PADDB           Add with Wrap-around on Byte

PADDB destination, source                            CPU: MMX

        Logic   mm(7..0)   <- mm(7..0)   + mm/m64(7..0)
                mm(15..8)  <- mm(15..8)  + mm/m64(15..8)
                mm(23..16) <- mm(23..16) + mm/m64(23..16)
                mm(31..24) <- mm(31..24) + mm/m64(31..24)
                mm(39..32) <- mm(39..32) + mm/m64(39..32)
                mm(47..40) <- mm(47..40) + mm/m64(47..40)
                mm(55..48) <- mm(55..48) + mm/m64(55..48)
                mm(63..56) <- mm(63..56) + mm/m64(63..56)

    PADDB adds the bytes of the source operand to the bytes of the
    destination operand and writes the results to the destination.

    When the result is too large to be represented in a packed byte
    (overflow), the result wraps around and the lower 8 bits are written
    to the destination register.

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


    Opcode      Format
    0F FC /r    PADDB mm, mm/64