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+//===- llvm/CodeGen/SelectionDAGNodes.h - SelectionDAG Nodes ----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares the SDNode class and derived classes, which are used to
+// represent the nodes and operations present in a SelectionDAG.  These nodes
+// and operations are machine code level operations, with some similarities to
+// the GCC RTL representation.
+//
+// Clients should include the SelectionDAG.h file instead of this file directly.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_SELECTIONDAGNODES_H
+#define LLVM_CODEGEN_SELECTIONDAGNODES_H
+
+#include "llvm/ADT/APFloat.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/BitVector.h"
+#include "llvm/ADT/FoldingSet.h"
+#include "llvm/ADT/GraphTraits.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/ilist_node.h"
+#include "llvm/ADT/iterator.h"
+#include "llvm/ADT/iterator_range.h"
+#include "llvm/CodeGen/ISDOpcodes.h"
+#include "llvm/CodeGen/MachineMemOperand.h"
+#include "llvm/CodeGen/ValueTypes.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/DebugLoc.h"
+#include "llvm/IR/Instruction.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/Metadata.h"
+#include "llvm/Support/AlignOf.h"
+#include "llvm/Support/AtomicOrdering.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/MachineValueType.h"
+#include <algorithm>
+#include <cassert>
+#include <climits>
+#include <cstddef>
+#include <cstdint>
+#include <cstring>
+#include <iterator>
+#include <string>
+#include <tuple>
+
+namespace llvm {
+
+class APInt;
+class Constant;
+template <typename T> struct DenseMapInfo;
+class GlobalValue;
+class MachineBasicBlock;
+class MachineConstantPoolValue;
+class MCSymbol;
+class raw_ostream;
+class SDNode;
+class SelectionDAG;
+class Type;
+class Value;
+
+void checkForCycles(const SDNode *N, const SelectionDAG *DAG = nullptr,
+                    bool force = false);
+
+/// This represents a list of ValueType's that has been intern'd by
+/// a SelectionDAG.  Instances of this simple value class are returned by
+/// SelectionDAG::getVTList(...).
+///
+struct SDVTList {
+  const EVT *VTs;
+  unsigned int NumVTs;
+};
+
+namespace ISD {
+
+  /// Node predicates
+
+  /// If N is a BUILD_VECTOR node whose elements are all the same constant or
+  /// undefined, return true and return the constant value in \p SplatValue.
+  bool isConstantSplatVector(const SDNode *N, APInt &SplatValue);
+
+  /// Return true if the specified node is a BUILD_VECTOR where all of the
+  /// elements are ~0 or undef.
+  bool isBuildVectorAllOnes(const SDNode *N);
+
+  /// Return true if the specified node is a BUILD_VECTOR where all of the
+  /// elements are 0 or undef.
+  bool isBuildVectorAllZeros(const SDNode *N);
+
+  /// Return true if the specified node is a BUILD_VECTOR node of all
+  /// ConstantSDNode or undef.
+  bool isBuildVectorOfConstantSDNodes(const SDNode *N);
+
+  /// Return true if the specified node is a BUILD_VECTOR node of all
+  /// ConstantFPSDNode or undef.
+  bool isBuildVectorOfConstantFPSDNodes(const SDNode *N);
+
+  /// Return true if the node has at least one operand and all operands of the
+  /// specified node are ISD::UNDEF.
+  bool allOperandsUndef(const SDNode *N);
+
+} // end namespace ISD
+
+//===----------------------------------------------------------------------===//
+/// Unlike LLVM values, Selection DAG nodes may return multiple
+/// values as the result of a computation.  Many nodes return multiple values,
+/// from loads (which define a token and a return value) to ADDC (which returns
+/// a result and a carry value), to calls (which may return an arbitrary number
+/// of values).
+///
+/// As such, each use of a SelectionDAG computation must indicate the node that
+/// computes it as well as which return value to use from that node.  This pair
+/// of information is represented with the SDValue value type.
+///
+class SDValue {
+  friend struct DenseMapInfo<SDValue>;
+
+  SDNode *Node = nullptr; // The node defining the value we are using.
+  unsigned ResNo = 0;     // Which return value of the node we are using.
+
+public:
+  SDValue() = default;
+  SDValue(SDNode *node, unsigned resno);
+
+  /// get the index which selects a specific result in the SDNode
+  unsigned getResNo() const { return ResNo; }
+
+  /// get the SDNode which holds the desired result
+  SDNode *getNode() const { return Node; }
+
+  /// set the SDNode
+  void setNode(SDNode *N) { Node = N; }
+
+  inline SDNode *operator->() const { return Node; }
+
+  bool operator==(const SDValue &O) const {
+    return Node == O.Node && ResNo == O.ResNo;
+  }
+  bool operator!=(const SDValue &O) const {
+    return !operator==(O);
+  }
+  bool operator<(const SDValue &O) const {
+    return std::tie(Node, ResNo) < std::tie(O.Node, O.ResNo);
+  }
+  explicit operator bool() const {
+    return Node != nullptr;
+  }
+
+  SDValue getValue(unsigned R) const {
+    return SDValue(Node, R);
+  }
+
+  /// Return true if this node is an operand of N.
+  bool isOperandOf(const SDNode *N) const;
+
+  /// Return the ValueType of the referenced return value.
+  inline EVT getValueType() const;
+
+  /// Return the simple ValueType of the referenced return value.
+  MVT getSimpleValueType() const {
+    return getValueType().getSimpleVT();
+  }
+
+  /// Returns the size of the value in bits.
+  unsigned getValueSizeInBits() const {
+    return getValueType().getSizeInBits();
+  }
+
+  unsigned getScalarValueSizeInBits() const {
+    return getValueType().getScalarType().getSizeInBits();
+  }
+
+  // Forwarding methods - These forward to the corresponding methods in SDNode.
+  inline unsigned getOpcode() const;
+  inline unsigned getNumOperands() const;
+  inline const SDValue &getOperand(unsigned i) const;
+  inline uint64_t getConstantOperandVal(unsigned i) const;
+  inline bool isTargetMemoryOpcode() const;
+  inline bool isTargetOpcode() const;
+  inline bool isMachineOpcode() const;
+  inline bool isUndef() const;
+  inline unsigned getMachineOpcode() const;
+  inline const DebugLoc &getDebugLoc() const;
+  inline void dump() const;
+  inline void dump(const SelectionDAG *G) const;
+  inline void dumpr() const;
+  inline void dumpr(const SelectionDAG *G) const;
+
+  /// Return true if this operand (which must be a chain) reaches the
+  /// specified operand without crossing any side-effecting instructions.
+  /// In practice, this looks through token factors and non-volatile loads.
+  /// In order to remain efficient, this only
+  /// looks a couple of nodes in, it does not do an exhaustive search.
+  bool reachesChainWithoutSideEffects(SDValue Dest,
+                                      unsigned Depth = 2) const;
+
+  /// Return true if there are no nodes using value ResNo of Node.
+  inline bool use_empty() const;
+
+  /// Return true if there is exactly one node using value ResNo of Node.
+  inline bool hasOneUse() const;
+};
+
+template<> struct DenseMapInfo<SDValue> {
+  static inline SDValue getEmptyKey() {
+    SDValue V;
+    V.ResNo = -1U;
+    return V;
+  }
+
+  static inline SDValue getTombstoneKey() {
+    SDValue V;
+    V.ResNo = -2U;
+    return V;
+  }
+
+  static unsigned getHashValue(const SDValue &Val) {
+    return ((unsigned)((uintptr_t)Val.getNode() >> 4) ^
+            (unsigned)((uintptr_t)Val.getNode() >> 9)) + Val.getResNo();
+  }
+
+  static bool isEqual(const SDValue &LHS, const SDValue &RHS) {
+    return LHS == RHS;
+  }
+};
+template <> struct isPodLike<SDValue> { static const bool value = true; };
+
+/// Allow casting operators to work directly on
+/// SDValues as if they were SDNode*'s.
+template<> struct simplify_type<SDValue> {
+  using SimpleType = SDNode *;
+
+  static SimpleType getSimplifiedValue(SDValue &Val) {
+    return Val.getNode();
+  }
+};
+template<> struct simplify_type<const SDValue> {
+  using SimpleType = /*const*/ SDNode *;
+
+  static SimpleType getSimplifiedValue(const SDValue &Val) {
+    return Val.getNode();
+  }
+};
+
+/// Represents a use of a SDNode. This class holds an SDValue,
+/// which records the SDNode being used and the result number, a
+/// pointer to the SDNode using the value, and Next and Prev pointers,
+/// which link together all the uses of an SDNode.
+///
+class SDUse {
+  /// Val - The value being used.
+  SDValue Val;
+  /// User - The user of this value.
+  SDNode *User = nullptr;
+  /// Prev, Next - Pointers to the uses list of the SDNode referred by
+  /// this operand.
+  SDUse **Prev = nullptr;
+  SDUse *Next = nullptr;
+
+public:
+  SDUse() = default;
+  SDUse(const SDUse &U) = delete;
+  SDUse &operator=(const SDUse &) = delete;
+
+  /// Normally SDUse will just implicitly convert to an SDValue that it holds.
+  operator const SDValue&() const { return Val; }
+
+  /// If implicit conversion to SDValue doesn't work, the get() method returns
+  /// the SDValue.
+  const SDValue &get() const { return Val; }
+
+  /// This returns the SDNode that contains this Use.
+  SDNode *getUser() { return User; }
+
+  /// Get the next SDUse in the use list.
+  SDUse *getNext() const { return Next; }
+
+  /// Convenience function for get().getNode().
+  SDNode *getNode() const { return Val.getNode(); }
+  /// Convenience function for get().getResNo().
+  unsigned getResNo() const { return Val.getResNo(); }
+  /// Convenience function for get().getValueType().
+  EVT getValueType() const { return Val.getValueType(); }
+
+  /// Convenience function for get().operator==
+  bool operator==(const SDValue &V) const {
+    return Val == V;
+  }
+
+  /// Convenience function for get().operator!=
+  bool operator!=(const SDValue &V) const {
+    return Val != V;
+  }
+
+  /// Convenience function for get().operator<
+  bool operator<(const SDValue &V) const {
+    return Val < V;
+  }
+
+private:
+  friend class SelectionDAG;
+  friend class SDNode;
+  // TODO: unfriend HandleSDNode once we fix its operand handling.
+  friend class HandleSDNode;
+
+  void setUser(SDNode *p) { User = p; }
+
+  /// Remove this use from its existing use list, assign it the
+  /// given value, and add it to the new value's node's use list.
+  inline void set(const SDValue &V);
+  /// Like set, but only supports initializing a newly-allocated
+  /// SDUse with a non-null value.
+  inline void setInitial(const SDValue &V);
+  /// Like set, but only sets the Node portion of the value,
+  /// leaving the ResNo portion unmodified.
+  inline void setNode(SDNode *N);
+
+  void addToList(SDUse **List) {
+    Next = *List;
+    if (Next) Next->Prev = &Next;
+    Prev = List;
+    *List = this;
+  }
+
+  void removeFromList() {
+    *Prev = Next;
+    if (Next) Next->Prev = Prev;
+  }
+};
+
+/// simplify_type specializations - Allow casting operators to work directly on
+/// SDValues as if they were SDNode*'s.
+template<> struct simplify_type<SDUse> {
+  using SimpleType = SDNode *;
+
+  static SimpleType getSimplifiedValue(SDUse &Val) {
+    return Val.getNode();
+  }
+};
+
+/// These are IR-level optimization flags that may be propagated to SDNodes.
