diff options
| author | orivej <[email protected]> | 2022-02-10 16:45:01 +0300 |
|---|---|---|
| committer | Daniil Cherednik <[email protected]> | 2022-02-10 16:45:01 +0300 |
| commit | 2d37894b1b037cf24231090eda8589bbb44fb6fc (patch) | |
| tree | be835aa92c6248212e705f25388ebafcf84bc7a1 /contrib/libs/llvm12/lib/CodeGen/LiveDebugVariables.cpp | |
| parent | 718c552901d703c502ccbefdfc3c9028d608b947 (diff) | |
Restoring authorship annotation for <[email protected]>. Commit 2 of 2.
Diffstat (limited to 'contrib/libs/llvm12/lib/CodeGen/LiveDebugVariables.cpp')
| -rw-r--r-- | contrib/libs/llvm12/lib/CodeGen/LiveDebugVariables.cpp | 2886 |
1 files changed, 1443 insertions, 1443 deletions
diff --git a/contrib/libs/llvm12/lib/CodeGen/LiveDebugVariables.cpp b/contrib/libs/llvm12/lib/CodeGen/LiveDebugVariables.cpp index 8223b4e71fe..2325341070a 100644 --- a/contrib/libs/llvm12/lib/CodeGen/LiveDebugVariables.cpp +++ b/contrib/libs/llvm12/lib/CodeGen/LiveDebugVariables.cpp @@ -1,441 +1,441 @@ -//===- 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/InitializePasses.h" -#include "llvm/MC/MCRegisterInfo.h" -#include "llvm/Pass.h" -#include "llvm/Support/Casting.h" -#include "llvm/Support/CommandLine.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 }; - +//===- 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/InitializePasses.h" +#include "llvm/MC/MCRegisterInfo.h" +#include "llvm/Pass.h" +#include "llvm/Support/Casting.h" +#include "llvm/Support/CommandLine.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 }; + namespace { -/// Describes a debug variable value by location number and expression along -/// with some flags about the original usage of the location. -class DbgVariableValue { -public: - DbgVariableValue(unsigned LocNo, bool WasIndirect, - const DIExpression &Expression) - : LocNo(LocNo), WasIndirect(WasIndirect), Expression(&Expression) { - assert(getLocNo() == LocNo && "location truncation"); - } - - DbgVariableValue() : LocNo(0), WasIndirect(0) {} - - const DIExpression *getExpression() const { return Expression; } - unsigned getLocNo() const { - // Fix up the undef location number, which gets truncated. - return LocNo == INT_MAX ? UndefLocNo : LocNo; - } - bool getWasIndirect() const { return WasIndirect; } - bool isUndef() const { return getLocNo() == UndefLocNo; } - - DbgVariableValue changeLocNo(unsigned NewLocNo) const { - return DbgVariableValue(NewLocNo, WasIndirect, *Expression); - } - - friend inline bool operator==(const DbgVariableValue &LHS, - const DbgVariableValue &RHS) { - return LHS.LocNo == RHS.LocNo && LHS.WasIndirect == RHS.WasIndirect && - LHS.Expression == RHS.Expression; - } - - friend inline bool operator!=(const DbgVariableValue &LHS, - const DbgVariableValue &RHS) { - return !(LHS == RHS); - } - -private: - unsigned LocNo : 31; - unsigned WasIndirect : 1; - const DIExpression *Expression = nullptr; -}; +/// Describes a debug variable value by location number and expression along +/// with some flags about the original usage of the location. +class DbgVariableValue { +public: + DbgVariableValue(unsigned LocNo, bool WasIndirect, + const DIExpression &Expression) + : LocNo(LocNo), WasIndirect(WasIndirect), Expression(&Expression) { + assert(getLocNo() == LocNo && "location truncation"); + } + + DbgVariableValue() : LocNo(0), WasIndirect(0) {} + + const DIExpression *getExpression() const { return Expression; } + unsigned getLocNo() const { + // Fix up the undef location number, which gets truncated. + return LocNo == INT_MAX ? UndefLocNo : LocNo; + } + bool getWasIndirect() const { return WasIndirect; } + bool isUndef() const { return getLocNo() == UndefLocNo; } + + DbgVariableValue changeLocNo(unsigned NewLocNo) const { + return DbgVariableValue(NewLocNo, WasIndirect, *Expression); + } + + friend inline bool operator==(const DbgVariableValue &LHS, + const DbgVariableValue &RHS) { + return LHS.LocNo == RHS.LocNo && LHS.WasIndirect == RHS.WasIndirect && + LHS.Expression == RHS.Expression; + } + + friend inline bool operator!=(const DbgVariableValue &LHS, + const DbgVariableValue &RHS) { + return !(LHS == RHS); + } + +private: + unsigned LocNo : 31; + unsigned WasIndirect : 1; + const DIExpression *Expression = nullptr; +}; } // namespace - -/// Map of where a user value is live to that value. -using LocMap = IntervalMap<SlotIndex, DbgVariableValue, 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 user value is a part of a debug info user variable. -/// -/// A DBG_VALUE instruction notes that (a sub-register of) a virtual register -/// holds part of a user variable. The part is identified by a byte offset. -/// -/// UserValues are grouped into equivalence classes for easier searching. Two -/// user values are related if they are held by the same virtual register. The -/// equivalence class is the transitive closure of that relation. -class UserValue { - const DILocalVariable *Variable; ///< The debug