HP Fortran Programmer's Guide (March 2010)

Compiling and linking
Compiling with the f90 command
Chapter 276
The default is +Onoparmsoverlap.
+O[no]pipeline
+Opipeline enables software pipelining. This option is only effective at
optimization level 2 or higher.
Use +Onopipeline (disable software pipelining) to conserve code space.
The default is +Opipeline.
+Oprefetch_latency=num option
Applies to loops for which the compiler generates data prefetch instructions.
For a given loop, the compiler divides “cycles” by the estimated loop length
to arrive at the number of loop iterations for which to generate advance
prefetches. The default value is 480 cycles for loops containing floating-point
accesses and 150 cycles for loops that do not contain any floating-point
accesses. For tuning purposes, it is recommended that users measure their
application’s performance using a few different prefetch latency settings to
determine the optimal value. Some floating-point codes may benefit by
increasing the distance to 960. Parallel applications frequently benefit from
a shorter prefetch distance of 150.
+O[no]procelim When +Oprocelim is specified, procedures that are not referenced by the
application are eliminated from the output executable file. When
+Onoprocelim is specified, procedures that are not referenced by the
application are not eliminated from the output executable file. You can use
this option at any level of optimization.
Use +Oprocelim to reduce the size of the executable file, especially when
optimizing at levels 3 and 4, when inlining can remove all calls to some
routines.
The default is +Onoprocelim at levels 0-3, and +Oprocelim at level 4.
+Oprofile=use:filename
Specify filname as the name of the profile database file. This option is a
synonym for the +P, +dffilename options.The :filename argument is optional
(the default filename is flow.data). See ld (1), +P, and +df for more details.
This option is only valid for Itanium-based applications.
+Oprofile=collect[:<qualifiers>]
In the absence of qualifiers, +Oprofile=collect is the same as +I.
<qualifiers> are a comma-separated list of profile collection qualifiers.
Supported profile collection qualifiers are: