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 | /// \file |
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 |
13 | /// set. |
14 | //===----------------------------------------------------------------------===// |
15 | |
16 | #ifndef LLVM_ADT_FOLDINGSET_H |
17 | #define LLVM_ADT_FOLDINGSET_H |
18 | |
19 | #include "llvm/ADT/APInt.h" |
20 | #include "llvm/ADT/Hashing.h" |
21 | #include "llvm/ADT/STLForwardCompat.h" |
22 | #include "llvm/ADT/SmallVector.h" |
23 | #include "llvm/ADT/iterator.h" |
24 | #include "llvm/Support/Allocator.h" |
25 | #include <cassert> |
26 | #include <cstddef> |
27 | #include <cstdint> |
28 | #include <type_traits> |
29 | #include <utility> |
30 | |
31 | namespace llvm { |
32 | |
33 | /// This folding set used for two purposes: |
34 | /// 1. Given information about a node we want to create, look up the unique |
35 | /// instance of the node in the set. If the node already exists, return |
36 | /// it, otherwise return the bucket it should be inserted into. |
37 | /// 2. Given a node that has already been created, remove it from the set. |
38 | /// |
39 | /// This class is implemented as a single-link chained hash table, where the |
40 | /// "buckets" are actually the nodes themselves (the next pointer is in the |
41 | /// node). The last node points back to the bucket to simplify node removal. |
42 | /// |
43 | /// Any node that is to be included in the folding set must be a subclass of |
44 | /// FoldingSetNode. The node class must also define a Profile method used to |
45 | /// establish the unique bits of data for the node. The Profile method is |
46 | /// passed a FoldingSetNodeID object which is used to gather the bits. Just |
47 | /// call one of the Add* functions defined in the FoldingSetBase::NodeID class. |
48 | /// NOTE: That the folding set does not own the nodes and it is the |
49 | /// responsibility of the user to dispose of the nodes. |
50 | /// |
51 | /// Eg. |
52 | /// class MyNode : public FoldingSetNode { |
53 | /// private: |
54 | /// std::string Name; |
55 | /// unsigned Value; |
56 | /// public: |
57 | /// MyNode(const char *N, unsigned V) : Name(N), Value(V) {} |
58 | /// ... |
59 | /// void Profile(FoldingSetNodeID &ID) const { |
60 | /// ID.AddString(Name); |
61 | /// ID.AddInteger(Value); |
62 | /// } |
63 | /// ... |
64 | /// }; |
65 | /// |
66 | /// To define the folding set itself use the FoldingSet template; |
67 | /// |
68 | /// Eg. |
69 | /// FoldingSet<MyNode> MyFoldingSet; |
70 | /// |
71 | /// Four public methods are available to manipulate the folding set; |
72 | /// |
73 | /// 1) If you have an existing node that you want add to the set but unsure |
74 | /// that the node might already exist then call; |
75 | /// |
76 | /// MyNode *M = MyFoldingSet.GetOrInsertNode(N); |
77 | /// |
78 | /// If The result is equal to the input then the node has been inserted. |
79 | /// Otherwise, the result is the node existing in the folding set, and the |
80 | /// input can be discarded (use the result instead.) |
81 | /// |
82 | /// 2) If you are ready to construct a node but want to check if it already |
83 | /// exists, then call FindNodeOrInsertPos with a FoldingSetNodeID of the bits to |
84 | /// check; |
85 | /// |
86 | /// FoldingSetNodeID ID; |
87 | /// ID.AddString(Name); |
88 | /// ID.AddInteger(Value); |
89 | /// void *InsertPoint; |
90 | /// |
91 | /// MyNode *M = MyFoldingSet.FindNodeOrInsertPos(ID, InsertPoint); |
92 | /// |
93 | /// If found then M will be non-NULL, else InsertPoint will point to where it |
94 | /// should be inserted using InsertNode. |
95 | /// |
96 | /// 3) If you get a NULL result from FindNodeOrInsertPos then you can insert a |
97 | /// new node with InsertNode; |
98 | /// |
99 | /// MyFoldingSet.InsertNode(M, InsertPoint); |
100 | /// |
101 | /// 4) Finally, if you want to remove a node from the folding set call; |
102 | /// |
103 | /// bool WasRemoved = MyFoldingSet.RemoveNode(M); |
104 | /// |
105 | /// The result indicates whether the node existed in the folding set. |
106 | |
107 | class FoldingSetNodeID; |
108 | class StringRef; |
109 | |
110 | //===----------------------------------------------------------------------===// |
111 | /// FoldingSetBase - Implements the folding set functionality. The main |
112 | /// structure is an array of buckets. Each bucket is indexed by the hash of |
113 | /// the nodes it contains. The bucket itself points to the nodes contained |
114 | /// in the bucket via a singly linked list. The last node in the list points |
