RFR: 8342941: IGV: Add new graph dumps for post loop, empty loop removal, and one iteration removal [v2]

[Saranya Natarajan]

On Thu, 12 Jun 2025 06:17:55 GMT, Christian Hagedorn <chagedorn at openjdk.org> wrote:

>> Saranya Natarajan has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Addressing review comments
>
> Thanks for adding those!
> 
> You are currently dumping the `CountedLoop` for the "before" and "after" dump. I think we could improve the "after" dump to show the actual change:
> - In the "after" dump of the post loop, we could dump the new post loop instead of the old one.
> - For the empty loop removal we could dump the `final_iv` instead:
> https://github.com/openjdk/jdk/blob/c5a1543ee3e68775f09ca29fb07efd9aebfdb33e/src/hotspot/share/opto/loopTransform.cpp#L3172
> - For the one iteration removal, I'm not sure if it's worth to print anything. I think we can either print nothing or the init which replaces the iv:
> https://github.com/openjdk/jdk/blob/c5a1543ee3e68775f09ca29fb07efd9aebfdb33e/src/hotspot/share/opto/loopTransform.cpp#L3334

@chhagedorn Thank you for the comments. I have addressed them. Could you see if this is okay ?

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PR Comment: https://git.openjdk.org/jdk/pull/25756#issuecomment-2987108747