1//===- llvm/ADT/FoldingSet.h - Uniquing Hash Set ----------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file defines a hash set that can be used to remove duplication of nodes
10// in a graph. This code was originally created by Chris Lattner for use with
11// SelectionDAGCSEMap, but was isolated to provide use across the llvm code set.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_ADT_FOLDINGSET_H
16#define LLVM_ADT_FOLDINGSET_H
17
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/ADT/iterator.h"
20#include "llvm/Support/Allocator.h"
21#include <cassert>
22#include <cstddef>
23#include <cstdint>
24#include <utility>
25
26namespace llvm {
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 FoldingSetBase::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 will 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 insert a
92/// new node with InsertNode;
93///
94/// MyFoldingSet.InsertNode(M, InsertPoint);
95///
96/// 4) Finally, if you want to remove a node from the folding set call;
97///
98/// bool WasRemoved = MyFoldingSet.RemoveNode(M);
99///
100/// The result indicates whether the node existed in the folding set.
101
102class FoldingSetNodeID;
103class StringRef;
104
105//===----------------------------------------------------------------------===//
106/// FoldingSetBase - Implements the folding set functionality. The main
107/// structure is an array of buckets. Each bucket is indexed by the hash of
108/// the nodes it contains. The bucket itself points to the nodes contained
109/// in the bucket via a singly linked list. The last node in the list points
110/// back to the bucket to facilitate node removal.
111///
112class FoldingSetBase {
113protected:
114 /// Buckets - Array of bucket chains.
115 void **Buckets;
116
117 /// NumBuckets - Length of the Buckets array. Always a power of 2.
118 unsigned NumBuckets;
119
120 /// NumNodes - Number of nodes in the folding set. Growth occurs when NumNodes
121 /// is greater than twice the number of buckets.
122 unsigned NumNodes;
123
124 explicit FoldingSetBase(unsigned Log2InitSize = 6);
125 FoldingSetBase(FoldingSetBase &&Arg);
126 FoldingSetBase &operator=(FoldingSetBase &&RHS);
127 ~FoldingSetBase();
128
129public:
130 //===--------------------------------------------------------------------===//
131 /// Node - This class is used to maintain the singly linked bucket list in
132 /// a folding set.
133 class Node {
134 private:
135 // NextInFoldingSetBucket - next link in the bucket list.
136 void *NextInFoldingSetBucket = nullptr;
137
138 public:
139 Node() = default;
140
141 // Accessors
142 void *getNextInBucket() const { return NextInFoldingSetBucket; }
143 void SetNextInBucket(void *N) { NextInFoldingSetBucket = N; }
144 };
145
146 /// clear - Remove all nodes from the folding set.
147 void clear();
148
149 /// size - Returns the number of nodes in the folding set.
150 unsigned size() const { return NumNodes; }
151
152 /// empty - Returns true if there are no nodes in the folding set.
153 bool empty() const { return NumNodes == 0; }
154
155 /// capacity - Returns the number of nodes permitted in the folding set
156 /// before a rebucket operation is performed.
157 unsigned capacity() {
158 // We allow a load factor of up to 2.0,
159 // so that means our capacity is NumBuckets * 2
160 return NumBuckets * 2;
161 }
162
163protected:
164 /// Functions provided by the derived class to compute folding properties.
165 /// This is effectively a vtable for FoldingSetBase, except that we don't
166 /// actually store a pointer to it in the object.
167 struct FoldingSetInfo {
168 /// GetNodeProfile - Instantiations of the FoldingSet template implement
169 /// this function to gather data bits for the given node.
170 void (*GetNodeProfile)(const FoldingSetBase *Self, Node *N,
171 FoldingSetNodeID &ID);
172
173 /// NodeEquals - Instantiations of the FoldingSet template implement
174 /// this function to compare the given node with the given ID.
175 bool (*NodeEquals)(const FoldingSetBase *Self, Node *N,
176 const FoldingSetNodeID &ID, unsigned IDHash,
177 FoldingSetNodeID &TempID);
178
179 /// ComputeNodeHash - Instantiations of the FoldingSet template implement
180 /// this function to compute a hash value for the given node.
