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;;;; This file contains miscellaneous utilities used for manipulating
;;;; the IR1 representation.
;;;; This software is part of the SBCL system. See the README file for
;;;; more information.
;;;;
;;;; This software is derived from the CMU CL system, which was
;;;; written at Carnegie Mellon University and released into the
;;;; public domain. The software is in the public domain and is
;;;; provided with absolutely no warranty. See the COPYING and CREDITS
;;;; files for more information.
(in-package "SB!C")
;;;; cleanup hackery
;;; Return the innermost cleanup enclosing NODE, or NIL if there is
;;; none in its function. If NODE has no cleanup, but is in a LET,
;;; then we must still check the environment that the call is in.
(defun node-enclosing-cleanup (node)
(declare (type node node))
(do ((lexenv (node-lexenv node)
(lambda-call-lexenv (lexenv-lambda lexenv))))
((null lexenv) nil)
(let ((cup (lexenv-cleanup lexenv)))
(when cup (return cup)))))
;;; Convert the FORM in a block inserted between BLOCK1 and BLOCK2 as
;;; an implicit MV-PROG1. The inserted block is returned. NODE is used
;;; for IR1 context when converting the form. Note that the block is
;;; not assigned a number, and is linked into the DFO at the
;;; beginning. We indicate that we have trashed the DFO by setting
;;; COMPONENT-REANALYZE. If CLEANUP is supplied, then convert with
;;; that cleanup.
(defun insert-cleanup-code (block1 block2 node form &optional cleanup)
(declare (type cblock block1 block2) (type node node)
(type (or cleanup null) cleanup))
(setf (component-reanalyze (block-component block1)) t)
(with-ir1-environment-from-node node
(with-component-last-block (*current-component*
(block-next (component-head *current-component*)))
(let* ((start (make-continuation))
(block (continuation-starts-block start))
(cont (make-continuation))
(*lexenv* (if cleanup
(make-lexenv :cleanup cleanup)
*lexenv*)))
(change-block-successor block1 block2 block)
(link-blocks block block2)
(ir1-convert start cont form)
(setf (block-last block) (continuation-use cont))
block))))
;;;; continuation use hacking
;;; Return a list of all the nodes which use Cont.
(declaim (ftype (function (continuation) list) find-uses))
(defun find-uses (cont)
(ecase (continuation-kind cont)
((:block-start :deleted-block-start)
(block-start-uses (continuation-block cont)))
(:inside-block (list (continuation-use cont)))
(:unused nil)
(:deleted nil)))
(defun principal-continuation-use (cont)
(let ((use (continuation-use cont)))
(if (cast-p use)
(principal-continuation-use (cast-value use))
use)))
;;; Update continuation use information so that NODE is no longer a
;;; use of its CONT. If the old continuation doesn't start its block,
;;; then we don't update the BLOCK-START-USES, since it will be
;;; deleted when we are done.
;;;
;;; Note: if you call this function, you may have to do a
;;; REOPTIMIZE-CONTINUATION to inform IR1 optimization that something
;;; has changed.
(declaim (ftype (function (node) (values)) delete-continuation-use))
(defun delete-continuation-use (node)
(let* ((cont (node-cont node))
(block (continuation-block cont)))
(ecase (continuation-kind cont)
(:deleted)
((:block-start :deleted-block-start)
(let ((uses (delete node (block-start-uses block))))
(setf (block-start-uses block) uses)
(setf (continuation-use cont)
(if (cdr uses) nil (car uses)))))
(:inside-block
(setf (continuation-kind cont) :unused)
(setf (continuation-block cont) nil)
(setf (continuation-use cont) nil)
(setf (continuation-next cont) nil)))
(setf (node-cont node) nil))
(values))
;;; Update continuation use information so that NODE uses CONT. If
;;; CONT is :UNUSED, then we set its block to NODE's NODE-BLOCK (which
;;; must be set.)
;;;
;;; Note: if you call this function, you may have to do a
;;; REOPTIMIZE-CONTINUATION to inform IR1 optimization that something
;;; has changed.
(declaim (ftype (function (node continuation) (values)) add-continuation-use))
(defun add-continuation-use (node cont)
(aver (not (node-cont node)))
(let ((block (continuation-block cont)))
(ecase (continuation-kind cont)
(:deleted)
(:unused
(aver (not block))
(let ((block (node-block node)))
(aver block)
(setf (continuation-block cont) block))
(setf (continuation-kind cont) :inside-block)
(setf (continuation-use cont) node))
((:block-start :deleted-block-start)
(let ((uses (cons node (block-start-uses block))))
(setf (block-start-uses block) uses)
(setf (continuation-use cont)
(if (cdr uses) nil (car uses)))
(let ((block (node-block node)))
(unless (block-last block)
(setf (block-last block) node)))))))
(setf (node-cont node) cont)
(values))
;;; Return true if CONT is the NODE-CONT for NODE and CONT is
;;; transferred to immediately after the evaluation of NODE.
(defun immediately-used-p (cont node)
(declare (type continuation cont) (type node node))
(and (eq (node-cont node) cont)
(not (eq (continuation-kind cont) :deleted))
(let ((cblock (continuation-block cont))
(nblock (node-block node)))
(or (eq cblock nblock)
(let ((succ (block-succ nblock)))
(and (= (length succ) 1)
(eq (first succ) cblock)))))))
;;;; continuation substitution
;;; In OLD's DEST, replace OLD with NEW. NEW's DEST must initially be
;;; NIL. When we are done, we call FLUSH-DEST on OLD to clear its DEST
;;; and to note potential optimization opportunities.
(defun substitute-continuation (new old)
(declare (type continuation old new))
(aver (not (continuation-dest new)))
(let ((dest (continuation-dest old)))
(etypecase dest
((or ref bind))
(cif (setf (if-test dest) new))
(cset (setf (set-value dest) new))
(creturn (setf (return-result dest) new))
(exit (setf (exit-value dest) new))
(basic-combination
(if (eq old (basic-combination-fun dest))
(setf (basic-combination-fun dest) new)
(setf (basic-combination-args dest)
(nsubst new old (basic-combination-args dest)))))
(cast (setf (cast-value dest) new))
(null))
(when dest (flush-dest old))
(setf (continuation-dest new) dest)
(flush-continuation-externally-checkable-type new))
(values))
;;; Replace all uses of OLD with uses of NEW, where NEW has an
;;; arbitary number of uses. If NEW will end up with more than one
;;; use, then we must arrange for it to start a block if it doesn't
;;; already.
(defun substitute-continuation-uses (new old)
(declare (type continuation old new))
(unless (and (eq (continuation-kind new) :unused)
(eq (continuation-kind old) :inside-block))
(ensure-block-start new))
(do-uses (node old)
(delete-continuation-use node)
(add-continuation-use node new))
(dolist (lexenv-use (continuation-lexenv-uses old)) ; FIXME - APD
(setf (cadr lexenv-use) new))
(reoptimize-continuation new)
(values))
;;;; block starting/creation
;;; Return the block that CONT is the start of, making a block if
;;; necessary. This function is called by IR1 translators which may
;;; cause a continuation to be used more than once. Every continuation
;;; which may be used more than once must start a block by the time
;;; that anyone does a USE-CONTINUATION on it.
;;;
;;; We also throw the block into the next/prev list for the
;;; *CURRENT-COMPONENT* so that we keep track of which blocks we have
;;; made.
