Author: Tord Romstad
Date: 03:41:11 02/17/04
Go up one level in this thread
On February 16, 2004 at 14:38:44, Robert Hyatt wrote:
>On February 16, 2004 at 14:25:10, Tord Romstad wrote:
>
>>On February 16, 2004 at 14:03:11, Robert Hyatt wrote:
>>
>>>Please re-read my statement. Look at the date. Then re-read yours.
>>>
>>>My statement was written in 1997. In general Lisp _was_ interpreted.
>>
>>No, it wasn't. Lisp has been a compiled language for *decades*. If you
>>look at the ANSI Common Lisp standard (from 1991, if I recall correctly),
>>you will see that the standard even *requires* a compiler. There is
>>one implementation (CLISP) which compiles only to bytecode, all other
>>major Lisp implementations have compiled to machine code since a very
>>long time.
>>
>>>Of
>>>course, so was BASIC. Yet there were basic compilers as well. My primary point
>>>was speed. Lisp is slow. It always was slow. It always will be slow.
>>
>>It *isn't* necessarily slow. I have even provided one data point (from
>>1999, just two years after your statement was written) to illustrate that
>>Lisp in practice often enables you to write *faster* programs in *less*
>>time compared to C/C++.
>
>Personally, I would take _any_ challenge to compete with a lisp program, when
>the goal is performance. Granted, high-level languages may reduce the
>_development_ time. All the previous languages I have mentioned come to mind,
>from Prolog, to APL, to Snobol. But when execution speed is the issue, I'll
>take C _every_ time, and if I were unable to beat a lisp program at speed, for
>the same functionality, I'd probably turn in my coding pad. :)
>
>Just as surely as I would take assembly over C if speed were the ultimate goal,
>no matter how good the C optimizer is. A bad programmer can write bad C code.
>A programmer that is not familiar with a computer (take a Cray) will probably
>get beaten by the optimizer. But for a human that knows the architecture, I'll
>take the lowest-level language every time, when raw NPS or whatever is the goal.
The key point is the "knows the architecture" part. Just like an assembly
language program doesn't automatically run faster than a C program just
because it is written in assembly language, a C program doesn't automatically
run faster than a Lisp program just because it is written in C. In both
cases, you need some in-depth knowledge of the computer hardware to take
advantage of the low-level features of C or assembly language. In both
cases, the performance gain given by the lowest-level language isn't
extremely big. Given optimizing compilers of the same quality, the
performance difference between assembly language and C is probably
comparable to the difference between C and Lisp.
>>For complicated programs, it sometimes requires somewhat more expertise
>>to write fast code in Lisp compared to C. You will also need some
>>familarity with the internals of your Lisp implementation.
>>
>>I know what I am talking about -- I am not making all of this up. I
>>have been working as a full-time Lisp programmer for almost three years,
>>and I have used Lisp extensively before and after that time as well
>>(mostly for mathematical tasks). In most cases, I find it very hard
>>to write a C program which performs as well as my Lisp solution to the
>>same problem.
>
>
>Perhaps that says more about your C programming than your Lisp programming.
I've already conceded that point. If you read my last post again, you
will see that I explicitly state that I am a much better Lisp programmer
than C programmer. You are one of those who have detailed knowledge and
lots of experience with low-level programming and computer hardware,
and you are therefore able to squeeze out more performance from a C or
assembly language program than I would ever manage. Without such
knowledge (which, I think, most of us do not posess), C simply doesn't
offer any significant performance advantage.
>I've never seen anyone claim that a high-level language produces faster
>executables than low-level languages. The normal claim is "reduced development
>time" at the expense of "program performance". Claiming the opposite boggles my
>imagination. IE do you also believe that a good LISP programmer can beat a good
>assembly programmer, since he can beat a good C programmer?
>
>Not on my watch...
There is noone who forces you to use the same language for the whole program,
of course. Performance-critical parts of a Lisp program could be rewritten
in C or assembly language. Mixing Lisp and assembly language tends to be
much easier and more comfortable than mixing C and assembly language, because
of the power of Lisp macros.
>>To a certain extent, the explanation of this is of course that I am
>>a much better Lisp programmer than C programmer. But I am not a
>>complete idiot in C either. After all, my chess engine, written in C,
>>is stronger than most amateur engines.
>
>Why not "my chess engine, written in lisp?"
>
>???
If you read a few more lines of my post, you would see the answer.
Portability. I want to use the same code on Mac OS X, Linux and
Windows, and I have long-term plans to port my engine to Palm OS.
>>
>>>That is why there has been no successful chess engine based on LISP yet.
>>
>>There hasn't been any attempt to write a conventional chess engine in
>>Lisp yet. But I know that my engine would have been no weaker if I had
>>implemented it in CMUCL instead of using gcc. My reason to use C rather
>>than Lisp is not efficiency, but portability.
>>
>>Tord
>
>
>
>There have been Lisp chess programs in the past. I'm not even sure that Steven
>didn't write one a long while back, although I am thinking of "AI Chess" and he
>might have used something else.
Yes, Steven started on a project called CIL ("Chess In Lisp"). It is not
a complete program. The code which is there is entirely unoptimized and
looks like a complete joke, probably because the project was abandoned
early.
The only complete Lisp chess engine I have seen is called BCE. This is
terribly weak, but the authors C chess program ("Bace") is not much
better (rated 1319 on Leo's rating list).
I repeat; there has been no serious effort to make any conventional chess
engine in a modern version of Lisp, and I know that my own engine (currently
rated 2733 in blitz on ICC, on a PIV 2.4 GHz) would perform at most
marginally worse if I rewrote it in Lisp.
Tord
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