X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Fpack.lisp;h=b4c5a67f3863e656c041ddce9500368444af6263;hb=94ea2b2082deaa0331dfb66fa6af6ca12dd8dc83;hp=ef8b22f702d869ff8fb4e6b2aefaf5b14ac94ac1;hpb=cea4896b2482b7b2b429c1631d774b4cfbc0efba;p=sbcl.git diff --git a/src/compiler/pack.lisp b/src/compiler/pack.lisp index ef8b22f..b4c5a67 100644 --- a/src/compiler/pack.lisp +++ b/src/compiler/pack.lisp @@ -24,19 +24,21 @@ ;;;; 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)) @@ -50,7 +52,7 @@ (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)) @@ -76,21 +78,21 @@ (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)) @@ -102,12 +104,12 @@ (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)) @@ -121,9 +123,26 @@ (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))) @@ -133,15 +152,16 @@ (when (ir2-block-number 2block) (return (1+ (ir2-block-number 2block)))))) -;;; 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. +;;; 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) (let ((nblocks (ir2-block-count component))) (dolist (sb *backend-sb-list*) (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) @@ -170,7 +190,8 @@ (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)) @@ -179,15 +200,16 @@ (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 larger, then use that -;;; size. +;;; 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)) (let* ((sb (sc-sb sc)) @@ -204,7 +226,7 @@ (ir2-block-count *component-being-compiled*) (length (the simple-vector (svref conflicts 0)))))) (declare (type index inc new-size)) - (assert (eq (sb-kind sb) :unbounded)) + (aver (eq (sb-kind sb) :unbounded)) (when (> new-size (length conflicts)) (let ((new-conf (make-array new-size))) @@ -231,6 +253,12 @@ :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) @@ -239,45 +267,12 @@ (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*) ;;;; 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)) @@ -285,55 +280,56 @@ (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 we -;;; restricted to pack TN in its SC. +;;; Called when we failed to pack TN. If RESTRICTED is true, then we +;;; are restricted to pack TN in its SC. (defun failed-to-pack-error (tn restricted) (declare (type tn tn)) (let* ((sc (tn-sc tn)) (scs (cons sc (sc-alternate-scs sc)))) (cond (restricted - (error "Failed to pack restricted TN ~S in its SC ~S." + (error "failed to pack restricted TN ~S in its SC ~S" tn (sc-name sc))) (t - (assert (not (find :unbounded scs - :key #'(lambda (x) (sb-kind (sc-sb x)))))) + (aver (not (find :unbounded scs + :key (lambda (x) (sb-kind (sc-sb x)))))) (let ((ptype (tn-primitive-type tn))) (cond (ptype - (assert (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." + (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." (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 Op's VOP. +;;; Return a list of format arguments describing how TN is used in +;;; OP's VOP. (defun describe-tn-use (loc tn op) (let* ((vop (tn-ref-vop op)) (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 @@ -362,8 +358,8 @@ (t `("~2D: not referenced?" ,loc))))) -;;; If load TN packing fails, try to give a helpful error message. We find -;;; a TN in each location that conflicts, and print it. +;;; If load TN packing fails, try to give a helpful error message. We +;;; find a TN in each location that conflicts, and print it. (defun failed-to-pack-load-tn-error (scs op) (declare (list scs) (type tn-ref op)) (collect ((used) @@ -371,7 +367,7 @@ (dolist (sc scs) (let* ((sb (sc-sb sc)) (confs (finite-sb-live-tns sb))) - (assert (eq (sb-kind sb) :finite)) + (aver (eq (sb-kind sb) :finite)) (dolist (el (sc-locations sc)) (declare (type index el)) (let ((conf (load-tn-conflicts-in-sc op sc el t))) @@ -390,23 +386,23 @@ (multiple-value-bind (arg-p n more-p costs load-scs incon) (get-operand-info op) (declare (ignore costs load-scs)) - (assert (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.~]" + (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.