FoldingSet.h revision 3063410e52a760584501b825dc6ffb4c52f4d93b
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/System/DataTypes.h" 20#include "llvm/ADT/SmallVector.h" 21#include "llvm/ADT/StringRef.h" 22 23namespace llvm { 24 class APFloat; 25 class APInt; 26 class BumpPtrAllocator; 27 28/// This folding set used for two purposes: 29/// 1. Given information about a node we want to create, look up the unique 30/// instance of the node in the set. If the node already exists, return 31/// it, otherwise return the bucket it should be inserted into. 32/// 2. Given a node that has already been created, remove it from the set. 33/// 34/// This class is implemented as a single-link chained hash table, where the 35/// "buckets" are actually the nodes themselves (the next pointer is in the 36/// node). The last node points back to the bucket to simplify node removal. 37/// 38/// Any node that is to be included in the folding set must be a subclass of 39/// FoldingSetNode. The node class must also define a Profile method used to 40/// establish the unique bits of data for the node. The Profile method is 41/// passed a FoldingSetNodeID object which is used to gather the bits. Just 42/// call one of the Add* functions defined in the FoldingSetImpl::NodeID class. 43/// NOTE: That the folding set does not own the nodes and it is the 44/// responsibility of the user to dispose of the nodes. 45/// 46/// Eg. 47/// class MyNode : public FoldingSetNode { 48/// private: 49/// std::string Name; 50/// unsigned Value; 51/// public: 52/// MyNode(const char *N, unsigned V) : Name(N), Value(V) {} 53/// ... 54/// void Profile(FoldingSetNodeID &ID) const { 55/// ID.AddString(Name); 56/// ID.AddInteger(Value); 57/// } 58/// ... 59/// }; 60/// 61/// To define the folding set itself use the FoldingSet template; 62/// 63/// Eg. 64/// FoldingSet<MyNode> MyFoldingSet; 65/// 66/// Four public methods are available to manipulate the folding set; 67/// 68/// 1) If you have an existing node that you want add to the set but unsure 69/// that the node might already exist then call; 70/// 71/// MyNode *M = MyFoldingSet.GetOrInsertNode(N); 72/// 73/// If The result is equal to the input then the node has been inserted. 74/// Otherwise, the result is the node existing in the folding set, and the 75/// input can be discarded (use the result instead.) 76/// 77/// 2) If you are ready to construct a node but want to check if it already 78/// exists, then call FindNodeOrInsertPos with a FoldingSetNodeID of the bits to 79/// check; 80/// 81/// FoldingSetNodeID ID; 82/// ID.AddString(Name); 83/// ID.AddInteger(Value); 84/// void *InsertPoint; 85/// 86/// MyNode *M = MyFoldingSet.FindNodeOrInsertPos(ID, InsertPoint); 87/// 88/// If found then M with be non-NULL, else InsertPoint will point to where it 89/// should be inserted using InsertNode. 90/// 91/// 3) If you get a NULL result from FindNodeOrInsertPos then you can as a new 92/// node with FindNodeOrInsertPos; 93/// 94/// InsertNode(N, InsertPoint); 95/// 96/// 4) Finally, if you want to remove a node from the folding set call; 97/// 98/// bool WasRemoved = RemoveNode(N); 99/// 100/// The result indicates whether the node existed in the folding set. 101 102class FoldingSetNodeID; 103 104//===----------------------------------------------------------------------===// 105/// FoldingSetImpl - Implements the folding set functionality. The main 106/// structure is an array of buckets. Each bucket is indexed by the hash of 107/// the nodes it contains. The bucket itself points to the nodes contained 108/// in the bucket via a singly linked list. The last node in the list points 109/// back to the bucket to facilitate node removal. 