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4d6922ee | 1 | /* ET-trees data structure implementation. |
f1cfb09f | 2 | Contributed by Pavel Nejedly |
7adcbafe | 3 | Copyright (C) 2002-2022 Free Software Foundation, Inc. |
f1cfb09f JH |
4 | |
5 | This file is part of the libiberty library. | |
6 | Libiberty is free software; you can redistribute it and/or | |
7 | modify it under the terms of the GNU Library General Public | |
8 | License as published by the Free Software Foundation; either | |
9dcd6f09 | 9 | version 3 of the License, or (at your option) any later version. |
f1cfb09f JH |
10 | |
11 | Libiberty is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Library General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU Library General Public | |
9dcd6f09 NC |
17 | License along with libiberty; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. | |
f1cfb09f JH |
19 | |
20 | The ET-forest structure is described in: | |
21 | D. D. Sleator and R. E. Tarjan. A data structure for dynamic trees. | |
22 | J. G'omput. System Sci., 26(3):362 381, 1983. | |
23 | */ | |
24 | ||
25 | #include "config.h" | |
26 | #include "system.h" | |
4977bab6 | 27 | #include "coretypes.h" |
f6cb56fa | 28 | #include "alloc-pool.h" |
64afff5b | 29 | #include "et-forest.h" |
d9b950dd | 30 | #include "selftest.h" |
f1cfb09f | 31 | |
b2b29377 | 32 | /* We do not enable this with CHECKING_P, since it is awfully slow. */ |
d47cc544 | 33 | #undef DEBUG_ET |
f1cfb09f | 34 | |
d47cc544 | 35 | #ifdef DEBUG_ET |
c7131fb2 | 36 | #include "backend.h" |
60393bbc | 37 | #include "hard-reg-set.h" |
d47cc544 | 38 | #endif |
f1cfb09f | 39 | |
1f52178b | 40 | /* The occurrence of a node in the et tree. */ |
d47cc544 | 41 | struct et_occ |
f1cfb09f | 42 | { |
d47cc544 SB |
43 | struct et_node *of; /* The node. */ |
44 | ||
45 | struct et_occ *parent; /* Parent in the splay-tree. */ | |
46 | struct et_occ *prev; /* Left son in the splay-tree. */ | |
47 | struct et_occ *next; /* Right son in the splay-tree. */ | |
48 | ||
49 | int depth; /* The depth of the node is the sum of depth | |
50 | fields on the path to the root. */ | |
51 | int min; /* The minimum value of the depth in the subtree | |
52 | is obtained by adding sum of depth fields | |
53 | on the path to the root. */ | |
1f52178b | 54 | struct et_occ *min_occ; /* The occurrence in the subtree with the minimal |
d47cc544 SB |
55 | depth. */ |
56 | }; | |
f1cfb09f | 57 | |
fcb87c50 MM |
58 | static object_allocator<et_node> et_nodes ("et_nodes pool"); |
59 | static object_allocator<et_occ> et_occurrences ("et_occ pool"); | |
f1cfb09f | 60 | |
d47cc544 | 61 | /* Changes depth of OCC to D. */ |
f1cfb09f | 62 | |
d47cc544 SB |
63 | static inline void |
64 | set_depth (struct et_occ *occ, int d) | |
65 | { | |
66 | if (!occ) | |
67 | return; | |
f1cfb09f | 68 | |
d47cc544 SB |
69 | occ->min += d - occ->depth; |
70 | occ->depth = d; | |
71 | } | |
f1cfb09f | 72 | |
d47cc544 | 73 | /* Adds D to the depth of OCC. */ |
f1cfb09f | 74 | |
d47cc544 SB |
75 | static inline void |
76 | set_depth_add (struct et_occ *occ, int d) | |
f1cfb09f | 77 | { |
d47cc544 SB |
78 | if (!occ) |
79 | return; | |
f1cfb09f | 80 | |
d47cc544 SB |
81 | occ->min += d; |
82 | occ->depth += d; | |
83 | } | |
f1cfb09f | 84 | |
d47cc544 | 85 | /* Sets prev field of OCC to P. */ |
f1cfb09f | 86 | |
