Mercurial > hg > CbC > CbC_gcc
annotate gcc/et-forest.c @ 67:f6334be47118
update gcc from gcc-4.6-20100522 to gcc-4.6-20110318
| author | nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp> |
|---|---|
| date | Tue, 22 Mar 2011 17:18:12 +0900 |
| parents | 77e2b8dfacca |
| children | 04ced10e8804 |
| rev | line source |
|---|---|
| 0 | 1 /* ET-trees data structure implementation. |
| 2 Contributed by Pavel Nejedly | |
|
67
f6334be47118
update gcc from gcc-4.6-20100522 to gcc-4.6-20110318
nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
55
diff
changeset
|
3 Copyright (C) 2002, 2003, 2004, 2005, 2007, 2008, 2010 Free Software |
| 0 | 4 Foundation, Inc. |
| 5 | |
| 6 This file is part of the libiberty library. | |
| 7 Libiberty is free software; you can redistribute it and/or | |
| 8 modify it under the terms of the GNU Library General Public | |
| 9 License as published by the Free Software Foundation; either | |
| 10 version 3 of the License, or (at your option) any later version. | |
| 11 | |
| 12 Libiberty is distributed in the hope that it will be useful, | |
| 13 but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 15 Library General Public License for more details. | |
| 16 | |
| 17 You should have received a copy of the GNU Library General Public | |
| 18 License along with libiberty; see the file COPYING3. If not see | |
| 19 <http://www.gnu.org/licenses/>. | |
| 20 | |
| 21 The ET-forest structure is described in: | |
| 22 D. D. Sleator and R. E. Tarjan. A data structure for dynamic trees. | |
| 23 J. G'omput. System Sci., 26(3):362 381, 1983. | |
| 24 */ | |
| 25 | |
| 26 #include "config.h" | |
| 27 #include "system.h" | |
| 28 #include "coretypes.h" | |
| 29 #include "et-forest.h" | |
| 30 #include "alloc-pool.h" | |
| 31 | |
| 32 /* We do not enable this with ENABLE_CHECKING, since it is awfully slow. */ | |
| 33 #undef DEBUG_ET | |
| 34 | |
| 35 #ifdef DEBUG_ET | |
| 36 #include "basic-block.h" | |
| 37 #endif | |
| 38 | |
| 39 /* The occurrence of a node in the et tree. */ | |
| 40 struct et_occ | |
| 41 { | |
| 42 struct et_node *of; /* The node. */ | |
| 43 | |
| 44 struct et_occ *parent; /* Parent in the splay-tree. */ | |
| 45 struct et_occ *prev; /* Left son in the splay-tree. */ | |
| 46 struct et_occ *next; /* Right son in the splay-tree. */ | |
| 47 | |
| 48 int depth; /* The depth of the node is the sum of depth | |
| 49 fields on the path to the root. */ | |
| 50 int min; /* The minimum value of the depth in the subtree | |
| 51 is obtained by adding sum of depth fields | |
| 52 on the path to the root. */ | |
| 53 struct et_occ *min_occ; /* The occurrence in the subtree with the minimal | |
| 54 depth. */ | |
| 55 }; | |
| 56 | |
| 57 static alloc_pool et_nodes; | |
| 58 static alloc_pool et_occurrences; | |
| 59 | |
| 60 /* Changes depth of OCC to D. */ | |
| 61 | |
| 62 static inline void | |
| 63 set_depth (struct et_occ *occ, int d) | |
| 64 { | |
| 65 if (!occ) | |
| 66 return; | |
| 67 | |
| 68 occ->min += d - occ->depth; | |
| 69 occ->depth = d; | |
| 70 } | |
| 71 | |
| 72 /* Adds D to the depth of OCC. */ | |
| 73 | |
| 74 static inline void | |
| 75 set_depth_add (struct et_occ *occ, int d) | |
| 76 { | |
| 77 if (!occ) | |
| 78 return; | |
| 79 | |
| 80 occ->min += d; | |
