(list<int>) (1 element forward)", std_rotate);
108 bm.operator()<std::vector<int>>("rng::rotate(vector<int>) (1 element forward)", std::ranges::rotate);
109 bm.operator()<std::deque<int>>("rng::rotate(deque<int>) (1 element forward)", std::ranges::rotate);
110 bm.operator()<std::list<int>>("rng::rotate(list<int>) (1 element forward)", std::ranges::rotate);
111
112 bm.operator()<std::vector<bool>>("std::rotate(vector<bool>) (1 element forward)", std_rotate);
113#if TEST_STD_VER >= 23 // vector<bool>::iterator is not std::permutable before C++23
114 bm.operator()<std::vector<bool>>("rng::rotate(vector<bool>) (1 element forward)", std::ranges::rotate);
115#endif
116 }
117
118 // Benchmark {std,ranges}::rotate where we rotate a single element from the end to the beginning of the range.
119 {
120 auto bm = []<class Container>(std::string name, auto rotate) {
121 benchmark::RegisterBenchmark(
122 name,
123 [rotate](auto& st) {
124 std::size_t const size = st.range(0);
125 using ValueType = typename Container::value_type;
126 Container c;
127 std::generate_n(std::back_inserter(c), size, [] { return Generate<ValueType>::random(); });
128
129 auto pivot = std::next(c.begin(), size - 1);
130 for ([[maybe_unused]] auto _ : st) {
131 benchmark::DoNotOptimize(c);
132 auto result = rotate(c.begin(), pivot, c.end());
133 benchmark::DoNotOptimize(result);
134 }
135 })
136 ->Arg(32)
137 ->Arg(50) // non power-of-two
138 ->Arg(1024)
139 ->Arg(8192);
140 };
141 bm.operator()<std::vector<int>>("std::rotate(vector<int>) (1 element backward)", std_rotate);
142 bm.operator()<std::deque<int>>("std::rotate(deque<int>) (1 element backward)", std_rotate);
143 bm.operator()<std::list<int>>("std::rotate(list<int>) (1 element backward)", std_rotate);
144 bm.operator()<std::vector<int>>("rng::rotate(vector<int>) (1 element backward)", std::ranges::rotate);
145 bm.operator()<std::deque<int>>("rng::rotate(deque<int>) (1 element backward)", std::ranges::rotate);
146 bm.operator()<std::list<int>>("rng::rotate(list<int>) (1 element backward)", std::ranges::rotate);
147
148 bm.operator()<std::vector<bool>>("std::rotate(vector<bool>) (1 element backward)", std_rotate);
149#if TEST_STD_VER >= 23 // vector<bool>::iterator is not std::permutable before C++23
150 bm.operator()<std::vector<bool>>("rng::rotate(vector<bool>) (1 element backward)", std::ranges::rotate);
151#endif
152 }
153
154 benchmark::Initialize(&argc, argv);
155 benchmark::RunSpecifiedBenchmarks();
156 benchmark::Shutdown();
157 return 0;
158}
159

source code of libcxx/test/benchmarks/algorithms/modifying/rotate.bench.cpp