RFR: JDK-8141634 Implement VarHandles/Unsafe intrinsics on SPARC

[Trevor Watson]

I've updated the code based on David's feedback and successfully run 
JPRT hotspot and jtreg compiler/unsafe tests.

Revised code is at:
http://cr.openjdk.java.net/~alanbur/JDK-8141634/

Many thanks,
Trevor

On 26/08/16 09:34, Trevor Watson wrote:
> Ok, thanks. I'll remove that code from my changes, retest and resubmit
> the webrev.
>
> On 26/08/16 09:02, David Holmes wrote:
>> Hi Trevor,
>>
>> On 26/08/2016 6:00 PM, Trevor Watson wrote:
>>> Hi David,
>>>
>>> Thanks for that information. I already suspected that 32-bit was no
>>> longer supported, but as I'm new to working on this code I didn't want
>>> to go changing to many things at once.
>>>
>>> Would you be okay if I logged a separate bug to remove the 32-bit checks
>>> and supports_cx8 predicate? That was I can focus on just those things.
>>
>> I was only suggesting not including them in this new code. Removing them
>> from existing code is a different matter.
>>
>> Thanks,
>> David
>>
>>> Trevor
>>>
>>> On 26/08/16 04:44, David Holmes wrote:
>>>> Hi Trevor,
>>>>
>>>> Not a full review as I'm not familiar with .ad file syntax and
>>>> structure. Two observations:
>>>>
>>>> 1. We no longer support 32-bit so that code could be elided.
>>>> 2. supports_cx8 is true for sparc so doesn't need to verified in sparc
>>>> specific code (it is intended for use in shared code).
>>>>
>>>> Cheers,
>>>> David
>>>>
>>>> On 26/08/2016 12:01 AM, Trevor Watson wrote:
>>>>> Hi All,
>>>>>
>>>>> Please can I get a review of these updates to sparc.ad which adds in
>>>>> the
>>>>> C2 compareAndExchange intriniscs for int, long, pointer and object?
>>>>>
>>>>> I've run the hotspot jtreg tests locally and the JPRT hotspot tests
>>>>> successfully.
>>>>>
>>>>> The implementation of these intrinsics gives a 9x to 20x performance
>>>>> improvement for compareAndExchange operatios.
>>>>>
>>>>> http://cr.openjdk.java.net/~alanbur/JDK-8141634/
>>>>>
>>>>> Thanks,
>>>>> Trevor