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

[Severin Gehwolf]

Hi Sean,

On Wed, 2018-10-10 at 16:32 +0100, Seán Coffey wrote:
> Please add an appropriate noreg- label to the master bug record.
> 
> http://openjdk.java.net/guide/changePlanning.html#noreg

I've added noreg-hard.

> Approved for jdk8u-dev.

Thanks!

Cheers,
Severin

> 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
> > 
> 
>