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:

For Linux:

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.

	NOTE: This autodouble feature is supported in the regular and multithreaded MPI libraries, but not in the diagnostic library.

For Windows CCP:

/integer_size:64
/4I8
-i8
/real_size:64
/4R8
/Qautodouble
-r8

If these flags are given to the mpif90.bat script at link time, then the application will be linked enabling HP-MPI to interpret the datatype MPI_REAL as 8 bytes (etc. as appropriate) at runtime.

However, if your application is written to explicitly handle the autodoubled datatypes (e.g. if a variable is declared real and the code is compiled -r8 and corresponding MPI calls are given MPI_DOUBLE for the datatype), then the autodouble related command line arguments should not be passed to mpif90.bat at link time (because that would cause the datatypes to be automatically changed).