[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 #10 from David Edelsohn <dje at gcc dot gnu.org> 2012-01-25 15:43:51 UTC ---
> All that has to be done is replace the two __sync_fetch_and_add(...) with
> __atomic_fetch_add(.., __ATOMIC_ACQ_REL)  in atomicity.h isn't it?

In src/libstdc++-v3/include/ext/atomicity.h and in
src/libstdc++-v3/config/cpu/generic/atomicity_builtins/atomicity.h