LLVM  10.0.0svn
FoldingSet.cpp
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1 //===-- Support/FoldingSet.cpp - 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 implements a hash set that can be used to remove duplication of
10 // nodes in a graph.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/ADT/FoldingSet.h"
15 #include "llvm/ADT/Hashing.h"
16 #include "llvm/Support/Allocator.h"
18 #include "llvm/Support/Host.h"
20 #include <cassert>
21 #include <cstring>
22 using namespace llvm;
23 
24 //===----------------------------------------------------------------------===//
25 // FoldingSetNodeIDRef Implementation
26 
27 /// ComputeHash - Compute a strong hash value for this FoldingSetNodeIDRef,
28 /// used to lookup the node in the FoldingSetBase.
30  return static_cast<unsigned>(hash_combine_range(Data, Data+Size));
31 }
32 
34  if (Size != RHS.Size) return false;
35  return memcmp(Data, RHS.Data, Size*sizeof(*Data)) == 0;
36 }
37 
38 /// Used to compare the "ordering" of two nodes as defined by the
39 /// profiled bits and their ordering defined by memcmp().
41  if (Size != RHS.Size)
42  return Size < RHS.Size;
43  return memcmp(Data, RHS.Data, Size*sizeof(*Data)) < 0;
44 }
45 
46 //===----------------------------------------------------------------------===//
47 // FoldingSetNodeID Implementation
48 
49 /// Add* - Add various data types to Bit data.
50 ///
51 void FoldingSetNodeID::AddPointer(const void *Ptr) {
52  // Note: this adds pointers to the hash using sizes and endianness that
53  // depend on the host. It doesn't matter, however, because hashing on
54  // pointer values is inherently unstable. Nothing should depend on the
55  // ordering of nodes in the folding set.
56  static_assert(sizeof(uintptr_t) <= sizeof(unsigned long long),
57  "unexpected pointer size");
58  AddInteger(reinterpret_cast<uintptr_t>(Ptr));
59 }
61  Bits.push_back(I);
62 }
64  Bits.push_back(I);
65 }
67  AddInteger((unsigned long)I);
68 }
69 void FoldingSetNodeID::AddInteger(unsigned long I) {
70  if (sizeof(long) == sizeof(int))
71  AddInteger(unsigned(I));
72  else if (sizeof(long) == sizeof(long long)) {
73  AddInteger((unsigned long long)I);
74  } else {
75  llvm_unreachable("unexpected sizeof(long)");
76  }
77 }
79  AddInteger((unsigned long long)I);
80 }
81 void FoldingSetNodeID::AddInteger(unsigned long long I) {
82  AddInteger(unsigned(I));
83  AddInteger(unsigned(I >> 32));
84 }
85 
87  unsigned Size = String.size();
88  Bits.push_back(Size);
89  if (!Size) return;
90 
91  unsigned Units = Size / 4;
92  unsigned Pos = 0;
93  const unsigned *Base = (const unsigned*) String.data();
94 
95  // If the string is aligned do a bulk transfer.
96  if (!((intptr_t)Base & 3)) {
97  Bits.append(Base, Base + Units);
98  Pos = (Units + 1) * 4;
99  } else {
100  // Otherwise do it the hard way.
101  // To be compatible with above bulk transfer, we need to take endianness
102  // into account.
104  "Unexpected host endianness");
105  if (sys::IsBigEndianHost) {
106  for (Pos += 4; Pos <= Size; Pos += 4) {
107  unsigned V = ((unsigned char)String[Pos - 4] << 24) |
108  ((unsigned char)String[Pos - 3] << 16) |
109  ((unsigned char)String[Pos - 2] << 8) |
110  (unsigned char)String[Pos - 1];
111  Bits.push_back(V);
112  }
113  } else { // Little-endian host
114  for (Pos += 4; Pos <= Size; Pos += 4) {
115  unsigned V = ((unsigned char)String[Pos - 1] << 24) |
116  ((unsigned char)String[Pos - 2] << 16) |
117  ((unsigned char)String[Pos - 3] << 8) |
118  (unsigned char)String[Pos - 4];
119  Bits.push_back(V);
120  }
121  }
122  }
123 
124  // With the leftover bits.
