libcxx/benchmarks/algorithms/find.bench.cpp

   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 #include <algorithm>
  10 #include <benchmark/benchmark.h>
  11 #include <cstring>
  12 #include <random>
  13 #include <vector>
  14
  15 template <class T>
  16 static void bm_find(benchmark::State& state) {
  17   std::vector<T> vec1(state.range(), '1');
  18   std::mt19937_64 rng(std::random_device{}());
  19
  20   for (auto _ : state) {
  21     auto idx  = rng() % vec1.size();
  22     vec1[idx] = '2';
  23     benchmark::DoNotOptimize(vec1);
  24     benchmark::DoNotOptimize(std::find(vec1.begin(), vec1.end(), T('2')));
  25     vec1[idx] = '1';
  26   }
  27 }
  28 BENCHMARK(bm_find<char>)->DenseRange(1, 8)->Range(16, 1 << 20);
  29 BENCHMARK(bm_find<short>)->DenseRange(1, 8)->Range(16, 1 << 20);
  30 BENCHMARK(bm_find<int>)->DenseRange(1, 8)->Range(16, 1 << 20);
  31
  32 template <class T>
  33 static void bm_ranges_find(benchmark::State& state) {
  34   std::vector<T> vec1(state.range(), '1');
  35   std::mt19937_64 rng(std::random_device{}());
  36
  37   for (auto _ : state) {
  38     auto idx  = rng() % vec1.size();
  39     vec1[idx] = '2';
  40     benchmark::DoNotOptimize(vec1);
  41     benchmark::DoNotOptimize(std::ranges::find(vec1, T('2')));
  42     vec1[idx] = '1';
  43   }
  44 }
  45 BENCHMARK(bm_ranges_find<char>)->DenseRange(1, 8)->Range(16, 1 << 20);
  46 BENCHMARK(bm_ranges_find<short>)->DenseRange(1, 8)->Range(16, 1 << 20);
  47 BENCHMARK(bm_ranges_find<int>)->DenseRange(1, 8)->Range(16, 1 << 20);
  48
  49 static void bm_vector_bool_find(benchmark::State& state) {
  50   std::vector<bool> vec1(state.range(), false);
  51   std::mt19937_64 rng(std::random_device{}());
  52
  53   for (auto _ : state) {
  54     auto idx  = rng() % vec1.size();
  55     vec1[idx] = true;
  56     benchmark::DoNotOptimize(vec1);
  57     benchmark::DoNotOptimize(std::find(vec1.begin(), vec1.end(), true));
  58     vec1[idx] = false;
  59   }
  60 }
  61 BENCHMARK(bm_vector_bool_find)->DenseRange(1, 8)->Range(16, 1 << 20);
  62
  63 static void bm_vector_bool_ranges_find(benchmark::State& state) {
  64   std::vector<bool> vec1(state.range(), false);
  65   std::mt19937_64 rng(std::random_device{}());
  66
  67   for (auto _ : state) {
  68     auto idx  = rng() % vec1.size();
  69     vec1[idx] = true;
  70     benchmark::DoNotOptimize(vec1);
  71     benchmark::DoNotOptimize(std::ranges::find(vec1, true));
  72     vec1[idx] = false;
  73   }
  74 }
  75 BENCHMARK(bm_vector_bool_ranges_find)->DenseRange(1, 8)->Range(16, 1 << 20);
  76
  77 BENCHMARK_MAIN();