RFR (XXL): JEP 243: Java-Level JVM Compiler Interface

[Christian Thalinger]

> On Sep 15, 2015, at 4:07 AM, Volker Simonis <volker.simonis at gmail.com> wrote:
> 
> Hi Christian,
> 
> can you please merge the following changes into your code:
> 
> http://cr.openjdk.java.net/~simonis/webrevs/2015/JVMCI_hs_ppc/
> 
> They fix the build on our ppc64 platforms (Linux and AIX).

http://hg.openjdk.java.net/graal/graal-jvmci-9/hotspot/rev/93deccb356cc <http://hg.openjdk.java.net/graal/graal-jvmci-9/hotspot/rev/93deccb356cc>

> Of course
> there's still a lot to do in order to implement the full interface for
> PowerPC (currently only the two options tests pass and all the runtime
> tests fail as expected), but this is a first step :)

Sure :-)

> 
> My webrev contains only one shared change in jvmciRuntime.cpp which is
> necessary to fix a warning because unreachable code introduced by the
> CHECK_NULL macro in a return statement.

Ahh, thanks for catching that one.  Pushed:

http://hg.openjdk.java.net/graal/graal-jvmci-9/hotspot/rev/3ae34e1ac57e <http://hg.openjdk.java.net/graal/graal-jvmci-9/hotspot/rev/3ae34e1ac57e>

> 
> Finally, I also want to ask if it is expected that the current C1/C2
> JIT compilers and/or the standard JDK class will eventually depend on
> the JVMCI library or will the JVMCI remain an optional component like
> for example the SA agent.

It’s very unlikely that we will retrofit C1 or C2 to the JVMCI.  For JDK 9 the JVMCI is an experimental feature and at this point we we don’t know if and when it will become a product feature.

> 
> Thank you and best regards,
> Volker
> 
> PS: are there any JVMCI documents/presentation available other than
> the JEP description?

There is an internal JVMCI Design Document.  Let me see if I can put this somewhere publicly available.

> 
> 
> On Mon, Sep 14, 2015 at 9:24 AM, Christian Thalinger
> <christian.thalinger at oracle.com> wrote:
>> The JEP itself can be found here:
>> 
>> https://bugs.openjdk.java.net/browse/JDK-8062493 <https://bugs.openjdk.java.net/browse/JDK-8062493>
>> 
>> Here are the webrevs:
>> 
>> http://cr.openjdk.java.net/~kvn/JVMCI/webrev.top/ <http://cr.openjdk.java.net/~kvn/JVMCI/webrev.top/>
>> http://cr.openjdk.java.net/~kvn/JVMCI/webrev.hotspot/ <http://cr.openjdk.java.net/~kvn/JVMCI/webrev.hotspot/>
>> 
>> The change has already undergone a few iterations of internal review by different people of different teams.  Most comments and suggestions were handled accordingly.  Although there is one open item we agreed we will address after the integration of JEP 243 and that work is captured in RFE:
>> 
>> https://bugs.openjdk.java.net/browse/JDK-8134994 <https://bugs.openjdk.java.net/browse/JDK-8134994>
>> 
>> SQE is still working on the tests and all test tasks can be seen as sub-tasks of the JEP.
>> 
>> The integration will happen under the bug number:
>> 
>> https://bugs.openjdk.java.net/browse/JDK-8136421 <https://bugs.openjdk.java.net/browse/JDK-8136421>
>>