Depends on the contents of register 11. B040 will be quad word aligned only
if register 11 is itself quad word aligned. If you got this from a STORAGE
OBTAIN or GETMAIN, then the alignment is only guaranteed to be double word
aligned, unless you ask for it to be page aligned. There is no way to
request quad word alignment on the STORAGE OBTAIN or GETMAIN request, other
than asking for page aligned. Come to think of it, it is possible that even
in a program object, if might only be double word aligned, unless you told
the BINDER to force page alignment.


On Mon, Feb 25, 2013 at 11:40 AM, Donald Likens <[email protected]>wrote:

> I am missing something:
>
> The Principles of Operations states:
>
> COMPARE DOUBLE AND SWAP (CDSG) must
> be designated on a quadword boundary. The R1
> and R2 fields for COMPARE DOUBLE AND
> SWAP must each designate an even-numbered
> register. Otherwise, a specification exception is
> recognized.
>
> I think the following instruction meets all of these requirements but I am
> getting an S0C6?
>
>  EB42 B040 003E       CDSG  R4,R2,SEG
>
> Am I correct is saying B040 is a quadword boundary?
>
> Is there a good way in assembler to insure a double word starts on a
> quadword boundary?
>
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-- 
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actual emergency, do you really think we'd stick around to tell you?

Maranatha! <><
John McKown

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