LCOV - code coverage report
Current view: top level - lib/CodeGen - LiveDebugVariables.cpp (source / functions) Hit Total Coverage
Test: llvm-toolchain.info Lines: 392 396 99.0 %
Date: 2018-07-13 00:08:38 Functions: 43 43 100.0 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : //===- LiveDebugVariables.cpp - Tracking debug info variables -------------===//
       2             : //
       3             : //                     The LLVM Compiler Infrastructure
       4             : //
       5             : // This file is distributed under the University of Illinois Open Source
       6             : // License. See LICENSE.TXT for details.
       7             : //
       8             : //===----------------------------------------------------------------------===//
       9             : //
      10             : // This file implements the LiveDebugVariables analysis.
      11             : //
      12             : // Remove all DBG_VALUE instructions referencing virtual registers and replace
      13             : // them with a data structure tracking where live user variables are kept - in a
      14             : // virtual register or in a stack slot.
      15             : //
      16             : // Allow the data structure to be updated during register allocation when values
      17             : // are moved between registers and stack slots. Finally emit new DBG_VALUE
      18             : // instructions after register allocation is complete.
      19             : //
      20             : //===----------------------------------------------------------------------===//
      21             : 
      22             : #include "LiveDebugVariables.h"
      23             : #include "llvm/ADT/ArrayRef.h"
      24             : #include "llvm/ADT/DenseMap.h"
      25             : #include "llvm/ADT/IntervalMap.h"
      26             : #include "llvm/ADT/STLExtras.h"
      27             : #include "llvm/ADT/SmallSet.h"
      28             : #include "llvm/ADT/SmallVector.h"
      29             : #include "llvm/ADT/Statistic.h"
      30             : #include "llvm/ADT/StringRef.h"
      31             : #include "llvm/CodeGen/LexicalScopes.h"
      32             : #include "llvm/CodeGen/LiveInterval.h"
      33             : #include "llvm/CodeGen/LiveIntervals.h"
      34             : #include "llvm/CodeGen/MachineBasicBlock.h"
      35             : #include "llvm/CodeGen/MachineDominators.h"
      36             : #include "llvm/CodeGen/MachineFunction.h"
      37             : #include "llvm/CodeGen/MachineInstr.h"
      38             : #include "llvm/CodeGen/MachineInstrBuilder.h"
      39             : #include "llvm/CodeGen/MachineOperand.h"
      40             : #include "llvm/CodeGen/MachineRegisterInfo.h"
      41             : #include "llvm/CodeGen/SlotIndexes.h"
      42             : #include "llvm/CodeGen/TargetInstrInfo.h"
      43             : #include "llvm/CodeGen/TargetOpcodes.h"
      44             : #include "llvm/CodeGen/TargetRegisterInfo.h"
      45             : #include "llvm/CodeGen/TargetSubtargetInfo.h"
      46             : #include "llvm/CodeGen/VirtRegMap.h"
      47             : #include "llvm/Config/llvm-config.h"
      48             : #include "llvm/IR/DebugInfoMetadata.h"
      49             : #include "llvm/IR/DebugLoc.h"
      50             : #include "llvm/IR/Function.h"
      51             : #include "llvm/IR/Metadata.h"
      52             : #include "llvm/MC/MCRegisterInfo.h"
      53             : #include "llvm/Pass.h"
      54             : #include "llvm/Support/Casting.h"
      55             : #include "llvm/Support/CommandLine.h"
      56             : #include "llvm/Support/Compiler.h"
      57             : #include "llvm/Support/Debug.h"
      58             : #include "llvm/Support/raw_ostream.h"
      59             : #include <algorithm>
      60             : #include <cassert>
      61             : #include <iterator>
      62             : #include <memory>
      63             : #include <utility>
      64             : 
      65             : using namespace llvm;
      66             : 
      67             : #define DEBUG_TYPE "livedebugvars"
      68             : 
      69             : static cl::opt<bool>
      70      299229 : EnableLDV("live-debug-variables", cl::init(true),
      71      299229 :           cl::desc("Enable the live debug variables pass"), cl::Hidden);
      72             : 
      73             : STATISTIC(NumInsertedDebugValues, "Number of DBG_VALUEs inserted");
      74             : 
      75             : char LiveDebugVariables::ID = 0;
      76             : 
      77       26316 : INITIALIZE_PASS_BEGIN(LiveDebugVariables, DEBUG_TYPE,
      78             :                 "Debug Variable Analysis", false, false)
      79       26316 : INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
      80       26316 : INITIALIZE_PASS_DEPENDENCY(LiveIntervals)
      81      341794 : INITIALIZE_PASS_END(LiveDebugVariables, DEBUG_TYPE,
      82             :                 "Debug Variable Analysis", false, false)
      83             : 
      84       18644 : void LiveDebugVariables::getAnalysisUsage(AnalysisUsage &AU) const {
      85             :   AU.addRequired<MachineDominatorTree>();
      86             :   AU.addRequiredTransitive<LiveIntervals>();
      87             :   AU.setPreservesAll();
      88       18644 :   MachineFunctionPass::getAnalysisUsage(AU);
      89       18644 : }
      90             : 
      91       18644 : LiveDebugVariables::LiveDebugVariables() : MachineFunctionPass(ID) {
      92       18644 :   initializeLiveDebugVariablesPass(*PassRegistry::getPassRegistry());
      93       18644 : }
      94             : 
      95             : enum : unsigned { UndefLocNo = ~0U };
      96             : 
      97             : /// Describes a location by number along with some flags about the original
      98             : /// usage of the location.
      99             : class DbgValueLocation {
     100             : public:
     101             :   DbgValueLocation(unsigned LocNo, bool WasIndirect)
     102       64526 :       : LocNo(LocNo), WasIndirect(WasIndirect) {
     103             :     static_assert(sizeof(*this) == sizeof(unsigned), "bad bitfield packing");
     104             :     assert(locNo() == LocNo && "location truncation");
     105             :   }
     106             : 
     107      100475 :   DbgValueLocation() : LocNo(0), WasIndirect(0) {}
     108             : 
     109             :   unsigned locNo() const {
     110             :     // Fix up the undef location number, which gets truncated.
     111      186472 :     return LocNo == INT_MAX ? UndefLocNo : LocNo;
     112             :   }
     113       51676 :   bool wasIndirect() const { return WasIndirect; }
     114             :   bool isUndef() const { return locNo() == UndefLocNo; }
     115             : 
     116             :   DbgValueLocation changeLocNo(unsigned NewLocNo) const {
     117       31403 :     return DbgValueLocation(NewLocNo, WasIndirect);
     118             :   }
     119             : 
     120             :   friend inline bool operator==(const DbgValueLocation &LHS,
     121             :                                 const DbgValueLocation &RHS) {
     122       57455 :     return LHS.LocNo == RHS.LocNo && LHS.WasIndirect == RHS.WasIndirect;
     123             :   }
     124             : 
     125             :   friend inline bool operator!=(const DbgValueLocation &LHS,
     126             :                                 const DbgValueLocation &RHS) {
     127             :     return !(LHS == RHS);
     128             :   }
     129             : 
     130             : private:
     131             :   unsigned LocNo : 31;
     132             :   unsigned WasIndirect : 1;
     133             : };
     134             : 
     135             : /// LocMap - Map of where a user value is live, and its location.
     136             : using LocMap = IntervalMap<SlotIndex, DbgValueLocation, 4>;
     137             : 
     138             : namespace {
     139             : 
     140             : class LDVImpl;
     141             : 
     142             : /// UserValue - A user value is a part of a debug info user variable.
     143             : ///
     144             : /// A DBG_VALUE instruction notes that (a sub-register of) a virtual register
     145             : /// holds part of a user variable. The part is identified by a byte offset.
     146             : ///
     147             : /// UserValues are grouped into equivalence classes for easier searching. Two
     148             : /// user values are related if they refer to the same variable, or if they are
     149             : /// held by the same virtual register. The equivalence class is the transitive
     150             : /// closure of that relation.
     151       45836 : class UserValue {
     152             :   const DILocalVariable *Variable; ///< The debug info variable we are part of.
     153             :   const DIExpression *Expression; ///< Any complex address expression.
     154             :   DebugLoc dl;            ///< The debug location for the variable. This is
     155             :                           ///< used by dwarf writer to find lexical scope.
     156             :   UserValue *leader;      ///< Equivalence class leader.
     157             :   UserValue *next = nullptr; ///< Next value in equivalence class, or null.
     158             : 
     159             :   /// Numbered locations referenced by locmap.
     160             :   SmallVector<MachineOperand, 4> locations;
     161             : 
     162             :   /// Map of slot indices where this value is live.
