missing memory barrier in acmp with C2

[Andrew Haley]

On 26/10/16 19:48, Vitaly Davidovich wrote:

> So I see you took Hans' example, but his example has Thread 1 also
> reading some state during construction, which can be modified by
> Thread 2 concurrently.  That is a problem, but your example was a
> bit too slimmed down to illustrate that.

Again, construction is a red herring.  All the example says is that
the store to x.blah can become visible before the initialization of x.
This is not "initialization" in the sense of executing in a
constructor, which is safe before the address of the object is
published.

Andrew.