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Diffstat (limited to 'llvm/lib/CodeGen/LiveDebugVariables.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/LiveDebugVariables.cpp | 1422 |
1 files changed, 1422 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/LiveDebugVariables.cpp b/llvm/lib/CodeGen/LiveDebugVariables.cpp new file mode 100644 index 0000000000000..2dd462fc72b3a --- /dev/null +++ b/llvm/lib/CodeGen/LiveDebugVariables.cpp @@ -0,0 +1,1422 @@ +//===- LiveDebugVariables.cpp - Tracking debug info variables -------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// 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. +// +// Allow the data structure to be updated during register allocation when values +// are moved between registers and stack slots. Finally emit new DBG_VALUE +// instructions after register allocation is complete. +// +//===----------------------------------------------------------------------===// + +#include "LiveDebugVariables.h" +#include "llvm/ADT/ArrayRef.h" +#include "llvm/ADT/DenseMap.h" +#include "llvm/ADT/IntervalMap.h" +#include "llvm/ADT/MapVector.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> +EnableLDV("live-debug-variables", cl::init(true), + cl::desc("Enable the live debug variables pass"), cl::Hidden); + +STATISTIC(NumInsertedDebugValues, "Number of DBG_VALUEs inserted"); +STATISTIC(NumInsertedDebugLabels, "Number of DBG_LABELs inserted"); + +char LiveDebugVariables::ID = 0; + +INITIALIZE_PASS_BEGIN(LiveDebugVariables, DEBUG_TYPE, + "Debug Variable Analysis", false, false) +INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree) +INITIALIZE_PASS_DEPENDENCY(LiveIntervals) +INITIALIZE_PASS_END(LiveDebugVariables, DEBUG_TYPE, + "Debug Variable Analysis", false, false) + +void LiveDebugVariables::getAnalysisUsage(AnalysisUsage &AU) const { + AU.addRequired<MachineDominatorTree>(); + AU.addRequiredTransitive<LiveIntervals>(); + AU.setPreservesAll(); + 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) + : LocNo(LocNo) { + static_assert(sizeof(*this) == sizeof(unsigned), "bad bitfield packing"); + assert(locNo() == LocNo && "location truncation"); + } + + DbgValueLocation() : LocNo(0) {} + + unsigned locNo() const { + // Fix up the undef location number, which gets truncated. + return LocNo == INT_MAX ? UndefLocNo : LocNo; + } + bool isUndef() const { return locNo() == UndefLocNo; } + + DbgValueLocation changeLocNo(unsigned NewLocNo) const { + return DbgValueLocation(NewLocNo); + } + + friend inline bool operator==(const DbgValueLocation &LHS, + const DbgValueLocation &RHS) { + return LHS.LocNo == RHS.LocNo; + } + + friend inline bool operator!=(const DbgValueLocation &LHS, + const DbgValueLocation &RHS) { + return !(LHS == RHS); + } + +private: + unsigned LocNo; +}; + +/// Map of where a user value is live, and its location. +using LocMap = IntervalMap<SlotIndex, DbgValueLocation, 4>; + +/// Map of stack slot offsets for spilled locations. +/// Non-spilled locations are not added to the map. +using SpillOffsetMap = DenseMap<unsigned, unsigned>; + +namespace { + +class LDVImpl; + +/// A UserValue is uniquely identified by the source variable it refers to +/// (Variable), the expression describing how to get the value (Expression) and +/// the specific usage (InlinedAt). InlinedAt differentiates both between +/// inline and non-inline functions, and multiple inlined instances in the same +/// scope. FIXME: The only part of the Expression which matters for UserValue +/// identification is the fragment part. +class UserValueIdentity { +private: + /// The debug info variable we are part of. + const DILocalVariable *Variable; + /// Any complex address expression. + const DIExpression *Expression; + /// Function usage identification. + const DILocation *InlinedAt; + +public: + UserValueIdentity(const DILocalVariable *Var, const DIExpression *Expr, + const DILocation *IA) + : Variable(Var), Expression(Expr), InlinedAt(IA) {} + + bool match(const DILocalVariable *Var, const DIExpression *Expr, + const DILocation *IA) const { + // FIXME: The fragment should be part of the identity, but not + // other things in the expression like stack values. + return Var == Variable && Expr == Expression && IA == InlinedAt; + } + + bool match(const UserValueIdentity &Other) const { + return match(Other.Variable, Other.Expression, Other.InlinedAt); + } + + unsigned hash_value() const { + return hash_combine(Variable, Expression, InlinedAt); + } +}; + +/// 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. +class UserValue { + const DILocalVariable *Variable; ///< The debug info variable we are part of. + const DIExpression *Expression; ///< Any complex address expression. + DebugLoc dl; ///< The debug location for the variable. This is + ///< used by dwarf writer to find lexical scope. + + /// Numbered locations referenced by locmap. + SmallVector<MachineOperand, 4> locations; + + /// Map of slot indices where this value is live. + LocMap locInts; + + /// 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, + const TargetRegisterInfo &TRI); + + /// 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); + +public: + UserValue(const UserValue &) = delete; + + /// Create a new UserValue. + UserValue(const DILocalVariable *var, const DIExpression *expr, DebugLoc L, + LocMap::Allocator &alloc) + : Variable(var), Expression(expr), dl(std::move(L)), locInts(alloc) {} + + UserValueIdentity getId() { + return UserValueIdentity(Variable, Expression, dl->getInlinedAt()); + } + + /// Return the location number that matches Loc. + /// + /// For undef values we always return location number UndefLocNo without + /// inserting anything in locations. Since locations is a vector and the + /// location number is the position in the vector and UndefLocNo is ~0, + /// we would need a very big vector to put the value at the right position. + unsigned getLocationNo(const MachineOperand &LocMO) { + if (LocMO.isReg()) { + if (LocMO.getReg() == 0) + return UndefLocNo; + // For register locations we dont care about use/def and other flags. + for (unsigned i = 0, e = locations.size(); i != e; ++i) + if (locations[i].isReg() && + locations[i].getReg() == LocMO.getReg() && + locations[i].getSubReg() == LocMO.getSubReg()) + return i; + } else + for (unsigned i = 0, e = locations.size(); i != e; ++i) + if (LocMO.isIdenticalTo(locations[i])) + return i; + locations.push_back(LocMO); + // We are storing a MachineOperand outside a MachineInstr. + locations.back().clearParent(); + // Don't store def operands. + if (locations.back().isReg()) { + if (locations.back().isDef()) + locations.back().setIsDead(false); + locations.back().setIsUse(); + } + return locations.size() - 1; + } + + /// Ensure that all virtual register locations are mapped. + void mapVirtRegs(LDVImpl *LDV); + + /// Add a definition point to this value. + void addDef(SlotIndex Idx, const MachineOperand &LocMO) { + DbgValueLocation Loc(getLocationNo(LocMO)); + // Add a singular (Idx,Idx) -> Loc mapping. + LocMap::iterator I = locInts.find(Idx); + if (!I.valid() || I.start() != Idx) + I.insert(Idx, Idx.getNextSlot(), Loc); + else + // A later DBG_VALUE at the same SlotIndex overrides the old location. + I.setValue(Loc); + } + + /// Extend the current definition as far as possible down. + /// + /// Stop when meeting an existing def or when leaving the live + /// range of VNI. End points where VNI is no longer live are added to Kills. + /// + /// We only propagate DBG_VALUES locally here. LiveDebugValues performs a + /// data-flow analysis to propagate them beyond basic block boundaries. + /// + /// \param Idx Starting point for the definition. + /// \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 [out] 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, + LiveIntervals &LIS); + + /// 