     163             :   LocMap locInts;
     164             : 
     165             :   /// Set of interval start indexes that have been trimmed to the
     166             :   /// lexical scope.
     167             :   SmallSet<SlotIndex, 2> trimmedDefs;
     168             : 
     169             :   /// insertDebugValue - Insert a DBG_VALUE into MBB at Idx for LocNo.
     170             :   void insertDebugValue(MachineBasicBlock *MBB, SlotIndex StartIdx,
     171             :                         SlotIndex StopIdx,
     172             :                         DbgValueLocation Loc, bool Spilled, LiveIntervals &LIS,
     173             :                         const TargetInstrInfo &TII,
     174             :                         const TargetRegisterInfo &TRI);
     175             : 
     176             :   /// splitLocation - Replace OldLocNo ranges with NewRegs ranges where NewRegs
     177             :   /// is live. Returns true if any changes were made.
     178             :   bool splitLocation(unsigned OldLocNo, ArrayRef<unsigned> NewRegs,
     179             :                      LiveIntervals &LIS);
     180             : 
     181             : public:
     182             :   /// UserValue - Create a new UserValue.
     183       22918 :   UserValue(const DILocalVariable *var, const DIExpression *expr, DebugLoc L,
     184             :             LocMap::Allocator &alloc)
     185       22918 :       : Variable(var), Expression(expr), dl(std::move(L)), leader(this),
     186       68754 :         locInts(alloc) {}
     187             : 
     188             :   /// getLeader - Get the leader of this value's equivalence class.
     189             :   UserValue *getLeader() {
     190       82366 :     UserValue *l = leader;
     191       82366 :     while (l != l->leader)
     192             :       l = l->leader;
     193       82366 :     return leader = l;
     194             :   }
     195             : 
     196             :   /// getNext - Return the next UserValue in the equivalence class.
     197             :   UserValue *getNext() const { return next; }
     198             : 
     199             :   /// match - Does this UserValue match the parameters?
     200       59960 :   bool match(const DILocalVariable *Var, const DIExpression *Expr,
     201             :              const DILocation *IA) const {
     202             :     // FIXME: The fragment should be part of the equivalence class, but not
     203             :     // other things in the expression like stack values.
     204      106940 :     return Var == Variable && Expr == Expression && dl->getInlinedAt() == IA;
     205             :   }
     206             : 
     207             :   /// merge - Merge equivalence classes.
     208       40173 :   static UserValue *merge(UserValue *L1, UserValue *L2) {
     209             :     L2 = L2->getLeader();
     210       40173 :     if (!L1)
     211             :       return L2;
     212             :     L1 = L1->getLeader();
     213       21488 :     if (L1 == L2)
     214             :       return L1;
     215             :     // Splice L2 before L1's members.
     216             :     UserValue *End = L2;
     217       39784 :     while (End->next) {
     218       11586 :       End->leader = L1;
     219             :       End = End->next;
     220             :     }
     221       16612 :     End->leader = L1;
     222       16612 :     End->next = L1->next;
     223       16612 :     L1->next = L2;
     224       16612 :     return L1;
     225             :   }
     226             : 
     227             :   /// Return the location number that matches Loc.
     228             :   ///
     229             :   /// For undef values we always return location number UndefLocNo without
     230             :   /// inserting anything in locations. Since locations is a vector and the
     231             :   /// location number is the position in the vector and UndefLocNo is ~0,
     232             :   /// we would need a very big vector to put the value at the right position.
     233       35312 :   unsigned getLocationNo(const MachineOperand &LocMO) {
     234       35312 :     if (LocMO.isReg()) {
     235       32666 :       if (LocMO.getReg() == 0)
     236             :         return UndefLocNo;
     237             :       // For register locations we dont care about use/def and other flags.
     238       35529 :       for (unsigned i = 0, e = locations.size(); i != e; ++i)
     239       23783 :         if (locations[i].isReg() &&
     240       13949 :             locations[i].getReg() == LocMO.getReg() &&
     241             :             locations[i].getSubReg() == LocMO.getSubReg())
     242             :           return i;
     243             :     } else
     244        2791 :       for (unsigned i = 0, e = locations.size(); i != e; ++i)
     245         692 :         if (LocMO.isIdenticalTo(locations[i]))
     246             :           return i;
     247       25670 :     locations.push_back(LocMO);
     248             :     // We are storing a MachineOperand outside a MachineInstr.
     249       25670 :     locations.back().clearParent();
     250             :     // Don't store def operands.
     251       51340 :     if (locations.back().isReg()) {
     252       23225 :       if (locations.back().isDef())
     253             :         locations.back().setIsDead(false);
     254       23225 :       locations.back().setIsUse();
     255             :     }
     256       25670 :     return locations.size() - 1;
     257             :   }
     258             : 
     259             :   /// mapVirtRegs - Ensure that all virtual register locations are mapped.
     260             :   void mapVirtRegs(LDVImpl *LDV);
     261             : 
     262             :   /// addDef - Add a definition point to this value.
     263       33082 :   void addDef(SlotIndex Idx, const MachineOperand &LocMO, bool IsIndirect) {
     264       33082 :     DbgValueLocation Loc(getLocationNo(LocMO), IsIndirect);
     265             :     // Add a singular (Idx,Idx) -> Loc mapping.
     266       33082 :     LocMap::iterator I = locInts.find(Idx);
     267        1163 :     if (!I.valid() || I.start() != Idx)
     268       31919 :       I.insert(Idx, Idx.getNextSlot(), Loc);
     269             :     else
     270             :       // A later DBG_VALUE at the same SlotIndex overrides the old location.
     271        1163 :       I.setValue(Loc);
     272       33082 :   }
     273             : 
     274             :   /// extendDef - Extend the current definition as far as possible down.
     275             :   /// Stop when meeting an existing def or when leaving the live
     276             :   /// range of VNI.
     277             :   /// End points where VNI is no longer live are added to Kills.
     278             :   /// @param Idx   Starting point for the definition.
     279             :   /// @param Loc   Location number to propagate.
     280             :   /// @param LR    Restrict liveness to where LR has the value VNI. May be null.
     281             :   /// @param VNI   When LR is not null, this is the value to restrict to.
     282             :   /// @param Kills Append end points of VNI's live range to Kills.
     283             :   /// @param LIS   Live intervals analysis.
     284             :   void extendDef(SlotIndex Idx, DbgValueLocation Loc,
     285             :                  LiveRange *LR, const VNInfo *VNI,
     286             :                  SmallVectorImpl<SlotIndex> *Kills,
     287             :                  LiveIntervals &LIS);
     288             : 
     289             :   /// addDefsFromCopies - The value in LI/LocNo may be copies to other
     290             :   /// registers. Determine if any of the copies are available at the kill
     291             :   /// points, and add defs if possible.
     292             :   /// @param LI      Scan for copies of the value in LI->reg.
     293             :   /// @param LocNo   Location number of LI->reg.
     294             :   /// @param WasIndirect Indicates if the original use of LI->reg was indirect
     295             :   /// @param Kills   Points where the range of LocNo could be extended.
     296             :   /// @param NewDefs Append (Idx, LocNo) of inserted defs here.
     297             :   void addDefsFromCopies(
     298             :       LiveInterval *LI, unsigned LocNo, bool WasIndirect,
     299             :       const SmallVectorImpl<SlotIndex> &Kills,
     300             :       SmallVectorImpl<std::pair<SlotIndex, DbgValueLocation>> &NewDefs,
     301             :       MachineRegisterInfo &MRI, LiveIntervals &LIS);
     302             : 
     303             :   /// computeIntervals - Compute the live intervals of all locations after
     304             :   /// collecting all their def points.
     305             :   void computeIntervals(MachineRegisterInfo &MRI, const TargetRegisterInfo &TRI,
     306             :                         LiveIntervals &LIS, LexicalScopes &LS);
     307             : 
     308             :   /// splitRegister - Replace OldReg ranges with NewRegs ranges where NewRegs is
     309             :   /// live. Returns true if any changes were made.
     310             :   bool splitRegister(unsigned OldLocNo, ArrayRef<unsigned> NewRegs,
     311             :                      LiveIntervals &LIS);
     312             : 
     313             :   /// rewriteLocations - Rewrite virtual register locations according to the
     314             :   /// provided virtual register map. Record which locations were spilled.
     315             :   void rewriteLocations(VirtRegMap &VRM, const TargetRegisterInfo &TRI,
     316             :                         BitVector &SpilledLocations);
     317             : 
     318             :   /// emitDebugValues - Recreate DBG_VALUE instruction from data structures.