info variable we are part of. - /// The part of the variable we describe. - const Optional<DIExpression::FragmentInfo> Fragment; - DebugLoc dl; ///< The debug location for the variable. This is - ///< used by dwarf writer to find lexical scope. - UserValue *leader; ///< Equivalence class leader. - UserValue *next = nullptr; ///< Next value in equivalence class, or null. - - /// Numbered locations referenced by locmap. - SmallVector<MachineOperand, 4> locations; - - /// Map of slot indices where this value is live. - LocMap locInts; - - /// Set of interval start indexes that have been trimmed to the - /// lexical scope. - SmallSet<SlotIndex, 2> trimmedDefs; - - /// Insert a DBG_VALUE into MBB at Idx for DbgValue. - void insertDebugValue(MachineBasicBlock *MBB, SlotIndex StartIdx, - SlotIndex StopIdx, DbgVariableValue DbgValue, - 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<Register> NewRegs, - LiveIntervals &LIS); - -public: - /// Create a new UserValue. - UserValue(const DILocalVariable *var, - Optional<DIExpression::FragmentInfo> Fragment, DebugLoc L, - LocMap::Allocator &alloc) - : Variable(var), Fragment(Fragment), dl(std::move(L)), leader(this), - locInts(alloc) {} - - /// Get the leader of this value's equivalence class. - UserValue *getLeader() { - UserValue *l = leader; - while (l != l->leader) - l = l->leader; - return leader = l; - } - - /// Return the next UserValue in the equivalence class. - UserValue *getNext() const { return next; } - - /// Merge equivalence classes. - static UserValue *merge(UserValue *L1, UserValue *L2) { - L2 = L2->getLeader(); - if (!L1) - return L2; - L1 = L1->getLeader(); - if (L1 == L2) - return L1; - // Splice L2 before L1's members. - UserValue *End = L2; - while (End->next) { - End->leader = L1; - End = End->next; - } - End->leader = L1; - End->next = L1->next; - L1->next = L2; - return L1; - } - - /// 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; - } - - /// Remove (recycle) a location number. If \p LocNo still is used by the - /// locInts nothing is done. - void removeLocationIfUnused(unsigned LocNo) { - // Bail out if LocNo still is used. - for (LocMap::const_iterator I = locInts.begin(); I.valid(); ++I) { - DbgVariableValue DbgValue = I.value(); - if (DbgValue.getLocNo() == LocNo) - return; - } - // Remove the entry in the locations vector, and adjust all references to - // location numbers above the removed entry. - locations.erase(locations.begin() + LocNo); - for (LocMap::iterator I = locInts.begin(); I.valid(); ++I) { - DbgVariableValue DbgValue = I.value(); - if (!DbgValue.isUndef() && DbgValue.getLocNo() > LocNo) - I.setValueUnchecked(DbgValue.changeLocNo(DbgValue.getLocNo() - 1)); - } - } - - /// Ensure that all virtual register locations are mapped. - void mapVirtRegs(LDVImpl *LDV); - - /// Add a definition point to this user value. - void addDef(SlotIndex Idx, const MachineOperand &LocMO, bool IsIndirect, - const DIExpression &Expr) { - DbgVariableValue DbgValue(getLocationNo(LocMO), IsIndirect, Expr); - // Add a singular (Idx,Idx) -> value mapping. - LocMap::iterator I = locInts.find(Idx); - if (!I.valid() || I.start() != Idx) - I.insert(Idx, Idx.getNextSlot(), DbgValue); - else - // A later DBG_VALUE at the same SlotIndex overrides the old location. - I.setValue(DbgValue); - } - - /// 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 DbgValue value 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, DbgVariableValue DbgValue, LiveRange *LR, - const VNInfo *VNI, SmallVectorImpl<SlotIndex> *Kills, - LiveIntervals &LIS); - - /// The value in LI 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 DbgValue Location number of LI->reg, and DIExpression. - /// \param Kills Points where the range of DbgValue could be extended. - /// \param [in,out] NewDefs Append (Idx, DbgValue) of inserted defs here. - void addDefsFromCopies( - LiveInterval *LI, DbgVariableValue DbgValue, - const SmallVectorImpl<SlotIndex> &Kills, - SmallVectorImpl<std::pair<SlotIndex, DbgVariableValue>> &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(Register OldReg, ArrayRef<Register> 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 *); -}; - -/// 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 matches(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; - + +/// Map of where a user value is live to that value. +using LocMap = IntervalMap<SlotIndex, DbgVariableValue, 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 user value is a part of a debug info user variable. +/// +/// A DBG_VALUE instruction notes that (a sub-register of) a virtual register +/// holds part of a user variable. The part is identified by a byte offset. +/// +/// UserValues are grouped into equivalence classes for easier searching. Two +/// user values are related if they are held by the same virtual register. The +/// equivalence class is the transitive closure of that relation. +class UserValue { + const