RFR 8047737 Move array component mirror to instance of java/lang/Class

[Coleen Phillimore]

Thank you, Fred, and thanks for correcting the link below.
Coleen

On 6/30/14, 10:27 AM, Frederic Parain wrote:
>
>
> On 30/06/2014 14:42, Coleen Phillimore wrote:
>>
>> On 6/30/14, 1:55 AM, David Holmes wrote:
>>> Hi Coleen,
>>>
>>> Your webrev links are to internal locations.
>>
>> Sorry, I cut/pasted the wrong links.  They are:
>>
>> http://cr.openjdk.java.net/~coleenp/8047737_jdk/
>> http://cr.openjdk.java.net/~coleenp/8047737_hotspot/
>
> First step looks good.
>
>> and the full version
>>
>> http://cr.openjdk.java.net/~coleenp/8047737_hotspot/
>
> The correct link to the full version seems to be:
> http://cr.openjdk.java.net/~coleenp/8047737_hotspot_full/
>
> I haven't reviewed the full version yet.
>
> Fred
>
>> Thank you for pointing this out David.
>>
>> Coleen
>>
>>>
>>> David
>>>
>>> On 28/06/2014 5:24 AM, Coleen Phillimore wrote:
>>>> Summary: Add field in java.lang.Class for componentType to simplify 
>>>> oop
>>>> processing and intrinsics in JVM
>>>>
>>>> This is part of ongoing work to clean up oop pointers in the metadata
>>>> and simplify the interface between the JDK j.l.C and the JVM. 
>>>> There's a
>>>> performance benefit at the end of all of this if we can remove all oop
>>>> pointers from metadata.   mirror in Klass is the only one left after
>>>> this full change.
>>>>
>>>> See bug https://bugs.openjdk.java.net/browse/JDK-8047737
>>>>
>>>> There are a couple steps to this change because Hotspot testing is 
>>>> done
>>>> with promoted JDKs.  The first step is this webrev:
>>>>
>>>> http://oklahoma.us.oracle.com/~cphillim/webrev/8047737_jdk/
>>>> http://oklahoma.us.oracle.com/~cphillim/webrev/8047737_hotspot/
>>>>
>>>> When the JDK is promoted, the code to remove
>>>> ArrayKlass::_component_mirror will be changed under a new bug id.
>>>>
>>>> http://oklahoma.us.oracle.com/~cphillim/webrev/8047737_hotspot_full
>>>>
>>>> Finally, a compatibility request and licensee notification will 
>>>> occur to
>>>> remove the function JVM_GetComponentType.
>>>>
>>>> Performance testing was done that shows no difference in performance.
>>>> The isArray() call is a compiler intrinsic which is now called instead
>>>> of getComponentType, which was recognized as a compiler intrinsic.
>>>>
>>>> JDK jtreg testing, hotspot jtreg testing, hotspot NSK testing and jck8
>>>> tests were performed on both the change requested (1st one) and the 
>>>> full
>>>> change.
>>>>
>>>> hotspot NSK tests were run on the hotspot-only change with a promoted
>>>> JDK.
>>>>
>>>> Please send your comments.
>>>>
>>>> Thanks,
>>>> Coleen
>>
>