1 ;;;; This file implements local call analysis. A local call is a
2 ;;;; function call between functions being compiled at the same time.
3 ;;;; If we can tell at compile time that such a call is legal, then we
4 ;;;; change the combination to call the correct lambda, mark it as
5 ;;;; local, and add this link to our call graph. Once a call is local,
6 ;;;; it is then eligible for let conversion, which places the body of
7 ;;;; the function inline.
9 ;;;; We cannot always do a local call even when we do have the
10 ;;;; function being called. Calls that cannot be shown to have legal
11 ;;;; arg counts are not converted.
13 ;;;; This software is part of the SBCL system. See the README file for
14 ;;;; more information.
16 ;;;; This software is derived from the CMU CL system, which was
17 ;;;; written at Carnegie Mellon University and released into the
18 ;;;; public domain. The software is in the public domain and is
19 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
20 ;;;; files for more information.
24 ;;; This function propagates information from the variables in the
25 ;;; function FUN to the actual arguments in CALL. This is also called
26 ;;; by the VALUES IR1 optimizer when it sleazily converts MV-BINDs to
29 ;;; We flush all arguments to CALL that correspond to unreferenced
30 ;;; variables in FUN. We leave NILs in the COMBINATION-ARGS so that
31 ;;; the remaining args still match up with their vars.
33 ;;; We also apply the declared variable type assertion to the argument
35 (defun propagate-to-args (call fun)
36 (declare (type combination call) (type clambda fun))
37 (do ((args (basic-combination-args call) (cdr args))
38 (vars (lambda-vars fun) (cdr vars)))
40 (let ((arg (car args))
42 (cond ((leaf-refs var)
43 (assert-continuation-type arg (leaf-type var)
44 (lexenv-policy (node-lexenv call))))
47 (setf (car args) nil)))))
51 ;;; This function handles merging the tail sets if CALL is potentially
52 ;;; tail-recursive, and is a call to a function with a different
53 ;;; TAIL-SET than CALL's FUN. This must be called whenever we alter
54 ;;; IR1 so as to place a local call in what might be a tail-recursive
55 ;;; context. Note that any call which returns its value to a RETURN is
56 ;;; considered potentially tail-recursive, since any implicit MV-PROG1
57 ;;; might be optimized away.
59 ;;; We destructively modify the set for the calling function to
60 ;;; represent both, and then change all the functions in callee's set
61 ;;; to reference the first. If we do merge, we reoptimize the
62 ;;; RETURN-RESULT continuation to cause IR1-OPTIMIZE-RETURN to
63 ;;; recompute the tail set type.
64 (defun merge-tail-sets (call &optional (new-fun (combination-lambda call)))
65 (declare (type basic-combination call) (type clambda new-fun))
66 (let ((return (continuation-dest (node-cont call))))
67 (when (return-p return)
68 (let ((call-set (lambda-tail-set (node-home-lambda call)))
69 (fun-set (lambda-tail-set new-fun)))
70 (unless (eq call-set fun-set)
71 (let ((funs (tail-set-funs fun-set)))
73 (setf (lambda-tail-set fun) call-set))
74 (setf (tail-set-funs call-set)
75 (nconc (tail-set-funs call-set) funs)))
76 (reoptimize-continuation (return-result return))
79 ;;; Convert a combination into a local call. We PROPAGATE-TO-ARGS, set
80 ;;; the combination kind to :LOCAL, add FUN to the CALLS of the
81 ;;; function that the call is in, call MERGE-TAIL-SETS, then replace
82 ;;; the function in the REF node with the new function.
84 ;;; We change the REF last, since changing the reference can trigger
85 ;;; LET conversion of the new function, but will only do so if the
86 ;;; call is local. Note that the replacement may trigger LET
87 ;;; conversion or other changes in IR1. We must call MERGE-TAIL-SETS
88 ;;; with NEW-FUN before the substitution, since after the substitution
89 ;;; (and LET conversion), the call may no longer be recognizable as
91 (defun convert-call (ref call fun)
92 (declare (type ref ref) (type combination call) (type clambda fun))
93 (propagate-to-args call fun)
94 (setf (basic-combination-kind call) :local)
95 (pushnew fun (lambda-calls-or-closes (node-home-lambda call)))
96 (merge-tail-sets call fun)
97 (change-ref-leaf ref fun)
100 ;;;; external entry point creation
102 ;;; Return a LAMBDA form that can be used as the definition of the XEP
105 ;;; If FUN is a LAMBDA, then we check the number of arguments
106 ;;; (conditional on policy) and call FUN with all the arguments.
108 ;;; If FUN is an OPTIONAL-DISPATCH, then we dispatch off of the number
109 ;;; of supplied arguments by doing do an = test for each entry-point,
110 ;;; calling the entry with the appropriate prefix of the passed
113 ;;; If there is a &MORE arg, then there are a couple of optimizations
114 ;;; that we make (more for space than anything else):
115 ;;; -- If MIN-ARGS is 0, then we make the more entry a T clause, since
116 ;;; no argument count error is possible.
117 ;;; -- We can omit the = clause for the last entry-point, allowing the
118 ;;; case of 0 more args to fall through to the more entry.
120 ;;; We don't bother to policy conditionalize wrong arg errors in
121 ;;; optional dispatches, since the additional overhead is negligible
122 ;;; compared to the cost of everything else going on.
124 ;;; Note that if policy indicates it, argument type declarations in
125 ;;; FUN will be verified. Since nothing is known about the type of the
126 ;;; XEP arg vars, type checks will be emitted when the XEP's arg vars
127 ;;; are passed to the actual function.
