1320 lines
		
	
	
		
			47 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			1320 lines
		
	
	
		
			47 KiB
		
	
	
	
		
			C++
		
	
	
	
| //===- LiveDebugVariables.cpp - Tracking debug info variables -------------===//
 | |
| //
 | |
| //                     The LLVM Compiler Infrastructure
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| //
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| // This file is distributed under the University of Illinois Open Source
 | |
| // License. See LICENSE.TXT for details.
 | |
| //
 | |
| //===----------------------------------------------------------------------===//
 | |
| //
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| // This file implements the LiveDebugVariables analysis.
 | |
| //
 | |
| // Remove all DBG_VALUE instructions referencing virtual registers and replace
 | |
| // them with a data structure tracking where live user variables are kept - in a
 | |
| // virtual register or in a stack slot.
 | |
| //
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| // Allow the data structure to be updated during register allocation when values
 | |
| // 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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| 
 | |
| #include "LiveDebugVariables.h"
 | |
| #include "llvm/ADT/ArrayRef.h"
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| #include "llvm/ADT/DenseMap.h"
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| #include "llvm/ADT/IntervalMap.h"
 | |
| #include "llvm/ADT/STLExtras.h"
 | |
| #include "llvm/ADT/SmallSet.h"
 | |
| #include "llvm/ADT/SmallVector.h"
 | |
| #include "llvm/ADT/Statistic.h"
 | |
| #include "llvm/ADT/StringRef.h"
 | |
| #include "llvm/CodeGen/LexicalScopes.h"
 | |
| #include "llvm/CodeGen/LiveInterval.h"
 | |
| #include "llvm/CodeGen/LiveIntervals.h"
 | |
| #include "llvm/CodeGen/MachineBasicBlock.h"
 | |
| #include "llvm/CodeGen/MachineDominators.h"
 | |
| #include "llvm/CodeGen/MachineFunction.h"
 | |
| #include "llvm/CodeGen/MachineInstr.h"
 | |
| #include "llvm/CodeGen/MachineInstrBuilder.h"
 | |
| #include "llvm/CodeGen/MachineOperand.h"
 | |
| #include "llvm/CodeGen/MachineRegisterInfo.h"
 | |
| #include "llvm/CodeGen/SlotIndexes.h"
 | |
| #include "llvm/CodeGen/TargetInstrInfo.h"
 | |
| #include "llvm/CodeGen/TargetOpcodes.h"
 | |
| #include "llvm/CodeGen/TargetRegisterInfo.h"
 | |
| #include "llvm/CodeGen/TargetSubtargetInfo.h"
 | |
| #include "llvm/CodeGen/VirtRegMap.h"
 | |
| #include "llvm/Config/llvm-config.h"
 | |
| #include "llvm/IR/DebugInfoMetadata.h"
 | |
| #include "llvm/IR/DebugLoc.h"
 | |
| #include "llvm/IR/Function.h"
 | |
| #include "llvm/IR/Metadata.h"
 | |
| #include "llvm/MC/MCRegisterInfo.h"
 | |
| #include "llvm/Pass.h"
 | |
| #include "llvm/Support/Casting.h"
 | |
| #include "llvm/Support/CommandLine.h"
 | |
| #include "llvm/Support/Compiler.h"
 | |
| #include "llvm/Support/Debug.h"
 | |
| #include "llvm/Support/raw_ostream.h"
 | |
| #include <algorithm>
 | |
| #include <cassert>
 | |
| #include <iterator>
 | |
| #include <memory>
 | |
| #include <utility>
 | |
| 
 | |
| using namespace llvm;
 | |
| 
 | |
| #define DEBUG_TYPE "livedebugvars"
 | |
| 
 | |
| static cl::opt<bool>
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| EnableLDV("live-debug-variables", cl::init(true),
 | |
|           cl::desc("Enable the live debug variables pass"), cl::Hidden);
 | |
| 
 | |
| STATISTIC(NumInsertedDebugValues, "Number of DBG_VALUEs inserted");
 | |
| 
 | |
| char LiveDebugVariables::ID = 0;
 | |
| 
 | |
| INITIALIZE_PASS_BEGIN(LiveDebugVariables, DEBUG_TYPE,
 | |
|                 "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, DEBUG_TYPE,
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|                 "Debug Variable Analysis", false, false)
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| 
 | |
| void LiveDebugVariables::getAnalysisUsage(AnalysisUsage &AU) const {
 | |
|   AU.addRequired<MachineDominatorTree>();
 | |
|   AU.addRequiredTransitive<LiveIntervals>();
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|   AU.setPreservesAll();
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|   MachineFunctionPass::getAnalysisUsage(AU);
 | |
| }
 | |
| 
 | |
| LiveDebugVariables::LiveDebugVariables() : MachineFunctionPass(ID) {
 | |
|   initializeLiveDebugVariablesPass(*PassRegistry::getPassRegistry());
 | |
| }
 | |
| 
 | |
| enum : unsigned { UndefLocNo = ~0U };
 | |
| 
 | |
| /// Describes a location by number along with some flags about the original
 | |
| /// usage of the location.
 | |
| class DbgValueLocation {
 | |
| public:
 | |
|   DbgValueLocation(unsigned LocNo, bool WasIndirect)
 | |
|       : LocNo(LocNo), WasIndirect(WasIndirect) {
 | |
|     static_assert(sizeof(*this) == sizeof(unsigned), "bad bitfield packing");
 | |
|     assert(locNo() == LocNo && "location truncation");
 | |
|   }
 | |
| 
 | |
|   DbgValueLocation() : LocNo(0), WasIndirect(0) {}
 | |
| 
 | |
|   unsigned locNo() const {
 | |
|     // Fix up the undef location number, which gets truncated.
 | |
|     return LocNo == INT_MAX ? UndefLocNo : LocNo;
 | |
|   }
 | |
|   bool wasIndirect() const { return WasIndirect; }
 | |
|   bool isUndef() const { return locNo() == UndefLocNo; }
 | |
| 
 | |
|   DbgValueLocation changeLocNo(unsigned NewLocNo) const {
 | |
|     return DbgValueLocation(NewLocNo, WasIndirect);
 | |
|   }
 | |
| 
 | |
|   friend inline bool operator==(const DbgValueLocation &LHS,
 | |
|                                 const DbgValueLocation &RHS) {
 | |
|     return LHS.LocNo == RHS.LocNo && LHS.WasIndirect == RHS.WasIndirect;
 | |
|   }
 | |
| 
 | |
|   friend inline bool operator!=(const DbgValueLocation &LHS,
 | |
|                                 const DbgValueLocation &RHS) {
 | |
|     return !(LHS == RHS);
 | |
|   }
 | |
| 
 | |
| private:
 | |
|   unsigned LocNo : 31;
 | |
|   unsigned WasIndirect : 1;
 | |
| };
 | |
| 
 | |
| /// LocMap - Map of where a user value is live, and its location.
 | |
| using LocMap = IntervalMap<SlotIndex, DbgValueLocation, 4>;
 | |
| 
 | |
| /// SpillOffsetMap - Map of stack slot offsets for spilled locations.
 | |
| /// Non-spilled locations are not added to the map.
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| using SpillOffsetMap = DenseMap<unsigned, unsigned>;
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| 
 | |
| namespace {
 | |
| 
 | |
| class LDVImpl;
 | |
| 
 | |
| /// UserValue - A user value is a part of a debug info user variable.
 | |
| ///
 | |
| /// A DBG_VALUE instruction notes that (a sub-register of) a virtual register
 | |
| /// holds part of a user variable. The part is identified by a byte offset.
 | |
| ///
 | |
| /// UserValues are grouped into equivalence classes for easier searching. Two
 | |
| /// user values are related if they refer to the same variable, or if they are
 | |
| /// held by the same virtual register. The equivalence class is the transitive
 | |
| /// closure of that relation.
 | |
| class UserValue {
 | |
|   const DILocalVariable *Variable; ///< The debug info variable we are part of.
 | |
|   const DIExpression *Expression; ///< Any complex address expression.
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|   DebugLoc dl;            ///< The debug location for the variable. This is
 | |
|                           ///< used by dwarf writer to find lexical scope.
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|   UserValue *leader;      ///< Equivalence class leader.
 | |
|   UserValue *next = nullptr; ///< Next value in equivalence class, or null.
