ImmutableSet.h revision 263508
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/Support/Allocator.h" 20#include "llvm/Support/DataTypes.h" 21#include "llvm/Support/ErrorHandling.h" 22#include <cassert> 23#include <functional> 24#include <vector> 25 26namespace llvm { 27 28//===----------------------------------------------------------------------===// 29// Immutable AVL-Tree Definition. 30//===----------------------------------------------------------------------===// 31 32template <typename ImutInfo> class ImutAVLFactory; 33template <typename ImutInfo> class ImutIntervalAVLFactory; 34template <typename ImutInfo> class ImutAVLTreeInOrderIterator; 35template <typename ImutInfo> class ImutAVLTreeGenericIterator; 36 37template <typename ImutInfo > 38class ImutAVLTree { 39public: 40 typedef typename ImutInfo::key_type_ref key_type_ref; 41 typedef typename ImutInfo::value_type value_type; 42 typedef typename ImutInfo::value_type_ref value_type_ref; 43 44 typedef ImutAVLFactory<ImutInfo> Factory; 45 friend class ImutAVLFactory<ImutInfo>; 46 friend class ImutIntervalAVLFactory<ImutInfo>; 47 48 friend class ImutAVLTreeGenericIterator<ImutInfo>; 49 50 typedef ImutAVLTreeInOrderIterator<ImutInfo> iterator; 51 52 //===----------------------------------------------------===// 53 // Public Interface. 54 //===----------------------------------------------------===// 55 56 /// Return a pointer to the left subtree. This value 57 /// is NULL if there is no left subtree. 58 ImutAVLTree *getLeft() const { return left; } 59 60 /// Return a pointer to the right subtree. This value is 61 /// NULL if there is no right subtree. 62 ImutAVLTree *getRight() const { return right; } 63 64 /// getHeight - Returns the height of the tree. A tree with no subtrees 65 /// has a height of 1. 66 unsigned getHeight() const { return height; } 67 68 /// getValue - Returns the data value associated with the tree node. 69 const value_type& getValue() const { return value; } 70 71 /// find - Finds the subtree associated with the specified key value. 72 /// This method returns NULL if no matching subtree is found. 73 ImutAVLTree* find(key_type_ref K) { 74 ImutAVLTree *T = this; 75 while (T) { 76 key_type_ref CurrentKey = ImutInfo::KeyOfValue(T->getValue()); 77 if (ImutInfo::isEqual(K,CurrentKey)) 78 return T; 79 else if (ImutInfo::isLess(K,CurrentKey)) 80 T = T->getLeft(); 81 else 82 T = T->getRight(); 83 } 84 return NULL; 85 } 86 87 /// getMaxElement - Find the subtree associated with the highest ranged 88 /// key value. 89 ImutAVLTree* getMaxElement() { 90 ImutAVLTree *T = this; 91 ImutAVLTree *Right = T->getRight(); 92 while (Right) { T = Right; Right = T->getRight(); } 93 return T; 94 } 95 96 /// size - Returns the number of nodes in the tree, which includes 97 /// both leaves and non-leaf nodes. 98 unsigned size() const { 99 unsigned n = 1; 100 if (const ImutAVLTree* L = getLeft()) 101 n += L->size(); 102 if (const ImutAVLTree* R = getRight()) 103 n += R->size(); 104 return n; 105 } 106 107 /// begin - Returns an iterator that iterates over the nodes of the tree 108 /// in an inorder traversal. The returned iterator thus refers to the 109 /// the tree node with the minimum data element. 110 iterator begin() const { return iterator(this); } 111 112 /// end - Returns an iterator for the tree that denotes the end of an 113 /// inorder traversal. 114 iterator end() const { return iterator(); } 115 116 bool isElementEqual(value_type_ref V) const { 117 // Compare the keys. 118 if (!ImutInfo::isEqual(ImutInfo::KeyOfValue(getValue()), 119 ImutInfo::KeyOfValue(V))) 120 return false; 121 122 // Also compare the data values. 123 if (!ImutInfo::isDataEqual(ImutInfo::DataOfValue(getValue()), 124 ImutInfo::DataOfValue(V))) 125 return false; 126 127 return true; 128 } 129 130 bool isElementEqual(const ImutAVLTree* RHS) const { 131 return isElementEqual(RHS->getValue()); 132 } 133 134 /// isEqual - Compares two trees for structural equality and returns true 135 /// if they are equal. This worst case performance of this operation is 136 // linear in the sizes of the trees. 137 bool isEqual(const ImutAVLTree& RHS) const { 138 if (&RHS == this) 139 return true; 140 141 iterator LItr = begin(), LEnd = end(); 142 iterator RItr = RHS.begin(), REnd = RHS.end(); 143 144 while (LItr != LEnd && RItr != REnd) { 145 if (*LItr == *RItr) { 146 LItr.skipSubTree(); 147 RItr.skipSubTree(); 148 continue; 149 } 150 151 if (!LItr->isElementEqual(*RItr)) 152 return false; 153 154 ++LItr; 155 ++RItr; 156 } 157 158 return LItr == LEnd && RItr == REnd; 159 } 160 161 /// isNotEqual - Compares two trees for structural inequality. Performance 162 /// is the same is isEqual. 163 bool isNotEqual(const ImutAVLTree& RHS) const { return !isEqual(RHS); } 164 165 /// contains - Returns true if this tree contains a subtree (node) that 166 /// has an data element that matches the specified key. Complexity 167 /// is logarithmic in the size of the tree. 168 bool contains(key_type_ref K) { return (bool) find(K); } 169 170 /// foreach - A member template the accepts invokes operator() on a functor 171 /// object (specifed by Callback) for every node/subtree in the tree. 172 /// Nodes are visited using an inorder traversal. 