d47cc544 SB |
87 | static inline void |
88 | set_prev (struct et_occ *occ, struct et_occ *t) | |
f1cfb09f | 89 | { |
d47cc544 | 90 | #ifdef DEBUG_ET |
5b0264cb | 91 | gcc_assert (occ != t); |
d47cc544 | 92 | #endif |
f1cfb09f | 93 | |
d47cc544 SB |
94 | occ->prev = t; |
95 | if (t) | |
96 | t->parent = occ; | |
f1cfb09f JH |
97 | } |
98 | ||
d47cc544 SB |
99 | /* Sets next field of OCC to P. */ |
100 | ||
101 | static inline void | |
102 | set_next (struct et_occ *occ, struct et_occ *t) | |
f1cfb09f | 103 | { |
d47cc544 | 104 | #ifdef DEBUG_ET |
5b0264cb | 105 | gcc_assert (occ != t); |
d47cc544 SB |
106 | #endif |
107 | ||
108 | occ->next = t; | |
109 | if (t) | |
110 | t->parent = occ; | |
f1cfb09f JH |
111 | } |
112 | ||
1f52178b | 113 | /* Recompute minimum for occurrence OCC. */ |
f1cfb09f | 114 | |
d47cc544 SB |
115 | static inline void |
116 | et_recomp_min (struct et_occ *occ) | |
f1cfb09f | 117 | { |
d47cc544 | 118 | struct et_occ *mson = occ->prev; |
f1cfb09f | 119 | |
d47cc544 SB |
120 | if (!mson |
121 | || (occ->next | |
122 | && mson->min > occ->next->min)) | |
123 | mson = occ->next; | |
f1cfb09f | 124 | |
d47cc544 SB |
125 | if (mson && mson->min < 0) |
126 | { | |
127 | occ->min = mson->min + occ->depth; | |
128 | occ->min_occ = mson->min_occ; | |
129 | } | |
130 | else | |
131 | { | |
132 | occ->min = occ->depth; | |
133 | occ->min_occ = occ; | |
134 | } | |
135 | } | |
f1cfb09f | 136 | |
d47cc544 | 137 | #ifdef DEBUG_ET |
2a7e31df | 138 | /* Checks whether neighborhood of OCC seems sane. */ |
f1cfb09f | 139 | |
d47cc544 SB |
140 | static void |
141 | et_check_occ_sanity (struct et_occ *occ) | |
142 | { | |
143 | if (!occ) | |
144 | return; | |
f1cfb09f | 145 | |
5b0264cb NS |
146 | gcc_assert (occ->parent != occ); |
147 | gcc_assert (occ->prev != occ); | |
148 | gcc_assert (occ->next != occ); | |
149 | gcc_assert (!occ->next || occ->next != occ->prev); | |
f1cfb09f | 150 | |
d47cc544 | 151 | if (occ->next) |
f1cfb09f | 152 | { |
5b0264cb NS |
153 | gcc_assert (occ->next != occ->parent); |
154 | gcc_assert (occ->next->parent == occ); | |
502b8322 | 155 | } |
d47cc544 SB |
156 | |
157 | if (occ->prev) | |
f1cfb09f | 158 | { |
5b0264cb NS |
159 | gcc_assert (occ->prev != occ->parent); |
160 | gcc_assert (occ->prev->parent == occ); | |
f1cfb09f JH |
161 | } |
162 | ||
5b0264cb NS |
163 | gcc_assert (!occ->parent |
164 | || occ->parent->prev == occ | |
165 | || occ->parent->next == occ); | |
f1cfb09f JH |
166 | } |
167 | ||
d47cc544 SB |
168 | /* Checks whether tree rooted at OCC is sane. */ |
169 | ||
f1cfb09f | 170 | static void |
d47cc544 | 171 | et_check_sanity (struct et_occ *occ) |
f1cfb09f | 172 | { |
d47cc544 SB |
173 | et_check_occ_sanity (occ); |
174 | if (occ->prev) | |
175 | et_check_sanity (occ->prev); | |
176 | if (occ->next) | |
177 | et_check_sanity (occ->next); | |
178 | } | |
f1cfb09f | 179 | |
d47cc544 | 180 | /* Checks whether tree containing OCC is sane. */ |
f1cfb09f | 181 | |
d47cc544 SB |
182 | static void |
183 | et_check_tree_sanity (struct et_occ *occ) | |
184 | { | |
185 | while (occ->parent) | |
186 | occ = occ->parent; | |
f1cfb09f | 187 | |
d47cc544 SB |
188 | et_check_sanity (occ); |
189 | } | |
f1cfb09f | 190 | |
d47cc544 | 191 | /* For recording the paths. */ |
f1cfb09f | 192 | |
6de9cd9a DN |
193 | /* An ad-hoc constant; if the function has more blocks, this won't work, |