DILocalVariable *Variable; ///< The debug info variable we are part of. + /// The part of the variable we describe. + const Optional<DIExpression::FragmentInfo> Fragment; + DebugLoc dl; ///< The debug location for the variable. This is + ///< used by dwarf writer to find lexical scope. + UserValue *leader; ///< Equivalence class leader. + UserValue *next = nullptr; ///< Next value in equivalence class, or null. + + /// Numbered locations referenced by locmap. + SmallVector<MachineOperand, 4> locations; + + /// Map of slot indices where this value is live. + LocMap locInts; + + /// Set of interval start indexes that have been trimmed to the + /// lexical scope. + SmallSet<SlotIndex, 2> trimmedDefs; + + /// Insert a DBG_VALUE into MBB at Idx for DbgValue. + void insertDebugValue(MachineBasicBlock *MBB, SlotIndex StartIdx, + SlotIndex StopIdx, DbgVariableValue DbgValue, + 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<Register> NewRegs, + LiveIntervals &LIS); + +public: + /// Create a new UserValue. + UserValue(const DILocalVariable *var, + Optional<DIExpression::FragmentInfo> Fragment, DebugLoc L, + LocMap::Allocator &alloc) + : Variable(var), Fragment(Fragment), dl(std::move(L)), leader(this), + locInts(alloc) {} + + /// Get the leader of this value's equivalence class. + UserValue *getLeader() { + UserValue *l = leader; + while (l != l->leader) + l = l->leader; + return leader = l; + } + + /// Return the next UserValue in the equivalence class. + UserValue *getNext() const { return next; } + + /// Merge equivalence classes. + static UserValue *merge(UserValue *L1, UserValue *L2) { + L2 = L2->getLeader(); + if (!L1) + return L2; + L1 = L1->getLeader(); + if (L1 == L2) + return L1; + // Splice L2 before L1's members. + UserValue *End = L2; + while (End->next) { + End->leader = L1; + End = End->next; + } + End->leader = L1; + End->next = L1->next; + L1->next = L2; + return L1; + } + + /// 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; + } + + /// Remove (recycle) a location number. If \p LocNo still is used by the + /// locInts nothing is done. + void removeLocationIfUnused(unsigned LocNo) { + // Bail out if LocNo still is used. + for (LocMap::const_iterator I = locInts.begin(); I.valid(); ++I) { + DbgVariableValue DbgValue = I.value(); + if (DbgValue.getLocNo() == LocNo) + return; + } + // Remove the entry in the locations vector, and adjust all references to + // location numbers above the removed entry. + locations.erase(locations.begin() + LocNo); + for (LocMap::iterator I = locInts.begin(); I.valid(); ++I) { + DbgVariableValue DbgValue = I.value(); + if (!DbgValue.isUndef() && DbgValue.getLocNo() > LocNo) + I.setValueUnchecked(DbgValue.changeLocNo(DbgValue.getLocNo() - 1)); + } + } + + /// Ensure that all virtual register locations are mapped. + void mapVirtRegs(LDVImpl *LDV); + + /// Add a definition point to this user value. + void addDef(SlotIndex Idx, const MachineOperand &LocMO, bool IsIndirect, + const DIExpression &Expr) { + DbgVariableValue DbgValue(getLocationNo(LocMO), IsIndirect, Expr); + // Add a singular (Idx,Idx) -> value mapping. + LocMap::iterator I = locInts.find(Idx); + if (!I.valid() || I.start() != Idx) + I.insert(Idx, Idx.getNextSlot(), DbgValue); + else + // A later DBG_VALUE at the same SlotIndex overrides the old location. + I.setValue(DbgValue); + } + + /// 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 DbgValue value 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, DbgVariableValue DbgValue, LiveRange *LR, + const VNInfo *VNI, SmallVectorImpl<SlotIndex> *Kills, + LiveIntervals &LIS); + + /// The value in LI 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 DbgValue Location number of LI->reg, and DIExpression. + /// \param Kills Points where the range of DbgValue could be extended. + /// \param [in,out] NewDefs Append (Idx, DbgValue) of inserted defs here. + void addDefsFromCopies( + LiveInterval *LI, DbgVariableValue DbgValue, + const SmallVectorImpl<SlotIndex> &Kills, + SmallVectorImpl<std::pair<SlotIndex, DbgVariableValue>> &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(Register OldReg, ArrayRef<Register> 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 *); +}; + +/// 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 matches(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; + using StashedInstrRef = std::tuple<unsigned, unsigned, const DILocalVariable *, const DIExpression *, DebugLoc>; std::map<SlotIndex, std::vector<StashedInstrRef>> StashedInstrReferences; - /// 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 eq class leader. - using VRMap = DenseMap<unsigned, UserValue *>; - VRMap virtRegToEqClass; - - /// Map to find existing UserValue instances. - using UVMap = DenseMap<DebugVariable, UserValue *>; - UVMap userVarMap; - - /// Find or create a UserValue. - UserValue *getUserValue(const DILocalVariable *Var, - Optional<DIExpression::FragmentInfo> Fragment, - const