X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Fphysenvanal.lisp;h=86e41ed3f015f423093ad13d51e86e4ccccef12a;hb=4ed3f0d08c3a57a6762018d9622f253ab9d0f2b6;hp=c96bd4427a1701b5ad9fc4451f59d94b508d25cb;hpb=ed7ba4dad8a79726fdfeba5aa12e276ea852c540;p=sbcl.git

diff --git a/src/compiler/physenvanal.lisp b/src/compiler/physenvanal.lisp
index c96bd44..86e41ed 100644
--- a/src/compiler/physenvanal.lisp
+++ b/src/compiler/physenvanal.lisp
@@ -30,10 +30,10 @@
   (declare (type component component))
   (aver (every (lambda (x)
 		 (eq (functional-kind x) :deleted))
-	       (component-new-funs component)))
-  (setf (component-new-funs component) ())
-  (dolist (fun (component-lambdas component))
-    (reinit-lambda-physenv fun))
+	       (component-new-functionals component)))
+  (setf (component-new-functionals component) ())
+  (dolist (clambda (component-lambdas component))
+    (reinit-lambda-physenv clambda))
   (mapc #'add-lambda-vars-and-let-vars-to-closures
 	(component-lambdas component))
 
@@ -48,7 +48,7 @@
 		    (functional-has-external-references-p fun))
 	  (aver (member kind '(:optional :cleanup :escape)))
 	  (setf (functional-kind fun) nil)
-	  (delete-functional fun)))))
+          (delete-functional fun)))))
 
   (values))
 
@@ -123,9 +123,8 @@
 ;;; If FUN has no physical environment, assign one, otherwise clean up
 ;;; the old physical environment, removing/flagging variables that
 ;;; have no sets or refs. If a var has no references, we remove it
-;;; from the closure. If it has no sets, we clear the INDIRECT flag.
-;;; This is necessary because pre-analysis is done before
-;;; optimization.
+;;; from the closure. We always clear the INDIRECT flag. This is
+;;; necessary because pre-analysis is done before optimization.
 (defun reinit-lambda-physenv (fun)
   (let ((old (lambda-physenv (lambda-home fun))))
     (cond (old
@@ -136,8 +135,7 @@
 			    (physenv-closure old)))
 	   (flet ((clear (fun)
 		    (dolist (var (lambda-vars fun))
-		      (unless (lambda-var-sets var)
-			(setf (lambda-var-indirect var) nil)))))
+		      (setf (lambda-var-indirect var) nil))))
 	     (clear fun)
 	     (map nil #'clear (lambda-lets fun))))
 	  (t
@@ -171,11 +169,22 @@
 	    (setq did-something t)
 	    (close-over var ref-physenv physenv))))
       (dolist (set (basic-var-sets var))
-	(let ((set-physenv (get-node-physenv set)))
-	  (unless (eq set-physenv physenv)
-	    (setq did-something t)
-	    (setf (lambda-var-indirect var) t)
-	    (close-over var set-physenv physenv)))))
+
+	;; Variables which are set but never referenced can be
+	;; optimized away, and closing over them here would just
+	;; interfere with that. (In bug 147, it *did* interfere with
+	;; that, causing confusion later. This UNLESS solves that
+	;; problem, but I (WHN) am not 100% sure it's best to solve
+	;; the problem this way instead of somehow solving it
+	;; somewhere upstream and just doing (AVER (LEAF-REFS VAR))
+	;; here.)
+	(unless (null (leaf-refs var))
+
+	  (let ((set-physenv (get-node-physenv set)))
+	    (unless (eq set-physenv physenv)
+              (setf did-something t
+		    (lambda-var-indirect var) t)
+	      (close-over var set-physenv physenv))))))
     did-something))
 
