status of inter-class inlining in Java?

Fri Jul 16 08:08:00 GMT 2004

Consider the following sort of potential situation in libgcj:
class System {
 public static final foo() {
 B.foo();
 }
}
class VMSystem {
 static final foo() {
 ...
 }
}
Preferably VMSystem.foo should be inlined into System.foo during compilation.
(This would make it reasonable to merge a bunch more with Classpath, and
would more generally help with the indirection penalty caused by the rampant
forwarding methods used in much of Java.)
>From what I can tell, however, this doesn't seem to happen. I suppose this
is because the VMSystem class might theoretically change after compilation
of the System class; the two are compiled separately.
Is it reasonable to consider using -combine to build parts of the libraries
with intermodule optimization? Would this work? Is there an analogue when
building the .class files?
(It would clearly be impossible, memory-wise, to compile the whole library
at once. But significant gains could still be had, most likely, by compiling
collections of particularly interwined classes this way.)
So is this worth looking into?
-- 
There are none so blind as those who will not see.