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b275fb26 AW |
1 | ;;; Tree-IL partial evaluator |
2 | ||
3404ada0 | 3 | ;; Copyright (C) 2011, 2012, 2013 Free Software Foundation, Inc. |
b275fb26 AW |
4 | |
5 | ;;;; This library is free software; you can redistribute it and/or | |
6 | ;;;; modify it under the terms of the GNU Lesser General Public | |
7 | ;;;; License as published by the Free Software Foundation; either | |
8 | ;;;; version 3 of the License, or (at your option) any later version. | |
9 | ;;;; | |
10 | ;;;; This library is distributed in the hope that it will be useful, | |
11 | ;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | ;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | ;;;; Lesser General Public License for more details. | |
14 | ;;;; | |
15 | ;;;; You should have received a copy of the GNU Lesser General Public | |
16 | ;;;; License along with this library; if not, write to the Free Software | |
17 | ;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
18 | ||
19 | (define-module (language tree-il peval) | |
20 | #:use-module (language tree-il) | |
21 | #:use-module (language tree-il primitives) | |
a36e7870 | 22 | #:use-module (language tree-il effects) |
b275fb26 AW |
23 | #:use-module (ice-9 vlist) |
24 | #:use-module (ice-9 match) | |
25 | #:use-module (srfi srfi-1) | |
26 | #:use-module (srfi srfi-9) | |
27 | #:use-module (srfi srfi-11) | |
28 | #:use-module (srfi srfi-26) | |
4ad329cb | 29 | #:use-module (ice-9 control) |
b275fb26 AW |
30 | #:export (peval)) |
31 | ||
32 | ;;; | |
47974c30 AW |
33 | ;;; Partial evaluation is Guile's most important source-to-source |
34 | ;;; optimization pass. It performs copy propagation, dead code | |
35 | ;;; elimination, inlining, and constant folding, all while preserving | |
36 | ;;; the order of effects in the residual program. | |
37 | ;;; | |
38 | ;;; For more on partial evaluation, see William Cook’s excellent | |
39 | ;;; tutorial on partial evaluation at DSL 2011, called “Build your own | |
40 | ;;; partial evaluator in 90 minutes”[0]. | |
41 | ;;; | |
42 | ;;; Our implementation of this algorithm was heavily influenced by | |
43 | ;;; Waddell and Dybvig's paper, "Fast and Effective Procedure Inlining", | |
44 | ;;; IU CS Dept. TR 484. | |
45 | ;;; | |
46 | ;;; [0] http://www.cs.utexas.edu/~wcook/tutorial/. | |
b275fb26 AW |
47 | ;;; |
48 | ||
47974c30 AW |
49 | ;; First, some helpers. |
50 | ;; | |
30669991 AW |
51 | (define-syntax *logging* (identifier-syntax #f)) |
52 | ||
41d43584 | 53 | ;; For efficiency we define *logging* to inline to #f, so that the call |
30669991 AW |
54 | ;; to log* gets optimized out. If you want to log, uncomment these |
55 | ;; lines: | |
41d43584 | 56 | ;; |
30669991 AW |
57 | ;; (define %logging #f) |
58 | ;; (define-syntax *logging* (identifier-syntax %logging)) | |
41d43584 AW |
59 | ;; |
60 | ;; Then you can change %logging at runtime. | |
41d43584 AW |
61 | |
62 | (define-syntax log | |
63 | (syntax-rules (quote) | |
64 | ((log 'event arg ...) | |
65 | (if (and *logging* | |
66 | (or (eq? *logging* #t) | |
67 | (memq 'event *logging*))) | |
68 | (log* 'event arg ...))))) | |
69 | ||
70 | (define (log* event . args) | |
71 | (let ((pp (module-ref (resolve-interface '(ice-9 pretty-print)) | |
72 | 'pretty-print))) | |
73 | (pp `(log ,event . ,args)) | |
74 | (newline) | |
75 | (values))) | |
b275fb26 | 76 | |
b275fb26 AW |
77 | (define (tree-il-any proc exp) |
78 | (let/ec k | |
79 | (tree-il-fold (lambda (exp res) | |
80 | (let ((res (proc exp))) | |
81 | (if res (k res) #f))) | |
b275fb26 AW |
82 | (lambda (exp res) #f) |
83 | #f exp))) | |
84 | ||
85 | (define (vlist-any proc vlist) | |
86 | (let ((len (vlist-length vlist))) | |
87 | (let lp ((i 0)) | |
88 | (and (< i len) | |
89 | (or (proc (vlist-ref vlist i)) | |
90 | (lp (1+ i))))))) | |
91 | ||
7cbadbc4 AW |
92 | (define (singly-valued-expression? exp) |
93 | (match exp | |
94 | (($ <const>) #t) | |
95 | (($ <lexical-ref>) #t) | |
96 | (($ <void>) #t) | |
97 | (($ <lexical-ref>) #t) | |
98 | (($ <primitive-ref>) #t) | |
99 | (($ <module-ref>) #t) | |
100 | (($ <toplevel-ref>) #t) | |
296004b3 AW |
101 | (($ <primcall> _ (? singly-valued-primitive?)) #t) |
102 | (($ <primcall> _ 'values (val)) #t) | |
7cbadbc4 | 103 | (($ <lambda>) #t) |
e6450062 AW |
104 | (($ <conditional> _ test consequent alternate) |
105 | (and (singly-valued-expression? consequent) | |
106 | (singly-valued-expression? alternate))) | |
7cbadbc4 AW |
107 | (else #f))) |
108 | ||
bcec8858 LC |
109 | (define (truncate-values x) |
110 | "Discard all but the first value of X." | |
7cbadbc4 AW |
111 | (if (singly-valued-expression? x) |
112 | x | |
296004b3 | 113 | (make-primcall (tree-il-src x) 'values (list x)))) |
bcec8858 | 114 | |
47974c30 AW |
115 | ;; Peval will do a one-pass analysis on the source program to determine |
116 | ;; the set of assigned lexicals, and to identify unreferenced and | |
117 | ;; singly-referenced lexicals. | |
118 | ;; | |
b275fb26 AW |
119 | (define-record-type <var> |
120 | (make-var name gensym refcount set?) | |
121 | var? | |
122 | (name var-name) | |
123 | (gensym var-gensym) | |
124 | (refcount var-refcount set-var-refcount!) | |
125 | (set? var-set? set-var-set?!)) | |
126 | ||
127 | (define* (build-var-table exp #:optional (table vlist-null)) | |
128 | (tree-il-fold | |
129 | (lambda (exp res) | |
130 | (match exp | |
131 | (($ <lexical-ref> src name gensym) | |
75170872 AW |
132 | (let ((var (cdr (vhash-assq gensym res)))) |
133 | (set-var-refcount! var (1+ (var-refcount var))) | |
134 | res)) | |
75170872 AW |
135 | (($ <lambda-case> src req opt rest kw init gensyms body alt) |
136 | (fold (lambda (name sym res) | |
137 | (vhash-consq sym (make-var name sym 0 #f) res)) | |
138 | res | |
139 | (append req (or opt '()) (if rest (list rest) '()) | |
140 | (match kw | |
141 | ((aok? (kw name sym) ...) name) | |
142 | (_ '()))) | |
143 | gensyms)) | |
144 | (($ <let> src names gensyms vals body) | |
145 | (fold (lambda (name sym res) | |
146 | (vhash-consq sym (make-var name sym 0 #f) res)) | |
147 | res names gensyms)) | |
148 | (($ <letrec> src in-order? names gensyms vals body) | |
149 | (fold (lambda (name sym res) | |
150 | (vhash-consq sym (make-var name sym 0 #f) res)) | |
151 | res names gensyms)) | |
152 | (($ <fix> src names gensyms vals body) | |
153 | (fold (lambda (name sym res) | |
154 | (vhash-consq sym (make-var name sym 0 #f) res)) | |
155 | res names gensyms)) | |
b275fb26 | 156 | (($ <lexical-set> src name gensym exp) |
75170872 AW |
157 | (set-var-set?! (cdr (vhash-assq gensym res)) #t) |
158 | res) | |
b275fb26 AW |
159 | (_ res))) |
160 | (lambda (exp res) res) | |
161 | table exp)) | |
162 | ||
47974c30 AW |
163 | ;; Counters are data structures used to limit the effort that peval |
164 | ;; spends on particular inlining attempts. Each call site in the source | |
165 | ;; program is allocated some amount of effort. If peval exceeds the | |
166 | ;; effort counter while attempting to inline a call site, it aborts the | |
167 | ;; inlining attempt and residualizes a call instead. | |
168 | ;; | |
169 | ;; As there is a fixed number of call sites, that makes `peval' O(N) in | |
170 | ;; the number of call sites in the source program. | |
171 | ;; | |
172 | ;; Counters should limit the size of the residual program as well, but | |
173 | ;; currently this is not implemented. | |
174 | ;; | |
175 | ;; At the top level, before seeing any peval call, there is no counter, | |
176 | ;; because inlining will terminate as there is no recursion. When peval | |
177 | ;; sees a call at the top level, it will make a new counter, allocating | |
178 | ;; it some amount of effort and size. | |
179 | ;; | |
180 | ;; This top-level effort counter effectively "prints money". Within a | |
181 | ;; toplevel counter, no more effort is printed ex nihilo; for a nested | |
182 | ;; inlining attempt to proceed, effort must be transferred from the | |
183 | ;; toplevel counter to the nested counter. | |
184 | ;; | |
185 | ;; Via `data' and `prev', counters form a linked list, terminating in a | |
186 | ;; toplevel counter. In practice `data' will be the a pointer to the | |
