1 //===--- ImmutableSet.h - Immutable (functional) set interface --*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file defines the ImutAVLTree and ImmutableSet classes. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_ADT_IMMUTABLESET_H 15 #define LLVM_ADT_IMMUTABLESET_H 16 17 #include "llvm/ADT/DenseMap.h" 18 #include "llvm/ADT/FoldingSet.h" 19 #include "llvm/ADT/iterator.h" 20 #include "llvm/ADT/SmallVector.h" 21 #include "llvm/Support/Allocator.h" 22 #include "llvm/Support/ErrorHandling.h" 23 #include <cassert> 24 #include <functional> 25 #include <vector> 26 #include <cstdint> 27 #include <iterator> 28 #include <new> 29 30 namespace llvm { 31 32 //===----------------------------------------------------------------------===// 33 // Immutable AVL-Tree Definition. 34 //===----------------------------------------------------------------------===// 35 36 template <typename ImutInfo> class ImutAVLFactory; 37 template <typename ImutInfo> class ImutIntervalAVLFactory; 38 template <typename ImutInfo> class ImutAVLTreeInOrderIterator; 39 template <typename ImutInfo> class ImutAVLTreeGenericIterator; 40 41 template <typename ImutInfo > 42 class ImutAVLTree { 43 public: 44 typedef typename ImutInfo::key_type_ref key_type_ref; 45 typedef typename ImutInfo::value_type value_type; 46 typedef typename ImutInfo::value_type_ref value_type_ref; 47 48 typedef ImutAVLFactory<ImutInfo> Factory; 49 friend class ImutAVLFactory<ImutInfo>; 50 friend class ImutIntervalAVLFactory<ImutInfo>; 51 52 friend class ImutAVLTreeGenericIterator<ImutInfo>; 53 54 typedef ImutAVLTreeInOrderIterator<ImutInfo> iterator; 55 56 //===----------------------------------------------------===// 57 // Public Interface. 58 //===----------------------------------------------------===// 59 60 /// Return a pointer to the left subtree. This value 61 /// is NULL if there is no left subtree. 62 ImutAVLTree *getLeft() const { return left; } 63 64 /// Return a pointer to the right subtree. This value is 65 /// NULL if there is no right subtree. 66 ImutAVLTree *getRight() const { return right; } 67 68 /// getHeight - Returns the height of the tree. A tree with no subtrees 69 /// has a height of 1. 70 unsigned getHeight() const { return height; } 71 72 /// getValue - Returns the data value associated with the tree node. 73 const value_type& getValue() const { return value; } 74 75 /// find - Finds the subtree associated with the specified key value. 76 /// This method returns NULL if no matching subtree is found. 77 ImutAVLTree* find(key_type_ref K) { 78 ImutAVLTree *T = this; 79 while (T) { 80 key_type_ref CurrentKey = ImutInfo::KeyOfValue(T->getValue()); 81 if (ImutInfo::isEqual(K,CurrentKey)) 82 return T; 83 else if (ImutInfo::isLess(K,CurrentKey)) 84 T = T->getLeft(); 85 else 86 T = T->getRight(); 87 } 88 return nullptr; 89 } 90 91 /// getMaxElement - Find the subtree associated with the highest ranged 92 /// key value. 93 ImutAVLTree* getMaxElement() { 94 ImutAVLTree *T = this; 95 ImutAVLTree *Right = T->getRight(); 96 while (Right) { T = Right; Right = T->getRight(); } 97 return T; 98 } 99 100 /// size - Returns the number of nodes in the tree, which includes 101 /// both leaves and non-leaf nodes. 102 unsigned size() const { 103 unsigned n = 1; 104 if (const ImutAVLTree* L = getLeft()) 105 n += L->size(); 106 if (const ImutAVLTree* R = getRight()) 107 n += R->size(); 108 return n; 109 } 110 111 /// begin - Returns an iterator that iterates over the nodes of the tree 112 /// in an inorder traversal. The returned iterator thus refers to the 113 /// the tree node with the minimum data element. 114 iterator begin() const { return iterator(this); } 115 116 /// end - Returns an iterator for the tree that denotes the end of an 117 /// inorder traversal. 118 iterator end() const { return iterator(); } 119 120 bool isElementEqual(value_type_ref V) const { 121 // Compare the keys. 122 if (!ImutInfo::isEqual(ImutInfo::KeyOfValue(getValue()), 123 ImutInfo::KeyOfValue(V))) 124 return false; 125 126 // Also compare the data values. 127 if (!ImutInfo::isDataEqual(ImutInfo::DataOfValue(getValue()), 128 ImutInfo::DataOfValue(V))) 129 return false; 130 131 return true; 132 } 133 134 bool isElementEqual(const ImutAVLTree* RHS) const { 135 return isElementEqual(RHS->getValue()); 136 } 137 138 /// isEqual - Compares two trees for structural equality and returns true 139 /// if they are equal. This worst case performance of this operation is 140 // linear in the sizes of the trees. 141 bool isEqual(const ImutAVLTree& RHS) const { 142 if (&RHS == this) 143 return true; 144 145 iterator LItr = begin(), LEnd = end(); 146 iterator RItr = RHS.begin(), REnd = RHS.end(); 147 148 while (LItr != LEnd && RItr != REnd) { 149 if (&*LItr == &*RItr) { 150 LItr.skipSubTree(); 151 RItr.skipSubTree(); 152 continue; 153 } 154 155 if (!LItr->isElementEqual(&*RItr)) 156 return false; 157 158 ++LItr; 159 ++RItr; 160 } 161 162 return LItr == LEnd && RItr == REnd; 163 } 164 165 /// isNotEqual - Compares two trees for structural inequality. Performance 166 /// is the same is isEqual. 