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			712 lines
		
	
	
		
			24 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			712 lines
		
	
	
		
			24 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| //===- LiveDebugVariables.cpp - Tracking debug info variables -------------===//
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| //
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| //                     The LLVM Compiler Infrastructure
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| //
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| // This file is distributed under the University of Illinois Open Source
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| // License. See LICENSE.TXT for details.
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| //
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| //===----------------------------------------------------------------------===//
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| //
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| // This file implements the LiveDebugVariables analysis.
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| //
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| // Remove all DBG_VALUE instructions referencing virtual registers and replace
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| // them with a data structure tracking where live user variables are kept - in a
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| // virtual register or in a stack slot.
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| //
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| // Allow the data structure to be updated during register allocation when values
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| // are moved between registers and stack slots. Finally emit new DBG_VALUE
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| // instructions after register allocation is complete.
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| //
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| //===----------------------------------------------------------------------===//
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| 
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| #define DEBUG_TYPE "livedebug"
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| #include "LiveDebugVariables.h"
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| #include "VirtRegMap.h"
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| #include "llvm/Constants.h"
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| #include "llvm/Metadata.h"
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| #include "llvm/Value.h"
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| #include "llvm/ADT/IntervalMap.h"
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| #include "llvm/CodeGen/LiveIntervalAnalysis.h"
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| #include "llvm/CodeGen/MachineDominators.h"
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| #include "llvm/CodeGen/MachineFunction.h"
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| #include "llvm/CodeGen/MachineInstrBuilder.h"
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| #include "llvm/CodeGen/Passes.h"
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| #include "llvm/Support/CommandLine.h"
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| #include "llvm/Support/Debug.h"
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| #include "llvm/Target/TargetInstrInfo.h"
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| #include "llvm/Target/TargetMachine.h"
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| #include "llvm/Target/TargetRegisterInfo.h"
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| 
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| using namespace llvm;
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| 
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| static cl::opt<bool>
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| EnableLDV("live-debug-variables", cl::init(true),
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|           cl::desc("Enable the live debug variables pass"), cl::Hidden);
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| 
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| char LiveDebugVariables::ID = 0;
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| 
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| INITIALIZE_PASS_BEGIN(LiveDebugVariables, "livedebugvars",
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|                 "Debug Variable Analysis", false, false)
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| INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
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| INITIALIZE_PASS_DEPENDENCY(LiveIntervals)
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| INITIALIZE_PASS_END(LiveDebugVariables, "livedebugvars",
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|                 "Debug Variable Analysis", false, false)
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| 
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| void LiveDebugVariables::getAnalysisUsage(AnalysisUsage &AU) const {
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|   AU.addRequired<MachineDominatorTree>();
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|   AU.addRequiredTransitive<LiveIntervals>();
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|   AU.setPreservesAll();
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|   MachineFunctionPass::getAnalysisUsage(AU);
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| }
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| 
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| LiveDebugVariables::LiveDebugVariables() : MachineFunctionPass(ID), pImpl(0) {
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|   initializeLiveDebugVariablesPass(*PassRegistry::getPassRegistry());
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| }
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| 
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| /// LocMap - Map of where a user value is live, and its location.
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| typedef IntervalMap<SlotIndex, unsigned, 4> LocMap;
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| 
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| /// UserValue - A user value is a part of a debug info user variable.
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| ///
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| /// A DBG_VALUE instruction notes that (a sub-register of) a virtual register
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| /// holds part of a user variable. The part is identified by a byte offset.
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| ///
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| /// UserValues are grouped into equivalence classes for easier searching. Two
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| /// user values are related if they refer to the same variable, or if they are
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| /// held by the same virtual register. The equivalence class is the transitive
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| /// closure of that relation.
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| namespace {
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| class UserValue {
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|   const MDNode *variable; ///< The debug info variable we are part of.
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|   unsigned offset;        ///< Byte offset into variable.
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|   DebugLoc dl;            ///< The debug location for the variable. This is
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|                           ///< used by dwarf writer to find lexical scope.
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|   UserValue *leader;      ///< Equivalence class leader.
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|   UserValue *next;        ///< Next value in equivalence class, or null.
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| 
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|   /// Numbered locations referenced by locmap.
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|   SmallVector<MachineOperand, 4> locations;
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| 
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|   /// Map of slot indices where this value is live.