128 (defun make-xep-lambda-expression (fun)
129 (declare (type functional fun))
132 (let ((nargs (length (lambda-vars fun)))
133 (n-supplied (gensym))
134 (temps (make-gensym-list (length (lambda-vars fun)))))
135 `(lambda (,n-supplied ,@temps)
136 (declare (type index ,n-supplied))
137 ,(if (policy *lexenv* (zerop verify-arg-count))
138 `(declare (ignore ,n-supplied))
139 `(%verify-arg-count ,n-supplied ,nargs))
141 (declare (optimize (let-convertion 3)))
142 (%funcall ,fun ,@temps)))))
144 (let* ((min (optional-dispatch-min-args fun))
145 (max (optional-dispatch-max-args fun))
146 (more (optional-dispatch-more-entry fun))
147 (n-supplied (gensym))
148 (temps (make-gensym-list max)))
150 (do ((eps (optional-dispatch-entry-points fun) (rest eps))
153 (entries `((= ,n-supplied ,n)
154 (%funcall ,(first eps) ,@(subseq temps 0 n)))))
155 `(lambda (,n-supplied ,@temps)
156 ;; FIXME: Make sure that INDEX type distinguishes between
157 ;; target and host. (Probably just make the SB!XC:DEFTYPE
158 ;; different from CL:DEFTYPE.)
159 (declare (type index ,n-supplied))
161 ,@(if more (butlast (entries)) (entries))
163 `((,(if (zerop min) t `(>= ,n-supplied ,max))
164 ,(let ((n-context (gensym))
166 `(multiple-value-bind (,n-context ,n-count)
167 (%more-arg-context ,n-supplied ,max)
169 ;; KLUDGE: As above, we're trying to
170 ;; enable tail recursion optimization and
171 ;; any other effects of this declaration
172 ;; are accidental. -- WHN 2002-07-08
173 (declare (optimize (speed 2) (debug 1)))
174 (%funcall ,more ,@temps ,n-context ,n-count)))))))
176 (%arg-count-error ,n-supplied)))))))))
178 ;;; Make an external entry point (XEP) for FUN and return it. We
179 ;;; convert the result of MAKE-XEP-LAMBDA in the correct environment,
180 ;;; then associate this lambda with FUN as its XEP. After the
181 ;;; conversion, we iterate over the function's associated lambdas,
182 ;;; redoing local call analysis so that the XEP calls will get
185 ;;; We set REANALYZE and REOPTIMIZE in the component, just in case we
186 ;;; discover an XEP after the initial local call analyze pass.
187 (defun make-xep (fun)
188 (declare (type functional fun))
189 (aver (null (functional-entry-fun fun)))
190 (with-ir1-environment-from-node (lambda-bind (main-entry fun))
191 (let ((res (ir1-convert-lambda (make-xep-lambda-expression fun)
192 :debug-name (debug-namify
194 (leaf-debug-name fun)))))
195 (setf (functional-kind res) :external
196 (leaf-ever-used res) t
197 (functional-entry-fun res) fun
198 (functional-entry-fun fun) res
199 (component-reanalyze *current-component*) t
200 (component-reoptimize *current-component*) t)
203 (locall-analyze-fun-1 fun))
205 (dolist (ep (optional-dispatch-entry-points fun))
206 (locall-analyze-fun-1 ep))
207 (when (optional-dispatch-more-entry fun)
208 (locall-analyze-fun-1 (optional-dispatch-more-entry fun)))))
211 ;;; Notice a REF that is not in a local-call context. If the REF is
212 ;;; already to an XEP, then do nothing, otherwise change it to the
213 ;;; XEP, making an XEP if necessary.
215 ;;; If REF is to a special :CLEANUP or :ESCAPE function, then we treat
216 ;;; it as though it was not an XEP reference (i.e. leave it alone).
217 (defun reference-entry-point (ref)
218 (declare (type ref ref))
219 (let ((fun (ref-leaf ref)))
220 (unless (or (xep-p fun)
221 (member (functional-kind fun) '(:escape :cleanup)))
222 (change-ref-leaf ref (or (functional-entry-fun fun)
225 ;;; Attempt to convert all references to FUN to local calls. The
226 ;;; reference must be the function for a call, and the function
227 ;;; continuation must be used only once, since otherwise we cannot be
228 ;;; sure what function is to be called. The call continuation would be
229 ;;; multiply used if there is hairy stuff such as conditionals in the
230 ;;; expression that computes the function.
232 ;;; If we cannot convert a reference, then we mark the referenced
233 ;;; function as an entry-point, creating a new XEP if necessary. We
234 ;;; don't try to convert calls that are in error (:ERROR kind.)
236 ;;; This is broken off from LOCALL-ANALYZE-COMPONENT so that people
237 ;;; can force analysis of newly introduced calls. Note that we don't
238 ;;; do LET conversion here.
239 (defun locall-analyze-fun-1 (fun)
240 (declare (type functional fun))
241 (let ((refs (leaf-refs fun))
244 (let* ((cont (node-cont ref))
245 (dest (continuation-dest cont)))
246 (cond ((and (basic-combination-p dest)
247 (eq (basic-combination-fun dest) cont)
248 (eq (continuation-use cont) ref))
250 (convert-call-if-possible ref dest)
252 (unless (eq (basic-combination-kind dest) :local)
253 (reference-entry-point ref)))
255 (reference-entry-point ref))))
256 (setq first-time nil)))
260 ;;; We examine all NEW-FUNCTIONALS in COMPONENT, attempting to convert
261 ;;; calls into local calls when it is legal. We also attempt to
262 ;;; convert each LAMBDA to a LET. LET conversion is also triggered by
263 ;;; deletion of a function reference, but functions that start out
264 ;;; eligible for conversion must be noticed sometime.
266 ;;; Note that there is a lot of action going on behind the scenes
267 ;;; here, triggered by reference deletion. In particular, the
268 ;;; COMPONENT-LAMBDAS are being hacked to remove newly deleted and LET
269 ;;; converted LAMBDAs, so it is important that the LAMBDA is added to
270 ;;; the COMPONENT-LAMBDAS when it is. Also, the
271 ;;; COMPONENT-NEW-FUNCTIONALS may contain all sorts of drivel, since
272 ;;; it is not updated when we delete functions, etc. Only
273 ;;; COMPONENT-LAMBDAS is updated.
275 ;;; COMPONENT-REANALYZE-FUNCTIONALS is treated similarly to
276 ;;; COMPONENT-NEW-FUNCTIONALS, but we don't add lambdas to the
278 (defun locall-analyze-component (component)
279 (declare (type component component))
280 (aver-live-component component)
282 (let* ((new-functional (pop (component-new-functionals component)))
283 (functional (or new-functional
284 (pop (component-reanalyze-functionals component)))))
287 (let ((kind (functional-kind functional)))
288 (cond ((or (functional-somewhat-letlike-p functional)
290 (values)) ; nothing to do
291 ((and (null (leaf-refs functional)) (eq kind nil)
292 (not (functional-entry-fun functional)))
293 (delete-functional functional))
295 ;; Fix/check FUNCTIONAL's relationship to COMPONENT-LAMDBAS.
