1 //===-- llvm/ADT/FoldingSet.h - Uniquing Hash Set ---------------*- 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 a hash set that can be used to remove duplication of nodes 11 // in a graph. This code was originally created by Chris Lattner for use with 12 // SelectionDAGCSEMap, but was isolated to provide use across the llvm code set. 13 // 14 //===----------------------------------------------------------------------===// 15 16 #ifndef LLVM_ADT_FOLDINGSET_H 17 #define LLVM_ADT_FOLDINGSET_H 18 19 #include "llvm/ADT/SmallVector.h" 20 #include "llvm/ADT/StringRef.h" 21 #include "llvm/ADT/iterator.h" 22 #include "llvm/Support/Allocator.h" 23 #include "llvm/Support/DataTypes.h" 24 25 namespace llvm { 26 /// This folding set used for two purposes: 27 /// 1. Given information about a node we want to create, look up the unique 28 /// instance of the node in the set. If the node already exists, return 29 /// it, otherwise return the bucket it should be inserted into. 30 /// 2. Given a node that has already been created, remove it from the set. 31 /// 32 /// This class is implemented as a single-link chained hash table, where the 33 /// "buckets" are actually the nodes themselves (the next pointer is in the 34 /// node). The last node points back to the bucket to simplify node removal. 35 /// 36 /// Any node that is to be included in the folding set must be a subclass of 37 /// FoldingSetNode. The node class must also define a Profile method used to 38 /// establish the unique bits of data for the node. The Profile method is 39 /// passed a FoldingSetNodeID object which is used to gather the bits. Just 40 /// call one of the Add* functions defined in the FoldingSetImpl::NodeID class. 41 /// NOTE: That the folding set does not own the nodes and it is the 42 /// responsibility of the user to dispose of the nodes. 43 /// 44 /// Eg. 45 /// class MyNode : public FoldingSetNode { 46 /// private: 47 /// std::string Name; 48 /// unsigned Value; 49 /// public: 50 /// MyNode(const char *N, unsigned V) : Name(N), Value(V) {} 51 /// ... 52 /// void Profile(FoldingSetNodeID &ID) const { 53 /// ID.AddString(Name); 54 /// ID.AddInteger(Value); 55 /// } 56 /// ... 57 /// }; 58 /// 59 /// To define the folding set itself use the FoldingSet template; 60 /// 61 /// Eg. 62 /// FoldingSet<MyNode> MyFoldingSet; 63 /// 64 /// Four public methods are available to manipulate the folding set; 65 /// 66 /// 1) If you have an existing node that you want add to the set but unsure 67 /// that the node might already exist then call; 68 /// 69 /// MyNode *M = MyFoldingSet.GetOrInsertNode(N); 70 /// 71 /// If The result is equal to the input then the node has been inserted. 72 /// Otherwise, the result is the node existing in the folding set, and the 73 /// input can be discarded (use the result instead.) 74 /// 75 /// 2) If you are ready to construct a node but want to check if it already 76 /// exists, then call FindNodeOrInsertPos with a FoldingSetNodeID of the bits to 77 /// check; 78 /// 79 /// FoldingSetNodeID ID; 80 /// ID.AddString(Name); 81 /// ID.AddInteger(Value); 82 /// void *InsertPoint; 83 /// 84 /// MyNode *M = MyFoldingSet.FindNodeOrInsertPos(ID, InsertPoint); 85 /// 86 /// If found then M with be non-NULL, else InsertPoint will point to where it 87 /// should be inserted using InsertNode. 