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Revision 1.83 - (hide annotations)
Mon Aug 30 14:55:38 2004 UTC (9 years, 7 months ago) by rtoy
Branch: MAIN
CVS Tags: release-19b-pre1, release-19b-pre2, snapshot-2004-10, snapshot-2004-09, release-19c, release-19c-base, snapshot-2004-12, snapshot-2004-11, snapshot-2005-07, snapshot-2005-03, release-19b-base, snapshot-2005-10, snapshot-2005-01, release-19c-pre1, snapshot-2005-06, snapshot-2005-05, snapshot-2005-04, ppc_gencgc_snap_2005-05-14, snapshot-2005-02, snapshot-2005-09, snapshot-2005-08
Branch point for: release-19b-branch, ppc_gencgc_branch, release-19c-branch
Changes since 1.82: +7 -2 lines
Apply patch from Jan Rychter that implements return-from-frame
(debug-return).  No bootstrap file or cross-compile needed.
Return-from-frame only works when debug = 3.
1 wlott 1.1 ;;; -*- Package: C; Log: C.Log -*-
2     ;;;
3     ;;; **********************************************************************
4 ram 1.24 ;;; This code was written as part of the CMU Common Lisp project at
5     ;;; Carnegie Mellon University, and has been placed in the public domain.
6     ;;;
7     (ext:file-comment
8 rtoy 1.83 "$Header: /tiger/var/lib/cvsroots/cmucl/src/compiler/ir1opt.lisp,v 1.83 2004/08/30 14:55:38 rtoy Exp $")
9 ram 1.24 ;;;
10 wlott 1.1 ;;; **********************************************************************
11     ;;;
12     ;;; This file implements the IR1 optimization phase of the compiler. IR1
13     ;;; optimization is a grab-bag of optimizations that don't make major changes
14     ;;; to the block-level control flow and don't use flow analysis. These
15     ;;; optimizations can mostly be classified as "meta-evaluation", but there is a
16     ;;; sizable top-down component as well.
17     ;;;
18     ;;; Written by Rob MacLachlan
19     ;;;
20 ram 1.46 (in-package :c)
21 wlott 1.1
22    
23     ;;;; Interface for obtaining results of constant folding:
24    
25     ;;; Constant-Continuation-P -- Interface
26     ;;;
27     ;;; Return true if the sole use of Cont is a reference to a constant leaf.
28     ;;;
29     (defun constant-continuation-p (cont)
30 dtc 1.71 (declare (type continuation cont) (values boolean))
31 wlott 1.1 (let ((use (continuation-use cont)))
32     (and (ref-p use)
33     (constant-p (ref-leaf use)))))
34    
35    
36     ;;; Continuation-Value -- Interface
37     ;;;
38     ;;; Return the constant value for a continuation whose only use is a
39     ;;; constant node.
40     ;;;
41     (defun continuation-value (cont)
42 dtc 1.71 (declare (type continuation cont))
43 ram 1.10 (assert (constant-continuation-p cont))
44 wlott 1.1 (constant-value (ref-leaf (continuation-use cont))))
45    
46    
47     ;;;; Interface for obtaining results of type inference:
48    
49     ;;; CONTINUATION-PROVEN-TYPE -- Interface
50     ;;;
51     ;;; Return a (possibly values) type that describes what we have proven about
52     ;;; the type of Cont without taking any type assertions into consideration.
53     ;;; This is just the union of the NODE-DERIVED-TYPE of all the uses. Most
54     ;;; often people use CONTINUATION-DERIVED-TYPE or CONTINUATION-TYPE instead of
55     ;;; using this function directly.
56     ;;;
57     (defun continuation-proven-type (cont)
58     (declare (type continuation cont))
59     (ecase (continuation-kind cont)
60     ((:block-start :deleted-block-start)
61     (let ((uses (block-start-uses (continuation-block cont))))
62     (if uses
63     (do ((res (node-derived-type (first uses))
64     (values-type-union (node-derived-type (first current))
65     res))
66     (current (rest uses) (rest current)))
67     ((null current) res))
68     *empty-type*)))
69     (:inside-block
70 gerd 1.80 (node-derived-type (continuation-use cont)))
71     (:unused
72     *empty-type*)))
73 wlott 1.1
74    
75     ;;; Continuation-Derived-Type -- Interface
76     ;;;
77     ;;; Our best guess for the type of this continuation's value. Note that
78     ;;; this may be Values or Function type, which cannot be passed as an argument
79     ;;; to the normal type operations. See Continuation-Type. This may be called
80     ;;; on deleted continuations, always returning *.
81     ;;;
82     ;;; What we do is call CONTINUATION-PROVEN-TYPE and check whether the result
83     ;;; is a subtype of the assertion. If so, return the proven type and set
84     ;;; TYPE-CHECK to nil. Otherwise, return the intersection of the asserted and
85     ;;; proven types, and set TYPE-CHECK T. If TYPE-CHECK already has a non-null
86     ;;; value, then preserve it. Only in the somewhat unusual circumstance of
87     ;;; a newly discovered assertion will we change TYPE-CHECK from NIL to T.
88     ;;;
89     ;;; The result value is cached in the Continuation-%Derived-Type. If the
90     ;;; slot is true, just return that value, otherwise recompute and stash the
91     ;;; value there.
92     ;;;
93 pw 1.74 (declaim (inline continuation-derived-type))
94 wlott 1.1 (defun continuation-derived-type (cont)
95     (declare (type continuation cont))
96     (or (continuation-%derived-type cont)
97     (%continuation-derived-type cont)))
98     ;;;
99     (defun %continuation-derived-type (cont)
100     (declare (type continuation cont))
101     (let ((proven (continuation-proven-type cont))
102     (asserted (continuation-asserted-type cont)))
103     (cond ((values-subtypep proven asserted)
104     (setf (continuation-%type-check cont) nil)
105     (setf (continuation-%derived-type cont) proven))
106     (t
107     (unless (or (continuation-%type-check cont)
108     (not (continuation-dest cont))
109     (eq asserted *universal-type*))
110     (setf (continuation-%type-check cont) t))
111    
112     (setf (continuation-%derived-type cont)
113     (values-type-intersection asserted proven))))))
114    
115    
116     ;;; CONTINUATION-TYPE-CHECK -- Interface
117     ;;;
118     ;;; Call CONTINUATION-DERIVED-TYPE to make sure the slot is up to date, then
119     ;;; return it.
120     ;;;
121 pw 1.74 (declaim (inline continuation-type-check))
122 wlott 1.1 (defun continuation-type-check (cont)
123     (declare (type continuation cont))
124     (continuation-derived-type cont)
125     (continuation-%type-check cont))
126    
127    
128     ;;; Continuation-Type -- Interface
129     ;;;
130     ;;; Return the derived type for Cont's first value. This is guaranteed not
131     ;;; to be a Values or Function type.
132     ;;;
133     (defun continuation-type (cont)
134 dtc 1.71 (declare (type continuation cont) (values ctype))
135 wlott 1.1 (single-value-type (continuation-derived-type cont)))
136    
137    
138     ;;;; Interface routines used by optimizers:
139    
140     ;;; Reoptimize-Continuation -- Interface
141     ;;;
142     ;;; This function is called by optimizers to indicate that something
143     ;;; interesting has happened to the value of Cont. Optimizers must make sure
144     ;;; that they don't call for reoptimization when nothing has happened, since
145     ;;; optimization will fail to terminate.
146     ;;;
147     ;;; We clear any cached type for the continuation and set the reoptimize
148     ;;; flags on everything in sight, unless the continuation is deleted (in which
149     ;;; case we do nothing.)
150     ;;;
151     ;;; Since this can get called curing IR1 conversion, we have to be careful
152     ;;; not to fly into space when the Dest's Prev is missing.
153     ;;;
154     (defun reoptimize-continuation (cont)
155     (declare (type continuation cont))
156 ram 1.29 (unless (member (continuation-kind cont) '(:deleted :unused))
157 wlott 1.1 (setf (continuation-%derived-type cont) nil)
158     (let ((dest (continuation-dest cont)))
159     (when dest
160     (setf (continuation-reoptimize cont) t)
161     (setf (node-reoptimize dest) t)
162     (let ((prev (node-prev dest)))
163     (when prev
164     (let* ((block (continuation-block prev))
165     (component (block-component block)))
166 ram 1.18 (when (typep dest 'cif)
167     (setf (block-test-modified block) t))
168 wlott 1.1 (setf (block-reoptimize block) t)
169     (setf (component-reoptimize component) t))))))
170     (do-uses (node cont)
171     (setf (block-type-check (node-block node)) t)))
172     (undefined-value))
173    
174    
175     ;;; Derive-Node-Type -- Interface
176     ;;;
177     ;;; Annotate Node to indicate that its result has been proven to be typep to
178     ;;; RType. After IR1 conversion has happened, this is the only correct way to
179     ;;; supply information discovered about a node's type. If you fuck with the
180     ;;; Node-Derived-Type directly, then information may be lost and reoptimization
181     ;;; may not happen.
182     ;;;
183     ;;; What we do is intersect Rtype with Node's Derived-Type. If the
184     ;;; intersection is different from the old type, then we do a
185     ;;; Reoptimize-Continuation on the Node-Cont.
186     ;;;
187     (defun derive-node-type (node rtype)
188     (declare (type node node) (type ctype rtype))
189     (let ((node-type (node-derived-type node)))
190     (unless (eq node-type rtype)
191     (let ((int (values-type-intersection node-type rtype)))
192     (when (type/= node-type int)
193 ram 1.38 (when (and *check-consistency*
194     (eq int *empty-type*)
195 ram 1.34 (not (eq rtype *empty-type*)))
196     (let ((*compiler-error-context* node))
197     (compiler-warning
198     "New inferred type ~S conflicts with old type:~
199     ~% ~S~%*** Bug?"
200     (type-specifier rtype) (type-specifier node-type))))
201 wlott 1.1 (setf (node-derived-type node) int)
202     (reoptimize-continuation (node-cont node))))))
203     (undefined-value))
204    
205 dtc 1.70 (declaim (start-block assert-continuation-type
206     assert-continuation-optional-type assert-call-type))
207 wlott 1.1
208     ;;; Assert-Continuation-Type -- Interface
209     ;;;
210     ;;; Similar to Derive-Node-Type, but asserts that it is an error for Cont's
211     ;;; value not to be typep to Type. If we improve the assertion, we set
212 ram 1.11 ;;; TYPE-CHECK and TYPE-ASSERTED to guarantee that the new assertion will be
213     ;;; checked.
