cxx-mem-model merge [6 of 9] - libstdc++-v3

[Andrew MacLeod]

On 11/08/2011 12:05 AM, Hans-Peter Nilsson wrote:
>
>> So, what DO we do if there is no basic level of atomic
>> support...
> I just realized I may be feeding you an inconsistent
> configuration, see the atomicity stuff in
> libstdc++-v3/config/cpu/cris.  Is that just obsolete and unused
> now or what do I need to add for that to work?
>

You don't need to do anything there. I think that atomicity stuff will 
soon be obsolete, but bkoz will have to answer that question.

It looks to me like that was some gnu atomic extentions which predate 
atomic support in the standard.  In theory, that would all be able to go 
away or be integrated into the gcc machine description with the modern 
patterns, if its not already there.

I expect that for the next release we'll manage to get rid of all the 
little warts and uses of older mechanisms that are sprinkled around.

bkoz: As relates to the existing problem, how is the legacy support 
invoked in compatibility-atomic-c++0x.cc?  That has the old style 
implementation of atomic_flag with a lock, which would allow this target 
to compile...  which is another option perhaps.  or is that purely for 
pervious releases somehow?

Andrew