实现memcpy函数

#include <iostream>
#include <time.h>

using namespace std;

char buf1[10010] = { 0 };
char buf2[10020] = { 0 };

void *myMemcpy(void *dst,void * const src, size_t len)
{
    uint64_t *dst_u64 = reinterpret_cast<uint64_t *>(dst);
    uint64_t *src_u64 = reinterpret_cast<uint64_t *>(src);
    size_t n = len;

    //64位拷贝
    while (n > sizeof(uint64_t))
    {
        *(dst_u64++) = *(src_u64++);
        n -= sizeof(uint64_t);
    }

    uint8_t *dst_u8 = reinterpret_cast<uint8_t *>(dst);
    uint8_t *src_u8 = reinterpret_cast<uint8_t *>(src);

    //8位拷贝
    while (n)
    {
        *dst_u8++ = *src_u8++;
        n -= sizeof(uint8_t);
    }

    return dst;
}

int main()
{
    myMemcpy(buf1, buf2, 10000);
    cout << "Time: " << clock() << endl;
    getc(stdin);
    return 0;
}