187 | ;; source expression of the procedure being inlined. | |
188 | ;; | |
189 | ;; In this way peval can detect a recursive inlining attempt, by walking | |
190 | ;; back on the `prev' links looking for matching `data'. Recursive | |
191 | ;; counters receive a more limited effort allocation, as we don't want | |
192 | ;; to spend all of the effort for a toplevel inlining site on loops. | |
193 | ;; Also, recursive counters don't need a prompt at each inlining site: | |
194 | ;; either the call chain folds entirely, or it will be residualized at | |
195 | ;; its original call. | |
196 | ;; | |
b275fb26 AW |
197 | (define-record-type <counter> |
198 | (%make-counter effort size continuation recursive? data prev) | |
199 | counter? | |
200 | (effort effort-counter) | |
201 | (size size-counter) | |
202 | (continuation counter-continuation) | |
75170872 | 203 | (recursive? counter-recursive? set-counter-recursive?!) |
b275fb26 AW |
204 | (data counter-data) |
205 | (prev counter-prev)) | |
206 | ||
207 | (define (abort-counter c) | |
208 | ((counter-continuation c))) | |
209 | ||
210 | (define (record-effort! c) | |
211 | (let ((e (effort-counter c))) | |
212 | (if (zero? (variable-ref e)) | |
213 | (abort-counter c) | |
214 | (variable-set! e (1- (variable-ref e)))))) | |
215 | ||
216 | (define (record-size! c) | |
217 | (let ((s (size-counter c))) | |
218 | (if (zero? (variable-ref s)) | |
219 | (abort-counter c) | |
220 | (variable-set! s (1- (variable-ref s)))))) | |
221 | ||
222 | (define (find-counter data counter) | |
223 | (and counter | |
224 | (if (eq? data (counter-data counter)) | |
225 | counter | |
226 | (find-counter data (counter-prev counter))))) | |
227 | ||
228 | (define* (transfer! from to #:optional | |
229 | (effort (variable-ref (effort-counter from))) | |
230 | (size (variable-ref (size-counter from)))) | |
231 | (define (transfer-counter! from-v to-v amount) | |
232 | (let* ((from-balance (variable-ref from-v)) | |
233 | (to-balance (variable-ref to-v)) | |
234 | (amount (min amount from-balance))) | |
235 | (variable-set! from-v (- from-balance amount)) | |
236 | (variable-set! to-v (+ to-balance amount)))) | |
237 | ||
238 | (transfer-counter! (effort-counter from) (effort-counter to) effort) | |
239 | (transfer-counter! (size-counter from) (size-counter to) size)) | |
240 | ||
241 | (define (make-top-counter effort-limit size-limit continuation data) | |
242 | (%make-counter (make-variable effort-limit) | |
243 | (make-variable size-limit) | |
244 | continuation | |
245 | #t | |
246 | data | |
247 | #f)) | |
248 | ||
249 | (define (make-nested-counter continuation data current) | |
250 | (let ((c (%make-counter (make-variable 0) | |
251 | (make-variable 0) | |
252 | continuation | |
253 | #f | |
254 | data | |
255 | current))) | |
256 | (transfer! current c) | |
257 | c)) | |
258 | ||
259 | (define (make-recursive-counter effort-limit size-limit orig current) | |
260 | (let ((c (%make-counter (make-variable 0) | |
261 | (make-variable 0) | |
262 | (counter-continuation orig) | |
263 | #t | |
264 | (counter-data orig) | |
265 | current))) | |
266 | (transfer! current c effort-limit size-limit) | |
267 | c)) | |
268 | ||
580a59e7 AW |
269 | ;; Operand structures allow bindings to be processed lazily instead of |
270 | ;; eagerly. By doing so, hopefully we can get process them in a way | |
271 | ;; appropriate to their use contexts. Operands also prevent values from | |
272 | ;; being visited multiple times, wasting effort. | |
75170872 AW |
273 | ;; |
274 | ;; TODO: Record value size in operand structure? | |
580a59e7 AW |
275 | ;; |
276 | (define-record-type <operand> | |
997ed300 | 277 | (%make-operand var sym visit source visit-count use-count |
985702f7 | 278 | copyable? residual-value constant-value alias-value) |
580a59e7 AW |
279 | operand? |
280 | (var operand-var) | |
281 | (sym operand-sym) | |
282 | (visit %operand-visit) | |
283 | (source operand-source) | |
284 | (visit-count operand-visit-count set-operand-visit-count!) | |
997ed300 | 285 | (use-count operand-use-count set-operand-use-count!) |
580a59e7 | 286 | (copyable? operand-copyable? set-operand-copyable?!) |
7cbadbc4 | 287 | (residual-value operand-residual-value %set-operand-residual-value!) |
985702f7 AW |
288 | (constant-value operand-constant-value set-operand-constant-value!) |
289 | (alias-value operand-alias-value set-operand-alias-value!)) | |
580a59e7 | 290 | |
985702f7 | 291 | (define* (make-operand var sym #:optional source visit alias) |
a36e7870 AW |
292 | ;; Bind SYM to VAR, with value SOURCE. Unassigned bound operands are |
293 | ;; considered copyable until we prove otherwise. If we have a source | |
294 | ;; expression, truncate it to one value. Copy propagation does not | |
295 | ;; work on multiply-valued expressions. | |
7cbadbc4 | 296 | (let ((source (and=> source truncate-values))) |
997ed300 | 297 | (%make-operand var sym visit source 0 0 |
985702f7 AW |
298 | (and source (not (var-set? var))) #f #f |
299 | (and (not (var-set? var)) alias)))) | |
300 | ||
301 | (define* (make-bound-operands vars syms sources visit #:optional aliases) | |
302 | (if aliases | |
303 | (map (lambda (name sym source alias) | |
304 | (make-operand name sym source visit alias)) | |
305 | vars syms sources aliases) | |
306 | (map (lambda (name sym source) | |
307 | (make-operand name sym source visit #f)) | |
308 | vars syms sources))) | |
580a59e7 AW |
309 | |
310 | (define (make-unbound-operands vars syms) | |
311 | (map make-operand vars syms)) | |
312 | ||
7cbadbc4 AW |
313 | (define (set-operand-residual-value! op val) |
314 | (%set-operand-residual-value! | |
315 | op | |
316 | (match val | |
296004b3 | 317 | (($ <primcall> src 'values (first)) |
7cbadbc4 AW |
318 | ;; The continuation of a residualized binding does not need the |
319 | ;; introduced `values' node, so undo the effects of truncation. | |
320 | first) | |
321 | (else | |
322 | val)))) | |
323 | ||
580a59e7 AW |
324 | (define* (visit-operand op counter ctx #:optional effort-limit size-limit) |
325 | ;; Peval is O(N) in call sites of the source program. However, | |
326 | ;; visiting an operand can introduce new call sites. If we visit an | |
327 | ;; operand outside a counter -- i.e., outside an inlining attempt -- | |
328 | ;; this can lead to divergence. So, if we are visiting an operand to | |
329 | ;; try to copy it, and there is no counter, make a new one. | |
330 | ;; | |
331 | ;; This will only happen at most as many times as there are lexical | |
332 | ;; references in the source program. | |
333 | (and (zero? (operand-visit-count op)) | |
334 | (dynamic-wind | |
335 | (lambda () | |
336 | (set-operand-visit-count! op (1+ (operand-visit-count op)))) | |
337 | (lambda () | |
338 | (and (operand-source op) | |
339 | (if (or counter (and (not effort-limit) (not size-limit))) | |
340 | ((%operand-visit op) (operand-source op) counter ctx) | |
341 | (let/ec k | |
985702f7 AW |
342 | (define (abort) |
343 | ;; If we abort when visiting the value in a | |
344 | ;; fresh context, we won't succeed in any future | |
345 | ;; attempt, so don't try to copy it again. | |
346 | (set-operand-copyable?! op #f) | |
347 | (k #f)) | |
580a59e7 AW |
348 | ((%operand-visit op) |
349 | (operand-source op) | |
350 | (make-top-counter effort-limit size-limit abort op) | |
351 | ctx))))) | |
352 | (lambda () | |
353 | (set-operand-visit-count! op (1- (operand-visit-count op))))))) | |
354 | ||
355 | ;; A helper for constant folding. | |
356 | ;; | |
b275fb26 AW |
357 | (define (types-check? primitive-name args) |
358 | (case primitive-name | |
359 | ((values) #t) | |
360 | ((not pair? null? list? symbol? vector? struct?) | |
361 | (= (length args) 1)) | |
362 | ((eq? eqv? equal?) | |
363 | (= (length args) 2)) | |
364 | ;; FIXME: add more cases? | |
365 | (else #f))) | |
366 | ||
367 | (define* (peval exp #:optional (cenv (current-module)) (env vlist-null) | |
368 | #:key | |
369 | (operator-size-limit 40) | |
370 | (operand-size-limit 20) | |
371 | (value-size-limit 10) | |
372 | (effort-limit 500) | |
373 | (recursive-effort-limit 100)) | |
