//===- llvm/CodeGen/SelectionDAG.h - InstSelection DAG ----------*- 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
 
//
 
//===----------------------------------------------------------------------===//
 
//
 
// This file declares the SelectionDAG class, and transitively defines the
 
// SDNode class and subclasses.
 
//
 
//===----------------------------------------------------------------------===//
 
 
 
#ifndef LLVM_CODEGEN_SELECTIONDAG_H
 
#define LLVM_CODEGEN_SELECTIONDAG_H
 
 
 
#include "llvm/ADT/APFloat.h"
 
#include "llvm/ADT/APInt.h"
 
#include "llvm/ADT/ArrayRef.h"
 
#include "llvm/ADT/DenseMap.h"
 
#include "llvm/ADT/DenseSet.h"
 
#include "llvm/ADT/FoldingSet.h"
 
#include "llvm/ADT/SmallVector.h"
 
#include "llvm/ADT/StringMap.h"
 
#include "llvm/ADT/ilist.h"
 
#include "llvm/ADT/iterator.h"
 
#include "llvm/ADT/iterator_range.h"
 
#include "llvm/CodeGen/DAGCombine.h"
 
#include "llvm/CodeGen/ISDOpcodes.h"
 
#include "llvm/CodeGen/MachineFunction.h"
 
#include "llvm/CodeGen/MachineMemOperand.h"
 
#include "llvm/CodeGen/SelectionDAGNodes.h"
 
#include "llvm/CodeGen/ValueTypes.h"
 
#include "llvm/IR/DebugLoc.h"
 
#include "llvm/IR/Metadata.h"
 
#include "llvm/Support/Allocator.h"
 
#include "llvm/Support/ArrayRecycler.h"
 
#include "llvm/Support/CodeGen.h"
 
#include "llvm/Support/ErrorHandling.h"
 
#include "llvm/Support/MachineValueType.h"
 
#include "llvm/Support/RecyclingAllocator.h"
 
#include <cassert>
 
#include <cstdint>
 
#include <functional>
 
#include <map>
 
#include <string>
 
#include <tuple>
 
#include <utility>
 
#include <vector>
 
 
 
namespace llvm {
 
 
 
class DIExpression;
 
class DILabel;
 
class DIVariable;
 
class Function;
 
class Pass;
 
class Type;
 
template <class GraphType> struct GraphTraits;
 
template <typename T, unsigned int N> class SmallSetVector;
 
template <typename T, typename Enable> struct FoldingSetTrait;
 
class AAResults;
 
class BlockAddress;
 
class BlockFrequencyInfo;
 
class Constant;
 
class ConstantFP;
 
class ConstantInt;
 
class DataLayout;
 
struct fltSemantics;
 
class FunctionLoweringInfo;
 
class FunctionVarLocs;
 
class GlobalValue;
 
struct KnownBits;
 
class LegacyDivergenceAnalysis;
 
class LLVMContext;
 
class MachineBasicBlock;
 
class MachineConstantPoolValue;
 
class MCSymbol;
 
class OptimizationRemarkEmitter;
 
class ProfileSummaryInfo;
 
class SDDbgValue;
 
class SDDbgOperand;
 
class SDDbgLabel;
 
class SelectionDAG;
 
class SelectionDAGTargetInfo;
 
class TargetLibraryInfo;
 
class TargetLowering;
 
class TargetMachine;
 
class TargetSubtargetInfo;
 
class Value;
 
 
 
class SDVTListNode : public FoldingSetNode {
 
  friend struct FoldingSetTrait<SDVTListNode>;
 
 
 
  /// A reference to an Interned FoldingSetNodeID for this node.
 
  /// The Allocator in SelectionDAG holds the data.
 
  /// SDVTList contains all types which are frequently accessed in SelectionDAG.
 
  /// The size of this list is not expected to be big so it won't introduce
 
  /// a memory penalty.
 
  FoldingSetNodeIDRef FastID;
 
  const EVT *VTs;
 
  unsigned int NumVTs;
 
  /// The hash value for SDVTList is fixed, so cache it to avoid
 
  /// hash calculation.
 
  unsigned HashValue;
 
 
 
public:
 
  SDVTListNode(const FoldingSetNodeIDRef ID, const EVT *VT, unsigned int Num) :
 
      FastID(ID), VTs(VT), NumVTs(Num) {
 
    HashValue = ID.ComputeHash();
 
  }
 
 
 
  SDVTList getSDVTList() {
 
    SDVTList result = {VTs, NumVTs};
 
    return result;
 
  }
 
};
 
 
 
/// Specialize FoldingSetTrait for SDVTListNode
 
/// to avoid computing temp FoldingSetNodeID and hash value.
 
template<> struct FoldingSetTrait<SDVTListNode> : DefaultFoldingSetTrait<SDVTListNode> {
 
  static void Profile(const SDVTListNode &X, FoldingSetNodeID& ID) {
 
    ID = X.FastID;
 
  }
 
 
 
  static bool Equals(const SDVTListNode &X, const FoldingSetNodeID &ID,
 
                     unsigned IDHash, FoldingSetNodeID &TempID) {
 
    if (X.HashValue != IDHash)
 
      return false;
 
    return ID == X.FastID;
 
  }
 
 
 
  static unsigned ComputeHash(const SDVTListNode &X, FoldingSetNodeID &TempID) {
 
    return X.HashValue;
 
  }
 
};
 
 
 
template <> struct ilist_alloc_traits<SDNode> {
 
  static void deleteNode(SDNode *) {
 
    llvm_unreachable("ilist_traits<SDNode> shouldn't see a deleteNode call!");
 
  }
 
};
 
 
 
/// Keeps track of dbg_value information through SDISel.  We do
 
/// not build SDNodes for these so as not to perturb the generated code;
 
/// instead the info is kept off to the side in this structure. Each SDNode may
 
/// have one or more associated dbg_value entries. This information is kept in
 
/// DbgValMap.
 
/// Byval parameters are handled separately because they don't use alloca's,
 
/// which busts the normal mechanism.  There is good reason for handling all
 
/// parameters separately:  they may not have code generated for them, they
 
/// should always go at the beginning of the function regardless of other code
 
/// motion, and debug info for them is potentially useful even if the parameter
 
/// is unused.  Right now only byval parameters are handled separately.
 
class SDDbgInfo {
 
  BumpPtrAllocator Alloc;
 
  SmallVector<SDDbgValue*, 32> DbgValues;
 
  SmallVector<SDDbgValue*, 32> ByvalParmDbgValues;
 
  SmallVector<SDDbgLabel*, 4> DbgLabels;
 
  using DbgValMapType = DenseMap<const SDNode *, SmallVector<SDDbgValue *, 2>>;
 
  DbgValMapType DbgValMap;
 
 
 
public:
 
  SDDbgInfo() = default;
 
  SDDbgInfo(const SDDbgInfo &) = delete;
 
  SDDbgInfo &operator=(const SDDbgInfo &) = delete;
 
 
 
  void add(SDDbgValue *V, bool isParameter);
 
 
 
  void add(SDDbgLabel *L) { DbgLabels.push_back(L); }
 
 
 
  /// Invalidate all DbgValues attached to the node and remove
 
  /// it from the Node-to-DbgValues map.
 
  void erase(const SDNode *Node);
 
 
 
  void clear() {
 
    DbgValMap.clear();
 
    DbgValues.clear();
 
    ByvalParmDbgValues.clear();
 
    DbgLabels.clear();
 
    Alloc.Reset();
 
  }
 
 
 
  BumpPtrAllocator &getAlloc() { return Alloc; }
 
 
 
  bool empty() const {
 
    return DbgValues.empty() && ByvalParmDbgValues.empty() && DbgLabels.empty();
 
  }
 
 
 
  ArrayRef<SDDbgValue*> getSDDbgValues(const SDNode *Node) const {
 
    auto I = DbgValMap.find(Node);
 
    if (I != DbgValMap.end())
 
      return I->second;
 
    return ArrayRef<SDDbgValue*>();
 
  }
 
 
 
  using DbgIterator = SmallVectorImpl<SDDbgValue*>::iterator;
 
  using DbgLabelIterator = SmallVectorImpl<SDDbgLabel*>::iterator;
 
 
 
  DbgIterator DbgBegin() { return DbgValues.begin(); }
 
  DbgIterator DbgEnd()   { return DbgValues.end(); }
 
  DbgIterator ByvalParmDbgBegin() { return ByvalParmDbgValues.begin(); }
 
  DbgIterator ByvalParmDbgEnd()   { return ByvalParmDbgValues.end(); }
 
  DbgLabelIterator DbgLabelBegin() { return DbgLabels.begin(); }
 
  DbgLabelIterator DbgLabelEnd()   { return DbgLabels.end(); }
 
};
 
 
 
void checkForCycles(const SelectionDAG *DAG, bool force = false);
 
 
 
/// This is used to represent a portion of an LLVM function in a low-level
 
/// Data Dependence DAG representation suitable for instruction selection.
 
/// This DAG is constructed as the first step of instruction selection in order
 
/// to allow implementation of machine specific optimizations
 
/// and code simplifications.
 
///
 
/// The representation used by the SelectionDAG is a target-independent
 
/// representation, which has some similarities to the GCC RTL representation,
 
/// but is significantly more simple, powerful, and is a graph form instead of a
 
/// linear form.
 
///
 
class SelectionDAG {
 
  const TargetMachine &TM;
 
  const SelectionDAGTargetInfo *TSI = nullptr;
 
  const TargetLowering *TLI = nullptr;
 
  const TargetLibraryInfo *LibInfo = nullptr;
 
  const FunctionVarLocs *FnVarLocs = nullptr;
 
  MachineFunction *MF;
 
  Pass *SDAGISelPass = nullptr;
 
  LLVMContext *Context;
 
  CodeGenOpt::Level OptLevel;
 
 
 
  LegacyDivergenceAnalysis * DA = nullptr;
 
  FunctionLoweringInfo * FLI = nullptr;
 
 
 
  /// The function-level optimization remark emitter.  Used to emit remarks
 
  /// whenever manipulating the DAG.
 
  OptimizationRemarkEmitter *ORE;
 
 
 
  ProfileSummaryInfo *PSI = nullptr;
 
  BlockFrequencyInfo *BFI = nullptr;
 
 
 
  /// List of non-single value types.
 
  FoldingSet<SDVTListNode> VTListMap;
 
 
 
  /// Pool allocation for misc. objects that are created once per SelectionDAG.
 
  BumpPtrAllocator Allocator;
 
 
 
  /// The starting token.
 
  SDNode EntryNode;
 
 
 
  /// The root of the entire DAG.
 
  SDValue Root;
 
 
 
  /// A linked list of nodes in the current DAG.
 
  ilist<SDNode> AllNodes;
 
 
 
  /// The AllocatorType for allocating SDNodes. We use
 
  /// pool allocation with recycling.
 
  using NodeAllocatorType = RecyclingAllocator<BumpPtrAllocator, SDNode,
 
                                               sizeof(LargestSDNode),
 
                                               alignof(MostAlignedSDNode)>;
 
 
 
  /// Pool allocation for nodes.
 
