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ASSEMBLER-L - Sortierung von Literalen

Subject:

Re: LARL vs. Literal Alignment

From:

Bernd Oppolzer <bernd.oppolzer@T-ONLINE.DE>

Reply-To:

IBM Mainframe Assembler List <ASSEMBLER-LIST@LISTSERV.UGA.EDU>

Date:

2010.08.23 11:47:53


After reading again, I see your point, but: what is a one byte literal requiring
doubleword alignment? I only know of doublewords or multiples of doublewords
(larger areas), that require doubleword alignment.

With the relative addressing facility, we have for the first time the
possibility that areas of odd length require alignment on even addresses,
because the addressing relative to the PSW counts halfwords, not bytes. This is
new, and this requires a new class of literals in the literal pool with special
alignment requirements. At least, that's my opinion.

The sorting of the literal pools by lengths multiple of 8, of 4, of 2 is IMHO
done already since the very first days of ASSEMBLER, to do proper alignment of
the literals (even if the literals don't have the appropriate type specifier)
and to avoid padding bytes.

Kind regards

Bernd



E.J. schrieb:
> Bernd Oppolzer wrote:
>> I believe that literals could be sorted by alignment requirement
>> instead of length, this way minimizing the needed padding bytes.
>
> Using this scheme, one byte literals requiring doubleword alignment will
> require seven padding bytes each. It would be better if literals without
> alignment requirements could be somehow placed into these voids.
>

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