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|   LocMap locInts;
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| 
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|   /// coalesceLocation - After LocNo was changed, check if it has become
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|   /// identical to another location, and coalesce them. This may cause LocNo or
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|   /// a later location to be erased, but no earlier location will be erased.
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|   void coalesceLocation(unsigned LocNo);
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| 
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|   /// insertDebugValue - Insert a DBG_VALUE into MBB at Idx for LocNo.
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|   void insertDebugValue(MachineBasicBlock *MBB, SlotIndex Idx, unsigned LocNo,
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|                         LiveIntervals &LIS, const TargetInstrInfo &TII);
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| 
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|   /// insertDebugKill - Insert an undef DBG_VALUE into MBB at Idx.
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|   void insertDebugKill(MachineBasicBlock *MBB, SlotIndex Idx,
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|                        LiveIntervals &LIS, const TargetInstrInfo &TII);
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| 
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| public:
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|   /// UserValue - Create a new UserValue.
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|   UserValue(const MDNode *var, unsigned o, DebugLoc L, 
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|             LocMap::Allocator &alloc)
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|     : variable(var), offset(o), dl(L), leader(this), next(0), locInts(alloc)
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|   {}
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| 
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|   /// getLeader - Get the leader of this value's equivalence class.
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|   UserValue *getLeader() {
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|     UserValue *l = leader;
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|     while (l != l->leader)
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|       l = l->leader;
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|     return leader = l;
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|   }
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| 
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|   /// getNext - Return the next UserValue in the equivalence class.
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|   UserValue *getNext() const { return next; }
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| 
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|   /// match - Does this UserValue match the aprameters?
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|   bool match(const MDNode *Var, unsigned Offset) const {
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|     return Var == variable && Offset == offset;
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|   }
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| 
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|   /// merge - Merge equivalence classes.
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|   static UserValue *merge(UserValue *L1, UserValue *L2) {
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|     L2 = L2->getLeader();
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|     if (!L1)
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|       return L2;
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|     L1 = L1->getLeader();
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|     if (L1 == L2)
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|       return L1;
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|     // Splice L2 before L1's members.
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|     UserValue *End = L2;
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|     while (End->next)
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|       End->leader = L1, End = End->next;
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|     End->leader = L1;
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|     End->next = L1->next;
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|     L1->next = L2;
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|     return L1;
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|   }
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| 
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|   /// getLocationNo - Return the location number that matches Loc.
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|   unsigned getLocationNo(const MachineOperand &LocMO) {
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|     if (LocMO.isReg() && LocMO.getReg() == 0)
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|       return ~0u;
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|     for (unsigned i = 0, e = locations.size(); i != e; ++i)
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|       if (LocMO.isIdenticalTo(locations[i]))
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|         return i;
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|     locations.push_back(LocMO);
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|     // We are storing a MachineOperand outside a MachineInstr.
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|     locations.back().clearParent();
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|     return locations.size() - 1;
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|   }
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| 
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|   /// addDef - Add a definition point to this value.
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|   void addDef(SlotIndex Idx, const MachineOperand &LocMO) {
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|     // Add a singular (Idx,Idx) -> Loc mapping.
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|     LocMap::iterator I = locInts.find(Idx);
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|     if (!I.valid() || I.start() != Idx)
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|       I.insert(Idx, Idx.getNextSlot(), getLocationNo(LocMO));
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|   }
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| 
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|   /// extendDef - Extend the current definition as far as possible down the
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|   /// dominator tree. Stop when meeting an existing def or when leaving the live
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|   /// range of VNI.
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|   /// @param Idx   Starting point for the definition.
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|   /// @param LocNo Location number to propagate.
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|   /// @param LI    Restrict liveness to where LI has the value VNI. May be null.
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|   /// @param VNI   When LI is not null, this is the value to restrict to.
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|   /// @param LIS   Live intervals analysis.
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|   /// @param MDT   Dominator tree.
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|   void extendDef(SlotIndex Idx, unsigned LocNo,
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|                  LiveInterval *LI, const VNInfo *VNI,
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|                  LiveIntervals &LIS, MachineDominatorTree &MDT);
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| 
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|   /// computeIntervals - Compute the live intervals of all locations after
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|   /// collecting all their def points.
