1Re: Yes, they are special, but...0

[Mabry Tyson <TYSON@WARBUCKS.AI.SRI.COM>]

    Date: Mon, 19 Jun 89 11:44 EDT
    From: miller@CS.ROCHESTER.EDU (Brad Miller)

	...

1    Then why is Latex 20x slower (or worse) than a unix box? Genera is doing
    *something* poorly.... maybe it's just the Pascal compiler. But that just
    point up the issue of trying to compete with boxes where there are thousands
    of programmers generating applications/languages/etc. vs. one in which there
    are at most a couple hundred. So "general purpose" here means something like
    providing an environment with a lot of tools that work pretty well, vs. one
    in which LISP is terrific but other things, well... I'm getting tired of
    Zmail bugs, how about you?

0Latex:  We run a version that is derived from a Pascal-to-Lisp
translator that was developed by Art Flatau.  It is somewhat faster (2x,
I think I recall) than the one that is run through the Pascal compiler.
In looking at where the time was taken in the inner loop, there is one
statement that is a big case statement (the kind where the next
instruction is gotten by adding the index to the PC).  In Lisp, it was
a COND and so potentially did a lot more work.  But that is one
instruction that was not in the 3600 (I haven't looked at the Ivory)
instruction set that would have sped this program up somewhat.
In any case, I don't think the Pascal compiler is responsible for more
than about a 2x slowdown.  (Probably less, as I changed some macros to
make certain assumptions about the code that I knew to be true.)


Zmail:  In my early days of using ZMAIL, I made lots of complaints.  I
don't know how much the code has changed to fit me or how much I have
changed to fit the code, but I hardly have any problems any more.  I do
know that our people using Unix don't have any mail programs they are
happy with.  Certainly Symbolics was using domain-style addressing
before Sun and my belief is Symbolics is still ahead of Sun on this.
(As another example, for security's sake, our SUNs can't talk to any
other network in the world so that noone can talk to them.  On the other
hand, our Symbolics can talk to other nets while avoiding other machines
from getting into them.  There are an amazing number of security holes that
have been found on the Suns.)

If Symbolics were to come out with a machine that performs as the Ivory was
supposed to perform, we would be happy (for a while, anyway).  So far, we
haven't yet seen that sort of improvement.  (I will point out we haven't
seen the MacIvory 2 yet.)