(defun continuation-starts-block (cont)
(declare (type continuation cont))
(ecase (continuation-kind cont)
(:unused
(aver (not (continuation-block cont)))
(let* ((next (component-last-block *current-component*))
(prev (block-prev next))
(new-block (make-block cont)))
(setf (block-next new-block) next
(block-prev new-block) prev
(block-prev next) new-block
(block-next prev) new-block
(continuation-block cont) new-block
(continuation-use cont) nil
(continuation-kind cont) :block-start)
new-block))
(:block-start
(continuation-block cont))))
;;; Ensure that CONT is the start of a block (or deleted) so that
;;; the use set can be freely manipulated.
;;; -- If the continuation is :UNUSED or is :INSIDE-BLOCK and the
;;; CONT of LAST in its block, then we make it the start of a new
;;; deleted block.
;;; -- If the continuation is :INSIDE-BLOCK inside a block, then we
;;; split the block using NODE-ENDS-BLOCK, which makes the
;;; continuation be a :BLOCK-START.
(defun ensure-block-start (cont)
(declare (type continuation cont))
(let ((kind (continuation-kind cont)))
(ecase kind
((:deleted :block-start :deleted-block-start))
((:unused :inside-block)
(let ((block (continuation-block cont)))
(cond ((or (eq kind :unused)
(eq (node-cont (block-last block)) cont))
(setf (continuation-block cont)
(make-block-key :start cont
:component nil
:start-uses (find-uses cont)))
(setf (continuation-kind cont) :deleted-block-start))
(t
(node-ends-block (continuation-use cont))))))))
(values))
;;;;
;;; Filter values of CONT with a destination through FORM, which must
;;; be an ordinary/mv call. First argument must be 'DUMMY, which will
;;; be replaced with CONT. In case of an ordinary call the function
;;; should not have return type NIL.
;;;
;;; TODO: remove preconditions.
(defun filter-continuation (cont form)
(declare (type continuation cont) (type list form))
(let ((dest (continuation-dest cont)))
(declare (type node dest))
(with-ir1-environment-from-node dest
;; Ensuring that CONT starts a block lets us freely manipulate its uses.
(ensure-block-start cont)
;; Make a new continuation and move CONT's uses to it.
(let ((new-start (make-continuation))
(prev (node-prev dest)))
(continuation-starts-block new-start)
(substitute-continuation-uses new-start cont)
;; Make the DEST node start its block so that we can splice in
;; the LAMBDA code.
(when (continuation-use prev)
(node-ends-block (continuation-use prev)))
(let* ((prev-block (continuation-block prev))
(new-block (continuation-block new-start))
(dummy (make-continuation)))
;; Splice in the new block before DEST, giving the new block
;; all of DEST's predecessors.
(dolist (block (block-pred prev-block))
(change-block-successor block prev-block new-block))
;; Convert the lambda form, using the new block start as
;; START and a dummy continuation as CONT.
(ir1-convert new-start dummy form)
;; TODO: Why should this be true? -- WHN 19990601
;;
;; It is somehow related to the precondition of non-NIL
;; return type of the function. -- APD 2003-3-24
(aver (eq (continuation-block dummy) new-block))
;; KLUDGE: Comments at the head of this function in CMU CL
;; said that somewhere in here we
;; Set the new block's start and end cleanups to the *start*
;; cleanup of PREV's block. This overrides the incorrect
;; default from WITH-IR1-ENVIRONMENT-FROM-NODE.
;; Unfortunately I can't find any code which corresponds to this.
;; Perhaps it was a stale comment? Or perhaps I just don't
;; understand.. -- WHN 19990521
(let ((node (continuation-use dummy)))
(setf (block-last new-block) node)
;; Change the use to a use of CONT. (We need to use the
;; dummy continuation to get the control transfer right,
;; because we want to go to PREV's block, not CONT's.)
(delete-continuation-use node)
(add-continuation-use node cont))
;; Link the new block to PREV's block.
(link-blocks new-block prev-block))
;; Replace 'DUMMY with the new continuation. (We can find
;; 'DUMMY because no LET conversion has been done yet.) The
;; [mv-]combination code from the call in the form will be the
;; use of the new check continuation. We substitute for the
;; first argument of this node.
(let* ((node (continuation-use cont))
(args (basic-combination-args node))
(victim (first args)))
(aver (eq (constant-value (ref-leaf (continuation-use victim)))
'dummy))
(substitute-continuation new-start victim)))
;; Invoking local call analysis converts this call to a LET.
(locall-analyze-component *current-component*)
(values))))
;;;; miscellaneous shorthand functions
;;; Return the home (i.e. enclosing non-LET) CLAMBDA for NODE. Since
;;; the LEXENV-LAMBDA may be deleted, we must chain up the
;;; LAMBDA-CALL-LEXENV thread until we find a CLAMBDA that isn't
;;; deleted, and then return its home.
(defun node-home-lambda (node)
(declare (type node node))
(do ((fun (lexenv-lambda (node-lexenv node))
(lexenv-lambda (lambda-call-lexenv fun))))
((not (eq (functional-kind fun) :deleted))
(lambda-home fun))
(when (eq (lambda-home fun) fun)
(return fun))))
(defun node-block (node)
(declare (type node node))
(the cblock (continuation-block (node-prev node))))
(defun node-component (node)
(declare (type node node))
(block-component (node-block node)))
(defun node-physenv (node)
(declare (type node node))
(the physenv (lambda-physenv (node-home-lambda node))))
(defun lambda-block (clambda)
(declare (type clambda clambda))
(node-block (lambda-bind clambda)))
(defun lambda-component (clambda)
(block-component (lambda-block clambda)))
;;; Return the enclosing cleanup for environment of the first or last
;;; node in BLOCK.
(defun block-start-cleanup (block)
(declare (type cblock block))
(node-enclosing-cleanup (continuation-next (block-start block))))
(defun block-end-cleanup (block)
(declare (type cblock block))
(node-enclosing-cleanup (block-last block)))
;;; Return the non-LET LAMBDA that holds BLOCK's code, or NIL
;;; if there is none.
;;;
;;; There can legitimately be no home lambda in dead code early in the
;;; IR1 conversion process, e.g. when IR1-converting the SETQ form in
;;; (BLOCK B (RETURN-FROM B) (SETQ X 3))
;;; where the block is just a placeholder during parsing and doesn't
;;; actually correspond to code which will be written anywhere.
(declaim (ftype (sfunction (cblock) (or clambda null)) block-home-lambda-or-null))
(defun block-home-lambda-or-null (block)
(if (node-p (block-last block))
;; This is the old CMU CL way of doing it.
(node-home-lambda (block-last block))
;; Now that SBCL uses this operation more aggressively than CMU
;; CL did, the old CMU CL way of doing it can fail in two ways.
;; 1. It can fail in a few cases even when a meaningful home
;; lambda exists, e.g. in IR1-CONVERT of one of the legs of
;; an IF.
;; 2. It can fail when converting a form which is born orphaned
;; so that it never had a meaningful home lambda, e.g. a form
;; which follows a RETURN-FROM or GO form.
(let ((pred-list (block-pred block)))
;; To deal with case 1, we reason that
;; previous-in-target-execution-order blocks should be in the
;; same lambda, and that they seem in practice to be
;; previous-in-compilation-order blocks too, so we look back
;; to find one which is sufficiently initialized to tell us
;; what the home lambda is.
(if pred-list
;; We could get fancy about this, flooding through the
;; graph of all the previous blocks, but in practice it
;; seems to work just to grab the first previous block and
;; use it.
(node-home-lambda (block-last (first pred-list)))
;; In case 2, we end up with an empty PRED-LIST and
;; have to punt: There's no home lambda.
nil))))
;;; Return the non-LET LAMBDA that holds BLOCK's code.
