1 #include "benchmark/benchmark.h"
2
3 #include <assert.h>
4 #include <math.h>
5 #include <stdint.h>
6
7 #include <chrono>
8 #include <cstdlib>
9 #include <iostream>
10 #include <limits>
11 #include <list>
12 #include <map>
13 #include <mutex>
14 #include <set>
15 #include <sstream>
16 #include <string>
17 #include <thread>
18 #include <utility>
19 #include <vector>
20
21 #if defined(__GNUC__)
22 #define BENCHMARK_NOINLINE __attribute__((noinline))
23 #else
24 #define BENCHMARK_NOINLINE
25 #endif
26
27 namespace {
28
Factorial(uint32_t n)29 int BENCHMARK_NOINLINE Factorial(uint32_t n) {
30 return (n == 1) ? 1 : n * Factorial(n - 1);
31 }
32
CalculatePi(int depth)33 double CalculatePi(int depth) {
34 double pi = 0.0;
35 for (int i = 0; i < depth; ++i) {
36 double numerator = static_cast<double>(((i % 2) * 2) - 1);
37 double denominator = static_cast<double>((2 * i) - 1);
38 pi += numerator / denominator;
39 }
40 return (pi - 1.0) * 4;
41 }
42
ConstructRandomSet(int size)43 std::set<int> ConstructRandomSet(int size) {
44 std::set<int> s;
45 for (int i = 0; i < size; ++i) s.insert(s.end(), i);
46 return s;
47 }
48
49 std::mutex test_vector_mu;
50 std::vector<int>* test_vector = nullptr;
51
52 } // end namespace
53
BM_Factorial(benchmark::State & state)54 static void BM_Factorial(benchmark::State& state) {
55 int fac_42 = 0;
56 for (auto _ : state) fac_42 = Factorial(8);
57 // Prevent compiler optimizations
58 std::stringstream ss;
59 ss << fac_42;
60 state.SetLabel(ss.str());
61 }
62 BENCHMARK(BM_Factorial);
63 BENCHMARK(BM_Factorial)->UseRealTime();
64
BM_CalculatePiRange(benchmark::State & state)65 static void BM_CalculatePiRange(benchmark::State& state) {
66 double pi = 0.0;
67 for (auto _ : state) pi = CalculatePi(state.range(0));
68 std::stringstream ss;
69 ss << pi;
70 state.SetLabel(ss.str());
71 }
72 BENCHMARK_RANGE(BM_CalculatePiRange, 1, 1024 * 1024);
73
BM_CalculatePi(benchmark::State & state)74 static void BM_CalculatePi(benchmark::State& state) {
75 static const int depth = 1024;
76 for (auto _ : state) {
77 benchmark::DoNotOptimize(CalculatePi(depth));
78 }
79 }
80 BENCHMARK(BM_CalculatePi)->Threads(8);
81 BENCHMARK(BM_CalculatePi)->ThreadRange(1, 32);
82 BENCHMARK(BM_CalculatePi)->ThreadPerCpu();
83
BM_SetInsert(benchmark::State & state)84 static void BM_SetInsert(benchmark::State& state) {
85 std::set<int> data;
86 for (auto _ : state) {
87 state.PauseTiming();
88 data = ConstructRandomSet(state.range(0));
89 state.ResumeTiming();
90 for (int j = 0; j < state.range(1); ++j) data.insert(rand());
91 }
92 state.SetItemsProcessed(state.iterations() * state.range(1));
93 state.SetBytesProcessed(state.iterations() * state.range(1) * sizeof(int));
94 }
95
96 // Test many inserts at once to reduce the total iterations needed. Otherwise, the slower,
97 // non-timed part of each iteration will make the benchmark take forever.
98 BENCHMARK(BM_SetInsert)->Ranges({{1 << 10, 8 << 10}, {128, 512}});
99
100 template <typename Container,
101 typename ValueType = typename Container::value_type>
BM_Sequential(benchmark::State & state)102 static void BM_Sequential(benchmark::State& state) {
103 ValueType v = 42;
104 for (auto _ : state) {
105 Container c;
106 for (int i = state.range(0); --i;) c.push_back(v);
107 }
108 const size_t items_processed = state.iterations() * state.range(0);
109 state.SetItemsProcessed(items_processed);
110 state.SetBytesProcessed(items_processed * sizeof(v));
111 }
112 BENCHMARK_TEMPLATE2(BM_Sequential, std::vector<int>, int)
113 ->Range(1 << 0, 1 << 10);
114 BENCHMARK_TEMPLATE(BM_Sequential, std::list<int>)->Range(1 << 0, 1 << 10);
115 // Test the variadic version of BENCHMARK_TEMPLATE in C++11 and beyond.
116 #ifdef BENCHMARK_HAS_CXX11
117 BENCHMARK_TEMPLATE(BM_Sequential, std::vector<int>, int)->Arg(512);
118 #endif
119
BM_StringCompare(benchmark::State & state)120 static void BM_StringCompare(benchmark::State& state) {
121 std::string s1(state.range(0), '-');
122 std::string s2(state.range(0), '-');
123 for (auto _ : state) benchmark::DoNotOptimize(s1.compare(s2));
124 }
125 BENCHMARK(BM_StringCompare)->Range(1, 1 << 20);
126
BM_SetupTeardown(benchmark::State & state)127 static void BM_SetupTeardown(benchmark::State& state) {
128 if (state.thread_index == 0) {
129 // No need to lock test_vector_mu here as this is running single-threaded.
