http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46572
--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> 2010-11-20 06:02:33 UTC --- hmm, no, I have no opinion about this except to say a non-normative note doesn't imply non-portable requirements. I think the standard doesn't mean "should have absolutely no overhead compared with the most optimised, non-portable implementation if you use attributes" this could be left open as an enhancement, but I don't know if anyone would ever work on it.