296 (cond ((not (lambda-p functional))
297 ;; Since FUNCTIONAL isn't a LAMBDA, this doesn't
300 (new-functional ; FUNCTIONAL came from
301 ; NEW-FUNCTIONALS, hence is new.
302 ;; FUNCTIONAL becomes part of COMPONENT-LAMBDAS now.
303 (aver (not (member functional
304 (component-lambdas component))))
305 (push functional (component-lambdas component)))
306 (t ; FUNCTIONAL is old.
307 ;; FUNCTIONAL should be in COMPONENT-LAMBDAS already.
308 (aver (member functional (component-lambdas
310 (locall-analyze-fun-1 functional)
311 (when (lambda-p functional)
312 (maybe-let-convert functional)))))))
315 (defun locall-analyze-clambdas-until-done (clambdas)
317 (let ((did-something nil))
318 (dolist (clambda clambdas)
319 (let* ((component (lambda-component clambda))
320 (*all-components* (list component)))
321 ;; The original CMU CL code seemed to implicitly assume that
322 ;; COMPONENT is the only one here. Let's make that explicit.
323 (aver (= 1 (length (functional-components clambda))))
324 (aver (eql component (first (functional-components clambda))))
325 (when (component-new-functionals component)
326 (setf did-something t)
327 (locall-analyze-component component))))
328 (unless did-something
332 ;;; If policy is auspicious and CALL is not in an XEP and we don't seem
333 ;;; to be in an infinite recursive loop, then change the reference to
334 ;;; reference a fresh copy. We return whichever function we decide to
336 (defun maybe-expand-local-inline (original-functional ref call)
337 (if (and (policy call
338 (and (>= speed space)
339 (>= speed compilation-speed)))
340 (not (eq (functional-kind (node-home-lambda call)) :external))
341 (inline-expansion-ok call))
342 (multiple-value-bind (losing-local-functional converted-lambda)
343 (catch 'locall-already-let-converted
344 (with-ir1-environment-from-node call
345 (let ((*lexenv* (functional-lexenv original-functional)))
348 (functional-inline-expansion original-functional)
349 :debug-name (debug-namify
352 original-functional)))))))
353 (cond (losing-local-functional
354 (let ((*compiler-error-context* call))
355 (compiler-note "couldn't inline expand because expansion ~
356 calls this LET-converted local function:~
358 (leaf-debug-name losing-local-functional)))
361 (change-ref-leaf ref converted-lambda)
363 original-functional))
365 ;;; Dispatch to the appropriate function to attempt to convert a call.
366 ;;; REF must be a reference to a FUNCTIONAL. This is called in IR1
367 ;;; optimization as well as in local call analysis. If the call is is
368 ;;; already :LOCAL, we do nothing. If the call is already scheduled
369 ;;; for deletion, also do nothing (in addition to saving time, this
370 ;;; also avoids some problems with optimizing collections of functions
371 ;;; that are partially deleted.)
373 ;;; This is called both before and after FIND-INITIAL-DFO runs. When
374 ;;; called on a :INITIAL component, we don't care whether the caller
375 ;;; and callee are in the same component. Afterward, we must stick
376 ;;; with whatever component division we have chosen.
378 ;;; Before attempting to convert a call, we see whether the function
379 ;;; is supposed to be inline expanded. Call conversion proceeds as
380 ;;; before after any expansion.
382 ;;; We bind *COMPILER-ERROR-CONTEXT* to the node for the call so that
383 ;;; warnings will get the right context.
384 (defun convert-call-if-possible (ref call)
385 (declare (type ref ref) (type basic-combination call))
386 (let* ((block (node-block call))
387 (component (block-component block))
388 (original-fun (ref-leaf ref)))
389 (aver (functional-p original-fun))
390 (unless (or (member (basic-combination-kind call) '(:local :error))
391 (block-delete-p block)
392 (eq (functional-kind (block-home-lambda block)) :deleted)
393 (member (functional-kind original-fun)
394 '(:toplevel-xep :deleted))
395 (not (or (eq (component-kind component) :initial)
398 (lambda-bind (main-entry original-fun))))
400 (let ((fun (if (xep-p original-fun)
401 (functional-entry-fun original-fun)
403 (*compiler-error-context* call))
405 (when (and (eq (functional-inlinep fun) :inline)
406 (rest (leaf-refs original-fun)))
407 (setq fun (maybe-expand-local-inline fun ref call)))
409 (aver (member (functional-kind fun)
410 '(nil :escape :cleanup :optional)))
411 (cond ((mv-combination-p call)
412 (convert-mv-call ref call fun))
414 (convert-lambda-call ref call fun))
416 (convert-hairy-call ref call fun))))))
420 ;;; Attempt to convert a multiple-value call. The only interesting
421 ;;; case is a call to a function that LOOKS-LIKE-AN-MV-BIND, has
422 ;;; exactly one reference and no XEP, and is called with one values
425 ;;; We change the call to be to the last optional entry point and
426 ;;; change the call to be local. Due to our preconditions, the call
427 ;;; should eventually be converted to a let, but we can't do that now,
428 ;;; since there may be stray references to the e-p lambda due to
429 ;;; optional defaulting code.
431 ;;; We also use variable types for the called function to construct an
432 ;;; assertion for the values continuation.
434 ;;; See CONVERT-CALL for additional notes on MERGE-TAIL-SETS, etc.
