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1 | (* Copyright (C) 2009,2011,2017 Matthew Fluet. |
2 | * Copyright (C) 1999-2008 Henry Cejtin, Matthew Fluet, Suresh | |
3 | * Jagannathan, and Stephen Weeks. | |
4 | * Copyright (C) 1997-2000 NEC Research Institute. | |
5 | * | |
6 | * MLton is released under a BSD-style license. | |
7 | * See the file MLton-LICENSE for details. | |
8 | *) | |
9 | ||
10 | functor Shrink (S: SHRINK_STRUCTS): SHRINK = | |
11 | struct | |
12 | ||
13 | open S | |
14 | ||
15 | structure Exp = | |
16 | struct | |
17 | open Exp | |
18 | ||
19 | val isProfile = | |
20 | fn Profile _ => true | |
21 | | _ => false | |
22 | end | |
23 | ||
24 | structure Statement = | |
25 | struct | |
26 | open Statement | |
27 | ||
28 | fun isProfile (T {exp, ...}) = Exp.isProfile exp | |
29 | end | |
30 | ||
31 | structure Array = | |
32 | struct | |
33 | open Array | |
34 | ||
35 | fun inc (a: int t, i: int): unit = update (a, i, 1 + sub (a, i)) | |
36 | fun dec (a: int t, i: int): unit = update (a, i, sub (a, i) - 1) | |
37 | end | |
38 | ||
39 | datatype z = datatype Exp.t | |
40 | datatype z = datatype Transfer.t | |
41 | ||
42 | structure VarInfo = | |
43 | struct | |
44 | datatype t = T of {isUsed: bool ref, | |
45 | numOccurrences: int ref, | |
46 | ty: Type.t option, | |
47 | value: value option ref, | |
48 | var: Var.t} | |
49 | and value = | |
50 | Con of {con: Con.t, | |
51 | args: t vector} | |
52 | | Const of Const.t | |
53 | | Select of {tuple: t, offset: int} | |
54 | | Tuple of t vector | |
55 | ||
56 | fun equals (T {var = x, ...}, T {var = y, ...}) = Var.equals (x, y) | |
57 | ||
58 | fun layout (T {isUsed, numOccurrences, ty, value, var}) = | |
59 | let open Layout | |
60 | in record [("isUsed", Bool.layout (!isUsed)), | |
61 | ("numOccurrences", Int.layout (!numOccurrences)), | |
62 | ("ty", Option.layout Type.layout ty), | |
63 | ("value", Option.layout layoutValue (!value)), | |
64 | ("var", Var.layout var)] | |
65 | end | |
66 | and layoutValue v = | |
67 | let open Layout | |
68 | in case v of | |
69 | Con {con, args} => seq [Con.layout con, | |
70 | Vector.layout layout args] | |
71 | | Const c => Const.layout c | |
72 | | Select {tuple, offset} => seq [str "#", Int.layout (offset + 1), | |
73 | str " ", layout tuple] | |
74 | | Tuple vis => Vector.layout layout vis | |
75 | end | |
76 | ||
77 | fun new (x: Var.t, ty: Type.t option) = T {isUsed = ref false, | |
78 | numOccurrences = ref 0, | |
79 | ty = ty, | |
80 | value = ref NONE, | |
81 | var = x} | |
82 | ||
83 | fun setValue (T {value, ...}, v) = | |
84 | (Assert.assert ("Ssa.Shrink.VarInfo.setValue", fn () => Option.isNone (!value)) | |
85 | ; value := SOME v) | |
86 | ||
87 | ||
88 | fun numOccurrences (T {numOccurrences = r, ...}) = r | |
89 | fun ty (T {ty, ...}): Type.t option = ty | |
90 | fun value (T {value, ...}): value option = !value | |
91 | fun var (T {var, ...}): Var.t = var | |
92 | end | |
93 | ||
94 | structure Value = | |
95 | struct | |
96 | datatype t = datatype VarInfo.value | |
97 | end | |
98 | ||
99 | structure Position = | |
100 | struct | |
101 | datatype t = | |
102 | Formal of int | |
103 | | Free of Var.t | |
104 | ||
105 | fun layout (p: t) = | |
106 | case p of | |
107 | Formal i => Int.layout i | |
108 | | Free x => Var.layout x | |
109 | ||
110 | val equals = | |
111 | fn (Formal i, Formal i') => i = i' | |
112 | | (Free x, Free x') => Var.equals (x, x') | |
113 | | _ => false | |
114 | end | |
115 | ||
116 | structure Positions = MonoVector (Position) | |
117 | ||
118 | structure LabelMeaning = | |
119 | struct | |
120 | datatype t = T of {aux: aux, | |
121 | blockIndex: int, (* The index of the block *) | |
122 | label: Label.t} (* redundant, the label of the block *) | |
123 | ||
124 | and aux = | |
125 | Block | |
126 | | Bug | |
127 | | Case of {canMove: Statement.t list, | |
128 | cases: Cases.t, | |
129 | default: Label.t option} | |
130 | | Goto of {canMove: Statement.t list, | |
131 | dst: t, | |
132 | args: Positions.t} | |
133 | | Raise of {args: Positions.t, | |
134 | canMove: Statement.t list} | |
135 | | Return of {args: Positions.t, | |
136 | canMove: Statement.t list} | |
137 | ||
138 | local | |
139 | fun make f (T r) = f r | |
140 | in | |
141 | val aux = make #aux | |
142 | val blockIndex = make #blockIndex | |
143 | end | |
144 | ||
145 | fun layout (T {aux, label, ...}) = | |
146 | let | |
147 | open Layout | |
148 | in | |
149 | seq [Label.layout label, | |
150 | str " ", | |
151 | case aux of | |
152 | Block => str "Block " | |
153 | | Bug => str "Bug" | |
154 | | Case _ => str "Case" | |
155 | | Goto {dst, args, ...} => | |
156 | seq [str "Goto ", | |
157 | tuple [layout dst, Positions.layout args]] | |
158 | | Raise {args, ...} => | |
159 | seq [str "Raise ", Positions.layout args] | |
160 | | Return {args, ...} => | |
161 | seq [str "Return ", Positions.layout args]] | |
162 | end | |
163 | end | |
164 | ||
165 | structure State = | |
166 | struct | |
167 | datatype state = | |
168 | Unvisited | |
169 | | Visited of LabelMeaning.t | |
170 | | Visiting | |
171 | ||
172 | val layout = | |
173 | let | |
174 | open Layout | |
175 | in | |
176 | fn Unvisited => str "Unvisited" | |
177 | | Visited m => LabelMeaning.layout m | |
178 | | Visiting => str "Visiting" | |
179 | end | |
180 | end | |
181 | ||
182 | val traceApplyInfo = Trace.info "Ssa.Shrink.Prim.apply" | |
183 | ||
184 | fun shrinkFunction {globals: Statement.t vector} = | |
