tce-load -i compiletc cmake libxml2-dev libffi-dev ninja

wget https://github.com/llvm/llvm-project/releases/download/llvmorg-13.0.0/llvm-13.0.0.src.tar.xz
wget https://github.com/llvm/llvm-project/releases/download/llvmorg-13.0.0/clang-13.0.0.src.tar.xz
wget https://github.com/llvm/llvm-project/releases/download/llvmorg-13.0.0/compiler-rt-13.0.0.src.tar.xz

cd llvm-13.0.0.src

tar -xf ../clang-13.0.0.src.tar.xz -C tools
mv tools/clang-13.0.0.src tools/clang

tar -xf ../compiler-rt-13.0.0.src.tar.xz -C projects
mv projects/compiler-rt-13.0.0.src projects/compiler-rt

grep -rl '#!.*python' | xargs sed -i '1s/python$/python3/'

mkdir build
cd build

cmake -LAH -DCMAKE_C_FLAGS_RELEASE="-mtune=generic -Os -pipe" -DCMAKE_CXX_FLAGS_RELEASE="-mtune=generic -Os -pipe" -DCMAKE_INSTALL_PREFIX=/usr/local -DLLVM_ENABLE_FFI=ON -DLLVM_BUILD_LLVM_DYLIB=ON -DLLVM_LINK_LLVM_DYLIB=ON -DLLVM_TARGETS_TO_BUILD="host;AMDGPU;BPF" -DLLVM_ENABLE_RTTI=ON -DCMAKE_BUILD_TYPE=Release -DCMAKE_VERBOSE_MAKEFILE=TRUE -DLLVM_BINUTILS_INCDIR=/usr/local/include -DCMAKE_INSTALL_LIBDIR=lib -DCMAKE_INSTALL_LIBEXECDIR=lib/clang -Wno-dev -G Ninja ../

[static libs huge with -flto]

find . -name flags.make -type f -exec sed -i 's/ -O3 -g//g' {} \;
find . -name flags.make -type f -exec sed -i 's/ -O3//g' {} \;
find . -name link.txt -type f -exec sed -i 's/-Wl,-O3/-Wl -Os/g' {} \;
find . -name AddLLVM.cmake -type f -exec sed -i 's/-Wl,-O3/-Wl,-Os/g' {} \;
find . -name compile_commands.json -type f -exec sed -i 's/ -O3 -g//g' {} \;
find . -name build.make -type f -exec sed -i 's/ -O3 -g//g' {} \;

ninja [ 2h 10m 02s]
sudo ninja install

sudo mkdir /usr/local/lib/bfd-plugins
cd /usr/local/lib/bfd-plugins
sudo ln -s ../LLVMgold.so ./

[links against ncursesw without ncursesw-dev]