HP Fortran Programmer's Guide (September 2007)

Compiling and linking
Compiling with the f90 command
Chapter 2 63
+O[no]cxlimitedrange
Enables [disables] the use of floating point math in the compilation unit.
The default is +Onocxlimitedrange.
+O[no]cross_region_addressing
Enable [disable] the use of cross-region addressing. Cross-region addressing
is required if a pointer (such as an array base) points to a different region
than the data being addressed. This is usually due to an offset which results
in a cross-over into another region. Standard-conforming applications do not
require the use of cross-region addressing.
The default is +onocross_region_addressing.
+O[no]dataprefetch
+Odataprefetch causes the optimizer to insert instructions within
innermost loops to explicitly prefetch data from memory into the data cache.
Data prefetch instructions will be inserted only for data structures
referenced within innermost loops using simple loop varying
addresses—that is, in a simple arithmetic progression. This option is only
effective at optimization level 2 or higher. It is not available for PA-RISC 1.1
targets.
Use this option for applications that have high data cache miss overhead.
The default is +Onodataprefetch.
+O[no]dataprefetch=[direct|indirect|none]
Control generation of data prefetch instructions for data structures
referenced within innermost loops. The defined values for kind are:
direct—enable generation of data prefetch instructions for the benefit of
direct memory accesses, but not indirect memory accesses.
indirect—enable generation of data prefetch instructions for the benefit of
both direct and indirect memory accesses. This is the default at optimization
levels +O2 and above.
none—disable generation of data prefetch instructions. This is the default at
optimization levels +O1 and below.
+O[no]entrysched
+Oentrysched allows the optimizer to perform instruction scheduling on a
subprogram’s entry and exit code sequences. This option is only effective at
optimization level 1 or higher.