88 /// 89 /// 3) If you get a NULL result from FindNodeOrInsertPos then you can as a new 90 /// node with FindNodeOrInsertPos; 91 /// 92 /// InsertNode(N, InsertPoint); 93 /// 94 /// 4) Finally, if you want to remove a node from the folding set call; 95 /// 96 /// bool WasRemoved = RemoveNode(N); 97 /// 98 /// The result indicates whether the node existed in the folding set. 99 100 class FoldingSetNodeID; 101 102 //===----------------------------------------------------------------------===// 103 /// FoldingSetImpl - Implements the folding set functionality. The main 104 /// structure is an array of buckets. Each bucket is indexed by the hash of 105 /// the nodes it contains. The bucket itself points to the nodes contained 106 /// in the bucket via a singly linked list. The last node in the list points 107 /// back to the bucket to facilitate node removal. 108 /// 109 class FoldingSetImpl { 110 virtual void anchor(); // Out of line virtual method. 111 112 protected: 113 /// Buckets - Array of bucket chains. 114 /// 115 void **Buckets; 116 117 /// NumBuckets - Length of the Buckets array. Always a power of 2. 118 /// 119 unsigned NumBuckets; 120 121 /// NumNodes - Number of nodes in the folding set. Growth occurs when NumNodes 122 /// is greater than twice the number of buckets. 123 unsigned NumNodes; 124 125 ~FoldingSetImpl(); 126 127 explicit FoldingSetImpl(unsigned Log2InitSize = 6); 128 129 public: 130 //===--------------------------------------------------------------------===// 131 /// Node - This class is used to maintain the singly linked bucket list in 132 /// a folding set. 133 /// 134 class Node { 135 private: 136 // NextInFoldingSetBucket - next link in the bucket list. 137 void *NextInFoldingSetBucket; 138 139 public: 140 141 Node() : NextInFoldingSetBucket(nullptr) {} 142 143 // Accessors 144 void *getNextInBucket() const { return NextInFoldingSetBucket; } 145 void SetNextInBucket(void *N) { NextInFoldingSetBucket = N; } 146 }; 147 148 /// clear - Remove all nodes from the folding set. 149 void clear(); 150 151 /// RemoveNode - Remove a node from the folding set, returning true if one 152 /// was removed or false if the node was not in the folding set. 153 bool RemoveNode(Node *N); 154 155 /// GetOrInsertNode - If there is an existing simple Node exactly 156 /// equal to the specified node, return it. Otherwise, insert 'N' and return 157 /// it instead. 158 Node *GetOrInsertNode(Node *N); 159 160 /// FindNodeOrInsertPos - Look up the node specified by ID. If it exists, 161 /// return it. If not, return the insertion token that will make insertion 162 /// faster. 163 Node *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos); 164 165 /// InsertNode - Insert the specified node into the folding set, knowing that 166 /// it is not already in the folding set. InsertPos must be obtained from 167 /// FindNodeOrInsertPos. 168 void InsertNode(Node *N, void *InsertPos); 169 170 /// InsertNode - Insert the specified node into the folding set, knowing that 171 /// it is not already in the folding set. 172 void InsertNode(Node *N) { 173 Node *Inserted = GetOrInsertNode(N); 174 (void)Inserted; 175 assert(Inserted == N && "Node already inserted!"); 176 } 177 178 /// size - Returns the number of nodes in the folding set. 179 unsigned size() const { return NumNodes; } 180 181 /// empty - Returns true if there are no nodes in the folding set. 182 bool empty() const { return NumNodes == 0; } 183 184 private: 185 186 /// GrowHashTable - Double the size of the hash table and rehash everything. 