[aarch64-port-dev ] RFR 8233401: Shenandoah: Refactor/cleanup Shenandoah load barrier code

[Zhengyu Gu]

Thanks for the review, Aleksey.

On 11/6/19 8:45 AM, Aleksey Shipilev wrote:
> On 11/6/19 1:18 PM, Zhengyu Gu wrote:
>> Updated: http://cr.openjdk.java.net/~zgu/JDK-8233401/webrev.02/index.html
> 
> Minor nits:
> 
> *) shenandoahBarrierSetAssembler_aarch64.cpp: excess space between parentheses:
> 
>   368   if (!is_reference_type(type) ) {

Will fix before push.

> 
> *) shenandoahBarrierSetC1.cpp: so, native oop loads used to call to
> ShenandoahRuntime::load_reference_barrier_native before this refactoring? That would mean it is
> enabled even when "passive" is enabled (which implies -ShenandoahLRB)? Current change looks fine,
> but we need to recognize this is the behavioral change. Please link the issue where that regression
> was introduced.

Correct, we don't need load_reference_barrier_native barrier if weak 
roots are processed at STW pauses.

Added comments about this behavioral change in CR and linked to JDK-8227635.

-Zhengyu



> 
> Otherwise looks fine to me, let Roman ack it too.
>