1 //===-- llvm/ADT/FoldingSet.h - Uniquing Hash Set ---------------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines a hash set that can be used to remove duplication of nodes
11 // in a graph. This code was originally created by Chris Lattner for use with
12 // SelectionDAGCSEMap, but was isolated to provide use across the llvm code set.
13 //
14 //===----------------------------------------------------------------------===//
15
16 #ifndef LLVM_ADT_FOLDINGSET_H
17 #define LLVM_ADT_FOLDINGSET_H
18
19 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/ADT/StringRef.h"
21 #include "llvm/Support/DataTypes.h"
22
23 namespace 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
102 class 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 ///
111 class FoldingSetImpl {
112 protected:
113 /// Buckets - Array of bucket chains.
114 ///
115 void **Buckets;
116
117 /// NumBuckets - Length of the Buckets array. Always a power of 2.
118 ///
119 unsigned NumBuckets;
120
121 /// NumNodes - Number of nodes in the folding set. Growth occurs when NumNodes
122 /// is greater than twice the number of buckets.
123 unsigned NumNodes;
124
125 public:
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
Node()140 Node() : NextInFoldingSetBucket(0) {}
141
142 // Accessors
getNextInBucket()143 void *getNextInBucket() const { return NextInFoldingSetBucket; }
SetNextInBucket(void * N)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.
InsertNode(Node * N)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.
size()178 unsigned size() const { return NumNodes; }
179
180 /// empty - Returns true if there are no nodes in the folding set.
empty()181 bool empty() const { return NumNodes == 0; }
182
183 private:
184
185 /// GrowHashTable - Double the size of the hash table and rehash everything.
186 ///
187 void GrowHashTable();
188
189 protected:
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, unsigned IDHash,
197 FoldingSetNodeID &TempID) const=0;
198 /// ComputeNodeHash - Instantiations of the FoldingSet template implement
199 /// this function to compute a hash value for the given node.
200 virtual unsigned ComputeNodeHash(Node *N, FoldingSetNodeID &TempID) const = 0;
201 };
202
203 //===----------------------------------------------------------------------===//
204
205 template<typename T> struct FoldingSetTrait;
206
207 /// DefaultFoldingSetTrait - This class provides default implementations
208 /// for FoldingSetTrait implementations.
209 ///
210 template<typename T> struct DefaultFoldingSetTrait {
ProfileDefaultFoldingSetTrait211 static void Profile(const T &X, FoldingSetNodeID &ID) {
212 X.Profile(ID);
213 }
ProfileDefaultFoldingSetTrait214 static void Profile(T &X, FoldingSetNodeID &ID) {
215 X.Profile(ID);
216 }
217
218 // Equals - Test if the profile for X would match ID, using TempID
219 // to compute a temporary ID if necessary. The default implementation
220 // just calls Profile and does a regular comparison. Implementations
221 // can override this to provide more efficient implementations.
222 static inline bool Equals(T &X, const FoldingSetNodeID &ID, unsigned IDHash,
223 FoldingSetNodeID &TempID);
224
225 // ComputeHash - Compute a hash value for X, using TempID to
226 // compute a temporary ID if necessary. The default implementation
227 // just calls Profile and does a regular hash computation.
228 // Implementations can override this to provide more efficient
229 // implementations.
230 static inline unsigned ComputeHash(T &X, FoldingSetNodeID &TempID);
231 };
232
233 /// FoldingSetTrait - This trait class is used to define behavior of how
234 /// to "profile" (in the FoldingSet parlance) an object of a given type.
235 /// The default behavior is to invoke a 'Profile' method on an object, but
236 /// through template specialization the behavior can be tailored for specific
237 /// types. Combined with the FoldingSetNodeWrapper class, one can add objects
238 /// to FoldingSets that were not originally designed to have that behavior.
239 template<typename T> struct FoldingSetTrait
240 : public DefaultFoldingSetTrait<T> {};
241
242 template<typename T, typename Ctx> struct ContextualFoldingSetTrait;
243
244 /// DefaultContextualFoldingSetTrait - Like DefaultFoldingSetTrait, but
245 /// for ContextualFoldingSets.
