Why not use IILF? It inserts a full word immediate value into the lower
fullword of the specified register. There are a bunch of the IIxx
instructions to load to full word or half words into any of the 2 full word
or 4 halfwords within a given register with an immediate value. Gotta have
the proper hardware, of course

There is also an LGFI .It loads a fullword immediate value into the Grande
register. The sign bit is propogated into the high word of the Grande
register. This assumes you're on the proper hardware level.

I can, maybe, see why ISVK would be protected. If anybody could use, the
malevolent programmer could use it to scan memory for memory areas that
could be corrupted without detection. This would be especially nasty for
that code which still insists on getting common memory (CSA, ECSA in z/OS,
I don't know z/VSE) in a user's protect key "because it's easier". Maybe
z/VSE people are not so stupid.

I looked at what is in control register 0 and didn't personally find
anything of interest.

On Tue, Jul 9, 2013 at 2:30 PM, Richard Verville <[email protected]>wrote:

> Has anyone done benchmarks on different scenarios with instructions with
> immediate & relative instructions versus the old instructions. I have to
> rewrite some code for CICS on zOS & VSE and I wonder if it's worth it. Also
> I can't find a Load Fullword Immediate instruction (like LHI) where the
> intent is to load a value greater than 64K into a register and finally, why
> can't we inspect control register 0 in problem state (without the
> extraction bit on), instructions like ISVK should be "free", don't you
> think ? Richard
>
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-- 
This is a test of the Emergency Broadcast System. If this had been an
actual emergency, do you really think we'd stick around to tell you?

Maranatha! <><
John McKown

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