RFR(s): 8013171: G1: C1 x86_64 barriers use 32-bit accesses to 64-bit PtrQueue::_index

[Roland Westrelin]

> Yes, it happens to be the same thing is this case, but bordering on being sloppy given that it's not a pointer. But if this is the preferred way then I can live with that.

You could add a comment that says you’re using the *ptr variants for non pointer things.
I don’t know if it’s the preferred way but that’s what I would do because less #ifdef makes the code easier to read.

> Updated webrev: http://cr.openjdk.java.net/~pliden/8013171/webrev.1/

That looks good to me.

Roland.