+/// TODO: This data structure should be shared by the IR optimizer and the
+/// the backend.
+struct SDNodeFlags {
+private:
+  // This bit is used to determine if the flags are in a defined state.
+  // Flag bits can only be masked out during intersection if the masking flags
+  // are defined.
+  bool AnyDefined : 1;
+
+  bool NoUnsignedWrap : 1;
+  bool NoSignedWrap : 1;
+  bool Exact : 1;
+  bool UnsafeAlgebra : 1;
+  bool NoNaNs : 1;
+  bool NoInfs : 1;
+  bool NoSignedZeros : 1;
+  bool AllowReciprocal : 1;
+  bool VectorReduction : 1;
+  bool AllowContract : 1;
+
+public:
+  /// Default constructor turns off all optimization flags.
+  SDNodeFlags()
+      : AnyDefined(false), NoUnsignedWrap(false), NoSignedWrap(false),
+        Exact(false), UnsafeAlgebra(false), NoNaNs(false), NoInfs(false),
+        NoSignedZeros(false), AllowReciprocal(false), VectorReduction(false),
+        AllowContract(false) {}
+
+  /// Sets the state of the flags to the defined state.
+  void setDefined() { AnyDefined = true; }
+  /// Returns true if the flags are in a defined state.
+  bool isDefined() const { return AnyDefined; }
+
+  // These are mutators for each flag.
+  void setNoUnsignedWrap(bool b) {
+    setDefined();
+    NoUnsignedWrap = b;
+  }
+  void setNoSignedWrap(bool b) {
+    setDefined();
+    NoSignedWrap = b;
+  }
+  void setExact(bool b) {
+    setDefined();
+    Exact = b;
+  }
+  void setUnsafeAlgebra(bool b) {
+    setDefined();
+    UnsafeAlgebra = b;
+  }
+  void setNoNaNs(bool b) {
+    setDefined();
+    NoNaNs = b;
+  }
+  void setNoInfs(bool b) {
+    setDefined();
+    NoInfs = b;
+  }
+  void setNoSignedZeros(bool b) {
+    setDefined();
+    NoSignedZeros = b;
+  }
+  void setAllowReciprocal(bool b) {
+    setDefined();
+    AllowReciprocal = b;
+  }
+  void setVectorReduction(bool b) {
+    setDefined();
+    VectorReduction = b;
+  }
+  void setAllowContract(bool b) {
+    setDefined();
+    AllowContract = b;
+  }
+
+  // These are accessors for each flag.
+  bool hasNoUnsignedWrap() const { return NoUnsignedWrap; }
+  bool hasNoSignedWrap() const { return NoSignedWrap; }
+  bool hasExact() const { return Exact; }
+  bool hasUnsafeAlgebra() const { return UnsafeAlgebra; }
+  bool hasNoNaNs() const { return NoNaNs; }
+  bool hasNoInfs() const { return NoInfs; }
+  bool hasNoSignedZeros() const { return NoSignedZeros; }
+  bool hasAllowReciprocal() const { return AllowReciprocal; }
+  bool hasVectorReduction() const { return VectorReduction; }
+  bool hasAllowContract() const { return AllowContract; }
+
+  /// Clear any flags in this flag set that aren't also set in Flags.
+  /// If the given Flags are undefined then don't do anything.
+  void intersectWith(const SDNodeFlags Flags) {
+    if (!Flags.isDefined())
+      return;
+    NoUnsignedWrap &= Flags.NoUnsignedWrap;
+    NoSignedWrap &= Flags.NoSignedWrap;
+    Exact &= Flags.Exact;
+    UnsafeAlgebra &= Flags.UnsafeAlgebra;
+    NoNaNs &= Flags.NoNaNs;
+    NoInfs &= Flags.NoInfs;
+    NoSignedZeros &= Flags.NoSignedZeros;
+    AllowReciprocal &= Flags.AllowReciprocal;
+    VectorReduction &= Flags.VectorReduction;
+    AllowContract &= Flags.AllowContract;
+  }
+};
+
+/// Represents one node in the SelectionDAG.
+///
+class SDNode : public FoldingSetNode, public ilist_node<SDNode> {
+private:
+  /// The operation that this node performs.
+  int16_t NodeType;
+
+protected:
+  // We define a set of mini-helper classes to help us interpret the bits in our
+  // SubclassData.  These are designed to fit within a uint16_t so they pack
+  // with NodeType.
+
+  class SDNodeBitfields {
+    friend class SDNode;
+    friend class MemIntrinsicSDNode;
+    friend class MemSDNode;
+    friend class SelectionDAG;
+
+    uint16_t HasDebugValue : 1;
+    uint16_t IsMemIntrinsic : 1;
+    uint16_t IsDivergent : 1;
+  };
+  enum { NumSDNodeBits = 3 };
+
+  class ConstantSDNodeBitfields {
+    friend class ConstantSDNode;
+
+    uint16_t : NumSDNodeBits;
+
+    uint16_t IsOpaque : 1;
+  };
+
+  class MemSDNodeBitfields {
+    friend class MemSDNode;
+    friend class MemIntrinsicSDNode;
+    friend class AtomicSDNode;
+
+    uint16_t : NumSDNodeBits;
+
+    uint16_t IsVolatile : 1;
+    uint16_t IsNonTemporal : 1;
+    uint16_t IsDereferenceable : 1;
+    uint16_t IsInvariant : 1;
+  };
+  enum { NumMemSDNodeBits = NumSDNodeBits + 4 };
+
+  class LSBaseSDNodeBitfields {
+    friend class LSBaseSDNode;
+
+    uint16_t : NumMemSDNodeBits;
+
+    uint16_t AddressingMode : 3; // enum ISD::MemIndexedMode
+  };
+  enum { NumLSBaseSDNodeBits = NumMemSDNodeBits + 3 };
+
+  class LoadSDNodeBitfields {
+    friend class LoadSDNode;
+    friend class MaskedLoadSDNode;
+
+    uint16_t : NumLSBaseSDNodeBits;
+
+    uint16_t ExtTy : 2; // enum ISD::LoadExtType
+    uint16_t IsExpanding : 1;
+  };
+
+  class StoreSDNodeBitfields {
+    friend class StoreSDNode;
+    friend class MaskedStoreSDNode;
+
+    uint16_t : NumLSBaseSDNodeBits;
+
+    uint16_t IsTruncating : 1;
+    uint16_t IsCompressing : 1;
+  };
+
+  union {
+    char RawSDNodeBits[sizeof(uint16_t)];
+    SDNodeBitfields SDNodeBits;
+    ConstantSDNodeBitfields ConstantSDNodeBits;
+    MemSDNodeBitfields MemSDNodeBits;
+    LSBaseSDNodeBitfields LSBaseSDNodeBits;
+    LoadSDNodeBitfields LoadSDNodeBits;
+    StoreSDNodeBitfields StoreSDNodeBits;
+  };
+
+  // RawSDNodeBits must cover the entirety of the union.  This means that all of
+  // the union's members must have size <= RawSDNodeBits.  We write the RHS as
+  // "2" instead of sizeof(RawSDNodeBits) because MSVC can't handle the latter.
+  static_assert(sizeof(SDNodeBitfields) <= 2, "field too wide");
+  static_assert(sizeof(ConstantSDNodeBitfields) <= 2, "field too wide");
+  static_assert(sizeof(MemSDNodeBitfields) <= 2, "field too wide");
+  static_assert(sizeof(LSBaseSDNodeBitfields) <= 2, "field too wide");
+  static_assert(sizeof(LoadSDNodeBitfields) <= 4, "field too wide");
+  static_assert(sizeof(StoreSDNodeBitfields) <= 2, "field too wide");
+
+private:
+  friend class SelectionDAG;
+  // TODO: unfriend HandleSDNode once we fix its operand handling.
+  friend class HandleSDNode;
+
+  /// Unique id per SDNode in the DAG.
+  int NodeId = -1;
+
+  /// The values that are used by this operation.
+  SDUse *OperandList = nullptr;
+
+  /// The types of the values this node defines.  SDNode's may
+  /// define multiple values simultaneously.
+  const EVT *ValueList;
+
+  /// List of uses for this SDNode.
+  SDUse *UseList = nullptr;
+
+  /// The number of entries in the Operand/Value list.
+  unsigned short NumOperands = 0;
+  unsigned short NumValues;
+
+  // The ordering of the SDNodes. It roughly corresponds to the ordering of the
+  // original LLVM instructions.
+  // This is used for turning off scheduling, because we'll forgo
+  // the normal scheduling algorithms and output the instructions according to
+  // this ordering.
+  unsigned IROrder;
+
+  /// Source line information.
+  DebugLoc debugLoc;
+
+  /// Return a pointer to the specified value type.
+  static const EVT *getValueTypeList(EVT VT);
+
+  SDNodeFlags Flags;
+
+public:
+  /// Unique and persistent id per SDNode in the DAG.
+  /// Used for debug printing.
+  uint16_t PersistentId;
+
+  //===--------------------------------------------------------------------===//
+  //  Accessors
+  //
+
+  /// Return the SelectionDAG opcode value for this node. For
+  /// pre-isel nodes (those for which isMachineOpcode returns false), these
+  /// are the opcode values in the ISD and <target>ISD namespaces. For
+  /// post-isel opcodes, see getMachineOpcode.
+  unsigned getOpcode()  const { return (unsigned short)NodeType; }
+
+  /// Test if this node has a target-specific opcode (in the
+  /// \<target\>ISD namespace).
+  bool isTargetOpcode() const { return NodeType >= ISD::BUILTIN_OP_END; }
+
+  /// Test if this node has a target-specific
+  /// memory-referencing opcode (in the \<target\>ISD namespace and
+  /// greater than FIRST_TARGET_MEMORY_OPCODE).
+  bool isTargetMemoryOpcode() const {
+    return NodeType >= ISD::FIRST_TARGET_MEMORY_OPCODE;
+  }
+
+  /// Return true if the type of the node type undefined.
+  bool isUndef() const { return NodeType == ISD::UNDEF; }
+
+  /// Test if this node is a memory intrinsic (with valid pointer information).
+  /// INTRINSIC_W_CHAIN and INTRINSIC_VOID nodes are sometimes created for
+  /// non-memory intrinsics (with chains) that are not really instances of
+  /// MemSDNode. For such nodes, we need some extra state to determine the
+  /// proper classof relationship.
+  bool isMemIntrinsic() const {
+    return (NodeType == ISD::INTRINSIC_W_CHAIN ||
+            NodeType == ISD::INTRINSIC_VOID) &&
+           SDNodeBits.IsMemIntrinsic;
+  }
+
+  /// Test if this node is a strict floating point pseudo-op.
+  bool isStrictFPOpcode() {
+    switch (NodeType) {
+      default:
+        return false;
+      case ISD::STRICT_FADD:
+      case ISD::STRICT_FSUB:
+      case ISD::STRICT_FMUL:
+      case ISD::STRICT_FDIV:
+      case ISD::STRICT_FREM:
+      case ISD::STRICT_FMA:
+      case ISD::STRICT_FSQRT:
+      case ISD::STRICT_FPOW:
+      case ISD::STRICT_FPOWI:
+      case ISD::STRICT_FSIN:
+      case ISD::STRICT_FCOS:
+      case ISD::STRICT_FEXP:
+      case ISD::STRICT_FEXP2:
+      case ISD::STRICT_FLOG:
+      case ISD::STRICT_FLOG10:
+      case ISD::STRICT_FLOG2:
+      case ISD::STRICT_FRINT:
+      case ISD::STRICT_FNEARBYINT:
+        return true;
+    }
+  }
+
+  /// Test if this node has a post-isel opcode, directly
+  /// corresponding to a MachineInstr opcode.