     319             :   void emitDebugValues(VirtRegMap *VRM, LiveIntervals &LIS,
     320             :                        const TargetInstrInfo &TII,
     321             :                        const TargetRegisterInfo &TRI,
     322             :                        const BitVector &SpilledLocations);
     323             : 
     324             :   /// getDebugLoc - Return DebugLoc of this UserValue.
     325             :   DebugLoc getDebugLoc() { return dl;}
     326             : 
     327             :   void print(raw_ostream &, const TargetRegisterInfo *);
     328             : };
     329             : 
     330             : /// LDVImpl - Implementation of the LiveDebugVariables pass.
     331        1527 : class LDVImpl {
     332             :   LiveDebugVariables &pass;
     333             :   LocMap::Allocator allocator;
     334             :   MachineFunction *MF = nullptr;
     335             :   LiveIntervals *LIS;
     336             :   const TargetRegisterInfo *TRI;
     337             : 
     338             :   /// Whether emitDebugValues is called.
     339             :   bool EmitDone = false;
     340             : 
     341             :   /// Whether the machine function is modified during the pass.
     342             :   bool ModifiedMF = false;
     343             : 
     344             :   /// userValues - All allocated UserValue instances.
     345             :   SmallVector<std::unique_ptr<UserValue>, 8> userValues;
     346             : 
     347             :   /// Map virtual register to eq class leader.
     348             :   using VRMap = DenseMap<unsigned, UserValue *>;
     349             :   VRMap virtRegToEqClass;
     350             : 
     351             :   /// Map user variable to eq class leader.
     352             :   using UVMap = DenseMap<const DILocalVariable *, UserValue *>;
     353             :   UVMap userVarMap;
     354             : 
     355             :   /// getUserValue - Find or create a UserValue.
     356             :   UserValue *getUserValue(const DILocalVariable *Var, const DIExpression *Expr,
     357             :                           const DebugLoc &DL);
     358             : 
     359             :   /// lookupVirtReg - Find the EC leader for VirtReg or null.
     360             :   UserValue *lookupVirtReg(unsigned VirtReg);
     361             : 
     362             :   /// handleDebugValue - Add DBG_VALUE instruction to our maps.
     363             :   /// @param MI  DBG_VALUE instruction
     364             :   /// @param Idx Last valid SLotIndex before instruction.
     365             :   /// @return    True if the DBG_VALUE instruction should be deleted.
     366             :   bool handleDebugValue(MachineInstr &MI, SlotIndex Idx);
     367             : 
     368             :   /// collectDebugValues - Collect and erase all DBG_VALUE instructions, adding
     369             :   /// a UserValue def for each instruction.
     370             :   /// @param mf MachineFunction to be scanned.
     371             :   /// @return True if any debug values were found.
     372             :   bool collectDebugValues(MachineFunction &mf);
     373             : 
     374             :   /// computeIntervals - Compute the live intervals of all user values after
     375             :   /// collecting all their def points.
     376             :   void computeIntervals();
     377             : 
     378             : public:
     379        2040 :   LDVImpl(LiveDebugVariables *ps) : pass(*ps) {}
     380             : 
     381             :   bool runOnMachineFunction(MachineFunction &mf);
     382             : 
     383             :   /// clear - Release all memory.
     384       13510 :   void clear() {
     385       13510 :     MF = nullptr;
     386             :     userValues.clear();
     387       13510 :     virtRegToEqClass.clear();
     388       13510 :     userVarMap.clear();
     389             :     // Make sure we call emitDebugValues if the machine function was modified.
     390             :     assert((!ModifiedMF || EmitDone) &&
     391             :            "Dbg values are not emitted in LDV");
     392       13510 :     EmitDone = false;
     393       13510 :     ModifiedMF = false;
     394       13510 :   }
     395             : 
     396             :   /// mapVirtReg - Map virtual register to an equivalence class.
     397             :   void mapVirtReg(unsigned VirtReg, UserValue *EC);
     398             : 
     399             :   /// splitRegister -  Replace all references to OldReg with NewRegs.
     400             :   void splitRegister(unsigned OldReg, ArrayRef<unsigned> NewRegs);
     401             : 
     402             :   /// emitDebugValues - Recreate DBG_VALUE instruction from data structures.
     403             :   void emitDebugValues(VirtRegMap *VRM);
     404             : 
     405             :   void print(raw_ostream&);
     406             : };
     407             : 
     408             : } // end anonymous namespace
     409             : 
     410             : #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
     411             : static void printDebugLoc(const DebugLoc &DL, raw_ostream &CommentOS,
     412             :                           const LLVMContext &Ctx) {
     413             :   if (!DL)
     414             :     return;
     415             : 
     416             :   auto *Scope = cast<DIScope>(DL.getScope());
     417             :   // Omit the directory, because it's likely to be long and uninteresting.
     418             :   CommentOS << Scope->getFilename();
     419             :   CommentOS << ':' << DL.getLine();
     420             :   if (DL.getCol() != 0)
     421             :     CommentOS << ':' << DL.getCol();
     422             : 
     423             :   DebugLoc InlinedAtDL = DL.getInlinedAt();
     424             :   if (!InlinedAtDL)
     425             :     return;
     426             : 
     427             :   CommentOS << " @[ ";
     428             :   printDebugLoc(InlinedAtDL, CommentOS, Ctx);
     429             :   CommentOS << " ]";
     430             : }
     431             : 
     432             : static void printExtendedName(raw_ostream &OS, const DILocalVariable *V,
     433             :                               const DILocation *DL) {
     434             :   const LLVMContext &Ctx = V->getContext();
     435             :   StringRef Res = V->getName();
     436             :   if (!Res.empty())
     437             :     OS << Res << "," << V->getLine();
     438             :   if (auto *InlinedAt = DL->getInlinedAt()) {
     439             :     if (DebugLoc InlinedAtDL = InlinedAt) {
     440             :       OS << " @[";
     441             :       printDebugLoc(InlinedAtDL, OS, Ctx);
     442             :       OS << "]";
     443             :     }
     444             :   }
     445             : }
     446             : 
     447             : void UserValue::print(raw_ostream &OS, const TargetRegisterInfo *TRI) {
     448             :   auto *DV = cast<DILocalVariable>(Variable);
     449             :   OS << "!\"";
     450             :   printExtendedName(OS, DV, dl);
     451             : 
     452             :   OS << "\"\t";
     453             :   for (LocMap::const_iterator I = locInts.begin(); I.valid(); ++I) {
     454             :     OS << " [" << I.start() << ';' << I.stop() << "):";
     455             :     if (I.value().isUndef())
     456             :       OS << "undef";
     457             :     else {
     458             :       OS << I.value().locNo();
     459             :       if (I.value().wasIndirect())
     460             :         OS << " ind";
     461             :     }
     462             :   }
     463             :   for (unsigned i = 0, e = locations.size(); i != e; ++i) {
     464             :     OS << " Loc" << i << '=';
     465             :     locations[i].print(OS, TRI);
     466             :   }
     467             :   OS << '\n';
     468             : }
     469             : 
     470             : void LDVImpl::print(raw_ostream &OS) {
     471             :   OS << "********** DEBUG VARIABLES **********\n";
     472             :   for (unsigned i = 0, e = userValues.size(); i != e; ++i)
     473             :     userValues[i]->print(OS, TRI);
     474             : }
     475             : #endif
     476             : 
     477       22918 : void UserValue::mapVirtRegs(LDVImpl *LDV) {
     478       46399 :   for (unsigned i = 0, e = locations.size(); i != e; ++i)
     479       67998 :     if (locations[i].isReg() &&
     480       21036 :         TargetRegisterInfo::isVirtualRegister(locations[i].getReg()))
     481       16455 :       LDV->mapVirtReg(locations[i].getReg(), this);
     482       22918 : }
     483             : 
     484       33082 : UserValue *LDVImpl::getUserValue(const DILocalVariable *Var,
     485             :                                  const DIExpression *Expr, const DebugLoc &DL) {
     486       33082 :   UserValue *&Leader = userVarMap[Var];
     487       33082 :   if (Leader) {
     488             :     UserValue *UV = Leader->getLeader();
     489       20093 :     Leader = UV;
     490      119685 :     for (; UV; UV = UV->getNext())
     491       59960 :       if (UV->match(Var, Expr, DL->getInlinedAt()))
     492             :         return UV;
     493             :   }
     494             : 
     495       45836 :   userValues.push_back(
     496       45836 :       llvm::make_unique<UserValue>(Var, Expr, DL, allocator));
     497       22918 :   UserValue *UV = userValues.back().get();
     498       22918 :   Leader = UserValue::merge(Leader, UV);
     499       22918 :   return UV;
     500             : }
     501             : 
     502       17255 : void LDVImpl::mapVirtReg(unsigned VirtReg, UserValue *EC) {
     503             :   assert(TargetRegisterInfo::isVirtualRegister(VirtReg) && "Only map VirtRegs");
     504       17255 :   UserValue *&Leader = virtRegToEqClass[VirtReg];
     505       17255 :   Leader = UserValue::merge(Leader, EC);
     506       17255 : }
     507             : 
     508       20108 : UserValue *LDVImpl::lookupVirtReg(unsigned VirtReg) {
     509       20720 :   if (UserValue *UV = virtRegToEqClass.lookup(VirtReg))
     510         612 :     return UV->getLeader();
     511             :   return nullptr;
     512             : }
     513             : 
     514       33082 : bool LDVImpl::handleDebugValue(MachineInstr &MI, SlotIndex Idx) {
     515             :   // DBG_VALUE loc, offset, variable
     516       66164 :   if (MI.getNumOperands() != 4 ||
     517       67336 :       !(MI.getOperand(1).isReg() || MI.getOperand(1).isImm()) ||
     518             :       !MI.getOperand(2).isMetadata()) {
     519             :     LLVM_DEBUG(dbgs() << "Can't handle " << MI);
     520             :     return false;
     521             :   }
     522             : 
     523             :   // Detect invalid DBG_VALUE instructions, with a debug-use of a virtual
     524             :   // register that hasn't been defined yet. If we do not remove those here, then
     525             :   // the re-insertion of the DBG_VALUE instruction after register allocation
     526             :   // will be incorrect.
