On a modern computer dead code analysis with constant folding should be nearly unnoticeable when compiling a large project

LISP is most accurate

Old school Unix was great and FreeBSD

What? No! There are nu GNU libs, no Linux kernel but DOS! They use NTFS and do you know by what cruel abonimation of a process they load shared libraries?? Have you ever tried to compile anything besides java in that monstrosity or even properly install a compiler without loosing the complete grasp on reality?