CDQ             Convert Double to Quad               Flags: Not altered

CDQ                                                  CPU: 386+

        Logic   if EAX < 80000000h
                   EDX ← 0
                else
                   EDX ← FFFFFFFFh
                endif

    CDQ converts the signed doubleword in EAX to a signed 64-bit
    integer in the register pair EDX:EAX by extending the most
    significant bit of EAX (the sign bit) into all the bits of EDX.

    Note
    CDQ is the 32-bit form of CWD.


    Opcode      Format
    99          CDQ


    Length and timing
    Operands    Bytes   8088    186     286     386     486     Pentium
    -            1                               2       3       2   NP