I wrote a lisp compiler recently, and that involved generating assembly language.

My output is linux/amd64 assembly language which is compiled by nasm. I don't link to glibc, so I had to implement my "print int", "print string", and similar primitives in raw assembly.

I successfully implemented a stop&copy garbage collector, and other interfaces to the OS such as reading command-line arguments, environmental variables, and so on. All in assembly. Though my compiler is written in golang the runtime, and all supporting functions have to be in assembly to make sure that the binaries it produced are static.

(I wrote a lisp interpreter which can be compiled, and which can be used to run itself, so I got an indirect REPL.)

An efficient concurrent garbage collector would be something I would buy a book for. (In fact I have one GC book on my bookshelf).

But assembly? I'm not sure, honestly. Architectures change, and you can easily converge to good code by talking to an LLM.

May I ask why you didn't use LLVM as a target?