194 | but since it is used for debugging only, it does not matter. */ | |
195 | #define MAX_NODES 100000 | |
196 | ||
d47cc544 | 197 | static int len; |
6de9cd9a DN |
198 | static void *datas[MAX_NODES]; |
199 | static int depths[MAX_NODES]; | |
f1cfb09f | 200 | |
d47cc544 | 201 | /* Records the path represented by OCC, with depth incremented by DEPTH. */ |
f1cfb09f | 202 | |
d47cc544 SB |
203 | static int |
204 | record_path_before_1 (struct et_occ *occ, int depth) | |
205 | { | |
206 | int mn, m; | |
f1cfb09f | 207 | |
d47cc544 SB |
208 | depth += occ->depth; |
209 | mn = depth; | |
210 | ||
211 | if (occ->prev) | |
212 | { | |
b8698a0f | 213 | m = record_path_before_1 (occ->prev, depth); |
d47cc544 SB |
214 | if (m < mn) |
215 | mn = m; | |
f1cfb09f JH |
216 | } |
217 | ||
d47cc544 | 218 | fprintf (stderr, "%d (%d); ", ((basic_block) occ->of->data)->index, depth); |
6de9cd9a | 219 | |
5b0264cb | 220 | gcc_assert (len < MAX_NODES); |
6de9cd9a | 221 | |
d47cc544 SB |
222 | depths[len] = depth; |
223 | datas[len] = occ->of; | |
224 | len++; | |
225 | ||
226 | if (occ->next) | |
f1cfb09f | 227 | { |
d47cc544 SB |
228 | m = record_path_before_1 (occ->next, depth); |
229 | if (m < mn) | |
230 | mn = m; | |
231 | } | |
f1cfb09f | 232 | |
5b0264cb | 233 | gcc_assert (mn == occ->min + depth - occ->depth); |
f1cfb09f | 234 | |
d47cc544 SB |
235 | return mn; |
236 | } | |
f1cfb09f | 237 | |
d47cc544 | 238 | /* Records the path represented by a tree containing OCC. */ |
f1cfb09f | 239 | |
d47cc544 SB |
240 | static void |
241 | record_path_before (struct et_occ *occ) | |
242 | { | |
243 | while (occ->parent) | |
244 | occ = occ->parent; | |
f1cfb09f | 245 | |
d47cc544 SB |
246 | len = 0; |
247 | record_path_before_1 (occ, 0); | |
248 | fprintf (stderr, "\n"); | |
f1cfb09f JH |
249 | } |
250 | ||
d47cc544 SB |
251 | /* Checks whether the path represented by OCC, with depth incremented by DEPTH, |
252 | was not changed since the last recording. */ | |
253 | ||
254 | static int | |
255 | check_path_after_1 (struct et_occ *occ, int depth) | |
f1cfb09f | 256 | { |
d47cc544 SB |
257 | int mn, m; |
258 | ||
259 | depth += occ->depth; | |
260 | mn = depth; | |
f1cfb09f | 261 | |
d47cc544 | 262 | if (occ->next) |
f1cfb09f | 263 | { |
b8698a0f | 264 | m = check_path_after_1 (occ->next, depth); |
d47cc544 SB |
265 | if (m < mn) |
266 | mn = m; | |
267 | } | |
f1cfb09f | 268 | |
d47cc544 | 269 | len--; |
5b0264cb | 270 | gcc_assert (depths[len] == depth && datas[len] == occ->of); |
d47cc544 SB |
271 | |
272 | if (occ->prev) | |
273 | { | |
274 | m = check_path_after_1 (occ->prev, depth); | |
275 | if (m < mn) | |
276 | mn = m; | |
f1cfb09f JH |
277 | } |
278 | ||
5b0264cb | 279 | gcc_assert (mn == occ->min + depth - occ->depth); |
d47cc544 SB |
280 | |
281 | return mn; | |
f1cfb09f JH |
282 | } |
283 | ||
d47cc544 SB |
284 | /* Checks whether the path represented by a tree containing OCC was |
285 | not changed since the last recording. */ | |
286 | ||
287 | static void | |
288 | check_path_after (struct et_occ *occ) | |
289 | { | |
290 | while (occ->parent) | |
291 | occ = occ->parent; | |
292 | ||
293 | check_path_after_1 (occ, 0); | |
5b0264cb | 294 | gcc_assert (!len); |
d47cc544 | 295 | } |
f1cfb09f | 296 | |
d47cc544 | 297 | #endif |
f1cfb09f | 298 | |