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| 
 | |
|   /// Numbered locations referenced by locmap.
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|   SmallVector<MachineOperand, 4> locations;
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| 
 | |
|   /// Map of slot indices where this value is live.
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|   LocMap locInts;
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| 
 | |
|   /// Set of interval start indexes that have been trimmed to the
 | |
|   /// lexical scope.
 | |
|   SmallSet<SlotIndex, 2> trimmedDefs;
 | |
| 
 | |
|   /// insertDebugValue - Insert a DBG_VALUE into MBB at Idx for LocNo.
 | |
|   void insertDebugValue(MachineBasicBlock *MBB, SlotIndex StartIdx,
 | |
|                         SlotIndex StopIdx, DbgValueLocation Loc, bool Spilled,
 | |
|                         unsigned SpillOffset, LiveIntervals &LIS,
 | |
|                         const TargetInstrInfo &TII,
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|                         const TargetRegisterInfo &TRI);
 | |
| 
 | |
|   /// splitLocation - Replace OldLocNo ranges with NewRegs ranges where NewRegs
 | |
|   /// is live. Returns true if any changes were made.
 | |
|   bool splitLocation(unsigned OldLocNo, ArrayRef<unsigned> NewRegs,
 | |
|                      LiveIntervals &LIS);
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| 
 | |
| public:
 | |
|   /// UserValue - Create a new UserValue.
 | |
|   UserValue(const DILocalVariable *var, const DIExpression *expr, DebugLoc L,
 | |
|             LocMap::Allocator &alloc)
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|       : Variable(var), Expression(expr), dl(std::move(L)), leader(this),
 | |
|         locInts(alloc) {}
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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;
 | |
|     return leader = l;
 | |
|   }
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| 
 | |
|   /// getNext - Return the next UserValue in the equivalence class.
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|   UserValue *getNext() const { return next; }
 | |
| 
 | |
|   /// match - Does this UserValue match the parameters?
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|   bool match(const DILocalVariable *Var, const DIExpression *Expr,
 | |
|              const DILocation *IA) const {
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|     // FIXME: The fragment should be part of the equivalence class, but not
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|     // other things in the expression like stack values.
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|     return Var == Variable && Expr == Expression && dl->getInlinedAt() == IA;
 | |
|   }
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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;
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|       End = End->next;
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|     }
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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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|   /// Return the location number that matches Loc.
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|   ///
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|   /// For undef values we always return location number UndefLocNo without
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|   /// inserting anything in locations. Since locations is a vector and the
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|   /// location number is the position in the vector and UndefLocNo is ~0,
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|   /// we would need a very big vector to put the value at the right position.
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|   unsigned getLocationNo(const MachineOperand &LocMO) {
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|     if (LocMO.isReg()) {
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|       if (LocMO.getReg() == 0)
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|         return UndefLocNo;
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|       // For register locations we dont care about use/def and other flags.
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|       for (unsigned i = 0, e = locations.size(); i != e; ++i)
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|         if (locations[i].isReg() &&
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|             locations[i].getReg() == LocMO.getReg() &&
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|             locations[i].getSubReg() == LocMO.getSubReg())
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|           return i;
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|     } else
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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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|     // Don't store def operands.
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|     if (locations.back().isReg()) {
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|       if (locations.back().isDef())
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|         locations.back().setIsDead(false);
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|       locations.back().setIsUse();
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|     }
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|     return locations.size() - 1;
 | |
|   }
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| 
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|   /// mapVirtRegs - Ensure that all virtual register locations are mapped.
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|   void mapVirtRegs(LDVImpl *LDV);
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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, bool IsIndirect) {
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|     DbgValueLocation Loc(getLocationNo(LocMO), IsIndirect);
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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(), Loc);
 | |
|     else
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|       // A later DBG_VALUE at the same SlotIndex overrides the old location.
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|       I.setValue(Loc);
 | |
|   }
 | |
| 
 | |
|   /// extendDef - Extend the current definition as far as possible down.
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|   /// Stop when meeting an existing def or when leaving the live
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|   /// range of VNI.
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|   /// End points where VNI is no longer live are added to Kills.
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|   /// @param Idx   Starting point for the definition.
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|   /// @param Loc   Location number to propagate.
 | |
|   /// @param LR    Restrict liveness to where LR has the value VNI. May be null.
 | |
|   /// @param VNI   When LR is not null, this is the value to restrict to.
 | |
|   /// @param Kills Append end points of VNI's live range to Kills.
 | |
|   /// @param LIS   Live intervals analysis.
 | |
|   void extendDef(SlotIndex Idx, DbgValueLocation Loc,
 | |
|                  LiveRange *LR, const VNInfo *VNI,
 | |
|                  SmallVectorImpl<SlotIndex> *Kills,
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|                  LiveIntervals &LIS);
 | |
| 
 | |
|   /// addDefsFromCopies - The value in LI/LocNo may be copies to other
 | |
|   /// registers. Determine if any of the copies are available at the kill
 | |
|   /// points, and add defs if possible.
 | |
|   /// @param LI      Scan for copies of the value in LI->reg.
 | |
|   /// @param LocNo   Location number of LI->reg.
 | |
|   /// @param WasIndirect Indicates if the original use of LI->reg was indirect
 | |
|   /// @param Kills   Points where the range of LocNo could be extended.
 | |
|   /// @param NewDefs Append (Idx, LocNo) of inserted defs here.
 | |
|   void addDefsFromCopies(
 | |
|       LiveInterval *LI, unsigned LocNo, bool WasIndirect,
 | |
|       const SmallVectorImpl<SlotIndex> &Kills,
 | |
|       SmallVectorImpl<std::pair<SlotIndex, DbgValueLocation>> &NewDefs,
 | |
|       MachineRegisterInfo &MRI, LiveIntervals &LIS);
 | |
| 
 | |
|   /// computeIntervals - Compute the live intervals of all locations after
 | |
|   /// collecting all their def points.
 | |
|   void computeIntervals(MachineRegisterInfo &MRI, const TargetRegisterInfo &TRI,
 | |
|                         LiveIntervals &LIS, LexicalScopes &LS);
 | |
| 
 | |
|   /// splitRegister - Replace OldReg ranges with NewRegs ranges where NewRegs is
 | |
|   /// live. Returns true if any changes were made.
 | |
|   bool splitRegister(unsigned OldReg, ArrayRef<unsigned> NewRegs,
 | |
|                      LiveIntervals &LIS);
 | |
| 
 | |
|   /// rewriteLocations - Rewrite virtual register locations according to the
 | |
|   /// provided virtual register map. Record the stack slot offsets for the
 | |
|   /// locations that were spilled.
 | |
|   void rewriteLocations(VirtRegMap &VRM, const MachineFunction &MF,
 | |
|                         const TargetInstrInfo &TII,
 | |
|                         const TargetRegisterInfo &TRI,
 | |
|                         SpillOffsetMap &SpillOffsets);
 | |
| 
 | |
|   /// emitDebugValues - Recreate DBG_VALUE instruction from data structures.
 | |
|   void emitDebugValues(VirtRegMap *VRM, LiveIntervals &LIS,
 | |
|                        const TargetInstrInfo &TII,
 | |
|                        const TargetRegisterInfo &TRI,
 | |
|                        const SpillOffsetMap &SpillOffsets);
 | |
| 
 | |
|   /// getDebugLoc - Return DebugLoc of this UserValue.
 | |
|   DebugLoc getDebugLoc() { return dl;}
 | |
| 
 | |
|   void print(raw_ostream &, const TargetRegisterInfo *);
 | |
| };
 | |
| 
 | |
| /// LDVImpl - Implementation of the LiveDebugVariables pass.
 | |
| class LDVImpl {
 | |
|   LiveDebugVariables &pass;
 | |
|   LocMap::Allocator allocator;
 | |
|   MachineFunction *MF = nullptr;
 | |
|   LiveIntervals *LIS;
 | |
|   const TargetRegisterInfo *TRI;
 | |
| 
 | |
|   /// Whether emitDebugValues is called.
 | |
|   bool EmitDone = false;
 | |
| 
 | |
|   /// Whether the machine function is modified during the pass.
 | |
|   bool ModifiedMF = false;
 | |
| 
 | |
|   /// userValues - All allocated UserValue instances.