185 | let | |
186 | fun use (VarInfo.T {isUsed, var, ...}): Var.t = | |
187 | (isUsed := true | |
188 | ; var) | |
189 | fun uses (vis: VarInfo.t vector): Var.t vector = Vector.map (vis, use) | |
190 | (* varInfo can't be getSetOnce because of setReplacement. *) | |
191 | val {get = varInfo: Var.t -> VarInfo.t, set = setVarInfo, ...} = | |
192 | Property.getSet (Var.plist, | |
193 | Property.initFun (fn x => VarInfo.new (x, NONE))) | |
194 | (* Property.getSet (Var.plist, Property.initFun VarInfo.new) *) | |
195 | val setVarInfo = | |
196 | Trace.trace2 ("Ssa.Shrink.setVarInfo", | |
197 | Var.layout, VarInfo.layout, Unit.layout) | |
198 | setVarInfo | |
199 | fun varInfos xs = Vector.map (xs, varInfo) | |
200 | fun simplifyVar (x: Var.t) = use (varInfo x) | |
201 | val simplifyVar = | |
202 | Trace.trace ("Ssa.Shrink.simplifyVar", Var.layout, Var.layout) simplifyVar | |
203 | fun simplifyVars xs = Vector.map (xs, simplifyVar) | |
204 | fun incVarInfo (x: VarInfo.t): unit = | |
205 | Int.inc (VarInfo.numOccurrences x) | |
206 | fun incVar (x: Var.t): unit = incVarInfo (varInfo x) | |
207 | fun incVars xs = Vector.foreach (xs, incVar) | |
208 | fun numVarOccurrences (x: Var.t): int = | |
209 | ! (VarInfo.numOccurrences (varInfo x)) | |
210 | val _ = | |
211 | Vector.foreach | |
212 | (globals, fn Statement.T {var, exp, ty} => | |
213 | let | |
214 | val _ = Option.app | |
215 | (var, fn x => | |
216 | setVarInfo (x, VarInfo.new (x, SOME ty))) | |
217 | fun construct v = | |
218 | Option.app (var, fn x => VarInfo.setValue (varInfo x, v)) | |
219 | in case exp of | |
220 | ConApp {con, args} => | |
221 | construct (Value.Con {con = con, | |
222 | args = Vector.map (args, varInfo)}) | |
223 | | Const c => construct (Value.Const c) | |
224 | | Select {tuple, offset} => | |
225 | construct (Value.Select {tuple = varInfo tuple, | |
226 | offset = offset}) | |
227 | | Tuple xs => construct (Value.Tuple (Vector.map (xs, varInfo))) | |
228 | | Var y => Option.app (var, fn x => setVarInfo (x, varInfo y)) | |
229 | | _ => () | |
230 | end) | |
231 | in | |
232 | fn f: Function.t => | |
233 | let | |
234 | val _ = Function.clear f | |
235 | val {args, blocks, mayInline, name, raises, returns, start, ...} = | |
236 | Function.dest f | |
237 | val _ = Vector.foreach | |
238 | (args, fn (x, ty) => | |
239 | setVarInfo (x, VarInfo.new (x, SOME ty))) | |
240 | (* Index the labels by their defining block in blocks. *) | |
241 | val {get = labelIndex, set = setLabelIndex, ...} = | |
242 | Property.getSetOnce (Label.plist, | |
243 | Property.initRaise ("index", Label.layout)) | |
244 | val _ = Vector.foreachi (blocks, fn (i, Block.T {label, ...}) => | |
245 | setLabelIndex (label, i)) | |
246 | val numBlocks = Vector.length blocks | |
247 | (* Do a DFS to compute occurrence counts and set label meanings *) | |
248 | val states = Array.array (numBlocks, State.Unvisited) | |
249 | val inDegree = Array.array (numBlocks, 0) | |
250 | fun addLabelIndex i = Array.inc (inDegree, i) | |
251 | val isHeader = Array.array (numBlocks, false) | |
252 | val numHandlerUses = Array.array (numBlocks, 0) | |
253 | fun layoutLabel (l: Label.t): Layout.t = | |
254 | let | |
255 | val i = labelIndex l | |
256 | in | |
257 | Layout.record [("label", Label.layout l), | |
258 | ("inDegree", Int.layout (Array.sub (inDegree, i)))] | |
259 | end | |
260 | fun incAux aux = | |
261 | case aux of | |
262 | LabelMeaning.Goto {dst, ...} => | |
263 | addLabelIndex (LabelMeaning.blockIndex dst) | |
264 | | _ => () | |
265 | fun incLabel (l: Label.t): unit = | |
266 | incLabelMeaning (labelMeaning l) | |
267 | and incLabelMeaning (LabelMeaning.T {aux, blockIndex, ...}): unit = | |
268 | let | |
269 | val i = blockIndex | |
270 | val n = Array.sub (inDegree, i) | |
271 | val _ = Array.update (inDegree, i, 1 + n) | |
272 | in | |
273 | if n = 0 | |
274 | then incAux aux | |
275 | else () | |
276 | end | |
277 | and labelMeaning (l: Label.t): LabelMeaning.t = | |
278 | let | |
279 | val i = labelIndex l | |
280 | in | |
281 | case Array.sub (states, i) of | |
282 | State.Visited m => m | |
283 | | State.Visiting => | |
284 | (Array.update (isHeader, i, true) | |
285 | ; (LabelMeaning.T | |
286 | {aux = LabelMeaning.Block, | |
287 | blockIndex = i, | |
288 | label = Block.label (Vector.sub (blocks, i))})) | |
289 | | State.Unvisited => | |
290 | let | |
291 | val _ = Array.update (states, i, State.Visiting) | |
292 | val m = computeMeaning i | |
293 | val _ = Array.update (states, i, State.Visited m) | |
294 | in | |
295 | m | |
296 | end | |
297 | end | |
298 | and computeMeaning (i: int): LabelMeaning.t = | |
299 | let | |
300 | val Block.T {args, statements, transfer, ...} = | |
301 | Vector.sub (blocks, i) | |
302 | val _ = | |
303 | Vector.foreach (args, fn (x, ty) => | |
304 | setVarInfo (x, VarInfo.new (x, SOME ty))) | |
305 | val _ = | |
306 | Vector.foreach | |
307 | (statements, fn s => Exp.foreachVar (Statement.exp s, incVar)) | |
308 | fun extract (actuals: Var.t vector): Positions.t = | |
309 | let | |
310 | val {get: Var.t -> Position.t, set, destroy} = | |
311 | Property.destGetSetOnce | |
312 | (Var.plist, Property.initFun Position.Free) | |
313 | val _ = Vector.foreachi (args, fn (i, (x, _)) => | |
314 | set (x, Position.Formal i)) | |
315 | val ps = Vector.map (actuals, get) | |
316 | val _ = destroy () | |
317 | in ps | |
318 | end | |
319 | fun doit aux = | |
