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IBM-MAIN - Performance von Enterprise PL/1 (Init. von AUTO-Bereichen)

Subject:

Re: Enterprise PL/1 performance

From:

Bernd Oppolzer <bernd.oppolzer@T-ONLINE.DE>

Reply-To:

IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU>

Date:

2015.02.24 19:10:31


IMO the older versions of PL/1 didn't have such options to initialize automatic
storage.  Or, if they had, it was VERY uncommon to use them ...

I would suggest to check the old versions reference manuals and if there indeed
is such an option (I don't think so, but maybe), then I would look at old
compile listings (which should have been archived) and check if this option has
been used (hopefully not).  If there was no such option or if it has not been
used, there is no danger to switch it off.

Kind regards

Bernd



Am 24.02.2015 um 17:35 schrieb D.G.:
>> Region default                    STORAGE(00,NONE,00,0)
>> The third parameter set to zero is a killer, get rid of it! The consequence of
>> using it Is that all automatic storage in a procedure will be set to binary
>> zeroes upon each entry to the procedure, and if you've got deeply nested
>> procedures with lots of local variables, you will suffer, big, big, big time! If
>> you need specific variables to be initialised use INIT(whatever) on those, and
>> only those.
>
> While what you state is all true, its not a good advice to change that without
> proper testing, because they might have old (e.g. COBOL) LE programs, that rely
> on the storage being zero'd out by LE, because they do not have INIT or VALUES
> clauses and programs cannot be changed in time to allow the third parm to be
> set to something other than 00.
>
> For example VS COBOL used to have the option WSCLEAR, which did not require
> initializing variables, I don't know about pre Enterprise Versions of PL/I.
>
> D.

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