[Libjit-developers] Re: lost message: various free JIT libraries

[Aleksey Demakov]

Hi Basile,

> Aleksey, if you got this message from the list robot (and not only
> directly from me), could you tell me please?

 I got your mail only once.

> First: where is the current libjit CVS? Still on
> cvs -z3 \
>   -d:pserver:address@hidden:/sources/dotgnu-pnet \
>   co libjit
> Is there some more active CVS or other repository (SVN? darcs?)
>

It is still on savannah cvs.

> Does any one have comparaisons between various free opensource JIT
> libraries, a bit like:
>
>     libjit
>        GPL licence
>        medium sized library (65KLOC)
>        offer an internal VM for machines not yet targetted
>        target x86 (32bits), ARM, Alpha
>        missing AMD64 target
>        generate code of medium-good quality at medium-good speed
>        may produce *.so ELF files
>        handles several registers well
>        C & C++ API: the abstract syntax tree is built in memory then JITed
>        medium sized community
>        small community
>        used in DotGnu PNET
>

currently only the x86 backend is fully functional for use. ARM and alpha
ports are not complete. support of ELF files is not complete too.

> What I would be interested in is what (opensource) projects are using
> these JIT libraries, and ideally a quantitative comparison of them...
>

Well, I did look at some libs, but not much. So I cannot provide
you with an exhaustive survey. On the first glance LLVM looks
good but it is also may be too heavy for some uses.

The best open-source JITs are probably Sun JVM and Jikes RVM.
They are not libraries though.

> For Libjit, I only know of dotnet using it. what else?
>

I am aware of 2 other projects that currently use libjit. They are
mentioned here:

http://demakov.com/projects/

In the past there was another attempt to use libjit:

http://tromey.com/blog/?p=15
http://tromey.com/blog/?p=16

> Are there any programs which uses several JIT-ing libraries and is able
> to compare them in term of : speed of the JITting (ie machine code
> generation) and speed/size of the generated machine code
>

There may be cases when people try/evaluate one JIT and then switch
to another as did Tom Tromey with gcj, but I do not think that it might make
any practical sense to use several libraries at once. There is too much
difference between them.

Regards,
Aleksey