320 | LabelMeaning.T {aux = aux, | |
321 | blockIndex = i, | |
322 | label = Block.label (Vector.sub (blocks, i))} | |
323 | fun normal () = doit LabelMeaning.Block | |
324 | fun canMove () = | |
325 | Vector.toListMap | |
326 | (statements, fn Statement.T {exp, ty, ...} => | |
327 | Statement.T {exp = exp, ty = ty, var = NONE}) | |
328 | fun rr (xs: Var.t vector, make) = | |
329 | let | |
330 | val _ = incVars xs | |
331 | (* | |
332 | val n = Vector.length statements | |
333 | fun loop (i, ac) = | |
334 | if i = n | |
335 | then | |
336 | if 0 = Vector.length xs | |
337 | orelse 0 < Vector.length args | |
338 | then doit (make {args = extract xs, | |
339 | canMove = rev ac}) | |
340 | else normal () | |
341 | else | |
342 | let | |
343 | val Statement.T {exp, ty, ...} = | |
344 | Vector.sub (statements, i) | |
345 | in | |
346 | if Exp.isProfile exp | |
347 | then loop (i + 1, | |
348 | Statement.T {exp = exp, | |
349 | ty = ty, | |
350 | var = NONE} :: ac) | |
351 | else normal () | |
352 | end | |
353 | in | |
354 | loop (0, []) | |
355 | end | |
356 | *) | |
357 | in | |
358 | if Vector.forall (statements, Statement.isProfile) | |
359 | andalso (0 = Vector.length xs | |
360 | orelse 0 < Vector.length args) | |
361 | then doit (make {args = extract xs, | |
362 | canMove = canMove ()}) | |
363 | else normal () | |
364 | end | |
365 | in | |
366 | case transfer of | |
367 | Arith {args, overflow, success, ...} => | |
368 | (incVars args | |
369 | ; incLabel overflow | |
370 | ; incLabel success | |
371 | ; normal ()) | |
372 | | Bug => | |
373 | if Vector.forall (statements, Statement.isProfile) | |
374 | andalso (case returns of | |
375 | NONE => true | |
376 | | SOME ts => | |
377 | Vector.equals | |
378 | (ts, args, fn (t, (_, t')) => | |
379 | Type.equals (t, t'))) | |
380 | then doit LabelMeaning.Bug | |
381 | else normal () | |
382 | | Call {args, return, ...} => | |
383 | let | |
384 | val _ = incVars args | |
385 | val _ = | |
386 | Return.foreachHandler | |
387 | (return, fn l => | |
388 | Array.inc (numHandlerUses, labelIndex l)) | |
389 | val _ = Return.foreachLabel (return, incLabel) | |
390 | in | |
391 | normal () | |
392 | end | |
393 | | Case {test, cases, default} => | |
394 | let | |
395 | val _ = incVar test | |
396 | val _ = Cases.foreach (cases, incLabel) | |
397 | val _ = Option.app (default, incLabel) | |
398 | in | |
399 | if Vector.forall (statements, Statement.isProfile) | |
400 | andalso not (Array.sub (isHeader, i)) | |
401 | andalso 1 = Vector.length args | |
402 | andalso 1 = numVarOccurrences test | |
403 | andalso Var.equals (test, #1 (Vector.first args)) | |
404 | then | |
405 | doit (LabelMeaning.Case {canMove = canMove (), | |
406 | cases = cases, | |
407 | default = default}) | |
408 | else | |
409 | normal () | |
410 | end | |
411 | | Goto {dst, args = actuals} => | |
412 | let | |
413 | val _ = incVars actuals | |
414 | val m = labelMeaning dst | |
415 | in | |
416 | if Vector.exists (statements, not o Statement.isProfile) | |
417 | orelse Array.sub (isHeader, i) | |
418 | then (incLabelMeaning m | |
419 | ; normal ()) | |
420 | else | |
421 | if Vector.isEmpty statements | |
422 | andalso | |
423 | Vector.equals (args, actuals, fn ((x, _), x') => | |
424 | Var.equals (x, x') | |
425 | andalso 1 = numVarOccurrences x) | |
426 | then m (* It's an eta. *) | |
427 | else | |
428 | let | |
429 | val ps = extract actuals | |
430 | val n = | |
431 | Vector.fold (args, 0, fn ((x, _), n) => | |
432 | n + numVarOccurrences x) | |
433 | val n' = | |
434 | Vector.fold (ps, 0, fn (p, n) => | |
435 | case p of | |
436 | Position.Formal _ => n + 1 | |
437 | | _ => n) | |
438 | datatype z = datatype LabelMeaning.aux | |
439 | in | |
440 | if n <> n' | |
441 | then (incLabelMeaning m | |
442 | ; normal ()) | |
443 | else | |
444 | let | |
445 | fun extract (ps': Positions.t) | |
446 | : Positions.t = | |
447 | Vector.map | |
448 | (ps', fn p => | |
449 | let | |
450 | datatype z = datatype Position.t | |
451 | in | |
452 | case p of | |
453 | Free x => Free x | |
454 | | Formal i => Vector.sub (ps, i) | |
455 | end) | |
456 | val canMove' = canMove () | |
457 | val a = | |
458 | case LabelMeaning.aux m of | |
459 | Block => | |
460 | Goto {canMove = canMove', | |
461 | dst = m, | |
462 | args = ps} | |
463 | | Bug => | |
464 | if (case returns of | |
465 | NONE => true | |
466 | | SOME ts => | |
467 | Vector.equals | |
468 | (ts, args, fn (t, (_, t')) => | |
469 | Type.equals (t, t'))) | |
470 | then Bug | |
471 | else Goto {canMove = canMove', | |
472 | dst = m, | |
473 | args = ps} | |
474 | | Case _ => | |
475 | Goto {canMove = canMove', | |
476 | dst = m, | |
477 | args = ps} | |
478 | | Goto {canMove, dst, args} => | |
479 | Goto {canMove = canMove' @ canMove, | |
480 | dst = dst, | |
481 | args = extract args} | |
482 | | Raise {args, canMove} => | |
483 | Raise {args = extract args, | |
484 | canMove = canMove' @ canMove} | |
485 | | Return {args, canMove} => | |
486 | Return {args = extract args, | |
487 | canMove = canMove' @ canMove} | |
488 | in | |
489 | doit a | |
490 | end | |
491 | end | |
492 | end | |
493 | | Raise xs => rr (xs, LabelMeaning.Raise) | |
494 | | Return xs => rr (xs, LabelMeaning.Return) | |
495 | | Runtime {args, return, ...} => | |
496 | (incVars args | |
497 | ; incLabel return | |
498 | ; normal ()) | |
499 | end | |
500 | val _ = incLabel start | |
501 | fun indexMeaning i = | |
502 | case Array.sub (states, i) of | |