| 81 occ->depth += d; | |
| 82 } | |
| 83 | |
| 84 /* Sets prev field of OCC to P. */ | |
| 85 | |
| 86 static inline void | |
| 87 set_prev (struct et_occ *occ, struct et_occ *t) | |
| 88 { | |
| 89 #ifdef DEBUG_ET | |
| 90 gcc_assert (occ != t); | |
| 91 #endif | |
| 92 | |
| 93 occ->prev = t; | |
| 94 if (t) | |
| 95 t->parent = occ; | |
| 96 } | |
| 97 | |
| 98 /* Sets next field of OCC to P. */ | |
| 99 | |
| 100 static inline void | |
| 101 set_next (struct et_occ *occ, struct et_occ *t) | |
| 102 { | |
| 103 #ifdef DEBUG_ET | |
| 104 gcc_assert (occ != t); | |
| 105 #endif | |
| 106 | |
| 107 occ->next = t; | |
| 108 if (t) | |
| 109 t->parent = occ; | |
| 110 } | |
| 111 | |
| 112 /* Recompute minimum for occurrence OCC. */ | |
| 113 | |
| 114 static inline void | |
| 115 et_recomp_min (struct et_occ *occ) | |
| 116 { | |
| 117 struct et_occ *mson = occ->prev; | |
| 118 | |
| 119 if (!mson | |
| 120 || (occ->next | |
| 121 && mson->min > occ->next->min)) | |
| 122 mson = occ->next; | |
| 123 | |
| 124 if (mson && mson->min < 0) | |
| 125 { | |
| 126 occ->min = mson->min + occ->depth; | |
| 127 occ->min_occ = mson->min_occ; | |
| 128 } | |
| 129 else | |
| 130 { | |
| 131 occ->min = occ->depth; | |
| 132 occ->min_occ = occ; | |
| 133 } | |
| 134 } | |
| 135 | |
| 136 #ifdef DEBUG_ET | |
| 137 /* Checks whether neighborhood of OCC seems sane. */ | |
| 138 | |
| 139 static void | |
| 140 et_check_occ_sanity (struct et_occ *occ) | |
| 141 { | |
| 142 if (!occ) | |
| 143 return; | |
| 144 | |
| 145 gcc_assert (occ->parent != occ); | |
| 146 gcc_assert (occ->prev != occ); | |
| 147 gcc_assert (occ->next != occ); | |
| 148 gcc_assert (!occ->next || occ->next != occ->prev); | |
| 149 | |
| 150 if (occ->next) | |
| 151 { | |
| 152 gcc_assert (occ->next != occ->parent); | |
| 153 gcc_assert (occ->next->parent == occ); | |
| 154 } | |
| 155 | |
| 156 if (occ->prev) | |
| 157 { | |
| 158 gcc_assert (occ->prev != occ->parent); | |
| 159 gcc_assert (occ->prev->parent == occ); | |
| 160 } | |
| 161 | |
| 162 gcc_assert (!occ->parent | |
| 163 || occ->parent->prev == occ | |
| 164 || occ->parent->next == occ); | |
| 165 } | |
| 166 | |
| 167 /* Checks whether tree rooted at OCC is sane. */ | |
| 168 | |
| 169 static void | |
| 170 et_check_sanity (struct et_occ *occ) | |
| 171 { | |
| 172 et_check_occ_sanity (occ); | |
| 173 if (occ->prev) | |
| 174 et_check_sanity (occ->prev); | |
| 175 if (occ->next) | |
| 176 et_check_sanity (occ->next); | |
| 177 } | |
| 178 | |
| 179 /* Checks whether tree containing OCC is sane. */ | |
| 180 | |
| 181 static void | |
| 182 et_check_tree_sanity (struct et_occ *occ) | |
| 183 { | |
| 184 while (occ->parent) | |
| 185 occ = occ->parent; | |
| 186 | |
| 187 et_check_sanity (occ); | |
| 188 } | |
| 189 | |
| 190 /* For recording the paths. */ | |
| 191 | |
| 192 /* An ad-hoc constant; if the function has more blocks, this won't work, | |
| 193 but since it is used for debugging only, it does not matter. */ | |
| 194 #define MAX_NODES 100000 | |
| 195 | |
| 196 static int len; | |
| 197 static void *datas[MAX_NODES]; | |
| 198 static int depths[MAX_NODES]; | |
| 199 | |
| 200 /* Records the path represented by OCC, with depth incremented by DEPTH. */ | |
| 201 | |
| 202 static int | |