~]" (mapcar #'sc-name scs) n arg-p (vop-info-name (vop-info (tn-ref-vop op))) (unused) (used) incon)))) -;;; Called when none of the SCs that we can load Op into are allowed by Op's -;;; primitive-type. +;;; This is called when none of the SCs that we can load OP into are +;;; allowed by OP's primitive-type. (defun no-load-scs-allowed-by-primitive-type-error (ref) (declare (type tn-ref ref)) (let* ((tn (tn-ref-tn ref)) @@ -414,14 +410,14 @@ (multiple-value-bind (arg-p pos more-p costs load-scs incon) (get-operand-info ref) (declare (ignore costs)) - (assert (not more-p)) + (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) @@ -438,22 +434,23 @@ (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))) (dolist (alt (sc-alternate-scs (tn-sc tn)) - (error "No unbounded alternate for SC ~S." + (error "no unbounded alternate for SC ~S" (sc-name (tn-sc tn)))) (when (eq (sb-kind (sc-sb alt)) :unbounded) (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 +;;; Find the load function for moving from SRC to DEST and emit a ;;; MOVE-OPERAND VOP with that function as its info arg. (defun emit-operand-load (node block src dest before) (declare (type node node) (type ir2-block block) @@ -461,30 +458,31 @@ (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)) -;;; Find the preceding use of the VOP NAME in the emit order, starting with -;;; VOP. We must find the VOP in the same IR1 block. +;;; Find the preceding use of the VOP NAME in the emit order, starting +;;; with VOP. We must find the VOP in the same IR1 block. (defun reverse-find-vop (name vop) (do* ((block (vop-block vop) (ir2-block-prev block)) (last vop (ir2-block-last-vop block))) (nil) - (assert (eq (ir2-block-block block) (ir2-block-block (vop-block vop)))) + (aver (eq (ir2-block-block block) (ir2-block-block (vop-block vop)))) (do ((current last (vop-prev current))) ((null current)) (when (eq (vop-info-name (vop-info current)) name) (return-from reverse-find-vop current))))) -;;; For TNs that have other than one writer, we save the TN before each -;;; call. If a local call (MOVE-ARGS is :LOCAL-CALL), then we scan back for -;;; the ALLOCATE-FRAME VOP, and emit the save there. This is necessary because -;;; in a self-recursive local call, the registers holding the current arguments -;;; may get trashed by setting up the call arguments. The ALLOCATE-FRAME VOP -;;; marks a place at which the values are known to be good. +;;; For TNs that have other than one writer, we save the TN before +;;; each call. If a local call (MOVE-ARGS is :LOCAL-CALL), then we +;;; scan back for the ALLOCATE-FRAME VOP, and emit the save there. +;;; This is necessary because in a self-recursive local call, the +;;; registers holding the current arguments may get trashed by setting +;;; up the call arguments. The ALLOCATE-FRAME VOP marks a place at +;;; which the values are known to be good. (defun save-complex-writer-tn (tn vop) (let ((save (or (tn-save-tn tn) (pack-save-tn tn))) @@ -493,7 +491,7 @@ (next (vop-next vop))) (when (eq (tn-kind save) :specified-save) (setf (tn-kind save) :save)) - (assert (eq (tn-kind save) :save)) + (aver (eq (tn-kind save) :save)) (emit-operand-load node block tn save (if (eq (vop-info-move-args (vop-info vop)) :local-call) @@ -501,16 +499,16 @@ 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. For -;;; correctness, it is only required that this location be after any possible -;;; write and before any possible restore location. +;;; 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. ;;; -;;; In practice, we return the unique writer VOP, but give up if the TN is -;;; ever read by a VOP with MOVE-ARGS :LOCAL-CALL. This prevents us from being -;;; confused by non-tail local calls. +;;; In practice, we return the unique writer VOP, but give up if the +;;; TN is ever read by a VOP with MOVE-ARGS :LOCAL-CALL. This prevents +;;; us from being confused by non-tail local calls. ;;; -;;; When looking for writes, we have to ignore uses of MOVE-OPERAND, since they -;;; will correspond to restores that we have already done. +;;; When looking for writes, we have to ignore uses of MOVE-OPERAND, +;;; since they will correspond to restores that we have already done. (defun find-single-writer (tn) (declare (type tn tn)) (do ((write (tn-writes tn) (tn-ref-next write)) @@ -531,8 +529,8 @@ (when res (return nil)) (setq res write)))) -;;; Try to save TN at a single location. If we succeed, return T, otherwise -;;; NIL. +;;; Try to save TN at a single location. If we succeed, return T, +;;; otherwise NIL. (defun save-single-writer-tn (tn) (declare (type tn tn)) (let* ((old-save (tn-save-tn tn)) @@ -550,7 +548,7 @@ (defun restore-single-writer-tn (tn vop) (declare (type tn) (type vop vop)) (let ((save (tn-save-tn tn))) - (assert (eq (tn-kind save) :save-once)) + (aver (eq (tn-kind save) :save-once)) (emit-operand-load (vop-node vop) (vop-block vop) save tn (vop-next vop))) (values)) @@ -567,8 +565,8 @@ (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))) @@ -583,24 +581,25 @@ ;;;; 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 new VOP. +;;; 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 +;;; new VOP. (defun save-if-necessary (tn before context) (declare (type tn tn) (type (or vop null) before) (type vop context)) (let ((save (tn-save-tn tn))) (when (eq (tn-kind save) :specified-save) (setf (tn-kind save) :save)) - (assert (member (tn-kind save) '(:save :save-once))) + (aver (member (tn-kind save) '(:save :save-once))) (unless (eq (tn-kind save) :save-once) (or (save-single-writer-tn tn) (emit-operand-load (vop-node context) (vop-block context) tn save before)))) (values)) -;;; Load the TN from its save location, allocating one if necessary. The -;;; load is inserted Before the specifier VOP. Context is a VOP used to tell -;;; which node/block to use for the new VOP. +;;; Load the TN from its save location, allocating one if necessary. +;;; 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)) (let ((save (or (tn-save-tn tn) (pack-save-tn tn)))) @@ -622,31 +621,33 @@ ) ; EVAL-WHEN -;;; Start scanning backward at the end of Block, looking which TNs are live -;;; and looking for places where we have to save. We manipulate two sets: -;;; SAVES and RESTORES. +;;; Start scanning backward at the end of BLOCK, looking which TNs are +;;; live and looking for places where we have to save. We manipulate +;;; two sets: SAVES and RESTORES. ;;; -;;; SAVES is a set of all the TNs that have to be saved because they are -;;; restored after some call. We normally delay saving until the beginning of -;;; the block, but we must save immediately if we see a write of the saved TN. -;;; We also immediately save all TNs and exit when we see a -;;; NOTE-ENVIRONMENT-START VOP, since saves can't be done before the -;;; environment is properly initialized. +;;; SAVES is a set of all the TNs that have to be saved because they +;;; are restored after some call. We normally delay saving until the +;;; beginning of the block, but we must save immediately if we see a +;;; write of the saved TN. We also immediately save all TNs and exit +;;; when we see a NOTE-ENVIRONMENT-START VOP, since saves can't be +;;; done before the environment is properly initialized. ;;; -;;; RESTORES is a set of all the TNs read (and not written) between here and -;;; the next call, i.e. the set of TNs that must be restored when we reach the -;;; next (earlier) call VOP. Unlike SAVES, this set is cleared when we do -;;; the restoring after a call. Any TNs that were in RESTORES are moved into -;;; SAVES to ensure that they are saved at some point. +;;; RESTORES is a set of all the TNs read (and not written) between +;;; here and the next call, i.e. the set of TNs that must be restored +;;; when we reach the next (earlier) call VOP. Unlike SAVES, this set +;;; is cleared when we do the restoring after a call. Any TNs that +;;; were in RESTORES are moved into SAVES to ensure that they are +;;; saved at some point. ;;; -;;; 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 sets (the initial contents -;;; are ignored.) +;;; 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 +;;; sets (the initial contents are ignored.) ;;; -;;; 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. +;;; 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. (defun optimized-emit-saves-block (block saves restores) (declare (type ir2-block block) (type simple-bit-vector saves restores)) (let ((1block (ir2-block-block block)) @@ -666,7 +667,7 @@ (do ((block block (ir2-block-prev block)) (prev nil block)) ((not (eq (ir2-block-block block) 1block)) - (assert (not skipping)) + (aver (not skipping)) (dolist (save saves-list) (let ((start (ir2-block-start-vop prev))) (save-if-necessary save start start))) @@ -676,10 +677,10 @@ (let ((info (vop-info vop))) (case (vop-info-name info) (allocate-frame - (assert skipping) + (aver skipping) (setq skipping nil)) (note-environment-start - (assert (not skipping)) + (aver (not skipping)) (dolist (save saves-list) (save-if-necessary save (vop-next vop) vop)) (return-from optimized-emit-saves-block block))) @@ -734,11 +735,12 @@ (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 blocks in the component, -;;; which locates blocks that need saving done. + +;;; 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) (declare (type component component)) (let* ((gtn-count (1+ (ir2-component-global-tn-counter @@ -756,10 +758,10 @@ (setq block (optimized-emit-saves-block block saves restores))) (setq block (ir2-block-prev block))))) -;;; Iterate over the normal TNs, finding the cost of packing on the stack in -;;; units of the number of references. We count all references as +1, and -;;; subtract out REGISTER-SAVE-PENALTY for each place where we would have to -;;; save a register. +;;; Iterate over the normal TNs, finding the cost of packing on the +;;; stack in units of the number of references. We count all +;;; references