246 template<typename T, typename Ctx>
247 struct DefaultContextualFoldingSetTrait {
ProfileDefaultContextualFoldingSetTrait248 static void Profile(T &X, FoldingSetNodeID &ID, Ctx Context) {
249 X.Profile(ID, Context);
250 }
251 static inline bool Equals(T &X, const FoldingSetNodeID &ID, unsigned IDHash,
252 FoldingSetNodeID &TempID, Ctx Context);
253 static inline unsigned ComputeHash(T &X, FoldingSetNodeID &TempID,
254 Ctx Context);
255 };
256
257 /// ContextualFoldingSetTrait - Like FoldingSetTrait, but for
258 /// ContextualFoldingSets.
259 template<typename T, typename Ctx> struct ContextualFoldingSetTrait
260 : public DefaultContextualFoldingSetTrait<T, Ctx> {};
261
262 //===--------------------------------------------------------------------===//
263 /// FoldingSetNodeIDRef - This class describes a reference to an interned
264 /// FoldingSetNodeID, which can be a useful to store node id data rather
265 /// than using plain FoldingSetNodeIDs, since the 32-element SmallVector
266 /// is often much larger than necessary, and the possibility of heap
267 /// allocation means it requires a non-trivial destructor call.
268 class FoldingSetNodeIDRef {
269 const unsigned *Data;
270 size_t Size;
271 public:
FoldingSetNodeIDRef()272 FoldingSetNodeIDRef() : Data(0), Size(0) {}
FoldingSetNodeIDRef(const unsigned * D,size_t S)273 FoldingSetNodeIDRef(const unsigned *D, size_t S) : Data(D), Size(S) {}
274
275 /// ComputeHash - Compute a strong hash value for this FoldingSetNodeIDRef,
276 /// used to lookup the node in the FoldingSetImpl.
277 unsigned ComputeHash() const;
278
279 bool operator==(FoldingSetNodeIDRef) const;
280
281 /// Used to compare the "ordering" of two nodes as defined by the
282 /// profiled bits and their ordering defined by memcmp().
283 bool operator<(FoldingSetNodeIDRef) const;
284
getData()285 const unsigned *getData() const { return Data; }
getSize()286 size_t getSize() const { return Size; }
287 };
288
289 //===--------------------------------------------------------------------===//
290 /// FoldingSetNodeID - This class is used to gather all the unique data bits of
291 /// a node. When all the bits are gathered this class is used to produce a
292 /// hash value for the node.
293 ///
294 class FoldingSetNodeID {
295 /// Bits - Vector of all the data bits that make the node unique.
296 /// Use a SmallVector to avoid a heap allocation in the common case.
297 SmallVector<unsigned, 32> Bits;
298
299 public:
FoldingSetNodeID()300 FoldingSetNodeID() {}
301
FoldingSetNodeID(FoldingSetNodeIDRef Ref)302 FoldingSetNodeID(FoldingSetNodeIDRef Ref)
303 : Bits(Ref.getData(), Ref.getData() + Ref.getSize()) {}
304
305 /// Add* - Add various data types to Bit data.
306 ///
307 void AddPointer(const void *Ptr);
308 void AddInteger(signed I);
309 void AddInteger(unsigned I);
310 void AddInteger(long I);
311 void AddInteger(unsigned long I);
312 void AddInteger(long long I);
313 void AddInteger(unsigned long long I);
AddBoolean(bool B)314 void AddBoolean(bool B) { AddInteger(B ? 1U : 0U); }
315 void AddString(StringRef String);
316 void AddNodeID(const FoldingSetNodeID &ID);
317
318 template <typename T>
Add(const T & x)319 inline void Add(const T &x) { FoldingSetTrait<T>::Profile(x, *this); }
320
321 /// clear - Clear the accumulated profile, allowing this FoldingSetNodeID
322 /// object to be used to compute a new profile.
clear()323 inline void clear() { Bits.clear(); }
324
325 /// ComputeHash - Compute a strong hash value for this FoldingSetNodeID, used
326 /// to lookup the node in the FoldingSetImpl.
327 unsigned ComputeHash() const;
328
329 /// operator== - Used to compare two nodes to each other.
330 ///
331 bool operator==(const FoldingSetNodeID &RHS) const;
332 bool operator==(const FoldingSetNodeIDRef RHS) const;
333
334 /// Used to compare the "ordering" of two nodes as defined by the
335 /// profiled bits and their ordering defined by memcmp().
336 bool operator<(const FoldingSetNodeID &RHS) const;
337 bool operator<(const FoldingSetNodeIDRef RHS) const;
338
339 /// Intern - Copy this node's data to a memory region allocated from the
340 /// given allocator and return a FoldingSetNodeIDRef describing the
341 /// interned data.
