0.7.10.18:

[sbcl.git] / src / compiler / physenvanal.lisp

diff --git a/src/compiler/physenvanal.lisp b/src/compiler/physenvanal.lisp
index ef0257f..2ded900 100644 (file)
--- a/src/compiler/physenvanal.lisp
+++ b/src/compiler/physenvanal.lisp
@@ -279,7 +279,7 @@
 ;;;    the component tail.
 ;;; -- Close over the NLX-INFO in the exit environment.
 ;;; -- If the exit is from an :ESCAPE function, then substitute a
-;;;    constant reference to NLX-Info structure for the escape
+;;;    constant reference to NLX-INFO structure for the escape
 ;;;    function reference. This will cause the escape function to
 ;;;    be deleted (although not removed from the DFO.)  The escape
 ;;;    function is no longer needed, and we don't want to emit code
@@ -402,20 +402,29 @@
              (emit-cleanups block1 block2)))))))
   (values))
 
-;;; Mark all tail-recursive uses of function result continuations with
-;;; the corresponding TAIL-SET. Nodes whose type is NIL (i.e. don't
-;;; return) such as calls to ERROR are never annotated as tail in
-;;; order to preserve debugging information.
+;;; Mark optimizable tail-recursive uses of function result
+;;; continuations with the corresponding TAIL-SET.
 (defun tail-annotate (component)
   (declare (type component component))
   (dolist (fun (component-lambdas component))
     (let ((ret (lambda-return fun)))
+      ;; Nodes whose type is NIL (i.e. don't return) such as calls to
+      ;; ERROR are never annotated as TAIL-P, in order to preserve
+      ;; debugging information.
+      ;;
+      ;; FIXME: It might be better to add another DEFKNOWN property
+      ;; (e.g. NO-TAIL-RECURSION) and use it for error-handling
+      ;; functions like ERROR, instead of spreading this special case
+      ;; net so widely.
       (when ret
        (let ((result (return-result ret)))
          (do-uses (use result)
-           (when (and (immediately-used-p result use)
+           (when (and (policy use
+                              (or (> space debug)
+                                  (> speed debug)))
+                      (immediately-used-p result use)
                       (or (not (eq (node-derived-type use) *empty-type*))
                           (not (basic-combination-p use))
                           (eq (basic-combination-kind use) :local)))
-               (setf (node-tail-p use) t)))))))
+             (setf (node-tail-p use) t)))))))
   (values))