RFR: Consolidate assembly write barriers

[Aleksey Shipilev]

On 07/09/2018 08:12 PM, Aleksey Shipilev wrote:
> On 07/09/2018 08:08 PM, Roman Kennke wrote:
>>>     // The set of registers to be saved+restored is the same as in the write-barrier above.
>>>     // Those are the commonly used registers in the interpreter.
>>
>> The write-barrier goes through the stub, which saves the registers.
> 
> Ah! Okay then.
> 
>> Remaining patch:
>> http://cr.openjdk.java.net/~rkennke/shenandoahwb/webrev.01/
> 
> Looks good.

On a second thought, I think it hides the bug in SBSA::write_barrier_impl: it only goes through read
barrier if (EVAC|TRAVERSAL), which is not complete, and it should go via that path when
HAS_FORWARDED is true as well. I am preparing the fix.

-Aleksey