+  bool isMachineOpcode() const { return NodeType < 0; }
+
+  /// This may only be called if isMachineOpcode returns
+  /// true. It returns the MachineInstr opcode value that the node's opcode
+  /// corresponds to.
+  unsigned getMachineOpcode() const {
+    assert(isMachineOpcode() && "Not a MachineInstr opcode!");
+    return ~NodeType;
+  }
+
+  bool getHasDebugValue() const { return SDNodeBits.HasDebugValue; }
+  void setHasDebugValue(bool b) { SDNodeBits.HasDebugValue = b; }
+
+  bool isDivergent() const { return SDNodeBits.IsDivergent; }
+
+  /// Return true if there are no uses of this node.
+  bool use_empty() const { return UseList == nullptr; }
+
+  /// Return true if there is exactly one use of this node.
+  bool hasOneUse() const {
+    return !use_empty() && std::next(use_begin()) == use_end();
+  }
+
+  /// Return the number of uses of this node. This method takes
+  /// time proportional to the number of uses.
+  size_t use_size() const { return std::distance(use_begin(), use_end()); }
+
+  /// Return the unique node id.
+  int getNodeId() const { return NodeId; }
+
+  /// Set unique node id.
+  void setNodeId(int Id) { NodeId = Id; }
+
+  /// Return the node ordering.
+  unsigned getIROrder() const { return IROrder; }
+
+  /// Set the node ordering.
+  void setIROrder(unsigned Order) { IROrder = Order; }
+
+  /// Return the source location info.
+  const DebugLoc &getDebugLoc() const { return debugLoc; }
+
+  /// Set source location info.  Try to avoid this, putting
+  /// it in the constructor is preferable.
+  void setDebugLoc(DebugLoc dl) { debugLoc = std::move(dl); }
+
+  /// This class provides iterator support for SDUse
+  /// operands that use a specific SDNode.
+  class use_iterator
+    : public std::iterator<std::forward_iterator_tag, SDUse, ptrdiff_t> {
+    friend class SDNode;
+
+    SDUse *Op = nullptr;
+
+    explicit use_iterator(SDUse *op) : Op(op) {}
+
+  public:
+    using reference = std::iterator<std::forward_iterator_tag,
+                                    SDUse, ptrdiff_t>::reference;
+    using pointer = std::iterator<std::forward_iterator_tag,
+                                  SDUse, ptrdiff_t>::pointer;
+
+    use_iterator() = default;
+    use_iterator(const use_iterator &I) : Op(I.Op) {}
+
+    bool operator==(const use_iterator &x) const {
+      return Op == x.Op;
+    }
+    bool operator!=(const use_iterator &x) const {
+      return !operator==(x);
+    }
+
+    /// Return true if this iterator is at the end of uses list.
+    bool atEnd() const { return Op == nullptr; }
+
+    // Iterator traversal: forward iteration only.
+    use_iterator &operator++() {          // Preincrement
+      assert(Op && "Cannot increment end iterator!");
+      Op = Op->getNext();
+      return *this;
+    }
+
+    use_iterator operator++(int) {        // Postincrement
+      use_iterator tmp = *this; ++*this; return tmp;
+    }
+
+    /// Retrieve a pointer to the current user node.
+    SDNode *operator*() const {
+      assert(Op && "Cannot dereference end iterator!");
+      return Op->getUser();
+    }
+
+    SDNode *operator->() const { return operator*(); }
+
+    SDUse &getUse() const { return *Op; }
+
+    /// Retrieve the operand # of this use in its user.
+    unsigned getOperandNo() const {
+      assert(Op && "Cannot dereference end iterator!");
+      return (unsigned)(Op - Op->getUser()->OperandList);
+    }
+  };
+
+  /// Provide iteration support to walk over all uses of an SDNode.
+  use_iterator use_begin() const {
+    return use_iterator(UseList);
+  }
+
+  static use_iterator use_end() { return use_iterator(nullptr); }
+
+  inline iterator_range<use_iterator> uses() {
+    return make_range(use_begin(), use_end());
+  }
+  inline iterator_range<use_iterator> uses() const {
+    return make_range(use_begin(), use_end());
+  }
+
+  /// Return true if there are exactly NUSES uses of the indicated value.
+  /// This method ignores uses of other values defined by this operation.
+  bool hasNUsesOfValue(unsigned NUses, unsigned Value) const;
+
+  /// Return true if there are any use of the indicated value.
+  /// This method ignores uses of other values defined by this operation.
+  bool hasAnyUseOfValue(unsigned Value) const;
+
+  /// Return true if this node is the only use of N.
+  bool isOnlyUserOf(const SDNode *N) const;
+
+  /// Return true if this node is an operand of N.
+  bool isOperandOf(const SDNode *N) const;
+
+  /// Return true if this node is a predecessor of N.
+  /// NOTE: Implemented on top of hasPredecessor and every bit as
+  /// expensive. Use carefully.
+  bool isPredecessorOf(const SDNode *N) const {
+    return N->hasPredecessor(this);
+  }
+
+  /// Return true if N is a predecessor of this node.
+  /// N is either an operand of this node, or can be reached by recursively
+  /// traversing up the operands.
+  /// NOTE: This is an expensive method. Use it carefully.
+  bool hasPredecessor(const SDNode *N) const;
+
+  /// Returns true if N is a predecessor of any node in Worklist. This
+  /// helper keeps Visited and Worklist sets externally to allow unions
+  /// searches to be performed in parallel, caching of results across
+  /// queries and incremental addition to Worklist. Stops early if N is
+  /// found but will resume. Remember to clear Visited and Worklists
+  /// if DAG changes. MaxSteps gives a maximum number of nodes to visit before
+  /// giving up. The TopologicalPrune flag signals that positive NodeIds are
+  /// topologically ordered (Operands have strictly smaller node id) and search
+  /// can be pruned leveraging this.
+  static bool hasPredecessorHelper(const SDNode *N,
+                                   SmallPtrSetImpl<const SDNode *> &Visited,
+                                   SmallVectorImpl<const SDNode *> &Worklist,
+                                   unsigned int MaxSteps = 0,
+                                   bool TopologicalPrune = false) {
+    SmallVector<const SDNode *, 8> DeferredNodes;
+    if (Visited.count(N))
+      return true;
+
+    // Node Id's are assigned in three places: As a topological
+    // ordering (> 0), during legalization (results in values set to
+    // 0), new nodes (set to -1). If N has a topolgical id then we
+    // know that all nodes with ids smaller than it cannot be
+    // successors and we need not check them. Filter out all node
+    // that can't be matches. We add them to the worklist before exit
+    // in case of multiple calls. Note that during selection the topological id
+    // may be violated if a node's predecessor is selected before it. We mark
+    // this at selection negating the id of unselected successors and
+    // restricting topological pruning to positive ids.
+
+    int NId = N->getNodeId();
+    // If we Invalidated the Id, reconstruct original NId.
+    if (NId < -1)
+      NId = -(NId + 1);
+
+    bool Found = false;
+    while (!Worklist.empty()) {
+      const SDNode *M = Worklist.pop_back_val();
+      int MId = M->getNodeId();
+      if (TopologicalPrune && M->getOpcode() != ISD::TokenFactor && (NId > 0) &&
+          (MId > 0) && (MId < NId)) {
+        DeferredNodes.push_back(M);
+        continue;
+      }
+      for (const SDValue &OpV : M->op_values()) {
+        SDNode *Op = OpV.getNode();
+        if (Visited.insert(Op).second)
+          Worklist.push_back(Op);
+        if (Op == N)
+          Found = true;
+      }
+      if (Found)
+        break;
+      if (MaxSteps != 0 && Visited.size() >= MaxSteps)
+        break;
+    }
+    // Push deferred nodes back on worklist.
+    Worklist.append(DeferredNodes.begin(), DeferredNodes.end());
+    // If we bailed early, conservatively return found.
+    if (MaxSteps != 0 && Visited.size() >= MaxSteps)
+      return true;
+    return Found;
+  }
+
+  /// Return true if all the users of N are contained in Nodes.
+  /// NOTE: Requires at least one match, but doesn't require them all.
+  static bool areOnlyUsersOf(ArrayRef<const SDNode *> Nodes, const SDNode *N);
+
+  /// Return the number of values used by this operation.
+  unsigned getNumOperands() const { return NumOperands; }
+
+  /// Helper method returns the integer value of a ConstantSDNode operand.
+  inline uint64_t getConstantOperandVal(unsigned Num) const;
+
+  const SDValue &getOperand(unsigned Num) const {
+    assert(Num < NumOperands && "Invalid child # of SDNode!");
+    return OperandList[Num];
+  }
+
+  using op_iterator = SDUse *;
+
+  op_iterator op_begin() const { return OperandList; }
+  op_iterator op_end() const { return OperandList+NumOperands; }
+  ArrayRef<SDUse> ops() const { return makeArrayRef(op_begin(), op_end()); }
+
+  /// Iterator for directly iterating over the operand SDValue's.
+  struct value_op_iterator
+      : iterator_adaptor_base<value_op_iterator, op_iterator,
+                              std::random_access_iterator_tag, SDValue,
+                              ptrdiff_t, value_op_iterator *,
+                              value_op_iterator *> {
+    explicit value_op_iterator(SDUse *U = nullptr)
+      : iterator_adaptor_base(U) {}
+
+    const SDValue &operator*() const { return I->get(); }
+  };
+
+  iterator_range<value_op_iterator> op_values() const {
+    return make_range(value_op_iterator(op_begin()),
+                      value_op_iterator(op_end()));
+  }
+
+  SDVTList getVTList() const {
+    SDVTList X = { ValueList, NumValues };
+    return X;
+  }
+
+  /// If this node has a glue operand, return the node
+  /// to which the glue operand points. Otherwise return NULL.
+  SDNode *getGluedNode() const {
+    if (getNumOperands() != 0 &&
+        getOperand(getNumOperands()-1).getValueType() == MVT::Glue)
+      return getOperand(getNumOperands()-1).getNode();
+    return nullptr;
+  }
+
+  /// If this node has a glue value with a user, return
+  /// the user (there is at most one). Otherwise return NULL.
+  SDNode *getGluedUser() const {
+    for (use_iterator UI = use_begin(), UE = use_end(); UI != UE; ++UI)
+      if (UI.getUse().get().getValueType() == MVT::Glue)
+        return *UI;
+    return nullptr;
+  }
+
+  const SDNodeFlags getFlags() const { return Flags; }
+  void setFlags(SDNodeFlags NewFlags) { Flags = NewFlags; }
+
+  /// Clear any flags in this node that aren't also set in Flags.
+  /// If Flags is not in a defined state then this has no effect.
+  void intersectFlagsWith(const SDNodeFlags Flags);
+
+  /// Return the number of values defined/returned by this operator.
+  unsigned getNumValues() const { return NumValues; }
+
+  /// Return the type of a specified result.
+  EVT getValueType(unsigned ResNo) const {
+    assert(ResNo < NumValues && "Illegal result number!");
+    return ValueList[ResNo];
+  }
+
+  /// Return the type of a specified result as a simple type.