342 FoldingSetNodeIDRef Intern(BumpPtrAllocator &Allocator) const;
343 };
344
345 // Convenience type to hide the implementation of the folding set.
346 typedef FoldingSetImpl::Node FoldingSetNode;
347 template<class T> class FoldingSetIterator;
348 template<class T> class FoldingSetBucketIterator;
349
350 // Definitions of FoldingSetTrait and ContextualFoldingSetTrait functions, which
351 // require the definition of FoldingSetNodeID.
352 template<typename T>
353 inline bool
Equals(T & X,const FoldingSetNodeID & ID,unsigned IDHash,FoldingSetNodeID & TempID)354 DefaultFoldingSetTrait<T>::Equals(T &X, const FoldingSetNodeID &ID,
355 unsigned IDHash, FoldingSetNodeID &TempID) {
356 FoldingSetTrait<T>::Profile(X, TempID);
357 return TempID == ID;
358 }
359 template<typename T>
360 inline unsigned
ComputeHash(T & X,FoldingSetNodeID & TempID)361 DefaultFoldingSetTrait<T>::ComputeHash(T &X, FoldingSetNodeID &TempID) {
362 FoldingSetTrait<T>::Profile(X, TempID);
363 return TempID.ComputeHash();
364 }
365 template<typename T, typename Ctx>
366 inline bool
Equals(T & X,const FoldingSetNodeID & ID,unsigned IDHash,FoldingSetNodeID & TempID,Ctx Context)367 DefaultContextualFoldingSetTrait<T, Ctx>::Equals(T &X,
368 const FoldingSetNodeID &ID,
369 unsigned IDHash,
370 FoldingSetNodeID &TempID,
371 Ctx Context) {
372 ContextualFoldingSetTrait<T, Ctx>::Profile(X, TempID, Context);
373 return TempID == ID;
374 }
375 template<typename T, typename Ctx>
376 inline unsigned
ComputeHash(T & X,FoldingSetNodeID & TempID,Ctx Context)377 DefaultContextualFoldingSetTrait<T, Ctx>::ComputeHash(T &X,
378 FoldingSetNodeID &TempID,
379 Ctx Context) {
380 ContextualFoldingSetTrait<T, Ctx>::Profile(X, TempID, Context);
381 return TempID.ComputeHash();
382 }
383
384 //===----------------------------------------------------------------------===//
385 /// FoldingSet - This template class is used to instantiate a specialized
386 /// implementation of the folding set to the node class T. T must be a
387 /// subclass of FoldingSetNode and implement a Profile function.
388 ///
389 template<class T> class FoldingSet : public FoldingSetImpl {
390 private:
391 /// GetNodeProfile - Each instantiatation of the FoldingSet needs to provide a
392 /// way to convert nodes into a unique specifier.
GetNodeProfile(Node * N,FoldingSetNodeID & ID)393 virtual void GetNodeProfile(Node *N, FoldingSetNodeID &ID) const {
394 T *TN = static_cast<T *>(N);
395 FoldingSetTrait<T>::Profile(*TN, ID);
396 }
397 /// NodeEquals - Instantiations may optionally provide a way to compare a
398 /// node with a specified ID.
NodeEquals(Node * N,const FoldingSetNodeID & ID,unsigned IDHash,FoldingSetNodeID & TempID)399 virtual bool NodeEquals(Node *N, const FoldingSetNodeID &ID, unsigned IDHash,
400 FoldingSetNodeID &TempID) const {
401 T *TN = static_cast<T *>(N);
402 return FoldingSetTrait<T>::Equals(*TN, ID, IDHash, TempID);
403 }
404 /// ComputeNodeHash - Instantiations may optionally provide a way to compute a
405 /// hash value directly from a node.