 | |
|   SmallVector<std::unique_ptr<UserValue>, 8> userValues;
 | |
| 
 | |
|   /// Map virtual register to eq class leader.
 | |
|   using VRMap = DenseMap<unsigned, UserValue *>;
 | |
|   VRMap virtRegToEqClass;
 | |
| 
 | |
|   /// Map user variable to eq class leader.
 | |
|   using UVMap = DenseMap<const DILocalVariable *, UserValue *>;
 | |
|   UVMap userVarMap;
 | |
| 
 | |
|   /// getUserValue - Find or create a UserValue.
 | |
|   UserValue *getUserValue(const DILocalVariable *Var, const DIExpression *Expr,
 | |
|                           const DebugLoc &DL);
 | |
| 
 | |
|   /// lookupVirtReg - Find the EC leader for VirtReg or null.
 | |
|   UserValue *lookupVirtReg(unsigned VirtReg);
 | |
| 
 | |
|   /// handleDebugValue - Add DBG_VALUE instruction to our maps.
 | |
|   /// @param MI  DBG_VALUE instruction
 | |
|   /// @param Idx Last valid SLotIndex before instruction.
 | |
|   /// @return    True if the DBG_VALUE instruction should be deleted.
 | |
|   bool handleDebugValue(MachineInstr &MI, SlotIndex Idx);
 | |
| 
 | |
|   /// collectDebugValues - Collect and erase all DBG_VALUE instructions, adding
 | |
|   /// a UserValue def for each instruction.
 | |
|   /// @param mf MachineFunction to be scanned.
 | |
|   /// @return True if any debug values were found.
 | |
|   bool collectDebugValues(MachineFunction &mf);
 | |
| 
 | |
|   /// computeIntervals - Compute the live intervals of all user values after
 | |
|   /// collecting all their def points.
 | |
|   void computeIntervals();
 | |
| 
 | |
| public:
 | |
|   LDVImpl(LiveDebugVariables *ps) : pass(*ps) {}
 | |
| 
 | |
|   bool runOnMachineFunction(MachineFunction &mf);
 | |
| 
 | |
|   /// clear - Release all memory.
 | |
|   void clear() {
 | |
|     MF = nullptr;
 | |
|     userValues.clear();
 | |
|     virtRegToEqClass.clear();
 | |
|     userVarMap.clear();
 | |
|     // Make sure we call emitDebugValues if the machine function was modified.
 | |
|     assert((!ModifiedMF || EmitDone) &&
 | |
|            "Dbg values are not emitted in LDV");
 | |
|     EmitDone = false;
 | |
|     ModifiedMF = false;
 | |
|   }
 | |
| 
 | |
|   /// mapVirtReg - Map virtual register to an equivalence class.
 | |
|   void mapVirtReg(unsigned VirtReg, UserValue *EC);
 | |
| 
 | |
|   /// splitRegister -  Replace all references to OldReg with NewRegs.
 | |
|   void splitRegister(unsigned OldReg, ArrayRef<unsigned> NewRegs);
 | |
| 
 | |
|   /// emitDebugValues - Recreate DBG_VALUE instruction from data structures.
 | |
|   void emitDebugValues(VirtRegMap *VRM);
 | |
| 
 | |
|   void print(raw_ostream&);
 | |
| };
 | |
| 
 | |
| } // end anonymous namespace
 | |
| 
 | |
| #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 | |
| static void printDebugLoc(const DebugLoc &DL, raw_ostream &CommentOS,
 | |
|                           const LLVMContext &Ctx) {
 | |
|   if (!DL)
 | |
|     return;
 | |
| 
 | |
|   auto *Scope = cast<DIScope>(DL.getScope());
 | |
|   // Omit the directory, because it's likely to be long and uninteresting.
 | |
|   CommentOS << Scope->getFilename();
 | |
|   CommentOS << ':' << DL.getLine();
 | |
|   if (DL.getCol() != 0)
 | |
|     CommentOS << ':' << DL.getCol();
 | |
| 
 | |
|   DebugLoc InlinedAtDL = DL.getInlinedAt();
 | |
|   if (!InlinedAtDL)
 | |
|     return;
 | |
| 
 | |
|   CommentOS << " @[ ";
 | |
|   printDebugLoc(InlinedAtDL, CommentOS, Ctx);
 | |
|   CommentOS << " ]";
 | |
| }
 | |
| 
 | |
| static void printExtendedName(raw_ostream &OS, const DILocalVariable *V,
 | |
|                               const DILocation *DL) {
 | |
|   const LLVMContext &Ctx = V->getContext();
 | |
|   StringRef Res = V->getName();
 | |
|   if (!Res.empty())
 | |
|     OS << Res << "," << V->getLine();
 | |
|   if (auto *InlinedAt = DL->getInlinedAt()) {
 | |
|     if (DebugLoc InlinedAtDL = InlinedAt) {
 | |
|       OS << " @[";
 | |
|       printDebugLoc(InlinedAtDL, OS, Ctx);
 | |
|       OS << "]";
 | |
|     }
 | |
|   }
 | |
| }
 | |
| 
 | |
| void UserValue::print(raw_ostream &OS, const TargetRegisterInfo *TRI) {
 | |
|   auto *DV = cast<DILocalVariable>(Variable);
 | |
|   OS << "!\"";
 | |
|   printExtendedName(OS, DV, dl);
 | |
| 
 | |
|   OS << "\"\t";
 | |
|   for (LocMap::const_iterator I = locInts.begin(); I.valid(); ++I) {
 | |
|     OS << " [" << I.start() << ';' << I.stop() << "):";
 | |
|     if (I.value().isUndef())
 | |
|       OS << "undef";
 | |
|     else {
 | |
|       OS << I.value().locNo();
 | |
|       if (I.value().wasIndirect())
 | |
|         OS << " ind";
 | |
|     }
 | |
|   }
 | |
|   for (unsigned i = 0, e = locations.size(); i != e; ++i) {
 | |
|     OS << " Loc" << i << '=';
 | |
|     locations[i].print(OS, TRI);
 | |
|   }
 | |
|   OS << '\n';
 | |
| }
 | |
| 
 | |
| void LDVImpl::print(raw_ostream &OS) {
 | |
|   OS << "********** DEBUG VARIABLES **********\n";
 | |
|   for (unsigned i = 0, e = userValues.size(); i != e; ++i)
 | |
|     userValues[i]->print(OS, TRI);
 | |
| }
 | |
| #endif
 | |
| 
 | |
| void UserValue::mapVirtRegs(LDVImpl *LDV) {
 | |
|   for (unsigned i = 0, e = locations.size(); i != e; ++i)
 | |
|     if (locations[i].isReg() &&
 | |
|         TargetRegisterInfo::isVirtualRegister(locations[i].getReg()))
 | |
|       LDV->mapVirtReg(locations[i].getReg(), this);
 | |
| }
 | |
| 
 | |
| UserValue *LDVImpl::getUserValue(const DILocalVariable *Var,
 | |
|                                  const DIExpression *Expr, const DebugLoc &DL) {
 | |
|   UserValue *&Leader = userVarMap[Var];
 | |
|   if (Leader) {
 | |
|     UserValue *UV = Leader->getLeader();
 | |
|     Leader = UV;
 | |
|     for (; UV; UV = UV->getNext())
 | |
|       if (UV->match(Var, Expr, DL->getInlinedAt()))
 | |
|         return UV;
 | |
|   }
 | |
| 
 | |
|   userValues.push_back(
 | |
|       llvm::make_unique<UserValue>(Var, Expr, DL, allocator));
 | |
|   UserValue *UV = userValues.back().get();
 | |
|   Leader = UserValue::merge(Leader, UV);
 | |
|   return UV;
 | |
| }
 | |
| 
 | |
| void LDVImpl::mapVirtReg(unsigned VirtReg, UserValue *EC) {
 | |
|   assert(TargetRegisterInfo::isVirtualRegister(VirtReg) && "Only map VirtRegs");
 | |
|   UserValue *&Leader = virtRegToEqClass[VirtReg];
 | |
|   Leader = UserValue::merge(Leader, EC);
 | |
| }
 | |
| 
 | |
| UserValue *LDVImpl::lookupVirtReg(unsigned VirtReg) {
 | |
|   if (UserValue *UV = virtRegToEqClass.lookup(VirtReg))
 | |
|     return UV->getLeader();
 | |
|   return nullptr;
 | |
| }
 | |
| 
 | |
| bool LDVImpl::handleDebugValue(MachineInstr &MI, SlotIndex Idx) {
 | |
|   // DBG_VALUE loc, offset, variable
 | |
|   if (MI.getNumOperands() != 4 ||
 | |
|       !(MI.getOperand(1).isReg() || MI.getOperand(1).isImm()) ||
 | |
|       !MI.getOperand(2).isMetadata()) {
 | |
|     LLVM_DEBUG(dbgs() << "Can't handle " << MI);
 | |
|     return false;
 | |
|   }
 | |
| 
 | |
|   // Detect invalid DBG_VALUE instructions, with a debug-use of a virtual
 | |
|   // register that hasn't been defined yet. If we do not remove those here, then
 | |
|   // the re-insertion of the DBG_VALUE instruction after register allocation
 | |
|   // will be incorrect.
