small webrev to fix bug in hsail kernel argument logic

[Deneau, Tom]

Christain --

You're right, our hsail graal backend is designed for compiling and
dispatching functions coming from something like IntStream.forEach or
ObjectStream.forEach. (The java 7 based junit tests don't actually use
the Stream interface but the interface they do use is similar).

So for now, the only functions we compile to be hsail kernels must
either:

   * have int as a final parameter in which case it gets filled from
     the workitemid.

   * have an Object as the final parameter in which case it gets
     filled from the supplied object array indexed by the workitemid.

In java 8, the lambdas that satisfy IntConsumer or Consumer<T> meet
these requirements.

-- Tom

> -----Original Message-----
> From: Christian Thalinger [mailto:christian.thalinger at oracle.com]
> Sent: Thursday, February 06, 2014 3:35 PM
> To: Deneau, Tom
> Cc: Doug Simon; graal-dev at openjdk.java.net
> Subject: Re: small webrev to fix bug in hsail kernel argument logic
> 
> 
> On Feb 6, 2014, at 4:06 AM, Deneau, Tom <tom.deneau at amd.com> wrote:
> 
> > Christian --
> >
> > I'm not sure what is being referred to as fragile here.
> >
> > If it is the logic of not passing a last parameter when it is an int,
> that has been there all along.
> > (This webrev just firms up the way it decides whether it is the last
> parameter or not).
> 
> Yes, I know it's not part of this change.
> 
> >
> > The code that sets up the kernel prologue uses similar logic in that
> > when it wants to load an int parameter and it is the final int
> > parameter, it knows that that parameter should not be loaded from the
> kernel arguments but instead should be set from the hsail workitemabsid
> instruction.
> 
> Maybe the fact that I don't know about the other code involved in this
> contract makes it look fragile to me.  Is there no other way to get to
> this method than for IntStream?
> 
> >
> > -- Tom
> >
> >
> >> -----Original Message-----
> >> From: Christian Thalinger [mailto:christian.thalinger at oracle.com]
> >> Sent: Wednesday, February 05, 2014 9:54 PM
> >> To: Deneau, Tom
> >> Cc: Doug Simon; graal-dev at openjdk.java.net
> >> Subject: Re: small webrev to fix bug in hsail kernel argument logic
> >>
> >> The change looks good but in general this looks fragile:
> >>
> >>  93 void HSAILKernelArguments::do_int() {
> >>  94   // The last int is the iteration variable in an IntStream, but
> we
> >> don't pass it
> >>  95   // since we use the HSAIL workitemid in place of that int value
> >>  96   if (isLastParameter()) {
> >>  97     if (TraceGPUInteraction) {
> >>  98       tty->print_cr("[HSAIL] HSAILKernelArguments::not pushing
> >> trailing int");
> >>  99     }
> >> 100     return;
> >> 101   }
> >>
> >> On Feb 5, 2014, at 12:35 PM, Deneau, Tom <tom.deneau at amd.com> wrote:
> >>
> >>> Doug --
> >>>
> >>> The small webrev
> >>>
> >>> http://cr.openjdk.java.net/~tdeneau/graal-webrevs/webrev-kernarg-fix
> >>> es
> >>> /webrev/
> >>>
> >>> fixes some problems in the HsailKernelArguments code that caused
> >>> some crashes with certain kernel argument combinations (not any of
> >>> the existing junit test cases).]
> >>>
> >>> In addition added some new test cases that would have failed but now
> >> pass.
> >>>
> >>> -- Tom
> >>
> >
> >
>