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
23namespace llvm {
24
25class MachineFrameInfo;
26class MachineMemOperand;
27class raw_ostream;
28
29raw_ostream &operator<<(raw_ostream &OS, const MachineMemOperand &MMO);
30class PseudoSourceValue;
31raw_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.
36class PseudoSourceValue {
37public:
38  enum PSVKind {
39    Stack,
40    GOT,
41    JumpTable,
42    ConstantPool,
43    FixedStack,
44    GlobalValueCallEntry,
45    ExternalSymbolCallEntry
46  };
47
48private:
49  PSVKind Kind;
50  friend raw_ostream &llvm::operator<<(raw_ostream &OS,
51                                       const PseudoSourceValue* PSV);
52
53  friend class MachineMemOperand; // For printCustom().
54
55  /// Implement printing for PseudoSourceValue. This is called from
56  /// Value::print or Value's operator<<.
57  virtual void printCustom(raw_ostream &O) const;
58
59public:
60  explicit PseudoSourceValue(PSVKind Kind);
61
62  virtual ~PseudoSourceValue();
63
64  PSVKind kind() const { return Kind; }
65
66  bool isStack() const { return Kind == Stack; }
67  bool isGOT() const { return Kind == GOT; }
68  bool isConstantPool() const { return Kind == ConstantPool; }
69  bool isJumpTable() const { return Kind == JumpTable; }
70
71  /// Test whether the memory pointed to by this PseudoSourceValue has a
72  /// constant value.
73  virtual bool isConstant(const MachineFrameInfo *) const;
74
75  /// Test whether the memory pointed to by this PseudoSourceValue may also be
76  /// pointed to by an LLVM IR Value.
77  virtual bool isAliased(const MachineFrameInfo *) const;
78
79  /// Return true if the memory pointed to by this PseudoSourceValue can ever
80  /// alias an LLVM IR Value.
81  virtual bool mayAlias(const MachineFrameInfo *) const;
82};
83
84/// A specialized PseudoSourceValue for holding FixedStack values, which must
85/// include a frame index.
86class FixedStackPseudoSourceValue : public PseudoSourceValue {
87  const int FI;
88
89public:
90  explicit FixedStackPseudoSourceValue(int FI)
91      : PseudoSourceValue(FixedStack), FI(FI) {}
92
93  static inline bool classof(const PseudoSourceValue *V) {
94    return V->kind() == FixedStack;
95  }
96
97  bool isConstant(const MachineFrameInfo *MFI) const override;
98
99  bool isAliased(const MachineFrameInfo *MFI) const override;
100
101  bool mayAlias(const MachineFrameInfo *) const override;
102
103  void printCustom(raw_ostream &OS) const override;
104
105  int getFrameIndex() const { return FI; }
106};
107
108class CallEntryPseudoSourceValue : public PseudoSourceValue {
109protected:
110  CallEntryPseudoSourceValue(PSVKind Kind);
111
112public:
113  bool isConstant(const MachineFrameInfo *) const override;
114  bool isAliased(const MachineFrameInfo *) const override;
115  bool mayAlias(const MachineFrameInfo *) const override;
116};
117
118/// A specialized pseudo soruce value for holding GlobalValue values.
119class GlobalValuePseudoSourceValue : public CallEntryPseudoSourceValue {
120  const GlobalValue *GV;
121
122public:
123  GlobalValuePseudoSourceValue(const GlobalValue *GV);
124
125  static inline bool classof(const PseudoSourceValue *V) {
126    return V->kind() == GlobalValueCallEntry;
127  }
128
129  const GlobalValue *getValue() const { return GV; }
130};
131
132/// A specialized pseudo source value for holding external symbol values.
133class ExternalSymbolPseudoSourceValue : public CallEntryPseudoSourceValue {
134  const char *ES;
135
136public:
137  ExternalSymbolPseudoSourceValue(const char *ES);
138
139  static inline bool classof(const PseudoSourceValue *V) {
140    return V->kind() == ExternalSymbolCallEntry;
141  }
142
143  const char *getSymbol() const { return ES; }
144};
145
146/// Manages creation of pseudo source values.
147class PseudoSourceValueManager {
148  const PseudoSourceValue StackPSV, GOTPSV, JumpTablePSV, ConstantPoolPSV;
149  std::map<int, std::unique_ptr<FixedStackPseudoSourceValue>> FSValues;
150  StringMap<std::unique_ptr<const ExternalSymbolPseudoSourceValue>>
151      ExternalCallEntries;
152  ValueMap<const GlobalValue *,
153           std::unique_ptr<const GlobalValuePseudoSourceValue>>
154      GlobalCallEntries;
155
156public:
157  PseudoSourceValueManager();
158
159  /// Return a pseudo source value referencing the area below the stack frame of
160  /// a function, e.g., the argument space.
161  const PseudoSourceValue *getStack();
162
163  /// Return a pseudo source value referencing the global offset table
164  /// (or something the like).
165  const PseudoSourceValue *getGOT();
166
167  /// Return a pseudo source value referencing the constant pool. Since constant
168  /// pools are constant, this doesn't need to identify a specific constant
169  /// pool entry.
170  const PseudoSourceValue *getConstantPool();
171
172  /// Return a pseudo source value referencing a jump table. Since jump tables
173  /// are constant, this doesn't need to identify a specific jump table.
174  const PseudoSourceValue *getJumpTable();
175
176  /// Return a pseudo source value referencing a fixed stack frame entry,
177  /// e.g., a spill slot.
178  const PseudoSourceValue *getFixedStack(int FI);
179
180  const PseudoSourceValue *getGlobalValueCallEntry(const GlobalValue *GV);
181
182  const PseudoSourceValue *getExternalSymbolCallEntry(const char *ES);
183};
184
185} // end namespace llvm
186
187#endif
188