diff options
Diffstat (limited to 'third_party/abseil-cpp/absl/flags/flag_benchmark.cc')
| -rw-r--r-- | third_party/abseil-cpp/absl/flags/flag_benchmark.cc | 157 |
1 files changed, 148 insertions, 9 deletions
diff --git a/third_party/abseil-cpp/absl/flags/flag_benchmark.cc b/third_party/abseil-cpp/absl/flags/flag_benchmark.cc index 87f731704c..fc572d9ce3 100644 --- a/third_party/abseil-cpp/absl/flags/flag_benchmark.cc +++ b/third_party/abseil-cpp/absl/flags/flag_benchmark.cc @@ -13,7 +13,16 @@ // See the License for the specific language governing permissions and // limitations under the License. +#include <stdint.h> + +#include <string> +#include <vector> + #include "absl/flags/flag.h" +#include "absl/flags/marshalling.h" +#include "absl/flags/parse.h" +#include "absl/flags/reflection.h" +#include "absl/strings/string_view.h" #include "absl/time/time.h" #include "absl/types/optional.h" #include "benchmark/benchmark.h" @@ -92,20 +101,150 @@ std::string AbslUnparseFlag(const UDT&) { return ""; } A(AbslDuration) \ A(UDT) -#define FLAG_DEF(T) ABSL_FLAG(T, T##_flag, {}, ""); +#define REPLICATE_0(A, T, name, index) A(T, name, index) +#define REPLICATE_1(A, T, name, index) \ + REPLICATE_0(A, T, name, index##0) REPLICATE_0(A, T, name, index##1) +#define REPLICATE_2(A, T, name, index) \ + REPLICATE_1(A, T, name, index##0) REPLICATE_1(A, T, name, index##1) +#define REPLICATE_3(A, T, name, index) \ + REPLICATE_2(A, T, name, index##0) REPLICATE_2(A, T, name, index##1) +#define REPLICATE_4(A, T, name, index) \ + REPLICATE_3(A, T, name, index##0) REPLICATE_3(A, T, name, index##1) +#define REPLICATE_5(A, T, name, index) \ + REPLICATE_4(A, T, name, index##0) REPLICATE_4(A, T, name, index##1) +#define REPLICATE_6(A, T, name, index) \ + REPLICATE_5(A, T, name, index##0) REPLICATE_5(A, T, name, index##1) +#define REPLICATE_7(A, T, name, index) \ + REPLICATE_6(A, T, name, index##0) REPLICATE_6(A, T, name, index##1) +#define REPLICATE_8(A, T, name, index) \ + REPLICATE_7(A, T, name, index##0) REPLICATE_7(A, T, name, index##1) +#define REPLICATE_9(A, T, name, index) \ + REPLICATE_8(A, T, name, index##0) REPLICATE_8(A, T, name, index##1) +#if defined(_MSC_VER) +#define REPLICATE(A, T, name) \ + REPLICATE_7(A, T, name, 0) REPLICATE_7(A, T, name, 1) +#define SINGLE_FLAG(T) FLAGS_##T##_flag_00000000 +#else +#define REPLICATE(A, T, name) \ + REPLICATE_9(A, T, name, 0) REPLICATE_9(A, T, name, 1) +#define SINGLE_FLAG(T) FLAGS_##T##_flag_0000000000 +#endif +#define REPLICATE_ALL(A, T, name) \ + REPLICATE_9(A, T, name, 0) REPLICATE_9(A, T, name, 1) + +#define COUNT(T, name, index) +1 +constexpr size_t kNumFlags = 0 REPLICATE(COUNT, _, _); +#if defined(__clang__) && defined(__linux__) +// Force the flags used for benchmarks into a separate ELF section. +// This ensures that, even when other parts of the code might change size, +// the layout of the flags across cachelines is kept constant. This makes +// benchmark results more reproducible across unrelated code changes. +#pragma clang section data = ".benchmark_flags" +#endif +#define DEFINE_FLAG(T, name, index) ABSL_FLAG(T, name##_##index, {}, ""); +#define FLAG_DEF(T) REPLICATE(DEFINE_FLAG, T, T##_flag); BENCHMARKED_TYPES(FLAG_DEF) +#if