/FLOAT
       /FLOAT=option
       /FLOAT=G_FLOAT (Alpha only) (D)
       /FLOAT=IEEE_FLOAT (I64 only) (D)

    Controls the format of floating-point variables. The options are:

    Option          Usage

    D_FLOAT         double variables are represented in VAX D_
                    floating format. float variables are represented
                    in VAX F_floating format. The __D_FLOAT macro is
                    predefined.
    G_FLOAT         double variables are represented in VAX G_
                    floating format. float variables are represented
                    in VAX F_floating format. The __G_FLOAT macro is
                    predefined.
    IEEE_FLOAT      float and double variables are represented in
                    IEEE floating-point format (S_float and T_
                    float, respectively). The __IEEE_FLOAT macro
                    is predefined. Use the /IEEE_MODE qualifier for
                    controlling the handling of IEEE exceptional
                    values.

    On Alpha systems, the default is /FLOAT=G_FLOAT.

    On I64 systems, the default is /FLOAT=IEEE_FLOAT.

    See the HP C++ User's Guide for OpenVMS Systems for additional
    information on floating-point representation on I64 and Alpha
    systems.