http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51798
--- Comment #8 from David Edelsohn <dje at gcc dot gnu.org> 2012-01-25 15:14:29 UTC --- > At least at this point I'd feel much safer if libstdc++ used just acq_rel > semantics for the all atomic_fetch_and_add places, instead of somewhere acq > and > somewhere rel semantics. Can we at least apply the ACQ_REL patch using the new atomic intrinsics? Unfortunately, without my patch, libstdc++ users of atomicity.h (basic_string, shared_ptr) do not distinguish between ACQUIRE and RELEASE, so POWER cannot provide its own atomicity.h with the improved implementation.
