Project restructuring to support the new direction

example/asm/runtime.scm

@@ -0,0 +1,153 @@
+(push main)
+(jmp)
+
+;; Note that this is scheme syntax wrapping asm for a stack machine
+(variable eol 0)
+(variable scan 0)
+(variable free 0)
+;; These need to be initialized with the runtime
+(variable eom 0)
+(variable old 0) 
+(variable new 0)
+(variable root 0)
+
+alloc ;; ( -- p)
+;; Test if free will go beyond eom
+(ref free)
+(dup) ; ( -- free free)
+(push 8)
+(+)
+(dup) ; ( -- free free+8 free+8)
+(ref eom)
+(<) ; ( -- free free+8 (free+8 < eom))
+(push alloc-do-gc)
+(if)
+;; write free+8 to free
+(set! free)
+;; return the old free, it is memory the program can use
+(return)
+alloc-do-gc
+;; Empty the stack
+(drop)
+(drop)
+;; Run garbage collection
+(push gc-run)
+(call)
+;; Tail-call allocation
+(push alloc)
+(jmp)
+
+gc-run ;; ( -- )
+; Move scan & free to start of new memory
+(ref new)
+(dup)
+(set! free)
+(set! scan)
+(ref root)
+(push relocate-cons)
+(call)
+(push gc-loop)
+(call)
+; Flip old and new
+(ref old)
+(dup)
+(ref new)
+(set! old)
+(set! new)
+(push 512)
+(+)
+(set! eom)
+(return)
+
+relocate-cons ;; (o -- )
+(dup)
+(@)
+(push relocate-reg)
+(call)
+(push 4)
+(+)
+(@)
+(push relocate-reg)
+
+relocate-reg ;; (r -- )
+(dup)
+(push #x80000000) ;; Is this a cons?
+(and)
+(push reg-relocated)
+(if)
+(dup)
+(ref eol)
+(=) ;; Is this eol?
+(not)
+(push reg-relocated)
+(if)
+(dup)
+(push #x40000000) ;; Is it a broken heart?
+(and)
+(push copy-and-construct)
+(if)
+(dup) ;; Broken heart, copy updated address from cdr
+(push 4)
+(+)
+(@)   ;; Retrieve new address
+(dup)
+(!)   ;; Write it here
+(push reg-relocated)
+(jmp)
+copy-and-construct
+(dup) ;; Wasn't a broken heart, move car to new memory
+(@) 
+(push free)
+(!)
+(dup) ;; Push cdr to new memory
+(push 4)
+(+)
+(@)
+(push free)
+(push 4)
+(+)
+(!)
+(push #x40000000)
+(over)
+(!)
+(ref free)
+(over)
+(push 4)
+(+)
+(!)
+(ref free) ;; Move free pointer
+(push 8)
+(+)
+(set! free)
+reg-relocated
+(drop)
+(return)
+
+gc-loop
+(ref free)
+(ref scan)
+(<)
+(branch gc-loop-done)
+(ref scan)
+(push relocate-reg)
+(push gc-loop)
+(jmp)
+gc-loop-done
+(return)
+
+
+main
+;; These need to be initialized with the runtime
+(push memory)
+(dup)
+(set! new)
+(push 512)
+(+)
+(dup)
+(set! eom)
+(set! old)
+;; TODO set up root
+;; <<USER PROGRAM HERE >>
+(bye)
+
+memory