 | |
|   // TODO: If earlier passes are corrected to generate sane debug information
 | |
|   // (and if the machine verifier is improved to catch this), then these checks
 | |
|   // could be removed or replaced by asserts.
 | |
|   bool Discard = false;
 | |
|   if (MI.getOperand(0).isReg() &&
 | |
|       TargetRegisterInfo::isVirtualRegister(MI.getOperand(0).getReg())) {
 | |
|     const unsigned Reg = MI.getOperand(0).getReg();
 | |
|     if (!LIS->hasInterval(Reg)) {
 | |
|       // The DBG_VALUE is described by a virtual register that does not have a
 | |
|       // live interval. Discard the DBG_VALUE.
 | |
|       Discard = true;
 | |
|       LLVM_DEBUG(dbgs() << "Discarding debug info (no LIS interval): " << Idx
 | |
|                         << " " << MI);
 | |
|     } else {
 | |
|       // The DBG_VALUE is only valid if either Reg is live out from Idx, or Reg
 | |
|       // is defined dead at Idx (where Idx is the slot index for the instruction
 | |
|       // preceeding the DBG_VALUE).
 | |
|       const LiveInterval &LI = LIS->getInterval(Reg);
 | |
|       LiveQueryResult LRQ = LI.Query(Idx);
 | |
|       if (!LRQ.valueOutOrDead()) {
 | |
|         // We have found a DBG_VALUE with the value in a virtual register that
 | |
|         // is not live. Discard the DBG_VALUE.
 | |
|         Discard = true;
 | |
|         LLVM_DEBUG(dbgs() << "Discarding debug info (reg not live): " << Idx
 | |
|                           << " " << MI);
 | |
|       }
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   // Get or create the UserValue for (variable,offset) here.
 | |
|   bool IsIndirect = MI.getOperand(1).isImm();
 | |
|   if (IsIndirect)
 | |
|     assert(MI.getOperand(1).getImm() == 0 && "DBG_VALUE with nonzero offset");
 | |
|   const DILocalVariable *Var = MI.getDebugVariable();
 | |
|   const DIExpression *Expr = MI.getDebugExpression();
 | |
|   UserValue *UV =
 | |
|       getUserValue(Var, Expr, MI.getDebugLoc());
 | |
|   if (!Discard)
 | |
|     UV->addDef(Idx, MI.getOperand(0), IsIndirect);
 | |
|   else {
 | |
|     MachineOperand MO = MachineOperand::CreateReg(0U, false);
 | |
|     MO.setIsDebug();
 | |
|     UV->addDef(Idx, MO, false);
 | |
|   }
 | |
|   return true;
 | |
| }
 | |
| 
 | |
| bool LDVImpl::collectDebugValues(MachineFunction &mf) {
 | |
|   bool Changed = false;
 | |
|   for (MachineFunction::iterator MFI = mf.begin(), MFE = mf.end(); MFI != MFE;
 | |
|        ++MFI) {
 | |
|     MachineBasicBlock *MBB = &*MFI;
 | |
|     for (MachineBasicBlock::iterator MBBI = MBB->begin(), MBBE = MBB->end();
 | |
|          MBBI != MBBE;) {
 | |
|       // Use the first debug instruction in the sequence to get a SlotIndex
 | |
|       // for following consecutive debug instructions.
 | |
|       if (!MBBI->isDebugInstr()) {
 | |
|         ++MBBI;
 | |
|         continue;
 | |
|       }
 | |
|       // Debug instructions has no slot index. Use the previous
 | |
|       // non-debug instruction's SlotIndex as its SlotIndex.
 | |
|       SlotIndex Idx =
 | |
|           MBBI == MBB->begin()
 | |
|               ? LIS->getMBBStartIdx(MBB)
 | |
|               : LIS->getInstructionIndex(*std::prev(MBBI)).getRegSlot();
 | |
|       // Handle consecutive debug instructions with the same slot index.
 | |
|       do {
 | |
|         // Only handle DBG_VALUE in handleDebugValue(). Skip all other
 | |
|         // kinds of debug instructions.
 | |
|         if (MBBI->isDebugValue() && handleDebugValue(*MBBI, Idx)) {
 | |
|           MBBI = MBB->erase(MBBI);
 | |
|           Changed = true;
 | |
|         } else
 | |
|           ++MBBI;
 | |
|       } while (MBBI != MBBE && MBBI->isDebugInstr());
 | |
|     }
 | |
|   }
 | |
|   return Changed;
 | |
| }
 | |
| 
 | |
| /// We only propagate DBG_VALUES locally here. LiveDebugValues performs a
 | |
| /// data-flow analysis to propagate them beyond basic block boundaries.
 | |
| void UserValue::extendDef(SlotIndex Idx, DbgValueLocation Loc, LiveRange *LR,
 | |
|                           const VNInfo *VNI, SmallVectorImpl<SlotIndex> *Kills,
 | |
|                           LiveIntervals &LIS) {
 | |
|   SlotIndex Start = Idx;
 | |
|   MachineBasicBlock *MBB = LIS.getMBBFromIndex(Start);
 | |
|   SlotIndex Stop = LIS.getMBBEndIdx(MBB);
 | |
|   LocMap::iterator I = locInts.find(Start);
 | |
| 
 | |
|   // Limit to VNI's live range.
 | |
|   bool ToEnd = true;
 | |
|   if (LR && VNI) {
 | |
|     LiveInterval::Segment *Segment = LR->getSegmentContaining(Start);
 | |
|     if (!Segment || Segment->valno != VNI) {
 | |
|       if (Kills)
 | |
|         Kills->push_back(Start);
 | |
|       return;
 | |
|     }
 | |
|     if (Segment->end < Stop) {
 | |
|       Stop = Segment->end;
 | |
|       ToEnd = false;
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   // There could already be a short def at Start.
 | |
|   if (I.valid() && I.start() <= Start) {
 | |
|     // Stop when meeting a different location or an already extended interval.
 | |
|     Start = Start.getNextSlot();
 | |
|     if (I.value() != Loc || I.stop() != Start)
 | |
|       return;
 | |
|     // This is a one-slot placeholder. Just skip it.
 | |
|     ++I;
 | |
|   }
 | |
| 
 | |
|   // Limited by the next def.
 | |
|   if (I.valid() && I.start() < Stop) {
 | |
|     Stop = I.start();
 | |
|     ToEnd = false;
 | |
|   }
 | |
|   // Limited by VNI's live range.
 | |
|   else if (!ToEnd && Kills)
 | |
|     Kills->push_back(Stop);
 | |
| 
 | |
|   if (Start < Stop)
 | |
|     I.insert(Start, Stop, Loc);
 | |
| }
 | |
| 
 | |
| void UserValue::addDefsFromCopies(
 | |
|     LiveInterval *LI, unsigned LocNo, bool WasIndirect,
 | |
|     const SmallVectorImpl<SlotIndex> &Kills,
 | |
|     SmallVectorImpl<std::pair<SlotIndex, DbgValueLocation>> &NewDefs,
 | |
|     MachineRegisterInfo &MRI, LiveIntervals &LIS) {
 | |
|   if (Kills.empty())
 | |
|     return;
 | |
|   // Don't track copies from physregs, there are too many uses.
 | |
|   if (!TargetRegisterInfo::isVirtualRegister(LI->reg))
 | |
|     return;
 | |
| 
 | |
|   // Collect all the (vreg, valno) pairs that are copies of LI.
