MachineLocation.h revision 2d28617de2b0b731c08d1af9e830f31e14ac75b4 
1//===-- llvm/MC/MachineLocation.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// The MachineLocation class is used to represent a simple location in a machine
10// frame.  Locations will be one of two forms; a register or an address formed
11// from a base address plus an offset.  Register indirection can be specified by
12// using an offset of zero.
13//
14// The MachineMove class is used to represent abstract move operations in the
15// prolog/epilog of a compiled function.  A collection of these objects can be
16// used by a debug consumer to track the location of values when unwinding stack
17// frames.
18//===----------------------------------------------------------------------===//
19
20
21#ifndef LLVM_MC_MACHINELOCATION_H
22#define LLVM_MC_MACHINELOCATION_H
23
24namespace llvm {
25  class MCSymbol;
26
27class MachineLocation {
28private:
29  bool IsRegister;                      // True if location is a register.
30  unsigned Register;                    // gcc/gdb register number.
31  int Offset;                           // Displacement if not register.
32public:
33  enum {
34    // The target register number for an abstract frame pointer. The value is
35    // an arbitrary value that doesn't collide with any real target register.
36    VirtualFP = ~0U
37  };
38  MachineLocation()
39    : IsRegister(false), Register(0), Offset(0) {}
40  explicit MachineLocation(unsigned R)
41    : IsRegister(true), Register(R), Offset(0) {}
42  MachineLocation(unsigned R, int O)
43    : IsRegister(false), Register(R), Offset(O) {}
44
45  bool operator==(const MachineLocation &Other) const {
46      return IsRegister == Other.IsRegister && Register == Other.Register &&
47        Offset == Other.Offset;
48  }
49
50  // Accessors
51  bool isReg()           const { return IsRegister; }
52  unsigned getReg()      const { return Register; }
53  int getOffset()        const { return Offset; }
54  void setIsRegister(bool Is)  { IsRegister = Is; }
55  void setRegister(unsigned R) { Register = R; }
56  void setOffset(int O)        { Offset = O; }
57  void set(unsigned R) {
58    IsRegister = true;
59    Register = R;
60    Offset = 0;
61  }
62  void set(unsigned R, int O) {
63    IsRegister = false;
64    Register = R;
65    Offset = O;
66  }
67
68#ifndef NDEBUG
69  void dump();
70#endif
71};
72
73/// MachineMove - This class represents the save or restore of a callee saved
74/// register that exception or debug info needs to know about.
75class MachineMove {
76private:
77  /// Label - Symbol for post-instruction address when result of move takes
78  /// effect.
79  MCSymbol *Label;
80
81  // Move to & from location.
82  MachineLocation Destination, Source;
83public:
84  MachineMove() : Label(0) {}
85
86  MachineMove(MCSymbol *label, const MachineLocation &D,
87              const MachineLocation &S)
88  : Label(label), Destination(D), Source(S) {}
89
90  // Accessors
91  MCSymbol *getLabel()                    const { return Label; }
92  const MachineLocation &getDestination() const { return Destination; }
93  const MachineLocation &getSource()      const { return Source; }
94};
95
96} // End llvm namespace
97
98#endif
99