Add offset label class

wip-duuqnd/user-side-compiler/high-level.lisp

@@ -47,8 +47,7 @@
     (format stream "@~D" (ref-index object))))
 
 (defmethod dereference ((ref reference-variable))
-  (produce-instruction 'inst-ldy-immediate (ref-index ref))
-  (produce-instruction 'inst-lda-absolute-y "VARVEC"))
+  (produce-instruction 'inst-lda-absolute (make-offset-label *varvec* (ref-index ref))))
 
 (defclass node ()
   ((%next :accessor next :accessor normal-next :initform nil)))
@@ -77,7 +76,7 @@
     (loop :for ref :in (arguments node)
           :for index :from 0
           :do (dereference ref)
-          :do (produce-instruction 'inst-sta-absolute (format nil "ARGVEC+~D" index)))
+          :do (produce-instruction 'inst-sta-absolute (make-offset-label *argvec* index)))
     (produce-instruction 'inst-jsr-absolute (callee node))))
 
 (defclass node-branch (node)

wip-duuqnd/user-side-compiler/label.lisp

@@ -26,3 +26,22 @@
   (when (null name)
     (setf name (make-label-name (if (null name-prefix) "L" name-prefix))))
   (make-instance 'label :name name :address address))
+
+(defclass offset-label (label)
+  ((%offset-from :accessor offset-from :initarg :offset-from)
+   (%offset :accessor offset :initarg :offset)))
+
+(defmethod address ((object offset-label))
+  (+ (address (offset-from object))
+     (offset object)))
+
+(defmethod name ((object offset-label))
+  (format nil "~A~C~D"
+          (name (offset-from object))
+          (if (minusp (offset object))
+              #\-
+              #\+)
+          (offset object)))
+
+(defun make-offset-label (src-label offset)
+  (make-instance 'offset-label :offset-from src-label :offset offset))