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From: SCHMIDT@SUMEX-AIM.STANFORD.EDU (Christopher Schmidt)
Newsgroups: comp.sys.xerox
Subject: Re: Programming in Common Lisp on an 1108-110
Message-ID: <12352768156.13.SCHMIDT@SUMEX-AIM.STANFORD.EDU>
Date: Sun, 22-Nov-87 20:42:06 EST
Article-I.D.: SUMEX-AI.12352768156.13.SCHMIDT
Posted: Sun Nov 22 20:42:06 1987
Date-Received: Wed, 25-Nov-87 20:56:18 EST
References: <8711200129.AA09718@orstcs.CS.ORST.EDU>
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Organization: The ARPA Internet
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    Has anyone written any large common lisp programs in Lyric on the 1108?
    We have found Lyric to be essentially unusable because it is too slow
    and there is not enough stack space to do interpreted execution of
    sizable programs for debugging.  We've stopped running background
    processes because we need the stack space.

We did find that Lyric is unusably slow on our 1108-105's, but it was our
conclusion that the problem is that the size of the working set of even
the minimal sysout is just too big for 1.5 Mb of memory to cope with.

Indeed, our 1108-110's (which differ from the 1108-105's only in that
they have 3.7 Mb of memory) do not suffer the same swapping problem and
are *much* more usable.  I am surprised that if you have 3.7 Mb of memory
in your machines that you find them much slower than when using Koto.
I've not run much interpreted code on the 1108-110, though.  Maybe that's
the difference between your experience and mine?  Try using the compiler
more and see if that helps.  I guarantee it will cut down your stack
usage by at least a factor of 4.

On our dandetigers and doves (with 3.7 or 3.8 Mb of memory in all
cases), Lyric is actually a little faster than Koto.  We believe this
is because both ASSOC and GETPROP are in microcode.  (In the past,
either one or the other opcode has faulted back to macrocode.)  The
microcode is 20% larger, but we haven't made any fine-grained attempt
to figure out what has been speeded up.

The Common Lisp compiler hasn't yet had as many optimizers added to it
as the old Interlisp compiler did, so there is still some room for work
there.  I invite readers to submit any they have written to Info-1100.
--Christopher
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