374 | "Partially evaluate EXP in compilation environment CENV, with | |
47974c30 | 375 | top-level bindings from ENV and return the resulting expression." |
b275fb26 AW |
376 | |
377 | ;; This is a simple partial evaluator. It effectively performs | |
378 | ;; constant folding, copy propagation, dead code elimination, and | |
47974c30 AW |
379 | ;; inlining. |
380 | ||
381 | ;; TODO: | |
382 | ;; | |
383 | ;; Propagate copies across toplevel bindings, if we can prove the | |
384 | ;; bindings to be immutable. | |
b275fb26 | 385 | ;; |
47974c30 | 386 | ;; Specialize lambda expressions with invariant arguments. |
b275fb26 AW |
387 | |
388 | (define local-toplevel-env | |
389 | ;; The top-level environment of the module being compiled. | |
ca128245 AW |
390 | (let () |
391 | (define (env-folder x env) | |
392 | (match x | |
393 | (($ <toplevel-define> _ name) | |
394 | (vhash-consq name #t env)) | |
395 | (($ <seq> _ head tail) | |
396 | (env-folder tail (env-folder head env))) | |
397 | (_ env))) | |
398 | (env-folder exp vlist-null))) | |
b275fb26 AW |
399 | |
400 | (define (local-toplevel? name) | |
401 | (vhash-assq name local-toplevel-env)) | |
402 | ||
47974c30 AW |
403 | ;; gensym -> <var> |
404 | ;; renamed-term -> original-term | |
405 | ;; | |
b275fb26 AW |
406 | (define store (build-var-table exp)) |
407 | ||
4bf9e928 AW |
408 | (define (record-new-temporary! name sym refcount) |
409 | (set! store (vhash-consq sym (make-var name sym refcount #f) store))) | |
410 | ||
75170872 | 411 | (define (lookup-var sym) |
b275fb26 | 412 | (let ((v (vhash-assq sym store))) |
75170872 AW |
413 | (if v (cdr v) (error "unbound var" sym (vlist->list store))))) |
414 | ||
415 | (define (fresh-gensyms vars) | |
416 | (map (lambda (var) | |
417 | (let ((new (gensym (string-append (symbol->string (var-name var)) | |
3404ada0 | 418 | " ")))) |
75170872 AW |
419 | (set! store (vhash-consq new var store)) |
420 | new)) | |
421 | vars)) | |
422 | ||
91c763ee AW |
423 | (define (fresh-temporaries ls) |
424 | (map (lambda (elt) | |
425 | (let ((new (gensym "tmp "))) | |
426 | (record-new-temporary! 'tmp new 1) | |
427 | new)) | |
428 | ls)) | |
429 | ||
75170872 AW |
430 | (define (assigned-lexical? sym) |
431 | (var-set? (lookup-var sym))) | |
b275fb26 AW |
432 | |
433 | (define (lexical-refcount sym) | |
75170872 | 434 | (var-refcount (lookup-var sym))) |
b275fb26 | 435 | |
47974c30 AW |
436 | ;; ORIG has been alpha-renamed to NEW. Analyze NEW and record a link |
437 | ;; from it to ORIG. | |
438 | ;; | |
b275fb26 | 439 | (define (record-source-expression! orig new) |
75170872 | 440 | (set! store (vhash-consq new (source-expression orig) store)) |
b275fb26 AW |
441 | new) |
442 | ||
47974c30 AW |
443 | ;; Find the source expression corresponding to NEW. Used to detect |
444 | ;; recursive inlining attempts. | |
445 | ;; | |
b275fb26 AW |
446 | (define (source-expression new) |
447 | (let ((x (vhash-assq new store))) | |
448 | (if x (cdr x) new))) | |
449 | ||
997ed300 AW |
450 | (define (record-operand-use op) |
451 | (set-operand-use-count! op (1+ (operand-use-count op)))) | |
452 | ||
453 | (define (unrecord-operand-uses op n) | |
454 | (let ((count (- (operand-use-count op) n))) | |
455 | (when (zero? count) | |
456 | (set-operand-residual-value! op #f)) | |
457 | (set-operand-use-count! op count))) | |
458 | ||
75170872 AW |
459 | (define* (residualize-lexical op #:optional ctx val) |
460 | (log 'residualize op) | |
997ed300 | 461 | (record-operand-use op) |
fff39e1a | 462 | (if (memq ctx '(value values)) |
75170872 AW |
463 | (set-operand-residual-value! op val)) |
464 | (make-lexical-ref #f (var-name (operand-var op)) (operand-sym op))) | |
b275fb26 | 465 | |
30fcf30f | 466 | (define (fold-constants src name args ctx) |
7cbadbc4 AW |
467 | (define (apply-primitive name args) |
468 | ;; todo: further optimize commutative primitives | |
469 | (catch #t | |
470 | (lambda () | |
471 | (call-with-values | |
472 | (lambda () | |
473 | (apply (module-ref the-scm-module name) args)) | |
474 | (lambda results | |
475 | (values #t results)))) | |
476 | (lambda _ | |
477 | (values #f '())))) | |
7cbadbc4 AW |
478 | (define (make-values src values) |
479 | (match values | |
480 | ((single) single) ; 1 value | |
481 | ((_ ...) ; 0, or 2 or more values | |
296004b3 | 482 | (make-primcall src 'values values)))) |
30fcf30f | 483 | (define (residualize-call) |
4938d3cb | 484 | (make-primcall src name args)) |
30fcf30f AW |
485 | (cond |
486 | ((every const? args) | |
487 | (let-values (((success? values) | |
488 | (apply-primitive name (map const-exp args)))) | |
489 | (log 'fold success? values name args) | |
490 | (if success? | |
491 | (case ctx | |
492 | ((effect) (make-void src)) | |
493 | ((test) | |
494 | ;; Values truncation: only take the first | |
495 | ;; value. | |
496 | (if (pair? values) | |
497 | (make-const src (car values)) | |
498 | (make-values src '()))) | |
499 | (else | |
500 | (make-values src (map (cut make-const src <>) values)))) | |
501 | (residualize-call)))) | |
502 | ((and (eq? ctx 'effect) (types-check? name args)) | |
503 | (make-void #f)) | |
504 | (else | |
505 | (residualize-call)))) | |
506 | ||
85edd670 | 507 | (define (inline-values src exp nmin nmax consumer) |
b275fb26 AW |
508 | (let loop ((exp exp)) |
509 | (match exp | |
510 | ;; Some expression types are always singly-valued. | |
511 | ((or ($ <const>) | |
512 | ($ <void>) | |
513 | ($ <lambda>) | |
514 | ($ <lexical-ref>) | |
515 | ($ <toplevel-ref>) | |
516 | ($ <module-ref>) | |
517 | ($ <primitive-ref>) | |
518 | ($ <dynref>) | |
519 | ($ <lexical-set>) ; FIXME: these set! expressions | |
520 | ($ <toplevel-set>) ; could return zero values in | |
521 | ($ <toplevel-define>) ; the future | |
522 | ($ <module-set>) ; | |
85edd670 | 523 | ($ <dynset>) ; |
9b977c83 | 524 | ($ <primcall> src (? singly-valued-primitive?))) |
85edd670 | 525 | (and (<= nmin 1) (or (not nmax) (>= nmax 1)) |
9b977c83 | 526 | (make-call src (make-lambda #f '() consumer) (list exp)))) |
b275fb26 AW |
527 | |
528 | ;; Statically-known number of values. | |
ca128245 | 529 | (($ <primcall> src 'values vals) |
85edd670 | 530 | (and (<= nmin (length vals)) (or (not nmax) (>= nmax (length vals))) |
9b977c83 | 531 | (make-call src (make-lambda #f '() consumer) vals))) |
b275fb26 AW |
532 | |
533 | ;; Not going to copy code into both branches. | |
534 | (($ <conditional>) #f) | |
535 | ||
536 | ;; Bail on other applications. | |
ca128245 AW |
537 | (($ <call>) #f) |
538 | (($ <primcall>) #f) | |
b275fb26 AW |
539 | |
540 | ;; Bail on prompt and abort. | |
541 | (($ <prompt>) #f) | |
542 | (($ <abort>) #f) | |
543 | ||
544 | ;; Propagate to tail positions. | |
545 | (($ <let> src names gensyms vals body) | |
546 | (let ((body (loop body))) | |
547 | (and body | |
548 | (make-let src names gensyms vals body)))) | |
549 | (($ <letrec> src in-order? names gensyms vals body) | |
550 | (let ((body (loop body))) | |
551 | (and body | |
552 | (make-letrec src in-order? names gensyms vals body)))) | |
553 | (($ <fix> src names gensyms vals body) | |
554 | (let ((body (loop body))) | |
555 | (and body | |
556 | (make-fix src names gensyms vals body)))) | |
557 | (($ <let-values> src exp | |
558 | ($ <lambda-case> src2 req opt rest kw inits gensyms body #f)) | |
559 | (let ((body (loop body))) | |
560 | (and body | |
561 | (make-let-values src exp | |
562 | (make-lambda-case src2 req opt rest kw | |
563 | inits gensyms body #f))))) | |
b275fb26 AW |
564 | (($ <dynlet> src fluids vals body) |
565 | (let ((body (loop body))) | |
566 | (and body | |
567 | (make-dynlet src fluids vals body)))) | |
ca128245 AW |
568 | (($ <seq> src head tail) |
569 | (let ((tail (loop tail))) | |
570 | (and tail (make-seq src head tail))))))) | |
b275fb26 | 571 | |
a36e7870 AW |
572 | (define compute-effects |
573 | (make-effects-analyzer assigned-lexical?)) | |
574 | ||
b275fb26 | 575 | (define (constant-expression? x) |
16d3e013 AW |
576 | ;; Return true if X is constant, for the purposes of copying or |
577 | ;; elision---i.e., if it is known to have no effects, does not | |
578 | ;; allocate storage for a mutable object, and does not access | |
