Subversion Repositories QNX 8.QNX8 LLVM/Clang compiler suite

//===- llvm/CodeGen/MachineFunction.h ---------------------------*- C++ -*-===//

//

// 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

//

//===----------------------------------------------------------------------===//

//

// Collect native machine code for a function.  This class contains a list of

// MachineBasicBlock instances that make up the current compiled function.

//

// This class also contains pointers to various classes which hold

// target-specific information about the generated code.

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_CODEGEN_MACHINEFUNCTION_H

#define LLVM_CODEGEN_MACHINEFUNCTION_H

#include "llvm/ADT/ArrayRef.h"

#include "llvm/ADT/BitVector.h"

#include "llvm/ADT/DenseMap.h"

#include "llvm/ADT/GraphTraits.h"

#include "llvm/ADT/SmallVector.h"

#include "llvm/ADT/ilist.h"

#include "llvm/ADT/iterator.h"

#include "llvm/Analysis/EHPersonalities.h"

#include "llvm/CodeGen/MachineBasicBlock.h"

#include "llvm/CodeGen/MachineInstr.h"

#include "llvm/CodeGen/MachineMemOperand.h"

#include "llvm/Support/Allocator.h"

#include "llvm/Support/ArrayRecycler.h"

#include "llvm/Support/AtomicOrdering.h"

#include "llvm/Support/Compiler.h"

#include "llvm/Support/Recycler.h"

#include "llvm/Target/TargetOptions.h"

#include <cassert>

#include <cstdint>

#include <memory>

#include <utility>

#include <vector>

namespace llvm {

class BasicBlock;

class BlockAddress;

class DataLayout;

class DebugLoc;

struct DenormalMode;

class DIExpression;

class DILocalVariable;

class DILocation;

class Function;

class GISelChangeObserver;

class GlobalValue;

class LLVMTargetMachine;

class MachineConstantPool;

class MachineFrameInfo;

class MachineFunction;

class MachineJumpTableInfo;

class MachineModuleInfo;

class MachineRegisterInfo;

class MCContext;

class MCInstrDesc;

class MCSymbol;

class MCSection;

class Pass;

class PseudoSourceValueManager;

class raw_ostream;

class SlotIndexes;

class StringRef;

class TargetRegisterClass;

class TargetSubtargetInfo;

struct WasmEHFuncInfo;

struct WinEHFuncInfo;

template <> struct ilist_alloc_traits<MachineBasicBlock> {

  void deleteNode(MachineBasicBlock *MBB);

};

template <> struct ilist_callback_traits<MachineBasicBlock> {

  void addNodeToList(MachineBasicBlock* N);

  void removeNodeFromList(MachineBasicBlock* N);

  template <class Iterator>

  void transferNodesFromList(ilist_callback_traits &OldList, Iterator, Iterator) {

    assert(this == &OldList && "never transfer MBBs between functions");

  }

};

/// MachineFunctionInfo - This class can be derived from and used by targets to

/// hold private target-specific information for each MachineFunction.  Objects

/// of type are accessed/created with MF::getInfo and destroyed when the

/// MachineFunction is destroyed.

struct MachineFunctionInfo {

  virtual ~MachineFunctionInfo();

  /// Factory function: default behavior is to call new using the

  /// supplied allocator.

  ///

  /// This function can be overridden in a derive class.

  template <typename FuncInfoTy, typename SubtargetTy = TargetSubtargetInfo>

  static FuncInfoTy *create(BumpPtrAllocator &Allocator, const Function &F,

                            const SubtargetTy *STI) {

    return new (Allocator.Allocate<FuncInfoTy>()) FuncInfoTy(F, STI);

  }

  template <typename Ty>

  static Ty *create(BumpPtrAllocator &Allocator, const Ty &MFI) {

    return new (Allocator.Allocate<Ty>()) Ty(MFI);

  }

  /// Make a functionally equivalent copy of this MachineFunctionInfo in \p MF.

  /// This requires remapping MachineBasicBlock references from the original

  /// parent to values in the new function. Targets may assume that virtual

  /// register and frame index values are preserved in the new function.

  virtual MachineFunctionInfo *

  clone(BumpPtrAllocator &Allocator, MachineFunction &DestMF,

        const DenseMap<MachineBasicBlock *, MachineBasicBlock *> &Src2DstMBB)

      const {

    return nullptr;

  }

};

/// Properties which a MachineFunction may have at a given point in time.

