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/iterator.h" 21 #include "llvm/Support/Allocator.h" 22 #include <cassert> 23 #include <cstddef> 24 #include <cstdint> 25 #include <utility> 26 27 namespace llvm { 28 29 /// This folding set used for two purposes: 30 /// 1. Given information about a node we want to create, look up the unique 31 /// instance of the node in the set. If the node already exists, return 32 /// it, otherwise return the bucket it should be inserted into. 33 /// 2. Given a node that has already been created, remove it from the set. 34 /// 35 /// This class is implemented as a single-link chained hash table, where the 36 /// "buckets" are actually the nodes themselves (the next pointer is in the 37 /// node). The last node points back to the bucket to simplify node removal. 38 /// 39 /// Any node that is to be included in the folding set must be a subclass of 40 /// FoldingSetNode. The node class must also define a Profile method used to 41 /// establish the unique bits of data for the node. The Profile method is 42 /// passed a FoldingSetNodeID object which is used to gather the bits. Just 43 /// call one of the Add* functions defined in the FoldingSetBase::NodeID class. 44 /// NOTE: That the folding set does not own the nodes and it is the 45 /// responsibility of the user to dispose of the nodes. 46 /// 47 /// Eg. 48 /// class MyNode : public FoldingSetNode { 49 /// private: 50 /// std::string Name; 51 /// unsigned Value; 52 /// public: 53 /// MyNode(const char *N, unsigned V) : Name(N), Value(V) {} 54 /// ... 55 /// void Profile(FoldingSetNodeID &ID) const { 56 /// ID.AddString(Name); 57 /// ID.AddInteger(Value); 58 /// } 59 /// ... 60 /// }; 61 /// 62 /// To define the folding set itself use the FoldingSet template; 63 /// 64 /// Eg. 65 /// FoldingSet<MyNode> MyFoldingSet; 66 /// 67 /// Four public methods are available to manipulate the folding set; 68 /// 69 /// 1) If you have an existing node that you want add to the set but unsure 70 /// that the node might already exist then call; 71 /// 72 /// MyNode *M = MyFoldingSet.GetOrInsertNode(N); 73 /// 74 /// If The result is equal to the input then the node has been inserted. 75 /// Otherwise, the result is the node existing in the folding set, and the 76 /// input can be discarded (use the result instead.) 77 /// 78 /// 2) If you are ready to construct a node but want to check if it already 79 /// exists, then call FindNodeOrInsertPos with a FoldingSetNodeID of the bits to 80 /// check; 81 /// 82 /// FoldingSetNodeID ID; 83 /// ID.AddString(Name); 84 /// ID.AddInteger(Value); 85 /// void *InsertPoint; 86 /// 87 /// MyNode *M = MyFoldingSet.FindNodeOrInsertPos(ID, InsertPoint); 88 /// 89 /// If found then M with be non-NULL, else InsertPoint will point to where it 90 /// should be inserted using InsertNode. 91 /// 92 /// 3) If you get a NULL result from FindNodeOrInsertPos then you can as a new 93 /// node with FindNodeOrInsertPos; 94 /// 95 /// InsertNode(N, InsertPoint); 96 /// 97 /// 4) Finally, if you want to remove a node from the folding set call; 98 /// 99 /// bool WasRemoved = RemoveNode(N); 100 /// 101 /// The result indicates whether the node existed in the folding set. 102 103 class FoldingSetNodeID; 104 class StringRef; 105 106 //===----------------------------------------------------------------------===// 107 /// FoldingSetBase - Implements the folding set functionality. The main 108 /// structure is an array of buckets. Each bucket is indexed by the hash of 109 /// the nodes it contains. The bucket itself points to the nodes contained 110 /// in the bucket via a singly linked list. The last node in the list points 111 /// back to the bucket to facilitate node removal. 