Can JIT be enabled on jdk-6?

[Andrew Hughes]

----- Original Message -----
> Hi Fernando,
> 
> I don't see any principal problems with getting the port into openjdk-6.
> 
> I would pick all changes of 'goetz' and 'simonis'  from
> http://hg.openjdk.java.net/ppc-aix-port/jdk7u/hotspot/
> and push them step by step to the new repo.
> Or maybe better take the reviewed changes from
> http://hg.openjdk.java.net/ppc-aix-port/stage/hotspot/
> which is a jdk8 repository.  These changes have a bugid and
> are reviewed, so they are better to track.
> 
> But do you actually want to do this?  6 is old. And there are quite some open
> issues with the ppc64le port in 8 and 9 , which could be fixed:
> 
> 8073139: PPC64: User-visible arch directory and os.arch value on ppc64le
> cause issues with Java tooling
> https://bugs.openjdk.java.net/browse/JDK-8073139
> http://mail.openjdk.java.net/pipermail/hotspot-dev/2015-July/019415.html
> I think this issue really should be resolved.
> 
> 8139258: PPC64LE: argument passing problem when passing 15 floats in native
> call
> https://bugs.openjdk.java.net/browse/JDK-8139258
> http://mail.openjdk.java.net/pipermail/ppc-aix-port-dev/2015-July/002282.html
> 
> Also, a row of jtreg tests are failing with the serviceability agent on
> ppc/ppcle:
>   serviceability/sa/jmap-hashcode/Test8028623.java
>   serviceability/sa/TestStackTrace.java
>   gc/metaspace/CompressedClassSpaceSizeInJmapHeap.java
>   serviceability/sa/TestClassLoaderStats.java
> The last two fail on ppc64le only.
> 
> Best regards,
>   Goetz
> 
> 
> 
> -----Original Message-----
> From: ppc-aix-port-dev [mailto:ppc-aix-port-dev-bounces at openjdk.java.net] On
> Behalf Of Fernando Seiti Furusato
> Sent: Donnerstag, 8. Oktober 2015 16:19
> To: ppc-aix-port-dev at openjdk.java.net
> Cc: Breno Leitao
> Subject: Can JIT be enabled on jdk-6?
> 
> Hello.
> 
> I work with porting on ppc64le and I am looking for some info regarding
> enabling JIT on openjdk-6.
> I am sure it is not a simple task, but I have to ask :)
> If anyone could help me out with this I would appreciate.
> These are the initial quetions I have:
> 
> 1 - Is it possible to do a "backport" of what has been done on openjdk-7?
> 2 - How long do you think one would take to do that work of enabling JIT on
> openjdk-6, in case it is possible?
> 
> Thanks in advance.
> --
> 
> Fernando Seiti Furusato
> IBM Linux Technology Center
> 
> 

My personal recommendation would be to build OpenJDK 6 and replace
its HotSpot tree with the IcedTea 2.x HotSpot tree, which is based
on OpenJDK 7, but contains the PPC64, PPC64LE and AArch64 ports.

i.e.

1. Checkout OpenJDK 6
2. rm -rf hotspot
3. hg clone http://icedtea.classpath.org/hg/icedtea7-forest/hotspot
4. Build

I'm actually considering making this an option for the IcedTea 1.14.0
release, as people have also been asking about AArch64 support.

I think attempting to backport individual 8 changesets onto HotSpot
23 would be much harder and unnecessary.
-- 
Andrew :)

Senior Free Java Software Engineer
Red Hat, Inc. (http://www.redhat.com)

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