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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
#include <algorithm>
#include <cstddef>
#include <deque>
#include <iterator>
#include <list>
#include <string>
#include <vector>
#include "benchmark/benchmark.h"
#include "../../GenerateInput.h"
int main(int argc, char** argv) {
auto std_replace = [](auto first, auto last, auto old, auto new_) { return std::replace(first, last, old, new_); };
auto std_replace_if = [](auto first, auto last, auto old, auto new_) {
auto pred = [&](auto element) {
benchmark::DoNotOptimize(element);
return element == old;
};
return std::replace_if(first, last, pred, new_);
};
auto ranges_replace_if = [](auto first, auto last, auto old, auto new_) {
auto pred = [&](auto element) {
benchmark::DoNotOptimize(element);
return element == old;
};
return std::ranges::replace_if(first, last, pred, new_);
};
// Create a sequence of the form xxxxxxxxxxyyyyyyyyyy, replace
// into zzzzzzzzzzzyyyyyyyyyy and then back.
//
// This measures the performance of replace() when replacing a large
// contiguous sequence of equal values.
{
auto bm = []<class Container>(std::string name, auto replace) {
benchmark::RegisterBenchmark(
name,
[replace](auto& st) {
std::size_t const size = st.range(0);
using ValueType = typename Container::value_type;
Container c;
ValueType x = Generate<ValueType>::random();
ValueType y = random_different_from({x});
ValueType z = random_different_from({x, y});
std::fill_n(std::back_inserter(c), size / 2, x);
std::fill_n(std::back_inserter(c), size / 2, y);
for ([[maybe_unused]] auto _ : st) {
benchmark::DoNotOptimize(c);
benchmark::DoNotOptimize(x);
benchmark::DoNotOptimize(z);
replace(c.begin(), c.end(), x, z);
benchmark::DoNotOptimize(c);
std::swap(x, z);
}
})
->Arg(32)
->Arg(50) // non power-of-two
->Arg(1024)
->Arg(8192);
};
// {std,ranges}::replace
bm.operator()<std::vector<int>>("std::replace(vector<int>) (prefix)", std_replace);
bm.operator()<std::deque<int>>("std::replace(deque<int>) (prefix)", std_replace);
bm.operator()<std::list<int>>("std::replace(list<int>) (prefix)", std_replace);
bm.operator()<std::vector<int>>("rng::replace(vector<int>) (prefix)", std::ranges::replace);
bm.operator()<std::deque<int>>("rng::replace(deque<int>) (prefix)", std::ranges::replace);
bm.operator()<std::list<int>>("rng::replace(list<int>) (prefix)", std::ranges::replace);
// {std,ranges}::replace_if
bm.operator()<std::vector<int>>("std::replace_if(vector<int>) (prefix)", std_replace_if);
bm.operator()<std::deque<int>>("std::replace_if(deque<int>) (prefix)", std_replace_if);
bm.operator()<std::list<int>>("std::replace_if(list<int>) (prefix)", std_replace_if);
bm.operator()<std::vector<int>>("rng::replace_if(vector<int>) (prefix)", ranges_replace_if);
bm.operator()<std::deque<int>>("rng::replace_if(deque<int>) (prefix)", ranges_replace_if);
bm.operator()<std::list<int>>("rng::replace_if(list<int>) (prefix)", ranges_replace_if);
}
// Sprinkle elements to replace inside the range, like xyxyxyxyxyxyxyxyxyxy.
{
auto bm = []<class Container>(std::string name, auto replace) {
benchmark::RegisterBenchmark(
name,
[replace](auto& st) {
std::size_t const size = st.range(0);
using ValueType = typename Container::value_type;
Container c;
ValueType x = Generate<ValueType>::random();
ValueType y = random_different_from({x});
ValueType z = random_different_from({x, y});
for (std::size_t i = 0; i != size; ++i) {
c.push_back(i % 2 == 0 ? x : y);
}
for ([[maybe_unused]] auto _ : st) {
benchmark::DoNotOptimize(c);
benchmark::DoNotOptimize(x);
benchmark::DoNotOptimize(z);
replace(c.begin(), c.end(), x, z);
benchmark::DoNotOptimize(c);
std::swap(x, z);
}
})
->Arg(32)
->Arg(50) // non power-of-two
->Arg(1024)
->Arg(8192);
};
// {std,ranges}::replace
bm.operator()<std::vector<int>>("std::replace(vector<int>) (sprinkled)", std_replace);
bm.operator()<std::deque<int>>("std::replace(deque<int>) (sprinkled)", std_replace);
bm.operator()<std::list<int>>("std::replace(list<int>) (sprinkled)", std_replace);
bm.operator()<std::vector<int>>("rng::replace(vector<int>) (sprinkled)", std::ranges::replace);
bm.operator()<std::deque<int>>("rng::replace(deque<int>) (sprinkled)", std::ranges::replace);
bm.operator()<std::list<int>>("rng::replace(list<int>) (sprinkled)", std::ranges::replace);
// {std,ranges}::replace_if
bm.operator()<std::vector<int>>("std::replace_if(vector<int>) (sprinkled)", std_replace_if);
bm.operator()<std::deque<int>>("std::replace_if(deque<int>) (sprinkled)", std_replace_if);
bm.operator()<std::list<int>>("std::replace_if(list<int>) (sprinkled)", std_replace_if);
bm.operator()<std::vector<int>>("rng::replace_if(vector<int>) (sprinkled)", ranges_replace_if);
bm.operator()<std::deque<int>>("rng::replace_if(deque<int>) (sprinkled)", ranges_replace_if);
bm.operator()<std::list<int>>("rng::replace_if(list<int>) (sprinkled)", ranges_replace_if);
}
benchmark::Initialize(&argc, argv);
benchmark::RunSpecifiedBenchmarks();
benchmark::Shutdown();
return 0;
}
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