http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49688
--- Comment #14 from Richard Henderson <rth at gcc dot gnu.org> 2011-07-14 21:34:16 UTC --- Well, .cfi handling in gas isn't totally untested because there's plenty of glibc asm files that use it. But I have to concede that there might be a bug. We'll have to examine the actual generated unwind info with and without the change.