[13] RFR(S): 8218201: Failures when vmIntrinsics::_getClass is not inlined

[Tobias Hartmann]

Thanks Nils!

Best regards,
Tobias

On 07.03.19 15:32, Nils Eliasson wrote:
> +1
> 
> // Nils
> 
> On 2019-03-07 14:23, Claes Redestad wrote:
>> Looks good, and nice touch cleaning up the unused return values!
>>
>> /Claes
>>
>> On 2019-03-07 13:54, Tobias Hartmann wrote:
>>> Hi,
>>>
>>> please review the following patch:
>>> https://bugs.openjdk.java.net/browse/JDK-8218201
>>> http://cr.openjdk.java.net/~thartmann/8218201/webrev.00/
>>>
>>> When intrinsification is disabled, the BCEscapeAnalyzer marks the return value of the (native)
>>> method Object::getClass as "return allocated value" which means that "only newly allocated unescaped
>>> objects are returned". The OptimizePtrCompare optimization then uses this information to incorrectly
>>> fold 'obj.getClass() == Object.class' (see TestGetClass.java:39) to always false.
>>>
>>> This is a very old issue and I can't trace back why a special case for the _getClass intrinsic has
>>> been added to the BCEscapeAnalyzer. Since I don't think we should make any assumptions about the
>>> returned Object, I've removed the special case.
>>>
>>> Thanks,
>>> Tobias
>>>