RFR 8233500: Shenandoah: Shenandoah load barrier should save registers before calling keep alive barrier on x86

[Aleksey Shipilev]

On 11/4/19 5:55 PM, Zhengyu Gu wrote:
> This bug was found and fixed during concurrent class unloading work in shenandoah/jdk. However, I
> don't think it is concurrent class unloading specific issue, and could result hard to find problem
> in jdk/jdk.
> 
> BTW: AArch64 already does right thing.

Where? Please be specific when saying this (i.e. point to code), for archival reasons.


> Bug: https://bugs.openjdk.java.net/browse/JDK-8233500
> Webrev: http://cr.openjdk.java.net/~zgu/JDK-8233500/webrev.00/

I don't understand this.

SATB handling is similar to G1 is doing, where's the similar code in G1? The patch adds save/restore
at in SBSA::load_at, but there is a similar block in SBSA::store_at, why it is not needed there?

-- 
Thanks,
-Aleksey