X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Fdfo.lisp;h=ca91eab36dcd08d462e3948ff815b0a34036b24c;hb=09957fcf57b49ed5ae5f05d62ad12d7ddbfd8e1d;hp=f312dff9f7967a3f9d144db3aaaca8e0c828247a;hpb=416152f084604094445a758ff399871132dff2bd;p=sbcl.git diff --git a/src/compiler/dfo.lisp b/src/compiler/dfo.lisp index f312dff..ca91eab 100644 --- a/src/compiler/dfo.lisp +++ b/src/compiler/dfo.lisp @@ -25,7 +25,6 @@ (unless (block-flag ep) (find-dfo-aux ep head component) (return nil)))))) - (let ((num 0)) (declare (fixnum num)) (do-blocks-backwards (block component :both) @@ -69,10 +68,10 @@ (setf (component-lambdas new) (nconc (component-lambdas old) (component-lambdas new))) - (setf (component-lambdas old) ()) - (setf (component-new-functions new) - (nconc (component-new-functions old) (component-new-functions new))) - (setf (component-new-functions old) ()) + (setf (component-lambdas old) nil) + (setf (component-new-funs new) (nconc (component-new-funs old) + (component-new-funs new)) + (component-new-funs old) nil) (dolist (xp (block-pred old-tail)) (unlink-blocks xp old-tail) @@ -89,22 +88,19 @@ (defun find-dfo-aux (block head component) (unless (eq (block-component block) component) (join-components component (block-component block))) - (unless (block-flag block) (setf (block-flag block) t) (dolist (succ (block-succ block)) (find-dfo-aux succ head component)) - (remove-from-dfo block) (add-to-dfo block head)) (values)) ;;; This function is called on each block by FIND-INITIAL-DFO-AUX -;;; before it walks the successors. It looks at the home lambda's bind -;;; block to see whether that block is in some other component: - +;;; before it walks the successors. It looks at the home CLAMBDA's +;;; BIND block to see whether that block is in some other component: ;;; -- If the block is in the initial component, then do -;;; DFO-WALK-CALL-GRAPH on the home function to move it +;;; DFO-SCAVENGE-DEPENDENCY-GRAPH on the home function to move it ;;; into COMPONENT. ;;; -- If the block is in some other component, join COMPONENT into ;;; it and return that component. @@ -117,15 +113,14 @@ ;;; the same component, even when they might not seem reachable from ;;; the environment entry. Consider the case of code that is only ;;; reachable from a non-local exit. -(defun walk-home-call-graph (block component) +(defun scavenge-home-dependency-graph (block component) (declare (type cblock block) (type component component)) - (let ((home (block-home-lambda block))) - (if (eq (functional-kind home) :deleted) + (let ((home-lambda (block-home-lambda block))) + (if (eq (functional-kind home-lambda) :deleted) component - (let* ((bind-block (node-block (lambda-bind home))) - (home-component (block-component bind-block))) + (let ((home-component (lambda-component home-lambda))) (cond ((eq (component-kind home-component) :initial) - (dfo-walk-call-graph home component)) + (dfo-scavenge-dependency-graph home-lambda component)) ((eq home-component component) component) (t @@ -156,10 +151,9 @@ ((block-flag block) component) (t (setf (block-flag block) t) - (let ((current (walk-home-call-graph block component))) + (let ((current (scavenge-home-dependency-graph block component))) (dolist (succ (block-succ block)) (setq current (find-initial-dfo-aux succ current))) - (remove-from-dfo block) (add-to-dfo block (component-head current)) current))))) @@ -170,21 +164,21 @@ ;;; References to functions which local call analysis could not (or ;;; were chosen not) to local call convert will appear as references ;;; to XEP lambdas. We can ignore references to XEPs that appear in -;;; :TOP-LEVEL components, since environment analysis goes to special -;;; effort to allow closing over of values from a separate top-level +;;; :TOPLEVEL components, since environment analysis goes to special +;;; effort to allow closing over of values from a separate top level ;;; component. (And now that HAS-EXTERNAL-REFERENCES-P-ness -;;; generalizes :TOP-LEVEL-ness, we ignore those too.) All other +;;; generalizes :TOPLEVEL-ness, we ignore those too.) All other ;;; references must cause components to be joined. ;;; ;;; References in deleted functions are also ignored, since this code ;;; will be deleted eventually. -(defun find-reference-functions (fun) +(defun find-reference-funs (fun) (collect ((res)) (dolist (ref (leaf-refs fun)) (let* ((home (node-home-lambda ref)) (home-kind (functional-kind home)) (home-externally-visible-p - (or (eq home-kind :top-level) + (or (eq home-kind :toplevel) (functional-has-external-references-p home)))) (unless (or (and home-externally-visible-p (eq (functional-kind fun) :external)) @@ -192,9 +186,17 @@ (res home)))) (res))) -;;; Move the code for FUN and all functions called by it into -;;; COMPONENT. If FUN is already in COMPONENT, then we just return -;;; that component. +;;; If CLAMBDA is not already in COMPONENT, just return that +;;; component. Otherwise, move the code for CLAMBDA and all lambdas it +;;; physically depends on (either because of calls or because of +;;; closure relationships) into COMPONENT, or possibly into another +;;; COMPONENT that we find to be related. Return whatever COMPONENT we +;;; actually merged into. +;;; +;;; (Note: The analogous CMU CL code only scavenged call-based +;;; dependencies, not closure dependencies. That seems to've been by +;;; oversight, not by design, as per the bug reported by WHN on +;;; cmucl-imp ca. 2001-11-29 and explained by DTC shortly after.) ;;; ;;; If the function is in an initial component, then we move its head ;;; and tail to COMPONENT and add it to COMPONENT's lambdas. It is @@ -202,16 +204,16 @@ ;;; unreachable) because if the return is unreachable it (and its ;;; successor link) will be deleted in the post-deletion pass. ;;; -;;; We then do a FIND-DFO-AUX starting at the head of FUN. If this +;;; We then do a FIND-DFO-AUX starting at the head of CLAMBDA. If this ;;; flow-graph walk encounters another component (which can only ;;; happen due to a non-local exit), then we move code into that ;;; component instead. We then recurse on all functions called from -;;; FUN, moving code into whichever component the preceding call +;;; CLAMBDA, moving code into whichever component the preceding call ;;; returned. ;;; -;;; If FUN is in the initial component, but the BLOCK-FLAG is set in -;;; the bind block, then we just return COMPONENT, since we must have -;;; already reached this function in the current walk (or the +;;; If CLAMBDA is in the initial component, but the BLOCK-FLAG is set +;;; in the bind block, then we just return COMPONENT, since we must +;;; have already reached this function in the current walk (or the ;;; component would have been changed). ;;; ;;; If the function is an XEP, then we also walk all functions that @@ -220,153 +222,213 @@ ;;; ensures that conversion of a full call to a local call won't ;;; result in a need to join components, since the components will ;;; already be one. -(defun dfo-walk-call-graph (fun component) - (declare (type clambda fun) (type component component)) - (let* ((bind-block (node-block (lambda-bind fun))) - (this (block-component bind-block)) - (return (lambda-return fun))) +(defun dfo-scavenge-dependency-graph (clambda component) + (declare (type clambda clambda) (type component component)) + (assert (not (eql (lambda-kind clambda) :deleted))) + (let* ((bind-block (node-block (lambda-bind clambda))) + (old-lambda-component (block-component bind-block)) + (return (lambda-return clambda))) (cond - ((eq this component) component) - ((not (eq (component-kind this) :initial)) - (join-components this component) - this) + ((eq old-lambda-component component) + component) + ((not (eq (component-kind old-lambda-component) :initial)) + (join-components old-lambda-component component) + old-lambda-component) ((block-flag bind-block) component) (t - (push fun (component-lambdas component)) - (setf (component-lambdas this) - (delete fun (component-lambdas this))) + (push clambda (component-lambdas component)) + (setf (component-lambdas old-lambda-component) + (delete clambda (component-lambdas old-lambda-component))) (link-blocks (component-head component) bind-block) - (unlink-blocks (component-head this) bind-block) + (unlink-blocks (component-head old-lambda-component) bind-block) (when return (let ((return-block (node-block return))) (link-blocks return-block (component-tail component)) - (unlink-blocks return-block (component-tail this)))) - (let ((calls (if (eq (functional-kind fun) :external) - (append (find-reference-functions fun) - (lambda-calls fun)) - (lambda-calls