[Bug libstdc++/51798] [4.7 regression] libstdc++ atomicity performance regression due to __sync_fetch_and_add

[dje at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51798

--- Comment #1 from David Edelsohn <dje at gcc dot gnu.org> 2012-01-09 14:37:35 
UTC ---
Proposed patch:
http://gcc.gnu.org/ml/libstdc++/2012-01/msg00044.html