Hotspot on PPC

[Bob Vandette]

Hi Gary,

I should be able to answer your questions on PowerPC Hotspot and the 
portable interpreter.

PORTABLE INTERPRETER

When we did the original IA64 port of Hotspot, we decided to use a "C" 
interpreter in order to get the
port done quicker.   On architectures with many CPU registers, the "C" 
interpreter is actually just as fast or even faster
than the generated assembly version.  We use the GCC computed goto in 
order to avoid the typical dispatching
overhead of switch statements.  This interpreter is in 
hotspot/src/share/vm/interpreter/cInterpretMethod.hpp.
The problem is that the only architecture that uses the cInterpreter is 
IA64 and as far as I know,
this code isn't open sourced.  You'd need to see the glue logic that 
exists in the CPU directory to use
this interpreter.


EXISTING POWERPC PORTS

I don't know if you are aware of a Java 5 version of PowerPC that is on 
our Java SE Embedded site.
It is a hotspot implementation of Java SE 5.0 for Linux platforms.  It 
uses the Hotspot client JIT compiler and
is only 32 bit but it has passed the fully JCK certification. 


Let me know if you've got any other PPC questions.

Bob Vandette
Java Software