/// Each of these has checking code in the MachineVerifier, and passes can

/// require that a property be set.

class MachineFunctionProperties {

  // Possible TODO: Allow targets to extend this (perhaps by allowing the

  // constructor to specify the size of the bit vector)

  // Possible TODO: Allow requiring the negative (e.g. VRegsAllocated could be

  // stated as the negative of "has vregs"

public:

  // The properties are stated in "positive" form; i.e. a pass could require

  // that the property hold, but not that it does not hold.

  // Property descriptions:

  // IsSSA: True when the machine function is in SSA form and virtual registers

  //  have a single def.

  // NoPHIs: The machine function does not contain any PHI instruction.

  // TracksLiveness: True when tracking register liveness accurately.

  //  While this property is set, register liveness information in basic block

  //  live-in lists and machine instruction operands (e.g. implicit defs) is

  //  accurate, kill flags are conservatively accurate (kill flag correctly

  //  indicates the last use of a register, an operand without kill flag may or

  //  may not be the last use of a register). This means it can be used to

  //  change the code in ways that affect the values in registers, for example

  //  by the register scavenger.

  //  When this property is cleared at a very late time, liveness is no longer

  //  reliable.

  // NoVRegs: The machine function does not use any virtual registers.

  // Legalized: In GlobalISel: the MachineLegalizer ran and all pre-isel generic

  //  instructions have been legalized; i.e., all instructions are now one of:

  //   - generic and always legal (e.g., COPY)

  //   - target-specific

  //   - legal pre-isel generic instructions.

  // RegBankSelected: In GlobalISel: the RegBankSelect pass ran and all generic

  //  virtual registers have been assigned to a register bank.

  // Selected: In GlobalISel: the InstructionSelect pass ran and all pre-isel

  //  generic instructions have been eliminated; i.e., all instructions are now

  //  target-specific or non-pre-isel generic instructions (e.g., COPY).

  //  Since only pre-isel generic instructions can have generic virtual register

  //  operands, this also means that all generic virtual registers have been

  //  constrained to virtual registers (assigned to register classes) and that

  //  all sizes attached to them have been eliminated.

  // TiedOpsRewritten: The twoaddressinstruction pass will set this flag, it

  //  means that tied-def have been rewritten to meet the RegConstraint.

  // FailsVerification: Means that the function is not expected to pass machine

  //  verification. This can be set by passes that introduce known problems that

  //  have not been fixed yet.

  // TracksDebugUserValues: Without this property enabled, debug instructions

  // such as DBG_VALUE are allowed to reference virtual registers even if those

  // registers do not have a definition. With the property enabled virtual

  // registers must only be used if they have a definition. This property

  // allows earlier passes in the pipeline to skip updates of `DBG_VALUE`

  // instructions to save compile time.

  enum class Property : unsigned {

    IsSSA,

    NoPHIs,

    TracksLiveness,

    NoVRegs,

    FailedISel,

    Legalized,

    RegBankSelected,

    Selected,

    TiedOpsRewritten,

    FailsVerification,

    TracksDebugUserValues,

    LastProperty = TracksDebugUserValues,

  };

  bool hasProperty(Property P) const {

    return Properties[static_cast<unsigned>(P)];

  }

  MachineFunctionProperties &set(Property P) {

    Properties.set(static_cast<unsigned>(P));

    return *this;

  }

  MachineFunctionProperties &reset(Property P) {

    Properties.reset(static_cast<unsigned>(P));

    return *this;

  }

  /// Reset all the properties.

  MachineFunctionProperties &reset() {

    Properties.reset();

    return *this;

  }

  MachineFunctionProperties &set(const MachineFunctionProperties &MFP) {

    Properties |= MFP.Properties;

    return *this;

  }

  MachineFunctionProperties &reset(const MachineFunctionProperties &MFP) {

    Properties.reset(MFP.Properties);

    return *this;

  }

  // Returns true if all properties set in V (i.e. required by a pass) are set

  // in this.

  bool verifyRequiredProperties(const MachineFunctionProperties &V) const {

    return !V.Properties.test(Properties);

  }

  /// Print the MachineFunctionProperties in human-readable form.

  void print(raw_ostream &OS) const;

private:

  BitVector Properties =

      BitVector(static_cast<unsigned>(Property::LastProperty)+1);

};

struct SEHHandler {

  /// Filter or finally function. Null indicates a catch-all.

  const Function *FilterOrFinally;

  /// Address of block to recover at. Null for a finally handler.

  const BlockAddress *RecoverBA;

};

/// This structure is used to retain landing pad info for the current function.

struct LandingPadInfo {

  MachineBasicBlock *LandingPadBlock;      // Landing pad block.

