forked from OSchip/llvm-project
				
			
		
			
				
	
	
		
			58 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			58 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			C++
		
	
	
	
#include "benchmark/benchmark.h"
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#include <cstdlib>
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#include <map>
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namespace {
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std::map<int, int> ConstructRandomMap(int size) {
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  std::map<int, int> m;
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  for (int i = 0; i < size; ++i) {
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    m.insert(std::make_pair(std::rand() % size, std::rand() % size));
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  }
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  return m;
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}
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}  // namespace
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// Basic version.
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static void BM_MapLookup(benchmark::State& state) {
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  const int size = static_cast<int>(state.range(0));
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  std::map<int, int> m;
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  for (auto _ : state) {
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    state.PauseTiming();
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    m = ConstructRandomMap(size);
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    state.ResumeTiming();
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    for (int i = 0; i < size; ++i) {
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      benchmark::DoNotOptimize(m.find(std::rand() % size));
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    }
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  }
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  state.SetItemsProcessed(state.iterations() * size);
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}
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BENCHMARK(BM_MapLookup)->Range(1 << 3, 1 << 12);
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// Using fixtures.
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class MapFixture : public ::benchmark::Fixture {
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 public:
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  void SetUp(const ::benchmark::State& st) {
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    m = ConstructRandomMap(static_cast<int>(st.range(0)));
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  }
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  void TearDown(const ::benchmark::State&) { m.clear(); }
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  std::map<int, int> m;
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};
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BENCHMARK_DEFINE_F(MapFixture, Lookup)(benchmark::State& state) {
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  const int size = static_cast<int>(state.range(0));
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  for (auto _ : state) {
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    for (int i = 0; i < size; ++i) {
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      benchmark::DoNotOptimize(m.find(std::rand() % size));
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    }
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  }
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  state.SetItemsProcessed(state.iterations() * size);
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}
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BENCHMARK_REGISTER_F(MapFixture, Lookup)->Range(1 << 3, 1 << 12);
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BENCHMARK_MAIN();
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