115 | /// back to the bucket to facilitate node removal. |
116 | /// |
117 | class FoldingSetBase { |
118 | protected: |
119 | /// Buckets - Array of bucket chains. |
120 | void **Buckets; |
121 | |
122 | /// NumBuckets - Length of the Buckets array. Always a power of 2. |
123 | unsigned NumBuckets; |
124 | |
125 | /// NumNodes - Number of nodes in the folding set. Growth occurs when NumNodes |
126 | /// is greater than twice the number of buckets. |
127 | unsigned NumNodes; |
128 | |
129 | explicit FoldingSetBase(unsigned Log2InitSize = 6); |
130 | FoldingSetBase(FoldingSetBase &&Arg); |
131 | FoldingSetBase &operator=(FoldingSetBase &&RHS); |
132 | ~FoldingSetBase(); |
133 | |
134 | public: |
135 | //===--------------------------------------------------------------------===// |
136 | /// Node - This class is used to maintain the singly linked bucket list in |
137 | /// a folding set. |
138 | class Node { |
139 | private: |
140 | // NextInFoldingSetBucket - next link in the bucket list. |
141 | void *NextInFoldingSetBucket = nullptr; |
142 | |
143 | public: |
144 | Node() = default; |
145 | |
146 | // Accessors |
147 | void *getNextInBucket() const { return NextInFoldingSetBucket; } |
148 | void SetNextInBucket(void *N) { NextInFoldingSetBucket = N; } |
149 | }; |
150 | |
151 | /// clear - Remove all nodes from the folding set. |
152 | void clear(); |
153 | |
154 | /// size - Returns the number of nodes in the folding set. |
155 | unsigned size() const { return NumNodes; } |
156 | |
157 | /// empty - Returns true if there are no nodes in the folding set. |
158 | bool empty() const { return NumNodes == 0; } |
159 | |
160 | /// capacity - Returns the number of nodes permitted in the folding set |
161 | /// before a rebucket operation is performed. |
162 | unsigned capacity() { |
163 | // We allow a load factor of up to 2.0, |
164 | // so that means our capacity is NumBuckets * 2 |
165 | return NumBuckets * 2; |
166 | } |
167 | |
168 | protected: |
169 | /// Functions provided by the derived class to compute folding properties. |
170 | /// This is effectively a vtable for FoldingSetBase, except that we don't |
171 | /// actually store a pointer to it in the object. |
172 | struct FoldingSetInfo { |
173 | /// GetNodeProfile - Instantiations of the FoldingSet template implement |
174 | /// this function to gather data bits for the given node. |
175 | void (*GetNodeProfile)(const FoldingSetBase *Self, Node *N, |
176 | FoldingSetNodeID &ID); |
177 | |
178 | /// NodeEquals - Instantiations of the FoldingSet template implement |
179 | /// this function to compare the given node with the given ID. |
180 | bool (*NodeEquals)(const FoldingSetBase *Self, Node *N, |
181 | const FoldingSetNodeID &ID, unsigned IDHash, |
182 | FoldingSetNodeID &TempID); |
183 | |
184 | /// ComputeNodeHash - Instantiations of the FoldingSet template implement |
185 | /// this function to compute a hash value for the given node. |
186 | unsigned (*ComputeNodeHash)(const FoldingSetBase *Self, Node *N, |
187 | FoldingSetNodeID &TempID); |
188 | }; |
189 | |
190 | private: |
191 | /// GrowHashTable - Double the size of the hash table and rehash everything. |
192 | void GrowHashTable(const FoldingSetInfo &Info); |
193 | |
194 | /// GrowBucketCount - resize the hash table and rehash everything. |
195 | /// NewBucketCount must be a power of two, and must be greater than the old |
196 | /// bucket count. |
197 | void GrowBucketCount(unsigned NewBucketCount, const FoldingSetInfo &Info); |
198 | |
199 | protected: |
200 | // The below methods are protected to encourage subclasses to provide a more |
201 | // type-safe API. |
202 | |
203 | /// reserve - Increase the number of buckets such that adding the |
204 | /// EltCount-th node won't cause a rebucket operation. reserve is permitted |
205 | /// to allocate more space than requested by EltCount. |
206 | void reserve(unsigned EltCount, const FoldingSetInfo &Info); |
207 | |
208 | /// RemoveNode - Remove a node from the folding set, returning true if one |
209 | /// was removed or false if the node was not in the folding set. |
210 | bool RemoveNode(Node *N); |
211 | |
212 | /// GetOrInsertNode - If there is an existing simple Node exactly |
213 | /// equal to the specified node, return it. Otherwise, insert 'N' and return |
214 | /// it instead. |
215 | Node *GetOrInsertNode(Node *N, const FoldingSetInfo &Info); |
216 | |
217 | /// FindNodeOrInsertPos - Look up the node specified by ID. If it exists, |
218 | /// return it. If not, return the insertion token that will make insertion |
