HP Fortran Programmer Guide (766160-001, March 2014)

Table 29 Fine-tuning optimization options (continued)
FunctionLevelLevel
Enable [disable] register
association. The default is
+Oregreassoc.
NOTE: This option is valid
only on the PA-RISC systems.
+O2or higher +O2or higher+O[no]regreassoc
This option provides a hint
to the optimizer that the
All+Ono_return
named functions never return
to the call site. If the
+Ono_return:filenameform
is used, the file filename
contains a list of function
names separated by spaces
or newlines. This
optimization is available at
all optimization levels.
All objects of size bytes or
smaller are placed in the
All+Oshortdata[=size]
short data area, and
references to such data
assume it resides in the short
data area. Valid values of
size are a decimal number
between 8 and 4,194,304
(4MB). If no size is
specified, all data is placed
in the short data area.
The default is
+Oshortdata=8.
This option controls the
generation of source position
All+[no]srcpos
information for HP Caliper.
The default is +srcpos.
When +srcpos, is in effect,
the compiler generates
source position information.
When+nosrcposis in
effect, the compiler does not
generate this information
and the compiler instructs the
linker to discard any of this
information found in the
object files.
This option preserves [does
not preserve] the original
All+O[no]store_ordering
program order for stores to
memory that is visible to
multiple threads. This does
not imply strong ordering.
The default is
+Onostore_ordering.
Replace [do not replace]
eligible loops with calls to
+O3or higher+O[no]vectorize
the math library; for more
information, see “Using the
+Ovectorizeoption” on
page168. The default
is+Onovectorize.
98 Performance and optimization