https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80479
--- Comment #6 from Martin Liška <marxin at gcc dot gnu.org> ---
The memcmp is emitted directly by isntructions, it would need someone who can
verify that it's not touching the uninitialized bytes of str{1,2} (bytes 8-15).
After calling memset for these bytes, the error is gone in valgrind.