173 template <typename Callback> 174 void foreach(Callback& C) { 175 if (ImutAVLTree* L = getLeft()) 176 L->foreach(C); 177 178 C(value); 179 180 if (ImutAVLTree* R = getRight()) 181 R->foreach(C); 182 } 183 184 /// validateTree - A utility method that checks that the balancing and 185 /// ordering invariants of the tree are satisifed. It is a recursive 186 /// method that returns the height of the tree, which is then consumed 187 /// by the enclosing validateTree call. External callers should ignore the 188 /// return value. An invalid tree will cause an assertion to fire in 189 /// a debug build. 190 unsigned validateTree() const { 191 unsigned HL = getLeft() ? getLeft()->validateTree() : 0; 192 unsigned HR = getRight() ? getRight()->validateTree() : 0; 193 (void) HL; 194 (void) HR; 195 196 assert(getHeight() == ( HL > HR ? HL : HR ) + 1 197 && "Height calculation wrong"); 198 199 assert((HL > HR ? HL-HR : HR-HL) <= 2 200 && "Balancing invariant violated"); 201 202 assert((!getLeft() || 203 ImutInfo::isLess(ImutInfo::KeyOfValue(getLeft()->getValue()), 204 ImutInfo::KeyOfValue(getValue()))) && 205 "Value in left child is not less that current value"); 206 207 208 assert(!(getRight() || 209 ImutInfo::isLess(ImutInfo::KeyOfValue(getValue()), 210 ImutInfo::KeyOfValue(getRight()->getValue()))) && 211 "Current value is not less that value of right child"); 212 213 return getHeight(); 214 } 215 216 //===----------------------------------------------------===// 217 // Internal values. 218 //===----------------------------------------------------===// 219 220private: 221 Factory *factory; 222 ImutAVLTree *left; 223 ImutAVLTree *right; 224 ImutAVLTree *prev; 225 ImutAVLTree *next; 226 227 unsigned height : 28; 228 unsigned IsMutable : 1; 229 unsigned IsDigestCached : 1; 230 unsigned IsCanonicalized : 1; 231 232 value_type value; 233 uint32_t digest; 234 uint32_t refCount; 235 236 //===----------------------------------------------------===// 237 // Internal methods (node manipulation; used by Factory). 238 //===----------------------------------------------------===// 239 240private: 241 /// ImutAVLTree - Internal constructor that is only called by 242 /// ImutAVLFactory. 243 ImutAVLTree(Factory *f, ImutAVLTree* l, ImutAVLTree* r, value_type_ref v, 244 unsigned height) 245 : factory(f), left(l), right(r), prev(0), next(0), height(height), 246 IsMutable(true), IsDigestCached(false), IsCanonicalized(0), 247 value(v), digest(0), refCount(0) 248 { 249 if (left) left->retain(); 250 if (right) right->retain(); 251 } 252 253 /// isMutable - Returns true if the left and right subtree references 254 /// (as well as height) can be changed. If this method returns false, 255 /// the tree is truly immutable. Trees returned from an ImutAVLFactory 256 /// object should always have this method return true. Further, if this 257 /// method returns false for an instance of ImutAVLTree, all subtrees 258 /// will also have this method return false. The converse is not true. 259 bool isMutable() const { return IsMutable; } 260 261 /// hasCachedDigest - Returns true if the digest for this tree is cached. 262 /// This can only be true if the tree is immutable. 263 bool hasCachedDigest() const { return IsDigestCached; } 264 265 //===----------------------------------------------------===// 266 // Mutating operations. A tree root can be manipulated as 267 // long as its reference has not "escaped" from internal 268 // methods of a factory object (see below). When a tree 269 // pointer is externally viewable by client code, the 270 // internal "mutable bit" is cleared to mark the tree 271 // immutable. Note that a tree that still has its mutable 272 // bit set may have children (subtrees) that are themselves 273 // immutable. 274 //===----------------------------------------------------===// 275 276 /// markImmutable - Clears the mutable flag for a tree. After this happens, 277 /// it is an error to call setLeft(), setRight(), and setHeight(). 278 void markImmutable() { 279 assert(isMutable() && "Mutable flag already removed."); 280 IsMutable = false; 281 } 282 283 /// markedCachedDigest - Clears the NoCachedDigest flag for a tree. 284 void markedCachedDigest() { 285 assert(!hasCachedDigest() && "NoCachedDigest flag already removed."); 286 IsDigestCached = true; 287 } 288 289 /// setHeight - Changes the height of the tree. Used internally by 290 /// ImutAVLFactory. 291 void setHeight(unsigned h) { 292 assert(isMutable() && "Only a mutable tree can have its height changed."); 293 height = h; 294 } 295 296 static inline 297 uint32_t computeDigest(ImutAVLTree* L, ImutAVLTree* R, value_type_ref V) { 298 uint32_t digest = 0; 299 300 if (L) 301 digest += L->computeDigest(); 302 303 // Compute digest of stored data. 304 FoldingSetNodeID ID; 305 ImutInfo::Profile(ID,V); 306 digest += ID.ComputeHash(); 307 308 if (R) 309 digest += R->computeDigest(); 310 311 return digest; 312 } 313 314 inline uint32_t computeDigest() { 315 // Check the lowest bit to determine if digest has actually been 316 // pre-computed. 