219 | /// faster. |
220 | Node *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos, |
221 | const FoldingSetInfo &Info); |
222 | |
223 | /// InsertNode - Insert the specified node into the folding set, knowing that |
224 | /// it is not already in the folding set. InsertPos must be obtained from |
225 | /// FindNodeOrInsertPos. |
226 | void InsertNode(Node *N, void *InsertPos, const FoldingSetInfo &Info); |
227 | }; |
228 | |
229 | //===----------------------------------------------------------------------===// |
230 | |
231 | /// DefaultFoldingSetTrait - This class provides default implementations |
232 | /// for FoldingSetTrait implementations. |
233 | template<typename T> struct DefaultFoldingSetTrait { |
234 | static void Profile(const T &X, FoldingSetNodeID &ID) { |
235 | X.Profile(ID); |
236 | } |
237 | static void Profile(T &X, FoldingSetNodeID &ID) { |
238 | X.Profile(ID); |
239 | } |
240 | |
241 | // Equals - Test if the profile for X would match ID, using TempID |
242 | // to compute a temporary ID if necessary. The default implementation |
243 | // just calls Profile and does a regular comparison. Implementations |
244 | // can override this to provide more efficient implementations. |
245 | static inline bool Equals(T &X, const FoldingSetNodeID &ID, unsigned IDHash, |
246 | FoldingSetNodeID &TempID); |
247 | |
248 | // ComputeHash - Compute a hash value for X, using TempID to |
249 | // compute a temporary ID if necessary. The default implementation |
250 | // just calls Profile and does a regular hash computation. |
251 | // Implementations can override this to provide more efficient |
252 | // implementations. |
253 | static inline unsigned ComputeHash(T &X, FoldingSetNodeID &TempID); |
254 | }; |
255 | |
256 | /// FoldingSetTrait - This trait class is used to define behavior of how |
257 | /// to "profile" (in the FoldingSet parlance) an object of a given type. |
258 | /// The default behavior is to invoke a 'Profile' method on an object, but |
259 | /// through template specialization the behavior can be tailored for specific |
260 | /// types. Combined with the FoldingSetNodeWrapper class, one can add objects |
261 | /// to FoldingSets that were not originally designed to have that behavior. |
262 | template <typename T, typename Enable = void> |
263 | struct FoldingSetTrait : public DefaultFoldingSetTrait<T> {}; |
264 | |
265 | /// DefaultContextualFoldingSetTrait - Like DefaultFoldingSetTrait, but |
266 | /// for ContextualFoldingSets. |
267 | template<typename T, typename Ctx> |
268 | struct DefaultContextualFoldingSetTrait { |
269 | static void Profile(T &X, FoldingSetNodeID &ID, Ctx Context) { |
270 | X.Profile(ID, Context); |
271 | } |
272 | |
273 | static inline bool Equals(T &X, const FoldingSetNodeID &ID, unsigned IDHash, |
274 | FoldingSetNodeID &TempID, Ctx Context); |
275 | static inline unsigned ComputeHash(T &X, FoldingSetNodeID &TempID, |
276 | Ctx Context); |
277 | }; |
278 | |
279 | /// ContextualFoldingSetTrait - Like FoldingSetTrait, but for |
280 | /// ContextualFoldingSets. |
281 | template<typename T, typename Ctx> struct ContextualFoldingSetTrait |
282 | : public DefaultContextualFoldingSetTrait<T, Ctx> {}; |
283 | |
284 | //===--------------------------------------------------------------------===// |
285 | /// FoldingSetNodeIDRef - This class describes a reference to an interned |
286 | /// FoldingSetNodeID, which can be a useful to store node id data rather |
287 | /// than using plain FoldingSetNodeIDs, since the 32-element SmallVector |
288 | /// is often much larger than necessary, and the possibility of heap |
289 | /// allocation means it requires a non-trivial destructor call. |
290 | class FoldingSetNodeIDRef { |
291 | const unsigned *Data = nullptr; |
292 | size_t Size = 0; |
293 | |
294 | public: |
295 | FoldingSetNodeIDRef() = default; |
296 | FoldingSetNodeIDRef(const unsigned *D, size_t S) : Data(D), Size(S) {} |
297 | |
298 | /// ComputeHash - Compute a strong hash value for this FoldingSetNodeIDRef, |
299 | /// used to lookup the node in the FoldingSetBase. |
300 | unsigned ComputeHash() const { |
301 | return static_cast<unsigned>(hash_combine_range(first: Data, last: Data + Size)); |
302 | } |
303 | |
304 | bool operator==(FoldingSetNodeIDRef) const; |
305 | |
306 | bool operator!=(FoldingSetNodeIDRef RHS) const { return !(*this == RHS); } |
307 | |
308 | /// Used to compare the "ordering" of two nodes as defined by the |