defined(__clang__) && defined(__linux__) +#pragma clang section data = "" +#endif +// Register thousands of flags to bloat up the size of the registry. +// This mimics real life production binaries. +#define BLOAT_FLAG(_unused1, _unused2, index) \ + ABSL_FLAG(int, bloat_flag_##index, 0, ""); +REPLICATE_ALL(BLOAT_FLAG, _, _) namespace { -#define BM_GetFlag(T) \ - void BM_GetFlag_##T(benchmark::State& state) { \ - for (auto _ : state) { \ - benchmark::DoNotOptimize(absl::GetFlag(FLAGS_##T##_flag)); \ - } \ - } \ - BENCHMARK(BM_GetFlag_##T); +#define FLAG_PTR(T, name, index) &FLAGS_##name##_##index, +#define FLAG_PTR_ARR(T) \ + static constexpr absl::Flag<T>* FlagPtrs_##T[] = { \ + REPLICATE(FLAG_PTR, T, T##_flag)}; +BENCHMARKED_TYPES(FLAG_PTR_ARR) + +#define BM_SingleGetFlag(T) \ + void BM_SingleGetFlag_##T(benchmark::State& state) { \ + for (auto _ : state) { \ + benchmark::DoNotOptimize(absl::GetFlag(SINGLE_FLAG(T))); \ + } \ + } \ + BENCHMARK(BM_SingleGetFlag_##T)->ThreadRange(1, 16); + +BENCHMARKED_TYPES(BM_SingleGetFlag) + +template <typename T> +struct Accumulator { + using type = T; +}; +template <> +struct Accumulator<String> { + using type = size_t; +}; +template <> +struct Accumulator<VectorOfStrings> { + using type = size_t; +}; +template <> +struct Accumulator<OptionalInt> { + using type = bool; +}; +template <> +struct Accumulator<OptionalString> { + using type = bool; +}; +template <> +struct Accumulator<UDT> { + using type = bool; +}; + +template <typename T> +void Accumulate(typename Accumulator<T>::type& a, const T& f) { + a += f; +} +void Accumulate(bool& a, bool f) { a = a || f; } +void Accumulate(size_t& a, const std::string& f) { a += f.size(); } +void Accumulate(size_t& a, const std::vector<std::string>& f) { a += f.size(); } +void Accumulate(bool& a, const OptionalInt& f) { a |= f.has_value(); } +void Accumulate(bool& a, const OptionalString& f) { a |= f.has_value(); } +void Accumulate(bool& a, const UDT& f) { + a |= reinterpret_cast<int64_t>(&f) & 0x1; +} + +#define BM_ManyGetFlag(T) \ + void BM_ManyGetFlag_##T(benchmark::State& state) { \ + Accumulator<T>::type res = {}; \ + while (state.KeepRunningBatch(kNumFlags)) { \ + for (auto* flag_ptr : FlagPtrs_##T) { \ + Accumulate(res, absl::GetFlag(*flag_ptr)); \ + } \ + } \ + benchmark::DoNotOptimize(res); \ + } \ + BENCHMARK(BM_ManyGetFlag_##T)->ThreadRange(1, 8); + +BENCHMARKED_TYPES(BM_ManyGetFlag) -BENCHMARKED_TYPES(BM_GetFlag) +void BM_ThreadedFindCommandLineFlag(benchmark::State& state) { + char dummy[] = "dummy"; + char* argv[] = {dummy}; + // We need to ensure that flags have been parsed. That is where the registry + // is finalized. + absl::ParseCommandLine(1, argv); + + while (state.KeepRunningBatch(kNumFlags)) { + for (auto* flag_ptr : FlagPtrs_bool) { + benchmark::DoNotOptimize(absl::FindCommandLineFlag(flag_ptr->Name())); + } + } +} +BENCHMARK(BM_ThreadedFindCommandLineFlag)->ThreadRange(1, 16); } // namespace + +#define InvokeGetFlag(T) \ + T AbslInvokeGetFlag##T() { return absl::GetFlag(SINGLE_FLAG(T)); } \ + int odr##T = (benchmark::DoNotOptimize(AbslInvokeGetFlag##T), 1); + +BENCHMARKED_TYPES(InvokeGetFlag) + +// To veiw disassembly use: gdb ${BINARY} -batch -ex "disassemble /s $FUNC" |