/FLOAT=[option]

  Specifies the floating-point data format to be used in memory
  for single and double precision data items.

  You can use the /FLOAT qualifier at compile time to specify
  either VAX F_floating or IEEE S_floating formats for single
  precision data items or VAX D_floating or VAX G_floating or
  IEEE T_floating formats for double precision data items.  You
  cannot mix VAX and IEEE formats in the same compilation unit.

  You can select one of the following options:

  D_FLOAT         Specifies that the memory format for COMP-1
                  data is VAX F_floating and for COMP-2 data
                  is VAX D_floating.  The default is D_FLOAT
                  on OpenVMS Alpha.

                  Note that D_floating on Alpha and I64 is
                  not 100% compatible with D_floating on VAX.

  G_FLOAT         Specifies that the memory format for COMP-1
                  data is VAX F_floating and for COMP-2 data
                  is VAX G_floating.

                  Note that G_floating on I64 is not 100%
                  compatible with G_floating on Alpha and VAX.

  IEEE_FLOAT      Specifies that the memory format for COMP-1
                  data is IEEE S_floating and for COMP-2 data
                  is IEEE T_floating.  The default is IEEE_FLOAT
                  on OpenVMS I64.

  The IEEE standard for binary floating-point arithmetic,
  ANSI/IEEE 754-1985, defines four floating-point formats in two
  groups, basic and extended, each group having two widths, single
  and double.  The Alpha architecture supports the basic single
  and double formats.  Refer to the Alpha Architecture Reference Manual
  for more information about using floating-point data types with
  the Alpha architecture.

  Because the Alpha and I64 architectures are IEEE-compliant, you can run
  existing COBOL programs containing IEEE floating-point data formats
  with VSI COBOL.

  Specifying /FLOAT without an option is equivalent to specifying
  /FLOAT=D_FLOAT on OpenVMS Alpha and /FLOAT=IEEE_FLOAT on OpenVMS I64.