;;; invariant that all pushes come after the last pop.
(defun find-pushed-lvars (block)
(let* ((2block (block-info block))
- (popped (ir2-block-popped 2block))
- (last-pop (if popped
- (lvar-dest (car (last popped)))
- nil)))
+ (popped (ir2-block-popped 2block))
+ (last-pop (if popped
+ (lvar-dest (car (last popped)))
+ nil)))
(collect ((pushed))
(let ((saw-last nil))
- (do-nodes (node lvar block)
- (when (eq node last-pop)
- (setq saw-last t))
+ (do-nodes (node lvar block)
+ (when (eq node last-pop)
+ (setq saw-last t))
- (when (and lvar
+ (when (and lvar
(or (lvar-dynamic-extent lvar)
(let ((dest (lvar-dest lvar))
(2lvar (lvar-info lvar)))
;;; been changed.
(defun merge-uvl-live-sets (early late)
(declare (type list early late))
+ ;; FIXME: O(N^2)
(dolist (e late early)
(pushnew e early)))
block
(lambda (dx-cleanup)
(dolist (lvar (cleanup-info dx-cleanup))
- (let* ((generator (lvar-use lvar))
- (block (node-block generator))
- (2block (block-info block)))
- (aver (eq generator (block-last block)))
- ;; DX objects, living in the LVAR, are
- ;; alive in the environment, protected by
- ;; the CLEANUP. We also cannot move them
- ;; (because, in general, we cannot track
- ;; all references to them). Therefore,
- ;; everything, allocated deeper than a DX
- ;; object, should be kept alive until the
- ;; object is deallocated.
- (setq new-end (merge-uvl-live-sets
- new-end (ir2-block-end-stack 2block)))
- (setq new-end (merge-uvl-live-sets
- new-end (ir2-block-pushed 2block)))))))
+ (do-uses (generator lvar)
+ (let* ((block (node-block generator))
+ (2block (block-info block)))
+ ;; DX objects, living in the LVAR, are alive in
+ ;; the environment, protected by the CLEANUP. We
+ ;; also cannot move them (because, in general, we
+ ;; cannot track all references to them).
+ ;; Therefore, everything, allocated deeper than a
+ ;; DX object -- that is, before the DX object --
+ ;; should be kept alive until the object is
+ ;; deallocated.
+ ;;
+ ;; Since DX generators end their blocks, we can
+ ;; find out UVLs allocated before them by looking
+ ;; at the stack at the end of the block.
+ ;;
+ ;; FIXME: This is not quite true: REFs to DX
+ ;; closures don't end their blocks!
+ (setq new-end (merge-uvl-live-sets
+ new-end (ir2-block-end-stack 2block)))
+ (setq new-end (merge-uvl-live-sets
+ new-end (ir2-block-pushed 2block))))))))
(setf (ir2-block-end-stack 2block) new-end)
(defun order-uvl-sets (component)
(clear-flags component)
+ ;; KLUDGE: Workaround for lp#308914: we keep track of number of blocks
+ ;; needing repeats, and bug out if we get stuck.
(loop with head = (component-head component)
- with repeat-p do
- (setq repeat-p nil)
- (do-blocks (block component)
- (unless (block-flag block)
- (let ((pred (find-if #'block-flag (block-pred block))))
- (when (and (eq pred head)
- (not (bind-p (block-start-node block))))
- (let ((entry (nle-block-entry-block block)))
- (setq pred (if (block-flag entry) entry nil))))
- (cond (pred
- (setf (block-flag block) t)
- (order-block-uvl-sets block pred))
- (t
- (setq repeat-p t))))))
- while repeat-p))
+ with todo = 0
+ with last-todo = 0
+ do (psetq last-todo todo
+ todo 0)
+ do (do-blocks (block component)
+ (unless (block-flag block)
+ (let ((pred (find-if #'block-flag (block-pred block))))
+ (when (and (eq pred head)
+ (not (bind-p (block-start-node block))))
+ (let ((entry (nle-block-entry-block block)))
+ (setq pred (if (block-flag entry) entry nil))))
+ (cond (pred
+ (setf (block-flag block) t)
+ (order-block-uvl-sets block pred))
+ (t
+ (incf todo))))))
+ do (when (= last-todo todo)
+ ;; If the todo count is the same as on last iteration, it means
+ ;; we are stuck, which in turn means the unmarked blocks are
+ ;; actually unreachable, so UVL set ordering for them doesn't
+ ;; matter.
+ (return-from order-uvl-sets))
+ while (plusp todo)))
\f
;;; This is called when we discover that the stack-top unknown-values
;;; lvar at the end of BLOCK1 is different from that at the start of
(collect ((res nil adjoin))
(dolist (rec receivers)
(dolist (pop (ir2-block-popped (block-info rec)))
- (do-uses (use pop)
- (unless (exit-p use)
- (res (node-block use))))))
+ (do-uses (use pop)
+ (unless (exit-p use)
+ (res (node-block use))))))
(dolist (dx-lvar dx-lvars)
(do-uses (use dx-lvar)
(res (node-block use))))
(defun stack-analyze (component)
(declare (type component component))
(let* ((2comp (component-info component))
- (receivers (ir2-component-values-receivers 2comp))
- (generators (find-pushing-blocks receivers
+ (receivers (ir2-component-values-receivers 2comp))
+ (generators (find-pushing-blocks receivers
(component-dx-lvars component))))
(dolist (block generators)
(do-blocks (block component)
(let ((top (ir2-block-end-stack (block-info block))))
- (dolist (succ (block-succ block))
- (when (and (block-start succ)
- (not (eq (ir2-block-start-stack (block-info succ))
- top)))
- (discard-unused-values block succ))))))
+ (dolist (succ (block-succ block))
+ (when (and (block-start succ)
+ (not (eq (ir2-block-start-stack (block-info succ))
+ top)))
+ (discard-unused-values block succ))))))
(values))