(defun block-home-lambda (block)
(the clambda
(block-home-lambda-or-null block)))
;;; Return the IR1 physical environment for BLOCK.
(defun block-physenv (block)
(declare (type cblock block))
(lambda-physenv (block-home-lambda block)))
;;; Return the Top Level Form number of PATH, i.e. the ordinal number
;;; of its original source's top level form in its compilation unit.
(defun source-path-tlf-number (path)
(declare (list path))
(car (last path)))
;;; Return the (reversed) list for the PATH in the original source
;;; (with the Top Level Form number last).
(defun source-path-original-source (path)
(declare (list path) (inline member))
(cddr (member 'original-source-start path :test #'eq)))
;;; Return the Form Number of PATH's original source inside the Top
;;; Level Form that contains it. This is determined by the order that
;;; we walk the subforms of the top level source form.
(defun source-path-form-number (path)
(declare (list path) (inline member))
(cadr (member 'original-source-start path :test #'eq)))
;;; Return a list of all the enclosing forms not in the original
;;; source that converted to get to this form, with the immediate
;;; source for node at the start of the list.
(defun source-path-forms (path)
(subseq path 0 (position 'original-source-start path)))
;;; Return the innermost source form for NODE.
(defun node-source-form (node)
(declare (type node node))
(let* ((path (node-source-path node))
(forms (source-path-forms path)))
(if forms
(first forms)
(values (find-original-source path)))))
;;; Return NODE-SOURCE-FORM, T if continuation has a single use,
;;; otherwise NIL, NIL.
(defun continuation-source (cont)
(let ((use (continuation-use cont)))
(if use
(values (node-source-form use) t)
(values nil nil))))
;;; Return the LAMBDA that is CONT's home, or NIL if there is none.
(declaim (ftype (sfunction (continuation) (or clambda null))
continuation-home-lambda-or-null))
(defun continuation-home-lambda-or-null (cont)
;; KLUDGE: This function is a post-CMU-CL hack by WHN, and this
;; implementation might not be quite right, or might be uglier than
;; necessary. It appears that the original Python never found a need
;; to do this operation. The obvious things based on
;; NODE-HOME-LAMBDA of CONTINUATION-USE usually work; then if that
;; fails, BLOCK-HOME-LAMBDA of CONTINUATION-BLOCK works, given that
;; we generalize it enough to grovel harder when the simple CMU CL
;; approach fails, and furthermore realize that in some exceptional
;; cases it might return NIL. -- WHN 2001-12-04
(cond ((continuation-use cont)
(node-home-lambda (continuation-use cont)))
((continuation-block cont)
(block-home-lambda-or-null (continuation-block cont)))
(t
(bug "confused about home lambda for ~S"))))
;;; Return the LAMBDA that is CONT's home.
(defun continuation-home-lambda (cont)
(the clambda
(continuation-home-lambda-or-null cont)))
#!-sb-fluid (declaim (inline continuation-single-value-p))
(defun continuation-single-value-p (cont)
(not (typep (continuation-dest cont)
'(or creturn exit mv-combination cast))))
;;; Return a new LEXENV just like DEFAULT except for the specified
;;; slot values. Values for the alist slots are NCONCed to the
;;; beginning of the current value, rather than replacing it entirely.
(defun make-lexenv (&key (default *lexenv*)
funs vars blocks tags
type-restrictions weakend-type-restrictions
(lambda (lexenv-lambda default))
(cleanup (lexenv-cleanup default))
(policy (lexenv-policy default)))
(macrolet ((frob (var slot)
`(let ((old (,slot default)))
(if ,var
(nconc ,var old)
old))))
(internal-make-lexenv
(frob funs lexenv-funs)
(frob vars lexenv-vars)
(frob blocks lexenv-blocks)
(frob tags lexenv-tags)
(frob type-restrictions lexenv-type-restrictions)
(frob weakend-type-restrictions lexenv-weakend-type-restrictions)
lambda cleanup policy)))
;;; Makes a LEXENV, suitable for using in a MACROLET introduced
;;; macroexpander
(defun make-restricted-lexenv (lexenv)
(flet ((fun-good-p (fun)
(destructuring-bind (name . thing) fun
(declare (ignore name))
(etypecase thing
(functional nil)
(global-var t)
(cons (aver (eq (car thing) 'macro))
t))))
(var-good-p (var)
(destructuring-bind (name . thing) var
(declare (ignore name))
(etypecase thing
(leaf nil)
(cons (aver (eq (car thing) 'macro))
t)
(heap-alien-info nil)))))
(internal-make-lexenv
(remove-if-not #'fun-good-p (lexenv-funs lexenv))
(remove-if-not #'var-good-p (lexenv-vars lexenv))
nil
nil
(lexenv-type-restrictions lexenv) ; XXX
(lexenv-weakend-type-restrictions lexenv)
nil
nil
(lexenv-policy lexenv))))
;;;; flow/DFO/component hackery
;;; Join BLOCK1 and BLOCK2.
(defun link-blocks (block1 block2)
(declare (type cblock block1 block2))
(setf (block-succ block1)
(if (block-succ block1)
(%link-blocks block1 block2)
(list block2)))
(push block1 (block-pred block2))
(values))
(defun %link-blocks (block1 block2)
(declare (type cblock block1 block2) (inline member))
(let ((succ1 (block-succ block1)))
(aver (not (member block2 succ1 :test #'eq)))
(cons block2 succ1)))
;;; This is like LINK-BLOCKS, but we separate BLOCK1 and BLOCK2. If
;;; this leaves a successor with a single predecessor that ends in an
;;; IF, then set BLOCK-TEST-MODIFIED so that any test constraint will
;;; now be able to be propagated to the successor.
(defun unlink-blocks (block1 block2)
(declare (type cblock block1 block2))
(let ((succ1 (block-succ block1)))
(if (eq block2 (car succ1))
(setf (block-succ block1) (cdr succ1))
(do ((succ (cdr succ1) (cdr succ))
(prev succ1 succ))
((eq (car succ) block2)
(setf (cdr prev) (cdr succ)))
(aver succ))))
(let ((new-pred (delq block1 (block-pred block2))))
(setf (block-pred block2) new-pred)
(when (and new-pred (null (rest new-pred)))
(let ((pred-block (first new-pred)))
(when (if-p (block-last pred-block))
(setf (block-test-modified pred-block) t)))))
(values))
;;; Swing the succ/pred link between BLOCK and OLD to be between BLOCK
;;; and NEW. If BLOCK ends in an IF, then we have to fix up the
;;; consequent/alternative blocks to point to NEW. We also set
;;; BLOCK-TEST-MODIFIED so that any test constraint will be applied to
;;; the new successor.
(defun change-block-successor (block old new)
(declare (type cblock new old block) (inline member))
(unlink-blocks block old)
(let ((last (block-last block))
(comp (block-component block)))
(setf (component-reanalyze comp) t)
(typecase last
(cif
(setf (block-test-modified block) t)
(let* ((succ-left (block-succ block))
(new (if (and (eq new (component-tail comp))
succ-left)
(first succ-left)
new)))
(unless (member new succ-left :test #'eq)
(link-blocks block new))
(macrolet ((frob (slot)
`(when (eq (,slot last) old)
(setf (,slot last) new))))
(frob if-consequent)
(frob if-alternative)
(when (eq (if-consequent last)
(if-alternative last))
(setf (component-reoptimize (block-component block)) t)))))
(t
(unless (member new (block-succ block) :test #'eq)
(link-blocks block new)))))
(values))
;;; Unlink a block from the next/prev chain. We also null out the
;;; COMPONENT.
