HP Fortran Programmer's Guide (B3908-90031; September 2011)

Compiling and linking
Compiling with the f90 command
Chapter 262
• +FPD
+FPD is enabled only if +Oaggressive is used on the link line.
NOTE The +Oaggressive option is incompatible with +Oconservative.
The default is +Onoaggressive.
NOTE This option is only valid on the PA-RISC systems.
+O[no]all
+Oall performs maximum optimization, including aggressive optimizations and
optimizations that can significantly increase compile time and memory usage. The
+Oall option automatically invokes the highest level of optimization.
The default is +Onoall.
This option has been deprecated on version HP-UX 11i and later.
+O[no]autopar
+O[no]autopar controls automatic parallelization of loops that are deemed safe and
profitable by the loop parallelizer.
The auto-parallelization feature enables applications to use the idle resources on
multicore or multiprocessor systems, by automatically transforming the serial loops of
code in the program into multithreaded parallel code.
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.
On HP 9000 systems, when +Oautopar is used with the +Oparallel option, +O4 is
inhibited. If automatic parallelization is desired along with +O4, then use +Oautopar
and omit +Oparallel.
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 Itanium-based systems and HP 9000 systems.
+O[no]conservative