110/// 111class FoldingSetImpl { 112protected: 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 125public: 126 explicit FoldingSetImpl(unsigned Log2InitSize = 6); 127 virtual ~FoldingSetImpl(); 128 129 //===--------------------------------------------------------------------===// 130 /// Node - This class is used to maintain the singly linked bucket list in 131 /// a folding set. 132 /// 133 class Node { 134 private: 135 // NextInFoldingSetBucket - next link in the bucket list. 136 void *NextInFoldingSetBucket; 137 138 public: 139 140 Node() : NextInFoldingSetBucket(0) {} 141 142 // Accessors 143 void *getNextInBucket() const { return NextInFoldingSetBucket; } 144 void SetNextInBucket(void *N) { NextInFoldingSetBucket = N; } 145 }; 146 147 /// clear - Remove all nodes from the folding set. 148 void clear(); 149 150 /// RemoveNode - Remove a node from the folding set, returning true if one 151 /// was removed or false if the node was not in the folding set. 152 bool RemoveNode(Node *N); 153 154 /// GetOrInsertNode - If there is an existing simple Node exactly 155 /// equal to the specified node, return it. Otherwise, insert 'N' and return 156 /// it instead. 157 Node *GetOrInsertNode(Node *N); 158 159 /// FindNodeOrInsertPos - Look up the node specified by ID. If it exists, 160 /// return it. If not, return the insertion token that will make insertion 161 /// faster. 162 Node *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos); 163 164 /// InsertNode - Insert the specified node into the folding set, knowing that 165 /// it is not already in the folding set. InsertPos must be obtained from 166 /// FindNodeOrInsertPos. 167 void InsertNode(Node *N, void *InsertPos); 168 169 /// InsertNode - Insert the specified node into the folding set, knowing that 170 /// it is not already in the folding set. 171 void InsertNode(Node *N) { 172 Node *Inserted = GetOrInsertNode(N); 173 (void)Inserted; 174 assert(Inserted == N && "Node already inserted!"); 175 } 176 177 /// size - Returns the number of nodes in the folding set. 178 unsigned size() const { return NumNodes; } 179 180 /// empty - Returns true if there are no nodes in the folding set. 181 bool empty() const { return NumNodes == 0; } 182 183private: 184 185 /// GrowHashTable - Double the size of the hash table and rehash everything. 186 /// 187 void GrowHashTable(); 188 189protected: 190 191 /// GetNodeProfile - Instantiations of the FoldingSet template implement 192 /// this function to gather data bits for the given node. 193 virtual void GetNodeProfile(Node *N, FoldingSetNodeID &ID) const = 0; 194 /// NodeEquals - Instantiations of the FoldingSet template implement 195 /// this function to compare the given node with the given ID. 196 virtual bool NodeEquals(Node *N, const FoldingSetNodeID &ID, 197 FoldingSetNodeID &TempID) const=0; 198 /// NodeEquals - Instantiations of the FoldingSet template implement 199 /// this function to compute a hash value for the given node. 200 virtual unsigned ComputeNodeHash(Node *N, 201 FoldingSetNodeID &TempID) const = 0; 202}; 203 204//===----------------------------------------------------------------------===// 205 206template<typename T> struct FoldingSetTrait; 207 208/// DefaultFoldingSetTrait - This class provides default implementations 209/// for FoldingSetTrait implementations. 210/// 211template<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, 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. 240template<typename T> struct FoldingSetTrait 241 : public DefaultFoldingSetTrait<T> {}; 242 243template<typename T, typename Ctx> struct ContextualFoldingSetTrait; 244 245/// DefaultContextualFoldingSetTrait - Like DefaultFoldingSetTrait, but 246/// for ContextualFoldingSets. 247template<typename T, typename Ctx> 248struct 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, 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. 