After I used SDKmanager, my system have a aarch64 gcc tool named aarch64-linux-gnu-gcc, whose version is as bellow:
aarch64-linux-gnu-gcc (Ubuntu/Linaro 5.4.0-6ubuntu1~16.04.9) 5.4.0 20160609 Copyright (C) 2015 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
and it is old version. So I download new tool: gcc-linaro-7.3.1-2018.05-x86_64_aarch64-linux-gnu.tar.xz
but I don’t know replace the old version. The old version is installed in usr/aarch64-linux-gnu/bin.