benchmark/test/complexity_test.cc
2016-05-21 11:51:42 +02:00

99 lines
3.3 KiB
C++

#include "benchmark/benchmark_api.h"
#include <string>
#include <vector>
#include <map>
#include <algorithm>
std::vector<int> ConstructRandomVector(int size) {
std::vector<int> v;
v.reserve(size);
for (int i = 0; i < size; ++i) {
v.push_back(rand() % size);
}
return v;
}
std::map<int, int> ConstructRandomMap(int size) {
std::map<int, int> m;
for (int i = 0; i < size; ++i) {
m.insert(std::make_pair(rand() % size, rand() % size));
}
return m;
}
void BM_Complexity_O1(benchmark::State& state) {
while (state.KeepRunning()) {
}
}
BENCHMARK(BM_Complexity_O1) -> Range(1, 1<<18) -> Complexity(benchmark::O_1);
static void BM_Complexity_O_N(benchmark::State& state) {
auto v = ConstructRandomVector(state.range_x());
const int itemNotInVector = state.range_x()*2; // Test worst case scenario (item not in vector)
while (state.KeepRunning()) {
benchmark::DoNotOptimize(std::find(v.begin(), v.end(), itemNotInVector));
}
}
BENCHMARK(BM_Complexity_O_N) -> RangeMultiplier(2) -> Range(1<<10, 1<<16) -> Complexity(benchmark::O_N);
BENCHMARK(BM_Complexity_O_N) -> RangeMultiplier(2) -> Range(1<<10, 1<<16) -> Complexity(benchmark::O_Auto);
static void BM_Complexity_O_N_Squared(benchmark::State& state) {
std::string s1(state.range_x(), '-');
std::string s2(state.range_x(), '-');
while (state.KeepRunning())
for(char& c1 : s1) {
for(char& c2 : s2) {
benchmark::DoNotOptimize(c1 = 'a');
benchmark::DoNotOptimize(c2 = 'b');
}
}
}
BENCHMARK(BM_Complexity_O_N_Squared) -> Range(1, 1<<8) -> Complexity(benchmark::O_N_Squared);
static void BM_Complexity_O_N_Cubed(benchmark::State& state) {
std::string s1(state.range_x(), '-');
std::string s2(state.range_x(), '-');
std::string s3(state.range_x(), '-');
while (state.KeepRunning())
for(char& c1 : s1) {
for(char& c2 : s2) {
for(char& c3 : s3) {
benchmark::DoNotOptimize(c1 = 'a');
benchmark::DoNotOptimize(c2 = 'b');
benchmark::DoNotOptimize(c3 = 'c');
}
}
}
}
BENCHMARK(BM_Complexity_O_N_Cubed) -> DenseRange(1, 8) -> Complexity(benchmark::O_N_Cubed);
static void BM_Complexity_O_log_N(benchmark::State& state) {
auto m = ConstructRandomMap(state.range_x());
const int itemNotInVector = state.range_x()*2; // Test worst case scenario (item not in vector)
while (state.KeepRunning()) {
benchmark::DoNotOptimize(m.find(itemNotInVector));
}
}
BENCHMARK(BM_Complexity_O_log_N)
-> RangeMultiplier(2) -> Range(1<<10, 1<<16) -> Complexity(benchmark::O_log_N);
static void BM_Complexity_O_N_log_N(benchmark::State& state) {
auto v = ConstructRandomVector(state.range_x());
while (state.KeepRunning()) {
std::sort(v.begin(), v.end());
}
}
BENCHMARK(BM_Complexity_O_N_log_N) -> RangeMultiplier(2) -> Range(1<<10, 1<<16) -> Complexity(benchmark::O_N_log_N);
BENCHMARK(BM_Complexity_O_N_log_N) -> RangeMultiplier(2) -> Range(1<<10, 1<<16) -> Complexity(benchmark::O_Auto);
// Test benchmark with no range and check no complexity is calculated.
void BM_Extreme_Cases(benchmark::State& state) {
while (state.KeepRunning()) {
}
}
BENCHMARK(BM_Extreme_Cases) -> Complexity(benchmark::O_N_log_N);
BENCHMARK(BM_Extreme_Cases) -> Arg(42) -> Complexity(benchmark::O_Auto);
BENCHMARK_MAIN()