spinlock variable protection

[Malte Vesper]

Spinlocks imply memory barriers as far as I am aware...

Read here: 
http://lxr.free-electrons.com/source/Documentation/memory-barriers.txt#L1634

On 30/01/15 14:20, Matwey V. Kornilov wrote:
> 2015-01-30 16:52 GMT+03:00 buyitian <buyitian at gmail.com>:
>> Please check the assembly code to double confirm the GCC behavior.
>> Why will GCC change the order as what you mentioned? Only assembly code can tell you.
> It does not change at the moment. I think it can change it.
>
> Because from line
>    ret = hdl->count;
> until line
>    return ret;
> there is no access to either ret or hdl->count. So it is reasonable to
> optimizer to think that their values are the same and eliminate
> unneeded variable.
>