317 if (hasCachedDigest()) 318 return digest; 319 320 uint32_t X = computeDigest(getLeft(), getRight(), getValue()); 321 digest = X; 322 markedCachedDigest(); 323 return X; 324 } 325 326 //===----------------------------------------------------===// 327 // Reference count operations. 328 //===----------------------------------------------------===// 329 330public: 331 void retain() { ++refCount; } 332 void release() { 333 assert(refCount > 0); 334 if (--refCount == 0) 335 destroy(); 336 } 337 void destroy() { 338 if (left) 339 left->release(); 340 if (right) 341 right->release(); 342 if (IsCanonicalized) { 343 if (next) 344 next->prev = prev; 345 346 if (prev) 347 prev->next = next; 348 else 349 factory->Cache[factory->maskCacheIndex(computeDigest())] = next; 350 } 351 352 // We need to clear the mutability bit in case we are 353 // destroying the node as part of a sweep in ImutAVLFactory::recoverNodes(). 354 IsMutable = false; 355 factory->freeNodes.push_back(this); 356 } 357}; 358 359//===----------------------------------------------------------------------===// 360// Immutable AVL-Tree Factory class. 361//===----------------------------------------------------------------------===// 362 363template <typename ImutInfo > 364class ImutAVLFactory { 365 friend class ImutAVLTree<ImutInfo>; 366 typedef ImutAVLTree<ImutInfo> TreeTy; 367 typedef typename TreeTy::value_type_ref value_type_ref; 368 typedef typename TreeTy::key_type_ref key_type_ref; 369 370 typedef DenseMap<unsigned, TreeTy*> CacheTy; 371 372 CacheTy Cache; 373 uintptr_t Allocator; 374 std::vector<TreeTy*> createdNodes; 375 std::vector<TreeTy*> freeNodes; 376 377 bool ownsAllocator() const { 378 return Allocator & 0x1 ? false : true; 379 } 380 381 BumpPtrAllocator& getAllocator() const { 382 return *reinterpret_cast<BumpPtrAllocator*>(Allocator & ~0x1); 383 } 384 385 //===--------------------------------------------------===// 386 // Public interface. 387 //===--------------------------------------------------===// 388 389public: 390 ImutAVLFactory() 391 : Allocator(reinterpret_cast<uintptr_t>(new BumpPtrAllocator())) {} 392 393 ImutAVLFactory(BumpPtrAllocator& Alloc) 394 : Allocator(reinterpret_cast<uintptr_t>(&Alloc) | 0x1) {} 395 396 ~ImutAVLFactory() { 397 if (ownsAllocator()) delete &getAllocator(); 398 } 399 400 TreeTy* add(TreeTy* T, value_type_ref V) { 401 T = add_internal(V,T); 402 markImmutable(T); 403 recoverNodes(); 404 return T; 405 } 406 407 TreeTy* remove(TreeTy* T, key_type_ref V) { 408 T = remove_internal(V,T); 409 markImmutable(T); 410 recoverNodes(); 411 return T; 412 } 413 414 TreeTy* getEmptyTree() const { return NULL; } 415 416protected: 417 418 //===--------------------------------------------------===// 419 // A bunch of quick helper functions used for reasoning 420 // about the properties of trees and their children. 421 // These have succinct names so that the balancing code 422 // is as terse (and readable) as possible. 423 //===--------------------------------------------------===// 424 425 bool isEmpty(TreeTy* T) const { return !T; } 426 unsigned getHeight(TreeTy* T) const { return T ? T->getHeight() : 0; } 427 TreeTy* getLeft(TreeTy* T) const { return T->getLeft(); } 428 TreeTy* getRight(TreeTy* T) const { return T->getRight(); } 429 value_type_ref getValue(TreeTy* T) const { return T->value; } 430 431 // Make sure the index is not the Tombstone or Entry key of the DenseMap. 432 static inline unsigned maskCacheIndex(unsigned I) { 433 return (I & ~0x02); 434 } 435 436 unsigned incrementHeight(TreeTy* L, TreeTy* R) const { 437 unsigned hl = getHeight(L); 438 unsigned hr = getHeight(R); 439 return (hl > hr ? hl : hr) + 1; 440 } 441 442 static bool compareTreeWithSection(TreeTy* T, 443 typename TreeTy::iterator& TI, 444 typename TreeTy::iterator& TE) { 445 typename TreeTy::iterator I = T->begin(), E = T->end(); 446 for ( ; I!=E ; ++I, ++TI) { 447 if (TI == TE || !I->isElementEqual(*TI)) 448 return false; 449 } 450 return true; 451 } 452 453 //===--------------------------------------------------===// 454 // "createNode" is used to generate new tree roots that link 455 // to other trees. The functon may also simply move links 456 // in an existing root if that root is still marked mutable. 457 // This is necessary because otherwise our balancing code 458 // would leak memory as it would create nodes that are 459 // then discarded later before the finished tree is 460 // returned to the caller. 