503 | State.Visited m => m | |
504 | | _ => Error.bug "Ssa.Shrink.indexMeaning: not computed" | |
505 | val indexMeaning = | |
506 | Trace.trace ("Ssa.Shrink.indexMeaning", Int.layout, LabelMeaning.layout) | |
507 | indexMeaning | |
508 | val labelMeaning = indexMeaning o labelIndex | |
509 | val labelMeaning = | |
510 | Trace.trace ("Ssa.Shrink.labelMeaning", | |
511 | Label.layout, LabelMeaning.layout) | |
512 | labelMeaning | |
513 | fun meaningLabel m = | |
514 | Block.label (Vector.sub (blocks, LabelMeaning.blockIndex m)) | |
515 | fun labelArgs l = | |
516 | Block.args (Vector.sub (blocks, labelIndex l)) | |
517 | fun meaningArgs m = | |
518 | Block.args (Vector.sub (blocks, LabelMeaning.blockIndex m)) | |
519 | fun save (f, s) = | |
520 | let | |
521 | val {destroy, controlFlowGraph, ...} = | |
522 | Function.layoutDot (f, Var.layout) | |
523 | in | |
524 | File.withOut | |
525 | (concat ["/tmp/", Func.toString (Function.name f), | |
526 | ".", s, ".dot"], | |
527 | fn out => Layout.outputl (controlFlowGraph, out)) | |
528 | ; destroy () | |
529 | end | |
530 | val _ = if true then () else save (f, "pre") | |
531 | (* *) | |
532 | val _ = | |
533 | if true | |
534 | then () | |
535 | else | |
536 | Layout.outputl | |
537 | (Vector.layout | |
538 | (fn i => | |
539 | (Layout.record | |
540 | [("label", | |
541 | Label.layout (Block.label (Vector.sub (blocks, i)))), | |
542 | ("inDegree", Int.layout (Array.sub (inDegree, i))), | |
543 | ("state", State.layout (Array.sub (states, i)))])) | |
544 | (Vector.tabulate (numBlocks, fn i => i)), | |
545 | Out.error) | |
546 | val _ = | |
547 | Assert.assert | |
548 | ("Ssa.Shrink.labelMeanings", fn () => | |
549 | let | |
550 | val inDegree' = Array.array (numBlocks, 0) | |
551 | fun bumpIndex i = Array.inc (inDegree', i) | |
552 | fun bumpMeaning m = bumpIndex (LabelMeaning.blockIndex m) | |
553 | val bumpLabel = bumpMeaning o labelMeaning | |
554 | fun doit (LabelMeaning.T {aux, blockIndex, ...}) = | |
555 | let | |
556 | datatype z = datatype LabelMeaning.aux | |
557 | in | |
558 | case aux of | |
559 | Block => | |
560 | Transfer.foreachLabel | |
561 | (Block.transfer (Vector.sub (blocks, blockIndex)), | |
562 | bumpLabel) | |
563 | | Bug => () | |
564 | | Case {cases, default, ...} => | |
565 | (Cases.foreach (cases, bumpLabel) | |
566 | ; Option.app (default, bumpLabel)) | |
567 | | Goto {dst, ...} => bumpMeaning dst | |
568 | | Raise _ => () | |
569 | | Return _ => () | |
570 | end | |
571 | val _ = | |
572 | Array.foreachi | |
573 | (states, fn (i, s) => | |
574 | if Array.sub (inDegree, i) > 0 | |
575 | then | |
576 | (case s of | |
577 | State.Visited m => doit m | |
578 | | _ => ()) | |
579 | else ()) | |
580 | val _ = bumpMeaning (labelMeaning start) | |
581 | in | |
582 | Array.equals (inDegree, inDegree', Int.equals) | |
583 | orelse | |
584 | let | |
585 | val _ = | |
586 | Layout.outputl | |
587 | (Vector.layout | |
588 | (fn i => | |
589 | (Layout.record | |
590 | [("label", | |
591 | Label.layout (Block.label (Vector.sub (blocks, i)))), | |
592 | ("inDegree", Int.layout (Array.sub (inDegree, i))), | |
593 | ("inDegree'", Int.layout (Array.sub (inDegree', i))), | |
594 | ("state", State.layout (Array.sub (states, i)))])) | |
595 | (Vector.tabulate (numBlocks, fn i => i)), | |
596 | Out.error) | |
597 | in | |
598 | false | |
599 | end | |
600 | end) | |
601 | val isBlock = Array.array (numBlocks, false) | |
602 | (* Functions for maintaining inDegree. *) | |
603 | val addLabelIndex = | |
604 | fn i => | |
605 | (Assert.assert ("Ssa.Shrink.addLabelIndex", fn () => | |
606 | Array.sub (inDegree, i) > 0) | |
607 | ; addLabelIndex i) | |
608 | val addLabelMeaning = addLabelIndex o LabelMeaning.blockIndex | |
609 | fun layoutLabelMeaning m = | |
610 | Layout.record | |
611 | [("inDegree", Int.layout (Array.sub | |
612 | (inDegree, LabelMeaning.blockIndex m))), | |
613 | ("meaning", LabelMeaning.layout m)] | |
614 | val traceDeleteLabelMeaning = | |
615 | Trace.trace ("SSa.Shrink.deleteLabelMeaning", | |
616 | layoutLabelMeaning, Unit.layout) | |
617 | fun deleteLabel l = deleteLabelMeaning (labelMeaning l) | |
618 | and deleteLabelMeaning arg: unit = | |
619 | traceDeleteLabelMeaning | |
620 | (fn (m: LabelMeaning.t) => | |
621 | let | |
622 | val i = LabelMeaning.blockIndex m | |
623 | val n = Array.sub (inDegree, i) - 1 | |
624 | val _ = Array.update (inDegree, i, n) | |
625 | val _ = Assert.assert ("Ssa.Shrink.deleteLabelMeaning", fn () => n >= 0) | |
626 | in | |
627 | if n = 0 (* andalso not (Array.sub (isBlock, i)) *) | |
628 | then | |
629 | let | |
630 | datatype z = datatype LabelMeaning.aux | |
631 | in | |
632 | case LabelMeaning.aux m of | |
633 | Block => | |
634 | let | |
635 | val t = Block.transfer (Vector.sub (blocks, i)) | |
636 | val _ = Transfer.foreachLabel (t, deleteLabel) | |
637 | val _ = | |
638 | case t of | |
639 | Transfer.Call {return, ...} => | |
640 | Return.foreachHandler | |
641 | (return, fn l => | |
642 | Array.dec (numHandlerUses, | |
643 | (LabelMeaning.blockIndex | |
644 | (labelMeaning l)))) | |
645 | | _ => () | |
646 | in | |
647 | () | |
648 | end | |
649 | | Bug => () | |
650 | | Case {cases, default, ...} => | |
651 | (Cases.foreach (cases, deleteLabel) | |
652 | ; Option.app (default, deleteLabel)) | |
653 | | Goto {dst, ...} => deleteLabelMeaning dst | |
654 | | Raise _ => () | |
655 | | Return _ => () | |
656 | end | |
657 | else () | |