fun)))) - (do ((res (find-initial-dfo-aux bind-block component) - (dfo-walk-call-graph (first funs) res)) - (funs calls (rest funs))) - ((null funs) res) - (declare (type component res)))))))) - -;;; Return true if FUN is either an XEP or has EXITS to some of its -;;; ENTRIES. -(defun has-xep-or-nlx (fun) - (declare (type clambda fun)) - (or (eq (functional-kind fun) :external) - (let ((entries (lambda-entries fun))) + (unlink-blocks return-block (component-tail old-lambda-component)))) + (let ((res (find-initial-dfo-aux bind-block component))) + (declare (type component res)) + ;; Scavenge related lambdas. + (labels ((scavenge-lambda (clambda) + (setf res + (dfo-scavenge-dependency-graph (lambda-home clambda) + res))) + (scavenge-possibly-deleted-lambda (clambda) + (unless (eql (lambda-kind clambda) :deleted) + (scavenge-lambda clambda))) + ;; Scavenge call relationship. + (scavenge-call (called-lambda) + (scavenge-lambda called-lambda)) + ;; Scavenge closure over a variable: if CLAMBDA + ;; refers to a variable whose home lambda is not + ;; CLAMBDA, then the home lambda should be in the + ;; same component as CLAMBDA. (sbcl-0.6.13, and CMU + ;; CL, didn't do this, leading to the occasional + ;; failure when physenv analysis, which is local to + ;; each component, would bogusly conclude that a + ;; closed-over variable was unused and thus delete + ;; it. See e.g. cmucl-imp 2001-11-29.) + (scavenge-closure-var (var) + (unless (null (lambda-var-refs var)) ; unless var deleted + (let ((var-home-home (lambda-home (lambda-var-home var)))) + (scavenge-possibly-deleted-lambda var-home-home)))) + ;; Scavenge closure over an entry for nonlocal exit. + ;; This is basically parallel to closure over a + ;; variable above. + (scavenge-entry (entry) + (declare (type entry entry)) + (let ((entry-home (node-home-lambda entry))) + (scavenge-possibly-deleted-lambda entry-home)))) + (dolist (cc (lambda-calls-or-closes clambda)) + (etypecase cc + (clambda (scavenge-call cc)) + (lambda-var (scavenge-closure-var cc)) + (entry (scavenge-entry cc)))) + (when (eq (lambda-kind clambda) :external) + (mapc #'scavenge-call (find-reference-funs clambda)))) + ;; Voila. + res))))) + +;;; Return true if CLAMBDA either is an XEP or has EXITS to some of +;;; its ENTRIES. +(defun has-xep-or-nlx (clambda) + (declare (type clambda clambda)) + (or (eq (functional-kind clambda) :external) + (let ((entries (lambda-entries clambda))) (and entries (find-if #'entry-exits entries))))) ;;; Compute the result of FIND-INITIAL-DFO given the list of all -;;; resulting components. Components with a :TOP-LEVEL lambda, but no -;;; normal XEPs or potential non-local exits are marked as :TOP-LEVEL. -;;; If there is a :TOP-LEVEL lambda, and also a normal XEP, then we +;;; resulting components. Components with a :TOPLEVEL lambda, but no +;;; normal XEPs or potential non-local exits are marked as :TOPLEVEL. +;;; If there is a :TOPLEVEL lambda, and also a normal XEP, then we ;;; treat the component as normal, but also return such components in ;;; a list as the third value. Components with no entry of any sort ;;; are deleted. -(defun find-top-level-components (components) +(defun separate-toplevelish-components (components) (declare (list components)) (collect ((real) (top) (real-top)) - (dolist (com components) - (unless (eq (block-next (component-head com)) (component-tail com)) - (let* ((funs (component-lambdas com)) - (has-top (find :top-level funs :key #'functional-kind)) + (dolist (component components) + (unless (eq (block-next (component-head component)) + (component-tail component)) + (let* ((funs (component-lambdas component)) + (has-top (find :toplevel funs :key #'functional-kind)) (has-external-references (some #'functional-has-external-references-p funs))) (cond (;; The FUNCTIONAL-HAS-EXTERNAL-REFERENCES-P concept ;; is newer than the rest of this function, and ;; doesn't really seem to fit into its mindset. Here ;; we mark components which contain such FUNCTIONs - ;; them as :COMPLEX-TOP-LEVEL, since they do get + ;; them as :COMPLEX-TOPLEVEL, since they do get ;; executed at run time, and since it's not valid to ;; delete them just because they don't have any - ;; references from pure :TOP-LEVEL components. -- WHN + ;; references from pure :TOPLEVEL