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|   void computeIntervals(LiveIntervals &LIS, MachineDominatorTree &MDT);
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| 
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|   /// renameRegister - Update locations to rewrite OldReg as NewReg:SubIdx.
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|   void renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx,
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|                       const TargetRegisterInfo *TRI);
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| 
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|   /// rewriteLocations - Rewrite virtual register locations according to the
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|   /// provided virtual register map.
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|   void rewriteLocations(VirtRegMap &VRM, const TargetRegisterInfo &TRI);
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| 
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|   /// emitDebugVariables - Recreate DBG_VALUE instruction from data structures.
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|   void emitDebugValues(VirtRegMap *VRM,
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|                        LiveIntervals &LIS, const TargetInstrInfo &TRI);
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| 
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|   /// findDebugLoc - Return DebugLoc used for this DBG_VALUE instruction. A
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|   /// variable may have more than one corresponding DBG_VALUE instructions. 
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|   /// Only first one needs DebugLoc to identify variable's lexical scope
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|   /// in source file.
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|   DebugLoc findDebugLoc();
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|   void print(raw_ostream&, const TargetRegisterInfo*);
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| };
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| } // namespace
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| 
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| /// LDVImpl - Implementation of the LiveDebugVariables pass.
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| namespace {
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| class LDVImpl {
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|   LiveDebugVariables &pass;
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|   LocMap::Allocator allocator;
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|   MachineFunction *MF;
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|   LiveIntervals *LIS;
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|   MachineDominatorTree *MDT;
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|   const TargetRegisterInfo *TRI;
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| 
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|   /// userValues - All allocated UserValue instances.
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|   SmallVector<UserValue*, 8> userValues;
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| 
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|   /// Map virtual register to eq class leader.
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|   typedef DenseMap<unsigned, UserValue*> VRMap;
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|   VRMap virtRegToEqClass;
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| 
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|   /// Map user variable to eq class leader.
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|   typedef DenseMap<const MDNode *, UserValue*> UVMap;
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|   UVMap userVarMap;
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| 
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|   /// getUserValue - Find or create a UserValue.
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|   UserValue *getUserValue(const MDNode *Var, unsigned Offset, DebugLoc DL);
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| 
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|   /// lookupVirtReg - Find the EC leader for VirtReg or null.
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|   UserValue *lookupVirtReg(unsigned VirtReg);
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| 
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|   /// mapVirtReg - Map virtual register to an equivalence class.
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|   void mapVirtReg(unsigned VirtReg, UserValue *EC);
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| 
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|   /// handleDebugValue - Add DBG_VALUE instruction to our maps.
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|   /// @param MI  DBG_VALUE instruction
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|   /// @param Idx Last valid SLotIndex before instruction.
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|   /// @return    True if the DBG_VALUE instruction should be deleted.
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|   bool handleDebugValue(MachineInstr *MI, SlotIndex Idx);
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| 
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|   /// collectDebugValues - Collect and erase all DBG_VALUE instructions, adding
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|   /// a UserValue def for each instruction.
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|   /// @param mf MachineFunction to be scanned.
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|   /// @return True if any debug values were found.
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|   bool collectDebugValues(MachineFunction &mf);
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| 
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|   /// computeIntervals - Compute the live intervals of all user values after
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|   /// collecting all their def points.
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|   void computeIntervals();
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| 
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| public:
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|   LDVImpl(LiveDebugVariables *ps) : pass(*ps) {}
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|   bool runOnMachineFunction(MachineFunction &mf);
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| 
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|   /// clear - Relase all memory.
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|   void clear() {
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|     DeleteContainerPointers(userValues);
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|     userValues.clear();
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|     virtRegToEqClass.clear();
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|     userVarMap.clear();
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|   }
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| 
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|   /// renameRegister - Replace all references to OldReg wiht NewReg:SubIdx.
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|   void renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx);
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| 
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|   /// emitDebugVariables - Recreate DBG_VALUE instruction from data structures.
