>>20
Try to do static array bound check elimination in Lisp. Oh, I forgot, with Lisp runtime has to check the type of every element of every collection, so if you want to add two arrays with billions of floats in them, Lisp has to check types billions of times.
That's why you use a Lisp machine. Your CPU is designed for paging and running programs in separate address spaces. Imagine running Unix on a system with no virtual addressing that had to swap the entire process memory to disk and read in a new process instead of just switching the page tables. Pretty inefficient, eh? That's the same with Lisp. Just like Unix/VMS/Windows machines have hardware to run processes in separate address spaces, Lisp machines have hardware to check the types and bounds of arrays. This bounds checking is Lisp's memory protection model.