260template<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. 269class FoldingSetNodeIDRef { 270 const unsigned* Data; 271 size_t Size; 272public: 273 FoldingSetNodeIDRef() : Data(0), 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 const unsigned *getData() const { return Data; } 283 size_t getSize() const { return Size; } 284}; 285 286//===--------------------------------------------------------------------===// 287/// FoldingSetNodeID - This class is used to gather all the unique data bits of 288/// a node. When all the bits are gathered this class is used to produce a 289/// hash value for the node. 290/// 291class FoldingSetNodeID { 292 /// Bits - Vector of all the data bits that make the node unique. 293 /// Use a SmallVector to avoid a heap allocation in the common case. 294 SmallVector<unsigned, 32> Bits; 295 296public: 297 FoldingSetNodeID() {} 298 299 FoldingSetNodeID(FoldingSetNodeIDRef Ref) 300 : Bits(Ref.getData(), Ref.getData() + Ref.getSize()) {} 301 302 /// Add* - Add various data types to Bit data. 303 /// 304 void AddPointer(const void *Ptr); 305 void AddInteger(signed I); 306 void AddInteger(unsigned I); 307 void AddInteger(long I); 308 void AddInteger(unsigned long I); 309 void AddInteger(long long I); 310 void AddInteger(unsigned long long I); 311 void AddBoolean(bool B) { AddInteger(B ? 1U : 0U); } 312 void AddString(StringRef String); 313 314 template <typename T> 315 inline void Add(const T& x) { FoldingSetTrait<T>::Profile(x, *this); } 316 317 /// clear - Clear the accumulated profile, allowing this FoldingSetNodeID 318 /// object to be used to compute a new profile. 319 inline void clear() { Bits.clear(); } 320 321 /// ComputeHash - Compute a strong hash value for this FoldingSetNodeID, used 322 /// to lookup the node in the FoldingSetImpl. 323 unsigned ComputeHash() const; 324 325 /// operator== - Used to compare two nodes to each other. 326 /// 327 bool operator==(const FoldingSetNodeID &RHS) const; 328 bool operator==(const FoldingSetNodeIDRef RHS) const; 329 330 /// Intern - Copy this node's data to a memory region allocated from the 331 /// given allocator and return a FoldingSetNodeIDRef describing the 332 /// interned data. 333 FoldingSetNodeIDRef Intern(BumpPtrAllocator &Allocator) const; 334}; 335 336// Convenience type to hide the implementation of the folding set. 337typedef FoldingSetImpl::Node FoldingSetNode; 338template<class T> class FoldingSetIterator; 339template<class T> class FoldingSetBucketIterator; 340 341// Definitions of FoldingSetTrait and ContextualFoldingSetTrait functions, which 342// require the definition of FoldingSetNodeID. 343template<typename T> 344inline bool 345DefaultFoldingSetTrait<T>::Equals(T &X, const FoldingSetNodeID &ID, 346 FoldingSetNodeID &TempID) { 347 FoldingSetTrait<T>::Profile(X, TempID); 348 return TempID == ID; 349} 350template<typename T> 351inline unsigned 352DefaultFoldingSetTrait<T>::ComputeHash(T &X, FoldingSetNodeID &TempID) { 353 FoldingSetTrait<T>::Profile(X, TempID); 354 return TempID.ComputeHash(); 355} 356template<typename T, typename Ctx> 357inline bool 358DefaultContextualFoldingSetTrait<T, Ctx>::Equals(T &X, 359 const FoldingSetNodeID &ID, 360 FoldingSetNodeID &TempID, 361 Ctx Context) { 362 ContextualFoldingSetTrait<T, Ctx>::Profile(X, TempID, Context); 363 return TempID == ID; 364} 365template<typename T, typename Ctx> 366inline unsigned 367DefaultContextualFoldingSetTrait<T, Ctx>::ComputeHash(T &X, 368 FoldingSetNodeID &TempID, 369 Ctx Context) { 370 ContextualFoldingSetTrait<T, Ctx>::Profile(X, TempID, Context); 371 return TempID.ComputeHash(); 372} 373 374//===----------------------------------------------------------------------===// 375/// FoldingSet - This template class is used to instantiate a specialized 376/// implementation of the folding set to the node class T. T must be a 377/// subclass of FoldingSetNode and implement a Profile function. 