1 #include <unordered_set>
2 #include <vector>
3 #include <cstdint>
4 
5 #include "benchmark/benchmark.h"
6 #include "GenerateInput.hpp"
7 
8 constexpr std::size_t MAX_STRING_LEN = 8 << 14;
9 
10 // Benchmark when there is no match.
11 static void BM_StringFindNoMatch(benchmark::State &state) {
12   std::string s1(state.range(0), '-');
13   std::string s2(8, '*');
14   while (state.KeepRunning())
15     benchmark::DoNotOptimize(s1.find(s2));
16 }
17 BENCHMARK(BM_StringFindNoMatch)->Range(10, MAX_STRING_LEN);
18 
19 // Benchmark when the string matches first time.
20 static void BM_StringFindAllMatch(benchmark::State &state) {
21   std::string s1(MAX_STRING_LEN, '-');
22   std::string s2(state.range(0), '-');
23   while (state.KeepRunning())
24     benchmark::DoNotOptimize(s1.find(s2));
25 }
26 BENCHMARK(BM_StringFindAllMatch)->Range(1, MAX_STRING_LEN);
27 
28 // Benchmark when the string matches somewhere in the end.
29 static void BM_StringFindMatch1(benchmark::State &state) {
30   std::string s1(MAX_STRING_LEN / 2, '*');
31   s1 += std::string(state.range(0), '-');
32   std::string s2(state.range(0), '-');
33   while (state.KeepRunning())
34     benchmark::DoNotOptimize(s1.find(s2));
35 }
36 BENCHMARK(BM_StringFindMatch1)->Range(1, MAX_STRING_LEN / 4);
37 
38 // Benchmark when the string matches somewhere from middle to the end.
39 static void BM_StringFindMatch2(benchmark::State &state) {
40   std::string s1(MAX_STRING_LEN / 2, '*');
41   s1 += std::string(state.range(0), '-');
42   s1 += std::string(state.range(0), '*');
43   std::string s2(state.range(0), '-');
44   while (state.KeepRunning())
45     benchmark::DoNotOptimize(s1.find(s2));
46 }
47 BENCHMARK(BM_StringFindMatch2)->Range(1, MAX_STRING_LEN / 4);
48 
49 static void BM_StringCtorDefault(benchmark::State &state) {
50   while (state.KeepRunning()) {
51     for (unsigned I=0; I < 1000; ++I) {
52       std::string Default;
53       benchmark::DoNotOptimize(Default.c_str());
54     }
55   }
56 }
57 BENCHMARK(BM_StringCtorDefault);
58 
59 static void BM_StringCtorCStr(benchmark::State &state) {
60   std::string Input = getRandomString(state.range(0));
61   const char *Str = Input.c_str();
62   benchmark::DoNotOptimize(Str);
63   while (state.KeepRunning()) {
64     std::string Tmp(Str);
65     benchmark::DoNotOptimize(Tmp.c_str());
66   }
67 }
68 BENCHMARK(BM_StringCtorCStr)->Arg(1)->Arg(8)->Range(16, MAX_STRING_LEN / 4);
69 
70 BENCHMARK_MAIN();
71