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|   void emitDebugValues(VirtRegMap *VRM);
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| 
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|   void print(raw_ostream&);
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| };
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| } // namespace
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| 
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| void UserValue::print(raw_ostream &OS, const TargetRegisterInfo *TRI) {
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|   if (const MDString *MDS = dyn_cast<MDString>(variable->getOperand(2)))
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|     OS << "!\"" << MDS->getString() << "\"\t";
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|   if (offset)
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|     OS << '+' << offset;
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|   for (LocMap::const_iterator I = locInts.begin(); I.valid(); ++I) {
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|     OS << " [" << I.start() << ';' << I.stop() << "):";
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|     if (I.value() == ~0u)
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|       OS << "undef";
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|     else
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|       OS << I.value();
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|   }
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|   for (unsigned i = 0, e = locations.size(); i != e; ++i)
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|     OS << " Loc" << i << '=' << locations[i];
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|   OS << '\n';
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| }
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| 
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| void LDVImpl::print(raw_ostream &OS) {
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|   OS << "********** DEBUG VARIABLES **********\n";
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|   for (unsigned i = 0, e = userValues.size(); i != e; ++i)
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|     userValues[i]->print(OS, TRI);
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| }
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| 
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| void UserValue::coalesceLocation(unsigned LocNo) {
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|   unsigned KeepLoc = 0;
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|   for (unsigned e = locations.size(); KeepLoc != e; ++KeepLoc) {
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|     if (KeepLoc == LocNo)
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|       continue;
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|     if (locations[KeepLoc].isIdenticalTo(locations[LocNo]))
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|       break;
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|   }
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|   // No matches.
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|   if (KeepLoc == locations.size())
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|     return;
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| 
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|   // Keep the smaller location, erase the larger one.
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|   unsigned EraseLoc = LocNo;
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|   if (KeepLoc > EraseLoc)
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|     std::swap(KeepLoc, EraseLoc);
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|   locations.erase(locations.begin() + EraseLoc);
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| 
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|   // Rewrite values.
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|   for (LocMap::iterator I = locInts.begin(); I.valid(); ++I) {
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|     unsigned v = I.value();
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|     if (v == EraseLoc)
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|       I.setValue(KeepLoc);      // Coalesce when possible.
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|     else if (v > EraseLoc)
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|       I.setValueUnchecked(v-1); // Avoid coalescing with untransformed values.
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|   }
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| }
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| 
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| UserValue *LDVImpl::getUserValue(const MDNode *Var, unsigned Offset,
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|                                  DebugLoc DL) {
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|   UserValue *&Leader = userVarMap[Var];
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|   if (Leader) {
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|     UserValue *UV = Leader->getLeader();
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|     Leader = UV;
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|     for (; UV; UV = UV->getNext())
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|       if (UV->match(Var, Offset))
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|         return UV;
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|   }
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| 
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|   UserValue *UV = new UserValue(Var, Offset, DL, allocator);
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|   userValues.push_back(UV);
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|   Leader = UserValue::merge(Leader, UV);
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|   return UV;
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| }
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| 
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| void LDVImpl::mapVirtReg(unsigned VirtReg, UserValue *EC) {
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|   assert(TargetRegisterInfo::isVirtualRegister(VirtReg) && "Only map VirtRegs");
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|   UserValue *&Leader = virtRegToEqClass[VirtReg];
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|   Leader = UserValue::merge(Leader, EC);
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| }
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| 
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| UserValue *LDVImpl::lookupVirtReg(unsigned VirtReg) {
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|   if (UserValue *UV = virtRegToEqClass.lookup(VirtReg))
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|     return UV->getLeader();
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|   return 0;
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| }
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| 
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| bool LDVImpl::handleDebugValue(MachineInstr *MI, SlotIndex Idx) {
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|   // DBG_VALUE loc, offset, variable
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|   if (MI->getNumOperands() != 3 ||
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|       !MI->getOperand(1).isImm() || !MI->getOperand(2).isMetadata()) {
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|     DEBUG(dbgs() << "Can't handle " << *MI);
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|     return false;
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|   }
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| 
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|   // Get or create the UserValue for (variable,offset).
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|   unsigned Offset = MI->getOperand(1).getImm();
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|   const MDNode *Var = MI->getOperand(2).getMetadata();
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|   UserValue *UV = getUserValue(Var, Offset, MI->getDebugLoc());
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| 
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|   // If the location is a virtual register, make sure it is mapped.