461 //===--------------------------------------------------===// 462 463 TreeTy* createNode(TreeTy* L, value_type_ref V, TreeTy* R) { 464 BumpPtrAllocator& A = getAllocator(); 465 TreeTy* T; 466 if (!freeNodes.empty()) { 467 T = freeNodes.back(); 468 freeNodes.pop_back(); 469 assert(T != L); 470 assert(T != R); 471 } else { 472 T = (TreeTy*) A.Allocate<TreeTy>(); 473 } 474 new (T) TreeTy(this, L, R, V, incrementHeight(L,R)); 475 createdNodes.push_back(T); 476 return T; 477 } 478 479 TreeTy* createNode(TreeTy* newLeft, TreeTy* oldTree, TreeTy* newRight) { 480 return createNode(newLeft, getValue(oldTree), newRight); 481 } 482 483 void recoverNodes() { 484 for (unsigned i = 0, n = createdNodes.size(); i < n; ++i) { 485 TreeTy *N = createdNodes[i]; 486 if (N->isMutable() && N->refCount == 0) 487 N->destroy(); 488 } 489 createdNodes.clear(); 490 } 491 492 /// balanceTree - Used by add_internal and remove_internal to 493 /// balance a newly created tree. 494 TreeTy* balanceTree(TreeTy* L, value_type_ref V, TreeTy* R) { 495 unsigned hl = getHeight(L); 496 unsigned hr = getHeight(R); 497 498 if (hl > hr + 2) { 499 assert(!isEmpty(L) && "Left tree cannot be empty to have a height >= 2"); 500 501 TreeTy *LL = getLeft(L); 502 TreeTy *LR = getRight(L); 503 504 if (getHeight(LL) >= getHeight(LR)) 505 return createNode(LL, L, createNode(LR,V,R)); 506 507 assert(!isEmpty(LR) && "LR cannot be empty because it has a height >= 1"); 508 509 TreeTy *LRL = getLeft(LR); 510 TreeTy *LRR = getRight(LR); 511 512 return createNode(createNode(LL,L,LRL), LR, createNode(LRR,V,R)); 513 } 514 515 if (hr > hl + 2) { 516 assert(!isEmpty(R) && "Right tree cannot be empty to have a height >= 2"); 517 518 TreeTy *RL = getLeft(R); 519 TreeTy *RR = getRight(R); 520 521 if (getHeight(RR) >= getHeight(RL)) 522 return createNode(createNode(L,V,RL), R, RR); 523 524 assert(!isEmpty(RL) && "RL cannot be empty because it has a height >= 1"); 525 526 TreeTy *RLL = getLeft(RL); 527 TreeTy *RLR = getRight(RL); 528 529 return createNode(createNode(L,V,RLL), RL, createNode(RLR,R,RR)); 530 } 531 532 return createNode(L,V,R); 533 } 534 535 /// add_internal - Creates a new tree that includes the specified 536 /// data and the data from the original tree. If the original tree 537 /// already contained the data item, the original tree is returned. 538 TreeTy* add_internal(value_type_ref V, TreeTy* T) { 539 if (isEmpty(T)) 540 return createNode(T, V, T); 541 assert(!T->isMutable()); 542 543 key_type_ref K = ImutInfo::KeyOfValue(V); 544 key_type_ref KCurrent = ImutInfo::KeyOfValue(getValue(T)); 545 546 if (ImutInfo::isEqual(K,KCurrent)) 547 return createNode(getLeft(T), V, getRight(T)); 548 else if (ImutInfo::isLess(K,KCurrent)) 549 return balanceTree(add_internal(V, getLeft(T)), getValue(T), getRight(T)); 550 else 551 return balanceTree(getLeft(T), getValue(T), add_internal(V, getRight(T))); 552 } 553 554 /// remove_internal - Creates a new tree that includes all the data 555 /// from the original tree except the specified data. If the 556 /// specified data did not exist in the original tree, the original 557 /// tree is returned. 558 TreeTy* remove_internal(key_type_ref K, TreeTy* T) { 559 if (isEmpty(T)) 560 return T; 561 562 assert(!T->isMutable()); 563 564 key_type_ref KCurrent = ImutInfo::KeyOfValue(getValue(T)); 565 566 if (ImutInfo::isEqual(K,KCurrent)) { 567 return combineTrees(getLeft(T), getRight(T)); 568 } else if (ImutInfo::isLess(K,KCurrent)) { 569 return balanceTree(remove_internal(K, getLeft(T)), 570 getValue(T), getRight(T)); 571 } else { 572 return balanceTree(getLeft(T), getValue(T), 573 remove_internal(K, getRight(T))); 574 } 575 } 576 577 TreeTy* combineTrees(TreeTy* L, TreeTy* R) { 578 if (isEmpty(L)) 579 return R; 580 if (isEmpty(R)) 581 return L; 582 TreeTy* OldNode; 583 TreeTy* newRight = removeMinBinding(R,OldNode); 584 return balanceTree(L, getValue(OldNode), newRight); 585 } 586 587 TreeTy* removeMinBinding(TreeTy* T, TreeTy*& Noderemoved) { 588 assert(!isEmpty(T)); 589 if (isEmpty(getLeft(T))) { 590 Noderemoved = T; 591 return getRight(T); 592 } 593 return balanceTree(removeMinBinding(getLeft(T), Noderemoved), 594 getValue(T), getRight(T)); 595 } 596 597 /// markImmutable - Clears the mutable bits of a root and all of its 598 /// descendants. 599 void markImmutable(TreeTy* T) { 600 if (!T || !T->isMutable()) 601 return; 602 T->markImmutable(); 603 markImmutable(getLeft(T)); 604 markImmutable(getRight(T)); 605 } 606 607public: 608 TreeTy *getCanonicalTree(TreeTy *TNew) { 609 if (!TNew) 610 return 0; 611 612 if (TNew->IsCanonicalized) 613 return TNew; 614 615 // Search the hashtable for another tree with the same digest, and 616 // if find a collision compare those trees by their contents. 617 unsigned digest = TNew->computeDigest(); 618 TreeTy *&entry = Cache[maskCacheIndex(digest)]; 619 do { 620 if (!entry) 621 break; 622 for (TreeTy *T = entry ; T != 0; T = T->next) { 623 // Compare the Contents('T') with Contents('TNew') 624 typename TreeTy::iterator TI = T->begin(), TE = T->end(); 625 if (!compareTreeWithSection(TNew, TI, TE)) 626 continue; 627 if (TI != TE) 628 continue; // T has more contents than TNew. 629 // Trees did match! Return 'T'. 630 if (TNew->refCount == 0) 631 TNew->destroy(); 632 return T; 633 } 634 entry->prev = TNew; 635 TNew->next = entry; 636 } 637 while (false); 638 639 entry = TNew; 640 TNew->IsCanonicalized = true; 641 return TNew; 642 } 643}; 644 645//===----------------------------------------------------------------------===// 646// Immutable AVL-Tree Iterators. 