asm/runtime.scm

@@ -1,28 +1,33 @@
 ;; Note that this is scheme syntax wrapping asm for a stack machine
-(variable eom 1024)
-;; These need to be initialized with the runtime
 (variable scan 0)
 (variable free 0)
+(variable eom 1024)
+;; These need to be initialized later
 (variable root 0)
-(variable old 0) 
+(variable the-cars 0) 
-(variable new 0)
+(variable the-cdrs 0)
+(variable new-cars 0)
+(variable new-cdrs 0)
+
 
 (push main)
 (jmp)
 
-alloc ;; ( -- p)
+alloc
 ;; Test if free will go beyond eom
-(ref free)
+(push free)
+(@)
 (dup) ; ( -- free free)
 (push 8)
 (+)
 (dup) ; ( -- free free+8 free+8)
-(ref eom)
+(push eom)
+(@)
 (<) ; ( -- free free+8 (free+8 < eom))
-(push alloc-do-gc)
+(branch alloc-do-gc)
-(if)
 ;; write free+8 to free
-(set! free)
+(push free)
+(!)
 ;; return the old free, it is memory the program can use
 (return)
 alloc-do-gc
@@ -36,21 +41,36 @@ alloc-do-gc
 (push alloc)
 (jmp)
 
-gc-start ;; ( -- )
+gc-start
-; Move scan & free to start of new memory
+; Move scan & free back to 0
-(ref new)
+(push 0)
-(dup)
+(push free)
-(set! free)
+(!)
-(set! scan)
+(push 0)
-(ref root)
+(push scan)
-(push relocate-object)
+(!)
-(call)
+; Push the first cons to relocate (root)
+(push root)
+(@)
+; Call the relocation routine
 (push gc-loop)
 (call)
+; Swap new and old cars and cdrs
+(push new-cars)
+(@)
+(push the-cars)
+(@)
+(push new-cars)
+(!)
+(push the-cars)
+(!)
+(push new-cdrs)
+(@)
+(push the-cdrs)
+(@)
+(push new-cdrs)
+(!)
+(push the-cdrs)
+(!)
+; return to allocation
 (return)
-
-relocate-object ;; (o -- )
-;; TODO
-
-main
-;; TODO

scmvm/assembler.scm

@@ -7,14 +7,8 @@
                 #:select (write-u8 write-bytevector))
   #:export (assemble))
 
-(define *aliases*
-  '((if . branch)))
-
-(define (or-alias inst)
-  (or (assq-ref *aliases* inst) inst))
-
 (define (lookup-instruction inst)
-  (define inst-obj (assq (or-alias inst) *instruction-set*))
+  (define inst-obj (assq inst *instruction-set*))
   (if inst-obj
       inst-obj
       (error (format #f "could not find instruction ~a" inst))))

tests.scm

@@ -32,7 +32,7 @@
       (=)
       (or)
       (push recur)
-      (if)
+      (branch)
       (return)
     recur
       (dup)