112 /// 113 class FoldingSetBase { 114 virtual void anchor(); // Out of line virtual method. 115 116 protected: 117 /// Buckets - Array of bucket chains. 118 /// 119 void **Buckets; 120 121 /// NumBuckets - Length of the Buckets array. Always a power of 2. 122 /// 123 unsigned NumBuckets; 124 125 /// NumNodes - Number of nodes in the folding set. Growth occurs when NumNodes 126 /// is greater than twice the number of buckets. 127 unsigned NumNodes; 128 129 explicit FoldingSetBase(unsigned Log2InitSize = 6); 130 FoldingSetBase(FoldingSetBase &&Arg); 131 FoldingSetBase &operator=(FoldingSetBase &&RHS); 132 ~FoldingSetBase(); 133 134 public: 135 //===--------------------------------------------------------------------===// 136 /// Node - This class is used to maintain the singly linked bucket list in 137 /// a folding set. 138 /// 139 class Node { 140 private: 141 // NextInFoldingSetBucket - next link in the bucket list. 142 void *NextInFoldingSetBucket; 143 144 public: 145 Node() : NextInFoldingSetBucket(nullptr) {} 146 147 // Accessors 148 void *getNextInBucket() const { return NextInFoldingSetBucket; } 149 void SetNextInBucket(void *N) { NextInFoldingSetBucket = N; } 150 }; 151 152 /// clear - Remove all nodes from the folding set. 153 void clear(); 154 155 /// size - Returns the number of nodes in the folding set. 156 unsigned size() const { return NumNodes; } 157 158 /// empty - Returns true if there are no nodes in the folding set. 159 bool empty() const { return NumNodes == 0; } 160 161 /// reserve - Increase the number of buckets such that adding the 162 /// EltCount-th node won't cause a rebucket operation. reserve is permitted 163 /// to allocate more space than requested by EltCount. 164 void reserve(unsigned EltCount); 165 166 /// capacity - Returns the number of nodes permitted in the folding set 167 /// before a rebucket operation is performed. 168 unsigned capacity() { 169 // We allow a load factor of up to 2.0, 170 // so that means our capacity is NumBuckets * 2 171 return NumBuckets * 2; 172 } 173 174 private: 175 /// GrowHashTable - Double the size of the hash table and rehash everything. 176 void GrowHashTable(); 177 178 /// GrowBucketCount - resize the hash table and rehash everything. 179 /// NewBucketCount must be a power of two, and must be greater than the old 180 /// bucket count. 181 void GrowBucketCount(unsigned NewBucketCount); 182 183 protected: 184 /// GetNodeProfile - Instantiations of the FoldingSet template implement 185 /// this function to gather data bits for the given node. 186 virtual void GetNodeProfile(Node *N, FoldingSetNodeID &ID) const = 0; 187 188 /// NodeEquals - Instantiations of the FoldingSet template implement 189 /// this function to compare the given node with the given ID. 190 virtual bool NodeEquals(Node *N, const FoldingSetNodeID &ID, unsigned IDHash, 191 FoldingSetNodeID &TempID) const=0; 192 193 /// ComputeNodeHash - Instantiations of the FoldingSet template implement 194 /// this function to compute a hash value for the given node. 195 virtual unsigned ComputeNodeHash(Node *N, FoldingSetNodeID &TempID) const = 0; 196 197 // The below methods are protected to encourage subclasses to provide a more 198 // type-safe API. 199 200 /// RemoveNode - Remove a node from the folding set, returning true if one 201 /// was removed or false if the node was not in the folding set. 202 bool RemoveNode(Node *N); 203 204 /// GetOrInsertNode - If there is an existing simple Node exactly 205 /// equal to the specified node, return it. Otherwise, insert 'N' and return 206 /// it instead. 