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|   if (MI->getOperand(0).isReg()) {
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|     unsigned Reg = MI->getOperand(0).getReg();
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|     if (TargetRegisterInfo::isVirtualRegister(Reg))
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|       mapVirtReg(Reg, UV);
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|   }
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| 
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|   UV->addDef(Idx, MI->getOperand(0));
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|   return true;
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| }
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| 
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| bool LDVImpl::collectDebugValues(MachineFunction &mf) {
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|   bool Changed = false;
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|   for (MachineFunction::iterator MFI = mf.begin(), MFE = mf.end(); MFI != MFE;
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|        ++MFI) {
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|     MachineBasicBlock *MBB = MFI;
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|     for (MachineBasicBlock::iterator MBBI = MBB->begin(), MBBE = MBB->end();
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|          MBBI != MBBE;) {
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|       if (!MBBI->isDebugValue()) {
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|         ++MBBI;
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|         continue;
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|       }
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|       // DBG_VALUE has no slot index, use the previous instruction instead.
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|       SlotIndex Idx = MBBI == MBB->begin() ?
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|         LIS->getMBBStartIdx(MBB) :
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|         LIS->getInstructionIndex(llvm::prior(MBBI)).getDefIndex();
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|       // Handle consecutive DBG_VALUE instructions with the same slot index.
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|       do {
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|         if (handleDebugValue(MBBI, Idx)) {
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|           MBBI = MBB->erase(MBBI);
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|           Changed = true;
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|         } else
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|           ++MBBI;
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|       } while (MBBI != MBBE && MBBI->isDebugValue());
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|     }
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|   }
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|   return Changed;
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| }
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| 
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| void UserValue::extendDef(SlotIndex Idx, unsigned LocNo,
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|                           LiveInterval *LI, const VNInfo *VNI,
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|                           LiveIntervals &LIS, MachineDominatorTree &MDT) {
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|   SmallVector<SlotIndex, 16> Todo;
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|   Todo.push_back(Idx);
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| 
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|   do {
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|     SlotIndex Start = Todo.pop_back_val();
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|     MachineBasicBlock *MBB = LIS.getMBBFromIndex(Start);
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|     SlotIndex Stop = LIS.getMBBEndIdx(MBB);
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|     LocMap::iterator I = locInts.find(Start);
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| 
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|     // Limit to VNI's live range.
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|     bool ToEnd = true;
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|     if (LI && VNI) {
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|       LiveRange *Range = LI->getLiveRangeContaining(Start);
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|       if (!Range || Range->valno != VNI)
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|         continue;
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|       if (Range->end < Stop)
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|         Stop = Range->end, ToEnd = false;
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|     }
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| 
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|     // There could already be a short def at Start.
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|     if (I.valid() && I.start() <= Start) {
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|       // Stop when meeting a different location or an already extended interval.
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|       Start = Start.getNextSlot();
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|       if (I.value() != LocNo || I.stop() != Start)
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|         continue;
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|       // This is a one-slot placeholder. Just skip it.
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|       ++I;
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|     }
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| 
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|     // Limited by the next def.
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|     if (I.valid() && I.start() < Stop)
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|       Stop = I.start(), ToEnd = false;
 | |
| 
 | |
|     if (Start >= Stop)
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|       continue;
 | |
| 
 | |
|     I.insert(Start, Stop, LocNo);
 | |
| 
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|     // If we extended to the MBB end, propagate down the dominator tree.
 | |
|     if (!ToEnd)
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|       continue;
 | |
|     const std::vector<MachineDomTreeNode*> &Children =
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|       MDT.getNode(MBB)->getChildren();
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|     for (unsigned i = 0, e = Children.size(); i != e; ++i)
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|       Todo.push_back(LIS.getMBBStartIdx(Children[i]->getBlock()));
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|   } while (!Todo.empty());
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| }
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| 
 | |
| void
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| UserValue::computeIntervals(LiveIntervals &LIS, MachineDominatorTree &MDT) {
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|   SmallVector<std::pair<SlotIndex, unsigned>, 16> Defs;
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| 
 | |
|   // Collect all defs to be extended (Skipping undefs).
 | |
|   for (LocMap::const_iterator I = locInts.begin(); I.valid(); ++I)
 | |
|     if (I.value() != ~0u)
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|       Defs.push_back(std::make_pair(I.start(), I.value()));
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| 
 | |
|   for (unsigned i = 0, e = Defs.size(); i != e; ++i) {
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|     SlotIndex Idx = Defs[i].first;
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|     unsigned LocNo = Defs[i].second;
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|     const MachineOperand &Loc = locations[LocNo];
 | |
| 
 | |
|     // Register locations are constrained to where the register value is live.
