(return t)))
(setq block (optimized-emit-saves-block block saves restores)))
(setq block (ir2-block-prev block)))))
-
+\f
;;; Iterate over the normal TNs, finding the cost of packing on the
;;; stack in units of the number of references. We count all read
;;; references as +1, write references as + *tn-write-cost*, and
;;; The subtraction reflects the fact that having a value in a
;;; register around a call means that code to spill and unspill must
;;; be inserted.
+;;;
+;;; The costs also take into account the loop depth at which each
+;;; reference occurs: the penalty or cost is incremented by the depth
+;;; scaled by *tn-loop-depth-multiplier*. The default (NIL) is to let
+;;; this be one more than the max of the cost for reads (1), for write
+;;; references and for being live across a call.
(defvar *tn-write-cost* 2)
-(defun assign-tn-costs (component)
- (let ((save-penalty *backend-register-save-penalty*))
- (do-ir2-blocks (block component)
- (do ((vop (ir2-block-start-vop block) (vop-next vop)))
- ((null vop))
- (when (eq (vop-info-save-p (vop-info vop)) t)
- (do-live-tns (tn (vop-save-set vop) block)
- (decf (tn-cost tn) save-penalty))))))
+(defvar *tn-loop-depth-multiplier* nil)
- (let ((write-cost *tn-write-cost*))
- (do ((tn (ir2-component-normal-tns (component-info component))
- (tn-next tn)))
- ((null tn))
- (let ((cost (tn-cost tn)))
- (declare (fixnum cost))
- (do ((ref (tn-reads tn) (tn-ref-next ref)))
- ((null ref))
- (incf cost))
- (do ((ref (tn-writes tn) (tn-ref-next ref)))
- ((null ref))
- (incf cost write-cost))
- (setf (tn-cost tn) cost)))))
+(defun assign-tn-costs (component)
+ (let* ((save-penalty *backend-register-save-penalty*)
+ (write-cost *tn-write-cost*)
+ (depth-scale (or *tn-loop-depth-multiplier*
+ (1+ (max 1 write-cost save-penalty)))))
+ (flet ((vop-depth-cost (vop)
+ (let ((loop (block-loop
+ (ir2-block-block
+ (vop-block vop)))))
+ (if loop
+ (* depth-scale (loop-depth loop))
+ 0))))
+ (do-ir2-blocks (block component)
+ (do ((vop (ir2-block-start-vop block) (vop-next vop)))
+ ((null vop))
+ (when (eq (vop-info-save-p (vop-info vop)) t)
+ (let ((penalty (+ save-penalty (vop-depth-cost vop))))
+ (do-live-tns (tn (vop-save-set vop) block)
+ (decf (tn-cost tn) penalty))))))
+
+ (do ((tn (ir2-component-normal-tns (component-info component))
+ (tn-next tn)))
+ ((null tn))
+ (let ((cost (tn-cost tn)))
+ (declare (fixnum cost))
+ (do ((ref (tn-reads tn) (tn-ref-next ref)))
+ ((null ref))
+ (incf cost (1+ (vop-depth-cost (tn-ref-vop ref)))))
+ (do ((ref (tn-writes tn) (tn-ref-next ref)))
+ ((null ref))
+ (incf cost (+ write-cost (vop-depth-cost (tn-ref-vop ref)))))
+ (setf (tn-cost tn) cost))))))
;;; Iterate over the normal TNs, folding over the depth of the looops
;;; that the TN is used in and storing the result in TN-LOOP-DEPTH.
(frob (tn-reads tn))
(frob (tn-writes tn))
(setf (tn-loop-depth tn) depth))))))
-
-(defun tn-loop-depth-cost-> (x y)
- (declare (type tn x y))
- (let ((depth-x (tn-loop-depth x))
- (depth-y (tn-loop-depth y)))
- (or (> depth-x depth-y)
- (and (= depth-x depth-y)
- (> (tn-cost x) (tn-cost y))))))
\f
;;;; load TN packing
((null tn))
(pack-wired-tn tn optimize))
- ;; Pack restricted component TNs.
- (do ((tn (ir2-component-restricted-tns 2comp) (tn-next tn)))
- ((null tn))
- (when (and (eq (tn-kind tn) :component) (not (unbounded-tn-p tn)))
- ;; unbounded SCs will be handled in the final pass
- (pack-tn tn t optimize)))
-
- ;; Pack other restricted TNs.
- (do ((tn (ir2-component-restricted-tns 2comp) (tn-next tn)))
- ((null tn))
- (unless (or (tn-offset tn) (unbounded-tn-p tn))
- (pack-tn tn t optimize)))
-
- (cond (*loop-analyze*
- ;; Allocate normal TNs, starting with the TNs that are used
- ;; in deep loops. Only allocate in finite SCs (i.e. not on
+ ;; Then, pack restricted TNs, ones that are live over the whole
+ ;; component first (they cause no fragmentation). Sort by TN cost
+ ;; to help important TNs get good targeting.
+ (collect ((component)
+ (normal))
+ (do ((tn (ir2-component-restricted-tns 2comp) (tn-next tn)))
+ ((null tn))
+ (unless (or (tn-offset tn) (unbounded-tn-p tn))
+ (if (eq :component (tn-kind tn))
+ (component tn)
+ (normal tn))))
+ (flet ((pack-tns (tns)
+ (dolist (tn (stable-sort tns #'> :key #'tn-cost))
+ (pack-tn tn t optimize))))
+ (pack-tns (component))
+ (pack-tns (normal))))
+
+ (cond ((and *loop-analyze* *pack-assign-costs*)
+ ;; Allocate normal TNs, starting with the TNs that are
+ ;; heavily used in deep loops (which is taken into account in
+ ;; TN spill costs). Only allocate in finite SCs (i.e. not on
;; the stack).
- (when *pack-assign-costs*
- (assign-tn-depths component))
(collect ((tns))
(do ((tn (ir2-component-normal-tns 2comp) (tn-next tn)))
((null tn))
(unless (or (tn-offset tn)
(eq (tn-kind tn) :more)
- (unbounded-tn-p tn))
+ (unbounded-tn-p tn)
+ (and (sc-save-p (tn-sc tn)) ; SC caller-save, but TN
+ (minusp (tn-cost tn)))) ; lives over many calls
(tns tn)))
- (dolist (tn (stable-sort (tns) #'tn-loop-depth-cost->))
+ (dolist (tn (stable-sort (tns) #'> :key #'tn-cost))
(unless (tn-offset tn)
+ ;; if it can't fit in a bounded SC, the final pass will
+ ;; take care of stack packing.
(pack-tn tn nil optimize :allow-unbounded-sc nil)))))
(t
;; If loop analysis has been disabled we might as well revert
projects / sbcl.git / commitdiff