| 203 record_path_before_1 (struct et_occ *occ, int depth) | |
| 204 { | |
| 205 int mn, m; | |
| 206 | |
| 207 depth += occ->depth; | |
| 208 mn = depth; | |
| 209 | |
| 210 if (occ->prev) | |
| 211 { | |
|
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77e2b8dfacca
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ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
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diff
changeset
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212 m = record_path_before_1 (occ->prev, depth); |
| 0 | 213 if (m < mn) |
| 214 mn = m; | |
| 215 } | |
| 216 | |
| 217 fprintf (stderr, "%d (%d); ", ((basic_block) occ->of->data)->index, depth); | |
| 218 | |
| 219 gcc_assert (len < MAX_NODES); | |
| 220 | |
| 221 depths[len] = depth; | |
| 222 datas[len] = occ->of; | |
| 223 len++; | |
| 224 | |
| 225 if (occ->next) | |
| 226 { | |
| 227 m = record_path_before_1 (occ->next, depth); | |
| 228 if (m < mn) | |
| 229 mn = m; | |
| 230 } | |
| 231 | |
| 232 gcc_assert (mn == occ->min + depth - occ->depth); | |
| 233 | |
| 234 return mn; | |
| 235 } | |
| 236 | |
| 237 /* Records the path represented by a tree containing OCC. */ | |
| 238 | |
| 239 static void | |
| 240 record_path_before (struct et_occ *occ) | |
| 241 { | |
| 242 while (occ->parent) | |
| 243 occ = occ->parent; | |
| 244 | |
| 245 len = 0; | |
| 246 record_path_before_1 (occ, 0); | |
| 247 fprintf (stderr, "\n"); | |
| 248 } | |
| 249 | |
| 250 /* Checks whether the path represented by OCC, with depth incremented by DEPTH, | |
| 251 was not changed since the last recording. */ | |
| 252 | |
| 253 static int | |
| 254 check_path_after_1 (struct et_occ *occ, int depth) | |
| 255 { | |
| 256 int mn, m; | |
| 257 | |
| 258 depth += occ->depth; | |
| 259 mn = depth; | |
| 260 | |
| 261 if (occ->next) | |
| 262 { | |
|
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263 m = check_path_after_1 (occ->next, depth); |
| 0 | 264 if (m < mn) |
| 265 mn = m; | |
| 266 } | |
| 267 | |
| 268 len--; | |
| 269 gcc_assert (depths[len] == depth && datas[len] == occ->of); | |
| 270 | |
| 271 if (occ->prev) | |
| 272 { | |
| 273 m = check_path_after_1 (occ->prev, depth); | |
| 274 if (m < mn) | |
| 275 mn = m; | |
| 276 } | |
| 277 | |
| 278 gcc_assert (mn == occ->min + depth - occ->depth); | |
| 279 | |
| 280 return mn; | |
| 281 } | |
| 282 | |
| 283 /* Checks whether the path represented by a tree containing OCC was | |
| 284 not changed since the last recording. */ | |
| 285 | |
| 286 static void | |
| 287 check_path_after (struct et_occ *occ) | |
| 288 { | |
| 289 while (occ->parent) | |
| 290 occ = occ->parent; | |
| 291 | |
| 292 check_path_after_1 (occ, 0); | |
| 293 gcc_assert (!len); | |
| 294 } | |
| 295 | |
| 296 #endif | |
| 297 | |
| 298 /* Splay the occurrence OCC to the root of the tree. */ | |
| 299 | |
| 300 static void | |
| 301 et_splay (struct et_occ *occ) | |
| 302 { | |
| 303 struct et_occ *f, *gf, *ggf; | |
| 304 int occ_depth, f_depth, gf_depth; | |
| 305 | |
| 306 #ifdef DEBUG_ET | |
| 307 record_path_before (occ); | |
| 308 et_check_tree_sanity (occ); | |
| 309 #endif | |
|
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310 |
| 0 | 311 while (occ->parent) |
| 312 { | |
| 313 occ_depth = occ->depth; | |
