(declare (type component component))
(aver (every (lambda (x)
(eq (functional-kind x) :deleted))
- (component-new-functions component)))
- (setf (component-new-functions component) ())
- (dolist (fun (component-lambdas component))
- (reinit-lambda-physenv fun))
- (dolist (fun (component-lambdas component))
- (compute-closure fun)
- (dolist (let (lambda-lets fun))
- (compute-closure let)))
+ (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))
(find-non-local-exits component)
+ (recheck-dynamic-extent-lvars component)
(find-cleanup-points component)
(tail-annotate component)
(functional-has-external-references-p fun))
(aver (member kind '(:optional :cleanup :escape)))
(setf (functional-kind fun) nil)
- (delete-functional fun)))))
+ (delete-functional fun)))))
+ (setf (component-nlx-info-generated-p component) t)
(values))
;;; This is to be called on a COMPONENT with top level LAMBDAs before
(declare (type component component))
(let ((found-it nil))
(dolist (lambda (component-lambdas component))
- (when (compute-closure lambda)
- (setq found-it t))
- (dolist (let (lambda-lets lambda))
- (when (compute-closure let)
- (setq found-it t))))
+ (when (add-lambda-vars-and-let-vars-to-closures lambda)
+ (setq found-it t)))
found-it))
;;; This is like old CMU CL PRE-ENVIRONMENT-ANALYZE-TOPLEVEL, except
;;; post-pass will use the existing structure, rather than
;;; allocating a new one. We return true if we discover any
;;; possible closure vars.
-;;; But that doesn't seem to explain why it's important. I do observe
-;;; that when it's not done, compiler assertions occasionally fail. My
-;;; tentative hypothesis is that other environment analysis expects to
+;;; But that doesn't seem to explain either why it's important to do
+;;; this for top level lambdas, or why it's important to do it only
+;;; for top level lambdas instead of just doing it indiscriminately
+;;; for all lambdas. I do observe that when it's not done, compiler
+;;; assertions occasionally fail. My tentative hypothesis for why it's
+;;; important to do it is that other environment analysis expects to
;;; bottom out on the outermost enclosing thing, and (insert
;;; mysterious reason here) it's important to set up bottomed-out-here
-;;; environments before anything else. -- WHN 2001-09-30
+;;; environments before anything else. I haven't been able to guess
+;;; why it's important to do it selectively instead of
+;;; indiscriminately. -- WHN 2001-11-10
(defun preallocate-physenvs-for-toplevelish-lambdas (component)
(dolist (clambda (component-lambdas component))
(when (lambda-toplevelish-p clambda)
- (compute-closure clambda)))
+ (add-lambda-vars-and-let-vars-to-closures clambda)))
(values))
-;;; If CLAMBDA has a PHYSENV , return it, otherwise assign an empty one.
+;;; If CLAMBDA has a PHYSENV, return it, otherwise assign an empty one
+;;; and return that.
(defun get-lambda-physenv (clambda)
(declare (type clambda clambda))
(let ((homefun (lambda-home clambda)))
(or (lambda-physenv homefun)
- (let ((res (make-physenv :function homefun)))
+ (let ((res (make-physenv :lambda homefun)))
(setf (lambda-physenv homefun) res)
+ ;; All the LETLAMBDAs belong to HOMEFUN, and share the same
+ ;; PHYSENV. Thus, (1) since HOMEFUN's PHYSENV was NIL,
+ ;; theirs should be NIL too, and (2) since we're modifying
+ ;; HOMEFUN's PHYSENV, we should modify theirs, too.
(dolist (letlambda (lambda-lets homefun))
- ;; This assertion is to make explicit an
- ;; apparently-otherwise-undocumented property of existing
- ;; code: We never overwrite an old LAMBDA-PHYSENV.
- ;; -- WHN 2001-09-30
- (aver (null (lambda-physenv letlambda)))
- ;; I *think* this is true regardless of LAMBDA-KIND.
