LLVM  10.0.0svn
UniqueVector.h
Go to the documentation of this file.
1 //===- llvm/ADT/UniqueVector.h ----------------------------------*- 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 #ifndef LLVM_ADT_UNIQUEVECTOR_H
10 #define LLVM_ADT_UNIQUEVECTOR_H
11 
12 #include <cassert>
13 #include <cstddef>
14 #include <map>
15 #include <vector>
16 
17 namespace llvm {
18 
19 //===----------------------------------------------------------------------===//
20 /// UniqueVector - This class produces a sequential ID number (base 1) for each
21 /// unique entry that is added. T is the type of entries in the vector. This
22 /// class should have an implementation of operator== and of operator<.
23 /// Entries can be fetched using operator[] with the entry ID.
24 template<class T> class UniqueVector {
25 public:
26  using VectorType = typename std::vector<T>;
27  using iterator = typename VectorType::iterator;
28  using const_iterator = typename VectorType::const_iterator;
29 
30 private:
31  // Map - Used to handle the correspondence of entry to ID.
32  std::map<T, unsigned> Map;
33 
34  // Vector - ID ordered vector of entries. Entries can be indexed by ID - 1.
35  VectorType Vector;
36 
37 public:
38  /// insert - Append entry to the vector if it doesn't already exist. Returns
39  /// the entry's index + 1 to be used as a unique ID.
40  unsigned insert(const T &Entry) {
41  // Check if the entry is already in the map.
42  unsigned &Val = Map[Entry];
43 
44  // See if entry exists, if so return prior ID.
45  if (Val) return Val;
46 
47  // Compute ID for entry.
48  Val = static_cast<unsigned>(Vector.size()) + 1;
49 
50  // Insert in vector.
51  Vector.push_back(Entry);
52  return Val;
53  }
54 
55  /// idFor - return the ID for an existing entry. Returns 0 if the entry is
56  /// not found.
57  unsigned idFor(const T &Entry) const {
58  // Search for entry in the map.
59  typename std::map<T, unsigned>::const_iterator MI = Map.find(Entry);
60 
61  // See if entry exists, if so return ID.
62  if (MI != Map.end()) return MI->second;
63 
64  // No luck.
65  return 0;
66  }
67 
68  /// operator[] - Returns a reference to the entry with the specified ID.
69  const T &operator[](unsigned ID) const {
70  assert(ID-1 < size() && "ID is 0 or out of range!");
71  return Vector[ID - 1];
72  }
73 
74  /// Return an iterator to the start of the vector.
75  iterator begin() { return Vector.begin(); }
76 
77  /// Return an iterator to the start of the vector.
78  const_iterator begin() const { return Vector.begin(); }
79 
80  /// Return an iterator to the end of the vector.
81  iterator end() { return Vector.end(); }
82 
83  /// Return an iterator to the end of the vector.
84  const_iterator end() const { return Vector.end(); }
85 
86  /// size - Returns the number of entries in the vector.
87  size_t size() const { return Vector.size(); }
88 
89  /// empty - Returns true if the vector is empty.
90  bool empty() const { return Vector.empty(); }
91 
92  /// reset - Clears all the entries.
93  void reset() {
94  Map.clear();
95  Vector.resize(0, 0);
96  }
97 };
98 
99 } // end namespace llvm
100 
101 #endif // LLVM_ADT_UNIQUEVECTOR_H
This class represents lattice values for constants.
Definition: AllocatorList.h:23
const T & operator[](unsigned ID) const
operator[] - Returns a reference to the entry with the specified ID.
Definition: UniqueVector.h:69
bool empty() const
empty - Returns true if the vector is empty.
Definition: UniqueVector.h:90
unsigned idFor(const T &Entry) const
idFor - return the ID for an existing entry.
Definition: UniqueVector.h:57
const_iterator end() const
Return an iterator to the end of the vector.
Definition: UniqueVector.h:84
typename VectorType::const_iterator const_iterator
Definition: UniqueVector.h:28
typename VectorType::iterator iterator
Definition: UniqueVector.h:27
void reset()
reset - Clears all the entries.
Definition: UniqueVector.h:93
iterator begin()
Return an iterator to the start of the vector.
Definition: UniqueVector.h:75
size_t size() const
size - Returns the number of entries in the vector.
Definition: UniqueVector.h:87
const_iterator begin() const
Return an iterator to the start of the vector.
Definition: UniqueVector.h:78
iterator end()
Return an iterator to the end of the vector.
Definition: UniqueVector.h:81
unsigned insert(const T &Entry)
insert - Append entry to the vector if it doesn&#39;t already exist.
Definition: UniqueVector.h:40
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
IRTranslator LLVM IR MI
UniqueVector - This class produces a sequential ID number (base 1) for each unique entry that is adde...
Definition: UniqueVector.h:24