Choosing compiler features to enhance performance
Your choice of performance-related compiler options and
your use of the
USE FOR DEBUGGING ON ALL PROCEDURES statement
can affect how well your program is optimized.
You might have a customized system that requires certain options for optimum performance. Do these steps:
- To see what your system defaults are, get a short listing for any program and review the listed option settings.
- Determine which options are fixed as nonoverridable at your installation by checking with your system programmer.
- For the options not fixed at installation,
select performance-related options
for compiling your programs.
Important: Confer with your system programmer about how to tune COBOL programs. Doing so will ensure that the options you choose are appropriate for programs at your site.
Another compiler feature to consider is the
FOR DEBUGGING ON ALL PROCEDURES statement. It can greatly
affect the compiler optimizer. The
ON ALL PROCEDURES option
generates extra code at each transfer to a procedure name. Although
very useful for debugging, it can make the program significantly larger
and inhibit optimization substantially.
Although COBOL allows segmentation language, you will not improve storage allocation by using it, because COBOL does not perform overlay.
Performance-related compiler options