435 (defun convert-mv-call (ref call fun)
436 (declare (type ref ref) (type mv-combination call) (type functional fun))
437 (when (and (looks-like-an-mv-bind fun)
438 (not (functional-entry-fun fun))
439 (= (length (leaf-refs fun)) 1)
440 (= (length (basic-combination-args call)) 1))
441 (let ((ep (car (last (optional-dispatch-entry-points fun)))))
442 (setf (basic-combination-kind call) :local)
443 (pushnew ep (lambda-calls-or-closes (node-home-lambda call)))
444 (merge-tail-sets call ep)
445 (change-ref-leaf ref ep)
447 (assert-continuation-type
448 (first (basic-combination-args call))
449 (make-values-type :optional (mapcar #'leaf-type (lambda-vars ep))
450 :rest *universal-type*)
451 (lexenv-policy (node-lexenv call)))))
454 ;;; Attempt to convert a call to a lambda. If the number of args is
455 ;;; wrong, we give a warning and mark the call as :ERROR to remove it
456 ;;; from future consideration. If the argcount is O.K. then we just
458 (defun convert-lambda-call (ref call fun)
459 (declare (type ref ref) (type combination call) (type clambda fun))
460 (let ((nargs (length (lambda-vars fun)))
461 (call-args (length (combination-args call))))
462 (cond ((= call-args nargs)
463 (convert-call ref call fun))
465 ;; FIXME: ANSI requires in "3.2.5 Exceptional Situations in the
466 ;; Compiler" that calling a function with "the wrong number of
467 ;; arguments" be only a STYLE-ERROR. I think, though, that this
468 ;; should only apply when the number of arguments is inferred
469 ;; from a previous definition. If the number of arguments
470 ;; is DECLAIMed, surely calling with the wrong number is a
471 ;; real WARNING. As long as SBCL continues to use CMU CL's
472 ;; non-ANSI DEFUN-is-a-DECLAIM policy, we're in violation here,
473 ;; but as long as we continue to use that policy, that's the
474 ;; not our biggest problem.:-| When we fix that policy, this
475 ;; should come back into compliance. (So fix that policy!)
477 ;; FIXME, continued: Except that section "3.2.2.3 Semantic
478 ;; Constraints" says that if it's within the same file, it's
479 ;; wrong. And we're in locall.lisp here, so it's probably
480 ;; (haven't checked this..) a call to something in the same
481 ;; file. So maybe it deserves a full warning anyway.
483 "function called with ~R argument~:P, but wants exactly ~R"
485 (setf (basic-combination-kind call) :error)))))
487 ;;;; &OPTIONAL, &MORE and &KEYWORD calls
489 ;;; This is similar to CONVERT-LAMBDA-CALL, but deals with
490 ;;; OPTIONAL-DISPATCHes. If only fixed args are supplied, then convert
491 ;;; a call to the correct entry point. If &KEY args are supplied, then
492 ;;; dispatch to a subfunction. We don't convert calls to functions
493 ;;; that have a &MORE (or &REST) arg.
494 (defun convert-hairy-call (ref call fun)
495 (declare (type ref ref) (type combination call)
496 (type optional-dispatch fun))
497 (let ((min-args (optional-dispatch-min-args fun))
498 (max-args (optional-dispatch-max-args fun))
499 (call-args (length (combination-args call))))
500 (cond ((< call-args min-args)
501 ;; FIXME: See FIXME note at the previous
502 ;; wrong-number-of-arguments warnings in this file.
504 "function called with ~R argument~:P, but wants at least ~R"
506 (setf (basic-combination-kind call) :error))
507 ((<= call-args max-args)
508 (convert-call ref call
509 (elt (optional-dispatch-entry-points fun)
510 (- call-args min-args))))
511 ((optional-dispatch-more-entry fun)
512 (convert-more-call ref call fun))
514 ;; FIXME: See FIXME note at the previous
515 ;; wrong-number-of-arguments warnings in this file.
517 "function called with ~R argument~:P, but wants at most ~R"
519 (setf (basic-combination-kind call) :error))))
522 ;;; This function is used to convert a call to an entry point when
523 ;;; complex transformations need to be done on the original arguments.
524 ;;; ENTRY is the entry point function that we are calling. VARS is a
525 ;;; list of variable names which are bound to the original call
526 ;;; arguments. IGNORES is the subset of VARS which are ignored. ARGS
527 ;;; is the list of arguments to the entry point function.
529 ;;; In order to avoid gruesome graph grovelling, we introduce a new
530 ;;; function that rearranges the arguments and calls the entry point.
531 ;;; We analyze the new function and the entry point immediately so
532 ;;; that everything gets converted during the single pass.
533 (defun convert-hairy-fun-entry (ref call entry vars ignores args)
534 (declare (list vars ignores args) (type ref ref) (type combination call)
535 (type clambda entry))
537 (with-ir1-environment-from-node call
540 (declare (ignorable . ,ignores))
541 (%funcall ,entry . ,args))
542 :debug-name (debug-namify "hairy function entry ~S"
543 (continuation-fun-name
544 (basic-combination-fun call)))))))
545 (convert-call ref call new-fun)
546 (dolist (ref (leaf-refs entry))
547 (convert-call-if-possible ref (continuation-dest (node-cont ref))))))
549 ;;; Use CONVERT-HAIRY-FUN-ENTRY to convert a &MORE-arg call to a known
550 ;;; function into a local call to the MAIN-ENTRY.
552 ;;; First we verify that all keywords are constant and legal. If there
553 ;;; aren't, then we warn the user and don't attempt to convert the call.
555 ;;; We massage the supplied &KEY arguments into the order expected
556 ;;; by the main entry. This is done by binding all the arguments to
557 ;;; the keyword call to variables in the introduced lambda, then
558 ;;; passing these values variables in the correct order when calling
559 ;;; the main entry. Unused arguments (such as the keywords themselves)
560 ;;; are discarded simply by not passing them along.
