tce-load -i compiletc 

wget https://github.com/unicode-org/icu/releases/download/release-70-1/icu4c-70_1-src.tgz

cd icu/source

sed -i 's|LDFLAGSICUDT|#LDFLAGSICUDT|' config/mh-linux

CC="gcc -flto -mtune=generic -Os -pipe" CXX="g++ -flto  -mtune=generic -Os -pipe -fno-exceptions" ./configure --prefix=/usr/local --localstatedir=/var

find . -name icudefs.mk -type f -exec sed -i 's/-O2//g' {} \;
find . -name Makefile -type f -exec sed -i 's/-O2//g' {} \;

make [5m 33.72s]
sudo make install