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//===----------------------------------------------------------------------===//
//
// 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, c++20
#include <algorithm>
#include <cassert>
#include <cstddef>
#include <deque>
#include <iterator>
#include <list>
#include <vector>
#include <benchmark/benchmark.h>
#include "../../GenerateInput.h"
int main(int argc, char** argv) {
// Benchmark ranges::contains_subrange where we never find the needle, which is the
// worst case.
{
auto bm = []<class Container>(std::string name) {
benchmark::RegisterBenchmark(
name,
[](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 haystack(size, x);
std::size_t n = size / 10; // needle size is 10% of the haystack, but we'll never find it
assert(n > 0);
Container needle(n, y);
for ([[maybe_unused]] auto _ : st) {
benchmark::DoNotOptimize(haystack);
benchmark::DoNotOptimize(needle);
auto result = std::ranges::contains_subrange(haystack, needle);
benchmark::DoNotOptimize(result);
}
})
->Arg(16)
->Arg(32)
->Arg(50) // non power-of-two
->Arg(8192)
->Arg(1 << 20);
};
bm.operator()<std::vector<int>>("rng::contains_subrange(vector<int>) (process all)");
bm.operator()<std::deque<int>>("rng::contains_subrange(deque<int>) (process all)");
bm.operator()<std::list<int>>("rng::contains_subrange(list<int>) (process all)");
}
// Benchmark ranges::contains_subrange where we intersperse "near matches" inside the haystack.
{
auto bm = []<class Container>(std::string name) {
benchmark::RegisterBenchmark(
name,
[](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 haystack(size, x);
std::size_t n = size / 10; // needle size is 10% of the haystack, but we'll never find it
assert(n > 0);
Container needle(n, y);
// intersperse near-matches inside the haystack
{
auto first = haystack.begin();
for (int i = 0; i != 10; ++i) {
first = std::copy_n(needle.begin(), n - 1, first);
++first; // this causes the subsequence not to match because it has length n-1
}
}
for ([[maybe_unused]] auto _ : st) {
benchmark::DoNotOptimize(haystack);
benchmark::DoNotOptimize(needle);
auto result = std::ranges::contains_subrange(haystack, needle);
benchmark::DoNotOptimize(result);
}
})
->Arg(1000) // non power-of-two
->Arg(1024)
->Arg(8192);
};
bm.operator()<std::vector<int>>("rng::contains_subrange(vector<int>) (near matches)");
bm.operator()<std::deque<int>>("rng::contains_subrange(deque<int>) (near matches)");
bm.operator()<std::list<int>>("rng::contains_subrange(list<int>) (near matches)");
}
// Special case: the two ranges are the same length (and they are equal, which is the worst case).
{
auto bm = []<class Container>(std::string name) {
benchmark::RegisterBenchmark(
name,
[](auto& st) {
std::size_t const size = st.range(0);
using ValueType = typename Container::value_type;
ValueType x = Generate<ValueType>::random();
Container haystack(size, x);
Container needle(size, x);
for ([[maybe_unused]] auto _ : st) {
benchmark::DoNotOptimize(haystack);
benchmark::DoNotOptimize(needle);
auto result = std::ranges::contains_subrange(haystack, needle);
benchmark::DoNotOptimize(result);
}
})
->Arg(16)
->Arg(32)
->Arg(50) // non power-of-two
->Arg(8192)
->Arg(1 << 20);
};
bm.operator()<std::vector<int>>("rng::contains_subrange(vector<int>) (same length)");
bm.operator()<std::deque<int>>("rng::contains_subrange(deque<int>) (same length)");
bm.operator()<std::list<int>>("rng::contains_subrange(list<int>) (same length)");
}
// Special case: the needle contains a single element (which we never find, i.e. the worst case).
{
auto bm = []<class Container>(std::string name) {
benchmark::RegisterBenchmark(
name,
[](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 haystack(size, x);
Container needle(1, y);
for ([[maybe_unused]] auto _ : st) {
benchmark::DoNotOptimize(haystack);
benchmark::DoNotOptimize(needle);
auto result = std::ranges::contains_subrange(haystack, needle);
benchmark::DoNotOptimize(result);
}
})
->Arg(16)
->Arg(32)
->Arg(50) // non power-of-two
->Arg(8192)
->Arg(1 << 20);
};
bm.operator()<std::vector<int>>("rng::contains_subrange(vector<int>) (single element)");
bm.operator()<std::deque<int>>("rng::contains_subrange(deque<int>) (single element)");
bm.operator()<std::list<int>>("rng::contains_subrange(list<int>) (single element)");
}
benchmark::Initialize(&argc, argv);
benchmark::RunSpecifiedBenchmarks();
benchmark::Shutdown();
return 0;
}
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