tce-load -i compiletc cmake 

wget https://bitbucket.org/multicoreware/x265_git/downloads/x265_4.1.tar.gz

cd x265_4.1

sed -r '/cmake_policy.*(0025|0054)/d' -i source/CMakeLists.txt

mkdir bld
cd bld

cmake -LAH -DCMAKE_C_FLAGS_RELEASE="-march=armv7-a -mtune=cortex-a53 -Os -pipe" -DCMAKE_CXX_FLAGS_RELEASE="-march=armv7-a -mtune=cortex-a53 -Os -pipe" -DCMAKE_INSTALL_PREFIX=/usr/local -DCMAKE_BUILD_TYPE=Release -DCMAKE_VERBOSE_MAKEFILE=TRUE -DGIT_ARCHETYPE=1 -Wno-dev ../source

find . -name flags.make -type f -exec sed -i 's/-mcpu=native//g' {} \;
find . -name flags.make -type f -exec sed -i 's/-mfpu=neon//g' {} \;
find . -name flags.make -type f -exec sed -i 's/-marm//g' {} \;
find . -name flags.make -type f -exec sed -i 's/-DHAVE_ARMV6=1/-DHAVE_ARMV7=1/g' {} \;

[-fno-rtti fails]

make [6m 23.32s]
sudo make install