647//===----------------------------------------------------------------------===// 648 649template <typename ImutInfo> 650class ImutAVLTreeGenericIterator { 651 SmallVector<uintptr_t,20> stack; 652public: 653 enum VisitFlag { VisitedNone=0x0, VisitedLeft=0x1, VisitedRight=0x3, 654 Flags=0x3 }; 655 656 typedef ImutAVLTree<ImutInfo> TreeTy; 657 typedef ImutAVLTreeGenericIterator<ImutInfo> _Self; 658 659 inline ImutAVLTreeGenericIterator() {} 660 inline ImutAVLTreeGenericIterator(const TreeTy* Root) { 661 if (Root) stack.push_back(reinterpret_cast<uintptr_t>(Root)); 662 } 663 664 TreeTy* operator*() const { 665 assert(!stack.empty()); 666 return reinterpret_cast<TreeTy*>(stack.back() & ~Flags); 667 } 668 669 uintptr_t getVisitState() const { 670 assert(!stack.empty()); 671 return stack.back() & Flags; 672 } 673 674 675 bool atEnd() const { return stack.empty(); } 676 677 bool atBeginning() const { 678 return stack.size() == 1 && getVisitState() == VisitedNone; 679 } 680 681 void skipToParent() { 682 assert(!stack.empty()); 683 stack.pop_back(); 684 if (stack.empty()) 685 return; 686 switch (getVisitState()) { 687 case VisitedNone: 688 stack.back() |= VisitedLeft; 689 break; 690 case VisitedLeft: 691 stack.back() |= VisitedRight; 692 break; 693 default: 694 llvm_unreachable("Unreachable."); 695 } 696 } 697 698 inline bool operator==(const _Self& x) const { 699 if (stack.size() != x.stack.size()) 700 return false; 701 for (unsigned i = 0 ; i < stack.size(); i++) 702 if (stack[i] != x.stack[i]) 703 return false; 704 return true; 705 } 706 707 inline bool operator!=(const _Self& x) const { return !operator==(x); } 708 709 _Self& operator++() { 710 assert(!stack.empty()); 711 TreeTy* Current = reinterpret_cast<TreeTy*>(stack.back() & ~Flags); 712 assert(Current); 713 switch (getVisitState()) { 714 case VisitedNone: 715 if (TreeTy* L = Current->getLeft()) 716 stack.push_back(reinterpret_cast<uintptr_t>(L)); 717 else 718 stack.back() |= VisitedLeft; 719 break; 720 case VisitedLeft: 721 if (TreeTy* R = Current->getRight()) 722 stack.push_back(reinterpret_cast<uintptr_t>(R)); 723 else 724 stack.back() |= VisitedRight; 725 break; 726 case VisitedRight: 727 skipToParent(); 728 break; 729 default: 730 llvm_unreachable("Unreachable."); 731 } 732 return *this; 733 } 734 735 _Self& operator--() { 736 assert(!stack.empty()); 737 TreeTy* Current = reinterpret_cast<TreeTy*>(stack.back() & ~Flags); 738 assert(Current); 739 switch (getVisitState()) { 740 case VisitedNone: 741 stack.pop_back(); 742 break; 743 case VisitedLeft: 744 stack.back() &= ~Flags; // Set state to "VisitedNone." 745 if (TreeTy* L = Current->getLeft()) 746 stack.push_back(reinterpret_cast<uintptr_t>(L) | VisitedRight); 747 break; 748 case VisitedRight: 749 stack.back() &= ~Flags; 750 stack.back() |= VisitedLeft; 751 if (TreeTy* R = Current->getRight()) 752 stack.push_back(reinterpret_cast<uintptr_t>(R) | VisitedRight); 753 break; 754 default: 755 llvm_unreachable("Unreachable."); 756 } 757 return *this; 758 } 759}; 760 761template <typename ImutInfo> 762class ImutAVLTreeInOrderIterator { 763 typedef ImutAVLTreeGenericIterator<ImutInfo> InternalIteratorTy; 764 InternalIteratorTy InternalItr; 765 766public: 767 typedef ImutAVLTree<ImutInfo> TreeTy; 768 typedef ImutAVLTreeInOrderIterator<ImutInfo> _Self; 769 770 ImutAVLTreeInOrderIterator(const TreeTy* Root) : InternalItr(Root) { 771 if (Root) operator++(); // Advance to first element. 772 } 773 774 ImutAVLTreeInOrderIterator() : InternalItr() {} 775 776 inline bool operator==(const _Self& x) const { 777 return InternalItr == x.InternalItr; 778 } 779 780 inline bool operator!=(const _Self& x) const { return !operator==(x); } 781 782 inline TreeTy* operator*() const { return *InternalItr; } 783 inline TreeTy* operator->() const { return *InternalItr; } 784 785 inline _Self& operator++() { 786 do ++InternalItr; 787 while (!InternalItr.atEnd() && 788 InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft); 789 790 return *this; 791 } 792 793 inline _Self& operator--() { 794 do --InternalItr; 795 while (!InternalItr.atBeginning() && 796 InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft); 797 798 return *this; 799 } 800 801 inline void skipSubTree() { 802 InternalItr.skipToParent(); 803 804 while (!InternalItr.atEnd() && 805 InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft) 806 ++InternalItr; 807 } 808}; 809 810//===----------------------------------------------------------------------===// 811// Trait classes for Profile information. 812//===----------------------------------------------------------------------===// 813 814/// Generic profile template. The default behavior is to invoke the 815/// profile method of an object. Specializations for primitive integers 816/// and generic handling of pointers is done below. 