Re: GNU Java Compiler and Swarm

[Tom Wainwright]

Wunnerful news, can't wait to try it.  Maybe you should take more vacations if
this is what we get when you come back.

--Tom Wainwright

"Marcus G. Daniels" wrote:
> 
> With today's Swarm snapshot, it is possible to build models using the
> (just released) native code GNU Java Compiler in GCC 3.0.  This is an
> advantage for several reasons:
> 
>   1) It can facilitate development of faster models by removing the
>      indirection of the Java virtual machine.  With GCC, there are
>      many more options for controlling the optimization of code.
> 
>      GCC is a traditional static analysis compiler and thus it can do
>      much deeper analysis of code than the common just-in-time compilers
>      (JITs).
> 
>   2) It unifies debugging with GDB.  Current (snapshot) versions of GDB
>      available from sources.redhat.com have full Java support.  A crash,
>      whether in Swarm or in a model are all handled in the same way.
> 
>   3) It provides a unified profiling environment.
> 
>   4) It provides a way to make C++ look like Java code and vice versa.
> 
>   5) It's just the right thing to do.  :-)
> 
> There is one extra step on the Swarm side, which is that you need
> to make a shared library of the Java Swarm stubs.  You can do that
> by making a build done in the usual way, and then, having your PATH
> setup so that gcj from GCC 3.0 is available, run:
> 
>  $ cd /build/swarm-jdk # your Swarm build area
>  $ cd java
>  $ make gcjswarm.so
> 
> Then, in your model, add a rule like this:
> 
> model: $(SOURCES)
>         CLASSPATH=/build/swarm-jdk/java gcj -O2 -g --main=StartModel -o model 
> $(SOURCES) /build/swarm-jdk/java/gcjswarm.so
> 
> StartModel would be the class having the `main' you want to run.
> 
> I know this works on Intel Linux, but other architectures may have
> problems.  E.g. I know of a bug in the GCJ compiler and the libffi library
> that prevent it working on Sparc.  I can't say when I'll have time to
> fix them.  (They aren't bugs in Swarm.)
> 
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-- 
Tom Wainwright
NOAA/NMFS/NWFSC
2030 S Marine Science Dr
Newport, OR 97365 USA
address@hidden

                  ==================================
   Swarm-Support is for discussion of the technical details of the day
   to day usage of Swarm.  For list administration needs (esp.
   [un]subscribing), please send a message to <address@hidden>
   with "help" in the body of the message.