ComputeNodeHash(Node * N,FoldingSetNodeID & TempID)406 virtual unsigned ComputeNodeHash(Node *N, FoldingSetNodeID &TempID) const {
407 T *TN = static_cast<T *>(N);
408 return FoldingSetTrait<T>::ComputeHash(*TN, TempID);
409 }
410
411 public:
412 explicit FoldingSet(unsigned Log2InitSize = 6)
FoldingSetImpl(Log2InitSize)413 : FoldingSetImpl(Log2InitSize)
414 {}
415
416 typedef FoldingSetIterator<T> iterator;
begin()417 iterator begin() { return iterator(Buckets); }
end()418 iterator end() { return iterator(Buckets+NumBuckets); }
419
420 typedef FoldingSetIterator<const T> const_iterator;
begin()421 const_iterator begin() const { return const_iterator(Buckets); }
end()422 const_iterator end() const { return const_iterator(Buckets+NumBuckets); }
423
424 typedef FoldingSetBucketIterator<T> bucket_iterator;
425
bucket_begin(unsigned hash)426 bucket_iterator bucket_begin(unsigned hash) {
427 return bucket_iterator(Buckets + (hash & (NumBuckets-1)));
428 }
429
bucket_end(unsigned hash)430 bucket_iterator bucket_end(unsigned hash) {
431 return bucket_iterator(Buckets + (hash & (NumBuckets-1)), true);
432 }
433
434 /// GetOrInsertNode - If there is an existing simple Node exactly
435 /// equal to the specified node, return it. Otherwise, insert 'N' and
436 /// return it instead.
GetOrInsertNode(Node * N)437 T *GetOrInsertNode(Node *N) {
438 return static_cast<T *>(FoldingSetImpl::GetOrInsertNode(N));
439 }
440
441 /// FindNodeOrInsertPos - Look up the node specified by ID. If it exists,
442 /// return it. If not, return the insertion token that will make insertion
443 /// faster.
FindNodeOrInsertPos(const FoldingSetNodeID & ID,void * & InsertPos)444 T *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos) {
445 return static_cast<T *>(FoldingSetImpl::FindNodeOrInsertPos(ID, InsertPos));
446 }
447 };
448
449 //===----------------------------------------------------------------------===//
450 /// ContextualFoldingSet - This template class is a further refinement
451 /// of FoldingSet which provides a context argument when calling
452 /// Profile on its nodes. Currently, that argument is fixed at
453 /// initialization time.
454 ///
455 /// T must be a subclass of FoldingSetNode and implement a Profile
456 /// function with signature
457 /// void Profile(llvm::FoldingSetNodeID &, Ctx);
458 template <class T, class Ctx>
459 class ContextualFoldingSet : public FoldingSetImpl {
460 // Unfortunately, this can't derive from FoldingSet<T> because the
461 // construction vtable for FoldingSet<T> requires
462 // FoldingSet<T>::GetNodeProfile to be instantiated, which in turn
463 // requires a single-argument T::Profile().
464
465 private:
466 Ctx Context;
467
468 /// GetNodeProfile - Each instantiatation of the FoldingSet needs to provide a
469 /// way to convert nodes into a unique specifier.
GetNodeProfile(FoldingSetImpl::Node * N,FoldingSetNodeID & ID)470 virtual void GetNodeProfile(FoldingSetImpl::Node *N,
471 FoldingSetNodeID &ID) const {
472 T *TN = static_cast<T *>(N);
473 ContextualFoldingSetTrait<T, Ctx>::Profile(*TN, ID, Context);
474 }
NodeEquals(FoldingSetImpl::Node * N,const FoldingSetNodeID & ID,unsigned IDHash,FoldingSetNodeID & TempID)475 virtual bool NodeEquals(FoldingSetImpl::Node *N,
476 const FoldingSetNodeID &ID, unsigned IDHash,
477 FoldingSetNodeID &TempID) const {
478 T *TN = static_cast<T *>(N);
479 return ContextualFoldingSetTrait<T, Ctx>::Equals(*TN, ID, IDHash, TempID,
480 Context);
481 }
ComputeNodeHash(FoldingSetImpl::Node * N,FoldingSetNodeID & TempID)482 virtual unsigned ComputeNodeHash(FoldingSetImpl::Node *N,
483 FoldingSetNodeID &TempID) const {
484 T *TN = static_cast<T *>(N);
485 return ContextualFoldingSetTrait<T, Ctx>::ComputeHash(*TN, TempID, Context);
486 }
487
488 public:
489 explicit ContextualFoldingSet(Ctx Context, unsigned Log2InitSize = 6)
FoldingSetImpl(Log2InitSize)490 : FoldingSetImpl(Log2InitSize), Context(Context)
491 {}
492
getContext()493 Ctx getContext() const { return Context; }
494
495
496 typedef FoldingSetIterator<T> iterator;
begin()497 iterator begin() { return iterator(Buckets); }
end()498 iterator end() { return iterator(Buckets+NumBuckets); }
499
500 typedef FoldingSetIterator<const T> const_iterator;
begin()501 const_iterator begin() const { return const_iterator(Buckets); }
end()502 const_iterator end() const { return const_iterator(Buckets+NumBuckets); }
503
504 typedef FoldingSetBucketIterator<T> bucket_iterator;
505
bucket_begin(unsigned hash)506 bucket_iterator bucket_begin(unsigned hash) {
507 return bucket_iterator(Buckets + (hash & (NumBuckets-1)));
508 }
509
bucket_end(unsigned hash)510 bucket_iterator bucket_end(unsigned hash) {
511 return bucket_iterator(Buckets + (hash & (NumBuckets-1)), true);
512 }
513
514 /// GetOrInsertNode - If there is an existing simple Node exactly
515 /// equal to the specified node, return it. Otherwise, insert 'N'
516 /// and return it instead.
