\f
;;;; conflict determination
-;;; Return true if the element at the specified offset in SB has a conflict
-;;; with TN:
-;;; -- If an component-live TN (:component kind), then iterate over all the
-;;; blocks. If the element at Offset is used anywhere in any of the
-;;; component's blocks (always-live /= 0), then there is a conflict.
-;;; -- If TN is global (Confs true), then iterate over the blocks TN is live in
-;;; (using TN-Global-Conflicts). If the TN is live everywhere in the block
-;;; (:Live), then there is a conflict if the element at offset is used
-;;; anywhere in the block (Always-Live /= 0). Otherwise, we use the local
-;;; TN number for TN in block to find whether TN has a conflict at Offset in
+;;; Return true if the element at the specified offset in SB has a
+;;; conflict with TN:
+;;; -- If a component-live TN (:COMPONENT kind), then iterate over
+;;; all the blocks. If the element at OFFSET is used anywhere in
+;;; any of the component's blocks (always-live /= 0), then there
+;;; is a conflict.
+;;; -- If TN is global (Confs true), then iterate over the blocks TN
+;;; is live in (using TN-GLOBAL-CONFLICTS). If the TN is live
+;;; everywhere in the block (:LIVE), then there is a conflict
+;;; if the element at offset is used anywhere in the block
+;;; (Always-Live /= 0). Otherwise, we use the local TN number for
+;;; TN in block to find whether TN has a conflict at Offset in
;;; that block.
-;;; -- If TN is local, then we just check for a conflict in the block it is
-;;; local to.
+;;; -- If TN is local, then we just check for a conflict in the block
+;;; it is local to.
(defun offset-conflicts-in-sb (tn sb offset)
(declare (type tn tn) (type finite-sb sb) (type index offset))
(let ((confs (tn-global-conflicts tn))
(confs
(let ((loc-confs (svref (finite-sb-conflicts sb) offset))
(loc-live (svref (finite-sb-always-live sb) offset)))
- (do ((conf confs (global-conflicts-tn-next conf)))
+ (do ((conf confs (global-conflicts-next-tnwise conf)))
((null conf)
nil)
(let* ((block (global-conflicts-block conf))
(when (offset-conflicts-in-sb tn sb (+ offset i))
(return t)))))
-;;; Add TN's conflicts into the conflicts for the location at Offset in SC.
-;;; We iterate over each location in TN, adding to the conflicts for that
-;;; location:
-;;; -- If TN is a :Component TN, then iterate over all the blocks, setting
-;;; all of the local conflict bits and the always-live bit. This records a
-;;; conflict with any TN that has a LTN number in the block, as well as with
-;;; :Always-Live and :Environment TNs.
+;;; Add TN's conflicts into the conflicts for the location at OFFSET
+;;; in SC. We iterate over each location in TN, adding to the
+;;; conflicts for that location:
+;;; -- If TN is a :COMPONENT TN, then iterate over all the blocks,
+;;; setting all of the local conflict bits and the always-live bit.
+;;; This records a conflict with any TN that has a LTN number in
+;;; the block, as well as with :ALWAYS-LIVE and :ENVIRONMENT TNs.
;;; -- If TN is global, then iterate over the blocks TN is live in. In
-;;; addition to setting the always-live bit to represent the conflict with
-;;; TNs live throughout the block, we also set bits in the local conflicts.
-;;; If TN is :Always-Live in the block, we set all the bits, otherwise we or
-;;; in the local conflict bits.
-;;; -- If the TN is local, then we just do the block it is local to, setting
-;;; always-live and OR'ing in the local conflicts.
-(defun add-location-conflicts (tn sc offset)
+;;; addition to setting the always-live bit to represent the conflict
+;;; with TNs live throughout the block, we also set bits in the
+;;; local conflicts. If TN is :ALWAYS-LIVE in the block, we set all
+;;; the bits, otherwise we OR in the local conflict bits.
+;;; -- If the TN is local, then we just do the block it is local to,
+;;; setting always-live and OR'ing in the local conflicts.
+(defun add-location-conflicts (tn sc offset optimize)
(declare (type tn tn) (type sc sc) (type index offset))
(let ((confs (tn-global-conflicts tn))
(sb (sc-sb sc))
(loc-live (svref (finite-sb-always-live sb) this-offset)))
(cond
((eq kind :component)
- (dotimes (num (ir2-block-count *component-being-compiled*) nil)
+ (dotimes (num (ir2-block-count *component-being-compiled*))
(declare (type index num))
(setf (sbit loc-live num) 1)
(set-bit-vector (svref loc-confs num))))
(confs
- (do ((conf confs (global-conflicts-tn-next conf)))
+ (do ((conf confs (global-conflicts-next-tnwise conf)))
((null conf))
(let* ((block (global-conflicts-block conf))
(num (ir2-block-number block))
(let ((num (ir2-block-number (tn-local tn))))
(setf (sbit loc-live num) 1)
(bit-ior (the local-tn-bit-vector (svref loc-confs num))
- (tn-local-conflicts tn) t))))))))
+ (tn-local-conflicts tn) t))))
+ ;; Calculating ALWAYS-LIVE-COUNT is moderately expensive, and
+ ;; currently the information isn't used unless (> SPEED
+ ;; COMPILE-SPEED).
+ (when optimize
+ (setf (svref (finite-sb-always-live-count sb) this-offset)
+ (find-location-usage sb this-offset))))))
+ (values))
-;;; Return the total number of IR2 blocks in Component.
+;; A rought measure of how much a given OFFSET in SB is currently
+;; used. Current implementation counts the amount of blocks where the
+;; offset has been marked as ALWAYS-LIVE.