309 | /// profiled bits and their ordering defined by memcmp(). |
310 | bool operator<(FoldingSetNodeIDRef) const; |
311 | |
312 | const unsigned *getData() const { return Data; } |
313 | size_t getSize() const { return Size; } |
314 | }; |
315 | |
316 | //===--------------------------------------------------------------------===// |
317 | /// FoldingSetNodeID - This class is used to gather all the unique data bits of |
318 | /// a node. When all the bits are gathered this class is used to produce a |
319 | /// hash value for the node. |
320 | class FoldingSetNodeID { |
321 | /// Bits - Vector of all the data bits that make the node unique. |
322 | /// Use a SmallVector to avoid a heap allocation in the common case. |
323 | SmallVector<unsigned, 32> Bits; |
324 | |
325 | public: |
326 | FoldingSetNodeID() = default; |
327 | |
328 | FoldingSetNodeID(FoldingSetNodeIDRef Ref) |
329 | : Bits(Ref.getData(), Ref.getData() + Ref.getSize()) {} |
330 | |
331 | /// Add* - Add various data types to Bit data. |
332 | void AddPointer(const void *Ptr) { |
333 | // Note: this adds pointers to the hash using sizes and endianness that |
334 | // depend on the host. It doesn't matter, however, because hashing on |
335 | // pointer values is inherently unstable. Nothing should depend on the |
336 | // ordering of nodes in the folding set. |
337 | static_assert(sizeof(uintptr_t) <= sizeof(unsigned long long), |
338 | "unexpected pointer size" ); |
339 | AddInteger(I: reinterpret_cast<uintptr_t>(Ptr)); |
340 | } |
341 | void AddInteger(signed I) { Bits.push_back(Elt: I); } |
342 | void AddInteger(unsigned I) { Bits.push_back(Elt: I); } |
343 | void AddInteger(long I) { AddInteger(I: (unsigned long)I); } |
344 | void AddInteger(unsigned long I) { |
345 | if (sizeof(long) == sizeof(int)) |
346 | AddInteger(I: unsigned(I)); |
347 | else if (sizeof(long) == sizeof(long long)) { |
348 | AddInteger(I: (unsigned long long)I); |
349 | } else { |
350 | llvm_unreachable("unexpected sizeof(long)" ); |
351 | } |
352 | } |
353 | void AddInteger(long long I) { AddInteger(I: (unsigned long long)I); } |
354 | void AddInteger(unsigned long long I) { |
355 | AddInteger(I: unsigned(I)); |
356 | AddInteger(I: unsigned(I >> 32)); |
357 | } |
358 | void AddInteger(const APInt &Int) { |
359 | AddInteger(I: Int.getBitWidth()); |
360 | const auto *Parts = Int.getRawData(); |
361 | for (int i = 0, N = Int.getNumWords(); i < N; ++i) { |
362 | AddInteger(I: Parts[i]); |
363 | } |
364 | } |
365 | |
366 | void AddBoolean(bool B) { AddInteger(I: B ? 1U : 0U); } |
367 | void AddString(StringRef String); |
368 | void AddNodeID(const FoldingSetNodeID &ID); |
369 | |
370 | template <typename T> |
371 | inline void Add(const T &x) { FoldingSetTrait<T>::Profile(x, *this); } |
372 | |
373 | /// clear - Clear the accumulated profile, allowing this FoldingSetNodeID |
374 | /// object to be used to compute a new profile. |
375 | inline void clear() { Bits.clear(); } |
376 | |
377 | /// ComputeHash - Compute a strong hash value for this FoldingSetNodeID, used |
378 | /// to lookup the node in the FoldingSetBase. |
379 | unsigned ComputeHash() const { |
380 | return FoldingSetNodeIDRef(Bits.data(), Bits.size()).ComputeHash(); |
381 | } |
382 | |
383 | /// operator== - Used to compare two nodes to each other. |
384 | bool operator==(const FoldingSetNodeID &RHS) const; |
385 | bool operator==(const FoldingSetNodeIDRef RHS) const; |
386 | |
387 | bool operator!=(const FoldingSetNodeID &RHS) const { return !(*this == RHS); } |
388 | bool operator!=(const FoldingSetNodeIDRef RHS) const { return !(*this ==RHS);} |
389 | |
390 | /// Used to compare the "ordering" of two nodes as defined by the |
391 | /// profiled bits and their ordering defined by memcmp(). |
392 | bool operator<(const FoldingSetNodeID &RHS) const; |
393 | bool operator<(const FoldingSetNodeIDRef RHS) const; |
394 | |
395 | /// Intern - Copy this node's data to a memory region allocated from the |
396 | /// given allocator and return a FoldingSetNodeIDRef describing the |
397 | /// interned data. |
398 | FoldingSetNodeIDRef Intern(BumpPtrAllocator &Allocator) const; |
399 | }; |
400 | |
401 | // Convenience type to hide the implementation of the folding set. |
402 | using FoldingSetNode = FoldingSetBase::Node; |
403 | template<class T> class FoldingSetIterator; |
404 | template<class T> class FoldingSetBucketIterator; |
405 | |
406 | // Definitions of FoldingSetTrait and ContextualFoldingSetTrait functions, which |
407 | // require the definition of FoldingSetNodeID. |
