Re: llvm backend for gcjx

[Mike Emmel <mike dot emmel at gmail dot com>]

On 12/4/05, Jakob Praher <jpraher@yahoo.de> wrote:
> Hi Mike,
>
> thank you very much for your response.
>
> On Sam, 2005-12-03 at 21:08 -0600, Mike Emmel wrote:
> > Hi Jakob I'm currently studying the LLVM gcc 4.0 patches and the
> > current gcjx gcc and bytecode backends code to do the tree to tree
> > conversions. The code is currently just on my hard drive I've not
> > checked it in.
> >
> > Its in a very early state I have a a gcjx tree vistor compiling and
> > the llvm backend hooked in I was just starting on converting the
> > method signatures. I'm just now doing the type conversions right now.
> > So as you can see its very early.
> >
>
> Ok. so what you do is use the gcc llvm c bindings to emit the llvm
> bytecode? Or do you use the native C++ API for generating
> llvm::Modules ?
>
No I am not using the tree bindings I'm simply using them as a
tutorial/example. I'm doing a direct C++ API.

> > I'm using the llvm build system but as I work on the project it seems
> > that it should be moved to be a sub project of the gcjx library like
> > the bytecode emitter. I can use the gcc 4.0 llvm code to see how to
> > link using gcc's build system.
> >
> I am using that too in my project. But I've changed the configure
> subsystem to work in a separate location. Yeah integrating the system
> with the gcc build system is interesting/challenging. The LLVM build
> system is nice in that it follows the BSD make tradition. I haven't
> looked at the gcc-llvm-emitter API right now. I am using the native C++
> API to work with. In the latter there is quite some magic wrapped in the
> Makefile.rules file. But on the other hand, it is a gcc tradition to
> configure dependent autonomous subprojects. So what you could do is,
> like I did it in my case, separate your LLLVM code completly from the
> LLVM project and mount it as a subproject in the gcc code tree (I think
> Tom did that for the gcjx too). Then, if enabled, the llvm subsystem
> will be configured as a standalone LLVM project.
>

Ahh got you yes I've set it up as a LLVM project in a different build area.
So if you have LLVM installed then you have its build system.
Next I'll make it as a subproject of gcjx but it builds using the LLVM
makefiles.
Not sure if that a hack or really slick :)

> > I'd be happy to put a tarball somewhere even though its still very
> > very early. Even at this stage llvm is very nice to work with the C
> > emitter is great for this type of work.
> > I don't miss the gcc tree's one bit :)
>
> Yes the LLVM API is quite nice. (Everything is a llvm::Value, Instead of
> everything is a Tree)
> I would be very happy if you could make a tarball or a patchset of your
> changes to the gcjx.
>
Okay I will tomorrow let me bang on it some more this morning I'm
crashing at the moment.

Mike
> -- Jakob
>
>
> >
> > Mike
> >
> >
> > On 12/3/05, Jakob Praher <jpraher@yahoo.de> wrote:
> > > hi Mike,
> > > hi all,
> > >
> > > I'm currently pretty busy. But I saw that you are working on a LLVM
> > > backend for gcjx - great.
> > >
> > > Do you have the source code somewhere. If my time permits it, I'd like
> > > to help you in implemneting it, I have some experience with LLVM (I am
> > > doing my master thesis project on it).
> > >
> > > What are your design plans?
> > > I have some experience with the LLVM JIT and JITEmitter things. Perhaps
> > > we could discuss that a little bit.
> > >
> > > cheers
> > > -- Jakob
> > >
> > >
>
>