579 | ;; mutable data (like `car' or toplevel references). | |
a36e7870 | 580 | (constant? (compute-effects x))) |
b275fb26 | 581 | |
75170872 AW |
582 | (define (prune-bindings ops in-order? body counter ctx build-result) |
583 | ;; This helper handles both `let' and `letrec'/`fix'. In the latter | |
584 | ;; cases we need to make sure that if referenced binding A needs | |
585 | ;; as-yet-unreferenced binding B, that B is processed for value. | |
586 | ;; Likewise if C, when processed for effect, needs otherwise | |
587 | ;; unreferenced D, then D needs to be processed for value too. | |
588 | ;; | |
589 | (define (referenced? op) | |
590 | ;; When we visit lambdas in operator context, we just copy them, | |
591 | ;; as we will process their body later. However this does have | |
592 | ;; the problem that any free var referenced by the lambda is not | |
593 | ;; marked as needing residualization. Here we hack around this | |
594 | ;; and treat all bindings as referenced if we are in operator | |
595 | ;; context. | |
997ed300 AW |
596 | (or (eq? ctx 'operator) |
597 | (not (zero? (operand-use-count op))))) | |
75170872 AW |
598 | |
599 | ;; values := (op ...) | |
600 | ;; effects := (op ...) | |
601 | (define (residualize values effects) | |
602 | ;; Note, values and effects are reversed. | |
603 | (cond | |
604 | (in-order? | |
605 | (let ((values (filter operand-residual-value ops))) | |
606 | (if (null? values) | |
b275fb26 | 607 | body |
75170872 AW |
608 | (build-result (map (compose var-name operand-var) values) |
609 | (map operand-sym values) | |
610 | (map operand-residual-value values) | |
611 | body)))) | |
612 | (else | |
613 | (let ((body | |
614 | (if (null? effects) | |
615 | body | |
616 | (let ((effect-vals (map operand-residual-value effects))) | |
a215c159 | 617 | (list->seq #f (reverse (cons body effect-vals))))))) |
75170872 AW |
618 | (if (null? values) |
619 | body | |
620 | (let ((values (reverse values))) | |
621 | (build-result (map (compose var-name operand-var) values) | |
622 | (map operand-sym values) | |
623 | (map operand-residual-value values) | |
624 | body))))))) | |
625 | ||
626 | ;; old := (bool ...) | |
627 | ;; values := (op ...) | |
628 | ;; effects := ((op . value) ...) | |
629 | (let prune ((old (map referenced? ops)) (values '()) (effects '())) | |
630 | (let lp ((ops* ops) (values values) (effects effects)) | |
631 | (cond | |
632 | ((null? ops*) | |
633 | (let ((new (map referenced? ops))) | |
634 | (if (not (equal? new old)) | |
635 | (prune new values '()) | |
636 | (residualize values | |
637 | (map (lambda (op val) | |
638 | (set-operand-residual-value! op val) | |
639 | op) | |
640 | (map car effects) (map cdr effects)))))) | |
641 | (else | |
642 | (let ((op (car ops*))) | |
643 | (cond | |
644 | ((memq op values) | |
645 | (lp (cdr ops*) values effects)) | |
646 | ((operand-residual-value op) | |
647 | (lp (cdr ops*) (cons op values) effects)) | |
648 | ((referenced? op) | |
649 | (set-operand-residual-value! op (visit-operand op counter 'value)) | |
650 | (lp (cdr ops*) (cons op values) effects)) | |
651 | (else | |
652 | (lp (cdr ops*) | |
653 | values | |
654 | (let ((effect (visit-operand op counter 'effect))) | |
655 | (if (void? effect) | |
656 | effects | |
657 | (acons op effect effects)))))))))))) | |
b275fb26 AW |
658 | |
659 | (define (small-expression? x limit) | |
660 | (let/ec k | |
661 | (tree-il-fold | |
b275fb26 AW |
662 | (lambda (x res) ; down |
663 | (1+ res)) | |
664 | (lambda (x res) ; up | |
665 | (if (< res limit) | |
666 | res | |
667 | (k #f))) | |
668 | 0 x) | |
669 | #t)) | |
670 | ||
75170872 AW |
671 | (define (extend-env sym op env) |
672 | (vhash-consq (operand-sym op) op (vhash-consq sym op env))) | |
673 | ||
b275fb26 | 674 | (let loop ((exp exp) |
75170872 | 675 | (env vlist-null) ; vhash of gensym -> <operand> |
b275fb26 | 676 | (counter #f) ; inlined call stack |
7cbadbc4 | 677 | (ctx 'values)) ; effect, value, values, test, operator, or call |
b275fb26 | 678 | (define (lookup var) |
75170872 AW |
679 | (cond |
680 | ((vhash-assq var env) => cdr) | |
681 | (else (error "unbound var" var)))) | |
b275fb26 | 682 | |
d21537ef AW |
683 | ;; Find a value referenced a specific number of times. This is a hack |
684 | ;; that's used for propagating fresh data structures like rest lists and | |
685 | ;; prompt tags. Usually we wouldn't copy consed data, but we can do so in | |
686 | ;; some special cases like `apply' or prompts if we can account | |
687 | ;; for all of its uses. | |
688 | ;; | |
8598dd8d AW |
689 | ;; You don't want to use this in general because it introduces a slight |
690 | ;; nonlinearity by running peval again (though with a small effort and size | |
691 | ;; counter). | |
d21537ef AW |
692 | ;; |
693 | (define (find-definition x n-aliases) | |
694 | (cond | |
695 | ((lexical-ref? x) | |
696 | (cond | |
697 | ((lookup (lexical-ref-gensym x)) | |
698 | => (lambda (op) | |
699 | (let ((y (or (operand-residual-value op) | |
8598dd8d AW |
700 | (visit-operand op counter 'value 10 10) |
701 | (operand-source op)))) | |
d21537ef AW |
702 | (cond |
703 | ((and (lexical-ref? y) | |
704 | (= (lexical-refcount (lexical-ref-gensym x)) 1)) | |
705 | ;; X is a simple alias for Y. Recurse, regardless of | |
706 | ;; the number of aliases we were expecting. | |
707 | (find-definition y n-aliases)) | |
708 | ((= (lexical-refcount (lexical-ref-gensym x)) n-aliases) | |
709 | ;; We found a definition that is aliased the right | |
710 | ;; number of times. We still recurse in case it is a | |
711 | ;; lexical. | |
712 | (values (find-definition y 1) | |
713 | op)) | |
714 | (else | |
715 | ;; We can't account for our aliases. | |
716 | (values #f #f)))))) | |
717 | (else | |
718 | ;; A formal parameter. Can't say anything about that. | |
719 | (values #f #f)))) | |
720 | ((= n-aliases 1) | |
721 | ;; Not a lexical: success, but only if we are looking for an | |
722 | ;; unaliased value. | |
723 | (values x #f)) | |
724 | (else (values #f #f)))) | |
725 | ||
904981ee | 726 | (define (visit exp ctx) |
b275fb26 AW |
727 | (loop exp env counter ctx)) |
728 | ||
904981ee | 729 | (define (for-value exp) (visit exp 'value)) |
7cbadbc4 | 730 | (define (for-values exp) (visit exp 'values)) |
904981ee AW |
731 | (define (for-test exp) (visit exp 'test)) |
732 | (define (for-effect exp) (visit exp 'effect)) | |
75170872 | 733 | (define (for-call exp) (visit exp 'call)) |
904981ee AW |
734 | (define (for-tail exp) (visit exp ctx)) |
735 | ||
b275fb26 AW |
736 | (if counter |
737 | (record-effort! counter)) | |
738 | ||
41d43584 AW |
739 | (log 'visit ctx (and=> counter effort-counter) |
740 | (unparse-tree-il exp)) | |
741 | ||
b275fb26 AW |
742 | (match exp |
743 | (($ <const>) | |
744 | (case ctx | |
745 | ((effect) (make-void #f)) | |
746 | (else exp))) | |
747 | (($ <void>) | |
748 | (case ctx | |
749 | ((test) (make-const #f #t)) | |
750 | (else exp))) | |
751 | (($ <lexical-ref> _ _ gensym) | |
75170872 AW |
752 | (log 'begin-copy gensym) |
753 | (let ((op (lookup gensym))) | |
754 | (cond | |
755 | ((eq? ctx 'effect) | |
756 | (log 'lexical-for-effect gensym) | |
757 | (make-void #f)) | |
985702f7 AW |
758 | ((operand-alias-value op) |
759 | ;; This is an unassigned operand that simply aliases some | |
760 | ;; other operand. Recurse to avoid residualizing the leaf | |
761 | ;; binding. | |
762 | => for-tail) | |
75170872 AW |
763 | ((eq? ctx 'call) |
764 | ;; Don't propagate copies if we are residualizing a call. | |
765 | (log 'residualize-lexical-call gensym op) | |
766 | (residualize-lexical op)) | |
767 | ((var-set? (operand-var op)) | |
768 | ;; Assigned lexicals don't copy-propagate. | |
769 | (log 'assigned-var gensym op) | |
770 | (residualize-lexical op)) | |
771 | ((not (operand-copyable? op)) | |
772 | ;; We already know that this operand is not copyable. | |
773 | (log 'not-copyable gensym op) | |
774 | (residualize-lexical op)) | |
775 | ((and=> (operand-constant-value op) | |
776 | (lambda (x) (or (const? x) (void? x) (primitive-ref? x)))) | |
777 | ;; A cache hit. | |
778 | (let ((val (operand-constant-value op))) | |
779 | (log 'memoized-constant gensym val) | |