+(defun find-location-usage (sb offset)
+ (declare (optimize speed))
+ (declare (type sb sb) (type index offset))
+ (let* ((always-live (svref (finite-sb-always-live sb) offset)))
+ (declare (simple-bit-vector always-live))
+ (count 1 always-live)))
+
+;;; Return the total number of IR2-BLOCKs in COMPONENT.
(defun ir2-block-count (component)
(declare (type component component))
(do ((2block (block-info (block-next (component-head component)))
(when (ir2-block-number 2block)
(return (1+ (ir2-block-number 2block))))))
-;;; Ensure that the conflicts vectors for each :Finite SB are large
+;;; Ensure that the conflicts vectors for each :FINITE SB are large
;;; enough for the number of blocks allocated. Also clear any old
;;; conflicts and reset the current size to the initial size.
(defun init-sb-vectors (component)
(unless (eq (sb-kind sb) :non-packed)
(let* ((conflicts (finite-sb-conflicts sb))
(always-live (finite-sb-always-live sb))
+ (always-live-count (finite-sb-always-live-count sb))
(max-locs (length conflicts))
(last-count (finite-sb-last-block-count sb)))
(unless (zerop max-locs)
(setf (svref conflicts i) new-vec))
(setf (svref always-live i)
(make-array new-size :element-type 'bit
- :initial-element 0)))))
+ :initial-element 0))
+ (setf (svref always-live-count i) 0))))
(t
(dotimes (i (finite-sb-current-size sb))
(declare (type index i))
(dotimes (j last-count)
(declare (type index j))
(clear-bit-vector (svref conf j))))
- (clear-bit-vector (svref always-live i)))))))
+ (clear-bit-vector (svref always-live i))
+ (setf (svref always-live-count i) 0))))))
(setf (finite-sb-last-block-count sb) nblocks)
(setf (finite-sb-current-size sb) (sb-size sb))
(setf (finite-sb-last-offset sb) 0))))))
-;;; Expand the :Unbounded SB backing SC by either the initial size or
-;;; the SC element size, whichever is larger. If Needed-Size is
+;;; Expand the :UNBOUNDED SB backing SC by either the initial size or
+;;; the SC element size, whichever is larger. If NEEDED-SIZE is
;;; larger, then use that size.
(defun grow-sc (sc &optional (needed-size 0))
(declare (type sc sc) (type index needed-size))
:element-type 'bit)))
(setf (finite-sb-always-live sb) new-live))
+ (let ((new-live-count (make-array new-size)))
+ (declare (optimize speed)) ;; FILL deftransform
+ (replace new-live-count (finite-sb-always-live-count sb))
+ (fill new-live-count 0 :start size)
+ (setf (finite-sb-always-live-count sb) new-live-count))
+
(let ((new-tns (make-array new-size :initial-element nil)))
(replace new-tns (finite-sb-live-tns sb))
(fill (finite-sb-live-tns sb) nil)
(setf (finite-sb-current-size sb) new-size))
(values))
-;;; This variable is true whenever we are in pack (and thus the per-SB
-;;; conflicts information is in use.)
-(defvar *in-pack* nil)
-
-;;; In order to prevent the conflict data structures from growing
-;;; arbitrarily large, we clear them whenever a GC happens and we
-;;; aren't currently in pack. We revert to the initial number of
-;;; locations and 0 blocks.
-(defun pack-before-gc-hook ()
- (unless *in-pack*
- (dolist (sb *backend-sb-list*)
- (unless (eq (sb-kind sb) :non-packed)
- (let ((size (sb-size sb)))
- (fill nil (finite-sb-always-live sb))
- (setf (finite-sb-always-live sb)
- (make-array size
- :initial-element
- #-sb-xc #*
- ;; The cross-compiler isn't very good at dumping
- ;; specialized arrays, so we delay construction of
- ;; this SIMPLE-BIT-VECTOR until runtime.
- #+sb-xc (make-array 0 :element-type 'bit)))
-
- (fill nil (finite-sb-conflicts sb))
- (setf (finite-sb-conflicts sb)
- (make-array size :initial-element '#()))
-
- (fill nil (finite-sb-live-tns sb))
- (setf (finite-sb-live-tns sb)
- (make-array size :initial-element nil))))))
- (values))
-
-(pushnew 'pack-before-gc-hook sb!ext:*before-gc-hooks*)
\f
;;;; internal errors
-;;; Give someone a hard time because there isn't any load function defined
-;;; to move from Src to Dest.
-(defun no-load-function-error (src dest)
+;;; Give someone a hard time because there isn't any load function
+;;; defined to move from SRC to DEST.
+(defun no-load-fun-error (src dest)
(let* ((src-sc (tn-sc src))
(src-name (sc-name src-sc))
(dest-sc (tn-sc dest))
(cond ((eq (sb-kind (sc-sb src-sc)) :non-packed)
(unless (member src-sc (sc-constant-scs dest-sc))
(error "loading from an invalid constant SC?~@
- VM definition inconsistent, try recompiling."))
+ VM definition inconsistent, try recompiling."))
(error "no load function defined to load SC ~S ~
- from its constant SC ~S"
+ from its constant SC ~S"
dest-name src-name))
((member src-sc (sc-alternate-scs dest-sc))
(error "no load function defined to load SC ~S from its ~
- alternate SC ~S"
+ alternate SC ~S"
dest-name src-name))
((member dest-sc (sc-alternate-scs src-sc))
(error "no load function defined to save SC ~S in its ~
- alternate SC ~S"
+ alternate SC ~S"
src-name dest-name))
(t
;; FIXME: "VM definition is inconsistent" shouldn't be a
;; possibility in SBCL.