181 unsigned (*ComputeNodeHash)(const FoldingSetBase *Self, Node *N,
182 FoldingSetNodeID &TempID);
183 };
184
185private:
186 /// GrowHashTable - Double the size of the hash table and rehash everything.
187 void GrowHashTable(const FoldingSetInfo &Info);
188
189 /// GrowBucketCount - resize the hash table and rehash everything.
190 /// NewBucketCount must be a power of two, and must be greater than the old
191 /// bucket count.
192 void GrowBucketCount(unsigned NewBucketCount, const FoldingSetInfo &Info);
193
194protected:
195 // The below methods are protected to encourage subclasses to provide a more
196 // type-safe API.
197
198 /// reserve - Increase the number of buckets such that adding the
199 /// EltCount-th node won't cause a rebucket operation. reserve is permitted
200 /// to allocate more space than requested by EltCount.
201 void reserve(unsigned EltCount, const FoldingSetInfo &Info);
202
203 /// RemoveNode - Remove a node from the folding set, returning true if one
204 /// was removed or false if the node was not in the folding set.
205 bool RemoveNode(Node *N);
206
207 /// GetOrInsertNode - If there is an existing simple Node exactly
208 /// equal to the specified node, return it. Otherwise, insert 'N' and return
209 /// it instead.
210 Node *GetOrInsertNode(Node *N, const FoldingSetInfo &Info);
211
212 /// FindNodeOrInsertPos - Look up the node specified by ID. If it exists,
213 /// return it. If not, return the insertion token that will make insertion
214 /// faster.
215 Node *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos,
216 const FoldingSetInfo &Info);
217
218 /// InsertNode - Insert the specified node into the folding set, knowing that
219 /// it is not already in the folding set. InsertPos must be obtained from
220 /// FindNodeOrInsertPos.
221 void InsertNode(Node *N, void *InsertPos, const FoldingSetInfo &Info);
222};
223
224//===----------------------------------------------------------------------===//
225
226/// DefaultFoldingSetTrait - This class provides default implementations
227/// for FoldingSetTrait implementations.
228template<typename T> struct DefaultFoldingSetTrait {
229 static void Profile(const T &X, FoldingSetNodeID &ID) {
230 X.Profile(ID);
231 }
232 static void Profile(T &X, FoldingSetNodeID &ID) {
233 X.Profile(ID);
234 }
235
236 // Equals - Test if the profile for X would match ID, using TempID
237 // to compute a temporary ID if necessary. The default implementation
238 // just calls Profile and does a regular comparison. Implementations
239 // can override this to provide more efficient implementations.
240 static inline bool Equals(T &X, const FoldingSetNodeID &ID, unsigned IDHash,
241 FoldingSetNodeID &TempID);
242
243 // ComputeHash - Compute a hash value for X, using TempID to
244 // compute a temporary ID if necessary. The default implementation
245 // just calls Profile and does a regular hash computation.
246 // Implementations can override this to provide more efficient
247 // implementations.
248 static inline unsigned ComputeHash(T &X, FoldingSetNodeID &TempID);
249};
250
251/// FoldingSetTrait - This trait class is used to define behavior of how
252/// to "profile" (in the FoldingSet parlance) an object of a given type.
253/// The default behavior is to invoke a 'Profile' method on an object, but
254/// through template specialization the behavior can be tailored for specific
255/// types. Combined with the FoldingSetNodeWrapper class, one can add objects
256/// to FoldingSets that were not originally designed to have that behavior.
257template<typename T> struct FoldingSetTrait
258 : public DefaultFoldingSetTrait<T> {};
259
260/// DefaultContextualFoldingSetTrait - Like DefaultFoldingSetTrait, but
261/// for ContextualFoldingSets.
262template<typename T, typename Ctx>
263struct DefaultContextualFoldingSetTrait {
264 static void Profile(T &X, FoldingSetNodeID &ID, Ctx Context) {
265 X.Profile(ID, Context);
266 }
267
268 static inline bool Equals(T &X, const FoldingSetNodeID &ID, unsigned IDHash,
269 FoldingSetNodeID &TempID, Ctx Context);
270 static inline unsigned ComputeHash(T &X, FoldingSetNodeID &TempID,
271 Ctx Context);
272};
273
274/// ContextualFoldingSetTrait - Like FoldingSetTrait, but for
275/// ContextualFoldingSets.
