Re: PCL benchmark

[Gregor.pa@Xerox.COM]

    Date: Thu, 13 Oct 88 17:50:07 BST
    From: Jeff Dalton <jeff%aiai.edinburgh.ac.uk@NSS.Cs.Ucl.AC.UK>

    Is the TI version a complete, working, available system?  If so,
    on which machines?  Does it depend on special hardware?  Are there
    any *other* native implementations?  On stock hardware?

I can't speak for availability of the TI implementation.  What I know of
it technically is that it looks real good, and has good performance.  It
depends on microcode of their chip to run, so in some sense it is a
custom implementation.  On the other hand, the basic architecture is
portable, it shares many ideas with PCL.

We are at a stage where many vendors have agreed to help in the porting
of PCL.  The PCL architecture can support a much higher level of
performance, this just requires digging into the underlying lisp a
little more.

In the next few months, I expect PCL performance will increase pretty
dramatically.

I expect most vendors will use this highly optimized PCL for a while (1
or 2 releases) and then will begin more agressive custom implementation
efforts.  Some vendors will begin these sooner than others of course, as
we have seen TI has already done one.

    Unfortunately, most people have to base their view of CLOS on PCL
    because it's the only version for stock hardware they've seen.

This isn't all that unfortunate, as I have said PCL performance can be
improved dramatically with a modest amount of effort.  What is
unfortunate is that people assume that the PCL performance they get in
one Common Lisp is the same as the PCL performance they would get in all
Common Lisps.  This just isn't true.
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