780 | (for-tail val))) | |
7cbadbc4 AW |
781 | ((visit-operand op counter (if (eq? ctx 'values) 'value ctx) |
782 | recursive-effort-limit operand-size-limit) | |
75170872 AW |
783 | => |
784 | ;; If we end up deciding to residualize this value instead of | |
785 | ;; copying it, save that residualized value. | |
786 | (lambda (val) | |
787 | (cond | |
788 | ((not (constant-expression? val)) | |
789 | (log 'not-constant gensym op) | |
790 | ;; At this point, ctx is operator, test, or value. A | |
791 | ;; value that is non-constant in one context will be | |
792 | ;; non-constant in the others, so it's safe to record | |
793 | ;; that here, and avoid future visits. | |
794 | (set-operand-copyable?! op #f) | |
795 | (residualize-lexical op ctx val)) | |
796 | ((or (const? val) | |
797 | (void? val) | |
798 | (primitive-ref? val)) | |
799 | ;; Always propagate simple values that cannot lead to | |
800 | ;; code bloat. | |
801 | (log 'copy-simple gensym val) | |
802 | ;; It could be this constant is the result of folding. | |
803 | ;; If that is the case, cache it. This helps loop | |
804 | ;; unrolling get farther. | |
7cbadbc4 | 805 | (if (or (eq? ctx 'value) (eq? ctx 'values)) |
75170872 AW |
806 | (begin |
807 | (log 'memoize-constant gensym val) | |
808 | (set-operand-constant-value! op val))) | |
809 | val) | |
810 | ((= 1 (var-refcount (operand-var op))) | |
811 | ;; Always propagate values referenced only once. | |
812 | (log 'copy-single gensym val) | |
813 | val) | |
814 | ;; FIXME: do demand-driven size accounting rather than | |
815 | ;; these heuristics. | |
816 | ((eq? ctx 'operator) | |
817 | ;; A pure expression in the operator position. Inline | |
818 | ;; if it's a lambda that's small enough. | |
819 | (if (and (lambda? val) | |
820 | (small-expression? val operator-size-limit)) | |
821 | (begin | |
822 | (log 'copy-operator gensym val) | |
823 | val) | |
824 | (begin | |
825 | (log 'too-big-for-operator gensym val) | |
826 | (residualize-lexical op ctx val)))) | |
827 | (else | |
828 | ;; A pure expression, processed for call or for value. | |
829 | ;; Don't inline lambdas, because they will probably won't | |
830 | ;; fold because we don't know the operator. | |
831 | (if (and (small-expression? val value-size-limit) | |
832 | (not (tree-il-any lambda? val))) | |
833 | (begin | |
834 | (log 'copy-value gensym val) | |
835 | val) | |
836 | (begin | |
837 | (log 'too-big-or-has-lambda gensym val) | |
838 | (residualize-lexical op ctx val))))))) | |
839 | (else | |
840 | ;; Visit failed. Either the operand isn't bound, as in | |
841 | ;; lambda formal parameters, or the copy was aborted. | |
842 | (log 'unbound-or-aborted gensym op) | |
843 | (residualize-lexical op))))) | |
b275fb26 | 844 | (($ <lexical-set> src name gensym exp) |
75170872 AW |
845 | (let ((op (lookup gensym))) |
846 | (if (zero? (var-refcount (operand-var op))) | |
847 | (let ((exp (for-effect exp))) | |
848 | (if (void? exp) | |
849 | exp | |
a215c159 | 850 | (make-seq src exp (make-void #f)))) |
75170872 | 851 | (begin |
997ed300 | 852 | (record-operand-use op) |
75170872 | 853 | (make-lexical-set src name (operand-sym op) (for-value exp)))))) |
91c763ee AW |
854 | (($ <let> src |
855 | (names ... rest) | |
856 | (gensyms ... rest-sym) | |
9b977c83 | 857 | (vals ... ($ <primcall> _ 'list rest-args)) |
39caffe7 | 858 | ($ <primcall> asrc 'apply |
91c763ee AW |
859 | (proc args ... |
860 | ($ <lexical-ref> _ | |
861 | (? (cut eq? <> rest)) | |
862 | (? (lambda (sym) | |
863 | (and (eq? sym rest-sym) | |
864 | (= (lexical-refcount sym) 1)))))))) | |
865 | (let* ((tmps (make-list (length rest-args) 'tmp)) | |
866 | (tmp-syms (fresh-temporaries tmps))) | |
867 | (for-tail | |
868 | (make-let src | |
869 | (append names tmps) | |
870 | (append gensyms tmp-syms) | |
871 | (append vals rest-args) | |
9b977c83 | 872 | (make-call |
91c763ee AW |
873 | asrc |
874 | proc | |
875 | (append args | |
876 | (map (cut make-lexical-ref #f <> <>) | |
877 | tmps tmp-syms))))))) | |
b275fb26 | 878 | (($ <let> src names gensyms vals body) |
985702f7 AW |
879 | (define (compute-alias exp) |
880 | ;; It's very common for macros to introduce something like: | |
881 | ;; | |
882 | ;; ((lambda (x y) ...) x-exp y-exp) | |
883 | ;; | |
884 | ;; In that case you might end up trying to inline something like: | |
885 | ;; | |
886 | ;; (let ((x x-exp) (y y-exp)) ...) | |
887 | ;; | |
888 | ;; But if x-exp is itself a lexical-ref that aliases some much | |
889 | ;; larger expression, perhaps it will fail to inline due to | |
890 | ;; size. However we don't want to introduce a useless alias | |
891 | ;; (in this case, x). So if the RHS of a let expression is a | |
892 | ;; lexical-ref, we record that expression. If we end up having | |
893 | ;; to residualize X, then instead we residualize X-EXP, as long | |
894 | ;; as it isn't assigned. | |
895 | ;; | |
896 | (match exp | |
897 | (($ <lexical-ref> _ _ sym) | |
898 | (let ((op (lookup sym))) | |
899 | (and (not (var-set? (operand-var op))) | |
900 | (or (operand-alias-value op) | |
901 | exp)))) | |
902 | (_ #f))) | |
903 | ||
75170872 AW |
904 | (let* ((vars (map lookup-var gensyms)) |
905 | (new (fresh-gensyms vars)) | |
906 | (ops (make-bound-operands vars new vals | |
907 | (lambda (exp counter ctx) | |
985702f7 AW |
908 | (loop exp env counter ctx)) |
909 | (map compute-alias vals))) | |
75170872 AW |
910 | (env (fold extend-env env gensyms ops)) |
911 | (body (loop body env counter ctx))) | |
b275fb26 AW |
912 | (cond |
913 | ((const? body) | |
ca128245 | 914 | (for-tail (list->seq src (append vals (list body))))) |
b275fb26 | 915 | ((and (lexical-ref? body) |
75170872 | 916 | (memq (lexical-ref-gensym body) new)) |
b275fb26 | 917 | (let ((sym (lexical-ref-gensym body)) |
75170872 | 918 | (pairs (map cons new vals))) |
b275fb26 AW |
919 | ;; (let ((x foo) (y bar) ...) x) => (begin bar ... foo) |
920 | (for-tail | |
ca128245 | 921 | (list->seq |
b275fb26 AW |
922 | src |
923 | (append (map cdr (alist-delete sym pairs eq?)) | |
924 | (list (assq-ref pairs sym))))))) | |
925 | (else | |
926 | ;; Only include bindings for which lexical references | |
927 | ;; have been residualized. | |
75170872 | 928 | (prune-bindings ops #f body counter ctx |
b275fb26 AW |
929 | (lambda (names gensyms vals body) |
930 | (if (null? names) (error "what!" names)) | |
931 | (make-let src names gensyms vals body))))))) | |
932 | (($ <letrec> src in-order? names gensyms vals body) | |
75170872 AW |
933 | ;; Note the difference from the `let' case: here we use letrec* |
934 | ;; so that the `visit' procedure for the new operands closes over | |
985702f7 AW |
935 | ;; an environment that includes the operands. Also we don't try |
936 | ;; to elide aliases, because we can't sensibly reduce something | |
937 | ;; like (letrec ((a b) (b a)) a). | |
75170872 AW |
938 | (letrec* ((visit (lambda (exp counter ctx) |
939 | (loop exp env* counter ctx))) | |
940 | (vars (map lookup-var gensyms)) | |
941 | (new (fresh-gensyms vars)) | |
942 | (ops (make-bound-operands vars new vals visit)) | |
943 | (env* (fold extend-env env gensyms ops)) | |
944 | (body* (visit body counter ctx))) | |
16d3e013 AW |
945 | (if (and (const? body*) (every constant-expression? vals)) |
946 | ;; We may have folded a loop completely, even though there | |
947 | ;; might be cyclical references between the bound values. | |
948 | ;; Handle this degenerate case specially. | |
75170872 AW |
949 | body* |
950 | (prune-bindings ops in-order? body* counter ctx | |
b275fb26 AW |
951 | (lambda (names gensyms vals body) |
952 | (make-letrec src in-order? | |
953 | names gensyms vals body)))))) | |
954 | (($ <fix> src names gensyms vals body) | |
75170872 AW |
955 | (letrec* ((visit (lambda (exp counter ctx) |
956 | (loop exp env* counter ctx))) | |
957 | (vars (map lookup-var gensyms)) | |
958 | (new (fresh-gensyms vars)) | |
959 | (ops (make-bound-operands vars new vals visit)) | |
960 | (env* (fold extend-env env gensyms ops)) | |
961 | (body* (visit body counter ctx))) | |
962 | (if (const? body*) | |
963 | body* | |
964 | (prune-bindings ops #f body* counter ctx | |
b275fb26 AW |
965 | (lambda (names gensyms vals body) |
