Am 07.09.2023 um 01:40 schrieb Leonard D Woren:
Michael Stein wrote on 9/6/2023 3:45 PM:
[...] PL/1 F level subroutine calls did a getmain/freemain for each
subroutine call. Too much overhead to call even one subroutine for
each of 30K records on a 360/91 & MVT.
Well, my recollection is that if you had only Static storage, no
Automatic storage, it didn't do a GETMAIN.
Or was that an enhancement in the new PL/I compiler? Was that PLIX?
Yeah, not using stuff for decades can cause memory fade.
/Leonard
I first came into contact with PL/1 in the end of the 1980s at the
beforementionend insurance company.
At that time, they had the V2.3 optimizer (IIRC), and it produced pretty
amazing code. I was asked to
do PL/1 classes for the developers there. This company made (and still
makes) heavy use of automatic storage and tried to
code all modules "naturally reentrant", that is: no modified static
storage. So the problems with getmain/freemain
at procedure startup and end must have been long gone. That company
started with PL/1 in the beginning of the 1980s,
before that is was an ASSEMBLER only shop. (C came later, from 1992 on).
1992 (and 1994 again) I was asked to do a dump analysis class in another
PL/1 company. They indeed had
DEFEAULT RANGE(*) STATIC;
in almost every program. I didn't understand the reason at that time and
thought is was for dump reading,
because static variable (in the STATIC CSECT which is part of the load
module) are much easier to find than
auto variables (living in the stack). But now I have the impression that
this could have simply been a performance
issue in the beginning.
Kind regards
Bernd
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