187 /// 188 void GrowHashTable(); 189 190 protected: 191 192 /// GetNodeProfile - Instantiations of the FoldingSet template implement 193 /// this function to gather data bits for the given node. 194 virtual void GetNodeProfile(Node *N, FoldingSetNodeID &ID) const = 0; 195 /// NodeEquals - Instantiations of the FoldingSet template implement 196 /// this function to compare the given node with the given ID. 197 virtual bool NodeEquals(Node *N, const FoldingSetNodeID &ID, unsigned IDHash, 198 FoldingSetNodeID &TempID) const=0; 199 /// ComputeNodeHash - Instantiations of the FoldingSet template implement 200 /// this function to compute a hash value for the given node. 201 virtual unsigned ComputeNodeHash(Node *N, FoldingSetNodeID &TempID) const = 0; 202 }; 203 204 //===----------------------------------------------------------------------===// 205 206 template<typename T> struct FoldingSetTrait; 207 208 /// DefaultFoldingSetTrait - This class provides default implementations 209 /// for FoldingSetTrait implementations. 210 /// 211 template<typename T> struct DefaultFoldingSetTrait { 212 static void Profile(const T &X, FoldingSetNodeID &ID) { 213 X.Profile(ID); 214 } 215 static void Profile(T &X, FoldingSetNodeID &ID) { 216 X.Profile(ID); 217 } 218 219 // Equals - Test if the profile for X would match ID, using TempID 220 // to compute a temporary ID if necessary. The default implementation 221 // just calls Profile and does a regular comparison. Implementations 222 // can override this to provide more efficient implementations. 223 static inline bool Equals(T &X, const FoldingSetNodeID &ID, unsigned IDHash, 224 FoldingSetNodeID &TempID); 225 226 // ComputeHash - Compute a hash value for X, using TempID to 227 // compute a temporary ID if necessary. The default implementation 228 // just calls Profile and does a regular hash computation. 229 // Implementations can override this to provide more efficient 230 // implementations. 231 static inline unsigned ComputeHash(T &X, FoldingSetNodeID &TempID); 232 }; 233 234 /// FoldingSetTrait - This trait class is used to define behavior of how 235 /// to "profile" (in the FoldingSet parlance) an object of a given type. 236 /// The default behavior is to invoke a 'Profile' method on an object, but 237 /// through template specialization the behavior can be tailored for specific 238 /// types. Combined with the FoldingSetNodeWrapper class, one can add objects 239 /// to FoldingSets that were not originally designed to have that behavior. 240 template<typename T> struct FoldingSetTrait 241 : public DefaultFoldingSetTrait<T> {}; 242 243 template<typename T, typename Ctx> struct ContextualFoldingSetTrait; 244 245 /// DefaultContextualFoldingSetTrait - Like DefaultFoldingSetTrait, but 246 /// for ContextualFoldingSets. 247 template<typename T, typename Ctx> 248 struct DefaultContextualFoldingSetTrait { 249 static void Profile(T &X, FoldingSetNodeID &ID, Ctx Context) { 250 X.Profile(ID, Context); 251 } 252 static inline bool Equals(T &X, const FoldingSetNodeID &ID, unsigned IDHash, 253 FoldingSetNodeID &TempID, Ctx Context); 254 static inline unsigned ComputeHash(T &X, FoldingSetNodeID &TempID, 255 Ctx Context); 256 }; 257 258 /// ContextualFoldingSetTrait - Like FoldingSetTrait, but for 259 /// ContextualFoldingSets. 260 template<typename T, typename Ctx> struct ContextualFoldingSetTrait 261 : public DefaultContextualFoldingSetTrait<T, Ctx> {}; 262 263 //===--------------------------------------------------------------------===// 264 /// FoldingSetNodeIDRef - This class describes a reference to an interned 265 /// FoldingSetNodeID, which can be a useful to store node id data rather 266 /// than using plain FoldingSetNodeIDs, since the 32-element SmallVector 267 /// is often much larger than necessary, and the possibility of heap 268 /// allocation means it requires a non-trivial destructor call. 269 class FoldingSetNodeIDRef { 270 const unsigned *Data; 271 size_t Size; 272 public: 273 FoldingSetNodeIDRef() : Data(nullptr), Size(0) {} 274 FoldingSetNodeIDRef(const unsigned *D, size_t S) : Data(D), Size(S) {} 275 276 /// ComputeHash - Compute a strong hash value for this FoldingSetNodeIDRef, 277 /// used to lookup the node in the FoldingSetImpl. 