(error "loading to/from SCs that aren't alternates?~@
- VM definition is inconsistent, try recompiling.")))))
+ VM definition is inconsistent, try recompiling.")))))
;;; Called when we failed to pack TN. If RESTRICTED is true, then we
;;; are restricted to pack TN in its SC.
tn (sc-name sc)))
(t
(aver (not (find :unbounded scs
- :key #'(lambda (x) (sb-kind (sc-sb x))))))
+ :key (lambda (x) (sb-kind (sc-sb x))))))
(let ((ptype (tn-primitive-type tn)))
(cond
(ptype
(aver (member (sc-number sc) (primitive-type-scs ptype)))
- (error "SC ~S doesn't have any :Unbounded alternate SCs, but is~@
- a SC for primitive-type ~S."
+ (error "SC ~S doesn't have any :UNBOUNDED alternate SCs, but is~@
+ a SC for primitive-type ~S."
(sc-name sc) (primitive-type-name ptype)))
(t
- (error "SC ~S doesn't have any :Unbounded alternate SCs."
+ (error "SC ~S doesn't have any :UNBOUNDED alternate SCs."
(sc-name sc)))))))))
;;; Return a list of format arguments describing how TN is used in
(args (vop-args vop))
(results (vop-results vop))
(name (with-output-to-string (stream)
- (print-tn tn stream)))
+ (print-tn-guts tn stream)))
(2comp (component-info *component-being-compiled*))
temp)
(cond
(declare (ignore costs load-scs))
(aver (not more-p))
(error "unable to pack a Load-TN in SC ~{~A~#[~^~;, or ~:;,~]~} ~
- for the ~:R ~:[result~;argument~] to~@
- the ~S VOP,~@
- ~:[since all SC elements are in use:~:{~%~@?~}~%~;~
- ~:*but these SC elements are not in use:~% ~S~%Bug?~*~]~
- ~:[~;~@
- Current cost info inconsistent with that in effect at compile ~
- time. Recompile.~%Compilation order may be incorrect.~]"
+ for the ~:R ~:[result~;argument~] to~@
+ the ~S VOP,~@
+ ~:[since all SC elements are in use:~:{~%~@?~}~%~;~
+ ~:*but these SC elements are not in use:~% ~S~%Bug?~*~]~
+ ~:[~;~@
+ Current cost info inconsistent with that in effect at compile ~
+ time. Recompile.~%Compilation order may be incorrect.~]"
(mapcar #'sc-name scs)
n arg-p
(vop-info-name (vop-info (tn-ref-vop op)))
(declare (ignore costs))
(aver (not more-p))
(error "~S is not valid as the ~:R ~:[result~;argument~] to VOP:~
- ~% ~S,~@
- since the TN's primitive type ~S doesn't allow any of the SCs~@
- allowed by the operand restriction:~% ~S~
- ~:[~;~@
- Current cost info inconsistent with that in effect at compile ~
- time. Recompile.~%Compilation order may be incorrect.~]"
+ ~% ~S,~@
+ since the TN's primitive type ~S doesn't allow any of the SCs~@
+ allowed by the operand restriction:~% ~S~
+ ~:[~;~@
+ Current cost info inconsistent with that in effect at compile ~
+ time. Recompile.~%Compilation order may be incorrect.~]"
tn pos arg-p
(template-name (vop-info (tn-ref-vop ref)))
(primitive-type-name ptype)
(pushnew tn (gethash vop (ir2-component-spilled-vops 2comp)))))
(values))
-;;; Make a save TN for TN, pack it, and return it. We copy various conflict
-;;; information from the TN so that pack does the right thing.
+;;; Make a save TN for TN, pack it, and return it. We copy various
+;;; conflict information from the TN so that pack does the right
+;;; thing.
(defun pack-save-tn (tn)
(declare (type tn tn))
(let ((res (make-tn 0 :save nil nil)))
(setf (tn-save-tn tn) res)
(setf (tn-save-tn res) tn)
(setf (tn-sc res) alt)
- (pack-tn res t)
+ (pack-tn res t nil)
(return res)))))
;;; Find the load function for moving from SRC to DEST and emit a
(emit-load-template node block
(template-or-lose 'move-operand)
src dest
- (list (or (svref (sc-move-functions (tn-sc dest))
+ (list (or (svref (sc-move-funs (tn-sc dest))
(sc-number (tn-sc src)))
- (no-load-function-error src dest)))
+ (no-load-fun-error src dest)))
before)
(values))
vop))
(emit-operand-load node block save tn next)))
-;;; Return a VOP after which is an o.k. place to save the value of TN.
+;;; Return a VOP after which is an OK place to save the value of TN.
;;; For correctness, it is only required that this location be after
;;; any possible write and before any possible restore location.
;;;
(save-complex-writer-tn tn vop))))
(values))
-;;; Scan over the VOPs in Block, emiting saving code for TNs noted in the
-;;; codegen info that are packed into saved SCs.
+;;; Scan over the VOPs in BLOCK, emiting saving code for TNs noted in
+;;; the codegen info that are packed into saved SCs.
(defun emit-saves (block)
(declare (type ir2-block block))
(do ((vop (ir2-block-start-vop block) (vop-next vop)))
;;;; optimized saving
;;; Save TN if it isn't a single-writer TN that has already been
-;;; saved. If multi-write, we insert the save Before the specified
-;;; VOP. Context is a VOP used to tell which node/block to use for the
+;;; saved. If multi-write, we insert the save BEFORE the specified
+;;; VOP. CONTEXT is a VOP used to tell which node/block to use for the
;;; new VOP.
