RFR: 8261579: AArch64: Support for weaker memory ordering in Atomic [v4]

[Andrew Dinn]

On Fri, 25 Jun 2021 15:02:35 GMT, Andrew Haley <aph at openjdk.org> wrote:

>> At present the Atomic operations in HotSpot only support conservative (the very strongest) and relaxed (the weakest) memory ordering.
>> We should add at least seq_cst for LSE. This patch also adds a release-only CAS, needed for Shenandoah.
>
> Andrew Haley has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Sanitize memory order for BSD CAS

All looks good to me apart from the bsd changes which I am in not really in a position to comment on. I'll have to take your word for it that the builtin CAS requires the trailing mode arguments you specify.

-------------

Marked as reviewed by adinn (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/4597