276template<typename T, typename Ctx> struct ContextualFoldingSetTrait
277 : public DefaultContextualFoldingSetTrait<T, Ctx> {};
278
279//===--------------------------------------------------------------------===//
280/// FoldingSetNodeIDRef - This class describes a reference to an interned
281/// FoldingSetNodeID, which can be a useful to store node id data rather
282/// than using plain FoldingSetNodeIDs, since the 32-element SmallVector
283/// is often much larger than necessary, and the possibility of heap
284/// allocation means it requires a non-trivial destructor call.
285class FoldingSetNodeIDRef {
286 const unsigned *Data = nullptr;
287 size_t Size = 0;
288
289public:
290 FoldingSetNodeIDRef() = default;
291 FoldingSetNodeIDRef(const unsigned *D, size_t S) : Data(D), Size(S) {}
292
293 /// ComputeHash - Compute a strong hash value for this FoldingSetNodeIDRef,
294 /// used to lookup the node in the FoldingSetBase.
295 unsigned ComputeHash() const;
296
297 bool operator==(FoldingSetNodeIDRef) const;
298
299 bool operator!=(FoldingSetNodeIDRef RHS) const { return !(*this == RHS); }
300
301 /// Used to compare the "ordering" of two nodes as defined by the
302 /// profiled bits and their ordering defined by memcmp().
303 bool operator<(FoldingSetNodeIDRef) const;
304
305 const unsigned *getData() const { return Data; }
306 size_t getSize() const { return Size; }
307};
308
309//===--------------------------------------------------------------------===//
310/// FoldingSetNodeID - This class is used to gather all the unique data bits of
311/// a node. When all the bits are gathered this class is used to produce a
312/// hash value for the node.
313class FoldingSetNodeID {
314 /// Bits - Vector of all the data bits that make the node unique.
315 /// Use a SmallVector to avoid a heap allocation in the common case.
316 SmallVector<unsigned, 32> Bits;
317
318public:
319 FoldingSetNodeID() = default;
320
321 FoldingSetNodeID(FoldingSetNodeIDRef Ref)
322 : Bits(Ref.getData(), Ref.getData() + Ref.getSize()) {}
323
324 /// Add* - Add various data types to Bit data.
325 void AddPointer(const void *Ptr);
326 void AddInteger(signed I);
327 void AddInteger(unsigned I);
328 void AddInteger(long I);
329 void AddInteger(unsigned long I);
330 void AddInteger(long long I);
331 void AddInteger(unsigned long long I);
332 void AddBoolean(bool B) { AddInteger(B ? 1U : 0U); }
333 void AddString(StringRef String);
334 void AddNodeID(const FoldingSetNodeID &ID);
335
336 template <typename T>
337 inline void Add(const T &x) { FoldingSetTrait<T>::Profile(x, *this); }
338
339 /// clear - Clear the accumulated profile, allowing this FoldingSetNodeID
340 /// object to be used to compute a new profile.
341 inline void clear() { Bits.clear(); }
342
343 /// ComputeHash - Compute a strong hash value for this FoldingSetNodeID, used
344 /// to lookup the node in the FoldingSetBase.
345 unsigned ComputeHash() const;
346
347 /// operator== - Used to compare two nodes to each other.
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.
366using FoldingSetNode = FoldingSetBase::Node;
367template<class T> class FoldingSetIterator;
368template<class T> class FoldingSetBucketIterator;
369
370// Definitions of FoldingSetTrait and ContextualFoldingSetTrait functions, which
371// require the definition of FoldingSetNodeID.
372template<typename T>
373inline bool
374DefaultFoldingSetTrait<T>::Equals(T &X, const FoldingSetNodeID &ID,
375 unsigned /*IDHash*/,
376 FoldingSetNodeID &TempID) {
377 FoldingSetTrait<T>::Profile(X, TempID);
378 return TempID == ID;
379}
380template<typename T>
381inline unsigned
382DefaultFoldingSetTrait<T>::ComputeHash(T &X, FoldingSetNodeID &TempID) {
383 FoldingSetTrait<T>::Profile(X, TempID);
384 return TempID.ComputeHash();
385}
386template<typename T, typename Ctx>
387inline bool
388DefaultContextualFoldingSetTrait<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}
396template<typename T, typename Ctx>
397inline unsigned
398DefaultContextualFoldingSetTrait<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.
