HP-MPI User's Guide (11th Edition)

Understanding HP-MPI
Autodouble functionality
Chapter 352
Autodouble functionality
HP-MPI supports Fortran programs compiled 64-bit with any of the
following options (some of which are not supported on all Fortran
compilers):
For HP-UX:
• +i8
Set default KIND of integer variables is 8.
• +r8
Set default size of REAL to 8 bytes.
• +autodbl4
Same as +i8 and +r8.
• +autodbl
Same as +i8, +r8, and set default size of REAL to 16 bytes.
For Linux:
• -i8
Set default KIND of integer variables is 8.
• -r8
Set default size of REAL to 8 bytes.
• -r16
Set default size of REAL to 16 bytes.
• -autodouble
Same as -r8.
The decision of how the Fortran arguments will be interpreted by the
MPI library is made at link time.
If the mpif90 compiler wrapper is supplied with one of the above options
at link time, the necessary object files will automatically link, informing
MPI how to interpret the Fortran arguments.