as +1, and subtract out REGISTER-SAVE-PENALTY for each +;;; place where we would have to save a register. (defun assign-tn-costs (component) (do-ir2-blocks (block component) (do ((vop (ir2-block-start-vop block) (vop-next vop))) @@ -780,23 +782,57 @@ ((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)))))))))) + ;;;; 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. +;;; 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. (defvar *live-block*) (defvar *live-vop*) -;;; If we unpack some TNs, then we mark all affected blocks by sticking them in -;;; this hash-table. This is initially null. We create the hashtable if we do -;;; any unpacking. +;;; If we unpack some TNs, then we mark all affected blocks by +;;; sticking them in this hash-table. This is initially null. We +;;; create the hashtable if we do any unpacking. (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) @@ -817,10 +853,11 @@ (values)) -;;; 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. +;;; 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. (defun compute-live-tns (block vop) (declare (type ir2-block block) (type vop vop)) (unless (eq block *live-block*) @@ -851,7 +888,7 @@ (end (+ (tn-offset ltn) (sc-element-size sc)))) ((= offset end)) (declare (type index offset end)) - (assert (null (svref tns offset))))))))) + (aver (null (svref tns offset))))))))) (let* ((tn (tn-ref-tn ref)) (sc (tn-sc tn)) @@ -865,16 +902,16 @@ (if (tn-ref-write-p ref) (setf (svref tns offset) nil) (let ((old (svref tns offset))) - (assert (or (null old) (eq old tn)) (old tn)) + (aver (or (null old) (eq old tn))) (setf (svref tns offset) tn))))))))) (setq *live-vop* vop) (values)) -;;; 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: +;;; 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: ;;; 1. The reference is a result, and the same location is either: ;;; -- Used by some other result. ;;; -- Used in any way after the reference (exclusive). @@ -883,21 +920,22 @@ ;;; -- Used in any way before the reference (exclusive). ;;; ;;; In 1 (and 2) above, the first bullet corresponds to result-result -;;; (and argument-argument) conflicts. We need this case because there aren't -;;; any TN-REFs to represent the implicit reading of results or writing of -;;; arguments. +;;; (and argument-argument) conflicts. We need this case because there +;;; aren't any TN-REFs to represent the implicit reading of results or +;;; writing of arguments. ;;; ;;; The second bullet corresponds conflicts with temporaries or between ;;; arguments and results. ;;; -;;; We consider both the TN-REF-TN and the TN-REF-LOAD-TN (if any) to be -;;; referenced simultaneously and in the same way. This causes load-TNs to -;;; appear live to the beginning (or end) of the VOP, as appropriate. +;;; We consider both the TN-REF-TN and the TN-REF-LOAD-TN (if any) to +;;; be referenced simultaneously and in the same way. This causes +;;; load-TNs to appear live to the beginning (or end) of the VOP, as +;;; appropriate. ;;; ;;; We return a conflicting TN if there is a conflict. (defun load-tn-offset-conflicts-in-sb (op sb offset) (declare (type tn-ref op) (type finite-sb sb) (type index offset)) - (assert (eq (sb-kind sb) :finite)) + (aver (eq (sb-kind sb) :finite)) (let ((vop (tn-ref-vop op))) (labels ((tn-overlaps (tn) (let ((sc (tn-sc tn)) @@ -932,11 +970,11 @@ (is-ref (tn-ref-next-ref op) nil)))))) ;;; Iterate over all the elements in the SB that would be allocated by -;;; allocating a TN in SC at Offset, checking for conflict with load-TNs or -;;; other TNs (live in the LIVE-TNS, which must be set up.) We also return -;;; true if there aren't enough locations after Offset to hold a TN in SC. -;;; If Ignore-Live is true, then we ignore the live-TNs, considering only -;;; references within Op's VOP. +;;; allocating a TN in SC at Offset, checking for conflict with +;;; load-TNs or other TNs (live in the LIVE-TNS, which must be set +;;; up.) We also return true if there aren't enough locations after +;;; Offset to hold a TN in SC. If Ignore-Live is true, then we ignore +;;; the live-TNs, considering only references within Op's VOP. ;;; ;;; We return a conflicting TN, or :OVERFLOW if the TN won't fit. (defun load-tn-conflicts-in-sc (op sc offset ignore-live) @@ -952,16 +990,18 @@ (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 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 now. +;;; 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 +;;; now. ;;; -;;; We require the target to be in SC (and not merely to overlap with SC). -;;; This prevents SC information from being lost in load TNs (we won't pack a -;;; load TN in ANY-REG