207 Node *GetOrInsertNode(Node *N); 208 209 /// FindNodeOrInsertPos - Look up the node specified by ID. If it exists, 210 /// return it. If not, return the insertion token that will make insertion 211 /// faster. 212 Node *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos); 213 214 /// InsertNode - Insert the specified node into the folding set, knowing that 215 /// it is not already in the folding set. InsertPos must be obtained from 216 /// FindNodeOrInsertPos. 217 void InsertNode(Node *N, void *InsertPos); 218 }; 219 220 //===----------------------------------------------------------------------===// 221 222 /// DefaultFoldingSetTrait - This class provides default implementations 223 /// for FoldingSetTrait implementations. 224 /// 225 template<typename T> struct DefaultFoldingSetTrait { 226 static void Profile(const T &X, FoldingSetNodeID &ID) { 227 X.Profile(ID); 228 } 229 static void Profile(T &X, FoldingSetNodeID &ID) { 230 X.Profile(ID); 231 } 232 233 // Equals - Test if the profile for X would match ID, using TempID 234 // to compute a temporary ID if necessary. The default implementation 235 // just calls Profile and does a regular comparison. Implementations 236 // can override this to provide more efficient implementations. 237 static inline bool Equals(T &X, const FoldingSetNodeID &ID, unsigned IDHash, 238 FoldingSetNodeID &TempID); 239 240 // ComputeHash - Compute a hash value for X, using TempID to 241 // compute a temporary ID if necessary. The default implementation 242 // just calls Profile and does a regular hash computation. 243 // Implementations can override this to provide more efficient 244 // implementations. 245 static inline unsigned ComputeHash(T &X, FoldingSetNodeID &TempID); 246 }; 247 248 /// FoldingSetTrait - This trait class is used to define behavior of how 249 /// to "profile" (in the FoldingSet parlance) an object of a given type. 250 /// The default behavior is to invoke a 'Profile' method on an object, but 251 /// through template specialization the behavior can be tailored for specific 252 /// types. Combined with the FoldingSetNodeWrapper class, one can add objects 253 /// to FoldingSets that were not originally designed to have that behavior. 254 template<typename T> struct FoldingSetTrait 255 : public DefaultFoldingSetTrait<T> {}; 256 257 /// DefaultContextualFoldingSetTrait - Like DefaultFoldingSetTrait, but 258 /// for ContextualFoldingSets. 259 template<typename T, typename Ctx> 260 struct DefaultContextualFoldingSetTrait { 261 static void Profile(T &X, FoldingSetNodeID &ID, Ctx Context) { 262 X.Profile(ID, Context); 263 } 264 265 static inline bool Equals(T &X, const FoldingSetNodeID &ID, unsigned IDHash, 266 FoldingSetNodeID &TempID, Ctx Context); 267 static inline unsigned ComputeHash(T &X, FoldingSetNodeID &TempID, 268 Ctx Context); 269 }; 270 271 /// ContextualFoldingSetTrait - Like FoldingSetTrait, but for 272 /// ContextualFoldingSets. 273 template<typename T, typename Ctx> struct ContextualFoldingSetTrait 274 : public DefaultContextualFoldingSetTrait<T, Ctx> {}; 275 276 //===--------------------------------------------------------------------===// 277 /// FoldingSetNodeIDRef - This class describes a reference to an interned 278 /// FoldingSetNodeID, which can be a useful to store node id data rather 279 /// than using plain FoldingSetNodeIDs, since the 32-element SmallVector 280 /// is often much larger than necessary, and the possibility of heap 281 /// allocation means it requires a non-trivial destructor call. 282 class FoldingSetNodeIDRef { 283 const unsigned *Data = nullptr; 284 size_t Size = 0; 285 286 public: 287 FoldingSetNodeIDRef() = default; 288 FoldingSetNodeIDRef(const unsigned *D, size_t S) : Data(D), Size(S) {} 289 290 /// ComputeHash - Compute a strong hash value for this FoldingSetNodeIDRef, 291 /// used to lookup the node in the FoldingSetBase. 