[lworld] Integrated: 8353432: [lworld] Deoptimization needs to handle nullable, flat fields in non-value class holders

[Quan Anh Mai]

On Sat, 31 May 2025 10:49:57 GMT, Quan Anh Mai <qamai at openjdk.org> wrote:

> Hi,
> 
> This patch adds handling of nullable flat fields in non-value class holder. Currently, we add all the fields to the safepoint, then add all the null markers. I decide to change this to adding the null marker of a flat field right after all the subfields of it. It makes the shape similar to how we pass nullable flat fields in the ABI, as well as simplifies the implementation since we do not have to keep track of all null markers when traversing the object payload.
> 
> Please take a look and leave your reviews, thanks a lot.

This pull request has now been integrated.

Changeset: fdac9ab4
Author:    Quan Anh Mai <qamai at openjdk.org>
Committer: Tobias Hartmann <thartmann at openjdk.org>
URL:       https://git.openjdk.org/valhalla/commit/fdac9ab4e6eaa84c0ae31623afc566bbc97abca6
Stats:     381 lines in 7 files changed: 188 ins; 138 del; 55 mod

8353432: [lworld] Deoptimization needs to handle nullable, flat fields in non-value class holders

Reviewed-by: thartmann

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PR: https://git.openjdk.org/valhalla/pull/1478