OR              OR operation                         Flags: O D I T S Z A P C
                                                            0 - - - * * ? * 0
OR destination,source

        Logic   destination ← destination OR source

    OR performs a bit-by-bit logical inclusive OR operation on its
    operands and returns the result to destination. OR sets each bit
    of the result to one if either or both of the corresponding bits
    of the operands are one.


                          OR truth table
                        a       b     a OR b
                        0       0       0
                        0       1       1
                        1       0       1
                        1       1       1


    Opcode      Format
    08 /r       OR   r/m8,r8
    09 /r       OR   r/m16,r16
    09 /r       OR   r/m32,r32
    0A /r       OR   r8,r/m8
    0B /r       OR   r16,r/m16
    0B /r       OR   r32,r/m32
    0C ib       OR   AL,imm8
    0D iw       OR   AX,imm16
    0D id       OR   EAX,imm32
    80 /1 ib    OR   r/m8,imm8
    81 /1 iw    OR   r/m16,imm16
    81 /1 id    OR   r/m32,imm32
    83 /1 ib    OR   r/m16,imm8
    83 /1 ib    OR   r/m32,imm8


    Length and timing
    Operands    Bytes   8088    186     286     386     486     Pentium
    reg, reg     2       3       3       2       2       1       1   UV
    mem, reg  2+d(0,2)  24+EA   10       7       7       3       3   UV
    reg, mem  2+d(0,2)  13+EA   10       7       6       2       2   UV
    reg, imm  2+i(1,2)   4       4       3       2       1       1   UV
    mem, imm  2+d(0,2)  23+EA   16       7       7       3       3   UV*
               +i(1,2)
    acc, imm  1+i(1,2)   4       4       3       2       1       1   UV

        * = not pairable if there is a displacement and immediate