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/IR/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 Value *V) {
54      return V->getValueID() == PseudoSourceValueVal ||
55             V->getValueID() == FixedStackPseudoSourceValueVal;
56    }
57
58    /// A pseudo source value referencing a fixed stack frame entry,
59    /// e.g., a spill slot.
60    static const PseudoSourceValue *getFixedStack(int FI);
61
62    /// A pseudo source value referencing the area below the stack frame of
63    /// a function, e.g., the argument space.
64    static const PseudoSourceValue *getStack();
65
66    /// A pseudo source value referencing the global offset table
67    /// (or something the like).
68    static const PseudoSourceValue *getGOT();
69
70    /// A pseudo source value referencing the constant pool. Since constant
71    /// pools are constant, this doesn't need to identify a specific constant
72    /// pool entry.
73    static const PseudoSourceValue *getConstantPool();
74
75    /// A pseudo source value referencing a jump table. Since jump tables are
76    /// constant, this doesn't need to identify a specific jump table.
77    static const PseudoSourceValue *getJumpTable();
78  };
79
80  /// FixedStackPseudoSourceValue - A specialized PseudoSourceValue
81  /// for holding FixedStack values, which must include a frame
82  /// index.
83  class FixedStackPseudoSourceValue : public PseudoSourceValue {
84    const int FI;
85  public:
86    explicit FixedStackPseudoSourceValue(int fi) :
87        PseudoSourceValue(FixedStackPseudoSourceValueVal), FI(fi) {}
88
89    /// classof - Methods for support type inquiry through isa, cast, and
90    /// dyn_cast:
91    ///
92    static inline bool classof(const Value *V) {
93      return V->getValueID() == FixedStackPseudoSourceValueVal;
94    }
95
96    virtual bool isConstant(const MachineFrameInfo *MFI) const;
97
98    virtual bool isAliased(const MachineFrameInfo *MFI) const;
99
100    virtual bool mayAlias(const MachineFrameInfo *) const;
101
102    virtual void printCustom(raw_ostream &OS) const;
103
104    int getFrameIndex() const { return FI; }
105  };
106} // End llvm namespace
107
108#endif
109