(defun save-if-necessary (tn before context)
(declare (type tn tn) (type (or vop null) before) (type vop context))
(values))
;;; Load the TN from its save location, allocating one if necessary.
-;;; The load is inserted Before the specifier VOP. Context is a VOP
+;;; The load is inserted BEFORE the specifier VOP. CONTEXT is a VOP
;;; used to tell which node/block to use for the new VOP.
(defun restore-tn (tn before context)
(declare (type tn tn) (type (or vop null) before) (type vop context))
;;;
;;; SAVES and RESTORES are represented using both a list and a
;;; bit-vector so that we can quickly iterate and test for membership.
-;;; The incoming Saves and Restores args are used for computing these
+;;; The incoming SAVES and RESTORES args are used for computing these
;;; sets (the initial contents are ignored.)
;;;
-;;; When we hit a VOP with :COMPUTE-ONLY Save-P (an internal error
+;;; When we hit a VOP with :COMPUTE-ONLY SAVE-P (an internal error
;;; location), we pretend that all live TNs were read, unless (= speed
;;; 3), in which case we mark all the TNs that are live but not
;;; restored as spilled.
(do ((read (vop-args vop) (tn-ref-across read)))
((null read))
(save-note-read (tn-ref-tn read))))))))))
-
-;;; Like EMIT-SAVES, only different. We avoid redundant saving within
-;;; the block, and don't restore values that aren't used before the
-;;; next call. This function is just the top level loop over the
+
+;;; This is like EMIT-SAVES, only different. We avoid redundant saving
+;;; within the block, and don't restore values that aren't used before
+;;; the next call. This function is just the top level loop over the
;;; blocks in the component, which locates blocks that need saving
;;; done.
(defun optimized-emit-saves (component)
((null ref))
(incf cost))
(setf (tn-cost tn) cost))))
+
+;;; Iterate over the normal TNs, storing the depth of the deepest loop
+;;; that the TN is used in TN-LOOP-DEPTH.
+(defun assign-tn-depths (component)
+ (when *loop-analyze*
+ (do-ir2-blocks (block component)
+ (do ((vop (ir2-block-start-vop block)
+ (vop-next vop)))
+ ((null vop))
+ (flet ((find-all-tns (head-fun)
+ (collect ((tns))
+ (do ((ref (funcall head-fun vop) (tn-ref-across ref)))
+ ((null ref))
+ (tns (tn-ref-tn ref)))
+ (tns))))
+ (dolist (tn (nconc (find-all-tns #'vop-args)
+ (find-all-tns #'vop-results)
+ (find-all-tns #'vop-temps)
+ ;; What does "references in this VOP
+ ;; mean"? Probably something that isn't
+ ;; useful in this context, since these
+ ;; TN-REFs are linked with TN-REF-NEXT
+ ;; instead of TN-REF-ACROSS. --JES
+ ;; 2004-09-11
+ ;; (find-all-tns #'vop-refs)
+ ))
+ (setf (tn-loop-depth tn)
+ (max (tn-loop-depth tn)
+ (let* ((ir1-block (ir2-block-block (vop-block vop)))
+ (loop (block-loop ir1-block)))
+ (if loop
+ (loop-depth loop)
+ 0))))))))))
+
\f
;;;; load TN packing
;;; These variables indicate the last location at which we computed
-;;; the Live-TNs. They hold the Block and VOP values that were passed
-;;; to Compute-Live-TNs.
+;;; the Live-TNs. They hold the BLOCK and VOP values that were passed
+;;; to COMPUTE-LIVE-TNS.
(defvar *live-block*)
(defvar *live-vop*)
(defvar *repack-blocks*)
(declaim (type (or hash-table null) *repack-blocks*))
-;;; Set the Live-TNs vectors in all :Finite SBs to represent the TNs
-;;; live at the end of Block.
+;;; Set the LIVE-TNS vectors in all :FINITE SBs to represent the TNs
+;;; live at the end of BLOCK.
(defun init-live-tns (block)
(dolist (sb *backend-sb-list*)
(when (eq (sb-kind sb) :finite)
(values))
-;;; Set the Live-TNs in :Finite SBs to represent the TNs live
-;;; immediately after the evaluation of VOP in Block, excluding
+;;; Set the LIVE-TNs in :FINITE SBs to represent the TNs live
+;;; immediately after the evaluation of VOP in BLOCK, excluding
;;; results of the VOP. If VOP is null, then compute the live TNs at
;;; the beginning of the block. Sequential calls on the same block
;;; must be in reverse VOP order.
(setq *live-vop* vop)
(values))
-;;; This is kind of like Offset-Conflicts-In-SB, except that it uses
+;;; This is kind of like OFFSET-CONFLICTS-IN-SB, except that it uses
;;; the VOP refs to determine whether a Load-TN for OP could be packed
;;; in the specified location, disregarding conflicts with TNs not
;;; referenced by this VOP. There is a conflict if either:
(load-tn-offset-conflicts-in-sb op sb i))))
(when res (return res))))))
-;;; If a load-TN for Op is targeted to a legal location in SC, then
+;;; If a load-TN for OP is targeted to a legal location in SC, then
;;; return the offset, otherwise return NIL. We see whether the target
;;; of the operand is packed, and try that location. There isn't any
;;; need to chain down the target path, since everything is packed
(return res))))
(push sc allowed)))))))))
-;;; Scan a list of load-SCs vectors and a list of TN-Refs threaded by
-;;; TN-Ref-Across. When we find a reference whose TN doesn't satisfy
+;;; Scan a list of load-SCs vectors and a list of TN-REFS threaded by
+;;; TN-REF-ACROSS. When we find a reference whose TN doesn't satisfy
;;; the restriction, we pack a Load-TN and load the operand into it.