(declaim (ftype (function (cblock) (values)) remove-from-dfo))
(defun remove-from-dfo (block)
(let ((next (block-next block))
(prev (block-prev block)))
(setf (block-component block) nil)
(setf (block-next prev) next)
(setf (block-prev next) prev))
(values))
;;; Add BLOCK to the next/prev chain following AFTER. We also set the
;;; COMPONENT to be the same as for AFTER.
(defun add-to-dfo (block after)
(declare (type cblock block after))
(let ((next (block-next after))
(comp (block-component after)))
(aver (not (eq (component-kind comp) :deleted)))
(setf (block-component block) comp)
(setf (block-next after) block)
(setf (block-prev block) after)
(setf (block-next block) next)
(setf (block-prev next) block))
(values))
;;; Set the FLAG for all the blocks in COMPONENT to NIL, except for
;;; the head and tail which are set to T.
(declaim (ftype (function (component) (values)) clear-flags))
(defun clear-flags (component)
(let ((head (component-head component))
(tail (component-tail component)))
(setf (block-flag head) t)
(setf (block-flag tail) t)
(do-blocks (block component)
(setf (block-flag block) nil)))
(values))
;;; Make a component with no blocks in it. The BLOCK-FLAG is initially
;;; true in the head and tail blocks.
(declaim (ftype (function nil component) make-empty-component))
(defun make-empty-component ()
(let* ((head (make-block-key :start nil :component nil))
(tail (make-block-key :start nil :component nil))
(res (make-component head tail)))
(setf (block-flag head) t)
(setf (block-flag tail) t)
(setf (block-component head) res)
(setf (block-component tail) res)
(setf (block-next head) tail)
(setf (block-prev tail) head)
res))
;;; Make NODE the LAST node in its block, splitting the block if necessary.
;;; The new block is added to the DFO immediately following NODE's block.
(defun node-ends-block (node)
(declare (type node node))
(let* ((block (node-block node))
(start (node-cont node))
(last (block-last block))
(last-cont (node-cont last)))
(unless (eq last node)
(aver (and (eq (continuation-kind start) :inside-block)
(not (block-delete-p block))))
(let* ((succ (block-succ block))
(new-block
(make-block-key :start start
:component (block-component block)
:start-uses (list (continuation-use start))
:succ succ :last last)))
(setf (continuation-kind start) :block-start)
(dolist (b succ)
(setf (block-pred b)
(cons new-block (remove block (block-pred b)))))
(setf (block-succ block) ())
(setf (block-last block) node)
(link-blocks block new-block)
(add-to-dfo new-block block)
(setf (component-reanalyze (block-component block)) t)
(do ((cont start (node-cont (continuation-next cont))))
((eq cont last-cont)
(when (eq (continuation-kind last-cont) :inside-block)
(setf (continuation-block last-cont) new-block)))
(setf (continuation-block cont) new-block))
(setf (block-type-asserted block) t)
(setf (block-test-modified block) t))))
(values))
;;;; deleting stuff
;;; Deal with deleting the last (read) reference to a LAMBDA-VAR.
(defun delete-lambda-var (leaf)
(declare (type lambda-var leaf))
;; Iterate over all local calls flushing the corresponding argument,
;; allowing the computation of the argument to be deleted. We also
;; mark the LET for reoptimization, since it may be that we have
;; deleted its last variable.
(let* ((fun (lambda-var-home leaf))
(n (position leaf (lambda-vars fun))))
(dolist (ref (leaf-refs fun))
(let* ((cont (node-cont ref))
(dest (continuation-dest cont)))
(when (and (combination-p dest)
(eq (basic-combination-fun dest) cont)
(eq (basic-combination-kind dest) :local))
(let* ((args (basic-combination-args dest))
(arg (elt args n)))
(reoptimize-continuation arg)
(flush-dest arg)
(setf (elt args n) nil))))))
;; The LAMBDA-VAR may still have some SETs, but this doesn't cause
;; too much difficulty, since we can efficiently implement
;; write-only variables. We iterate over the SETs, marking their
;; blocks for dead code flushing, since we can delete SETs whose
;; value is unused.
(dolist (set (lambda-var-sets leaf))
(setf (block-flush-p (node-block set)) t))
(values))
;;; Note that something interesting has happened to VAR.
(defun reoptimize-lambda-var (var)
(declare (type lambda-var var))
(let ((fun (lambda-var-home var)))
;; We only deal with LET variables, marking the corresponding
;; initial value arg as needing to be reoptimized.
(when (and (eq (functional-kind fun) :let)
(leaf-refs var))
(do ((args (basic-combination-args
(continuation-dest
(node-cont
(first (leaf-refs fun)))))
(cdr args))
(vars (lambda-vars fun) (cdr vars)))
((eq (car vars) var)
(reoptimize-continuation (car args))))))
(values))
;;; Delete a function that has no references. This need only be called
;;; on functions that never had any references, since otherwise
;;; DELETE-REF will handle the deletion.
(defun delete-functional (fun)
(aver (and (null (leaf-refs fun))
(not (functional-entry-fun fun))))
(etypecase fun
(optional-dispatch (delete-optional-dispatch fun))
(clambda (delete-lambda fun)))
(values))
;;; Deal with deleting the last reference to a CLAMBDA. Since there is
;;; only one way into a CLAMBDA, deleting the last reference to a
;;; CLAMBDA ensures that there is no way to reach any of the code in
;;; it. So we just set the FUNCTIONAL-KIND for FUN and its LETs to
;;; :DELETED, causing IR1 optimization to delete blocks in that
;;; CLAMBDA.
(defun delete-lambda (clambda)
(declare (type clambda clambda))
(let ((original-kind (functional-kind clambda))
(bind (lambda-bind clambda)))
(aver (not (member original-kind '(:deleted :optional :toplevel))))
(aver (not (functional-has-external-references-p clambda)))
(setf (functional-kind clambda) :deleted)
(setf (lambda-bind clambda) nil)
(dolist (let (lambda-lets clambda))
(setf (lambda-bind let) nil)
(setf (functional-kind let) :deleted))
;; LET may be deleted if its BIND is unreachable. Autonomous
;; function may be deleted if it has no reachable references.
(unless (member original-kind '(:let :mv-let :assignment))
(dolist (ref (lambda-refs clambda))
(mark-for-deletion (node-block ref))))
;; (The IF test is (FUNCTIONAL-SOMEWHAT-LETLIKE-P CLAMBDA), except
;; that we're using the old value of the KIND slot, not the
;; current slot value, which has now been set to :DELETED.)
(if (member original-kind '(:let :mv-let :assignment))
(let ((home (lambda-home clambda)))
(setf (lambda-lets home) (delete clambda (lambda-lets home))))
;; If the function isn't a LET, we unlink the function head
;; and tail from the component head and tail to indicate that
;; the code is unreachable. We also delete the function from
;; COMPONENT-LAMBDAS (it won't be there before local call
;; analysis, but no matter.) If the lambda was never
;; referenced, we give a note.
(let* ((bind-block (node-block bind))
(component (block-component bind-block))
(return (lambda-return clambda))
(return-block (and return (node-block return))))
(unless (leaf-ever-used clambda)
(let ((*compiler-error-context* bind))
(compiler-note "deleting unused function~:[.~;~:*~% ~S~]"
(leaf-debug-name clambda))))
(unless (block-delete-p bind-block)
(unlink-blocks (component-head component) bind-block))
(when (and return-block (not (block-delete-p return-block)))
(mark-for-deletion return-block)
(unlink-blocks return-block (component-tail component)))
(setf (component-reanalyze component) t)
(let ((tails (lambda-tail-set clambda)))
(setf (tail-set-funs tails)
(delete clambda (tail-set-funs tails)))
(setf (lambda-tail-set clambda) nil))
(setf (component-lambdas component)
(delete clambda (component-lambdas component)))))
;; If the lambda is an XEP, then we null out the ENTRY-FUN in its
;; ENTRY-FUN so that people will know that it is not an entry
;; point anymore.