  NodeAllocatorType NodeAllocator;
 
 
 
  /// This structure is used to memoize nodes, automatically performing
 
  /// CSE with existing nodes when a duplicate is requested.
 
  FoldingSet<SDNode> CSEMap;
 
 
 
  /// Pool allocation for machine-opcode SDNode operands.
 
  BumpPtrAllocator OperandAllocator;
 
  ArrayRecycler<SDUse> OperandRecycler;
 
 
 
  /// Tracks dbg_value and dbg_label information through SDISel.
 
  SDDbgInfo *DbgInfo;
 
 
 
  using CallSiteInfo = MachineFunction::CallSiteInfo;
 
  using CallSiteInfoImpl = MachineFunction::CallSiteInfoImpl;
 
 
 
  struct NodeExtraInfo {
 
    CallSiteInfo CSInfo;
 
    MDNode *HeapAllocSite = nullptr;
 
    MDNode *PCSections = nullptr;
 
    bool NoMerge = false;
 
  };
 
  /// Out-of-line extra information for SDNodes.
 
  DenseMap<const SDNode *, NodeExtraInfo> SDEI;
 
 
 
  /// PersistentId counter to be used when inserting the next
 
  /// SDNode to this SelectionDAG. We do not place that under
 
  /// `#if LLVM_ENABLE_ABI_BREAKING_CHECKS` intentionally because
 
  /// it adds unneeded complexity without noticeable
 
  /// benefits (see discussion with @thakis in D120714).
 
  uint16_t NextPersistentId = 0;
 
 
 
public:
 
  /// Clients of various APIs that cause global effects on
 
  /// the DAG can optionally implement this interface.  This allows the clients
 
  /// to handle the various sorts of updates that happen.
 
  ///
 
  /// A DAGUpdateListener automatically registers itself with DAG when it is
 
  /// constructed, and removes itself when destroyed in RAII fashion.
 
  struct DAGUpdateListener {
 
    DAGUpdateListener *const Next;
 
    SelectionDAG &DAG;
 
 
 
    explicit DAGUpdateListener(SelectionDAG &D)
 
      : Next(D.UpdateListeners), DAG(D) {
 
      DAG.UpdateListeners = this;
 
    }
 
 
 
    virtual ~DAGUpdateListener() {
 
      assert(DAG.UpdateListeners == this &&
 
             "DAGUpdateListeners must be destroyed in LIFO order");
 
      DAG.UpdateListeners = Next;
 
    }
 
 
 
    /// The node N that was deleted and, if E is not null, an
 
    /// equivalent node E that replaced it.
 
    virtual void NodeDeleted(SDNode *N, SDNode *E);
 
 
 
    /// The node N that was updated.
 
    virtual void NodeUpdated(SDNode *N);
 
 
 
    /// The node N that was inserted.
 
    virtual void NodeInserted(SDNode *N);
 
  };
 
 
 
  struct DAGNodeDeletedListener : public DAGUpdateListener {
 
    std::function<void(SDNode *, SDNode *)> Callback;
 
 
 
    DAGNodeDeletedListener(SelectionDAG &DAG,
 
                           std::function<void(SDNode *, SDNode *)> Callback)
 
        : DAGUpdateListener(DAG), Callback(std::move(Callback)) {}
 
 
 
    void NodeDeleted(SDNode *N, SDNode *E) override { Callback(N, E); }
 
 
 
   private:
 
    virtual void anchor();
 
  };
 
 
 
  struct DAGNodeInsertedListener : public DAGUpdateListener {
 
    std::function<void(SDNode *)> Callback;
 
 
 
    DAGNodeInsertedListener(SelectionDAG &DAG,
 
                            std::function<void(SDNode *)> Callback)
 
        : DAGUpdateListener(DAG), Callback(std::move(Callback)) {}
 
 
 
    void NodeInserted(SDNode *N) override { Callback(N); }
 
 
 
  private:
 
    virtual void anchor();
 
  };
 
 
 
  /// Help to insert SDNodeFlags automatically in transforming. Use
 
  /// RAII to save and resume flags in current scope.
 
  class FlagInserter {
 
    SelectionDAG &DAG;
 
    SDNodeFlags Flags;
 
    FlagInserter *LastInserter;
 
 
 
  public:
 
    FlagInserter(SelectionDAG &SDAG, SDNodeFlags Flags)
 
        : DAG(SDAG), Flags(Flags),
 
          LastInserter(SDAG.getFlagInserter()) {
 
      SDAG.setFlagInserter(this);
 
    }
 
    FlagInserter(SelectionDAG &SDAG, SDNode *N)
 
        : FlagInserter(SDAG, N->getFlags()) {}
 
 
 
    FlagInserter(const FlagInserter &) = delete;
 
    FlagInserter &operator=(const FlagInserter &) = delete;
 
    ~FlagInserter() { DAG.setFlagInserter(LastInserter); }
 
 
 
    SDNodeFlags getFlags() const { return Flags; }
 
  };
 
 
 
  /// When true, additional steps are taken to
 
  /// ensure that getConstant() and similar functions return DAG nodes that
 
  /// have legal types. This is important after type legalization since
 
  /// any illegally typed nodes generated after this point will not experience
 
  /// type legalization.
 
  bool NewNodesMustHaveLegalTypes = false;
 
 
 
private:
 
  /// DAGUpdateListener is a friend so it can manipulate the listener stack.
 
  friend struct DAGUpdateListener;
 
 
 
  /// Linked list of registered DAGUpdateListener instances.
 
  /// This stack is maintained by DAGUpdateListener RAII.
 
  DAGUpdateListener *UpdateListeners = nullptr;
 
 
 
  /// Implementation of setSubgraphColor.
 
  /// Return whether we had to truncate the search.
 
  bool setSubgraphColorHelper(SDNode *N, const char *Color,
 
                              DenseSet<SDNode *> &visited,
 
                              int level, bool &printed);
 
 
 
  template <typename SDNodeT, typename... ArgTypes>
 
  SDNodeT *newSDNode(ArgTypes &&... Args) {
 
    return new (NodeAllocator.template Allocate<SDNodeT>())
 
        SDNodeT(std::forward<ArgTypes>(Args)...);
 
  }
 
 
 
  /// Build a synthetic SDNodeT with the given args and extract its subclass
 
  /// data as an integer (e.g. for use in a folding set).
 
  ///
 
  /// The args to this function are the same as the args to SDNodeT's
 
  /// constructor, except the second arg (assumed to be a const DebugLoc&) is
 
  /// omitted.
 
  template <typename SDNodeT, typename... ArgTypes>
 
  static uint16_t getSyntheticNodeSubclassData(unsigned IROrder,
 
                                               ArgTypes &&... Args) {
 
    // The compiler can reduce this expression to a constant iff we pass an
 
    // empty DebugLoc.  Thankfully, the debug location doesn't have any bearing
 
    // on the subclass data.
 
    return SDNodeT(IROrder, DebugLoc(), std::forward<ArgTypes>(Args)...)
 
        .getRawSubclassData();
 
  }
 
 
 
  template <typename SDNodeTy>
 
  static uint16_t getSyntheticNodeSubclassData(unsigned Opc, unsigned Order,
 
                                                SDVTList VTs, EVT MemoryVT,
 
                                                MachineMemOperand *MMO) {
 
    return SDNodeTy(Opc, Order, DebugLoc(), VTs, MemoryVT, MMO)
 
         .getRawSubclassData();
 
  }
 
 
 
  void createOperands(SDNode *Node, ArrayRef<SDValue> Vals);
 
 
 
  void removeOperands(SDNode *Node) {
 
    if (!Node->OperandList)
 
      return;
 
    OperandRecycler.deallocate(
 
        ArrayRecycler<SDUse>::Capacity::get(Node->NumOperands),
 
        Node->OperandList);
 
    Node->NumOperands = 0;
 
    Node->OperandList = nullptr;
 
  }
 
  void CreateTopologicalOrder(std::vector<SDNode*>& Order);
 
 
 
public:
 
  // Maximum depth for recursive analysis such as computeKnownBits, etc.
 
  static constexpr unsigned MaxRecursionDepth = 6;
 
 
 
  explicit SelectionDAG(const TargetMachine &TM, CodeGenOpt::Level);
 
  SelectionDAG(const SelectionDAG &) = delete;
 
  SelectionDAG &operator=(const SelectionDAG &) = delete;
 
  ~SelectionDAG();
 
 
 
  /// Prepare this SelectionDAG to process code in the given MachineFunction.
 
  void init(MachineFunction &NewMF, OptimizationRemarkEmitter &NewORE,
 
            Pass *PassPtr, const TargetLibraryInfo *LibraryInfo,
 
            LegacyDivergenceAnalysis *Divergence, ProfileSummaryInfo *PSIin,
 
            BlockFrequencyInfo *BFIin, FunctionVarLocs const *FnVarLocs);
 
 
 
  void setFunctionLoweringInfo(FunctionLoweringInfo * FuncInfo) {
 
    FLI = FuncInfo;
 
  }
 
 
 
  /// Clear state and free memory necessary to make this
 
  /// SelectionDAG ready to process a new block.
 
  void clear();
 
 
 
  MachineFunction &getMachineFunction() const { return *MF; }
 
  const Pass *getPass() const { return SDAGISelPass; }
 
 
 
  const DataLayout &getDataLayout() const { return MF->getDataLayout(); }
 
  const TargetMachine &getTarget() const { return TM; }
 
  const TargetSubtargetInfo &getSubtarget() const { return MF->getSubtarget(); }
 
  template <typename STC> const STC &getSubtarget() const {
 
    return MF->getSubtarget<STC>();
 
  }
 
  const TargetLowering &getTargetLoweringInfo() const { return *TLI; }
 
  const TargetLibraryInfo &getLibInfo() const { return *LibInfo; }
 
  const SelectionDAGTargetInfo &getSelectionDAGInfo() const { return *TSI; }
 
  const LegacyDivergenceAnalysis *getDivergenceAnalysis() const { return DA; }
 
  /// Returns the result of the AssignmentTrackingAnalysis pass if it's
 
  /// available, otherwise return nullptr.
 
  const FunctionVarLocs *getFunctionVarLocs() const { return FnVarLocs; }
 
  LLVMContext *getContext() const { return Context; }
 
  OptimizationRemarkEmitter &getORE() const { return *ORE; }
 
  ProfileSummaryInfo *getPSI() const { return PSI; }
 
  BlockFrequencyInfo *getBFI() const { return BFI; }
 
 
 
  FlagInserter *getFlagInserter() { return Inserter; }
 
  void setFlagInserter(FlagInserter *FI) { Inserter = FI; }
 
 
 
  /// Just dump dot graph to a user-provided path and title.
 
  /// This doesn't open the dot viewer program and
 
  /// helps visualization when outside debugging session.
 
  /// FileName expects absolute path. If provided
 
  /// without any path separators then the file
 
  /// will be created in the current directory.
 