1f52178b | 299 | /* Splay the occurrence OCC to the root of the tree. */ |
f1cfb09f | 300 | |
965514bd | 301 | static void |
d47cc544 | 302 | et_splay (struct et_occ *occ) |
f1cfb09f | 303 | { |
d47cc544 SB |
304 | struct et_occ *f, *gf, *ggf; |
305 | int occ_depth, f_depth, gf_depth; | |
306 | ||
307 | #ifdef DEBUG_ET | |
308 | record_path_before (occ); | |
309 | et_check_tree_sanity (occ); | |
310 | #endif | |
b8698a0f | 311 | |
d47cc544 SB |
312 | while (occ->parent) |
313 | { | |
314 | occ_depth = occ->depth; | |
f1cfb09f | 315 | |
d47cc544 SB |
316 | f = occ->parent; |
317 | f_depth = f->depth; | |
f1cfb09f | 318 | |
d47cc544 | 319 | gf = f->parent; |
f1cfb09f | 320 | |
d47cc544 SB |
321 | if (!gf) |
322 | { | |
323 | set_depth_add (occ, f_depth); | |
324 | occ->min_occ = f->min_occ; | |
325 | occ->min = f->min; | |
f1cfb09f | 326 | |
d47cc544 SB |
327 | if (f->prev == occ) |
328 | { | |
329 | /* zig */ | |
330 | set_prev (f, occ->next); | |
331 | set_next (occ, f); | |
332 | set_depth_add (f->prev, occ_depth); | |
333 | } | |
334 | else | |
335 | { | |
336 | /* zag */ | |
337 | set_next (f, occ->prev); | |
338 | set_prev (occ, f); | |
339 | set_depth_add (f->next, occ_depth); | |
340 | } | |
341 | set_depth (f, -occ_depth); | |
342 | occ->parent = NULL; | |
343 | ||
344 | et_recomp_min (f); | |
345 | #ifdef DEBUG_ET | |
346 | et_check_tree_sanity (occ); | |
347 | check_path_after (occ); | |
348 | #endif | |
349 | return; | |
350 | } | |
351 | ||
352 | gf_depth = gf->depth; | |
353 | ||
354 | set_depth_add (occ, f_depth + gf_depth); | |
355 | occ->min_occ = gf->min_occ; | |
356 | occ->min = gf->min; | |
357 | ||
358 | ggf = gf->parent; | |
359 | ||
360 | if (gf->prev == f) | |
361 | { | |
362 | if (f->prev == occ) | |
363 | { | |
364 | /* zig zig */ | |
365 | set_prev (gf, f->next); | |
366 | set_prev (f, occ->next); | |
367 | set_next (occ, f); | |
368 | set_next (f, gf); | |
369 | ||
370 | set_depth (f, -occ_depth); | |
371 | set_depth_add (f->prev, occ_depth); | |
372 | set_depth (gf, -f_depth); | |
373 | set_depth_add (gf->prev, f_depth); | |
374 | } | |
375 | else | |
376 | { | |
377 | /* zag zig */ | |
378 | set_prev (gf, occ->next); | |
379 | set_next (f, occ->prev); | |
380 | set_prev (occ, f); | |
381 | set_next (occ, gf); | |
382 | ||
383 | set_depth (f, -occ_depth); | |
384 | set_depth_add (f->next, occ_depth); | |
385 | set_depth (gf, -occ_depth - f_depth); | |
386 | set_depth_add (gf->prev, occ_depth + f_depth); | |
387 | } | |
388 | } | |
389 | else | |
390 | { | |
391 | if (f->prev == occ) | |
392 | { | |
393 | /* zig zag */ | |
394 | set_next (gf, occ->prev); | |
395 | set_prev (f, occ->next); | |
396 | set_prev (occ, gf); | |
397 | set_next (occ, f); | |
398 | ||
399 | set_depth (f, -occ_depth); | |
400 | set_depth_add (f->prev, occ_depth); | |
401 | set_depth (gf, -occ_depth - f_depth); | |
402 | set_depth_add (gf->next, occ_depth + f_depth); | |
403 | } | |
404 | else | |
405 | { | |
406 | /* zag zag */ | |
407 | set_next (gf, f->prev); | |
408 | set_next (f, occ->prev); | |
409 | set_prev (occ, f); | |
410 | set_prev (f, gf); | |
411 | ||
412 | set_depth (f, -occ_depth); | |
413 | set_depth_add (f->next, occ_depth); | |
414 | set_depth (gf, -f_depth); | |
415 | set_depth_add (gf->next, f_depth); | |
416 | } | |
417 | } | |
418 | ||
419 | occ->parent = ggf; | |
420 | if (ggf) | |
421 | { | |
