https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63577
--- Comment #16 from Jeffrey A. Law <law at redhat dot com> --- I'd agree it's too invasive to backport -- both changes are new optimizations and there may well have been follow-up patches for both. The potential for destabilizing the release branches would seem to outweigh the benefits for reducing the compile time on this code.