167 bool isNotEqual(const ImutAVLTree& RHS) const { return !isEqual(RHS); } 168 169 /// contains - Returns true if this tree contains a subtree (node) that 170 /// has an data element that matches the specified key. Complexity 171 /// is logarithmic in the size of the tree. 172 bool contains(key_type_ref K) { return (bool) find(K); } 173 174 /// foreach - A member template the accepts invokes operator() on a functor 175 /// object (specifed by Callback) for every node/subtree in the tree. 176 /// Nodes are visited using an inorder traversal. 177 template <typename Callback> 178 void foreach(Callback& C) { 179 if (ImutAVLTree* L = getLeft()) 180 L->foreach(C); 181 182 C(value); 183 184 if (ImutAVLTree* R = getRight()) 185 R->foreach(C); 186 } 187 188 /// validateTree - A utility method that checks that the balancing and 189 /// ordering invariants of the tree are satisifed. It is a recursive 190 /// method that returns the height of the tree, which is then consumed 191 /// by the enclosing validateTree call. External callers should ignore the 192 /// return value. An invalid tree will cause an assertion to fire in 193 /// a debug build. 194 unsigned validateTree() const { 195 unsigned HL = getLeft() ? getLeft()->validateTree() : 0; 196 unsigned HR = getRight() ? getRight()->validateTree() : 0; 197 (void) HL; 198 (void) HR; 199 200 assert(getHeight() == ( HL > HR ? HL : HR ) + 1 201 && "Height calculation wrong"); 202 203 assert((HL > HR ? HL-HR : HR-HL) <= 2 204 && "Balancing invariant violated"); 205 206 assert((!getLeft() || 207 ImutInfo::isLess(ImutInfo::KeyOfValue(getLeft()->getValue()), 208 ImutInfo::KeyOfValue(getValue()))) && 209 "Value in left child is not less that current value"); 210 211 212 assert(!(getRight() || 213 ImutInfo::isLess(ImutInfo::KeyOfValue(getValue()), 214 ImutInfo::KeyOfValue(getRight()->getValue()))) && 215 "Current value is not less that value of right child"); 216 217 return getHeight(); 218 } 219 220 //===----------------------------------------------------===// 221 // Internal values. 222 //===----------------------------------------------------===// 223 224 private: 225 Factory *factory; 226 ImutAVLTree *left; 227 ImutAVLTree *right; 228 ImutAVLTree *prev; 229 ImutAVLTree *next; 230 231 unsigned height : 28; 232 unsigned IsMutable : 1; 233 unsigned IsDigestCached : 1; 234 unsigned IsCanonicalized : 1; 235 236 value_type value; 237 uint32_t digest; 238 uint32_t refCount; 239 240 //===----------------------------------------------------===// 241 // Internal methods (node manipulation; used by Factory). 242 //===----------------------------------------------------===// 243 244 private: 245 /// ImutAVLTree - Internal constructor that is only called by 246 /// ImutAVLFactory. 247 ImutAVLTree(Factory *f, ImutAVLTree* l, ImutAVLTree* r, value_type_ref v, 248 unsigned height) 249 : factory(f), left(l), right(r), prev(nullptr), next(nullptr), 250 height(height), IsMutable(true), IsDigestCached(false), 251 IsCanonicalized(0), value(v), digest(0), refCount(0) 252 { 253 if (left) left->retain(); 254 if (right) right->retain(); 255 } 256 257 /// isMutable - Returns true if the left and right subtree references 258 /// (as well as height) can be changed. If this method returns false, 259 /// the tree is truly immutable. Trees returned from an ImutAVLFactory 260 /// object should always have this method return true. Further, if this 261 /// method returns false for an instance of ImutAVLTree, all subtrees 262 /// will also have this method return false. The converse is not true. 263 bool isMutable() const { return IsMutable; } 264 265 /// hasCachedDigest - Returns true if the digest for this tree is cached. 266 /// This can only be true if the tree is immutable. 267 bool hasCachedDigest() const { return IsDigestCached; } 268 269 //===----------------------------------------------------===// 270 // Mutating operations. A tree root can be manipulated as 271 // long as its reference has not "escaped" from internal 272 // methods of a factory object (see below). When a tree 273 // pointer is externally viewable by client code, the 274 // internal "mutable bit" is cleared to mark the tree 275 // immutable. Note that a tree that still has its mutable 276 // bit set may have children (subtrees) that are themselves 277 // immutable. 278 //===----------------------------------------------------===// 279 280 /// markImmutable - Clears the mutable flag for a tree. After this happens, 281 /// it is an error to call setLeft(), setRight(), and setHeight(). 282 void markImmutable() { 283 assert(isMutable() && "Mutable flag already removed."); 284 IsMutable = false; 285 } 286 287 /// markedCachedDigest - Clears the NoCachedDigest flag for a tree. 288 void markedCachedDigest() { 289 assert(!hasCachedDigest() && "NoCachedDigest flag already removed."); 290 IsDigestCached = true; 291 } 292 293 /// setHeight - Changes the height of the tree. Used internally by 294 /// ImutAVLFactory. 