422 | if (ggf->prev == gf) | |
423 | ggf->prev = occ; | |
424 | else | |
425 | ggf->next = occ; | |
426 | } | |
427 | ||
428 | et_recomp_min (gf); | |
429 | et_recomp_min (f); | |
430 | #ifdef DEBUG_ET | |
431 | et_check_tree_sanity (occ); | |
432 | #endif | |
433 | } | |
434 | ||
435 | #ifdef DEBUG_ET | |
436 | et_check_sanity (occ); | |
437 | check_path_after (occ); | |
438 | #endif | |
439 | } | |
440 | ||
1f52178b | 441 | /* Create a new et tree occurrence of NODE. */ |
d47cc544 SB |
442 | |
443 | static struct et_occ * | |
444 | et_new_occ (struct et_node *node) | |
f1cfb09f | 445 | { |
fb0b2914 | 446 | et_occ *nw = et_occurrences.allocate (); |
d47cc544 SB |
447 | |
448 | nw->of = node; | |
449 | nw->parent = NULL; | |
450 | nw->prev = NULL; | |
451 | nw->next = NULL; | |
452 | ||
453 | nw->depth = 0; | |
454 | nw->min_occ = nw; | |
455 | nw->min = 0; | |
456 | ||
457 | return nw; | |
f1cfb09f JH |
458 | } |
459 | ||
d47cc544 SB |
460 | /* Create a new et tree containing DATA. */ |
461 | ||
462 | struct et_node * | |
463 | et_new_tree (void *data) | |
f1cfb09f | 464 | { |
fb0b2914 | 465 | et_node *nw = et_nodes.allocate (); |
d47cc544 SB |
466 | |
467 | nw->data = data; | |
468 | nw->father = NULL; | |
469 | nw->left = NULL; | |
470 | nw->right = NULL; | |
471 | nw->son = NULL; | |
472 | ||
473 | nw->rightmost_occ = et_new_occ (nw); | |
474 | nw->parent_occ = NULL; | |
475 | ||
476 | return nw; | |
f1cfb09f JH |
477 | } |
478 | ||
d47cc544 SB |
479 | /* Releases et tree T. */ |
480 | ||
481 | void | |
482 | et_free_tree (struct et_node *t) | |
f1cfb09f | 483 | { |
d47cc544 SB |
484 | while (t->son) |
485 | et_split (t->son); | |
f1cfb09f | 486 | |
d47cc544 SB |
487 | if (t->father) |
488 | et_split (t); | |
f1cfb09f | 489 | |
fb0b2914 ML |
490 | et_occurrences.remove (t->rightmost_occ); |
491 | et_nodes.remove (t); | |
f1cfb09f JH |
492 | } |
493 | ||
bef87a34 KH |
494 | /* Releases et tree T without maintaining other nodes. */ |
495 | ||
496 | void | |
497 | et_free_tree_force (struct et_node *t) | |
498 | { | |
fb0b2914 | 499 | et_occurrences.remove (t->rightmost_occ); |
5a6ccafd | 500 | if (t->parent_occ) |
fb0b2914 ML |
501 | et_occurrences.remove (t->parent_occ); |
502 | et_nodes.remove (t); | |
bef87a34 KH |
503 | } |
504 | ||
5a6ccafd RG |
505 | /* Release the alloc pools, if they are empty. */ |
506 | ||
507 | void | |
508 | et_free_pools (void) | |
509 | { | |
fb0b2914 ML |
510 | et_occurrences.release_if_empty (); |
511 | et_nodes.release_if_empty (); | |
5a6ccafd RG |
512 | } |
513 | ||
d47cc544 SB |
514 | /* Sets father of et tree T to FATHER. */ |
515 | ||
f1cfb09f | 516 | void |
d47cc544 | 517 | et_set_father (struct et_node *t, struct et_node *father) |
f1cfb09f | 518 | { |
d47cc544 SB |
519 | struct et_node *left, *right; |
520 | struct et_occ *rmost, *left_part, *new_f_occ, *p; | |
f1cfb09f | 521 | |
d47cc544 SB |
522 | /* Update the path represented in the splay tree. */ |
523 | new_f_occ = et_new_occ (father); | |
f1cfb09f | 524 | |
d47cc544 SB |
525 | rmost = father->rightmost_occ; |
526 | et_splay (rmost); | |
f1cfb09f | 527 | |
d47cc544 | 528 | left_part = rmost->prev; |
f1cfb09f | 529 | |
d47cc544 SB |
530 | p = t->rightmost_occ; |
531 | et_splay (p); | |
f1cfb09f | 532 | |
d47cc544 SB |
533 | set_prev (new_f_occ, left_part); |
534 | set_next (new_f_occ, p); | |
535 | ||