     527             :   // TODO: If earlier passes are corrected to generate sane debug information
     528             :   // (and if the machine verifier is improved to catch this), then these checks
     529             :   // could be removed or replaced by asserts.
     530             :   bool Discard = false;
     531       63518 :   if (MI.getOperand(0).isReg() &&
     532       30436 :       TargetRegisterInfo::isVirtualRegister(MI.getOperand(0).getReg())) {
     533             :     const unsigned Reg = MI.getOperand(0).getReg();
     534       18088 :     if (!LIS->hasInterval(Reg)) {
     535             :       // The DBG_VALUE is described by a virtual register that does not have a
     536             :       // live interval. Discard the DBG_VALUE.
     537             :       Discard = true;
     538             :       LLVM_DEBUG(dbgs() << "Discarding debug info (no LIS interval): " << Idx
     539             :                         << " " << MI);
     540             :     } else {
     541             :       // The DBG_VALUE is only valid if either Reg is live out from Idx, or Reg
     542             :       // is defined dead at Idx (where Idx is the slot index for the instruction
     543             :       // preceeding the DBG_VALUE).
     544       18012 :       const LiveInterval &LI = LIS->getInterval(Reg);
     545       18012 :       LiveQueryResult LRQ = LI.Query(Idx);
     546       18012 :       if (!LRQ.valueOutOrDead()) {
     547             :         // We have found a DBG_VALUE with the value in a virtual register that
     548             :         // is not live. Discard the DBG_VALUE.
     549             :         Discard = true;
     550             :         LLVM_DEBUG(dbgs() << "Discarding debug info (reg not live): " << Idx
     551             :                           << " " << MI);
     552             :       }
     553             :     }
     554             :   }
     555             : 
     556             :   // Get or create the UserValue for (variable,offset) here.
     557       33082 :   bool IsIndirect = MI.getOperand(1).isImm();
     558             :   if (IsIndirect)
     559             :     assert(MI.getOperand(1).getImm() == 0 && "DBG_VALUE with nonzero offset");
     560       33082 :   const DILocalVariable *Var = MI.getDebugVariable();
     561       33082 :   const DIExpression *Expr = MI.getDebugExpression();
     562             :   UserValue *UV =
     563       33082 :       getUserValue(Var, Expr, MI.getDebugLoc());
     564       33082 :   if (!Discard)
     565       32944 :     UV->addDef(Idx, MI.getOperand(0), IsIndirect);
     566             :   else {
     567             :     MachineOperand MO = MachineOperand::CreateReg(0U, false);
     568             :     MO.setIsDebug();
     569         138 :     UV->addDef(Idx, MO, false);
     570             :   }
     571             :   return true;
     572             : }
     573             : 
     574        6599 : bool LDVImpl::collectDebugValues(MachineFunction &mf) {
     575             :   bool Changed = false;
     576      136203 :   for (MachineFunction::iterator MFI = mf.begin(), MFE = mf.end(); MFI != MFE;
     577             :        ++MFI) {
     578             :     MachineBasicBlock *MBB = &*MFI;
     579      129604 :     for (MachineBasicBlock::iterator MBBI = MBB->begin(), MBBE = MBB->end();
     580     1907671 :          MBBI != MBBE;) {
     581     3546653 :       if (!MBBI->isDebugValue()) {
     582             :         ++MBBI;
     583     1768586 :         continue;
     584             :       }
     585             :       // DBG_VALUE has no slot index, use the previous instruction instead.
     586             :       SlotIndex Idx =
     587             :           MBBI == MBB->begin()
     588        2508 :               ? LIS->getMBBStartIdx(MBB)
     589       28443 :               : LIS->getInstructionIndex(*std::prev(MBBI)).getRegSlot();
     590             :       // Handle consecutive DBG_VALUE instructions with the same slot index.
     591             :       do {
     592       33082 :         if (handleDebugValue(*MBBI, Idx)) {
     593       33082 :           MBBI = MBB->erase(MBBI);
     594             :           Changed = true;
     595             :         } else
     596             :           ++MBBI;
     597       66036 :       } while (MBBI != MBBE && MBBI->isDebugValue());
     598             :     }
     599             :   }
     600        6599 :   return Changed;
     601             : }
     602             : 
     603             : /// We only propagate DBG_VALUES locally here. LiveDebugValues performs a
     604             : /// data-flow analysis to propagate them beyond basic block boundaries.
     605       19914 : void UserValue::extendDef(SlotIndex Idx, DbgValueLocation Loc, LiveRange *LR,
     606             :                           const VNInfo *VNI, SmallVectorImpl<SlotIndex> *Kills,
     607             :                           LiveIntervals &LIS) {
     608       19914 :   SlotIndex Start = Idx;
     609       19914 :   MachineBasicBlock *MBB = LIS.getMBBFromIndex(Start);
     610       39828 :   SlotIndex Stop = LIS.getMBBEndIdx(MBB);
     611       19914 :   LocMap::iterator I = locInts.find(Start);
     612             : 
     613             :   // Limit to VNI's live range.
     614             :   bool ToEnd = true;
     615       19914 :   if (LR && VNI) {
     616             :     LiveInterval::Segment *Segment = LR->getSegmentContaining(Start);
     617       17319 :     if (!Segment || Segment->valno != VNI) {
     618           0 :       if (Kills)
     619           0 :         Kills->push_back(Start);
     620             :       return;
     621             :     }
     622       17319 :     if (Segment->end < Stop) {
     623        4087 :       Stop = Segment->end;
     624             :       ToEnd = false;
     625             :     }
     626             :   }
     627             : 
     628             :   // There could already be a short def at Start.
     629       19914 :   if (I.valid() && I.start() <= Start) {
     630             :     // Stop when meeting a different location or an already extended interval.
     631       19914 :     Start = Start.getNextSlot();
     632       19914 :     if (I.value() != Loc || I.stop() != Start)
     633             :       return;
     634             :     // This is a one-slot placeholder. Just skip it.
     635             :     ++I;
     636             :   }
     637             : 
     638             :   // Limited by the next def.
     639        2029 :   if (I.valid() && I.start() < Stop) {
     640         179 :     Stop = I.start();
     641             :     ToEnd = false;
     642             :   }
     643             :   // Limited by VNI's live range.
     644       19735 :   else if (!ToEnd && Kills)
     645        4055 :     Kills->push_back(Stop);
     646             : 
     647       19914 :   if (Start < Stop)
     648       19889 :     I.insert(Start, Stop, Loc);
     649             : }
     650             : 
     651       17319 : void UserValue::addDefsFromCopies(
     652             :     LiveInterval *LI, unsigned LocNo, bool WasIndirect,
     653             :     const SmallVectorImpl<SlotIndex> &Kills,
     654             :     SmallVectorImpl<std::pair<SlotIndex, DbgValueLocation>> &NewDefs,
     655             :     MachineRegisterInfo &MRI, LiveIntervals &LIS) {
     656       17319 :   if (Kills.empty())
     657       16919 :     return;
     658             :   // Don't track copies from physregs, there are too many uses.
