Compiler options

The NEC manuals describe all options in detail. A short overview for the fortran compiler will be given here:

sxf90   [external opts] \
        [-Wp "<preprocessor options>"] \
        [-Wf "<internal options>"] \
        [-Wl "<linker options>"]
        <files>

The most important external options are:

      -C [ hopt | vopt | sopt | vsafe | ssafe | debug ]

They set the optimization level. Default is vopt (= vector optimization). The letters v and s mean vector and scalar, resp. hopt is the highest level of optimization and should be used with care. Be sure to check your results! (The -O option is a NEC internal option and not related to the parameter of the CRAY compiler.)

        -EP oder -Ep

activates the C preprocessor for suffixes f and f90. (-EP creates a file with preprocessor output, -Ep not)

               -ftrace

is used for detailed performance analysis.

      -eC

tells the compiler to instrument the code with the ABC test (=Array Bounds Check). Optimization is turned off then.

              -P[ auto | multi | openmp | stack | static ]

creates parallel code. Default is static (no parallel code, all variables are static). Parameter auto specifies that the automatic parallelizing function -similar to the CRAY autotasking- will be used. (see Parallelverarbeitung auf SX-6 )

        -Rn (n=0,1,2,3,4,5)

The iteration count is important for vectorization. The compiler makes an assumption depending on array dimensions in a do loop. If this is not possible in complex loops the default value (5000) is taken. This may be too small in some cases and should be increased to the maximum possible loopcount (further information in the manual, Programmer's Guide ...).

       -Wf "-pvctl noassume loopcnt=n"

Libraries

You can also link libraries in SX-6 format in the cross environment. Some important libraries are installed on cross. Specially optimized versions of BLAS, LAPACK and other libs which are distributed as the MathKeisan package can be found in /pool/SX-6/MathKeisan. The MathKeisan manual describes these libs in detail.

Further you find versions of the mathematical libraries NAG and IMSL as well as of the netCDF I/O libraries in /pool/SX-6. An overview of the installed Libraries on cross and hurrikan can be found in SX-6 software list

Some of the libraries are installed in the default search path of the linker. Example for compile runs:

sxf90 -o foo foo.f90  -lblas

sxf90 -o foo foo.f -L/pool/SX-6/netcdf/netcdf-<version>/lib -lnetcdf

#PBS -S /bin/csh
#PBS -l cpunum_prc=1    # 1 cpus
#PBS -l cputim_job=2:00:00 # 2 h cputime
#PBS -l memsz_job=1gb   # 1 Gbyte memory
#PBS -j o               # join err and out to out

#PBS -N job_II          # job name
#PBS -M myname@mymail.de  # you should always specify your email 
                          # address for error messages etc

setenv F_FILEINF YES    # information about I/O to stderr {NO|YES|DETAIL},
                        # may increase I/O time if not {NO}

setenv F_PROGINF DETAIL # program information about speed, vectorization
                        # {NO|YES|DETAIL}

setenv F_FTRACE  YES    # analysis list from compile option -ftrace {NO|YES}
                        # compile option -ftrace should be used only during
                        # optimization runs (causes overhead in execution time)

/bin/echo " job started at: " \\c
date
/bin/echo " Account code:   " \\c
showacct                 # print account code used in this hurrikan job
/bin/echo " ExecutionHost:  " \\c
hostname                 # print name of current host 

echo $PBS_O_WORKDIR      # helpful variables for the specific request
echo $PBS_JOBNAME
echo $PBS_JOBID

cd $PBS_O_WORKDIR

./prog [argument_1] [argument_2]

/bin/echo " job completed at: " \\c
date

###########################

 qsub -A <accountcode> ...