214 wlott 1.1 ;;;
215     (defun assert-continuation-type (cont type)
216     (declare (type continuation cont) (type ctype type))
217     (let ((cont-type (continuation-asserted-type cont)))
218     (unless (eq cont-type type)
219     (let ((int (values-type-intersection cont-type type)))
220     (when (type/= cont-type int)
221     (setf (continuation-asserted-type cont) int)
222     (do-uses (node cont)
223 ram 1.11 (setf (block-attributep (block-flags (node-block node))
224     type-check type-asserted)
225     t))
226 wlott 1.1 (reoptimize-continuation cont)))))
227     (undefined-value))
228    
229    
230 dtc 1.70 ;;; Assert-continuation-optional-type -- Interface
231     ;;;
232     ;;; Similar to Assert-Continuation-Type, but asserts that the type is
233     ;;; for an optional argument and that other arguments may be received.
234     ;;;
235     (defun assert-continuation-optional-type (cont type)
236     (declare (type continuation cont) (type ctype type))
237     (let ((opt-type (make-values-type :optional (list type)
238     :rest *universal-type*)))
239     (assert-continuation-type cont opt-type)))
240    
241    
242 wlott 1.1 ;;; Assert-Call-Type -- Interface
243     ;;;
244     ;;; Assert that Call is to a function of the specified Type. It is assumed
245     ;;; that the call is legal and has only constants in the keyword positions.
246     ;;;
247     (defun assert-call-type (call type)
248     (declare (type combination call) (type function-type type))
249     (derive-node-type call (function-type-returns type))
250     (let ((args (combination-args call)))
251     (dolist (req (function-type-required type))
252     (when (null args) (return-from assert-call-type))
253     (let ((arg (pop args)))
254 dtc 1.70 (assert-continuation-optional-type arg req)))
255 wlott 1.1 (dolist (opt (function-type-optional type))
256     (when (null args) (return-from assert-call-type))
257     (let ((arg (pop args)))
258 dtc 1.70 (assert-continuation-optional-type arg opt)))
259 wlott 1.1
260     (let ((rest (function-type-rest type)))
261     (when rest
262     (dolist (arg args)
263 dtc 1.70 (assert-continuation-optional-type arg rest))))
264 wlott 1.1
265     (dolist (key (function-type-keywords type))
266     (let ((name (key-info-name key)))
267     (do ((arg args (cddr arg)))
268     ((null arg))
269     (when (eq (continuation-value (first arg)) name)
270 dtc 1.70 (assert-continuation-optional-type
271 wlott 1.1 (second arg) (key-info-type key)))))))
272     (undefined-value))
273    
274    
275 ram 1.50 ;;;; IR1-OPTIMIZE:
276    
277     (declaim (start-block ir1-optimize))
278    
279 wlott 1.1 ;;; IR1-Optimize -- Interface
280     ;;;
281     ;;; Do one forward pass over Component, deleting unreachable blocks and
282 ram 1.11 ;;; doing IR1 optimizations. We can ignore all blocks that don't have the
283     ;;; Reoptimize flag set. If Component-Reoptimize is true when we are done,
284 wlott 1.1 ;;; then another iteration would be beneficial.
285     ;;;
286     ;;; We delete blocks when there is either no predecessor or the block is in
287     ;;; a lambda that has been deleted. These blocks would eventually be deleted
288     ;;; by DFO recomputation, but doing it here immediately makes the effect
289     ;;; avaliable to IR1 optimization.
290     ;;;
291     (defun ir1-optimize (component)
292     (declare (type component component))
293     (setf (component-reoptimize component) nil)
294     (do-blocks (block component)
295     (cond
296 gerd 1.82 ((block-unreachable-p block)
297 wlott 1.1 (delete-block block))
298     (t
299     (loop
300     (let ((succ (block-succ block)))
301     (unless (and succ (null (rest succ)))
302     (return)))
303    
304     (let ((last (block-last block)))
305     (typecase last
306     (cif
307 gerd 1.82 (let ((if-test (if-test last)))
308     ;; Don't flush an if-test if it requires a type check.
309     (unless (memq (continuation-type-check if-test) '(nil :deleted))
310     (return))
311     (flush-dest if-test)
312     (when (unlink-node last)
313     (return))))
314 wlott 1.1 (exit
315 gerd 1.82 (when (maybe-delete-exit last)
316     (return)))))
317 wlott 1.1
318     (unless (join-successor-if-possible block)
319     (return)))
320 gerd 1.82 ;;
321     ;; Block-Component is nil for deleted blocks.
322     (when (block-component block)
323     (cond ((block-unreachable-p block)
324     (delete-block block))
325     (t
326     (when (block-reoptimize block)
327     (ir1-optimize-block block))
328     (when (and (block-flush-p block)
329     (block-component block))
330     (flush-dead-code block))))))))
331     (values))
332 wlott 1.1
333     ;;; IR1-Optimize-Block -- Internal
334     ;;;
335     ;;; Loop over the nodes in Block, looking for stuff that needs to be
336     ;;; optimized. We dispatch off of the type of each node with its reoptimize
337     ;;; flag set:
338     ;;; -- With a combination, we call Propagate-Function-Change whenever the
339     ;;; function changes, and call IR1-Optimize-Combination if any argument
340     ;;; changes.
341     ;;; -- With an Exit, we derive the node's type from the Value's type. We don't
342     ;;; propagate Cont's assertion to the Value, since if we did, this would
343     ;;; move the checking of Cont's assertion to the exit. This wouldn't work
344     ;;; with Catch and UWP, where the Exit node is just a placeholder for the
345     ;;; actual unknown exit.
346     ;;;
347     ;;; Note that we clear the node & block reoptimize flags *before* doing the
348     ;;; optimization. This ensures that the node or block will be reoptimized if
349 ram 1.19 ;;; necessary. We leave the NODE-OPTIMIZE flag set going into
350 wlott 1.1 ;;; IR1-OPTIMIZE-RETURN, since it wants to clear the flag itself.
351     ;;;
352     (defun ir1-optimize-block (block)
353     (declare (type cblock block))
354     (setf (block-reoptimize block) nil)
355 ram 1.19 (do-nodes (node cont block :restart-p t)
356 wlott 1.1 (when (node-reoptimize node)
357     (setf (node-reoptimize node) nil)
358     (typecase node
359     (ref)
360     (combination
361 ram 1.50 (ir1-optimize-combination node))
362 wlott 1.1 (cif
363     (ir1-optimize-if node))
364     (creturn
365     (setf (node-reoptimize node) t)
366     (ir1-optimize-return node))
367 ram 1.6 (mv-combination
368 ram 1.21 (ir1-optimize-mv-combination node))
369 wlott 1.1 (exit
370     (let ((value (exit-value node)))
371     (when value
372     (derive-node-type node (continuation-derived-type value)))))
373     (cset
374     (ir1-optimize-set node)))))
375     (undefined-value))
376    
377 ram 1.50
378 wlott 1.1 ;;; Join-Successor-If-Possible -- Internal
379     ;;;
380     ;;; We cannot combine with a successor block if:
381     ;;; 1] The successor has more than one predecessor.
382     ;;; 2] The last node's Cont is also used somewhere else.
383     ;;; 3] The successor is the current block (infinite loop).
384     ;;; 4] The next block has a different cleanup, and thus we may want to insert
385     ;;; cleanup code between the two blocks at some point.
386     ;;; 5] The next block has a different home lambda, and thus the control
387     ;;; transfer is a non-local exit.
388     ;;;
389     ;;; If we succeed, we return true, otherwise false.
390     ;;;
391     ;;; Joining is easy when the successor's Start continuation is the same from
392     ;;; our Last's Cont. If they differ, then we can still join when the last
393     ;;; continuation has no next and the next continuation has no uses. In this
394 ram 1.5 ;;; case, we replace the next continuation with the last before joining the
395 wlott 1.1 ;;; blocks.
396     ;;;
397     (defun join-successor-if-possible (block)
398     (declare (type cblock block))
399     (let ((next (first (block-succ block))))
400 ram 1.11 (when (block-start next)
401 wlott 1.1 (let* ((last (block-last block))
402     (last-cont (node-cont last))
403 ram 1.11 (next-cont (block-start next)))
404 wlott 1.1 (cond ((or (rest (block-pred next))
405 ram 1.5 (not (eq (continuation-use last-cont) last))
406 wlott 1.1 (eq next block)
407 ram 1.11 (not (eq (block-end-cleanup block)
408     (block-start-cleanup next)))
409     (not (eq (block-home-lambda block)
410     (block-home-lambda next))))
411 wlott 1.1 nil)
412 ram 1.5 ((eq last-cont next-cont)
413 wlott 1.1 (join-blocks block next)
414     t)
415 ram 1.5 ((and (null (block-start-uses next))
416     (eq (continuation-kind last-cont) :inside-block))
417     (let ((next-node (continuation-next next-cont)))
418 ram 1.30 ;;
419     ;; If next-cont does have a dest, it must be unreachable,
420     ;; since there are no uses. DELETE-CONTINUATION will mark the
421     ;; dest block as delete-p [and also this block, unless it is
422     ;; no longer backward reachable from the dest block.]
423 ram 1.5 (delete-continuation next-cont)
424     (setf (node-prev next-node) last-cont)
425     (setf (continuation-next last-cont) next-node)
426     (setf (block-start next) last-cont)
427     (join-blocks block next))
428 wlott 1.1 t)
429     (t
430     nil))))))
431    
432    
433     ;;; Join-Blocks -- Internal
434     ;;;
435     ;;; Join together two blocks which have the same ending/starting
436     ;;; continuation. The code in Block2 is moved into Block1 and Block2 is
437 ram 1.11 ;;; deleted from the DFO. We combine the optimize flags for the two blocks so
438     ;;; that any indicated optimization gets done.