 | |
|   SmallVector<std::pair<LiveInterval*, const VNInfo*>, 8> CopyValues;
 | |
|   for (MachineOperand &MO : MRI.use_nodbg_operands(LI->reg)) {
 | |
|     MachineInstr *MI = MO.getParent();
 | |
|     // Copies of the full value.
 | |
|     if (MO.getSubReg() || !MI->isCopy())
 | |
|       continue;
 | |
|     unsigned DstReg = MI->getOperand(0).getReg();
 | |
| 
 | |
|     // Don't follow copies to physregs. These are usually setting up call
 | |
|     // arguments, and the argument registers are always call clobbered. We are
 | |
|     // better off in the source register which could be a callee-saved register,
 | |
|     // or it could be spilled.
 | |
|     if (!TargetRegisterInfo::isVirtualRegister(DstReg))
 | |
|       continue;
 | |
| 
 | |
|     // Is LocNo extended to reach this copy? If not, another def may be blocking
 | |
|     // it, or we are looking at a wrong value of LI.
 | |
|     SlotIndex Idx = LIS.getInstructionIndex(*MI);
 | |
|     LocMap::iterator I = locInts.find(Idx.getRegSlot(true));
 | |
|     if (!I.valid() || I.value().locNo() != LocNo)
 | |
|       continue;
 | |
| 
 | |
|     if (!LIS.hasInterval(DstReg))
 | |
|       continue;
 | |
|     LiveInterval *DstLI = &LIS.getInterval(DstReg);
 | |
|     const VNInfo *DstVNI = DstLI->getVNInfoAt(Idx.getRegSlot());
 | |
|     assert(DstVNI && DstVNI->def == Idx.getRegSlot() && "Bad copy value");
 | |
|     CopyValues.push_back(std::make_pair(DstLI, DstVNI));
 | |
|   }
 | |
| 
 | |
|   if (CopyValues.empty())
 | |
|     return;
 | |
| 
 | |
|   LLVM_DEBUG(dbgs() << "Got " << CopyValues.size() << " copies of " << *LI
 | |
|                     << '\n');
 | |
| 
 | |
|   // Try to add defs of the copied values for each kill point.
 | |
|   for (unsigned i = 0, e = Kills.size(); i != e; ++i) {
 | |
|     SlotIndex Idx = Kills[i];
 | |
|     for (unsigned j = 0, e = CopyValues.size(); j != e; ++j) {
 | |
|       LiveInterval *DstLI = CopyValues[j].first;
 | |
|       const VNInfo *DstVNI = CopyValues[j].second;
 | |
|       if (DstLI->getVNInfoAt(Idx) != DstVNI)
 | |
|         continue;
 | |
|       // Check that there isn't already a def at Idx
 | |
|       LocMap::iterator I = locInts.find(Idx);
 | |
|       if (I.valid() && I.start() <= Idx)
 | |
|         continue;
 | |
|       LLVM_DEBUG(dbgs() << "Kill at " << Idx << " covered by valno #"
 | |
|                         << DstVNI->id << " in " << *DstLI << '\n');
 | |
|       MachineInstr *CopyMI = LIS.getInstructionFromIndex(DstVNI->def);
 | |
|       assert(CopyMI && CopyMI->isCopy() && "Bad copy value");
 | |
|       unsigned LocNo = getLocationNo(CopyMI->getOperand(0));
 | |
|       DbgValueLocation NewLoc(LocNo, WasIndirect);
 | |
|       I.insert(Idx, Idx.getNextSlot(), NewLoc);
 | |
|       NewDefs.push_back(std::make_pair(Idx, NewLoc));
 | |
|       break;
 | |
|     }
 | |
|   }
 | |
| }
 | |
| 
 | |
| void UserValue::computeIntervals(MachineRegisterInfo &MRI,
 | |
|                                  const TargetRegisterInfo &TRI,
 | |
|                                  LiveIntervals &LIS, LexicalScopes &LS) {
 | |
|   SmallVector<std::pair<SlotIndex, DbgValueLocation>, 16> Defs;
 | |
| 
 | |
|   // Collect all defs to be extended (Skipping undefs).
 | |
|   for (LocMap::const_iterator I = locInts.begin(); I.valid(); ++I)
 | |
|     if (!I.value().isUndef())
 | |
|       Defs.push_back(std::make_pair(I.start(), I.value()));
 | |
| 
 | |
|   // Extend all defs, and possibly add new ones along the way.
 | |
|   for (unsigned i = 0; i != Defs.size(); ++i) {
 | |
|     SlotIndex Idx = Defs[i].first;
 | |
|     DbgValueLocation Loc = Defs[i].second;
 | |
|     const MachineOperand &LocMO = locations[Loc.locNo()];
 | |
| 
 | |
|     if (!LocMO.isReg()) {
 | |
|       extendDef(Idx, Loc, nullptr, nullptr, nullptr, LIS);
 | |
|       continue;
 | |
|     }
 | |
| 
 | |
|     // Register locations are constrained to where the register value is live.
 | |
|     if (TargetRegisterInfo::isVirtualRegister(LocMO.getReg())) {
 | |
|       LiveInterval *LI = nullptr;
 | |
|       const VNInfo *VNI = nullptr;
 | |
|       if (LIS.hasInterval(LocMO.getReg())) {
 | |
|         LI = &LIS.getInterval(LocMO.getReg());
 | |
|         VNI = LI->getVNInfoAt(Idx);
 | |
|       }
 | |
|       SmallVector<SlotIndex, 16> Kills;
 | |
|       extendDef(Idx, Loc, LI, VNI, &Kills, LIS);
 | |
|       // FIXME: Handle sub-registers in addDefsFromCopies. The problem is that
 | |
|       // if the original location for example is %vreg0:sub_hi, and we find a
 | |
|       // full register copy in addDefsFromCopies (at the moment it only handles
 | |
|       // full register copies), then we must add the sub1 sub-register index to
 | |
|       // the new location. However, that is only possible if the new virtual
 | |
|       // register is of the same regclass (or if there is an equivalent
 | |
|       // sub-register in that regclass). For now, simply skip handling copies if
 | |
|       // a sub-register is involved.
 | |
|       if (LI && !LocMO.getSubReg())
 | |
|         addDefsFromCopies(LI, Loc.locNo(), Loc.wasIndirect(), Kills, Defs, MRI,
 | |
|                           LIS);
 | |
|       continue;
 | |
|     }
 | |
| 
 | |
|     // For physregs, we only mark the start slot idx. DwarfDebug will see it
 | |
|     // as if the DBG_VALUE is valid up until the end of the basic block, or
 | |
|     // the next def of the physical register. So we do not need to extend the
 | |
|     // range. It might actually happen that the DBG_VALUE is the last use of
 | |
|     // the physical register (e.g. if this is an unused input argument to a
 | |
|     // function).
 | |
|   }
 | |
| 
 | |
|   // The computed intervals may extend beyond the range of the debug
 | |
|   // location's lexical scope. In this case, splitting of an interval
 | |
|   // can result in an interval outside of the scope being created,
 | |
|   // causing extra unnecessary DBG_VALUEs to be emitted. To prevent
 | |
|   // this, trim the intervals to the lexical scope.
 | |
| 
 | |
|   LexicalScope *Scope = LS.findLexicalScope(dl);
 | |
|   if (!Scope)
 | |
|     return;
 | |
| 
 | |
|   SlotIndex PrevEnd;
 | |
|   LocMap::iterator I = locInts.begin();
 | |
| 
 | |
|   // Iterate over the lexical scope ranges. Each time round the loop
 | |
|   // we check the intervals for overlap with the end of the previous
 | |
|   // range and the start of the next. The first range is handled as
 | |
|   // a special case where there is no PrevEnd.
 | |
|   for (const InsnRange &Range : Scope->getRanges()) {
 | |
|     SlotIndex RStart = LIS.getInstructionIndex(*Range.first);
 | |
|     SlotIndex REnd = LIS.getInstructionIndex(*Range.second);
 | |
| 
 | |
|     // At the start of each iteration I has been advanced so that
 | |
|     // I.stop() >= PrevEnd. Check for overlap.
 | |
|     if (PrevEnd && I.start() < PrevEnd) {
 | |
|       SlotIndex IStop = I.stop();
 | |
|       DbgValueLocation Loc = I.value();
 | |
| 
 | |
|       // Stop overlaps previous end - trim the end of the interval to
 | |
|       // the scope range.
