RFA: 8211387: [Zero] atomic_copy64: Use ldrexd for atomic reads on ARMv7

[Seán Coffey]

Please add an appropriate noreg- label to the master bug record.

http://openjdk.java.net/guide/changePlanning.html#noreg

Approved for jdk8u-dev.

Regards,
Sean.

On 09/10/18 10:25, Severin Gehwolf wrote:
> Hi,
>
> Please approve this Zero JVM only change for 8u. It makes Zero use
> ldrexd for atomic reads on ARMv7. Since we build 8u Zero on ARM 32 in
> Fedora this is useful to us to get upstream. Patch is the same as for
> JDK 12, post path-unshuffeling.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8211387
> changeset: http://hg.openjdk.java.net/jdk/jdk/rev/6ee9500fe653
>
> Testing: bootcyle-images Zero builds on ARMv7.
>
> Thanks,
> Severin
>