memcpy_implenations

fast_memcpy.c

void *fast_memcpy(void *dest, const void *src, size_t n) {
    size_t *d = (size_t *)dest;
    const size_t *s = (const size_t *)src;
    size_t block_size = sizeof(size_t);
    
    while (n >= block_size) {
        *d++ = *s++;
        n -= block_size;
    }
    
    char *d_bytes = (char *)d;
    const char *s_bytes = (const char *)s;
    while (n > 0) {
        *d_bytes++ = *s_bytes++;
        n--;
    }

    return dest;
}

naive_memcpy.c

void *naive_memcpy(void *dest, const void *src, size_t n) {
    char *d = (char *)dest;
    const char *s = (const char *)src;
    for (size_t i = 0; i < n; i++) {
        *d++ = *s++;
    }
    return dest;
}