RFR: 8238190 : [JVMCI] Fix single implementor speculation for diamond shapes.

[coleen.phillimore at oracle.com]

http://cr.openjdk.java.net/~davleopo/JDK-8238190/webrev.001/test/hotspot/jtreg/compiler/jvmci/jdk.vm.ci.runtime.test/src/jdk/vm/ci/runtime/test/TestSingleImplementor.java.html

Can you add @bug 8238190 to this test, and a @summary would be really 
nice too.   Also could this test would appear in 
test/hotspot/jtreg/compiler/jvmci directory so we all run it regularly 
as well?

Yes, officially Reviewed.  Good find!
Coleen

On 1/31/20 12:47 PM, Vladimir Kozlov wrote:
> CCing to Runtime group since it is runtime code. Coleen already looked 
> on this fix but we need official review here.
>
> David, it seems you did not pull latest fixes from JDK. Most of 
> failures in your testing should be fixed already. There are testing 
> infra "red" failures which are nothing to do with changes.
> I would suggest to pull latest changes before push (after reviews) and 
> run tier1-2 again.
>
> In short, I don't see new failures in tier1-2 testing and tier3-graal. 
> Fix looks good to me.
>
> Thanks,
> Vladimir
>
> On 1/31/20 12:49 AM, David Leopoldseder wrote:
>> Hi,
>>
>> Please review this tiny change (+ a new test case exercising the 
>> pattern) to
>> fix the single implementor logic in instanceKlass for diamond shaped 
>> class hierarchies.
>>
>> This bug was revealed in Graal where we use the single implementor 
>> logic for invokeinterface devirtualization.
>>
>> https://bugs.openjdk.java.net/browse/JDK-8238190
>> http://cr.openjdk.java.net/~davleopo/JDK-8238190/webrev.001/
>>
>> Thank you.
>>
>> - david
>>