Add two integers using only bitwise operators?

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Here is an example for your amusement

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

The loop could be unrolled. Number of times it executes, depends on the number of bits set in operands, but it’s never greater than the width of unsigned int. Once carry becomes 0, next iterations don’t change anything.

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