  /// Error will be emitted if the path is insane.
 
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 
  LLVM_DUMP_METHOD void dumpDotGraph(const Twine &FileName, const Twine &Title);
 
#endif
 
 
 
  /// Pop up a GraphViz/gv window with the DAG rendered using 'dot'.
 
  void viewGraph(const std::string &Title);
 
  void viewGraph();
 
 
 
#if LLVM_ENABLE_ABI_BREAKING_CHECKS
 
  std::map<const SDNode *, std::string> NodeGraphAttrs;
 
#endif
 
 
 
  /// Clear all previously defined node graph attributes.
 
  /// Intended to be used from a debugging tool (eg. gdb).
 
  void clearGraphAttrs();
 
 
 
  /// Set graph attributes for a node. (eg. "color=red".)
 
  void setGraphAttrs(const SDNode *N, const char *Attrs);
 
 
 
  /// Get graph attributes for a node. (eg. "color=red".)
 
  /// Used from getNodeAttributes.
 
  std::string getGraphAttrs(const SDNode *N) const;
 
 
 
  /// Convenience for setting node color attribute.
 
  void setGraphColor(const SDNode *N, const char *Color);
 
 
 
  /// Convenience for setting subgraph color attribute.
 
  void setSubgraphColor(SDNode *N, const char *Color);
 
 
 
  using allnodes_const_iterator = ilist<SDNode>::const_iterator;
 
 
 
  allnodes_const_iterator allnodes_begin() const { return AllNodes.begin(); }
 
  allnodes_const_iterator allnodes_end() const { return AllNodes.end(); }
 
 
 
  using allnodes_iterator = ilist<SDNode>::iterator;
 
 
 
  allnodes_iterator allnodes_begin() { return AllNodes.begin(); }
 
  allnodes_iterator allnodes_end() { return AllNodes.end(); }
 
 
 
  ilist<SDNode>::size_type allnodes_size() const {
 
    return AllNodes.size();
 
  }
 
 
 
  iterator_range<allnodes_iterator> allnodes() {
 
    return make_range(allnodes_begin(), allnodes_end());
 
  }
 
  iterator_range<allnodes_const_iterator> allnodes() const {
 
    return make_range(allnodes_begin(), allnodes_end());
 
  }
 
 
 
  /// Return the root tag of the SelectionDAG.
 
  const SDValue &getRoot() const { return Root; }
 
 
 
  /// Return the token chain corresponding to the entry of the function.
 
  SDValue getEntryNode() const {
 
    return SDValue(const_cast<SDNode *>(&EntryNode), 0);
 
  }
 
 
 
  /// Set the current root tag of the SelectionDAG.
 
  ///
 
  const SDValue &setRoot(SDValue N) {
 
    assert((!N.getNode() || N.getValueType() == MVT::Other) &&
 
           "DAG root value is not a chain!");
 
    if (N.getNode())
 
      checkForCycles(N.getNode(), this);
 
    Root = N;
 
    if (N.getNode())
 
      checkForCycles(this);
 
    return Root;
 
  }
 
 
 
#ifndef NDEBUG
 
  void VerifyDAGDivergence();
 
#endif
 
 
 
  /// This iterates over the nodes in the SelectionDAG, folding
 
  /// certain types of nodes together, or eliminating superfluous nodes.  The
 
  /// Level argument controls whether Combine is allowed to produce nodes and
 
  /// types that are illegal on the target.
 
  void Combine(CombineLevel Level, AAResults *AA,
 
               CodeGenOpt::Level OptLevel);
 
 
 
  /// This transforms the SelectionDAG into a SelectionDAG that
 
  /// only uses types natively supported by the target.
 
  /// Returns "true" if it made any changes.
 
  ///
 
  /// Note that this is an involved process that may invalidate pointers into
 
  /// the graph.
 
  bool LegalizeTypes();
 
 
 
  /// This transforms the SelectionDAG into a SelectionDAG that is
 
  /// compatible with the target instruction selector, as indicated by the
 
  /// TargetLowering object.
 
  ///
 
  /// Note that this is an involved process that may invalidate pointers into
 
  /// the graph.
 
  void Legalize();
 
 
 
  /// Transforms a SelectionDAG node and any operands to it into a node
 
  /// that is compatible with the target instruction selector, as indicated by
 
  /// the TargetLowering object.
 
  ///
 
  /// \returns true if \c N is a valid, legal node after calling this.
 
  ///
 
  /// This essentially runs a single recursive walk of the \c Legalize process
 
  /// over the given node (and its operands). This can be used to incrementally
 
  /// legalize the DAG. All of the nodes which are directly replaced,
 
  /// potentially including N, are added to the output parameter \c
 
  /// UpdatedNodes so that the delta to the DAG can be understood by the
 
  /// caller.
 
  ///
 
  /// When this returns false, N has been legalized in a way that make the
 
  /// pointer passed in no longer valid. It may have even been deleted from the
 
  /// DAG, and so it shouldn't be used further. When this returns true, the
 
  /// N passed in is a legal node, and can be immediately processed as such.
 
  /// This may still have done some work on the DAG, and will still populate
 
  /// UpdatedNodes with any new nodes replacing those originally in the DAG.
 
  bool LegalizeOp(SDNode *N, SmallSetVector<SDNode *, 16> &UpdatedNodes);
 
 
 
  /// This transforms the SelectionDAG into a SelectionDAG
 
  /// that only uses vector math operations supported by the target.  This is
 
  /// necessary as a separate step from Legalize because unrolling a vector
 
  /// operation can introduce illegal types, which requires running
 
  /// LegalizeTypes again.
 
  ///
 
  /// This returns true if it made any changes; in that case, LegalizeTypes
 
  /// is called again before Legalize.
 
  ///
 
  /// Note that this is an involved process that may invalidate pointers into
 
  /// the graph.
 
  bool LegalizeVectors();
 
 
 
  /// This method deletes all unreachable nodes in the SelectionDAG.
 
  void RemoveDeadNodes();
 
 
 
  /// Remove the specified node from the system.  This node must
 
  /// have no referrers.
 
  void DeleteNode(SDNode *N);
 
 
 
  /// Return an SDVTList that represents the list of values specified.
 
  SDVTList getVTList(EVT VT);
 
  SDVTList getVTList(EVT VT1, EVT VT2);
 
  SDVTList getVTList(EVT VT1, EVT VT2, EVT VT3);
 
  SDVTList getVTList(EVT VT1, EVT VT2, EVT VT3, EVT VT4);
 
  SDVTList getVTList(ArrayRef<EVT> VTs);
 
 
 
  //===--------------------------------------------------------------------===//
 
  // Node creation methods.
 
 
 
  /// Create a ConstantSDNode wrapping a constant value.
 
  /// If VT is a vector type, the constant is splatted into a BUILD_VECTOR.
 
  ///
 
  /// If only legal types can be produced, this does the necessary
 
  /// transformations (e.g., if the vector element type is illegal).
 
  /// @{
 
  SDValue getConstant(uint64_t Val, const SDLoc &DL, EVT VT,
 
                      bool isTarget = false, bool isOpaque = false);
 
  SDValue getConstant(const APInt &Val, const SDLoc &DL, EVT VT,
 
                      bool isTarget = false, bool isOpaque = false);
 
 
 
  SDValue getAllOnesConstant(const SDLoc &DL, EVT VT, bool IsTarget = false,
 
                             bool IsOpaque = false) {
 
    return getConstant(APInt::getAllOnes(VT.getScalarSizeInBits()), DL, VT,
 
                       IsTarget, IsOpaque);
 
  }
 
 
 
  SDValue getConstant(const ConstantInt &Val, const SDLoc &DL, EVT VT,
 
                      bool isTarget = false, bool isOpaque = false);
 
  SDValue getIntPtrConstant(uint64_t Val, const SDLoc &DL,
 
                            bool isTarget = false);
 
  SDValue getShiftAmountConstant(uint64_t Val, EVT VT, const SDLoc &DL,
 
                                 bool LegalTypes = true);
 
  SDValue getVectorIdxConstant(uint64_t Val, const SDLoc &DL,
 
                               bool isTarget = false);
 
 
 
  SDValue getTargetConstant(uint64_t Val, const SDLoc &DL, EVT VT,
 
                            bool isOpaque = false) {
 
    return getConstant(Val, DL, VT, true, isOpaque);
 
  }
 
  SDValue getTargetConstant(const APInt &Val, const SDLoc &DL, EVT VT,
 
                            bool isOpaque = false) {
 
    return getConstant(Val, DL, VT, true, isOpaque);
 
  }
 
  SDValue getTargetConstant(const ConstantInt &Val, const SDLoc &DL, EVT VT,
 
                            bool isOpaque = false) {
 
    return getConstant(Val, DL, VT, true, isOpaque);
 
  }
 
 
 
  /// Create a true or false constant of type \p VT using the target's
 
  /// BooleanContent for type \p OpVT.
 
  SDValue getBoolConstant(bool V, const SDLoc &DL, EVT VT, EVT OpVT);
 
  /// @}
 
 
 
  /// Create a ConstantFPSDNode wrapping a constant value.
 
  /// If VT is a vector type, the constant is splatted into a BUILD_VECTOR.
 
  ///
 
  /// If only legal types can be produced, this does the necessary
 
  /// transformations (e.g., if the vector element type is illegal).
 
  /// The forms that take a double should only be used for simple constants
 
  /// that can be exactly represented in VT.  No checks are made.
 