292 unsigned ComputeHash() const; 293 294 bool operator==(FoldingSetNodeIDRef) const; 295 296 bool operator!=(FoldingSetNodeIDRef RHS) const { return !(*this == RHS); } 297 298 /// Used to compare the "ordering" of two nodes as defined by the 299 /// profiled bits and their ordering defined by memcmp(). 300 bool operator<(FoldingSetNodeIDRef) const; 301 302 const unsigned *getData() const { return Data; } 303 size_t getSize() const { return Size; } 304 }; 305 306 //===--------------------------------------------------------------------===// 307 /// FoldingSetNodeID - This class is used to gather all the unique data bits of 308 /// a node. When all the bits are gathered this class is used to produce a 309 /// hash value for the node. 310 /// 311 class FoldingSetNodeID { 312 /// Bits - Vector of all the data bits that make the node unique. 313 /// Use a SmallVector to avoid a heap allocation in the common case. 314 SmallVector<unsigned, 32> Bits; 315 316 public: 317 FoldingSetNodeID() = default; 318 319 FoldingSetNodeID(FoldingSetNodeIDRef Ref) 320 : Bits(Ref.getData(), Ref.getData() + Ref.getSize()) {} 321 322 /// Add* - Add various data types to Bit data. 323 /// 324 void AddPointer(const void *Ptr); 325 void AddInteger(signed I); 326 void AddInteger(unsigned I); 327 void AddInteger(long I); 328 void AddInteger(unsigned long I); 329 void AddInteger(long long I); 330 void AddInteger(unsigned long long I); 331 void AddBoolean(bool B) { AddInteger(B ? 1U : 0U); } 332 void AddString(StringRef String); 333 void AddNodeID(const FoldingSetNodeID &ID); 334 335 template <typename T> 336 inline void Add(const T &x) { FoldingSetTrait<T>::Profile(x, *this); } 337 338 /// clear - Clear the accumulated profile, allowing this FoldingSetNodeID 339 /// object to be used to compute a new profile. 340 inline void clear() { Bits.clear(); } 341 342 /// ComputeHash - Compute a strong hash value for this FoldingSetNodeID, used 343 /// to lookup the node in the FoldingSetBase. 344 unsigned ComputeHash() const; 345 346 /// operator== - Used to compare two nodes to each other. 347 /// 348 bool operator==(const FoldingSetNodeID &RHS) const; 349 bool operator==(const FoldingSetNodeIDRef RHS) const; 350 351 bool operator!=(const FoldingSetNodeID &RHS) const { return !(*this == RHS); } 352 bool operator!=(const FoldingSetNodeIDRef RHS) const { return !(*this ==RHS);} 353 354 /// Used to compare the "ordering" of two nodes as defined by the 355 /// profiled bits and their ordering defined by memcmp(). 356 bool operator<(const FoldingSetNodeID &RHS) const; 357 bool operator<(const FoldingSetNodeIDRef RHS) const; 358 359 /// Intern - Copy this node's data to a memory region allocated from the 360 /// given allocator and return a FoldingSetNodeIDRef describing the 361 /// interned data. 362 FoldingSetNodeIDRef Intern(BumpPtrAllocator &Allocator) const; 363 }; 364 365 // Convenience type to hide the implementation of the folding set. 366 typedef FoldingSetBase::Node FoldingSetNode; 367 template<class T> class FoldingSetIterator; 368 template<class T> class FoldingSetBucketIterator; 369 370 // Definitions of FoldingSetTrait and ContextualFoldingSetTrait functions, which 371 // require the definition of FoldingSetNodeID. 