http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56470
--- Comment #3 from Richard Earnshaw <rearnsha at gcc dot gnu.org> 2013-03-05 07:01:42 UTC --- Definitely a back-end bug. I'm not disputing that. My surprise is that this hasn't bitten us long before now, since the code has been this way for well over ten years.