;;; If a load-tn has already been allocated, we can assume that the
;;; restriction is satisfied.
(values))
-;;; Scan the VOPs in Block, looking for operands whose SC restrictions
+;;; Scan the VOPs in BLOCK, looking for operands whose SC restrictions
;;; aren't satisfied. We do the results first, since they are
;;; evaluated later, and our conflict analysis is a backward scan.
(defun pack-load-tns (block)
(vop-args vop))))))
(values))
\f
-;;;; location-selection, targeting & pack interface
-
;;;; targeting
-;;; Link the TN-Refs Read and Write together using the TN-Ref-Target when
-;;; this seems like a good idea. Currently we always do, as this increases the
-;;; success of load-TN targeting.
+;;; Link the TN-REFS READ and WRITE together using the TN-REF-TARGET
+;;; when this seems like a good idea. Currently we always do, as this
+;;; increases the success of load-TN targeting.
(defun target-if-desirable (read write)
(declare (type tn-ref read write))
+ ;; As per the comments at the definition of TN-REF-TARGET, read and
+ ;; write refs are always paired, with TARGET in the read pointing to
+ ;; the write and vice versa.
+ (aver (eq (tn-ref-write-p read)
+ (not (tn-ref-write-p write))))
(setf (tn-ref-target read) write)
(setf (tn-ref-target write) read))
;;; If TN can be packed into SC so as to honor a preference to TARGET,
;;; then return the offset to pack at, otherwise return NIL. TARGET
-;;; must be already packed. We can honor a preference if:
-;;; -- TARGET's location is in SC's locations.
-;;; -- The element sizes of the two SCs are the same.
-;;; -- TN doesn't conflict with target's location.
+;;; must be already packed.
(defun check-ok-target (target tn sc)
(declare (type tn target tn) (type sc sc) (inline member))
(let* ((loc (tn-offset target))
(target-sc (tn-sc target))
(target-sb (sc-sb target-sc)))
(declare (type index loc))
+ ;; We can honor a preference if:
+ ;; -- TARGET's location is in SC's locations.
+ ;; -- The element sizes of the two SCs are the same.
+ ;; -- TN doesn't conflict with target's location.
(if (and (eq target-sb (sc-sb sc))
(or (eq (sb-kind target-sb) :unbounded)
(member loc (sc-locations sc)))
nil)))
;;; Scan along the target path from TN, looking at readers or writers.
-;;; When we find a packed TN, return Check-OK-Target of that TN. If
+;;; When we find a packed TN, return CHECK-OK-TARGET of that TN. If
;;; there is no target, or if the TN has multiple readers (writers),
;;; then we return NIL. We also always return NIL after 10 iterations
;;; to get around potential circularity problems.
-(macrolet ((frob (slot)
- `(let ((count 10)
- (current tn))
- (declare (type index count))
- (loop
- (let ((refs (,slot current)))
- (unless (and (plusp count) refs (not (tn-ref-next refs)))
- (return nil))
- (let ((target (tn-ref-target refs)))
- (unless target (return nil))
- (setq current (tn-ref-tn target))
- (when (tn-offset current)
- (return (check-ok-target current tn sc)))
- (decf count)))))))
- (defun find-ok-target-offset (tn sc)
- (declare (type tn tn) (type sc sc))
- (or (frob tn-reads)
- (frob tn-writes))))
-
+;;;
+;;; FIXME: (30 minutes of reverse engineering?) It'd be nice to
+;;; rewrite the header comment here to explain the interface and its
+;;; motivation, and move remarks about implementation details (like
+;;; 10!) inside.
+(defun find-ok-target-offset (tn sc)
+ (declare (type tn tn) (type sc sc))
+ (flet ((frob-slot (slot-fun)
+ (declare (type function slot-fun))
+ (let ((count 10)
+ (current tn))
+ (declare (type index count))
+ (loop
+ (let ((refs (funcall slot-fun current)))
+ (unless (and (plusp count)
+ refs
+ (not (tn-ref-next refs)))
+ (return nil))
+ (let ((target (tn-ref-target refs)))
+ (unless target (return nil))
+ (setq current (tn-ref-tn target))
+ (when (tn-offset current)
+ (return (check-ok-target current tn sc)))
+ (decf count)))))))
+ (declare (inline frob-slot)) ; until DYNAMIC-EXTENT works
+ (or (frob-slot #'tn-reads)
+ (frob-slot #'tn-writes))))
+\f
;;;; location selection
;;; Select some location for TN in SC, returning the offset if we
-;;; succeed, and NIL if we fail. We start scanning at the Last-Offset
-;;; in an attempt to distribute the TNs across all storage.
-;;;
-;;; We call Offset-Conflicts-In-SB directly, rather than using
-;;; Conflicts-In-SC. This allows us to more efficient in packing
-;;; multi-location TNs: we don't have to multiply the number of tests
-;;; by the TN size. This falls out natually, since we have to be aware
-;;; of TN size anyway so that we don't call Conflicts-In-SC on a bogus
-;;; offset.
-;;;
-;;; We give up on finding a location after our current pointer has
-;;; wrapped twice. This will result in testing some locations twice in
-;;; the case that we fail, but is simpler than trying to figure out
-;;; the soonest failure point.
+;;; succeed, and NIL if we fail.
