- abacaab4b11a69dd4db627bd183571d7cabb8def Refinement to previous time.h edit (in this same github p... by Greg Falcon <gfalcon@google.com>

  - 64db19b773134c6c8004e3b23c9ca892efbf8bae Move SpinLock's adaptive spin count computation from a st... by Derek Mauro <dmauro@google.com>
  - 6f9533fb44a52485a7c2bbb9b4efc7bf8d6c359a Import of CCTZ from GitHub. by Abseil Team <absl-team@google.com>
  - a211d7255c986e8dd4ceada362c0d054a6a1969a Cleanup exception flags by Abseil Team <absl-team@google.com>
  - babdb29c590126fe9bba5229fe91034b5b5c358a Release time benchmarks. by Alex Strelnikov <strel@google.com>
  - 5803b32a3ff123d1fb57a0c471d199c818357c9f Release memutil microbenchmarks. by Alex Strelnikov <strel@google.com>
  - 5357d4890d30e80c53beb05af32500fb20e9402b Add parens around expansion of ABSL_PREDICT_{FALSE,TRUE} ... by Abseil Team <absl-team@google.com>
  - 32023f61a239a5f6b1c59e577bfe81b179bbcd2d Reformat build rule tag. by Alex Strelnikov <strel@google.com>
  - 833758ecf2b0cf7a42bbd50b5b127e416425c168 Release uint128 microbenchmarks. by Alex Strelnikov <strel@google.com>
  - c115a9bca1f944b90fdc78a56b2de176466b124f Disambiguate bitwise-not of size_type by Abseil Team <absl-team@google.com>
  - f6905f5b5f6e425792de646edafde440548d9346 Updates ConstructorTracker and TrackedObjects with 1) a m... by Abseil Team <absl-team@google.com>
  - 147c553bdd5d2db20a38f75c4d1ef973d6c709c5 Changes the absl::Duration factory functions to disallow ... by Greg Miller <jgm@google.com>
  - dba2b96d11b5264546b283ba452f2de1303b0f07 White space fix by Alex Strelnikov <strel@google.com>

GitOrigin-RevId: abacaab4b11a69dd4db627bd183571d7cabb8def
Change-Id: I6fa34f20d0b2f898e7b5475a603111413bb80a67

2 files changed, 233 insertions, 0 deletions

diff --git a/absl/numeric/BUILD.bazel b/absl/numeric/BUILD.bazel
index 0791145..f49571e 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 0000000..1cb7d0e
--- /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