On 5/5/2012 8:53 AM, Alex Rønne Petersen wrote: On the druntime mailing list, we ended up discussing whether D respects that global (__gshared) variables may well be changed by any thread at any point in time. Is this the case? Yes. > I.e. will the optimizer > refrain from treating a read of a __gshared value as invariant in a > loop? Yes.