966 | (make-fix src names gensyms vals body)))))) | |
967 | (($ <let-values> lv-src producer consumer) | |
968 | ;; Peval the producer, then try to inline the consumer into | |
969 | ;; the producer. If that succeeds, peval again. Otherwise | |
970 | ;; reconstruct the let-values, pevaling the consumer. | |
7cbadbc4 | 971 | (let ((producer (for-values producer))) |
b275fb26 | 972 | (or (match consumer |
64fc50c2 AW |
973 | (($ <lambda-case> src (req-name) #f #f #f () (req-sym) body #f) |
974 | (for-tail | |
975 | (make-let src (list req-name) (list req-sym) (list producer) | |
976 | body))) | |
e6450062 AW |
977 | ((and ($ <lambda-case> src () #f rest #f () (rest-sym) body #f) |
978 | (? (lambda _ (singly-valued-expression? producer)))) | |
979 | (let ((tmp (gensym "tmp "))) | |
980 | (record-new-temporary! 'tmp tmp 1) | |
981 | (for-tail | |
982 | (make-let | |
983 | src (list 'tmp) (list tmp) (list producer) | |
984 | (make-let | |
985 | src (list rest) (list rest-sym) | |
986 | (list | |
987 | (make-primcall #f 'list | |
988 | (list (make-lexical-ref #f 'tmp tmp)))) | |
989 | body))))) | |
85edd670 AW |
990 | (($ <lambda-case> src req opt rest #f inits gensyms body #f) |
991 | (let* ((nmin (length req)) | |
992 | (nmax (and (not rest) (+ nmin (if opt (length opt) 0))))) | |
993 | (cond | |
994 | ((inline-values lv-src producer nmin nmax consumer) | |
995 | => for-tail) | |
996 | (else #f)))) | |
b275fb26 AW |
997 | (_ #f)) |
998 | (make-let-values lv-src producer (for-tail consumer))))) | |
b275fb26 AW |
999 | (($ <dynlet> src fluids vals body) |
1000 | (make-dynlet src (map for-value fluids) (map for-value vals) | |
1001 | (for-tail body))) | |
1002 | (($ <dynref> src fluid) | |
1003 | (make-dynref src (for-value fluid))) | |
1004 | (($ <dynset> src fluid exp) | |
1005 | (make-dynset src (for-value fluid) (for-value exp))) | |
1006 | (($ <toplevel-ref> src (? effect-free-primitive? name)) | |
ef9ffe5e | 1007 | exp) |
b275fb26 AW |
1008 | (($ <toplevel-ref>) |
1009 | ;; todo: open private local bindings. | |
1010 | exp) | |
16d50b8e LC |
1011 | (($ <module-ref> src module (? effect-free-primitive? name) #f) |
1012 | (let ((module (false-if-exception | |
1013 | (resolve-module module #:ensure #f)))) | |
1014 | (if (module? module) | |
1015 | (let ((var (module-variable module name))) | |
1016 | (if (eq? var (module-variable the-scm-module name)) | |
1017 | (make-primitive-ref src name) | |
1018 | exp)) | |
1019 | exp))) | |
b275fb26 AW |
1020 | (($ <module-ref>) |
1021 | exp) | |
1022 | (($ <module-set> src mod name public? exp) | |
1023 | (make-module-set src mod name public? (for-value exp))) | |
1024 | (($ <toplevel-define> src name exp) | |
1025 | (make-toplevel-define src name (for-value exp))) | |
1026 | (($ <toplevel-set> src name exp) | |
1027 | (make-toplevel-set src name (for-value exp))) | |
1028 | (($ <primitive-ref>) | |
1029 | (case ctx | |
1030 | ((effect) (make-void #f)) | |
1031 | ((test) (make-const #f #t)) | |
1032 | (else exp))) | |
1033 | (($ <conditional> src condition subsequent alternate) | |
f49fd9af AW |
1034 | (define (call-with-failure-thunk exp proc) |
1035 | (match exp | |
74bbb994 AW |
1036 | (($ <call> _ _ ()) (proc exp)) |
1037 | (($ <primcall> _ _ ()) (proc exp)) | |
f49fd9af AW |
1038 | (($ <const>) (proc exp)) |
1039 | (($ <void>) (proc exp)) | |
1040 | (($ <lexical-ref>) (proc exp)) | |
1041 | (_ | |
1042 | (let ((t (gensym "failure-"))) | |
1043 | (record-new-temporary! 'failure t 2) | |
1044 | (make-let | |
1045 | src (list 'failure) (list t) | |
1046 | (list | |
1047 | (make-lambda | |
1048 | #f '() | |
1049 | (make-lambda-case #f '() #f #f #f '() '() exp #f))) | |
74bbb994 AW |
1050 | (proc (make-call #f (make-lexical-ref #f 'failure t) |
1051 | '()))))))) | |
f49fd9af AW |
1052 | (define (simplify-conditional c) |
1053 | (match c | |
1054 | ;; Swap the arms of (if (not FOO) A B), to simplify. | |
74bbb994 | 1055 | (($ <conditional> src ($ <primcall> _ 'not (pred)) |
f49fd9af AW |
1056 | subsequent alternate) |
1057 | (simplify-conditional | |
1058 | (make-conditional src pred alternate subsequent))) | |
1059 | ;; Special cases for common tests in the predicates of chains | |
1060 | ;; of if expressions. | |
1061 | (($ <conditional> src | |
1062 | ($ <conditional> src* outer-test inner-test ($ <const> _ #f)) | |
1063 | inner-subsequent | |
1064 | alternate) | |
1065 | (let lp ((alternate alternate)) | |
1066 | (match alternate | |
1067 | ;; Lift a common repeated test out of a chain of if | |
1068 | ;; expressions. | |
1069 | (($ <conditional> _ (? (cut tree-il=? outer-test <>)) | |
1070 | other-subsequent alternate) | |
1071 | (make-conditional | |
1072 | src outer-test | |
9b1750ed AW |
1073 | (simplify-conditional |
1074 | (make-conditional src* inner-test inner-subsequent | |
1075 | other-subsequent)) | |
f49fd9af AW |
1076 | alternate)) |
1077 | ;; Likewise, but punching through any surrounding | |
1078 | ;; failure continuations. | |
1079 | (($ <let> let-src (name) (sym) ((and thunk ($ <lambda>))) body) | |
1080 | (make-let | |
1081 | let-src (list name) (list sym) (list thunk) | |
1082 | (lp body))) | |
1083 | ;; Otherwise, rotate AND tests to expose a simple | |
1084 | ;; condition in the front. Although this may result in | |
1085 | ;; lexically binding failure thunks, the thunks will be | |
1086 | ;; compiled to labels allocation, so there's no actual | |
1087 | ;; code growth. | |
1088 | (_ | |
1089 | (call-with-failure-thunk | |
1090 | alternate | |
1091 | (lambda (failure) | |
1092 | (make-conditional | |
1093 | src outer-test | |
9b1750ed AW |
1094 | (simplify-conditional |
1095 | (make-conditional src* inner-test inner-subsequent failure)) | |
f49fd9af AW |
1096 | failure))))))) |
1097 | (_ c))) | |
a36e7870 AW |
1098 | (match (for-test condition) |
1099 | (($ <const> _ val) | |
1100 | (if val | |
1101 | (for-tail subsequent) | |
1102 | (for-tail alternate))) | |
a36e7870 | 1103 | (c |
f49fd9af AW |
1104 | (simplify-conditional |
1105 | (make-conditional src c (for-tail subsequent) | |
1106 | (for-tail alternate)))))) | |
0fcc39a0 | 1107 | (($ <primcall> src 'call-with-values |
b275fb26 AW |
1108 | (producer |
1109 | ($ <lambda> _ _ | |
1110 | (and consumer | |
1111 | ;; No optional or kwargs. | |
1112 | ($ <lambda-case> | |
1113 | _ req #f rest #f () gensyms body #f))))) | |
ca128245 | 1114 | (for-tail (make-let-values src (make-call src producer '()) |
b275fb26 | 1115 | consumer))) |
880e7948 | 1116 | (($ <primcall> src 'dynamic-wind (w thunk u)) |
9b965638 AW |
1117 | (define (with-temporaries exps refcount k) |
1118 | (let* ((pairs (map (match-lambda | |
1119 | ((and exp (? constant-expression?)) | |
1120 | (cons #f exp)) | |
1121 | (exp | |
1122 | (let ((sym (gensym "tmp "))) | |
1123 | (record-new-temporary! 'tmp sym refcount) | |
1124 | (cons sym exp)))) | |
1125 | exps)) | |
1126 | (tmps (filter car pairs))) | |
1127 | (match tmps | |
1128 | (() (k exps)) | |
1129 | (tmps | |
1130 | (make-let src | |
1131 | (make-list (length tmps) 'tmp) | |
1132 | (map car tmps) | |
1133 | (map cdr tmps) | |
1134 | (k (map (match-lambda | |
1135 | ((#f . val) val) | |
1136 | ((sym . _) | |
1137 | (make-lexical-ref #f 'tmp sym))) | |
1138 | pairs))))))) | |
1139 | (define (make-begin0 src first second) | |
1140 | (make-let-values | |
1141 | src | |
1142 | first | |
1143 | (let ((vals (gensym "vals "))) | |
1144 | (record-new-temporary! 'vals vals 1) | |
1145 | (make-lambda-case | |
1146 | #f | |
1147 | '() #f 'vals #f '() (list vals) | |
1148 | (make-seq | |
1149 | src | |
1150 | second | |
1151 | (make-primcall #f 'apply | |
1152 | (list | |
1153 | (make-primitive-ref #f 'values) | |
1154 | (make-lexical-ref #f 'vals vals)))) | |
1155 | #f)))) | |
880e7948 | 1156 | (for-tail |
9b965638 AW |
1157 | (with-temporaries |
1158 | (list w u) 2 | |
1159 | (match-lambda | |
1160 | ((w u) | |
bb97e4ab AW |
1161 | (make-seq |
1162 | src | |
1163 | (make-seq | |
1164 | src | |
1165 | (make-conditional | |
1166 | src | |
1167 | ;; fixme: introduce logic to fold thunk? | |
1168 | (make-primcall src 'thunk? (list u)) | |
1169 | (make-call src w '()) | |
1170 | (make-primcall | |