  SmallVector<MCSymbol *, 1> BeginLabels;  // Labels prior to invoke.

  SmallVector<MCSymbol *, 1> EndLabels;    // Labels after invoke.

  SmallVector<SEHHandler, 1> SEHHandlers;  // SEH handlers active at this lpad.

  MCSymbol *LandingPadLabel = nullptr;     // Label at beginning of landing pad.

  std::vector<int> TypeIds;                // List of type ids (filters negative).

  explicit LandingPadInfo(MachineBasicBlock *MBB)

      : LandingPadBlock(MBB) {}

};

class LLVM_EXTERNAL_VISIBILITY MachineFunction {

  Function &F;

  const LLVMTargetMachine &Target;

  const TargetSubtargetInfo *STI;

  MCContext &Ctx;

  MachineModuleInfo &MMI;

  // RegInfo - Information about each register in use in the function.

  MachineRegisterInfo *RegInfo;

  // Used to keep track of target-specific per-machine function information for

  // the target implementation.

  MachineFunctionInfo *MFInfo;

  // Keep track of objects allocated on the stack.

  MachineFrameInfo *FrameInfo;

  // Keep track of constants which are spilled to memory

  MachineConstantPool *ConstantPool;

  // Keep track of jump tables for switch instructions

  MachineJumpTableInfo *JumpTableInfo;

  // Keep track of the function section.

  MCSection *Section = nullptr;

  // Catchpad unwind destination info for wasm EH.

  // Keeps track of Wasm exception handling related data. This will be null for

  // functions that aren't using a wasm EH personality.

  WasmEHFuncInfo *WasmEHInfo = nullptr;

  // Keeps track of Windows exception handling related data. This will be null

  // for functions that aren't using a funclet-based EH personality.

  WinEHFuncInfo *WinEHInfo = nullptr;

  // Function-level unique numbering for MachineBasicBlocks.  When a

  // MachineBasicBlock is inserted into a MachineFunction is it automatically

  // numbered and this vector keeps track of the mapping from ID's to MBB's.

  std::vector<MachineBasicBlock*> MBBNumbering;

  // Pool-allocate MachineFunction-lifetime and IR objects.

  BumpPtrAllocator Allocator;

  // Allocation management for instructions in function.

  Recycler<MachineInstr> InstructionRecycler;

  // Allocation management for operand arrays on instructions.

  ArrayRecycler<MachineOperand> OperandRecycler;

  // Allocation management for basic blocks in function.

  Recycler<MachineBasicBlock> BasicBlockRecycler;

  // List of machine basic blocks in function

  using BasicBlockListType = ilist<MachineBasicBlock>;

  BasicBlockListType BasicBlocks;

  /// FunctionNumber - This provides a unique ID for each function emitted in

  /// this translation unit.

  ///

  unsigned FunctionNumber;

  /// Alignment - The alignment of the function.

  Align Alignment;

  /// ExposesReturnsTwice - True if the function calls setjmp or related

  /// functions with attribute "returns twice", but doesn't have

  /// the attribute itself.

  /// This is used to limit optimizations which cannot reason

  /// about the control flow of such functions.

  bool ExposesReturnsTwice = false;

  /// True if the function includes any inline assembly.

  bool HasInlineAsm = false;

  /// True if any WinCFI instruction have been emitted in this function.

  bool HasWinCFI = false;

  /// Current high-level properties of the IR of the function (e.g. is in SSA

  /// form or whether registers have been allocated)

  MachineFunctionProperties Properties;

  // Allocation management for pseudo source values.

  std::unique_ptr<PseudoSourceValueManager> PSVManager;

  /// List of moves done by a function's prolog.  Used to construct frame maps

  /// by debug and exception handling consumers.

