lib/CodeGen/LiveDebugVariables.h

   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_LIB_CODEGEN_LIVEDEBUGVARIABLES_H
  22 #define LLVM_LIB_CODEGEN_LIVEDEBUGVARIABLES_H
  23
  24 #include "llvm/ADT/ArrayRef.h"
  25 #include "llvm/CodeGen/MachineFunctionPass.h"
  26 #include "llvm/IR/DebugInfo.h"
  27
  28 namespace llvm {
  29
  30 class LiveInterval;
  31 class LiveIntervals;
  32 class VirtRegMap;
  33
  34 class LLVM_LIBRARY_VISIBILITY LiveDebugVariables : public MachineFunctionPass {
  35   void *pImpl;
  36
  37 public:
  38   static char ID; // Pass identification, replacement for typeid
  39
  40   LiveDebugVariables();
  41   ~LiveDebugVariables() override;
  42
  43   /// renameRegister - Move any user variables in OldReg to NewReg:SubIdx.
  44   /// @param OldReg Old virtual register that is going away.
  45   /// @param NewReg New register holding the user variables.
  46   /// @param SubIdx If NewReg is a virtual register, SubIdx may indicate a sub-
  47   ///               register.
  48   void renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx);
  49
  50   /// splitRegister - Move any user variables in OldReg to the live ranges in
  51   /// NewRegs where they are live. Mark the values as unavailable where no new
  52   /// register is live.
  53   void splitRegister(unsigned OldReg, ArrayRef<unsigned> NewRegs,
  54                      LiveIntervals &LIS);
  55
  56   /// emitDebugValues - Emit new DBG_VALUE instructions reflecting the changes
  57   /// that happened during register allocation.
  58   /// @param VRM Rename virtual registers according to map.
  59   void emitDebugValues(VirtRegMap *VRM);
  60
  61   /// dump - Print data structures to dbgs().
  62   void dump();
  63
  64 private:
  65
  66   bool runOnMachineFunction(MachineFunction &) override;
  67   void releaseMemory() override;
  68   void getAnalysisUsage(AnalysisUsage &) const override;
  69   bool doInitialization(Module &) override;
  70
  71 };
  72
  73 } // namespace llvm
  74
  75 #endif