295 void setHeight(unsigned h) { 296 assert(isMutable() && "Only a mutable tree can have its height changed."); 297 height = h; 298 } 299 300 static uint32_t computeDigest(ImutAVLTree *L, ImutAVLTree *R, 301 value_type_ref V) { 302 uint32_t digest = 0; 303 304 if (L) 305 digest += L->computeDigest(); 306 307 // Compute digest of stored data. 308 FoldingSetNodeID ID; 309 ImutInfo::Profile(ID,V); 310 digest += ID.ComputeHash(); 311 312 if (R) 313 digest += R->computeDigest(); 314 315 return digest; 316 } 317 318 uint32_t computeDigest() { 319 // Check the lowest bit to determine if digest has actually been 320 // pre-computed. 321 if (hasCachedDigest()) 322 return digest; 323 324 uint32_t X = computeDigest(getLeft(), getRight(), getValue()); 325 digest = X; 326 markedCachedDigest(); 327 return X; 328 } 329 330 //===----------------------------------------------------===// 331 // Reference count operations. 332 //===----------------------------------------------------===// 333 334 public: 335 void retain() { ++refCount; } 336 337 void release() { 338 assert(refCount > 0); 339 if (--refCount == 0) 340 destroy(); 341 } 342 343 void destroy() { 344 if (left) 345 left->release(); 346 if (right) 347 right->release(); 348 if (IsCanonicalized) { 349 if (next) 350 next->prev = prev; 351 352 if (prev) 353 prev->next = next; 354 else 355 factory->Cache[factory->maskCacheIndex(computeDigest())] = next; 356 } 357 358 // We need to clear the mutability bit in case we are 359 // destroying the node as part of a sweep in ImutAVLFactory::recoverNodes(). 360 IsMutable = false; 361 factory->freeNodes.push_back(this); 362 } 363 }; 364 365 //===----------------------------------------------------------------------===// 366 // Immutable AVL-Tree Factory class. 367 //===----------------------------------------------------------------------===// 368 369 template <typename ImutInfo > 370 class ImutAVLFactory { 371 friend class ImutAVLTree<ImutInfo>; 372 typedef ImutAVLTree<ImutInfo> TreeTy; 373 typedef typename TreeTy::value_type_ref value_type_ref; 374 typedef typename TreeTy::key_type_ref key_type_ref; 375 376 typedef DenseMap<unsigned, TreeTy*> CacheTy; 377 378 CacheTy Cache; 379 uintptr_t Allocator; 380 std::vector<TreeTy*> createdNodes; 381 std::vector<TreeTy*> freeNodes; 382 383 bool ownsAllocator() const { 384 return (Allocator & 0x1) == 0; 385 } 386 387 BumpPtrAllocator& getAllocator() const { 388 return *reinterpret_cast<BumpPtrAllocator*>(Allocator & ~0x1); 389 } 390 391 //===--------------------------------------------------===// 392 // Public interface. 393 //===--------------------------------------------------===// 394 395 public: 396 ImutAVLFactory() 397 : Allocator(reinterpret_cast<uintptr_t>(new BumpPtrAllocator())) {} 398 399 ImutAVLFactory(BumpPtrAllocator& Alloc) 400 : Allocator(reinterpret_cast<uintptr_t>(&Alloc) | 0x1) {} 401 402 ~ImutAVLFactory() { 403 if (ownsAllocator()) delete &getAllocator(); 404 } 405 406 TreeTy* add(TreeTy* T, value_type_ref V) { 407 T = add_internal(V,T); 408 markImmutable(T); 409 recoverNodes(); 410 return T; 411 } 412 413 TreeTy* remove(TreeTy* T, key_type_ref V) { 414 T = remove_internal(V,T); 415 markImmutable(T); 416 recoverNodes(); 417 return T; 418 } 419 420 TreeTy* getEmptyTree() const { return nullptr; } 421 422 protected: 423 //===--------------------------------------------------===// 424 // A bunch of quick helper functions used for reasoning 425 // about the properties of trees and their children. 426 // These have succinct names so that the balancing code 427 // is as terse (and readable) as possible. 428 //===--------------------------------------------------===// 429 430 bool isEmpty(TreeTy* T) const { return !T; } 431 unsigned getHeight(TreeTy* T) const { return T ? T->getHeight() : 0; } 432 TreeTy* getLeft(TreeTy* T) const { return T->getLeft(); } 433 TreeTy* getRight(TreeTy* T) const { return T->getRight(); } 434 value_type_ref getValue(TreeTy* T) const { return T->value; } 435 436 // Make sure the index is not the Tombstone or Entry key of the DenseMap. 437 static unsigned maskCacheIndex(unsigned I) { return (I & ~0x02); } 438 439 unsigned incrementHeight(TreeTy* L, TreeTy* R) const { 440 unsigned hl = getHeight(L); 441 unsigned hr = getHeight(R); 442 return (hl > hr ? hl : hr) + 1; 443 } 444 445 static bool compareTreeWithSection(TreeTy* T, 446 typename TreeTy::iterator& TI, 447 typename TreeTy::iterator& TE) { 448 typename TreeTy::iterator I = T->begin(), E = T->end(); 449 for ( ; I!=E ; ++I, ++TI) { 450 if (TI == TE || !I->isElementEqual(&*TI)) 451 return false; 452 } 453 return true; 454 } 455 456 //===--------------------------------------------------===// 457 // "createNode" is used to generate new tree roots that link 458 // to other trees. The functon may also simply move links 459 // in an existing root if that root is still marked mutable. 