DebugLoc &DL); - - /// Find the EC leader for VirtReg or null. - UserValue *lookupVirtReg(Register 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); - + /// 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 eq class leader. + using VRMap = DenseMap<unsigned, UserValue *>; + VRMap virtRegToEqClass; + + /// Map to find existing UserValue instances. + using UVMap = DenseMap<DebugVariable, UserValue *>; + UVMap userVarMap; + + /// Find or create a UserValue. + UserValue *getUserValue(const DILocalVariable *Var, + Optional<DIExpression::FragmentInfo> Fragment, + const DebugLoc &DL); + + /// Find the EC leader for VirtReg or null. + UserValue *lookupVirtReg(Register 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); + /// Track a DBG_INSTR_REF. This needs to be removed from the MachineFunction /// during regalloc -- but there's no need to maintain live ranges, as we /// refer to a value rather than a location. @@ -446,242 +446,242 @@ class LDVImpl { /// \returns True if the DBG_VALUE instruction should be deleted. bool handleDebugInstrRef(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; + /// 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; StashedInstrReferences.clear(); - userValues.clear(); - userLabels.clear(); - virtRegToEqClass.clear(); - userVarMap.clear(); - // Make sure we call emitDebugValues if the machine function was modified. - assert((!ModifiedMF || EmitDone) && - "Dbg values are not emitted in LDV"); - EmitDone = false; - ModifiedMF = false; - } - - /// Map virtual register to an equivalence class. - void mapVirtReg(Register VirtReg, UserValue *EC); - - /// Replace all references to OldReg with NewRegs. - void splitRegister(Register OldReg, ArrayRef<Register> 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 = 0; - 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().getLocNo(); - if (I.value().getWasIndirect()) - OS << " ind"; - } - } - 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, - Optional<DIExpression::FragmentInfo> Fragment, - const DebugLoc &DL) { - // FIXME: Handle partially overlapping fragments. See - // https://reviews.llvm.org/D70121#1849741. - DebugVariable ID(Var, Fragment, DL->getInlinedAt()); - UserValue *&UV = userVarMap[ID]; - if (!UV) { - userValues.push_back( - std::make_unique<UserValue>(Var, Fragment, DL, allocator)); - UV = userValues.back().get(); - } - return UV; -} - -void LDVImpl::mapVirtReg(Register VirtReg, UserValue *EC) { - assert(Register::isVirtualRegister(VirtReg) && "Only map VirtRegs"); - UserValue *&Leader = virtRegToEqClass[VirtReg]; - Leader = UserValue::merge(Leader, EC); -} - -UserValue *LDVImpl::lookupVirtReg(Register VirtReg) { - if (UserValue *UV = virtRegToEqClass.lookup(VirtReg)) - return UV->getLeader(); - return nullptr; -} - -bool LDVImpl::handleDebugValue(MachineInstr &MI, SlotIndex Idx) { - // DBG_VALUE loc, offset, variable - if (MI.getNumOperands() != 4 || - !(MI.getDebugOffset().isReg() || MI.getDebugOffset().isImm()) || - !MI.getDebugVariableOp().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.getDebugOperand(0).isReg() && - Register::isVirtualRegister(MI.getDebugOperand(0).getReg())) { - const Register Reg = MI.getDebugOperand(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. - bool IsIndirect = MI.isDebugOffsetImm(); - if (IsIndirect) - assert(MI.getDebugOffset().getImm() == 0 && - "DBG_VALUE with nonzero offset"); - const DILocalVariable *Var = MI.getDebugVariable(); - const DIExpression *Expr = MI.getDebugExpression(); - UserValue *UV = getUserValue(Var, Expr->getFragmentInfo(), MI.getDebugLoc()); - if (!Discard) - UV->addDef(Idx, MI.getDebugOperand(0), IsIndirect, *Expr); - else { - MachineOperand MO = MachineOperand::CreateReg(0U, false); - MO.setIsDebug(); - UV->addDef(Idx, MO, false, *Expr); - } - return true; -} - + userValues.clear(); + userLabels.clear(); + virtRegToEqClass.clear(); + userVarMap.clear(); + // Make sure we call emitDebugValues if the machine function was modified. + assert((!ModifiedMF || EmitDone) && + "Dbg values are not emitted in LDV"); + EmitDone = false; + ModifiedMF = false; + } + + /// Map virtual register to an equivalence class. + void mapVirtReg(Register VirtReg, UserValue *EC); + + /// Replace all references to OldReg with NewRegs. + void splitRegister(Register OldReg, ArrayRef<Register> 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 = 0; + 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().getLocNo(); + if (I.value().getWasIndirect()) + OS << " ind"; + } + } + 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, + Optional<DIExpression::FragmentInfo> Fragment, + const DebugLoc &DL) { + // FIXME: Handle partially overlapping fragments. See + // https://reviews.llvm.org/D70121#1849741. + DebugVariable ID(Var, Fragment, DL->getInlinedAt()); + UserValue *&UV = userVarMap[ID]; + if (!UV) { + userValues.push_back( + std::make_unique<UserValue>(Var, Fragment, DL, allocator)); + UV = userValues.back().get(); + } + return UV; +} + +void LDVImpl::mapVirtReg(Register VirtReg, UserValue *EC) { + assert(Register::isVirtualRegister(VirtReg) && "Only map VirtRegs"); + UserValue *&Leader = virtRegToEqClass[VirtReg]; + Leader = UserValue::merge(Leader, EC); +} + +UserValue *LDVImpl::lookupVirtReg(Register VirtReg) { + if (UserValue *UV = virtRegToEqClass.lookup(VirtReg)) + return UV->getLeader(); + return nullptr; +} + +bool LDVImpl::handleDebugValue(MachineInstr &MI, SlotIndex Idx) { + // DBG_VALUE loc, offset, variable + if (MI.getNumOperands() != 4 || + !