mb.cpp

#include <benchmark/benchmark.h>

static void mfence_bench(benchmark::State& state)
{
    for (auto _ : state) {
        __asm__ __volatile__("mfence" ::: "memory");
    }
}

static void add_stack(benchmark::State& state)
{
    for (auto _ : state) {
        __asm__ __volatile__("lock addq $0, (%%rsp)" ::: "memory");
    }
}

static unsigned long shite_global;

static void add_global(benchmark::State& state)
{
    for (auto _ : state) {
        __asm__ __volatile__("lock addq $0, %0" :: "m"(shite_global) : "memory");
    }
}

BENCHMARK(mfence_bench);
BENCHMARK(add_stack);
BENCHMARK(add_global);

BENCHMARK_MAIN();