408 | template<typename T> |
409 | inline bool |
410 | DefaultFoldingSetTrait<T>::Equals(T &X, const FoldingSetNodeID &ID, |
411 | unsigned /*IDHash*/, |
412 | FoldingSetNodeID &TempID) { |
413 | FoldingSetTrait<T>::Profile(X, TempID); |
414 | return TempID == ID; |
415 | } |
416 | template<typename T> |
417 | inline unsigned |
418 | DefaultFoldingSetTrait<T>::ComputeHash(T &X, FoldingSetNodeID &TempID) { |
419 | FoldingSetTrait<T>::Profile(X, TempID); |
420 | return TempID.ComputeHash(); |
421 | } |
422 | template<typename T, typename Ctx> |
423 | inline bool |
424 | DefaultContextualFoldingSetTrait<T, Ctx>::Equals(T &X, |
425 | const FoldingSetNodeID &ID, |
426 | unsigned /*IDHash*/, |
427 | FoldingSetNodeID &TempID, |
428 | Ctx Context) { |
429 | ContextualFoldingSetTrait<T, Ctx>::Profile(X, TempID, Context); |
430 | return TempID == ID; |
431 | } |
432 | template<typename T, typename Ctx> |
433 | inline unsigned |
434 | DefaultContextualFoldingSetTrait<T, Ctx>::ComputeHash(T &X, |
435 | FoldingSetNodeID &TempID, |
436 | Ctx Context) { |
437 | ContextualFoldingSetTrait<T, Ctx>::Profile(X, TempID, Context); |
438 | return TempID.ComputeHash(); |
439 | } |
440 | |
441 | //===----------------------------------------------------------------------===// |
442 | /// FoldingSetImpl - An implementation detail that lets us share code between |
443 | /// FoldingSet and ContextualFoldingSet. |
444 | template <class Derived, class T> class FoldingSetImpl : public FoldingSetBase { |
445 | protected: |
446 | explicit FoldingSetImpl(unsigned Log2InitSize) |
447 | : FoldingSetBase(Log2InitSize) {} |
448 | |
449 | FoldingSetImpl(FoldingSetImpl &&Arg) = default; |
450 | FoldingSetImpl &operator=(FoldingSetImpl &&RHS) = default; |
451 | ~FoldingSetImpl() = default; |
452 | |
453 | public: |
454 | using iterator = FoldingSetIterator<T>; |
455 | |
456 | iterator begin() { return iterator(Buckets); } |
457 | iterator end() { return iterator(Buckets+NumBuckets); } |
458 | |
459 | using const_iterator = FoldingSetIterator<const T>; |
460 | |
461 | const_iterator begin() const { return const_iterator(Buckets); } |
462 | const_iterator end() const { return const_iterator(Buckets+NumBuckets); } |
463 | |
464 | using bucket_iterator = FoldingSetBucketIterator<T>; |
465 | |
466 | bucket_iterator bucket_begin(unsigned hash) { |
467 | return bucket_iterator(Buckets + (hash & (NumBuckets-1))); |
468 | } |
469 | |
470 | bucket_iterator bucket_end(unsigned hash) { |
471 | return bucket_iterator(Buckets + (hash & (NumBuckets-1)), true); |
472 | } |
473 | |
474 | /// reserve - Increase the number of buckets such that adding the |
475 | /// EltCount-th node won't cause a rebucket operation. reserve is permitted |
476 | /// to allocate more space than requested by EltCount. |
477 | void reserve(unsigned EltCount) { |
478 | return FoldingSetBase::reserve(EltCount, Info: Derived::getFoldingSetInfo()); |
479 | } |
480 | |
481 | /// RemoveNode - Remove a node from the folding set, returning true if one |
482 | /// was removed or false if the node was not in the folding set. |
483 | bool RemoveNode(T *N) { |
484 | return FoldingSetBase::RemoveNode(N); |
485 | } |
486 | |
487 | /// GetOrInsertNode - If there is an existing simple Node exactly |
488 | /// equal to the specified node, return it. Otherwise, insert 'N' and |
489 | /// return it instead. |
490 | T *GetOrInsertNode(T *N) { |
491 | return static_cast<T *>( |
492 | FoldingSetBase::GetOrInsertNode(N, Info: Derived::getFoldingSetInfo())); |
493 | } |
494 | |
495 | /// FindNodeOrInsertPos - Look up the node specified by ID. If it exists, |
496 | /// return it. If not, return the insertion token that will make insertion |
497 | /// faster. |
498 | T *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos) { |
499 | return static_cast<T *>(FoldingSetBase::FindNodeOrInsertPos( |
500 | ID, InsertPos, Info: Derived::getFoldingSetInfo())); |
501 | } |
502 | |
503 | /// InsertNode - Insert the specified node into the folding set, knowing that |
504 | /// it is not already in the folding set. InsertPos must be obtained from |
505 | /// FindNodeOrInsertPos. |
506 | void InsertNode(T *N, void *InsertPos) { |
507 | FoldingSetBase::InsertNode(N, InsertPos, Info: Derived::getFoldingSetInfo()); |
508 | } |
509 | |
510 | /// InsertNode - Insert the specified node into the folding set, knowing that |
511 | /// it is not already in the folding set. |
512 | void InsertNode(T *N) { |
513 | T *Inserted = GetOrInsertNode(N); |
514 | (void)Inserted; |