     659        8110 :   if (!TargetRegisterInfo::isVirtualRegister(LI->reg))
     660             :     return;
     661             : 
     662             :   // Collect all the (vreg, valno) pairs that are copies of LI.
     663             :   SmallVector<std::pair<LiveInterval*, const VNInfo*>, 8> CopyValues;
     664       22204 :   for (MachineOperand &MO : MRI.use_nodbg_operands(LI->reg)) {
     665       18149 :     MachineInstr *MI = MO.getParent();
     666             :     // Copies of the full value.
     667       35966 :     if (MO.getSubReg() || !MI->isCopy())
     668       33482 :       continue;
     669        2346 :     unsigned DstReg = MI->getOperand(0).getReg();
     670             : 
     671             :     // Don't follow copies to physregs. These are usually setting up call
     672             :     // arguments, and the argument registers are always call clobbered. We are
     673             :     // better off in the source register which could be a callee-saved register,
     674             :     // or it could be spilled.
     675        2346 :     if (!TargetRegisterInfo::isVirtualRegister(DstReg))
     676        1814 :       continue;
     677             : 
     678             :     // Is LocNo extended to reach this copy? If not, another def may be blocking
     679             :     // it, or we are looking at a wrong value of LI.
     680         532 :     SlotIndex Idx = LIS.getInstructionIndex(*MI);
     681         532 :     LocMap::iterator I = locInts.find(Idx.getRegSlot(true));
     682         560 :     if (!I.valid() || I.value().locNo() != LocNo)
     683          62 :       continue;
     684             : 
     685           0 :     if (!LIS.hasInterval(DstReg))
     686           0 :       continue;
     687         470 :     LiveInterval *DstLI = &LIS.getInterval(DstReg);
     688         470 :     const VNInfo *DstVNI = DstLI->getVNInfoAt(Idx.getRegSlot());
     689             :     assert(DstVNI && DstVNI->def == Idx.getRegSlot() && "Bad copy value");
     690         470 :     CopyValues.push_back(std::make_pair(DstLI, DstVNI));
     691             :   }
     692             : 
     693        4055 :   if (CopyValues.empty())
     694             :     return;
     695             : 
     696             :   LLVM_DEBUG(dbgs() << "Got " << CopyValues.size() << " copies of " << *LI
     697             :                     << '\n');
     698             : 
     699             :   // Try to add defs of the copied values for each kill point.
     700         800 :   for (unsigned i = 0, e = Kills.size(); i != e; ++i) {
     701         800 :     SlotIndex Idx = Kills[i];
     702         829 :     for (unsigned j = 0, e = CopyValues.size(); j != e; ++j) {
     703         940 :       LiveInterval *DstLI = CopyValues[j].first;
     704         470 :       const VNInfo *DstVNI = CopyValues[j].second;
     705         940 :       if (DstLI->getVNInfoAt(Idx) != DstVNI)
     706         858 :         continue;
     707             :       // Check that there isn't already a def at Idx
     708          41 :       LocMap::iterator I = locInts.find(Idx);
     709           9 :       if (I.valid() && I.start() <= Idx)
     710             :         continue;
     711             :       LLVM_DEBUG(dbgs() << "Kill at " << Idx << " covered by valno #"
     712             :                         << DstVNI->id << " in " << *DstLI << '\n');
     713             :       MachineInstr *CopyMI = LIS.getInstructionFromIndex(DstVNI->def);
     714             :       assert(CopyMI && CopyMI->isCopy() && "Bad copy value");
     715          41 :       unsigned LocNo = getLocationNo(CopyMI->getOperand(0));
     716             :       DbgValueLocation NewLoc(LocNo, WasIndirect);
     717          41 :       I.insert(Idx, Idx.getNextSlot(), NewLoc);
     718          82 :       NewDefs.push_back(std::make_pair(Idx, NewLoc));
     719             :       break;
     720             :     }
     721             :   }
     722             : }
     723             : 
     724       22918 : void UserValue::computeIntervals(MachineRegisterInfo &MRI,
     725             :                                  const TargetRegisterInfo &TRI,
     726             :                                  LiveIntervals &LIS, LexicalScopes &LS) {
     727             :   SmallVector<std::pair<SlotIndex, DbgValueLocation>, 16> Defs;
     728             : 
     729             :   // Collect all defs to be extended (Skipping undefs).
     730       77755 :   for (LocMap::const_iterator I = locInts.begin(); I.valid(); ++I)
     731             :     if (!I.value().isUndef())
     732       24491 :       Defs.push_back(std::make_pair(I.start(), I.value()));
     733             : 
     734             :   // Extend all defs, and possibly add new ones along the way.
     735      119432 :   for (unsigned i = 0; i != Defs.size(); ++i) {
     736       24532 :     SlotIndex Idx = Defs[i].first;
     737       24532 :     DbgValueLocation Loc = Defs[i].second;
     738       24532 :     const MachineOperand &LocMO = locations[Loc.locNo()];
     739             : 
     740       27127 :     if (!LocMO.isReg()) {
     741        2595 :       extendDef(Idx, Loc, nullptr, nullptr, nullptr, LIS);
     742       19914 :       continue;
     743             :     }
     744             : 
     745             :     // Register locations are constrained to where the register value is live.
     746       43874 :     if (TargetRegisterInfo::isVirtualRegister(LocMO.getReg())) {
     747             :       LiveInterval *LI = nullptr;
     748             :       const VNInfo *VNI = nullptr;
     749             :       if (LIS.hasInterval(LocMO.getReg())) {
     750       17319 :         LI = &LIS.getInterval(LocMO.getReg());
     751       17319 :         VNI = LI->getVNInfoAt(Idx);
     752             :       }
     753             :       SmallVector<SlotIndex, 16> Kills;
     754       17319 :       extendDef(Idx, Loc, LI, VNI, &Kills, LIS);
     755       17319 :       if (LI)
     756       34638 :         addDefsFromCopies(LI, Loc.locNo(), Loc.wasIndirect(), Kills, Defs, MRI,
     757             :                           LIS);
     758             :       continue;
     759             :     }
     760             : 
     761             :     // For physregs, we only mark the start slot idx. DwarfDebug will see it
     762             :     // as if the DBG_VALUE is valid up until the end of the basic block, or
     763             :     // the next def of the physical register. So we do not need to extend the
     764             :     // range. It might actually happen that the DBG_VALUE is the last use of
     765             :     // the physical register (e.g. if this is an unused input argument to a
     766             :     // function).
     767             :   }
     768             : 
     769             :   // The computed intervals may extend beyond the range of the debug
     770             :   // location's lexical scope. In this case, splitting of an interval
     771             :   // can result in an interval outside of the scope being created,
     772             :   // causing extra unnecessary DBG_VALUEs to be emitted. To prevent
     773             :   // this, trim the intervals to the lexical scope.
     774             : 
     775       45836 :   LexicalScope *Scope = LS.findLexicalScope(dl);
     776       22918 :   if (!Scope)
     777             :     return;
     778             : 
     779             :   SlotIndex PrevEnd;
     780             :   LocMap::iterator I = locInts.begin();
     781             : 
     782             :   // Iterate over the lexical scope ranges. Each time round the loop
     783             :   // we check the intervals for overlap with the end of the previous
     784             :   // range and the start of the next. The first range is handled as
     785             :   // a special case where there is no PrevEnd.
     786       34754 :   for (const InsnRange &Range : Scope->getRanges()) {
     787       49080 :     SlotIndex RStart = LIS.getInstructionIndex(*Range.first);
     788       24540 :     SlotIndex REnd = LIS.getInstructionIndex(*Range.second);
     789             : 
     790             :     // At the start of each iteration I has been advanced so that
     791             :     // I.stop() >= PrevEnd. Check for overlap.
     792       28112 :     if (PrevEnd && I.start() < PrevEnd) {
     793        2368 :       SlotIndex IStop = I.stop();
     794        2368 :       DbgValueLocation Loc = I.value();
     795             : 
     796             :       // Stop overlaps previous end - trim the end of the interval to
     797             :       // the scope range.
     798        2368 :       I.setStopUnchecked(PrevEnd);
     799             :       ++I;
     800             : 
     801             :       // If the interval also overlaps the start of the "next" (i.e.
     802             :       // current) range create a new interval for the remainder (which
     803             :       // may be further trimmed).
     804        2368 :       if (RStart < IStop)
     805        2244 :         I.insert(RStart, IStop, Loc);
     806             :     }
     807             : 
     808             :     // Advance I so that I.stop() >= RStart, and check for overlap.