(when (eq original-kind :external)
(let ((fun (functional-entry-fun clambda)))
(setf (functional-entry-fun fun) nil)
(when (optional-dispatch-p fun)
(delete-optional-dispatch fun)))))
(values))
;;; Deal with deleting the last reference to an OPTIONAL-DISPATCH. We
;;; have to be a bit more careful than with lambdas, since DELETE-REF
;;; is used both before and after local call analysis. Afterward, all
;;; references to still-existing OPTIONAL-DISPATCHes have been moved
;;; to the XEP, leaving it with no references at all. So we look at
;;; the XEP to see whether an optional-dispatch is still really being
;;; used. But before local call analysis, there are no XEPs, and all
;;; references are direct.
;;;
;;; When we do delete the OPTIONAL-DISPATCH, we grovel all of its
;;; entry-points, making them be normal lambdas, and then deleting the
;;; ones with no references. This deletes any e-p lambdas that were
;;; either never referenced, or couldn't be deleted when the last
;;; reference was deleted (due to their :OPTIONAL kind.)
;;;
;;; Note that the last optional entry point may alias the main entry,
;;; so when we process the main entry, its KIND may have been changed
;;; to NIL or even converted to a LETlike value.
(defun delete-optional-dispatch (leaf)
(declare (type optional-dispatch leaf))
(let ((entry (functional-entry-fun leaf)))
(unless (and entry (leaf-refs entry))
(aver (or (not entry) (eq (functional-kind entry) :deleted)))
(setf (functional-kind leaf) :deleted)
(flet ((frob (fun)
(unless (eq (functional-kind fun) :deleted)
(aver (eq (functional-kind fun) :optional))
(setf (functional-kind fun) nil)
(let ((refs (leaf-refs fun)))
(cond ((null refs)
(delete-lambda fun))
((null (rest refs))
(or (maybe-let-convert fun)
(maybe-convert-to-assignment fun)))
(t
(maybe-convert-to-assignment fun)))))))
(dolist (ep (optional-dispatch-entry-points leaf))
(frob ep))
(when (optional-dispatch-more-entry leaf)
(frob (optional-dispatch-more-entry leaf)))
(let ((main (optional-dispatch-main-entry leaf)))
(when (eq (functional-kind main) :optional)
(frob main))))))
(values))
;;; Do stuff to delete the semantic attachments of a REF node. When
;;; this leaves zero or one reference, we do a type dispatch off of
;;; the leaf to determine if a special action is appropriate.
(defun delete-ref (ref)
(declare (type ref ref))
(let* ((leaf (ref-leaf ref))
(refs (delete ref (leaf-refs leaf))))
(setf (leaf-refs leaf) refs)
(cond ((null refs)
(typecase leaf
(lambda-var
(delete-lambda-var leaf))
(clambda
(ecase (functional-kind leaf)
((nil :let :mv-let :assignment :escape :cleanup)
(aver (null (functional-entry-fun leaf)))
(delete-lambda leaf))
(:external
(delete-lambda leaf))
((:deleted :optional))))
(optional-dispatch
(unless (eq (functional-kind leaf) :deleted)
(delete-optional-dispatch leaf)))))
((null (rest refs))
(typecase leaf
(clambda (or (maybe-let-convert leaf)
(maybe-convert-to-assignment leaf)))
(lambda-var (reoptimize-lambda-var leaf))))
(t
(typecase leaf
(clambda (maybe-convert-to-assignment leaf))))))
(values))
;;; This function is called by people who delete nodes; it provides a
;;; way to indicate that the value of a continuation is no longer
;;; used. We null out the CONTINUATION-DEST, set FLUSH-P in the blocks
;;; containing uses of CONT and set COMPONENT-REOPTIMIZE. If the PREV
;;; of the use is deleted, then we blow off reoptimization.
;;;
;;; If the continuation is :DELETED, then we don't do anything, since
;;; all semantics have already been flushed. :DELETED-BLOCK-START
;;; start continuations are treated just like :BLOCK-START; it is
;;; possible that the continuation may be given a new dest (e.g. by
;;; SUBSTITUTE-CONTINUATION), so we don't want to delete it.
(defun flush-dest (cont)
(declare (type continuation cont))
(unless (eq (continuation-kind cont) :deleted)
(aver (continuation-dest cont))
(setf (continuation-dest cont) nil)
(flush-continuation-externally-checkable-type cont)
(do-uses (use cont)
(let ((prev (node-prev use)))
(unless (eq (continuation-kind prev) :deleted)
(let ((block (continuation-block prev)))
(setf (component-reoptimize (block-component block)) t)
(setf (block-attributep (block-flags block) flush-p type-asserted)
t))))))
(values))
;;; Do a graph walk backward from BLOCK, marking all predecessor
;;; blocks with the DELETE-P flag.
(defun mark-for-deletion (block)
(declare (type cblock block))
(let* ((component (block-component block))
(head (component-head component)))
(labels ((helper (block)
(setf (block-delete-p block) t)
(dolist (pred (block-pred block))
(unless (or (block-delete-p pred)
(eq pred head))
(helper pred)))))
(unless (block-delete-p block)
(helper block)
(setf (component-reanalyze component) t))))
(values))
;;; Delete CONT, eliminating both control and value semantics. We set
;;; FLUSH-P and COMPONENT-REOPTIMIZE similarly to in FLUSH-DEST. Here
;;; we must get the component from the use block, since the
;;; continuation may be a :DELETED-BLOCK-START.
;;;
;;; If CONT has DEST, then it must be the case that the DEST is
;;; unreachable, since we can't compute the value desired. In this
;;; case, we call MARK-FOR-DELETION to cause the DEST block and its
;;; predecessors to tell people to ignore them, and to cause them to
;;; be deleted eventually.
(defun delete-continuation (cont)
(declare (type continuation cont))
(aver (not (eq (continuation-kind cont) :deleted)))
(do-uses (use cont)
(let ((prev (node-prev use)))
(unless (eq (continuation-kind prev) :deleted)
(let ((block (continuation-block prev)))
(setf (block-attributep (block-flags block) flush-p type-asserted) t)
(setf (component-reoptimize (block-component block)) t)))))
(let ((dest (continuation-dest cont)))
(when dest
(let ((prev (node-prev dest)))
(when (and prev
(not (eq (continuation-kind prev) :deleted)))
(let ((block (continuation-block prev)))
(unless (block-delete-p block)
(mark-for-deletion block)))))))
(setf (continuation-kind cont) :deleted)
(setf (continuation-dest cont) nil)
(flush-continuation-externally-checkable-type cont)
(setf (continuation-next cont) nil)
(setf (continuation-%derived-type cont) *empty-type*)
(setf (continuation-use cont) nil)
(setf (continuation-block cont) nil)
(setf (continuation-reoptimize cont) nil)
(setf (continuation-info cont) nil)
(values))
;;; This function does what is necessary to eliminate the code in it
;;; from the IR1 representation. This involves unlinking it from its
;;; predecessors and successors and deleting various node-specific
;;; semantic information.
