More on memory barriers

[Doug Lea]

On 09/17/2014 06:31 AM, Andrew Haley wrote:
> On 09/16/2014 08:40 AM, Andrew Haley wrote:
>> On 15/09/14 17:20, Vitaly Davidovich wrote:
>>> Looking at hg history, MemBarStoreStore was added a few years ago, whereas
>>> the code in question is much older.  The comments in the changelist adding
>>> MemBarStoreStore seem to indicate it was done to address a specific issue,
>>> and my guess is that it wasn't "retrofitted" into all possible places.
>>
>> That sounds plausible.  I'll change this to a StoreStore in the AArch64
>> port and do some testing.
>
> Bah, that doesn't work.  Escape analysis assumes that a StoreStore
> is only used in certain contexts.  Back to the drawing board.
>

The setup for StoreStore seems suspicious. I believe that this could
only work in C2 if done in the way I mentioned: StoreStore must be
handled identically to Release by c2, but possibly more cheaply
matched. Can StoreStore be reworked as a subtype or property of
Release?

-Doug