RtlExtendedLargeIntegerDivide

LARGE_INTEGER
    RtlExtendedLargeIntegerDivide(

        IN LARGE_INTEGER  Dividend,
        IN ULONG  Divisor,
        IN OUT PULONG  Remainder
        );

RtlExtendedLargeIntegerDivide is exported to support existing driver binaries and is obsolete.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