     809       24540 :     I.advanceTo(RStart);
     810             :     if (!I.valid())
     811       17647 :       return;
     812             : 
     813       14736 :     if (I.start() < RStart) {
     814             :       // Interval start overlaps range - trim to the scope range.
     815             :       I.setStartUnchecked(RStart);
     816             :       // Remember that this interval was trimmed.
     817        7063 :       trimmedDefs.insert(RStart);
     818             :     }
     819             : 
     820             :     // The end of a lexical scope range is the last instruction in the
     821             :     // range. To convert to an interval we need the index of the
     822             :     // instruction after it.
     823             :     REnd = REnd.getNextIndex();
     824             : 
     825             :     // Advance I to first interval outside current range.
     826       14736 :     I.advanceTo(REnd);
     827             :     if (!I.valid())
     828             :       return;
     829             : 
     830             :     PrevEnd = REnd;
     831             :   }
     832             : 
     833             :   // Check for overlap with end of final range.
     834        6642 :   if (PrevEnd && I.start() < PrevEnd)
     835        2478 :     I.setStopUnchecked(PrevEnd);
     836             : }
     837             : 
     838        6599 : void LDVImpl::computeIntervals() {
     839        6599 :   LexicalScopes LS;
     840        6599 :   LS.initialize(*MF);
     841             : 
     842       29517 :   for (unsigned i = 0, e = userValues.size(); i != e; ++i) {
     843       45836 :     userValues[i]->computeIntervals(MF->getRegInfo(), *TRI, *LIS, LS);
     844       22918 :     userValues[i]->mapVirtRegs(this);
     845             :   }
     846        6599 : }
     847             : 
     848        6599 : bool LDVImpl::runOnMachineFunction(MachineFunction &mf) {
     849        6599 :   clear();
     850        6599 :   MF = &mf;
     851        6599 :   LIS = &pass.getAnalysis<LiveIntervals>();
     852        6599 :   TRI = mf.getSubtarget().getRegisterInfo();
     853             :   LLVM_DEBUG(dbgs() << "********** COMPUTING LIVE DEBUG VARIABLES: "
     854             :                     << mf.getName() << " **********\n");
     855             : 
     856        6599 :   bool Changed = collectDebugValues(mf);
     857        6599 :   computeIntervals();
     858             :   LLVM_DEBUG(print(dbgs()));
     859        6599 :   ModifiedMF = Changed;
     860        6599 :   return Changed;
     861             : }
     862             : 
     863      175224 : static void removeDebugValues(MachineFunction &mf) {
     864      388850 :   for (MachineBasicBlock &MBB : mf) {
     865     2245436 :     for (auto MBBI = MBB.begin(), MBBE = MBB.end(); MBBI != MBBE; ) {
     866     3636338 :       if (!MBBI->isDebugValue()) {
     867             :         ++MBBI;
     868     1818154 :         continue;
     869             :       }
     870          30 :       MBBI = MBB.erase(MBBI);
     871             :     }
     872             :   }
     873      175224 : }
     874             : 
     875      181823 : bool LiveDebugVariables::runOnMachineFunction(MachineFunction &mf) {
     876      181823 :   if (!EnableLDV)
     877             :     return false;
     878      181823 :   if (!mf.getFunction().getSubprogram()) {
     879      175224 :     removeDebugValues(mf);
     880      175224 :     return false;
     881             :   }
     882        6599 :   if (!pImpl)
     883         510 :     pImpl = new LDVImpl(this);
     884        6599 :   return static_cast<LDVImpl*>(pImpl)->runOnMachineFunction(mf);
     885             : }
     886             : 
     887      181839 : void LiveDebugVariables::releaseMemory() {
     888      181839 :   if (pImpl)
     889        6911 :     static_cast<LDVImpl*>(pImpl)->clear();
     890      181839 : }
     891             : 
     892       55650 : LiveDebugVariables::~LiveDebugVariables() {
     893       18550 :   if (pImpl)
     894         509 :     delete static_cast<LDVImpl*>(pImpl);
     895       37100 : }
     896             : 
     897             : //===----------------------------------------------------------------------===//
     898             : //                           Live Range Splitting
     899             : //===----------------------------------------------------------------------===//
     900             : 
     901             : bool
     902        1863 : UserValue::splitLocation(unsigned OldLocNo, ArrayRef<unsigned> NewRegs,
     903             :                          LiveIntervals& LIS) {
     904             :   LLVM_DEBUG({
     905             :     dbgs() << "Splitting Loc" << OldLocNo << '\t';
     906             :     print(dbgs(), nullptr);
     907             :   });
     908             :   bool DidChange = false;
     909             :   LocMap::iterator LocMapI;
     910        1863 :   LocMapI.setMap(locInts);
     911       12183 :   for (unsigned i = 0; i != NewRegs.size(); ++i) {
     912       10320 :     LiveInterval *LI = &LIS.getInterval(NewRegs[i]);
     913        5160 :     if (LI->empty())
     914          45 :       continue;
     915             : 
     916             :     // Don't allocate the new LocNo until it is needed.
     917             :     unsigned NewLocNo = UndefLocNo;
     918             : 
     919             :     // Iterate over the overlaps between locInts and LI.
     920        5115 :     LocMapI.find(LI->beginIndex());
     921        2707 :     if (!LocMapI.valid())
     922        2707 :       continue;
     923        4816 :     LiveInterval::iterator LII = LI->advanceTo(LI->begin(), LocMapI.start());
     924             :     LiveInterval::iterator LIE = LI->end();
     925        2985 :     while (LocMapI.valid() && LII != LIE) {
     926             :       // At this point, we know that LocMapI.stop() > LII->start.
     927        2804 :       LII = LI->advanceTo(LII, LocMapI.start());
     928        2804 :       if (LII == LIE)
     929             :         break;
     930             : 
     931             :       // Now LII->end > LocMapI.start(). Do we have an overlap?
     932        5097 :       if (LocMapI.value().locNo() == OldLocNo && LII->start < LocMapI.stop()) {
     933             :         // Overlapping correct location. Allocate NewLocNo now.
     934        2253 :         if (NewLocNo == UndefLocNo) {
     935        2189 :           MachineOperand MO = MachineOperand::CreateReg(LI->reg, false);
     936        2189 :           MO.setSubReg(locations[OldLocNo].getSubReg());
     937        2189 :           NewLocNo = getLocationNo(MO);
     938             :           DidChange = true;
     939             :         }
     940             : 
     941        2253 :         SlotIndex LStart = LocMapI.start();
     942        2253 :         SlotIndex LStop  = LocMapI.stop();
     943        2253 :         DbgValueLocation OldLoc = LocMapI.value();
     944             : 
     945             :         // Trim LocMapI down to the LII overlap.
     946        2253 :         if (LStart < LII->start)
     947             :           LocMapI.setStartUnchecked(LII->start);
     948        2253 :         if (LStop > LII->end)
     949          34 :           LocMapI.setStopUnchecked(LII->end);
     950             : 
     951             :         // Change the value in the overlap. This may trigger coalescing.
     952        2253 :         LocMapI.setValue(OldLoc.changeLocNo(NewLocNo));
     953             : 
     954             :         // Re-insert any removed OldLocNo ranges.
     955        2253 :         if (LStart < LocMapI.start()) {
     956         301 :           LocMapI.insert(LStart, LocMapI.start(), OldLoc);
     957             :           ++LocMapI;
     958             :           assert(LocMapI.valid() && "Unexpected coalescing");
     959             :         }
     960        2253 :         if (LStop > LocMapI.stop()) {
     961             :           ++LocMapI;
     962          34 :           LocMapI.insert(LII->end, LStop, OldLoc);
     963             :           --LocMapI;
     964             :         }
     965             :       }
     966             : 
     967             :       // Advance to the next overlap.
     968        2804 :       if (LII->end < LocMapI.stop()) {
     969         299 :         if (++LII == LIE)
     970             :           break;
     971          12 :         LocMapI.advanceTo(LII->start);
     972             :       } else {
     973             :         ++LocMapI;
     974             :         if (!LocMapI.valid())
     975             :           break;
     976         569 :         LII = LI->advanceTo(LII, LocMapI.start());
     977             :       }
     978             :     }
     979             :   }
     980             : 
     981             :   // Finally, remove any remaining OldLocNo intervals and OldLocNo itself.
     982        1863 :   locations.erase(locations.begin() + OldLocNo);
     983        1863 :   LocMapI.goToBegin();
     984        3294 :   while (LocMapI.valid()) {
     985        3294 :     DbgValueLocation v = LocMapI.value();
     986        3294 :     if (v.locNo() == OldLocNo) {
     987             :       LLVM_DEBUG(dbgs() << "Erasing [" << LocMapI.start() << ';'
     988             :                         << LocMapI.stop() << ")\n");
     989           1 :       LocMapI.erase();
     990             :     } else {
     991             :       // Undef values always have location number UndefLocNo, so don't change
     992             :       // locNo in that case. See getLocationNo().