- ;; -- WHN 2001-09-30
(aver (eql (lambda-home letlambda) homefun))
+ (aver (null (lambda-physenv letlambda)))
(setf (lambda-physenv letlambda) res))
res))))
;;; 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
(setf (physenv-closure old)
- (delete-if #'(lambda (x)
- (and (lambda-var-p x)
- (null (leaf-refs x))))
+ (delete-if (lambda (x)
+ (and (lambda-var-p x)
+ (null (leaf-refs x))))
(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)
- (dolist (let (lambda-lets fun))
- (clear let))))
+ (map nil #'clear (lambda-lets fun))))
(t
(get-lambda-physenv fun))))
(values))
(declare (type node node))
(get-lambda-physenv (node-home-lambda node)))
-;;; Find any variables in FUN with references outside of the home
-;;; environment and close over them. If a closed over variable is set,
-;;; then we set the INDIRECT flag so that we will know the closed over
-;;; value is really a pointer to the value cell. We also warn about
-;;; unreferenced variables here, just because it's a convenient place
-;;; to do it. We return true if we close over anything.
-(defun compute-closure (fun)
- (declare (type clambda fun))
- (let ((env (get-lambda-physenv fun))
+;;; private guts of ADD-LAMBDA-VARS-AND-LET-VARS-TO-CLOSURES
+;;;
+;;; This is the old CMU CL COMPUTE-CLOSURE, which only works on
+;;; LAMBDA-VARS directly, not on the LAMBDA-VARS of LAMBDA-LETS. It
+;;; seems never to be valid to use this operation alone, so in SBCL,
+;;; it's private, and the public interface,
+;;; ADD-LAMBDA-VARS-AND-LET-VARS-TO-CLOSURES, always runs over all the
+;;; variables, not only the LAMBDA-VARS of CLAMBDA itself but also
+;;; the LAMBDA-VARS of CLAMBDA's LAMBDA-LETS.
+(defun %add-lambda-vars-to-closures (clambda)
+ (let ((physenv (get-lambda-physenv clambda))
(did-something nil))
- (note-unreferenced-vars fun)
- (dolist (var (lambda-vars fun))
+ (note-unreferenced-vars clambda)
+ (dolist (var (lambda-vars clambda))
(dolist (ref (leaf-refs var))
- (let ((ref-env (get-node-physenv ref)))
- (unless (eq ref-env env)
+ (let ((ref-physenv (get-node-physenv ref)))
+ (unless (eq ref-physenv physenv)
(when (lambda-var-sets var)
(setf (lambda-var-indirect var) t))
(setq did-something t)
- (close-over var ref-env env))))
+ (close-over var ref-physenv physenv))))
(dolist (set (basic-var-sets var))
- (let ((set-env (get-node-physenv set)))
- (unless (eq set-env env)
- (setq did-something t)
- (setf (lambda-var-indirect var) t)
- (close-over var set-env env)))))
+
+ ;; 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))
-;;; Make sure that THING is closed over in REF-ENV and in all
-;;; environments for the functions that reference REF-ENV's function
-;;; (not just calls.) HOME-ENV is THING's home environment. When we
+;;; Find any variables in CLAMBDA -- either directly in LAMBDA-VARS or
+;;; in the LAMBDA-VARS of elements of LAMBDA-LETS -- with references
+;;; outside of the home environment and close over them. If a
+;;; closed-over variable is set, then we set the INDIRECT flag so that
+;;; we will know the closed over value is really a pointer to the
+;;; value cell. We also warn about unreferenced variables here, just
+;;; because it's a convenient place to do it. We return true if we
+;;; close over anything.
+(defun add-lambda-vars-and-let-vars-to-closures (clambda)
+ (declare (type clambda clambda))
+ (let ((did-something nil))
+ (when (%add-lambda-vars-to-closures clambda)
+ (setf did-something t))
+ (dolist (lambda-let (lambda-lets clambda))
+ ;; There's no need to recurse through full COMPUTE-CLOSURE
+ ;; here, since LETS only go one layer deep.
+ (aver (null (lambda-lets lambda-let)))
+ (when (%add-lambda-vars-to-closures lambda-let)
+ (setf did-something t)))
+ did-something))
+
+(defun xep-allocator (xep)
+ (let ((entry (functional-entry-fun xep)))
+ (functional-allocator entry)))
+
+;;; Make sure that THING is closed over in REF-PHYSENV and in all
+;;; PHYSENVs for the functions that reference REF-PHYSENV's function
+;;; (not just calls). HOME-PHYSENV is THING's home environment. When we
;;; reach the home environment, we stop propagating the closure.
