Cross-Posted to IBM-Main and IBM-ASSEMBLER-List
I believe it has been discussed before:
the term "baseless programming" is an over-simplification.
It should be "an ASSEMBLER programming technique, where the
code area is not covered by base registers" - which requires
separation of code area and data area and relative branch instructions;
take care of your literals.
If you have large code areas, this may save you some registers,
or you may save some time otherwise needed to save and reload
the registers which cover the code area.
I managed to convert most of our inhouse macros in the last few months
to "baseless", including the site-specific SP macros, so now I don't have
restrictions regarding the size of the code areas any more. Of course,
it is not good to have large code areas (small functional blocks are
better),
but if you want to add trace output macros or other test facilities to a
functional block, you don't like it if code area size restrictions
prevent you
from doing it. This was the main reason for my "baseless" effort - I had
to do some maintenance to some very large and very old programs, and
the only way to do it was to add some trace output.
Thanks to Ed Jaffe for the link to the SHARE presentation, BTW.
Kind regards
Bernd
Am 06.12.2013 02:05, schrieb John McKown:
On Thu, Dec 5, 2013 at 6:09 PM, zMan <zedgarhoo...@gmail.com> wrote:
Ouch. SO true.
Yes. In this same vein, but a bit more seriously, why don't we start using
RI-programming (for Relative & Immediate) or RelImm-programming. Because
there is _no_ way that I can think of to write _useful_ code which does not
use at least a few base+displacement instructions. At the very least for
the incoming parameter list. Well, maybe a random() type program could be
written without using any base+displacement instructions if it did some
sort of manipulation of the data returned by the STCKE instruction instead
of having a seed and basing the current result on the previous one.
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