aboutsummaryrefslogtreecommitdiffstats
path: root/include/llvm/IR/User.h
blob: d39378dd57da89452e7e391dbcae66245ddcc9b5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
//===-- llvm/User.h - User class definition ---------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This class defines the interface that one who uses a Value must implement.
// Each instance of the Value class keeps track of what User's have handles
// to it.
//
//  * Instructions are the largest class of Users.
//  * Constants may be users of other constants (think arrays and stuff)
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_IR_USER_H
#define LLVM_IR_USER_H

#include "llvm/ADT/iterator.h"
#include "llvm/ADT/iterator_range.h"
#include "llvm/IR/Value.h"
#include "llvm/Support/ErrorHandling.h"

namespace llvm {

/// \brief Compile-time customization of User operands.
///
/// Customizes operand-related allocators and accessors.
template <class>
struct OperandTraits;

class User : public Value {
  User(const User &) = delete;
  void *operator new(size_t) = delete;
  template <unsigned>
  friend struct HungoffOperandTraits;
  virtual void anchor();
protected:
  /// \brief This is a pointer to the array of Uses for this User.
  ///
  /// For nodes of fixed arity (e.g. a binary operator) this array will live
  /// prefixed to some derived class instance.  For nodes of resizable variable
  /// arity (e.g. PHINodes, SwitchInst etc.), this memory will be dynamically
  /// allocated and should be destroyed by the classes' virtual dtor.
  Use *OperandList;

  void *operator new(size_t s, unsigned Us);
  User(Type *ty, unsigned vty, Use *OpList, unsigned NumOps)
      : Value(ty, vty), OperandList(OpList) {
    NumOperands = NumOps;
  }
  Use *allocHungoffUses(unsigned) const;
  void dropHungoffUses() {
    Use::zap(OperandList, OperandList + NumOperands, true);
    OperandList = nullptr;
    // Reset NumOperands so User::operator delete() does the right thing.
    NumOperands = 0;
  }
public:
  ~User() {
    Use::zap(OperandList, OperandList + NumOperands);
  }
  /// \brief Free memory allocated for User and Use objects.
  void operator delete(void *Usr);
  /// \brief Placement delete - required by std, but never called.
  void operator delete(void*, unsigned) {
    llvm_unreachable("Constructor throws?");
  }
  /// \brief Placement delete - required by std, but never called.
  void operator delete(void*, unsigned, bool) {
    llvm_unreachable("Constructor throws?");
  }
protected:
  template <int Idx, typename U> static Use &OpFrom(const U *that) {
    return Idx < 0
      ? OperandTraits<U>::op_end(const_cast<U*>(that))[Idx]
      : OperandTraits<U>::op_begin(const_cast<U*>(that))[Idx];
  }
  template <int Idx> Use &Op() {
    return OpFrom<Idx>(this);
  }
  template <int Idx> const Use &Op() const {
    return OpFrom<Idx>(this);
  }
public:
  Value *getOperand(unsigned i) const {
    assert(i < NumOperands && "getOperand() out of range!");
    return OperandList[i];
  }
  void setOperand(unsigned i, Value *Val) {
    assert(i < NumOperands && "setOperand() out of range!");
    assert((!isa<Constant>((const Value*)this) ||
            isa<GlobalValue>((const Value*)this)) &&
           "Cannot mutate a constant with setOperand!");
    OperandList[i] = Val;
  }
  const Use &getOperandUse(unsigned i) const {
    assert(i < NumOperands && "getOperandUse() out of range!");
    return OperandList[i];
  }
  Use &getOperandUse(unsigned i) {
    assert(i < NumOperands && "getOperandUse() out of range!");
    return OperandList[i];
  }

  unsigned getNumOperands() const { return NumOperands; }

  // ---------------------------------------------------------------------------
  // Operand Iterator interface...
  //
  typedef Use*       op_iterator;
  typedef const Use* const_op_iterator;
  typedef iterator_range<op_iterator> op_range;
  typedef iterator_range<const_op_iterator> const_op_range;

  inline op_iterator       op_begin()       { return OperandList; }
  inline const_op_iterator op_begin() const { return OperandList; }
  inline op_iterator       op_end()         { return OperandList+NumOperands; }
  inline const_op_iterator op_end()   const { return OperandList+NumOperands; }
  inline op_range operands() {
    return op_range(op_begin(), op_end());
  }
  inline const_op_range operands() const {
    return const_op_range(op_begin(), op_end());
  }

  /// \brief Iterator for directly iterating over the operand Values.
  struct value_op_iterator
      : iterator_adaptor_base<value_op_iterator, op_iterator,
                              std::random_access_iterator_tag, Value *,
                              ptrdiff_t, Value *, Value *> {
    explicit value_op_iterator(Use *U = nullptr) : iterator_adaptor_base(U) {}

    Value *operator*() const { return *I; }
    Value *operator->() const { return operator*(); }
  };

  inline value_op_iterator value_op_begin() {
    return value_op_iterator(op_begin());
  }
  inline value_op_iterator value_op_end() {
    return value_op_iterator(op_end());
  }
  inline iterator_range<value_op_iterator> operand_values() {
    return iterator_range<value_op_iterator>(value_op_begin(), value_op_end());
  }

  /// \brief Drop all references to operands.
  ///
  /// This function is in charge of "letting go" of all objects that this User
  /// refers to.  This allows one to 'delete' a whole class at a time, even
  /// though there may be circular references...  First all references are
  /// dropped, and all use counts go to zero.  Then everything is deleted for
  /// real.  Note that no operations are valid on an object that has "dropped
  /// all references", except operator delete.
  void dropAllReferences() {
    for (Use &U : operands())
      U.set(nullptr);
  }

  /// \brief Replace uses of one Value with another.
  ///
  /// Replaces all references to the "From" definition with references to the
  /// "To" definition.
  void replaceUsesOfWith(Value *From, Value *To);

  // Methods for support type inquiry through isa, cast, and dyn_cast:
  static inline bool classof(const Value *V) {
    return isa<Instruction>(V) || isa<Constant>(V);
  }
};

template<> struct simplify_type<User::op_iterator> {
  typedef Value* SimpleType;
  static SimpleType getSimplifiedValue(User::op_iterator &Val) {
    return Val->get();
  }
};
template<> struct simplify_type<User::const_op_iterator> {
  typedef /*const*/ Value* SimpleType;
  static SimpleType getSimplifiedValue(User::const_op_iterator &Val) {
    return Val->get();
  }
};

} // End llvm namespace

#endif