-(defun close-over (thing ref-env home-env)
- (declare (type physenv ref-env home-env))
- (cond ((eq ref-env home-env))
- ((member thing (physenv-closure ref-env)))
- (t
- (push thing (physenv-closure ref-env))
- (dolist (call (leaf-refs (physenv-function ref-env)))
- (close-over thing (get-node-physenv call) home-env))))
+(defun close-over (thing ref-physenv home-physenv)
+ (declare (type physenv ref-physenv home-physenv))
+ (let ((flooded-physenvs nil))
+ (labels ((flood (flooded-physenv)
+ (unless (or (eql flooded-physenv home-physenv)
+ (member flooded-physenv flooded-physenvs))
+ (push flooded-physenv flooded-physenvs)
+ (unless (memq thing (physenv-closure flooded-physenv))
+ (push thing (physenv-closure flooded-physenv))
+ (let ((lambda (physenv-lambda flooded-physenv)))
+ (cond ((eq (functional-kind lambda) :external)
+ (let* ((alloc-node (xep-allocator lambda))
+ (alloc-lambda (node-home-lambda alloc-node))
+ (alloc-physenv (get-lambda-physenv alloc-lambda)))
+ (flood alloc-physenv)
+ (dolist (ref (leaf-refs lambda))
+ (close-over lambda
+ (get-node-physenv ref) alloc-physenv))))
+ (t (dolist (ref (leaf-refs lambda))
+ ;; FIXME: This assertion looks
+ ;; reasonable, but does not work for
+ ;; :CLEANUPs.
+ #+nil
+ (let ((dest (node-dest ref)))
+ (aver (basic-combination-p dest))
+ (aver (eq (basic-combination-kind dest) :local)))
+ (flood (get-node-physenv ref))))))))))
+ (flood ref-physenv)))
(values))
\f
;;;; non-local exit
;;; knows what entry is being done.
;;;
;;; The link from the EXIT block to the entry stub is changed to be a
-;;; link to the component head. Similarly, the EXIT block is linked to
-;;; the component tail. This leaves the entry stub reachable, but
+;;; link from the component head. Similarly, the EXIT block is linked
+;;; to the component tail. This leaves the entry stub reachable, but
;;; makes the flow graph less confusing to flow analysis.
;;;
;;; 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.
(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))
(link-blocks (component-head component) new-block)
+ (setf (exit-nlx-info exit) info)
(setf (nlx-info-target info) new-block)
(push info (physenv-nlx-info env))
(push info (cleanup-nlx-info cleanup))
;;; 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
+;;; -- 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
;;; 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
-;;; for it. We then also change the %NLX-ENTRY call to use the
-;;; NLX continuation so that there will be a use to represent
-;;; the NLX use.
+;;; for it.
+;;; -- Change the %NLX-ENTRY call to use the NLX lvar so that 1) there
+;;; will be a use to represent the NLX use; 2) make life easier for
+;;; the stack analysis.
