How to add bits using bitwise?

问题

I was trying to figure out how to add bits (up to 2 bytes) using only the following bitwise operations: ~ & ^ | << >>. I've been trying for a while with no luck. I was wondering if anyone knew how.

int logicalByteAdd(int x, int y) {

return ;
}

回答1:

unsigned short add(unsigned short a, unsigned short b)
{
    unsigned short carry = a & b;
    unsigned short result = a ^ b;
    while(carry != 0)
    {
        unsigned short shiftedcarry = carry << 1;
        carry = result & shiftedcarry;
        result ^= shiftedcarry;
    }
    return result;
}

Proof of Correctness provided by Mooing Duck

来源：https://stackoverflow.com/questions/22026777/how-to-add-bits-using-bitwise