Re: [Libjit-developers] libjit vs LLVM

[Rhys Weatherley]

On Friday 28 May 2004 02:43 pm, Chris Lattner wrote:

> > P.S. LLVM is very cool - I have nothing against it per se.  I've merely
> > set my sights a little lower in the interest of VM authors.
>
> I guess I really don't understand this attitude.  I imagine that you want
> libjit to continue growing into a capable and powerful system, at which
> point you will add some of the things that LLVM provides.  The alternative
> is to go the direction of GNU lightning, which is a very restricted system
> that is pretty hard to use for many tasks: and it certainly does not
> provide performance.

The choice isn't binary: super-optimization or no optimization.  There are
plenty of shades in the middle, and libjit already generates better code than
GNU Lightning with a much nicer API.  Of course libjit will grow.  Everyone
has to start somewhere.

There's no law that says there can be only one project of this kind.  You
obviously feel that you have a lead in this area.  Feel free to exploit it to
my disadvantage if you'd like. :-)

If you believe that I'm mischaracterising LLVM in the documentation, I will
replace the reference.  You are probably correct that LLVM is generic as to
front-end language.  But LLVM is a hammer, where I need a screwdriver.

How about the following:

    LLVM has similar characteristics to libjit, in that its intermediate
    format is generic across front end languages.  LLVM can be adapted to
    function as a JIT, but its primary purpose is as a tool for writing
highly
    optimizing compilers.

Or you can suggest some other suitable wording and I'll include it.

Cheers,

Rhys.