From: neeri@iis.ethz.ch (Matthias Neeracher)
Subject: Re: The need for an assembler (was: Favori
Organization: Integrated Systems Laboratory, ETH, Zurich
	<1992Aug11.090108.111@news.columbia.edu>
	<1992Aug12.171241.14907@sctc.com>
	<1992Aug14.074141.21987@news.columbia.edu>
Date: Tue, 18 Aug 1992 17:07:29 GMT

In article <1992Aug14.074141.21987@news.columbia.edu> lasner@watsun.cc.columbia.edu (Charles Lasner) writes:
>*good* assembly programmers do not optimize their code, they write it
>correctly the first time.

Correctly or optimal ? And does this sentence mean that we finally agree that
Mel was no good assembly programmer :-) ?

> I am not claiming I am
>at the top of this category by any reckoning, but I think that a fair amount
>of the code I have written over the last 24 years wouldn't ever be optimized
>by me or anyone else at any point because it truly is the best way to deal
>with the specifics at hand.

This sounds somewhat vague to me. Do you claim that your code can not be
made faster in any way, or that it wouldn't be worth the effort ?

>  Contrary
>to the notions of people questioning this, all architectures are capable of
>being understood at a symbolic level that is not only at a one-one
>correspondance level with the hardware, but sufficiently that there won't
>be any "tricks" left to apply.

Given that for current members of the Motorola 680X0 series, not even Motorola
seems to be able to provide accurate instruction timing information for all the
possible cases (aligned, in-cache, etc.), I doubt this statement.

>  Furthermore,
>assembler programmers are virtually the only source of all of the "tricks"
>added to compilers.

Does this mean you do dependence analysis using Banerjee inequalities when you
write assember programs ?

>  But look at the "lifetime" of
>machines in this business.  There really haven't been too many total turnovers
>over the years.  How many decades are we going to have MAC and 68K-based unix
>people essentially whining "we better not learn how to use 68000 family
>assembler in any serious way, because any time now it's going to be so
>obsolete that no one can ever make use of it anymore in any way".

I predict that the majority of new Macintoshes sold by the end of 1994 will not
be 680X0 based anymore. I also have the impression that the market share of
68000 based UNIX workstations is constantly shrinking.

On the other hand, this would still give a lifetime of 680X0 based Macs of
about 15 years, which is more than enough to justify learning assembler.

>DEC is saying that
>the Alpha chip is going to take them well into the next century.  I guess that
>means we shouldn't learn it either to any extent because DEC might retract
>that statement any time now, right?

No, that means that DEC has made a prediction for a timespan which is almost
as long as their current existence. It seems to me that DEC is trying to
announce the end of progress in architectural design, which to me just seems
*slightly* premature.

Matthias

-----
Matthias Neeracher                                      neeri@iis.ethz.ch
  "Rock and Roll adolescent hoodlums storm the streets of all nations."
                            -- William Burroughs, _The Naked Lunch_