515 | assert(Inserted == N && "Node already inserted!" ); |
516 | } |
517 | }; |
518 | |
519 | //===----------------------------------------------------------------------===// |
520 | /// FoldingSet - This template class is used to instantiate a specialized |
521 | /// implementation of the folding set to the node class T. T must be a |
522 | /// subclass of FoldingSetNode and implement a Profile function. |
523 | /// |
524 | /// Note that this set type is movable and move-assignable. However, its |
525 | /// moved-from state is not a valid state for anything other than |
526 | /// move-assigning and destroying. This is primarily to enable movable APIs |
527 | /// that incorporate these objects. |
528 | template <class T> |
529 | class FoldingSet : public FoldingSetImpl<FoldingSet<T>, T> { |
530 | using Super = FoldingSetImpl<FoldingSet, T>; |
531 | using Node = typename Super::Node; |
532 | |
533 | /// GetNodeProfile - Each instantiation of the FoldingSet needs to provide a |
534 | /// way to convert nodes into a unique specifier. |
535 | static void GetNodeProfile(const FoldingSetBase *, Node *N, |
536 | FoldingSetNodeID &ID) { |
537 | T *TN = static_cast<T *>(N); |
538 | FoldingSetTrait<T>::Profile(*TN, ID); |
539 | } |
540 | |
541 | /// NodeEquals - Instantiations may optionally provide a way to compare a |
542 | /// node with a specified ID. |
543 | static bool NodeEquals(const FoldingSetBase *, Node *N, |
544 | const FoldingSetNodeID &ID, unsigned IDHash, |
545 | FoldingSetNodeID &TempID) { |
546 | T *TN = static_cast<T *>(N); |
547 | return FoldingSetTrait<T>::Equals(*TN, ID, IDHash, TempID); |
548 | } |
549 | |
550 | /// ComputeNodeHash - Instantiations may optionally provide a way to compute a |
551 | /// hash value directly from a node. |
552 | static unsigned ComputeNodeHash(const FoldingSetBase *, Node *N, |
553 | FoldingSetNodeID &TempID) { |
554 | T *TN = static_cast<T *>(N); |
555 | return FoldingSetTrait<T>::ComputeHash(*TN, TempID); |
556 | } |
557 | |
558 | static const FoldingSetBase::FoldingSetInfo &getFoldingSetInfo() { |
559 | static constexpr FoldingSetBase::FoldingSetInfo Info = { |
560 | GetNodeProfile, NodeEquals, ComputeNodeHash}; |
561 | return Info; |
562 | } |
563 | friend Super; |
564 | |
565 | public: |
566 | explicit FoldingSet(unsigned Log2InitSize = 6) : Super(Log2InitSize) {} |
567 | FoldingSet(FoldingSet &&Arg) = default; |
568 | FoldingSet &operator=(FoldingSet &&RHS) = default; |
569 | }; |
570 | |
571 | //===----------------------------------------------------------------------===// |
572 | /// ContextualFoldingSet - This template class is a further refinement |
573 | /// of FoldingSet which provides a context argument when calling |
574 | /// Profile on its nodes. Currently, that argument is fixed at |
575 | /// initialization time. |
576 | /// |
577 | /// T must be a subclass of FoldingSetNode and implement a Profile |
578 | /// function with signature |
579 | /// void Profile(FoldingSetNodeID &, Ctx); |
580 | template <class T, class Ctx> |
581 | class ContextualFoldingSet |
582 | : public FoldingSetImpl<ContextualFoldingSet<T, Ctx>, T> { |
583 | // Unfortunately, this can't derive from FoldingSet<T> because the |
584 | // construction of the vtable for FoldingSet<T> requires |
585 | // FoldingSet<T>::GetNodeProfile to be instantiated, which in turn |
586 | // requires a single-argument T::Profile(). |
587 | |
588 | using Super = FoldingSetImpl<ContextualFoldingSet, T>; |
589 | using Node = typename Super::Node; |
590 | |
591 | Ctx Context; |
592 | |
593 | static const Ctx &getContext(const FoldingSetBase *Base) { |
594 | return static_cast<const ContextualFoldingSet*>(Base)->Context; |
595 | } |
596 | |
597 | /// GetNodeProfile - Each instantiatation of the FoldingSet needs to provide a |
598 | /// way to convert nodes into a unique specifier. |
599 | static void GetNodeProfile(const FoldingSetBase *Base, Node *N, |
600 | FoldingSetNodeID &ID) { |
601 | T *TN = static_cast<T *>(N); |
602 | ContextualFoldingSetTrait<T, Ctx>::Profile(*TN, ID, getContext(Base)); |
603 | } |
604 | |
605 | static bool NodeEquals(const FoldingSetBase *Base, Node *N, |
606 | const FoldingSetNodeID &ID, unsigned IDHash, |
607 | FoldingSetNodeID &TempID) { |
608 | T *TN = static_cast<T *>(N); |
609 | return ContextualFoldingSetTrait<T, Ctx>::Equals(*TN, ID, IDHash, TempID, |
610 | getContext(Base)); |
611 | } |
612 | |
613 | static unsigned ComputeNodeHash(const FoldingSetBase *Base, Node *N, |
614 | FoldingSetNodeID &TempID) { |
615 | T *TN = static_cast<T *>(N); |
