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

Table 29 Fine-tuning optimization options (continued)
FunctionLevelLevel
collisions. The default is
+Onocache_pad_common.
Insert [do not insert]
instructions within innermost
+O2 or higher+O[no]dataprefetch
loops to explicitly prefetch
data from memory into the
data cache. The default is
+Onodataprefetch.
Enable [disable] dynamic
optimization for the output
All+O[no]dynopt
file, if the run-time
environment supports this
feature. Both forms of this
option change the default
setting, which allows the
run-time environment to
enable or disable dynamic
optimization according to a
system-wide default. This
option applies only to
executable files and shared
libraries.chatr(1) can be
used to change this setting,
including restoration of the
default setting, after the
output file has been created.
Perform [do not perform]
instruction scheduling on
All+O[no]entrysched
entry and exit code. The
default is
+Onoentrysched.
NOTE: This option is valid
only on the PA-RISC systems.
Enable [disable] fast access
to global data. The default
All+O[no]fastaccess
is +Onofastaccessat
levels 1, 2, and 3;
+Ofastaccessat level 4.
Select a combination of
optimization options for
All+Ofast
optimum execution speed
and reasonable build times.
Currently chosen options
are:
• +O2
• +Ofltacc=relaxed
• +Onolimit
• +DSnative
• +FPD
• Wl,+pi,1M-
• -Wl,+pd,1M
• -Wl,+mergeseg
Using options to control optimization 93