460 // This is necessary because otherwise our balancing code 461 // would leak memory as it would create nodes that are 462 // then discarded later before the finished tree is 463 // returned to the caller. 464 //===--------------------------------------------------===// 465 466 TreeTy* createNode(TreeTy* L, value_type_ref V, TreeTy* R) { 467 BumpPtrAllocator& A = getAllocator(); 468 TreeTy* T; 469 if (!freeNodes.empty()) { 470 T = freeNodes.back(); 471 freeNodes.pop_back(); 472 assert(T != L); 473 assert(T != R); 474 } else { 475 T = (TreeTy*) A.Allocate<TreeTy>(); 476 } 477 new (T) TreeTy(this, L, R, V, incrementHeight(L,R)); 478 createdNodes.push_back(T); 479 return T; 480 } 481 482 TreeTy* createNode(TreeTy* newLeft, TreeTy* oldTree, TreeTy* newRight) { 483 return createNode(newLeft, getValue(oldTree), newRight); 484 } 485 486 void recoverNodes() { 487 for (unsigned i = 0, n = createdNodes.size(); i < n; ++i) { 488 TreeTy *N = createdNodes[i]; 489 if (N->isMutable() && N->refCount == 0) 490 N->destroy(); 491 } 492 createdNodes.clear(); 493 } 494 495 /// balanceTree - Used by add_internal and remove_internal to 496 /// balance a newly created tree. 497 TreeTy* balanceTree(TreeTy* L, value_type_ref V, TreeTy* R) { 498 unsigned hl = getHeight(L); 499 unsigned hr = getHeight(R); 500 501 if (hl > hr + 2) { 502 assert(!isEmpty(L) && "Left tree cannot be empty to have a height >= 2"); 503 504 TreeTy *LL = getLeft(L); 505 TreeTy *LR = getRight(L); 506 507 if (getHeight(LL) >= getHeight(LR)) 508 return createNode(LL, L, createNode(LR,V,R)); 509 510 assert(!isEmpty(LR) && "LR cannot be empty because it has a height >= 1"); 511 512 TreeTy *LRL = getLeft(LR); 513 TreeTy *LRR = getRight(LR); 514 515 return createNode(createNode(LL,L,LRL), LR, createNode(LRR,V,R)); 516 } 517 518 if (hr > hl + 2) { 519 assert(!isEmpty(R) && "Right tree cannot be empty to have a height >= 2"); 520 521 TreeTy *RL = getLeft(R); 522 TreeTy *RR = getRight(R); 523 524 if (getHeight(RR) >= getHeight(RL)) 525 return createNode(createNode(L,V,RL), R, RR); 526 527 assert(!isEmpty(RL) && "RL cannot be empty because it has a height >= 1"); 528 529 TreeTy *RLL = getLeft(RL); 530 TreeTy *RLR = getRight(RL); 531 532 return createNode(createNode(L,V,RLL), RL, createNode(RLR,R,RR)); 533 } 534 535 return createNode(L,V,R); 536 } 537 538 /// add_internal - Creates a new tree that includes the specified 539 /// data and the data from the original tree. If the original tree 540 /// already contained the data item, the original tree is returned. 541 TreeTy* add_internal(value_type_ref V, TreeTy* T) { 542 if (isEmpty(T)) 543 return createNode(T, V, T); 544 assert(!T->isMutable()); 545 546 key_type_ref K = ImutInfo::KeyOfValue(V); 547 key_type_ref KCurrent = ImutInfo::KeyOfValue(getValue(T)); 548 549 if (ImutInfo::isEqual(K,KCurrent)) 550 return createNode(getLeft(T), V, getRight(T)); 551 else if (ImutInfo::isLess(K,KCurrent)) 552 return balanceTree(add_internal(V, getLeft(T)), getValue(T), getRight(T)); 553 else 554 return balanceTree(getLeft(T), getValue(T), add_internal(V, getRight(T))); 555 } 556 557 /// remove_internal - Creates a new tree that includes all the data 558 /// from the original tree except the specified data. If the 559 /// specified data did not exist in the original tree, the original 560 /// tree is returned. 561 TreeTy* remove_internal(key_type_ref K, TreeTy* T) { 562 if (isEmpty(T)) 563 return T; 564 565 assert(!T->isMutable()); 566 567 key_type_ref KCurrent = ImutInfo::KeyOfValue(getValue(T)); 568 569 if (ImutInfo::isEqual(K,KCurrent)) { 570 return combineTrees(getLeft(T), getRight(T)); 571 } else if (ImutInfo::isLess(K,KCurrent)) { 572 return balanceTree(remove_internal(K, getLeft(T)), 573 getValue(T), getRight(T)); 574 } else { 575 return balanceTree(getLeft(T), getValue(T), 576 remove_internal(K, getRight(T))); 577 } 578 } 579 580 TreeTy* combineTrees(TreeTy* L, TreeTy* R) { 581 if (isEmpty(L)) 582 return R; 583 if (isEmpty(R)) 584 return L; 585 TreeTy* OldNode; 586 TreeTy* newRight = removeMinBinding(R,OldNode); 587 return balanceTree(L, getValue(OldNode), newRight); 588 } 589 590 TreeTy* removeMinBinding(TreeTy* T, TreeTy*& Noderemoved) { 591 assert(!isEmpty(T)); 592 if (isEmpty(getLeft(T))) { 593 Noderemoved = T; 594 return getRight(T); 595 } 596 return balanceTree(removeMinBinding(getLeft(T), Noderemoved), 597 getValue(T), getRight(T)); 598 } 599 600 /// markImmutable - Clears the mutable bits of a root and all of its 601 /// descendants. 602 void markImmutable(TreeTy* T) { 603 if (!T || !T->isMutable()) 604 return; 605 T->markImmutable(); 606 markImmutable(getLeft(T)); 607 markImmutable(getRight(T)); 608 } 609 610 public: 611 TreeTy *getCanonicalTree(TreeTy *TNew) { 612 if (!TNew) 613 return nullptr; 614 615 if (TNew->IsCanonicalized) 616 return TNew; 617 618 // Search the hashtable for another tree with the same digest, and 619 // if find a collision compare those trees by their contents. 