On Linux, here’s how I’ve been able to make and compile Intel Graphics Compiler. This includes building llvm 11:
git clone https://github.com/intel/intel-graphics-compiler igc
git clone https://github.com/intel/vc-intrinsics vc-intrinsics
git clone -b llvmorg-11.1.0 https://github.com/llvm/llvm-project llvm-project
git clone -b ocl-open-110 https://github.com/intel/opencl-clang llvm-project/llvm/projects/opencl-clang
git clone -b llvm_release_110 https://github.com/KhronosGroup/SPIRV-LLVM-Translator llvm-project/llvm/projects/llvm-spirv
git clone https://github.com/KhronosGroup/SPIRV-Tools.git SPIRV-Tools
git clone https://github.com/KhronosGroup/SPIRV-Headers.git SPIRV-Headers
mkdir build
cd build
cmake -DCMAKE_INSTALL_PREFIX=/usr -DCMAKE_BUILD_TYPE=Release -DIGC_OPTION__LLVM_MODE=Source -DIGC_OPTION__LLVM_STOCK_SOURCES=ON ../igc
make
sudo make install