125  unsigned V = 0;
126  // Pos will have overshot size by 4 - #bytes left over.
127  // No need to take endianness into account here - this is always executed.
128  switch (Pos - Size) {
129  case 1: V = (V << 8) | (unsigned char)String[Size - 3]; LLVM_FALLTHROUGH;
130  case 2: V = (V << 8) | (unsigned char)String[Size - 2]; LLVM_FALLTHROUGH;
131  case 3: V = (V << 8) | (unsigned char)String[Size - 1]; break;
132  default: return; // Nothing left.
133  }
134 
135  Bits.push_back(V);
136 }
137 
138 // AddNodeID - Adds the Bit data of another ID to *this.
140  Bits.append(ID.Bits.begin(), ID.Bits.end());
141 }
142 
143 /// ComputeHash - Compute a strong hash value for this FoldingSetNodeID, used to
144 /// lookup the node in the FoldingSetBase.
146  return FoldingSetNodeIDRef(Bits.data(), Bits.size()).ComputeHash();
147 }
148 
149 /// operator== - Used to compare two nodes to each other.
150 ///
152  return *this == FoldingSetNodeIDRef(RHS.Bits.data(), RHS.Bits.size());
153 }
154 
155 /// operator== - Used to compare two nodes to each other.
156 ///
158  return FoldingSetNodeIDRef(Bits.data(), Bits.size()) == RHS;
159 }
160 
161 /// Used to compare the "ordering" of two nodes as defined by the
162 /// profiled bits and their ordering defined by memcmp().
164  return *this < FoldingSetNodeIDRef(RHS.Bits.data(), RHS.Bits.size());
165 }
166 
168  return FoldingSetNodeIDRef(Bits.data(), Bits.size()) < RHS;
169 }
170 
171 /// Intern - Copy this node's data to a memory region allocated from the
172 /// given allocator and return a FoldingSetNodeIDRef describing the
173 /// interned data.
176  unsigned *New = Allocator.Allocate<unsigned>(Bits.size());
177  std::uninitialized_copy(Bits.begin(), Bits.end(), New);
178  return FoldingSetNodeIDRef(New, Bits.size());
179 }
180 
181 //===----------------------------------------------------------------------===//
182 /// Helper functions for FoldingSetBase.
183 
184 /// GetNextPtr - In order to save space, each bucket is a
185 /// singly-linked-list. In order to make deletion more efficient, we make
186 /// the list circular, so we can delete a node without computing its hash.
187 /// The problem with this is that the start of the hash buckets are not
188 /// Nodes. If NextInBucketPtr is a bucket pointer, this method returns null:
189 /// use GetBucketPtr when this happens.
190 static FoldingSetBase::Node *GetNextPtr(void *NextInBucketPtr) {
191  // The low bit is set if this is the pointer back to the bucket.
192  if (reinterpret_cast<intptr_t>(NextInBucketPtr) & 1)
193  return nullptr;
194 
195  return static_cast<FoldingSetBase::Node*>(NextInBucketPtr);
196 }
197 
198 
199 /// testing.
200 static void **GetBucketPtr(void *NextInBucketPtr) {
201  intptr_t Ptr = reinterpret_cast<intptr_t>(NextInBucketPtr);
202  assert((Ptr & 1) && "Not a bucket pointer");
203  return reinterpret_cast<void**>(Ptr & ~intptr_t(1));
204 }
205 
206 /// GetBucketFor - Hash the specified node ID and return the hash bucket for
207 /// the specified ID.
208 static void **GetBucketFor(unsigned Hash, void **Buckets, unsigned NumBuckets) {
209  // NumBuckets is always a power of 2.
210  unsigned BucketNum = Hash & (NumBuckets-1);
211  return Buckets + BucketNum;
212 }
213 
214 /// AllocateBuckets - Allocated initialized bucket memory.
215 static void **AllocateBuckets(unsigned NumBuckets) {
216  void **Buckets = static_cast<void**>(safe_calloc(NumBuckets + 1,
217  sizeof(void*)));
218  // Set the very last bucket to be a non-null "pointer".