when it is targeted to a DESCRIPTOR-REG.) This -;;; shouldn't hurt the code as long as all relevant overlapping SCs are allowed -;;; in the operand SC restriction. +;;; We require the target to be in SC (and not merely to overlap with +;;; SC). This prevents SC information from being lost in load TNs (we +;;; won't pack a load TN in ANY-REG when it is targeted to a +;;; DESCRIPTOR-REG.) This shouldn't hurt the code as long as all +;;; relevant overlapping SCs are allowed in the operand SC +;;; restriction. (defun find-load-tn-target (op sc) (declare (inline member)) (let ((target (tn-ref-target op))) @@ -974,8 +1014,9 @@ loc nil))))) -;;; Select a legal location for a load TN for Op in SC. We just iterate -;;; over the SC's locations. If we can't find a legal location, return NIL. +;;; Select a legal location for a load TN for Op in SC. We just +;;; iterate over the SC's locations. If we can't find a legal +;;; location, return NIL. (defun select-load-tn-location (op sc) (declare (type tn-ref op) (type sc sc)) @@ -995,9 +1036,10 @@ (defevent unpack-tn "Unpacked a TN to satisfy operand SC restriction.") -;;; Make TN's location the same as for its save TN (allocating a save TN if -;;; necessary.) Delete any save/restore code that has been emitted thus far. -;;; Mark all blocks containing references as needing to be repacked. +;;; Make TN's location the same as for its save TN (allocating a save +;;; TN if necessary.) Delete any save/restore code that has been +;;; emitted thus far. Mark all blocks containing references as needing +;;; to be repacked. (defun unpack-tn (tn) (event unpack-tn) (let ((stn (or (tn-save-tn tn) @@ -1018,17 +1060,17 @@ (defevent unpack-fallback "Unpacked some operand TN.") -;;; Called by Pack-Load-TN where there isn't any location free that we can -;;; pack into. What we do is move some live TN in one of the specified SCs to -;;; memory, then mark this block all blocks that reference the TN as needing -;;; repacking. If we succeed, we throw to UNPACKED-TN. If we fail, we return -;;; NIL. +;;; This is called by PACK-LOAD-TN where there isn't any location free +;;; that we can pack into. What we do is move some live TN in one of +;;; the specified SCs to memory, then mark this block all blocks that +;;; reference the TN as needing repacking. If we succeed, we throw to +;;; UNPACKED-TN. If we fail, we return NIL. ;;; -;;; We can unpack any live TN that appears in the NORMAL-TNs list (isn't wired -;;; or restricted.) We prefer to unpack TNs that are not used by the VOP. If -;;; we can't find any such TN, then we unpack some argument or result -;;; TN. The only way we can fail is if all locations in SC are used by -;;; load-TNs or temporaries in VOP. +;;; We can unpack any live TN that appears in the NORMAL-TNs list +;;; (isn't wired or restricted.) We prefer to unpack TNs that are not +;;; used by the VOP. If we can't find any such TN, then we unpack some +;;; argument or result TN. The only way we can fail is if all +;;; locations in SC are used by load-TNs or temporaries in VOP. (defun unpack-for-load-tn (sc op) (declare (type sc sc) (type tn-ref op)) (let ((sb (sc-sb sc)) @@ -1074,17 +1116,18 @@ nil) -;;; Try to pack a load TN in the SCs indicated by Load-SCs. If we run out -;;; of SCs, then we unpack some TN and try again. We return the packed load -;;; TN. +;;; Try to pack a load TN in the SCs indicated by Load-SCs. If we run +;;; out of SCs, then we unpack some TN and try again. We return the +;;; packed load TN. ;;; -;;; Note: we allow a Load-TN to be packed in the target location even if that -;;; location is in a SC not allowed by the primitive type. (The SC must still -;;; be allowed by the operand restriction.) This makes move VOPs more -;;; efficient, since we won't do a move from the stack into a non-descriptor -;;; any-reg though a descriptor argument load-TN. This does give targeting -;;; some real semantics, making it not a pure advisory to pack. It allows pack -;;; to do some packing it wouldn't have done before. +;;; Note: we allow a Load-TN to be packed in the target location even +;;; if that location is in a SC not allowed by the primitive type. +;;; (The SC must still be allowed by the operand restriction.) This +;;; makes move VOPs more efficient, since we won't do a move from the +;;; stack into a non-descriptor any-reg though a descriptor argument +;;; load-TN. This does give targeting some real semantics, making it +;;; not a pure advisory to pack. It allows pack to do some packing it +;;; wouldn't have done before. (defun pack-load-tn (load-scs op) (declare (type sc-vector load-scs) (type tn-ref op)) (let ((vop (tn-ref-vop op))) @@ -1115,11 +1158,11 @@ (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 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. +;;; 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. #!