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-rw-r--r--absl/numeric/BUILD.bazel12
-rw-r--r--absl/numeric/int128_benchmark.cc221
2 files changed, 233 insertions, 0 deletions
diff --git a/absl/numeric/BUILD.bazel b/absl/numeric/BUILD.bazel
index 0791145d..f49571eb 100644
--- a/absl/numeric/BUILD.bazel
+++ b/absl/numeric/BUILD.bazel
@@ -53,3 +53,15 @@ cc_test(
"@com_google_googletest//:gtest_main",
],
)
+
+cc_test(
+ name = "int128_benchmark",
+ srcs = ["int128_benchmark.cc"],
+ copts = ABSL_TEST_COPTS,
+ tags = ["benchmark"],
+ deps = [
+ ":int128",
+ "//absl/base:config",
+ "@com_github_google_benchmark//:benchmark_main",
+ ],
+)
diff --git a/absl/numeric/int128_benchmark.cc b/absl/numeric/int128_benchmark.cc
new file mode 100644
index 00000000..1cb7d0ed
--- /dev/null
+++ b/absl/numeric/int128_benchmark.cc
@@ -0,0 +1,221 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/numeric/int128.h"
+
+#include <algorithm>
+#include <cstdint>
+#include <random>
+#include <vector>
+
+#include "benchmark/benchmark.h"
+#include "absl/base/config.h"
+
+namespace {
+
+constexpr size_t kSampleSize = 1000000;
+
+std::mt19937 MakeRandomEngine() {
+ std::random_device r;
+ std::seed_seq seed({r(), r(), r(), r(), r(), r(), r(), r()});
+ return std::mt19937(seed);
+}
+
+std::vector<std::pair<absl::uint128, absl::uint128>>
+GetRandomClass128SampleUniformDivisor() {
+ std::vector<std::pair<absl::uint128, absl::uint128>> values;
+ std::mt19937 random = MakeRandomEngine();
+ std::uniform_int_distribution<uint64_t> uniform_uint64;
+ values.reserve(kSampleSize);
+ for (size_t i = 0; i < kSampleSize; ++i) {
+ absl::uint128 a =
+ absl::MakeUint128(uniform_uint64(random), uniform_uint64(random));
+ absl::uint128 b =
+ absl::MakeUint128(uniform_uint64(random), uniform_uint64(random));
+ values.emplace_back(std::max(a, b),
+ std::max(absl::uint128(2), std::min(a, b)));
+ }
+ return values;
+}
+
+void BM_DivideClass128UniformDivisor(benchmark::State& state) {
+ auto values = GetRandomClass128SampleUniformDivisor();
+ while (state.KeepRunningBatch(values.size())) {
+ for (const auto& pair : values) {
+ benchmark::DoNotOptimize(pair.first / pair.second);
+ }
+ }
+}
+BENCHMARK(BM_DivideClass128UniformDivisor);
+
+std::vector<std::pair<absl::uint128, uint64_t>>
+GetRandomClass128SampleSmallDivisor() {
+ std::vector<std::pair<absl::uint128, uint64_t>> values;
+ std::mt19937 random = MakeRandomEngine();
+ std::uniform_int_distribution<uint64_t> uniform_uint64;
+ values.reserve(kSampleSize);
+ for (size_t i = 0; i < kSampleSize; ++i) {
+ absl::uint128 a =
+ absl::MakeUint128(uniform_uint64(random), uniform_uint64(random));
+ uint64_t b = std::max(uint64_t{2}, uniform_uint64(random));
+ values.emplace_back(std::max(a, absl::uint128(b)), b);
+ }
+ return values;
+}
+
+void BM_DivideClass128SmallDivisor(benchmark::State& state) {
+ auto values = GetRandomClass128SampleSmallDivisor();
+ while (state.KeepRunningBatch(values.size())) {
+ for (const auto& pair : values) {
+ benchmark::DoNotOptimize(pair.first / pair.second);
+ }
+ }
+}
+BENCHMARK(BM_DivideClass128SmallDivisor);
+
+std::vector<std::pair<absl::uint128, absl::uint128>> GetRandomClass128Sample() {
+ std::vector<std::pair<absl::uint128, absl::uint128>> values;
+ std::mt19937 random = MakeRandomEngine();
+ std::uniform_int_distribution<uint64_t> uniform_uint64;
+ values.reserve(kSampleSize);
+ for (size_t i = 0; i < kSampleSize; ++i) {
+ values.emplace_back(
+ absl::MakeUint128(uniform_uint64(random), uniform_uint64(random)),
+ absl::MakeUint128(uniform_uint64(random), uniform_uint64(random)));
+ }
+ return values;
+}
+
+void BM_MultiplyClass128(benchmark::State& state) {
+ auto values = GetRandomClass128Sample();
+ while (state.KeepRunningBatch(values.size())) {
+ for (const auto& pair : values) {
+ benchmark::DoNotOptimize(pair.first * pair.second);
+ }
+ }
+}
+BENCHMARK(BM_MultiplyClass128);
+
+void BM_AddClass128(benchmark::State& state) {
+ auto values = GetRandomClass128Sample();
+ while (state.KeepRunningBatch(values.size())) {
+ for (const auto& pair : values) {
+ benchmark::DoNotOptimize(pair.first + pair.second);
+ }
+ }
+}
+BENCHMARK(BM_AddClass128);
+
+#ifdef ABSL_HAVE_INTRINSIC_INT128
+
+// Some implementations of <random> do not support __int128 when it is
+// available, so we make our own uniform_int_distribution-like type.