562 ;;; If there is a &REST arg, then we bundle up the args and pass them
564 (defun convert-more-call (ref call fun)
565 (declare (type ref ref) (type combination call) (type optional-dispatch fun))
566 (let* ((max (optional-dispatch-max-args fun))
567 (arglist (optional-dispatch-arglist fun))
568 (args (combination-args call))
569 (more (nthcdr max args))
570 (flame (policy call (or (> speed inhibit-warnings)
571 (> space inhibit-warnings))))
575 (temps (make-gensym-list max))
576 (more-temps (make-gensym-list (length more))))
581 (dolist (var arglist)
582 (let ((info (lambda-var-arg-info var)))
584 (ecase (arg-info-kind info)
588 ((:more-context :more-count)
589 (compiler-warn "can't local-call functions with &MORE args")
590 (setf (basic-combination-kind call) :error)
591 (return-from convert-more-call))))))
593 (when (optional-dispatch-keyp fun)
594 (when (oddp (length more))
595 (compiler-warn "function called with odd number of ~
596 arguments in keyword portion")
598 (setf (basic-combination-kind call) :error)
599 (return-from convert-more-call))
601 (do ((key more (cddr key))
602 (temp more-temps (cddr temp)))
604 (let ((cont (first key)))
605 (unless (constant-continuation-p cont)
607 (compiler-note "non-constant keyword in keyword call"))
608 (setf (basic-combination-kind call) :error)
609 (return-from convert-more-call))
611 (let ((name (continuation-value cont))
614 ;; FIXME: check whether KEY was supplied earlier
615 (when (and (eq name :allow-other-keys) (not allow-found))
616 (let ((val (second key)))
617 (cond ((constant-continuation-p val)
619 allowp (continuation-value val)))
621 (compiler-note "non-constant :ALLOW-OTHER-KEYS value"))
622 (setf (basic-combination-kind call) :error)
623 (return-from convert-more-call)))))
624 (dolist (var (key-vars)
627 (unless (eq name :allow-other-keys)
629 (let ((info (lambda-var-arg-info var)))
630 (when (eq (arg-info-key info) name)
632 (supplied (cons var val))
635 (when (and loser (not (optional-dispatch-allowp fun)) (not allowp))
636 (compiler-warn "function called with unknown argument keyword ~S"
638 (setf (basic-combination-kind call) :error)
639 (return-from convert-more-call)))
641 (collect ((call-args))
642 (do ((var arglist (cdr var))
643 (temp temps (cdr temp)))
645 (let ((info (lambda-var-arg-info (car var))))
647 (ecase (arg-info-kind info)
649 (call-args (car temp))
650 (when (arg-info-supplied-p info)
653 (call-args `(list ,@more-temps))
657 (call-args (car temp)))))
659 (dolist (var (key-vars))
660 (let ((info (lambda-var-arg-info var))
661 (temp (cdr (assoc var (supplied)))))
664 (call-args (arg-info-default info)))
665 (when (arg-info-supplied-p info)
666 (call-args (not (null temp))))))
668 (convert-hairy-fun-entry ref call (optional-dispatch-main-entry fun)
669 (append temps more-temps)
670 (ignores) (call-args)))))
676 ;;;; Converting to a LET has differing significance to various parts
677 ;;;; of the compiler:
678 ;;;; -- The body of a LET is spliced in immediately after the
679 ;;;; corresponding combination node, making the control transfer
680 ;;;; explicit and allowing LETs to be mashed together into a single
681 ;;;; block. The value of the LET is delivered directly to the
682 ;;;; original continuation for the call, eliminating the need to
683 ;;;; propagate information from the dummy result continuation.
684 ;;;; -- As far as IR1 optimization is concerned, it is interesting in
685 ;;;; that there is only one expression that the variable can be bound
686 ;;;; to, and this is easily substituted for.
687 ;;;; -- LETs are interesting to environment analysis and to the back
688 ;;;; end because in most ways a LET can be considered to be "the
689 ;;;; same function" as its home function.
690 ;;;; -- LET conversion has dynamic scope implications, since control
691 ;;;; transfers within the same environment are local. In a local
692 ;;;; control transfer, cleanup code must be emitted to remove
693 ;;;; dynamic bindings that are no longer in effect.
695 ;;; Set up the control transfer to the called CLAMBDA. We split the
696 ;;; call block immediately after the call, and link the head of
697 ;;; CLAMBDA to the call block. The successor block after splitting
698 ;;; (where we return to) is returned.
700 ;;; If the lambda is is a different component than the call, then we
701 ;;; call JOIN-COMPONENTS. This only happens in block compilation
702 ;;; before FIND-INITIAL-DFO.
703 (defun insert-let-body (clambda call)
704 (declare (type clambda clambda) (type basic-combination call))
705 (let* ((call-block (node-block call))
706 (bind-block (node-block (lambda-bind clambda)))
707 (component (block-component call-block)))
708 (aver-live-component component)
709 (let ((clambda-component (block-component bind-block)))
710 (unless (eq clambda-component component)
711 (aver (eq (component-kind component) :initial))
712 (join-components component clambda-component)))
713 (let ((*current-component* component))
714 (node-ends-block call))
715 ;; FIXME: Use DESTRUCTURING-BIND here, and grep for other
716 ;; uses of '=.*length' which could also be converted to use
717 ;; DESTRUCTURING-BIND or PROPER-LIST-OF-LENGTH-P.
718 (aver (= (length (block-succ call-block)) 1))
719 (let ((next-block (first (block-succ call-block))))
720 (unlink-blocks call-block next-block)
721 (link-blocks call-block bind-block)
724 ;;; Remove CLAMBDA from the tail set of anything it used to be in the
725 ;;; same set as; but leave CLAMBDA with a valid tail set value of
726 ;;; its own, for the benefit of code which might try to pull
727 ;;; something out of it (e.g. return type).
728 (defun depart-from-tail-set (clambda)
729 ;; Until sbcl-0.pre7.37.flaky5.2, we did
730 ;; (LET ((TAILS (LAMBDA-TAIL-SET CLAMBDA)))
731 ;; (SETF (TAIL-SET-FUNS TAILS)
732 ;; (DELETE CLAMBDA (TAIL-SET-FUNS TAILS))))
733 ;; (SETF (LAMBDA-TAIL-SET CLAMBDA) NIL)
734 ;; here. Apparently the idea behind the (SETF .. NIL) was that since
735 ;; TAIL-SET-FUNS no longer thinks we're in the tail set, it's
736 ;; inconsistent, and perhaps unsafe, for us to think we're in the
737 ;; tail set. Unfortunately..
739 ;; The (SETF .. NIL) caused problems in sbcl-0.pre7.37.flaky5.2 when
740 ;; I was trying to get Python to emit :EXTERNAL LAMBDAs directly
741 ;; (instead of only being able to emit funny little :TOPLEVEL stubs
742 ;; which you called in order to get the address of an external LAMBDA):
743 ;; the external function was defined in terms of internal function,
744 ;; which was LET-converted, and then things blew up downstream when
745 ;; FINALIZE-XEP-DEFINITION tried to find out its DEFINED-TYPE from
746 ;; the now-NILed-out TAIL-SET. So..
