Le 05/08/2009 03:17, Charles Oliver Nutter a écrit :
On Tue, Aug 4, 2009 at 8:16 PM, Rémi Forax<fo...@univ-mlv.fr> wrote:
- remove the assertion that invokedynamic can only appear
in class 1.7 compatible (version 51.0) class,
currently your classes are not compiled with version 51.
BTW, John, It should not work with the JSR 292 RI too ?
Yes, ASM allows us to emit invokedynamic, and we always default our
generated bytecode to whatever version of JVM we're running on, so
it's possible we'll get a combination of<51 and indy if someone turns
that flag on for a lower JVM (as in this case).
We could certainly change that on our end too.
Yes, It will avoid to crawle all classes but only the ones with
invokedynamic.
So it will reduce the startup time.
- optimize concurrently with the running program
(hotspot do that, not the backport)
In most cases we run code immediately after generating it, so we're
not offloading compilation either. We'd probably want to consider
doing that so that we wouldn't now have the additional cost of waiting
for the backport to run.
Yes.
The main problem is that the backport is not able to optimize
the produced method handle tree.
One problem is that the method InvokeDynamicsupport.pollAndGetClass is
private
but exported by PGC. The backport has the same contraint that
any Java code, so it is not able to optimize any method adapter tree
that contains PGC.
Ahh...well I could certainly make it public if it would help the
optimization. I understand that this is a natural limitation of the
backport.
Ok, the backport is now able to correctly optimize your code
(a stupid && instead of ||)
and i'm happy to say that the backport now performs better.
time bin/jruby --client
-J-javaagent:../indy-backport/lib/jsr292-backport.jar
-J-Xbootclasspath/p:../indy-backport/lib/jsr292-backport.jar
-J-Djruby.compile.invokedynamic=true -J-Djruby.jit.logging.verbose=true
bench/bench_fib_recursive.rb 100
real 0m45.438s
user 0m45.102s
sys 0m0.252s
time bin/jruby --client bench/bench_fib_recursive.rb 100
real 0m38.535s
user 0m38.239s
sys 0m0.168s
time bin/jruby --server
-J-javaagent:../indy-backport/lib/jsr292-backport.jar
-J-Xbootclasspath/p:../indy-backport/lib/jsr292-backport.jar
-J-Djruby.compile.invokedynamic=true -J-Djruby.jit.logging.verbose=true
bench/bench_fib_recursive.rb 100
real 0m38.887s
user 0m44.930s
sys 0m0.497s
time bin/jruby --server bench/bench_fib_recursive.rb 100
real 0m27.885s
user 0m27.645s
sys 0m0.197s
The next room of improvement is to directly put the bytecode weaver
of the backport at the end of the JRuby ASM compiler.
I hope this will reduce the startup time.
- Charlie
Rémi
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