This patch adds string optimize codes and some auxiliary codes.
Signed-off-by: NChen Linfei <linfei_chen@c-sky.com>
Signed-off-by: NMao Han <han_mao@c-sky.com>
Signed-off-by: NGuo Ren <ren_guo@c-sky.com>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>