(MI.getDebugOffset().isReg() || MI.getDebugOffset().isImm()) || + !MI.getDebugVariableOp().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.getDebugOperand(0).isReg() && + Register::isVirtualRegister(MI.getDebugOperand(0).getReg())) { + const Register Reg = MI.getDebugOperand(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. + bool IsIndirect = MI.isDebugOffsetImm(); + if (IsIndirect) + assert(MI.getDebugOffset().getImm() == 0 && + "DBG_VALUE with nonzero offset"); + const DILocalVariable *Var = MI.getDebugVariable(); + const DIExpression *Expr = MI.getDebugExpression(); + UserValue *UV = getUserValue(Var, Expr->getFragmentInfo(), MI.getDebugLoc()); + if (!Discard) + UV->addDef(Idx, MI.getDebugOperand(0), IsIndirect, *Expr); + else { + MachineOperand MO = MachineOperand::CreateReg(0U, false); + MO.setIsDebug(); + UV->addDef(Idx, MO, false, *Expr); + } + return true; +} + bool LDVImpl::handleDebugInstrRef(MachineInstr &MI, SlotIndex Idx) { assert(MI.isDebugRef()); unsigned InstrNum = MI.getOperand(0).getImm(); @@ -695,776 +695,776 @@ bool LDVImpl::handleDebugInstrRef(MachineInstr &MI, SlotIndex Idx) { 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->matches(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)) || +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->matches(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->isDebugRef() && handleDebugInstrRef(*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, DbgVariableValue DbgValue, 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() != DbgValue || 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, DbgValue); -} - -void UserValue::addDefsFromCopies( - LiveInterval *LI, DbgVariableValue DbgValue, - const SmallVectorImpl<SlotIndex> &Kills, - SmallVectorImpl<std::pair<SlotIndex, DbgVariableValue>> &NewDefs, - MachineRegisterInfo &MRI, LiveIntervals &LIS) { - if (Kills.empty()) - return; - // Don't track copies from physregs, there are too many uses. + (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, DbgVariableValue DbgValue, 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() != DbgValue || 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, DbgValue); +} + +void UserValue::addDefsFromCopies( + LiveInterval *LI, DbgVariableValue DbgValue, + const SmallVectorImpl<SlotIndex> &Kills, + SmallVectorImpl<std::pair<SlotIndex, DbgVariableValue>> &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; + 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 the value 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() != DbgValue) - 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)); - DbgVariableValue NewValue = DbgValue.changeLocNo(LocNo); - I.insert(Idx, Idx.getNextSlot(), NewValue); - NewDefs.push_back(std::make_pair(Idx, NewValue)); - break; - } - } -} - -void UserValue::computeIntervals(MachineRegisterInfo &MRI, - const TargetRegisterInfo &TRI, - LiveIntervals &LIS, LexicalScopes &LS) { - SmallVector<std::pair<SlotIndex, DbgVariableValue>, 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; - DbgVariableValue DbgValue = Defs[i].second; - const MachineOperand &LocMO = locations[DbgValue.getLocNo()]; - - if (!LocMO.isReg()) { - extendDef(Idx, DbgValue, 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, DbgValue, 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, DbgValue, 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); - - // Variable locations at the first instruction of a block should be - // based on the block's SlotIndex, not the first instruction's index. - if (Range.first == Range.first->getParent()->begin()) - RStart = LIS.getSlotIndexes()->getIndexBefore(*Range.first); - - // 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(); - DbgVariableValue DbgValue = I.value(); - - // Stop overlaps previous end - trim the end of the interval to - // the scope range. - I.setStopUnchecked(PrevEnd); - ++I; - - // If the interval also overlaps the start of the "next" (i.e. - // current) range create a new interval for the remainder (which - // may be further trimmed). - if (RStart < IStop) - I.insert(RStart, IStop, DbgValue); - } - - // Advance I so that I.stop() >= RStart, and check for overlap. - I.advanceTo(RStart); - if (!I.valid()) - return; - - if (I.start() < RStart) { - // Interval start overlaps range - trim to the scope