278 unsigned ComputeHash() const; 279 280 bool operator==(FoldingSetNodeIDRef) const; 281 282 bool operator!=(FoldingSetNodeIDRef RHS) const { return !(*this == RHS); } 283 284 /// Used to compare the "ordering" of two nodes as defined by the 285 /// profiled bits and their ordering defined by memcmp(). 286 bool operator<(FoldingSetNodeIDRef) const; 287 288 const unsigned *getData() const { return Data; } 289 size_t getSize() const { return Size; } 290 }; 291 292 //===--------------------------------------------------------------------===// 293 /// FoldingSetNodeID - This class is used to gather all the unique data bits of 294 /// a node. When all the bits are gathered this class is used to produce a 295 /// hash value for the node. 296 /// 297 class FoldingSetNodeID { 298 /// Bits - Vector of all the data bits that make the node unique. 299 /// Use a SmallVector to avoid a heap allocation in the common case. 300 SmallVector<unsigned, 32> Bits; 301 302 public: 303 FoldingSetNodeID() {} 304 305 FoldingSetNodeID(FoldingSetNodeIDRef Ref) 306 : Bits(Ref.getData(), Ref.getData() + Ref.getSize()) {} 307 308 /// Add* - Add various data types to Bit data. 309 /// 310 void AddPointer(const void *Ptr); 311 void AddInteger(signed I); 312 void AddInteger(unsigned I); 313 void AddInteger(long I); 314 void AddInteger(unsigned long I); 315 void AddInteger(long long I); 316 void AddInteger(unsigned long long I); 317 void AddBoolean(bool B) { AddInteger(B ? 1U : 0U); } 318 void AddString(StringRef String); 319 void AddNodeID(const FoldingSetNodeID &ID); 320 321 template <typename T> 322 inline void Add(const T &x) { FoldingSetTrait<T>::Profile(x, *this); } 323 324 /// clear - Clear the accumulated profile, allowing this FoldingSetNodeID 325 /// object to be used to compute a new profile. 326 inline void clear() { Bits.clear(); } 327 328 /// ComputeHash - Compute a strong hash value for this FoldingSetNodeID, used 329 /// to lookup the node in the FoldingSetImpl. 330 unsigned ComputeHash() const; 331 332 /// operator== - Used to compare two nodes to each other. 333 /// 334 bool operator==(const FoldingSetNodeID &RHS) const; 335 bool operator==(const FoldingSetNodeIDRef RHS) const; 336 337 bool operator!=(const FoldingSetNodeID &RHS) const { return !(*this == RHS); } 338 bool operator!=(const FoldingSetNodeIDRef RHS) const { return !(*this ==RHS);} 339 340 /// Used to compare the "ordering" of two nodes as defined by the 341 /// profiled bits and their ordering defined by memcmp(). 342 bool operator<(const FoldingSetNodeID &RHS) const; 343 bool operator<(const FoldingSetNodeIDRef RHS) const; 344 345 /// Intern - Copy this node's data to a memory region allocated from the 346 /// given allocator and return a FoldingSetNodeIDRef describing the 347 /// interned data. 348 FoldingSetNodeIDRef Intern(BumpPtrAllocator &Allocator) const; 349 }; 350 351 // Convenience type to hide the implementation of the folding set. 352 typedef FoldingSetImpl::Node FoldingSetNode; 353 template<class T> class FoldingSetIterator; 354 template<class T> class FoldingSetBucketIterator; 355 356 // Definitions of FoldingSetTrait and ContextualFoldingSetTrait functions, which 357 // require the definition of FoldingSetNodeID. 