(eq (ctran-next it) dest))
(t (eq (block-start (first (block-succ (node-block node))))
(node-prev dest))))))
+
+;;; Return true if LVAR destination is executed after node with only
+;;; uninteresting nodes intervening.
+;;;
+;;; Uninteresting nodes are nodes in the same block which are either
+;;; REFs, external CASTs to the same destination, or known combinations
+;;; that never unwind.
+(defun almost-immediately-used-p (lvar node)
+ (declare (type lvar lvar)
+ (type node node))
+ (aver (eq (node-lvar node) lvar))
+ (let ((dest (lvar-dest lvar)))
+ (tagbody
+ :next
+ (let ((ctran (node-next node)))
+ (cond (ctran
+ (setf node (ctran-next ctran))
+ (if (eq node dest)
+ (return-from almost-immediately-used-p t)
+ (typecase node
+ (ref
+ (go :next))
+ (cast
+ (when (and (eq :external (cast-type-check node))
+ (eq dest (node-dest node)))
+ (go :next)))
+ (combination
+ ;; KLUDGE: Unfortunately we don't have an attribute for
+ ;; "never unwinds", so we just special case
+ ;; %ALLOCATE-CLOSURES: it is easy to run into with eg.
+ ;; FORMAT and a non-constant first argument.
+ (when (eq '%allocate-closures (combination-fun-source-name node nil))
+ (go :next))))))
+ (t
+ (when (eq (block-start (first (block-succ (node-block node))))
+ (node-prev dest))
+ (return-from almost-immediately-used-p t))))))))
\f
;;;; lvar substitution
(awhen (node-lvar node)
(lvar-dynamic-extent it)))
+(defun flushable-combination-p (call)
+ (declare (combination call))
+ (let ((kind (combination-kind call))
+ (info (combination-fun-info call)))
+ (when (and (eq kind :known) (fun-info-p info))
+ (let ((attr (fun-info-attributes info)))
+ (when (and (not (ir1-attributep attr call))
+ ;; FIXME: For now, don't consider potentially flushable
+ ;; calls flushable when they have the CALL attribute.
+ ;; Someday we should look at the functional args to
+ ;; determine if they have any side effects.
+ (if (policy call (= safety 3))
+ (ir1-attributep attr flushable)
+ (ir1-attributep attr unsafely-flushable)))
+ t)))))
+
+(defun note-no-stack-allocation (lvar &key flush)
+ (do-uses (use (principal-lvar lvar))
+ (unless (or
+ ;; Don't complain about not being able to stack allocate constants.
+ (and (ref-p use) (constant-p (ref-leaf use)))
+ ;; If we're flushing, don't complain if we can flush the combination.
+ (and flush (combination-p use) (flushable-combination-p use)))
+ (let ((*compiler-error-context* use))
+ (compiler-notify "could not stack allocate the result of ~S"
+ (find-original-source (node-source-path use)))))))
+
+
(declaim (ftype (sfunction (node (member nil t :truly) &optional (or null component))
boolean) use-good-for-dx-p))
(declaim (ftype (sfunction (lvar (member nil t :truly) &optional (or null component))
(defun lvar-good-for-dx-p (lvar dx &optional component)
(let ((uses (lvar-uses lvar)))
(if (listp uses)
- (every (lambda (use)
- (use-good-for-dx-p use dx component))
- uses)
+ (when uses
+ (every (lambda (use)
+ (use-good-for-dx-p use dx component))
+ uses))
(use-good-for-dx-p uses dx component))))
(defun known-dx-combination-p (use dx)
(defun flush-dest (lvar)
(declare (type (or lvar null) lvar))
(unless (null lvar)
+ (when (lvar-dynamic-extent lvar)
+ (note-no-stack-allocation lvar :flush t))
(setf (lvar-dest lvar) nil)
(flush-lvar-externally-checkable-type lvar)
(do-uses (use lvar)
(all (combination-args call))
(new-args (reverse (subseq all 0 n-positional)))
(key-args (subseq all n-positional))
- (parameters nil))
+ (parameters nil)
+ (flushed-keys nil))
(loop while key-args
do (let* ((key (pop key-args))
(val (pop key-args))
(spec (or (assoc keyword specs :test #'eq)
(give-up-ir1-transform))))
(push val new-args)
- (flush-dest key)
+ (push key flushed-keys)
(push (second spec) parameters)
;; In case of duplicate keys.
(setf (second spec) (gensym))))
+ (dolist (key flushed-keys)
+ (flush-dest key))
(setf (combination-args call) (reverse new-args))
(reverse parameters)))
;;; Return the source name of a combination. (This is an idiom
;;; which was used in CMU CL. I gather it always works. -- WHN)
-(defun combination-fun-source-name (combination)
- (let ((ref (lvar-uses (combination-fun combination))))
- (leaf-source-name (ref-leaf ref))))
+(defun combination-fun-source-name (combination &optional (errorp t))
+ (let ((leaf (ref-leaf (lvar-uses (combination-fun combination)))))
+ (when (or errorp (leaf-has-source-name-p leaf))
+ (leaf-source-name leaf))))
;;; Return the COMBINATION node that is the call to the LET FUN.
(defun let-combination (fun)
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