Dear Squeakers,

I have changed my mind a little bit after studying some Squeak sources.

Now I plan to implement LargeInteger primitives (20-39) _without_ changing
the representation of LargeIntegers by extending the Interpreter arithmetic
primitives using the CCodeGenerator.
This avoids some problems dealing with different platforms.

In a later step changing the representation to bigger 'digits' (16,32,..
bits?) _could_ be interesting.


What do you think?

Stephan

P.S.: Is [Q] the right string to get attention from Squeak Central?

> -----Original Message-----
> From: Stephan Rudlof [mailto:stephan.rudlof at ipk.fhg.de]
> Sent: Dienstag, 26. Oktober 1999 11:24
> To: squeak
> Subject: RE: Better integer performance possible?
>
>
> Dan, Michael and others,
>
> > There are three reasons LargeInts are slower:
> >
> > 	It is all written in ST (no primitive support)
> > 	The inner loops runs byte by byte
> > 		[FYI, they were written when Squeak had 12-bit smallInts
> > 		 -- can you guess out why?]
> > 	Squeak does not have a JIT -- yet.
> >
>
> If I'd have the freedom to change the representation of LargeInts I would
> like to implement this stuff as primitives in C.
>
> > We would happily invite a replacement LargeInt package into
> > Squeak if it were at least as simple and understandable (I cannot
> > imagine this not being the case!!), and if it did not add a
> > significant overhead to the VM.
>
> And change some Smalltalk methods to call the new primitives.
>
> Timeline: Because I'm a new squeaker - but familiar with VW
> Smalltalk - and
> haven't change implementations of a VM - but implemented user
> primitives for
> VW Smalltalk - I'm planning quiet some time to become familiar with it. I
> could start in the mid of November - then I will have holidays -
> and I think
> I could finish around christmas.
>
> What do you think?
>
> Greetings,
>
> Stephan Rudlof
>
> sr (stephan.rudlof at ipk.fhg.de)
>    "Genius doesn't work on an assembly line basis.
>     You can't simply say, 'Today I will be brilliant.'"
>     -- Kirk, "The Ultimate Computer", stardate 4731.3
>
> > -----Original Message-----
> > From: Dan Ingalls [mailto:Dan.Ingalls at disney.com]
> > Sent: Montag, 25. Oktober 1999 22:32
> > To: squeak at cs.uiuc.edu
> > Subject: Re: Better integer performance possible?
> >
> >
> > Stephan Rudlof <stephan.rudlof at ipk.fhg.de> wrote...
> >
> > >The integer performance of Squeak is poor compared with other
> Smalltalks,
> > >especially for big ints (~ factor 500) and not so much for
> small ones (~
> > >factor 3).
> > >
> > >What's the reason? Does anybody know if improvements are possible?
> >
> > There are three reasons LargeInts are slower:
> >
> > 	It is all written in ST (no primitive support)
> > 	The inner loops runs byte by byte
> > 		[FYI, they were written when Squeak had 12-bit smallInts
> > 		 -- can you guess out why?]
> > 	Squeak does not have a JIT -- yet.
> >
> > There is one reason SmallInts are slower:
> >
> > 	Squeak does not have a JIT -- yet.
> > 		Also, in the factorial example, it may matter that
> > 		Squeak allocates real objects for all contextx
> >
> > Ask Ian about Jitter -- he has been having fun with it recently.
> > When he's done, I think the SmallInt comparison will be much
> > better.  LargeInts will be similarly better, but not like the
> > Dolphin numbers.  I personally have not ever found LargeInt speed
> > to be a concern in any useful code.
> >
> > We would happily invite a replacement LargeInt package into
> > Squeak if it were at least as simple and understandable (I cannot
> > imagine this not being the case!!), and if it did not add a
> > significant overhead to the VM.
> >
> > 	- Dan
> >
> > PS:  I know Squeak's bytecode speed got better on Windows in a
> > recent VM, so 2.6 may be somewhat faster than 2.5.
> >
> > >WinNT Dolphin Smalltalk Version 2.1 Patch Level 2:
> > >
> > >Time millisecondsToRun: [2000 factorial]. "big ints"
> > > 76 75 76
> > >Time millisecondsToRun: [1000 timesRepeat: [12 factorial]].
> "small ints"
> > > 11 11 10
> > >
> > >WinNT Squeak 2.5:
> > >Time millisecondsToRun: [2000 factorial]. "big ints"
> > > 34520 34520 35080
> > >Time millisecondsToRun: [1000 timesRepeat: [12 factorial]].
> "small ints"
> > > 30 30 30
> > >
> > >Stephan
> >
> >
> >
> >
> >
>
>