RFR: 8305236: Some LoadLoad barriers in the interpreter are unnecessary after JDK-8220051 [v3]

[Fei Yang]

On Tue, 4 Apr 2023 05:13:09 GMT, SUN Guoyun <duke at openjdk.org> wrote:

>> After JDK-8220051, Interpreter::notice_safepoints() only be executed at a safe point, so LoadLoad barrier is useless.
>> Barrier directives are generally time-consuming, so this patch removes LoadLoad be used for aarch64 and riscv.
>> 
>> Jtreg tier1-2 testing for aarch64 has been done.
>> 
>> Please help review it.
>> 
>> Thanks.
>
> SUN Guoyun has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains one commit:
> 
>   8305236: Some LoadLoad barriers in the interpreter are unnecessary after JDK-8220051

Performed tier1-3 tests on linux-riscv64, result looks good. Also run jcstress test overnight.
Better to have an ACK from the aarch64 reviewers.

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Marked as reviewed by fyang (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/13244#pullrequestreview-1373907539