Arguments

 

input_value

   OpenVMS usage:varying_arg
   type:         unspecified
   access:       read only
   mechanism:    by reference

   The address of a data area containing a floating-point number
   that is to be converted. The input_value argument may contain
   floating-point data in F_Floating, D_Floating, G_Floating, H_
   Floating, IEEE_S_Floating, IEEE_T_Floating, IEEE_X_Floating, IBM_
   Long_Floating, IBM_Short_Floating, or CRAY_Floating format. The
   value of the input_type_code argument determines the format and
   size of the input_value argument.
 

input_type_code

   OpenVMS usage:longword_unsigned
   type:         longword (unsigned)
   access:       read only
   mechanism:    by value

   The value of a longword bit mask specifying the type of floating-
   point data being passed in the input_value argument. Valid type
   codes are:

                                                         Size in
   input_type_code          Format                       Bytes

   CVT$K_VAX_F              F_Floating                   4
   CVT$K_VAX_D              D_Floating                   8
   CVT$K_VAX_G              G_Floating                   8
   CVT$K_VAX_H              H_Floating                   16
   CVT$K_IEEE_S             IEEE_S_Floating              4
   CVT$K_IEEE_T             IEEE_T_Floating              8
   CVT$K_IEEE_X             IEEE_X_Floating              16
   CVT$K_IBM_LONG           IBM_Long_Floating            8
   CVT$K_IBM_SHORT          IBM_Short_Floating           4
   CVT$K_CRAY               CRAY_Floating                8

   Declarations for the input_type_code argument are in the $CVTDEF
   module found in the system symbol libraries.
 

output_value

   OpenVMS usage:varying_arg
   type:         unspecified
   access:       write only
   mechanism:    by reference

   The address of a data area that receives the converted floating-
   point number. The output_value argument can contain floating-
   point data in F_Floating, D_Floating, G_Floating, H_Floating,
   IEEE_S_Floating, IEEE_T_Floating, IEEE_X_Floating, IBM_Long_
   Floating, IBM_Short_Floating, or CRAY_Floating format. The value
   of the output_type_code argument determines the size and format
   of the data placed into the output_value argument.
 

output_type_code

   OpenVMS usage:longword_unsigned
   type:         longword (unsigned)
   access:       read only
   mechanism:    by value

   The value of a longword bit mask specifying the type of floating-
   point data that the input_value argument will be converted into
   and returned in the output_value argument. Valid type codes are:

                                                         Size in
   output_type_code         Format                       Bytes

   CVT$K_VAX_F              F_Floating                   4
   CVT$K_VAX_D              D_Floating                   8
   CVT$K_VAX_G              G_Floating                   8
   CVT$K_VAX_H              H_Floating                   16
   CVT$K_IEEE_S             IEEE_S_Floating              4
   CVT$K_IEEE_T             IEEE_T_Floating              8
   CVT$K_IEEE_X             IEEE_X_Floating              16
   CVT$K_IBM_LONG           IBM_Long_Floating            8
   CVT$K_IBM_SHORT          IBM_Short_Floating           4
   CVT$K_CRAY               CRAY_Floating                8

   Declarations for the output_type_code argument are in the $CVTDEF
   module found in the system symbol libraries.
 

options

   OpenVMS usage:mask_longword
   type:         longword (unsigned)
   access:       read only
   mechanism:    by value

   Conversion option specifier. The options argument is the address
   of a longword bit mask in which each option bit set causes the
   corresponding option to be used during the conversion.

   The following options can be specified using the options
   argument:

   Option                 Description

   CVT$M_ROUND_TO_        The default rounding option for
   NEAREST                conversions to IEEE data types. This
                          IEEE Std. 754 rounding mode results in
                          the representable output value nearest to
                          the infinitely precise result. If the two
                          nearest representable values are equally
                          near, the one whose least significant bit
                          is 0 is the result.
   CVT$M_VAX_ROUNDING     The default rounding option for
                          conversions to non-IEEE data types.
                          Performs "traditional" style rounding.
                          This mode results in the representable
                          output value nearest to the infinitely
                          precise result. If the two nearest
                          representable values are equally near,
                          the output value is the closest to either
                          positive infinity or negative infinity,
                          depending on the sign of the input value.
   CVT$M_TRUNCATE         Round the output value toward zero
                          (truncate).
   CVT$M_ROUND_TO_POS     Round the output value toward positive
                          infinity.
   CVT$M_ROUND_TO_NEG     Round the output value toward negative
                          infinity.
   CVT$M_BIG_ENDIAN       Interprets IEEE data types as Big Endian.
   CVT$M_ERR_UNDERFLOW    Report underflow conditions as errors.

   Declarations for the options argument are in the $CVTDEF module
   found in the system symbol libraries.