GetOrInsertNode(Node * N)517 T *GetOrInsertNode(Node *N) {
518 return static_cast<T *>(FoldingSetImpl::GetOrInsertNode(N));
519 }
520
521 /// FindNodeOrInsertPos - Look up the node specified by ID. If it
522 /// exists, return it. If not, return the insertion token that will
523 /// make insertion faster.
FindNodeOrInsertPos(const FoldingSetNodeID & ID,void * & InsertPos)524 T *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos) {
525 return static_cast<T *>(FoldingSetImpl::FindNodeOrInsertPos(ID, InsertPos));
526 }
527 };
528
529 //===----------------------------------------------------------------------===//
530 /// FoldingSetVectorIterator - This implements an iterator for
531 /// FoldingSetVector. It is only necessary because FoldingSetIterator provides
532 /// a value_type of T, while the vector in FoldingSetVector exposes
533 /// a value_type of T*. Fortunately, FoldingSetIterator doesn't expose very
534 /// much besides operator* and operator->, so we just wrap the inner vector
535 /// iterator and perform the extra dereference.
536 template <class T, class VectorIteratorT>
537 class FoldingSetVectorIterator {
538 // Provide a typedef to workaround the lack of correct injected class name
539 // support in older GCCs.
540 typedef FoldingSetVectorIterator<T, VectorIteratorT> SelfT;
541
542 VectorIteratorT Iterator;
543
544 public:
FoldingSetVectorIterator(VectorIteratorT I)545 FoldingSetVectorIterator(VectorIteratorT I) : Iterator(I) {}
546
547 bool operator==(const SelfT &RHS) const {
548 return Iterator == RHS.Iterator;
549 }
550 bool operator!=(const SelfT &RHS) const {
551 return Iterator != RHS.Iterator;
552 }
553
554 T &operator*() const { return **Iterator; }
555
556 T *operator->() const { return *Iterator; }
557
558 inline SelfT &operator++() {
559 ++Iterator;
560 return *this;
561 }
562 SelfT operator++(int) {
563 SelfT tmp = *this;
564 ++*this;
565 return tmp;
566 }
567 };
568
569 //===----------------------------------------------------------------------===//
570 /// FoldingSetVector - This template class combines a FoldingSet and a vector
571 /// to provide the interface of FoldingSet but with deterministic iteration
572 /// order based on the insertion order. T must be a subclass of FoldingSetNode
573 /// and implement a Profile function.
574 template <class T, class VectorT = SmallVector<T*, 8> >
575 class FoldingSetVector {
576 FoldingSet<T> Set;
577 VectorT Vector;
578
579 public:
580 explicit FoldingSetVector(unsigned Log2InitSize = 6)
Set(Log2InitSize)581 : Set(Log2InitSize) {
582 }
583
584 typedef FoldingSetVectorIterator<T, typename VectorT::iterator> iterator;
begin()585 iterator begin() { return Vector.begin(); }
end()586 iterator end() { return Vector.end(); }
587
588 typedef FoldingSetVectorIterator<const T, typename VectorT::const_iterator>
589 const_iterator;
begin()590 const_iterator begin() const { return Vector.begin(); }
end()591 const_iterator end() const { return Vector.end(); }
592
593 /// clear - Remove all nodes from the folding set.
clear()594 void clear() { Set.clear(); Vector.clear(); }
595
596 /// FindNodeOrInsertPos - Look up the node specified by ID. If it exists,
597 /// return it. If not, return the insertion token that will make insertion
598 /// faster.