219  Buckets[NumBuckets] = reinterpret_cast<void*>(-1);
220  return Buckets;
221 }
222 
223 //===----------------------------------------------------------------------===//
224 // FoldingSetBase Implementation
225 
226 void FoldingSetBase::anchor() {}
227 
228 FoldingSetBase::FoldingSetBase(unsigned Log2InitSize) {
229  assert(5 < Log2InitSize && Log2InitSize < 32 &&
230  "Initial hash table size out of range");
231  NumBuckets = 1 << Log2InitSize;
232  Buckets = AllocateBuckets(NumBuckets);
233  NumNodes = 0;
234 }
235 
237  : Buckets(Arg.Buckets), NumBuckets(Arg.NumBuckets), NumNodes(Arg.NumNodes) {
238  Arg.Buckets = nullptr;
239  Arg.NumBuckets = 0;
240  Arg.NumNodes = 0;
241 }
242 
244  free(Buckets); // This may be null if the set is in a moved-from state.
245  Buckets = RHS.Buckets;
246  NumBuckets = RHS.NumBuckets;
247  NumNodes = RHS.NumNodes;
248  RHS.Buckets = nullptr;
249  RHS.NumBuckets = 0;
250  RHS.NumNodes = 0;
251  return *this;
252 }
253 
255  free(Buckets);
256 }
257 
259  // Set all but the last bucket to null pointers.
260  memset(Buckets, 0, NumBuckets*sizeof(void*));
261 
262  // Set the very last bucket to be a non-null "pointer".
263  Buckets[NumBuckets] = reinterpret_cast<void*>(-1);
264 
265  // Reset the node count to zero.
266  NumNodes = 0;
267 }
268 
269 void FoldingSetBase::GrowBucketCount(unsigned NewBucketCount) {
270  assert((NewBucketCount > NumBuckets) && "Can't shrink a folding set with GrowBucketCount");
271  assert(isPowerOf2_32(NewBucketCount) && "Bad bucket count!");
272  void **OldBuckets = Buckets;
273  unsigned OldNumBuckets = NumBuckets;
274 
275  // Clear out new buckets.
276  Buckets = AllocateBuckets(NewBucketCount);
277  // Set NumBuckets only if allocation of new buckets was successful.
278  NumBuckets = NewBucketCount;
279  NumNodes = 0;
280 
281  // Walk the old buckets, rehashing nodes into their new place.
282  FoldingSetNodeID TempID;
283  for (unsigned i = 0; i != OldNumBuckets; ++i) {
284  void *Probe = OldBuckets[i];
285  if (!Probe) continue;
286  while (Node *NodeInBucket = GetNextPtr(Probe)) {
287  // Figure out the next link, remove NodeInBucket from the old link.
288  Probe = NodeInBucket->getNextInBucket();
289  NodeInBucket->SetNextInBucket(nullptr);
290 
291  // Insert the node into the new bucket, after recomputing the hash.
292  InsertNode(NodeInBucket,
293  GetBucketFor(ComputeNodeHash(NodeInBucket, TempID),
294  Buckets, NumBuckets));
295  TempID.clear();
296  }
297  }
298 
299  free(OldBuckets);
300 }
301 
302 /// GrowHashTable - Double the size of the hash table and rehash everything.
303 ///
304 void FoldingSetBase::GrowHashTable() {
305  GrowBucketCount(NumBuckets * 2);
306 }
307 
308 void FoldingSetBase::reserve(unsigned EltCount) {
309  // This will give us somewhere between EltCount / 2 and
310  // EltCount buckets. This puts us in the load factor
311  // range of 1.0 - 2.0.
312  if(EltCount < capacity())
313  return;
314  GrowBucketCount(PowerOf2Floor(EltCount));
315 }
316 
317 /// FindNodeOrInsertPos - Look up the node specified by ID. If it exists,
318 /// return it. If not, return the insertion token that will make insertion
319 /// faster.
322  void *&InsertPos) {
323  unsigned IDHash = ID.ComputeHash();
324  void **Bucket = GetBucketFor(IDHash, Buckets, NumBuckets);
325  void *Probe = *Bucket;
326 
327  InsertPos = nullptr;
328 
329  FoldingSetNodeID TempID;
330  while (Node *NodeInBucket = GetNextPtr(Probe)) {
331  if (NodeEquals(NodeInBucket, ID, IDHash, TempID))
332  return NodeInBucket;
333  TempID.clear();
334 
335  Probe = NodeInBucket->getNextInBucket();
336  }
337 
338  // Didn't find the node, return null with the bucket as the InsertPos.
