Question on "JEP: JVMCI based JIT Compiler pre-compiled as shared library"

Andrew Dinn adinn at
Thu Nov 28 15:40:06 UTC 2019

Hi Vladimir,

On 22/11/2019 18:23, Vladimir Kozlov wrote:
> As you remember during this JVMLS we talked about our plan to transition
> to Graal from C2 in a future. And using AOT'ed (SVM'ed) Graal (libgraal)
> is important part of this transition, 8220623 is part of that. Most work
> is done by GraalVM group in Oracle. They just released 19.3 version of
> GraalVM that is based on JDK 11 and using libgraal by default which use
> JVMCI changes from 8220623.

I am not sure that last statement is 100% correct :-)

It depends what you mean by 'based' on jdk11. The latest GraalVM relies
on a specific downstream jdk11 tree maintained by Oracle. GraalVM users
have to download a build derived from that tree in order to be able to
use the Graal JIT and Substrate native image generator to build native
images and shared libraries including, I believe, libgraal. I understand
that the changes made to that downstream repo are public i.e. Oracle's
GraalVM team have published sources for this tree which include the
relevant backports of upstream patches.

Red Hat as maintainers of jdk11u would very much like to correct that
situation (as, I believe, would the GraalVM team). We have a list of all
the JIRAs whose patches have been backported. Is there any reason you
are aware of for the jdk11u maintainers not to backport the relevant
patches from the jdk dev tree to jdk11u?

> On OpenJDK side we plan to release libgraal EA based on Metropolis
> repository, as I said during JVMLS. This is tracked by RFE [1]. RFE's
> description is outdated since Metropolis repo is based on JDK 14 now and
> I need to update it. There is also Graal's PR, Bob V. is working on, to
> adjust upstream Graal/SVM code to API changes done in JDK 14.

That's very good news. I'm very much looking forward to seeing
Metropolis acquire both a JIT and a VM implemented in Java.


Andrew Dinn

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