378/// 379template<class T> class FoldingSet : public FoldingSetImpl { 380private: 381 /// GetNodeProfile - Each instantiatation of the FoldingSet needs to provide a 382 /// way to convert nodes into a unique specifier. 383 virtual void GetNodeProfile(Node *N, FoldingSetNodeID &ID) const { 384 T *TN = static_cast<T *>(N); 385 FoldingSetTrait<T>::Profile(*TN, ID); 386 } 387 /// NodeEquals - Instantiations may optionally provide a way to compare a 388 /// node with a specified ID. 389 virtual bool NodeEquals(Node *N, const FoldingSetNodeID &ID, 390 FoldingSetNodeID &TempID) const { 391 T *TN = static_cast<T *>(N); 392 return FoldingSetTrait<T>::Equals(*TN, ID, TempID); 393 } 394 /// NodeEquals - Instantiations may optionally provide a way to compute a 395 /// hash value directly from a node. 396 virtual unsigned ComputeNodeHash(Node *N, 397 FoldingSetNodeID &TempID) const { 398 T *TN = static_cast<T *>(N); 399 return FoldingSetTrait<T>::ComputeHash(*TN, TempID); 400 } 401 402public: 403 explicit FoldingSet(unsigned Log2InitSize = 6) 404 : FoldingSetImpl(Log2InitSize) 405 {} 406 407 typedef FoldingSetIterator<T> iterator; 408 iterator begin() { return iterator(Buckets); } 409 iterator end() { return iterator(Buckets+NumBuckets); } 410 411 typedef FoldingSetIterator<const T> const_iterator; 412 const_iterator begin() const { return const_iterator(Buckets); } 413 const_iterator end() const { return const_iterator(Buckets+NumBuckets); } 414 415 typedef FoldingSetBucketIterator<T> bucket_iterator; 416 417 bucket_iterator bucket_begin(unsigned hash) { 418 return bucket_iterator(Buckets + (hash & (NumBuckets-1))); 419 } 420 421 bucket_iterator bucket_end(unsigned hash) { 422 return bucket_iterator(Buckets + (hash & (NumBuckets-1)), true); 423 } 424 425 /// GetOrInsertNode - If there is an existing simple Node exactly 426 /// equal to the specified node, return it. Otherwise, insert 'N' and 427 /// return it instead. 428 T *GetOrInsertNode(Node *N) { 429 return static_cast<T *>(FoldingSetImpl::GetOrInsertNode(N)); 430 } 431 432 /// FindNodeOrInsertPos - Look up the node specified by ID. If it exists, 433 /// return it. If not, return the insertion token that will make insertion 434 /// faster. 435 T *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos) { 436 return static_cast<T *>(FoldingSetImpl::FindNodeOrInsertPos(ID, InsertPos)); 437 } 438}; 439 440//===----------------------------------------------------------------------===// 441/// ContextualFoldingSet - This template class is a further refinement 442/// of FoldingSet which provides a context argument when calling 443/// Profile on its nodes. Currently, that argument is fixed at 444/// initialization time. 445/// 446/// T must be a subclass of FoldingSetNode and implement a Profile 447/// function with signature 448/// void Profile(llvm::FoldingSetNodeID &, Ctx); 449template <class T, class Ctx> 450class ContextualFoldingSet : public FoldingSetImpl { 451 // Unfortunately, this can't derive from FoldingSet<T> because the 452 // construction vtable for FoldingSet<T> requires 453 // FoldingSet<T>::GetNodeProfile to be instantiated, which in turn 454 // requires a single-argument T::Profile(). 455 456private: 457 Ctx Context; 458 459 /// GetNodeProfile - Each instantiatation of the FoldingSet needs to provide a 460 /// way to convert nodes into a unique specifier. 