On 3/23/2016 5:36 AM, David Crayford wrote:
On 23/03/2016 5:41 AM, Charles Mills wrote:
There is a compiler for Rexx but its performance improvement is moderate.
It depends on what the REXX is doing. We compiled the ISPF DTL compiler
and saw a significant performance improvement.
IIRC, automation products like NetView get a free REXX compiler (they
need it) and for that domain it makes a lot of sense. Lots of string
parsing.
The REXX compiler unfortunately can produce suboptimal code that is much
slower than interpreted REXX if you do a lot of memory
allocations, think queues and stem variables. I profiled a compiled REXX
program in APA and it appears to be doing a GETMAIN for each
allocation. Nearly 95% of the CPU time was spent in GETMAIN! Ouch :^/
David,
Thank you very much for verifying this. I reported this issue to the
Rexx compiler team about 10 years ago when the product was still
supported. I use stems like crazy, and compiling the Rexx exec made it
run a lot longer. I also had this weird thing where the job took two
hours to exit the system after it was done running. FREEMAINs?
Regards,
Tom Conley
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