harmony-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Egor Pasko <egor.pa...@gmail.com>
Subject Re: [drlvm] Jitrino.OPT performs incorrect GC enumeration in nested loop with array accesses
Date Thu, 05 Oct 2006 12:06:09 GMT
On the 0x1F9 day of Apache Harmony Ivan Volosyuk wrote:
> On 05 Oct 2006 17:09:35 +0700, Egor Pasko <egor.pasko@gmail.com> wrote:
> > Hello, JIT & GC gurus!
> >
> > I'd like to share my observations on HARMONY-1862 and move the
> > discussion from JIRA. Mikhail, Ivan, your opinions are extremely
> > valuable!
> >
> > > Mikhail Fursov commented on HARMONY-1682:
> > > -----------------------------------------
> > >
> > > Ivan, I checked the test you sent
> > > The test fails and GC runs only once before the failure.
> > > I moved all methods except the problem one to Jitrino.JET and
> > > Jitrino.OPT reports only 2 items: one object and one [mptr,
> > > object] pair with a small offset.
> 
> Well, I have little knowledge in jitrino internals, same for my
> ability to read IR trees.
> 
> "The offset == MAX_INT is interpreted as unknown. In this case the
> correct base for a
> managed pointer is chosen in runtime: the algorithm searches for the nearest
> known base."
> 
> Is this can be a problem? If the base pointer is optimized out and we
> will find different object base?

Yes, it can be. Base pointers should be preserved by Jitrino. There is
a mechanism for that in CG, but I see that the "base" is optimized out
as deadcode in "cg_dce". Mikhail, do you see that?

-- 
Egor Pasko, Intel Managed Runtime Division


---------------------------------------------------------------------
Terms of use : http://incubator.apache.org/harmony/mailing.html
To unsubscribe, e-mail: harmony-dev-unsubscribe@incubator.apache.org
For additional commands, e-mail: harmony-dev-help@incubator.apache.org


Mime
View raw message