;;;
-;;; We also give up without bothering to wrap if the current size
-;;; isn't large enough to hold a single element of element-size
-;;; without bothering to wrap. If it doesn't fit this iteration, it
-;;; won't fit next.
+;;; For :UNBOUNDED SCs just find the smallest correctly aligned offset
+;;; where the TN doesn't conflict with the TNs that have already been
+;;; packed. For :FINITE SCs try to pack the TN into the most heavily
+;;; used locations first (as estimated in FIND-LOCATION-USAGE).
;;;
-;;; ### Note that we actually try to pack as many consecutive TNs as
-;;; possible in the same location, since we start scanning at the same
-;;; offset that the last TN was successfully packed in. This is a
-;;; weakening of the scattering hueristic that was put in to prevent
-;;; restricted VOP temps from hogging all of the registers. This way,
-;;; all of these temps probably end up in one register.
-(defun select-location (tn sc &optional use-reserved-locs)
+;;; Historically SELECT-LOCATION tried did the opposite and tried to
+;;; distribute the TNs evenly across the available locations. At least
+;;; on register-starved architectures (x86) this seems to be a bad
+;;; strategy. -- JES 2004-09-11
+(defun select-location (tn sc &key use-reserved-locs optimize)
(declare (type tn tn) (type sc sc) (inline member))
(let* ((sb (sc-sb sc))
(element-size (sc-element-size sc))
(alignment (sc-alignment sc))
(align-mask (1- alignment))
- (size (finite-sb-current-size sb))
- (start-offset (finite-sb-last-offset sb)))
- (let ((current-start
- (logandc2 (the index (+ start-offset align-mask)) align-mask))
- (wrap-p nil))
- (declare (type index current-start))
- (loop
- (when (> (+ current-start element-size) size)
- (cond ((or wrap-p (> element-size size))
- (return nil))
- (t
- (setq current-start 0)
- (setq wrap-p t))))
-
- (if (or (eq (sb-kind sb) :unbounded)
- (and (member current-start (sc-locations sc))
- (or use-reserved-locs
- (not (member current-start
- (sc-reserve-locations sc))))))
- (dotimes (i element-size
- (return-from select-location current-start))
- (declare (type index i))
- (let ((offset (+ current-start i)))
- (when (offset-conflicts-in-sb tn sb offset)
- (setq current-start
- (logandc2 (the index (+ (the index (1+ offset))
- align-mask))
- align-mask))
- (return))))
- (incf current-start alignment))))))
+ (size (finite-sb-current-size sb)))
+ (flet ((attempt-location (start-offset)
+ (dotimes (i element-size
+ (return-from select-location start-offset))
+ (declare (type index i))
+ (let ((offset (+ start-offset i)))
+ (when (offset-conflicts-in-sb tn sb offset)
+ (return (logandc2 (the index (+ (the index (1+ offset))
+ align-mask))
+ align-mask)))))))
+ (if (eq (sb-kind sb) :unbounded)
+ (loop with offset = 0
+ until (> (+ offset element-size) size) do
+ (setf offset (attempt-location offset)))
+ (let ((locations (sc-locations sc)))
+ (when optimize
+ (setf locations
+ (stable-sort (copy-list locations) #'>
+ :key (lambda (location-offset)
+ (loop for offset from location-offset
+ repeat element-size
+ maximize (svref
+ (finite-sb-always-live-count sb)
+ offset))))))
+ (dolist (offset locations)
+ (when (or use-reserved-locs
+ (not (member offset
+ (sc-reserve-locations sc))))
+ (attempt-location offset))))))))
;;; If a save TN, return the saved TN, otherwise return TN. This is
;;; useful for getting the conflicts of a TN that might be a save TN.
(if (member (tn-kind tn) '(:save :save-once :specified-save))
(tn-save-tn tn)
tn))
-
+\f
;;;; pack interface
;;; Attempt to pack TN in all possible SCs, first in the SC chosen by
;;; If we are attempting to pack in the SC of the save TN for a TN
;;; with a :SPECIFIED-SAVE TN, then we pack in that location, instead
;;; of allocating a new stack location.
-(defun pack-tn (tn restricted)
+(defun pack-tn (tn restricted optimize)
(declare (type tn tn))
(let* ((original (original-tn tn))
(fsc (tn-sc tn))
(when (and save
(eq (tn-kind save) :specified-save))
(tn-sc save))))
-
(do ((sc fsc (pop alternates)))
((null sc)
(failed-to-pack-error tn restricted))
(when (eq sc specified-save-sc)
(unless (tn-offset save)
- (pack-tn save nil))
+ (pack-tn save nil optimize))
(setf (tn-offset tn) (tn-offset save))
(setf (tn-sc tn) (tn-sc save))
(return))
(let ((loc (or (find-ok-target-offset original sc)
(select-location original sc)
(and restricted
- (select-location original sc t))
+ (select-location original sc :use-reserved-locs t))
(when (eq (sb-kind (sc-sb sc)) :unbounded)
(grow-sc sc)
(or (select-location original sc)
(error "failed to pack after growing SC?"))))))
(when loc
- (add-location-conflicts original sc loc)
+ (add-location-conflicts original sc loc optimize)
(setf (tn-sc tn) sc)
(setf (tn-offset tn) loc)
(return))))))
-
(values))
;;; Pack a wired TN, checking that the offset is in bounds for the SB,
;;; and that the TN doesn't conflict with some other TN already packed
;;; in that location. If the TN is wired to a location beyond the end
-;;; of a :Unbounded SB, then grow the SB enough to hold the TN.
+;;; of a :UNBOUNDED SB, then grow the SB enough to hold the TN.
;;;
;;; ### Checking for conflicts is disabled for :SPECIFIED-SAVE TNs.
