New separate pass for assigning numbers to labels.

src/new-cmp/cmpbackend.lsp

@@ -34,8 +34,8 @@
          (when (plusp (tag-ref form))
            (let ((label (tag-label form)))
              (unless label
-               (setf (tag-label form) (setf label (next-label))))
-             (wt-label (tag-label form)))))
+               (error "No label for tag ~A" form))
+             (wt-label label))))
         ((c1form-p form)
          (pprint-c1form form)
          (let* ((*file* (c1form-file form))

src/new-cmp/cmppass.lsp

@@ -225,3 +225,23 @@ form in its read/set nodes, and add other consistency checks."
             (error ";;; Inconsistent form ~S form with arguments~{~&;;;   ~A~}"
                    (c1form-name form) args)))
     forms))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;;
+;;; ASSIGN LABELS
+;;;
+
+(defun pass-assign-labels (function forms)
+  (loop with *last-label* = 0
+     with last = nil
+     for f in forms
+     do (cond ((not (tag-p f))
+               (setf last nil))
+              (last
+               (setf (tag-label f) last
+                     (tag-ref f) 0))
+              (t
+               (setf last (next-label)
+                     (tag-label f) last)))
+     finally (setf (fun-last-label function) *last-label*))
+  forms)

src/new-cmp/cmptop.lsp

@@ -152,6 +152,7 @@
     (execute-pass 'pass-delete-no-side-effects)
     (execute-pass 'pass-delete-unused-bindings)
     (execute-pass 'pass-decide-var-rep-types)
+    (execute-pass 'pass-assign-labels)
 
     ;; Emit entry function
     (let ((*compile-to-linking-call* nil))