From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID
	autolearn=no autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,ef33c33c4f98bde1
X-Google-Attributes: gid103376,public
From: "Robert C. Leif, Ph.D." <rleif@rleif.com>
Subject: RE: Compiler for Z80/6510
Date: 1999/11/26
Message-ID: <NBBBJNOMKDIAJALCEFIJAEMFDFAA.rleif@rleif.com>#1/1
X-Deja-AN: 553552580
Content-Transfer-Encoding: 7bit
References: <1103_943587334@DZOG-CHEN>
To: <comp.lang.ada@ada.eu.org>
X-Priority: 3 (Normal)
Content-Type: text/plain; charset="iso-8859-1"
X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2314.1300
X-Complaints-To: usenet@enst.fr
Importance: Normal
X-Trace: menuisier.enst.fr 943683202 12699 137.194.161.2 (27 Nov 1999 06:13:22
 GMT)
Organization: ENST, France
X-BeenThere: comp.lang.ada@ada.eu.org
X-MSMail-Priority: Normal
Mime-Version: 1.0
Reply-To: comp.lang.ada@ada.eu.org
NNTP-Posting-Date: 27 Nov 1999 06:13:22 GMT
Newsgroups: comp.lang.ada
Date: 1999-11-27T06:13:22+00:00
List-Id: <comp.lang.ada>

From: Bob Leif
To: Comp.Lang.Ada
I attended the original presentation. I believe the key was it was possible
for the compiler by brute force to try a huge number of possibilities. I
also believe that the CPU was a DSP. DSPs can have peculiar architectures
that can be better suited for machine than human analysis.

In any event, if a computer can beat a chess grand-master, it should be
possible to beat a human creating assembly code. Again, being possible need
not mean that it is practical for all situations today.

-----Original Message-----
From: USENET News Admin @flash [mailto:news@sd.aonix.com]On Behalf Of Ed
Falis
Sent: Thursday, November 25, 1999 7:36 PM
To: comp.lang.ada@ada.eu.org
Subject: Re: Compiler for Z80/6510


On Thu, 25 Nov 1999 23:38:20 GMT, Peter Milliken
<peter.milliken@australia.boeing.com> wrote:

> Would you care to comment then on the paper written by Lawlis and Elam
> which was published in Tri-Ada '92 titled "Ada Outperforms Assembly: A
> Case Study" where, in point 6, they draw conclusions such as: compiler
> optimisation has reached such a state of the art that it can implement
> "hundreds of heuristics from a library of knowledge in this area of
> technology" and generate code which can "beat assembly code in both size
> and performance"?
>
> I am curious, on the one hand we have this paper (advertised in the Ada
> Home page) and on the other hand, experienced compiler writers such as
> yourself. These statements seem to contradict each other. I do not have
> any experience in compiler writing but I have been prepared to accept
> the paper at it's face value (having no way to confirm or deny :-)). Did
> Lawlis and Elam get it wrong? Were they correct for their particular
> circumstances and environment? I have shown the paper to non Ada
> software engineers and received various responses, the worst being open
> ridicule and statements that the paper must be a pure fabrication.
>
> Thanks
> Peter

My take on it, having been involved in Ada compilers for a long time, is
that an optimizing compiler can do well compared to the average programmer,
turned to assembly language.  But, a good assembly programmer for a given
architecture can do better.  This isn't rocket science - human intelligence
generally
beats what we can simulate with machines.

- Ed