620 unsigned digest = TNew->computeDigest(); 621 TreeTy *&entry = Cache[maskCacheIndex(digest)]; 622 do { 623 if (!entry) 624 break; 625 for (TreeTy *T = entry ; T != nullptr; T = T->next) { 626 // Compare the Contents('T') with Contents('TNew') 627 typename TreeTy::iterator TI = T->begin(), TE = T->end(); 628 if (!compareTreeWithSection(TNew, TI, TE)) 629 continue; 630 if (TI != TE) 631 continue; // T has more contents than TNew. 632 // Trees did match! Return 'T'. 633 if (TNew->refCount == 0) 634 TNew->destroy(); 635 return T; 636 } 637 entry->prev = TNew; 638 TNew->next = entry; 639 } 640 while (false); 641 642 entry = TNew; 643 TNew->IsCanonicalized = true; 644 return TNew; 645 } 646 }; 647 648 //===----------------------------------------------------------------------===// 649 // Immutable AVL-Tree Iterators. 650 //===----------------------------------------------------------------------===// 651 652 template <typename ImutInfo> 653 class ImutAVLTreeGenericIterator 654 : public std::iterator<std::bidirectional_iterator_tag, 655 ImutAVLTree<ImutInfo>> { 656 SmallVector<uintptr_t,20> stack; 657 658 public: 659 enum VisitFlag { VisitedNone=0x0, VisitedLeft=0x1, VisitedRight=0x3, 660 Flags=0x3 }; 661 662 typedef ImutAVLTree<ImutInfo> TreeTy; 663 664 ImutAVLTreeGenericIterator() = default; 665 ImutAVLTreeGenericIterator(const TreeTy *Root) { 666 if (Root) stack.push_back(reinterpret_cast<uintptr_t>(Root)); 667 } 668 669 TreeTy &operator*() const { 670 assert(!stack.empty()); 671 return *reinterpret_cast<TreeTy *>(stack.back() & ~Flags); 672 } 673 TreeTy *operator->() const { return &*this; } 674 675 uintptr_t getVisitState() const { 676 assert(!stack.empty()); 677 return stack.back() & Flags; 678 } 679 680 bool atEnd() const { return stack.empty(); } 681 682 bool atBeginning() const { 683 return stack.size() == 1 && getVisitState() == VisitedNone; 684 } 685 686 void skipToParent() { 687 assert(!stack.empty()); 688 stack.pop_back(); 689 if (stack.empty()) 690 return; 691 switch (getVisitState()) { 692 case VisitedNone: 693 stack.back() |= VisitedLeft; 694 break; 695 case VisitedLeft: 696 stack.back() |= VisitedRight; 697 break; 698 default: 699 llvm_unreachable("Unreachable."); 700 } 701 } 702 703 bool operator==(const ImutAVLTreeGenericIterator &x) const { 704 return stack == x.stack; 705 } 706 707 bool operator!=(const ImutAVLTreeGenericIterator &x) const { 708 return !(*this == x); 709 } 710 711 ImutAVLTreeGenericIterator &operator++() { 712 assert(!stack.empty()); 713 TreeTy* Current = reinterpret_cast<TreeTy*>(stack.back() & ~Flags); 714 assert(Current); 715 switch (getVisitState()) { 716 case VisitedNone: 717 if (TreeTy* L = Current->getLeft()) 718 stack.push_back(reinterpret_cast<uintptr_t>(L)); 719 else 720 stack.back() |= VisitedLeft; 721 break; 722 case VisitedLeft: 723 if (TreeTy* R = Current->getRight()) 724 stack.push_back(reinterpret_cast<uintptr_t>(R)); 725 else 726 stack.back() |= VisitedRight; 727 break; 728 case VisitedRight: 729 skipToParent(); 730 break; 731 default: 732 llvm_unreachable("Unreachable."); 733 } 734 return *this; 735 } 736 737 ImutAVLTreeGenericIterator &operator--() { 738 assert(!stack.empty()); 739 TreeTy* Current = reinterpret_cast<TreeTy*>(stack.back() & ~Flags); 740 assert(Current); 741 switch (getVisitState()) { 742 case VisitedNone: 743 stack.pop_back(); 744 break; 745 case VisitedLeft: 746 stack.back() &= ~Flags; // Set state to "VisitedNone." 747 if (TreeTy* L = Current->getLeft()) 748 stack.push_back(reinterpret_cast<uintptr_t>(L) | VisitedRight); 749 break; 750 case VisitedRight: 751 stack.back() &= ~Flags; 752 stack.back() |= VisitedLeft; 753 if (TreeTy* R = Current->getRight()) 754 stack.push_back(reinterpret_cast<uintptr_t>(R) | VisitedRight); 755 break; 756 default: 757 llvm_unreachable("Unreachable."); 758 } 759 return *this; 760 } 761 }; 762 763 template <typename ImutInfo> 764 class ImutAVLTreeInOrderIterator 765 : public std::iterator<std::bidirectional_iterator_tag, 766 ImutAVLTree<ImutInfo>> { 767 typedef ImutAVLTreeGenericIterator<ImutInfo> InternalIteratorTy; 768 InternalIteratorTy InternalItr; 769 770 public: 771 typedef ImutAVLTree<ImutInfo> TreeTy; 772 773 ImutAVLTreeInOrderIterator(const TreeTy* Root) : InternalItr(Root) { 774 if (Root) 775 ++*this; // Advance to first element. 776 } 777 778 ImutAVLTreeInOrderIterator() : InternalItr() {} 779 780 bool operator==(const ImutAVLTreeInOrderIterator &x) const { 781 return InternalItr == x.InternalItr; 782 } 783 784 bool operator!=(const ImutAVLTreeInOrderIterator &x) const { 785 return !