372 template<typename T> 373 inline bool 374 DefaultFoldingSetTrait<T>::Equals(T &X, const FoldingSetNodeID &ID, 375 unsigned /*IDHash*/, 376 FoldingSetNodeID &TempID) { 377 FoldingSetTrait<T>::Profile(X, TempID); 378 return TempID == ID; 379 } 380 template<typename T> 381 inline unsigned 382 DefaultFoldingSetTrait<T>::ComputeHash(T &X, FoldingSetNodeID &TempID) { 383 FoldingSetTrait<T>::Profile(X, TempID); 384 return TempID.ComputeHash(); 385 } 386 template<typename T, typename Ctx> 387 inline bool 388 DefaultContextualFoldingSetTrait<T, Ctx>::Equals(T &X, 389 const FoldingSetNodeID &ID, 390 unsigned /*IDHash*/, 391 FoldingSetNodeID &TempID, 392 Ctx Context) { 393 ContextualFoldingSetTrait<T, Ctx>::Profile(X, TempID, Context); 394 return TempID == ID; 395 } 396 template<typename T, typename Ctx> 397 inline unsigned 398 DefaultContextualFoldingSetTrait<T, Ctx>::ComputeHash(T &X, 399 FoldingSetNodeID &TempID, 400 Ctx Context) { 401 ContextualFoldingSetTrait<T, Ctx>::Profile(X, TempID, Context); 402 return TempID.ComputeHash(); 403 } 404 405 //===----------------------------------------------------------------------===// 406 /// FoldingSetImpl - An implementation detail that lets us share code between 407 /// FoldingSet and ContextualFoldingSet. 408 template <class T> class FoldingSetImpl : public FoldingSetBase { 409 protected: 410 explicit FoldingSetImpl(unsigned Log2InitSize) 411 : FoldingSetBase(Log2InitSize) {} 412 413 FoldingSetImpl(FoldingSetImpl &&Arg) = default; 414 FoldingSetImpl &operator=(FoldingSetImpl &&RHS) = default; 415 ~FoldingSetImpl() = default; 416 417 public: 418 typedef FoldingSetIterator<T> iterator; 419 iterator begin() { return iterator(Buckets); } 420 iterator end() { return iterator(Buckets+NumBuckets); } 421 422 typedef FoldingSetIterator<const T> const_iterator; 423 const_iterator begin() const { return const_iterator(Buckets); } 424 const_iterator end() const { return const_iterator(Buckets+NumBuckets); } 425 426 typedef FoldingSetBucketIterator<T> bucket_iterator; 427 428 bucket_iterator bucket_begin(unsigned hash) { 429 return bucket_iterator(Buckets + (hash & (NumBuckets-1))); 430 } 431 432 bucket_iterator bucket_end(unsigned hash) { 433 return bucket_iterator(Buckets + (hash & (NumBuckets-1)), true); 434 } 435 436 /// RemoveNode - Remove a node from the folding set, returning true if one 437 /// was removed or false if the node was not in the folding set. 438 bool RemoveNode(T *N) { return FoldingSetBase::RemoveNode(N); } 439 440 /// GetOrInsertNode - If there is an existing simple Node exactly 441 /// equal to the specified node, return it. Otherwise, insert 'N' and 442 /// return it instead. 443 T *GetOrInsertNode(T *N) { 444 return static_cast<T *>(FoldingSetBase::GetOrInsertNode(N)); 445 } 446 447 /// FindNodeOrInsertPos - Look up the node specified by ID. If it exists, 448 /// return it. If not, return the insertion token that will make insertion 449 /// faster. 450 T *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos) { 451 return static_cast<T *>(FoldingSetBase::FindNodeOrInsertPos(ID, InsertPos)); 452 } 453 454 /// InsertNode - Insert the specified node into the folding set, knowing that 455 /// it is not already in the folding set. InsertPos must be obtained from 456 /// FindNodeOrInsertPos. 457 void InsertNode(T *N, void *InsertPos) { 458 FoldingSetBase::InsertNode(N, InsertPos); 459 } 460 461 /// InsertNode - Insert the specified node into the folding set, knowing that 462 /// it is not already in the folding set. 463 void InsertNode(T *N) { 464 T *Inserted = GetOrInsertNode(N); 465 (void)Inserted; 466 assert(Inserted == N && "Node already inserted!"); 467 } 468 }; 469 470 //===----------------------------------------------------------------------===// 471 /// FoldingSet - This template class is used to instantiate a specialized 472 /// implementation of the folding set to the node class T. T must be a 473 /// subclass of FoldingSetNode and implement a Profile function. 