midpoint benchmark

midpoint_bench.cpp

#include <numeric>

int midpointb(int l, int r) {
    return (l + r) >> 1;
}

int midpointw(int l, int r) {
    return l + (r - l) / 2;
}

int midpoint(int l, int r) {
    return static_cast<unsigned int>(l + r) >> 1;
}

int L = std::numeric_limits<int>::max();
int R = L - 2;

static void MidpointW(benchmark::State& state) {
  for (auto _ : state) {
    benchmark::DoNotOptimize(midpointw(L, R));
  }
}
BENCHMARK(MidpointW);

static void Midpoint(benchmark::State& state) {
  for (auto _ : state) {
    benchmark::DoNotOptimize(midpoint(L, R));
  }
}
BENCHMARK(Midpoint);

static void StdMidpoint(benchmark::State& state) {
  for (auto _ : state) {
    benchmark::DoNotOptimize(std::midpoint(L, R));
  }
}
BENCHMARK(StdMidpoint);