HP UX Fortran Software manual +Oparallelintrinsics, Default is+Onoparmsoverlap, +Onopipeline

	on Itanium®-based systems for HP Fortran Version 3.2
	and later. You can use the +Oautopar option instead
	of +Oparallel on Itanium® based systems.
	NOTE: The +Oparallel option should not be used
	for programs that make explicit calls to the kernel threads
	library.
+Oparallel_intrinsics	+Oparallel_intrinsics links in the parallel version
	of many of the Fortran intrinsics located in
	libF90_parallel.
+O[no]parmsoverlap	+Oparmsoverlap causes the optimizer to assume that
	the actual arguments of function calls overlap in memory,
	thus preventing any optimizations that violate this
	assumption. This option is only effective at optimization
	level 2 or higher.
	Use the +Onoparmsoverlapoption with programs that
	conform to the standard requirement that parameters
	must not overlap
	The default is+Onoparmsoverlap.
+O[no]pipeline	+Opipelineenables 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.
	NOTE: This option is valid only on the PA-RISC systems.
+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 +Oprocelimis 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 +Oprocelimto 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 +Onoprocelimat levels 0-3, and
	+Oprocelimat 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=collectis
	the same as +I.
	< qualifiers > are a comma-separated list of profile
	collection qualifiers. Supported profile collection qualifiers
	are :

Fine-tuning optimization options 47