474 /// 475 /// Note that this set type is movable and move-assignable. However, its 476 /// moved-from state is not a valid state for anything other than 477 /// move-assigning and destroying. This is primarily to enable movable APIs 478 /// that incorporate these objects. 479 template <class T> class FoldingSet final : public FoldingSetImpl<T> { 480 using Super = FoldingSetImpl<T>; 481 using Node = typename Super::Node; 482 483 /// GetNodeProfile - Each instantiatation of the FoldingSet needs to provide a 484 /// way to convert nodes into a unique specifier. 485 void GetNodeProfile(Node *N, FoldingSetNodeID &ID) const override { 486 T *TN = static_cast<T *>(N); 487 FoldingSetTrait<T>::Profile(*TN, ID); 488 } 489 490 /// NodeEquals - Instantiations may optionally provide a way to compare a 491 /// node with a specified ID. 492 bool NodeEquals(Node *N, const FoldingSetNodeID &ID, unsigned IDHash, 493 FoldingSetNodeID &TempID) const override { 494 T *TN = static_cast<T *>(N); 495 return FoldingSetTrait<T>::Equals(*TN, ID, IDHash, TempID); 496 } 497 498 /// ComputeNodeHash - Instantiations may optionally provide a way to compute a 499 /// hash value directly from a node. 500 unsigned ComputeNodeHash(Node *N, FoldingSetNodeID &TempID) const override { 501 T *TN = static_cast<T *>(N); 502 return FoldingSetTrait<T>::ComputeHash(*TN, TempID); 503 } 504 505 public: 506 explicit FoldingSet(unsigned Log2InitSize = 6) 507 : Super(Log2InitSize) {} 508 509 FoldingSet(FoldingSet &&Arg) = default; 510 FoldingSet &operator=(FoldingSet &&RHS) = default; 511 }; 512 513 //===----------------------------------------------------------------------===// 514 /// ContextualFoldingSet - This template class is a further refinement 515 /// of FoldingSet which provides a context argument when calling 516 /// Profile on its nodes. Currently, that argument is fixed at 517 /// initialization time. 518 /// 519 /// T must be a subclass of FoldingSetNode and implement a Profile 520 /// function with signature 521 /// void Profile(FoldingSetNodeID &, Ctx); 522 template <class T, class Ctx> 523 class ContextualFoldingSet final : public FoldingSetImpl<T> { 524 // Unfortunately, this can't derive from FoldingSet<T> because the 525 // construction of the vtable for FoldingSet<T> requires 526 // FoldingSet<T>::GetNodeProfile to be instantiated, which in turn 527 // requires a single-argument T::Profile(). 528 529 using Super = FoldingSetImpl<T>; 530 using Node = typename Super::Node; 531 532 Ctx Context; 533 534 /// GetNodeProfile - Each instantiatation of the FoldingSet needs to provide a 535 /// way to convert nodes into a unique specifier. 536 void GetNodeProfile(Node *N, FoldingSetNodeID &ID) const override { 537 T *TN = static_cast<T *>(N); 538 ContextualFoldingSetTrait<T, Ctx>::Profile(*TN, ID, Context); 539 } 540 541 bool NodeEquals(Node *N, const FoldingSetNodeID &ID, unsigned IDHash, 542 FoldingSetNodeID &TempID) const override { 543 T *TN = static_cast<T *>(N); 544 return ContextualFoldingSetTrait<T, Ctx>::Equals(*TN, ID, IDHash, TempID, 545 Context); 546 } 547 548 unsigned ComputeNodeHash(Node *N, FoldingSetNodeID &TempID) const override { 549 T *TN = static_cast<T *>(N); 550 return ContextualFoldingSetTrait<T, Ctx>::ComputeHash(*TN, TempID, Context); 551 } 552 553 public: 554 explicit ContextualFoldingSet(Ctx Context, unsigned Log2InitSize = 6) 555 : Super(Log2InitSize), Context(Context) 556 {} 557 558 Ctx getContext() const { return Context; } 559 }; 560 561 //===----------------------------------------------------------------------===// 562 /// FoldingSetVector - This template class combines a FoldingSet and a vector 563 /// to provide the interface of FoldingSet but with deterministic iteration 564 /// order based on the insertion order. T must be a subclass of FoldingSetNode 565 /// and implement a Profile function. 