range. - I.setStartUnchecked(RStart); - // Remember that this interval was trimmed. - trimmedDefs.insert(RStart); - } - - // The end of a lexical scope range is the last instruction in the - // range. To convert to an interval we need the index of the - // instruction after it. - REnd = REnd.getNextIndex(); - - // Advance I to first interval outside current range. - I.advanceTo(REnd); - if (!I.valid()) - return; - - PrevEnd = REnd; - } - - // Check for overlap with end of final range. - if (PrevEnd && I.start() < PrevEnd) - I.setStopUnchecked(PrevEnd); -} - -void LDVImpl::computeIntervals() { - LexicalScopes LS; - LS.initialize(*MF); - - for (unsigned i = 0, e = userValues.size(); i != e; ++i) { - userValues[i]->computeIntervals(MF->getRegInfo(), *TRI, *LIS, LS); - userValues[i]->mapVirtRegs(this); - } -} - -bool LDVImpl::runOnMachineFunction(MachineFunction &mf) { - clear(); - MF = &mf; - LIS = &pass.getAnalysis<LiveIntervals>(); - TRI = mf.getSubtarget().getRegisterInfo(); - LLVM_DEBUG(dbgs() << "********** COMPUTING LIVE DEBUG VARIABLES: " - << mf.getName() << " **********\n"); - - bool Changed = collectDebugValues(mf); - computeIntervals(); - LLVM_DEBUG(print(dbgs())); - ModifiedMF = Changed; - return Changed; -} - + 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 the value 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() != DbgValue) + 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)); + DbgVariableValue NewValue = DbgValue.changeLocNo(LocNo); + I.insert(Idx, Idx.getNextSlot(), NewValue); + NewDefs.push_back(std::make_pair(Idx, NewValue)); + break; + } + } +} + +void UserValue::computeIntervals(MachineRegisterInfo &MRI, + const TargetRegisterInfo &TRI, + LiveIntervals &LIS, LexicalScopes &LS) { + SmallVector<std::pair<SlotIndex, DbgVariableValue>, 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; + DbgVariableValue DbgValue = Defs[i].second; + const MachineOperand &LocMO = locations[DbgValue.getLocNo()]; + + if (!LocMO.isReg()) { + extendDef(Idx, DbgValue, 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, DbgValue, 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, DbgValue, 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); + + // Variable locations at the first instruction of a block should be + // based on the block's SlotIndex, not the first instruction's index. + if (Range.first == Range.first->getParent()->begin()) + RStart = LIS.getSlotIndexes()->getIndexBefore(*Range.first); + + // 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(); + DbgVariableValue DbgValue = I.value(); + + // Stop overlaps previous end - trim the end of the interval to + // the scope range. + I.setStopUnchecked(PrevEnd); + ++I; + + // If the interval also overlaps the start of the "next" (i.e. + // current) range create a new interval for the remainder (which + // may be further trimmed). + if (RStart < IStop) + I.insert(RStart, IStop, DbgValue); + } + + // Advance I so that I.stop() >= RStart, and check for overlap. + I.advanceTo(RStart); + if (!I.valid()) + return; + + if (I.start() < RStart) { + // Interval start overlaps range - trim to the scope range. + I.setStartUnchecked(RStart); + // Remember that this interval was trimmed. + trimmedDefs.insert(RStart); + } + + // The end of a lexical scope range is the last instruction in the + // range. To convert to an interval we need the index of the + // instruction after it. + REnd = REnd.getNextIndex(); + + // Advance I to first interval outside current range. + I.advanceTo(REnd); + if (!I.valid()) + return; + + PrevEnd = REnd; + } + + // Check for overlap with end of final range. + if (PrevEnd && I.start() < PrevEnd) + I.setStopUnchecked(PrevEnd); +} + +void LDVImpl::computeIntervals() { + LexicalScopes LS; + LS.initialize(*MF); + + for (unsigned i = 0, e = userValues.size(); i != e; ++i) { + userValues[i]->computeIntervals(MF->getRegInfo(), *TRI, *LIS, LS); + userValues[i]->mapVirtRegs(this); + } +} + +bool LDVImpl::runOnMachineFunction(MachineFunction &mf) { + clear(); + MF = &mf; + LIS = &pass.getAnalysis<LiveIntervals>(); + TRI = mf.getSubtarget().getRegisterInfo(); + LLVM_DEBUG(dbgs() << "********** COMPUTING LIVE DEBUG VARIABLES: " + << mf.getName() << " **********\n"); + + bool Changed = collectDebugValues(mf); + computeIntervals(); + LLVM_DEBUG(print(dbgs())); + ModifiedMF = Changed; + return Changed; +} + static void removeDebugInstrs(MachineFunction &mf) { - for (MachineBasicBlock &MBB : mf) { - for (auto MBBI = MBB.begin(), MBBE = MBB.end(); MBBI != MBBE; ) { + for (MachineBasicBlock &MBB : mf) { + for (auto MBBI = MBB.begin(), MBBE = MBB.end(); MBBI != MBBE; ) { if (!MBBI->isDebugInstr()) { - ++MBBI; - continue; - } - MBBI = MBB.erase(MBBI); - } - } -} - -bool LiveDebugVariables::runOnMachineFunction(MachineFunction &mf) { - if (!EnableLDV) - return false; - if (!mf.getFunction().getSubprogram()) { + ++MBBI; + continue; + } + MBBI = MBB.erase(MBBI); + } + } +} + +bool