RFR: 8354541: Remove Shenandoah post barrier expand loop opts

[Aleksey Shipilev]

On Mon, 14 Apr 2025 18:42:23 GMT, Cesar Soares Lucas <cslucas at openjdk.org> wrote:

> Please review this patch to remove Shenandoah post-barrier expand loop optimizations. This optimization was added in the first iteration os Shenandoah barriers. Nowadays, we try to always insert LRB at the earliest place and the impact of these optimizations is minimal; they are also frequent source of bugs.
> 
> Tested on OSX Aarch64 & Linux amd64 with JTREG tier1-3.

Looks OK in principle. This would likely not matter also when we switch to late barrier expansion for Shenandoah, following the examples of Z an G1. Have you seen any performance impact at all with this patch?

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Marked as reviewed by shade (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/24630#pullrequestreview-2768339030