  std::vector<MCCFIInstruction> FrameInstructions;

  /// List of basic blocks immediately following calls to _setjmp. Used to

  /// construct a table of valid longjmp targets for Windows Control Flow Guard.

  std::vector<MCSymbol *> LongjmpTargets;

  /// List of basic blocks that are the target of catchrets. Used to construct

  /// a table of valid targets for Windows EHCont Guard.

  std::vector<MCSymbol *> CatchretTargets;

  /// \name Exception Handling

  /// \{

  /// List of LandingPadInfo describing the landing pad information.

  std::vector<LandingPadInfo> LandingPads;

  /// Map a landing pad's EH symbol to the call site indexes.

  DenseMap<MCSymbol*, SmallVector<unsigned, 4>> LPadToCallSiteMap;

  /// Map a landing pad to its index.

  DenseMap<const MachineBasicBlock *, unsigned> WasmLPadToIndexMap;

  /// Map of invoke call site index values to associated begin EH_LABEL.

  DenseMap<MCSymbol*, unsigned> CallSiteMap;

  /// CodeView label annotations.

  std::vector<std::pair<MCSymbol *, MDNode *>> CodeViewAnnotations;

  bool CallsEHReturn = false;

  bool CallsUnwindInit = false;

  bool HasEHCatchret = false;

  bool HasEHScopes = false;

  bool HasEHFunclets = false;

  /// BBID to assign to the next basic block of this function.

  unsigned NextBBID = 0;

  /// Section Type for basic blocks, only relevant with basic block sections.

  BasicBlockSection BBSectionsType = BasicBlockSection::None;

  /// List of C++ TypeInfo used.

  std::vector<const GlobalValue *> TypeInfos;

  /// List of typeids encoding filters used.

  std::vector<unsigned> FilterIds;

  /// List of the indices in FilterIds corresponding to filter terminators.

  std::vector<unsigned> FilterEnds;

  EHPersonality PersonalityTypeCache = EHPersonality::Unknown;

  /// \}

  /// Clear all the members of this MachineFunction, but the ones used

  /// to initialize again the MachineFunction.

  /// More specifically, this deallocates all the dynamically allocated

  /// objects and get rid of all the XXXInfo data structure, but keep

  /// unchanged the references to Fn, Target, MMI, and FunctionNumber.

  void clear();

  /// Allocate and initialize the different members.

  /// In particular, the XXXInfo data structure.

  /// \pre Fn, Target, MMI, and FunctionNumber are properly set.

  void init();

public:

  struct VariableDbgInfo {

    const DILocalVariable *Var;

    const DIExpression *Expr;

    // The Slot can be negative for fixed stack objects.

    int Slot;

    const DILocation *Loc;

    VariableDbgInfo(const DILocalVariable *Var, const DIExpression *Expr,

                    int Slot, const DILocation *Loc)

        : Var(Var), Expr(Expr), Slot(Slot), Loc(Loc) {}

  };

  class Delegate {

    virtual void anchor();

  public:

    virtual ~Delegate() = default;

    /// Callback after an insertion. This should not modify the MI directly.

    virtual void MF_HandleInsertion(MachineInstr &MI) = 0;

    /// Callback before a removal. This should not modify the MI directly.

    virtual void MF_HandleRemoval(MachineInstr &MI) = 0;

  };

  /// Structure used to represent pair of argument number after call lowering

  /// and register used to transfer that argument.

  /// For now we support only cases when argument is transferred through one

  /// register.

  struct ArgRegPair {

    Register Reg;

    uint16_t ArgNo;

    ArgRegPair(Register R, unsigned Arg) : Reg(R), ArgNo(Arg) {

      assert(Arg < (1 << 16) && "Arg out of range");

    }

  };

  /// Vector of call argument and its forwarding register.

  using CallSiteInfo = SmallVector<ArgRegPair, 1>;

  using CallSiteInfoImpl = SmallVectorImpl<ArgRegPair>;

private:

  Delegate *TheDelegate = nullptr;

  GISelChangeObserver *Observer = nullptr;

  using CallSiteInfoMap = DenseMap<const MachineInstr *, CallSiteInfo>;

  /// Map a call instruction to call site arguments forwarding info.

