RFR: 8331341: secondary_super_cache does not scale well: C1 and interpreter [v8]

[Vladimir Ivanov]

On Thu, 25 Jul 2024 13:56:34 GMT, Andrew Haley <aph at openjdk.org> wrote:

>> Thanks, now I see that `Class::isInstance(Object)` is backed by `Runtime1::is_instance_of()` which uses `oopDesc::is_a()` to do the job.
>> 
>> If it turns out to be performance critical, the intrinsic implementation should be rewritten to exercise existing subtype checking support in C1. As it is implemented now, it's already quite inefficient.
>
> I did write an intrinsic for that, but it made this patch even larger. I have a small patch for C1, for some other time.

FYI I filed a low-priority RFE against C1 to track it ([JDK-8337251](https://bugs.openjdk.org/browse/JDK-8337251)).

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PR Review Comment: https://git.openjdk.org/jdk/pull/19989#discussion_r1692548251