Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!ames!sun-barr!apple!motcsd!hpda!hpcuhb!hpcllla!hpclisp!hpcldko!daryl
From: daryl@hpcldko.HP.COM (Daryl Odnert)
Newsgroups: comp.arch
Subject: Re: Re: Memory utilization....[really: RISC and languauges]
Message-ID: <650013@hpcldko.HP.COM>
Date: 11 Sep 89 20:59:41 GMT
References: <26305@winchester.mips.COM>
Organization: Hewlett-Packard Calif. Language Lab
Lines: 33

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.

A couple of quotes from the article:

   "There are two instructions, DCOR (decimal correct) and IDCOR
   (intermediate decimal correct), that provide invaluable assistance
   for decimal arithmetic.  One of the criticisms often leveled at
   typical RISC architectures is that they provide insufficient support
   for decimal operations, [...].  Using a biasing scheme and the DCOR
   and IDCOR instructions, compilers for HP Precision Architecture
   systems can implement decimal additions and subtractions with the
   ordinary ADD and SUB instructions and minimal extra instructions."

   "HP Precision Architecture machines running the most popular COBOL
   processor benchmarks outperform their CISC counterparts by a factor of
   1.3 to 4.2, above and beyond differences in the the machines' respective
   MIPS rates.  Furthermore, this performance is achieved using 15% to 30%
   fewer inline instructions."

Daryl Odnert                daryl%hpcllla@hplabs.hp.com
Hewlett-Packard             ...!hplabs!hpcllla!daryl
California Languages Lab