  CallSiteInfoMap CallSitesInfo;

  /// A helper function that returns call site info for a give call

  /// instruction if debug entry value support is enabled.

  CallSiteInfoMap::iterator getCallSiteInfo(const MachineInstr *MI);

  // Callbacks for insertion and removal.

  void handleInsertion(MachineInstr &MI);

  void handleRemoval(MachineInstr &MI);

  friend struct ilist_traits<MachineInstr>;

public:

  using VariableDbgInfoMapTy = SmallVector<VariableDbgInfo, 4>;

  VariableDbgInfoMapTy VariableDbgInfos;

  /// A count of how many instructions in the function have had numbers

  /// assigned to them. Used for debug value tracking, to determine the

  /// next instruction number.

  unsigned DebugInstrNumberingCount = 0;

  /// Set value of DebugInstrNumberingCount field. Avoid using this unless

  /// you're deserializing this data.

  void setDebugInstrNumberingCount(unsigned Num);

  /// Pair of instruction number and operand number.

  using DebugInstrOperandPair = std::pair<unsigned, unsigned>;

  /// Replacement definition for a debug instruction reference. Made up of a

  /// source instruction / operand pair, destination pair, and a qualifying

  /// subregister indicating what bits in the operand make up the substitution.

  // For example, a debug user

  /// of %1:

  ///    %0:gr32 = someinst, debug-instr-number 1

  ///    %1:gr16 = %0.some_16_bit_subreg, debug-instr-number 2

  /// Would receive the substitution {{2, 0}, {1, 0}, $subreg}, where $subreg is

  /// the subregister number for some_16_bit_subreg.

  class DebugSubstitution {

  public:

    DebugInstrOperandPair Src;  ///< Source instruction / operand pair.

    DebugInstrOperandPair Dest; ///< Replacement instruction / operand pair.

    unsigned Subreg;            ///< Qualifier for which part of Dest is read.

    DebugSubstitution(const DebugInstrOperandPair &Src,

                      const DebugInstrOperandPair &Dest, unsigned Subreg)

        : Src(Src), Dest(Dest), Subreg(Subreg) {}

    /// Order only by source instruction / operand pair: there should never

    /// be duplicate entries for the same source in any collection.

    bool operator<(const DebugSubstitution &Other) const {

      return Src < Other.Src;

    }

  };

  /// Debug value substitutions: a collection of DebugSubstitution objects,

  /// recording changes in where a value is defined. For example, when one

  /// instruction is substituted for another. Keeping a record allows recovery

  /// of variable locations after compilation finishes.

  SmallVector<DebugSubstitution, 8> DebugValueSubstitutions;

  /// Location of a PHI instruction that is also a debug-info variable value,

  /// for the duration of register allocation. Loaded by the PHI-elimination

  /// pass, and emitted as DBG_PHI instructions during VirtRegRewriter, with

  /// maintenance applied by intermediate passes that edit registers (such as

  /// coalescing and the allocator passes).

  class DebugPHIRegallocPos {

  public:

    MachineBasicBlock *MBB; ///< Block where this PHI was originally located.

    Register Reg;           ///< VReg where the control-flow-merge happens.

    unsigned SubReg;        ///< Optional subreg qualifier within Reg.

    DebugPHIRegallocPos(MachineBasicBlock *MBB, Register Reg, unsigned SubReg)

        : MBB(MBB), Reg(Reg), SubReg(SubReg) {}

  };

  /// Map of debug instruction numbers to the position of their PHI instructions

  /// during register allocation. See DebugPHIRegallocPos.

  DenseMap<unsigned, DebugPHIRegallocPos> DebugPHIPositions;

  /// Flag for whether this function contains DBG_VALUEs (false) or

  /// DBG_INSTR_REF (true).

  bool UseDebugInstrRef = false;

  /// Create a substitution between one <instr,operand> value to a different,

  /// new value.

  void makeDebugValueSubstitution(DebugInstrOperandPair, DebugInstrOperandPair,

                                  unsigned SubReg = 0);

  /// Create substitutions for any tracked values in \p Old, to point at

  /// \p New. Needed when we re-create an instruction during optimization,

  /// which has the same signature (i.e., def operands in the same place) but

  /// a modified instruction type, flags, or otherwise. An example: X86 moves

  /// are sometimes transformed into equivalent LEAs.