658 | end) arg | |
659 | fun primApp (prim: Type.t Prim.t, args: VarInfo.t vector) | |
660 | : (Type.t, VarInfo.t) Prim.ApplyResult.t = | |
661 | let | |
662 | val args' = | |
663 | Vector.map | |
664 | (args, fn vi => | |
665 | case vi of | |
666 | VarInfo.T {value = ref (SOME v), ...} => | |
667 | (case v of | |
668 | Value.Con {con, args} => | |
669 | if Vector.isEmpty args | |
670 | then Prim.ApplyArg.Con {con = con, | |
671 | hasArg = false} | |
672 | else Prim.ApplyArg.Var vi | |
673 | | Value.Const c => Prim.ApplyArg.Const c | |
674 | | _ => Prim.ApplyArg.Var vi) | |
675 | | _ => Prim.ApplyArg.Var vi) | |
676 | in | |
677 | Trace.traceInfo' | |
678 | (traceApplyInfo, | |
679 | fn (p, args, _) => | |
680 | let | |
681 | open Layout | |
682 | in | |
683 | seq [Prim.layout p, str " ", | |
684 | List.layout (Prim.ApplyArg.layout | |
685 | (Var.layout o VarInfo.var)) args] | |
686 | end, | |
687 | Prim.ApplyResult.layout (Var.layout o VarInfo.var)) | |
688 | Prim.apply | |
689 | (prim, Vector.toList args', VarInfo.equals) | |
690 | end | |
691 | (* Another DFS, this time accumulating the new blocks. *) | |
692 | val traceForceMeaningBlock = | |
693 | Trace.trace ("Ssa.Shrink.forceMeaningBlock", | |
694 | layoutLabelMeaning, Unit.layout) | |
695 | val traceSimplifyBlock = | |
696 | Trace.trace2 ("Ssa.Shrink.simplifyBlock", | |
697 | List.layout Statement.layout, | |
698 | layoutLabel o Block.label, | |
699 | Layout.tuple2 (List.layout Statement.layout, | |
700 | Transfer.layout)) | |
701 | val traceGotoMeaning = | |
702 | Trace.trace3 | |
703 | ("Ssa.Shrink.gotoMeaning", | |
704 | List.layout Statement.layout, | |
705 | layoutLabelMeaning, | |
706 | Vector.layout VarInfo.layout, | |
707 | Layout.tuple2 (List.layout Statement.layout, Transfer.layout)) | |
708 | val traceEvalStatement = | |
709 | Trace.trace | |
710 | ("Ssa.Shrink.evalStatement", | |
711 | Statement.layout, | |
712 | Layout.ignore: (Statement.t list -> Statement.t list) -> Layout.t) | |
713 | val traceSimplifyTransfer = | |
714 | Trace.trace ("Ssa.Shrink.simplifyTransfer", | |
715 | Transfer.layout, | |
716 | Layout.tuple2 (List.layout Statement.layout, | |
717 | Transfer.layout)) | |
718 | val traceSimplifyCase = | |
719 | Trace.trace | |
720 | ("Ssa.Shrink2.simplifyCase", | |
721 | fn {canMove, cases, default, test, ...} => | |
722 | Layout.record [("canMove", List.layout Statement.layout canMove), | |
723 | ("cantSimplify", Layout.str "fn () => ..."), | |
724 | ("gone", Layout.str "fn () => ..."), | |
725 | ("test", VarInfo.layout test), | |
726 | ("cases/default", | |
727 | (Transfer.layout o Transfer.Case) | |
728 | {cases = cases, | |
729 | default = default, | |
730 | test = VarInfo.var test})], | |
731 | Layout.tuple2 (List.layout Statement.layout, Transfer.layout)) | |
732 | val newBlocks = ref [] | |
733 | fun simplifyLabel l = | |
734 | let | |
735 | val m = labelMeaning l | |
736 | val _ = forceMeaningBlock m | |
737 | in | |
738 | meaningLabel m | |
739 | end | |
740 | and forceMeaningBlock arg = | |
741 | traceForceMeaningBlock | |
742 | (fn (LabelMeaning.T {aux, blockIndex = i, ...}) => | |
743 | if Array.sub (isBlock, i) | |
744 | then () | |
745 | else | |
746 | let | |
747 | val _ = Array.update (isBlock, i, true) | |
748 | val block as Block.T {label, args, ...} = | |
749 | Vector.sub (blocks, i) | |
750 | fun extract (p: Position.t): VarInfo.t = | |
751 | varInfo (case p of | |
752 | Position.Formal n => #1 (Vector.sub (args, n)) | |
753 | | Position.Free x => x) | |
754 | val (statements, transfer) = | |
755 | let | |
756 | fun rr ({args, canMove}, make) = | |
757 | (canMove, | |
758 | make (Vector.map (args, use o extract))) | |
759 | datatype z = datatype LabelMeaning.aux | |
760 | in | |
761 | case aux of | |
762 | Block => simplifyBlock ([], block) | |
763 | | Bug => ([], Transfer.Bug) | |
764 | | Case _ => simplifyBlock ([], block) | |
765 | | Goto {canMove, dst, args} => | |
766 | gotoMeaning | |
767 | (canMove, | |
768 | dst, | |
769 | Vector.map (args, extract)) | |
770 | | Raise z => rr (z, Transfer.Raise) | |
771 | | Return z => rr (z, Transfer.Return) | |
772 | end | |
773 | val _ = | |
774 | List.push | |
775 | (newBlocks, | |
776 | Block.T {label = label, | |
777 | args = args, | |
778 | statements = Vector.fromList statements, | |
779 | transfer = transfer}) | |
780 | in | |
781 | () | |
782 | end) arg | |
783 | and simplifyBlock arg : Statement.t list * Transfer.t = | |
784 | traceSimplifyBlock | |
785 | (fn (canMoveIn, Block.T {statements, transfer, ...}) => | |
786 | let | |
787 | val f = evalStatements statements | |
788 | val (ss, transfer) = simplifyTransfer transfer | |
789 | in | |
790 | (canMoveIn @ (f ss), transfer) | |
791 | end) arg | |
792 | and evalStatements (ss: Statement.t vector) | |
793 | : Statement.t list -> Statement.t list = | |
794 | let | |
795 | val fs = Vector.map (ss, evalStatement) | |
796 | in | |
797 | fn ss => Vector.foldr (fs, ss, fn (f, ss) => f ss) | |
798 | end | |
799 | and simplifyTransfer arg : Statement.t list * Transfer.t = | |
800 | traceSimplifyTransfer | |
801 | (fn (t: Transfer.t) => | |
802 | case t of | |
803 | Arith {prim, args, overflow, success, ty} => | |
804 | let | |
805 | val args = varInfos args | |
806 | in | |
807 | case primApp (prim, args) of | |
808 | Prim.ApplyResult.Const c => | |
809 | let | |
810 | val _ = deleteLabel overflow | |
811 | val x = Var.newNoname () | |
812 | val isUsed = ref false | |