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|     if (Loc.isReg() && LIS.hasInterval(Loc.getReg())) {
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|       LiveInterval *LI = &LIS.getInterval(Loc.getReg());
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|       const VNInfo *VNI = LI->getVNInfoAt(Idx);
 | |
|       extendDef(Idx, LocNo, LI, VNI, LIS, MDT);
 | |
|     } else
 | |
|       extendDef(Idx, LocNo, 0, 0, LIS, MDT);
 | |
|   }
 | |
| 
 | |
|   // Finally, erase all the undefs.
 | |
|   for (LocMap::iterator I = locInts.begin(); I.valid();)
 | |
|     if (I.value() == ~0u)
 | |
|       I.erase();
 | |
|     else
 | |
|       ++I;
 | |
| }
 | |
| 
 | |
| void LDVImpl::computeIntervals() {
 | |
|   for (unsigned i = 0, e = userValues.size(); i != e; ++i)
 | |
|     userValues[i]->computeIntervals(*LIS, *MDT);
 | |
| }
 | |
| 
 | |
| bool LDVImpl::runOnMachineFunction(MachineFunction &mf) {
 | |
|   MF = &mf;
 | |
|   LIS = &pass.getAnalysis<LiveIntervals>();
 | |
|   MDT = &pass.getAnalysis<MachineDominatorTree>();
 | |
|   TRI = mf.getTarget().getRegisterInfo();
 | |
|   clear();
 | |
|   DEBUG(dbgs() << "********** COMPUTING LIVE DEBUG VARIABLES: "
 | |
|                << ((Value*)mf.getFunction())->getName()
 | |
|                << " **********\n");
 | |
| 
 | |
|   bool Changed = collectDebugValues(mf);
 | |
|   computeIntervals();
 | |
|   DEBUG(print(dbgs()));
 | |
|   return Changed;
 | |
| }
 | |
| 
 | |
| bool LiveDebugVariables::runOnMachineFunction(MachineFunction &mf) {
 | |
|   if (!EnableLDV)
 | |
|     return false;
 | |
|   if (!pImpl)
 | |
|     pImpl = new LDVImpl(this);
 | |
|   return static_cast<LDVImpl*>(pImpl)->runOnMachineFunction(mf);
 | |
| }
 | |
| 
 | |
| void LiveDebugVariables::releaseMemory() {
 | |
|   if (pImpl)
 | |
|     static_cast<LDVImpl*>(pImpl)->clear();
 | |
| }
 | |
| 
 | |
| LiveDebugVariables::~LiveDebugVariables() {
 | |
|   if (pImpl)
 | |
|     delete static_cast<LDVImpl*>(pImpl);
 | |
| }
 | |
| 
 | |
| void UserValue::
 | |
| renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx,
 | |
|                const TargetRegisterInfo *TRI) {
 | |
|   for (unsigned i = locations.size(); i; --i) {
 | |
|     unsigned LocNo = i - 1;
 | |
|     MachineOperand &Loc = locations[LocNo];
 | |
|     if (!Loc.isReg() || Loc.getReg() != OldReg)
 | |
|       continue;
 | |
|     if (TargetRegisterInfo::isPhysicalRegister(NewReg))
 | |
|       Loc.substPhysReg(NewReg, *TRI);
 | |
|     else
 | |
|       Loc.substVirtReg(NewReg, SubIdx, *TRI);
 | |
|     coalesceLocation(LocNo);
 | |
|   }
 | |
| }
 | |
| 
 | |
| void LDVImpl::
 | |
| renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx) {
 | |
|   UserValue *UV = lookupVirtReg(OldReg);
 | |
|   if (!UV)
 | |
|     return;
 | |
| 
 | |
|   if (TargetRegisterInfo::isVirtualRegister(NewReg))
 | |
|     mapVirtReg(NewReg, UV);
 | |
|   virtRegToEqClass.erase(OldReg);
 | |
| 
 | |
|   do {
 | |
|     UV->renameRegister(OldReg, NewReg, SubIdx, TRI);
 | |
|     UV = UV->getNext();
 | |
|   } while (UV);
 | |
| }
 | |
| 
 | |
| void LiveDebugVariables::
 | |
| renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx) {
 | |
|   if (pImpl)
 | |
|     static_cast<LDVImpl*>(pImpl)->renameRegister(OldReg, NewReg, SubIdx);
 | |
| }
 | |
| 
 | |
| void
 | |
| UserValue::rewriteLocations(VirtRegMap &VRM, const TargetRegisterInfo &TRI) {
 | |
|   // Iterate over locations in reverse makes it easier to handle coalescing.
