PXOR            Bitwise XOR

PXOR destination, source                             CPU: MMX

        Logic   mm <- mm XOR mm/m64

    The PXOR instruction performs a bitwise logical XOR on the 64 bits
    of the destination with the source operands and writes the result to
    destination register. 

    Each bit of the result is 1 if the corresponding bits of the two
    operands are different. Each bit is 0 if the corresponding bits of
    the operands are the same. 

    The source operand can either be an MMX register or a 64 bit memory
    operand.



    Opcode      Format
    0F EF /r    PXOR mm, mm/m64