358 template<typename T> 359 inline bool 360 DefaultFoldingSetTrait<T>::Equals(T &X, const FoldingSetNodeID &ID, 361 unsigned /*IDHash*/, 362 FoldingSetNodeID &TempID) { 363 FoldingSetTrait<T>::Profile(X, TempID); 364 return TempID == ID; 365 } 366 template<typename T> 367 inline unsigned 368 DefaultFoldingSetTrait<T>::ComputeHash(T &X, FoldingSetNodeID &TempID) { 369 FoldingSetTrait<T>::Profile(X, TempID); 370 return TempID.ComputeHash(); 371 } 372 template<typename T, typename Ctx> 373 inline bool 374 DefaultContextualFoldingSetTrait<T, Ctx>::Equals(T &X, 375 const FoldingSetNodeID &ID, 376 unsigned /*IDHash*/, 377 FoldingSetNodeID &TempID, 378 Ctx Context) { 379 ContextualFoldingSetTrait<T, Ctx>::Profile(X, TempID, Context); 380 return TempID == ID; 381 } 382 template<typename T, typename Ctx> 383 inline unsigned 384 DefaultContextualFoldingSetTrait<T, Ctx>::ComputeHash(T &X, 385 FoldingSetNodeID &TempID, 386 Ctx Context) { 387 ContextualFoldingSetTrait<T, Ctx>::Profile(X, TempID, Context); 388 return TempID.ComputeHash(); 389 } 390 391 //===----------------------------------------------------------------------===// 392 /// FoldingSet - This template class is used to instantiate a specialized 393 /// implementation of the folding set to the node class T. T must be a 394 /// subclass of FoldingSetNode and implement a Profile function. 395 /// 396 template <class T> class FoldingSet final : public FoldingSetImpl { 397 private: 398 /// GetNodeProfile - Each instantiatation of the FoldingSet needs to provide a 399 /// way to convert nodes into a unique specifier. 400 void GetNodeProfile(Node *N, FoldingSetNodeID &ID) const override { 401 T *TN = static_cast<T *>(N); 402 FoldingSetTrait<T>::Profile(*TN, ID); 403 } 404 /// NodeEquals - Instantiations may optionally provide a way to compare a 405 /// node with a specified ID. 406 bool NodeEquals(Node *N, const FoldingSetNodeID &ID, unsigned IDHash, 407 FoldingSetNodeID &TempID) const override { 408 T *TN = static_cast<T *>(N); 409 return FoldingSetTrait<T>::Equals(*TN, ID, IDHash, TempID); 410 } 411 /// ComputeNodeHash - Instantiations may optionally provide a way to compute a 412 /// hash value directly from a node. 413 unsigned ComputeNodeHash(Node *N, FoldingSetNodeID &TempID) const override { 414 T *TN = static_cast<T *>(N); 415 return FoldingSetTrait<T>::ComputeHash(*TN, TempID); 416 } 417 418 public: 419 explicit FoldingSet(unsigned Log2InitSize = 6) 420 : FoldingSetImpl(Log2InitSize) 421 {} 422 423 typedef FoldingSetIterator<T> iterator; 424 iterator begin() { return iterator(Buckets); } 425 iterator end() { return iterator(Buckets+NumBuckets); } 426 427 typedef FoldingSetIterator<const T> const_iterator; 428 const_iterator begin() const { return const_iterator(Buckets); } 429 const_iterator end() const { return const_iterator(Buckets+NumBuckets); } 430 431 typedef FoldingSetBucketIterator<T> bucket_iterator; 432 433 bucket_iterator bucket_begin(unsigned hash) { 434 return bucket_iterator(Buckets + (hash & (NumBuckets-1))); 435 } 436 437 bucket_iterator bucket_end(unsigned hash) { 438 return bucket_iterator(Buckets + (hash & (NumBuckets-1)), true); 439 } 440 441 /// GetOrInsertNode - If there is an existing simple Node exactly 442 /// equal to the specified node, return it. Otherwise, insert 'N' and 443 /// return it instead. 444 T *GetOrInsertNode(Node *N) { 445 return static_cast<T *>(FoldingSetImpl::GetOrInsertNode(N)); 446 } 447 448 /// FindNodeOrInsertPos - Look up the node specified by ID. If it exists, 449 /// return it. If not, return the insertion token that will make insertion 450 /// faster. 