FindNodeOrInsertPos(const FoldingSetNodeID & ID,void * & InsertPos)599 T *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos) {
600 return Set.FindNodeOrInsertPos(ID, InsertPos);
601 }
602
603 /// GetOrInsertNode - If there is an existing simple Node exactly
604 /// equal to the specified node, return it. Otherwise, insert 'N' and
605 /// return it instead.
GetOrInsertNode(T * N)606 T *GetOrInsertNode(T *N) {
607 T *Result = Set.GetOrInsertNode(N);
608 if (Result == N) Vector.push_back(N);
609 return Result;
610 }
611
612 /// InsertNode - Insert the specified node into the folding set, knowing that
613 /// it is not already in the folding set. InsertPos must be obtained from
614 /// FindNodeOrInsertPos.
InsertNode(T * N,void * InsertPos)615 void InsertNode(T *N, void *InsertPos) {
616 Set.InsertNode(N, InsertPos);
617 Vector.push_back(N);
618 }
619
620 /// InsertNode - Insert the specified node into the folding set, knowing that
621 /// it is not already in the folding set.
InsertNode(T * N)622 void InsertNode(T *N) {
623 Set.InsertNode(N);
624 Vector.push_back(N);
625 }
626
627 /// size - Returns the number of nodes in the folding set.
size()628 unsigned size() const { return Set.size(); }
629
630 /// empty - Returns true if there are no nodes in the folding set.
empty()631 bool empty() const { return Set.empty(); }
632 };
633
634 //===----------------------------------------------------------------------===//
635 /// FoldingSetIteratorImpl - This is the common iterator support shared by all
636 /// folding sets, which knows how to walk the folding set hash table.
637 class FoldingSetIteratorImpl {
638 protected:
639 FoldingSetNode *NodePtr;
640 FoldingSetIteratorImpl(void **Bucket);
641 void advance();
642
643 public:
644 bool operator==(const FoldingSetIteratorImpl &RHS) const {
645 return NodePtr == RHS.NodePtr;
646 }
647 bool operator!=(const FoldingSetIteratorImpl &RHS) const {
648 return NodePtr != RHS.NodePtr;
649 }
650 };
651
652
653 template<class T>
654 class FoldingSetIterator : public FoldingSetIteratorImpl {
655 public:
FoldingSetIterator(void ** Bucket)656 explicit FoldingSetIterator(void **Bucket) : FoldingSetIteratorImpl(Bucket) {}
657
658 T &operator*() const {
659 return *static_cast<T*>(NodePtr);
660 }
661
662 T *operator->() const {
663 return static_cast<T*>(NodePtr);
664 }
665
666 inline FoldingSetIterator &operator++() { // Preincrement
667 advance();
668 return *this;
669 }
670 FoldingSetIterator operator++(int) { // Postincrement
671 FoldingSetIterator tmp = *this; ++*this; return tmp;
672 }
673 };
674
675 //===----------------------------------------------------------------------===//
676 /// FoldingSetBucketIteratorImpl - This is the common bucket iterator support
677 /// shared by all folding sets, which knows how to walk a particular bucket
678 /// of a folding set hash table.
679
680 class FoldingSetBucketIteratorImpl {
681 protected:
682 void *Ptr;
683
684 explicit FoldingSetBucketIteratorImpl(void **Bucket);
685
FoldingSetBucketIteratorImpl(void ** Bucket,bool)686 FoldingSetBucketIteratorImpl(void **Bucket, bool)
687 : Ptr(Bucket) {}
688
advance()689 void advance() {
690 void *Probe = static_cast<FoldingSetNode*>(Ptr)->getNextInBucket();
691 uintptr_t x = reinterpret_cast<uintptr_t>(Probe) & ~0x1;
692 Ptr = reinterpret_cast<void*>(x);
693 }
694
695 public:
696 bool operator==(const FoldingSetBucketIteratorImpl &RHS) const {
697 return Ptr == RHS.Ptr;
698 }
699 bool operator!=(const FoldingSetBucketIteratorImpl &RHS) const {
700 return Ptr != RHS.Ptr;
701 }
702 };
703
704
705 template<class T>
706 class FoldingSetBucketIterator : public FoldingSetBucketIteratorImpl {
707 public:
FoldingSetBucketIterator(void ** Bucket)708 explicit FoldingSetBucketIterator(void **Bucket) :
709 FoldingSetBucketIteratorImpl(Bucket) {}
710
FoldingSetBucketIterator(void ** Bucket,bool)711 FoldingSetBucketIterator(void **Bucket, bool) :
712 FoldingSetBucketIteratorImpl(Bucket, true) {}
713
714 T &operator*() const { return *static_cast<T*>(Ptr); }
715 T *operator->() const { return static_cast<T*>(Ptr); }
716
717 inline FoldingSetBucketIterator &operator++() { // Preincrement
718 advance();
719 return *this;
720 }
721 FoldingSetBucketIterator operator++(int) { // Postincrement
722 FoldingSetBucketIterator tmp = *this; ++*this; return tmp;
723 }
724 };
725
726 //===----------------------------------------------------------------------===//
727 /// FoldingSetNodeWrapper - This template class is used to "wrap" arbitrary
728 /// types in an enclosing object so that they can be inserted into FoldingSets.
