RFR: 8325467: Support methods with many arguments in C2 [v13]

[Daniel Lundén]

On Tue, 1 Apr 2025 16:02:07 GMT, Roberto Castañeda Lozano <rcastanedalo at openjdk.org> wrote:

>> Daniel Lundén has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 20 commits:
>> 
>>  - Updates after comments
>>  - Tag short-lived register mask arena
>>  - Merge remote-tracking branch 'upstream/master' into many-arguments-8325467
>>  - Formatting updates
>>  - Add register mask fuzzer test
>>  - Extend example with offset register mask
>>  - Remove accidental leftover #endif
>>  - Update
>>  - Fix trailing whitespace
>>  - Merge remote-tracking branch 'upstream/master' into many-arguments-8325467
>>  - ... and 10 more: https://git.openjdk.org/jdk/compare/a1ab1d8d...76f6b8f8
>
> src/hotspot/share/opto/chaitin.cpp line 1591:
> 
>> 1589:         // will be a no-op.  (Later on, if lrg runs out of possible colors in
>> 1590:         // its chunk, a new chunk of color may be tried, in which case
>> 1591:         // examination of neighbors is started again, at retry_next_chunk.)
> 
> Doesn't the second part of the comment (`(Later on...)`) still apply after the changes?

Thanks, good catch. Now restored.

> src/hotspot/share/opto/matcher.cpp line 148:
> 
>> 146:       C->record_method_not_compilable("unsupported incoming calling sequence");
>> 147:       return OptoReg::Bad;
>> 148:     }
> 
> Please consider removing the failure polls after calling `warp_incoming_stk_arg`, I believe the removal of this bailout makes them unnecessary.

Thanks, I've removed the polls after `warp_incoming_stk_arg` and also after `warp_outgoing_stk_arg`.

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PR Review Comment: https://git.openjdk.org/jdk/pull/20404#discussion_r2026932391
PR Review Comment: https://git.openjdk.org/jdk/pull/20404#discussion_r2026930405