 | |
|       I.setStopUnchecked(PrevEnd);
 | |
|       ++I;
 | |
| 
 | |
|       // If the interval also overlaps the start of the "next" (i.e.
 | |
|       // current) range create a new interval for the remainder (which
 | |
|       // may be further trimmed).
 | |
|       if (RStart < IStop)
 | |
|         I.insert(RStart, IStop, Loc);
 | |
|     }
 | |
| 
 | |
|     // Advance I so that I.stop() >= RStart, and check for overlap.
 | |
|     I.advanceTo(RStart);
 | |
|     if (!I.valid())
 | |
|       return;
 | |
| 
 | |
|     if (I.start() < RStart) {
 | |
|       // Interval start overlaps range - trim to the scope range.
 | |
|       I.setStartUnchecked(RStart);
 | |
|       // Remember that this interval was trimmed.
 | |
|       trimmedDefs.insert(RStart);
 | |
|     }
 | |
| 
 | |
|     // The end of a lexical scope range is the last instruction in the
 | |
|     // range. To convert to an interval we need the index of the
 | |
|     // instruction after it.
 | |
|     REnd = REnd.getNextIndex();
 | |
| 
 | |
|     // Advance I to first interval outside current range.
 | |
|     I.advanceTo(REnd);
 | |
|     if (!I.valid())
 | |
|       return;
 | |
| 
 | |
|     PrevEnd = REnd;
 | |
|   }
 | |
| 
 | |
|   // Check for overlap with end of final range.
 | |
|   if (PrevEnd && I.start() < PrevEnd)
 | |
|     I.setStopUnchecked(PrevEnd);
 | |
| }
 | |
| 
 | |
| void LDVImpl::computeIntervals() {
 | |
|   LexicalScopes LS;
 | |
|   LS.initialize(*MF);
 | |
| 
 | |
|   for (unsigned i = 0, e = userValues.size(); i != e; ++i) {
 | |
|     userValues[i]->computeIntervals(MF->getRegInfo(), *TRI, *LIS, LS);
 | |
|     userValues[i]->mapVirtRegs(this);
 | |
|   }
 | |
| }
 | |
| 
 | |
| bool LDVImpl::runOnMachineFunction(MachineFunction &mf) {
 | |
|   clear();
 | |
|   MF = &mf;
 | |
|   LIS = &pass.getAnalysis<LiveIntervals>();
 | |
|   TRI = mf.getSubtarget().getRegisterInfo();
 | |
|   LLVM_DEBUG(dbgs() << "********** COMPUTING LIVE DEBUG VARIABLES: "
 | |
|                     << mf.getName() << " **********\n");
 | |
| 
 | |
|   bool Changed = collectDebugValues(mf);
 | |
|   computeIntervals();
 | |
|   LLVM_DEBUG(print(dbgs()));
 | |
|   ModifiedMF = Changed;
 | |
|   return Changed;
 | |
| }
 | |
| 
 | |
| static void removeDebugValues(MachineFunction &mf) {
 | |
|   for (MachineBasicBlock &MBB : mf) {
 | |
|     for (auto MBBI = MBB.begin(), MBBE = MBB.end(); MBBI != MBBE; ) {
 | |
|       if (!MBBI->isDebugValue()) {
 | |
|         ++MBBI;
 | |
|         continue;
 | |
|       }
 | |
|       MBBI = MBB.erase(MBBI);
 | |
|     }
 | |
|   }
 | |
| }
 | |
| 
 | |
| bool LiveDebugVariables::runOnMachineFunction(MachineFunction &mf) {
 | |
|   if (!EnableLDV)
 | |
|     return false;
 | |
|   if (!mf.getFunction().getSubprogram()) {
 | |
|     removeDebugValues(mf);
 | |
|     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);
 | |
| }
 | |
| 
 | |
| //===----------------------------------------------------------------------===//
 | |
| //                           Live Range Splitting
 | |
| //===----------------------------------------------------------------------===//
 | |
| 
 | |
| bool
 | |
| UserValue::splitLocation(unsigned OldLocNo, ArrayRef<unsigned> NewRegs,
 | |
|                          LiveIntervals& LIS) {
 | |
|   LLVM_DEBUG({
 | |
|     dbgs() << "Splitting Loc" << OldLocNo << '\t';
 | |
|     print(dbgs(), nullptr);
 | |
|   });
 | |
|   bool DidChange = false;
 | |
|   LocMap::iterator LocMapI;
 | |
|   LocMapI.setMap(locInts);
 | |
|   for (unsigned i = 0; i != NewRegs.size(); ++i) {
 | |
|     LiveInterval *LI = &LIS.getInterval(NewRegs[i]);
 | |
|     if (LI->empty())
 | |
|       continue;
 | |
| 
 | |
|     // Don't allocate the new LocNo until it is needed.
 | |
|     unsigned NewLocNo = UndefLocNo;
 | |
| 
 | |
|     // Iterate over the overlaps between locInts and LI.
 | |
|     LocMapI.find(LI->beginIndex());
 | |
|     if (!LocMapI.valid())
 | |
|       continue;
 | |
|     LiveInterval::iterator LII = LI->advanceTo(LI->begin(), LocMapI.start());
 | |
|     LiveInterval::iterator LIE = LI->end();
 | |
|     while (LocMapI.valid() && LII != LIE) {
 | |
|       // At this point, we know that LocMapI.stop() > LII->start.
 | |
|       LII = LI->advanceTo(LII, LocMapI.start());
 | |
|       if (LII == LIE)
 | |
|         break;
 | |
| 
 | |
|       // Now LII->end > LocMapI.start(). Do we have an overlap?
 | |
|       if (LocMapI.value().locNo() == OldLocNo && LII->start < LocMapI.stop()) {
 | |
|         // Overlapping correct location. Allocate NewLocNo now.
 | |
|         if (NewLocNo == UndefLocNo) {
 | |
|           MachineOperand MO = MachineOperand::CreateReg(LI->reg, false);
 | |
|           MO.setSubReg(locations[OldLocNo].getSubReg());
 | |
|           NewLocNo = getLocationNo(MO);
 | |
|           DidChange = true;
 | |
|         }
 | |
| 
 | |
|         SlotIndex LStart = LocMapI.start();
 | |
|         SlotIndex LStop  = LocMapI.stop();
 | |
|         DbgValueLocation OldLoc = LocMapI.value();
 | |
| 
 | |
|         // Trim LocMapI down to the LII overlap.
 | |
|         if (LStart < LII->start)
 | |
|           LocMapI.setStartUnchecked(LII->start);
 | |
|         if (LStop > LII->end)
 | |
|           LocMapI.setStopUnchecked(LII->end);
 | |
| 
 | |
|         // Change the value in the overlap. This may trigger coalescing.
 | |
|         LocMapI.setValue(OldLoc.changeLocNo(NewLocNo));
 | |
| 
 | |
|         // Re-insert any removed OldLocNo ranges.
 | |
|         if (LStart < LocMapI.start()) {
 | |
|           LocMapI.insert(LStart, LocMapI.start(), OldLoc);
 | |
|           ++LocMapI;
 | |
|           assert(LocMapI.valid() && "Unexpected coalescing");
 | |
|         }
 | |
|         if (LStop > LocMapI.stop()) {
 | |
|           ++LocMapI;
 | |
|           LocMapI.insert(LII->end, LStop, OldLoc);
 | |
|           --LocMapI;
 | |
|         }
 | |
|       }
 | |
| 
 | |
|       // Advance to the next overlap.
 | |
|       if (LII->end < LocMapI.stop()) {
 | |
|         if (++LII == LIE)
 | |
|           break;
 | |
|         LocMapI.advanceTo(LII->start);
 | |
|       } else {
 | |
|         ++LocMapI;
 | |
|         if (!LocMapI.valid())
 | |
|           break;
 | |
|         LII = LI->advanceTo(LII, LocMapI.start());
 | |
|       }
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   // Finally, remove any remaining OldLocNo intervals and OldLocNo itself.
