PseudoSourceValue.h revision 360784 
1//===-- llvm/CodeGen/PseudoSourceValue.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// This file contains the declaration of the PseudoSourceValue class.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_CODEGEN_PSEUDOSOURCEVALUE_H
14#define LLVM_CODEGEN_PSEUDOSOURCEVALUE_H
15
16#include "llvm/ADT/StringMap.h"
17#include "llvm/IR/GlobalValue.h"
18#include "llvm/IR/ValueMap.h"
19#include <map>
20
21namespace llvm {
22
23class MachineFrameInfo;
24class MachineMemOperand;
25class MIRFormatter;
26class raw_ostream;
27class TargetInstrInfo;
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 : unsigned {
39    Stack,
40    GOT,
41    JumpTable,
42    ConstantPool,
43    FixedStack,
44    GlobalValueCallEntry,
45    ExternalSymbolCallEntry,
46    TargetCustom
47  };
48
49private:
50  unsigned Kind;
51  unsigned AddressSpace;
52  friend raw_ostream &llvm::operator<<(raw_ostream &OS,
53                                       const PseudoSourceValue* PSV);
54
55  friend class MachineMemOperand; // For printCustom().
56  friend class MIRFormatter;      // For printCustom().
57
58  /// Implement printing for PseudoSourceValue. This is called from
59  /// Value::print or Value's operator<<.
60  virtual void printCustom(raw_ostream &O) const;
61
62public:
63  explicit PseudoSourceValue(unsigned Kind, const TargetInstrInfo &TII);
64
65  virtual ~PseudoSourceValue();
66
67  unsigned kind() const { return Kind; }
68
69  bool isStack() const { return Kind == Stack; }
70  bool isGOT() const { return Kind == GOT; }
71  bool isConstantPool() const { return Kind == ConstantPool; }
72  bool isJumpTable() const { return Kind == JumpTable; }
73
74  unsigned getAddressSpace() const { return AddressSpace; }
75
76  unsigned getTargetCustom() const {
77    return (Kind >= TargetCustom) ? ((Kind+1) - TargetCustom) : 0;
78  }
79
80  /// Test whether the memory pointed to by this PseudoSourceValue has a
81  /// constant value.
82  virtual bool isConstant(const MachineFrameInfo *) const;
83
84  /// Test whether the memory pointed to by this PseudoSourceValue may also be
85  /// pointed to by an LLVM IR Value.
86  virtual bool isAliased(const MachineFrameInfo *) const;
87
88  /// Return true if the memory pointed to by this PseudoSourceValue can ever
89  /// alias an LLVM IR Value.
90  virtual bool mayAlias(const MachineFrameInfo *) const;
91};
92
93/// A specialized PseudoSourceValue for holding FixedStack values, which must
94/// include a frame index.
95class FixedStackPseudoSourceValue : public PseudoSourceValue {
96  const int FI;
97
98public:
99  explicit FixedStackPseudoSourceValue(int FI, const TargetInstrInfo &TII)
100      : PseudoSourceValue(FixedStack, TII), FI(FI) {}
101
102  static bool classof(const PseudoSourceValue *V) {
103    return V->kind() == FixedStack;
104  }
105
106  bool isConstant(const MachineFrameInfo *MFI) const override;
107
108  bool isAliased(const MachineFrameInfo *MFI) const override;
109
110  bool mayAlias(const MachineFrameInfo *) const override;
111
112  void printCustom(raw_ostream &OS) const override;
113
114  int getFrameIndex() const { return FI; }
115};
116
117class CallEntryPseudoSourceValue : public PseudoSourceValue {
118protected:
119  CallEntryPseudoSourceValue(unsigned Kind, const TargetInstrInfo &TII);
120
121public:
122  bool isConstant(const MachineFrameInfo *) const override;
123  bool isAliased(const MachineFrameInfo *) const override;
124  bool mayAlias(const MachineFrameInfo *) const override;
125};
126
127/// A specialized pseudo source value for holding GlobalValue values.
128class GlobalValuePseudoSourceValue : public CallEntryPseudoSourceValue {
129  const GlobalValue *GV;
130
131public:
132  GlobalValuePseudoSourceValue(const GlobalValue *GV,
133                               const TargetInstrInfo &TII);
134
135  static bool classof(const PseudoSourceValue *V) {
136    return V->kind() == GlobalValueCallEntry;
137  }
138
139  const GlobalValue *getValue() const { return GV; }
140};
141
142/// A specialized pseudo source value for holding external symbol values.
143class ExternalSymbolPseudoSourceValue : public CallEntryPseudoSourceValue {
144  const char *ES;
145
146public:
147  ExternalSymbolPseudoSourceValue(const char *ES, const TargetInstrInfo &TII);
148
149  static bool classof(const PseudoSourceValue *V) {
150    return V->kind() == ExternalSymbolCallEntry;
151  }
152
153  const char *getSymbol() const { return ES; }
154};
155
156/// Manages creation of pseudo source values.
157class PseudoSourceValueManager {
158  const TargetInstrInfo &TII;
159  const PseudoSourceValue StackPSV, GOTPSV, JumpTablePSV, ConstantPoolPSV;
160  std::map<int, std::unique_ptr<FixedStackPseudoSourceValue>> FSValues;
161  StringMap<std::unique_ptr<const ExternalSymbolPseudoSourceValue>>
162      ExternalCallEntries;
163  ValueMap<const GlobalValue *,
164           std::unique_ptr<const GlobalValuePseudoSourceValue>>
165      GlobalCallEntries;
166
167public:
168  PseudoSourceValueManager(const TargetInstrInfo &TII);
169
170  /// Return a pseudo source value referencing the area below the stack frame of
171  /// a function, e.g., the argument space.
172  const PseudoSourceValue *getStack();
173
174  /// Return a pseudo source value referencing the global offset table
175  /// (or something the like).
176  const PseudoSourceValue *getGOT();
177
178  /// Return a pseudo source value referencing the constant pool. Since constant
179  /// pools are constant, this doesn't need to identify a specific constant
180  /// pool entry.
181  const PseudoSourceValue *getConstantPool();
182
183  /// Return a pseudo source value referencing a jump table. Since jump tables
184  /// are constant, this doesn't need to identify a specific jump table.
185  const PseudoSourceValue *getJumpTable();
186
187  /// Return a pseudo source value referencing a fixed stack frame entry,
188  /// e.g., a spill slot.
189  const PseudoSourceValue *getFixedStack(int FI);
190
191  const PseudoSourceValue *getGlobalValueCallEntry(const GlobalValue *GV);
192
193  const PseudoSourceValue *getExternalSymbolCallEntry(const char *ES);
194};
195
196} // end namespace llvm
197
198#endif
199