(*this == x); 786 } 787 788 TreeTy &operator*() const { return *InternalItr; } 789 TreeTy *operator->() const { return &*InternalItr; } 790 791 ImutAVLTreeInOrderIterator &operator++() { 792 do ++InternalItr; 793 while (!InternalItr.atEnd() && 794 InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft); 795 796 return *this; 797 } 798 799 ImutAVLTreeInOrderIterator &operator--() { 800 do --InternalItr; 801 while (!InternalItr.atBeginning() && 802 InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft); 803 804 return *this; 805 } 806 807 void skipSubTree() { 808 InternalItr.skipToParent(); 809 810 while (!InternalItr.atEnd() && 811 InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft) 812 ++InternalItr; 813 } 814 }; 815 816 /// Generic iterator that wraps a T::TreeTy::iterator and exposes 817 /// iterator::getValue() on dereference. 818 template <typename T> 819 struct ImutAVLValueIterator 820 : iterator_adaptor_base< 821 ImutAVLValueIterator<T>, typename T::TreeTy::iterator, 822 typename std::iterator_traits< 823 typename T::TreeTy::iterator>::iterator_category, 824 const typename T::value_type> { 825 ImutAVLValueIterator() = default; 826 explicit ImutAVLValueIterator(typename T::TreeTy *Tree) 827 : ImutAVLValueIterator::iterator_adaptor_base(Tree) {} 828 829 typename ImutAVLValueIterator::reference operator*() const { 830 return this->I->getValue(); 831 } 832 }; 833 834 //===----------------------------------------------------------------------===// 835 // Trait classes for Profile information. 836 //===----------------------------------------------------------------------===// 837 838 /// Generic profile template. The default behavior is to invoke the 839 /// profile method of an object. Specializations for primitive integers 840 /// and generic handling of pointers is done below. 841 template <typename T> 842 struct ImutProfileInfo { 843 typedef const T value_type; 844 typedef const T& value_type_ref; 845 846 static void Profile(FoldingSetNodeID &ID, value_type_ref X) { 847 FoldingSetTrait<T>::Profile(X,ID); 848 } 849 }; 850 851 /// Profile traits for integers. 852 template <typename T> 853 struct ImutProfileInteger { 854 typedef const T value_type; 855 typedef const T& value_type_ref; 856 857 static void Profile(FoldingSetNodeID &ID, value_type_ref X) { 858 ID.AddInteger(X); 859 } 860 }; 861 862 #define PROFILE_INTEGER_INFO(X)\ 863 template<> struct ImutProfileInfo<X> : ImutProfileInteger<X> {}; 864 865 PROFILE_INTEGER_INFO(char) 866 PROFILE_INTEGER_INFO(unsigned char) 867 PROFILE_INTEGER_INFO(short) 868 PROFILE_INTEGER_INFO(unsigned short) 869 PROFILE_INTEGER_INFO(unsigned) 870 PROFILE_INTEGER_INFO(signed) 871 PROFILE_INTEGER_INFO(long) 872 PROFILE_INTEGER_INFO(unsigned long) 873 PROFILE_INTEGER_INFO(long long) 874 PROFILE_INTEGER_INFO(unsigned long long) 875 876 #undef PROFILE_INTEGER_INFO 877 878 /// Profile traits for booleans. 879 template <> 880 struct ImutProfileInfo<bool> { 881 typedef const bool value_type; 882 typedef const bool& value_type_ref; 883 884 static void Profile(FoldingSetNodeID &ID, value_type_ref X) { 885 ID.AddBoolean(X); 886 } 887 }; 888 889 /// Generic profile trait for pointer types. We treat pointers as 890 /// references to unique objects. 891 template <typename T> 892 struct ImutProfileInfo<T*> { 893 typedef const T* value_type; 894 typedef value_type value_type_ref; 895 896 static void Profile(FoldingSetNodeID &ID, value_type_ref X) { 897 ID.AddPointer(X); 898 } 899 }; 900 901 //===----------------------------------------------------------------------===// 902 // Trait classes that contain element comparison operators and type 903 // definitions used by ImutAVLTree, ImmutableSet, and ImmutableMap. These 904 // inherit from the profile traits (ImutProfileInfo) to include operations 905 // for element profiling. 906 //===----------------------------------------------------------------------===// 907 908 /// ImutContainerInfo - Generic definition of comparison operations for 909 /// elements of immutable containers that defaults to using 910 /// std::equal_to<> and std::less<> to perform comparison of elements. 911 template <typename T> 912 struct ImutContainerInfo : public ImutProfileInfo<T> { 913 typedef typename ImutProfileInfo<T>::value_type value_type; 914 typedef typename ImutProfileInfo<T>::value_type_ref value_type_ref; 915 typedef value_type key_type; 916 typedef value_type_ref key_type_ref; 917 typedef bool data_type; 918 typedef bool data_type_ref; 919 920 static key_type_ref KeyOfValue(value_type_ref D) { return D; } 921 static data_type_ref DataOfValue(value_type_ref) { return true; } 922 923 static bool isEqual(key_type_ref LHS, key_type_ref RHS) { 924 return std::equal_to<key_type>()(LHS,RHS); 925 } 926 927 static bool isLess(key_type_ref LHS, key_type_ref RHS) { 928 return std::less<key_type>()(LHS,RHS); 929 } 930 931 static bool isDataEqual(data_type_ref, data_type_ref) { return true; } 932 }; 933 934 /// ImutContainerInfo - Specialization for pointer values to treat pointers 935 /// as references to unique objects. Pointers are thus compared by 936 /// their addresses. 