RFR: 8144993: Elide redundant memory barrier after AllocationNode

[Andrew Haley]

On 23/12/15 16:01, Hui Shi wrote:
> Axel has explained how concurrent GC thread will not scan newly created
> object for both CMS and G1. So original optimziation skips generating
> storestore memory barrier for none escape allocation is safe. It might need
> more explanation here.
> 
> Back to discussion about patch for this thread, Gotez's concern about newly
> allocated object referenced by object visible to concurrent GC thread is
> explained. I'm not sure if there is other correctness concerns about patch
> for this thread. Could I go forward and ask for sponsor help on JTPR test
> and push?

I think so.  I'm a little nervous, but it is a performance improvement.
We're going to need some appropriate comments.

Andrew.