;;;
;;; We mark the START as has having no next and remove the last node
;;; from its CONT's uses. We also flush the DEST for all continuations
;;; whose values are received by nodes in the block.
(defun delete-block (block)
(declare (type cblock block))
(aver (block-component block)) ; else block is already deleted!
(note-block-deletion block)
(setf (block-delete-p block) t)
(let* ((last (block-last block))
(cont (node-cont last)))
(delete-continuation-use last)
(if (eq (continuation-kind cont) :unused)
(delete-continuation cont)
(reoptimize-continuation cont)))
(dolist (b (block-pred block))
(unlink-blocks b block)
;; In bug 147 the almost-all-blocks-have-a-successor invariant was
;; broken when successors were deleted without setting the
;; BLOCK-DELETE-P flags of their predececessors. Make sure that
;; doesn't happen again.
(aver (not (and (null (block-succ b))
(not (block-delete-p b))
(not (eq b (component-head (block-component b))))))))
(dolist (b (block-succ block))
(unlink-blocks block b))
(do-nodes (node cont block)
(typecase node
(ref (delete-ref node))
(cif
(flush-dest (if-test node)))
;; The next two cases serve to maintain the invariant that a LET
;; always has a well-formed COMBINATION, REF and BIND. We delete
;; the lambda whenever we delete any of these, but we must be
;; careful that this LET has not already been partially deleted.
(basic-combination
(when (and (eq (basic-combination-kind node) :local)
;; Guards COMBINATION-LAMBDA agains the REF being deleted.
(continuation-use (basic-combination-fun node)))
(let ((fun (combination-lambda node)))
;; If our REF was the second-to-last ref, and has been
;; deleted, then FUN may be a LET for some other
;; combination.
(when (and (functional-letlike-p fun)
(eq (let-combination fun) node))
(delete-lambda fun))))
(flush-dest (basic-combination-fun node))
(dolist (arg (basic-combination-args node))
(when arg (flush-dest arg))))
(bind
(let ((lambda (bind-lambda node)))
(unless (eq (functional-kind lambda) :deleted)
(delete-lambda lambda))))
(exit
(let ((value (exit-value node))
(entry (exit-entry node)))
(when value
(flush-dest value))
(when entry
(setf (entry-exits entry)
(delete node (entry-exits entry))))))
(creturn
(flush-dest (return-result node))
(delete-return node))
(cset
(flush-dest (set-value node))
(let ((var (set-var node)))
(setf (basic-var-sets var)
(delete node (basic-var-sets var)))))
(cast
(flush-dest (cast-value node))))
(delete-continuation (node-prev node)))
(remove-from-dfo block)
(values))
;;; Do stuff to indicate that the return node Node is being deleted.
;;; We set the RETURN to NIL.
(defun delete-return (node)
(declare (type creturn node))
(let ((fun (return-lambda node)))
(aver (lambda-return fun))
(setf (lambda-return fun) nil))
(values))
;;; If any of the VARS in FUN was never referenced and was not
;;; declared IGNORE, then complain.
(defun note-unreferenced-vars (fun)
(declare (type clambda fun))
(dolist (var (lambda-vars fun))
(unless (or (leaf-ever-used var)
(lambda-var-ignorep var))
(let ((*compiler-error-context* (lambda-bind fun)))
(unless (policy *compiler-error-context* (= inhibit-warnings 3))
;; ANSI section "3.2.5 Exceptional Situations in the Compiler"
;; requires this to be no more than a STYLE-WARNING.
(compiler-style-warn "The variable ~S is defined but never used."
(leaf-debug-name var)))
(setf (leaf-ever-used var) t)))) ; to avoid repeated warnings? -- WHN
(values))
(defvar *deletion-ignored-objects* '(t nil))
;;; Return true if we can find OBJ in FORM, NIL otherwise. We bound
;;; our recursion so that we don't get lost in circular structures. We
;;; ignore the car of forms if they are a symbol (to prevent confusing
;;; function referencess with variables), and we also ignore anything
;;; inside ' or #'.
(defun present-in-form (obj form depth)
(declare (type (integer 0 20) depth))
(cond ((= depth 20) nil)
((eq obj form) t)
((atom form) nil)
(t
(let ((first (car form))
(depth (1+ depth)))
(if (member first '(quote function))
nil
(or (and (not (symbolp first))
(present-in-form obj first depth))
(do ((l (cdr form) (cdr l))
(n 0 (1+ n)))
((or (atom l) (> n 100))
nil)
(declare (fixnum n))
(when (present-in-form obj (car l) depth)
(return t)))))))))
;;; This function is called on a block immediately before we delete
;;; it. We check to see whether any of the code about to die appeared
;;; in the original source, and emit a note if so.
;;;
;;; If the block was in a lambda is now deleted, then we ignore the
;;; whole block, since this case is picked off in DELETE-LAMBDA. We
;;; also ignore the deletion of CRETURN nodes, since it is somewhat
;;; reasonable for a function to not return, and there is a different
;;; note for that case anyway.
;;;
;;; If the actual source is an atom, then we use a bunch of heuristics
;;; to guess whether this reference really appeared in the original
;;; source:
;;; -- If a symbol, it must be interned and not a keyword.
;;; -- It must not be an easily introduced constant (T or NIL, a fixnum
;;; or a character.)
;;; -- The atom must be "present" in the original source form, and
;;; present in all intervening actual source forms.
(defun note-block-deletion (block)
(let ((home (block-home-lambda block)))
(unless (eq (functional-kind home) :deleted)
(do-nodes (node cont block)
(let* ((path (node-source-path node))
(first (first path)))
(when (or (eq first 'original-source-start)
(and (atom first)
(or (not (symbolp first))
(let ((pkg (symbol-package first)))
(and pkg
(not (eq pkg (symbol-package :end))))))
(not (member first *deletion-ignored-objects*))
(not (typep first '(or fixnum character)))
(every (lambda (x)
(present-in-form first x 0))
(source-path-forms path))
(present-in-form first (find-original-source path)
0)))
(unless (return-p node)
(let ((*compiler-error-context* node))
(compiler-note "deleting unreachable code")))
(return))))))
(values))
;;; Delete a node from a block, deleting the block if there are no
;;; nodes left. We remove the node from the uses of its CONT, but we
;;; don't deal with cleaning up any type-specific semantic
;;; attachments. If the CONT is :UNUSED after deleting this use, then
;;; we delete CONT. (Note :UNUSED is not the same as no uses. A
;;; continuation will only become :UNUSED if it was :INSIDE-BLOCK
;;; before.)
;;;
;;; If the node is the last node, there must be exactly one successor.
;;; We link all of our precedessors to the successor and unlink the
;;; block. In this case, we return T, otherwise NIL. If no nodes are
;;; left, and the block is a successor of itself, then we replace the
;;; only node with a degenerate exit node. This provides a way to
;;; represent the bodyless infinite loop, given the prohibition on
;;; empty blocks in IR1.
