HP Fortran Programmer's Guide (March 2010)

Performance and optimization
Using options to control optimization
Chapter 6164
+O[no]whole_program_mode +O4 or
higher
Enable the assertion that only the files
that are compiled with this option directly
reference any global variables and
procedures that are defined in these files.
In other words, this option asserts that
there are no unseen accesses to the globals.
When this assertion is in effect, the
optimizer can hold global variables in
registers longer and delete inlined or
cloned global procedures. This option is in
effect only at +O4 level of optimization.
All files compiled with
+Owhole_program_mode must also be
compiled with +O4. If any of the files are
compiled with +O4 but are not compiled
with +Owhole_program_mode, the linker
disables the assertion for all files in the
program.
Use this option to increase performance
speed, but only when you are certain that
only the files compiled with
+Owhole_program_mode directly access
any globals that are defined in these files.
The default is +Onowhole_program_mode
which disables the assertion.
Table 6-3 Fine-tuning optimization options (Continued)
Option Level Function