HP aC++/HP C A.06.25 Programmer's Guide

Example 1
In the following example, the FLOW_DATA environment variable is used to override
the flow.data file name. The profile data is stored instead in /users/profiles/
prog.data.
export FLOW_DATA=/users/profiles/prog.data
aCC -c +Oprofile=collect sample.C
aCC -o sample.exe +Oprofile=collect sample.o
sample.exe < input.file1
aCC -o sample.exe +Oprofile=use +O3 sample.C
Example 2
In this example, the +Oprofile=use:filename option is used to override the
flow.data file name with the name /users/profiles/prog.data.
aCC -c +Oprofile=collect +O3 sample.C
aCC -o sample.exe +Oprofile=collect sample.o
sample.exe < input.file1
mv flow.data /users/profile/prog.data
aCC -o sample.exe +Oprofile=use:/users/profiles/prog.data +O3 sample.C
Performing Profile-Based Optimization
To optimize the program based on the previously collected runtime profile statistics,
recompile the program as follows:
aCC -o sample.exe +Oprofile=use +O3 sample.C
For more information on profile-based optimization, refer to the HP-UX Online Linker
and Libraries User’s Guide.
Pragmas That Control Optimization
Compiler options provide a high-level, global approach to optimization. To give you
more refinement in optimization, HP aC++ provides pragma OPT_LEVEL.
See “Optimization Pragmas” (page 135) for more information.
210 Optimizing HP aC++ Programs