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Re: compiling python

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On 2015-01-24, Bartc <bc@freeuk.com> wrote:
>>> You can see there is quite a difference (some 30 times slower) between
>>> my little language and Python.
>>
>> Clozure Common Lisp:
>>
>>    (defun test ()
>>      (do ((i 0 (1+ i)))
>>          ((> i 100000000))
>>        (declare
>>          (type fixnum i)
>>          (optimize (speed 3) (safety 0)))))
>>
>> CPU: Intel Core-i5-2310, 2.9 GHz.
>>
>>    ? (time (test))
>>    (TEST)
>>    took 210 milliseconds (0.210 seconds) to run.
>
> OK, let's say 2.1 seconds for a billion. That compares very well with 
> the above timings (ignoring the fact that your machine might be faster 
> or slower than mine).

One billion doesn't fit into a fixnum on the 32 bit version of Clozure Common
Lisp. On the 64 bit version I get more meaningful looking timings.

? (time (test))
(TEST)
took 1,329,000 microseconds (1.329000 seconds) to run.

Now with the version with declarations, there is a difference:

? (time (test))
(TEST)
took 345,000 microseconds (0.345000 seconds) to run.

Other data points, using LOOP instead of DO:

? (time (loop for i below 1000000000))
(LOOP FOR I BELOW 1000000000)
took 1,330,000 microseconds (1.330000 seconds) to run.

? (time (loop for i fixnum below 1000000000))
(LOOP FOR I FIXNUM BELOW 1000000000)
took 675,000 microseconds (0.675000 seconds) to run.

> CLISP took 65 seconds for the above, so presumably 10-11 minutes for a 
> billion. This is on the same machine where my /bytecode interpreter/ 
> executes in 3.7 seconds.

In CLISP, you have to compile code explicitly. Try

[1]> (compile 'test)

then repeat. However, note that the type annotations are wrong:

[2]> most-positive-fixnum
16777215

Oops! Looks like fixnums are only 25 bits including sign, on a 32 bit
build.

On a 64 bit Debian box where I have a 64 bit CLISP:

[1]> most-positive-fixnum
281474976710655

Note that in Lisp, if you use declarations, and request (safety 0),
you get undefined behavior if the program lies. Declarations must
be regarded as *promises* to the compiler that you know what you're doing,
rather than request for type checking.

>>    ? (disassemble 'test)
><snip>
>
> So you're saying it doesn't matter too much whether static type 
> information is present or not?

I think the number of iterations may just have been too short for
accurate timing.

> But it seems that you have a very effective language which is capable of 
> generating fast native code; why doesn't Python do the same? (Maybe it 
Clozure Common Lisp was previously known as OpenMCL.

http://en.wikipedia.org/wiki/Macintosh_Common_Lisp#History_of_MCL

There are other Common Lisps with good compilers.

> could just be translated to your Lisp!)

There is such a project: http://common-lisp.net/project/clpython/

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compiling python fir <profesor.fir@gmail.com> - 2015-01-09 15:36 -0800
  Re: compiling python BartC <bc@freeuk.com> - 2015-01-09 23:50 +0000
    Re: compiling python fir <profesor.fir@gmail.com> - 2015-01-09 15:59 -0800
      Re: compiling python BartC <bc@freeuk.com> - 2015-01-10 11:45 +0000
        Re: compiling python fir <profesor.fir@gmail.com> - 2015-01-10 07:09 -0800
    Re: compiling python Kaz Kylheku <kaz@kylheku.com> - 2015-01-10 19:19 +0000
      Re: compiling python BartC <bc@freeuk.com> - 2015-01-10 22:02 +0000
        Re: compiling python fir <profesor.fir@gmail.com> - 2015-01-11 10:52 -0800
        Re: compiling python Kaz Kylheku <kaz@kylheku.com> - 2015-01-11 19:24 +0000
          Re: compiling python BartC <bc@freeuk.com> - 2015-01-11 20:23 +0000
          Re: compiling python BartC <bc@freeuk.com> - 2015-01-24 15:01 +0000
            Re: compiling python Kaz Kylheku <kaz@kylheku.com> - 2015-01-24 16:58 +0000
              Re: compiling python Bartc <bc@freeuk.com> - 2015-01-24 19:18 +0000
                Re: compiling python Kaz Kylheku <kaz@kylheku.com> - 2015-01-24 23:54 +0000
                Re: compiling python Bartc <bc@freeuk.com> - 2015-01-25 01:26 +0000
  Re: compiling python Robert Wessel <robertwessel2@yahoo.com> - 2015-01-09 18:13 -0600
    Re: compiling python fir <profesor.fir@gmail.com> - 2015-01-09 16:27 -0800
  Re: compiling python Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-01-12 18:28 +0100

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