  /// If the two instructions are not the same opcode, limit which operands to

  /// examine for substitutions to the first N operands by setting

  /// \p MaxOperand.

  void substituteDebugValuesForInst(const MachineInstr &Old, MachineInstr &New,

                                    unsigned MaxOperand = UINT_MAX);

  /// Find the underlying  defining instruction / operand for a COPY instruction

  /// while in SSA form. Copies do not actually define values -- they move them

  /// between registers. Labelling a COPY-like instruction with an instruction

  /// number is to be avoided as it makes value numbers non-unique later in

  /// compilation. This method follows the definition chain for any sequence of

  /// COPY-like instructions to find whatever non-COPY-like instruction defines

  /// the copied value; or for parameters, creates a DBG_PHI on entry.

  /// May insert instructions into the entry block!

  /// \p MI The copy-like instruction to salvage.

  /// \p DbgPHICache A container to cache already-solved COPYs.

  /// \returns An instruction/operand pair identifying the defining value.

  DebugInstrOperandPair

  salvageCopySSA(MachineInstr &MI,

                 DenseMap<Register, DebugInstrOperandPair> &DbgPHICache);

  DebugInstrOperandPair salvageCopySSAImpl(MachineInstr &MI);

  /// Finalise any partially emitted debug instructions. These are DBG_INSTR_REF

  /// instructions where we only knew the vreg of the value they use, not the

  /// instruction that defines that vreg. Once isel finishes, we should have

  /// enough information for every DBG_INSTR_REF to point at an instruction

  /// (or DBG_PHI).

  void finalizeDebugInstrRefs();

  /// Determine whether, in the current machine configuration, we should use

  /// instruction referencing or not.

  bool shouldUseDebugInstrRef() const;

  /// Returns true if the function's variable locations are tracked with

  /// instruction referencing.

  bool useDebugInstrRef() const;

  /// Set whether this function will use instruction referencing or not.

  void setUseDebugInstrRef(bool UseInstrRef);

  /// A reserved operand number representing the instructions memory operand,

  /// for instructions that have a stack spill fused into them.

  const static unsigned int DebugOperandMemNumber;

  MachineFunction(Function &F, const LLVMTargetMachine &Target,

                  const TargetSubtargetInfo &STI, unsigned FunctionNum,

                  MachineModuleInfo &MMI);

  MachineFunction(const MachineFunction &) = delete;

  MachineFunction &operator=(const MachineFunction &) = delete;

  ~MachineFunction();

  /// Reset the instance as if it was just created.

  void reset() {

    clear();

    init();

  }

  /// Reset the currently registered delegate - otherwise assert.

  void resetDelegate(Delegate *delegate) {

    assert(TheDelegate == delegate &&

           "Only the current delegate can perform reset!");

    TheDelegate = nullptr;

  }

  /// Set the delegate. resetDelegate must be called before attempting

  /// to set.

  void setDelegate(Delegate *delegate) {

    assert(delegate && !TheDelegate &&

           "Attempted to set delegate to null, or to change it without "

           "first resetting it!");

    TheDelegate = delegate;

  }

  void setObserver(GISelChangeObserver *O) { Observer = O; }

  GISelChangeObserver *getObserver() const { return Observer; }

  MachineModuleInfo &getMMI() const { return MMI; }

  MCContext &getContext() const { return Ctx; }

  /// Returns the Section this function belongs to.

  MCSection *getSection() const { return Section; }

  /// Indicates the Section this function belongs to.

  void setSection(MCSection *S) { Section = S; }

  PseudoSourceValueManager &getPSVManager() const { return *PSVManager; }

  /// Return the DataLayout attached to the Module associated to this MF.

  const DataLayout &getDataLayout() const;

  /// Return the LLVM function that this machine code represents

  Function &getFunction() { return F; }

  /// Return the LLVM function that this machine code represents

  const Function &getFunction() const { return F; }

  /// getName - Return the name of the corresponding LLVM function.