  /// @{
 
  SDValue getConstantFP(double Val, const SDLoc &DL, EVT VT,
 
                        bool isTarget = false);
 
  SDValue getConstantFP(const APFloat &Val, const SDLoc &DL, EVT VT,
 
                        bool isTarget = false);
 
  SDValue getConstantFP(const ConstantFP &V, const SDLoc &DL, EVT VT,
 
                        bool isTarget = false);
 
  SDValue getTargetConstantFP(double Val, const SDLoc &DL, EVT VT) {
 
    return getConstantFP(Val, DL, VT, true);
 
  }
 
  SDValue getTargetConstantFP(const APFloat &Val, const SDLoc &DL, EVT VT) {
 
    return getConstantFP(Val, DL, VT, true);
 
  }
 
  SDValue getTargetConstantFP(const ConstantFP &Val, const SDLoc &DL, EVT VT) {
 
    return getConstantFP(Val, DL, VT, true);
 
  }
 
  /// @}
 
 
 
  SDValue getGlobalAddress(const GlobalValue *GV, const SDLoc &DL, EVT VT,
 
                           int64_t offset = 0, bool isTargetGA = false,
 
                           unsigned TargetFlags = 0);
 
  SDValue getTargetGlobalAddress(const GlobalValue *GV, const SDLoc &DL, EVT VT,
 
                                 int64_t offset = 0, unsigned TargetFlags = 0) {
 
    return getGlobalAddress(GV, DL, VT, offset, true, TargetFlags);
 
  }
 
  SDValue getFrameIndex(int FI, EVT VT, bool isTarget = false);
 
  SDValue getTargetFrameIndex(int FI, EVT VT) {
 
    return getFrameIndex(FI, VT, true);
 
  }
 
  SDValue getJumpTable(int JTI, EVT VT, bool isTarget = false,
 
                       unsigned TargetFlags = 0);
 
  SDValue getTargetJumpTable(int JTI, EVT VT, unsigned TargetFlags = 0) {
 
    return getJumpTable(JTI, VT, true, TargetFlags);
 
  }
 
  SDValue getConstantPool(const Constant *C, EVT VT,
 
                          MaybeAlign Align = std::nullopt, int Offs = 0,
 
                          bool isT = false, unsigned TargetFlags = 0);
 
  SDValue getTargetConstantPool(const Constant *C, EVT VT,
 
                                MaybeAlign Align = std::nullopt, int Offset = 0,
 
                                unsigned TargetFlags = 0) {
 
    return getConstantPool(C, VT, Align, Offset, true, TargetFlags);
 
  }
 
  SDValue getConstantPool(MachineConstantPoolValue *C, EVT VT,
 
                          MaybeAlign Align = std::nullopt, int Offs = 0,
 
                          bool isT = false, unsigned TargetFlags = 0);
 
  SDValue getTargetConstantPool(MachineConstantPoolValue *C, EVT VT,
 
                                MaybeAlign Align = std::nullopt, int Offset = 0,
 
                                unsigned TargetFlags = 0) {
 
    return getConstantPool(C, VT, Align, Offset, true, TargetFlags);
 
  }
 
  SDValue getTargetIndex(int Index, EVT VT, int64_t Offset = 0,
 
                         unsigned TargetFlags = 0);
 
  // When generating a branch to a BB, we don't in general know enough
 
  // to provide debug info for the BB at that time, so keep this one around.
 
  SDValue getBasicBlock(MachineBasicBlock *MBB);
 
  SDValue getExternalSymbol(const char *Sym, EVT VT);
 
  SDValue getTargetExternalSymbol(const char *Sym, EVT VT,
 
                                  unsigned TargetFlags = 0);
 
  SDValue getMCSymbol(MCSymbol *Sym, EVT VT);
 
 
 
  SDValue getValueType(EVT);
 
  SDValue getRegister(unsigned Reg, EVT VT);
 
  SDValue getRegisterMask(const uint32_t *RegMask);
 
  SDValue getEHLabel(const SDLoc &dl, SDValue Root, MCSymbol *Label);
 
  SDValue getLabelNode(unsigned Opcode, const SDLoc &dl, SDValue Root,
 
                       MCSymbol *Label);
 
  SDValue getBlockAddress(const BlockAddress *BA, EVT VT, int64_t Offset = 0,
 
                          bool isTarget = false, unsigned TargetFlags = 0);
 
  SDValue getTargetBlockAddress(const BlockAddress *BA, EVT VT,
 
                                int64_t Offset = 0, unsigned TargetFlags = 0) {
 
    return getBlockAddress(BA, VT, Offset, true, TargetFlags);
 
  }
 
 
 
  SDValue getCopyToReg(SDValue Chain, const SDLoc &dl, unsigned Reg,
 
                       SDValue N) {
 
    return getNode(ISD::CopyToReg, dl, MVT::Other, Chain,
 
                   getRegister(Reg, N.getValueType()), N);
 
  }
 
 
 
  // This version of the getCopyToReg method takes an extra operand, which
 
  // indicates that there is potentially an incoming glue value (if Glue is not
 
  // null) and that there should be a glue result.
 
  SDValue getCopyToReg(SDValue Chain, const SDLoc &dl, unsigned Reg, SDValue N,
 
                       SDValue Glue) {
 
    SDVTList VTs = getVTList(MVT::Other, MVT::Glue);
 
    SDValue Ops[] = { Chain, getRegister(Reg, N.getValueType()), N, Glue };
 
    return getNode(ISD::CopyToReg, dl, VTs,
 
                   ArrayRef(Ops, Glue.getNode() ? 4 : 3));
 
  }
 
 
 
  // Similar to last getCopyToReg() except parameter Reg is a SDValue
 
  SDValue getCopyToReg(SDValue Chain, const SDLoc &dl, SDValue Reg, SDValue N,
 
                       SDValue Glue) {
 
    SDVTList VTs = getVTList(MVT::Other, MVT::Glue);
 
    SDValue Ops[] = { Chain, Reg, N, Glue };
 
    return getNode(ISD::CopyToReg, dl, VTs,
 
                   ArrayRef(Ops, Glue.getNode() ? 4 : 3));
 
  }
 
 
 
  SDValue getCopyFromReg(SDValue Chain, const SDLoc &dl, unsigned Reg, EVT VT) {
 
    SDVTList VTs = getVTList(VT, MVT::Other);
 
    SDValue Ops[] = { Chain, getRegister(Reg, VT) };
 
    return getNode(ISD::CopyFromReg, dl, VTs, Ops);
 
  }
 
 
 
  // This version of the getCopyFromReg method takes an extra operand, which
 
  // indicates that there is potentially an incoming glue value (if Glue is not
 
  // null) and that there should be a glue result.
 
  SDValue getCopyFromReg(SDValue Chain, const SDLoc &dl, unsigned Reg, EVT VT,
 
                         SDValue Glue) {
 
    SDVTList VTs = getVTList(VT, MVT::Other, MVT::Glue);
 
    SDValue Ops[] = { Chain, getRegister(Reg, VT), Glue };
 
    return getNode(ISD::CopyFromReg, dl, VTs,
 
                   ArrayRef(Ops, Glue.getNode() ? 3 : 2));
 
  }
 
 
 
  SDValue getCondCode(ISD::CondCode Cond);
 
 
 
  /// Return an ISD::VECTOR_SHUFFLE node. The number of elements in VT,
 
  /// which must be a vector type, must match the number of mask elements
 
  /// NumElts. An integer mask element equal to -1 is treated as undefined.
 
  SDValue getVectorShuffle(EVT VT, const SDLoc &dl, SDValue N1, SDValue N2,
 
                           ArrayRef<int> Mask);
 
 
 
  /// Return an ISD::BUILD_VECTOR node. The number of elements in VT,
 
  /// which must be a vector type, must match the number of operands in Ops.
 
  /// The operands must have the same type as (or, for integers, a type wider
 
  /// than) VT's element type.
 
  SDValue getBuildVector(EVT VT, const SDLoc &DL, ArrayRef<SDValue> Ops) {
 
    // VerifySDNode (via InsertNode) checks BUILD_VECTOR later.
 
    return getNode(ISD::BUILD_VECTOR, DL, VT, Ops);
 
  }
 
 
 
  /// Return an ISD::BUILD_VECTOR node. The number of elements in VT,
 
  /// which must be a vector type, must match the number of operands in Ops.
 
  /// The operands must have the same type as (or, for integers, a type wider
 
  /// than) VT's element type.
 
  SDValue getBuildVector(EVT VT, const SDLoc &DL, ArrayRef<SDUse> Ops) {
 
    // VerifySDNode (via InsertNode) checks BUILD_VECTOR later.
 
    return getNode(ISD::BUILD_VECTOR, DL, VT, Ops);
 
  }
 
 
 
  /// Return a splat ISD::BUILD_VECTOR node, consisting of Op splatted to all
 
  /// elements. VT must be a vector type. Op's type must be the same as (or,
 
  /// for integers, a type wider than) VT's element type.
 
  SDValue getSplatBuildVector(EVT VT, const SDLoc &DL, SDValue Op) {
 
    // VerifySDNode (via InsertNode) checks BUILD_VECTOR later.
 
    if (Op.getOpcode() == ISD::UNDEF) {
 
      assert((VT.getVectorElementType() == Op.getValueType() ||
 
              (VT.isInteger() &&
 
               VT.getVectorElementType().bitsLE(Op.getValueType()))) &&
 
             "A splatted value must have a width equal or (for integers) "
 
             "greater than the vector element type!");
 
      return getNode(ISD::UNDEF, SDLoc(), VT);
 
    }
 
 
 
    SmallVector<SDValue, 16> Ops(VT.getVectorNumElements(), Op);
 
    return getNode(ISD::BUILD_VECTOR, DL, VT, Ops);
 
  }
 
 
 
  // Return a splat ISD::SPLAT_VECTOR node, consisting of Op splatted to all
 
  // elements.
 
  SDValue getSplatVector(EVT VT, const SDLoc &DL, SDValue Op) {
 
    if (Op.getOpcode() == ISD::UNDEF) {
 
      assert((VT.getVectorElementType() == Op.getValueType() ||
 
              (VT.isInteger() &&
 
               VT.getVectorElementType().bitsLE(Op.getValueType()))) &&
 
             "A splatted value must have a width equal or (for integers) "
 
             "greater than the vector element type!");
 
      return getNode(ISD::UNDEF, SDLoc(), VT);
 
    }
 
    return getNode(ISD::SPLAT_VECTOR, DL, VT, Op);
 
  }
 
 
 
  /// Returns a node representing a splat of one value into all lanes
 
  /// of the provided vector type.  This is a utility which returns
 
  /// either a BUILD_VECTOR or SPLAT_VECTOR depending on the
 
  /// scalability of the desired vector type.
 
  SDValue getSplat(EVT VT, const SDLoc &DL, SDValue Op) {
 
    assert(VT.isVector() && "Can't splat to non-vector type");
 
    return VT.isScalableVector() ?
 
      getSplatVector(VT, DL, Op) : getSplatBuildVector(VT, DL, Op);
 
  }
 
 
 
  /// Returns a vector of type ResVT whose elements contain the linear sequence
 
  ///   <0, Step, Step * 2, Step * 3, ...>
 
  SDValue getStepVector(const SDLoc &DL, EVT ResVT, APInt StepVal);
 
 
 
  /// Returns a vector of type ResVT whose elements contain the linear sequence
 
  ///   <0, 1, 2, 3, ...>
 
  SDValue getStepVector(const SDLoc &DL, EVT ResVT);
 
 
 
  /// Returns an ISD::VECTOR_SHUFFLE node semantically equivalent to
 
  /// the shuffle node in input but with swapped operands.
 
  ///
 
  /// Example: shuffle A, B, <0,5,2,7> -> shuffle B, A, <4,1,6,3>
 
  SDValue getCommutedVectorShuffle(const ShuffleVectorSDNode &SV);
 
 
 
  /// Convert Op, which must be of float type, to the
 
  /// float type VT, by either extending or rounding (by truncation).
 
