HP Fortran Programmer's Guide (March 2010)

Compiling and linking
Compiling with the f90 command
Chapter 2 75
+O[no]multiprocessor
+Omultiprocessor tells the compiler to appropriately optimize several
different processes on multiprocessor machines. The optimizations are those
appropriate for executables and or shared libraries. +Onomultiprocessor,
the default, disables the optimization of more than one process running on a
multiprocessor machine.
+O[no]openmp +Oopenmp allows users to enable the OpenMP directives. +Onoopenmp will
disable the OpenMP directives. +O[no]openmp is accepted at all
optimization levels. The default is +Onoopenmp.
+O[no]parallel
+Oparallel causes the compiler to transform eligible loops for parallel
execution on multiprocessor machines. This option is effective only at
optimization level 3 or higher. This option is available only on HP 9000
systems.
If you link separately from the command line and compile the program with
the +Oparallel option, you must link with the f90 command and specify
the +Oparallel option to link in the correct runtime support.
The +Onoparallel option disables parallelization for the target program. It
is the default at all levels of optimization.
The +Oparallel option is not available on Itanium-based systems for HP
Fortran Version 3.2 and later. You can use the +Oautopar option instead of
+Oparallel on Itanium-based systems.
NOTE The +Oparallel option should not be used for programs that
make explicit calls to the kernel threads library.
+Oparallel_intrinsics
+Oparallel_intrinsics links in the parallel version of many of the
Fortran intrinsics located in libF90_parallel.
+O[no]parmsoverlap
+Oparmsoverlap causes the optimizer to assume that the actual arguments
of function calls overlap in memory, thus preventing any optimizations that
violate this assumption. This option is only effective at optimization level 2
or higher.
Use the +Onoparmsoverlap option with programs that conform to the
standard requirement that parameters must not overlap.