MachineLocation.h revision 13131e62fc9a523b3cc8ad98cc9def97ff89391a 
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// explicitly passing an offset to the constructor.
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  /// Create a direct register location.
41  explicit MachineLocation(unsigned R)
42    : IsRegister(true), Register(R), Offset(0) {}
43  /// Create a register-indirect location with an offset.
44  MachineLocation(unsigned R, int O)
45    : IsRegister(false), Register(R), Offset(O) {}
46
47  bool operator==(const MachineLocation &Other) const {
48      return IsRegister == Other.IsRegister && Register == Other.Register &&
49        Offset == Other.Offset;
50  }
51
52  // Accessors
53  bool isIndirect()      const { return !IsRegister; }
54  bool isReg()           const { return IsRegister; }
55  unsigned getReg()      const { return Register; }
56  int getOffset()        const { return Offset; }
57  void setIsRegister(bool Is)  { IsRegister = Is; }
58  void setRegister(unsigned R) { Register = R; }
59  void setOffset(int O)        { Offset = O; }
60  /// Make this location a direct register location.
61  void set(unsigned R) {
62    IsRegister = true;
63    Register = R;
64    Offset = 0;
65  }
66  /// Make this location a register-indirect+offset location.
67  void set(unsigned R, int O) {
68    IsRegister = false;
69    Register = R;
70    Offset = O;
71  }
72
73#ifndef NDEBUG
74  void dump();
75#endif
76};
77
78/// MachineMove - This class represents the save or restore of a callee saved
79/// register that exception or debug info needs to know about.
80class MachineMove {
81private:
82  /// Label - Symbol for post-instruction address when result of move takes
83  /// effect.
84  MCSymbol *Label;
85
86  // Move to & from location.
87  MachineLocation Destination, Source;
88public:
89  MachineMove() : Label(0) {}
90
91  MachineMove(MCSymbol *label, const MachineLocation &D,
92              const MachineLocation &S)
93  : Label(label), Destination(D), Source(S) {}
94
95  // Accessors
96  MCSymbol *getLabel()                    const { return Label; }
97  const MachineLocation &getDestination() const { return Destination; }
98  const MachineLocation &getSource()      const { return Source; }
99};
100
101} // End llvm namespace
102
103#endif
104