  SDValue getFPExtendOrRound(SDValue Op, const SDLoc &DL, EVT VT);
 
 
 
  /// Convert Op, which must be a STRICT operation of float type, to the
 
  /// float type VT, by either extending or rounding (by truncation).
 
  std::pair<SDValue, SDValue>
 
  getStrictFPExtendOrRound(SDValue Op, SDValue Chain, const SDLoc &DL, EVT VT);
 
 
 
  /// Convert *_EXTEND_VECTOR_INREG to *_EXTEND opcode.
 
  static unsigned getOpcode_EXTEND(unsigned Opcode) {
 
    switch (Opcode) {
 
    case ISD::ANY_EXTEND:
 
    case ISD::ANY_EXTEND_VECTOR_INREG:
 
      return ISD::ANY_EXTEND;
 
    case ISD::ZERO_EXTEND:
 
    case ISD::ZERO_EXTEND_VECTOR_INREG:
 
      return ISD::ZERO_EXTEND;
 
    case ISD::SIGN_EXTEND:
 
    case ISD::SIGN_EXTEND_VECTOR_INREG:
 
      return ISD::SIGN_EXTEND;
 
    }
 
    llvm_unreachable("Unknown opcode");
 
  }
 
 
 
  /// Convert *_EXTEND to *_EXTEND_VECTOR_INREG opcode.
 
  static unsigned getOpcode_EXTEND_VECTOR_INREG(unsigned Opcode) {
 
    switch (Opcode) {
 
    case ISD::ANY_EXTEND:
 
    case ISD::ANY_EXTEND_VECTOR_INREG:
 
      return ISD::ANY_EXTEND_VECTOR_INREG;
 
    case ISD::ZERO_EXTEND:
 
    case ISD::ZERO_EXTEND_VECTOR_INREG:
 
      return ISD::ZERO_EXTEND_VECTOR_INREG;
 
    case ISD::SIGN_EXTEND:
 
    case ISD::SIGN_EXTEND_VECTOR_INREG:
 
      return ISD::SIGN_EXTEND_VECTOR_INREG;
 
    }
 
    llvm_unreachable("Unknown opcode");
 
  }
 
 
 
  /// Convert Op, which must be of integer type, to the
 
  /// integer type VT, by either any-extending or truncating it.
 
  SDValue getAnyExtOrTrunc(SDValue Op, const SDLoc &DL, EVT VT);
 
 
 
  /// Convert Op, which must be of integer type, to the
 
  /// integer type VT, by either sign-extending or truncating it.
 
  SDValue getSExtOrTrunc(SDValue Op, const SDLoc &DL, EVT VT);
 
 
 
  /// Convert Op, which must be of integer type, to the
 
  /// integer type VT, by either zero-extending or truncating it.
 
  SDValue getZExtOrTrunc(SDValue Op, const SDLoc &DL, EVT VT);
 
 
 
  /// Return the expression required to zero extend the Op
 
  /// value assuming it was the smaller SrcTy value.
 
  SDValue getZeroExtendInReg(SDValue Op, const SDLoc &DL, EVT VT);
 
 
 
  /// Convert Op, which must be of integer type, to the integer type VT, by
 
  /// either truncating it or performing either zero or sign extension as
 
  /// appropriate extension for the pointer's semantics.
 
  SDValue getPtrExtOrTrunc(SDValue Op, const SDLoc &DL, EVT VT);
 
 
 
  /// Return the expression required to extend the Op as a pointer value
 
  /// assuming it was the smaller SrcTy value. This may be either a zero extend
 
  /// or a sign extend.
 
  SDValue getPtrExtendInReg(SDValue Op, const SDLoc &DL, EVT VT);
 
 
 
  /// Convert Op, which must be of integer type, to the integer type VT,
 
  /// by using an extension appropriate for the target's
 
  /// BooleanContent for type OpVT or truncating it.
 
  SDValue getBoolExtOrTrunc(SDValue Op, const SDLoc &SL, EVT VT, EVT OpVT);
 
 
 
  /// Create negative operation as (SUB 0, Val).
 
  SDValue getNegative(SDValue Val, const SDLoc &DL, EVT VT);
 
 
 
  /// Create a bitwise NOT operation as (XOR Val, -1).
 
  SDValue getNOT(const SDLoc &DL, SDValue Val, EVT VT);
 
 
 
  /// Create a logical NOT operation as (XOR Val, BooleanOne).
 
  SDValue getLogicalNOT(const SDLoc &DL, SDValue Val, EVT VT);
 
 
 
  /// Create a vector-predicated logical NOT operation as (VP_XOR Val,
 
  /// BooleanOne, Mask, EVL).
 
  SDValue getVPLogicalNOT(const SDLoc &DL, SDValue Val, SDValue Mask,
 
                          SDValue EVL, EVT VT);
 
 
 
  /// Convert a vector-predicated Op, which must be an integer vector, to the
 
  /// vector-type VT, by performing either vector-predicated zext or truncating
 
  /// it. The Op will be returned as-is if Op and VT are vectors containing
 
  /// integer with same width.
 
  SDValue getVPZExtOrTrunc(const SDLoc &DL, EVT VT, SDValue Op, SDValue Mask,
 
                           SDValue EVL);
 
 
 
  /// Convert a vector-predicated Op, which must be of integer type, to the
 
  /// vector-type integer type VT, by either truncating it or performing either
 
  /// vector-predicated zero or sign extension as appropriate extension for the
 
  /// pointer's semantics. This function just redirects to getVPZExtOrTrunc
 
  /// right now.
 
  SDValue getVPPtrExtOrTrunc(const SDLoc &DL, EVT VT, SDValue Op, SDValue Mask,
 
                             SDValue EVL);
 
 
 
  /// Returns sum of the base pointer and offset.
 
  /// Unlike getObjectPtrOffset this does not set NoUnsignedWrap by default.
 
  SDValue getMemBasePlusOffset(SDValue Base, TypeSize Offset, const SDLoc &DL,
 
                               const SDNodeFlags Flags = SDNodeFlags());
 
  SDValue getMemBasePlusOffset(SDValue Base, SDValue Offset, const SDLoc &DL,
 
                               const SDNodeFlags Flags = SDNodeFlags());
 
 
 
  /// Create an add instruction with appropriate flags when used for
 
  /// addressing some offset of an object. i.e. if a load is split into multiple
 
  /// components, create an add nuw from the base pointer to the offset.
 
  SDValue getObjectPtrOffset(const SDLoc &SL, SDValue Ptr, TypeSize Offset) {
 
    SDNodeFlags Flags;
 
    Flags.setNoUnsignedWrap(true);
 
    return getMemBasePlusOffset(Ptr, Offset, SL, Flags);
 
  }
 
 
 
  SDValue getObjectPtrOffset(const SDLoc &SL, SDValue Ptr, SDValue Offset) {
 
    // The object itself can't wrap around the address space, so it shouldn't be
 
    // possible for the adds of the offsets to the split parts to overflow.
 
    SDNodeFlags Flags;
 
    Flags.setNoUnsignedWrap(true);
 
    return getMemBasePlusOffset(Ptr, Offset, SL, Flags);
 
  }
 
 
 
  /// Return a new CALLSEQ_START node, that starts new call frame, in which
 
  /// InSize bytes are set up inside CALLSEQ_START..CALLSEQ_END sequence and
 
  /// OutSize specifies part of the frame set up prior to the sequence.
 
  SDValue getCALLSEQ_START(SDValue Chain, uint64_t InSize, uint64_t OutSize,
 
                           const SDLoc &DL) {
 
    SDVTList VTs = getVTList(MVT::Other, MVT::Glue);
 
    SDValue Ops[] = { Chain,
 
                      getIntPtrConstant(InSize, DL, true),
 
                      getIntPtrConstant(OutSize, DL, true) };
 
    return getNode(ISD::CALLSEQ_START, DL, VTs, Ops);
 
  }
 
 
 
  /// Return a new CALLSEQ_END node, which always must have a
 
  /// glue result (to ensure it's not CSE'd).
 
  /// CALLSEQ_END does not have a useful SDLoc.
 
  SDValue getCALLSEQ_END(SDValue Chain, SDValue Op1, SDValue Op2,
 
                         SDValue InGlue, const SDLoc &DL) {
 
    SDVTList NodeTys = getVTList(MVT::Other, MVT::Glue);
 
    SmallVector<SDValue, 4> Ops;
 
    Ops.push_back(Chain);
 
    Ops.push_back(Op1);
 
    Ops.push_back(Op2);
 
    if (InGlue.getNode())
 
      Ops.push_back(InGlue);
 
    return getNode(ISD::CALLSEQ_END, DL, NodeTys, Ops);
 
  }
 
 
 
  SDValue getCALLSEQ_END(SDValue Chain, uint64_t Size1, uint64_t Size2,
 
                         SDValue Glue, const SDLoc &DL) {
 
    return getCALLSEQ_END(
 
        Chain, getIntPtrConstant(Size1, DL, /*isTarget=*/true),
 
        getIntPtrConstant(Size2, DL, /*isTarget=*/true), Glue, DL);
 
  }
 
 
 
  /// Return true if the result of this operation is always undefined.
 
  bool isUndef(unsigned Opcode, ArrayRef<SDValue> Ops);
 
 
 
  /// Return an UNDEF node. UNDEF does not have a useful SDLoc.
 
  SDValue getUNDEF(EVT VT) {
 
    return getNode(ISD::UNDEF, SDLoc(), VT);
 
  }
 
 
 
  /// Return a node that represents the runtime scaling 'MulImm * RuntimeVL'.
 
  SDValue getVScale(const SDLoc &DL, EVT VT, APInt MulImm) {
 
    assert(MulImm.getMinSignedBits() <= VT.getSizeInBits() &&
 
           "Immediate does not fit VT");
 
    return getNode(ISD::VSCALE, DL, VT,
 
                   getConstant(MulImm.sextOrTrunc(VT.getSizeInBits()), DL, VT));
 
  }
 
 
 
  /// Return a GLOBAL_OFFSET_TABLE node. This does not have a useful SDLoc.
 
  SDValue getGLOBAL_OFFSET_TABLE(EVT VT) {
 
    return getNode(ISD::GLOBAL_OFFSET_TABLE, SDLoc(), VT);
 
  }
 
 
 
  /// Gets or creates the specified node.
 
  ///
 
  SDValue getNode(unsigned Opcode, const SDLoc &DL, EVT VT,
 
                  ArrayRef<SDUse> Ops);
 
  SDValue getNode(unsigned Opcode, const SDLoc &DL, EVT VT,
 
                  ArrayRef<SDValue> Ops, const SDNodeFlags Flags);
 
  SDValue getNode(unsigned Opcode, const SDLoc &DL, ArrayRef<EVT> ResultTys,
 
                  ArrayRef<SDValue> Ops);
 
  SDValue getNode(unsigned Opcode, const SDLoc &DL, SDVTList VTList,
 
                  ArrayRef<SDValue> Ops, const SDNodeFlags Flags);
 
 
 
  // Use flags from current flag inserter.
 
  SDValue getNode(unsigned Opcode, const SDLoc &DL, EVT VT,
 
                  ArrayRef<SDValue> Ops);
 
  SDValue getNode(unsigned Opcode, const SDLoc &DL, SDVTList VTList,
 
                  ArrayRef<SDValue> Ops);
 
  SDValue getNode(unsigned Opcode, const SDLoc &DL, EVT VT, SDValue Operand);
 
  SDValue getNode(unsigned Opcode, const SDLoc &DL, EVT VT, SDValue N1,
 
                  SDValue N2);
 
  SDValue getNode(unsigned Opcode, const SDLoc &DL, EVT VT, SDValue N1,
 
                  SDValue N2, SDValue N3);
 
 
 
  // Specialize based on number of operands.
 