339  InsertPos = Bucket;
340  return nullptr;
341 }
342 
343 /// InsertNode - Insert the specified node into the folding set, knowing that it
344 /// is not already in the map. InsertPos must be obtained from
345 /// FindNodeOrInsertPos.
346 void FoldingSetBase::InsertNode(Node *N, void *InsertPos) {
347  assert(!N->getNextInBucket());
348  // Do we need to grow the hashtable?
349  if (NumNodes+1 > capacity()) {
350  GrowHashTable();
351  FoldingSetNodeID TempID;
352  InsertPos = GetBucketFor(ComputeNodeHash(N, TempID), Buckets, NumBuckets);
353  }
354 
355  ++NumNodes;
356 
357  /// The insert position is actually a bucket pointer.
358  void **Bucket = static_cast<void**>(InsertPos);
359 
360  void *Next = *Bucket;
361 
362  // If this is the first insertion into this bucket, its next pointer will be
363  // null. Pretend as if it pointed to itself, setting the low bit to indicate
364  // that it is a pointer to the bucket.
365  if (!Next)
366  Next = reinterpret_cast<void*>(reinterpret_cast<intptr_t>(Bucket)|1);
367 
368  // Set the node's next pointer, and make the bucket point to the node.
369  N->SetNextInBucket(Next);
370  *Bucket = N;
371 }
372 
373 /// RemoveNode - Remove a node from the folding set, returning true if one was
374 /// removed or false if the node was not in the folding set.
376  // Because each bucket is a circular list, we don't need to compute N's hash
377  // to remove it.
378  void *Ptr = N->getNextInBucket();
379  if (!Ptr) return false; // Not in folding set.
380 
381  --NumNodes;
382  N->SetNextInBucket(nullptr);
383 
384  // Remember what N originally pointed to, either a bucket or another node.
385  void *NodeNextPtr = Ptr;
386 
387  // Chase around the list until we find the node (or bucket) which points to N.
388  while (true) {
389  if (Node *NodeInBucket = GetNextPtr(Ptr)) {
390  // Advance pointer.
391  Ptr = NodeInBucket->getNextInBucket();
392 
393  // We found a node that points to N, change it to point to N's next node,
394  // removing N from the list.
395  if (Ptr == N) {
396  NodeInBucket->SetNextInBucket(NodeNextPtr);
397  return true;
398  }
399  } else {
400  void **Bucket = GetBucketPtr(Ptr);
401  Ptr = *Bucket;
402 
403  // If we found that the bucket points to N, update the bucket to point to
404  // whatever is next.
405  if (Ptr == N) {
406  *Bucket = NodeNextPtr;
407  return true;
408  }
409  }
410  }
411 }
412 
413 /// GetOrInsertNode - If there is an existing simple Node exactly
414 /// equal to the specified node, return it. Otherwise, insert 'N' and it
415 /// instead.
418  GetNodeProfile(N, ID);
419  void *IP;
420  if (Node *E = FindNodeOrInsertPos(ID, IP))
421  return E;
422  InsertNode(N, IP);
423  return N;
424 }
425 
426 //===----------------------------------------------------------------------===//
427 // FoldingSetIteratorImpl Implementation
428 
430  // Skip to the first non-null non-self-cycle bucket.
431  while (*Bucket != reinterpret_cast<void*>(-1) &&
432  (!*Bucket || !GetNextPtr(*Bucket)))
433  ++Bucket;
434 
435  NodePtr = static_cast<FoldingSetNode*>(*Bucket);
436 }
437 
439  // If there is another link within this bucket, go to it.
440  void *Probe = NodePtr->getNextInBucket();
441 
442  if (FoldingSetNode *NextNodeInBucket = GetNextPtr(Probe))
443  NodePtr = NextNodeInBucket;
444  else {
445  // Otherwise, this is the last link in this bucket.
