PseudoSourceValue.h revision 223017 
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/Value.h"
18
19namespace llvm {
20  class MachineFrameInfo;
21  class raw_ostream;
22
23  /// PseudoSourceValue - Special value supplied for machine level alias
24  /// analysis. It indicates that a memory access references the functions
25  /// stack frame (e.g., a spill slot), below the stack frame (e.g., argument
26  /// space), or constant pool.
27  class PseudoSourceValue : public Value {
28  private:
29    /// printCustom - Implement printing for PseudoSourceValue. This is called
30    /// from Value::print or Value's operator<<.
31    ///
32    virtual void printCustom(raw_ostream &O) const;
33
34  public:
35    explicit PseudoSourceValue(enum ValueTy Subclass = PseudoSourceValueVal);
36
37    /// isConstant - Test whether the memory pointed to by this
38    /// PseudoSourceValue has a constant value.
39    ///
40    virtual bool isConstant(const MachineFrameInfo *) const;
41
42    /// isAliased - Test whether the memory pointed to by this
43    /// PseudoSourceValue may also be pointed to by an LLVM IR Value.
44    virtual bool isAliased(const MachineFrameInfo *) const;
45
46    /// mayAlias - Return true if the memory pointed to by this
47    /// PseudoSourceValue can ever alias a LLVM IR Value.
48    virtual bool mayAlias(const MachineFrameInfo *) const;
49
50    /// classof - Methods for support type inquiry through isa, cast, and
51    /// dyn_cast:
52    ///
53    static inline bool classof(const PseudoSourceValue *) { return true; }
54    static inline bool classof(const Value *V) {
55      return V->getValueID() == PseudoSourceValueVal ||
56             V->getValueID() == FixedStackPseudoSourceValueVal;
57    }
58
59    /// A pseudo source value referencing a fixed stack frame entry,
60    /// e.g., a spill slot.
61    static const PseudoSourceValue *getFixedStack(int FI);
62
63    /// A pseudo source value referencing the area below the stack frame of
64    /// a function, e.g., the argument space.
65    static const PseudoSourceValue *getStack();
66
67    /// A pseudo source value referencing the global offset table
68    /// (or something the like).
69    static const PseudoSourceValue *getGOT();
70
71    /// A pseudo source value referencing the constant pool. Since constant
72    /// pools are constant, this doesn't need to identify a specific constant
73    /// pool entry.
74    static const PseudoSourceValue *getConstantPool();
75
76    /// A pseudo source value referencing a jump table. Since jump tables are
77    /// constant, this doesn't need to identify a specific jump table.
78    static const PseudoSourceValue *getJumpTable();
79  };
80
81  /// FixedStackPseudoSourceValue - A specialized PseudoSourceValue
82  /// for holding FixedStack values, which must include a frame
83  /// index.
84  class FixedStackPseudoSourceValue : public PseudoSourceValue {
85    const int FI;
86  public:
87    explicit FixedStackPseudoSourceValue(int fi) :
88        PseudoSourceValue(FixedStackPseudoSourceValueVal), FI(fi) {}
89
90    /// classof - Methods for support type inquiry through isa, cast, and
91    /// dyn_cast:
92    ///
93    static inline bool classof(const FixedStackPseudoSourceValue *) {
94      return true;
95    }
96    static inline bool classof(const Value *V) {
97      return V->getValueID() == FixedStackPseudoSourceValueVal;
98    }
99
100    virtual bool isConstant(const MachineFrameInfo *MFI) const;
101
102    virtual bool isAliased(const MachineFrameInfo *MFI) const;
103
104    virtual bool mayAlias(const MachineFrameInfo *) const;
105
106    virtual void printCustom(raw_ostream &OS) const;
107
108    int getFrameIndex() const { return FI; }
109  };
110} // End llvm namespace
111
112#endif
113