First debug your program, then recompile it with your desired optimization
options, and test the optimized program before placing the program
into production. If the optimized code does not produce the expected
results, you can attempt to isolate the specific optimization problems
in a debugging session.
The following list presents options that provide specialized information,
which can be helpful during the development of optimized code:
- -qsmp=noopt
- If you are debugging SMP code, -qsmp=noopt ensures that
the compiler performs only the minimum transformations necessary to
parallelize your code and preserves maximum debug capability.
- -qkeepparm
- Ensures that procedure parameters are stored on the stack even
during optimization. This can negatively impact execution performance.
The -qkeepparm option then provides access
to the values of incoming parameters to tools, such as debuggers,
simply by preserving those values on the stack.
- -qlist
- Instructs the compiler to emit an object listing. The object listing
includes hex and pseudo-assembly representations of the generated
instructions, traceback tables, and text constants.
- -qreport
- Instructs the compiler to produce a report of the loop transformations
it performed and how the program was parallelized. For -qreport to
generate a listing, the options -qhot or -qsmp should
also be specified.
- -qinitauto
- Instructs the compiler to emit code that initializes all automatic
variables to a given value.
- -qipa=list
- Instructs the compiler to emit an object listing that provides
information for IPA optimization.
You can also use the snapshot pragma to ensure that
certain variables are visible to the debugger at points in your application.