在现代Intel上，能否以任何方式通过C++11 atomic<>或C11 atomic_compare_exchange_strong生成CMPXCHG16B指令？

在现代Intel上，可以使用C++11的std::atomic<>或C11的atomic_compare_exchange_strong来生成CMPXCHG16B指令。下面是一个示例代码：

使用C++11的std::atomic<>：

#include <iostream>
#include <atomic>

int main() {
    std::atomic<uint64_t> data[2];
    data[0] = 0x1122334455667788;
    data[1] = 0x99aabbccddeeff00;

    uint64_t expected[2] = {0x1122334455667788, 0x99aabbccddeeff00};
    uint64_t desired[2] = {0xaabbccddeeff0011, 0x2233445566778899};

    bool success = std::atomic_compare_exchange_strong(data, expected, desired);
    if (success) {
        std::cout << "Atomic compare and exchange successful!" << std::endl;
    } else {
        std::cout << "Atomic compare and exchange failed!" << std::endl;
    }
    
    std::cout << "data[0]: 0x" << std::hex << data[0] << std::endl;
    std::cout << "data[1]: 0x" << std::hex << data[1] << std::endl;

    return 0;
}

使用C11的atomic_compare_exchange_strong：

#include <stdio.h>
#include <stdatomic.h>

int main() {
    _Atomic(uint64_t) data[2];
    atomic_init(&data[0], 0x1122334455667788);
    atomic_init(&data[1], 0x99aabbccddeeff00);

    uint64_t expected[2] = {0x1122334455667788, 0x99aabbccddeeff00};
    uint64_t desired[2] = {0xaabbccddeeff0011, 0x2233445566778899};

    bool success = atomic_compare_exchange_strong(data, expected, desired);
    if (success) {
        printf("Atomic compare and exchange successful!\n");
    } else {
        printf("Atomic compare and exchange failed!\n");
    }
    
    printf("data[0]: 0x%llx\n", atomic_load(&data[0]));
    printf("data[1]: 0x%llx\n", atomic_load(&data[1]));

    return 0;
}

这些代码将使用CMPXCHG16B指令来比较并交换data数组的值。如果expected和data中的值相等，则将desired的值存储到data中。如果比较和交换成功，success将为true。否则，success将为false。