(defun unlink-node (node)
(declare (type node node))
(let* ((cont (node-cont node))
(next (continuation-next cont))
(prev (node-prev node))
(block (continuation-block prev))
(prev-kind (continuation-kind prev))
(last (block-last block)))
(unless (eq (continuation-kind cont) :deleted)
(delete-continuation-use node)
(when (eq (continuation-kind cont) :unused)
(aver (not (continuation-dest cont)))
(delete-continuation cont)))
(setf (block-type-asserted block) t)
(setf (block-test-modified block) t)
(cond ((or (eq prev-kind :inside-block)
(and (eq prev-kind :block-start)
(not (eq node last))))
(cond ((eq node last)
(setf (block-last block) (continuation-use prev))
(setf (continuation-next prev) nil))
(t
(setf (continuation-next prev) next)
(setf (node-prev next) prev)))
(setf (node-prev node) nil)
nil)
(t
(aver (eq prev-kind :block-start))
(aver (eq node last))
(let* ((succ (block-succ block))
(next (first succ)))
(aver (and succ (null (cdr succ))))
(cond
((member block succ)
(with-ir1-environment-from-node node
(let ((exit (make-exit))
(dummy (make-continuation)))
(setf (continuation-next prev) nil)
(link-node-to-previous-continuation exit prev)
(add-continuation-use exit dummy)
(setf (block-last block) exit)))
(setf (node-prev node) nil)
nil)
(t
(aver (eq (block-start-cleanup block)
(block-end-cleanup block)))
(unlink-blocks block next)
(dolist (pred (block-pred block))
(change-block-successor pred block next))
(remove-from-dfo block)
(cond ((continuation-dest prev)
(setf (continuation-next prev) nil)
(setf (continuation-kind prev) :deleted-block-start))
(t
(delete-continuation prev)))
(setf (node-prev node) nil)
t)))))))
;;; Return true if NODE has been deleted, false if it is still a valid
;;; part of IR1.
(defun node-deleted (node)
(declare (type node node))
(let ((prev (node-prev node)))
(not (and prev
(not (eq (continuation-kind prev) :deleted))
(let ((block (continuation-block prev)))
(and (block-component block)
(not (block-delete-p block))))))))
;;; Delete all the blocks and functions in COMPONENT. We scan first
;;; marking the blocks as DELETE-P to prevent weird stuff from being
;;; triggered by deletion.
(defun delete-component (component)
(declare (type component component))
(aver (null (component-new-functionals component)))
(setf (component-kind component) :deleted)
(do-blocks (block component)
(setf (block-delete-p block) t))
(dolist (fun (component-lambdas component))
(setf (functional-kind fun) nil)
(setf (functional-entry-fun fun) nil)
(setf (leaf-refs fun) nil)
(delete-functional fun))
(do-blocks (block component)
(delete-block block))
(values))
;;; Convert code of the form
;;; (FOO ... (FUN ...) ...)
;;; to
;;; (FOO ... ... ...).
;;; In other words, replace the function combination FUN by its
;;; arguments. If there are any problems with doing this, use GIVE-UP
;;; to blow out of whatever transform called this. Note, as the number
;;; of arguments changes, the transform must be prepared to return a
;;; lambda with a new lambda-list with the correct number of
;;; arguments.
(defun extract-fun-args (cont fun num-args)
#!+sb-doc
"If CONT is a call to FUN with NUM-ARGS args, change those arguments
to feed directly to the continuation-dest of CONT, which must be
a combination."
(declare (type continuation cont)
(type symbol fun)
(type index num-args))
(let ((outside (continuation-dest cont))
(inside (continuation-use cont)))
(aver (combination-p outside))
(unless (combination-p inside)
(give-up-ir1-transform))
(let ((inside-fun (combination-fun inside)))
(unless (eq (continuation-fun-name inside-fun) fun)
(give-up-ir1-transform))
(let ((inside-args (combination-args inside)))
(unless (= (length inside-args) num-args)
(give-up-ir1-transform))
(let* ((outside-args (combination-args outside))
(arg-position (position cont outside-args))
(before-args (subseq outside-args 0 arg-position))
(after-args (subseq outside-args (1+ arg-position))))
(dolist (arg inside-args)
(setf (continuation-dest arg) outside)
(flush-continuation-externally-checkable-type arg))
(setf (combination-args inside) nil)
(setf (combination-args outside)
(append before-args inside-args after-args))
(change-ref-leaf (continuation-use inside-fun)
(find-free-fun 'list "???"))
(setf (combination-kind inside) :full)
(setf (node-derived-type inside) *wild-type*)
(flush-dest cont)
(values))))))
;;;; leaf hackery
;;; Change the LEAF that a REF refers to.
(defun change-ref-leaf (ref leaf)
(declare (type ref ref) (type leaf leaf))
(unless (eq (ref-leaf ref) leaf)
(push ref (leaf-refs leaf))
(delete-ref ref)
(setf (ref-leaf ref) leaf)
(setf (leaf-ever-used leaf) t)
(let ((ltype (leaf-type leaf)))
(if (fun-type-p ltype)
(setf (node-derived-type ref) ltype)
(derive-node-type ref ltype)))
(reoptimize-continuation (node-cont ref)))
(values))
;;; Change all REFS for OLD-LEAF to NEW-LEAF.
(defun substitute-leaf (new-leaf old-leaf)
(declare (type leaf new-leaf old-leaf))
(dolist (ref (leaf-refs old-leaf))
(change-ref-leaf ref new-leaf))
(values))
;;; like SUBSITUTE-LEAF, only there is a predicate on the REF to tell
;;; whether to substitute
(defun substitute-leaf-if (test new-leaf old-leaf)
(declare (type leaf new-leaf old-leaf) (type function test))
(dolist (ref (leaf-refs old-leaf))
(when (funcall test ref)
(change-ref-leaf ref new-leaf)))
(values))
;;; Return a LEAF which represents the specified constant object. If
;;; the object is not in *CONSTANTS*, then we create a new constant
;;; LEAF and enter it.
(defun find-constant (object)
(if (typep object
;; FIXME: What is the significance of this test? ("things
;; that are worth uniquifying"?)
'(or symbol number character instance))
(or (gethash object *constants*)
(setf (gethash object *constants*)
(make-constant :value object
:%source-name '.anonymous.
:type (ctype-of object)
:where-from :defined)))
(make-constant :value object
:%source-name '.anonymous.
:type (ctype-of object)
:where-from :defined)))
;;; If there is a non-local exit noted in ENTRY's environment that
;;; exits to CONT in that entry, then return it, otherwise return NIL.
(defun find-nlx-info (entry cont)
(declare (type entry entry) (type continuation cont))
(let ((entry-cleanup (entry-cleanup entry)))
(dolist (nlx (physenv-nlx-info (node-physenv entry)) nil)
(when (and (eq (nlx-info-continuation nlx) cont)
(eq (nlx-info-cleanup nlx) entry-cleanup))
(return nlx)))))
;;;; functional hackery
(declaim (ftype (function (functional) clambda) main-entry))
(defun main-entry (functional)
(etypecase functional
(clambda functional)
(optional-dispatch
(optional-dispatch-main-entry functional))))
;;; RETURN true if FUNCTIONAL is a thing that can be treated like
;;; MV-BIND when it appears in an MV-CALL. All fixed arguments must be
;;; optional with null default and no SUPPLIED-P. There must be a
;;; &REST arg with no references.
(declaim (ftype (function (functional) boolean) looks-like-an-mv-bind))
(defun looks-like-an-mv-bind (functional)
(and (optional-dispatch-p functional)
(do ((arg (optional-dispatch-arglist functional) (cdr arg)))
((null arg) nil)
(let ((info (lambda-var-arg-info (car arg))))
(unless info (return nil))
(case (arg-info-kind info)
(:optional
(when (or (arg-info-supplied-p info) (arg-info-default info))
(return nil)))
(:rest
(return (and (null (cdr arg)) (null (leaf-refs (car arg))))))
(t
(return nil)))))))
;;; Return true if function is an external entry point. This is true
;;; of normal XEPs (:EXTERNAL kind) and also of top level lambdas
;;; (:TOPLEVEL kind.)
