/POINTER_SIZE
       /POINTER_SIZE=option
       /NOPOINTER_SIZE (D)

    Controls whether pointer-size features are enabled, and whether
    pointers are 32 bits or 64 bits long.

    On both Alpha and I64 systems, the default is /NOPOINTER_SIZE,
    which disables pointer-size features, such as the ability to use
    #pragma pointer_size, and directs the compiler to assume that all
    pointers are 32-bit pointers. This default represents no change
    over previous versions of HP C++.

    You can specify one of the following options:

    SHORT        The compiler assumes 32-bit pointers.
    32           Same as SHORT.
    LONG         The compiler assumes 64-bit pointers.
    LONG[=ARGV]  The compiler assumes 64-bit pointers. If the ARGV
                 option to LONG or 64 is present, the main argument
                 argv will be an array of long pointers instead of an
                 array of short pointers. (I64 only)
    64           Same as LONG.

    Specifying /POINTER_SIZE=32 directs the compiler to assume that
    all pointers are 32-bit pointers. But unlike the default of
    /NOPOINTER_SIZE, /POINTER_SIZE=32 enables use of the #pragma
    pointer_size long and #pragma pointer_size short preprocessor
    directives to control pointer size throughout your program.

    Specifying /POINTER_SIZE=64 directs the compiler to assume that
    all pointers are 64-bit pointers, and also enables use of the
    #pragma pointer_size directives.