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

[Emanuel Peter]

On Thu, 19 Jun 2025 09:59:49 GMT, Roberto Castañeda Lozano <rcastanedalo 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.

I'm ok with that too. The fix looks reasonable, and not too risky. It is probably better to have this fix in than keeping the bug in the wild, as you say.

> > ```
> > * 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.

It would be good if you could find out what versions are really affected, and set the affected numbers accordingly.

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

PR Comment: https://git.openjdk.org/jdk/pull/25717#issuecomment-2990513890