 | |
|   for (unsigned i = locations.size(); i ; --i) {
 | |
|     unsigned LocNo = i-1;
 | |
|     MachineOperand &Loc = locations[LocNo];
 | |
|     // Only virtual registers are rewritten.
 | |
|     if (!Loc.isReg() || !Loc.getReg() ||
 | |
|         !TargetRegisterInfo::isVirtualRegister(Loc.getReg()))
 | |
|       continue;
 | |
|     unsigned VirtReg = Loc.getReg();
 | |
|     if (VRM.isAssignedReg(VirtReg) &&
 | |
|         TargetRegisterInfo::isPhysicalRegister(VRM.getPhys(VirtReg))) {
 | |
|       Loc.substPhysReg(VRM.getPhys(VirtReg), TRI);
 | |
|     } else if (VRM.getStackSlot(VirtReg) != VirtRegMap::NO_STACK_SLOT &&
 | |
|                VRM.isSpillSlotUsed(VRM.getStackSlot(VirtReg))) {
 | |
|       // FIXME: Translate SubIdx to a stackslot offset.
 | |
|       Loc = MachineOperand::CreateFI(VRM.getStackSlot(VirtReg));
 | |
|     } else {
 | |
|       Loc.setReg(0);
 | |
|       Loc.setSubReg(0);
 | |
|     }
 | |
|     coalesceLocation(LocNo);
 | |
|   }
 | |
|   DEBUG(print(dbgs(), &TRI));
 | |
| }
 | |
| 
 | |
| /// findInsertLocation - Find an iterator for inserting a DBG_VALUE
 | |
| /// instruction.
 | |
| static MachineBasicBlock::iterator
 | |
| findInsertLocation(MachineBasicBlock *MBB, SlotIndex Idx,
 | |
|                    LiveIntervals &LIS) {
 | |
|   SlotIndex Start = LIS.getMBBStartIdx(MBB);
 | |
|   Idx = Idx.getBaseIndex();
 | |
| 
 | |
|   // Try to find an insert location by going backwards from Idx.
 | |
|   MachineInstr *MI;
 | |
|   while (!(MI = LIS.getInstructionFromIndex(Idx))) {
 | |
|     // We've reached the beginning of MBB.
 | |
|     if (Idx == Start) {
 | |
|       MachineBasicBlock::iterator I = MBB->SkipPHIsAndLabels(MBB->begin());
 | |
|       return I;
 | |
|     }
 | |
|     Idx = Idx.getPrevIndex();
 | |
|   }
 | |
| 
 | |
|   // Don't insert anything after the first terminator, though.
 | |
|   return MI->getDesc().isTerminator() ? MBB->getFirstTerminator() :
 | |
|                                     llvm::next(MachineBasicBlock::iterator(MI));
 | |
| }
 | |
| 
 | |
| DebugLoc UserValue::findDebugLoc() {
 | |
|   DebugLoc D = dl;
 | |
|   dl = DebugLoc();
 | |
|   return D;
 | |
| }
 | |
| void UserValue::insertDebugValue(MachineBasicBlock *MBB, SlotIndex Idx,
 | |
|                                  unsigned LocNo,
 | |
|                                  LiveIntervals &LIS,
 | |
|                                  const TargetInstrInfo &TII) {
 | |
|   MachineBasicBlock::iterator I = findInsertLocation(MBB, Idx, LIS);
 | |
|   MachineOperand &Loc = locations[LocNo];
 | |
| 
 | |
|   // Frame index locations may require a target callback.
 | |
|   if (Loc.isFI()) {
 | |
|     MachineInstr *MI = TII.emitFrameIndexDebugValue(*MBB->getParent(),
 | |
|                                           Loc.getIndex(), offset, variable, 
 | |
|                                                     findDebugLoc());
 | |
|     if (MI) {
 | |
|       MBB->insert(I, MI);
 | |
|       return;
 | |
|     }
 | |
|   }
 | |
|   // This is not a frame index, or the target is happy with a standard FI.