817template <typename T> 818struct ImutProfileInfo { 819 typedef const T value_type; 820 typedef const T& value_type_ref; 821 822 static inline void Profile(FoldingSetNodeID& ID, value_type_ref X) { 823 FoldingSetTrait<T>::Profile(X,ID); 824 } 825}; 826 827/// Profile traits for integers. 828template <typename T> 829struct ImutProfileInteger { 830 typedef const T value_type; 831 typedef const T& value_type_ref; 832 833 static inline void Profile(FoldingSetNodeID& ID, value_type_ref X) { 834 ID.AddInteger(X); 835 } 836}; 837 838#define PROFILE_INTEGER_INFO(X)\ 839template<> struct ImutProfileInfo<X> : ImutProfileInteger<X> {}; 840 841PROFILE_INTEGER_INFO(char) 842PROFILE_INTEGER_INFO(unsigned char) 843PROFILE_INTEGER_INFO(short) 844PROFILE_INTEGER_INFO(unsigned short) 845PROFILE_INTEGER_INFO(unsigned) 846PROFILE_INTEGER_INFO(signed) 847PROFILE_INTEGER_INFO(long) 848PROFILE_INTEGER_INFO(unsigned long) 849PROFILE_INTEGER_INFO(long long) 850PROFILE_INTEGER_INFO(unsigned long long) 851 852#undef PROFILE_INTEGER_INFO 853 854/// Profile traits for booleans. 855template <> 856struct ImutProfileInfo<bool> { 857 typedef const bool value_type; 858 typedef const bool& value_type_ref; 859 860 static inline void Profile(FoldingSetNodeID& ID, value_type_ref X) { 861 ID.AddBoolean(X); 862 } 863}; 864 865 866/// Generic profile trait for pointer types. We treat pointers as 867/// references to unique objects. 868template <typename T> 869struct ImutProfileInfo<T*> { 870 typedef const T* value_type; 871 typedef value_type value_type_ref; 872 873 static inline void Profile(FoldingSetNodeID &ID, value_type_ref X) { 874 ID.AddPointer(X); 875 } 876}; 877 878//===----------------------------------------------------------------------===// 879// Trait classes that contain element comparison operators and type 880// definitions used by ImutAVLTree, ImmutableSet, and ImmutableMap. These 881// inherit from the profile traits (ImutProfileInfo) to include operations 882// for element profiling. 883//===----------------------------------------------------------------------===// 884 885 886/// ImutContainerInfo - Generic definition of comparison operations for 887/// elements of immutable containers that defaults to using 888/// std::equal_to<> and std::less<> to perform comparison of elements. 889template <typename T> 890struct ImutContainerInfo : public ImutProfileInfo<T> { 891 typedef typename ImutProfileInfo<T>::value_type value_type; 892 typedef typename ImutProfileInfo<T>::value_type_ref value_type_ref; 893 typedef value_type key_type; 894 typedef value_type_ref key_type_ref; 895 typedef bool data_type; 896 typedef bool data_type_ref; 897 898 static inline key_type_ref KeyOfValue(value_type_ref D) { return D; } 899 static inline data_type_ref DataOfValue(value_type_ref) { return true; } 900 901 static inline bool isEqual(key_type_ref LHS, key_type_ref RHS) { 902 return std::equal_to<key_type>()(LHS,RHS); 903 } 904 905 static inline bool isLess(key_type_ref LHS, key_type_ref RHS) { 906 return std::less<key_type>()(LHS,RHS); 907 } 908 909 static inline bool isDataEqual(data_type_ref,data_type_ref) { return true; } 910}; 911 912/// ImutContainerInfo - Specialization for pointer values to treat pointers 913/// as references to unique objects. Pointers are thus compared by 914/// their addresses. 915template <typename T> 916struct ImutContainerInfo<T*> : public ImutProfileInfo<T*> { 917 typedef typename ImutProfileInfo<T*>::value_type value_type; 918 typedef typename ImutProfileInfo<T*>::value_type_ref value_type_ref; 919 typedef value_type key_type; 920 typedef value_type_ref key_type_ref; 921 typedef bool data_type; 922 typedef bool data_type_ref; 923 924 static inline key_type_ref KeyOfValue(value_type_ref D) { return D; } 925 static inline data_type_ref DataOfValue(value_type_ref) { return true; } 926 927 static inline bool isEqual(key_type_ref LHS, key_type_ref RHS) { 928 return LHS == RHS; 929 } 930 931 static inline bool isLess(key_type_ref LHS, key_type_ref RHS) { 932 return LHS < RHS; 933 } 934 935 static inline bool isDataEqual(data_type_ref,data_type_ref) { return true; } 936}; 937 938//===----------------------------------------------------------------------===// 939// Immutable Set 940//===----------------------------------------------------------------------===// 941 942template <typename ValT, typename ValInfo = ImutContainerInfo<ValT> > 943class ImmutableSet { 944public: 945 typedef typename ValInfo::value_type value_type; 946 typedef typename ValInfo::value_type_ref value_type_ref; 947 typedef ImutAVLTree<ValInfo> TreeTy; 948 949private: 950 TreeTy *Root; 951 952public: 953 /// Constructs a set from a pointer to a tree root. In general one 954 /// should use a Factory object to create sets instead of directly 955 /// invoking the constructor, but there are cases where make this 956 /// constructor public is useful. 