446  void **Bucket = GetBucketPtr(Probe);
447 
448  // Skip to the next non-null non-self-cycle bucket.
449  do {
450  ++Bucket;
451  } while (*Bucket != reinterpret_cast<void*>(-1) &&
452  (!*Bucket || !GetNextPtr(*Bucket)));
453 
454  NodePtr = static_cast<FoldingSetNode*>(*Bucket);
455  }
456 }
457 
458 //===----------------------------------------------------------------------===//
459 // FoldingSetBucketIteratorImpl Implementation
460 
462  Ptr = (!*Bucket || !GetNextPtr(*Bucket)) ? (void*) Bucket : *Bucket;
463 }
void AddPointer(const void *Ptr)
Add* - Add various data types to Bit data.
Definition: FoldingSet.cpp:51
static void ** AllocateBuckets(unsigned NumBuckets)
AllocateBuckets - Allocated initialized bucket memory.
Definition: FoldingSet.cpp:215
void clear()
clear - Remove all nodes from the folding set.
Definition: FoldingSet.cpp:258
void reserve(unsigned EltCount)
reserve - Increase the number of buckets such that adding the EltCount-th node won&#39;t cause a rebucket...
Definition: FoldingSet.cpp:308
This class represents lattice values for constants.
Definition: AllocatorList.h:23
unsigned NumBuckets
NumBuckets - Length of the Buckets array. Always a power of 2.
Definition: FoldingSet.h:120
bool operator<(const FoldingSetNodeID &RHS) const
Used to compare the "ordering" of two nodes as defined by the profiled bits and their ordering define...
Definition: FoldingSet.cpp:163
FoldingSetNodeIDRef Intern(BumpPtrAllocator &Allocator) const
Intern - Copy this node&#39;s data to a memory region allocated from the given allocator and return a Fol...
Definition: FoldingSet.cpp:175
unsigned capacity()
capacity - Returns the number of nodes permitted in the folding set before a rebucket operation is pe...
Definition: FoldingSet.h:164
unsigned ComputeHash() const
ComputeHash - Compute a strong hash value for this FoldingSetNodeID, used to lookup the node in the F...
Definition: FoldingSet.cpp:145
This file defines the MallocAllocator and BumpPtrAllocator interfaces.
bool operator<(FoldingSetNodeIDRef) const
Used to compare the "ordering" of two nodes as defined by the profiled bits and their ordering define...
Definition: FoldingSet.cpp:40
static void ** GetBucketPtr(void *NextInBucketPtr)
testing.
Definition: FoldingSet.cpp:200
constexpr bool IsBigEndianHost
Definition: Host.h:46
virtual bool NodeEquals(Node *N, const FoldingSetNodeID &ID, unsigned IDHash, FoldingSetNodeID &TempID) const =0
NodeEquals - Instantiations of the FoldingSet template implement this function to compare the given n...
void AddInteger(signed I)
Definition: FoldingSet.cpp:60
static const bool IsLittleEndianHost
Definition: Host.h:49
Node * GetOrInsertNode(Node *N)
GetOrInsertNode - If there is an existing simple Node exactly equal to the specified node...
Definition: FoldingSet.cpp:416
LLVM_NODISCARD size_t size() const
size - Get the string size.
Definition: StringRef.h:130
void InsertNode(Node *N, void *InsertPos)
InsertNode - Insert the specified node into the folding set, knowing that it is not already in the fo...
Definition: FoldingSet.cpp:346
unsigned ComputeHash() const
ComputeHash - Compute a strong hash value for this FoldingSetNodeIDRef, used to lookup the node in th...
Definition: FoldingSet.cpp:29
FoldingSetNodeID - This class is used to gather all the unique data bits of a node.
Definition: FoldingSet.h:305
void SetNextInBucket(void *N)
Definition: FoldingSet.h:145
void AddNodeID(const FoldingSetNodeID &ID)
Definition: FoldingSet.cpp:139
constexpr bool isPowerOf2_32(uint32_t Value)
Return true if the argument is a power of two > 0.
Definition: MathExtras.h:428
Allocate memory in an ever growing pool, as if by bump-pointer.