 | |
|   BuildMI(*MBB, I, findDebugLoc(), TII.get(TargetOpcode::DBG_VALUE))
 | |
|     .addOperand(Loc).addImm(offset).addMetadata(variable);
 | |
| }
 | |
| 
 | |
| void UserValue::insertDebugKill(MachineBasicBlock *MBB, SlotIndex Idx,
 | |
|                                LiveIntervals &LIS, const TargetInstrInfo &TII) {
 | |
|   MachineBasicBlock::iterator I = findInsertLocation(MBB, Idx, LIS);
 | |
|   BuildMI(*MBB, I, findDebugLoc(), TII.get(TargetOpcode::DBG_VALUE)).addReg(0)
 | |
|     .addImm(offset).addMetadata(variable);
 | |
| }
 | |
| 
 | |
| void UserValue::emitDebugValues(VirtRegMap *VRM, LiveIntervals &LIS,
 | |
|                                 const TargetInstrInfo &TII) {
 | |
|   MachineFunction::iterator MFEnd = VRM->getMachineFunction().end();
 | |
| 
 | |
|   for (LocMap::const_iterator I = locInts.begin(); I.valid();) {
 | |
|     SlotIndex Start = I.start();
 | |
|     SlotIndex Stop = I.stop();
 | |
|     unsigned LocNo = I.value();
 | |
|     DEBUG(dbgs() << "\t[" << Start << ';' << Stop << "):" << LocNo);
 | |
|     MachineFunction::iterator MBB = LIS.getMBBFromIndex(Start);
 | |
|     SlotIndex MBBEnd = LIS.getMBBEndIdx(MBB);
 | |
| 
 | |
|     DEBUG(dbgs() << " BB#" << MBB->getNumber() << '-' << MBBEnd);
 | |
|     insertDebugValue(MBB, Start, LocNo, LIS, TII);
 | |
| 
 | |
|     // This interval may span multiple basic blocks.
 | |
|     // Insert a DBG_VALUE into each one.
 | |
|     while(Stop > MBBEnd) {
 | |
|       // Move to the next block.
 | |
|       Start = MBBEnd;
 | |
|       if (++MBB == MFEnd)
 | |
|         break;
 | |
|       MBBEnd = LIS.getMBBEndIdx(MBB);
 | |
|       DEBUG(dbgs() << " BB#" << MBB->getNumber() << '-' << MBBEnd);
 | |
|       insertDebugValue(MBB, Start, LocNo, LIS, TII);
 | |
|     }
 | |
|     DEBUG(dbgs() << '\n');
 | |
|     if (MBB == MFEnd)
 | |
|       break;
 | |
| 
 | |
|     ++I;
 | |
|     if (Stop == MBBEnd)
 | |
|       continue;
 | |
|     // The current interval ends before MBB.
 | |
|     // Insert a kill if there is a gap.
 | |
|     if (!I.valid() || I.start() > Stop)
 | |
|       insertDebugKill(MBB, Stop, LIS, TII);
 | |
|   }
 | |
| }
 | |
| 
 | |
| void LDVImpl::emitDebugValues(VirtRegMap *VRM) {
 | |
|   DEBUG(dbgs() << "********** EMITTING LIVE DEBUG VARIABLES **********\n");
 | |
|   const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
 | |
|   for (unsigned i = 0, e = userValues.size(); i != e; ++i) {
 | |
|     userValues[i]->rewriteLocations(*VRM, *TRI);
 | |
|     userValues[i]->emitDebugValues(VRM, *LIS, *TII);
 | |
|   }
 | |
| }
 | |
| 
 | |
| void LiveDebugVariables::emitDebugValues(VirtRegMap *VRM) {
 | |
|   if (pImpl)
 | |
|     static_cast<LDVImpl*>(pImpl)->emitDebugValues(VRM);
 | |
| }
 | |
| 
 | |
| 
 | |
| #ifndef NDEBUG
 | |
| void LiveDebugVariables::dump() {
 | |
|   if (pImpl)
 | |
|     static_cast<LDVImpl*>(pImpl)->print(dbgs());
 | |
| }
 | |
| #endif
 | |
| 
 |