RFR: 8354383: C2: enable sinking of Type nodes out of loop [v3]

[Christian Hagedorn]

On Mon, 26 May 2025 08:36:37 GMT, Roland Westrelin <roland at openjdk.org> wrote:

>> `PhaseIdealLoop::try_sink_out_of_loop()` excludes `Type` nodes because
>> we ran into some issues where a `Type` node is sunk and then becomes
>> `top` but the control path of its uses doesn't become unreachable.
>> 
>> 8349479 should have fixed that so that exception no longer makes
>> sense.
>
> Roland Westrelin has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Update src/hotspot/share/opto/loopopts.cpp
>   
>   Co-authored-by: Christian Hagedorn <christian.hagedorn at oracle.com>

I'm not sure either, we would not to further investigate if we can find cases that benefit from it. Should we file an RFE either way?

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PR Comment: https://git.openjdk.org/jdk/pull/25396#issuecomment-2913004024