113 lines
5.0 KiB
C++

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14, c++17
#include <algorithm>
#include <cstddef>
#include <deque>
#include <list>
#include <string>
#include <vector>
#include <benchmark/benchmark.h>
#include "../../GenerateInput.h"
int main(int argc, char** argv) {
auto std_mismatch_3leg = [](auto first1, auto last1, auto first2, auto) {
return std::mismatch(first1, last1, first2);
};
auto std_mismatch_4leg = [](auto first1, auto last1, auto first2, auto last2) {
return std::mismatch(first1, last1, first2, last2);
};
auto std_mismatch_3leg_pred = [](auto first1, auto last1, auto first2, auto) {
return std::mismatch(first1, last1, first2, [](auto x, auto y) {
benchmark::DoNotOptimize(x);
benchmark::DoNotOptimize(y);
return x == y;
});
};
auto std_mismatch_4leg_pred = [](auto first1, auto last1, auto first2, auto last2) {
return std::mismatch(first1, last1, first2, last2, [](auto x, auto y) {
benchmark::DoNotOptimize(x);
benchmark::DoNotOptimize(y);
return x == y;
});
};
auto ranges_mismatch_4leg_pred = [](auto first1, auto last1, auto first2, auto last2) {
return std::ranges::mismatch(first1, last1, first2, last2, [](auto x, auto y) {
benchmark::DoNotOptimize(x);
benchmark::DoNotOptimize(y);
return x == y;
});
};
// Benchmark {std,ranges}::mismatch where we find the mismatching element at the very end (worst case).
//
// TODO: Look into benchmarking aligned and unaligned memory explicitly
// (currently things happen to be aligned because they are malloced that way)
{
auto bm = []<class Container>(std::string name, auto mismatch) {
benchmark::RegisterBenchmark(
name,
[mismatch](auto& st) {
std::size_t const size = st.range(0);
using ValueType = typename Container::value_type;
ValueType x = Generate<ValueType>::random();
ValueType y = random_different_from({x});
Container c1(size, x);
Container c2(size, x);
c2.back() = y;
for ([[maybe_unused]] auto _ : st) {
benchmark::DoNotOptimize(c1);
benchmark::DoNotOptimize(c2);
auto result = mismatch(c1.begin(), c1.end(), c2.begin(), c2.end());
benchmark::DoNotOptimize(result);
}
})
->Arg(8)
->Arg(1000) // non power-of-two
->Arg(1024)
->Arg(8192)
->Arg(1 << 20);
};
// std::mismatch(it, it, it)
bm.operator()<std::vector<int>>("std::mismatch(vector<int>) (it, it, it)", std_mismatch_3leg);
bm.operator()<std::deque<int>>("std::mismatch(deque<int>) (it, it, it)", std_mismatch_3leg);
bm.operator()<std::list<int>>("std::mismatch(list<int>) (it, it, it)", std_mismatch_3leg);
// std::mismatch(it, it, it, pred)
bm.operator()<std::vector<int>>("std::mismatch(vector<int>) (it, it, it, pred)", std_mismatch_3leg_pred);
bm.operator()<std::deque<int>>("std::mismatch(deque<int>) (it, it, it, pred)", std_mismatch_3leg_pred);
bm.operator()<std::list<int>>("std::mismatch(list<int>) (it, it, it, pred)", std_mismatch_3leg_pred);
// {std,ranges}::mismatch(it, it, it, it)
bm.operator()<std::vector<int>>("std::mismatch(vector<int>) (it, it, it, it)", std_mismatch_4leg);
bm.operator()<std::deque<int>>("std::mismatch(deque<int>) (it, it, it, it)", std_mismatch_4leg);
bm.operator()<std::list<int>>("std::mismatch(list<int>) (it, it, it, it)", std_mismatch_4leg);
bm.operator()<std::vector<int>>("rng::mismatch(vector<int>) (it, it, it, it)", std::ranges::mismatch);
bm.operator()<std::deque<int>>("rng::mismatch(deque<int>) (it, it, it, it)", std::ranges::mismatch);
bm.operator()<std::list<int>>("rng::mismatch(list<int>) (it, it, it, it)", std::ranges::mismatch);
// {std,ranges}::mismatch(it, it, it, it, pred)
bm.operator()<std::vector<int>>("std::mismatch(vector<int>) (it, it, it, it, pred)", std_mismatch_4leg_pred);
bm.operator()<std::deque<int>>("std::mismatch(deque<int>) (it, it, it, it, pred)", std_mismatch_4leg_pred);
bm.operator()<std::list<int>>("std::mismatch(list<int>) (it, it, it, it, pred)", std_mismatch_4leg_pred);
bm.operator()<std::vector<int>>("rng::mismatch(vector<int>) (it, it, it, it, pred)", ranges_mismatch_4leg_pred);
bm.operator()<std::deque<int>>("rng::mismatch(deque<int>) (it, it, it, it, pred)", ranges_mismatch_4leg_pred);
bm.operator()<std::list<int>>("rng::mismatch(list<int>) (it, it, it, it, pred)", ranges_mismatch_4leg_pred);
}
benchmark::Initialize(&argc, argv);
benchmark::RunSpecifiedBenchmarks();
benchmark::Shutdown();
return 0;
}