This option specifies the data size of double and long double type.
[Specification format]
 
-  | Interpretation when omitted  | 
 
double and long double type are 8 bytes (this is the same result as when -Xdbl_size=8 is specified).
[Detailed description]
-  | This option specifies the data size of  double and long double type.  | 
 
-  | One of the following can be specified as num. An error will occur if any other item is specified.  | 
 
-  | 4 
double and long double type are 4 bytes.  | 
 
-  | 8 
double and long double type are 8 bytes.  |