crc32 hash

phash.cpp

#include <iostream>

#include <cstdlib>
#include <cstddef>
#include <cstdint>

#include <x86intrin.h>
 
struct phash
{
 
    std::size_t
    operator () (void * _offset) const noexcept
    {
#if defined(__x86_64__)
        return _mm_crc32_u64(0, reinterpret_cast< std::uintptr_t >(_offset));
#elif defined(__i386__)
        return _mm_crc32_u32(0, reinterpret_cast< std::uintptr_t >(_offset));
#endif
    }
 
};

int
main()
{
    using A = struct {};
    A a[2];
    std::cout << phash{}(a + 0) << '\t' << a + 0 << std::endl;
    std::cout << phash{}(a + 1) << '\t' << a + 1 << std::endl;
    return EXIT_SUCCESS;
}