I don't have a dog in this fight; I was just trying to clarify what the issue 
was. It seems reasonable, but I haven't come up with a use case.

 If I were designing USING ab initio I would probably allow the 
base-displacement form only on a labelled USING, if at all. The only real way 
to determine the need is for someone to do an RFE with a good business case and 
see how many other customers concur.

--
Shmuel (Seymour J.) Metz
http://mason.gmu.edu/~smetz3
עַם יִשְׂרָאֵל חַי
נֵ֣צַח יִשְׂרָאֵ֔ל לֹ֥א יְשַׁקֵּ֖ר

________________________________________
From: IBM Mainframe Assembler List <[email protected]> on behalf 
of Jonathan Scott <[email protected]>
Sent: Wednesday, February 28, 2024 7:42 AM
To: [email protected]
Subject: Re: Why am I getting ASMA145E (was Re: Macro parameters: parsing a

There are certainly cases where a base-displacement operand on
USING would appear at first glance to make sense, as in the
suggested case:

         USING SOMELABEL,24(R3)

or with a symbolic offset expression

         USING SOMELABEL,TWENTY_FOUR(R3)

However, even in concept some of the implications are not
obvious.  This would obviously be expected to work like a
dependent USING, but it does not have a base USING giving the
list of registers to be used, so it is not the same.  One might
expect it to act as if there was an implicit base USING for R3
pointing 24 bytes earlier, but without a label, which would be a
new concept.  But does that mean one could issue a DROP R3 and
that R3 would be currently considered in use as a base so that a
new USING for R3 would drop this use?  At least since the
language enhancement for PH42188 in 2021 to allow DROP for a
relocatable symbol, one would be able to use DROP SOMELABEL.

These are examples of the sorts of issues that arise when we
investigate possible language enhancements.  If there is a
strong justification for some enhancement, it may be worth
working through such issues and finding solutions.  However, as
far as I can see, the current suggestion would appear to require
new concepts and raise complications which appear to be out of
proportion to the potential benefits.

Jonathan Scott, HLASM
IBM Hursley, UK

Reply via email to