RFR: 8337251: C1: Improve Class.isInstance intrinsic [v2]

[Andrew Haley]

On Sat, 7 Dec 2024 02:06:15 GMT, Vladimir Ivanov <vlivanov at openjdk.org> wrote:

>> Andrew Haley has updated the pull request incrementally with seven additional commits since the last revision:
>> 
>>  - Windows fix, maybe.
>>  - Update
>>  - Update
>>  - Test fix/
>>  - Test fix/
>>  - Fix test failure
>>  - Reorganize C1 is_instance_of stub handling
>
> src/hotspot/share/c1/c1_LIRGenerator.cpp line 1247:
> 
>> 1245:   }
>> 1246: 
>> 1247: #ifdef HAVE_PD_C1_IS_INSTANCE_OF_STUB
> 
> Is it the first occurrence of optional stub on C1? Alternatively, you could provide a default implementation on all other platforms which simply calls into `Runtime1::is_instance_of`.
> 
> Also, the macro doesn't look pretty here. `c1_Defs_*.hpp` promote a different pattern (a constant). I understand that it requires changing all `c1_Defs_*.hpp` files, but it would definitely look cleaner here.

OK. How about this one, then?

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PR Review Comment: https://git.openjdk.org/jdk/pull/22491#discussion_r1930780683