RFR: 8356708: C2: loop strip mining expansion doesn't take sunk stores into account [v7]

[Roland Westrelin]

On Wed, 18 Jun 2025 11:17:03 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>     * Is this really something we want to put into JDK 25? Feels high-risk and it's and old issue after all. Maybe we can push this to JDK26 first, and backport a little later?

Either way is fine with me. It does feel like a nasty issue that wouldn't be easy to diagnose if someone runs into it in the wild.

>     * Is this really a regression from [JDK-8281322](https://bugs.openjdk.org/browse/JDK-8281322)? If not, the affects version in JBS should be updated such that we'll consider this for backporting.

I don't think it is. It's an issue that exists since loop strip mining exists AFAICT. I haven't tried how far back the test reproduces it though.

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PR Comment: https://git.openjdk.org/jdk/pull/25717#issuecomment-2984149787