谜题

Compute parity of word with a multiply

The following method computes the parity of the 32-bit value in only 8 operations using a multiply.
    unsigned int v; // 32-bit word
    v ^= v >> 1;
    v ^= v >> 2;
    v = (v & 0x11111111U) * 0x11111111U;
    return (v >> 28) & 1;