[aarch64-port-dev ] RFR: JDK-8214527 AArch64: ZGC for Aarch64

[Roman Kennke]

That's actually going in the same direction of what I already proposed:

https://mail.openjdk.java.net/pipermail/hotspot-gc-dev/2019-May/025693.html

We may want to pick up that discussion. Last thing I heard was that Erik
suggested to broaden the proposed API changes to let the GC own the
whole arraycopy stub generation. I.e. instead of:

GC-interface-prologue
actual arraycopy (without barriers)
GC-interface-epilogue

make one call to:

GC-interface-arraycopy

and let that generate prologue, copy and epilogue, or something totally
different.

The variant that I proposed was to keep the current structure, but allow
the prologue to skip the body:

GC-interface-prologue (possibly jump to exit)
actual arraycopy (without barriers)
GC-interface-epilogue
exit: ...

I didn't have time to follow-up on that yet, but I definitely want to.

WDYT?

Roman

> Thanks for looking Aleksey.  I'll generate a separate patch.
> 
> Are you happy that I deliberately left arraycopy_epilogue as it was?
> 
> On Fri, 17 May 2019 at 15:41, Aleksey Shipilev <shade at redhat.com> wrote:
>>
>> On 5/17/19 4:28 PM, Stuart Monteith wrote:
>>> The patchset is:
>>>       http://cr.openjdk.java.net/~smonteith/8214527/webrev.0/
>>
>> I think that the extension of arraycopy_prologue interface is better to be handled and tested
>> separately, to avoid surprises. GC interface should give us clean specific-GC-only patches for
>> specific-GC features.
>>
>> -Aleksey
>>
>>