  StringRef getName() const;

  /// getFunctionNumber - Return a unique ID for the current function.

  unsigned getFunctionNumber() const { return FunctionNumber; }

  /// Returns true if this function has basic block sections enabled.

  bool hasBBSections() const {

    return (BBSectionsType == BasicBlockSection::All ||

            BBSectionsType == BasicBlockSection::List ||

            BBSectionsType == BasicBlockSection::Preset);

  }

  /// Returns true if basic block labels are to be generated for this function.

  bool hasBBLabels() const {

    return BBSectionsType == BasicBlockSection::Labels;

  }

  void setBBSectionsType(BasicBlockSection V) { BBSectionsType = V; }

  /// Assign IsBeginSection IsEndSection fields for basic blocks in this

  /// function.

  void assignBeginEndSections();

  /// getTarget - Return the target machine this machine code is compiled with

  const LLVMTargetMachine &getTarget() const { return Target; }

  /// getSubtarget - Return the subtarget for which this machine code is being

  /// compiled.

  const TargetSubtargetInfo &getSubtarget() const { return *STI; }

  /// getSubtarget - This method returns a pointer to the specified type of

  /// TargetSubtargetInfo.  In debug builds, it verifies that the object being

  /// returned is of the correct type.

  template<typename STC> const STC &getSubtarget() const {

    return *static_cast<const STC *>(STI);

  }

  /// getRegInfo - Return information about the registers currently in use.

  MachineRegisterInfo &getRegInfo() { return *RegInfo; }

  const MachineRegisterInfo &getRegInfo() const { return *RegInfo; }

  /// getFrameInfo - Return the frame info object for the current function.

  /// This object contains information about objects allocated on the stack

  /// frame of the current function in an abstract way.

  MachineFrameInfo &getFrameInfo() { return *FrameInfo; }

  const MachineFrameInfo &getFrameInfo() const { return *FrameInfo; }

  /// getJumpTableInfo - Return the jump table info object for the current

  /// function.  This object contains information about jump tables in the

  /// current function.  If the current function has no jump tables, this will

  /// return null.

  const MachineJumpTableInfo *getJumpTableInfo() const { return JumpTableInfo; }

  MachineJumpTableInfo *getJumpTableInfo() { return JumpTableInfo; }

  /// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it

  /// does already exist, allocate one.

  MachineJumpTableInfo *getOrCreateJumpTableInfo(unsigned JTEntryKind);

  /// getConstantPool - Return the constant pool object for the current

  /// function.

  MachineConstantPool *getConstantPool() { return ConstantPool; }

  const MachineConstantPool *getConstantPool() const { return ConstantPool; }

  /// getWasmEHFuncInfo - Return information about how the current function uses

  /// Wasm exception handling. Returns null for functions that don't use wasm

  /// exception handling.

  const WasmEHFuncInfo *getWasmEHFuncInfo() const { return WasmEHInfo; }

  WasmEHFuncInfo *getWasmEHFuncInfo() { return WasmEHInfo; }

  /// getWinEHFuncInfo - Return information about how the current function uses

  /// Windows exception handling. Returns null for functions that don't use

  /// funclets for exception handling.

  const WinEHFuncInfo *getWinEHFuncInfo() const { return WinEHInfo; }

  WinEHFuncInfo *getWinEHFuncInfo() { return WinEHInfo; }

  /// getAlignment - Return the alignment of the function.

  Align getAlignment() const { return Alignment; }

  /// setAlignment - Set the alignment of the function.

  void setAlignment(Align A) { Alignment = A; }

  /// ensureAlignment - Make sure the function is at least A bytes aligned.

  void ensureAlignment(Align A) {

    if (Alignment < A)

      Alignment = A;

  }

  /// exposesReturnsTwice - Returns true if the function calls setjmp or

  /// any other similar functions with attribute "returns twice" without

  /// having the attribute itself.

  bool exposesReturnsTwice() const {

    return ExposesReturnsTwice;

  }

  /// setCallsSetJmp - Set a flag that indicates if there's a call to

  /// a "returns twice" function.

  void setExposesReturnsTwice(bool B) {

    ExposesReturnsTwice = B;

  }

  /// Returns true if the function contains any inline assembly.

  bool hasInlineAsm() const {

    return HasInlineAsm;

  }

  /// Set a flag that indicates that the function contains inline assembly.

  void setHasInlineAsm(bool B) {

    HasInlineAsm = B;

  }

  bool hasWinCFI() const {

    return HasWinCFI;

  }

  void setHasWinCFI(bool v) { HasWinCFI = v; }

  /// True if this function needs frame moves for debug or exceptions.

  bool needsFrameMoves() const;

  /// Get the function properties

  const MachineFunctionProperties &getProperties() const { return Properties; }

  MachineFunctionProperties &getProperties() { return Properties; }

  /// getInfo - Keep track of various per-function pieces of information for

  /// backends that would like to do so.

