RFR: 8374828: Save load_barrier_on_oop_field_preloaded in aot CodeCache

[Andrew Dinn]

On Tue, 13 Jan 2026 13:41:40 GMT, Stefan Karlsson <stefank at openjdk.org> wrote:

> > However, the fact that ZGC requires a barrier for an off-heap phantom oop load does mean that we must stick with ZGC in production when we use it in assembly and vice versa (while we can safely mix and match Serial, Parallel, G1 and Shenandoah GCs).
> 
> I don't think this is true. Both G1 and Shenandoah GC need their respective SATB load barrier when they are loading an off-heap phantom oop.

Well, that's what I thought when we were originally deciding whether or not to save c2i adapters and I'm struggling now to understand how it could not be. However, when @shipilev and I looked at this a few months ago we came to the conclusion that a native phantom oop lookup would not rely on a barrier. @shipilev any ideas?

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PR Comment: https://git.openjdk.org/jdk/pull/29129#issuecomment-3748850167