| 314 | |
| 315 f = occ->parent; | |
| 316 f_depth = f->depth; | |
| 317 | |
| 318 gf = f->parent; | |
| 319 | |
| 320 if (!gf) | |
| 321 { | |
| 322 set_depth_add (occ, f_depth); | |
| 323 occ->min_occ = f->min_occ; | |
| 324 occ->min = f->min; | |
| 325 | |
| 326 if (f->prev == occ) | |
| 327 { | |
| 328 /* zig */ | |
| 329 set_prev (f, occ->next); | |
| 330 set_next (occ, f); | |
| 331 set_depth_add (f->prev, occ_depth); | |
| 332 } | |
| 333 else | |
| 334 { | |
| 335 /* zag */ | |
| 336 set_next (f, occ->prev); | |
| 337 set_prev (occ, f); | |
| 338 set_depth_add (f->next, occ_depth); | |
| 339 } | |
| 340 set_depth (f, -occ_depth); | |
| 341 occ->parent = NULL; | |
| 342 | |
| 343 et_recomp_min (f); | |
| 344 #ifdef DEBUG_ET | |
| 345 et_check_tree_sanity (occ); | |
| 346 check_path_after (occ); | |
| 347 #endif | |
| 348 return; | |
| 349 } | |
| 350 | |
| 351 gf_depth = gf->depth; | |
| 352 | |
| 353 set_depth_add (occ, f_depth + gf_depth); | |
| 354 occ->min_occ = gf->min_occ; | |
| 355 occ->min = gf->min; | |
| 356 | |
| 357 ggf = gf->parent; | |
| 358 | |
| 359 if (gf->prev == f) | |
| 360 { | |
| 361 if (f->prev == occ) | |
| 362 { | |
| 363 /* zig zig */ | |
| 364 set_prev (gf, f->next); | |
| 365 set_prev (f, occ->next); | |
| 366 set_next (occ, f); | |
| 367 set_next (f, gf); | |
| 368 | |
| 369 set_depth (f, -occ_depth); | |
| 370 set_depth_add (f->prev, occ_depth); | |
| 371 set_depth (gf, -f_depth); | |
| 372 set_depth_add (gf->prev, f_depth); | |
| 373 } | |
| 374 else | |
| 375 { | |
| 376 /* zag zig */ | |
| 377 set_prev (gf, occ->next); | |
| 378 set_next (f, occ->prev); | |
| 379 set_prev (occ, f); | |
| 380 set_next (occ, gf); | |
| 381 | |
| 382 set_depth (f, -occ_depth); | |
| 383 set_depth_add (f->next, occ_depth); | |
| 384 set_depth (gf, -occ_depth - f_depth); | |
| 385 set_depth_add (gf->prev, occ_depth + f_depth); | |
| 386 } | |
| 387 } | |
| 388 else | |
| 389 { | |
| 390 if (f->prev == occ) | |
| 391 { | |
| 392 /* zig zag */ | |
| 393 set_next (gf, occ->prev); | |
| 394 set_prev (f, occ->next); | |
| 395 set_prev (occ, gf); | |
| 396 set_next (occ, f); | |
| 397 | |
| 398 set_depth (f, -occ_depth); | |
| 399 set_depth_add (f->prev, occ_depth); | |
| 400 set_depth (gf, -occ_depth - f_depth); | |
| 401 set_depth_add (gf->next, occ_depth + f_depth); | |
| 402 } | |
| 403 else | |
| 404 { | |
| 405 /* zag zag */ | |
| 406 set_next (gf, f->prev); | |
| 407 set_next (f, occ->prev); | |
| 408 set_prev (occ, f); | |
| 409 set_prev (f, gf); | |
| 410 | |
| 411 set_depth (f, -occ_depth); | |
| 412 set_depth_add (f->next, occ_depth); | |
| 413 set_depth (gf, -f_depth); | |
| 414 set_depth_add (gf->next, f_depth); | |
| 415 } | |
| 416 } | |
| 417 | |
| 418 occ->parent = ggf; | |
| 419 if (ggf) | |
| 420 { | |
| 421 if (ggf->prev == gf) | |
| 422 ggf->prev = occ; | |
| 423 else | |
| 424 ggf->next = occ; | |
| 425 } | |
| 426 | |
| 427 et_recomp_min (gf); | |
| 428 et_recomp_min (f); | |
| 429 #ifdef DEBUG_ET | |
| 430 et_check_tree_sanity (occ); | |
| 431 #endif | |
| 432 } | |
| 433 | |
| 434 #ifdef DEBUG_ET | |
| 435 et_check_sanity (occ); | |
| 436 check_path_after (occ); | |
| 437 #endif | |
| 438 } | |
| 439 | |
| 440 /* Create a new et tree occurrence of NODE. */ | |