 | |
|   locations.erase(locations.begin() + OldLocNo);
 | |
|   LocMapI.goToBegin();
 | |
|   while (LocMapI.valid()) {
 | |
|     DbgValueLocation v = LocMapI.value();
 | |
|     if (v.locNo() == OldLocNo) {
 | |
|       LLVM_DEBUG(dbgs() << "Erasing [" << LocMapI.start() << ';'
 | |
|                         << LocMapI.stop() << ")\n");
 | |
|       LocMapI.erase();
 | |
|     } else {
 | |
|       // Undef values always have location number UndefLocNo, so don't change
 | |
|       // locNo in that case. See getLocationNo().
 | |
|       if (!v.isUndef() && v.locNo() > OldLocNo)
 | |
|         LocMapI.setValueUnchecked(v.changeLocNo(v.locNo() - 1));
 | |
|       ++LocMapI;
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   LLVM_DEBUG({
 | |
|     dbgs() << "Split result: \t";
 | |
|     print(dbgs(), nullptr);
 | |
|   });
 | |
|   return DidChange;
 | |
| }
 | |
| 
 | |
| bool
 | |
| UserValue::splitRegister(unsigned OldReg, ArrayRef<unsigned> NewRegs,
 | |
|                          LiveIntervals &LIS) {
 | |
|   bool DidChange = false;
 | |
|   // Split locations referring to OldReg. Iterate backwards so splitLocation can
 | |
|   // safely erase unused locations.
 | |
|   for (unsigned i = locations.size(); i ; --i) {
 | |
|     unsigned LocNo = i-1;
 | |
|     const MachineOperand *Loc = &locations[LocNo];
 | |
|     if (!Loc->isReg() || Loc->getReg() != OldReg)
 | |
|       continue;
 | |
|     DidChange |= splitLocation(LocNo, NewRegs, LIS);
 | |
|   }
 | |
|   return DidChange;
 | |
| }
 | |
| 
 | |
| void LDVImpl::splitRegister(unsigned OldReg, ArrayRef<unsigned> NewRegs) {
 | |
|   bool DidChange = false;
 | |
|   for (UserValue *UV = lookupVirtReg(OldReg); UV; UV = UV->getNext())
 | |
|     DidChange |= UV->splitRegister(OldReg, NewRegs, *LIS);
 | |
| 
 | |
|   if (!DidChange)
 | |
|     return;
 | |
| 
 | |
|   // Map all of the new virtual registers.
 | |
|   UserValue *UV = lookupVirtReg(OldReg);
 | |
|   for (unsigned i = 0; i != NewRegs.size(); ++i)
 | |
|     mapVirtReg(NewRegs[i], UV);
 | |
| }
 | |
| 
 | |
| void LiveDebugVariables::
 | |
| splitRegister(unsigned OldReg, ArrayRef<unsigned> NewRegs, LiveIntervals &LIS) {
 | |
|   if (pImpl)
 | |
|     static_cast<LDVImpl*>(pImpl)->splitRegister(OldReg, NewRegs);
 | |
| }
 | |
| 
 | |
| void UserValue::rewriteLocations(VirtRegMap &VRM, const MachineFunction &MF,
 | |
|                                  const TargetInstrInfo &TII,
 | |
|                                  const TargetRegisterInfo &TRI,
 | |
|                                  SpillOffsetMap &SpillOffsets) {
 | |
|   // Build a set of new locations with new numbers so we can coalesce our
 | |
|   // IntervalMap if two vreg intervals collapse to the same physical location.
 | |
|   // Use MapVector instead of SetVector because MapVector::insert returns the
 | |
|   // position of the previously or newly inserted element. The boolean value
 | |
|   // tracks if the location was produced by a spill.
 | |
|   // FIXME: This will be problematic if we ever support direct and indirect
 | |
|   // frame index locations, i.e. expressing both variables in memory and
 | |
|   // 'int x, *px = &x'. The "spilled" bit must become part of the location.
 | |
|   MapVector<MachineOperand, std::pair<bool, unsigned>> NewLocations;
 | |
|   SmallVector<unsigned, 4> LocNoMap(locations.size());
 | |
|   for (unsigned I = 0, E = locations.size(); I != E; ++I) {
 | |
|     bool Spilled = false;
 | |
|     unsigned SpillOffset = 0;
 | |
|     MachineOperand Loc = locations[I];
 | |
|     // Only virtual registers are rewritten.
 | |
|     if (Loc.isReg() && Loc.getReg() &&
 | |
|         TargetRegisterInfo::isVirtualRegister(Loc.getReg())) {
 | |
|       unsigned VirtReg = Loc.getReg();
 | |
|       if (VRM.isAssignedReg(VirtReg) &&
 | |
|           TargetRegisterInfo::isPhysicalRegister(VRM.getPhys(VirtReg))) {
 | |
|         // This can create a %noreg operand in rare cases when the sub-register
 | |
|         // index is no longer available. That means the user value is in a
 | |
|         // non-existent sub-register, and %noreg is exactly what we want.
 | |
|         Loc.substPhysReg(VRM.getPhys(VirtReg), TRI);
 | |
|       } else if (VRM.getStackSlot(VirtReg) != VirtRegMap::NO_STACK_SLOT) {
 | |
|         // Retrieve the stack slot offset.
 | |
|         unsigned SpillSize;
 | |
|         const MachineRegisterInfo &MRI = MF.getRegInfo();
 | |
|         const TargetRegisterClass *TRC = MRI.getRegClass(VirtReg);
 | |
|         bool Success = TII.getStackSlotRange(TRC, Loc.getSubReg(), SpillSize,
 | |
|                                              SpillOffset, MF);
 | |
| 
 | |
|         // FIXME: Invalidate the location if the offset couldn't be calculated.
 | |
|         (void)Success;
 | |
| 
 | |
|         Loc = MachineOperand::CreateFI(VRM.getStackSlot(VirtReg));
 | |
|         Spilled = true;
 | |
|       } else {
 | |
|         Loc.setReg(0);
 | |
|         Loc.setSubReg(0);
 | |
|       }
 | |
|     }
 | |
| 
 | |
|     // Insert this location if it doesn't already exist and record a mapping
 | |
|     // from the old number to the new number.
 | |
|     auto InsertResult = NewLocations.insert({Loc, {Spilled, SpillOffset}});
 | |
|     unsigned NewLocNo = std::distance(NewLocations.begin(), InsertResult.first);
 | |
|     LocNoMap[I] = NewLocNo;
 | |
|   }
 | |
| 
 | |
|   // Rewrite the locations and record the stack slot offsets for spills.
 | |
|   locations.clear();
 | |
|   SpillOffsets.clear();
 | |
|   for (auto &Pair : NewLocations) {
 | |
|     bool Spilled;
 | |
|     unsigned SpillOffset;
 | |
|     std::tie(Spilled, SpillOffset) = Pair.second;
 | |
|     locations.push_back(Pair.first);
 | |
|     if (Spilled) {
 | |
|       unsigned NewLocNo = std::distance(&*NewLocations.begin(), &Pair);
 | |
|       SpillOffsets[NewLocNo] = SpillOffset;
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   // Update the interval map, but only coalesce left, since intervals to the
 | |
|   // right use the old location numbers. This should merge two contiguous
 | |
|   // DBG_VALUE intervals with different vregs that were allocated to the same
 | |
|   // physical register.
 | |
|   for (LocMap::iterator I = locInts.begin(); I.valid(); ++I) {
 | |
|     DbgValueLocation Loc = I.value();
 | |
|     // Undef values don't exist in locations (and thus not in LocNoMap either)
 | |
|     // so skip over them. See getLocationNo().
 | |
|     if (Loc.isUndef())
 | |
|       continue;
 | |
|     unsigned NewLocNo = LocNoMap[Loc.locNo()];
 | |
|     I.setValueUnchecked(Loc.changeLocNo(NewLocNo));
 | |
|     I.setStart(I.start());
 | |
|   }
 | |
| }
 | |
| 
 | |
| /// 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->SkipPHIsLabelsAndDebug(MBB->begin());
 | |
|       return I;
 | |
|     }
 | |
|     Idx = Idx.getPrevIndex();
 | |
|   }
 | |
| 
 | |
|   // Don't insert anything after the first terminator, though.
 | |
|   return MI->isTerminator() ? MBB->getFirstTerminator() :
 | |
|                               std::next(MachineBasicBlock::iterator(MI));
 | |
| }
 | |
| 
 | |
| /// Find an iterator for inserting the next DBG_VALUE instruction
 | |
| /// (or end if no more insert locations found).