461 virtual void GetNodeProfile(FoldingSetImpl::Node *N, 462 FoldingSetNodeID &ID) const { 463 T *TN = static_cast<T *>(N); 464 ContextualFoldingSetTrait<T, Ctx>::Profile(*TN, ID, Context); 465 } 466 virtual bool NodeEquals(FoldingSetImpl::Node *N, 467 const FoldingSetNodeID &ID, 468 FoldingSetNodeID &TempID) const { 469 T *TN = static_cast<T *>(N); 470 return ContextualFoldingSetTrait<T, Ctx>::Equals(*TN, ID, TempID, Context); 471 } 472 virtual unsigned ComputeNodeHash(FoldingSetImpl::Node *N, 473 FoldingSetNodeID &TempID) const { 474 T *TN = static_cast<T *>(N); 475 return ContextualFoldingSetTrait<T, Ctx>::ComputeHash(*TN, TempID, Context); 476 } 477 478public: 479 explicit ContextualFoldingSet(Ctx Context, unsigned Log2InitSize = 6) 480 : FoldingSetImpl(Log2InitSize), Context(Context) 481 {} 482 483 Ctx getContext() const { return Context; } 484 485 486 typedef FoldingSetIterator<T> iterator; 487 iterator begin() { return iterator(Buckets); } 488 iterator end() { return iterator(Buckets+NumBuckets); } 489 490 typedef FoldingSetIterator<const T> const_iterator; 491 const_iterator begin() const { return const_iterator(Buckets); } 492 const_iterator end() const { return const_iterator(Buckets+NumBuckets); } 493 494 typedef FoldingSetBucketIterator<T> bucket_iterator; 495 496 bucket_iterator bucket_begin(unsigned hash) { 497 return bucket_iterator(Buckets + (hash & (NumBuckets-1))); 498 } 499 500 bucket_iterator bucket_end(unsigned hash) { 501 return bucket_iterator(Buckets + (hash & (NumBuckets-1)), true); 502 } 503 504 /// GetOrInsertNode - If there is an existing simple Node exactly 505 /// equal to the specified node, return it. Otherwise, insert 'N' 506 /// and return it instead. 507 T *GetOrInsertNode(Node *N) { 508 return static_cast<T *>(FoldingSetImpl::GetOrInsertNode(N)); 509 } 510 511 /// FindNodeOrInsertPos - Look up the node specified by ID. If it 512 /// exists, return it. If not, return the insertion token that will 513 /// make insertion faster. 514 T *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos) { 515 return static_cast<T *>(FoldingSetImpl::FindNodeOrInsertPos(ID, InsertPos)); 516 } 517}; 518 519//===----------------------------------------------------------------------===// 520/// FoldingSetIteratorImpl - This is the common iterator support shared by all 521/// folding sets, which knows how to walk the folding set hash table. 522class FoldingSetIteratorImpl { 523protected: 524 FoldingSetNode *NodePtr; 525 FoldingSetIteratorImpl(void **Bucket); 526 void advance(); 527 528public: 529 bool operator==(const FoldingSetIteratorImpl &RHS) const { 530 return NodePtr == RHS.NodePtr; 531 } 532 bool operator!=(const FoldingSetIteratorImpl &RHS) const { 533 return NodePtr != RHS.NodePtr; 534 } 535}; 536 537 538template<class T> 539class FoldingSetIterator : public FoldingSetIteratorImpl { 540public: 541 explicit FoldingSetIterator(void **Bucket) : FoldingSetIteratorImpl(Bucket) {} 542 543 T &operator*() const { 544 return *static_cast<T*>(NodePtr); 545 } 546 547 T *operator->() const { 548 return static_cast<T*>(NodePtr); 549 } 550 551 inline FoldingSetIterator& operator++() { // Preincrement 552 advance(); 553 return *this; 554 } 555 FoldingSetIterator operator++(int) { // Postincrement 556 FoldingSetIterator tmp = *this; ++*this; return tmp; 557 } 558}; 559 560//===----------------------------------------------------------------------===// 561/// FoldingSetBucketIteratorImpl - This is the common bucket iterator support 562/// shared by all folding sets, which knows how to walk a particular bucket 563/// of a folding set hash table. 564 565class FoldingSetBucketIteratorImpl { 566protected: 567 void *Ptr; 568 569 explicit FoldingSetBucketIteratorImpl(void **Bucket); 570 571 FoldingSetBucketIteratorImpl(void **Bucket, bool) 572 : Ptr(Bucket) {} 573 574 void advance() { 575 void *Probe = static_cast<FoldingSetNode*>(Ptr)->getNextInBucket(); 576 uintptr_t x = reinterpret_cast<uintptr_t>(Probe) & ~0x1; 577 Ptr = reinterpret_cast<void*>(x); 578 } 579 580public: 581 bool operator==(const FoldingSetBucketIteratorImpl &RHS) const { 582 return Ptr == RHS.Ptr; 583 } 584 bool operator!