130 test_vector = new std::vector<int>();
131 }
132 int i = 0;
133 for (auto _ : state) {
134 std::lock_guard<std::mutex> l(test_vector_mu);
135 if (i % 2 == 0)
136 test_vector->push_back(i);
137 else
138 test_vector->pop_back();
139 ++i;
140 }
141 if (state.thread_index == 0) {
142 delete test_vector;
143 }
144 }
145 BENCHMARK(BM_SetupTeardown)->ThreadPerCpu();
146
BM_LongTest(benchmark::State & state)147 static void BM_LongTest(benchmark::State& state) {
148 double tracker = 0.0;
149 for (auto _ : state) {
150 for (int i = 0; i < state.range(0); ++i)
151 benchmark::DoNotOptimize(tracker += i);
152 }
153 }
154 BENCHMARK(BM_LongTest)->Range(1 << 16, 1 << 28);
155
BM_ParallelMemset(benchmark::State & state)156 static void BM_ParallelMemset(benchmark::State& state) {
157 int size = state.range(0) / static_cast<int>(sizeof(int));
158 int thread_size = size / state.threads;
159 int from = thread_size * state.thread_index;
160 int to = from + thread_size;
161
162 if (state.thread_index == 0) {
163 test_vector = new std::vector<int>(size);
164 }
165
166 for (auto _ : state) {
167 for (int i = from; i < to; i++) {
168 // No need to lock test_vector_mu as ranges
169 // do not overlap between threads.
170 benchmark::DoNotOptimize(test_vector->at(i) = 1);
171 }
172 }
173
174 if (state.thread_index == 0) {
175 delete test_vector;
176 }
177 }
178 BENCHMARK(BM_ParallelMemset)->Arg(10 << 20)->ThreadRange(1, 4);
179
BM_ManualTiming(benchmark::State & state)180 static void BM_ManualTiming(benchmark::State& state) {
181 size_t slept_for = 0;
182 int microseconds = state.range(0);
183 std::chrono::duration<double, std::micro> sleep_duration{
184 static_cast<double>(microseconds)};
185
186 for (auto _ : state) {
187 auto start = std::chrono::high_resolution_clock::now();
188 // Simulate some useful workload with a sleep
189 std::this_thread::sleep_for(
190 std::chrono::duration_cast<std::chrono::nanoseconds>(sleep_duration));
191 auto end = std::chrono::high_resolution_clock::now();
192
193 auto elapsed =
194 std::chrono::duration_cast<std::chrono::duration<double>>(end - start);
195
196 state.SetIterationTime(elapsed.count());
197 slept_for += microseconds;
198 }
199 state.SetItemsProcessed(slept_for);
200 }
201 BENCHMARK(BM_ManualTiming)->Range(1, 1 << 14)->UseRealTime();
202 BENCHMARK(BM_ManualTiming)->Range(1, 1 << 14)->UseManualTime();
203
204 #ifdef BENCHMARK_HAS_CXX11
205
206 template <class... Args>
BM_with_args(benchmark::State & state,Args &&...)207 void BM_with_args(benchmark::State& state, Args&&...) {
208 for (auto _ : state) {
209 }
210 }
211 BENCHMARK_CAPTURE(BM_with_args, int_test, 42, 43, 44);
212 BENCHMARK_CAPTURE(BM_with_args, string_and_pair_test, std::string("abc"),
213 std::pair<int, double>(42, 3.8));
214
BM_non_template_args(benchmark::State & state,int,double)215 void BM_non_template_args(benchmark::State& state, int, double) {
216 while(state.KeepRunning()) {}
217 }
218 BENCHMARK_CAPTURE(BM_non_template_args, basic_test, 0, 0);
219
220 #endif // BENCHMARK_HAS_CXX11
221
BM_DenseThreadRanges(benchmark::State & st)222 static void BM_DenseThreadRanges(benchmark::State& st) {
223 switch (st.range(0)) {
224 case 1:
225 assert(st.threads == 1 || st.threads == 2 || st.threads == 3);
226 break;
227 case 2:
228 assert(st.threads == 1 || st.threads == 3 || st.threads == 4);
229 break;
230 case 3:
231 assert(st.threads == 5 || st.threads == 8 || st.threads == 11 ||
232 st.threads == 14);
233 break;
234 default:
235 assert(false && "Invalid test case number");
236 }
237 while (st.KeepRunning()) {
238 }
239 }
240 BENCHMARK(BM_DenseThreadRanges)->Arg(1)->DenseThreadRange(1, 3);
241 BENCHMARK(BM_DenseThreadRanges)->Arg(2)->DenseThreadRange(1, 4, 2);
242 BENCHMARK(BM_DenseThreadRanges)->Arg(3)->DenseThreadRange(5, 14, 3);
243
244 BENCHMARK_MAIN();
245