937 template <typename T> 938 struct ImutContainerInfo<T*> : public ImutProfileInfo<T*> { 939 typedef typename ImutProfileInfo<T*>::value_type value_type; 940 typedef typename ImutProfileInfo<T*>::value_type_ref value_type_ref; 941 typedef value_type key_type; 942 typedef value_type_ref key_type_ref; 943 typedef bool data_type; 944 typedef bool data_type_ref; 945 946 static key_type_ref KeyOfValue(value_type_ref D) { return D; } 947 static data_type_ref DataOfValue(value_type_ref) { return true; } 948 949 static bool isEqual(key_type_ref LHS, key_type_ref RHS) { return LHS == RHS; } 950 951 static bool isLess(key_type_ref LHS, key_type_ref RHS) { return LHS < RHS; } 952 953 static bool isDataEqual(data_type_ref, data_type_ref) { return true; } 954 }; 955 956 //===----------------------------------------------------------------------===// 957 // Immutable Set 958 //===----------------------------------------------------------------------===// 959 960 template <typename ValT, typename ValInfo = ImutContainerInfo<ValT>> 961 class ImmutableSet { 962 public: 963 typedef typename ValInfo::value_type value_type; 964 typedef typename ValInfo::value_type_ref value_type_ref; 965 typedef ImutAVLTree<ValInfo> TreeTy; 966 967 private: 968 TreeTy *Root; 969 970 public: 971 /// Constructs a set from a pointer to a tree root. In general one 972 /// should use a Factory object to create sets instead of directly 973 /// invoking the constructor, but there are cases where make this 974 /// constructor public is useful. 975 explicit ImmutableSet(TreeTy* R) : Root(R) { 976 if (Root) { Root->retain(); } 977 } 978 979 ImmutableSet(const ImmutableSet &X) : Root(X.Root) { 980 if (Root) { Root->retain(); } 981 } 982 983 ImmutableSet &operator=(const ImmutableSet &X) { 984 if (Root != X.Root) { 985 if (X.Root) { X.Root->retain(); } 986 if (Root) { Root->release(); } 987 Root = X.Root; 988 } 989 return *this; 990 } 991 992 ~ImmutableSet() { 993 if (Root) { Root->release(); } 994 } 995 996 class Factory { 997 typename TreeTy::Factory F; 998 const bool Canonicalize; 999 1000 public: 1001 Factory(bool canonicalize = true) 1002 : Canonicalize(canonicalize) {} 1003 1004 Factory(BumpPtrAllocator& Alloc, bool canonicalize = true) 1005 : F(Alloc), Canonicalize(canonicalize) {} 1006 1007 Factory(const Factory& RHS) = delete; 1008 void operator=(const Factory& RHS) = delete; 1009 1010 /// getEmptySet - Returns an immutable set that contains no elements. 1011 ImmutableSet getEmptySet() { 1012 return ImmutableSet(F.getEmptyTree()); 1013 } 1014 1015 /// add - Creates a new immutable set that contains all of the values 1016 /// of the original set with the addition of the specified value. If 1017 /// the original set already included the value, then the original set is 1018 /// returned and no memory is allocated. The time and space complexity 1019 /// of this operation is logarithmic in the size of the original set. 1020 /// The memory allocated to represent the set is released when the 1021 /// factory object that created the set is destroyed. 1022 ImmutableSet add(ImmutableSet Old, value_type_ref V) { 1023 TreeTy *NewT = F.add(Old.Root, V); 1024 return ImmutableSet(Canonicalize ? F.getCanonicalTree(NewT) : NewT); 1025 } 1026 1027 /// remove - Creates a new immutable set that contains all of the values 1028 /// of the original set with the exception of the specified value. If 1029 /// the original set did not contain the value, the original set is 1030 /// returned and no memory is allocated. The time and space complexity 1031 /// of this operation is logarithmic in the size of the original set. 1032 /// The memory allocated to represent the set is released when the 1033 /// factory object that created the set is destroyed. 1034 ImmutableSet remove(ImmutableSet Old, value_type_ref V) { 1035 TreeTy *NewT = F.remove(Old.Root, V); 1036 return ImmutableSet(Canonicalize ? F.getCanonicalTree(NewT) : NewT); 1037 } 1038 1039 BumpPtrAllocator& getAllocator() { return F.getAllocator(); } 1040 1041 typename TreeTy::Factory *getTreeFactory() const { 1042 return const_cast<typename TreeTy::Factory *>(&F); 1043 } 1044 }; 1045 1046 friend class Factory; 1047 1048 /// Returns true if the set contains the specified value. 1049 bool contains(value_type_ref V) const { 1050 return Root ? Root->contains(V) : false; 1051 } 1052 1053 bool operator==(const ImmutableSet &RHS) const { 1054 return Root && RHS.Root ? Root->isEqual(*RHS.Root) : Root == RHS.Root; 1055 } 1056 1057 bool operator!=(const ImmutableSet &RHS) const { 1058 return Root && RHS.Root ? Root->isNotEqual(*RHS.Root) : Root != RHS.Root; 1059 } 1060 1061 TreeTy *getRoot() { 1062 if (Root) { Root->retain(); } 1063 return Root; 1064 } 1065 1066 TreeTy *getRootWithoutRetain() const { 1067 return Root; 1068 } 1069 1070 /// isEmpty - Return true if the set contains no elements. 1071 bool isEmpty() const { return !Root; } 1072 1073 /// isSingleton - Return true if the set contains exactly one element. 