 | |
| static MachineBasicBlock::iterator
 | |
| findNextInsertLocation(MachineBasicBlock *MBB,
 | |
|                        MachineBasicBlock::iterator I,
 | |
|                        SlotIndex StopIdx, MachineOperand &LocMO,
 | |
|                        LiveIntervals &LIS,
 | |
|                        const TargetRegisterInfo &TRI) {
 | |
|   if (!LocMO.isReg())
 | |
|     return MBB->instr_end();
 | |
|   unsigned Reg = LocMO.getReg();
 | |
| 
 | |
|   // Find the next instruction in the MBB that define the register Reg.
 | |
|   while (I != MBB->end() && !I->isTerminator()) {
 | |
|     if (!LIS.isNotInMIMap(*I) &&
 | |
|         SlotIndex::isEarlierEqualInstr(StopIdx, LIS.getInstructionIndex(*I)))
 | |
|       break;
 | |
|     if (I->definesRegister(Reg, &TRI))
 | |
|       // The insert location is directly after the instruction/bundle.
 | |
|       return std::next(I);
 | |
|     ++I;
 | |
|   }
 | |
|   return MBB->end();
 | |
| }
 | |
| 
 | |
| void UserValue::insertDebugValue(MachineBasicBlock *MBB, SlotIndex StartIdx,
 | |
|                                  SlotIndex StopIdx, DbgValueLocation Loc,
 | |
|                                  bool Spilled, unsigned SpillOffset,
 | |
|                                  LiveIntervals &LIS, const TargetInstrInfo &TII,
 | |
|                                  const TargetRegisterInfo &TRI) {
 | |
|   SlotIndex MBBEndIdx = LIS.getMBBEndIdx(&*MBB);
 | |
|   // Only search within the current MBB.
 | |
|   StopIdx = (MBBEndIdx < StopIdx) ? MBBEndIdx : StopIdx;
 | |
|   MachineBasicBlock::iterator I = findInsertLocation(MBB, StartIdx, LIS);
 | |
|   // Undef values don't exist in locations so create new "noreg" register MOs
 | |
|   // for them. See getLocationNo().
 | |
|   MachineOperand MO = !Loc.isUndef() ?
 | |
|     locations[Loc.locNo()] :
 | |
|     MachineOperand::CreateReg(/* Reg */ 0, /* isDef */ false, /* isImp */ false,
 | |
|                               /* isKill */ false, /* isDead */ false,
 | |
|                               /* isUndef */ false, /* isEarlyClobber */ false,
 | |
|                               /* SubReg */ 0, /* isDebug */ true);
 | |
| 
 | |
|   ++NumInsertedDebugValues;
 | |
| 
 | |
|   assert(cast<DILocalVariable>(Variable)
 | |
|              ->isValidLocationForIntrinsic(getDebugLoc()) &&
 | |
|          "Expected inlined-at fields to agree");
 | |
| 
 | |
|   // If the location was spilled, the new DBG_VALUE will be indirect. If the
 | |
|   // original DBG_VALUE was indirect, we need to add DW_OP_deref to indicate
 | |
|   // that the original virtual register was a pointer. Also, add the stack slot
 | |
|   // offset for the spilled register to the expression.
 | |
|   const DIExpression *Expr = Expression;
 | |
|   bool IsIndirect = Loc.wasIndirect();
 | |
|   if (Spilled) {
 | |
|     auto Deref = IsIndirect ? DIExpression::WithDeref : DIExpression::NoDeref;
 | |
|     Expr =
 | |
|         DIExpression::prepend(Expr, DIExpression::NoDeref, SpillOffset, Deref);
 | |
|     IsIndirect = true;
 | |
|   }
 | |
| 
 | |
|   assert((!Spilled || MO.isFI()) && "a spilled location must be a frame index");
 | |
| 
 | |
|   do {
 | |
|     BuildMI(*MBB, I, getDebugLoc(), TII.get(TargetOpcode::DBG_VALUE),
 | |
|             IsIndirect, MO, Variable, Expr);
 | |
| 
 | |
|     // Continue and insert DBG_VALUES after every redefinition of register
 | |
|     // associated with the debug value within the range
 | |
|     I = findNextInsertLocation(MBB, I, StopIdx, MO, LIS, TRI);
 | |
|   } while (I != MBB->end());
 | |
| }
 | |
| 
 | |
| void UserValue::emitDebugValues(VirtRegMap *VRM, LiveIntervals &LIS,
 | |
|                                 const TargetInstrInfo &TII,
 | |
|                                 const TargetRegisterInfo &TRI,
 | |
|                                 const SpillOffsetMap &SpillOffsets) {
 | |
|   MachineFunction::iterator MFEnd = VRM->getMachineFunction().end();
 | |
| 
 | |
|   for (LocMap::const_iterator I = locInts.begin(); I.valid();) {
 | |
|     SlotIndex Start = I.start();
 | |
|     SlotIndex Stop = I.stop();
 | |
|     DbgValueLocation Loc = I.value();
 | |
|     auto SpillIt =
 | |
|         !Loc.isUndef() ? SpillOffsets.find(Loc.locNo()) : SpillOffsets.end();
 | |
|     bool Spilled = SpillIt != SpillOffsets.end();
 | |
|     unsigned SpillOffset = Spilled ? SpillIt->second : 0;
 | |
| 
 | |
|     // If the interval start was trimmed to the lexical scope insert the
 | |
|     // DBG_VALUE at the previous index (otherwise it appears after the
 | |
|     // first instruction in the range).
 | |
|     if (trimmedDefs.count(Start))
 | |
|       Start = Start.getPrevIndex();
 | |
| 
 | |
|     LLVM_DEBUG(dbgs() << "\t[" << Start << ';' << Stop << "):" << Loc.locNo());
 | |
|     MachineFunction::iterator MBB = LIS.getMBBFromIndex(Start)->getIterator();
 | |
|     SlotIndex MBBEnd = LIS.getMBBEndIdx(&*MBB);
 | |
| 
 | |
|     LLVM_DEBUG(dbgs() << ' ' << printMBBReference(*MBB) << '-' << MBBEnd);
 | |
|     insertDebugValue(&*MBB, Start, Stop, Loc, Spilled, SpillOffset, LIS, TII,
 | |
|                      TRI);
 | |
|     // 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);
 | |
|       LLVM_DEBUG(dbgs() << ' ' << printMBBReference(*MBB) << '-' << MBBEnd);
 | |
|       insertDebugValue(&*MBB, Start, Stop, Loc, Spilled, SpillOffset, LIS, TII,
 | |
|                        TRI);
 | |
|     }
 | |
|     LLVM_DEBUG(dbgs() << '\n');
 | |
|     if (MBB == MFEnd)
 | |
|       break;
 | |
| 
 | |
|     ++I;
 | |
|   }
 | |
| }
 | |
| 
 | |
| void LDVImpl::emitDebugValues(VirtRegMap *VRM) {
 | |
|   LLVM_DEBUG(dbgs() << "********** EMITTING LIVE DEBUG VARIABLES **********\n");
 | |
|   if (!MF)
 | |
|     return;
 | |
|   const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
 | |
|   SpillOffsetMap SpillOffsets;
 | |
|   for (unsigned i = 0, e = userValues.size(); i != e; ++i) {
 | |
|     LLVM_DEBUG(userValues[i]->print(dbgs(), TRI));
 | |
|     userValues[i]->rewriteLocations(*VRM, *MF, *TII, *TRI, SpillOffsets);
 | |
|     userValues[i]->emitDebugValues(VRM, *LIS, *TII, *TRI, SpillOffsets);
 | |
|   }
 | |
|   EmitDone = true;
 | |
| }
 | |
| 
 | |
| void LiveDebugVariables::emitDebugValues(VirtRegMap *VRM) {
 | |
|   if (pImpl)
 | |
|     static_cast<LDVImpl*>(pImpl)->emitDebugValues(VRM);
 | |
| }
 | |
| 
 | |
| bool LiveDebugVariables::doInitialization(Module &M) {
 | |
|   return Pass::doInitialization(M);
 | |
| }
 | |
| 
 | |
| #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 | |
| LLVM_DUMP_METHOD void LiveDebugVariables::dump() const {
 | |
|   if (pImpl)
 | |
|     static_cast<LDVImpl*>(pImpl)->print(dbgs());
 | |
| }
 | |
| #endif
 |