616 | return ContextualFoldingSetTrait<T, Ctx>::ComputeHash(*TN, TempID, |
617 | getContext(Base)); |
618 | } |
619 | |
620 | static const FoldingSetBase::FoldingSetInfo &getFoldingSetInfo() { |
621 | static constexpr FoldingSetBase::FoldingSetInfo Info = { |
622 | GetNodeProfile, NodeEquals, ComputeNodeHash}; |
623 | return Info; |
624 | } |
625 | friend Super; |
626 | |
627 | public: |
628 | explicit ContextualFoldingSet(Ctx Context, unsigned Log2InitSize = 6) |
629 | : Super(Log2InitSize), Context(Context) {} |
630 | |
631 | Ctx getContext() const { return Context; } |
632 | }; |
633 | |
634 | //===----------------------------------------------------------------------===// |
635 | /// FoldingSetVector - This template class combines a FoldingSet and a vector |
636 | /// to provide the interface of FoldingSet but with deterministic iteration |
637 | /// order based on the insertion order. T must be a subclass of FoldingSetNode |
638 | /// and implement a Profile function. |
639 | template <class T, class VectorT = SmallVector<T*, 8>> |
640 | class FoldingSetVector { |
641 | FoldingSet<T> Set; |
642 | VectorT Vector; |
643 | |
644 | public: |
645 | explicit FoldingSetVector(unsigned Log2InitSize = 6) : Set(Log2InitSize) {} |
646 | |
647 | using iterator = pointee_iterator<typename VectorT::iterator>; |
648 | |
649 | iterator begin() { return Vector.begin(); } |
650 | iterator end() { return Vector.end(); } |
651 | |
652 | using const_iterator = pointee_iterator<typename VectorT::const_iterator>; |
653 | |
654 | const_iterator begin() const { return Vector.begin(); } |
655 | const_iterator end() const { return Vector.end(); } |
656 | |
657 | /// clear - Remove all nodes from the folding set. |
658 | void clear() { Set.clear(); Vector.clear(); } |
659 | |
660 | /// FindNodeOrInsertPos - Look up the node specified by ID. If it exists, |
661 | /// return it. If not, return the insertion token that will make insertion |
662 | /// faster. |
663 | T *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos) { |
664 | return Set.FindNodeOrInsertPos(ID, InsertPos); |
665 | } |
666 | |
667 | /// GetOrInsertNode - If there is an existing simple Node exactly |
668 | /// equal to the specified node, return it. Otherwise, insert 'N' and |
669 | /// return it instead. |
670 | T *GetOrInsertNode(T *N) { |
671 | T *Result = Set.GetOrInsertNode(N); |
672 | if (Result == N) Vector.push_back(N); |
673 | return Result; |
674 | } |
675 | |
676 | /// InsertNode - Insert the specified node into the folding set, knowing that |
677 | /// it is not already in the folding set. InsertPos must be obtained from |
678 | /// FindNodeOrInsertPos. |
679 | void InsertNode(T *N, void *InsertPos) { |
680 | Set.InsertNode(N, InsertPos); |
681 | Vector.push_back(N); |
682 | } |
683 | |
684 | /// InsertNode - Insert the specified node into the folding set, knowing that |
685 | /// it is not already in the folding set. |
686 | void InsertNode(T *N) { |
687 | Set.InsertNode(N); |
688 | Vector.push_back(N); |
689 | } |
690 | |
691 | /// size - Returns the number of nodes in the folding set. |
692 | unsigned size() const { return Set.size(); } |
693 | |
694 | /// empty - Returns true if there are no nodes in the folding set. |
695 | bool empty() const { return Set.empty(); } |
696 | }; |
697 | |
698 | //===----------------------------------------------------------------------===// |
699 | /// FoldingSetIteratorImpl - This is the common iterator support shared by all |
700 | /// folding sets, which knows how to walk the folding set hash table. |
701 | class FoldingSetIteratorImpl { |
702 | protected: |
703 | FoldingSetNode *NodePtr; |
704 | |
705 | FoldingSetIteratorImpl(void **Bucket); |
706 | |
707 | void advance(); |
708 | |
709 | public: |
710 | bool operator==(const FoldingSetIteratorImpl &RHS) const { |
711 | return NodePtr == RHS.NodePtr; |
712 | } |
713 | bool operator!=(const FoldingSetIteratorImpl &RHS) const { |
714 | return NodePtr != RHS.NodePtr; |
715 | } |
716 | }; |
717 | |
718 | template <class T> class FoldingSetIterator : public FoldingSetIteratorImpl { |
719 | public: |
720 | explicit FoldingSetIterator(void **Bucket) : FoldingSetIteratorImpl(Bucket) {} |
721 | |
722 | T &operator*() const { |
723 | return *static_cast<T*>(NodePtr); |
724 | } |
725 | |
726 | T *operator->() const { |
727 | return static_cast<T*>(NodePtr); |
728 | } |
729 | |
730 | inline FoldingSetIterator &operator++() { // Preincrement |
731 | advance(); |
732 | return *this; |
733 | } |
