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 <list>
15#include <string>
16#include <vector>
17
18#include <benchmark/benchmark.h>
19#include "../../GenerateInput.h"
20
21int main(int argc, char** argv) {
22 auto std_equal_3leg = [](auto first1, auto last1, auto first2, auto) { return std::equal(first1, last1, first2); };
23 auto std_equal_4leg = [](auto first1, auto last1, auto first2, auto last2) {
24 return std::equal(first1, last1, first2, last2);
25 };
26 auto std_equal_3leg_pred = [](auto first1, auto last1, auto first2, auto) {
27 return std::equal(first1, last1, first2, [](auto x, auto y) {
28 benchmark::DoNotOptimize(x);
29 benchmark::DoNotOptimize(y);
30 return x == y;
31 });
32 };
33 auto std_equal_4leg_pred = [](auto first1, auto last1, auto first2, auto last2) {
34 return std::equal(first1, last1, first2, last2, [](auto x, auto y) {
35 benchmark::DoNotOptimize(x);
36 benchmark::DoNotOptimize(y);
37 return x == y;
38 });
39 };
40 auto ranges_equal_4leg_pred = [](auto first1, auto last1, auto first2, auto last2) {
41 return std::ranges::equal(first1, last1, first2, last2, [](auto x, auto y) {
42 benchmark::DoNotOptimize(x);
43 benchmark::DoNotOptimize(y);
44 return x == y;
45 });
46 };
47
48 // Benchmark {std,ranges}::equal where we determine inequality at the very end (worst case).
49 {
50 auto bm = []<class Container>(std::string name, auto equal) {
51 benchmark::RegisterBenchmark(
52 name,
53 [equal](auto& st) {
54 std::size_t const size = st.range(0);
55 using ValueType = typename Container::value_type;
56 ValueType x = Generate<ValueType>::random();
57 ValueType y = random_different_from({x});
58 Container c1(size, x);
59 Container c2(size, x);
60 c2.back() = y;
61
62 for ([[maybe_unused]] auto _ : st) {
63 benchmark::DoNotOptimize(c1);
64 benchmark::DoNotOptimize(c2);
65 auto result = equal(c1.begin(), c1.end(), c2.begin(), c2.end());
66 benchmark::DoNotOptimize(result);
67 }
68 })
69 ->Arg(8)
70 ->Arg(50) // non power-of-two
71 ->Arg(1024)
72 ->Arg(8192)
73 ->Arg(1 << 20);
74 };
75
76 // std::equal(it, it, it)
77 bm.operator()<std::vector<int>>(name: "std::equal(vector<int>) (it, it, it)", equal: std_equal_3leg);
78 bm.operator()<std::deque<int>>(name: "std::equal(deque<int>) (it, it, it)", equal: std_equal_3leg);
79 bm.operator()<std::list<int>>(name: "std::equal(list<int>) (it, it, it)", equal: std_equal_3leg);
80
81 // std::equal(it, it, it, pred)
82 bm.operator()<std::vector<int>>(name: "std::equal(vector<int>) (it, it, it, pred)", equal: std_equal_3leg_pred);
83 bm.operator()<std::deque<int>>(name: "std::equal(deque<int>) (it, it, it, pred)", equal: std_equal_3leg_pred);
84 bm.operator()<std::list<int>>(name: "std::equal(list<int>) (it, it, it, pred)", equal: std_equal_3leg_pred);
85
86 // {std,ranges}::equal(it, it, it, it)
87 bm.operator()<std::vector<int>>(name: "std::equal(vector<int>) (it, it, it, it)", equal: std_equal_4leg);
88 bm.operator()<std::deque<int>>(name: "std::equal(deque<int>) (it, it, it, it)", equal: std_equal_4leg);
89 bm.operator()<std::list<int>>(name: "std::equal(list<int>) (it, it, it, it)", equal: std_equal_4leg);
90 bm.operator()<std::vector<int>>("rng::equal(vector<int>) (it, it, it, it)", std::ranges::equal);
91 bm.operator()<std::deque<int>>("rng::equal(deque<int>) (it, it, it, it)", std::ranges::equal);
92 bm.operator()<std::list<int>>("rng::equal(list<int>) (it, it, it, it)", std::ranges::equal);
93
94 // {std,ranges}::equal(it, it, it, it, pred)
95 bm.operator()<std::vector<int>>(name: "std::equal(vector<int>) (it, it, it, it, pred)", equal: std_equal_4leg_pred);
96 bm.operator()<std::deque<int>>(name: "std::equal(deque<int>) (it, it, it, it, pred)", equal: std_equal_4leg_pred);
97 bm.operator()<std::list<int>>(name: "std::equal(list<int>) (it, it, it, it, pred)", equal: std_equal_4leg_pred);
98 bm.operator()<std::vector<int>>(name: "rng::equal(vector<int>) (it, it, it, it, pred)", equal: ranges_equal_4leg_pred);
99 bm.operator()<std::deque<int>>(name: "rng::equal(deque<int>) (it, it, it, it, pred)", equal: ranges_equal_4leg_pred);
100 bm.operator()<std::list<int>>(name: "rng::equal(list<int>) (it, it, it, it, pred)", equal: ranges_equal_4leg_pred);
101 }
102
103 // Benchmark {std,ranges}::equal on vector<bool>.
104 {
105 auto bm = [](std::string name, auto equal, bool aligned) {
106 benchmark::RegisterBenchmark(
107 name,
108 [=](auto& st) {
109 std::size_t const size = st.range();
110 std::vector<bool> c1(size, true);
111 std::vector<bool> c2(size + 8, true);
112 auto first1 = c1.begin();
113 auto last1 = c1.end();
114 auto first2 = aligned ? c2.begin() : c2.begin() + 4;
115 auto last2 = aligned ? c2.end() : c2.end() - 4;
116 for ([[maybe_unused]] auto _ : st) {
117 benchmark::DoNotOptimize(c1);
118 benchmark::DoNotOptimize(c2);
119 auto result = equal(first1, last1, first2, last2);
120 benchmark::DoNotOptimize(result);
121 }
122 })
123 ->Arg(8)
124 ->Arg(50) // non power-of-two
125 ->Arg(1024)
126 ->Arg(8192)
127 ->Arg(1 << 20);
128 };
129
130 // {std,ranges}::equal(vector<bool>) (aligned)
131 bm("std::equal(vector<bool>) (aligned)", std_equal_4leg, true);
132 bm("rng::equal(vector<bool>) (aligned)", std::ranges::equal, true);
133
134 // {std,ranges}::equal(vector<bool>) (unaligned)
135 bm("std::equal(vector<bool>) (unaligned)", std_equal_4leg, false);
136 bm("rng::equal(vector<bool>) (unaligned)", std::ranges::equal, false);
137 }
138
139 benchmark::Initialize(&argc, argv);
140 benchmark::RunSpecifiedBenchmarks();
141 benchmark::Shutdown();
142 return 0;
143}
144

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