;;; This is kind of a hack to make specifying wired stack save
;;; locations for local call arguments (such as OLD-FP) work, since
;;; the caller and callee OLD-FP save locations may conflict when the
;;; save locations don't really (due to being in different frames.)
-(defun pack-wired-tn (tn)
+(defun pack-wired-tn (tn optimize)
(declare (type tn tn))
(let* ((sc (tn-sc tn))
(sb (sc-sb sc))
(when (and (not (eq (tn-kind tn) :specified-save))
(conflicts-in-sc original sc offset))
(format t "~&* Pack-wired-tn possible conflict:~% ~
- tn: ~S; tn-kind: ~S~% ~
- sc: ~S~% ~
- sb: ~S; sb-name: ~S; sb-kind: ~S~% ~
- offset: ~S; end: ~S~% ~
- original ~S~% ~
- tn-save-tn: ~S; tn-kind of tn-save-tn: ~S~%"
+ tn: ~S; tn-kind: ~S~% ~
+ sc: ~S~% ~
+ sb: ~S; sb-name: ~S; sb-kind: ~S~% ~
+ offset: ~S; end: ~S~% ~
+ original ~S~% ~
+ tn-save-tn: ~S; tn-kind of tn-save-tn: ~S~%"
tn (tn-kind tn) sc
sb (sb-name sb) (sb-kind sb)
offset end
(conflicts-in-sc original sc offset))
(error "~S is wired to a location that it conflicts with." tn))
- (add-location-conflicts original sc offset)))
+ (add-location-conflicts original sc offset optimize)))
(defevent repack-block "Repacked a block due to TN unpacking.")
-(defun pack (component)
- (aver (not *in-pack*))
- (let ((*in-pack* t)
- (optimize (policy *lexenv*
- (or (>= speed compilation-speed)
- (>= space compilation-speed))))
- (2comp (component-info component)))
- (init-sb-vectors component)
-
- ;; Call the target functions.
- (do-ir2-blocks (block component)
- (do ((vop (ir2-block-start-vop block) (vop-next vop)))
- ((null vop))
- (let ((target-fun (vop-info-target-function (vop-info vop))))
- (when target-fun
- (funcall target-fun vop)))))
-
-
- ;; Pack wired TNs first.
- (do ((tn (ir2-component-wired-tns 2comp) (tn-next tn)))
- ((null tn))
- (pack-wired-tn tn))
-
- ;; Pack restricted component TNs.
- (do ((tn (ir2-component-restricted-tns 2comp) (tn-next tn)))
- ((null tn))
- (when (eq (tn-kind tn) :component)
- (pack-tn tn t)))
-
- ;; Pack other restricted TNs.
- (do ((tn (ir2-component-restricted-tns 2comp) (tn-next tn)))
- ((null tn))
- (unless (tn-offset tn)
- (pack-tn tn t)))
-
- ;; Assign costs to normal TNs so we know which ones should always
- ;; be packed on the stack.
- (when (and optimize *pack-assign-costs*)
- (assign-tn-costs component))
-
- ;; Pack normal TNs in the order that they appear in the code. This
- ;; should have some tendency to pack important TNs first, since
- ;; control analysis favors the drop-through. This should also help
- ;; targeting, since we will pack the target TN soon after we
- ;; determine the location of the targeting TN.
- (do-ir2-blocks (block component)
- (let ((ltns (ir2-block-local-tns block)))
- (do ((i (1- (ir2-block-local-tn-count block)) (1- i)))
- ((minusp i))
- (declare (fixnum i))
- (let ((tn (svref ltns i)))
- (unless (or (null tn) (eq tn :more) (tn-offset tn))
- (pack-tn tn nil))))))
-
- ;; Pack any leftover normal TNs. This is to deal with :MORE TNs,
- ;; which could possibly not appear in any local TN map.
- (do ((tn (ir2-component-normal-tns 2comp) (tn-next tn)))
- ((null tn))
- (unless (tn-offset tn)
- (pack-tn tn nil)))
-
- ;; Do load TN packing and emit saves.
- (let ((*repack-blocks* nil))
- (cond ((and optimize *pack-optimize-saves*)
- (optimized-emit-saves component)
- (do-ir2-blocks (block component)
- (pack-load-tns block)))
- (t
- (do-ir2-blocks (block component)
- (emit-saves block)
- (pack-load-tns block))))
- (when *repack-blocks*
- (loop
- (when (zerop (hash-table-count *repack-blocks*)) (return))
- (maphash #'(lambda (block v)
- (declare (ignore v))
- (remhash block *repack-blocks*)
- (event repack-block)
- (pack-load-tns block))
- *repack-blocks*)))))
+;;; KLUDGE: Prior to SBCL version 0.8.9.xx, this function was known as
+;;; PACK-BEFORE-GC-HOOK, but was non-functional since approximately
+;;; version 0.8.3.xx since the removal of GC hooks from the system.
+;;; This currently (as of 2004-04-12) runs now after every call to
+;;; PACK, rather than -- as was originally intended -- once per GC
+;;; cycle; this is probably non-optimal, and might require tuning,
+;;; maybe to be called when the data structures exceed a certain size,
+;;; or maybe once every N times. The KLUDGE is that this rewrite has
+;;; done nothing to improve the reentrance or threadsafety of the
+;;; compiler; it still fails to be callable from several threads at
+;;; the same time.
+;;;
+;;; Brief experiments indicate that during a compilation cycle this
+;;; causes about 10% more consing, and takes about 1%-2% more time.
