RFR: 8180450: secondary_super_cache does not scale well [v14]

[Vladimir Ivanov]

On Fri, 12 Apr 2024 23:44:38 GMT, Dean Long <dlong at openjdk.org> wrote:

>> Andrew Haley has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   JDK-8180450: secondary_super_cache does not scale well
>
> src/hotspot/share/opto/matcher.cpp line 2503:
> 
>> 2501:       break;
>> 2502:     }
>> 2503:     case Op_PartialSubtypeCheck: {
> 
> This could use a comment.  Changing the shape with BinaryNode is standard, but duplicating inputs seems to be something new.

Good point. Does it look better?

      if (UseSecondarySupersTable && n->in(2)->is_Con()) {
        // PartialSubtypeCheck uses both constant and register operands for superclass input.
        n->set_req(2, new BinaryNode(n->in(2), n->in(2)));
        break;

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PR Review Comment: https://git.openjdk.org/jdk/pull/18309#discussion_r1563383350