actions -- Rebuilding the Interpreter Frames on the GPU

[Deneau, Tom]

Gilles, Doug --

A status update on our end...

   * We now generate HSAIL code to save the register state at deopt points

   * We have an HSAIL-specific CodeInstaller class based on the changes
     Doug added and we use this at compile time (code-install time) to
     build the ScopeDescs.  (This avoids the host-register specific code
     in the base CodeInstaller class).

   * At runtime, if we detect that a workitem deopted, we map the saved "HSAIL pc"
     to the relevant ScopeDesc and use each Location item in the ScopeDesc
     to retrieve the relevant HSAIL register from the HSAIL frame (where the
     registers were saved).

Right now we just print out the live locals or expression stack values
for the deopted workitem and they look correct.  The next step would be
to rebuild the interpreter frames.

Can I get an update on the "C++ changes needed to easily rebuild the
interpreter frames from a raw buffer provided by the GPU".

-- Tom




> -----Original Message-----
> From: graal-dev-bounces at openjdk.java.net [mailto:graal-dev-
> bounces at openjdk.java.net] On Behalf Of Gilles Duboscq
> Sent: Friday, December 20, 2013 4:31 AM
> To: Doug Simon
> Cc: graal-dev at openjdk.java.net
> Subject: Re: actions
> 
> As for me, I'll look into the C++ changes needed to easily rebuild the
> interpreter frames from a raw buffer provided by the GPU during
> deoptimization.
> 
> -Gilles
> 
> 
> On Thu, Dec 19, 2013 at 11:27 PM, Doug Simon <doug.simon at oracle.com>
> wrote:
> 
> > As a result of the Sumatra Skype meeting today on the topic of how to
> > handle deopt for HSAIL & PTX, I’ve signed up to investigate changes in
> > the
> > C++ layer of Graal to accommodate installing code whose debug info is
> > C++ not
> > in terms of host machine state (e.g. uses a different register set
> > than the host register set).
> >
> > -Doug
> >
> > On Dec 19, 2013, at 11:02 PM, Deneau, Tom <tom.deneau at amd.com> wrote:
> >
> > > Gilles, Doug --
> > >
> > > Could you post to the graal-dev list what the two action items you
> > > took
> > were?
> > >
> > > -- Tom
> >
> >