🚀 go-pugleaf

In article <650013@hpcldko.HP.COM> daryl@hpcldko.HP.COM (Daryl Odnert) writes:
>John Mashey writes:
>> Somewhere, there was a fine article written by someone at HP on the
>> HP PA design methodology, including a few paragraphs on the rationale
>> for dealing with COBOL as they did, with numbers.  Wherever it was,
>> it's at least 2 years old.  Maybe somebody from HP remembers where it
>> is and would kindly cite the reference, or maybe even quote the
>> parts relevant to COBOL.

>I believe the article John is talking about is "Hewlett-Packard
>Precision Architecture Compiler Performance" by Karl W. Pettis and
>William B. Buzbee, Hewlett-Packard Journal, Vol. 38, No. 3, March 1987,
>pgs 29-35.

I've managed to lose my copy of that somewhere.  What I was looking for
was the details about the analysis of the operations spent in a COBOL
environment actually doing decimal operations, i.e., with a rationale likeothe following, and based (I think) on HP3000 numbers:
	W % of the operations are spent in the OS
	X % of the operations are spent in I/O handlers, ISAM, etc, if not
		inside the OS
	Y % of the operations are actually spent inside the COBOL program.
Of the Y %, much of the time is spent doing moves, branches, leaving
Z% actually doing decimal arithmetic, where Z% is (unless my memory
fails me) on the order of 1%.  From there the main task is to make sure
that there is just enough support in the hardware to make sure that
a small operations-percentage doesn't turn into large cycle-count-percentage
by a complete lack of support.  I.e., if most operations were about
1 cycle, but the decimal ones took 100 cycles to implement,
then about 50% of the time would actually be consumed.
Hence, if there is modest help for the problem that would, say
keep the decimal work down to a few cycles per operation, they would
be reasonable to have (which is, of course, the conclusion HP came to,
for its job mix).  Anyway, that is my recollection.  My accurate
quotes would be good to hear.
-- 
-john mashey	DISCLAIMER: <generic disclaimer, I speak for me only, etc>
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