1//===- LiveDebugVariables.h - Tracking debug info variables ----*- 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 provides the interface to the LiveDebugVariables analysis.
11//
12// The analysis removes DBG_VALUE instructions for virtual registers and tracks
13// live user variables in a data structure that can be updated during register
14// allocation.
15//
16// After register allocation new DBG_VALUE instructions are emitted to reflect
17// the new locations of user variables.
18//
19//===----------------------------------------------------------------------===//
20
21#ifndef LLVM_CODEGEN_LIVEDEBUGVARIABLES_H
22#define LLVM_CODEGEN_LIVEDEBUGVARIABLES_H
23
24#include "llvm/ADT/ArrayRef.h"
25#include "llvm/CodeGen/MachineFunctionPass.h"
26
27namespace llvm {
28
29class LiveInterval;
30class VirtRegMap;
31
32class LiveDebugVariables : public MachineFunctionPass {
33  void *pImpl;
34public:
35  static char ID; // Pass identification, replacement for typeid
36
37  LiveDebugVariables();
38  ~LiveDebugVariables();
39
40  /// renameRegister - Move any user variables in OldReg to NewReg:SubIdx.
41  /// @param OldReg Old virtual register that is going away.
42  /// @param NewReg New register holding the user variables.
43  /// @param SubIdx If NewReg is a virtual register, SubIdx may indicate a sub-
44  ///               register.
45  void renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx);
46
47  /// splitRegister - Move any user variables in OldReg to the live ranges in
48  /// NewRegs where they are live. Mark the values as unavailable where no new
49  /// register is live.
50  void splitRegister(unsigned OldReg, ArrayRef<LiveInterval*> NewRegs);
51
52  /// emitDebugValues - Emit new DBG_VALUE instructions reflecting the changes
53  /// that happened during register allocation.
54  /// @param VRM Rename virtual registers according to map.
55  void emitDebugValues(VirtRegMap *VRM);
56
57  /// dump - Print data structures to dbgs().
58  void dump();
59
60private:
61
62  virtual bool runOnMachineFunction(MachineFunction &);
63  virtual void releaseMemory();
64  virtual void getAnalysisUsage(AnalysisUsage &) const;
65
66};
67
68} // namespace llvm
69
70#endif // LLVM_CODEGEN_LIVEDEBUGVARIABLES_H
71