https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89118
--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Jonathan Wakely from comment #2) > I cannot reproduce the valgrind errors with any version of GCC, using > valgrind 3.14.0 > > My guess is that these are false positives from valgrind, because it doesn't > know about the SSE4 tricks in your glibc. In other words, this is not a GCC > bug (and probably not a bug at all). Looks like it was https://bugs.kde.org/show_bug.cgi?id=388862 which is fixed in valgrind 3.14.0