RFR: 8366815: C2: Delay Mod/Div by constant transformation [v3]

[Emanuel Peter]

On Thu, 30 Oct 2025 18:23:46 GMT, Hannes Greule <hgreule at openjdk.org> wrote:

>> The test cases show examples of code where `Value()` previously wasn't run because idealization took place before, resulting in less precise type analysis.
>> 
>> Please let me know what you think.
>
> Hannes Greule has updated the pull request incrementally with one additional commit since the last revision:
> 
>   review

I'll approve it now as is.

If some is willing to produce a better solution in the future, then I'm happy to review it as well ;)

@merykitty a separate phase could be a good idea. It is some extra complexity though, so we have to weigh it off with the hacky-ness of the current solution (and other places where we do the delay-trick). But it would probably be worth it.

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Marked as reviewed by epeter (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/27886#pullrequestreview-3577133449