813 | val vi = | |
814 | VarInfo.T {isUsed = isUsed, | |
815 | numOccurrences = ref 0, | |
816 | ty = SOME ty, | |
817 | value = ref (SOME (Value.Const c)), | |
818 | var = x} | |
819 | val (ss, t) = goto (success, Vector.new1 vi) | |
820 | val ss = | |
821 | if !isUsed | |
822 | then Statement.T {var = SOME x, | |
823 | ty = Type.ofConst c, | |
824 | exp = Exp.Const c} | |
825 | :: ss | |
826 | else ss | |
827 | in | |
828 | (ss, t) | |
829 | end | |
830 | | Prim.ApplyResult.Var x => | |
831 | let | |
832 | val _ = deleteLabel overflow | |
833 | in | |
834 | goto (success, Vector.new1 x) | |
835 | end | |
836 | | Prim.ApplyResult.Overflow => | |
837 | let | |
838 | val _ = deleteLabel success | |
839 | in | |
840 | goto (overflow, Vector.new0 ()) | |
841 | end | |
842 | | Prim.ApplyResult.Apply (prim, args) => | |
843 | let val args = Vector.fromList args | |
844 | in | |
845 | ([], Arith {prim = prim, | |
846 | args = uses args, | |
847 | overflow = simplifyLabel overflow, | |
848 | success = simplifyLabel success, | |
849 | ty = ty}) | |
850 | end | |
851 | | _ => | |
852 | ([], Arith {prim = prim, | |
853 | args = uses args, | |
854 | overflow = simplifyLabel overflow, | |
855 | success = simplifyLabel success, | |
856 | ty = ty}) | |
857 | end | |
858 | | Bug => ([], Bug) | |
859 | | Call {func, args, return} => | |
860 | let | |
861 | val (statements, return) = | |
862 | case return of | |
863 | Return.NonTail {cont, handler} => | |
864 | let | |
865 | fun isEta (m: LabelMeaning.t, | |
866 | ps: Position.t vector): bool = | |
867 | Vector.length ps = Vector.length (meaningArgs m) | |
868 | andalso | |
869 | Vector.foralli | |
870 | (ps, | |
871 | fn (i, Position.Formal i') => i = i' | |
872 | | _ => false) | |
873 | val m = labelMeaning cont | |
874 | fun nonTail () = | |
875 | let | |
876 | val _ = forceMeaningBlock m | |
877 | val handler = | |
878 | Handler.map | |
879 | (handler, fn l => | |
880 | let | |
881 | val m = labelMeaning l | |
882 | val _ = forceMeaningBlock m | |
883 | in | |
884 | meaningLabel m | |
885 | end) | |
886 | in | |
887 | ([], | |
888 | Return.NonTail {cont = meaningLabel m, | |
889 | handler = handler}) | |
890 | end | |
891 | fun tail statements = | |
892 | (deleteLabelMeaning m | |
893 | ; (statements, Return.Tail)) | |
894 | fun cont handlerEta = | |
895 | case LabelMeaning.aux m of | |
896 | LabelMeaning.Bug => | |
897 | (case handlerEta of | |
898 | NONE => nonTail () | |
899 | | SOME canMove => tail canMove) | |
900 | | LabelMeaning.Return {args, canMove} => | |
901 | if isEta (m, args) | |
902 | then tail canMove | |
903 | else nonTail () | |
904 | | _ => nonTail () | |
905 | ||
906 | in | |
907 | case handler of | |
908 | Handler.Caller => cont NONE | |
909 | | Handler.Dead => cont NONE | |
910 | | Handler.Handle l => | |
911 | let | |
912 | val m = labelMeaning l | |
913 | in | |
914 | case LabelMeaning.aux m of | |
915 | LabelMeaning.Bug => cont NONE | |
916 | | LabelMeaning.Raise {args, canMove} => | |
917 | if isEta (m, args) | |
918 | then cont (SOME canMove) | |
919 | else nonTail () | |
920 | | _ => nonTail () | |
921 | end | |
922 | end | |
923 | | _ => ([], return) | |
924 | in | |
925 | (statements, | |
926 | Call {func = func, | |
927 | args = simplifyVars args, | |
928 | return = return}) | |
929 | end | |
930 | | Case {test, cases, default} => | |
931 | let | |
932 | val test = varInfo test | |
933 | fun cantSimplify () = | |
934 | ([], | |
935 | Case {test = use test, | |
936 | cases = Cases.map (cases, simplifyLabel), | |
937 | default = Option.map (default, simplifyLabel)}) | |
938 | in | |
939 | simplifyCase | |
940 | {canMove = [], | |
941 | cantSimplify = cantSimplify, | |
942 | cases = cases, | |
943 | default = default, | |
944 | gone = fn () => (Cases.foreach (cases, deleteLabel) | |
945 | ; Option.app (default, deleteLabel)), | |
946 | test = test} | |
947 | end | |
948 | | Goto {dst, args} => goto (dst, varInfos args) | |
949 | | Raise xs => ([], Raise (simplifyVars xs)) | |
950 | | Return xs => ([], Return (simplifyVars xs)) | |
951 | | Runtime {prim, args, return} => | |
952 | ([], Runtime {prim = prim, | |
953 | args = simplifyVars args, | |
954 | return = simplifyLabel return}) | |
955 | ) arg | |
956 | and simplifyCase arg : Statement.t list * Transfer.t = | |
957 | traceSimplifyCase | |
958 | (fn {canMove, cantSimplify, | |
959 | cases, default, gone, test: VarInfo.t} => | |
960 | let | |
961 | (* tryToEliminate makes sure that the destination meaning | |
962 | * hasn't already been simplified. If it has, then we can't | |
963 | * simplify the case. | |
964 | *) | |
965 | fun tryToEliminate m = | |
966 | let | |
967 | val i = LabelMeaning.blockIndex m | |
968 | in | |
969 | if Array.sub (inDegree, i) = 0 | |
970 | then cantSimplify () | |
971 | else | |
972 | let | |
973 | val _ = addLabelIndex i | |
974 | val _ = gone () | |
975 | in | |
976 | gotoMeaning (canMove, m, Vector.new0 ()) | |
977 | end | |
978 | end | |
979 | in | |
980 | if Cases.isEmpty cases | |
981 | then (case default of | |
982 | NONE => (canMove, Bug) | |
983 | | SOME l => tryToEliminate (labelMeaning l)) | |
984 | else | |
985 | let | |
986 | val l = Cases.hd cases | |
987 | fun isOk (l': Label.t): bool = Label.equals (l, l') | |
988 | in | |
989 | if Vector.isEmpty (labelArgs l) | |
990 | andalso Cases.forall (cases, isOk) | |
991 | andalso (case default of | |
992 | NONE => true | |
993 | | SOME l => isOk l) | |