957 explicit ImmutableSet(TreeTy* R) : Root(R) { 958 if (Root) { Root->retain(); } 959 } 960 ImmutableSet(const ImmutableSet &X) : Root(X.Root) { 961 if (Root) { Root->retain(); } 962 } 963 ImmutableSet &operator=(const ImmutableSet &X) { 964 if (Root != X.Root) { 965 if (X.Root) { X.Root->retain(); } 966 if (Root) { Root->release(); } 967 Root = X.Root; 968 } 969 return *this; 970 } 971 ~ImmutableSet() { 972 if (Root) { Root->release(); } 973 } 974 975 class Factory { 976 typename TreeTy::Factory F; 977 const bool Canonicalize; 978 979 public: 980 Factory(bool canonicalize = true) 981 : Canonicalize(canonicalize) {} 982 983 Factory(BumpPtrAllocator& Alloc, bool canonicalize = true) 984 : F(Alloc), Canonicalize(canonicalize) {} 985 986 /// getEmptySet - Returns an immutable set that contains no elements. 987 ImmutableSet getEmptySet() { 988 return ImmutableSet(F.getEmptyTree()); 989 } 990 991 /// add - Creates a new immutable set that contains all of the values 992 /// of the original set with the addition of the specified value. If 993 /// the original set already included the value, then the original set is 994 /// returned and no memory is allocated. The time and space complexity 995 /// of this operation is logarithmic in the size of the original set. 996 /// The memory allocated to represent the set is released when the 997 /// factory object that created the set is destroyed. 998 ImmutableSet add(ImmutableSet Old, value_type_ref V) { 999 TreeTy *NewT = F.add(Old.Root, V); 1000 return ImmutableSet(Canonicalize ? F.getCanonicalTree(NewT) : NewT); 1001 } 1002 1003 /// remove - Creates a new immutable set that contains all of the values 1004 /// of the original set with the exception of the specified value. If 1005 /// the original set did not contain the value, the original set is 1006 /// returned and no memory is allocated. The time and space complexity 1007 /// of this operation is logarithmic in the size of the original set. 1008 /// The memory allocated to represent the set is released when the 1009 /// factory object that created the set is destroyed. 1010 ImmutableSet remove(ImmutableSet Old, value_type_ref V) { 1011 TreeTy *NewT = F.remove(Old.Root, V); 1012 return ImmutableSet(Canonicalize ? F.getCanonicalTree(NewT) : NewT); 1013 } 1014 1015 BumpPtrAllocator& getAllocator() { return F.getAllocator(); } 1016 1017 typename TreeTy::Factory *getTreeFactory() const { 1018 return const_cast<typename TreeTy::Factory *>(&F); 1019 } 1020 1021 private: 1022 Factory(const Factory& RHS) LLVM_DELETED_FUNCTION; 1023 void operator=(const Factory& RHS) LLVM_DELETED_FUNCTION; 1024 }; 1025 1026 friend class Factory; 1027 1028 /// Returns true if the set contains the specified value. 1029 bool contains(value_type_ref V) const { 1030 return Root ? Root->contains(V) : false; 1031 } 1032 1033 bool operator==(const ImmutableSet &RHS) const { 1034 return Root && RHS.Root ? Root->isEqual(*RHS.Root) : Root == RHS.Root; 1035 } 1036 1037 bool operator!=(const ImmutableSet &RHS) const { 1038 return Root && RHS.Root ? Root->isNotEqual(*RHS.Root) : Root != RHS.Root; 1039 } 1040 1041 TreeTy *getRoot() { 1042 if (Root) { Root->retain(); } 1043 return Root; 1044 } 1045 1046 TreeTy *getRootWithoutRetain() const { 1047 return Root; 1048 } 1049 1050 /// isEmpty - Return true if the set contains no elements. 1051 bool isEmpty() const { return !Root; } 1052 1053 /// isSingleton - Return true if the set contains exactly one element. 1054 /// This method runs in constant time. 1055 bool isSingleton() const { return getHeight() == 1; } 1056 1057 template <typename Callback> 1058 void foreach(Callback& C) { if (Root) Root->foreach(C); } 1059 1060 template <typename Callback> 1061 void foreach() { if (Root) { Callback C; Root->foreach(C); } } 1062 1063 //===--------------------------------------------------===// 1064 // Iterators. 1065 //===--------------------------------------------------===// 1066 1067 class iterator { 1068 typename TreeTy::iterator itr; 1069 1070 iterator() {} 1071 iterator(TreeTy* t) : itr(t) {} 1072 friend class ImmutableSet<ValT,ValInfo>; 1073 1074 public: 1075 typedef ptrdiff_t difference_type; 1076 typedef typename ImmutableSet<ValT,ValInfo>::value_type value_type; 1077 typedef typename ImmutableSet<ValT,ValInfo>::value_type_ref reference; 1078 typedef typename iterator::value_type *pointer; 1079 typedef std::bidirectional_iterator_tag iterator_category; 1080 1081 typename iterator::reference operator*() const { return itr->getValue(); } 1082 typename iterator::pointer operator->() const { return &(operator*()); } 1083 1084 iterator& operator++() { ++itr; return *this; } 1085 iterator operator++(int) { iterator tmp(*this); ++itr; return tmp; } 1086 iterator& operator--() { --itr; return *this; } 1087 iterator operator--(int) { iterator tmp(*this); --itr; return tmp; } 1088 1089 bool operator==(const iterator& RHS) const { return RHS.itr == itr; } 1090 bool operator!=(const iterator& RHS) const { return RHS.itr != itr; } 1091 }; 1092 1093 iterator begin() const { return iterator(Root); } 1094 iterator end() const { return iterator(); } 1095 1096 //===--------------------------------------------------===// 1097 // Utility methods. 