RFR(M) 8148047: Move the vtable length field to Klass

[Mikael Gerdin]

Hi Coleen

On 2016-02-01 14:13, Coleen Phillimore wrote:
>
> Mikael,
>
> This looks good.   It looks like vtable length fills an alignment gap in
> the class.
>
> Did you run the colocated nsk.sajdi.testlist on this?  It's quarantined
> but they all pass on linux x64.

I've run through some SA testing but I can't recall exactly which ones. 
I'll run through that one as well.

Thanks
/Mikael

>
> Thanks,
> Coleen
>
> On 2/1/16 2:57 AM, Mikael Gerdin wrote:
>> Hi, can I get another review, from a Reviewer, on this change?
>>
>> /Mikael
>>
>> On 2016-01-22 16:49, Mikael Gerdin wrote:
>>> Hi all,
>>>
>>> Here's the second part of the set of changes to move most of the vtable
>>> related code to Klass.
>>>
>>> This change consists of the following parts:
>>> * Move the field _vtable_len to Klass, making its accessor nonvirtual.
>>>   -> Ensure that this does not result in any footprint regression by
>>> moving TRACE_DEFINE_KLASS_TRACE_ID in Klass and _itable_len in
>>> InstanceKlass to fill out alignment gaps.
>>>   -> Move vtable_length_offset to Klass. Move vtable_start_offset to
>>> Klass to keep the code consistent. vtable_start_offset depends on the
>>> size of InstanceKlass and must therefore be defined outside of
>>> klass.hpp.
>>>
>>> * Update all locations to refer to Klass::vtable_{length,start}_offset
>>> instead of InstanceKlass.
>>>
>>> * Modify SA to look for _vtable_len in Klass.
>>>
>>> * Rename CompilerToVM::Data::InstanceKlass_vtable_{length,start}_offset
>>> and
>>> jdk.vm.ci.hotspot.HotSpotVMConfig.instanceKlassVtable{Length,Start}Offset
>>> to
>>> properly represent where the offsets are coming from.
>>>
>>>
>>> Webrev: http://cr.openjdk.java.net/~mgerdin/8148047/webrev.0/
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8148047
>>>
>>> Testing: JPRT on Oracle supported platforms.
>>>
>>> As in the previous change I've updated the PPC64 and AARCH64 ports but I
>>> have not tested the changes. Build and test feedback from porters is
>>> most welcome!
>>>
>>> Thanks
>>> /Mikael
>>
>