439 wlott 1.1 ;;;
440     (defun join-blocks (block1 block2)
441     (declare (type cblock block1 block2))
442     (let* ((last (block-last block2))
443     (last-cont (node-cont last))
444     (succ (block-succ block2))
445     (start2 (block-start block2)))
446     (do ((cont start2 (node-cont (continuation-next cont))))
447     ((eq cont last-cont)
448     (when (eq (continuation-kind last-cont) :inside-block)
449     (setf (continuation-block last-cont) block1)))
450     (setf (continuation-block cont) block1))
451    
452     (unlink-blocks block1 block2)
453     (dolist (block succ)
454     (unlink-blocks block2 block)
455     (link-blocks block1 block))
456    
457     (setf (block-last block1) last)
458     (setf (continuation-kind start2) :inside-block))
459    
460 ram 1.11 (setf (block-flags block1)
461     (attributes-union (block-flags block1)
462     (block-flags block2)
463     (block-attributes type-asserted test-modified)))
464 wlott 1.1
465     (let ((next (block-next block2))
466     (prev (block-prev block2)))
467     (setf (block-next prev) next)
468     (setf (block-prev next) prev))
469    
470     (undefined-value))
471    
472 ram 1.50 ;;; Flush-Dead-Code -- Internal
473     ;;;
474     ;;; Delete any nodes in Block whose value is unused and have no
475     ;;; side-effects. We can delete sets of lexical variables when the set
476     ;;; variable has no references.
477     ;;;
478     ;;; [### For now, don't delete potentially flushable calls when they have the
479     ;;; Call attribute. Someday we should look at the funcitonal args to determine
480     ;;; if they have any side-effects.]
481     ;;;
482     (defun flush-dead-code (block)
483     (declare (type cblock block))
484     (do-nodes-backwards (node cont block)
485     (unless (continuation-dest cont)
486     (typecase node
487     (ref
488     (delete-ref node)
489     (unlink-node node))
490     (combination
491     (let ((info (combination-kind node)))
492     (when (function-info-p info)
493     (let ((attr (function-info-attributes info)))
494     (when (and (ir1-attributep attr flushable)
495     (not (ir1-attributep attr call)))
496 gerd 1.76 (if (policy node (= safety 3))
497     ;; Don't flush calls to flushable functions if
498     ;; their value is unused in safe code, because
499     ;; this means something like (PROGN (FBOUNDP 42)
500     ;; T) won't signal an error. KLUDGE: The right
501     ;; thing to do here is probably teaching
502     ;; MAYBE-NEGATE-CHECK and friends to accept nil
503     ;; continuation-dests instead of faking one.
504     ;; Can't be bothered at present.
505     ;; Gerd, 2003-04-26.
506     (setf (continuation-dest cont)
507     (continuation-next cont))
508     (progn
509     (flush-dest (combination-fun node))
510     (dolist (arg (combination-args node))
511     (flush-dest arg))
512     (unlink-node node))))))))
513 ram 1.50 (mv-combination
514     (when (eq (basic-combination-kind node) :local)
515     (let ((fun (combination-lambda node)))
516     (when (dolist (var (lambda-vars fun) t)
517     (when (or (leaf-refs var)
518     (lambda-var-sets var))
519     (return nil)))
520     (flush-dest (first (basic-combination-args node)))
521     (delete-let fun)))))
522     (exit
523     (let ((value (exit-value node)))
524     (when value
525     (flush-dest value)
526     (setf (exit-value node) nil))))
527     (cset
528     (let ((var (set-var node)))
529     (when (and (lambda-var-p var)
530     (null (leaf-refs var)))
531     (flush-dest (set-value node))
532     (setf (basic-var-sets var)
533     (delete node (basic-var-sets var)))
534     (unlink-node node)))))))
535    
536     (setf (block-flush-p block) nil)
537     (undefined-value))
538    
539     (declaim (end-block))
540    
541 wlott 1.1
542     ;;;; Local call return type propagation:
543    
544     ;;; Find-Result-Type -- Internal
545     ;;;
546     ;;; This function is called on RETURN nodes that have their REOPTIMIZE flag
547     ;;; set. It iterates over the uses of the RESULT, looking for interesting
548 ram 1.46 ;;; stuff to update the TAIL-SET. If a use isn't a local call, then we union
549     ;;; its type together with the types of other such uses. We assign to the
550     ;;; RETURN-RESULT-TYPE the intersection of this type with the RESULT's asserted
551     ;;; type. We can make this intersection now (potentially before type checking)
552     ;;; because this assertion on the result will eventually be checked (if
553     ;;; appropriate.)
554 wlott 1.1 ;;;
555 ram 1.46 ;;; We call MAYBE-CONVERT-TAIL-LOCAL-CALL on each local non-MV combination,
556     ;;; which may change the succesor of the call to be the called function, and if
557 ram 1.56 ;;; so, checks if the call can become an assignment. If we convert to an
558     ;;; assignment, we abort, since the RETURN has been deleted.
559 ram 1.46 ;;;
560     (defun find-result-type (node)
561 wlott 1.1 (declare (type creturn node))
562 ram 1.46 (let ((result (return-result node)))
563 wlott 1.1 (collect ((use-union *empty-type* values-type-union))
564     (do-uses (use result)
565 gerd 1.81 (let ((use-home (node-home-lambda use)))
566     (cond ((or (eq (functional-kind use-home) :deleted)
567     (block-delete-p (node-block use))))
568     ((and (basic-combination-p use)
569     (eq (basic-combination-kind use) :local))
570     (assert (eq (lambda-tail-set use-home)
571     (lambda-tail-set (combination-lambda use))))
572     (when (combination-p use)
573     (when (nth-value 1 (maybe-convert-tail-local-call use))
574     (return-from find-result-type (values)))))
575     (t
576     (use-union (node-derived-type use))))))
577 dtc 1.70 (let ((int (values-type-intersection (continuation-asserted-type result)
578     (use-union))))
579 ram 1.46 (setf (return-result-type node) int))))
580 gerd 1.81 (values))
581 wlott 1.1
582    
583     ;;; IR1-Optimize-Return -- Internal
584     ;;;
585     ;;; Do stuff to realize that something has changed about the value delivered
586     ;;; to a return node. Since we consider the return values of all functions in
587     ;;; the tail set to be equivalent, this amounts to bringing the entire tail set
588     ;;; up to date. We iterate over the returns for all the functions in the tail
589     ;;; set, reanalyzing them all (not treating Node specially.)
590     ;;;
591     ;;; When we are done, we check if the new type is different from the old
592     ;;; TAIL-SET-TYPE. If so, we set the type and also reoptimize all the
593     ;;; continuations for references to functions in the tail set. This will
594     ;;; cause IR1-OPTIMIZE-COMBINATION to derive the new type as the results of the
595     ;;; calls.
596     ;;;
597     (defun ir1-optimize-return (node)
598     (declare (type creturn node))
599 ram 1.46 (let* ((tails (lambda-tail-set (return-lambda node)))
600     (funs (tail-set-functions tails)))
601 wlott 1.1 (collect ((res *empty-type* values-type-union))
602 ram 1.46 (dolist (fun funs)
603     (let ((return (lambda-return fun)))
604     (when return
605     (when (node-reoptimize return)
606 ram 1.58 (setf (node-reoptimize return) nil)
607 ram 1.46 (find-result-type return))
608     (res (return-result-type return)))))
609 wlott 1.1
610     (when (type/= (res) (tail-set-type tails))
611     (setf (tail-set-type tails) (res))
612     (dolist (fun (tail-set-functions tails))
613     (dolist (ref (leaf-refs fun))
614     (reoptimize-continuation (node-cont ref)))))))
615    
616     (undefined-value))
617    
618    
619 ram 1.50 ;;; IF optimization:
620    
621     (declaim (start-block ir1-optimize-if))
622    
623 wlott 1.1 ;;; IR1-Optimize-If -- Internal
624     ;;;
625     ;;; If the test has multiple uses, replicate the node when possible. Also
626     ;;; check if the predicate is known to be true or false, deleting the IF node
627     ;;; in favor of the appropriate branch when this is the case.
628     ;;;
629     (defun ir1-optimize-if (node)
630     (declare (type cif node))
631     (let ((test (if-test node))
632     (block (node-block node)))
633    
634     (when (and (eq (block-start block) test)
635     (eq (continuation-next test) node)
636     (rest (block-start-uses block)))
637     (do-uses (use test)
638     (when (immediately-used-p test use)
639     (convert-if-if use node)
640     (when (continuation-use test) (return)))))
641 gerd 1.77 ;;
642     ;; Don't flush if-tests when they require a type check.
643     (when (memq (continuation-type-check test) '(nil :deleted))
644     (let* ((type (continuation-type test))
645     (victim
646     (cond ((constant-continuation-p test)
647     (if (continuation-value test)
648     (if-alternative node)
649     (if-consequent node)))
650     ((not (types-intersect type *null-type*))
651     (if-alternative node))
652     ((type= type *null-type*)
653     (if-consequent node)))))
654     (when victim
655     (flush-dest test)
656     (when (rest (block-succ block))
657     (unlink-blocks block victim))
658     (setf (component-reanalyze (block-component (node-block node))) t)
659     (unlink-node node)))))
660 wlott 1.1 (undefined-value))
661    
662    
663     ;;; Convert-If-If -- Internal
664     ;;;
665     ;;; Create a new copy of an IF Node that tests the value of the node Use.
666     ;;; The test must have >1 use, and must be immediately used by Use. Node must
667     ;;; be the only node in its block (implying that block-start = if-test).
668     ;;;
669     ;;; This optimization has an effect semantically similar to the
670     ;;; source-to-source transformation:
671     ;;; (IF (IF A B C) D E) ==>
672     ;;; (IF A (IF B D E) (IF C D E))
673     ;;;
674 ram 1.55 ;;; We clobber the NODE-SOURCE-PATH of both the original and the new node so
675     ;;; that dead code deletion notes will definitely not consider either node to
676     ;;; be part of the original source. One node might become unreachable,
677     ;;; resulting in a spurious note.