729 template <typename T>
730 class FoldingSetNodeWrapper : public FoldingSetNode {
731 T data;
732 public:
FoldingSetNodeWrapper(const T & x)733 explicit FoldingSetNodeWrapper(const T &x) : data(x) {}
~FoldingSetNodeWrapper()734 virtual ~FoldingSetNodeWrapper() {}
735
736 template<typename A1>
FoldingSetNodeWrapper(const A1 & a1)737 explicit FoldingSetNodeWrapper(const A1 &a1)
738 : data(a1) {}
739
740 template <typename A1, typename A2>
FoldingSetNodeWrapper(const A1 & a1,const A2 & a2)741 explicit FoldingSetNodeWrapper(const A1 &a1, const A2 &a2)
742 : data(a1,a2) {}
743
744 template <typename A1, typename A2, typename A3>
FoldingSetNodeWrapper(const A1 & a1,const A2 & a2,const A3 & a3)745 explicit FoldingSetNodeWrapper(const A1 &a1, const A2 &a2, const A3 &a3)
746 : data(a1,a2,a3) {}
747
748 template <typename A1, typename A2, typename A3, typename A4>
FoldingSetNodeWrapper(const A1 & a1,const A2 & a2,const A3 & a3,const A4 & a4)749 explicit FoldingSetNodeWrapper(const A1 &a1, const A2 &a2, const A3 &a3,
750 const A4 &a4)
751 : data(a1,a2,a3,a4) {}
752
753 template <typename A1, typename A2, typename A3, typename A4, typename A5>
FoldingSetNodeWrapper(const A1 & a1,const A2 & a2,const A3 & a3,const A4 & a4,const A5 & a5)754 explicit FoldingSetNodeWrapper(const A1 &a1, const A2 &a2, const A3 &a3,
755 const A4 &a4, const A5 &a5)
756 : data(a1,a2,a3,a4,a5) {}
757
758
Profile(FoldingSetNodeID & ID)759 void Profile(FoldingSetNodeID &ID) { FoldingSetTrait<T>::Profile(data, ID); }
760
getValue()761 T &getValue() { return data; }
getValue()762 const T &getValue() const { return data; }
763
764 operator T&() { return data; }
765 operator const T&() const { return data; }
766 };
767
768 //===----------------------------------------------------------------------===//
769 /// FastFoldingSetNode - This is a subclass of FoldingSetNode which stores
770 /// a FoldingSetNodeID value rather than requiring the node to recompute it
771 /// each time it is needed. This trades space for speed (which can be
772 /// significant if the ID is long), and it also permits nodes to drop
773 /// information that would otherwise only be required for recomputing an ID.
774 class FastFoldingSetNode : public FoldingSetNode {
775 FoldingSetNodeID FastID;
776 protected:
FastFoldingSetNode(const FoldingSetNodeID & ID)777 explicit FastFoldingSetNode(const FoldingSetNodeID &ID) : FastID(ID) {}
778 public:
Profile(FoldingSetNodeID & ID)779 void Profile(FoldingSetNodeID &ID) const {
780 ID.AddNodeID(FastID);
781 }
782 };
783
784 //===----------------------------------------------------------------------===//
785 // Partial specializations of FoldingSetTrait.
786
787 template<typename T> struct FoldingSetTrait<T*> {
788 static inline void Profile(T *X, FoldingSetNodeID &ID) {
789 ID.AddPointer(X);
790 }
791 };
792 } // End of namespace llvm.
793
794 #endif
795