994 | then | |
995 | (* All cases the same -- eliminate the case. *) | |
996 | tryToEliminate (labelMeaning l) | |
997 | else | |
998 | let | |
999 | fun findCase (cases, isCon, args) = | |
1000 | let | |
1001 | val n = Vector.length cases | |
1002 | fun doit (l, args) = | |
1003 | let | |
1004 | val m = labelMeaning l | |
1005 | val _ = addLabelMeaning m | |
1006 | val _ = gone () | |
1007 | in | |
1008 | gotoMeaning (canMove, m, args) | |
1009 | end | |
1010 | fun loop k = | |
1011 | if k = n | |
1012 | then | |
1013 | (case default of | |
1014 | NONE => (gone (); ([], Bug)) | |
1015 | | SOME l => doit (l, Vector.new0 ())) | |
1016 | else | |
1017 | let | |
1018 | val (con, l) = Vector.sub (cases, k) | |
1019 | in | |
1020 | if isCon con | |
1021 | then doit (l, args) | |
1022 | else loop (k + 1) | |
1023 | end | |
1024 | in | |
1025 | loop 0 | |
1026 | end | |
1027 | in | |
1028 | case (VarInfo.value test, cases) of | |
1029 | (SOME (Value.Const c), _) => | |
1030 | (case (cases, c) of | |
1031 | (Cases.Word (_, cs), Const.Word w) => | |
1032 | findCase (cs, | |
1033 | fn w' => WordX.equals (w, w'), | |
1034 | Vector.new0 ()) | |
1035 | | _ => | |
1036 | Error.bug "Ssa.Shrink.simplifyCases: strange constant") | |
1037 | | (SOME (Value.Con {con, args}), Cases.Con cases) => | |
1038 | findCase (cases, | |
1039 | fn c => Con.equals (con, c), | |
1040 | args) | |
1041 | | _ => cantSimplify () | |
1042 | end | |
1043 | end | |
1044 | end) arg | |
1045 | and goto (dst: Label.t, args: VarInfo.t vector) | |
1046 | : Statement.t list * Transfer.t = | |
1047 | gotoMeaning ([], labelMeaning dst, args) | |
1048 | and gotoMeaning arg : Statement.t list * Transfer.t = | |
1049 | traceGotoMeaning | |
1050 | (fn (canMoveIn, | |
1051 | m as LabelMeaning.T {aux, blockIndex = i, ...}, | |
1052 | args: VarInfo.t vector) => | |
1053 | let | |
1054 | val n = Array.sub (inDegree, i) | |
1055 | val _ = Assert.assert ("Ssa.Shrink.gotoMeaning", fn () => n >= 1) | |
1056 | fun normal () = | |
1057 | if n = 1 | |
1058 | then | |
1059 | let | |
1060 | val _ = Array.update (inDegree, i, 0) | |
1061 | val b = Vector.sub (blocks, i) | |
1062 | val _ = | |
1063 | Vector.foreach2 | |
1064 | (Block.args b, args, fn ((x, _), vi) => | |
1065 | setVarInfo (x, vi)) | |
1066 | in | |
1067 | simplifyBlock (canMoveIn, b) | |
1068 | end | |
1069 | else | |
1070 | let | |
1071 | val _ = forceMeaningBlock m | |
1072 | in | |
1073 | (canMoveIn, | |
1074 | Goto {dst = Block.label (Vector.sub (blocks, i)), | |
1075 | args = uses args}) | |
1076 | end | |
1077 | fun extract p = | |
1078 | case p of | |
1079 | Position.Formal n => Vector.sub (args, n) | |
1080 | | Position.Free x => varInfo x | |
1081 | fun rr ({args, canMove}, make) = | |
1082 | (canMoveIn @ canMove, | |
1083 | make (Vector.map (args, use o extract))) | |
1084 | datatype z = datatype LabelMeaning.aux | |
1085 | in | |
1086 | case aux of | |
1087 | Block => normal () | |
1088 | | Bug => ((*canMoveIn*)[], Transfer.Bug) | |
1089 | | Case {canMove, cases, default} => | |
1090 | simplifyCase {canMove = canMoveIn @ canMove, | |
1091 | cantSimplify = normal, | |
1092 | cases = cases, | |
1093 | default = default, | |
1094 | gone = fn () => deleteLabelMeaning m, | |
1095 | test = Vector.first args} | |
1096 | | Goto {canMove, dst, args} => | |
1097 | if Array.sub (isHeader, i) | |
1098 | orelse Array.sub (isBlock, i) | |
1099 | then normal () | |
1100 | else | |
1101 | let | |
1102 | val n' = n - 1 | |
1103 | val _ = Array.update (inDegree, i, n') | |
1104 | val _ = | |
1105 | if n' > 0 | |
1106 | then addLabelMeaning dst | |
1107 | else () | |
1108 | in | |
1109 | gotoMeaning (canMoveIn @ canMove, | |
1110 | dst, | |
1111 | Vector.map (args, extract)) | |
1112 | end | |
1113 | | Raise z => rr (z, Transfer.Raise) | |
1114 | | Return z => rr (z, Transfer.Return) | |
1115 | end) arg | |
1116 | and evalStatement arg : Statement.t list -> Statement.t list = | |
1117 | traceEvalStatement | |
1118 | (fn (Statement.T {var, ty, exp}) => | |
1119 | let | |
1120 | val _ = Option.app | |
1121 | (var, fn x => | |
1122 | setVarInfo (x, VarInfo.new (x, SOME ty))) | |
1123 | fun delete ss = ss | |
1124 | fun doit {makeExp: unit -> Exp.t, | |
1125 | sideEffect: bool, | |
1126 | value: Value.t option} = | |
1127 | let | |
1128 | fun make var = | |
1129 | Statement.T {var = var, | |
1130 | ty = ty, | |
1131 | exp = makeExp ()} | |
1132 | in | |
1133 | case var of | |
1134 | NONE => | |
1135 | if sideEffect | |
1136 | then (fn ss => make NONE :: ss) | |
1137 | else delete | |
1138 | | SOME x => | |
1139 | let | |
1140 | val VarInfo.T {isUsed, value = r, ...} = varInfo x | |
1141 | val _ = r := value | |
1142 | in | |
1143 | fn ss => | |
1144 | if !isUsed | |
1145 | then make (SOME x) :: ss | |
1146 | else if sideEffect | |
1147 | then make NONE :: ss | |
1148 | else ss | |
1149 | end | |
1150 | end | |
1151 | fun setVar vi = | |
1152 | (Option.app (var, fn x => setVarInfo (x, vi)) | |
1153 | ; delete) | |
1154 | fun construct (v: Value.t, makeExp) = | |
1155 | doit {makeExp = makeExp, | |
1156 | sideEffect = false, | |
1157 | value = SOME v} | |
1158 | in | |
1159 | case exp of | |
1160 | ConApp {con, args} => | |
1161 | let | |
1162 | val args = varInfos args | |
1163 | in | |
1164 | construct (Value.Con {con = con, args = args}, | |
1165 | fn () => ConApp {con = con, | |
1166 | args = uses args}) | |
1167 | end | |
1168 | | Const c => construct (Value.Const c, fn () => exp) | |