(defun xep-p (fun)
(declare (type functional fun))
(not (null (member (functional-kind fun) '(:external :toplevel)))))
;;; If CONT's only use is a non-notinline global function reference,
;;; then return the referenced symbol, otherwise NIL. If NOTINLINE-OK
;;; is true, then we don't care if the leaf is NOTINLINE.
(defun continuation-fun-name (cont &optional notinline-ok)
(declare (type continuation cont))
(let ((use (continuation-use cont)))
(if (ref-p use)
(let ((leaf (ref-leaf use)))
(if (and (global-var-p leaf)
(eq (global-var-kind leaf) :global-function)
(or (not (defined-fun-p leaf))
(not (eq (defined-fun-inlinep leaf) :notinline))
notinline-ok))
(leaf-source-name leaf)
nil))
nil)))
;;; Return the source name of a combination. (This is an idiom
;;; which was used in CMU CL. I gather it always works. -- WHN)
(defun combination-fun-source-name (combination)
(let ((ref (continuation-use (combination-fun combination))))
(leaf-source-name (ref-leaf ref))))
;;; Return the COMBINATION node that is the call to the LET FUN.
(defun let-combination (fun)
(declare (type clambda fun))
(aver (functional-letlike-p fun))
(continuation-dest (node-cont (first (leaf-refs fun)))))
;;; Return the initial value continuation for a LET variable, or NIL
;;; if there is none.
(defun let-var-initial-value (var)
(declare (type lambda-var var))
(let ((fun (lambda-var-home var)))
(elt (combination-args (let-combination fun))
(position-or-lose var (lambda-vars fun)))))
;;; Return the LAMBDA that is called by the local CALL.
(defun combination-lambda (call)
(declare (type basic-combination call))
(aver (eq (basic-combination-kind call) :local))
(ref-leaf (continuation-use (basic-combination-fun call))))
(defvar *inline-expansion-limit* 200
#!+sb-doc
"an upper limit on the number of inline function calls that will be expanded
in any given code object (single function or block compilation)")
;;; Check whether NODE's component has exceeded its inline expansion
;;; limit, and warn if so, returning NIL.
(defun inline-expansion-ok (node)
(let ((expanded (incf (component-inline-expansions
(block-component
(node-block node))))))
(cond ((> expanded *inline-expansion-limit*) nil)
((= expanded *inline-expansion-limit*)
;; FIXME: If the objective is to stop the recursive
;; expansion of inline functions, wouldn't it be more
;; correct to look back through surrounding expansions
;; (which are, I think, stored in the *CURRENT-PATH*, and
;; possibly stored elsewhere too) and suppress expansion
;; and print this warning when the function being proposed
;; for inline expansion is found there? (I don't like the
;; arbitrary numerical limit in principle, and I think
;; it'll be a nuisance in practice if we ever want the
;; compiler to be able to use WITH-COMPILATION-UNIT on
;; arbitrarily huge blocks of code. -- WHN)
(let ((*compiler-error-context* node))
(compiler-note "*INLINE-EXPANSION-LIMIT* (~W) was exceeded, ~
probably trying to~% ~
inline a recursive function."
*inline-expansion-limit*))
nil)
(t t))))
;;;; careful call
;;; Apply a function to some arguments, returning a list of the values
;;; resulting of the evaluation. If an error is signalled during the
;;; application, then we produce a warning message using WARN-FUN and
;;; return NIL as our second value to indicate this. NODE is used as
;;; the error context for any error message, and CONTEXT is a string
;;; that is spliced into the warning.
(declaim (ftype (function ((or symbol function) list node function string)
(values list boolean))
careful-call))
(defun careful-call (function args node warn-fun context)
(values
(multiple-value-list
(handler-case (apply function args)
(error (condition)
(let ((*compiler-error-context* node))
(funcall warn-fun "Lisp error during ~A:~%~A" context condition)
(return-from careful-call (values nil nil))))))
t))
;;; Variations of SPECIFIER-TYPE for parsing possibly wrong
;;; specifiers.
(macrolet
((deffrob (basic careful compiler transform)
`(progn
(defun ,careful (specifier)
(handler-case (,basic specifier)
(simple-error (condition)
(values nil (list* (simple-condition-format-control condition)
(simple-condition-format-arguments condition))))))
(defun ,compiler (specifier)
(multiple-value-bind (type error-args) (,careful specifier)
(or type
(apply #'compiler-error error-args))))
(defun ,transform (specifier)
(multiple-value-bind (type error-args) (,careful specifier)
(or type
(apply #'give-up-ir1-transform
error-args)))))))
(deffrob specifier-type careful-specifier-type compiler-specifier-type ir1-transform-specifier-type)
(deffrob values-specifier-type careful-values-specifier-type compiler-values-specifier-type ir1-transform-values-specifier-type))
;;;; utilities used at run-time for parsing &KEY args in IR1
;;; This function is used by the result of PARSE-DEFTRANSFORM to find
;;; the continuation for the value of the &KEY argument KEY in the
;;; list of continuations ARGS. It returns the continuation if the
;;; keyword is present, or NIL otherwise. The legality and
;;; constantness of the keywords should already have been checked.
(declaim (ftype (function (list keyword) (or continuation null))
find-keyword-continuation))
(defun find-keyword-continuation (args key)
(do ((arg args (cddr arg)))
((null arg) nil)
(when (eq (continuation-value (first arg)) key)
(return (second arg)))))
;;; This function is used by the result of PARSE-DEFTRANSFORM to
;;; verify that alternating continuations in ARGS are constant and
;;; that there is an even number of args.
(declaim (ftype (function (list) boolean) check-key-args-constant))
(defun check-key-args-constant (args)
(do ((arg args (cddr arg)))
((null arg) t)
(unless (and (rest arg)
(constant-continuation-p (first arg)))
(return nil))))
;;; This function is used by the result of PARSE-DEFTRANSFORM to
;;; verify that the list of continuations ARGS is a well-formed &KEY
;;; arglist and that only keywords present in the list KEYS are
;;; supplied.
(declaim (ftype (function (list list) boolean) check-transform-keys))
(defun check-transform-keys (args keys)
(and (check-key-args-constant args)
(do ((arg args (cddr arg)))
((null arg) t)
(unless (member (continuation-value (first arg)) keys)
(return nil)))))
;;;; miscellaneous
;;; Called by the expansion of the EVENT macro.
(declaim (ftype (function (event-info (or node null)) *) %event))
(defun %event (info node)
(incf (event-info-count info))
(when (and (>= (event-info-level info) *event-note-threshold*)
(policy (or node *lexenv*)
(= inhibit-warnings 0)))
(let ((*compiler-error-context* node))
(compiler-note (event-info-description info))))
(let ((action (event-info-action info)))
(when action (funcall action node))))
;;;
(defun make-cast (value type policy)
(declare (type continuation value)
(type ctype type)
(type policy policy))
(%make-cast :asserted-type type
:type-to-check (maybe-weaken-check type policy)
:value value
:derived-type type))
(defun cast-type-check (cast)
(declare (type cast cast))
(when (cast-reoptimize cast)
(ir1-optimize-cast cast t))
(cast-%type-check cast))
(defun note-single-valuified-continuation (cont)
(declare (type continuation cont))
(let ((use (continuation-use cont)))
(cond ((ref-p use)
(let ((leaf (ref-leaf use)))
(when (and (lambda-var-p leaf)
(null (rest (leaf-refs leaf))))
(reoptimize-lambda-var leaf))))
((or (null use) (combination-p use))
(dolist (node (find-uses cont))
(setf (node-reoptimize node) t)
(setf (block-reoptimize (node-block node)) t)
(setf (component-reoptimize (node-component node)) t))))))