     993        3284 :       if (!v.isUndef() && v.locNo() > OldLocNo)
     994        2350 :         LocMapI.setValueUnchecked(v.changeLocNo(v.locNo() - 1));
     995             :       ++LocMapI;
     996             :     }
     997             :   }
     998             : 
     999             :   LLVM_DEBUG({
    1000             :     dbgs() << "Split result: \t";
    1001             :     print(dbgs(), nullptr);
    1002             :   });
    1003        1863 :   return DidChange;
    1004             : }
    1005             : 
    1006             : bool
    1007        7898 : UserValue::splitRegister(unsigned OldReg, ArrayRef<unsigned> NewRegs,
    1008             :                          LiveIntervals &LIS) {
    1009             :   bool DidChange = false;
    1010             :   // Split locations referring to OldReg. Iterate backwards so splitLocation can
    1011             :   // safely erase unused locations.
    1012        7898 :   for (unsigned i = locations.size(); i ; --i) {
    1013        9823 :     unsigned LocNo = i-1;
    1014        9823 :     const MachineOperand *Loc = &locations[LocNo];
    1015        9823 :     if (!Loc->isReg() || Loc->getReg() != OldReg)
    1016        7960 :       continue;
    1017        1863 :     DidChange |= splitLocation(LocNo, NewRegs, LIS);
    1018             :   }
    1019        7898 :   return DidChange;
    1020             : }
    1021             : 
    1022       19805 : void LDVImpl::splitRegister(unsigned OldReg, ArrayRef<unsigned> NewRegs) {
    1023             :   bool DidChange = false;
    1024       27703 :   for (UserValue *UV = lookupVirtReg(OldReg); UV; UV = UV->getNext())
    1025        7898 :     DidChange |= UV->splitRegister(OldReg, NewRegs, *LIS);
    1026             : 
    1027       19805 :   if (!DidChange)
    1028             :     return;
    1029             : 
    1030             :   // Map all of the new virtual registers.
    1031         303 :   UserValue *UV = lookupVirtReg(OldReg);
    1032        1903 :   for (unsigned i = 0; i != NewRegs.size(); ++i)
    1033        1600 :     mapVirtReg(NewRegs[i], UV);
    1034             : }
    1035             : 
    1036       28851 : void LiveDebugVariables::
    1037             : splitRegister(unsigned OldReg, ArrayRef<unsigned> NewRegs, LiveIntervals &LIS) {
    1038       28851 :   if (pImpl)
    1039       19805 :     static_cast<LDVImpl*>(pImpl)->splitRegister(OldReg, NewRegs);
    1040       28851 : }
    1041             : 
    1042       22918 : void UserValue::rewriteLocations(VirtRegMap &VRM, const TargetRegisterInfo &TRI,
    1043             :                                  BitVector &SpilledLocations) {
    1044             :   // Build a set of new locations with new numbers so we can coalesce our
    1045             :   // IntervalMap if two vreg intervals collapse to the same physical location.
    1046             :   // Use MapVector instead of SetVector because MapVector::insert returns the
    1047             :   // position of the previously or newly inserted element. The boolean value
    1048             :   // tracks if the location was produced by a spill.
    1049             :   // FIXME: This will be problematic if we ever support direct and indirect
    1050             :   // frame index locations, i.e. expressing both variables in memory and
    1051             :   // 'int x, *px = &x'. The "spilled" bit must become part of the location.
    1052       22918 :   MapVector<MachineOperand, bool> NewLocations;
    1053       45836 :   SmallVector<unsigned, 4> LocNoMap(locations.size());
    1054       46725 :   for (unsigned I = 0, E = locations.size(); I != E; ++I) {
    1055             :     bool Spilled = false;
    1056       47614 :     MachineOperand Loc = locations[I];
    1057             :     // Only virtual registers are rewritten.
    1058       45169 :     if (Loc.isReg() && Loc.getReg() &&
    1059             :         TargetRegisterInfo::isVirtualRegister(Loc.getReg())) {
    1060             :       unsigned VirtReg = Loc.getReg();
    1061       16247 :       if (VRM.isAssignedReg(VirtReg) &&
    1062             :           TargetRegisterInfo::isPhysicalRegister(VRM.getPhys(VirtReg))) {
    1063             :         // This can create a %noreg operand in rare cases when the sub-register
    1064             :         // index is no longer available. That means the user value is in a
    1065             :         // non-existent sub-register, and %noreg is exactly what we want.
    1066       16190 :         Loc.substPhysReg(VRM.getPhys(VirtReg), TRI);
    1067         591 :       } else if (VRM.getStackSlot(VirtReg) != VirtRegMap::NO_STACK_SLOT) {
    1068             :         // FIXME: Translate SubIdx to a stackslot offset.
    1069         534 :         Loc = MachineOperand::CreateFI(VRM.getStackSlot(VirtReg));
    1070             :         Spilled = true;
    1071             :       } else {
    1072          57 :         Loc.setReg(0);
    1073             :         Loc.setSubReg(0);
    1074             :       }
    1075             :     }
    1076             : 
    1077             :     // Insert this location if it doesn't already exist and record a mapping
    1078             :     // from the old number to the new number.
    1079       23807 :     auto InsertResult = NewLocations.insert({Loc, Spilled});
    1080       23807 :     unsigned NewLocNo = std::distance(NewLocations.begin(), InsertResult.first);
    1081       23807 :     LocNoMap[I] = NewLocNo;
    1082             :   }
    1083             : 
    1084             :   // Rewrite the locations and record which ones were spill slots.
    1085             :   locations.clear();
    1086             :   SpilledLocations.clear();
    1087       22918 :   SpilledLocations.resize(NewLocations.size());
    1088       45709 :   for (auto &Pair : NewLocations) {
    1089       22791 :     locations.push_back(Pair.first);
    1090       22791 :     if (Pair.second) {
    1091         532 :       unsigned NewLocNo = std::distance(&*NewLocations.begin(), &Pair);
    1092             :       SpilledLocations.set(NewLocNo);
    1093             :     }
    1094             :   }
    1095             : 
    1096             :   // Update the interval map, but only coalesce left, since intervals to the
    1097             :   // right use the old location numbers. This should merge two contiguous
    1098             :   // DBG_VALUE intervals with different vregs that were allocated to the same
    1099             :   // physical register.
    1100       22918 :   for (LocMap::iterator I = locInts.begin(); I.valid(); ++I) {
    1101       34228 :     DbgValueLocation Loc = I.value();
    1102             :     // Undef values don't exist in locations (and thus not in LocNoMap either)
    1103             :     // so skip over them. See getLocationNo().
    1104        7428 :     if (Loc.isUndef())
    1105        7428 :       continue;
    1106       53600 :     unsigned NewLocNo = LocNoMap[Loc.locNo()];
    1107             :     I.setValueUnchecked(Loc.changeLocNo(NewLocNo));
    1108       26800 :     I.setStart(I.start());
    1109             :   }
    1110       22918 : }
    1111             : 
    1112             : /// Find an iterator for inserting a DBG_VALUE instruction.
    1113             : static MachineBasicBlock::iterator
    1114       34357 : findInsertLocation(MachineBasicBlock *MBB, SlotIndex Idx,
    1115             :                    LiveIntervals &LIS) {
    1116       34357 :   SlotIndex Start = LIS.getMBBStartIdx(MBB);
    1117             :   Idx = Idx.getBaseIndex();
    1118             : 
    1119             :   // Try to find an insert location by going backwards from Idx.
    1120             :   MachineInstr *MI;
    1121       41891 :   while (!(MI = LIS.getInstructionFromIndex(Idx))) {
    1122             :     // We've reached the beginning of MBB.
    1123       15525 :     if (Idx == Start) {
    1124       11758 :       MachineBasicBlock::iterator I = MBB->SkipPHIsLabelsAndDebug(MBB->begin());
    1125       11758 :       return I;
    1126             :     }
    1127             :     Idx = Idx.getPrevIndex();
    1128             :   }
    1129             : 
    1130             :   // Don't insert anything after the first terminator, though.
    1131             :   return MI->isTerminator() ? MBB->getFirstTerminator() :
    1132       22599 :                               std::next(MachineBasicBlock::iterator(MI));
    1133             : }
    1134             : 
    1135             : /// Find an iterator for inserting the next DBG_VALUE instruction
    1136             : /// (or end if no more insert locations found).