-sb-fluid (declaim (inline check-operand-restrictions)) (defun check-operand-restrictions (scs ops) (declare (list scs) (type (or tn-ref null) ops)) @@ -1135,7 +1178,7 @@ (sc-number (tn-sc (or load-tn (tn-ref-tn op))))))) (if load-tn - (assert (eq load-scs t)) + (aver (eq load-scs t)) (unless (eq load-scs t) (setf (tn-ref-load-tn op) (pack-load-tn (car scs) op)))))))) @@ -1150,16 +1193,16 @@ (sc-number (tn-sc (or load-tn (tn-ref-tn op))))))) (if load-tn - (assert (eq load-scs t)) + (aver (eq load-scs t)) (unless (eq load-scs t) (setf (tn-ref-load-tn op) (pack-load-tn (car scs) op)))))))) (values)) -;;; 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. +;;; 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) (catch 'unpacked-tn (let ((*live-block* nil) @@ -1173,30 +1216,34 @@ (vop-args vop)))))) (values)) -;;;; 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. +;;; 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. (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))) @@ -1206,102 +1253,97 @@ loc 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 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)))) - +;;; 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 +;;; 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. +;;; +;;; 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)))) + ;;;; 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. +;;; Select some location for TN in SC, returning the offset if we +;;; 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)))))) - -;;; If a save TN, return the saved TN, otherwise return TN. Useful for -;;; getting the conflicts of a TN that might be a save TN. + (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. (defun original-tn (tn) (declare (type tn tn)) (if (member (tn-kind tn) '(:save :save-once :specified-save)) (tn-save-tn tn) tn)) - + ;;;; pack interface ;;; Attempt to pack TN in all possible SCs, first in the SC chosen by @@ -1314,7 +1356,7 @@ ;;; 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)) @@ -1324,13 +1366,12 @@ (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)) @@ -1339,30 +1380,29 @@ (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?")))))) + (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. +;;; 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. ;;; -;;; ### 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) +;;; ### 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 optimize) (declare (type tn tn)) (let* ((sc (tn-sc tn)) (sb (sc-sb sc)) @@ -1374,37 +1414,37 @@ (error "~S is wired to a location that is out of bounds." tn)) (grow-sc sc end)) - ;; For non-x86 ports the presence of a save-tn associated with a tn is used - ;; to identify the old-fp and return-pc tns. It depends on the old-fp and - ;; return-pc being passed in registers. - #!-x86 + ;; For non-x86 ports the presence of a save-tn associated with a + ;; tn is used to identify the old-fp and return-pc tns. It depends + ;; on the old-fp and return-pc being passed in registers. + #!-(or x86 x86-64) (when (and (not (eq (tn-kind tn) :specified-save)) (conflicts-in-sc original sc offset)) (error "~S is wired to a location that it conflicts with." tn)) - ;; Use the above check, but only print a verbose warning. This can be - ;; helpful for debugging the x86 port. + ;; Use the above check, but only print a verbose warning. This can + ;; be helpful for debugging the x86 port. #+nil (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 original (tn-save-tn tn) (tn-kind (tn-save-tn tn)))) - ;; On the x86 ports the old-fp and return-pc are often passed on the stack - ;; so the above hack for the other ports does not always work. Here the - ;; old-fp and return-pc tns are identified by being on the stack in their - ;; standard save locations. - #!+x86 + ;; On the x86 ports the old-fp and return-pc are often passed on + ;; the stack so the above hack for the other ports does not always + ;; work. Here the old-fp and return-pc tns are identified by being + ;; on the stack in their standard save locations. + #!+(or x86 x86-64) (when (and (not (eq (tn-kind tn) :specified-save)) (not (and (string= (sb-name sb) "STACK") (or (= offset 0) @@ -1412,87 +1452,166 @@ (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) - (assert (not *in-pack*)) - (let ((*in-pack* t) - (optimize (policy nil (or (>= speed cspeed) (>= space cspeed)))) - (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)))