1171 | src 'scm-error | |
1172 | (list | |
1173 | (make-const #f 'wrong-type-arg) | |
1174 | (make-const #f "dynamic-wind") | |
1175 | (make-const #f "Wrong type (expecting thunk): ~S") | |
1176 | (make-primcall #f 'list (list u)) | |
1177 | (make-primcall #f 'list (list u))))) | |
1178 | (make-primcall src 'wind (list w u))) | |
1179 | (make-begin0 src | |
1180 | (make-call src thunk '()) | |
1181 | (make-seq src | |
1182 | (make-primcall src 'unwind '()) | |
1183 | (make-call src u '()))))))))) | |
880e7948 | 1184 | |
296004b3 | 1185 | (($ <primcall> src 'values exps) |
7cbadbc4 AW |
1186 | (cond |
1187 | ((null? exps) | |
1188 | (if (eq? ctx 'effect) | |
1189 | (make-void #f) | |
1190 | exp)) | |
1191 | (else | |
1192 | (let ((vals (map for-value exps))) | |
d646d81e AW |
1193 | (if (and (case ctx |
1194 | ((value test effect) #t) | |
1195 | (else (null? (cdr vals)))) | |
7cbadbc4 | 1196 | (every singly-valued-expression? vals)) |
296004b3 AW |
1197 | (for-tail (list->seq src (append (cdr vals) (list (car vals))))) |
1198 | (make-primcall src 'values vals)))))) | |
1199 | ||
39caffe7 | 1200 | (($ <primcall> src 'apply (proc args ... tail)) |
d21537ef | 1201 | (let lp ((tail* (find-definition tail 1)) (speculative? #t)) |
8598dd8d AW |
1202 | (define (copyable? x) |
1203 | ;; Inlining a result from find-definition effectively copies it, | |
1204 | ;; relying on the let-pruning to remove its original binding. We | |
1205 | ;; shouldn't copy non-constant expressions. | |
1206 | (or (not speculative?) (constant-expression? x))) | |
d21537ef AW |
1207 | (match tail* |
1208 | (($ <const> _ (args* ...)) | |
1209 | (let ((args* (map (cut make-const #f <>) args*))) | |
9b977c83 AW |
1210 | (for-tail (make-call src proc (append args args*))))) |
1211 | (($ <primcall> _ 'cons | |
8598dd8d | 1212 | ((and head (? copyable?)) (and tail (? copyable?)))) |
39caffe7 | 1213 | (for-tail (make-primcall src 'apply |
9b977c83 AW |
1214 | (cons proc |
1215 | (append args (list head tail)))))) | |
1216 | (($ <primcall> _ 'list | |
8598dd8d | 1217 | (and args* ((? copyable?) ...))) |
9b977c83 | 1218 | (for-tail (make-call src proc (append args args*)))) |
d21537ef AW |
1219 | (tail* |
1220 | (if speculative? | |
1221 | (lp (for-value tail) #f) | |
1222 | (let ((args (append (map for-value args) (list tail*)))) | |
39caffe7 | 1223 | (make-primcall src 'apply |
9b977c83 | 1224 | (cons (for-value proc) args)))))))) |
2aed2667 | 1225 | |
ca128245 | 1226 | (($ <primcall> src (? constructor-primitive? name) args) |
a215c159 AW |
1227 | (cond |
1228 | ((and (memq ctx '(effect test)) | |
1229 | (match (cons name args) | |
1230 | ((or ('cons _ _) | |
1231 | ('list . _) | |
1232 | ('vector . _) | |
1233 | ('make-prompt-tag) | |
1234 | ('make-prompt-tag ($ <const> _ (? string?)))) | |
1235 | #t) | |
1236 | (_ #f))) | |
1237 | ;; Some expressions can be folded without visiting the | |
1238 | ;; arguments for value. | |
1239 | (let ((res (if (eq? ctx 'effect) | |
1240 | (make-void #f) | |
1241 | (make-const #f #t)))) | |
1242 | (for-tail (list->seq src (append args (list res)))))) | |
1243 | (else | |
1244 | (match (cons name (map for-value args)) | |
bbc2364a | 1245 | (('cons x ($ <const> _ (? (cut eq? <> '())))) |
a215c159 AW |
1246 | (make-primcall src 'list (list x))) |
1247 | (('cons x ($ <primcall> _ 'list elts)) | |
1248 | (make-primcall src 'list (cons x elts))) | |
1249 | ((name . args) | |
1250 | (make-primcall src name args)))))) | |
1251 | ||
bb97e4ab AW |
1252 | (($ <primcall> src 'thunk? (proc)) |
1253 | (match (for-value proc) | |
1254 | (($ <lambda> _ _ ($ <lambda-case> _ req)) | |
1255 | (for-tail (make-const src (null? req)))) | |
1256 | (proc | |
1257 | (case ctx | |
1258 | ((effect) (make-void src)) | |
1259 | (else (make-primcall src 'thunk? (list proc))))))) | |
1260 | ||
a215c159 AW |
1261 | (($ <primcall> src (? accessor-primitive? name) args) |
1262 | (match (cons name (map for-value args)) | |
1263 | ;; FIXME: these for-tail recursions could take place outside | |
1264 | ;; an effort counter. | |
1265 | (('car ($ <primcall> src 'cons (head tail))) | |
1266 | (for-tail (make-seq src tail head))) | |
1267 | (('cdr ($ <primcall> src 'cons (head tail))) | |
1268 | (for-tail (make-seq src head tail))) | |
1269 | (('car ($ <primcall> src 'list (head . tail))) | |
1270 | (for-tail (list->seq src (append tail (list head))))) | |
1271 | (('cdr ($ <primcall> src 'list (head . tail))) | |
1272 | (for-tail (make-seq src head (make-primcall #f 'list tail)))) | |
1273 | ||
1274 | (('car ($ <const> src (head . tail))) | |
1275 | (for-tail (make-const src head))) | |
1276 | (('cdr ($ <const> src (head . tail))) | |
1277 | (for-tail (make-const src tail))) | |
1278 | (((or 'memq 'memv) k ($ <const> _ (elts ...))) | |
1279 | ;; FIXME: factor | |
1280 | (case ctx | |
1281 | ((effect) | |
1282 | (for-tail | |
1283 | (make-seq src k (make-void #f)))) | |
1284 | ((test) | |
1285 | (cond | |
1286 | ((const? k) | |
1287 | ;; A shortcut. The `else' case would handle it, but | |
1288 | ;; this way is faster. | |
1289 | (let ((member (case name ((memq) memq) ((memv) memv)))) | |
1290 | (make-const #f (and (member (const-exp k) elts) #t)))) | |
1291 | ((null? elts) | |
1292 | (for-tail | |
1293 | (make-seq src k (make-const #f #f)))) | |
1294 | (else | |
1295 | (let ((t (gensym "t ")) | |
1296 | (eq (if (eq? name 'memq) 'eq? 'eqv?))) | |
1297 | (record-new-temporary! 't t (length elts)) | |
1298 | (for-tail | |
1299 | (make-let | |
1300 | src (list 't) (list t) (list k) | |
1301 | (let lp ((elts elts)) | |
1302 | (define test | |
1303 | (make-primcall #f eq | |
1304 | (list (make-lexical-ref #f 't t) | |
1305 | (make-const #f (car elts))))) | |
1306 | (if (null? (cdr elts)) | |
1307 | test | |
1308 | (make-conditional src test | |
1309 | (make-const #f #t) | |
1310 | (lp (cdr elts))))))))))) | |
1311 | (else | |
1312 | (cond | |
1313 | ((const? k) | |
1314 | (let ((member (case name ((memq) memq) ((memv) memv)))) | |
1315 | (make-const #f (member (const-exp k) elts)))) | |
1316 | ((null? elts) | |
1317 | (for-tail (make-seq src k (make-const #f #f)))) | |
1318 | (else | |
1319 | (make-primcall src name (list k (make-const #f elts)))))))) | |
1320 | ((name . args) | |
17595572 | 1321 | (fold-constants src name args ctx)))) |
ca128245 | 1322 | |
3c65e3fd NL |
1323 | (($ <primcall> src (? equality-primitive? name) (a b)) |
1324 | (let ((val-a (for-value a)) | |
1325 | (val-b (for-value b))) | |
1326 | (log 'equality-primitive name val-a val-b) | |
1327 | (cond ((and (lexical-ref? val-a) (lexical-ref? val-b) | |
1328 | (eq? (lexical-ref-gensym val-a) | |
1329 | (lexical-ref-gensym val-b))) | |
1330 | (for-tail (make-const #f #t))) | |
1331 | (else | |
1332 | (fold-constants src name (list val-a val-b) ctx))))) | |
1333 | ||
ca128245 | 1334 | (($ <primcall> src (? effect-free-primitive? name) args) |
4938d3cb | 1335 | (fold-constants src name (map for-value args) ctx)) |
ca128245 AW |
1336 | |
1337 | (($ <primcall> src name args) | |
1338 | (make-primcall src name (map for-value args))) | |
1339 | ||
1340 | (($ <call> src orig-proc orig-args) | |
b275fb26 | 1341 | ;; todo: augment the global env with specialized functions |
30c3dac7 | 1342 | (let revisit-proc ((proc (visit orig-proc 'operator))) |
b275fb26 | 1343 | (match proc |
ca128245 AW |
1344 | (($ <primitive-ref> _ name) |
1345 | (for-tail (make-primcall src name orig-args))) | |
b275fb26 | 1346 | (($ <lambda> _ _ |
564f5e70 AW |
1347 | ($ <lambda-case> _ req opt rest #f inits gensyms body #f)) |
1348 | ;; Simple case: no keyword arguments. | |
b275fb26 AW |
1349 | ;; todo: handle the more complex cases |
1350 | (let* ((nargs (length orig-args)) | |
1351 | (nreq (length req)) | |
1352 | (nopt (if opt (length opt) 0)) | |
1353 | (key (source-expression proc))) | |
9b977c83 | 1354 | (define (inlined-call) |
564f5e70 AW |
1355 | (make-let src |
1356 | (append req | |
1357 | (or opt '()) | |
1358 | (if rest (list rest) '())) | |
1359 | gensyms | |
1360 | (if (> nargs (+ nreq nopt)) | |
1361 | (append (list-head orig-args (+ nreq nopt)) | |
1362 | (list | |
9b977c83 AW |
1363 | (make-primcall |
1364 | #f 'list | |
564f5e70 AW |
