[RFC] libstdc++ atomicity, x86 agnostic version

[Paolo Carlini]

Benjamin Kosnik wrote:

>>Can't we follow Jakub's advice?
>>    
>>
>It's something to look into. However, if you see this code being inlined
>in std::string in performance critical regions, I'd appreciate knowing
>exactly where.
>
>A testcase would still be nice....
>  
>
Hi again.

What's currently present in the performance testsuite tests the 
exponential growth policy: basically there are *no* calls of _M_refcopy 
and _M_dispose.

It's needed something completely different, but basically *every real 
world* test on a multi processor machine or in a MT environment can only 
be negatively affected by not inlining the operations done at 
construction and destruction time.

I suggest, pre-emptively to work out Jakub's proposal. I volunteer to do 
that (hopefully with some help from him), I can allocate time to that 
during the next few weeks.

Paolo.