678     ;;;
679 wlott 1.1 (defun convert-if-if (use node)
680     (declare (type node use) (type cif node))
681     (with-ir1-environment node
682     (let* ((block (node-block node))
683     (test (if-test node))
684     (cblock (if-consequent node))
685     (ablock (if-alternative node))
686     (use-block (node-block use))
687     (dummy-cont (make-continuation))
688     (new-cont (make-continuation))
689 ram 1.11 (new-node (make-if :test new-cont
690 wlott 1.1 :consequent cblock :alternative ablock))
691     (new-block (continuation-starts-block new-cont)))
692     (prev-link new-node new-cont)
693     (setf (continuation-dest new-cont) new-node)
694     (add-continuation-use new-node dummy-cont)
695     (setf (block-last new-block) new-node)
696    
697     (unlink-blocks use-block block)
698     (delete-continuation-use use)
699     (add-continuation-use use new-cont)
700     (link-blocks use-block new-block)
701    
702     (link-blocks new-block cblock)
703     (link-blocks new-block ablock)
704 ram 1.55
705     (push "<IF Duplication>" (node-source-path node))
706     (push "<IF Duplication>" (node-source-path new-node))
707 wlott 1.1
708     (reoptimize-continuation test)
709     (reoptimize-continuation new-cont)
710     (setf (component-reanalyze *current-component*) t)))
711     (undefined-value))
712    
713 ram 1.50 (declaim (end-block))
714    
715 wlott 1.1
716     ;;;; Exit IR1 optimization:
717    
718     ;;; Maybe-Delete-Exit -- Interface
719     ;;;
720     ;;; This function attempts to delete an exit node, returning true if it
721     ;;; deletes the block as a consequence:
722     ;;; -- If the exit is degenerate (has no Entry), then we don't do anything,
723     ;;; since there is nothing to be done.
724     ;;; -- If the exit node and its Entry have the same home lambda then we know
725     ;;; the exit is local, and can delete the exit. We change uses of the
726     ;;; Exit-Value to be uses of the original continuation, then unlink the
727 ram 1.46 ;;; node. If the exit is to a TR context, then we must do MERGE-TAIL-SETS
728     ;;; on any local calls which delivered their value to this exit.
729 wlott 1.1 ;;; -- If there is no value (as in a GO), then we skip the value semantics.
730     ;;;
731     ;;; This function is also called by environment analysis, since it wants all
732     ;;; exits to be optimized even if normal optimization was omitted.
733     ;;;
734     (defun maybe-delete-exit (node)
735     (declare (type exit node))
736     (let ((value (exit-value node))
737     (entry (exit-entry node))
738     (cont (node-cont node)))
739     (when (and entry
740 ram 1.11 (eq (node-home-lambda node) (node-home-lambda entry)))
741     (setf (entry-exits entry) (delete node (entry-exits entry)))
742 wlott 1.1 (prog1
743     (unlink-node node)
744     (when value
745 ram 1.46 (collect ((merges))
746     (when (return-p (continuation-dest cont))
747     (do-uses (use value)
748     (when (and (basic-combination-p use)
749     (eq (basic-combination-kind use) :local))
750     (merges use))))
751 gerd 1.79 (when (null (continuation-dest cont))
752     (flush-dest value))
753 ram 1.46 (substitute-continuation-uses cont value)
754     (dolist (merge (merges))
755     (merge-tail-sets merge))))))))
756 wlott 1.1
757    
758     ;;;; Combination IR1 optimization:
759    
760 ram 1.50 (declaim (start-block ir1-optimize-combination maybe-terminate-block
761     validate-call-type))
762    
763 wlott 1.1 ;;; Ir1-Optimize-Combination -- Internal
764     ;;;
765     ;;; Do IR1 optimizations on a Combination node.
766     ;;;
767     (defun ir1-optimize-combination (node)
768 dtc 1.71 (declare (type combination node))
769 ram 1.50 (when (continuation-reoptimize (basic-combination-fun node))
770     (propagate-function-change node))
771 wlott 1.1 (let ((args (basic-combination-args node))
772     (kind (basic-combination-kind node)))
773     (case kind
774     (:local
775     (let ((fun (combination-lambda node)))
776     (if (eq (functional-kind fun) :let)
777     (propagate-let-args node fun)
778     (propagate-local-call-args node fun))))
779 ram 1.50 ((:full :error)
780 wlott 1.1 (dolist (arg args)
781     (when arg
782     (setf (continuation-reoptimize arg) nil))))
783     (t
784     (dolist (arg args)
785     (when arg
786     (setf (continuation-reoptimize arg) nil)))
787    
788     (let ((attr (function-info-attributes kind)))
789     (when (and (ir1-attributep attr foldable)
790     (not (ir1-attributep attr call))
791     (every #'constant-continuation-p args)
792     (continuation-dest (node-cont node)))
793     (constant-fold-call node)
794     (return-from ir1-optimize-combination)))
795 ram 1.18
796 wlott 1.1 (let ((fun (function-info-derive-type kind)))
797     (when fun
798     (let ((res (funcall fun node)))
799     (when res
800 ram 1.50 (derive-node-type node res)
801     (maybe-terminate-block node nil)))))
802 ram 1.18
803 wlott 1.1 (let ((fun (function-info-optimizer kind)))
804     (unless (and fun (funcall fun node))
805     (dolist (x (function-info-transforms kind))
806 ram 1.28 (unless (ir1-transform node x)
807 wlott 1.2 (return))))))))
808 wlott 1.1
809     (undefined-value))
810    
811    
812 ram 1.29 ;;; MAYBE-TERMINATE-BLOCK -- Interface
813     ;;;
814     ;;; If Call is to a function that doesn't return (type NIL), then terminate
815 ram 1.31 ;;; the block there, and link it to the component tail. We also change the
816     ;;; call's CONT to be a dummy continuation to prevent the use from confusing
817     ;;; things.
818 ram 1.29 ;;;
819 ram 1.30 ;;; Except when called during IR1, we delete the continuation if it has no
820     ;;; other uses. (If it does have other uses, we reoptimize.)
821     ;;;
822 ram 1.31 ;;; Termination on the basis of a continuation type assertion is inhibited
823     ;;; when:
824     ;;; -- The continuation is deleted (hence the assertion is spurious), or
825     ;;; -- We are in IR1 conversion (where THE assertions are subject to
826     ;;; weakening.)
827     ;;;
828 ram 1.30 (defun maybe-terminate-block (call ir1-p)
829 ram 1.29 (declare (type basic-combination call))
830 ram 1.32 (let* ((block (node-block call))
831     (cont (node-cont call))
832     (tail (component-tail (block-component block)))
833     (succ (first (block-succ block))))
834     (unless (or (and (eq call (block-last block)) (eq succ tail))
835 ram 1.50 (block-delete-p block)
836     *converting-for-interpreter*)
837 ram 1.32 (when (or (and (eq (continuation-asserted-type cont) *empty-type*)
838     (not (or ir1-p (eq (continuation-kind cont) :deleted))))
839     (eq (node-derived-type call) *empty-type*))
840     (cond (ir1-p
841     (delete-continuation-use call)
842     (cond
843     ((block-last block)
844     (assert (and (eq (block-last block) call)
845     (eq (continuation-kind cont) :block-start))))
846     (t
847     (setf (block-last block) call)
848     (link-blocks block (continuation-starts-block cont)))))
849 ram 1.30 (t
850 ram 1.32 (node-ends-block call)
851     (delete-continuation-use call)
852     (if (eq (continuation-kind cont) :unused)
853     (delete-continuation cont)
854     (reoptimize-continuation cont))))
855    
856     (unlink-blocks block (first (block-succ block)))
857 ram 1.45 (setf (component-reanalyze (block-component block)) t)
858 ram 1.32 (assert (not (block-succ block)))
859     (link-blocks block tail)
860     (add-continuation-use call (make-continuation))
861     t))))
862 ram 1.30
863 ram 1.29
864 wlott 1.1 ;;; Recognize-Known-Call -- Interface
865     ;;;
866 ram 1.50 ;;; Called both by IR1 conversion and IR1 optimization when they have
867     ;;; verified the type signature for the call, and are wondering if something
868     ;;; should be done to special-case the call. If Call is a call to a global
869     ;;; function, then see if it defined or known:
870     ;;; -- If a DEFINED-FUNCTION should be inline expanded, then convert the
871     ;;; expansion and change the call to call it. Expansion is enabled if
872     ;;; :INLINE or if space=0. If the FUNCTIONAL slot is true, we never expand,
873     ;;; since this function has already been converted. Local call analysis
874     ;;; will duplicate the definition if necessary. We claim that the parent
875     ;;; form is LABELS for context declarations, since we don't want it to be
876     ;;; considered a real global function.
877     ;;; -- In addition to a direct check for the function name in the table, we
878     ;;; also must check for slot accessors. If the function is a slot accessor,
879     ;;; then we set the combination kind to the function info of %Slot-Setter or
880     ;;; %Slot-Accessor, as appropriate.
881     ;;; -- If it is a known function, mark it as such by setting the Kind.
882 wlott 1.1 ;;;
883 ram 1.50 ;;; We return the leaf referenced (NIL if not a leaf) and the function-info
884     ;;; assigned.
885 ram 1.19 ;;;
886 ram 1.50 (defun recognize-known-call (call ir1-p)
887 wlott 1.1 (declare (type combination call))
888 ram 1.50 (let* ((ref (continuation-use (basic-combination-fun call)))
889     (leaf (when (ref-p ref) (ref-leaf ref)))
890 gerd 1.78 (inlinep (if (defined-function-p leaf)
891 ram 1.50 (defined-function-inlinep leaf)
892     :no-chance)))
893 gerd 1.78 (when (and (or (byte-compiling)
894     *converting-for-interpreter*)
895     (member inlinep '(:inline :maybe-inline)))
896     (setq inlinep :notinline))
897 ram 1.50 (cond
898     ((eq inlinep :notinline) (values nil nil))
899     ((not (and (global-var-p leaf)
900     (eq (global-var-kind leaf) :global-function)))
901     (values leaf nil))
902     ((and (ecase inlinep
903     (:inline t)
904     (:no-chance nil)
905     ((nil :maybe-inline) (policy call (zerop space))))
906     (defined-function-inline-expansion leaf)
907     (let ((fun (defined-function-functional leaf)))
908     (or (not fun)
909     (and (eq inlinep :inline) (functional-kind fun))))
910     (inline-expansion-ok call))
911     (flet ((frob ()
912     (let ((res (ir1-convert-lambda-for-defun
913     (defined-function-inline-expansion leaf)
914 ram 1.53 leaf t
915 ram 1.50 #'ir1-convert-inline-lambda
916     'labels)))
917     (setf (defined-function-functional leaf) res)
918     (change-ref-leaf ref res))))
919     (if ir1-p
920     (frob)
921     (with-ir1-environment call
922     (frob)
923     (local-call-analyze *current-component*))))
924 ram 1.53
925 ram 1.50 (values (ref-leaf (continuation-use (basic-combination-fun call)))
926     nil))
927     (t
928     (let* ((name (leaf-name leaf))
929 pw 1.67 (info (info function info
930     (if (slot-accessor-p leaf)
931     (if (consp name)
932     '%slot-setter
933     '%slot-accessor)
934     name))))
935 ram 1.50 (if info
936     (values leaf (setf (basic-combination-kind call) info))
937     (values leaf nil)))))))
938 wlott 1.1
939    
940 ram 1.50 ;;; VALIDATE-CALL-TYPE -- Internal
941     ;;;
942     ;;; Check if Call satisfies Type. If so, apply the type to the call, and do
943     ;;; MAYBE-TERMINATE-BLOCK and return the values of RECOGNIZE-KNOWN-CALL. If an
944 ram 1.57 ;;; error, set the combination kind and return NIL, NIL. If the type is just
945     ;;; FUNCTION, then skip the syntax check, arg/result type processing, but still
946     ;;; call RECOGNIZE-KNOWN-CALL, since the call might be to a known lambda, and
947     ;;; that checking is done by local call analysis.
