RFR: 8171853: Remove Shark compiler

John Paul Adrian Glaubitz glaubitz at physik.fu-berlin.de
Sun Oct 15 20:44:16 UTC 2017

On 10/15/2017 10:34 PM, Roman Kennke wrote:
>> It's a pity that this value is not seen within the OpenJDK project.
> Yes, I agree with you. However, at this point, fixing Shark amounts to almost
> complete rewrite of it. It would nowadays be based on jvmci. It would use the
> new and presumably much better JIT interface of LLVM. It would not use a shadow
> stack and a sane interface between LLVM and the GC (which hasn't existed back then).

Ok, that gives me some consolation, although I'm still sad about this decision.

> It's a project I'd personally like to do just for the fun of it, but I simply don't
> have enough time and the nerve to pull it off alone. In any case, as I said, it
> would probably make sense to start it from scratch.

FWIW, there are actually quite a number of users for Zero who would be happy to
have a JIT-version of it. One major user for Zero is MIPS (big-, little-endian,
32 and 64 bit) which still doesn't have a native code generator in Hotspot.

But we're also using Zero on architectures like m68k (yes, that still exists
as people are upgrading their Amigas and Ataris with fast FPGA accelerators)
and SuperH and it works fine.

I have also contributed several patches already to get Zero into a better
shape which allows it to build within Debian without additional patches,
I would definitely be interested in helping with a new Shark JVM although
I understand that would be a bigger project :).

> I checked and noticed that it only affects debug builds. That's probably why it slipped through.
> I filed https://bugs.openjdk.java.net/browse/JDK-8189333 and will post an RFR later.

Ok, I'll test it once you've posted it.

>>> - I could not test any of the other arches that seemed to reference Shark (arm and sparc)
>> I will test this later. I am currently waiting for JDK-8186579 to get merged which fixes
>> the last problem on Linux-SPARC.
> Okidoki, thanks a lot!!

Let me pull this in and test Zero and Server on Linux SPARC.


  .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer - glaubitz at debian.org
`. `'   Freie Universitaet Berlin - glaubitz at physik.fu-berlin.de
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