RFR (S) 8247296: Optimize JVM_GetDeclaringClass
yumin.qi at oracle.com
Fri Jul 24 15:37:38 UTC 2020
On 7/23/20 11:44 PM, David Holmes wrote:
> I must stress I am sponsoring Christoph's change and only extended it
> within the current file. :) I'm sure there are many, many more
> opportunities for similar optimisations. Though you have to be careful
> to ensure you don't expose an unhandled oop.
>> Where thread_handle resolved multiple times.
> True that is unnecessary, but this is a compiler code and I'd need to
> extend the review so ... I'll pass on this one.
That is OK.
>> Where clazz resolved twice.
> Fixed this as it is the same pattern in a core runtime file. Webrev
> updated in place.
>> Do you want to include those two files in your list?
>> On 7/23/20 8:49 PM, David Holmes wrote:
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8247296
>>> webrev: http://cr.openjdk.java.net/~dholmes/8247296/webrev/
>>> Please review this simple optimization contributed by Christoph
>>> Dreis in its initial form and then expanded by me to cover other
>>> cases in jvm.cpp.
>>> There is a common pattern of code of the form:
>>> which resolves cls twice. There are also duplicate calls to as_Klass
>>> that can be removed in a couple of cases.
>>> Testing: tiers 1 - 3
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