/REAL_SIZE=n D=/REAL_SIZE=32

 Controls how the compiler interprets floating-point declarations
 that do not have a specified length.

 The default, /REAL_SIZE=32, defines REAL declarations, constants,
 functions, and intrinsics as REAL(KIND=4) (single precision) and
 COMPLEX declarations, constants, functions, and intrinsics as
 COMPLEX(KIND=4) (single COMPLEX).

 Specifying /REAL_SIZE=64 defines REAL declarations, constants,
 functions, and intrinsics as REAL(KIND=8) (DOUBLE PRECISION) and
 COMPLEX declarations, constants, functions, and intrinsics as
 COMPLEX(KIND=8) (DOUBLE COMPLEX).

 This also causes intrinsic functions to produce a double precision
 REAL(KIND=8) or COMPLEX(KIND=8) result instead of a single
 precision REAL(KIND=4) or COMPLEX(KIND=4) result, unless the
 argument is explicitly typed.

 For example, if you specify /REAL_SIZE=64, references to the CMPLX
 intrinsic produce DCMPLX results (COMPLEX(KIND=8)).  However, if
 the argument to CMPLX is explicitly typed as REAL(KIND=4) or
 COMPLEX(KIND=4), the resulting data type is COMPLEX(KIND=4).

 Specifying /REAL_SIZE=128 defines REAL declarations, constants,
 functions, and intrinsics as REAL(KIND=16).  It does not affect
 COMPLEX objects.