    1137             : static MachineBasicBlock::iterator
    1138       34444 : findNextInsertLocation(MachineBasicBlock *MBB,
    1139             :                        MachineBasicBlock::iterator I,
    1140             :                        SlotIndex StopIdx, MachineOperand &LocMO,
    1141             :                        LiveIntervals &LIS,
    1142             :                        const TargetRegisterInfo &TRI) {
    1143       34444 :   if (!LocMO.isReg())
    1144        3102 :     return MBB->instr_end();
    1145       31342 :   unsigned Reg = LocMO.getReg();
    1146             : 
    1147             :   // Find the next instruction in the MBB that define the register Reg.
    1148      527056 :   while (I != MBB->end() && !I->isTerminator()) {
    1149      335874 :     if (!LIS.isNotInMIMap(*I) &&
    1150       84243 :         SlotIndex::isEarlierEqualInstr(StopIdx, LIS.getInstructionIndex(*I)))
    1151             :       break;
    1152      232508 :     if (I->definesRegister(Reg, &TRI))
    1153             :       // The insert location is directly after the instruction/bundle.
    1154             :       return std::next(I);
    1155             :     ++I;
    1156             :   }
    1157             :   return MBB->end();
    1158             : }
    1159             : 
    1160       34357 : void UserValue::insertDebugValue(MachineBasicBlock *MBB, SlotIndex StartIdx,
    1161             :                                  SlotIndex StopIdx,
    1162             :                                  DbgValueLocation Loc, bool Spilled,
    1163             :                                  LiveIntervals &LIS,
    1164             :                                  const TargetInstrInfo &TII,
    1165             :                                  const TargetRegisterInfo &TRI) {
    1166       68714 :   SlotIndex MBBEndIdx = LIS.getMBBEndIdx(&*MBB);
    1167             :   // Only search within the current MBB.
    1168       34357 :   StopIdx = (MBBEndIdx < StopIdx) ? MBBEndIdx : StopIdx;
    1169       34357 :   MachineBasicBlock::iterator I = findInsertLocation(MBB, StartIdx, LIS);
    1170             :   // Undef values don't exist in locations so create new "noreg" register MOs
    1171             :   // for them. See getLocationNo().
    1172             :   MachineOperand MO = !Loc.isUndef() ?
    1173       26929 :     locations[Loc.locNo()] :
    1174             :     MachineOperand::CreateReg(/* Reg */ 0, /* isDef */ false, /* isImp */ false,
    1175             :                               /* isKill */ false, /* isDead */ false,
    1176             :                               /* isUndef */ false, /* isEarlyClobber */ false,
    1177       26929 :                               /* SubReg */ 0, /* isDebug */ true);
    1178             : 
    1179             :   ++NumInsertedDebugValues;
    1180             : 
    1181             :   assert(cast<DILocalVariable>(Variable)
    1182             :              ->isValidLocationForIntrinsic(getDebugLoc()) &&
    1183             :          "Expected inlined-at fields to agree");
    1184             : 
    1185             :   // If the location was spilled, the new DBG_VALUE will be indirect. If the
    1186             :   // original DBG_VALUE was indirect, we need to add DW_OP_deref to indicate
    1187             :   // that the original virtual register was a pointer.
    1188       34357 :   const DIExpression *Expr = Expression;
    1189             :   bool IsIndirect = Loc.wasIndirect();
    1190       34357 :   if (Spilled) {
    1191         550 :     if (IsIndirect)
    1192           7 :       Expr = DIExpression::prepend(Expr, DIExpression::WithDeref);
    1193             :     IsIndirect = true;
    1194             :   }
    1195             : 
    1196             :   assert((!Spilled || MO.isFI()) && "a spilled location must be a frame index");
    1197             : 
    1198             :   do {
    1199       68888 :     BuildMI(*MBB, I, getDebugLoc(), TII.get(TargetOpcode::DBG_VALUE),
    1200       34444 :             IsIndirect, MO, Variable, Expr);
    1201             : 
    1202             :     // Continue and insert DBG_VALUES after every redefinition of register
    1203             :     // associated with the debug value within the range
    1204       34444 :     I = findNextInsertLocation(MBB, I, StopIdx, MO, LIS, TRI);
    1205       34444 :   } while (I != MBB->end());
    1206       34357 : }
    1207             : 
    1208       22918 : void UserValue::emitDebugValues(VirtRegMap *VRM, LiveIntervals &LIS,
    1209             :                                 const TargetInstrInfo &TII,
    1210             :                                 const TargetRegisterInfo &TRI,
    1211             :                                 const BitVector &SpilledLocations) {
    1212       22918 :   MachineFunction::iterator MFEnd = VRM->getMachineFunction().end();
    1213             : 
    1214       80064 :   for (LocMap::const_iterator I = locInts.begin(); I.valid();) {
    1215       34228 :     SlotIndex Start = I.start();
    1216       34228 :     SlotIndex Stop = I.stop();
    1217       34228 :     DbgValueLocation Loc = I.value();
    1218       26800 :     bool Spilled = !Loc.isUndef() ? SpilledLocations.test(Loc.locNo()) : false;
    1219             : 
    1220             :     // If the interval start was trimmed to the lexical scope insert the
    1221             :     // DBG_VALUE at the previous index (otherwise it appears after the
    1222             :     // first instruction in the range).
    1223       34228 :     if (trimmedDefs.count(Start))
    1224        7063 :       Start = Start.getPrevIndex();
    1225             : 
    1226             :     LLVM_DEBUG(dbgs() << "\t[" << Start << ';' << Stop << "):" << Loc.locNo());
    1227       68456 :     MachineFunction::iterator MBB = LIS.getMBBFromIndex(Start)->getIterator();
    1228       34228 :     SlotIndex MBBEnd = LIS.getMBBEndIdx(&*MBB);
    1229             : 
    1230             :     LLVM_DEBUG(dbgs() << ' ' << printMBBReference(*MBB) << '-' << MBBEnd);
    1231       34228 :     insertDebugValue(&*MBB, Start, Stop, Loc, Spilled, LIS, TII, TRI);
    1232             :     // This interval may span multiple basic blocks.
    1233             :     // Insert a DBG_VALUE into each one.
    1234       34486 :     while (Stop > MBBEnd) {
    1235             :       // Move to the next block.
    1236         129 :       Start = MBBEnd;
    1237         129 :       if (++MBB == MFEnd)
    1238             :         break;
    1239         129 :       MBBEnd = LIS.getMBBEndIdx(&*MBB);
    1240             :       LLVM_DEBUG(dbgs() << ' ' << printMBBReference(*MBB) << '-' << MBBEnd);
    1241         129 :       insertDebugValue(&*MBB, Start, Stop, Loc, Spilled, LIS, TII, TRI);
    1242             :     }
    1243             :     LLVM_DEBUG(dbgs() << '\n');
    1244       34228 :     if (MBB == MFEnd)
    1245             :       break;
    1246             : 
    1247       34228 :     ++I;
    1248             :   }
    1249       22918 : }
    1250             : 
    1251        6911 : void LDVImpl::emitDebugValues(VirtRegMap *VRM) {
    1252             :   LLVM_DEBUG(dbgs() << "********** EMITTING LIVE DEBUG VARIABLES **********\n");
    1253        6911 :   if (!MF)
    1254         312 :     return;
    1255        6599 :   const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
    1256             :   BitVector SpilledLocations;
    1257       29517 :   for (unsigned i = 0, e = userValues.size(); i != e; ++i) {
    1258             :     LLVM_DEBUG(userValues[i]->print(dbgs(), TRI));
    1259       45836 :     userValues[i]->rewriteLocations(*VRM, *TRI, SpilledLocations);
    1260       22918 :     userValues[i]->emitDebugValues(VRM, *LIS, *TII, *TRI, SpilledLocations);
    1261             :   }
    1262        6599 :   EmitDone = true;
    1263             : }
    1264             : 
    1265      181801 : void LiveDebugVariables::emitDebugValues(VirtRegMap *VRM) {
    1266      181801 :   if (pImpl)
    1267        6911 :     static_cast<LDVImpl*>(pImpl)->emitDebugValues(VRM);
    1268      181801 : }
    1269             : 
    1270       18648 : bool LiveDebugVariables::doInitialization(Module &M) {
    1271       18648 :   return Pass::doInitialization(M);
    1272      299229 : }
    1273             : 
    1274             : #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
    1275             : LLVM_DUMP_METHOD void LiveDebugVariables::dump() const {
    1276             :   if (pImpl)
    1277             :     static_cast<LDVImpl*>(pImpl)->print(dbgs());
    1278             : }
    1279             : #endif

Generated by: LCOV version 1.13