[8u] RFR: 8221355: Performance regression after JDK-8155635 backport into 8u

[Severin Gehwolf]

On Wed, 2019-04-10 at 15:16 +0200, Roland Westrelin wrote:
> > > The left over comment is misleading, though, which I've now removed:
> > > http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8221355/02/webrev/
> > 
> > ...but now I am confused how that patch is supposed to work. It seems to me it accepts the accesses
> > to off-heap when object passed it is actually null, but not transparently-null for the compiler?
> > That is probably acceptable, but maybe someone savvy in this code can take a look? Vladimir I, Roland?
> 
> When base is known to be null, this patch causes c2 to not intrinsify
> object accesses and the native method is called. Without this patch, c2
> doesn't intrinsify object accesses unless it knows base to be not null
> which is indeed too conservative.
> 
> That looks good to me.

Thanks for the review!

Cheers,
Severin