734 | FoldingSetIterator operator++(int) { // Postincrement |
735 | FoldingSetIterator tmp = *this; ++*this; return tmp; |
736 | } |
737 | }; |
738 | |
739 | //===----------------------------------------------------------------------===// |
740 | /// FoldingSetBucketIteratorImpl - This is the common bucket iterator support |
741 | /// shared by all folding sets, which knows how to walk a particular bucket |
742 | /// of a folding set hash table. |
743 | class FoldingSetBucketIteratorImpl { |
744 | protected: |
745 | void *Ptr; |
746 | |
747 | explicit FoldingSetBucketIteratorImpl(void **Bucket); |
748 | |
749 | FoldingSetBucketIteratorImpl(void **Bucket, bool) : Ptr(Bucket) {} |
750 | |
751 | void advance() { |
752 | void *Probe = static_cast<FoldingSetNode*>(Ptr)->getNextInBucket(); |
753 | uintptr_t x = reinterpret_cast<uintptr_t>(Probe) & ~0x1; |
754 | Ptr = reinterpret_cast<void*>(x); |
755 | } |
756 | |
757 | public: |
758 | bool operator==(const FoldingSetBucketIteratorImpl &RHS) const { |
759 | return Ptr == RHS.Ptr; |
760 | } |
761 | bool operator!=(const FoldingSetBucketIteratorImpl &RHS) const { |
762 | return Ptr != RHS.Ptr; |
763 | } |
764 | }; |
765 | |
766 | template <class T> |
767 | class FoldingSetBucketIterator : public FoldingSetBucketIteratorImpl { |
768 | public: |
769 | explicit FoldingSetBucketIterator(void **Bucket) : |
770 | FoldingSetBucketIteratorImpl(Bucket) {} |
771 | |
772 | FoldingSetBucketIterator(void **Bucket, bool) : |
773 | FoldingSetBucketIteratorImpl(Bucket, true) {} |
774 | |
775 | T &operator*() const { return *static_cast<T*>(Ptr); } |
776 | T *operator->() const { return static_cast<T*>(Ptr); } |
777 | |
778 | inline FoldingSetBucketIterator &operator++() { // Preincrement |
779 | advance(); |
780 | return *this; |
781 | } |
782 | FoldingSetBucketIterator operator++(int) { // Postincrement |
783 | FoldingSetBucketIterator tmp = *this; ++*this; return tmp; |
784 | } |
785 | }; |
786 | |
787 | //===----------------------------------------------------------------------===// |
788 | /// FoldingSetNodeWrapper - This template class is used to "wrap" arbitrary |
789 | /// types in an enclosing object so that they can be inserted into FoldingSets. |
790 | template <typename T> |
791 | class FoldingSetNodeWrapper : public FoldingSetNode { |
792 | T data; |
793 | |
794 | public: |
795 | template <typename... Ts> |
796 | explicit FoldingSetNodeWrapper(Ts &&... Args) |
797 | : data(std::forward<Ts>(Args)...) {} |
798 | |
799 | void Profile(FoldingSetNodeID &ID) { FoldingSetTrait<T>::Profile(data, ID); } |
800 | |
801 | T &getValue() { return data; } |
802 | const T &getValue() const { return data; } |
803 | |
804 | operator T&() { return data; } |
805 | operator const T&() const { return data; } |
806 | }; |
807 | |
808 | //===----------------------------------------------------------------------===// |
809 | /// FastFoldingSetNode - This is a subclass of FoldingSetNode which stores |
810 | /// a FoldingSetNodeID value rather than requiring the node to recompute it |
811 | /// each time it is needed. This trades space for speed (which can be |
812 | /// significant if the ID is long), and it also permits nodes to drop |
813 | /// information that would otherwise only be required for recomputing an ID. |
814 | class FastFoldingSetNode : public FoldingSetNode { |
815 | FoldingSetNodeID FastID; |
816 | |
817 | protected: |
818 | explicit FastFoldingSetNode(const FoldingSetNodeID &ID) : FastID(ID) {} |
819 | |
820 | public: |
821 | void Profile(FoldingSetNodeID &ID) const { ID.AddNodeID(ID: FastID); } |
822 | }; |
823 | |
824 | //===----------------------------------------------------------------------===// |
825 | // Partial specializations of FoldingSetTrait. |
826 | |
827 | template<typename T> struct FoldingSetTrait<T*> { |
828 | static inline void Profile(T *X, FoldingSetNodeID &ID) { |
829 | ID.AddPointer(Ptr: X); |
830 | } |
831 | }; |
832 | template <typename T1, typename T2> |
833 | struct FoldingSetTrait<std::pair<T1, T2>> { |
834 | static inline void Profile(const std::pair<T1, T2> &P, |
835 | FoldingSetNodeID &ID) { |
836 | ID.Add(P.first); |
837 | ID.Add(P.second); |
838 | } |
839 | }; |
840 | |
841 | template <typename T> |
842 | struct FoldingSetTrait<T, std::enable_if_t<std::is_enum<T>::value>> { |
843 | static void Profile(const T &X, FoldingSetNodeID &ID) { |
844 | ID.AddInteger(llvm::to_underlying(X)); |
845 | } |
846 | }; |
847 | |
848 | } // end namespace llvm |
849 | |
850 | #endif // LLVM_ADT_FOLDINGSET_H |
851 | |