+  MVT getSimpleValueType(unsigned ResNo) const {
+    return getValueType(ResNo).getSimpleVT();
+  }
+
+  /// Returns MVT::getSizeInBits(getValueType(ResNo)).
+  unsigned getValueSizeInBits(unsigned ResNo) const {
+    return getValueType(ResNo).getSizeInBits();
+  }
+
+  using value_iterator = const EVT *;
+
+  value_iterator value_begin() const { return ValueList; }
+  value_iterator value_end() const { return ValueList+NumValues; }
+
+  /// Return the opcode of this operation for printing.
+  std::string getOperationName(const SelectionDAG *G = nullptr) const;
+  static const char* getIndexedModeName(ISD::MemIndexedMode AM);
+  void print_types(raw_ostream &OS, const SelectionDAG *G) const;
+  void print_details(raw_ostream &OS, const SelectionDAG *G) const;
+  void print(raw_ostream &OS, const SelectionDAG *G = nullptr) const;
+  void printr(raw_ostream &OS, const SelectionDAG *G = nullptr) const;
+
+  /// Print a SelectionDAG node and all children down to
+  /// the leaves.  The given SelectionDAG allows target-specific nodes
+  /// to be printed in human-readable form.  Unlike printr, this will
+  /// print the whole DAG, including children that appear multiple
+  /// times.
+  ///
+  void printrFull(raw_ostream &O, const SelectionDAG *G = nullptr) const;
+
+  /// Print a SelectionDAG node and children up to
+  /// depth "depth."  The given SelectionDAG allows target-specific
+  /// nodes to be printed in human-readable form.  Unlike printr, this
+  /// will print children that appear multiple times wherever they are
+  /// used.
+  ///
+  void printrWithDepth(raw_ostream &O, const SelectionDAG *G = nullptr,
+                       unsigned depth = 100) const;
+
+  /// Dump this node, for debugging.
+  void dump() const;
+
+  /// Dump (recursively) this node and its use-def subgraph.
+  void dumpr() const;
+
+  /// Dump this node, for debugging.
+  /// The given SelectionDAG allows target-specific nodes to be printed
+  /// in human-readable form.
+  void dump(const SelectionDAG *G) const;
+
+  /// Dump (recursively) this node and its use-def subgraph.
+  /// The given SelectionDAG allows target-specific nodes to be printed
+  /// in human-readable form.
+  void dumpr(const SelectionDAG *G) const;
+
+  /// printrFull to dbgs().  The given SelectionDAG allows
+  /// target-specific nodes to be printed in human-readable form.
+  /// Unlike dumpr, this will print the whole DAG, including children
+  /// that appear multiple times.
+  void dumprFull(const SelectionDAG *G = nullptr) const;
+
+  /// printrWithDepth to dbgs().  The given
+  /// SelectionDAG allows target-specific nodes to be printed in
+  /// human-readable form.  Unlike dumpr, this will print children
+  /// that appear multiple times wherever they are used.
+  ///
+  void dumprWithDepth(const SelectionDAG *G = nullptr,
+                      unsigned depth = 100) const;
+
+  /// Gather unique data for the node.
+  void Profile(FoldingSetNodeID &ID) const;
+
+  /// This method should only be used by the SDUse class.
+  void addUse(SDUse &U) { U.addToList(&UseList); }
+
+protected:
+  static SDVTList getSDVTList(EVT VT) {
+    SDVTList Ret = { getValueTypeList(VT), 1 };
+    return Ret;
+  }
+
+  /// Create an SDNode.
+  ///
+  /// SDNodes are created without any operands, and never own the operand
+  /// storage. To add operands, see SelectionDAG::createOperands.
+  SDNode(unsigned Opc, unsigned Order, DebugLoc dl, SDVTList VTs)
+      : NodeType(Opc), ValueList(VTs.VTs), NumValues(VTs.NumVTs),
+        IROrder(Order), debugLoc(std::move(dl)) {
+    memset(&RawSDNodeBits, 0, sizeof(RawSDNodeBits));
+    assert(debugLoc.hasTrivialDestructor() && "Expected trivial destructor");
+    assert(NumValues == VTs.NumVTs &&
+           "NumValues wasn't wide enough for its operands!");
+  }
+
+  /// Release the operands and set this node to have zero operands.
+  void DropOperands();
+};
+
+/// Wrapper class for IR location info (IR ordering and DebugLoc) to be passed
+/// into SDNode creation functions.
+/// When an SDNode is created from the DAGBuilder, the DebugLoc is extracted
+/// from the original Instruction, and IROrder is the ordinal position of
+/// the instruction.
+/// When an SDNode is created after the DAG is being built, both DebugLoc and
+/// the IROrder are propagated from the original SDNode.
+/// So SDLoc class provides two constructors besides the default one, one to
+/// be used by the DAGBuilder, the other to be used by others.
+class SDLoc {
+private:
+  DebugLoc DL;
+  int IROrder = 0;
+
+public:
+  SDLoc() = default;
+  SDLoc(const SDNode *N) : DL(N->getDebugLoc()), IROrder(N->getIROrder()) {}
+  SDLoc(const SDValue V) : SDLoc(V.getNode()) {}
+  SDLoc(const Instruction *I, int Order) : IROrder(Order) {
+    assert(Order >= 0 && "bad IROrder");
+    if (I)
+      DL = I->getDebugLoc();
+  }
+
+  unsigned getIROrder() const { return IROrder; }
+  const DebugLoc &getDebugLoc() const { return DL; }
+};
+
+// Define inline functions from the SDValue class.
+
+inline SDValue::SDValue(SDNode *node, unsigned resno)
+    : Node(node), ResNo(resno) {
+  // Explicitly check for !ResNo to avoid use-after-free, because there are
+  // callers that use SDValue(N, 0) with a deleted N to indicate successful
+  // combines.
+  assert((!Node || !ResNo || ResNo < Node->getNumValues()) &&
+         "Invalid result number for the given node!");
+  assert(ResNo < -2U && "Cannot use result numbers reserved for DenseMaps.");
+}
+
+inline unsigned SDValue::getOpcode() const {
+  return Node->getOpcode();
+}
+
+inline EVT SDValue::getValueType() const {
+  return Node->getValueType(ResNo);
+}
+
+inline unsigned SDValue::getNumOperands() const {
+  return Node->getNumOperands();
+}
+
+inline const SDValue &SDValue::getOperand(unsigned i) const {
+  return Node->getOperand(i);
+}
+
+inline uint64_t SDValue::getConstantOperandVal(unsigned i) const {
+  return Node->getConstantOperandVal(i);
+}
+
+inline bool SDValue::isTargetOpcode() const {
+  return Node->isTargetOpcode();
+}
+
+inline bool SDValue::isTargetMemoryOpcode() const {
+  return Node->isTargetMemoryOpcode();
+}
+
+inline bool SDValue::isMachineOpcode() const {
+  return Node->isMachineOpcode();
+}
+
+inline unsigned SDValue::getMachineOpcode() const {
+  return Node->getMachineOpcode();
+}
+
+inline bool SDValue::isUndef() const {
+  return Node->isUndef();
+}
+
+inline bool SDValue::use_empty() const {
+  return !Node->hasAnyUseOfValue(ResNo);
+}
+
+inline bool SDValue::hasOneUse() const {
+  return Node->hasNUsesOfValue(1, ResNo);
+}
+
+inline const DebugLoc &SDValue::getDebugLoc() const {
+  return Node->getDebugLoc();
+}
+
+inline void SDValue::dump() const {
+  return Node->dump();
+}
+
+inline void SDValue::dump(const SelectionDAG *G) const {
+  return Node->dump(G);
+}
+
+inline void SDValue::dumpr() const {
+  return Node->dumpr();
+}
+
+inline void SDValue::dumpr(const SelectionDAG *G) const {
+  return Node->dumpr(G);
+}
+
+// Define inline functions from the SDUse class.
+
+inline void SDUse::set(const SDValue &V) {
+  if (Val.getNode()) removeFromList();
+  Val = V;
+  if (V.getNode()) V.getNode()->addUse(*this);
+}
+
+inline void SDUse::setInitial(const SDValue &V) {
+  Val = V;
+  V.getNode()->addUse(*this);
+}
+
+inline void SDUse::setNode(SDNode *N) {
+  if (Val.getNode()) removeFromList();
+  Val.setNode(N);
+  if (N) N->addUse(*this);
+}
+
+/// This class is used to form a handle around another node that
+/// is persistent and is updated across invocations of replaceAllUsesWith on its
+/// operand.  This node should be directly created by end-users and not added to
+/// the AllNodes list.
+class HandleSDNode : public SDNode {
+  SDUse Op;
+
+public:
+  explicit HandleSDNode(SDValue X)
+    : SDNode(ISD::HANDLENODE, 0, DebugLoc(), getSDVTList(MVT::Other)) {
+    // HandleSDNodes are never inserted into the DAG, so they won't be
+    // auto-numbered. Use ID 65535 as a sentinel.
+    PersistentId = 0xffff;
+
+    // Manually set up the operand list. This node type is special in that it's
+    // always stack allocated and SelectionDAG does not manage its operands.
+    // TODO: This should either (a) not be in the SDNode hierarchy, or (b) not
+    // be so special.
+    Op.setUser(this);
+    Op.setInitial(X);
+    NumOperands = 1;
+    OperandList = &Op;
+  }
+  ~HandleSDNode();
+
+  const SDValue &getValue() const { return Op; }
+};
+
+class AddrSpaceCastSDNode : public SDNode {
+private:
+  unsigned SrcAddrSpace;
+  unsigned DestAddrSpace;
+
+public:
+  AddrSpaceCastSDNode(unsigned Order, const DebugLoc &dl, EVT VT,
+                      unsigned SrcAS, unsigned DestAS);
+
+  unsigned getSrcAddressSpace() const { return SrcAddrSpace; }
+  unsigned getDestAddressSpace() const { return DestAddrSpace; }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::ADDRSPACECAST;
+  }
+};
+
+/// This is an abstract virtual class for memory operations.
+class MemSDNode : public SDNode {
+private:
+  // VT of in-memory value.
+  EVT MemoryVT;
+
+protected:
+  /// Memory reference information.
+  MachineMemOperand *MMO;
+
+public:
+  MemSDNode(unsigned Opc, unsigned Order, const DebugLoc &dl, SDVTList VTs,
+            EVT MemoryVT, MachineMemOperand *MMO);
+
+  bool readMem() const { return MMO->isLoad(); }
+  bool writeMem() const { return MMO->isStore(); }
+
+  /// Returns alignment and volatility of the memory access
+  unsigned getOriginalAlignment() const {
+    return MMO->getBaseAlignment();
+  }
+  unsigned getAlignment() const {
+    return MMO->getAlignment();
+  }
+
+  /// Return the SubclassData value, without HasDebugValue. This contains an
+  /// encoding of the volatile flag, as well as bits used by subclasses. This
+  /// function should only be used to compute a FoldingSetNodeID value.
+  /// The HasDebugValue bit is masked out because CSE map needs to match
+  /// nodes with debug info with nodes without debug info. Same is about
+  /// isDivergent bit.
