[aarch64-port-dev ] RFR(T): 8226222: [JVMCI] Export AArch64 field VM_Version::_psr_info.dczid_el0

[Pengfei Li (Arm Technology China)]

Hi,

> > This looks fine to me. We can push it into jdk/jdk (which is jdk 14 now).
> > I am not sure where we should backport this. Doug, what do you think?
> 
> I’m not familiar with the OpenJDK backport decision making process so I’m
> not exactly sure what you’re asking me.

Thanks for your review.

I just read the JDK Update Guidance[1] and JDK Release Process[2]. According to the rules, this patch should be backported only to jdk11u. But as this change is just a support of Graal compiler optimization and latest Graal code won't be synced with jdk11u any more,  I don't think we have the need to do the backport. On the other hand, the Graal compiler has the ability to check the existence of a given field and give up optimization if required field is not present. So I think there should be no compatibility issue between the Graal compiler and multiple JDK versions, even if we don't do the backport.

[1] https://wiki.openjdk.java.net/display/JDKUpdates/JDK+Updates+Guidance
[2] http://openjdk.java.net/jeps/3

--
Thanks,
Pengfei