+;;;
+;;; -- CSR, 2004-04-12
+(defun clean-up-pack-structures ()
+ (dolist (sb *backend-sb-list*)
+ (unless (eq (sb-kind sb) :non-packed)
+ (let ((size (sb-size sb)))
+ (fill (finite-sb-always-live sb) nil)
+ (setf (finite-sb-always-live sb)
+ (make-array size
+ :initial-element
+ #-sb-xc #*
+ ;; The cross-compiler isn't very good at
+ ;; dumping specialized arrays, so we delay
+ ;; construction of this SIMPLE-BIT-VECTOR
+ ;; until runtime.
+ #+sb-xc (make-array 0 :element-type 'bit)))
+ (setf (finite-sb-always-live-count sb)
+ (make-array size
+ :initial-element
+ #-sb-xc #*
+ ;; Ibid
+ #+sb-xc (make-array 0 :element-type 'fixnum)))
+
+ (fill (finite-sb-conflicts sb) nil)
+ (setf (finite-sb-conflicts sb)
+ (make-array size :initial-element '#()))
+
+ (fill (finite-sb-live-tns sb) nil)
+ (setf (finite-sb-live-tns sb)
+ (make-array size :initial-element nil))))))
- (values))
+(defun pack (component)
+ (unwind-protect
+ (let ((optimize nil)
+ (2comp (component-info component)))
+ (init-sb-vectors component)
+
+ ;; Determine whether we want to do more expensive packing by
+ ;; checking whether any blocks in the component have (> SPEED
+ ;; COMPILE-SPEED).
+ ;;
+ ;; FIXME: This means that a declaration can have a minor
+ ;; effect even outside its scope, and as the packing is done
+ ;; component-globally it'd be tricky to use strict scoping. I
+ ;; think this is still acceptable since it's just a tradeoff
+ ;; between compilation speed and allocation quality and
+ ;; doesn't affect the semantics of the generated code in any
+ ;; way. -- JES 2004-10-06
+ (do-ir2-blocks (block component)
+ (when (policy (block-last (ir2-block-block block))
+ (> speed compilation-speed))
+ (setf optimize t)
+ (return)))
+
+ ;; Call the target functions.
+ (do-ir2-blocks (block component)
+ (do ((vop (ir2-block-start-vop block) (vop-next vop)))
+ ((null vop))
+ (let ((target-fun (vop-info-target-fun (vop-info vop))))
+ (when target-fun
+ (funcall target-fun vop)))))
+
+ ;; Pack wired TNs first.
+ (do ((tn (ir2-component-wired-tns 2comp) (tn-next tn)))
+ ((null tn))
+ (pack-wired-tn tn optimize))
+
+ ;; Pack restricted component TNs.
+ (do ((tn (ir2-component-restricted-tns 2comp) (tn-next tn)))
+ ((null tn))
+ (when (eq (tn-kind tn) :component)
+ (pack-tn tn t optimize)))
+
+ ;; Pack other restricted TNs.
+ (do ((tn (ir2-component-restricted-tns 2comp) (tn-next tn)))
+ ((null tn))
+ (unless (tn-offset tn)
+ (pack-tn tn t optimize)))
+
+ ;; Assign costs to normal TNs so we know which ones should
+ ;; always be packed on the stack.
+ (when *pack-assign-costs*
+ (assign-tn-costs component)
+ (assign-tn-depths component))
+
+ ;; Allocate normal TNs, starting with the TNs that are used
+ ;; in deep loops.
+ (collect ((tns))
+ (do-ir2-blocks (block component)
+ (let ((ltns (ir2-block-local-tns block)))
+ (do ((i (1- (ir2-block-local-tn-count block)) (1- i)))
+ ((minusp i))
+ (declare (fixnum i))
+ (let ((tn (svref ltns i)))
+ (unless (or (null tn)
+ (eq tn :more)
+ (tn-offset tn))
+ ;; If loop analysis has been disabled we might as
+ ;; well revert to the old behaviour of just
+ ;; packing TNs linearly as they appear.
+ (unless *loop-analyze*
+ (pack-tn tn nil optimize))
+ (tns tn))))))
+ (dolist (tn (stable-sort (tns)
+ (lambda (a b)
+ (cond
+ ((> (tn-loop-depth a)
+ (tn-loop-depth b))
+ t)
+ ((= (tn-loop-depth a)
+ (tn-loop-depth b))
+ (> (tn-cost a) (tn-cost b)))
+ (t nil)))))
+ (unless (tn-offset tn)
+ (pack-tn tn nil optimize))))
+
+ ;; Pack any leftover normal TNs. This is to deal with :MORE TNs,
+ ;; which could possibly not appear in any local TN map.
+ (do ((tn (ir2-component-normal-tns 2comp) (tn-next tn)))
+ ((null tn))
+ (unless (tn-offset tn)
+ (pack-tn tn nil optimize)))
+
+ ;; Do load TN packing and emit saves.
+ (let ((*repack-blocks* nil))
+ (cond ((and optimize *pack-optimize-saves*)
+ (optimized-emit-saves component)
+ (do-ir2-blocks (block component)
+ (pack-load-tns block)))
+ (t
+ (do-ir2-blocks (block component)
+ (emit-saves block)
+ (pack-load-tns block))))
+ (when *repack-blocks*
+ (loop
+ (when (zerop (hash-table-count *repack-blocks*)) (return))
+ (maphash (lambda (block v)
+ (declare (ignore v))
+ (remhash block *repack-blocks*)
+ (event repack-block)
+ (pack-load-tns block))
+ *repack-blocks*))))
+
+ (values))
+ (clean-up-pack-structures)))
projects / sbcl.git / blobdiff