RFR: 8372634: C2: Materialize type information from instanceof checks [v2]

[Vladimir Ivanov]

On Wed, 3 Dec 2025 02:19:46 GMT, Dean Long <dlong at openjdk.org> wrote:

>> Vladimir Ivanov has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Test fix
>
> src/hotspot/share/opto/parse2.cpp line 1737:
> 
>> 1735:     (*cast_type) = tcon->isa_klassptr()->as_instance_type();
>> 1736:     return true; // found
>> 1737:   }
> 
> The old code checked klass_is_exact() for this case, but the new code does not, so was it redundant, given we have a constant?

Yes, the check is redundant. Moreover, I tested the patch having the check turned into an assert.

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PR Review Comment: https://git.openjdk.org/jdk/pull/28517#discussion_r2594314864