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

[Emanuel Peter]

On Thu, 23 Oct 2025 06:56:10 GMT, Christian Hagedorn <chagedorn at openjdk.org> wrote:

> Is it really invalid or just not as accurate as it could be but still correct?

That is a good question. I'm sure there are places where it is indeed invalid, and not just "not as accurate as it could be". What is an example of "not as accurate as it could be" where the information is not invalid?

I suppose we would have to continue the work on `VerifyLoopOptimizations`, and see how far we can push that. Currently our verification is very basic, and most of `VerifyLoopOptimizations` is still commented out, because there are violations somewhere. Maybe we cannot get around doing `VerifyLoopOptimizations` and the documentation of `major_progress` together.

Still: it could be worth to at least add some documentation, even if we do not have 100% confidence. We should at least write down what we do think we know, and put a caveat that we are not sure, and need to improve the situation in the future.

-------------

PR Comment: https://git.openjdk.org/jdk/pull/27912#issuecomment-3435714750