536 | p->depth++; | |
537 | p->min++; | |
538 | et_recomp_min (new_f_occ); | |
f1cfb09f | 539 | |
d47cc544 | 540 | set_prev (rmost, new_f_occ); |
502b8322 | 541 | |
d47cc544 SB |
542 | if (new_f_occ->min + rmost->depth < rmost->min) |
543 | { | |
544 | rmost->min = new_f_occ->min + rmost->depth; | |
545 | rmost->min_occ = new_f_occ->min_occ; | |
546 | } | |
f1cfb09f | 547 | |
d47cc544 | 548 | t->parent_occ = new_f_occ; |
f1cfb09f | 549 | |
d47cc544 SB |
550 | /* Update the tree. */ |
551 | t->father = father; | |
552 | right = father->son; | |
553 | if (right) | |
554 | left = right->left; | |
555 | else | |
556 | left = right = t; | |
f1cfb09f | 557 | |
d47cc544 SB |
558 | left->right = t; |
559 | right->left = t; | |
560 | t->left = left; | |
561 | t->right = right; | |
f1cfb09f | 562 | |
d47cc544 | 563 | father->son = t; |
f1cfb09f | 564 | |
d47cc544 SB |
565 | #ifdef DEBUG_ET |
566 | et_check_tree_sanity (rmost); | |
567 | record_path_before (rmost); | |
568 | #endif | |
f1cfb09f JH |
569 | } |
570 | ||
d47cc544 SB |
571 | /* Splits the edge from T to its father. */ |
572 | ||
573 | void | |
574 | et_split (struct et_node *t) | |
f1cfb09f | 575 | { |
d47cc544 SB |
576 | struct et_node *father = t->father; |
577 | struct et_occ *r, *l, *rmost, *p_occ; | |
f1cfb09f | 578 | |
d47cc544 SB |
579 | /* Update the path represented by the splay tree. */ |
580 | rmost = t->rightmost_occ; | |
581 | et_splay (rmost); | |
f1cfb09f | 582 | |
d47cc544 SB |
583 | for (r = rmost->next; r->prev; r = r->prev) |
584 | continue; | |
b8698a0f | 585 | et_splay (r); |
f1cfb09f | 586 | |
d47cc544 SB |
587 | r->prev->parent = NULL; |
588 | p_occ = t->parent_occ; | |
589 | et_splay (p_occ); | |
590 | t->parent_occ = NULL; | |
f1cfb09f | 591 | |
d47cc544 SB |
592 | l = p_occ->prev; |
593 | p_occ->next->parent = NULL; | |
502b8322 | 594 | |
d47cc544 | 595 | set_prev (r, l); |
f1cfb09f | 596 | |
d47cc544 | 597 | et_recomp_min (r); |
f1cfb09f | 598 | |
d47cc544 SB |
599 | et_splay (rmost); |
600 | rmost->depth = 0; | |
601 | rmost->min = 0; | |
f1cfb09f | 602 | |
fb0b2914 | 603 | et_occurrences.remove (p_occ); |
f1cfb09f | 604 | |
d47cc544 SB |
605 | /* Update the tree. */ |
606 | if (father->son == t) | |
607 | father->son = t->right; | |
608 | if (father->son == t) | |
609 | father->son = NULL; | |
610 | else | |
f1cfb09f | 611 | { |
d47cc544 SB |
612 | t->left->right = t->right; |
613 | t->right->left = t->left; | |
614 | } | |
615 | t->left = t->right = NULL; | |
616 | t->father = NULL; | |
617 | ||
618 | #ifdef DEBUG_ET | |
619 | et_check_tree_sanity (rmost); | |
620 | record_path_before (rmost); | |
621 | ||
622 | et_check_tree_sanity (r); | |
623 | record_path_before (r); | |
624 | #endif | |
625 | } | |
626 | ||
627 | /* Finds the nearest common ancestor of the nodes N1 and N2. */ | |
628 | ||
629 | struct et_node * | |
630 | et_nca (struct et_node *n1, struct et_node *n2) | |
631 | { | |
632 | struct et_occ *o1 = n1->rightmost_occ, *o2 = n2->rightmost_occ, *om; | |
633 | struct et_occ *l, *r, *ret; | |
634 | int mn; | |
635 | ||
636 | if (n1 == n2) | |
637 | return n1; | |
638 | ||
639 | et_splay (o1); | |
640 | l = o1->prev; | |
641 | r = o1->next; | |
642 | if (l) | |
643 | l->parent = NULL; | |
644 | if (r) | |
645 | r->parent = NULL; | |
646 | et_splay (o2); | |
647 | ||
648 | if (l == o2 || (l && l->parent != NULL)) | |