  ///

  template<typename Ty>

  Ty *getInfo() {

    return static_cast<Ty*>(MFInfo);

  }

  template<typename Ty>

  const Ty *getInfo() const {

    return static_cast<const Ty *>(MFInfo);

  }

  template <typename Ty> Ty *cloneInfo(const Ty &Old) {

    assert(!MFInfo);

    MFInfo = Ty::template create<Ty>(Allocator, Old);

    return static_cast<Ty *>(MFInfo);

  }

  /// Initialize the target specific MachineFunctionInfo

  void initTargetMachineFunctionInfo(const TargetSubtargetInfo &STI);

  MachineFunctionInfo *cloneInfoFrom(

      const MachineFunction &OrigMF,

      const DenseMap<MachineBasicBlock *, MachineBasicBlock *> &Src2DstMBB) {

    assert(!MFInfo && "new function already has MachineFunctionInfo");

    if (!OrigMF.MFInfo)

      return nullptr;

    return OrigMF.MFInfo->clone(Allocator, *this, Src2DstMBB);

  }

  /// Returns the denormal handling type for the default rounding mode of the

  /// function.

  DenormalMode getDenormalMode(const fltSemantics &FPType) const;

  /// getBlockNumbered - MachineBasicBlocks are automatically numbered when they

  /// are inserted into the machine function.  The block number for a machine

  /// basic block can be found by using the MBB::getNumber method, this method

  /// provides the inverse mapping.

  MachineBasicBlock *getBlockNumbered(unsigned N) const {

    assert(N < MBBNumbering.size() && "Illegal block number");

    assert(MBBNumbering[N] && "Block was removed from the machine function!");

    return MBBNumbering[N];

  }

  /// Should we be emitting segmented stack stuff for the function

  bool shouldSplitStack() const;

  /// getNumBlockIDs - Return the number of MBB ID's allocated.

  unsigned getNumBlockIDs() const { return (unsigned)MBBNumbering.size(); }

  /// RenumberBlocks - This discards all of the MachineBasicBlock numbers and

  /// recomputes them.  This guarantees that the MBB numbers are sequential,

  /// dense, and match the ordering of the blocks within the function.  If a

  /// specific MachineBasicBlock is specified, only that block and those after

  /// it are renumbered.

  void RenumberBlocks(MachineBasicBlock *MBBFrom = nullptr);

  /// print - Print out the MachineFunction in a format suitable for debugging

  /// to the specified stream.

  void print(raw_ostream &OS, const SlotIndexes* = nullptr) const;

  /// viewCFG - This function is meant for use from the debugger.  You can just

  /// say 'call F->viewCFG()' and a ghostview window should pop up from the

  /// program, displaying the CFG of the current function with the code for each

  /// basic block inside.  This depends on there being a 'dot' and 'gv' program

  /// in your path.

  void viewCFG() const;

  /// viewCFGOnly - This function is meant for use from the debugger.  It works

  /// just like viewCFG, but it does not include the contents of basic blocks

  /// into the nodes, just the label.  If you are only interested in the CFG

  /// this can make the graph smaller.

  ///

  void viewCFGOnly() const;

  /// dump - Print the current MachineFunction to cerr, useful for debugger use.

  void dump() const;

  /// Run the current MachineFunction through the machine code verifier, useful

  /// for debugger use.

  /// \returns true if no problems were found.

  bool verify(Pass *p = nullptr, const char *Banner = nullptr,

              bool AbortOnError = true) const;

  // Provide accessors for the MachineBasicBlock list...

  using iterator = BasicBlockListType::iterator;

  using const_iterator = BasicBlockListType::const_iterator;

  using const_reverse_iterator = BasicBlockListType::const_reverse_iterator;

  using reverse_iterator = BasicBlockListType::reverse_iterator;

  /// Support for MachineBasicBlock::getNextNode().

  static BasicBlockListType MachineFunction::*