HP XC System 2.x Software manual Building Parallel Applications, Reserved Symbols and Names

3.7.1.15 Reserved Symbols and Names

The HP XC system reserves certain symbols and names for internal use. Reserved symbols and names should not be included in user code. If a reserved symbol or name is used, errors could occur.

3.7.2 Building Parallel Applications

This section describes how to build MPI and non-MPI parallel applications on an HP XC system.

3.7.2.1 Compiling and Linking Non-MPI Applications

If you are building non-MPI applications, such as an OpenMP application for example, you can compile and link them on an HP XC as you normally would, with standard header files and switches.

3.7.2.2 Compiling and Linking HP-MPI Applications

This section provides some general information about how to build an HP-MPI application in the HP XC environment. Refer to Chapter 8 for complete details, examples, and further information about building HP-MPI applications.

Compiling and linking an MPI application on an HP XC system is performed by invoking the HP-MPI compiler utilities. HP-MPI compiler utilities are scripts supplied by HP-MPI to make it easier to invoke a compiler with the appropriate libraries and search paths. The HP-MPI compiler utilities add all the necessary path locations and library specifications to the compile and link steps that are required to build a HP XC parallel application. It is highly recommended that you use the HP-MPI compiler utilities to compile and link your MPI application on an HP XC cluster, rather than invoke a compiler directly.

The mpicc, mpic++, mpif90, and mpif77 MPI compiler commands are used to invoke the HP-MPI compiler utilities that compile and link an MPI application. The mpicc and mpic++ commands invoke the drivers of the C and C++ compilers. The mpif77 and mpif90 commands invoke the drivers of the Fortran 77 and Fortran 90 compilers.

Before you can compile and link an MPI program using the MPI compiler commands, the MPI compiler utilities module (mpi) must be loaded, or you must arrange for them to be in your $PATH search list. The use of modules is described in Section 2.2.

3.7.2.3 Examples of Compiling and Linking HP-MPI Applications

The following examples show how to compile and link your application code by invoking a compiler utility.

If you have not already loaded the mpi compiler utilities module , load it now as follows:

$ module load mpi

To compile and link a C application using the mpicc command:

$ mpicc -o mycode hello.c

To compile and link a Fortran application using the mpif90 command:

$ mpif90 -o mycode hello.f

In the above examples, the HP-MPI commands invoke compiler utilities which call the C and Fortran compilers with appropriate libraries and search paths specified to build the parallel application called hello. The -ospecifies that output is directed to a file called mycode.

Refer to Chapter 8 for additional information about building applications with HP-MPI.

3-8Developing Applications