451 T *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos) { 452 return static_cast<T *>(FoldingSetImpl::FindNodeOrInsertPos(ID, InsertPos)); 453 } 454 }; 455 456 //===----------------------------------------------------------------------===// 457 /// ContextualFoldingSet - This template class is a further refinement 458 /// of FoldingSet which provides a context argument when calling 459 /// Profile on its nodes. Currently, that argument is fixed at 460 /// initialization time. 461 /// 462 /// T must be a subclass of FoldingSetNode and implement a Profile 463 /// function with signature 464 /// void Profile(llvm::FoldingSetNodeID &, Ctx); 465 template <class T, class Ctx> 466 class ContextualFoldingSet final : public FoldingSetImpl { 467 // Unfortunately, this can't derive from FoldingSet<T> because the 468 // construction vtable for FoldingSet<T> requires 469 // FoldingSet<T>::GetNodeProfile to be instantiated, which in turn 470 // requires a single-argument T::Profile(). 471 472 private: 473 Ctx Context; 474 475 /// GetNodeProfile - Each instantiatation of the FoldingSet needs to provide a 476 /// way to convert nodes into a unique specifier. 477 void GetNodeProfile(FoldingSetImpl::Node *N, 478 FoldingSetNodeID &ID) const override { 479 T *TN = static_cast<T *>(N); 480 ContextualFoldingSetTrait<T, Ctx>::Profile(*TN, ID, Context); 481 } 482 bool NodeEquals(FoldingSetImpl::Node *N, const FoldingSetNodeID &ID, 483 unsigned IDHash, FoldingSetNodeID &TempID) const override { 484 T *TN = static_cast<T *>(N); 485 return ContextualFoldingSetTrait<T, Ctx>::Equals(*TN, ID, IDHash, TempID, 486 Context); 487 } 488 unsigned ComputeNodeHash(FoldingSetImpl::Node *N, 489 FoldingSetNodeID &TempID) const override { 490 T *TN = static_cast<T *>(N); 491 return ContextualFoldingSetTrait<T, Ctx>::ComputeHash(*TN, TempID, Context); 492 } 493 494 public: 495 explicit ContextualFoldingSet(Ctx Context, unsigned Log2InitSize = 6) 496 : FoldingSetImpl(Log2InitSize), Context(Context) 497 {} 498 499 Ctx getContext() const { return Context; } 500 501 502 typedef FoldingSetIterator<T> iterator; 503 iterator begin() { return iterator(Buckets); } 504 iterator end() { return iterator(Buckets+NumBuckets); } 505 506 typedef FoldingSetIterator<const T> const_iterator; 507 const_iterator begin() const { return const_iterator(Buckets); } 508 const_iterator end() const { return const_iterator(Buckets+NumBuckets); } 509 510 typedef FoldingSetBucketIterator<T> bucket_iterator; 511 512 bucket_iterator bucket_begin(unsigned hash) { 513 return bucket_iterator(Buckets + (hash & (NumBuckets-1))); 514 } 515 516 bucket_iterator bucket_end(unsigned hash) { 517 return bucket_iterator(Buckets + (hash & (NumBuckets-1)), true); 518 } 519 520 /// GetOrInsertNode - If there is an existing simple Node exactly 521 /// equal to the specified node, return it. Otherwise, insert 'N' 522 /// and return it instead. 523 T *GetOrInsertNode(Node *N) { 524 return static_cast<T *>(FoldingSetImpl::GetOrInsertNode(N)); 525 } 526 527 /// FindNodeOrInsertPos - Look up the node specified by ID. If it 528 /// exists, return it. If not, return the insertion token that will 529 /// make insertion faster. 530 T *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos) { 531 return static_cast<T *>(FoldingSetImpl::FindNodeOrInsertPos(ID, InsertPos)); 532 } 533 }; 534 535 //===----------------------------------------------------------------------===// 536 /// FoldingSetVector - This template class combines a FoldingSet and a vector 537 /// to provide the interface of FoldingSet but with deterministic iteration 538 /// order based on the insertion order. T must be a subclass of FoldingSetNode 539 /// and implement a Profile function. 