> -----Original Message-----
> From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On
> Behalf Of Steve Comstock
> Sent: Tuesday, November 07, 2006 6:38 AM
> To: [email protected]
> Subject: Re: Assembler question
>
/snip/
> > Best practice: MVC TARGET(6),=XL6'402021212121'
>
> So why does the Assembler even bother calculating
> length values? I disagree on two points:
>
> * Never use literals; always define a constant
> and reference the label on the constant
>
> * Never code explicit lengths unless you are
> not using the value generated by the Assembler
>
> But I realize these are points of style / preference /
> local standards. I do not intend to start a holy war,
> these are just my preferences.
>
> > Note the length modifer. This surfaces both the exact length of the
> > source and the exact length of the move. People who omit the length
> > modifer are sentenced to the 9th level of hell for all eternity. Or
> even
> > longer.
>
> Well, there ya' go, the holy war has begun. But let's not
> persist. We let our opinions be known and now we move on.
>
> Kind regards,
>
> -Steve Comstock
/snip/
For my 2 cents worth:
1. I would like a controllable warning when the MVC/CLC target is
*longer* than the source literal operand. If the source operand
is not a literal, then trust the programmer and be quiet.
2. HLASM seems to treat "MVC FOO(1),BAR" the same as "MVC FOO(0),BAR".
I cannot think of a clean way to flag an improper FOO(0) while not
flagging a proper FOO(0). The MVC may be the target of EX. Perhaps
something like qualifying the MVC mnemonic?
MVC FOO(0),BAR this gets flagged
MVC.EX FOO(0),BAR this is an EX target and not flagged
It's not backward compatible and it's awkward. Suggestions for
improvement are welcome.
3. I prefer using labeled constants with implied lengths instead of
literals. I use an ASSERT macro to ensure compatible source/target
lengths. An HLASM implied check would be more convenient.
4. Compiler-generated source code can be very weird, but legitimate.
Any new warnings/errors/flagging should be controllable/suppressable.
Jeffrey D. Smith
Principal Product Architect
Farsight Systems Corporation
700 KEN PRATT BLVD. #204-159
LONGMONT, CO 80501-6452
303-774-9381 direct
303-484-6170 FAX
http://www.farsight-systems.com/
comments are invited on my encryption project
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