408template <class Derived, class T> class FoldingSetImpl : public FoldingSetBase {
409protected:
410 explicit FoldingSetImpl(unsigned Log2InitSize)
411 : FoldingSetBase(Log2InitSize) {}
412
413 FoldingSetImpl(FoldingSetImpl &&Arg) = default;
414 FoldingSetImpl &operator=(FoldingSetImpl &&RHS) = default;
415 ~FoldingSetImpl() = default;
416
417public:
418 using iterator = FoldingSetIterator<T>;
419
420 iterator begin() { return iterator(Buckets); }
421 iterator end() { return iterator(Buckets+NumBuckets); }
422
423 using const_iterator = FoldingSetIterator<const T>;
424
425 const_iterator begin() const { return const_iterator(Buckets); }
426 const_iterator end() const { return const_iterator(Buckets+NumBuckets); }
427
428 using bucket_iterator = FoldingSetBucketIterator<T>;
429
430 bucket_iterator bucket_begin(unsigned hash) {
431 return bucket_iterator(Buckets + (hash & (NumBuckets-1)));
432 }
433
434 bucket_iterator bucket_end(unsigned hash) {
435 return bucket_iterator(Buckets + (hash & (NumBuckets-1)), true);
436 }
437
438 /// reserve - Increase the number of buckets such that adding the
439 /// EltCount-th node won't cause a rebucket operation. reserve is permitted
440 /// to allocate more space than requested by EltCount.
441 void reserve(unsigned EltCount) {
442 return FoldingSetBase::reserve(EltCount, Derived::getFoldingSetInfo());
443 }
444
445 /// RemoveNode - Remove a node from the folding set, returning true if one
446 /// was removed or false if the node was not in the folding set.
447 bool RemoveNode(T *N) {
448 return FoldingSetBase::RemoveNode(N);
449 }
450
451 /// GetOrInsertNode - If there is an existing simple Node exactly
452 /// equal to the specified node, return it. Otherwise, insert 'N' and
453 /// return it instead.
454 T *GetOrInsertNode(T *N) {
455 return static_cast<T *>(
456 FoldingSetBase::GetOrInsertNode(N, Derived::getFoldingSetInfo()));
457 }
458
459 /// FindNodeOrInsertPos - Look up the node specified by ID. If it exists,
460 /// return it. If not, return the insertion token that will make insertion
461 /// faster.
462 T *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos) {
463 return static_cast<T *>(FoldingSetBase::FindNodeOrInsertPos(
464 ID, InsertPos, Derived::getFoldingSetInfo()));
465 }
466
467 /// InsertNode - Insert the specified node into the folding set, knowing that
468 /// it is not already in the folding set. InsertPos must be obtained from
469 /// FindNodeOrInsertPos.
470 void InsertNode(T *N, void *InsertPos) {
471 FoldingSetBase::InsertNode(N, InsertPos, Derived::getFoldingSetInfo());
472 }
473
474 /// InsertNode - Insert the specified node into the folding set, knowing that
475 /// it is not already in the folding set.
476 void InsertNode(T *N) {
477 T *Inserted = GetOrInsertNode(N);
478 (void)Inserted;
479 assert(Inserted == N && "Node already inserted!");
480 }
481};
482
483//===----------------------------------------------------------------------===//
484/// FoldingSet - This template class is used to instantiate a specialized
485/// implementation of the folding set to the node class T. T must be a
486/// subclass of FoldingSetNode and implement a Profile function.
487///
488/// Note that this set type is movable and move-assignable. However, its
489/// moved-from state is not a valid state for anything other than
490/// move-assigning and destroying. This is primarily to enable movable APIs
491/// that incorporate these objects.
492template <class T>
493class FoldingSet : public FoldingSetImpl<FoldingSet<T>, T> {
494 using Super = FoldingSetImpl<FoldingSet, T>;
495 using Node = typename Super::Node;
496
497 /// GetNodeProfile - Each instantiation of the FoldingSet needs to provide a
498 /// way to convert nodes into a unique specifier.
