> I don't know why you'd expect a difference, really. Try this: I just want to know precisely what measures the gcc take when a asm statement including a clobber of "memory", rather merely than a general description in the gcc manual. In Linux kernel code, the barrier() appears frequently in some kernel funcitons. So, I wish to get the exactly meaning of the barrier(). > int s = 0; So, just the variables which might be modified by some outer code unpredictable, such as interrupt handlers, other processes, etc, will be given more cares by the gcc. But, we need not to worry about whether or not a local variable in some function is consistent with the corresponding register, because it is impossible that a local variable will be modified outside the current code. Is that true?
