#include "benchmark/benchmark.h"

#define BASIC_BENCHMARK_TEST(x) BENCHMARK(x)->Arg(8)->Arg(512)->Arg(8192)

void BM_empty(benchmark::State& state) {
 for (auto _ : state) {
 auto iterations = double(state.iterations()) * double(state.iterations());
 benchmark::DoNotOptimize(iterations);
 }
}
BENCHMARK(BM_empty);
BENCHMARK(BM_empty)->ThreadPerCpu();

void BM_spin_empty(benchmark::State& state) {
 for (auto _ : state) {
 for (auto x = 0; x < state.range(0); ++x) {
 benchmark::DoNotOptimize(x);
 }
 }
}
BASIC_BENCHMARK_TEST(BM_spin_empty);
BASIC_BENCHMARK_TEST(BM_spin_empty)->ThreadPerCpu();

void BM_spin_pause_before(benchmark::State& state) {
 for (auto i = 0; i < state.range(0); ++i) {
 benchmark::DoNotOptimize(i);
 }
 for (auto _ : state) {
 for (auto i = 0; i < state.range(0); ++i) {
 benchmark::DoNotOptimize(i);
 }
 }
}
BASIC_BENCHMARK_TEST(BM_spin_pause_before);
BASIC_BENCHMARK_TEST(BM_spin_pause_before)->ThreadPerCpu();

void BM_spin_pause_during(benchmark::State& state) {
 for (auto _ : state) {
 state.PauseTiming();
 for (auto i = 0; i < state.range(0); ++i) {
 benchmark::DoNotOptimize(i);
 }
 state.ResumeTiming();
 for (auto i = 0; i < state.range(0); ++i) {
 benchmark::DoNotOptimize(i);
 }
 }
}
BASIC_BENCHMARK_TEST(BM_spin_pause_during);
BASIC_BENCHMARK_TEST(BM_spin_pause_during)->ThreadPerCpu();

void BM_pause_during(benchmark::State& state) {
 for (auto _ : state) {
 state.PauseTiming();
 state.ResumeTiming();
 }
}
BENCHMARK(BM_pause_during);
BENCHMARK(BM_pause_during)->ThreadPerCpu();
BENCHMARK(BM_pause_during)->UseRealTime();
BENCHMARK(BM_pause_during)->UseRealTime()->ThreadPerCpu();

void BM_spin_pause_after(benchmark::State& state) {
 for (auto _ : state) {
 for (auto i = 0; i < state.range(0); ++i) {
 benchmark::DoNotOptimize(i);
 }
 }
 for (auto i = 0; i < state.range(0); ++i) {
 benchmark::DoNotOptimize(i);
 }
}
BASIC_BENCHMARK_TEST(BM_spin_pause_after);
BASIC_BENCHMARK_TEST(BM_spin_pause_after)->ThreadPerCpu();

void BM_spin_pause_before_and_after(benchmark::State& state) {
 for (auto i = 0; i < state.range(0); ++i) {
 benchmark::DoNotOptimize(i);
 }
 for (auto _ : state) {
 for (auto i = 0; i < state.range(0); ++i) {
 benchmark::DoNotOptimize(i);
 }
 }
 for (auto i = 0; i < state.range(0); ++i) {
 benchmark::DoNotOptimize(i);
 }
}
BASIC_BENCHMARK_TEST(BM_spin_pause_before_and_after);
BASIC_BENCHMARK_TEST(BM_spin_pause_before_and_after)->ThreadPerCpu();

void BM_empty_stop_start(benchmark::State& state) {
 for (auto _ : state) {
 }
}
BENCHMARK(BM_empty_stop_start);
BENCHMARK(BM_empty_stop_start)->ThreadPerCpu();

void BM_KeepRunning(benchmark::State& state) {
 benchmark::IterationCount iter_count = 0;
 assert(iter_count == state.iterations());
 while (state.KeepRunning()) {
 ++iter_count;
 }
 assert(iter_count == state.iterations());
}
BENCHMARK(BM_KeepRunning);

void BM_KeepRunningBatch(benchmark::State& state) {
 // Choose a batch size >1000 to skip the typical runs with iteration
 // targets of 10, 100 and 1000. If these are not actually skipped the
 // bug would be detectable as consecutive runs with the same iteration
 // count. Below we assert that this does not happen.
 const benchmark::IterationCount batch_size = 1009;

 static benchmark::IterationCount prior_iter_count = 0;
 benchmark::IterationCount iter_count = 0;
 while (state.KeepRunningBatch(batch_size)) {
 iter_count += batch_size;
 }
 assert(state.iterations() == iter_count);

 // Verify that the iteration count always increases across runs (see
 // comment above).
 assert(iter_count == batch_size // max_iterations == 1
 || iter_count > prior_iter_count); // max_iterations > batch_size
 prior_iter_count = iter_count;
}
// Register with a fixed repetition count to establish the invariant that
// the iteration count should always change across runs. This overrides
// the --benchmark_repetitions command line flag, which would otherwise
// cause this test to fail if set > 1.
BENCHMARK(BM_KeepRunningBatch)->Repetitions(1);

void BM_RangedFor(benchmark::State& state) {
 benchmark::IterationCount iter_count = 0;
 for (auto _ : state) {
 ++iter_count;
 }
 assert(iter_count == state.max_iterations);
}
BENCHMARK(BM_RangedFor);

#ifdef BENCHMARK_HAS_CXX11
template <typename T>
void BM_OneTemplateFunc(benchmark::State& state) {
 auto arg = state.range(0);
 T sum = 0;
 for (auto _ : state) {
 sum += static_cast<T>(arg);
 }
}
BENCHMARK(BM_OneTemplateFunc<int>)->Arg(1);
BENCHMARK(BM_OneTemplateFunc<double>)->Arg(1);

template <typename A, typename B>
void BM_TwoTemplateFunc(benchmark::State& state) {
 auto arg = state.range(0);
 A sum = 0;
 B prod = 1;
 for (auto _ : state) {
 sum += static_cast<A>(arg);
 prod *= static_cast<B>(arg);
 }
}
BENCHMARK(BM_TwoTemplateFunc<int, double>)->Arg(1);
BENCHMARK(BM_TwoTemplateFunc<double, int>)->Arg(1);

#endif // BENCHMARK_HAS_CXX11

// Ensure that StateIterator provides all the necessary typedefs required to
// instantiate std::iterator_traits.
static_assert(
 std::is_same<typename std::iterator_traits<
 benchmark::State::StateIterator>::value_type,
 typename benchmark::State::StateIterator::value_type>::value,
 "");

BENCHMARK_MAIN();