+  unsigned getRawSubclassData() const {
+    uint16_t Data;
+    union {
+      char RawSDNodeBits[sizeof(uint16_t)];
+      SDNodeBitfields SDNodeBits;
+    };
+    memcpy(&RawSDNodeBits, &this->RawSDNodeBits, sizeof(this->RawSDNodeBits));
+    SDNodeBits.HasDebugValue = 0;
+    SDNodeBits.IsDivergent = false;
+    memcpy(&Data, &RawSDNodeBits, sizeof(RawSDNodeBits));
+    return Data;
+  }
+
+  bool isVolatile() const { return MemSDNodeBits.IsVolatile; }
+  bool isNonTemporal() const { return MemSDNodeBits.IsNonTemporal; }
+  bool isDereferenceable() const { return MemSDNodeBits.IsDereferenceable; }
+  bool isInvariant() const { return MemSDNodeBits.IsInvariant; }
+
+  // Returns the offset from the location of the access.
+  int64_t getSrcValueOffset() const { return MMO->getOffset(); }
+
+  /// Returns the AA info that describes the dereference.
+  AAMDNodes getAAInfo() const { return MMO->getAAInfo(); }
+
+  /// Returns the Ranges that describes the dereference.
+  const MDNode *getRanges() const { return MMO->getRanges(); }
+
+  /// Returns the synchronization scope ID for this memory operation.
+  SyncScope::ID getSyncScopeID() const { return MMO->getSyncScopeID(); }
+
+  /// Return the atomic ordering requirements for this memory operation. For
+  /// cmpxchg atomic operations, return the atomic ordering requirements when
+  /// store occurs.
+  AtomicOrdering getOrdering() const { return MMO->getOrdering(); }
+
+  /// Return the type of the in-memory value.
+  EVT getMemoryVT() const { return MemoryVT; }
+
+  /// Return a MachineMemOperand object describing the memory
+  /// reference performed by operation.
+  MachineMemOperand *getMemOperand() const { return MMO; }
+
+  const MachinePointerInfo &getPointerInfo() const {
+    return MMO->getPointerInfo();
+  }
+
+  /// Return the address space for the associated pointer
+  unsigned getAddressSpace() const {
+    return getPointerInfo().getAddrSpace();
+  }
+
+  /// Update this MemSDNode's MachineMemOperand information
+  /// to reflect the alignment of NewMMO, if it has a greater alignment.
+  /// This must only be used when the new alignment applies to all users of
+  /// this MachineMemOperand.
+  void refineAlignment(const MachineMemOperand *NewMMO) {
+    MMO->refineAlignment(NewMMO);
+  }
+
+  const SDValue &getChain() const { return getOperand(0); }
+  const SDValue &getBasePtr() const {
+    return getOperand(getOpcode() == ISD::STORE ? 2 : 1);
+  }
+
+  // Methods to support isa and dyn_cast
+  static bool classof(const SDNode *N) {
+    // For some targets, we lower some target intrinsics to a MemIntrinsicNode
+    // with either an intrinsic or a target opcode.
+    return N->getOpcode() == ISD::LOAD                ||
+           N->getOpcode() == ISD::STORE               ||
+           N->getOpcode() == ISD::PREFETCH            ||
+           N->getOpcode() == ISD::ATOMIC_CMP_SWAP     ||
+           N->getOpcode() == ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS ||
+           N->getOpcode() == ISD::ATOMIC_SWAP         ||
+           N->getOpcode() == ISD::ATOMIC_LOAD_ADD     ||
+           N->getOpcode() == ISD::ATOMIC_LOAD_SUB     ||
+           N->getOpcode() == ISD::ATOMIC_LOAD_AND     ||
+           N->getOpcode() == ISD::ATOMIC_LOAD_CLR     ||
+           N->getOpcode() == ISD::ATOMIC_LOAD_OR      ||
+           N->getOpcode() == ISD::ATOMIC_LOAD_XOR     ||
+           N->getOpcode() == ISD::ATOMIC_LOAD_NAND    ||
+           N->getOpcode() == ISD::ATOMIC_LOAD_MIN     ||
+           N->getOpcode() == ISD::ATOMIC_LOAD_MAX     ||
+           N->getOpcode() == ISD::ATOMIC_LOAD_UMIN    ||
+           N->getOpcode() == ISD::ATOMIC_LOAD_UMAX    ||
+           N->getOpcode() == ISD::ATOMIC_LOAD         ||
+           N->getOpcode() == ISD::ATOMIC_STORE        ||
+           N->getOpcode() == ISD::MLOAD               ||
+           N->getOpcode() == ISD::MSTORE              ||
+           N->getOpcode() == ISD::MGATHER             ||
+           N->getOpcode() == ISD::MSCATTER            ||
+           N->isMemIntrinsic()                        ||
+           N->isTargetMemoryOpcode();
+  }
+};
+
+/// This is an SDNode representing atomic operations.
+class AtomicSDNode : public MemSDNode {
+public:
+  AtomicSDNode(unsigned Opc, unsigned Order, const DebugLoc &dl, SDVTList VTL,
+               EVT MemVT, MachineMemOperand *MMO)
+      : MemSDNode(Opc, Order, dl, VTL, MemVT, MMO) {}
+
+  const SDValue &getBasePtr() const { return getOperand(1); }
+  const SDValue &getVal() const { return getOperand(2); }
+
+  /// Returns true if this SDNode represents cmpxchg atomic operation, false
+  /// otherwise.
+  bool isCompareAndSwap() const {
+    unsigned Op = getOpcode();
+    return Op == ISD::ATOMIC_CMP_SWAP ||
+           Op == ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS;
+  }
+
+  /// For cmpxchg atomic operations, return the atomic ordering requirements
+  /// when store does not occur.
+  AtomicOrdering getFailureOrdering() const {
+    assert(isCompareAndSwap() && "Must be cmpxchg operation");
+    return MMO->getFailureOrdering();
+  }
+
+  // Methods to support isa and dyn_cast
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::ATOMIC_CMP_SWAP     ||
+           N->getOpcode() == ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS ||
+           N->getOpcode() == ISD::ATOMIC_SWAP         ||
+           N->getOpcode() == ISD::ATOMIC_LOAD_ADD     ||
+           N->getOpcode() == ISD::ATOMIC_LOAD_SUB     ||
+           N->getOpcode() == ISD::ATOMIC_LOAD_AND     ||
+           N->getOpcode() == ISD::ATOMIC_LOAD_CLR     ||
+           N->getOpcode() == ISD::ATOMIC_LOAD_OR      ||
+           N->getOpcode() == ISD::ATOMIC_LOAD_XOR     ||
+           N->getOpcode() == ISD::ATOMIC_LOAD_NAND    ||
+           N->getOpcode() == ISD::ATOMIC_LOAD_MIN     ||
+           N->getOpcode() == ISD::ATOMIC_LOAD_MAX     ||
+           N->getOpcode() == ISD::ATOMIC_LOAD_UMIN    ||
+           N->getOpcode() == ISD::ATOMIC_LOAD_UMAX    ||
+           N->getOpcode() == ISD::ATOMIC_LOAD         ||
+           N->getOpcode() == ISD::ATOMIC_STORE;
+  }
+};
+
+/// This SDNode is used for target intrinsics that touch
+/// memory and need an associated MachineMemOperand. Its opcode may be
+/// INTRINSIC_VOID, INTRINSIC_W_CHAIN, PREFETCH, or a target-specific opcode
+/// with a value not less than FIRST_TARGET_MEMORY_OPCODE.
+class MemIntrinsicSDNode : public MemSDNode {
+public:
+  MemIntrinsicSDNode(unsigned Opc, unsigned Order, const DebugLoc &dl,
+                     SDVTList VTs, EVT MemoryVT, MachineMemOperand *MMO)
+      : MemSDNode(Opc, Order, dl, VTs, MemoryVT, MMO) {
+    SDNodeBits.IsMemIntrinsic = true;
+  }
+
+  // Methods to support isa and dyn_cast
+  static bool classof(const SDNode *N) {
+    // We lower some target intrinsics to their target opcode
+    // early a node with a target opcode can be of this class
+    return N->isMemIntrinsic()             ||
+           N->getOpcode() == ISD::PREFETCH ||
+           N->isTargetMemoryOpcode();
+  }
+};
+
+/// This SDNode is used to implement the code generator
+/// support for the llvm IR shufflevector instruction.  It combines elements
+/// from two input vectors into a new input vector, with the selection and
+/// ordering of elements determined by an array of integers, referred to as
+/// the shuffle mask.  For input vectors of width N, mask indices of 0..N-1
+/// refer to elements from the LHS input, and indices from N to 2N-1 the RHS.
+/// An index of -1 is treated as undef, such that the code generator may put
+/// any value in the corresponding element of the result.
+class ShuffleVectorSDNode : public SDNode {
+  // The memory for Mask is owned by the SelectionDAG's OperandAllocator, and
+  // is freed when the SelectionDAG object is destroyed.
+  const int *Mask;
+
+protected:
+  friend class SelectionDAG;
+
+  ShuffleVectorSDNode(EVT VT, unsigned Order, const DebugLoc &dl, const int *M)
+      : SDNode(ISD::VECTOR_SHUFFLE, Order, dl, getSDVTList(VT)), Mask(M) {}
+
+public:
+  ArrayRef<int> getMask() const {
+    EVT VT = getValueType(0);
+    return makeArrayRef(Mask, VT.getVectorNumElements());
+  }
+
+  int getMaskElt(unsigned Idx) const {
+    assert(Idx < getValueType(0).getVectorNumElements() && "Idx out of range!");
+    return Mask[Idx];
+  }
+
+  bool isSplat() const { return isSplatMask(Mask, getValueType(0)); }
+
+  int  getSplatIndex() const {
+    assert(isSplat() && "Cannot get splat index for non-splat!");
+    EVT VT = getValueType(0);
+    for (unsigned i = 0, e = VT.getVectorNumElements(); i != e; ++i) {
+      if (Mask[i] >= 0)
+        return Mask[i];
+    }
+    llvm_unreachable("Splat with all undef indices?");
+  }
+
+  static bool isSplatMask(const int *Mask, EVT VT);
+
+  /// Change values in a shuffle permute mask assuming
+  /// the two vector operands have swapped position.
+  static void commuteMask(MutableArrayRef<int> Mask) {
+    unsigned NumElems = Mask.size();
+    for (unsigned i = 0; i != NumElems; ++i) {
+      int idx = Mask[i];
+      if (idx < 0)
+        continue;
+      else if (idx < (int)NumElems)
+        Mask[i] = idx + NumElems;
+      else
+        Mask[i] = idx - NumElems;
+    }
+  }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::VECTOR_SHUFFLE;
+  }
+};
+
+class ConstantSDNode : public SDNode {
+  friend class SelectionDAG;
+
+  const ConstantInt *Value;
+
+  ConstantSDNode(bool isTarget, bool isOpaque, const ConstantInt *val,
+                 const DebugLoc &DL, EVT VT)
+      : SDNode(isTarget ? ISD::TargetConstant : ISD::Constant, 0, DL,
+               getSDVTList(VT)),
+        Value(val) {
+    ConstantSDNodeBits.IsOpaque = isOpaque;
+  }
+
+public:
+  const ConstantInt *getConstantIntValue() const { return Value; }
+  const APInt &getAPIntValue() const { return Value->getValue(); }
+  uint64_t getZExtValue() const { return Value->getZExtValue(); }
+  int64_t getSExtValue() const { return Value->getSExtValue(); }
+  uint64_t getLimitedValue(uint64_t Limit = UINT64_MAX) {
+    return Value->getLimitedValue(Limit);
+  }
+
+  bool isOne() const { return Value->isOne(); }
+  bool isNullValue() const { return Value->isZero(); }
+  bool isAllOnesValue() const { return Value->isMinusOne(); }
+
+  bool isOpaque() const { return ConstantSDNodeBits.IsOpaque; }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::Constant ||
+           N->getOpcode() == ISD::TargetConstant;
+  }
+};
+
+uint64_t SDNode::getConstantOperandVal(unsigned Num) const {
+  return cast<ConstantSDNode>(getOperand(Num))->getZExtValue();
+}
+
+class ConstantFPSDNode : public SDNode {
+  friend class SelectionDAG;
+
+  const ConstantFP *Value;
+
+  ConstantFPSDNode(bool isTarget, const ConstantFP *val, const DebugLoc &DL,
+                   EVT VT)
+      : SDNode(isTarget ? ISD::TargetConstantFP : ISD::ConstantFP, 0, DL,
+               getSDVTList(VT)),
+        Value(val) {}
+
+public:
+  const APFloat& getValueAPF() const { return Value->getValueAPF(); }
+  const ConstantFP *getConstantFPValue() const { return Value; }
+
+  /// Return true if the value is positive or negative zero.
