RFR: 8369190: JavaFrameAnchor on AArch64 has unnecessary barriers and wrong store order in MacroAssembler [v5]

[Justin King]

On Tue, 7 Oct 2025 08:29:26 GMT, Andrew Haley <aph at openjdk.org> wrote:

>> `OrderAccess::release()` is more than a compiler barrier on AArch64. I am guessing this was copied from x86 or one of the others where that same function is a compiler barrier? Should I move `compiler_barrier` from the random source files its in, into globalDefinitions, and use that?
>
> As far as I can see, the frame anchor is only accessed from its owner thread, so it doesn't matter.

I refactored `compiler_barrier()` into globalDefinitions and used it, it is potentially need to ensure the compiler doesn't change the store/load order so that `sp` is always last.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27645#discussion_r2410744044