LiveDebugVariables::runOnMachineFunction(MachineFunction &mf) { + if (!EnableLDV) + return false; + if (!mf.getFunction().getSubprogram()) { removeDebugInstrs(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<Register> 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().getLocNo() == OldLocNo && - LII->start < LocMapI.stop()) { - // Overlapping correct location. Allocate NewLocNo now. - if (NewLocNo == UndefLocNo) { + 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<Register> 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().getLocNo() == 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(); - DbgVariableValue OldDbgValue = 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(OldDbgValue.changeLocNo(NewLocNo)); - - // Re-insert any removed OldDbgValue ranges. - if (LStart < LocMapI.start()) { - LocMapI.insert(LStart, LocMapI.start(), OldDbgValue); - ++LocMapI; - assert(LocMapI.valid() && "Unexpected coalescing"); - } - if (LStop > LocMapI.stop()) { - ++LocMapI; - LocMapI.insert(LII->end, LStop, OldDbgValue); - --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 OldLocNo unless it is still used by some interval in the - // locInts map. One case when OldLocNo still is in use is when the register - // has been spilled. In such situations the spilled register is kept as a - // location until rewriteLocations is called (VirtRegMap is mapping the old - // register to the spill slot). So for a while we can have locations that map - // to virtual registers that have been removed from both the MachineFunction - // and from LiveIntervals. - // - // We may also just be using the location for a value with a different - // expression. - removeLocationIfUnused(OldLocNo); - - LLVM_DEBUG({ - dbgs() << "Split result: \t"; - print(dbgs(), nullptr); - }); - return DidChange; -} - -bool -UserValue::splitRegister(Register OldReg, ArrayRef<Register> 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(Register OldReg, ArrayRef<Register> NewRegs) { - bool DidChange = false; - for (UserValue *UV = lookupVirtReg(OldReg); UV; UV = UV->getNext()) - DidChange |= UV->splitRegister(OldReg, NewRegs, *LIS); - - if (!DidChange) - return; - - // Map all of the new virtual registers. - UserValue *UV = lookupVirtReg(OldReg); - for (unsigned i = 0; i != NewRegs.size(); ++i) - mapVirtReg(NewRegs[i], UV); -} - -void LiveDebugVariables:: -splitRegister(Register OldReg, ArrayRef<Register> 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) { - DbgVariableValue DbgValue = I.value(); - // Undef values don't exist in locations (and thus not in LocNoMap either) - // so skip over them. See getLocationNo(). - if (DbgValue.isUndef()) - continue; - unsigned NewLocNo = LocNoMap[DbgValue.getLocNo()]; - I.setValueUnchecked(DbgValue.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, DbgVariableValue DbgValue, - 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 = - !DbgValue.isUndef() - ? locations[DbgValue.getLocNo()] - : 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 = DbgValue.getExpression(); - uint8_t DIExprFlags = DIExpression::ApplyOffset; - bool IsIndirect = DbgValue.getWasIndirect(); - if (Spilled) { - if (IsIndirect) - DIExprFlags |= DIExpression::DerefAfter; - Expr = - DIExpression::prepend(Expr, DIExprFlags, SpillOffset); - IsIndirect = true; - } - - assert((!Spilled || MO.isFI()) && "a spilled location must be a frame index"); - - do { - BuildMI(*MBB, I, getDebugLoc(), TII.get(TargetOpcode::DBG_VALUE), - IsIndirect, MO, Variable, Expr); - - // Continue and insert DBG_VALUES after every redefinition of register - // associated with the debug value within the range - I = findNextInsertLocation(MBB, I, StopIdx, MO, LIS, TRI); - } while (I != MBB->end()); -} - -void 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(); - DbgVariableValue DbgValue = I.value(); - auto SpillIt = !DbgValue.isUndef() ? SpillOffsets.find(DbgValue.getLocNo()) - : SpillOffsets.end(); - bool Spilled = SpillIt != SpillOffsets.end(); - unsigned SpillOffset = Spilled ? SpillIt->second : 0; - - // If the interval start was trimmed to the lexical scope insert the - // DBG_VALUE at the previous index (otherwise it appears after the - // first instruction in the range). - if (trimmedDefs.count(Start)) - Start = Start.getPrevIndex(); - - LLVM_DEBUG(dbgs() << "\t[" << Start << ';' << Stop - << "):" << DbgValue.getLocNo()); - MachineFunction::iterator MBB = LIS.getMBBFromIndex(Start)->getIterator(); - SlotIndex MBBEnd = LIS.getMBBEndIdx(&*MBB); - - LLVM_DEBUG(dbgs() << ' ' << printMBBReference(*MBB) << '-' << MBBEnd); - insertDebugValue(&*MBB, Start, Stop, DbgValue, 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, DbgValue, 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); - } + MO.setSubReg(locations[OldLocNo].getSubReg()); + NewLocNo = getLocationNo(MO); + DidChange = true; + } + + SlotIndex LStart = LocMapI.start(); + SlotIndex LStop = LocMapI.stop(); + DbgVariableValue OldDbgValue = 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(OldDbgValue.changeLocNo(NewLocNo)); + + // Re-insert any removed OldDbgValue ranges. + if (LStart < LocMapI.start()) { + LocMapI.insert(LStart, LocMapI.start(), OldDbgValue); + ++LocMapI; + assert(LocMapI.valid() && "Unexpected coalescing"); + } + if (LStop > LocMapI.stop()) { + ++LocMapI; + LocMapI.insert(LII->end, LStop, OldDbgValue); + --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 OldLocNo unless it is still used by some interval in the + // locInts map. One case when OldLocNo still is in use is when the register + // has been spilled. In such situations the spilled register is kept as a + // location until rewriteLocations is called (VirtRegMap is mapping the old + // register to the spill slot). So for a while we can have locations that map + // to virtual registers that have been removed from both the MachineFunction + // and from LiveIntervals. + // + // We may also just be using the location for a value with a different + // expression. + removeLocationIfUnused(OldLocNo); + + LLVM_DEBUG({ + dbgs() << "Split result: \t"; + print(dbgs(), nullptr); + }); + return DidChange; +} + +bool +UserValue::splitRegister(Register OldReg, ArrayRef<Register> 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(Register OldReg, ArrayRef<Register> NewRegs) { + bool DidChange = false; + for (UserValue *UV = lookupVirtReg(OldReg); UV; UV = UV->getNext()) + DidChange |= UV->splitRegister(OldReg, NewRegs, *LIS); + + if (!DidChange) + return; + + // Map all of the new virtual registers. + UserValue *UV = lookupVirtReg(OldReg); + for (unsigned i = 0; i != NewRegs.size(); ++i) + mapVirtReg(NewRegs[i], UV); +} + +void LiveDebugVariables:: +splitRegister(Register OldReg, ArrayRef<Register> 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) { + DbgVariableValue DbgValue = I.value(); + // Undef values don't exist in locations (and thus not in LocNoMap either) + // so skip over them. See getLocationNo(). + if (DbgValue.isUndef()) + continue; + unsigned NewLocNo = LocNoMap[DbgValue.getLocNo()]; + I.setValueUnchecked(DbgValue.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, DbgVariableValue DbgValue, + 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 = + !DbgValue.isUndef() + ? locations[DbgValue.getLocNo()] + : 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 = DbgValue.getExpression(); + uint8_t DIExprFlags = DIExpression::ApplyOffset; + bool IsIndirect = DbgValue.getWasIndirect(); + if (Spilled) { + if (IsIndirect) + DIExprFlags |= DIExpression::DerefAfter; + Expr = + DIExpression::prepend(Expr, DIExprFlags, SpillOffset); + IsIndirect = true; + } + + assert((!Spilled || MO.isFI()) && "a spilled location must be a frame index"); + + do { + BuildMI(*MBB, I, getDebugLoc(), TII.get(TargetOpcode::DBG_VALUE), + IsIndirect, MO, Variable, Expr); + + // Continue and insert DBG_VALUES after every redefinition of register + // associated with the debug value within the range + I = findNextInsertLocation(MBB, I, StopIdx, MO, LIS, TRI); + } while (I != MBB->end()); +} + +void 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(); + DbgVariableValue DbgValue = I.value(); + auto SpillIt = !DbgValue.isUndef() ? SpillOffsets.find(DbgValue.getLocNo()) + : SpillOffsets.end(); + bool Spilled = SpillIt != SpillOffsets.end(); + unsigned SpillOffset = Spilled ? SpillIt->second : 0; + + // If the interval start was trimmed to the lexical scope insert the + // DBG_VALUE at the previous index (otherwise it appears after the + // first instruction in the range). + if (trimmedDefs.count(Start)) + Start = Start.getPrevIndex(); + + LLVM_DEBUG(dbgs() << "\t[" << Start << ';' << Stop + << "):" << DbgValue.getLocNo()); + MachineFunction::iterator MBB = LIS.getMBBFromIndex(Start)->getIterator(); + SlotIndex MBBEnd = LIS.getMBBEndIdx(&*MBB); + + LLVM_DEBUG(dbgs() << ' ' << printMBBReference(*MBB) << '-' << MBBEnd); + insertDebugValue(&*MBB, Start, Stop, DbgValue, 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, DbgValue, 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); + } LLVM_DEBUG(dbgs() << "********** EMITTING INSTR REFERENCES **********\n"); @@ -1487,17 +1487,17 @@ void LDVImpl::emitDebugValues(VirtRegMap *VRM) { } } - EmitDone = true; -} - -void LiveDebugVariables::emitDebugValues(VirtRegMap *VRM) { - if (pImpl) - static_cast<LDVImpl*>(pImpl)->emitDebugValues(VRM); -} - -#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) -LLVM_DUMP_METHOD void LiveDebugVariables::dump() const { - if (pImpl) - static_cast<LDVImpl*>(pImpl)->print(dbgs()); -} -#endif + EmitDone = true; +} + +void LiveDebugVariables::emitDebugValues(VirtRegMap *VRM) { + if (pImpl) + static_cast<LDVImpl*>(pImpl)->emitDebugValues(VRM); +} + +#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) +LLVM_DUMP_METHOD void LiveDebugVariables::dump() const { + if (pImpl) + static_cast<LDVImpl*>(pImpl)->print(dbgs()); +} +#endif |