[Libjit-developers] libjit vs LLVM

[Chris Lattner]

Hi All,

I was wondering what you could tell me about the differences in goals
between libjit and LLVM.  In particular, on this page:
http://www.southern-storm.com.au/doc/libjit/libjit_1.html

It is stated "Unlike other systems such as the JVM, .NET, Parrot, and
LLVM, libjit is not a virtual machine in its own right. It is the
foundation upon which a number of different virtual machines, dynamic
scripting languages, or customized rendering routines can be built."

I believe that the statement is true about .NET, JVM, and Parrot, but LLVM
is exactly what you describe: a framework that can be used to build a
number of different virtual machines.  In particular, LLVM assumes no
runtime model or library: we currently JIT C,C++,Stacker (a forth-like
language), and have good starts on Java, .NET, O-Caml, and Ruby
front-ends.

If you're not familiar with LLVM, it's actually a lot more than a JIT.
It's also a static, linktime, and offline optimizer that includes dozens
of aggressive SSA-based optimizations.  Another advantage of LLVM is that
it is mature and works well now.  :)  For more info, see:
http://llvm.cs.uiuc.edu/

Can you say a little bit about the advantages of using libjit over LLVM?
Also, can you please correct the quote above to accurately describe the
difference between libjit and LLVM?

Thanks,

-Chris

-- 
http://llvm.cs.uiuc.edu/
http://www.nondot.org/~sabre/Projects/