knuth multiplicative hash

Question

Is this a correct implementation of the Knuth multiplicative hash.

int hash(int v)
{
    v *= 2654435761;
    return v >> 32;
}

Does over

Answer 1

If the input argument is a pointer then I use this

#include 

uint32_t knuth_mul_hash(void* k) {
  ptrdiff_t v = (ptrdiff_t)k * UINT32_C(2654435761);
  v >>= ((sizeof(ptrdiff_t) - sizeof(uint32_t)) * 8); // Right-shift v by the size difference between a pointer and a 32-bit integer (0 for x86, 32 for x64)
  return (uint32_t)(v & UINT32_MAX);
}

I usually use this as the default fallback hashing function in hashmap implementations, dictionaries, sets, etc...