Definition: Allocator.h:140
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
LLVM_ATTRIBUTE_RETURNS_NONNULL LLVM_ATTRIBUTE_RETURNS_NOALIAS void * Allocate(size_t Size, size_t Alignment)
Allocate space at the specified alignment.
Definition: Allocator.h:214
void * getNextInBucket() const
Definition: FoldingSet.h:144
Node * FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos)
FindNodeOrInsertPos - Look up the node specified by ID.
Definition: FoldingSet.cpp:321
amdgpu Simplify well known AMD library false FunctionCallee Value * Arg
static void ** GetBucketFor(unsigned Hash, void **Buckets, unsigned NumBuckets)
GetBucketFor - Hash the specified node ID and return the hash bucket for the specified ID...
Definition: FoldingSet.cpp:208
void ** Buckets
Buckets - Array of bucket chains.
Definition: FoldingSet.h:117
size_t size() const
Definition: SmallVector.h:52
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
unsigned NumNodes
NumNodes - Number of nodes in the folding set.
Definition: FoldingSet.h:124
Basic Register Allocator
FoldingSetBase(unsigned Log2InitSize=6)
Definition: FoldingSet.cpp:228
void clear()
clear - Clear the accumulated profile, allowing this FoldingSetNodeID object to be used to compute a ...
Definition: FoldingSet.h:333
virtual void GetNodeProfile(Node *N, FoldingSetNodeID &ID) const =0
GetNodeProfile - Instantiations of the FoldingSet template implement this function to gather data bit...
FoldingSetBase - Implements the folding set functionality.
Definition: FoldingSet.h:112
static FoldingSetBase::Node * GetNextPtr(void *NextInBucketPtr)
Helper functions for FoldingSetBase.
Definition: FoldingSet.cpp:190
hash_code hash_combine_range(InputIteratorT first, InputIteratorT last)
Compute a hash_code for a sequence of values.
Definition: Hashing.h:478
bool operator==(FoldingSetNodeIDRef) const
Definition: FoldingSet.cpp:33
FoldingSetNodeIDRef - This class describes a reference to an interned FoldingSetNodeID, which can be a useful to store node id data rather than using plain FoldingSetNodeIDs, since the 32-element SmallVector is often much larger than necessary, and the possibility of heap allocation means it requires a non-trivial destructor call.
Definition: FoldingSet.h:277
pointer data()
Return a pointer to the vector&#39;s buffer, even if empty().
Definition: SmallVector.h:144
Merge contiguous icmps into a memcmp
Definition: MergeICmps.cpp:927
Node - This class is used to maintain the singly linked bucket list in a folding set.
Definition: FoldingSet.h:135
FoldingSetIteratorImpl(void **Bucket)
Definition: FoldingSet.cpp:429
#define I(x, y, z)
Definition: MD5.cpp:58
#define N
void AddString(StringRef String)
Definition: FoldingSet.cpp:86
virtual unsigned ComputeNodeHash(Node *N, FoldingSetNodeID &TempID) const =0
ComputeNodeHash - Instantiations of the FoldingSet template implement this function to compute a hash...
LLVM_NODISCARD const char * data() const
data - Get a pointer to the start of the string (which may not be null terminated).
Definition: StringRef.h:122
bool RemoveNode(Node *N)
RemoveNode - Remove a node from the folding set, returning true if one was removed or false if the no...
Definition: FoldingSet.cpp:375
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
FoldingSetBucketIteratorImpl(void **Bucket)
Definition: FoldingSet.cpp:461
uint64_t PowerOf2Floor(uint64_t A)
Returns the power of two which is less than or equal to the given value.
Definition: MathExtras.h:656
#define LLVM_FALLTHROUGH
LLVM_FALLTHROUGH - Mark fallthrough cases in switch statements.
Definition: Compiler.h:250
LLVM_ATTRIBUTE_RETURNS_NONNULL void * safe_calloc(size_t Count, size_t Sz)
Definition: MemAlloc.h:38
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:48
FoldingSetBase & operator=(FoldingSetBase &&RHS)
Definition: FoldingSet.cpp:243
bool operator==(const FoldingSetNodeID &RHS) const
operator== - Used to compare two nodes to each other.
Definition: FoldingSet.cpp:151