Withdrawn: 8253843: AArch64: Use ishst for storestore barrier
Alan Hayward
github.com+4146708+a74nh at openjdk.java.net
Thu Oct 8 12:50:46 UTC 2020
On Wed, 30 Sep 2020 08:34:14 GMT, Alan Hayward <github.com+4146708+a74nh at openjdk.org> wrote:
> AArch64 orderAccess uses gcc built in atomic functions, which expand
> inline to DMB barrier instructions. Specifically, they call the following:
>
> FULL_MEM_BARRIER -> DMB ISH
> READ_MEM_BARRIER -> DMB ISHLD
> WRITE_MEM_BARRIER -> DMB ISH
>
> However, storestore should be optimised to use ISHST.
>
> In addition, __sync_synchronize is marked as legacy. See:
> https://gcc.gnu.org/onlinedocs/gcc/_005f_005fatomic-Builtins.html
>
> In order for the code to match, I switched everything to call dmbs directly.
>
> Also, add AArch64 to the orderAccess documentation table.
This pull request has been closed without being integrated.
-------------
PR: https://git.openjdk.java.net/jdk/pull/427
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