499 static void GetNodeProfile(const FoldingSetBase *, Node *N,
500 FoldingSetNodeID &ID) {
501 T *TN = static_cast<T *>(N);
502 FoldingSetTrait<T>::Profile(*TN, ID);
503 }
504
505 /// NodeEquals - Instantiations may optionally provide a way to compare a
506 /// node with a specified ID.
507 static bool NodeEquals(const FoldingSetBase *, Node *N,
508 const FoldingSetNodeID &ID, unsigned IDHash,
509 FoldingSetNodeID &TempID) {
510 T *TN = static_cast<T *>(N);
511 return FoldingSetTrait<T>::Equals(*TN, ID, IDHash, TempID);
512 }
513
514 /// ComputeNodeHash - Instantiations may optionally provide a way to compute a
515 /// hash value directly from a node.
516 static unsigned ComputeNodeHash(const FoldingSetBase *, Node *N,
517 FoldingSetNodeID &TempID) {
518 T *TN = static_cast<T *>(N);
519 return FoldingSetTrait<T>::ComputeHash(*TN, TempID);
520 }
521
522 static const FoldingSetBase::FoldingSetInfo &getFoldingSetInfo() {
523 static constexpr FoldingSetBase::FoldingSetInfo Info = {
524 GetNodeProfile, NodeEquals, ComputeNodeHash};
525 return Info;
526 }
527 friend Super;
528
529public:
530 explicit FoldingSet(unsigned Log2InitSize = 6) : Super(Log2InitSize) {}
531 FoldingSet(FoldingSet &&Arg) = default;
532 FoldingSet &operator=(FoldingSet &&RHS) = default;
533};
534
535//===----------------------------------------------------------------------===//
536/// ContextualFoldingSet - This template class is a further refinement
537/// of FoldingSet which provides a context argument when calling
538/// Profile on its nodes. Currently, that argument is fixed at
539/// initialization time.
540///
541/// T must be a subclass of FoldingSetNode and implement a Profile
542/// function with signature
543/// void Profile(FoldingSetNodeID &, Ctx);
544template <class T, class Ctx>
545class ContextualFoldingSet
546 : public FoldingSetImpl<ContextualFoldingSet<T, Ctx>, T> {
547 // Unfortunately, this can't derive from FoldingSet<T> because the
548 // construction of the vtable for FoldingSet<T> requires
549 // FoldingSet<T>::GetNodeProfile to be instantiated, which in turn
550 // requires a single-argument T::Profile().
551
552 using Super = FoldingSetImpl<ContextualFoldingSet, T>;
553 using Node = typename Super::Node;
554
555 Ctx Context;
556
557 static const Ctx &getContext(const FoldingSetBase *Base) {
558 return static_cast<const ContextualFoldingSet*>(Base)->Context;
559 }
560
561 /// GetNodeProfile - Each instantiatation of the FoldingSet needs to provide a
562 /// way to convert nodes into a unique specifier.
563 static void GetNodeProfile(const FoldingSetBase *Base, Node *N,
564 FoldingSetNodeID &ID) {
565 T *TN = static_cast<T *>(N);
566 ContextualFoldingSetTrait<T, Ctx>::Profile(*TN, ID, getContext(Base));
567 }
568
569 static bool NodeEquals(const FoldingSetBase *Base, Node *N,
570 const FoldingSetNodeID &ID, unsigned IDHash,
571 FoldingSetNodeID &TempID) {
572 T *TN = static_cast<T *>(N);
573 return ContextualFoldingSetTrait<T, Ctx>::Equals(*TN, ID, IDHash, TempID,
574 getContext(Base));
575 }
576
577 static unsigned ComputeNodeHash(const FoldingSetBase *Base, Node *N,
578 FoldingSetNodeID &TempID) {
579 T *TN = static_cast<T *>(N);
580 return ContextualFoldingSetTrait<T, Ctx>::ComputeHash(*TN, TempID,
581 getContext(Base));
582 }
583
584 static const FoldingSetBase::FoldingSetInfo &getFoldingSetInfo() {
585 static constexpr FoldingSetBase::FoldingSetInfo Info = {
586 GetNodeProfile, NodeEquals, ComputeNodeHash};
587 return Info;
588 }
589 friend Super;
590
591public:
592 explicit ContextualFoldingSet(Ctx Context, unsigned Log2InitSize = 6)
593 : Super(Log2InitSize), Context(Context) {}
594
595 Ctx getContext() const { return Context; }
596};
597
598//===----------------------------------------------------------------------===//
599/// FoldingSetVector - This template class combines a FoldingSet and a vector
600/// to provide the interface of FoldingSet but with deterministic iteration
601/// order based on the insertion order. T must be a subclass of FoldingSetNode
602/// and implement a Profile function.
