llvm-capstone/libcxx/benchmarks/algorithms.partition_point.bench.cpp
Louis Dionne 04695a7539 [libcxx] Speeding up partition_point/lower_bound/upper_bound
This is a re-application of r345525, which had been reverted by fear of
a regression.

Reviewed as https://reviews.llvm.org/D53994.
Thanks to Denis Yaroshevskiy for the patch.

llvm-svn: 349358
2018-12-17 16:04:39 +00:00

125 lines
3.1 KiB
C++

#include <array>
#include <algorithm>
#include <cassert>
#include <cstdint>
#include <tuple>
#include <vector>
#include "benchmark/benchmark.h"
#include "CartesianBenchmarks.hpp"
#include "GenerateInput.hpp"
namespace {
template <typename I, typename N>
std::array<I, 10> every_10th_percentile_N(I first, N n) {
N step = n / 10;
std::array<I, 10> res;
for (size_t i = 0; i < 10; ++i) {
res[i] = first;
std::advance(first, step);
}
return res;
}
template <class IntT>
struct TestIntBase {
static std::vector<IntT> generateInput(size_t size) {
std::vector<IntT> Res(size);
std::generate(Res.begin(), Res.end(),
[] { return getRandomInteger<IntT>(); });
return Res;
}
};
struct TestInt32 : TestIntBase<std::int32_t> {
static constexpr const char* Name = "TestInt32";
};
struct TestInt64 : TestIntBase<std::int64_t> {
static constexpr const char* Name = "TestInt64";
};
struct TestUint32 : TestIntBase<std::uint32_t> {
static constexpr const char* Name = "TestUint32";
};
struct TestMediumString {
static constexpr const char* Name = "TestMediumString";
static constexpr size_t StringSize = 32;
static std::vector<std::string> generateInput(size_t size) {
std::vector<std::string> Res(size);
std::generate(Res.begin(), Res.end(), [] { return getRandomString(StringSize); });
return Res;
}
};
using AllTestTypes = std::tuple<TestInt32, TestInt64, TestUint32, TestMediumString>;
struct LowerBoundAlg {
template <class I, class V>
I operator()(I first, I last, const V& value) const {
return std::lower_bound(first, last, value);
}
static constexpr const char* Name = "LowerBoundAlg";
};
struct UpperBoundAlg {
template <class I, class V>
I operator()(I first, I last, const V& value) const {
return std::upper_bound(first, last, value);
}
static constexpr const char* Name = "UpperBoundAlg";
};
struct EqualRangeAlg {
template <class I, class V>
std::pair<I, I> operator()(I first, I last, const V& value) const {
return std::equal_range(first, last, value);
}
static constexpr const char* Name = "EqualRangeAlg";
};
using AllAlgs = std::tuple<LowerBoundAlg, UpperBoundAlg, EqualRangeAlg>;
template <class Alg, class TestType>
struct PartitionPointBench {
size_t Quantity;
std::string name() const {
return std::string("PartitionPointBench_") + Alg::Name + "_" +
TestType::Name + '/' + std::to_string(Quantity);
}
void run(benchmark::State& state) const {
auto Data = TestType::generateInput(Quantity);
std::sort(Data.begin(), Data.end());
auto Every10Percentile = every_10th_percentile_N(Data.begin(), Data.size());
for (auto _ : state) {
for (auto Test : Every10Percentile)
benchmark::DoNotOptimize(Alg{}(Data.begin(), Data.end(), *Test));
}
}
};
} // namespace
int main(int argc, char** argv) {
benchmark::Initialize(&argc, argv);
if (benchmark::ReportUnrecognizedArguments(argc, argv))
return 1;
const std::vector<size_t> Quantities = {1 << 8, 1 << 10, 1 << 20};
makeCartesianProductBenchmark<PartitionPointBench, AllAlgs, AllTestTypes>(
Quantities);
benchmark::RunSpecifiedBenchmarks();
}