649 | { | |
650 | ret = o2->next; | |
651 | ||
652 | set_prev (o1, o2); | |
653 | if (r) | |
654 | r->parent = o1; | |
f1cfb09f | 655 | } |
d2e60b7b | 656 | else if (r == o2 || (r && r->parent != NULL)) |
f1cfb09f | 657 | { |
d47cc544 SB |
658 | ret = o2->prev; |
659 | ||
660 | set_next (o1, o2); | |
661 | if (l) | |
662 | l->parent = o1; | |
f1cfb09f | 663 | } |
d2e60b7b ZD |
664 | else |
665 | { | |
666 | /* O1 and O2 are in different components of the forest. */ | |
667 | if (l) | |
668 | l->parent = o1; | |
669 | if (r) | |
670 | r->parent = o1; | |
671 | return NULL; | |
672 | } | |
502b8322 | 673 | |
01512446 | 674 | if (o2->depth > 0) |
f1cfb09f | 675 | { |
d47cc544 SB |
676 | om = o1; |
677 | mn = o1->depth; | |
678 | } | |
679 | else | |
680 | { | |
681 | om = o2; | |
682 | mn = o2->depth + o1->depth; | |
f1cfb09f JH |
683 | } |
684 | ||
d47cc544 SB |
685 | #ifdef DEBUG_ET |
686 | et_check_tree_sanity (o2); | |
687 | #endif | |
f1cfb09f | 688 | |
d47cc544 SB |
689 | if (ret && ret->min + o1->depth + o2->depth < mn) |
690 | return ret->min_occ->of; | |
691 | else | |
692 | return om->of; | |
f1cfb09f JH |
693 | } |
694 | ||
d47cc544 SB |
695 | /* Checks whether the node UP is an ancestor of the node DOWN. */ |
696 | ||
697 | bool | |
698 | et_below (struct et_node *down, struct et_node *up) | |
f1cfb09f | 699 | { |
d47cc544 SB |
700 | struct et_occ *u = up->rightmost_occ, *d = down->rightmost_occ; |
701 | struct et_occ *l, *r; | |
702 | ||
703 | if (up == down) | |
704 | return true; | |
705 | ||
706 | et_splay (u); | |
707 | l = u->prev; | |
708 | r = u->next; | |
709 | ||
710 | if (!l) | |
711 | return false; | |
712 | ||
713 | l->parent = NULL; | |
714 | ||
715 | if (r) | |
716 | r->parent = NULL; | |
f1cfb09f | 717 | |
d47cc544 SB |
718 | et_splay (d); |
719 | ||
720 | if (l == d || l->parent != NULL) | |
f1cfb09f | 721 | { |
d47cc544 SB |
722 | if (r) |
723 | r->parent = u; | |
724 | set_prev (u, d); | |
725 | #ifdef DEBUG_ET | |
726 | et_check_tree_sanity (u); | |
727 | #endif | |
f1cfb09f | 728 | } |
d47cc544 SB |
729 | else |
730 | { | |
731 | l->parent = u; | |
732 | ||
733 | /* In case O1 and O2 are in two different trees, we must just restore the | |
734 | original state. */ | |
735 | if (r && r->parent != NULL) | |
736 | set_next (u, d); | |
737 | else | |
738 | set_next (u, r); | |
739 | ||
740 | #ifdef DEBUG_ET | |
741 | et_check_tree_sanity (u); | |
742 | #endif | |
743 | return false; | |
744 | } | |
745 | ||
01512446 | 746 | if (d->depth <= 0) |
d47cc544 SB |
747 | return false; |
748 | ||
749 | return !d->next || d->next->min + d->depth >= 0; | |
f1cfb09f | 750 | } |
66f97d31 ZD |
751 | |
752 | /* Returns the root of the tree that contains NODE. */ | |
753 | ||
754 | struct et_node * | |
755 | et_root (struct et_node *node) | |
756 | { | |
757 | struct et_occ *occ = node->rightmost_occ, *r; | |
758 | ||
fa10beec | 759 | /* The root of the tree corresponds to the rightmost occurrence in the |
66f97d31 ZD |
760 | represented path. */ |
761 | et_splay (occ); | |
762 | for (r = occ; r->next; r = r->next) | |
763 | continue; | |
764 | et_splay (r); | |
765 | ||
766 | return r->of; | |
767 | } | |
d9b950dd DM |
768 | |
769 | #if CHECKING_P | |
770 | ||
771 | namespace selftest { | |
772 | ||
e53b6e56 | 773 | /* Selftests for et-forest.cc. */ |
d9b950dd DM |
774 | |