566 template <class T, class VectorT = SmallVector<T*, 8>> 567 class FoldingSetVector { 568 FoldingSet<T> Set; 569 VectorT Vector; 570 571 public: 572 explicit FoldingSetVector(unsigned Log2InitSize = 6) 573 : Set(Log2InitSize) { 574 } 575 576 typedef pointee_iterator<typename VectorT::iterator> iterator; 577 iterator begin() { return Vector.begin(); } 578 iterator end() { return Vector.end(); } 579 580 typedef pointee_iterator<typename VectorT::const_iterator> const_iterator; 581 const_iterator begin() const { return Vector.begin(); } 582 const_iterator end() const { return Vector.end(); } 583 584 /// clear - Remove all nodes from the folding set. 585 void clear() { Set.clear(); Vector.clear(); } 586 587 /// FindNodeOrInsertPos - Look up the node specified by ID. If it exists, 588 /// return it. If not, return the insertion token that will make insertion 589 /// faster. 590 T *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos) { 591 return Set.FindNodeOrInsertPos(ID, InsertPos); 592 } 593 594 /// GetOrInsertNode - If there is an existing simple Node exactly 595 /// equal to the specified node, return it. Otherwise, insert 'N' and 596 /// return it instead. 597 T *GetOrInsertNode(T *N) { 598 T *Result = Set.GetOrInsertNode(N); 599 if (Result == N) Vector.push_back(N); 600 return Result; 601 } 602 603 /// InsertNode - Insert the specified node into the folding set, knowing that 604 /// it is not already in the folding set. InsertPos must be obtained from 605 /// FindNodeOrInsertPos. 606 void InsertNode(T *N, void *InsertPos) { 607 Set.InsertNode(N, InsertPos); 608 Vector.push_back(N); 609 } 610 611 /// InsertNode - Insert the specified node into the folding set, knowing that 612 /// it is not already in the folding set. 613 void InsertNode(T *N) { 614 Set.InsertNode(N); 615 Vector.push_back(N); 616 } 617 618 /// size - Returns the number of nodes in the folding set. 619 unsigned size() const { return Set.size(); } 620 621 /// empty - Returns true if there are no nodes in the folding set. 622 bool empty() const { return Set.empty(); } 623 }; 624 625 //===----------------------------------------------------------------------===// 626 /// FoldingSetIteratorImpl - This is the common iterator support shared by all 627 /// folding sets, which knows how to walk the folding set hash table. 628 class FoldingSetIteratorImpl { 629 protected: 630 FoldingSetNode *NodePtr; 631 632 FoldingSetIteratorImpl(void **Bucket); 633 634 void advance(); 635 636 public: 637 bool operator==(const FoldingSetIteratorImpl &RHS) const { 638 return NodePtr == RHS.NodePtr; 639 } 640 bool operator!=(const FoldingSetIteratorImpl &RHS) const { 641 return NodePtr != RHS.NodePtr; 642 } 643 }; 644 645 template <class T> class FoldingSetIterator : public FoldingSetIteratorImpl { 646 public: 647 explicit FoldingSetIterator(void **Bucket) : FoldingSetIteratorImpl(Bucket) {} 648 649 T &operator*() const { 650 return *static_cast<T*>(NodePtr); 651 } 652 653 T *operator->() const { 654 return static_cast<T*>(NodePtr); 655 } 656 657 inline FoldingSetIterator &operator++() { // Preincrement 658 advance(); 659 return *this; 660 } 661 FoldingSetIterator operator++(int) { // Postincrement 662 FoldingSetIterator tmp = *this; ++*this; return tmp; 663 } 664 }; 665 666 //===----------------------------------------------------------------------===// 667 /// FoldingSetBucketIteratorImpl - This is the common bucket iterator support 668 /// shared by all folding sets, which knows how to walk a particular bucket 669 /// of a folding set hash table. 