On 24/02/2017 13:12, Dr. David Alan Gilbert wrote: >> Ok, yeah, it makes sense that the compiler can optimize that away without >> volatile. I wonder if adding volatile has much of a performance impact on >> this loop... > I don't think we have anything else in QEMU to do it (other than atomic's > but we don't need this to be atomic). I don't think the use of memset() > helps, because the compiler is free to optimise that out as well; so > I think 'volatile' is a reasonable use (although I seem to have a soft-spot > for volatile and I know everyone else tells me I'm mad).
Yes, I think it is fine to use volatile here. Paolo
