Use the pgf90 compiler (via the ftn wrapper) to link and provide the -Mnomain option.
If you are receiving the “multiple definition of main” error, you probably have a C program that calls Fortran, and you are linking with the Portland Group Fortran compiler. The Fortran compiler has its own default “main,” and now there is a second main from the C source. You may need to add the -Mnomain flag during link time...
Under the 1.5 programming environments used under Catamount, ftn linked in libC.a. Under the 2. programming environments used under CNL, ftn does not link in libC.a. Fortran codes that link in libraries that contain C++ objects will need to add -lC to the link line.
The Cray XT4 and XT5 are little-endian. There is a compiler switch -Mbyteswapio that makes the default Fortran unformatted I/O big-endian (read and write.)
Note that this little-endian-to-big-endian conversion feature is intended for Fortran unformatted I/O operations. It enables the development and processing of files with big-endian data organization. The feature also enables processing of the files developed on processors that generate big-endian data (such as IBM,...
At least three profiling tools are available on Kraken.
fpmpi is an unsupported product that can provide a very concise profile of MPI routines in an application. To use it, simply load the fpmpi (or fpmpi_papi) module and relink. Then rerun your application. There are a few environment variables to control profiling output:...Use the following process:
module load xt-craypat.-Mprof=func.pat_build -u -g mpi a.out.a.out+pat as you would a.out, BUT make sure PAT_RT_HWPC is set to 1 in batch script.
...For Kraken consult the “Cray online documentation” (http://docs.cray.com).
For C, search for the Cray “C and C++ Reference Manual” and for Fortran, consult the “Cray Fortran Compiler Commands and Directives Reference Manual”.
mpicc, mpif90, icc, ifort, pgCC, pgf90, etc)
with the following: cc (C), CC (C++) or ftn (Fortran).