748 ;; To deal with this problem, we no longer NIL out
749 ;; (LAMBDA-TAIL-SET CLAMBDA) here. Instead:
750 ;; * If we're the only function in TAIL-SET-FUNS, it should
751 ;; be safe to leave ourself linked to it, and it to you.
752 ;; * If there are other functions in TAIL-SET-FUNS, then we're
753 ;; afraid of future optimizations on those functions causing
754 ;; the TAIL-SET object no longer to be valid to describe our
755 ;; return value. Thus, we delete ourselves from that object;
756 ;; but we save a newly-allocated tail-set, derived from the old
757 ;; one, for ourselves, for the use of later code (e.g.
758 ;; FINALIZE-XEP-DEFINITION) which might want to
759 ;; know about our return type.
760 (let* ((old-tail-set (lambda-tail-set clambda))
761 (old-tail-set-funs (tail-set-funs old-tail-set)))
762 (unless (= 1 (length old-tail-set-funs))
763 (setf (tail-set-funs old-tail-set)
764 (delete clambda old-tail-set-funs))
765 (let ((new-tail-set (copy-tail-set old-tail-set)))
766 (setf (lambda-tail-set clambda) new-tail-set
767 (tail-set-funs new-tail-set) (list clambda)))))
768 ;; The documentation on TAIL-SET-INFO doesn't tell whether it could
769 ;; remain valid in this case, so we nuke it on the theory that
770 ;; missing information tends to be less dangerous than incorrect
772 (setf (tail-set-info (lambda-tail-set clambda)) nil))
774 ;;; Handle the PHYSENV semantics of LET conversion. We add CLAMBDA and
775 ;;; its LETs to LETs for the CALL's home function. We merge the calls
776 ;;; for CLAMBDA with the calls for the home function, removing CLAMBDA
777 ;;; in the process. We also merge the ENTRIES.
779 ;;; We also unlink the function head from the component head and set
780 ;;; COMPONENT-REANALYZE to true to indicate that the DFO should be
782 (defun merge-lets (clambda call)
784 (declare (type clambda clambda) (type basic-combination call))
786 (let ((component (node-component call)))
787 (unlink-blocks (component-head component) (lambda-block clambda))
788 (setf (component-lambdas component)
789 (delete clambda (component-lambdas component)))
790 (setf (component-reanalyze component) t))
791 (setf (lambda-call-lexenv clambda) (node-lexenv call))
793 (depart-from-tail-set clambda)
795 (let* ((home (node-home-lambda call))
796 (home-physenv (lambda-physenv home)))
798 (aver (not (eq home clambda)))
800 ;; CLAMBDA belongs to HOME now.
801 (push clambda (lambda-lets home))
802 (setf (lambda-home clambda) home)
803 (setf (lambda-physenv clambda) home-physenv)
805 ;; All of CLAMBDA's LETs belong to HOME now.
806 (let ((lets (lambda-lets clambda)))
808 (setf (lambda-home let) home)
809 (setf (lambda-physenv let) home-physenv))
810 (setf (lambda-lets home) (nconc lets (lambda-lets home))))
811 ;; CLAMBDA no longer has an independent existence as an entity
813 (setf (lambda-lets clambda) nil)
815 ;; HOME no longer calls CLAMBDA, and owns all of CLAMBDA's old
817 (setf (lambda-calls-or-closes home)
819 (nunion (lambda-calls-or-closes clambda)
820 (lambda-calls-or-closes home))))
821 ;; CLAMBDA no longer has an independent existence as an entity
822 ;; which calls things or has DFO dependencies.
823 (setf (lambda-calls-or-closes clambda) nil)
825 ;; All of CLAMBDA's ENTRIES belong to HOME now.
826 (setf (lambda-entries home)
827 (nconc (lambda-entries clambda)
828 (lambda-entries home)))
829 ;; CLAMBDA no longer has an independent existence as an entity
831 (setf (lambda-entries clambda) nil))
835 ;;; Handle the value semantics of LET conversion. Delete FUN's return
836 ;;; node, and change the control flow to transfer to NEXT-BLOCK
837 ;;; instead. Move all the uses of the result continuation to CALL's
840 ;;; If the actual continuation is only used by the LET call, then we
841 ;;; intersect the type assertion on the dummy continuation with the
842 ;;; assertion for the actual continuation; in all other cases
843 ;;; assertions on the dummy continuation are lost.
845 ;;; We also intersect the derived type of the CALL with the derived
846 ;;; type of all the dummy continuation's uses. This serves mainly to
847 ;;; propagate TRULY-THE through LETs.
848 (defun move-return-uses (fun call next-block)
849 (declare (type clambda fun) (type basic-combination call)
850 (type cblock next-block))
851 (let* ((return (lambda-return fun))
852 (return-block (node-block return)))
853 (unlink-blocks return-block
854 (component-tail (block-component return-block)))
855 (link-blocks return-block next-block)
857 (delete-return return)
858 (let ((result (return-result return))
859 (cont (node-cont call))
860 (call-type (node-derived-type call)))
861 (when (eq (continuation-use cont) call)
862 (set-continuation-type-assertion
864 (continuation-asserted-type result)
865 (continuation-type-to-check result)))
866 (unless (eq call-type *wild-type*)
867 (do-uses (use result)
868 (derive-node-type use call-type)))
869 (substitute-continuation-uses cont result)))
872 ;;; Change all CONT for all the calls to FUN to be the start
873 ;;; continuation for the bind node. This allows the blocks to be
874 ;;; joined if the caller count ever goes to one.