540 template <class T, class VectorT = SmallVector<T*, 8> > 541 class FoldingSetVector { 542 FoldingSet<T> Set; 543 VectorT Vector; 544 545 public: 546 explicit FoldingSetVector(unsigned Log2InitSize = 6) 547 : Set(Log2InitSize) { 548 } 549 550 typedef pointee_iterator<typename VectorT::iterator> iterator; 551 iterator begin() { return Vector.begin(); } 552 iterator end() { return Vector.end(); } 553 554 typedef pointee_iterator<typename VectorT::const_iterator> const_iterator; 555 const_iterator begin() const { return Vector.begin(); } 556 const_iterator end() const { return Vector.end(); } 557 558 /// clear - Remove all nodes from the folding set. 559 void clear() { Set.clear(); Vector.clear(); } 560 561 /// FindNodeOrInsertPos - Look up the node specified by ID. If it exists, 562 /// return it. If not, return the insertion token that will make insertion 563 /// faster. 564 T *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos) { 565 return Set.FindNodeOrInsertPos(ID, InsertPos); 566 } 567 568 /// GetOrInsertNode - If there is an existing simple Node exactly 569 /// equal to the specified node, return it. Otherwise, insert 'N' and 570 /// return it instead. 571 T *GetOrInsertNode(T *N) { 572 T *Result = Set.GetOrInsertNode(N); 573 if (Result == N) Vector.push_back(N); 574 return Result; 575 } 576 577 /// InsertNode - Insert the specified node into the folding set, knowing that 578 /// it is not already in the folding set. InsertPos must be obtained from 579 /// FindNodeOrInsertPos. 580 void InsertNode(T *N, void *InsertPos) { 581 Set.InsertNode(N, InsertPos); 582 Vector.push_back(N); 583 } 584 585 /// InsertNode - Insert the specified node into the folding set, knowing that 586 /// it is not already in the folding set. 587 void InsertNode(T *N) { 588 Set.InsertNode(N); 589 Vector.push_back(N); 590 } 591 592 /// size - Returns the number of nodes in the folding set. 593 unsigned size() const { return Set.size(); } 594 595 /// empty - Returns true if there are no nodes in the folding set. 596 bool empty() const { return Set.empty(); } 597 }; 598 599 //===----------------------------------------------------------------------===// 600 /// FoldingSetIteratorImpl - This is the common iterator support shared by all 601 /// folding sets, which knows how to walk the folding set hash table. 602 class FoldingSetIteratorImpl { 603 protected: 604 FoldingSetNode *NodePtr; 605 FoldingSetIteratorImpl(void **Bucket); 606 void advance(); 607 608 public: 609 bool operator==(const FoldingSetIteratorImpl &RHS) const { 610 return NodePtr == RHS.NodePtr; 611 } 612 bool operator!=(const FoldingSetIteratorImpl &RHS) const { 613 return NodePtr != RHS.NodePtr; 614 } 615 }; 616 617 618 template<class T> 619 class FoldingSetIterator : public FoldingSetIteratorImpl { 620 public: 621 explicit FoldingSetIterator(void **Bucket) : FoldingSetIteratorImpl(Bucket) {} 622 623 T &operator*() const { 624 return *static_cast<T*>(NodePtr); 625 } 626 627 T *operator->() const { 628 return static_cast<T*>(NodePtr); 629 } 630 631 inline FoldingSetIterator &operator++() { // Preincrement 632 advance(); 633 return *this; 634 } 635 FoldingSetIterator operator++(int) { // Postincrement 636 FoldingSetIterator tmp = *this; ++*this; return tmp; 637 } 638 }; 639 640 //===----------------------------------------------------------------------===// 641 /// FoldingSetBucketIteratorImpl - This is the common bucket iterator support 642 /// shared by all folding sets, which knows how to walk a particular bucket 643 /// of a folding set hash table. 