RFR: 8370077: C2: make Compile::_major_progress a boolean [v2]

[Christian Hagedorn]

On Wed, 22 Oct 2025 08:48:14 GMT, Marc Chevalier <mchevalier at openjdk.org> wrote:

>>> My understanding is that the flag is set if the loop-opts data-structures are invalid (or at least there is no guarantee that they are valid). So we need to re-build the loop tree.
>> 
>> Additionally, there are also cases where we think that we could apply more loop-opts even though the structures are still valid:
>> https://github.com/openjdk/jdk/blob/f475eb8ee7c9a3e360b2f1210ed71b629243cd2a/src/hotspot/share/opto/loopnode.cpp#L5113-L5119
>> 
>> One more reason that we should add some documentation about how we use `major_progress`.
>
> I don't think anyone is saying we should not have such comments. I just think it's out of scope here and mainly I just don't know enough to write anything useful and correct. But if somebody more knowledgeable in this gives me a patch that adds such documentation, I can sneak it in this PR. Otherwise, it will be another time.

Absolutely, it should not hold up this PR. It was more meant to be an endorsement that we should definitely add some documentation some point.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27912#discussion_r2451859576