On Wed, 25 Nov 2020 11:05:39 GMT, Per Liden <pli...@openjdk.org> wrote:
>> JDK-8188055 added the function Reference.refersTo. For performance, the
>> supporting native methods Reference.refersTo0 and PhantomReference.refersTo0
>> should be intrinsified by C2.
>>
>> Initial patch was prepared by @fisk.
>>
>> Tested hs-tier1-4. Added new compiler tests to test intrinsics.
>>
>> Ran new test with Shenandoah. Found only one issue. As result I disable
>> PhantomReference::refersTo intrinsic for COOP+ Shenandoah combination.
>> Someone from Shenandoah team have to test changes if that is enough.
>
> src/hotspot/share/opto/library_call.cpp line 5525:
>
>> 5523: Node* LibraryCallKit::load_field_from_object(Node* fromObj, const
>> char* fieldName, const char* fieldTypeString,
>> 5524: DecoratorSet decorators =
>> IN_HEAP, bool is_exact = false, bool is_static = false,
>> 5525: ciInstanceKlass* fromKls
>> = NULL) {
>
> It looks like the `is_exact` argument here can be removed, as all call-sites
> use the default value, which is `false`, and the only use of it in the
> function is this assert, which will never fail.
> assert(!is_exact || tinst->klass_is_exact(), "klass not exact");
Good suggestion.
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PR: https://git.openjdk.java.net/jdk/pull/1425
