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