tce-load -i compiletc 

cd icu (icu4c-62_1-src.tgz)
cd source

CC="gcc -flto -fuse-linker-plugin -march=i486 -mtune=i686 -Os -pipe" CXX="g++ -flto -fuse-linker-plugin -march=i486 -mtune=i686 -Os -pipe -fno-exceptions -D_GLIBCXX_USE_C99_MATH" ./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 [3m 21.21s]
sudo make install