For simple moves (i.e. non-padded) longer than 256 bytes and less than 4K,
I've started using MVCOS with R00 set to zero.  It's said to be more
expensive than MVC but does anyone know what the "break even" length is
(approximately)?
I'll probable continue using it regardless of the performance penalty since
it's very simple to set up for a variable length move (for lengths longer
than 4K, I'll stick with MVCL).

I'd also be interested in a comparison between EX/MVC and MVCOS if anyone
has that information.

Robert Ngan
CSC Financial Services Group

IBM Mainframe Assembler List <[email protected]> wrote on
2014/05/20 17:38:06:

> From: Gerhard Postpischil <[email protected]>
> To: [email protected]
> Date: 2014/05/21 02:49
> Subject: Re: MVCL
> Sent by: IBM Mainframe Assembler List <[email protected]>
>
> On 5/20/2014 11:44 PM, Robin Vowels wrote:
> > Sounds like overkill.
> > MVC with EX would be simpler.
>
> It depends very much on the requirement. For example, building a longer
> string from several different sources; MVCL sets the destination address
> and residual length after completion, allowing for simple chaining of
> multiple moves. While EX/MVC can accomplish the same thing, they require
> a little more arithmetic.
>
> Gerhard Postpischil
> Bradford, Vermont

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