875 (defun move-let-call-cont (fun)
876 (declare (type clambda fun))
877 (let ((new-cont (node-prev (lambda-bind fun))))
878 (dolist (ref (leaf-refs fun))
879 (let ((dest (continuation-dest (node-cont ref))))
880 (delete-continuation-use dest)
881 (add-continuation-use dest new-cont))))
884 ;;; We are converting FUN to be a LET when the call is in a non-tail
885 ;;; position. Any previously tail calls in FUN are no longer tail
886 ;;; calls, and must be restored to normal calls which transfer to
887 ;;; NEXT-BLOCK (FUN's return point.) We can't do this by DO-USES on
888 ;;; the RETURN-RESULT, because the return might have been deleted (if
889 ;;; all calls were TR.)
890 (defun unconvert-tail-calls (fun call next-block)
891 (dolist (called (lambda-calls-or-closes fun))
892 (when (lambda-p called)
893 (dolist (ref (leaf-refs called))
894 (let ((this-call (continuation-dest (node-cont ref))))
896 (node-tail-p this-call)
897 (eq (node-home-lambda this-call) fun))
898 (setf (node-tail-p this-call) nil)
899 (ecase (functional-kind called)
900 ((nil :cleanup :optional)
901 (let ((block (node-block this-call))
902 (cont (node-cont call)))
903 (ensure-block-start cont)
904 (unlink-blocks block (first (block-succ block)))
905 (link-blocks block next-block)
906 (delete-continuation-use this-call)
907 (add-continuation-use this-call cont)))
909 ;; The called function might be an assignment in the
910 ;; case where we are currently converting that function.
911 ;; In steady-state, assignments never appear as a called
914 (aver (eq called fun)))))))))
917 ;;; Deal with returning from a LET or assignment that we are
918 ;;; converting. FUN is the function we are calling, CALL is a call to
919 ;;; FUN, and NEXT-BLOCK is the return point for a non-tail call, or
920 ;;; NULL if call is a tail call.
922 ;;; If the call is not a tail call, then we must do
923 ;;; UNCONVERT-TAIL-CALLS, since a tail call is a call which returns
924 ;;; its value out of the enclosing non-let function. When call is
925 ;;; non-TR, we must convert it back to an ordinary local call, since
926 ;;; the value must be delivered to the receiver of CALL's value.
928 ;;; We do different things depending on whether the caller and callee
929 ;;; have returns left:
931 ;;; -- If the callee has no return we just do MOVE-LET-CALL-CONT.
932 ;;; Either the function doesn't return, or all returns are via
933 ;;; tail-recursive local calls.
934 ;;; -- If CALL is a non-tail call, or if both have returns, then
935 ;;; we delete the callee's return, move its uses to the call's
936 ;;; result continuation, and transfer control to the appropriate
938 ;;; -- If the callee has a return, but the caller doesn't, then we
939 ;;; move the return to the caller.
940 (defun move-return-stuff (fun call next-block)
941 (declare (type clambda fun) (type basic-combination call)
942 (type (or cblock null) next-block))
944 (unconvert-tail-calls fun call next-block))
945 (let* ((return (lambda-return fun))
946 (call-fun (node-home-lambda call))
947 (call-return (lambda-return call-fun)))
949 ((or next-block call-return)
950 (unless (block-delete-p (node-block return))
951 (move-return-uses fun call
952 (or next-block (node-block call-return)))))
954 (aver (node-tail-p call))
955 (setf (lambda-return call-fun) return)
956 (setf (return-lambda return) call-fun))))
957 (move-let-call-cont fun)
960 ;;; Actually do LET conversion. We call subfunctions to do most of the
961 ;;; work. We change the CALL's CONT to be the continuation heading the
962 ;;; BIND block, and also do REOPTIMIZE-CONTINUATION on the args and
963 ;;; CONT so that LET-specific IR1 optimizations get a chance. We blow
964 ;;; away any entry for the function in *FREE-FUNS* so that nobody
965 ;;; will create new references to it.
966 (defun let-convert (fun call)
967 (declare (type clambda fun) (type basic-combination call))
968 (let ((next-block (if (node-tail-p call)
970 (insert-let-body fun call))))
971 (move-return-stuff fun call next-block)
972 (merge-lets fun call)))
974 ;;; Reoptimize all of CALL's args and its result.
975 (defun reoptimize-call (call)
976 (declare (type basic-combination call))
977 (dolist (arg (basic-combination-args call))
979 (reoptimize-continuation arg)))
980 (reoptimize-continuation (node-cont call))
983 ;;; Are there any declarations in force to say CLAMBDA shouldn't be
985 (define-optimization-quality let-convertion
986 (if (<= debug speed) 3 0)
987 ("off" "maybe" "on" "on"))
988 (defun declarations-suppress-let-conversion-p (clambda)
989 ;; From the user's point of view, LET-converting something that
990 ;; has a name is inlining it. (The user can't see what we're doing
991 ;; with anonymous things, and suppressing inlining
992 ;; for such things can easily give Python acute indigestion, so
994 (when (leaf-has-source-name-p clambda)
995 ;; ANSI requires that explicit NOTINLINE be respected.
996 (or (eq (lambda-inlinep clambda) :notinline)
997 ;; If (= LET-CONVERTION 0) we can guess that inlining
998 ;; generally won't be appreciated, but if the user
999 ;; specifically requests inlining, that takes precedence over
1000 ;; our general guess.
1001 (and (policy clambda (= let-convertion 0))
1002 (not (eq (lambda-inlinep clambda) :inline))))))
1004 ;;; We also don't convert calls to named functions which appear in the
1005 ;;; initial component, delaying this until optimization. This
1006 ;;; minimizes the likelihood that we will LET-convert a function which
1007 ;;; may have references added due to later local inline expansion.
1008 (defun ok-initial-convert-p (fun)
1009 (not (and (leaf-has-source-name-p fun)
1010 (or (declarations-suppress-let-conversion-p fun)
1011 (eq (component-kind (lambda-component fun))
1014 ;;; This function is called when there is some reason to believe that
1015 ;;; CLAMBDA might be converted into a LET. This is done after local
1016 ;;; call analysis, and also when a reference is deleted. We return
1017 ;;; true if we converted.
1018 (defun maybe-let-convert (clambda)
1019 (declare (type clambda clambda))
1020 (unless (declarations-suppress-let-conversion-p clambda)
1021 ;; We only convert to a LET when the function is a normal local
1022 ;; function, has no XEP, and is referenced in exactly one local
1023 ;; call. Conversion is also inhibited if the only reference is in
1024 ;; a block about to be deleted.