components. -- WHN has-external-references - (setf (component-kind com) :complex-top-level) - (real com) - (real-top com)) + (setf (component-kind component) :complex-toplevel) + (real component) + (real-top component)) ((or (some #'has-xep-or-nlx funs) (and has-top (rest funs))) - (setf (component-name com) (find-component-name com)) - (real com) + (setf (component-name component) + (find-component-name component)) + (real component) (when has-top - (setf (component-kind com) :complex-top-level) - (real-top com))) + (setf (component-kind component) :complex-toplevel) + (real-top component))) (has-top - (setf (component-kind com) :top-level) - (setf (component-name com) "top-level form") - (top com)) + (setf (component-kind component) :toplevel) + (setf (component-name component) "top level form") + (top component)) (t - (delete-component com)))))) + (delete-component component)))))) (values (real) (top) (real-top)))) -;;; Given a list of top-level lambdas, return three lists of -;;; components representing the actual component division: -;;; 1. the non-top-level components, -;;; 2. and the second is the top-level components, and -;;; 3. Components in [1] that also have a top-level lambda. +;; COMPONENTs want strings for names, LEAF-DEBUG-NAMEs mightn't be +;; strings.. +(defun component-name-from-functional-debug-name (functional) + (declare (type functional functional)) + (let ((leaf-debug-name (leaf-debug-name functional))) + (the simple-string + (if (stringp leaf-debug-name) + leaf-debug-name + (debug-namify "function ~S" leaf-debug-name))))) + +;;; Given a list of top level lambdas, return +;;; (VALUES NONTOP-COMPONENTS TOP-COMPONENTS HAIRY-TOP-COMPONENTS). +;;; Each of the three values returned is a list of COMPONENTs: +;;; NONTOP-COMPONENTS = non-top-level-ish COMPONENTs; +;;; TOP-COMPONENTS = top-level-ish COMPONENTs; +;;; HAIRY-TOP-COMPONENTS = a subset of NONTOP-COMPONENTS, those +;;; elements which include a top-level-ish lambda. ;;; ;;; We assign the DFO for each component, and delete any unreachable -;;; blocks. We assume that the Flags have already been cleared. -;;; -;;; We iterate over the lambdas in each initial component, trying to -;;; put each function in its own component, but joining it to an -;;; existing component if we find that there are references between -;;; them. Any code that is left in an initial component must be -;;; unreachable, so we can delete it. Stray links to the initial -;;; component tail (due NIL function terminated blocks) are moved to -;;; the appropriate newc component tail. -;;; -;;; When we are done, we assign DFNs and call -;;; FIND-TOP-LEVEL-COMPONENTS to pull out top-level code. -(defun find-initial-dfo (lambdas) - (declare (list lambdas)) +;;; blocks. We assume that the FLAGS have already been cleared. +(defun find-initial-dfo (toplevel-lambdas) + (declare (list toplevel-lambdas)) (collect ((components)) - (let ((new (make-empty-component))) - (dolist (tll lambdas) - (let ((component (block-component (node-block (lambda-bind tll))))) - (dolist (fun (component-lambdas component)) - (aver (member (functional-kind fun) - '(:optional :external :top-level nil :escape - :cleanup))) - (let ((res (dfo-walk-call-graph fun new))) - (when (eq res new) - (components new) - (setq new (make-empty-component))))) - (when (eq (component-kind component) :initial) - (aver (null (component-lambdas component))) - (let ((tail (component-tail component))) - (dolist (pred (block-pred tail)) - (let ((pred-component (block-component pred))) - (unless (eq pred-component component) - (unlink-blocks pred tail) - (link-blocks pred (component-tail pred-component)))))) - (delete-component component))))) - - (dolist (com (components)) + ;; We iterate over the lambdas in each initial component, trying + ;; to put each function in its own component, but joining it to + ;; an existing component if we find that there are references + ;; between them. Any code that is left in an initial component + ;; must be unreachable, so we can delete it. Stray links to the + ;; initial component tail (due NIL function terminated blocks) + ;; are moved to the appropriate new component tail. + (dolist (toplevel-lambda toplevel-lambdas) + (let* ((old-component (lambda-component toplevel-lambda)) + (old-component-lambdas (component-lambdas