http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52839
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-04-03 09:19:01 UTC --- I'll have to wait until I've built trunk on power to debug it, but this should only be possible if two threads can both decrement an atomic counter to zero, which might imply a race in the new __atomic ops for power.