1026 ;; These rules limiting LET conversion may seem unnecessarily
1027 ;; restrictive, since there are some cases where we could do the
1028 ;; return with a jump that don't satisfy these requirements. The
1029 ;; reason for doing things this way is that it makes the concept
1030 ;; of a LET much more useful at the level of IR1 semantics. The
1031 ;; :ASSIGNMENT function kind provides another way to optimize
1032 ;; calls to single-return/multiple call functions.
1034 ;; We don't attempt to convert calls to functions that have an
1035 ;; XEP, since we might be embarrassed later when we want to
1036 ;; convert a newly discovered local call. Also, see
1037 ;; OK-INITIAL-CONVERT-P.
1038 (let ((refs (leaf-refs clambda)))
1041 (member (functional-kind clambda) '(nil :assignment))
1042 (not (functional-entry-fun clambda)))
1043 (let* ((ref (first refs))
1044 (ref-cont (node-cont ref))
1045 (dest (continuation-dest ref-cont)))
1047 (basic-combination-p dest)
1048 (eq (basic-combination-fun dest) ref-cont)
1049 (eq (basic-combination-kind dest) :local)
1050 (not (block-delete-p (node-block dest)))
1051 (cond ((ok-initial-convert-p clambda) t)
1053 (reoptimize-continuation ref-cont)
1055 (when (eq clambda (node-home-lambda dest))
1056 (delete-lambda clambda)
1057 (return-from maybe-let-convert nil))
1058 (unless (eq (functional-kind clambda) :assignment)
1059 (let-convert clambda dest))
1060 (reoptimize-call dest)
1061 (setf (functional-kind clambda)
1062 (if (mv-combination-p dest) :mv-let :let))))
1065 ;;;; tail local calls and assignments
1067 ;;; Return T if there are no cleanups between BLOCK1 and BLOCK2, or if
1068 ;;; they definitely won't generate any cleanup code. Currently we
1069 ;;; recognize lexical entry points that are only used locally (if at
1071 (defun only-harmless-cleanups (block1 block2)
1072 (declare (type cblock block1 block2))
1073 (or (eq block1 block2)
1074 (let ((cleanup2 (block-start-cleanup block2)))
1075 (do ((cleanup (block-end-cleanup block1)
1076 (node-enclosing-cleanup (cleanup-mess-up cleanup))))
1077 ((eq cleanup cleanup2) t)
1078 (case (cleanup-kind cleanup)
1080 (unless (null (entry-exits (cleanup-mess-up cleanup)))
1082 (t (return nil)))))))
1084 ;;; If a potentially TR local call really is TR, then convert it to
1085 ;;; jump directly to the called function. We also call
1086 ;;; MAYBE-CONVERT-TO-ASSIGNMENT. The first value is true if we
1087 ;;; tail-convert. The second is the value of M-C-T-A. We can switch
1088 ;;; the succesor (potentially deleting the RETURN node) unless:
1089 ;;; -- The call has already been converted.
1090 ;;; -- The call isn't TR (some implicit MV PROG1.)
1091 ;;; -- The call is in an XEP (thus we might decide to make it non-tail
1092 ;;; so that we can use known return inside the component.)
1093 ;;; -- There is a change in the cleanup between the call in the return,
1094 ;;; so we might need to introduce cleanup code.
1095 (defun maybe-convert-tail-local-call (call)
1096 (declare (type combination call))
1097 (let ((return (continuation-dest (node-cont call))))
1098 (aver (return-p return))
1099 (when (and (not (node-tail-p call))
1100 (immediately-used-p (return-result return) call)
1101 (not (eq (functional-kind (node-home-lambda call))
1103 (only-harmless-cleanups (node-block call)
1104 (node-block return)))
1105 (node-ends-block call)
1106 (let ((block (node-block call))
1107 (fun (combination-lambda call)))
1108 (setf (node-tail-p call) t)
1109 (unlink-blocks block (first (block-succ block)))
1110 (link-blocks block (lambda-block fun))
1111 (values t (maybe-convert-to-assignment fun))))))
1113 ;;; This is called when we believe it might make sense to convert
1114 ;;; CLAMBDA to an assignment. All this function really does is
1115 ;;; determine when a function with more than one call can still be
1116 ;;; combined with the calling function's environment. We can convert
1118 ;;; -- The function is a normal, non-entry function, and
1119 ;;; -- Except for one call, all calls must be tail recursive calls
1120 ;;; in the called function (i.e. are self-recursive tail calls)
1121 ;;; -- OK-INITIAL-CONVERT-P is true.
1123 ;;; There may be one outside call, and it need not be tail-recursive.
1124 ;;; Since all tail local calls have already been converted to direct
1125 ;;; transfers, the only control semantics needed are to splice in the
1126 ;;; body at the non-tail call. If there is no non-tail call, then we
1127 ;;; need only merge the environments. Both cases are handled by
1130 ;;; ### It would actually be possible to allow any number of outside
1131 ;;; calls as long as they all return to the same place (i.e. have the
1132 ;;; same conceptual continuation.) A special case of this would be
1133 ;;; when all of the outside calls are tail recursive.
1134 (defun maybe-convert-to-assignment (clambda)
1135 (declare (type clambda clambda))
1136 (when (and (not (functional-kind clambda))
1137 (not (functional-entry-fun clambda)))
1138 (let ((outside-non-tail-call nil)
1140 (when (and (dolist (ref (leaf-refs clambda) t)
1141 (let ((dest (continuation-dest (node-cont ref))))
1142 (when (or (not dest)
1143 (block-delete-p (node-block dest)))
1145 (let ((home (node-home-lambda ref)))
1146 (unless (eq home clambda)
1149 (setq outside-call dest))
1150 (unless (node-tail-p dest)
1151 (when (or outside-non-tail-call (eq home clambda))
1153 (setq outside-non-tail-call dest)))))
1154 (ok-initial-convert-p clambda))
1155 (cond (outside-call (setf (functional-kind clambda) :assignment)
1156 (let-convert clambda outside-call)
1157 (when outside-non-tail-call
1158 (reoptimize-call outside-non-tail-call))
1160 (t (delete-lambda clambda)