644 645 class FoldingSetBucketIteratorImpl { 646 protected: 647 void *Ptr; 648 649 explicit FoldingSetBucketIteratorImpl(void **Bucket); 650 651 FoldingSetBucketIteratorImpl(void **Bucket, bool) 652 : Ptr(Bucket) {} 653 654 void advance() { 655 void *Probe = static_cast<FoldingSetNode*>(Ptr)->getNextInBucket(); 656 uintptr_t x = reinterpret_cast<uintptr_t>(Probe) & ~0x1; 657 Ptr = reinterpret_cast<void*>(x); 658 } 659 660 public: 661 bool operator==(const FoldingSetBucketIteratorImpl &RHS) const { 662 return Ptr == RHS.Ptr; 663 } 664 bool operator!=(const FoldingSetBucketIteratorImpl &RHS) const { 665 return Ptr != RHS.Ptr; 666 } 667 }; 668 669 670 template<class T> 671 class FoldingSetBucketIterator : public FoldingSetBucketIteratorImpl { 672 public: 673 explicit FoldingSetBucketIterator(void **Bucket) : 674 FoldingSetBucketIteratorImpl(Bucket) {} 675 676 FoldingSetBucketIterator(void **Bucket, bool) : 677 FoldingSetBucketIteratorImpl(Bucket, true) {} 678 679 T &operator*() const { return *static_cast<T*>(Ptr); } 680 T *operator->() const { return static_cast<T*>(Ptr); } 681 682 inline FoldingSetBucketIterator &operator++() { // Preincrement 683 advance(); 684 return *this; 685 } 686 FoldingSetBucketIterator operator++(int) { // Postincrement 687 FoldingSetBucketIterator tmp = *this; ++*this; return tmp; 688 } 689 }; 690 691 //===----------------------------------------------------------------------===// 692 /// FoldingSetNodeWrapper - This template class is used to "wrap" arbitrary 693 /// types in an enclosing object so that they can be inserted into FoldingSets. 694 template <typename T> 695 class FoldingSetNodeWrapper : public FoldingSetNode { 696 T data; 697 public: 698 template <typename... Ts> 699 explicit FoldingSetNodeWrapper(Ts &&... Args) 700 : data(std::forward<Ts>(Args)...) {} 701 702 void Profile(FoldingSetNodeID &ID) { FoldingSetTrait<T>::Profile(data, ID); } 703 704 T &getValue() { return data; } 705 const T &getValue() const { return data; } 706 707 operator T&() { return data; } 708 operator const T&() const { return data; } 709 }; 710 711 //===----------------------------------------------------------------------===// 712 /// FastFoldingSetNode - This is a subclass of FoldingSetNode which stores 713 /// a FoldingSetNodeID value rather than requiring the node to recompute it 714 /// each time it is needed. This trades space for speed (which can be 715 /// significant if the ID is long), and it also permits nodes to drop 716 /// information that would otherwise only be required for recomputing an ID. 717 class FastFoldingSetNode : public FoldingSetNode { 718 FoldingSetNodeID FastID; 719 protected: 720 explicit FastFoldingSetNode(const FoldingSetNodeID &ID) : FastID(ID) {} 721 public: 722 void Profile(FoldingSetNodeID &ID) const { 723 ID.AddNodeID(FastID); 724 } 725 }; 726 727 //===----------------------------------------------------------------------===// 728 // Partial specializations of FoldingSetTrait. 729 730 template<typename T> struct FoldingSetTrait<T*> { 731 static inline void Profile(T *X, FoldingSetNodeID &ID) { 732 ID.AddPointer(X); 733 } 734 }; 735 template <typename T1, typename T2> 736 struct FoldingSetTrait<std::pair<T1, T2>> { 737 static inline void Profile(const std::pair<T1, T2> &P, 738 llvm::FoldingSetNodeID &ID) { 739 ID.Add(P.first); 740 ID.Add(P.second); 741 } 742 }; 743 } // End of namespace llvm. 744 745 #endif 746