http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55139
--- Comment #4 from Andi Kleen <andi-gcc at firstfloor dot org> 2012-11-09 14:06:20 UTC --- My earlier analysis was not correct. I was chasing the wrong warning. Rather the problem is in c-common.c, where the atomic models are checked again. I'm sending a patch for that.