 ;;; Find any variables in CLAMBDA -- either directly in LAMBDA-VARS or
@@ -229,7 +238,7 @@
 ;;;
 ;;; If a CATCH or an UNWIND-protect, then we set the LEXENV for the
 ;;; last node in the cleanup code to be the enclosing environment, to
-;;; represent the fact that the binding was undone as a side-effect of
+;;; represent the fact that the binding was undone as a side effect of
 ;;; the exit. This will cause a lexical exit to be broken up if we are
 ;;; actually exiting the scope (i.e. a BLOCK), and will also do any
 ;;; other cleanups that may have to be done on the way.
@@ -237,14 +246,13 @@
   (declare (type physenv env) (type exit exit))
   (let* ((exit-block (node-block exit))
 	 (next-block (first (block-succ exit-block)))
-	 (cleanup (entry-cleanup (exit-entry exit)))
-	 (info (make-nlx-info :cleanup cleanup
-			      :continuation (node-cont exit)))
 	 (entry (exit-entry exit))
+	 (cleanup (entry-cleanup entry))
+	 (info (make-nlx-info cleanup exit))
 	 (new-block (insert-cleanup-code exit-block next-block
 					 entry
 					 `(%nlx-entry ',info)
-					 (entry-cleanup entry)))
+					 cleanup))
 	 (component (block-component new-block)))
     (unlink-blocks exit-block new-block)
     (link-blocks exit-block (component-tail component))
@@ -263,12 +271,12 @@
 ;;; EXIT into ENV. This is called for each non-local exit node, of
 ;;; which there may be several per exit continuation. This is what we
 ;;; do:
-;;; -- If there isn't any NLX-Info entry in the environment, make
+;;; -- If there isn't any NLX-INFO entry in the environment, make
 ;;;    an entry stub, otherwise just move the exit block link to
 ;;;    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
@@ -277,16 +285,15 @@
 ;;;    the NLX use.
 (defun note-non-local-exit (env exit)
   (declare (type physenv env) (type exit exit))
-  (let ((entry (exit-entry exit))
-	(cont (node-cont exit))
+  (let ((lvar (node-lvar exit))
 	(exit-fun (node-home-lambda exit)))
-    (if (find-nlx-info entry cont)
+    (if (find-nlx-info exit)
 	(let ((block (node-block exit)))
 	  (aver (= (length (block-succ block)) 1))
 	  (unlink-blocks block (first (block-succ block)))
 	  (link-blocks block (component-tail (block-component block))))
 	(insert-nlx-entry-stub exit env))
-    (let ((info (find-nlx-info entry cont)))
+    (let ((info (find-nlx-info exit)))
       (aver info)
       (close-over info (node-physenv exit) env)
       (when (eq (functional-kind exit-fun) :escape)
@@ -295,8 +302,9 @@
 	      (leaf-refs exit-fun))
 	(substitute-leaf (find-constant info) exit-fun)
 	(let ((node (block-last (nlx-info-target info))))
-	  (delete-continuation-use node)
-	  (add-continuation-use node (nlx-info-continuation info))))))
+	  (delete-lvar-use node)
+          (aver (eq lvar (node-lvar exit)))
+	  (add-lvar-use node lvar)))))
   (values))
 
 ;;; Iterate over the EXITs in COMPONENT, calling NOTE-NON-LOCAL-EXIT
@@ -346,12 +354,12 @@
 		       (basic-combination-args node))))
 	  (ecase (cleanup-kind cleanup)
 	    (:special-bind
-	     (code `(%special-unbind ',(continuation-value (first args)))))
+	     (code `(%special-unbind ',(lvar-value (first args)))))
 	    (:catch
 	     (code `(%catch-breakup)))
 	    (:unwind-protect
 	     (code `(%unwind-protect-breakup))
-	     (let ((fun (ref-leaf (continuation-use (second args)))))
+	     (let ((fun (ref-leaf (lvar-uses (second args)))))
 	       (reanalyze-funs fun)
 	       (code `(%funcall ,fun))))
 	    ((:block :tagbody)
@@ -391,20 +399,27 @@
 	      (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)
-		     (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)))))))
+	    (when (and (policy use merge-tail-calls)
+                       (basic-combination-p use)
+		       (immediately-used-p result use)
+		       (or (not (eq (node-derived-type use) *empty-type*))
+			   (eq (basic-combination-kind use) :local)))
+	      (setf (node-tail-p use) t)))))))
   (values))