Specifies the default KIND for real variables.
Windows: Data > Default Real KIND
Linux: None
IA-32, IntelŪ EM64T, IntelŪ ItaniumŪ architecture
| Linux: | -real_size size |
| Windows: | /real_size:size |
| size | Is the size for real and complex variables. Possible values are: 32, 64, or 128. |
| real_size 32 | Default real and complex variables are 4 bytes long (REAL(KIND=4) and COMPLEX(KIND=4)). |
This option specifies the default size (in bits) for real and complex variables.
Option |
Description |
|---|---|
| real_size 32 | Makes default real and complex variables 4 bytes long. REAL declarations are treated as single precision REAL (REAL(KIND=4)) and COMPLEX declarations are treated as COMPLEX (COMPLEX(KIND=4)). |
| real_size 64 | Makes default real and complex variables 8 bytes long. REAL declarations are treated as DOUBLE PRECISION (REAL(KIND=8)) and COMPLEX declarations are treated as DOUBLE COMPLEX (COMPLEX(KIND=8)). |
| real_size 128 | Makes default real and complex variables 16 bytes long. REAL declarations are treated as extended precision REAL (REAL(KIND=16)); COMPLEX and DOUBLE COMPLEX declarations are treated as extended precision COMPLEX (COMPLEX(KIND=16)). |
These compiler options can affect the result type of intrinsic procedures, such as CMPLX, FLOAT, REAL, SNGL, and AIMAG, which normally produce single-precision REAL or COMPLEX results. To prevent this effect, you must explicitly declare the kind type for arguments of such intrinsic procedures.
For example, if real_size 64 is specified, the CMPLX intrinsic will produce a result of type DOUBLE COMPLEX (COMPLEX(KIND=8)). To prevent this, you must explicitly declare any real argument to be REAL(KIND=4), and any complex argument to be COMPLEX(KIND=4).
| real_size 64 | Linux: -r8, -autodouble Windows: /4R8, /Qautodouble |
| real_size 128 | Linux: -r16 Windows: /4R16 |