(delete-block block))))
(values))
-;;; Move all the code and entry points from Old to New. The code in
-;;; Old is inserted at the head of New. This is also called during let
-;;; conversion when we are about in insert the body of a let in a
+;;; Move all the code and entry points from OLD to NEW. The code in
+;;; OLD is inserted at the head of NEW. This is also called during LET
+;;; conversion when we are about in insert the body of a LET in a
;;; different component. [A local call can be to a different component
;;; before FIND-INITIAL-DFO runs.]
(declaim (ftype (function (component component) (values)) join-components))
(link-blocks head ep)))
(values))
-;;; Do a depth-first walk from Block, inserting ourself in the DFO
-;;; after Head. If we somehow find ourselves in another component,
+;;; Do a depth-first walk from BLOCK, inserting ourself in the DFO
+;;; after HEAD. If we somehow find ourselves in another component,
;;; then we join that component to our component.
(declaim (ftype (function (cblock cblock component) (values)) find-dfo-aux))
(defun find-dfo-aux (block head component)
(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:
-;;; -- If the block is in the initial component, then do DFO-Walk-Call-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.
-;;; -- If the home function is deleted, do nothing. Block must eventually be
-;;; discovered to be unreachable as well. This can happen when we have a
-;;; NLX into a function with no references. The escape function still has
-;;; refs (in the deleted function).
+;;; 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:
+
+;;; -- If the block is in the initial component, then do
+;;; DFO-WALK-CALL-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.
+;;; -- If the home function is deleted, do nothing. BLOCK must
+;;; eventually be discovered to be unreachable as well. This can
+;;; happen when we have a NLX into a function with no references.
+;;; The escape function still has refs (in the deleted function).
;;;
-;;; This ensures that all the blocks in a given environment will be in 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.
+;;; This ensures that all the blocks in a given environment will be in
+;;; 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)
(declare (type cblock block) (type component component))
(let ((home (block-home-lambda block)))
(join-components home-component component)
home-component))))))
-;;; Somewhat similar to Find-DFO-Aux, except that it merges the current
-;;; component with any strange component, rather than the other way around.
-;;; This is more efficient in the common case where the current component
-;;; doesn't have much stuff in it.
+;;; This is somewhat similar to FIND-DFO-AUX, except that it merges
+;;; the current component with any strange component, rather than the
+;;; other way around. This is more efficient in the common case where
+;;; the current component doesn't have much stuff in it.
;;;
-;;; We return the current component as a result, allowing the caller to
-;;; detect when the old current component has been merged with another.
+;;; We return the current component as a result, allowing the caller
+;;; to detect when the old current component has been merged with
+;;; another.
;;;
-;;; We walk blocks in initial components as though they were already in the
-;;; current component, moving them to the current component in the process.
-;;; The blocks are inserted at the head of the current component.
+;;; We walk blocks in initial components as though they were already
+;;; in the current component, moving them to the current component in
+;;; the process. The blocks are inserted at the head of the current
+;;; component.
(defun find-initial-dfo-aux (block component)
(declare (type cblock block) (type component component))
(let ((this (block-component block)))
(add-to-dfo block (component-head current))
current)))))
-;;; Return a list of all the home lambdas that reference Fun (may contain
-;;; duplications).
+;;; Return a list of all the home lambdas that reference FUN (may
+;;; contain duplications).
;;;
-;;; 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 component. All other references must
-;;; cause components to be joined.
+;;; 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
+;;; component. (And now that HAS-EXTERNAL-REFERENCES-P-ness
+;;; generalizes :TOP-LEVEL-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.
+;;; References in deleted functions are also ignored, since this code
+;;; will be deleted eventually.
(defun find-reference-functions (fun)
(collect ((res))
(dolist (ref (leaf-refs fun))
(let* ((home (node-home-lambda ref))
- (home-kind (functional-kind home)))
- (unless (or (and (eq home-kind :top-level)
+ (home-kind (functional-kind home))
+ (home-externally-visible-p
+ (or (eq home-kind :top-level)
+ (functional-has-external-references-p home))))
+ (unless (or (and home-externally-visible-p
(eq (functional-kind fun) :external))
(eq home-kind :deleted))
(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.