+  bool isZero() const { return Value->isZero(); }
+
+  /// Return true if the value is a NaN.
+  bool isNaN() const { return Value->isNaN(); }
+
+  /// Return true if the value is an infinity
+  bool isInfinity() const { return Value->isInfinity(); }
+
+  /// Return true if the value is negative.
+  bool isNegative() const { return Value->isNegative(); }
+
+  /// We don't rely on operator== working on double values, as
+  /// it returns true for things that are clearly not equal, like -0.0 and 0.0.
+  /// As such, this method can be used to do an exact bit-for-bit comparison of
+  /// two floating point values.
+
+  /// We leave the version with the double argument here because it's just so
+  /// convenient to write "2.0" and the like.  Without this function we'd
+  /// have to duplicate its logic everywhere it's called.
+  bool isExactlyValue(double V) const {
+    return Value->getValueAPF().isExactlyValue(V);
+  }
+  bool isExactlyValue(const APFloat& V) const;
+
+  static bool isValueValidForType(EVT VT, const APFloat& Val);
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::ConstantFP ||
+           N->getOpcode() == ISD::TargetConstantFP;
+  }
+};
+
+/// Returns true if \p V is a constant integer zero.
+bool isNullConstant(SDValue V);
+
+/// Returns true if \p V is an FP constant with a value of positive zero.
+bool isNullFPConstant(SDValue V);
+
+/// Returns true if \p V is an integer constant with all bits set.
+bool isAllOnesConstant(SDValue V);
+
+/// Returns true if \p V is a constant integer one.
+bool isOneConstant(SDValue V);
+
+/// Returns true if \p V is a bitwise not operation. Assumes that an all ones
+/// constant is canonicalized to be operand 1.
+bool isBitwiseNot(SDValue V);
+
+/// Returns the SDNode if it is a constant splat BuildVector or constant int.
+ConstantSDNode *isConstOrConstSplat(SDValue V);
+
+/// Returns the SDNode if it is a constant splat BuildVector or constant float.
+ConstantFPSDNode *isConstOrConstSplatFP(SDValue V);
+
+class GlobalAddressSDNode : public SDNode {
+  friend class SelectionDAG;
+
+  const GlobalValue *TheGlobal;
+  int64_t Offset;
+  unsigned char TargetFlags;
+
+  GlobalAddressSDNode(unsigned Opc, unsigned Order, const DebugLoc &DL,
+                      const GlobalValue *GA, EVT VT, int64_t o,
+                      unsigned char TargetFlags);
+
+public:
+  const GlobalValue *getGlobal() const { return TheGlobal; }
+  int64_t getOffset() const { return Offset; }
+  unsigned char getTargetFlags() const { return TargetFlags; }
+  // Return the address space this GlobalAddress belongs to.
+  unsigned getAddressSpace() const;
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::GlobalAddress ||
+           N->getOpcode() == ISD::TargetGlobalAddress ||
+           N->getOpcode() == ISD::GlobalTLSAddress ||
+           N->getOpcode() == ISD::TargetGlobalTLSAddress;
+  }
+};
+
+class FrameIndexSDNode : public SDNode {
+  friend class SelectionDAG;
+
+  int FI;
+
+  FrameIndexSDNode(int fi, EVT VT, bool isTarg)
+    : SDNode(isTarg ? ISD::TargetFrameIndex : ISD::FrameIndex,
+      0, DebugLoc(), getSDVTList(VT)), FI(fi) {
+  }
+
+public:
+  int getIndex() const { return FI; }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::FrameIndex ||
+           N->getOpcode() == ISD::TargetFrameIndex;
+  }
+};
+
+class JumpTableSDNode : public SDNode {
+  friend class SelectionDAG;
+
+  int JTI;
+  unsigned char TargetFlags;
+
+  JumpTableSDNode(int jti, EVT VT, bool isTarg, unsigned char TF)
+    : SDNode(isTarg ? ISD::TargetJumpTable : ISD::JumpTable,
+      0, DebugLoc(), getSDVTList(VT)), JTI(jti), TargetFlags(TF) {
+  }
+
+public:
+  int getIndex() const { return JTI; }
+  unsigned char getTargetFlags() const { return TargetFlags; }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::JumpTable ||
+           N->getOpcode() == ISD::TargetJumpTable;
+  }
+};
+
+class ConstantPoolSDNode : public SDNode {
+  friend class SelectionDAG;
+
+  union {
+    const Constant *ConstVal;
+    MachineConstantPoolValue *MachineCPVal;
+  } Val;
+  int Offset;  // It's a MachineConstantPoolValue if top bit is set.
+  unsigned Alignment;  // Minimum alignment requirement of CP (not log2 value).
+  unsigned char TargetFlags;
+
+  ConstantPoolSDNode(bool isTarget, const Constant *c, EVT VT, int o,
+                     unsigned Align, unsigned char TF)
+    : SDNode(isTarget ? ISD::TargetConstantPool : ISD::ConstantPool, 0,
+             DebugLoc(), getSDVTList(VT)), Offset(o), Alignment(Align),
+             TargetFlags(TF) {
+    assert(Offset >= 0 && "Offset is too large");
+    Val.ConstVal = c;
+  }
+
+  ConstantPoolSDNode(bool isTarget, MachineConstantPoolValue *v,
+                     EVT VT, int o, unsigned Align, unsigned char TF)
+    : SDNode(isTarget ? ISD::TargetConstantPool : ISD::ConstantPool, 0,
+             DebugLoc(), getSDVTList(VT)), Offset(o), Alignment(Align),
+             TargetFlags(TF) {
+    assert(Offset >= 0 && "Offset is too large");
+    Val.MachineCPVal = v;
+    Offset |= 1 << (sizeof(unsigned)*CHAR_BIT-1);
+  }
+
+public:
+  bool isMachineConstantPoolEntry() const {
+    return Offset < 0;
+  }
+
+  const Constant *getConstVal() const {
+    assert(!isMachineConstantPoolEntry() && "Wrong constantpool type");
+    return Val.ConstVal;
+  }
+
+  MachineConstantPoolValue *getMachineCPVal() const {
+    assert(isMachineConstantPoolEntry() && "Wrong constantpool type");
+    return Val.MachineCPVal;
+  }
+
+  int getOffset() const {
+    return Offset & ~(1 << (sizeof(unsigned)*CHAR_BIT-1));
+  }
+
+  // Return the alignment of this constant pool object, which is either 0 (for
+  // default alignment) or the desired value.
+  unsigned getAlignment() const { return Alignment; }
+  unsigned char getTargetFlags() const { return TargetFlags; }
+
+  Type *getType() const;
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::ConstantPool ||
+           N->getOpcode() == ISD::TargetConstantPool;
+  }
+};
+
+/// Completely target-dependent object reference.
+class TargetIndexSDNode : public SDNode {
+  friend class SelectionDAG;
+
+  unsigned char TargetFlags;
+  int Index;
+  int64_t Offset;
+
+public:
+  TargetIndexSDNode(int Idx, EVT VT, int64_t Ofs, unsigned char TF)
+    : SDNode(ISD::TargetIndex, 0, DebugLoc(), getSDVTList(VT)),
+      TargetFlags(TF), Index(Idx), Offset(Ofs) {}
+
+  unsigned char getTargetFlags() const { return TargetFlags; }
+  int getIndex() const { return Index; }
+  int64_t getOffset() const { return Offset; }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::TargetIndex;
+  }
+};
+
+class BasicBlockSDNode : public SDNode {
+  friend class SelectionDAG;
+
+  MachineBasicBlock *MBB;
+
+  /// Debug info is meaningful and potentially useful here, but we create
+  /// blocks out of order when they're jumped to, which makes it a bit
+  /// harder.  Let's see if we need it first.
+  explicit BasicBlockSDNode(MachineBasicBlock *mbb)
+    : SDNode(ISD::BasicBlock, 0, DebugLoc(), getSDVTList(MVT::Other)), MBB(mbb)
+  {}
+
+public:
+  MachineBasicBlock *getBasicBlock() const { return MBB; }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::BasicBlock;
+  }
+};
+
+/// A "pseudo-class" with methods for operating on BUILD_VECTORs.
+class BuildVectorSDNode : public SDNode {
+public:
+  // These are constructed as SDNodes and then cast to BuildVectorSDNodes.
+  explicit BuildVectorSDNode() = delete;
+
+  /// Check if this is a constant splat, and if so, find the
+  /// smallest element size that splats the vector.  If MinSplatBits is
+  /// nonzero, the element size must be at least that large.  Note that the
+  /// splat element may be the entire vector (i.e., a one element vector).
+  /// Returns the splat element value in SplatValue.  Any undefined bits in
+  /// that value are zero, and the corresponding bits in the SplatUndef mask
+  /// are set.  The SplatBitSize value is set to the splat element size in
+  /// bits.  HasAnyUndefs is set to true if any bits in the vector are
+  /// undefined.  isBigEndian describes the endianness of the target.
+  bool isConstantSplat(APInt &SplatValue, APInt &SplatUndef,
+                       unsigned &SplatBitSize, bool &HasAnyUndefs,
+                       unsigned MinSplatBits = 0,
+                       bool isBigEndian = false) const;
+
+  /// \brief Returns the splatted value or a null value if this is not a splat.
+  ///
+  /// If passed a non-null UndefElements bitvector, it will resize it to match
+  /// the vector width and set the bits where elements are undef.
+  SDValue getSplatValue(BitVector *UndefElements = nullptr) const;
+
+  /// \brief Returns the splatted constant or null if this is not a constant
+  /// splat.
+  ///
+  /// If passed a non-null UndefElements bitvector, it will resize it to match
+  /// the vector width and set the bits where elements are undef.
+  ConstantSDNode *
+  getConstantSplatNode(BitVector *UndefElements = nullptr) const;
+
+  /// \brief Returns the splatted constant FP or null if this is not a constant
+  /// FP splat.
+  ///
+  /// If passed a non-null UndefElements bitvector, it will resize it to match
+  /// the vector width and set the bits where elements are undef.
+  ConstantFPSDNode *
+  getConstantFPSplatNode(BitVector *UndefElements = nullptr) const;
+
+  /// \brief If this is a constant FP splat and the splatted constant FP is an
+  /// exact power or 2, return the log base 2 integer value.  Otherwise,
+  /// return -1.