  SDValue getNode(unsigned Opcode, const SDLoc &DL, EVT VT);
 
  SDValue getNode(unsigned Opcode, const SDLoc &DL, EVT VT, SDValue Operand,
 
                  const SDNodeFlags Flags);
 
  SDValue getNode(unsigned Opcode, const SDLoc &DL, EVT VT, SDValue N1,
 
                  SDValue N2, const SDNodeFlags Flags);
 
  SDValue getNode(unsigned Opcode, const SDLoc &DL, EVT VT, SDValue N1,
 
                  SDValue N2, SDValue N3, const SDNodeFlags Flags);
 
  SDValue getNode(unsigned Opcode, const SDLoc &DL, EVT VT, SDValue N1,
 
                  SDValue N2, SDValue N3, SDValue N4);
 
  SDValue getNode(unsigned Opcode, const SDLoc &DL, EVT VT, SDValue N1,
 
                  SDValue N2, SDValue N3, SDValue N4, SDValue N5);
 
 
 
  // Specialize again based on number of operands for nodes with a VTList
 
  // rather than a single VT.
 
  SDValue getNode(unsigned Opcode, const SDLoc &DL, SDVTList VTList);
 
  SDValue getNode(unsigned Opcode, const SDLoc &DL, SDVTList VTList, SDValue N);
 
  SDValue getNode(unsigned Opcode, const SDLoc &DL, SDVTList VTList, SDValue N1,
 
                  SDValue N2);
 
  SDValue getNode(unsigned Opcode, const SDLoc &DL, SDVTList VTList, SDValue N1,
 
                  SDValue N2, SDValue N3);
 
  SDValue getNode(unsigned Opcode, const SDLoc &DL, SDVTList VTList, SDValue N1,
 
                  SDValue N2, SDValue N3, SDValue N4);
 
  SDValue getNode(unsigned Opcode, const SDLoc &DL, SDVTList VTList, SDValue N1,
 
                  SDValue N2, SDValue N3, SDValue N4, SDValue N5);
 
 
 
  /// Compute a TokenFactor to force all the incoming stack arguments to be
 
  /// loaded from the stack. This is used in tail call lowering to protect
 
  /// stack arguments from being clobbered.
 
  SDValue getStackArgumentTokenFactor(SDValue Chain);
 
 
 
  SDValue getMemcpy(SDValue Chain, const SDLoc &dl, SDValue Dst, SDValue Src,
 
                    SDValue Size, Align Alignment, bool isVol,
 
                    bool AlwaysInline, bool isTailCall,
 
                    MachinePointerInfo DstPtrInfo,
 
                    MachinePointerInfo SrcPtrInfo,
 
                    const AAMDNodes &AAInfo = AAMDNodes(),
 
                    AAResults *AA = nullptr);
 
 
 
  SDValue getMemmove(SDValue Chain, const SDLoc &dl, SDValue Dst, SDValue Src,
 
                     SDValue Size, Align Alignment, bool isVol, bool isTailCall,
 
                     MachinePointerInfo DstPtrInfo,
 
                     MachinePointerInfo SrcPtrInfo,
 
                     const AAMDNodes &AAInfo = AAMDNodes(),
 
                     AAResults *AA = nullptr);
 
 
 
  SDValue getMemset(SDValue Chain, const SDLoc &dl, SDValue Dst, SDValue Src,
 
                    SDValue Size, Align Alignment, bool isVol,
 
                    bool AlwaysInline, bool isTailCall,
 
                    MachinePointerInfo DstPtrInfo,
 
                    const AAMDNodes &AAInfo = AAMDNodes());
 
 
 
  SDValue getAtomicMemcpy(SDValue Chain, const SDLoc &dl, SDValue Dst,
 
                          SDValue Src, SDValue Size, Type *SizeTy,
 
                          unsigned ElemSz, bool isTailCall,
 
                          MachinePointerInfo DstPtrInfo,
 
                          MachinePointerInfo SrcPtrInfo);
 
 
 
  SDValue getAtomicMemmove(SDValue Chain, const SDLoc &dl, SDValue Dst,
 
                           SDValue Src, SDValue Size, Type *SizeTy,
 
                           unsigned ElemSz, bool isTailCall,
 
                           MachinePointerInfo DstPtrInfo,
 
                           MachinePointerInfo SrcPtrInfo);
 
 
 
  SDValue getAtomicMemset(SDValue Chain, const SDLoc &dl, SDValue Dst,
 
                          SDValue Value, SDValue Size, Type *SizeTy,
 
                          unsigned ElemSz, bool isTailCall,
 
                          MachinePointerInfo DstPtrInfo);
 
 
 
  /// Helper function to make it easier to build SetCC's if you just have an
 
  /// ISD::CondCode instead of an SDValue.
 
  SDValue getSetCC(const SDLoc &DL, EVT VT, SDValue LHS, SDValue RHS,
 
                   ISD::CondCode Cond, SDValue Chain = SDValue(),
 
                   bool IsSignaling = false) {
 
    assert(LHS.getValueType().isVector() == RHS.getValueType().isVector() &&
 
           "Vector/scalar operand type mismatch for setcc");
 
    assert(LHS.getValueType().isVector() == VT.isVector() &&
 
           "Vector/scalar result type mismatch for setcc");
 
    assert(Cond != ISD::SETCC_INVALID &&
 
           "Cannot create a setCC of an invalid node.");
 
    if (Chain)
 
      return getNode(IsSignaling ? ISD::STRICT_FSETCCS : ISD::STRICT_FSETCC, DL,
 
                     {VT, MVT::Other}, {Chain, LHS, RHS, getCondCode(Cond)});
 
    return getNode(ISD::SETCC, DL, VT, LHS, RHS, getCondCode(Cond));
 
  }
 
 
 
  /// Helper function to make it easier to build VP_SETCCs if you just have an
 
  /// ISD::CondCode instead of an SDValue.
 
  SDValue getSetCCVP(const SDLoc &DL, EVT VT, SDValue LHS, SDValue RHS,
 
                     ISD::CondCode Cond, SDValue Mask, SDValue EVL) {
 
    assert(LHS.getValueType().isVector() && RHS.getValueType().isVector() &&
 
           "Cannot compare scalars");
 
    assert(Cond != ISD::SETCC_INVALID &&
 
           "Cannot create a setCC of an invalid node.");
 
    return getNode(ISD::VP_SETCC, DL, VT, LHS, RHS, getCondCode(Cond), Mask,
 
                   EVL);
 
  }
 
 
 
  /// Helper function to make it easier to build Select's if you just have
 
  /// operands and don't want to check for vector.
 
  SDValue getSelect(const SDLoc &DL, EVT VT, SDValue Cond, SDValue LHS,
 
                    SDValue RHS) {
 
    assert(LHS.getValueType() == VT && RHS.getValueType() == VT &&
 
           "Cannot use select on differing types");
 
    auto Opcode = Cond.getValueType().isVector() ? ISD::VSELECT : ISD::SELECT;
 
    return getNode(Opcode, DL, VT, Cond, LHS, RHS);
 
  }
 
 
 
  /// Helper function to make it easier to build SelectCC's if you just have an
 
  /// ISD::CondCode instead of an SDValue.
 
  SDValue getSelectCC(const SDLoc &DL, SDValue LHS, SDValue RHS, SDValue True,
 
                      SDValue False, ISD::CondCode Cond) {
 
    return getNode(ISD::SELECT_CC, DL, True.getValueType(), LHS, RHS, True,
 
                   False, getCondCode(Cond));
 
  }
 
 
 
  /// Try to simplify a select/vselect into 1 of its operands or a constant.
 
  SDValue simplifySelect(SDValue Cond, SDValue TVal, SDValue FVal);
 
 
 
  /// Try to simplify a shift into 1 of its operands or a constant.
 
  SDValue simplifyShift(SDValue X, SDValue Y);
 
 
 
  /// Try to simplify a floating-point binary operation into 1 of its operands
 
  /// or a constant.
 
  SDValue simplifyFPBinop(unsigned Opcode, SDValue X, SDValue Y,
 
                          SDNodeFlags Flags);
 
 
 
  /// VAArg produces a result and token chain, and takes a pointer
 
  /// and a source value as input.
 
  SDValue getVAArg(EVT VT, const SDLoc &dl, SDValue Chain, SDValue Ptr,
 
                   SDValue SV, unsigned Align);
 
 
 
  /// Gets a node for an atomic cmpxchg op. There are two
 
  /// valid Opcodes. ISD::ATOMIC_CMO_SWAP produces the value loaded and a
 
  /// chain result. ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS produces the value loaded,
 
  /// a success flag (initially i1), and a chain.
 
  SDValue getAtomicCmpSwap(unsigned Opcode, const SDLoc &dl, EVT MemVT,
 
                           SDVTList VTs, SDValue Chain, SDValue Ptr,
 
                           SDValue Cmp, SDValue Swp, MachineMemOperand *MMO);
 
 
 
  /// Gets a node for an atomic op, produces result (if relevant)
 
  /// and chain and takes 2 operands.
 
  SDValue getAtomic(unsigned Opcode, const SDLoc &dl, EVT MemVT, SDValue Chain,
 
                    SDValue Ptr, SDValue Val, MachineMemOperand *MMO);
 
 
 
  /// Gets a node for an atomic op, produces result and chain and
 
  /// takes 1 operand.
 
  SDValue getAtomic(unsigned Opcode, const SDLoc &dl, EVT MemVT, EVT VT,
 
                    SDValue Chain, SDValue Ptr, MachineMemOperand *MMO);
 
 
 
  /// Gets a node for an atomic op, produces result and chain and takes N
 
  /// operands.
 
  SDValue getAtomic(unsigned Opcode, const SDLoc &dl, EVT MemVT,
 
                    SDVTList VTList, ArrayRef<SDValue> Ops,
 
                    MachineMemOperand *MMO);
 
 
 
  /// Creates a MemIntrinsicNode that may produce a
 
  /// result and takes a list of operands. Opcode may be INTRINSIC_VOID,
 
  /// INTRINSIC_W_CHAIN, or a target-specific opcode with a value not
 
  /// less than FIRST_TARGET_MEMORY_OPCODE.
 