| 441 | |
| 442 static struct et_occ * | |
| 443 et_new_occ (struct et_node *node) | |
| 444 { | |
| 445 struct et_occ *nw; | |
|
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77e2b8dfacca
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ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
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diff
changeset
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446 |
| 0 | 447 if (!et_occurrences) |
| 448 et_occurrences = create_alloc_pool ("et_occ pool", sizeof (struct et_occ), 300); | |
| 449 nw = (struct et_occ *) pool_alloc (et_occurrences); | |
| 450 | |
| 451 nw->of = node; | |
| 452 nw->parent = NULL; | |
| 453 nw->prev = NULL; | |
| 454 nw->next = NULL; | |
| 455 | |
| 456 nw->depth = 0; | |
| 457 nw->min_occ = nw; | |
| 458 nw->min = 0; | |
| 459 | |
| 460 return nw; | |
| 461 } | |
| 462 | |
| 463 /* Create a new et tree containing DATA. */ | |
| 464 | |
| 465 struct et_node * | |
| 466 et_new_tree (void *data) | |
| 467 { | |
| 468 struct et_node *nw; | |
|
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ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
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changeset
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469 |
| 0 | 470 if (!et_nodes) |
| 471 et_nodes = create_alloc_pool ("et_node pool", sizeof (struct et_node), 300); | |
| 472 nw = (struct et_node *) pool_alloc (et_nodes); | |
| 473 | |
| 474 nw->data = data; | |
| 475 nw->father = NULL; | |
| 476 nw->left = NULL; | |
| 477 nw->right = NULL; | |
| 478 nw->son = NULL; | |
| 479 | |
| 480 nw->rightmost_occ = et_new_occ (nw); | |
| 481 nw->parent_occ = NULL; | |
| 482 | |
| 483 return nw; | |
| 484 } | |
| 485 | |
| 486 /* Releases et tree T. */ | |
| 487 | |
| 488 void | |
| 489 et_free_tree (struct et_node *t) | |
| 490 { | |
| 491 while (t->son) | |
| 492 et_split (t->son); | |
| 493 | |
| 494 if (t->father) | |
| 495 et_split (t); | |
| 496 | |
| 497 pool_free (et_occurrences, t->rightmost_occ); | |
| 498 pool_free (et_nodes, t); | |
| 499 } | |
| 500 | |
| 501 /* Releases et tree T without maintaining other nodes. */ | |
| 502 | |
| 503 void | |
| 504 et_free_tree_force (struct et_node *t) | |
| 505 { | |
| 506 pool_free (et_occurrences, t->rightmost_occ); | |
| 507 if (t->parent_occ) | |
| 508 pool_free (et_occurrences, t->parent_occ); | |
| 509 pool_free (et_nodes, t); | |
| 510 } | |
| 511 | |
| 512 /* Release the alloc pools, if they are empty. */ | |
| 513 | |
| 514 void | |
| 515 et_free_pools (void) | |
| 516 { | |
| 517 free_alloc_pool_if_empty (&et_occurrences); | |
| 518 free_alloc_pool_if_empty (&et_nodes); | |
| 519 } | |
| 520 | |
| 521 /* Sets father of et tree T to FATHER. */ | |
| 522 | |
| 523 void | |
| 524 et_set_father (struct et_node *t, struct et_node *father) | |
| 525 { | |
| 526 struct et_node *left, *right; | |
| 527 struct et_occ *rmost, *left_part, *new_f_occ, *p; | |
| 528 | |
| 529 /* Update the path represented in the splay tree. */ | |
| 530 new_f_occ = et_new_occ (father); | |
| 531 | |
| 532 rmost = father->rightmost_occ; | |
| 533 et_splay (rmost); | |
| 534 | |
| 535 left_part = rmost->prev; | |
| 536 | |
| 537 p = t->rightmost_occ; | |
| 538 et_splay (p); | |
| 539 | |
