HP Fortran Programmer's Guide (September 2007)

Performance and optimization
Using options to control optimization
Chapter 6 147
The options in both tables can be combined on the same command line, except as noted. For
example, the following command line requests aggressive optimizations at level 2 that do not
increase code size:
$ f90 +02 +Oaggressive +Osize prog.f90
Nearly all of the optimization options can be used to enable or disable an optimization or a
package of optimizations. For example, the following command line requests aggressive level
4 optimizations that do not result in roundoff errors:
$ f90 +O4 +Oaggressive +Ofltacc prog.f90
The f90.1 manpage fully describes all of the optimization options.
Table 6-2 Packaged optimization options
Option Level Function
+O[no]aggressive +O2 or higher Enable [disable] optimizations that can
significantly improve performance in
standard-conforming programs. The default
is +Onoaggressive. For more information
about this option, see “Conservative vs.
aggressive optimization” on page 152.
+O[no]all Invokes highest
level
Enable [disable] maximum optimization.
The default is +Onoall.