  SDValue getMemIntrinsicNode(
 
      unsigned Opcode, const SDLoc &dl, SDVTList VTList, ArrayRef<SDValue> Ops,
 
      EVT MemVT, MachinePointerInfo PtrInfo, Align Alignment,
 
      MachineMemOperand::Flags Flags = MachineMemOperand::MOLoad |
 
                                       MachineMemOperand::MOStore,
 
      uint64_t Size = 0, const AAMDNodes &AAInfo = AAMDNodes());
 
 
 
  inline SDValue getMemIntrinsicNode(
 
      unsigned Opcode, const SDLoc &dl, SDVTList VTList, ArrayRef<SDValue> Ops,
 
      EVT MemVT, MachinePointerInfo PtrInfo,
 
      MaybeAlign Alignment = std::nullopt,
 
      MachineMemOperand::Flags Flags = MachineMemOperand::MOLoad |
 
                                       MachineMemOperand::MOStore,
 
      uint64_t Size = 0, const AAMDNodes &AAInfo = AAMDNodes()) {
 
    // Ensure that codegen never sees alignment 0
 
    return getMemIntrinsicNode(Opcode, dl, VTList, Ops, MemVT, PtrInfo,
 
                               Alignment.value_or(getEVTAlign(MemVT)), Flags,
 
                               Size, AAInfo);
 
  }
 
 
 
  SDValue getMemIntrinsicNode(unsigned Opcode, const SDLoc &dl, SDVTList VTList,
 
                              ArrayRef<SDValue> Ops, EVT MemVT,
 
                              MachineMemOperand *MMO);
 
 
 
  /// Creates a LifetimeSDNode that starts (`IsStart==true`) or ends
 
  /// (`IsStart==false`) the lifetime of the portion of `FrameIndex` between
 
  /// offsets `Offset` and `Offset + Size`.
 
  SDValue getLifetimeNode(bool IsStart, const SDLoc &dl, SDValue Chain,
 
                          int FrameIndex, int64_t Size, int64_t Offset = -1);
 
 
 
  /// Creates a PseudoProbeSDNode with function GUID `Guid` and
 
  /// the index of the block `Index` it is probing, as well as the attributes
 
  /// `attr` of the probe.
 
  SDValue getPseudoProbeNode(const SDLoc &Dl, SDValue Chain, uint64_t Guid,
 
                             uint64_t Index, uint32_t Attr);
 
 
 
  /// Create a MERGE_VALUES node from the given operands.
 
  SDValue getMergeValues(ArrayRef<SDValue> Ops, const SDLoc &dl);
 
 
 
  /// Loads are not normal binary operators: their result type is not
 
  /// determined by their operands, and they produce a value AND a token chain.
 
  ///
 
  /// This function will set the MOLoad flag on MMOFlags, but you can set it if
 
  /// you want.  The MOStore flag must not be set.
 
  SDValue getLoad(EVT VT, const SDLoc &dl, SDValue Chain, SDValue Ptr,
 
                  MachinePointerInfo PtrInfo,
 
                  MaybeAlign Alignment = MaybeAlign(),
 
                  MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
 
                  const AAMDNodes &AAInfo = AAMDNodes(),
 
                  const MDNode *Ranges = nullptr);
 
  /// FIXME: Remove once transition to Align is over.
 
  LLVM_DEPRECATED("Use the getLoad function that takes a MaybeAlign instead",
 
                  "")
 
  inline SDValue
 
  getLoad(EVT VT, const SDLoc &dl, SDValue Chain, SDValue Ptr,
 
          MachinePointerInfo PtrInfo, unsigned Alignment,
 
          MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
 
          const AAMDNodes &AAInfo = AAMDNodes(),
 
          const MDNode *Ranges = nullptr) {
 
    return getLoad(VT, dl, Chain, Ptr, PtrInfo, MaybeAlign(Alignment), MMOFlags,
 
                   AAInfo, Ranges);
 
  }
 
  SDValue getLoad(EVT VT, const SDLoc &dl, SDValue Chain, SDValue Ptr,
 
                  MachineMemOperand *MMO);
 
  SDValue
 
  getExtLoad(ISD::LoadExtType ExtType, const SDLoc &dl, EVT VT, SDValue Chain,
 
             SDValue Ptr, MachinePointerInfo PtrInfo, EVT MemVT,
 
             MaybeAlign Alignment = MaybeAlign(),
 
             MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
 
             const AAMDNodes &AAInfo = AAMDNodes());
 
  SDValue getExtLoad(ISD::LoadExtType ExtType, const SDLoc &dl, EVT VT,
 
                     SDValue Chain, SDValue Ptr, EVT MemVT,
 
                     MachineMemOperand *MMO);
 
  SDValue getIndexedLoad(SDValue OrigLoad, const SDLoc &dl, SDValue Base,
 
                         SDValue Offset, ISD::MemIndexedMode AM);
 
  SDValue getLoad(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType, EVT VT,
 
                  const SDLoc &dl, SDValue Chain, SDValue Ptr, SDValue Offset,
 
                  MachinePointerInfo PtrInfo, EVT MemVT, Align Alignment,
 
                  MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
 
                  const AAMDNodes &AAInfo = AAMDNodes(),
 
                  const MDNode *Ranges = nullptr);
 
  inline SDValue getLoad(
 
      ISD::MemIndexedMode AM, ISD::LoadExtType ExtType, EVT VT, const SDLoc &dl,
 
      SDValue Chain, SDValue Ptr, SDValue Offset, MachinePointerInfo PtrInfo,
 
      EVT MemVT, MaybeAlign Alignment = MaybeAlign(),
 
      MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
 
      const AAMDNodes &AAInfo = AAMDNodes(), const MDNode *Ranges = nullptr) {
 
    // Ensures that codegen never sees a None Alignment.
 
    return getLoad(AM, ExtType, VT, dl, Chain, Ptr, Offset, PtrInfo, MemVT,
 
                   Alignment.value_or(getEVTAlign(MemVT)), MMOFlags, AAInfo,
 
                   Ranges);
 
  }
 
  /// FIXME: Remove once transition to Align is over.
 
  LLVM_DEPRECATED("Use the getLoad function that takes a MaybeAlign instead",
 
                  "")
 
  inline SDValue
 
  getLoad(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType, EVT VT,
 
          const SDLoc &dl, SDValue Chain, SDValue Ptr, SDValue Offset,
 
          MachinePointerInfo PtrInfo, EVT MemVT, unsigned Alignment,
 
          MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
 
          const AAMDNodes &AAInfo = AAMDNodes(),
 
          const MDNode *Ranges = nullptr) {
 
    return getLoad(AM, ExtType, VT, dl, Chain, Ptr, Offset, PtrInfo, MemVT,
 
                   MaybeAlign(Alignment), MMOFlags, AAInfo, Ranges);
 
  }
 
  SDValue getLoad(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType, EVT VT,
 
                  const SDLoc &dl, SDValue Chain, SDValue Ptr, SDValue Offset,
 
                  EVT MemVT, MachineMemOperand *MMO);
 
 
 
  /// Helper function to build ISD::STORE nodes.
 
  ///
 
  /// This function will set the MOStore flag on MMOFlags, but you can set it if
 
  /// you want.  The MOLoad and MOInvariant flags must not be set.
 
 
 
  SDValue
 
  getStore(SDValue Chain, const SDLoc &dl, SDValue Val, SDValue Ptr,
 
           MachinePointerInfo PtrInfo, Align Alignment,
 
           MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
 
           const AAMDNodes &AAInfo = AAMDNodes());
 
  inline SDValue
 
  getStore(SDValue Chain, const SDLoc &dl, SDValue Val, SDValue Ptr,
 
           MachinePointerInfo PtrInfo, MaybeAlign Alignment = MaybeAlign(),
 
           MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
 
           const AAMDNodes &AAInfo = AAMDNodes()) {
 
    return getStore(Chain, dl, Val, Ptr, PtrInfo,
 
                    Alignment.value_or(getEVTAlign(Val.getValueType())),
 
                    MMOFlags, AAInfo);
 
  }
 
  /// FIXME: Remove once transition to Align is over.
 
  LLVM_DEPRECATED("Use the version that takes a MaybeAlign instead", "")
 
  inline SDValue
 
  getStore(SDValue Chain, const SDLoc &dl, SDValue Val, SDValue Ptr,
 
           MachinePointerInfo PtrInfo, unsigned Alignment,
 
           MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
 
           const AAMDNodes &AAInfo = AAMDNodes()) {
 
    return getStore(Chain, dl, Val, Ptr, PtrInfo, MaybeAlign(Alignment),
 
                    MMOFlags, AAInfo);
 
  }
 
  SDValue getStore(SDValue Chain, const SDLoc &dl, SDValue Val, SDValue Ptr,
 
                   MachineMemOperand *MMO);
 
  SDValue
 
  getTruncStore(SDValue Chain, const SDLoc &dl, SDValue Val, SDValue Ptr,
 
                MachinePointerInfo PtrInfo, EVT SVT, Align Alignment,
 
                MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
 
                const AAMDNodes &AAInfo = AAMDNodes());
 
  inline SDValue
 
  getTruncStore(SDValue Chain, const SDLoc &dl, SDValue Val, SDValue Ptr,
 
                MachinePointerInfo PtrInfo, EVT SVT,
 
                MaybeAlign Alignment = MaybeAlign(),
 
                MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
 
                const AAMDNodes &AAInfo = AAMDNodes()) {
 
    return getTruncStore(Chain, dl, Val, Ptr, PtrInfo, SVT,
 
                         Alignment.value_or(getEVTAlign(SVT)), MMOFlags,
 
                         AAInfo);
 
  }
 
  /// FIXME: Remove once transition to Align is over.
 
  LLVM_DEPRECATED("Use the version that takes a MaybeAlign instead", "")
 
  inline SDValue
 
  getTruncStore(SDValue Chain, const SDLoc &dl, SDValue Val, SDValue Ptr,
 
                MachinePointerInfo PtrInfo, EVT SVT, unsigned Alignment,
 
                MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
 
                const AAMDNodes &AAInfo = AAMDNodes()) {
 
    return getTruncStore(Chain, dl, Val, Ptr, PtrInfo, SVT,
 
                         MaybeAlign(Alignment), MMOFlags, AAInfo);
 
  }
 
  SDValue getTruncStore(SDValue Chain, const SDLoc &dl, SDValue Val,
 
                        SDValue Ptr, EVT SVT, MachineMemOperand *MMO);
 
  SDValue getIndexedStore(SDValue OrigStore, const SDLoc &dl, SDValue Base,
 
                          SDValue Offset, ISD::MemIndexedMode AM);
 
 
 
  SDValue getLoadVP(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType, EVT VT,
 
                    const SDLoc &dl, SDValue Chain, SDValue Ptr, SDValue Offset,
 
                    SDValue Mask, SDValue EVL, MachinePointerInfo PtrInfo,
 
                    EVT MemVT, Align Alignment,
 
                    MachineMemOperand::Flags MMOFlags, const AAMDNodes &AAInfo,
 
                    const MDNode *Ranges = nullptr, bool IsExpanding = false);
 
  inline SDValue
 
  getLoadVP(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType, EVT VT,
 
            const SDLoc &dl, SDValue Chain, SDValue Ptr, SDValue Offset,
 
            SDValue Mask, SDValue EVL, MachinePointerInfo PtrInfo, EVT MemVT,
 
            MaybeAlign Alignment = MaybeAlign(),
 
            MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
 
            const AAMDNodes &AAInfo = AAMDNodes(),
 
            const MDNode *Ranges = nullptr, bool IsExpanding = false) {
 
    // Ensures that codegen never sees a None Alignment.
 