603template <class T, class VectorT = SmallVector<T*, 8>>
604class FoldingSetVector {
605 FoldingSet<T> Set;
606 VectorT Vector;
607
608public:
609 explicit FoldingSetVector(unsigned Log2InitSize = 6) : Set(Log2InitSize) {}
610
611 using iterator = pointee_iterator<typename VectorT::iterator>;
612
613 iterator begin() { return Vector.begin(); }
614 iterator end() { return Vector.end(); }
615
616 using const_iterator = pointee_iterator<typename VectorT::const_iterator>;
617
618 const_iterator begin() const { return Vector.begin(); }
619 const_iterator end() const { return Vector.end(); }
620
621 /// clear - Remove all nodes from the folding set.
622 void clear() { Set.clear(); Vector.clear(); }
623
624 /// FindNodeOrInsertPos - Look up the node specified by ID. If it exists,
625 /// return it. If not, return the insertion token that will make insertion
626 /// faster.
627 T *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos) {
628 return Set.FindNodeOrInsertPos(ID, InsertPos);
629 }
630
631 /// GetOrInsertNode - If there is an existing simple Node exactly
632 /// equal to the specified node, return it. Otherwise, insert 'N' and
633 /// return it instead.
634 T *GetOrInsertNode(T *N) {
635 T *Result = Set.GetOrInsertNode(N);
636 if (Result == N) Vector.push_back(N);
637 return Result;
638 }
639
640 /// InsertNode - Insert the specified node into the folding set, knowing that
641 /// it is not already in the folding set. InsertPos must be obtained from
642 /// FindNodeOrInsertPos.
643 void InsertNode(T *N, void *InsertPos) {
644 Set.InsertNode(N, InsertPos);
645 Vector.push_back(N);
646 }
647
648 /// InsertNode - Insert the specified node into the folding set, knowing that
649 /// it is not already in the folding set.
650 void InsertNode(T *N) {
651 Set.InsertNode(N);
652 Vector.push_back(N);
653 }
654
655 /// size - Returns the number of nodes in the folding set.
656 unsigned size() const { return Set.size(); }
657
658 /// empty - Returns true if there are no nodes in the folding set.
659 bool empty() const { return Set.empty(); }
660};
661
662//===----------------------------------------------------------------------===//
663/// FoldingSetIteratorImpl - This is the common iterator support shared by all
664/// folding sets, which knows how to walk the folding set hash table.
665class FoldingSetIteratorImpl {
666protected:
667 FoldingSetNode *NodePtr;
668
669 FoldingSetIteratorImpl(void **Bucket);
670
671 void advance();
672
673public:
674 bool operator==(const FoldingSetIteratorImpl &RHS) const {
675 return NodePtr == RHS.NodePtr;
676 }
677 bool operator!=(const FoldingSetIteratorImpl &RHS) const {
678 return NodePtr != RHS.NodePtr;
679 }
680};
681
682template <class T> class FoldingSetIterator : public FoldingSetIteratorImpl {
683public:
684 explicit FoldingSetIterator(void **Bucket) : FoldingSetIteratorImpl(Bucket) {}
685
686 T &operator*() const {
687 return *static_cast<T*>(NodePtr);
688 }
689
690 T *operator->() const {
691 return static_cast<T*>(NodePtr);
692 }
693
694 inline FoldingSetIterator &operator++() { // Preincrement
695 advance();
696 return *this;
697 }
698 FoldingSetIterator operator++(int) { // Postincrement
699 FoldingSetIterator tmp = *this; ++*this; return tmp;
700 }
701};
702
703//===----------------------------------------------------------------------===//
704/// FoldingSetBucketIteratorImpl - This is the common bucket iterator support
705/// shared by all folding sets, which knows how to walk a particular bucket
706/// of a folding set hash table.