1074 /// This method runs in constant time. 1075 bool isSingleton() const { return getHeight() == 1; } 1076 1077 template <typename Callback> 1078 void foreach(Callback& C) { if (Root) Root->foreach(C); } 1079 1080 template <typename Callback> 1081 void foreach() { if (Root) { Callback C; Root->foreach(C); } } 1082 1083 //===--------------------------------------------------===// 1084 // Iterators. 1085 //===--------------------------------------------------===// 1086 1087 typedef ImutAVLValueIterator<ImmutableSet> iterator; 1088 1089 iterator begin() const { return iterator(Root); } 1090 iterator end() const { return iterator(); } 1091 1092 //===--------------------------------------------------===// 1093 // Utility methods. 1094 //===--------------------------------------------------===// 1095 1096 unsigned getHeight() const { return Root ? Root->getHeight() : 0; } 1097 1098 static void Profile(FoldingSetNodeID &ID, const ImmutableSet &S) { 1099 ID.AddPointer(S.Root); 1100 } 1101 1102 void Profile(FoldingSetNodeID &ID) const { return Profile(ID, *this); } 1103 1104 //===--------------------------------------------------===// 1105 // For testing. 1106 //===--------------------------------------------------===// 1107 1108 void validateTree() const { if (Root) Root->validateTree(); } 1109 }; 1110 1111 // NOTE: This may some day replace the current ImmutableSet. 1112 template <typename ValT, typename ValInfo = ImutContainerInfo<ValT>> 1113 class ImmutableSetRef { 1114 public: 1115 typedef typename ValInfo::value_type value_type; 1116 typedef typename ValInfo::value_type_ref value_type_ref; 1117 typedef ImutAVLTree<ValInfo> TreeTy; 1118 typedef typename TreeTy::Factory FactoryTy; 1119 1120 private: 1121 TreeTy *Root; 1122 FactoryTy *Factory; 1123 1124 public: 1125 /// Constructs a set from a pointer to a tree root. In general one 1126 /// should use a Factory object to create sets instead of directly 1127 /// invoking the constructor, but there are cases where make this 1128 /// constructor public is useful. 1129 explicit ImmutableSetRef(TreeTy* R, FactoryTy *F) 1130 : Root(R), 1131 Factory(F) { 1132 if (Root) { Root->retain(); } 1133 } 1134 1135 ImmutableSetRef(const ImmutableSetRef &X) 1136 : Root(X.Root), 1137 Factory(X.Factory) { 1138 if (Root) { Root->retain(); } 1139 } 1140 1141 ImmutableSetRef &operator=(const ImmutableSetRef &X) { 1142 if (Root != X.Root) { 1143 if (X.Root) { X.Root->retain(); } 1144 if (Root) { Root->release(); } 1145 Root = X.Root; 1146 Factory = X.Factory; 1147 } 1148 return *this; 1149 } 1150 ~ImmutableSetRef() { 1151 if (Root) { Root->release(); } 1152 } 1153 1154 static ImmutableSetRef getEmptySet(FactoryTy *F) { 1155 return ImmutableSetRef(0, F); 1156 } 1157 1158 ImmutableSetRef add(value_type_ref V) { 1159 return ImmutableSetRef(Factory->add(Root, V), Factory); 1160 } 1161 1162 ImmutableSetRef remove(value_type_ref V) { 1163 return ImmutableSetRef(Factory->remove(Root, V), Factory); 1164 } 1165 1166 /// Returns true if the set contains the specified value. 1167 bool contains(value_type_ref V) const { 1168 return Root ? Root->contains(V) : false; 1169 } 1170 1171 ImmutableSet<ValT> asImmutableSet(bool canonicalize = true) const { 1172 return ImmutableSet<ValT>(canonicalize ? 1173 Factory->getCanonicalTree(Root) : Root); 1174 } 1175 1176 TreeTy *getRootWithoutRetain() const { 1177 return Root; 1178 } 1179 1180 bool operator==(const ImmutableSetRef &RHS) const { 1181 return Root && RHS.Root ? Root->isEqual(*RHS.Root) : Root == RHS.Root; 1182 } 1183 1184 bool operator!=(const ImmutableSetRef &RHS) const { 1185 return Root && RHS.Root ? Root->isNotEqual(*RHS.Root) : Root != RHS.Root; 1186 } 1187 1188 /// isEmpty - Return true if the set contains no elements. 1189 bool isEmpty() const { return !Root; } 1190 1191 /// isSingleton - Return true if the set contains exactly one element. 1192 /// This method runs in constant time. 1193 bool isSingleton() const { return getHeight() == 1; } 1194 1195 //===--------------------------------------------------===// 1196 // Iterators. 1197 //===--------------------------------------------------===// 1198 1199 typedef ImutAVLValueIterator<ImmutableSetRef> iterator; 1200 1201 iterator begin() const { return iterator(Root); } 1202 iterator end() const { return iterator(); } 1203 1204 //===--------------------------------------------------===// 1205 // Utility methods. 1206 //===--------------------------------------------------===// 1207 1208 unsigned getHeight() const { return Root ? Root->getHeight() : 0; } 1209 1210 static void Profile(FoldingSetNodeID &ID, const ImmutableSetRef &S) { 1211 ID.AddPointer(S.Root); 1212 } 1213 1214 void Profile(FoldingSetNodeID &ID) const { return Profile(ID, *this); } 1215 1216 //===--------------------------------------------------===// 1217 // For testing. 1218 //===--------------------------------------------------===// 1219 1220 void validateTree() const { if (Root) Root->validateTree(); } 1221 }; 1222 1223 } // end namespace llvm 1224 1225 #endif // LLVM_ADT_IMMUTABLESET_H 1226