948 ram 1.50 ;;;
949     (defun validate-call-type (call type ir1-p)
950     (declare (type combination call) (type ctype type))
951 ram 1.57 (cond ((not (function-type-p type))
952     (assert (multiple-value-bind
953     (val win)
954     (csubtypep type (specifier-type 'function))
955     (or val (not win))))
956     (recognize-known-call call ir1-p))
957 ram 1.50 ((valid-function-use call type
958     :argument-test #'always-subtypep
959     :result-test #'always-subtypep
960     :error-function #'compiler-warning
961     :warning-function #'compiler-note)
962     (assert-call-type call type)
963     (maybe-terminate-block call ir1-p)
964     (recognize-known-call call ir1-p))
965     (t
966     (setf (combination-kind call) :error)
967     (values nil nil))))
968    
969    
970 wlott 1.1 ;;; Propagate-Function-Change -- Internal
971     ;;;
972     ;;; Called by Ir1-Optimize when the function for a call has changed.
973 ram 1.50 ;;; If the call is local, we try to let-convert it, and derive the result type.
974     ;;; If it is a :FULL call, we validate it against the type, which recognizes
975     ;;; known calls, does inline expansion, etc. If a call to a predicate in a
976     ;;; non-conditional position or to a function with a source transform, then we
977     ;;; reconvert the form to give IR1 another chance.
978 wlott 1.1 ;;;
979     (defun propagate-function-change (call)
980     (declare (type combination call))
981 ram 1.50 (let ((*compiler-error-context* call)
982     (fun-cont (basic-combination-fun call)))
983     (setf (continuation-reoptimize fun-cont) nil)
984     (case (combination-kind call)
985     (:local
986     (let ((fun (combination-lambda call)))
987     (maybe-let-convert fun)
988     (unless (member (functional-kind fun) '(:let :assignment :deleted))
989     (derive-node-type call (tail-set-type (lambda-tail-set fun))))))
990     (:full
991     (multiple-value-bind
992     (leaf info)
993 ram 1.59 (validate-call-type call (continuation-type fun-cont) nil)
994 ram 1.50 (cond ((functional-p leaf)
995     (convert-call-if-possible
996     (continuation-use (basic-combination-fun call))
997     call))
998     ((not leaf))
999     ((or (info function source-transform (leaf-name leaf))
1000     (and info
1001     (ir1-attributep (function-info-attributes info)
1002     predicate)
1003     (let ((dest (continuation-dest (node-cont call))))
1004     (and dest (not (if-p dest))))))
1005     (let ((name (leaf-name leaf)))
1006     (when (symbolp name)
1007     (let ((dums (loop repeat (length (combination-args call))
1008     collect (gensym))))
1009     (transform-call call
1010     `(lambda ,dums
1011     (,name ,@dums))))))))))))
1012 wlott 1.1 (undefined-value))
1013    
1014    
1015     ;;;; Known function optimization:
1016    
1017 ram 1.15
1018     ;;; RECORD-OPTIMIZATION-FAILURE -- Internal
1019     ;;;
1020 ram 1.50 ;;; Add a failed optimization note to FAILED-OPTIMZATIONS for Node, Fun
1021 ram 1.28 ;;; and Args. If there is already a note for Node and Transform, replace it,
1022 ram 1.15 ;;; otherwise add a new one.
1023     ;;;
1024 ram 1.28 (defun record-optimization-failure (node transform args)
1025     (declare (type combination node) (type transform transform)
1026 ram 1.15 (type (or function-type list) args))
1027 ram 1.50 (let* ((table (component-failed-optimizations *compile-component*))
1028     (found (assoc transform (gethash node table))))
1029 ram 1.15 (if found
1030     (setf (cdr found) args)
1031 ram 1.50 (push (cons transform args) (gethash node table))))
1032 ram 1.15 (undefined-value))
1033    
1034    
1035 wlott 1.1 ;;; IR1-Transform -- Internal
1036     ;;;
1037     ;;; Attempt to transform Node using Function, subject to the call type
1038     ;;; constraint Type. If we are inhibited from doing the transform for some
1039     ;;; reason and Flame is true, then we make a note of the message in
1040 ram 1.50 ;;; FAILED-OPTIMIZATIONS for IR1 finalize to pick up. We return true if
1041 wlott 1.2 ;;; the transform failed, and thus further transformation should be
1042     ;;; attempted. We return false if either the transform suceeded or was
1043     ;;; aborted.
1044 wlott 1.1 ;;;
1045 ram 1.28 (defun ir1-transform (node transform)
1046     (declare (type combination node) (type transform transform))
1047     (let* ((type (transform-type transform))
1048     (fun (transform-function transform))
1049     (constrained (function-type-p type))
1050 ram 1.50 (table (component-failed-optimizations *compile-component*))
1051 wlott 1.41 (flame
1052     (if (transform-important transform)
1053     (policy node (>= speed brevity))
1054     (policy node (> speed brevity))))
1055 ram 1.28 (*compiler-error-context* node))
1056 ram 1.60 (cond ((let ((when (transform-when transform)))
1057     (not (or (eq when :both)
1058     (eq when (if *byte-compiling* :byte :native)))))
1059     t)
1060     ((or (not constrained)
1061 ram 1.19 (valid-function-use node type :strict-result t))
1062 wlott 1.1 (multiple-value-bind
1063     (severity args)
1064     (catch 'give-up
1065     (transform-call node (funcall fun node))
1066     (values :none nil))
1067     (ecase severity
1068 ram 1.15 (:none
1069 ram 1.50 (remhash node table)
1070 ram 1.15 nil)
1071 wlott 1.1 (:aborted
1072 ram 1.50 (setf (combination-kind node) :error)
1073 wlott 1.1 (when args
1074 wlott 1.2 (apply #'compiler-warning args))
1075 ram 1.50 (remhash node table)
1076 wlott 1.2 nil)
1077 wlott 1.1 (:failure
1078 ram 1.15 (if args
1079     (when flame
1080 ram 1.28 (record-optimization-failure node transform args))
1081 ram 1.50 (setf (gethash node table)
1082     (remove transform (gethash node table) :key #'car)))
1083 dtc 1.72 t)
1084     (:delayed
1085     (remhash node table)
1086     nil))))
1087 wlott 1.1 ((and flame
1088     (valid-function-use node type
1089     :argument-test #'types-intersect
1090     :result-test #'values-types-intersect))
1091 ram 1.28 (record-optimization-failure node transform type)
1092 wlott 1.13 t)
1093     (t
1094 wlott 1.2 t))))
1095 wlott 1.1
1096 ram 1.50 (declaim (end-block))
1097 wlott 1.1
1098 dtc 1.72 ;;; give-up, abort-transform -- Interface
1099 wlott 1.1 ;;;
1100     ;;; Just throw the severity and args...
1101     ;;;
1102     (defun give-up (&rest args)
1103     "This function is used to throw out of an IR1 transform, aborting this
1104     attempt to transform the call, but admitting the possibility that this or
1105     some other transform will later suceed. If arguments are supplied, they are
1106     format arguments for an efficiency note."
1107 dtc 1.71 (values nil)
1108 wlott 1.1 (throw 'give-up (values :failure args)))
1109     ;;;
1110     (defun abort-transform (&rest args)
1111     "This function is used to throw out of an IR1 transform and force a normal
1112     call to the function at run time. No further optimizations will be
1113     attempted."
1114     (throw 'give-up (values :aborted args)))
1115 dtc 1.72
1116     (defvar *delayed-transforms*)
1117    
1118     ;;; delay-transform -- Interface
1119     ;;;
1120     (defun delay-transform (node &rest reasons)
1121     "This function is used to throw out of an IR1 transform, and delay the
1122     transform on the node until later. The reasons specifies when the transform
1123     will be later retried. The :optimize reason causes the transform to be
1124     delayed until after the current IR1 optimization pass. The :constraint
1125     reason causes the transform to be delayed until after constraint
1126     propagation."
1127     (let ((assoc (assoc node *delayed-transforms*)))
1128     (cond ((not assoc)
1129     (setf *delayed-transforms*
1130     (acons node reasons *delayed-transforms*))
1131     (throw 'give-up :delayed))
1132     ((cdr assoc)
1133     (dolist (reason reasons)
1134     (pushnew reason (cdr assoc)))
1135     (throw 'give-up :delayed)))))
1136    
1137     ;;; retry-delayed-transforms -- Interface.
1138     ;;;
1139     ;;; Clear any delayed transform with no reasons - these should have been tried
1140     ;;; in the last pass. Then remove the reason from the delayed transform
1141     ;;; reasons, and if any become empty then set reoptimize flags for the
1142     ;;; node. Returns true if any transforms are to be retried.