old-component)) + (new-component nil)) + (aver (member toplevel-lambda old-component-lambdas)) + (dolist (component-lambda old-component-lambdas) + (aver (member (functional-kind component-lambda) + '(:optional :external :toplevel nil :escape + :cleanup))) + (unless new-component + (setf new-component (make-empty-component)) + (setf (component-name new-component) + ;; This isn't necessarily an ideal name for the + ;; component, since it might end up with multiple + ;; lambdas in it, not just this one, but it does + ;; seem a better name than just "". + (component-name-from-functional-debug-name + component-lambda))) + (let ((res (dfo-scavenge-dependency-graph component-lambda + new-component))) + (when (eq res new-component) + (aver (not (position new-component (components)))) + (components new-component) + (setq new-component nil)))) + (when (eq (component-kind old-component) :initial) + (aver (null (component-lambdas old-component))) + (let ((tail (component-tail old-component))) + (dolist (pred (block-pred tail)) + (let ((pred-component (block-component pred))) + (unless (eq pred-component old-component) + (unlink-blocks pred tail) + (link-blocks pred (component-tail pred-component)))))) + (delete-component old-component)))) + + ;; When we are done, we assign DFNs. + (dolist (component (components)) (let ((num 0)) (declare (fixnum num)) - (do-blocks-backwards (block com :both) + (do-blocks-backwards (block component :both) (setf (block-number block) (incf num))))) - (find-top-level-components (components)))) + ;; Pull out top-level-ish code. + (separate-toplevelish-components (components)))) ;;; Insert the code in LAMBDA at the end of RESULT-LAMBDA. -(defun merge-1-tl-lambda (result-lambda lambda) +(defun merge-1-toplevel-lambda (result-lambda lambda) (declare (type clambda result-lambda lambda)) ;; Delete the lambda, and combine the LETs and entries. (setf (functional-kind lambda) :deleted) (dolist (let (lambda-lets lambda)) (setf (lambda-home let) result-lambda) - (setf (lambda-environment let) (lambda-environment result-lambda)) + (setf (lambda-physenv let) (lambda-physenv result-lambda)) (push let (lambda-lets result-lambda))) (setf (lambda-entries result-lambda) (nconc (lambda-entries result-lambda) @@ -375,8 +437,7 @@ (let* ((bind (lambda-bind lambda)) (bind-block (node-block bind)) (component (block-component bind-block)) - (result-component - (block-component (node-block (lambda-bind result-lambda)))) + (result-component (lambda-component result-lambda)) (result-return-block (node-block (lambda-return result-lambda)))) ;; Move blocks into the new COMPONENT, and move any nodes directly @@ -423,7 +484,7 @@ ;; If there is a return, then delete it (making the preceding node ;; the last node) and link the block to the result return. There - ;; is always a preceding REF NIL node in top-level lambdas. + ;; is always a preceding REF NIL node in top level lambdas. (let ((return (lambda-return lambda))) (when return (let ((return-block (node-block return)) @@ -433,11 +494,11 @@ (delete-continuation result) (link-blocks return-block result-return-block)))))) -;;; Given a non-empty list of top-level LAMBDAs, smash them into a -;;; top-level lambda and component, returning these as values. We use +;;; Given a non-empty list of top level LAMBDAs, smash them into a +;;; top level lambda and component, returning these as values. We use ;;; the first lambda and its component, putting the other code in that ;;; component and deleting the other lambdas. -(defun merge-top-level-lambdas (lambdas) +(defun merge-toplevel-lambdas (lambdas) (declare (cons lambdas)) (let* ((result-lambda (first lambdas)) (result-return (lambda-return result-lambda))) @@ -457,13 +518,10 @@ (add-continuation-use use new)))) (dolist (lambda (rest lambdas)) - (merge-1-tl-lambda result-lambda lambda))) + (merge-1-toplevel-lambda result-lambda lambda))) (t (dolist (lambda (rest lambdas)) - (setf (functional-entry-function lambda) nil) - (delete-component - (block-component - (node-block (lambda-bind lambda))))))) + (setf (functional-entry-fun lambda) nil) + (delete-component (lambda-component lambda))))) - (values (block-component (node-block (lambda-bind result-lambda))) - result-lambda))) + (values (lambda-component result-lambda) result-lambda)))