RtlExtendedMagicDivide

LARGE_INTEGER
    RtlExtendedMagicDivide(

        IN LARGE_INTEGER  Dividend,
        IN LARGE_INTEGER  MagicDivisor,
        IN CCHAR  ShiftCount
        );

RtlExtendedMagicDivide is exported to support existing driver binaries and is obsolete. For better performance, use the compiler support for 64-bit integer operations.