1143     ;;;
1144     (defun retry-delayed-transforms (reason)
1145     (setf *delayed-transforms* (remove-if-not #'cdr *delayed-transforms*))
1146     (let ((reoptimize nil))
1147     (dolist (assoc *delayed-transforms*)
1148     (let ((reasons (remove reason (cdr assoc))))
1149     (setf (cdr assoc) reasons)
1150     (unless reasons
1151     (let ((node (car assoc)))
1152     (unless (node-deleted node)
1153     (setf reoptimize t)
1154     (setf (node-reoptimize node) t)
1155     (let ((block (node-block node)))
1156     (setf (block-reoptimize block) t)
1157     (setf (component-reoptimize (block-component block)) t)))))))
1158     reoptimize))
1159 wlott 1.1
1160    
1161     ;;; Transform-Call -- Internal
1162     ;;;
1163     ;;; Take the lambda-expression Res, IR1 convert it in the proper
1164     ;;; environment, and then install it as the function for the call Node. We do
1165     ;;; local call analysis so that the new function is integrated into the control
1166 ram 1.50 ;;; flow.
1167 wlott 1.1 ;;;
1168     (defun transform-call (node res)
1169     (declare (type combination node) (list res))
1170     (with-ir1-environment node
1171 ram 1.50 (let ((new-fun (ir1-convert-inline-lambda res))
1172 wlott 1.1 (ref (continuation-use (combination-fun node))))
1173     (change-ref-leaf ref new-fun)
1174     (setf (combination-kind node) :full)
1175     (local-call-analyze *current-component*)))
1176     (undefined-value))
1177    
1178     ;;; Constant-Fold-Call -- Internal
1179     ;;;
1180     ;;; Replace a call to a foldable function of constant arguments with the
1181     ;;; result of evaluating the form. We insert the resulting constant node after
1182     ;;; the call, stealing the call's continuation. We give the call a
1183     ;;; continuation with no Dest, which should cause it and its arguments to go
1184     ;;; away. If there is an error during the evaluation, we give a warning and
1185 ram 1.50 ;;; leave the call alone, making the call a :ERROR call.
1186 wlott 1.1 ;;;
1187 ram 1.50 ;;; If there is more than one value, then we transform the call into a
1188     ;;; values form.
1189 wlott 1.1 ;;;
1190     (defun constant-fold-call (call)
1191     (declare (type combination call))
1192     (let* ((args (mapcar #'continuation-value (combination-args call)))
1193     (ref (continuation-use (combination-fun call)))
1194     (fun (leaf-name (ref-leaf ref))))
1195    
1196     (multiple-value-bind (values win)
1197 gerd 1.77 (careful-call fun args call "constant folding")
1198     (cond ((not win)
1199     (setf (combination-kind call) :error))
1200     ;;
1201     ;; Don't constand-fold a call if one of its arguments
1202     ;; requires a type check.
1203     ((or (policy call (< safety 3))
1204     (loop for arg in (basic-combination-args call)
1205     as check = (continuation-type-check arg)
1206     always (member check '(nil :deleted))))
1207     (let ((dummies (loop repeat (length args) collect (gensym))))
1208     (transform-call
1209     call
1210     `(lambda ,dummies
1211     (declare (ignore ,@dummies))
1212     (values ,@(mapcar (lambda (x) `',x) values)))))))))
1213     (values))
1214 wlott 1.1
1215    
1216     ;;;; Local call optimization:
1217    
1218 ram 1.50 (declaim (start-block ir1-optimize-set constant-reference-p delete-let
1219     propagate-let-args propagate-local-call-args
1220 ram 1.52 propagate-to-refs propagate-from-sets
1221     ir1-optimize-mv-combination))
1222 ram 1.50
1223 wlott 1.1 ;;; Propagate-To-Refs -- Internal
1224     ;;;
1225     ;;; Propagate Type to Leaf and its Refs, marking things changed. If the
1226     ;;; leaf type is a function type, then just leave it alone, since TYPE is never
1227     ;;; going to be more specific than that (and TYPE-INTERSECTION would choke.)
1228     ;;;
1229     (defun propagate-to-refs (leaf type)
1230     (declare (type leaf leaf) (type ctype type))
1231     (let ((var-type (leaf-type leaf)))
1232     (unless (function-type-p var-type)
1233     (let ((int (type-intersection var-type type)))
1234     (when (type/= int var-type)
1235     (setf (leaf-type leaf) int)
1236     (dolist (ref (leaf-refs leaf))
1237     (derive-node-type ref int))))
1238     (undefined-value))))
1239    
1240    
1241     ;;; PROPAGATE-FROM-SETS -- Internal
1242     ;;;
1243     ;;; Figure out the type of a LET variable that has sets. We compute the
1244     ;;; union of the initial value Type and the types of all the set values and to
1245     ;;; a PROPAGATE-TO-REFS with this type.
1246     ;;;
1247     (defun propagate-from-sets (var type)
1248 ram 1.6 (collect ((res type type-union))
1249 wlott 1.1 (dolist (set (basic-var-sets var))
1250     (res (continuation-type (set-value set)))
1251     (setf (node-reoptimize set) nil))
1252     (propagate-to-refs var (res)))
1253     (undefined-value))
1254    
1255    
1256     ;;; IR1-OPTIMIZE-SET -- Internal
1257     ;;;
1258     ;;; If a let variable, find the initial value's type and do
1259     ;;; PROPAGATE-FROM-SETS. We also derive the VALUE's type as the node's type.
1260     ;;;
1261     (defun ir1-optimize-set (node)
1262     (declare (type cset node))
1263     (let ((var (set-var node)))
1264     (when (and (lambda-var-p var) (leaf-refs var))
1265     (let ((home (lambda-var-home var)))
1266     (when (eq (functional-kind home) :let)
1267     (let ((iv (let-var-initial-value var)))
1268     (setf (continuation-reoptimize iv) nil)
1269     (propagate-from-sets var (continuation-type iv)))))))
1270    
1271     (derive-node-type node (continuation-type (set-value node)))
1272     (undefined-value))
1273    
1274    
1275 ram 1.17 ;;; CONSTANT-REFERENCE-P -- Interface
1276 ram 1.7 ;;;
1277     ;;; Return true if the value of Ref will always be the same (and is thus
1278 ram 1.50 ;;; legal to substitute.)
1279 ram 1.7 ;;;
1280     (defun constant-reference-p (ref)
1281     (declare (type ref ref))
1282     (let ((leaf (ref-leaf ref)))
1283     (typecase leaf
1284 ram 1.50 ((or constant functional) t)
1285 ram 1.7 (lambda-var
1286     (null (lambda-var-sets leaf)))
1287 ram 1.50 (defined-function
1288     (not (eq (defined-function-inlinep leaf) :notinline)))
1289 ram 1.7 (global-var
1290     (case (global-var-kind leaf)
1291 ram 1.50 (:global-function t)
1292 ram 1.7 (:constant t))))))
1293    
1294    
1295     ;;; SUBSTITUTE-SINGLE-USE-CONTINUATION -- Internal
1296     ;;;
1297     ;;; If we have a non-set let var with a single use, then (if possible)
1298     ;;; replace the variable reference's CONT with the arg continuation. This is
1299     ;;; inhibited when:
1300     ;;; -- CONT has other uses, or
1301     ;;; -- CONT receives multiple values, or
1302 ram 1.9 ;;; -- the reference is in a different environment from the variable, or
1303     ;;; -- either continuation has a funky TYPE-CHECK annotation.
1304 ram 1.43 ;;; -- the continuations have incompatible assertions, so the new asserted type
1305     ;;; would be NIL.
1306 dtc 1.68 ;;; -- CONT's assertion is incompatbile with the proven type of ARG's, such as
1307     ;;; when ARG returns multiple values and CONT has a single value assertion.
1308 ram 1.27 ;;; -- the var's DEST has a different policy than the ARG's (think safety).
1309 ram 1.7 ;;;
1310     ;;; We change the Ref to be a reference to NIL with unused value, and let it
1311     ;;; be flushed as dead code. A side-effect of this substitution is to delete
1312     ;;; the variable.
1313     ;;;
1314     (defun substitute-single-use-continuation (arg var)
1315     (declare (type continuation arg) (type lambda-var var))
1316     (let* ((ref (first (leaf-refs var)))
1317     (cont (node-cont ref))
1318 ram 1.43 (cont-atype (continuation-asserted-type cont))
1319 ram 1.7 (dest (continuation-dest cont)))
1320     (when (and (eq (continuation-use cont) ref)
1321     dest
1322     (not (typep dest '(or creturn exit mv-combination)))
1323 ram 1.11 (eq (node-home-lambda ref)
1324 ram 1.9 (lambda-home (lambda-var-home var)))
1325     (member (continuation-type-check arg) '(t nil))
1326 ram 1.27 (member (continuation-type-check cont) '(t nil))
1327 ram 1.43 (not (eq (values-type-intersection
1328 dtc 1.68 cont-atype (continuation-asserted-type arg))
1329     *empty-type*))
1330     (not (eq (values-type-intersection
1331     cont-atype (continuation-proven-type arg))
1332 ram 1.43 *empty-type*))
1333 ram 1.27 (eq (lexenv-cookie (node-lexenv dest))
1334     (lexenv-cookie (node-lexenv (continuation-dest arg)))))
1335 ram 1.25 (assert (member (continuation-kind arg)
1336     '(:block-start :deleted-block-start :inside-block)))
1337 ram 1.43 (assert-continuation-type arg cont-atype)
1338 ram 1.34 (setf (node-derived-type ref) *wild-type*)
1339 ram 1.7 (change-ref-leaf ref (find-constant nil))
1340     (substitute-continuation arg cont)
1341     (reoptimize-continuation arg)
1342     t)))
1343    
1344    
1345 ram 1.19 ;;; DELETE-LET -- Interface
1346     ;;;
1347     ;;; Delete a Let, removing the call and bind nodes, and warning about any
1348     ;;; unreferenced variables. Note that FLUSH-DEAD-CODE will come along right
1349     ;;; away and delete the REF and then the lambda, since we flush the FUN
1350     ;;; continuation.
1351     ;;;
1352     (defun delete-let (fun)
1353     (declare (type clambda fun))
1354 ram 1.42 (assert (member (functional-kind fun) '(:let :mv-let)))
1355 ram 1.19 (note-unreferenced-vars fun)
1356     (let ((call (let-combination fun)))
1357 ram 1.42 (flush-dest (basic-combination-fun call))
1358 ram 1.19 (unlink-node call)
1359     (unlink-node (lambda-bind fun))
1360     (setf (lambda-bind fun) nil))
1361     (undefined-value))
1362    
1363    
1364 wlott 1.1 ;;; Propagate-Let-Args -- Internal
1365     ;;;
1366     ;;; This function is called when one of the arguments to a LET changes. We
1367     ;;; look at each changed argument. If the corresponding variable is set, then
1368     ;;; we call PROPAGATE-FROM-SETS. Otherwise, we consider substituting for the
1369     ;;; variable, and also propagate derived-type information for the arg to all
1370     ;;; the Var's refs.
