RFR: 8328528: C2 should optimize long-typed parallel iv in an int counted loop [v22]

[Tobias Hartmann]

On Wed, 9 Oct 2024 18:21:30 GMT, Kangcheng Xu <kxu at openjdk.org> wrote:

>> Currently, parallel iv optimization only happens in an int counted loop with int-typed parallel iv's. This PR adds support for long-typed iv to be optimized. 
>> 
>> Additionally, this ticket contributes to the resolution of [JDK-8275913](https://bugs.openjdk.org/browse/JDK-8275913). Meanwhile, I'm working on adding support for parallel IV replacement for long counted loops which will depend on this PR.
>
> Kangcheng Xu has updated the pull request incrementally with one additional commit since the last revision:
> 
>   remove <= test cases, disable StressLongCountedLoop and PerMethodTrapLimit

Thanks for the detailed investigation and feedback. The changes look good to me, I'll re-run testing and report back.

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PR Comment: https://git.openjdk.org/jdk/pull/18489#issuecomment-2413818288