+  ///
+  /// The BitWidth specifies the necessary bit precision.
+  int32_t getConstantFPSplatPow2ToLog2Int(BitVector *UndefElements,
+                                          uint32_t BitWidth) const;
+
+  bool isConstant() const;
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::BUILD_VECTOR;
+  }
+};
+
+/// An SDNode that holds an arbitrary LLVM IR Value. This is
+/// used when the SelectionDAG needs to make a simple reference to something
+/// in the LLVM IR representation.
+///
+class SrcValueSDNode : public SDNode {
+  friend class SelectionDAG;
+
+  const Value *V;
+
+  /// Create a SrcValue for a general value.
+  explicit SrcValueSDNode(const Value *v)
+    : SDNode(ISD::SRCVALUE, 0, DebugLoc(), getSDVTList(MVT::Other)), V(v) {}
+
+public:
+  /// Return the contained Value.
+  const Value *getValue() const { return V; }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::SRCVALUE;
+  }
+};
+
+class MDNodeSDNode : public SDNode {
+  friend class SelectionDAG;
+
+  const MDNode *MD;
+
+  explicit MDNodeSDNode(const MDNode *md)
+  : SDNode(ISD::MDNODE_SDNODE, 0, DebugLoc(), getSDVTList(MVT::Other)), MD(md)
+  {}
+
+public:
+  const MDNode *getMD() const { return MD; }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::MDNODE_SDNODE;
+  }
+};
+
+class RegisterSDNode : public SDNode {
+  friend class SelectionDAG;
+
+  unsigned Reg;
+
+  RegisterSDNode(unsigned reg, EVT VT)
+    : SDNode(ISD::Register, 0, DebugLoc(), getSDVTList(VT)), Reg(reg) {}
+
+public:
+  unsigned getReg() const { return Reg; }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::Register;
+  }
+};
+
+class RegisterMaskSDNode : public SDNode {
+  friend class SelectionDAG;
+
+  // The memory for RegMask is not owned by the node.
+  const uint32_t *RegMask;
+
+  RegisterMaskSDNode(const uint32_t *mask)
+    : SDNode(ISD::RegisterMask, 0, DebugLoc(), getSDVTList(MVT::Untyped)),
+      RegMask(mask) {}
+
+public:
+  const uint32_t *getRegMask() const { return RegMask; }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::RegisterMask;
+  }
+};
+
+class BlockAddressSDNode : public SDNode {
+  friend class SelectionDAG;
+
+  const BlockAddress *BA;
+  int64_t Offset;
+  unsigned char TargetFlags;
+
+  BlockAddressSDNode(unsigned NodeTy, EVT VT, const BlockAddress *ba,
+                     int64_t o, unsigned char Flags)
+    : SDNode(NodeTy, 0, DebugLoc(), getSDVTList(VT)),
+             BA(ba), Offset(o), TargetFlags(Flags) {}
+
+public:
+  const BlockAddress *getBlockAddress() const { return BA; }
+  int64_t getOffset() const { return Offset; }
+  unsigned char getTargetFlags() const { return TargetFlags; }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::BlockAddress ||
+           N->getOpcode() == ISD::TargetBlockAddress;
+  }
+};
+
+class LabelSDNode : public SDNode {
+  friend class SelectionDAG;
+
+  MCSymbol *Label;
+
+  LabelSDNode(unsigned Order, const DebugLoc &dl, MCSymbol *L)
+      : SDNode(ISD::EH_LABEL, Order, dl, getSDVTList(MVT::Other)), Label(L) {}
+
+public:
+  MCSymbol *getLabel() const { return Label; }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::EH_LABEL ||
+           N->getOpcode() == ISD::ANNOTATION_LABEL;
+  }
+};
+
+class ExternalSymbolSDNode : public SDNode {
+  friend class SelectionDAG;
+
+  const char *Symbol;
+  unsigned char TargetFlags;
+
+  ExternalSymbolSDNode(bool isTarget, const char *Sym, unsigned char TF, EVT VT)
+    : SDNode(isTarget ? ISD::TargetExternalSymbol : ISD::ExternalSymbol,
+             0, DebugLoc(), getSDVTList(VT)), Symbol(Sym), TargetFlags(TF) {}
+
+public:
+  const char *getSymbol() const { return Symbol; }
+  unsigned char getTargetFlags() const { return TargetFlags; }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::ExternalSymbol ||
+           N->getOpcode() == ISD::TargetExternalSymbol;
+  }
+};
+
+class MCSymbolSDNode : public SDNode {
+  friend class SelectionDAG;
+
+  MCSymbol *Symbol;
+
+  MCSymbolSDNode(MCSymbol *Symbol, EVT VT)
+      : SDNode(ISD::MCSymbol, 0, DebugLoc(), getSDVTList(VT)), Symbol(Symbol) {}
+
+public:
+  MCSymbol *getMCSymbol() const { return Symbol; }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::MCSymbol;
+  }
+};
+
+class CondCodeSDNode : public SDNode {
+  friend class SelectionDAG;
+
+  ISD::CondCode Condition;
+
+  explicit CondCodeSDNode(ISD::CondCode Cond)
+    : SDNode(ISD::CONDCODE, 0, DebugLoc(), getSDVTList(MVT::Other)),
+      Condition(Cond) {}
+
+public:
+  ISD::CondCode get() const { return Condition; }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::CONDCODE;
+  }
+};
+
+/// This class is used to represent EVT's, which are used
+/// to parameterize some operations.
+class VTSDNode : public SDNode {
+  friend class SelectionDAG;
+
+  EVT ValueType;
+
+  explicit VTSDNode(EVT VT)
+    : SDNode(ISD::VALUETYPE, 0, DebugLoc(), getSDVTList(MVT::Other)),
+      ValueType(VT) {}
+
+public:
+  EVT getVT() const { return ValueType; }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::VALUETYPE;
+  }
+};
+
+/// Base class for LoadSDNode and StoreSDNode
+class LSBaseSDNode : public MemSDNode {
+public:
+  LSBaseSDNode(ISD::NodeType NodeTy, unsigned Order, const DebugLoc &dl,
+               SDVTList VTs, ISD::MemIndexedMode AM, EVT MemVT,
+               MachineMemOperand *MMO)
+      : MemSDNode(NodeTy, Order, dl, VTs, MemVT, MMO) {
+    LSBaseSDNodeBits.AddressingMode = AM;
+    assert(getAddressingMode() == AM && "Value truncated");
+  }
+
+  const SDValue &getOffset() const {
+    return getOperand(getOpcode() == ISD::LOAD ? 2 : 3);
+  }
+
+  /// Return the addressing mode for this load or store:
+  /// unindexed, pre-inc, pre-dec, post-inc, or post-dec.
+  ISD::MemIndexedMode getAddressingMode() const {
+    return static_cast<ISD::MemIndexedMode>(LSBaseSDNodeBits.AddressingMode);
+  }
+
+  /// Return true if this is a pre/post inc/dec load/store.
+  bool isIndexed() const { return getAddressingMode() != ISD::UNINDEXED; }
+
+  /// Return true if this is NOT a pre/post inc/dec load/store.
+  bool isUnindexed() const { return getAddressingMode() == ISD::UNINDEXED; }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::LOAD ||
+           N->getOpcode() == ISD::STORE;
+  }
+};
+
+/// This class is used to represent ISD::LOAD nodes.
+class LoadSDNode : public LSBaseSDNode {
+  friend class SelectionDAG;
+
+  LoadSDNode(unsigned Order, const DebugLoc &dl, SDVTList VTs,
+             ISD::MemIndexedMode AM, ISD::LoadExtType ETy, EVT MemVT,
+             MachineMemOperand *MMO)
+      : LSBaseSDNode(ISD::LOAD, Order, dl, VTs, AM, MemVT, MMO) {
+    LoadSDNodeBits.ExtTy = ETy;
+    assert(readMem() && "Load MachineMemOperand is not a load!");
+    assert(!writeMem() && "Load MachineMemOperand is a store!");
+  }
+
+public:
+  /// Return whether this is a plain node,
+  /// or one of the varieties of value-extending loads.
+  ISD::LoadExtType getExtensionType() const {
+    return static_cast<ISD::LoadExtType>(LoadSDNodeBits.ExtTy);
+  }
+
+  const SDValue &getBasePtr() const { return getOperand(1); }
+  const SDValue &getOffset() const { return getOperand(2); }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::LOAD;
+  }
+};
+
+/// This class is used to represent ISD::STORE nodes.
+class StoreSDNode : public LSBaseSDNode {
+  friend class SelectionDAG;
+
+  StoreSDNode(unsigned Order, const DebugLoc &dl, SDVTList VTs,
+              ISD::MemIndexedMode AM, bool isTrunc, EVT MemVT,
+              MachineMemOperand *MMO)
+      : LSBaseSDNode(ISD::STORE, Order, dl, VTs, AM, MemVT, MMO) {
+    StoreSDNodeBits.IsTruncating = isTrunc;
+    assert(!readMem() && "Store MachineMemOperand is a load!");
+    assert(writeMem() && "Store MachineMemOperand is not a store!");
+  }
+
+public:
+  /// Return true if the op does a truncation before store.
+  /// For integers this is the same as doing a TRUNCATE and storing the result.
+  /// For floats, it is the same as doing an FP_ROUND and storing the result.
+  bool isTruncatingStore() const { return StoreSDNodeBits.IsTruncating; }
+  void setTruncatingStore(bool Truncating) {
+    StoreSDNodeBits.IsTruncating = Truncating;
+  }
+
+  const SDValue &getValue() const { return getOperand(1); }
+  const SDValue &getBasePtr() const { return getOperand(2); }
+  const SDValue &getOffset() const { return getOperand(3); }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::STORE;
+  }
+};
+
+/// This base class is used to represent MLOAD and MSTORE nodes
+class MaskedLoadStoreSDNode : public MemSDNode {
+public:
+  friend class SelectionDAG;
+
+  MaskedLoadStoreSDNode(ISD::NodeType NodeTy, unsigned Order,
+                        const DebugLoc &dl, SDVTList VTs, EVT MemVT,
+                        MachineMemOperand *MMO)
+      : MemSDNode(NodeTy, Order, dl, VTs, MemVT, MMO) {}
+
+  // In the both nodes address is Op1, mask is Op2:
+  // MaskedLoadSDNode (Chain, ptr, mask, src0), src0 is a passthru value
+  // MaskedStoreSDNode (Chain, ptr, mask, data)
+  // Mask is a vector of i1 elements
+  const SDValue &getBasePtr() const { return getOperand(1); }
+  const SDValue &getMask() const    { return getOperand(2); }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::MLOAD ||
+           N->getOpcode() == ISD::MSTORE;
+  }
+};
+
+/// This class is used to represent an MLOAD node
+class MaskedLoadSDNode : public MaskedLoadStoreSDNode {
+public:
+  friend class SelectionDAG;
+
+  MaskedLoadSDNode(unsigned Order, const DebugLoc &dl, SDVTList VTs,
+                   ISD::LoadExtType ETy, bool IsExpanding, EVT MemVT,
+                   MachineMemOperand *MMO)
+      : MaskedLoadStoreSDNode(ISD::MLOAD, Order, dl, VTs, MemVT, MMO) {
+    LoadSDNodeBits.ExtTy = ETy;
+    LoadSDNodeBits.IsExpanding = IsExpanding;
+  }
+
+  ISD::LoadExtType getExtensionType() const {
+    return static_cast<ISD::LoadExtType>(LoadSDNodeBits.ExtTy);
+  }
+
+  const SDValue &getSrc0() const { return getOperand(3); }
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::MLOAD;
+  }
+
+  bool isExpandingLoad() const { return LoadSDNodeBits.IsExpanding; }
+};
+
+/// This class is used to represent an MSTORE node
+class MaskedStoreSDNode : public MaskedLoadStoreSDNode {
+public:
+  friend class SelectionDAG;
+
+  MaskedStoreSDNode(unsigned Order, const DebugLoc &dl, SDVTList VTs,
+                    bool isTrunc, bool isCompressing, EVT MemVT,
+                    MachineMemOperand *MMO)
+      : MaskedLoadStoreSDNode(ISD::MSTORE, Order, dl, VTs, MemVT, MMO) {
+    StoreSDNodeBits.IsTruncating = isTrunc;
+    StoreSDNodeBits.IsCompressing = isCompressing;
+  }
+
+  /// Return true if the op does a truncation before store.