1365 | (drop orig-args (+ nreq nopt))))) |
1366 | (append orig-args | |
1367 | (drop inits (- nargs nreq)) | |
1368 | (if rest | |
1369 | (list (make-const #f '())) | |
1370 | '()))) | |
1371 | body)) | |
1372 | ||
b275fb26 | 1373 | (cond |
564f5e70 | 1374 | ((or (< nargs nreq) (and (not rest) (> nargs (+ nreq nopt)))) |
b275fb26 | 1375 | ;; An error, or effecting arguments. |
a215c159 | 1376 | (make-call src (for-call orig-proc) (map for-value orig-args))) |
b275fb26 AW |
1377 | ((or (and=> (find-counter key counter) counter-recursive?) |
1378 | (lambda? orig-proc)) | |
1379 | ;; A recursive call, or a lambda in the operator | |
1380 | ;; position of the source expression. Process again in | |
1381 | ;; tail context. | |
75170872 AW |
1382 | ;; |
1383 | ;; In the recursive case, mark intervening counters as | |
1384 | ;; recursive, so we can handle a toplevel counter that | |
1385 | ;; recurses mutually with some other procedure. | |
1386 | ;; Otherwise, the next time we see the other procedure, | |
1387 | ;; the effort limit would be clamped to 100. | |
1388 | ;; | |
1389 | (let ((found (find-counter key counter))) | |
1390 | (if (and found (counter-recursive? found)) | |
1391 | (let lp ((counter counter)) | |
1392 | (if (not (eq? counter found)) | |
1393 | (begin | |
1394 | (set-counter-recursive?! counter #t) | |
1395 | (lp (counter-prev counter))))))) | |
1396 | ||
41d43584 | 1397 | (log 'inline-recurse key) |
9b977c83 | 1398 | (loop (inlined-call) env counter ctx)) |
b275fb26 AW |
1399 | (else |
1400 | ;; An integration at the top-level, the first | |
1401 | ;; recursion of a recursive procedure, or a nested | |
1402 | ;; integration of a procedure that hasn't been seen | |
1403 | ;; yet. | |
41d43584 | 1404 | (log 'inline-begin exp) |
b275fb26 AW |
1405 | (let/ec k |
1406 | (define (abort) | |
41d43584 | 1407 | (log 'inline-abort exp) |
a215c159 | 1408 | (k (make-call src (for-call orig-proc) |
ca128245 | 1409 | (map for-value orig-args)))) |
b275fb26 AW |
1410 | (define new-counter |
1411 | (cond | |
1412 | ;; These first two cases will transfer effort | |
1413 | ;; from the current counter into the new | |
1414 | ;; counter. | |
1415 | ((find-counter key counter) | |
1416 | => (lambda (prev) | |
1417 | (make-recursive-counter recursive-effort-limit | |
1418 | operand-size-limit | |
1419 | prev counter))) | |
1420 | (counter | |
1421 | (make-nested-counter abort key counter)) | |
1422 | ;; This case opens a new account, effectively | |
1423 | ;; printing money. It should only do so once | |
1424 | ;; for each call site in the source program. | |
1425 | (else | |
1426 | (make-top-counter effort-limit operand-size-limit | |
1427 | abort key)))) | |
1428 | (define result | |
9b977c83 | 1429 | (loop (inlined-call) env new-counter ctx)) |
b275fb26 AW |
1430 | |
1431 | (if counter | |
1432 | ;; The nested inlining attempt succeeded. | |
1433 | ;; Deposit the unspent effort and size back | |
1434 | ;; into the current counter. | |
1435 | (transfer! new-counter counter)) | |
1436 | ||
41d43584 | 1437 | (log 'inline-end result exp) |
b275fb26 | 1438 | result))))) |
30c3dac7 AW |
1439 | (($ <let> _ _ _ vals _) |
1440 | ;; Attempt to inline `let' in the operator position. | |
1441 | ;; | |
1442 | ;; We have to re-visit the proc in value mode, since the | |
1443 | ;; `let' bindings might have been introduced or renamed, | |
1444 | ;; whereas the lambda (if any) in operator position has not | |
1445 | ;; been renamed. | |
1446 | (if (or (and-map constant-expression? vals) | |
1447 | (and-map constant-expression? orig-args)) | |
1448 | ;; The arguments and the let-bound values commute. | |
1449 | (match (for-value orig-proc) | |
1450 | (($ <let> lsrc names syms vals body) | |
1451 | (log 'inline-let orig-proc) | |
1452 | (for-tail | |
1453 | (make-let lsrc names syms vals | |
9b977c83 | 1454 | (make-call src body orig-args)))) |
30c3dac7 AW |
1455 | ;; It's possible for a `let' to go away after the |
1456 | ;; visit due to the fact that visiting a procedure in | |
1457 | ;; value context will prune unused bindings, whereas | |
1458 | ;; visiting in operator mode can't because it doesn't | |
1459 | ;; traverse through lambdas. In that case re-visit | |
1460 | ;; the procedure. | |
1461 | (proc (revisit-proc proc))) | |
9b977c83 AW |
1462 | (make-call src (for-call orig-proc) |
1463 | (map for-value orig-args)))) | |
b275fb26 | 1464 | (_ |
a215c159 | 1465 | (make-call src (for-call orig-proc) (map for-value orig-args)))))) |
b275fb26 AW |
1466 | (($ <lambda> src meta body) |
1467 | (case ctx | |
1468 | ((effect) (make-void #f)) | |
1469 | ((test) (make-const #f #t)) | |
1470 | ((operator) exp) | |
75170872 AW |
1471 | (else (record-source-expression! |
1472 | exp | |
19113f1c | 1473 | (make-lambda src meta (and body (for-values body))))))) |
b275fb26 | 1474 | (($ <lambda-case> src req opt rest kw inits gensyms body alt) |
eebcacf4 AW |
1475 | (define (lift-applied-lambda body gensyms) |
1476 | (and (not opt) rest (not kw) | |
1477 | (match body | |
39caffe7 | 1478 | (($ <primcall> _ 'apply |
19113f1c | 1479 | (($ <lambda> _ _ (and lcase ($ <lambda-case>))) |
eebcacf4 AW |
1480 | ($ <lexical-ref> _ _ sym) |
1481 | ...)) | |
1482 | (and (equal? sym gensyms) | |
1483 | (not (lambda-case-alternate lcase)) | |
1484 | lcase)) | |
1485 | (_ #f)))) | |
75170872 AW |
1486 | (let* ((vars (map lookup-var gensyms)) |
1487 | (new (fresh-gensyms vars)) | |
1488 | (env (fold extend-env env gensyms | |
1489 | (make-unbound-operands vars new))) | |
1490 | (new-sym (lambda (old) | |
eebcacf4 AW |
1491 | (operand-sym (cdr (vhash-assq old env))))) |
1492 | (body (loop body env counter ctx))) | |
1493 | (or | |
1494 | ;; (lambda args (apply (lambda ...) args)) => (lambda ...) | |
1495 | (lift-applied-lambda body new) | |
1496 | (make-lambda-case src req opt rest | |
1497 | (match kw | |
1498 | ((aok? (kw name old) ...) | |
1499 | (cons aok? (map list kw name (map new-sym old)))) | |
1500 | (_ #f)) | |
1501 | (map (cut loop <> env counter 'value) inits) | |
1502 | new | |
1503 | body | |
1504 | (and alt (for-tail alt)))))) | |
ca128245 AW |
1505 | (($ <seq> src head tail) |
1506 | (let ((head (for-effect head)) | |
1507 | (tail (for-tail tail))) | |
1508 | (if (void? head) | |
1509 | tail | |
1510 | (make-seq src | |
1511 | (if (and (seq? head) | |
1512 | (void? (seq-tail head))) | |
1513 | (seq-head head) | |
1514 | head) | |
1515 | tail)))) | |
b275fb26 | 1516 | (($ <prompt> src tag body handler) |
997ed300 AW |
1517 | (define (make-prompt-tag? x) |
1518 | (match x | |
2aed2667 | 1519 | (($ <primcall> _ 'make-prompt-tag (or () ((? constant-expression?)))) |
997ed300 AW |
1520 | #t) |
1521 | (_ #f))) | |
997ed300 AW |
1522 | |
1523 | (let ((tag (for-value tag)) | |
1524 | (body (for-tail body))) | |
1525 | (cond | |
1526 | ((find-definition tag 1) | |
1527 | (lambda (val op) | |
1528 | (make-prompt-tag? val)) | |
1529 | => (lambda (val op) | |
1530 | ;; There is no way that an <abort> could know the tag | |
1531 | ;; for this <prompt>, so we can elide the <prompt> | |
1532 | ;; entirely. | |
1533 | (unrecord-operand-uses op 1) | |
1534 | body)) | |
1535 | ((find-definition tag 2) | |
1536 | (lambda (val op) | |
1537 | (and (make-prompt-tag? val) | |
1538 | (abort? body) | |
1539 | (tree-il=? (abort-tag body) tag))) | |
1540 | => (lambda (val op) | |
1541 | ;; (let ((t (make-prompt-tag))) | |
1542 | ;; (call-with-prompt t | |
1543 | ;; (lambda () (abort-to-prompt t val ...)) | |
1544 | ;; (lambda (k arg ...) e ...))) | |
1545 | ;; => (let-values (((k arg ...) (values values val ...))) | |
1546 | ;; e ...) | |
1547 | (unrecord-operand-uses op 2) | |
1548 | (for-tail | |
1549 | (make-let-values | |
1550 | src | |
2aed2667 AW |
1551 | (make-primcall #f 'apply |
1552 | `(,(make-primitive-ref #f 'values) | |
1553 | ,(make-primitive-ref #f 'values) | |
1554 | ,@(abort-args body) | |
1555 | ,(abort-tail body))) | |
997ed300 AW |
1556 | (for-value handler))))) |
1557 | (else | |
1558 | (make-prompt src tag body (for-value handler)))))) | |
b275fb26 AW |
1559 | (($ <abort> src tag args tail) |
1560 | (make-abort src (for-value tag) (map for-value args) | |
1561 | (for-value tail)))))) |