RFR: 8334060: Implementation of Late Barrier Expansion for G1 [v2]

[Roberto Castañeda Lozano]

On Fri, 16 Aug 2024 20:54:25 GMT, Martin Doerr <mdoerr at openjdk.org> wrote:

>  The null check can be integrated into the oop decoding, so all Compressed Oops Modes would benefit.

But integrating the null check into the zero-based OOP decoding operation would require adding a conditional branch to OOP decoding (as prototyped [here](https://github.com/robcasloz/jdk/blob/ac71b1a02c8c1bd4989f762d27092fd3bf19ccd7/src/hotspot/cpu/x86/macroAssembler_x86.cpp#L5859-L5875)), right? This would effectively mean moving the post-barrier null check above the post-barrier inter-region check, which I am not sure is beneficial.

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PR Review Comment: https://git.openjdk.org/jdk/pull/19746#discussion_r1721697447