775 | /* Perform sanity checks for a tree consisting of a single node. */ | |
776 | ||
777 | static void | |
778 | test_single_node () | |
779 | { | |
780 | void *test_data = (void *)0xcafebabe; | |
781 | ||
782 | et_node *n = et_new_tree (test_data); | |
783 | ASSERT_EQ (n->data, test_data); | |
784 | ASSERT_EQ (n, et_root (n)); | |
785 | et_free_tree (n); | |
786 | } | |
787 | ||
788 | /* Test of this tree: | |
789 | a | |
790 | / \ | |
791 | / \ | |
792 | b c | |
793 | / \ | | |
794 | d e f. */ | |
795 | ||
796 | static void | |
797 | test_simple_tree () | |
798 | { | |
799 | et_node *a = et_new_tree (NULL); | |
800 | et_node *b = et_new_tree (NULL); | |
801 | et_node *c = et_new_tree (NULL); | |
802 | et_node *d = et_new_tree (NULL); | |
803 | et_node *e = et_new_tree (NULL); | |
804 | et_node *f = et_new_tree (NULL); | |
805 | ||
806 | et_set_father (b, a); | |
807 | et_set_father (c, a); | |
808 | et_set_father (d, b); | |
809 | et_set_father (e, b); | |
810 | et_set_father (f, c); | |
811 | ||
812 | ASSERT_TRUE (et_below (a, a)); | |
813 | ASSERT_TRUE (et_below (b, a)); | |
814 | ASSERT_TRUE (et_below (c, a)); | |
815 | ASSERT_TRUE (et_below (d, a)); | |
816 | ASSERT_TRUE (et_below (e, a)); | |
817 | ASSERT_TRUE (et_below (f, a)); | |
818 | ||
819 | ASSERT_FALSE (et_below (a, b)); | |
820 | ASSERT_TRUE (et_below (b, b)); | |
821 | ASSERT_FALSE (et_below (c, b)); | |
822 | ASSERT_TRUE (et_below (d, b)); | |
823 | ASSERT_TRUE (et_below (e, b)); | |
824 | ASSERT_FALSE (et_below (f, b)); | |
825 | ||
826 | ASSERT_FALSE (et_below (a, c)); | |
827 | ASSERT_FALSE (et_below (b, c)); | |
828 | ASSERT_TRUE (et_below (c, c)); | |
829 | ASSERT_FALSE (et_below (d, c)); | |
830 | ASSERT_FALSE (et_below (e, c)); | |
831 | ASSERT_TRUE (et_below (f, c)); | |
832 | ||
833 | ASSERT_FALSE (et_below (a, d)); | |
834 | ASSERT_FALSE (et_below (b, d)); | |
835 | ASSERT_FALSE (et_below (c, d)); | |
836 | ASSERT_TRUE (et_below (d, d)); | |
837 | ASSERT_FALSE (et_below (e, d)); | |
838 | ASSERT_FALSE (et_below (f, d)); | |
839 | ||
840 | ASSERT_FALSE (et_below (a, e)); | |
841 | ASSERT_FALSE (et_below (b, e)); | |
842 | ASSERT_FALSE (et_below (c, e)); | |
843 | ASSERT_FALSE (et_below (d, e)); | |
844 | ASSERT_TRUE (et_below (e, e)); | |
845 | ASSERT_FALSE (et_below (f, e)); | |
846 | ||
847 | ASSERT_FALSE (et_below (a, f)); | |
848 | ASSERT_FALSE (et_below (b, f)); | |
849 | ASSERT_FALSE (et_below (c, f)); | |
850 | ASSERT_FALSE (et_below (d, f)); | |
851 | ASSERT_FALSE (et_below (e, f)); | |
852 | ASSERT_TRUE (et_below (f, f)); | |
853 | ||
854 | et_free_tree_force (a); | |
855 | } | |
856 | ||
857 | /* Verify that two disconnected nodes are unrelated. */ | |
858 | ||
859 | static void | |
860 | test_disconnected_nodes () | |
861 | { | |
862 | et_node *a = et_new_tree (NULL); | |
863 | et_node *b = et_new_tree (NULL); | |
864 | ||
865 | ASSERT_FALSE (et_below (a, b)); | |
866 | ASSERT_FALSE (et_below (b, a)); | |
867 | ||
868 | et_free_tree (a); | |
869 | et_free_tree (b); | |
870 | } | |
871 | ||
872 | /* Run all of the selftests within this file. */ | |
873 | ||
874 | void | |
875 | et_forest_c_tests () | |
876 | { | |
877 | test_single_node (); | |
878 | test_simple_tree (); | |
879 | test_disconnected_nodes (); | |
880 | } | |
881 | ||
882 | } // namespace selftest | |
883 | ||
884 | #endif /* CHECKING_P */ |