Installing Gentoo on an X240
Installing Gentoo on a Thinkpad x240
These notes refer to installation of Gentoo on an X240 system
/etc/portage/make.conf
CHOST="x86_64-pc-linux-gnu" CFLAGS="-march=core-avx2 -O2 -pipe" CXXFLAGS="${CFLAGS}"
source: Safe CFLAGS Template:X240