Parallel Programming Guide for HP-UX Systems

MPI

Compiling and Linking

Chapter 220

Same as -r8.

For Tru64UNIX:

• -r8

Deﬁnes REAL declarations, constants, functions, and intrinsics as DOUBLE PRECISION

(REAL*8), and deﬁnes COMPLEX declarations, constants, functions, and intrinsics as

DOUBLE COMPLEX (COMPLEX*16). This option is the same as the -real_size 64

option.

• -r16

Deﬁnes REAL and DOUBLE PRECISION declarations, constants, functions, and

intrinsics as REAL*16. For f90, it also deﬁnes COMPLEX and DOUBLE COMPLEX

declarations, constants, functions, and intrinsics as COMPLEX*32. This option is the

same as the -real_size 128 option.

• -i8

Makes default integer and logical variables 8-bytes long (same as the -integer_size 64

option). The default is -integer_size 32.

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.

The following MPI functions accept user-deﬁned functions:

• MPI_Op_create()

• MPI_Errhandler_create()

• MPI_Keyval_create()

• MPI_Comm_create_errhandler()

• MPI_Comm_create_keyval()

• MPI_Win_create_errhandler()

• MPI_Win_create_keyval()