HP Fortran Programmer's Guide (September 2007)

Performance and optimization
Using options to control optimization
Chapter 6148
+O[no]autopar Do [do not] automatically parallelize loops
that are deemed safe and profitable by the
loop parallelizer. The default is
+Onoautopar. The +Oautopar option can be
used for programs at optimization levels,
+O3 and above.
If both +Oopenmp and +Oautopar are
specified on the command line, the OpenMP
directives gain precedence over the
+Oautopar option. The compiler
auto-parallelizes only the loops of code that
are not controlled by the OpenMP
directives.
To compile a program with +Oautopar
support, the libcps, libomp, and
libpthreads runtime support libraries
must be present at compile-time and
runtime. This feature is available on
Integrity systems and HP 9000 systems.
+O[no]conservative +O2 or higher Suppress [do not suppress] optimizations
that assume strict conformity to the
Fortran 90 standard. The default is
+Onoconservative. For more information
about this option, see “Conservative vs.
aggressive optimization” on page 152.
+O[no]limit +O2 or higher Enable [disable] optimizations that do not
make large demands on system resources.
The default is +Onolimit.
+O[no]size +O2 or higher Enable [disable] optimizations that do not
significantly increase code size. The default
is +Onosize.
Table 6-2 Packaged optimization options (Continued)
Option Level Function