LiveDebugVariables.h revision 36b56886974eae4f9c5ebc96befd3e7bfe5de338 
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 LiveIntervals;
31class VirtRegMap;
32
33class LiveDebugVariables : public MachineFunctionPass {
34  void *pImpl;
35public:
36  static char ID; // Pass identification, replacement for typeid
37
38  LiveDebugVariables();
39  ~LiveDebugVariables();
40
41  /// renameRegister - Move any user variables in OldReg to NewReg:SubIdx.
42  /// @param OldReg Old virtual register that is going away.
43  /// @param NewReg New register holding the user variables.
44  /// @param SubIdx If NewReg is a virtual register, SubIdx may indicate a sub-
45  ///               register.
46  void renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx);
47
48  /// splitRegister - Move any user variables in OldReg to the live ranges in
49  /// NewRegs where they are live. Mark the values as unavailable where no new
50  /// register is live.
51  void splitRegister(unsigned OldReg, ArrayRef<unsigned> NewRegs,
52                     LiveIntervals &LIS);
53
54  /// emitDebugValues - Emit new DBG_VALUE instructions reflecting the changes
55  /// that happened during register allocation.
56  /// @param VRM Rename virtual registers according to map.
57  void emitDebugValues(VirtRegMap *VRM);
58
59  /// dump - Print data structures to dbgs().
60  void dump();
61
62private:
63
64  bool runOnMachineFunction(MachineFunction &) override;
65  void releaseMemory() override;
66  void getAnalysisUsage(AnalysisUsage &) const override;
67
68};
69
70} // namespace llvm
71
72#endif // LLVM_CODEGEN_LIVEDEBUGVARIABLES_H
73