Useful links:
IBM compiler documentation:
``IBM: XL Fortran'',
especially
``IBM AIX compiler information center''.
Another source of the compiler documentation:
``Documentation for AIX Systems'',
especially
``IBM XL Fortran for AIX Version 8.1.1 Library''.
Particularly useful hints:
``Porting Programs from the Crays to the SP''.
The compiler to be used for OpenMP runs is called with xlf90_r
which
``binds the object files to the thread-safe components'' (IBM documentation).
For scalar code xlf90
might be sufficient.
Important switches are:
-qsuffix=f=f90 -qsuffix=cpp=F90
: To tell the compiler about the
existence of Fortran90 and to enable the preprocessing for files with
suffix ``F90''.
-qextname=flush:etime
: Append underscore to both routine names.
The non-standard routine call_system
used by the uio_mac_sun_module
is recognized automatically.
-WF,-Drhd_r03
: The compiler does not send switches starting
with -D
to the preprocessor but tries to interpret it itself - unlike
all othe compilers. Therefore, each switch (e.g. -Drhd_r03
)
has to ``escaped'' with -WF,
(as e.g. -WF,-Drhd_r03
).
-q64
: Activate the 64-bit mode. In the default 32-bit mode
a very small model (with total memory requirements far below the 2 GByte limit)
might run. However, experienced IBM users might experiment instead
with the compiler switches -bmaxstack
, -bmaxdata
, and -qsmallstack
,
with the UNIX commands limit
or ulimit
,
or with the settings in the header of the batch script...
-O3
: Choose optimization level.
Higher levels that involve interporcedural analysis cause the compiler to stop
with an error message.
-qarch=auto -qtune=auto -qcache=auto
: To allow optimization specific for the local machine
(default in the configure script).
``Cross compilation'' can be activated e.g. with -qarch=pwr3 -qtune=pwr3
or -qarch=pwr4 -qtune=pwr4
(by setting an environment variable, e.g. F90_MACHINE="(pwr3)"
before calling configure
).
-Q -Q+...
: To activate inlining
and to specify the list of routines that should be inlined (see Sect. 3.8.2).
-qsmp=noauto:omp
: Parallelization: OpenMP directives are activated.
A job script rhd.job
on the Loadleveler batch system on
io.cines.fr
can be submitted with
The jobs in the queue for user testuser
can be checked with
A job with ID n34.56789.0
can be cancelled with