1098 //===--------------------------------------------------===// 1099 1100 unsigned getHeight() const { return Root ? Root->getHeight() : 0; } 1101 1102 static inline void Profile(FoldingSetNodeID& ID, const ImmutableSet& S) { 1103 ID.AddPointer(S.Root); 1104 } 1105 1106 inline void Profile(FoldingSetNodeID& ID) const { 1107 return Profile(ID,*this); 1108 } 1109 1110 //===--------------------------------------------------===// 1111 // For testing. 1112 //===--------------------------------------------------===// 1113 1114 void validateTree() const { if (Root) Root->validateTree(); } 1115}; 1116 1117// NOTE: This may some day replace the current ImmutableSet. 1118template <typename ValT, typename ValInfo = ImutContainerInfo<ValT> > 1119class ImmutableSetRef { 1120public: 1121 typedef typename ValInfo::value_type value_type; 1122 typedef typename ValInfo::value_type_ref value_type_ref; 1123 typedef ImutAVLTree<ValInfo> TreeTy; 1124 typedef typename TreeTy::Factory FactoryTy; 1125 1126private: 1127 TreeTy *Root; 1128 FactoryTy *Factory; 1129 1130public: 1131 /// Constructs a set from a pointer to a tree root. In general one 1132 /// should use a Factory object to create sets instead of directly 1133 /// invoking the constructor, but there are cases where make this 1134 /// constructor public is useful. 1135 explicit ImmutableSetRef(TreeTy* R, FactoryTy *F) 1136 : Root(R), 1137 Factory(F) { 1138 if (Root) { Root->retain(); } 1139 } 1140 ImmutableSetRef(const ImmutableSetRef &X) 1141 : Root(X.Root), 1142 Factory(X.Factory) { 1143 if (Root) { Root->retain(); } 1144 } 1145 ImmutableSetRef &operator=(const ImmutableSetRef &X) { 1146 if (Root != X.Root) { 1147 if (X.Root) { X.Root->retain(); } 1148 if (Root) { Root->release(); } 1149 Root = X.Root; 1150 Factory = X.Factory; 1151 } 1152 return *this; 1153 } 1154 ~ImmutableSetRef() { 1155 if (Root) { Root->release(); } 1156 } 1157 1158 static inline ImmutableSetRef getEmptySet(FactoryTy *F) { 1159 return ImmutableSetRef(0, F); 1160 } 1161 1162 ImmutableSetRef add(value_type_ref V) { 1163 return ImmutableSetRef(Factory->add(Root, V), Factory); 1164 } 1165 1166 ImmutableSetRef remove(value_type_ref V) { 1167 return ImmutableSetRef(Factory->remove(Root, V), Factory); 1168 } 1169 1170 /// Returns true if the set contains the specified value. 1171 bool contains(value_type_ref V) const { 1172 return Root ? Root->contains(V) : false; 1173 } 1174 1175 ImmutableSet<ValT> asImmutableSet(bool canonicalize = true) const { 1176 return ImmutableSet<ValT>(canonicalize ? 1177 Factory->getCanonicalTree(Root) : Root); 1178 } 1179 1180 TreeTy *getRootWithoutRetain() const { 1181 return Root; 1182 } 1183 1184 bool operator==(const ImmutableSetRef &RHS) const { 1185 return Root && RHS.Root ? Root->isEqual(*RHS.Root) : Root == RHS.Root; 1186 } 1187 1188 bool operator!=(const ImmutableSetRef &RHS) const { 1189 return Root && RHS.Root ? Root->isNotEqual(*RHS.Root) : Root != RHS.Root; 1190 } 1191 1192 /// isEmpty - Return true if the set contains no elements. 1193 bool isEmpty() const { return !Root; } 1194 1195 /// isSingleton - Return true if the set contains exactly one element. 1196 /// This method runs in constant time. 1197 bool isSingleton() const { return getHeight() == 1; } 1198 1199 //===--------------------------------------------------===// 1200 // Iterators. 1201 //===--------------------------------------------------===// 1202 1203 class iterator { 1204 typename TreeTy::iterator itr; 1205 iterator(TreeTy* t) : itr(t) {} 1206 friend class ImmutableSetRef<ValT,ValInfo>; 1207 public: 1208 iterator() {} 1209 inline value_type_ref operator*() const { return itr->getValue(); } 1210 inline iterator& operator++() { ++itr; return *this; } 1211 inline iterator operator++(int) { iterator tmp(*this); ++itr; return tmp; } 1212 inline iterator& operator--() { --itr; return *this; } 1213 inline iterator operator--(int) { iterator tmp(*this); --itr; return tmp; } 1214 inline bool operator==(const iterator& RHS) const { return RHS.itr == itr; } 1215 inline bool operator!=(const iterator& RHS) const { return RHS.itr != itr; } 1216 inline value_type *operator->() const { return &(operator*()); } 1217 }; 1218 1219 iterator begin() const { return iterator(Root); } 1220 iterator end() const { return iterator(); } 1221 1222 //===--------------------------------------------------===// 1223 // Utility methods. 1224 //===--------------------------------------------------===// 1225 1226 unsigned getHeight() const { return Root ? Root->getHeight() : 0; } 1227 1228 static inline void Profile(FoldingSetNodeID& ID, const ImmutableSetRef& S) { 1229 ID.AddPointer(S.Root); 1230 } 1231 1232 inline void Profile(FoldingSetNodeID& ID) const { 1233 return Profile(ID,*this); 1234 } 1235 1236 //===--------------------------------------------------===// 1237 // For testing. 1238 //===--------------------------------------------------===// 1239 1240 void validateTree() const { if (Root) Root->validateTree(); } 1241}; 1242 1243} // end namespace llvm 1244 1245#endif 1246