And there is ASMDREG which also has equates for other registers:- Access,
Control, Floating Point....

-----Original Message-----
From: IBM Mainframe Assembler List [mailto:[email protected]]
On Behalf Of Paul Gilmartin
Sent: Wednesday, July 31, 2013 16:34
To: [email protected]
Subject: Re: YREGS MACRO doc?

On 2013-07-31 15:01, Gerhard Postpischil wrote:
> On 7/31/2013 1:44 PM, Bernd Oppolzer wrote:
>> When I came to the site where I am actually working 25 years ago, I
>> was very surprised that they use RA to RF for 10 to 15 - I never met
>> that before, but you get accustomed to that very quickly. It's always
>> two characters, after all ...
>
> I first came across this form in the OS/360 reader/interpreter.
> Personally I don't like it because searches on RB and RE get many more
> false hits than R11 and R14.
>
And, of course, since there's no standard, the system macros must use pure
numeric designators.  And with a mixture of conventions, XREF doesn't
reliably list register references.
IATYREGS is somewhat unusual among IBM macros in that it sets a flag so it
can exit if it's used twice, and some other JES3 macros invoke IATYREGS so
they _can_ use register mnemonics.

I think I've also seen GR0-GR15, which likewise reduces the likelihood of
false hits in searches.

CDC 6600 et al. made the register names predefined, reserved, and mandatory.
It was impossible to confuse L and LR; the operands distinguish them.  And
no need for unintuitive conventions such as "7" means constant 7 and "(7)"
means register 7 in macro arguments.  It was "7" or "X7".  So, no need for
such as IHBINRRA.  And less incentive to print macro expansions; they did
what they appeared to from the call.

-- gil

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