// 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
//
// https://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
