I really gotta get back into PL/1.  It was my first language, and I still like 
it.  Just haven't used it in a few decades.

---
Bob Bridges, robhbrid...@gmail.com, cell 336 382-7313

/* The more sophisticated the technology, the more vulnerable it is to 
primitive attack. People often overlook the obvious.  -Dr Who, 1978 */

-----Original Message-----
From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of 
Robert Prins
Sent: Sunday, March 17, 2024 10:44

....I've updated PL/I code myself reducing ***CPU*** time from well over three 
hours to just 20 minutes, by just changing two declarations, and while working 
at a Dutch airline company, I reduced CPU usage of two PL/I programs 
calculating CRCs by more than 99.5%, removing calls to the PL/I library. Hell, 
if you look at the current Enterprise PL/I Programming Guide, GI13-5620-00, on 
PDF page
372 (book page 316) in the "Avoiding calls to library routines" paragraph, the 
text that reads

<quote>
When your code refers to a member of a BASED structure with REFER, the compiler 
often has to generate one or more calls to a library routine to map the 
structure at run time.  These calls can be expensive, and so when the compiler 
makes these calls, it will issue a message so that you can locate these 
potential hot-spots in your code.

If you do have code that uses BASED structures with REFER, which the compiler 
flags with this message, you might get better performance by passing the 
structure to a subroutine that declares a corresponding structure with * 
extents. This will cause the structure to be mapped once at the CALL statement, 
but there will no further remappings when it is accessed in the called 
subroutine.
</quote>

is almost a literal copy of text in an email I sent to IBM's Peter Elderon 
close to 30 years ago, and if you use PL/I to build linked lists, and/or trees 
using BASED storage, I'd suggest you think about the second
(area-reference) parameter of the ALLOC builtin function, and the NEXTALLOC 
builtin, both are the result of my RFEs, and combining them with the EMPTY 
builtin, well think about it. ;)

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