LLVM  6.0.0svn
PseudoSourceValue.h
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1 //===-- llvm/CodeGen/PseudoSourceValue.h ------------------------*- 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 contains the declaration of the PseudoSourceValue class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_CODEGEN_PSEUDOSOURCEVALUE_H
15 #define LLVM_CODEGEN_PSEUDOSOURCEVALUE_H
16 
17 #include "llvm/ADT/StringMap.h"
18 #include "llvm/IR/GlobalValue.h"
19 #include "llvm/IR/Value.h"
20 #include "llvm/IR/ValueMap.h"
21 #include <map>
22 
23 namespace llvm {
24 
25 class MachineFrameInfo;
26 class MachineMemOperand;
27 class raw_ostream;
28 
29 raw_ostream &operator<<(raw_ostream &OS, const MachineMemOperand &MMO);
30 class PseudoSourceValue;
31 raw_ostream &operator<<(raw_ostream &OS, const PseudoSourceValue* PSV);
32 
33 /// Special value supplied for machine level alias analysis. It indicates that
34 /// a memory access references the functions stack frame (e.g., a spill slot),
35 /// below the stack frame (e.g., argument space), or constant pool.
37 public:
38  enum PSVKind {
40  GOT,
47  };
48 
49 private:
50  PSVKind Kind;
52  const PseudoSourceValue* PSV);
53 
54  friend class MachineMemOperand; // For printCustom().
55 
56  /// Implement printing for PseudoSourceValue. This is called from
57  /// Value::print or Value's operator<<.
58  virtual void printCustom(raw_ostream &O) const;
59 
60 public:
61  explicit PseudoSourceValue(PSVKind Kind);
62 
63  virtual ~PseudoSourceValue();
64 
65  PSVKind kind() const { return Kind; }
66 
67  bool isStack() const { return Kind == Stack; }
68  bool isGOT() const { return Kind == GOT; }
69  bool isConstantPool() const { return Kind == ConstantPool; }
70  bool isJumpTable() const { return Kind == JumpTable; }
71  unsigned getTargetCustom() const {
72  return (Kind >= TargetCustom) ? ((Kind+1) - TargetCustom) : 0;
73  }
74 
75  /// Test whether the memory pointed to by this PseudoSourceValue has a
76  /// constant value.
77  virtual bool isConstant(const MachineFrameInfo *) const;
78 
79  /// Test whether the memory pointed to by this PseudoSourceValue may also be
80  /// pointed to by an LLVM IR Value.
81  virtual bool isAliased(const MachineFrameInfo *) const;
82 
83  /// Return true if the memory pointed to by this PseudoSourceValue can ever
84  /// alias an LLVM IR Value.
85  virtual bool mayAlias(const MachineFrameInfo *) const;
86 };
87 
88 /// A specialized PseudoSourceValue for holding FixedStack values, which must
89 /// include a frame index.
91  const int FI;
92 
93 public:
94  explicit FixedStackPseudoSourceValue(int FI)
95  : PseudoSourceValue(FixedStack), FI(FI) {}
96 
97  static bool classof(const PseudoSourceValue *V) {
98  return V->kind() == FixedStack;
99  }
100 
101  bool isConstant(const MachineFrameInfo *MFI) const override;
102 
103  bool isAliased(const MachineFrameInfo *MFI) const override;
104 
105  bool mayAlias(const MachineFrameInfo *) const override;
106 
107  void printCustom(raw_ostream &OS) const override;
108 
109  int getFrameIndex() const { return FI; }
110 };
111 
113 protected:
115 
116 public:
117  bool isConstant(const MachineFrameInfo *) const override;
118  bool isAliased(const MachineFrameInfo *) const override;
119  bool mayAlias(const MachineFrameInfo *) const override;
120 };
121 
122 /// A specialized pseudo soruce value for holding GlobalValue values.
124  const GlobalValue *GV;
125 
126 public:
128 
129  static bool classof(const PseudoSourceValue *V) {
130  return V->kind() == GlobalValueCallEntry;
131  }
132 
133  const GlobalValue *getValue() const { return GV; }
134 };
135 
136 /// A specialized pseudo source value for holding external symbol values.
138  const char *ES;
139 
140 public:
141  ExternalSymbolPseudoSourceValue(const char *ES);
142 
143  static bool classof(const PseudoSourceValue *V) {
144  return V->kind() == ExternalSymbolCallEntry;
145  }
146 
147  const char *getSymbol() const { return ES; }
148 };
149 
150 /// Manages creation of pseudo source values.
152  const PseudoSourceValue StackPSV, GOTPSV, JumpTablePSV, ConstantPoolPSV;
153  std::map<int, std::unique_ptr<FixedStackPseudoSourceValue>> FSValues;
155  ExternalCallEntries;
156  ValueMap<const GlobalValue *,
157  std::unique_ptr<const GlobalValuePseudoSourceValue>>
158  GlobalCallEntries;
159 
160 public:
162 
163  /// Return a pseudo source value referencing the area below the stack frame of
164  /// a function, e.g., the argument space.
165  const PseudoSourceValue *getStack();
166 
167  /// Return a pseudo source value referencing the global offset table
168  /// (or something the like).
169  const PseudoSourceValue *getGOT();
170 
171  /// Return a pseudo source value referencing the constant pool. Since constant
172  /// pools are constant, this doesn't need to identify a specific constant
173  /// pool entry.
174  const PseudoSourceValue *getConstantPool();
175 
176  /// Return a pseudo source value referencing a jump table. Since jump tables
177  /// are constant, this doesn't need to identify a specific jump table.
178  const PseudoSourceValue *getJumpTable();
179 
180  /// Return a pseudo source value referencing a fixed stack frame entry,
181  /// e.g., a spill slot.
182  const PseudoSourceValue *getFixedStack(int FI);
183 
184  const PseudoSourceValue *getGlobalValueCallEntry(const GlobalValue *GV);
185 
186  const PseudoSourceValue *getExternalSymbolCallEntry(const char *ES);
187 };
188 
189 } // end namespace llvm
190 
191 #endif
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
virtual bool mayAlias(const MachineFrameInfo *) const
Return true if the memory pointed to by this PseudoSourceValue can ever alias an LLVM IR Value...
virtual bool isAliased(const MachineFrameInfo *) const
Test whether the memory pointed to by this PseudoSourceValue may also be pointed to by an LLVM IR Val...
virtual bool isConstant(const MachineFrameInfo *) const
Test whether the memory pointed to by this PseudoSourceValue has a constant value.
A description of a memory reference used in the backend.
The MachineFrameInfo class represents an abstract stack frame until prolog/epilog code is inserted...
unsigned getTargetCustom() const
static bool classof(const PseudoSourceValue *V)
See the file comment.
Definition: ValueMap.h:86
StringMap - This is an unconventional map that is specialized for handling keys that are "strings"...
Definition: StringMap.h:224
A specialized pseudo source value for holding external symbol values.
Special value supplied for machine level alias analysis.
A specialized pseudo soruce value for holding GlobalValue values.
static bool classof(const PseudoSourceValue *V)
const GlobalValue * getValue() const
static bool classof(const PseudoSourceValue *V)
raw_ostream & operator<<(raw_ostream &OS, const APInt &I)
Definition: APInt.h:2018
const unsigned Kind
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:44
Manages creation of pseudo source values.
A specialized PseudoSourceValue for holding FixedStack values, which must include a frame index...