RFR: 8369190: JavaFrameAnchor on AArch64 has unnecessary barriers and wrong store order in MacroAssembler [v6]

[Andrew Haley]

On Wed, 8 Oct 2025 12:31:39 GMT, Justin King <jcking at openjdk.org> wrote:

>> Remove unnecessary release barriers in `JavaFrameAnchor::{copy,clear}` and fix `MacroAssembler::set_last_Java_frame` to set `sp` last as expected by the profiler.
>
> Justin King has updated the pull request incrementally with eight additional commits since the last revision:
> 
>  - JDK-8369190: JavaFrameAnchor on AArch64 appears to be missing barriers
>    
>    Signed-off-by: Justin King <jcking at google.com>
>  - Revert "JDK-8369190: JavaFrameAnchor on AArch64 appears to be missing barriers"
>    
>    This reverts commit 462c63e588ebf0dcd478b5347684ccb6c2438686.
>  - Revert "Update comments"
>    
>    This reverts commit a0058eb4405a9afb0db80d9838e0657f725c9a15.
>  - Revert "Rename ACGT -> AGCT"
>    
>    This reverts commit a141449425a72a4095b9740e28c758cb295c9352.
>  - Revert "Remove barriers and just fix program order for sp store in MacroAssembler"
>    
>    This reverts commit 253417f98e7d5680a3ad6f8561b198fc0ae3b141.
>  - Revert "Add comment to JavaFrameAnchor regarding no need for fencing"
>    
>    This reverts commit 016769dfe4272d7cb37d46524f32e9f7a4887b11.
>  - Revert "Move compiler_barrier() to globalDefinitions.hpp and use it"
>    
>    This reverts commit 6dd80d947a343ad6c45d1738614643f7013afcbc.
>  - Revert "Add back header inclusion"
>    
>    This reverts commit 7dc3313c9fd6a4f2739c39dc4d9d075103894aa9.

Phew. Thank you for your patience.

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Marked as reviewed by aph (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/27645#pullrequestreview-3315023695