(defun note-non-local-exit (env exit)
(declare (type physenv env) (type exit exit))
- (let ((entry (exit-entry exit))
- (cont (node-cont exit))
- (exit-fun (node-home-lambda exit)))
-
- (if (find-nlx-info entry cont)
- (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)))
- (aver info)
- (close-over info (node-physenv exit) env)
- (when (eq (functional-kind exit-fun) :escape)
- (mapc #'(lambda (x)
- (setf (node-derived-type x) *wild-type*))
- (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))))))
-
+ (let ((lvar (node-lvar exit))
+ (exit-fun (node-home-lambda exit))
+ (info (find-nlx-info exit)))
+ (cond (info
+ (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)))
+ (setf (exit-nlx-info exit) info)))
+ (t
+ (insert-nlx-entry-stub exit env)
+ (setq info (exit-nlx-info exit))
+ (aver info)))
+ (close-over info (node-physenv exit) env)
+ (when (eq (functional-kind exit-fun) :escape)
+ (mapc (lambda (x)
+ (setf (node-derived-type x) *wild-type*))
+ (leaf-refs exit-fun))
+ (substitute-leaf (find-constant info) exit-fun))
+ (when lvar
+ (let ((node (block-last (nlx-info-target info))))
+ (unless (node-lvar node)
+ (aver (eq lvar (node-lvar exit)))
+ (setf (node-derived-type node) (lvar-derived-type lvar))
+ (add-lvar-use node lvar)))))
(values))
;;; Iterate over the EXITs in COMPONENT, calling NOTE-NON-LOCAL-EXIT
(dolist (lambda (component-lambdas component))
(dolist (entry (lambda-entries lambda))
(dolist (exit (entry-exits entry))
- (let ((target-env (node-physenv entry)))
- (if (eq (node-physenv exit) target-env)
+ (let ((target-physenv (node-physenv entry)))
+ (if (eq (node-physenv exit) target-physenv)
(maybe-delete-exit exit)
- (note-non-local-exit target-env exit))))))
-
+ (note-non-local-exit target-physenv exit))))))
+ (values))
+\f
+;;;; final decision on stack allocation of dynamic-extent structures
+(defun recheck-dynamic-extent-lvars (component)
+ (declare (type component component))
+ (dolist (lambda (component-lambdas component))
+ (loop for entry in (lambda-entries lambda)
+ for cleanup = (entry-cleanup entry)
+ do (when (eq (cleanup-kind cleanup) :dynamic-extent)
+ (collect ((real-dx-lvars))
+ (loop for what in (cleanup-info cleanup)
+ do (etypecase what
+ (lvar
+ (let* ((lvar what)
+ (use (lvar-uses lvar)))
+ (if (and (combination-p use)
+ (eq (basic-combination-kind use) :known)
+ (awhen (fun-info-stack-allocate-result
+ (basic-combination-fun-info use))
+ (funcall it use)))
+ (real-dx-lvars lvar)
+ (setf (lvar-dynamic-extent lvar) nil))))
+ (node ; DX closure
+ (let* ((call what)
+ (arg (first (basic-combination-args call)))
+ (funs (lvar-value arg))
+ (dx nil))
+ (dolist (fun funs)
+ (binding* ((() (leaf-dynamic-extent fun)
+ :exit-if-null)
+ (xep (functional-entry-fun fun)
+ :exit-if-null)
+ (closure (physenv-closure
+ (get-lambda-physenv xep))))
+ (cond (closure
+ (setq dx t))
+ (t
+ (setf (leaf-dynamic-extent fun) nil)))))
+ (when dx
+ (setf (lvar-dynamic-extent arg) cleanup)
+ (real-dx-lvars arg))))))
+ (setf (cleanup-info cleanup) (real-dx-lvars))
+ (setf (component-dx-lvars component)
+ (append (real-dx-lvars) (component-dx-lvars component)))))))
(values))
\f
;;;; cleanup emission
;;; in an implicit MV-PROG1. We have to force local call analysis of
;;; new references to UNWIND-PROTECT cleanup functions. If we don't
;;; actually have to do anything, then we don't insert any cleanup
-;;; code.
+;;; code. (FIXME: There's some confusion here, left over from CMU CL
+;;; comments. CLEANUP1 isn't mentioned in the code of this function.
+;;; It is in code elsewhere, but if the comments for this function
+;;; mention it they should explain the relationship to the other code.)
;;;
;;; If we do insert cleanup code, we check that BLOCK1 doesn't end in
;;; a "tail" local call.
(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)
(dolist (nlx (cleanup-nlx-info cleanup))
- (code `(%lexical-exit-breakup ',nlx)))))))
+ (code `(%lexical-exit-breakup ',nlx))))
+ (:dynamic-extent
+ (when (not (null (cleanup-info cleanup)))
+ (code `(%cleanup-point)))))))
(when (code)
(aver (not (node-tail-p (block-last block1))))
(block-last block1)
`(progn ,@(code)))
(dolist (fun (reanalyze-funs))
- (local-call-analyze-1 fun)))))
+ (locall-analyze-fun-1 fun)))))
(values))
(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))
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