Why when install, libtorch rebuild for ALL archs?

I use cmake to build libtorch, it’s easily to build libtorch specifically for my native arch sm_75. However, after building (cmake and make), libtorch has been built out as of size 166M, while I tried to install libtorch, libtorch is actually rebuilt for ALL archs, including sm_35, sm_50, sm_52, …sm_75, sm86 …

Did anybody find this issue? How to finally install libtorch after building?