RFR: 8290892: C2: Intrinsify Reference.reachabilityFence [v22]

[Emanuel Peter]

On Fri, 7 Nov 2025 11:37:22 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> Vladimir Ivanov has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   update
>
> src/hotspot/share/opto/reachability.cpp line 474:
> 
>> 472:       }
>> 473:     }
>> 474:     redundant_rfs.push(rf);
> 
> I think the name `redundant_rfs` is a bit confusing here. Because above you may just have checked if `is_redundant_rf` and it may have returned false. So it does not really make sense to call it a "redundant rf". This confused me when I was trying out a simple example in the debugger.

Another question:
What if `!is_redundant_rf` and we found no sfpt candidates? Is it ok to just eliminate the rf here?

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PR Review Comment: https://git.openjdk.org/jdk/pull/25315#discussion_r2502999947