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      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 
     27 namespace llvm {
     28 
     29 class LiveInterval;
     30 class VirtRegMap;
     31 
     32 class LiveDebugVariables : public MachineFunctionPass {
     33   void *pImpl;
     34 public:
     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 
     60 private:
     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