1371     ;;;
1372 ram 1.16 ;;; Substitution is inhibited when the arg leaf's derived type isn't a
1373     ;;; subtype of the argument's asserted type. This prevents type checking from
1374     ;;; being defeated, and also ensures that the best representation for the
1375     ;;; variable can be used.
1376 wlott 1.1 ;;;
1377 ram 1.26 ;;; Substitution of individual references is inhibited if the reference is
1378     ;;; in a different component from the home. This can only happen with closures
1379     ;;; over top-level lambda vars. In such cases, the references may have already
1380     ;;; been compiled, and thus can't be retroactively modified.
1381     ;;;
1382 dtc 1.73 ;;; If all of the variables are deleted (have no references) when we are
1383     ;;; done, then we delete the let.
1384 ram 1.19 ;;;
1385 wlott 1.1 ;;; Note that we are responsible for clearing the Continuation-Reoptimize
1386     ;;; flags.
1387     ;;;
1388     (defun propagate-let-args (call fun)
1389     (declare (type combination call) (type clambda fun))
1390 ram 1.19 (loop for arg in (combination-args call)
1391     and var in (lambda-vars fun) do
1392     (when (and arg (continuation-reoptimize arg))
1393     (setf (continuation-reoptimize arg) nil)
1394     (cond
1395     ((lambda-var-sets var)
1396     (propagate-from-sets var (continuation-type arg)))
1397     ((let ((use (continuation-use arg)))
1398     (when (ref-p use)
1399     (let ((leaf (ref-leaf use)))
1400     (when (and (constant-reference-p use)
1401     (values-subtypep (leaf-type leaf)
1402     (continuation-asserted-type arg)))
1403     (propagate-to-refs var (continuation-type arg))
1404 ram 1.26 (let ((this-comp (block-component (node-block use))))
1405     (substitute-leaf-if
1406     #'(lambda (ref)
1407     (cond ((eq (block-component (node-block ref))
1408     this-comp)
1409     t)
1410     (t
1411     (assert (eq (functional-kind (lambda-home fun))
1412     :top-level))
1413     nil)))
1414     leaf var))
1415 ram 1.19 t)))))
1416     ((and (null (rest (leaf-refs var)))
1417 wlott 1.47 (not *byte-compiling*)
1418 ram 1.19 (substitute-single-use-continuation arg var)))
1419     (t
1420     (propagate-to-refs var (continuation-type arg))))))
1421 dtc 1.73
1422     (when (every #'null (combination-args call))
1423 ram 1.19 (delete-let fun))
1424    
1425 wlott 1.1 (undefined-value))
1426    
1427    
1428     ;;; Propagate-Local-Call-Args -- Internal
1429     ;;;
1430     ;;; This function is called when one of the args to a non-let local call
1431     ;;; changes. For each changed argument corresponding to an unset variable, we
1432     ;;; compute the union of the types across all calls and propagate this type
1433     ;;; information to the var's refs.
1434     ;;;
1435     ;;; If the function has an XEP, then we don't do anything, since we won't
1436     ;;; discover anything.
1437     ;;;
1438     ;;; We can clear the Continuation-Reoptimize flags for arguments in all calls
1439     ;;; corresponding to changed arguments in Call, since the only use in IR1
1440     ;;; optimization of the Reoptimize flag for local call args is right here.
1441     ;;;
1442     (defun propagate-local-call-args (call fun)
1443     (declare (type combination call) (type clambda fun))
1444    
1445 ram 1.64 (unless (or (functional-entry-function fun)
1446     (lambda-optional-dispatch fun))
1447 wlott 1.1 (let* ((vars (lambda-vars fun))
1448     (union (mapcar #'(lambda (arg var)
1449     (when (and arg
1450     (continuation-reoptimize arg)
1451     (null (basic-var-sets var)))
1452     (continuation-type arg)))
1453     (basic-combination-args call)
1454     vars))
1455     (this-ref (continuation-use (basic-combination-fun call))))
1456    
1457     (dolist (arg (basic-combination-args call))
1458     (when arg
1459     (setf (continuation-reoptimize arg) nil)))
1460    
1461     (dolist (ref (leaf-refs fun))
1462 ram 1.63 (let ((dest (continuation-dest (node-cont ref))))
1463     (unless (or (eq ref this-ref) (not dest))
1464     (setq union
1465     (mapcar #'(lambda (this-arg old)
1466     (when old
1467     (setf (continuation-reoptimize this-arg) nil)
1468     (type-union (continuation-type this-arg) old)))
1469     (basic-combination-args dest)
1470     union)))))
1471 wlott 1.1
1472     (mapc #'(lambda (var type)
1473     (when type
1474     (propagate-to-refs var type)))
1475     vars union)))
1476    
1477 ram 1.6 (undefined-value))
1478    
1479 ram 1.50 (declaim (end-block))
1480    
1481 ram 1.6
1482 ram 1.19 ;;;; Multiple values optimization:
1483    
1484 ram 1.21 ;;; IR1-OPTIMIZE-MV-COMBINATION -- Internal
1485     ;;;
1486 ram 1.32 ;;; Do stuff to notice a change to a MV combination node. There are two
1487     ;;; main branches here:
1488     ;;; -- If the call is local, then it is already a MV let, or should become one.
1489     ;;; Note that although all :LOCAL MV calls must eventually be converted to
1490     ;;; :MV-LETs, there can be a window when the call is local, but has not
1491     ;;; been let converted yet. This is because the entry-point lambdas may
1492     ;;; have stray references (in other entry points) that have not been
1493     ;;; deleted yet.
1494     ;;; -- The call is full. This case is somewhat similar to the non-MV
1495     ;;; combination optimization: we propagate return type information and
1496     ;;; notice non-returning calls. We also have an optimization
1497     ;;; which tries to convert MV-CALLs into MV-binds.
1498 ram 1.21 ;;;
1499     (defun ir1-optimize-mv-combination (node)
1500 ram 1.50 (ecase (basic-combination-kind node)
1501     (:local
1502 ram 1.54 (let ((fun-cont (basic-combination-fun node)))
1503     (when (continuation-reoptimize fun-cont)
1504     (setf (continuation-reoptimize fun-cont) nil)
1505 ram 1.50 (maybe-let-convert (combination-lambda node))))
1506     (setf (continuation-reoptimize (first (basic-combination-args node))) nil)
1507     (when (eq (functional-kind (combination-lambda node)) :mv-let)
1508     (unless (convert-mv-bind-to-let node)
1509     (ir1-optimize-mv-bind node))))
1510     (:full
1511     (let* ((fun (basic-combination-fun node))
1512     (fun-changed (continuation-reoptimize fun))
1513     (args (basic-combination-args node)))
1514     (when fun-changed
1515     (setf (continuation-reoptimize fun) nil)
1516     (let ((type (continuation-type fun)))
1517     (when (function-type-p type)
1518     (derive-node-type node (function-type-returns type))))
1519     (maybe-terminate-block node nil)
1520     (let ((use (continuation-use fun)))
1521     (when (and (ref-p use) (functional-p (ref-leaf use)))
1522     (convert-call-if-possible use node)
1523 ram 1.54 (when (eq (basic-combination-kind node) :local)
1524     (maybe-let-convert (ref-leaf use))))))
1525 ram 1.50 (unless (or (eq (basic-combination-kind node) :local)
1526     (eq (continuation-function-name fun) '%throw))
1527     (ir1-optimize-mv-call node))
1528     (dolist (arg args)
1529     (setf (continuation-reoptimize arg) nil))))
1530     (:error))
1531 ram 1.21 (undefined-value))
1532    
1533    
1534 dtc 1.69 ;;; Values-types-defaulted -- Internal
1535     ;;;
1536     ;;; Like values-types, but returns the types of the given number of
1537     ;;; arguments. If optional of rest values must be used then the union
1538     ;;; with the null type is computed in case of defaulting, and if no
1539     ;;; values are available then they are defaulted to the null type.
1540     ;;;
1541     (defun values-types-defaulted (type count)
1542     (declare (type ctype type) (type index count))
1543     (cond ((eq type *wild-type*)
1544     (let ((types nil))
1545     (dotimes (i count types)
1546     (push *universal-type* types))))
1547     ((not (values-type-p type))
1548     (let ((types nil))
1549     (dotimes (i (1- count))
1550     (push *null-type* types))
1551     (push type types)))
1552     (t
1553     (let ((required (args-type-required type))
1554     (optional (args-type-optional type))
1555     (keyp-allowp (or (args-type-keyp type) (args-type-allowp type)))
1556     (rest (args-type-rest type)))
1557     (collect ((types))
1558     (dotimes (i count)
1559     (types (cond (required (single-value-type (pop required)))
1560     (optional (values-type-union
1561     (single-value-type (pop optional))
1562     *null-type*))
1563     (keyp-allowp *universal-type*)
1564     (rest (values-type-union (single-value-type rest)
1565     *null-type*))
1566     (t *null-type*))))
1567     (types))))))
1568    
1569    
1570 ram 1.6 ;;; IR1-OPTIMIZE-MV-BIND -- Internal
1571     ;;;
1572     ;;; Propagate derived type info from the values continuation to the vars.
1573     ;;;
1574     (defun ir1-optimize-mv-bind (node)
1575     (declare (type mv-combination node))
1576     (let ((arg (first (basic-combination-args node)))
1577     (vars (lambda-vars (combination-lambda node))))
1578 dtc 1.69 (let ((types (values-types-defaulted (continuation-derived-type arg)
1579     (length vars))))
1580     (mapc #'(lambda (var type)
1581     (if (basic-var-sets var)
1582     (propagate-from-sets var type)
1583     (propagate-to-refs var type)))
1584     vars types))
1585 ram 1.6
1586     (setf (continuation-reoptimize arg) nil))
1587 wlott 1.1 (undefined-value))
1588 ram 1.19
1589    
1590 ram 1.21 ;;; IR1-OPTIMIZE-MV-CALL -- Internal
1591 ram 1.19 ;;;
1592 ram 1.21 ;;; If possible, convert a general MV call to an MV-BIND. We can do this
1593     ;;; if:
1594 ram 1.22 ;;; -- The call has only one argument, and
1595 ram 1.21 ;;; -- The function has a known fixed number of arguments, or
1596 ram 1.22 ;;; -- The argument yields a known fixed number of values.