707class FoldingSetBucketIteratorImpl {
708protected:
709 void *Ptr;
710
711 explicit FoldingSetBucketIteratorImpl(void **Bucket);
712
713 FoldingSetBucketIteratorImpl(void **Bucket, bool) : Ptr(Bucket) {}
714
715 void advance() {
716 void *Probe = static_cast<FoldingSetNode*>(Ptr)->getNextInBucket();
717 uintptr_t x = reinterpret_cast<uintptr_t>(Probe) & ~0x1;
718 Ptr = reinterpret_cast<void*>(x);
719 }
720
721public:
722 bool operator==(const FoldingSetBucketIteratorImpl &RHS) const {
723 return Ptr == RHS.Ptr;
724 }
725 bool operator!=(const FoldingSetBucketIteratorImpl &RHS) const {
726 return Ptr != RHS.Ptr;
727 }
728};
729
730template <class T>
731class FoldingSetBucketIterator : public FoldingSetBucketIteratorImpl {
732public:
733 explicit FoldingSetBucketIterator(void **Bucket) :
734 FoldingSetBucketIteratorImpl(Bucket) {}
735
736 FoldingSetBucketIterator(void **Bucket, bool) :
737 FoldingSetBucketIteratorImpl(Bucket, true) {}
738
739 T &operator*() const { return *static_cast<T*>(Ptr); }
740 T *operator->() const { return static_cast<T*>(Ptr); }
741
742 inline FoldingSetBucketIterator &operator++() { // Preincrement
743 advance();
744 return *this;
745 }
746 FoldingSetBucketIterator operator++(int) { // Postincrement
747 FoldingSetBucketIterator tmp = *this; ++*this; return tmp;
748 }
749};
750
751//===----------------------------------------------------------------------===//
752/// FoldingSetNodeWrapper - This template class is used to "wrap" arbitrary
753/// types in an enclosing object so that they can be inserted into FoldingSets.
754template <typename T>
755class FoldingSetNodeWrapper : public FoldingSetNode {
756 T data;
757
758public:
759 template <typename... Ts>
760 explicit FoldingSetNodeWrapper(Ts &&... Args)
761 : data(std::forward<Ts>(Args)...) {}
762
763 void Profile(FoldingSetNodeID &ID) { FoldingSetTrait<T>::Profile(data, ID); }
764
765 T &getValue() { return data; }
766 const T &getValue() const { return data; }
767
768 operator T&() { return data; }
769 operator const T&() const { return data; }
770};
771
772//===----------------------------------------------------------------------===//
773/// FastFoldingSetNode - This is a subclass of FoldingSetNode which stores
774/// a FoldingSetNodeID value rather than requiring the node to recompute it
775/// each time it is needed. This trades space for speed (which can be
776/// significant if the ID is long), and it also permits nodes to drop
777/// information that would otherwise only be required for recomputing an ID.
778class FastFoldingSetNode : public FoldingSetNode {
779 FoldingSetNodeID FastID;
780
781protected:
782 explicit FastFoldingSetNode(const FoldingSetNodeID &ID) : FastID(ID) {}
783
784public:
785 void Profile(FoldingSetNodeID &ID) const { ID.AddNodeID(FastID); }
786};
787
788//===----------------------------------------------------------------------===//
789// Partial specializations of FoldingSetTrait.
790
791template<typename T> struct FoldingSetTrait<T*> {
792 static inline void Profile(T *X, FoldingSetNodeID &ID) {
793 ID.AddPointer(X);
794 }
795};
796template <typename T1, typename T2>
797struct FoldingSetTrait<std::pair<T1, T2>> {
798 static inline void Profile(const std::pair<T1, T2> &P,
799 FoldingSetNodeID &ID) {
800 ID.Add(P.first);
801 ID.Add(P.second);
802 }
803};
804
805} // end namespace llvm
806
807#endif // LLVM_ADT_FOLDINGSET_H
808