1169 | | PrimApp {prim, targs, args} => | |
1170 | let | |
1171 | val args = varInfos args | |
1172 | fun apply {prim, targs, args} = | |
1173 | doit {sideEffect = Prim.maySideEffect prim, | |
1174 | makeExp = fn () => PrimApp {prim = prim, | |
1175 | targs = targs, | |
1176 | args = uses args}, | |
1177 | value = NONE} | |
1178 | datatype z = datatype Prim.ApplyResult.t | |
1179 | in | |
1180 | case primApp (prim, args) of | |
1181 | Apply (prim, args) => | |
1182 | apply {prim = prim, targs = Vector.new0 (), | |
1183 | args = Vector.fromList args} | |
1184 | | Bool b => | |
1185 | let | |
1186 | val con = Con.fromBool b | |
1187 | in | |
1188 | construct (Value.Con {con = con, | |
1189 | args = Vector.new0 ()}, | |
1190 | fn () => | |
1191 | ConApp {con = con, | |
1192 | args = Vector.new0 ()}) | |
1193 | end | |
1194 | | Const c => construct (Value.Const c, | |
1195 | fn () => Exp.Const c) | |
1196 | | Var vi => setVar vi | |
1197 | | _ => apply {prim = prim, | |
1198 | targs = targs, | |
1199 | args = args} | |
1200 | end | |
1201 | | Select {tuple, offset} => | |
1202 | let | |
1203 | val tuple as VarInfo.T {value, ...} = varInfo tuple | |
1204 | in | |
1205 | case !value of | |
1206 | SOME (Value.Tuple vs) => | |
1207 | setVar (Vector.sub (vs, offset)) | |
1208 | | _ => | |
1209 | construct (Value.Select {tuple = tuple, | |
1210 | offset = offset}, | |
1211 | fn () => Select {tuple = use tuple, | |
1212 | offset = offset}) | |
1213 | end | |
1214 | | Tuple xs => | |
1215 | let | |
1216 | val xs = varInfos xs | |
1217 | in | |
1218 | case Exn.withEscape | |
1219 | (fn escape => | |
1220 | Vector.foldri | |
1221 | (xs, NONE, | |
1222 | fn (i, VarInfo.T {value, ...}, tuple') => | |
1223 | case !value of | |
1224 | SOME (Value.Select {offset, tuple}) => | |
1225 | if offset = i | |
1226 | then case tuple' of | |
1227 | NONE => | |
1228 | (case VarInfo.ty tuple of | |
1229 | SOME ty => | |
1230 | (case Type.deTupleOpt ty of | |
1231 | SOME ts => | |
1232 | if Vector.length xs = | |
1233 | Vector.length ts | |
1234 | then SOME tuple | |
1235 | else escape NONE | |
1236 | | NONE => escape NONE) | |
1237 | | NONE => escape NONE) | |
1238 | | SOME tuple'' => | |
1239 | if VarInfo.equals (tuple'', tuple) | |
1240 | then tuple' | |
1241 | else escape NONE | |
1242 | else escape NONE | |
1243 | | _ => escape NONE)) of | |
1244 | SOME tuple => setVar tuple | |
1245 | | NONE => construct (Value.Tuple xs, | |
1246 | fn () => Tuple (uses xs)) | |
1247 | end | |
1248 | | Var x => setVar (varInfo x) | |
1249 | | _ => doit {makeExp = fn () => exp, | |
1250 | sideEffect = true, | |
1251 | value = NONE} | |
1252 | end) arg | |
1253 | val start = labelMeaning start | |
1254 | val _ = forceMeaningBlock start | |
1255 | val f = | |
1256 | Function.new {args = args, | |
1257 | blocks = Vector.fromList (!newBlocks), | |
1258 | mayInline = mayInline, | |
1259 | name = name, | |
1260 | raises = raises, | |
1261 | returns = returns, | |
1262 | start = meaningLabel start} | |
1263 | val _ = if true then () else save (f, "post") | |
1264 | val _ = Function.clear f | |
1265 | in | |
1266 | f | |
1267 | end | |
1268 | end | |
1269 | ||
1270 | fun eliminateUselessProfile (f: Function.t): Function.t = | |
1271 | if !Control.profile = Control.ProfileNone | |
1272 | then f | |
1273 | else | |
1274 | let | |
1275 | fun eliminateInBlock (b as Block.T {args, label, statements, transfer}) | |
1276 | : Block.t = | |
1277 | if not (Vector.exists (statements, Statement.isProfile)) | |
1278 | then b | |
1279 | else | |
1280 | let | |
1281 | datatype z = datatype Exp.t | |
1282 | datatype z = datatype ProfileExp.t | |
1283 | val stack = | |
1284 | Vector.fold | |
1285 | (statements, [], fn (s as Statement.T {exp, ...}, stack) => | |
1286 | case exp of | |
1287 | Profile (Leave si) => | |
1288 | (case stack of | |
1289 | Statement.T {exp = Profile (Enter si'), ...} | |
1290 | :: rest => | |
1291 | if SourceInfo.equals (si, si') | |
1292 | then rest | |
1293 | else Error.bug "Ssa.Shrink.eliminateUselessProfile: mismatched Leave" | |
1294 | | _ => s :: stack) | |
1295 | | _ => s :: stack) | |
1296 | val statements = Vector.fromListRev stack | |
1297 | in | |
1298 | Block.T {args = args, | |
1299 | label = label, | |
1300 | statements = statements, | |
1301 | transfer = transfer} | |
1302 | end | |
1303 | val {args, blocks, mayInline, name, raises, returns, start} = | |
1304 | Function.dest f | |
1305 | val blocks = Vector.map (blocks, eliminateInBlock) | |
1306 | in | |
1307 | Function.new {args = args, | |
1308 | blocks = blocks, | |
1309 | mayInline = mayInline, | |
1310 | name = name, | |
1311 | raises = raises, | |
1312 | returns = returns, | |
1313 | start = start} | |
1314 | end | |
1315 | ||
1316 | val traceShrinkFunction = | |
1317 | Trace.trace ("Ssa.Shrink.shrinkFunction", Function.layout, Function.layout) | |
1318 | ||
1319 | val shrinkFunction = | |
1320 | fn g => | |
1321 | let | |
1322 | val s = shrinkFunction g | |
1323 | in | |
1324 | fn f => traceShrinkFunction s (eliminateUselessProfile f) | |
1325 | end | |
1326 | ||
1327 | fun shrink (Program.T {datatypes, globals, functions, main}) | |
1328 | = let | |
1329 | val s = shrinkFunction {globals = globals} | |
1330 | in | |
1331 | Program.T {datatypes = datatypes, | |
1332 | globals = globals, | |
1333 | functions = List.revMap (functions, s), | |
1334 | main = main} | |
1335 | end | |
1336 | ||
1337 | end |