| 540 set_prev (new_f_occ, left_part); | |
| 541 set_next (new_f_occ, p); | |
| 542 | |
| 543 p->depth++; | |
| 544 p->min++; | |
| 545 et_recomp_min (new_f_occ); | |
| 546 | |
| 547 set_prev (rmost, new_f_occ); | |
| 548 | |
| 549 if (new_f_occ->min + rmost->depth < rmost->min) | |
| 550 { | |
| 551 rmost->min = new_f_occ->min + rmost->depth; | |
| 552 rmost->min_occ = new_f_occ->min_occ; | |
| 553 } | |
| 554 | |
| 555 t->parent_occ = new_f_occ; | |
| 556 | |
| 557 /* Update the tree. */ | |
| 558 t->father = father; | |
| 559 right = father->son; | |
| 560 if (right) | |
| 561 left = right->left; | |
| 562 else | |
| 563 left = right = t; | |
| 564 | |
| 565 left->right = t; | |
| 566 right->left = t; | |
| 567 t->left = left; | |
| 568 t->right = right; | |
| 569 | |
| 570 father->son = t; | |
| 571 | |
| 572 #ifdef DEBUG_ET | |
| 573 et_check_tree_sanity (rmost); | |
| 574 record_path_before (rmost); | |
| 575 #endif | |
| 576 } | |
| 577 | |
| 578 /* Splits the edge from T to its father. */ | |
| 579 | |
| 580 void | |
| 581 et_split (struct et_node *t) | |
| 582 { | |
| 583 struct et_node *father = t->father; | |
| 584 struct et_occ *r, *l, *rmost, *p_occ; | |
| 585 | |
| 586 /* Update the path represented by the splay tree. */ | |
| 587 rmost = t->rightmost_occ; | |
| 588 et_splay (rmost); | |
| 589 | |
| 590 for (r = rmost->next; r->prev; r = r->prev) | |
| 591 continue; | |
|
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changeset
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592 et_splay (r); |
| 0 | 593 |
| 594 r->prev->parent = NULL; | |
| 595 p_occ = t->parent_occ; | |
| 596 et_splay (p_occ); | |
| 597 t->parent_occ = NULL; | |
| 598 | |
| 599 l = p_occ->prev; | |
| 600 p_occ->next->parent = NULL; | |
| 601 | |
| 602 set_prev (r, l); | |
| 603 | |
| 604 et_recomp_min (r); | |
| 605 | |
| 606 et_splay (rmost); | |
| 607 rmost->depth = 0; | |
| 608 rmost->min = 0; | |
| 609 | |
| 610 pool_free (et_occurrences, p_occ); | |
| 611 | |
| 612 /* Update the tree. */ | |
| 613 if (father->son == t) | |
| 614 father->son = t->right; | |
| 615 if (father->son == t) | |
| 616 father->son = NULL; | |
| 617 else | |
| 618 { | |
| 619 t->left->right = t->right; | |
| 620 t->right->left = t->left; | |
| 621 } | |
| 622 t->left = t->right = NULL; | |
| 623 t->father = NULL; | |
| 624 | |
| 625 #ifdef DEBUG_ET | |
| 626 et_check_tree_sanity (rmost); | |
| 627 record_path_before (rmost); | |
| 628 | |
| 629 et_check_tree_sanity (r); | |
| 630 record_path_before (r); | |
| 631 #endif | |
| 632 } | |
| 633 | |
| 634 /* Finds the nearest common ancestor of the nodes N1 and N2. */ | |
| 635 | |
| 636 struct et_node * | |
| 637 et_nca (struct et_node *n1, struct et_node *n2) | |
| 638 { | |
| 639 struct et_occ *o1 = n1->rightmost_occ, *o2 = n2->rightmost_occ, *om; | |
| 640 struct et_occ *l, *r, *ret; | |
| 641 int mn; | |
| 642 | |
| 643 if (n1 == n2) | |
| 644 return n1; | |
| 645 | |
| 646 et_splay (o1); | |
| 647 l = o1->prev; | |
| 648 r = o1->next; | |
| 649 if (l) | |
| 650 l->parent = NULL; | |
| 651 if (r) | |
| 652 r->parent = NULL; | |
| 653 et_splay (o2); | |
| 654 | |
| 655 if (l == o2 || (l && l->parent != NULL)) | |
| 656 { | |
| 657 ret = o2->next; | |
| 658 | |
| 659 set_prev (o1, o2); | |
| 660 if (r) | |