=(const FoldingSetBucketIteratorImpl &RHS) const { 585 return Ptr != RHS.Ptr; 586 } 587}; 588 589 590template<class T> 591class FoldingSetBucketIterator : public FoldingSetBucketIteratorImpl { 592public: 593 explicit FoldingSetBucketIterator(void **Bucket) : 594 FoldingSetBucketIteratorImpl(Bucket) {} 595 596 FoldingSetBucketIterator(void **Bucket, bool) : 597 FoldingSetBucketIteratorImpl(Bucket, true) {} 598 599 T& operator*() const { return *static_cast<T*>(Ptr); } 600 T* operator->() const { return static_cast<T*>(Ptr); } 601 602 inline FoldingSetBucketIterator& operator++() { // Preincrement 603 advance(); 604 return *this; 605 } 606 FoldingSetBucketIterator operator++(int) { // Postincrement 607 FoldingSetBucketIterator tmp = *this; ++*this; return tmp; 608 } 609}; 610 611//===----------------------------------------------------------------------===// 612/// FoldingSetNodeWrapper - This template class is used to "wrap" arbitrary 613/// types in an enclosing object so that they can be inserted into FoldingSets. 614template <typename T> 615class FoldingSetNodeWrapper : public FoldingSetNode { 616 T data; 617public: 618 explicit FoldingSetNodeWrapper(const T& x) : data(x) {} 619 virtual ~FoldingSetNodeWrapper() {} 620 621 template<typename A1> 622 explicit FoldingSetNodeWrapper(const A1& a1) 623 : data(a1) {} 624 625 template <typename A1, typename A2> 626 explicit FoldingSetNodeWrapper(const A1& a1, const A2& a2) 627 : data(a1,a2) {} 628 629 template <typename A1, typename A2, typename A3> 630 explicit FoldingSetNodeWrapper(const A1& a1, const A2& a2, const A3& a3) 631 : data(a1,a2,a3) {} 632 633 template <typename A1, typename A2, typename A3, typename A4> 634 explicit FoldingSetNodeWrapper(const A1& a1, const A2& a2, const A3& a3, 635 const A4& a4) 636 : data(a1,a2,a3,a4) {} 637 638 template <typename A1, typename A2, typename A3, typename A4, typename A5> 639 explicit FoldingSetNodeWrapper(const A1& a1, const A2& a2, const A3& a3, 640 const A4& a4, const A5& a5) 641 : data(a1,a2,a3,a4,a5) {} 642 643 644 void Profile(FoldingSetNodeID& ID) { FoldingSetTrait<T>::Profile(data, ID); } 645 646 T& getValue() { return data; } 647 const T& getValue() const { return data; } 648 649 operator T&() { return data; } 650 operator const T&() const { return data; } 651}; 652 653//===----------------------------------------------------------------------===// 654/// FastFoldingSetNode - This is a subclass of FoldingSetNode which stores 655/// a FoldingSetNodeID value rather than requiring the node to recompute it 656/// each time it is needed. This trades space for speed (which can be 657/// significant if the ID is long), and it also permits nodes to drop 658/// information that would otherwise only be required for recomputing an ID. 659class FastFoldingSetNode : public FoldingSetNode { 660 FoldingSetNodeID FastID; 661protected: 662 explicit FastFoldingSetNode(const FoldingSetNodeID &ID) : FastID(ID) {} 663public: 664 void Profile(FoldingSetNodeID& ID) const { ID = FastID; } 665}; 666 667//===----------------------------------------------------------------------===// 668// Partial specializations of FoldingSetTrait. 669 670template<typename T> struct FoldingSetTrait<T*> { 671 static inline void Profile(const T* X, FoldingSetNodeID& ID) { 672 ID.AddPointer(X); 673 } 674}; 675 676template<typename T> struct FoldingSetTrait<const T*> { 677 static inline void Profile(const T* X, FoldingSetNodeID& ID) { 678 ID.AddPointer(X); 679 } 680}; 681 682} // End of namespace llvm. 683 684#endif 685