+;;; 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 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 harmless to
-;;; move the tail (even though the return might be unreachable) because if the
-;;; return is unreachable it (and its successor link) will be deleted in the
-;;; post-deletion pass.
+;;; 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
+;;; harmless to move the tail (even though the return might be
+;;; 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
-;;; 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 returned.
+;;; We then do a FIND-DFO-AUX starting at the head of FUN. 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
+;;; 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 component would have been
-;;; changed).
+;;; 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
+;;; component would have been changed).
;;;
-;;; if the function is an XEP, then we also walk all functions that contain
-;;; references to the XEP. This is done so that environment analysis doesn't
-;;; need to cross component boundaries. This also 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.
+;;; If the function is an XEP, then we also walk all functions that
+;;; contain references to the XEP. This is done so that environment
+;;; analysis doesn't need to cross component boundaries. This also
+;;; 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)))
((null funs) res)
(declare (type component res))))))))
-;;; Return true if Fun is either an XEP or has EXITS to some of its ENTRIES.
+;;; 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)
(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 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.
+;;; 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
+;;; 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)
(declare (list components))
(collect ((real)
(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)))
- (cond ((or (find-if #'has-xep-or-nlx funs)
+ (has-top (find :top-level 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
+ ;; 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
+ has-external-references
+ (setf (component-kind com) :complex-top-level)
+ (real com)
+ (real-top com))
+ ((or (some #'has-xep-or-nlx funs)
(and has-top (rest funs)))
(setf (component-name com) (find-component-name com))
(real com)
(values (real) (top) (real-top))))
-;;; Given a list of top-level lambdas, return three lists of components
-;;; representing the actual component division:
+;;; 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.
;;;
-;;; We assign the DFO for each component, and delete any unreachable blocks.
-;;; We assume that the Flags have already been cleared.
+;;; 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.
+;;; 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.
+;;; 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))
(collect ((components))
(defun merge-1-tl-lambda (result-lambda lambda)
(declare (type clambda result-lambda lambda))
- ;; Delete the lambda, and combine the lets and entries.
+ ;; 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)
(block-component (node-block (lambda-bind result-lambda))))
(result-return-block (node-block (lambda-return result-lambda))))
- ;; Move blocks into the new component, and move any nodes directly in
- ;; the old lambda into the new one (lets implicitly moved by changing
- ;; their home.)
+ ;; Move blocks into the new COMPONENT, and move any nodes directly
+ ;; in the old LAMBDA into the new one (with LETs implicitly moved
+ ;; by changing their home.)
(do-blocks (block component)
(do-nodes (node cont block)
(let ((lexenv (node-lexenv node)))
(setf (lexenv-lambda lexenv) result-lambda))))
(setf (block-component block) result-component))
- ;; Splice the blocks into the new DFO, and unlink them from the old
- ;; component head and tail. Non-return blocks that jump to the tail
- ;; (NIL returning calls) are switched to go to the new tail.
+ ;; Splice the blocks into the new DFO, and unlink them from the
+ ;; old component head and tail. Non-return blocks that jump to the
+ ;; tail (NIL-returning calls) are switched to go to the new tail.
(let* ((head (component-head component))
(first (block-next head))
(tail (component-tail component))
(link-blocks pred bind-block))
(unlink-node bind)
- ;; 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.
+ ;; 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.
(let ((return (lambda-return lambda)))
(when return
(let ((return-block (node-block return))
(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 the first lambda
-;;; and its component, putting the other code in that component and deleting
-;;; the other lambdas.
+;;; 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)
(declare (cons lambdas))
(let* ((result-lambda (first lambdas))
(cond
(result-return
- ;; Make sure the result's return node starts a block so that we can
- ;; splice code in before it.
+ ;; Make sure the result's return node starts a block so that we
+ ;; can splice code in before it.
(let ((prev (node-prev
(continuation-use
(return-result result-return)))))
projects / sbcl.git / blobdiff