1597 ram 1.21 ;;;
1598     ;;; What we do is change the function in the MV-CALL to be a lambda that "looks
1599     ;;; like an MV bind", which allows IR1-OPTIMIZE-MV-COMBINATION to notice that
1600     ;;; this call can be converted (the next time around.) This new lambda just
1601 ram 1.31 ;;; calls the actual function with the MV-BIND variables as arguments. Note
1602     ;;; that this new MV bind is not let-converted immediately, as there are going
1603     ;;; to be stray references from the entry-point functions until they get
1604     ;;; deleted.
1605 ram 1.21 ;;;
1606     ;;; In order to avoid loss of argument count checking, we only do the
1607     ;;; transformation according to a known number of expected argument if safety
1608     ;;; is unimportant. We can always convert if we know the number of actual
1609     ;;; values, since the normal call that we build will still do any appropriate
1610     ;;; argument count checking.
1611     ;;;
1612     ;;; We only attempt the transformation if the called function is a constant
1613     ;;; reference. This allows us to just splice the leaf into the new function,
1614     ;;; instead of trying to somehow bind the function expression. The leaf must
1615     ;;; be constant because we are evaluating it again in a different place. This
1616     ;;; also has the effect of squelching multiple warnings when there is an
1617     ;;; argument count error.
1618     ;;;
1619     (defun ir1-optimize-mv-call (node)
1620     (let ((fun (basic-combination-fun node))
1621     (*compiler-error-context* node)
1622 ram 1.22 (ref (continuation-use (basic-combination-fun node)))
1623     (args (basic-combination-args node)))
1624 ram 1.21
1625 ram 1.22 (unless (and (ref-p ref) (constant-reference-p ref)
1626     args (null (rest args)))
1627 ram 1.21 (return-from ir1-optimize-mv-call))
1628    
1629     (multiple-value-bind (min max)
1630     (function-type-nargs (continuation-type fun))
1631 ram 1.22 (let ((total-nvals
1632     (multiple-value-bind
1633     (types nvals)
1634     (values-types (continuation-derived-type (first args)))
1635     (declare (ignore types))
1636     (if (eq nvals :unknown) nil nvals))))
1637 ram 1.21
1638 ram 1.22 (when total-nvals
1639     (when (and min (< total-nvals min))
1640     (compiler-warning
1641     "MULTIPLE-VALUE-CALL with ~R values when the function expects ~
1642     at least ~R."
1643     total-nvals min)
1644 ram 1.50 (setf (basic-combination-kind node) :error)
1645 ram 1.22 (return-from ir1-optimize-mv-call))
1646     (when (and max (> total-nvals max))
1647     (compiler-warning
1648     "MULTIPLE-VALUE-CALL with ~R values when the function expects ~
1649     at most ~R."
1650     total-nvals max)
1651 ram 1.50 (setf (basic-combination-kind node) :error)
1652 ram 1.22 (return-from ir1-optimize-mv-call)))
1653 ram 1.21
1654 ram 1.22 (let ((count (cond (total-nvals)
1655     ((and (policy node (zerop safety)) (eql min max))
1656     min)
1657     (t nil))))
1658     (when count
1659     (with-ir1-environment node
1660     (let* ((dums (loop repeat count collect (gensym)))
1661     (ignore (gensym))
1662     (fun (ir1-convert-lambda
1663     `(lambda (&optional ,@dums &rest ,ignore)
1664     (declare (ignore ,ignore))
1665 rtoy 1.83 (funcall ,(ref-leaf ref) ,@dums))
1666     nil ; name
1667     nil ; parent-form
1668     nil ; allow-debug-catch-tag
1669     'ir1-optimize-mv-call ; caller
1670     )))
1671 ram 1.22 (change-ref-leaf ref fun)
1672     (assert (eq (basic-combination-kind node) :full))
1673     (local-call-analyze *current-component*)
1674 ram 1.23 (assert (eq (basic-combination-kind node) :local)))))))))
1675 ram 1.21 (undefined-value))
1676    
1677    
1678     ;;; CONVERT-MV-BIND-TO-LET -- Internal
1679     ;;;
1680 ram 1.19 ;;; If we see:
1681     ;;; (multiple-value-bind (x y)
1682     ;;; (values xx yy)
1683     ;;; ...)
1684     ;;; Convert to:
1685     ;;; (let ((x xx)
1686     ;;; (y yy))
1687     ;;; ...)
1688     ;;;
1689     ;;; What we actually do is convert the VALUES combination into a normal let
1690 ram 1.31 ;;; combination calling the original :MV-LET lambda. If there are extra args to
1691 ram 1.19 ;;; VALUES, discard the corresponding continuations. If there are insufficient
1692     ;;; args, insert references to NIL.
1693     ;;;
1694 ram 1.21 (defun convert-mv-bind-to-let (call)
1695     (declare (type mv-combination call))
1696     (let* ((arg (first (basic-combination-args call)))
1697     (use (continuation-use arg)))
1698     (when (and (combination-p use)
1699     (eq (continuation-function-name (combination-fun use))
1700     'values))
1701     (let* ((fun (combination-lambda call))
1702 ram 1.19 (vars (lambda-vars fun))
1703 ram 1.21 (vals (combination-args use))
1704 ram 1.19 (nvars (length vars))
1705     (nvals (length vals)))
1706     (cond ((> nvals nvars)
1707     (mapc #'flush-dest (subseq vals nvars))
1708     (setq vals (subseq vals 0 nvars)))
1709     ((< nvals nvars)
1710 ram 1.21 (with-ir1-environment use
1711     (let ((node-prev (node-prev use)))
1712     (setf (node-prev use) nil)
1713 ram 1.19 (setf (continuation-next node-prev) nil)
1714     (collect ((res vals))
1715 ram 1.21 (loop as cont = (make-continuation use)
1716 ram 1.19 and prev = node-prev then cont
1717     repeat (- nvars nvals)
1718     do (reference-constant prev cont nil)
1719     (res cont))
1720     (setq vals (res)))
1721 ram 1.21 (prev-link use (car (last vals)))))))
1722     (setf (combination-args use) vals)
1723     (flush-dest (combination-fun use))
1724     (let ((fun-cont (basic-combination-fun call)))
1725     (setf (continuation-dest fun-cont) use)
1726     (setf (combination-fun use) fun-cont))
1727     (setf (combination-kind use) :local)
1728 ram 1.19 (setf (functional-kind fun) :let)
1729 ram 1.21 (flush-dest (first (basic-combination-args call)))
1730     (unlink-node call)
1731 ram 1.19 (when vals
1732 ram 1.20 (reoptimize-continuation (first vals)))
1733 ram 1.21 (propagate-to-args use fun))
1734     t)))
1735    
1736    
1737     ;;; VALUES-LIST IR1 optimizer -- Internal
1738     ;;;
1739     ;;; If we see:
1740     ;;; (values-list (list x y z))
1741     ;;;
1742     ;;; Convert to:
1743     ;;; (values x y z)
1744     ;;;
1745     ;;; In implementation, this is somewhat similar to CONVERT-MV-BIND-TO-LET. We
1746     ;;; grab the args of LIST and make them args of the VALUES-LIST call, flushing
1747     ;;; the old argument continuation (allowing the LIST to be flushed.)
1748     ;;;
1749     (defoptimizer (values-list optimizer) ((list) node)
1750     (let ((use (continuation-use list)))
1751     (when (and (combination-p use)
1752     (eq (continuation-function-name (combination-fun use))
1753     'list))
1754     (change-ref-leaf (continuation-use (combination-fun node))
1755     (find-free-function 'values "in a strange place"))
1756     (setf (combination-kind node) :full)
1757     (let ((args (combination-args use)))
1758     (dolist (arg args)
1759     (setf (continuation-dest arg) node))
1760     (setf (combination-args use) nil)
1761     (flush-dest list)
1762     (setf (combination-args node) args))
1763 ram 1.19 t)))
1764    
1765    
1766     ;;; VALUES IR1 transform -- Internal
1767     ;;;
1768     ;;; If VALUES appears in a non-MV context, then effectively convert it to a
1769     ;;; PROG1. This allows the computation of the additional values to become dead
1770 dtc 1.68 ;;; code. Some attempt is made to correct the node derived type, setting it to
1771     ;;; the received single-value-type. The node continuation asserted type must
1772     ;;; also be adjusted, taking care when the continuation has multiple uses.
1773 ram 1.19 ;;;
1774     (deftransform values ((&rest vals) * * :node node)
1775 dtc 1.68 (let ((cont (node-cont node)))
1776     (when (typep (continuation-dest cont) '(or creturn exit mv-combination))
1777     (give-up))
1778     (flet ((first-value-type (type)
1779     (declare (type ctype type))
1780     (cond ((values-type-p type)
1781     (let ((required (args-type-required type)))
1782     (if required
1783     (first required)
1784     (let ((otype (args-type-optional type)))
1785     (cond (otype (first otype))
1786     ((or (args-type-keyp type)
1787     (args-type-allowp type))
1788     *universal-type*)
1789     ((args-type-rest type))
1790     (t *null-type*))))))
1791     ((eq type *wild-type*)
1792     *universal-type*)
1793     (t
1794     type))))
1795     (cond ((= (length (find-uses cont)) 1)
1796     (setf (node-derived-type node)
1797     (single-value-type (node-derived-type node)))
1798     (setf (continuation-asserted-type cont)
1799     (first-value-type (continuation-asserted-type cont))))
1800     (t
1801     (setf (node-derived-type node)
1802     (single-value-type (node-derived-type node)))
1803     (setf (continuation-asserted-type cont)
1804     (values-type-union (continuation-asserted-type cont)
1805     (first-value-type
1806     (continuation-asserted-type cont)))))))
1807     (reoptimize-continuation cont)
1808     (if vals
1809     (let ((dummies (loop repeat (1- (length vals))
1810     collect (gensym))))
1811     `(lambda (val ,@dummies)
1812     (declare (ignore ,@dummies))
1813     val))
1814     'nil)))

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