1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9// UNSUPPORTED: c++03, c++11, c++14
10
11#include <array>
12#include <benchmark/benchmark.h>
13#include <cstring>
14#include <numeric>
15#include <random>
16
17template <class T>
18static std::array<T, 1000> generate(std::uniform_int_distribution<T> distribution = std::uniform_int_distribution<T>{
19 std::numeric_limits<T>::min() + 1, std::numeric_limits<T>::max()}) {
20 std::mt19937 generator;
21 std::array<T, 1000> result;
22 std::generate_n(result.begin(), result.size(), [&] { return distribution(generator); });
23 return result;
24}
25
26static void bm_gcd_random(benchmark::State& state) {
27 std::array data = generate<int>();
28 while (state.KeepRunningBatch(n: data.size() * data.size()))
29 for (auto v0 : data)
30 for (auto v1 : data)
31 benchmark::DoNotOptimize(value: std::gcd(m: v0, n: v1));
32}
33BENCHMARK(bm_gcd_random);
34
35static void bm_gcd_trivial(benchmark::State& state) {
36 int lhs = ~static_cast<int>(0), rhs = 1;
37 for (auto _ : state) {
38 benchmark::DoNotOptimize(value&: lhs);
39 benchmark::DoNotOptimize(value&: rhs);
40 benchmark::DoNotOptimize(value: std::gcd(m: lhs, n: rhs));
41 }
42}
43BENCHMARK(bm_gcd_trivial);
44
45static void bm_gcd_complex(benchmark::State& state) {
46 long long lhs = 2971215073;
47 long long rhs = 1836311903;
48 for (auto _ : state) {
49 benchmark::DoNotOptimize(value&: lhs);
50 benchmark::DoNotOptimize(value&: rhs);
51 benchmark::DoNotOptimize(value: std::gcd(m: lhs, n: rhs));
52 }
53}
54BENCHMARK(bm_gcd_complex);
55
56BENCHMARK_MAIN();
57

source code of libcxx/test/benchmarks/numeric/gcd.bench.cpp