benchmark/test/perf_counters_test.cc

99 lines
2.5 KiB
C++

#include <cstdarg>
#undef NDEBUG
#include "../src/commandlineflags.h"
#include "../src/perf_counters.h"
#include "benchmark/benchmark.h"
#include "output_test.h"
namespace benchmark {
BM_DECLARE_string(benchmark_perf_counters);
} // namespace benchmark
static void BM_Simple(benchmark::State& state) {
for (auto _ : state) {
auto iterations = state.iterations();
benchmark::DoNotOptimize(iterations);
}
}
BENCHMARK(BM_Simple);
ADD_CASES(TC_JSONOut, {{"\"name\": \"BM_Simple\",$"}});
const int kIters = 1000000;
void BM_WithoutPauseResume(benchmark::State& state) {
int n = 0;
for (auto _ : state) {
for (auto i = 0; i < kIters; ++i) {
n = 1 - n;
benchmark::DoNotOptimize(n);
}
}
}
BENCHMARK(BM_WithoutPauseResume);
ADD_CASES(TC_JSONOut, {{"\"name\": \"BM_WithoutPauseResume\",$"}});
void BM_WithPauseResume(benchmark::State& state) {
int m = 0, n = 0;
for (auto _ : state) {
for (auto i = 0; i < kIters; ++i) {
n = 1 - n;
benchmark::DoNotOptimize(n);
}
state.PauseTiming();
for (auto j = 0; j < kIters; ++j) {
m = 1 - m;
benchmark::DoNotOptimize(m);
}
state.ResumeTiming();
}
}
BENCHMARK(BM_WithPauseResume);
ADD_CASES(TC_JSONOut, {{"\"name\": \"BM_WithPauseResume\",$"}});
static void CheckSimple(Results const& e) {
CHECK_COUNTER_VALUE(e, double, "CYCLES", GT, 0);
CHECK_COUNTER_VALUE(e, double, "BRANCHES", GT, 0.0);
}
double withoutPauseResumeInstrCount = 0.0;
double withPauseResumeInstrCount = 0.0;
static void CheckInstrCount(double* counter, Results const& e) {
BM_CHECK_GT(e.NumIterations(), 0);
*counter = e.GetAs<double>("INSTRUCTIONS") / e.NumIterations();
}
static void CheckInstrCountWithoutResume(Results const& e) {
CheckInstrCount(&withoutPauseResumeInstrCount, e);
}
static void CheckInstrCountWithResume(Results const& e) {
CheckInstrCount(&withPauseResumeInstrCount, e);
}
CHECK_BENCHMARK_RESULTS("BM_Simple", &CheckSimple);
CHECK_BENCHMARK_RESULTS("BM_WithoutPauseResume", &CheckInstrCountWithoutResume);
CHECK_BENCHMARK_RESULTS("BM_WithPauseResume", &CheckInstrCountWithResume);
int main(int argc, char* argv[]) {
if (!benchmark::internal::PerfCounters::kSupported) {
return 0;
}
benchmark::FLAGS_benchmark_perf_counters = "CYCLES,BRANCHES,INSTRUCTIONS";
benchmark::internal::PerfCounters::Initialize();
RunOutputTests(argc, argv);
BM_CHECK_GT(withPauseResumeInstrCount, kIters);
BM_CHECK_GT(withoutPauseResumeInstrCount, kIters);
BM_CHECK_LT(withPauseResumeInstrCount, 1.5 * withoutPauseResumeInstrCount);
}