RFR: 8305895: Implement JEP 450: Compact Object Headers (Experimental) [v15]

[Roberto Castañeda Lozano]

On Mon, 16 Sep 2024 08:04:43 GMT, Roberto Castañeda Lozano <rcastanedalo at openjdk.org> wrote:

> I agree that this is the simplest and least intrusive way of getting klass loading working in C2 for this experimental version of the feature. However, the approach seems brittle and error-prone, and it may be hard to maintain in the long run. Therefore, I think that a more principled and robust modeling will be needed, after this PR is integrated, in preparation for the non-experimental version.

What do you think about this @rkennke? Do you agree on an alternative modeling of klass loading in C2 (without any reliance on `oopDesc::klass_offset_in_bytes()`) being a pre-condition for a future, non-experimental version of compact headers?

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

PR Comment: https://git.openjdk.org/jdk/pull/20677#issuecomment-2360673405