| 661 r->parent = o1; | |
| 662 } | |
|
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663 else if (r == o2 || (r && r->parent != NULL)) |
| 0 | 664 { |
| 665 ret = o2->prev; | |
| 666 | |
| 667 set_next (o1, o2); | |
| 668 if (l) | |
| 669 l->parent = o1; | |
| 670 } | |
|
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671 else |
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672 { |
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673 /* O1 and O2 are in different components of the forest. */ |
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674 if (l) |
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675 l->parent = o1; |
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676 if (r) |
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677 r->parent = o1; |
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678 return NULL; |
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679 } |
| 0 | 680 |
| 681 if (0 < o2->depth) | |
| 682 { | |
| 683 om = o1; | |
| 684 mn = o1->depth; | |
| 685 } | |
| 686 else | |
| 687 { | |
| 688 om = o2; | |
| 689 mn = o2->depth + o1->depth; | |
| 690 } | |
| 691 | |
| 692 #ifdef DEBUG_ET | |
| 693 et_check_tree_sanity (o2); | |
| 694 #endif | |
| 695 | |
| 696 if (ret && ret->min + o1->depth + o2->depth < mn) | |
| 697 return ret->min_occ->of; | |
| 698 else | |
| 699 return om->of; | |
| 700 } | |
| 701 | |
| 702 /* Checks whether the node UP is an ancestor of the node DOWN. */ | |
| 703 | |
| 704 bool | |
| 705 et_below (struct et_node *down, struct et_node *up) | |
| 706 { | |
| 707 struct et_occ *u = up->rightmost_occ, *d = down->rightmost_occ; | |
| 708 struct et_occ *l, *r; | |
| 709 | |
| 710 if (up == down) | |
| 711 return true; | |
| 712 | |
| 713 et_splay (u); | |
| 714 l = u->prev; | |
| 715 r = u->next; | |
| 716 | |
| 717 if (!l) | |
| 718 return false; | |
| 719 | |
| 720 l->parent = NULL; | |
| 721 | |
| 722 if (r) | |
| 723 r->parent = NULL; | |
| 724 | |
| 725 et_splay (d); | |
| 726 | |
| 727 if (l == d || l->parent != NULL) | |
| 728 { | |
| 729 if (r) | |
| 730 r->parent = u; | |
| 731 set_prev (u, d); | |
| 732 #ifdef DEBUG_ET | |
| 733 et_check_tree_sanity (u); | |
| 734 #endif | |
| 735 } | |
| 736 else | |
| 737 { | |
| 738 l->parent = u; | |
| 739 | |
| 740 /* In case O1 and O2 are in two different trees, we must just restore the | |
| 741 original state. */ | |
| 742 if (r && r->parent != NULL) | |
| 743 set_next (u, d); | |
| 744 else | |
| 745 set_next (u, r); | |
| 746 | |
| 747 #ifdef DEBUG_ET | |
| 748 et_check_tree_sanity (u); | |
| 749 #endif | |
| 750 return false; | |
| 751 } | |
| 752 | |
| 753 if (0 >= d->depth) | |
| 754 return false; | |
| 755 | |
| 756 return !d->next || d->next->min + d->depth >= 0; | |
| 757 } | |
| 758 | |
| 759 /* Returns the root of the tree that contains NODE. */ | |
| 760 | |
| 761 struct et_node * | |
| 762 et_root (struct et_node *node) | |
| 763 { | |
| 764 struct et_occ *occ = node->rightmost_occ, *r; | |
| 765 | |
| 766 /* The root of the tree corresponds to the rightmost occurrence in the | |
| 767 represented path. */ | |
| 768 et_splay (occ); | |
| 769 for (r = occ; r->next; r = r->next) | |
| 770 continue; | |
| 771 et_splay (r); | |
| 772 | |
| 773 return r->of; | |
| 774 } |