RFR: 8369448: C2 SuperWord: refactor VTransform to do move_unordered_reduction_out_of_loop during VTransform::optimize [v2]

[Christian Hagedorn]

On Mon, 13 Oct 2025 09:46:04 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

> Nice idea, I'll limit it to 10 or so. That should work at least for now.

Sounds good, thanks! 

> Not sure what you mean by bail out here. I think I'll just limit it to a debug assert.

I really meant like a safety bailout in case of looping endlessly. But I'm not sure how easy it is in that context or if we needed to bail out completely from Superword or even the compilation. Anyway, I raised it as an equivalence to IGVN where we also bail out, even from the entire compilation, if we loop for too long. We can also go with a simple assert for now and revisit it again if necessary 👍

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PR Review Comment: https://git.openjdk.org/jdk/pull/27704#discussion_r2426306809