http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52929
ncahill_alt at yahoo dot com changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |ncahill_alt at yahoo dot | |com --- Comment #1 from ncahill_alt at yahoo dot com 2012-04-10 18:54:51 UTC --- Regarding this, I've found that __ATOMIC_ACQ_REL is new in 4.7.0, it is not used in any 4.6.x. And also my source-built 4.7.0 is lacking a #define for this macro. Neil.