+class UniformIntDistribution128 {
+ public:
+ // NOLINTNEXTLINE: mimicking std::uniform_int_distribution API
+ unsigned __int128 operator()(std::mt19937& generator) {
+ return (static_cast<unsigned __int128>(dist64_(generator)) << 64) |
+ dist64_(generator);
+ }
+
+ private:
+ std::uniform_int_distribution<uint64_t> dist64_;
+};
+
+std::vector<std::pair<unsigned __int128, unsigned __int128>>
+GetRandomIntrinsic128SampleUniformDivisor() {
+ std::vector<std::pair<unsigned __int128, unsigned __int128>> values;
+ std::mt19937 random = MakeRandomEngine();
+ UniformIntDistribution128 uniform_uint128;
+ values.reserve(kSampleSize);
+ for (size_t i = 0; i < kSampleSize; ++i) {
+ unsigned __int128 a = uniform_uint128(random);
+ unsigned __int128 b = uniform_uint128(random);
+ values.emplace_back(
+ std::max(a, b),
+ std::max(static_cast<unsigned __int128>(2), std::min(a, b)));
+ }
+ return values;
+}
+
+void BM_DivideIntrinsic128UniformDivisor(benchmark::State& state) {
+ auto values = GetRandomIntrinsic128SampleUniformDivisor();
+ while (state.KeepRunningBatch(values.size())) {
+ for (const auto& pair : values) {
+ benchmark::DoNotOptimize(pair.first / pair.second);
+ }
+ }
+}
+BENCHMARK(BM_DivideIntrinsic128UniformDivisor);
+
+std::vector<std::pair<unsigned __int128, uint64_t>>
+GetRandomIntrinsic128SampleSmallDivisor() {
+ std::vector<std::pair<unsigned __int128, uint64_t>> values;
+ std::mt19937 random = MakeRandomEngine();
+ UniformIntDistribution128 uniform_uint128;
+ std::uniform_int_distribution<uint64_t> uniform_uint64;
+ values.reserve(kSampleSize);
+ for (size_t i = 0; i < kSampleSize; ++i) {
+ unsigned __int128 a = uniform_uint128(random);
+ uint64_t b = std::max(uint64_t{2}, uniform_uint64(random));
+ values.emplace_back(std::max(a, static_cast<unsigned __int128>(b)), b);
+ }
+ return values;
+}
+
+void BM_DivideIntrinsic128SmallDivisor(benchmark::State& state) {
+ auto values = GetRandomIntrinsic128SampleSmallDivisor();
+ while (state.KeepRunningBatch(values.size())) {
+ for (const auto& pair : values) {
+ benchmark::DoNotOptimize(pair.first / pair.second);
+ }
+ }
+}
+BENCHMARK(BM_DivideIntrinsic128SmallDivisor);
+
+std::vector<std::pair<unsigned __int128, unsigned __int128>>
+ GetRandomIntrinsic128Sample() {
+ std::vector<std::pair<unsigned __int128, unsigned __int128>> values;
+ std::mt19937 random = MakeRandomEngine();
+ UniformIntDistribution128 uniform_uint128;
+ values.reserve(kSampleSize);
+ for (size_t i = 0; i < kSampleSize; ++i) {
+ values.emplace_back(uniform_uint128(random), uniform_uint128(random));
+ }
+ return values;
+}
+
+void BM_MultiplyIntrinsic128(benchmark::State& state) {
+ auto values = GetRandomIntrinsic128Sample();
+ while (state.KeepRunningBatch(values.size())) {
+ for (const auto& pair : values) {
+ benchmark::DoNotOptimize(pair.first * pair.second);
+ }
+ }
+}
+BENCHMARK(BM_MultiplyIntrinsic128);
+
+void BM_AddIntrinsic128(benchmark::State& state) {
+ auto values = GetRandomIntrinsic128Sample();
+ while (state.KeepRunningBatch(values.size())) {
+ for (const auto& pair : values) {
+ benchmark::DoNotOptimize(pair.first + pair.second);
+ }
+ }
+}
+BENCHMARK(BM_AddIntrinsic128);
+
+#endif // ABSL_HAVE_INTRINSIC_INT128
+
+} // namespace
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