+  /// For integers this is the same as doing a TRUNCATE and storing the result.
+  /// For floats, it is the same as doing an FP_ROUND and storing the result.
+  bool isTruncatingStore() const { return StoreSDNodeBits.IsTruncating; }
+
+  /// Returns true if the op does a compression to the vector before storing.
+  /// The node contiguously stores the active elements (integers or floats)
+  /// in src (those with their respective bit set in writemask k) to unaligned
+  /// memory at base_addr.
+  bool isCompressingStore() const { return StoreSDNodeBits.IsCompressing; }
+
+  const SDValue &getValue() const { return getOperand(3); }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::MSTORE;
+  }
+};
+
+/// This is a base class used to represent
+/// MGATHER and MSCATTER nodes
+///
+class MaskedGatherScatterSDNode : public MemSDNode {
+public:
+  friend class SelectionDAG;
+
+  MaskedGatherScatterSDNode(ISD::NodeType NodeTy, unsigned Order,
+                            const DebugLoc &dl, SDVTList VTs, EVT MemVT,
+                            MachineMemOperand *MMO)
+      : MemSDNode(NodeTy, Order, dl, VTs, MemVT, MMO) {}
+
+  // In the both nodes address is Op1, mask is Op2:
+  // MaskedGatherSDNode  (Chain, passthru, mask, base, index, scale)
+  // MaskedScatterSDNode (Chain, value, mask, base, index, scale)
+  // Mask is a vector of i1 elements
+  const SDValue &getBasePtr() const { return getOperand(3); }
+  const SDValue &getIndex()   const { return getOperand(4); }
+  const SDValue &getMask()    const { return getOperand(2); }
+  const SDValue &getValue()   const { return getOperand(1); }
+  const SDValue &getScale()   const { return getOperand(5); }
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::MGATHER ||
+           N->getOpcode() == ISD::MSCATTER;
+  }
+};
+
+/// This class is used to represent an MGATHER node
+///
+class MaskedGatherSDNode : public MaskedGatherScatterSDNode {
+public:
+  friend class SelectionDAG;
+
+  MaskedGatherSDNode(unsigned Order, const DebugLoc &dl, SDVTList VTs,
+                     EVT MemVT, MachineMemOperand *MMO)
+      : MaskedGatherScatterSDNode(ISD::MGATHER, Order, dl, VTs, MemVT, MMO) {}
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::MGATHER;
+  }
+};
+
+/// This class is used to represent an MSCATTER node
+///
+class MaskedScatterSDNode : public MaskedGatherScatterSDNode {
+public:
+  friend class SelectionDAG;
+
+  MaskedScatterSDNode(unsigned Order, const DebugLoc &dl, SDVTList VTs,
+                      EVT MemVT, MachineMemOperand *MMO)
+      : MaskedGatherScatterSDNode(ISD::MSCATTER, Order, dl, VTs, MemVT, MMO) {}
+
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::MSCATTER;
+  }
+};
+
+/// An SDNode that represents everything that will be needed
+/// to construct a MachineInstr. These nodes are created during the
+/// instruction selection proper phase.
+class MachineSDNode : public SDNode {
+public:
+  using mmo_iterator = MachineMemOperand **;
+
+private:
+  friend class SelectionDAG;
+
+  MachineSDNode(unsigned Opc, unsigned Order, const DebugLoc &DL, SDVTList VTs)
+      : SDNode(Opc, Order, DL, VTs) {}
+
+  /// Memory reference descriptions for this instruction.
+  mmo_iterator MemRefs = nullptr;
+  mmo_iterator MemRefsEnd = nullptr;
+
+public:
+  mmo_iterator memoperands_begin() const { return MemRefs; }
+  mmo_iterator memoperands_end() const { return MemRefsEnd; }
+  bool memoperands_empty() const { return MemRefsEnd == MemRefs; }
+
+  /// Assign this MachineSDNodes's memory reference descriptor
+  /// list. This does not transfer ownership.
+  void setMemRefs(mmo_iterator NewMemRefs, mmo_iterator NewMemRefsEnd) {
+    for (mmo_iterator MMI = NewMemRefs, MME = NewMemRefsEnd; MMI != MME; ++MMI)
+      assert(*MMI && "Null mem ref detected!");
+    MemRefs = NewMemRefs;
+    MemRefsEnd = NewMemRefsEnd;
+  }
+
+  static bool classof(const SDNode *N) {
+    return N->isMachineOpcode();
+  }
+};
+
+class SDNodeIterator : public std::iterator<std::forward_iterator_tag,
+                                            SDNode, ptrdiff_t> {
+  const SDNode *Node;
+  unsigned Operand;
+
+  SDNodeIterator(const SDNode *N, unsigned Op) : Node(N), Operand(Op) {}
+
+public:
+  bool operator==(const SDNodeIterator& x) const {
+    return Operand == x.Operand;
+  }
+  bool operator!=(const SDNodeIterator& x) const { return !operator==(x); }
+
+  pointer operator*() const {
+    return Node->getOperand(Operand).getNode();
+  }
+  pointer operator->() const { return operator*(); }
+
+  SDNodeIterator& operator++() {                // Preincrement
+    ++Operand;
+    return *this;
+  }
+  SDNodeIterator operator++(int) { // Postincrement
+    SDNodeIterator tmp = *this; ++*this; return tmp;
+  }
+  size_t operator-(SDNodeIterator Other) const {
+    assert(Node == Other.Node &&
+           "Cannot compare iterators of two different nodes!");
+    return Operand - Other.Operand;
+  }
+
+  static SDNodeIterator begin(const SDNode *N) { return SDNodeIterator(N, 0); }
+  static SDNodeIterator end  (const SDNode *N) {
+    return SDNodeIterator(N, N->getNumOperands());
+  }
+
+  unsigned getOperand() const { return Operand; }
+  const SDNode *getNode() const { return Node; }
+};
+
+template <> struct GraphTraits<SDNode*> {
+  using NodeRef = SDNode *;
+  using ChildIteratorType = SDNodeIterator;
+
+  static NodeRef getEntryNode(SDNode *N) { return N; }
+
+  static ChildIteratorType child_begin(NodeRef N) {
+    return SDNodeIterator::begin(N);
+  }
+
+  static ChildIteratorType child_end(NodeRef N) {
+    return SDNodeIterator::end(N);
+  }
+};
+
+/// A representation of the largest SDNode, for use in sizeof().
+///
+/// This needs to be a union because the largest node differs on 32 bit systems
+/// with 4 and 8 byte pointer alignment, respectively.
+using LargestSDNode = AlignedCharArrayUnion<AtomicSDNode, TargetIndexSDNode,
+                                            BlockAddressSDNode,
+                                            GlobalAddressSDNode>;
+
+/// The SDNode class with the greatest alignment requirement.
+using MostAlignedSDNode = GlobalAddressSDNode;
+
+namespace ISD {
+
+  /// Returns true if the specified node is a non-extending and unindexed load.
+  inline bool isNormalLoad(const SDNode *N) {
+    const LoadSDNode *Ld = dyn_cast<LoadSDNode>(N);
+    return Ld && Ld->getExtensionType() == ISD::NON_EXTLOAD &&
+      Ld->getAddressingMode() == ISD::UNINDEXED;
+  }
+
+  /// Returns true if the specified node is a non-extending load.
+  inline bool isNON_EXTLoad(const SDNode *N) {
+    return isa<LoadSDNode>(N) &&
+      cast<LoadSDNode>(N)->getExtensionType() == ISD::NON_EXTLOAD;
+  }
+
+  /// Returns true if the specified node is a EXTLOAD.
+  inline bool isEXTLoad(const SDNode *N) {
+    return isa<LoadSDNode>(N) &&
+      cast<LoadSDNode>(N)->getExtensionType() == ISD::EXTLOAD;
+  }
+
+  /// Returns true if the specified node is a SEXTLOAD.
+  inline bool isSEXTLoad(const SDNode *N) {
+    return isa<LoadSDNode>(N) &&
+      cast<LoadSDNode>(N)->getExtensionType() == ISD::SEXTLOAD;
+  }
+
+  /// Returns true if the specified node is a ZEXTLOAD.
+  inline bool isZEXTLoad(const SDNode *N) {
+    return isa<LoadSDNode>(N) &&
+      cast<LoadSDNode>(N)->getExtensionType() == ISD::ZEXTLOAD;
+  }
+
+  /// Returns true if the specified node is an unindexed load.
+  inline bool isUNINDEXEDLoad(const SDNode *N) {
+    return isa<LoadSDNode>(N) &&
+      cast<LoadSDNode>(N)->getAddressingMode() == ISD::UNINDEXED;
+  }
+
+  /// Returns true if the specified node is a non-truncating
+  /// and unindexed store.
+  inline bool isNormalStore(const SDNode *N) {
+    const StoreSDNode *St = dyn_cast<StoreSDNode>(N);
+    return St && !St->isTruncatingStore() &&
+      St->getAddressingMode() == ISD::UNINDEXED;
+  }
+
+  /// Returns true if the specified node is a non-truncating store.
+  inline bool isNON_TRUNCStore(const SDNode *N) {
+    return isa<StoreSDNode>(N) && !cast<StoreSDNode>(N)->isTruncatingStore();
+  }
+
+  /// Returns true if the specified node is a truncating store.
+  inline bool isTRUNCStore(const SDNode *N) {
+    return isa<StoreSDNode>(N) && cast<StoreSDNode>(N)->isTruncatingStore();
+  }
+
+  /// Returns true if the specified node is an unindexed store.
+  inline bool isUNINDEXEDStore(const SDNode *N) {
+    return isa<StoreSDNode>(N) &&
+      cast<StoreSDNode>(N)->getAddressingMode() == ISD::UNINDEXED;
+  }
+
+  /// Attempt to match a unary predicate against a scalar/splat constant or
+  /// every element of a constant BUILD_VECTOR.
+  bool matchUnaryPredicate(SDValue Op,
+                           std::function<bool(ConstantSDNode *)> Match);
+
+  /// Attempt to match a binary predicate against a pair of scalar/splat
+  /// constants or every element of a pair of constant BUILD_VECTORs.
+  bool matchBinaryPredicate(
+      SDValue LHS, SDValue RHS,
+      std::function<bool(ConstantSDNode *, ConstantSDNode *)> Match);
+
+} // end namespace ISD
+
+} // end namespace llvm
+
+#endif // LLVM_CODEGEN_SELECTIONDAGNODES_H