670 671 class FoldingSetBucketIteratorImpl { 672 protected: 673 void *Ptr; 674 675 explicit FoldingSetBucketIteratorImpl(void **Bucket); 676 677 FoldingSetBucketIteratorImpl(void **Bucket, bool) 678 : Ptr(Bucket) {} 679 680 void advance() { 681 void *Probe = static_cast<FoldingSetNode*>(Ptr)->getNextInBucket(); 682 uintptr_t x = reinterpret_cast<uintptr_t>(Probe) & ~0x1; 683 Ptr = reinterpret_cast<void*>(x); 684 } 685 686 public: 687 bool operator==(const FoldingSetBucketIteratorImpl &RHS) const { 688 return Ptr == RHS.Ptr; 689 } 690 bool operator!=(const FoldingSetBucketIteratorImpl &RHS) const { 691 return Ptr != RHS.Ptr; 692 } 693 }; 694 695 template <class T> 696 class FoldingSetBucketIterator : public FoldingSetBucketIteratorImpl { 697 public: 698 explicit FoldingSetBucketIterator(void **Bucket) : 699 FoldingSetBucketIteratorImpl(Bucket) {} 700 701 FoldingSetBucketIterator(void **Bucket, bool) : 702 FoldingSetBucketIteratorImpl(Bucket, true) {} 703 704 T &operator*() const { return *static_cast<T*>(Ptr); } 705 T *operator->() const { return static_cast<T*>(Ptr); } 706 707 inline FoldingSetBucketIterator &operator++() { // Preincrement 708 advance(); 709 return *this; 710 } 711 FoldingSetBucketIterator operator++(int) { // Postincrement 712 FoldingSetBucketIterator tmp = *this; ++*this; return tmp; 713 } 714 }; 715 716 //===----------------------------------------------------------------------===// 717 /// FoldingSetNodeWrapper - This template class is used to "wrap" arbitrary 718 /// types in an enclosing object so that they can be inserted into FoldingSets. 719 template <typename T> 720 class FoldingSetNodeWrapper : public FoldingSetNode { 721 T data; 722 723 public: 724 template <typename... Ts> 725 explicit FoldingSetNodeWrapper(Ts &&... Args) 726 : data(std::forward<Ts>(Args)...) {} 727 728 void Profile(FoldingSetNodeID &ID) { FoldingSetTrait<T>::Profile(data, ID); } 729 730 T &getValue() { return data; } 731 const T &getValue() const { return data; } 732 733 operator T&() { return data; } 734 operator const T&() const { return data; } 735 }; 736 737 //===----------------------------------------------------------------------===// 738 /// FastFoldingSetNode - This is a subclass of FoldingSetNode which stores 739 /// a FoldingSetNodeID value rather than requiring the node to recompute it 740 /// each time it is needed. This trades space for speed (which can be 741 /// significant if the ID is long), and it also permits nodes to drop 742 /// information that would otherwise only be required for recomputing an ID. 743 class FastFoldingSetNode : public FoldingSetNode { 744 FoldingSetNodeID FastID; 745 746 protected: 747 explicit FastFoldingSetNode(const FoldingSetNodeID &ID) : FastID(ID) {} 748 749 public: 750 void Profile(FoldingSetNodeID &ID) const { ID.AddNodeID(FastID); } 751 }; 752 753 //===----------------------------------------------------------------------===// 754 // Partial specializations of FoldingSetTrait. 755 756 template<typename T> struct FoldingSetTrait<T*> { 757 static inline void Profile(T *X, FoldingSetNodeID &ID) { 758 ID.AddPointer(X); 759 } 760 }; 761 template <typename T1, typename T2> 762 struct FoldingSetTrait<std::pair<T1, T2>> { 763 static inline void Profile(const std::pair<T1, T2> &P, 764 FoldingSetNodeID &ID) { 765 ID.Add(P.first); 766 ID.Add(P.second); 767 } 768 }; 769 770 } // end namespace llvm 771 772 #endif // LLVM_ADT_FOLDINGSET_H 773