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 Kills Points where the range of LocNo could be extended. + /// \param [in,out] NewDefs Append (Idx, LocNo) of inserted defs here. + void addDefsFromCopies( + LiveInterval *LI, unsigned LocNo, + const SmallVectorImpl<SlotIndex> &Kills, + SmallVectorImpl<std::pair<SlotIndex, DbgValueLocation>> &NewDefs, + MachineRegisterInfo &MRI, LiveIntervals &LIS); + + /// Compute the live intervals of all locations after collecting all their + /// def points. + void computeIntervals(MachineRegisterInfo &MRI, const TargetRegisterInfo &TRI, + LiveIntervals &LIS, LexicalScopes &LS); + + /// 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); + + /// 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); + + /// Recreate DBG_VALUE instruction from data structures. + void emitDebugValues(VirtRegMap *VRM, LiveIntervals &LIS, + const TargetInstrInfo &TII, + const TargetRegisterInfo &TRI, + const SpillOffsetMap &SpillOffsets); + + /// Return DebugLoc of this UserValue. + DebugLoc getDebugLoc() { return dl;} + + void print(raw_ostream &, const TargetRegisterInfo *); +}; +} // namespace + +namespace llvm { +template <> struct DenseMapInfo<UserValueIdentity> { + static UserValueIdentity getEmptyKey() { + auto Key = DenseMapInfo<DILocalVariable *>::getEmptyKey(); + return UserValueIdentity(Key, nullptr, nullptr); + } + static UserValueIdentity getTombstoneKey() { + auto Key = DenseMapInfo<DILocalVariable *>::getTombstoneKey(); + return UserValueIdentity(Key, nullptr, nullptr); + } + static unsigned getHashValue(const UserValueIdentity &Val) { + return Val.hash_value(); + } + static bool isEqual(const UserValueIdentity &LHS, + const UserValueIdentity &RHS) { + return LHS.match(RHS); + } +}; +} // namespace llvm + +namespace { +/// A user label is a part of a debug info user label. +class UserLabel { + const DILabel *Label; ///< The debug info label we are part of. + DebugLoc dl; ///< The debug location for the label. This is + ///< used by dwarf writer to find lexical scope. + SlotIndex loc; ///< Slot used by the debug label. + + /// Insert a DBG_LABEL into MBB at Idx. + void insertDebugLabel(MachineBasicBlock *MBB, SlotIndex Idx, + LiveIntervals &LIS, const TargetInstrInfo &TII); + +public: + /// Create a new UserLabel. + UserLabel(const DILabel *label, DebugLoc L, SlotIndex Idx) + : Label(label), dl(std::move(L)), loc(Idx) {} + + /// Does this UserLabel match the parameters? + bool match(const DILabel *L, const DILocation *IA, + const SlotIndex Index) const { + return Label == L && dl->getInlinedAt() == IA && loc == Index; + } + + /// Recreate DBG_LABEL instruction from data structures. + void emitDebugLabel(LiveIntervals &LIS, const TargetInstrInfo &TII); + + /// Return DebugLoc of this UserLabel. + DebugLoc getDebugLoc() { return dl; } + + void print(raw_ostream &, const TargetRegisterInfo *); +}; + +/// 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; + + /// All allocated UserValue instances. + SmallVector<std::unique_ptr<UserValue>, 8> userValues; + + /// All allocated UserLabel instances. + SmallVector<std::unique_ptr<UserLabel>, 2> userLabels; + + /// Map virtual register to UserValues which use it. + using VRMap = DenseMap<unsigned, SmallVector<UserValue *, 4>>; + VRMap VirtRegToUserVals; + + /// Map unique UserValue identity to UserValue. + using UVMap = DenseMap<UserValueIdentity, UserValue *>; + UVMap UserVarMap; + + /// Find or create a UserValue. + UserValue *getUserValue(const DILocalVariable *Var, const DIExpression *Expr, + const DebugLoc &DL); + + /// Find the UserValues for VirtReg or null. + SmallVectorImpl<UserValue *> *lookupVirtReg(unsigned VirtReg); + + /// Add DBG_VALUE instruction to our maps. + /// + /// \param MI DBG_VALUE instruction + /// \param Idx Last valid SLotIndex before instruction. + /// + /// \returns True if the DBG_VALUE instruction should be deleted. + bool handleDebugValue(MachineInstr &MI, SlotIndex Idx); + + /// Add DBG_LABEL instruction to UserLabel. + /// + /// \param MI DBG_LABEL instruction + /// \param Idx Last valid SlotIndex before instruction. + /// + /// \returns True if the DBG_LABEL instruction should be deleted. + bool handleDebugLabel(MachineInstr &MI, SlotIndex Idx); + + /// Collect and erase all DBG_VALUE instructions, adding a UserValue def + /// for each instruction. + /// + /// \param mf MachineFunction to be scanned. + /// + /// \returns True if any debug values were found. + bool collectDebugValues(MachineFunction &mf); + + /// 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); + + /// Release all memory. + void clear() { + MF = nullptr; + userValues.clear(); + userLabels.clear(); + VirtRegToUserVals.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; + } + + /// Map virtual register to a UserValue. + void mapVirtReg(unsigned VirtReg, UserValue *UV); + + /// Replace all references to OldReg with NewRegs. + void splitRegister(unsigned OldReg, ArrayRef<unsigned> NewRegs); + + /// 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 DINode *Node, + const DILocation *DL) { + const LLVMContext &Ctx = Node->getContext(); + StringRef Res; + unsigned Line; + if (const auto *V = dyn_cast<const DILocalVariable>(Node)) { + Res = V->getName(); + Line = V->getLine(); + } else if (const auto *L = dyn_cast<const DILabel>(Node)) { + Res = L->getName(); + Line = L->getLine(); + } + + if (!Res.empty()) + OS << Res << "," << Line; + auto *InlinedAt = DL ? DL->getInlinedAt() : nullptr; + if (InlinedAt) { + if (DebugLoc InlinedAtDL = InlinedAt) { + OS << " @["; + printDebugLoc(InlinedAtDL, OS, Ctx); + OS << "]"; + } + } +} + +void UserValue::print(raw_ostream &OS, const TargetRegisterInfo *TRI) { + OS << "!\""; + printExtendedName(OS, Variable, 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(); + } + } + for (unsigned i = 0, e = locations.size(); i != e; ++i) { + OS << " Loc" << i << '='; + locations[i].print(OS, TRI); + } + OS << '\n'; +} + +void UserLabel::print(raw_ostream &OS, const TargetRegisterInfo *TRI) { + OS << "!\""; + printExtendedName(OS, Label, dl); + + OS << "\"\t"; + OS << loc; + OS << '\n'; +} + +void LDVImpl::print(raw_ostream &OS) { + OS << "********** DEBUG VARIABLES **********\n"; + for (auto &userValue : userValues) + userValue->print(OS, TRI); + OS << "********** DEBUG LABELS **********\n"; + for (auto &userLabel : userLabels) + userLabel->print(OS, TRI); +} +#endif + +void UserValue::mapVirtRegs(LDVImpl *LDV) { + for (unsigned i = 0, e = locations.size(); i != e; ++i) + if (locations[i].isReg() && + Register::isVirtualRegister(locations[i].getReg())) + LDV->mapVirtReg(locations[i].getReg(), this); +} + +UserValue *LDVImpl::getUserValue(const DILocalVariable *Var, + const DIExpression *Expr, const DebugLoc &DL) { + auto Ident = UserValueIdentity(Var, Expr, DL->getInlinedAt()); + UserValue *&UVEntry = UserVarMap[Ident]; + + if (UVEntry) + return UVEntry; + + userValues.push_back(std::make_unique<UserValue>(Var, Expr, DL, allocator)); + return UVEntry = userValues.back().get(); +} + +void LDVImpl::mapVirtReg(unsigned VirtReg, UserValue *UV) { + assert(Register::isVirtualRegister(VirtReg) && "Only map VirtRegs"); + assert(UserVarMap.find(UV->getId()) != UserVarMap.end() && + "UserValue should exist in UserVarMap"); + VirtRegToUserVals[VirtReg].push_back(UV); +} + +SmallVectorImpl<UserValue *> *LDVImpl::lookupVirtReg(unsigned VirtReg) { + VRMap::iterator Itr = VirtRegToUserVals.find(VirtReg); + if (Itr != VirtRegToUserVals.end()) + return &Itr->getSecond(); + 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() && + Register::isVirtualRegister(MI.getOperand(0).getReg())) { + const Register 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 + // preceding 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. + assert(!MI.getOperand(1).isImm() && "DBG_VALUE with indirect flag before " + "LiveDebugVariables"); + 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)); + else { + MachineOperand MO = MachineOperand::CreateReg(0U, false); + MO.setIsDebug(); + UV->addDef(Idx, MO); + } + return true; +} + +bool LDVImpl::handleDebugLabel(MachineInstr &MI, SlotIndex Idx) { + // DBG_LABEL label + if (MI.getNumOperands() != 1 || !MI.getOperand(0).isMetadata()) { + LLVM_DEBUG(dbgs() << "Can't handle " << MI); + return false; + } + + // Get or create the UserLabel for label here. + const DILabel *Label = MI.getDebugLabel(); + const DebugLoc &DL = MI.getDebugLoc(); + bool Found = false; + for (auto const &L : userLabels) { + if (L->match(Label, DL->getInlinedAt(), Idx)) { + Found = true; + break; + } + } + if (!Found) + userLabels.push_back(std::make_unique<UserLabel>(Label, DL, Idx)); + + 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->isDebugLabel() && handleDebugLabel(*MBBI, Idx))) { + MBBI = MBB->erase(MBBI); + Changed = true; + } else + ++MBBI; + } while (MBBI != MBBE && MBBI->isDebugInstr()); + } + } + return Changed; +} + +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(); + // 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, + 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 (!Register::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; + Register 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 (!Register::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); + 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 (Register::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(), 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 + 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; + + // 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; + if (auto *UserVals = lookupVirtReg(OldReg)) + for (auto *UV : *UserVals) + DidChange |= UV->splitRegister(OldReg, NewRegs, *LIS); + + if (!DidChange) + return; + + // Map all of the new virtual registers. + if (auto *UserVals = lookupVirtReg(OldReg)) + for (auto *UV : *UserVals) + 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() && + Register::isVirtualRegister(Loc.getReg())) { + Register VirtReg = Loc.getReg(); + if (VRM.isAssignedReg(VirtReg) && + Register::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(); + Register 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; + if (Spilled) + Expr = DIExpression::prepend(Expr, DIExpression::ApplyOffset, SpillOffset); + + assert((!Spilled || MO.isFI()) && "a spilled location must be a frame index"); + + do { + BuildMI(*MBB, I, getDebugLoc(), TII.get(TargetOpcode::DBG_VALUE), + Spilled, 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 UserLabel::insertDebugLabel(MachineBasicBlock *MBB, SlotIndex Idx, + LiveIntervals &LIS, + const TargetInstrInfo &TII) { + MachineBasicBlock::iterator I = findInsertLocation(MBB, Idx, LIS); + ++NumInsertedDebugLabels; + BuildMI(*MBB, I, getDebugLoc(), TII.get(TargetOpcode::DBG_LABEL)) + .addMetadata(Label); +} + +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; + + 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 UserLabel::emitDebugLabel(LiveIntervals &LIS, const TargetInstrInfo &TII) { + LLVM_DEBUG(dbgs() << "\t" << loc); + MachineFunction::iterator MBB = LIS.getMBBFromIndex(loc)->getIterator(); + + LLVM_DEBUG(dbgs() << ' ' << printMBBReference(*MBB)); + insertDebugLabel(&*MBB, loc, LIS, TII); + + LLVM_DEBUG(dbgs() << '\n'); +} + +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 (auto &userValue : userValues) { + LLVM_DEBUG(userValue->print(dbgs(), TRI)); + userValue->rewriteLocations(*VRM, *MF, *TII, *TRI, SpillOffsets); + userValue->emitDebugValues(VRM, *LIS, *TII, *TRI, SpillOffsets); + } + LLVM_DEBUG(dbgs() << "********** EMITTING LIVE DEBUG LABELS **********\n"); + for (auto &userLabel : userLabels) { + LLVM_DEBUG(userLabel->print(dbgs(), TRI)); + userLabel->emitDebugLabel(*LIS, *TII); + } + 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 |