    return getLoadVP(AM, ExtType, VT, dl, Chain, Ptr, Offset, Mask, EVL,
 
                     PtrInfo, MemVT, Alignment.value_or(getEVTAlign(MemVT)),
 
                     MMOFlags, AAInfo, Ranges, IsExpanding);
 
  }
 
  SDValue getLoadVP(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType, EVT VT,
 
                    const SDLoc &dl, SDValue Chain, SDValue Ptr, SDValue Offset,
 
                    SDValue Mask, SDValue EVL, EVT MemVT,
 
                    MachineMemOperand *MMO, bool IsExpanding = false);
 
  SDValue getLoadVP(EVT VT, const SDLoc &dl, SDValue Chain, SDValue Ptr,
 
                    SDValue Mask, SDValue EVL, MachinePointerInfo PtrInfo,
 
                    MaybeAlign Alignment, MachineMemOperand::Flags MMOFlags,
 
                    const AAMDNodes &AAInfo, const MDNode *Ranges = nullptr,
 
                    bool IsExpanding = false);
 
  SDValue getLoadVP(EVT VT, const SDLoc &dl, SDValue Chain, SDValue Ptr,
 
                    SDValue Mask, SDValue EVL, MachineMemOperand *MMO,
 
                    bool IsExpanding = false);
 
  SDValue getExtLoadVP(ISD::LoadExtType ExtType, const SDLoc &dl, EVT VT,
 
                       SDValue Chain, SDValue Ptr, SDValue Mask, SDValue EVL,
 
                       MachinePointerInfo PtrInfo, EVT MemVT,
 
                       MaybeAlign Alignment, MachineMemOperand::Flags MMOFlags,
 
                       const AAMDNodes &AAInfo, bool IsExpanding = false);
 
  SDValue getExtLoadVP(ISD::LoadExtType ExtType, const SDLoc &dl, EVT VT,
 
                       SDValue Chain, SDValue Ptr, SDValue Mask, SDValue EVL,
 
                       EVT MemVT, MachineMemOperand *MMO,
 
                       bool IsExpanding = false);
 
  SDValue getIndexedLoadVP(SDValue OrigLoad, const SDLoc &dl, SDValue Base,
 
                           SDValue Offset, ISD::MemIndexedMode AM);
 
  SDValue getStoreVP(SDValue Chain, const SDLoc &dl, SDValue Val, SDValue Ptr,
 
                     SDValue Offset, SDValue Mask, SDValue EVL, EVT MemVT,
 
                     MachineMemOperand *MMO, ISD::MemIndexedMode AM,
 
                     bool IsTruncating = false, bool IsCompressing = false);
 
  SDValue getTruncStoreVP(SDValue Chain, const SDLoc &dl, SDValue Val,
 
                          SDValue Ptr, SDValue Mask, SDValue EVL,
 
                          MachinePointerInfo PtrInfo, EVT SVT, Align Alignment,
 
                          MachineMemOperand::Flags MMOFlags,
 
                          const AAMDNodes &AAInfo, bool IsCompressing = false);
 
  SDValue getTruncStoreVP(SDValue Chain, const SDLoc &dl, SDValue Val,
 
                          SDValue Ptr, SDValue Mask, SDValue EVL, EVT SVT,
 
                          MachineMemOperand *MMO, bool IsCompressing = false);
 
  SDValue getIndexedStoreVP(SDValue OrigStore, const SDLoc &dl, SDValue Base,
 
                            SDValue Offset, ISD::MemIndexedMode AM);
 
 
 
  SDValue getStridedLoadVP(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType,
 
                           EVT VT, const SDLoc &DL, SDValue Chain, SDValue Ptr,
 
                           SDValue Offset, SDValue Stride, SDValue Mask,
 
                           SDValue EVL, MachinePointerInfo PtrInfo, EVT MemVT,
 
                           Align Alignment, MachineMemOperand::Flags MMOFlags,
 
                           const AAMDNodes &AAInfo,
 
                           const MDNode *Ranges = nullptr,
 
                           bool IsExpanding = false);
 
  inline SDValue getStridedLoadVP(
 
      ISD::MemIndexedMode AM, ISD::LoadExtType ExtType, EVT VT, const SDLoc &DL,
 
      SDValue Chain, SDValue Ptr, SDValue Offset, SDValue Stride, SDValue Mask,
 
      SDValue EVL, MachinePointerInfo PtrInfo, EVT MemVT,
 
      MaybeAlign Alignment = MaybeAlign(),
 
      MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
 
      const AAMDNodes &AAInfo = AAMDNodes(), const MDNode *Ranges = nullptr,
 
      bool IsExpanding = false) {
 
    // Ensures that codegen never sees a None Alignment.
 
    return getStridedLoadVP(AM, ExtType, VT, DL, Chain, Ptr, Offset, Stride,
 
                            Mask, EVL, PtrInfo, MemVT,
 
                            Alignment.value_or(getEVTAlign(MemVT)), MMOFlags,
 
                            AAInfo, Ranges, IsExpanding);
 
  }
 
  SDValue getStridedLoadVP(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType,
 
                           EVT VT, const SDLoc &DL, SDValue Chain, SDValue Ptr,
 
                           SDValue Offset, SDValue Stride, SDValue Mask,
 
                           SDValue EVL, EVT MemVT, MachineMemOperand *MMO,
 
                           bool IsExpanding = false);
 
  SDValue getStridedLoadVP(EVT VT, const SDLoc &DL, SDValue Chain, SDValue Ptr,
 
                           SDValue Stride, SDValue Mask, SDValue EVL,
 
                           MachinePointerInfo PtrInfo, MaybeAlign Alignment,
 
                           MachineMemOperand::Flags MMOFlags,
 
                           const AAMDNodes &AAInfo,
 
                           const MDNode *Ranges = nullptr,
 
                           bool IsExpanding = false);
 
  SDValue getStridedLoadVP(EVT VT, const SDLoc &DL, SDValue Chain, SDValue Ptr,
 
                           SDValue Stride, SDValue Mask, SDValue EVL,
 
                           MachineMemOperand *MMO, bool IsExpanding = false);
 
  SDValue
 
  getExtStridedLoadVP(ISD::LoadExtType ExtType, const SDLoc &DL, EVT VT,
 
                      SDValue Chain, SDValue Ptr, SDValue Stride, SDValue Mask,
 
                      SDValue EVL, MachinePointerInfo PtrInfo, EVT MemVT,
 
                      MaybeAlign Alignment, MachineMemOperand::Flags MMOFlags,
 
                      const AAMDNodes &AAInfo, bool IsExpanding = false);
 
  SDValue getExtStridedLoadVP(ISD::LoadExtType ExtType, const SDLoc &DL, EVT VT,
 
                              SDValue Chain, SDValue Ptr, SDValue Stride,
 
                              SDValue Mask, SDValue EVL, EVT MemVT,
 
                              MachineMemOperand *MMO, bool IsExpanding = false);
 
  SDValue getIndexedStridedLoadVP(SDValue OrigLoad, const SDLoc &DL,
 
                                  SDValue Base, SDValue Offset,
 
                                  ISD::MemIndexedMode AM);
 
  SDValue getStridedStoreVP(SDValue Chain, const SDLoc &DL, SDValue Val,
 
                            SDValue Ptr, SDValue Offset, SDValue Stride,
 
                            SDValue Mask, SDValue EVL, EVT MemVT,
 
                            MachineMemOperand *MMO, ISD::MemIndexedMode AM,
 
                            bool IsTruncating = false,
 
                            bool IsCompressing = false);
 
  SDValue getTruncStridedStoreVP(SDValue Chain, const SDLoc &DL, SDValue Val,
 
                                 SDValue Ptr, SDValue Stride, SDValue Mask,
 
                                 SDValue EVL, MachinePointerInfo PtrInfo,
 
                                 EVT SVT, Align Alignment,
 
                                 MachineMemOperand::Flags MMOFlags,
 
                                 const AAMDNodes &AAInfo,
 
                                 bool IsCompressing = false);
 
  SDValue getTruncStridedStoreVP(SDValue Chain, const SDLoc &DL, SDValue Val,
 
                                 SDValue Ptr, SDValue Stride, SDValue Mask,
 
                                 SDValue EVL, EVT SVT, MachineMemOperand *MMO,
 
                                 bool IsCompressing = false);
 
  SDValue getIndexedStridedStoreVP(SDValue OrigStore, const SDLoc &DL,
 
                                   SDValue Base, SDValue Offset,
 
                                   ISD::MemIndexedMode AM);
 
 
 
  SDValue getGatherVP(SDVTList VTs, EVT VT, const SDLoc &dl,
 
                      ArrayRef<SDValue> Ops, MachineMemOperand *MMO,
 
                      ISD::MemIndexType IndexType);
 
  SDValue getScatterVP(SDVTList VTs, EVT VT, const SDLoc &dl,
 
                       ArrayRef<SDValue> Ops, MachineMemOperand *MMO,
 
                       ISD::MemIndexType IndexType);
 
 
 
  SDValue getMaskedLoad(EVT VT, const SDLoc &dl, SDValue Chain, SDValue Base,
 
                        SDValue Offset, SDValue Mask, SDValue Src0, EVT MemVT,
 
                        MachineMemOperand *MMO, ISD::MemIndexedMode AM,
 
                        ISD::LoadExtType, bool IsExpanding = false);
 
  SDValue getIndexedMaskedLoad(SDValue OrigLoad, const SDLoc &dl, SDValue Base,
 
                               SDValue Offset, ISD::MemIndexedMode AM);
 
  SDValue getMaskedStore(SDValue Chain, const SDLoc &dl, SDValue Val,
 
                         SDValue Base, SDValue Offset, SDValue Mask, EVT MemVT,
 
                         MachineMemOperand *MMO, ISD::MemIndexedMode AM,
 
                         bool IsTruncating = false, bool IsCompressing = false);
 
  SDValue getIndexedMaskedStore(SDValue OrigStore, const SDLoc &dl,
 
                                SDValue Base, SDValue Offset,
 
                                ISD::MemIndexedMode AM);
 
  SDValue getMaskedGather(SDVTList VTs, EVT MemVT, const SDLoc &dl,
 
                          ArrayRef<SDValue> Ops, MachineMemOperand *MMO,
 
                          ISD::MemIndexType IndexType, ISD::LoadExtType ExtTy);
 
  SDValue getMaskedScatter(SDVTList VTs, EVT MemVT, const SDLoc &dl,
 
                           ArrayRef<SDValue> Ops, MachineMemOperand *MMO,
 
                           ISD::MemIndexType IndexType,
 
                           bool IsTruncating = false);
 
 
 
  /// Construct a node to track a Value* through the backend.
 
  SDValue getSrcValue(const Value *v);
 
 
 
  /// Return an MDNodeSDNode which holds an MDNode.
 
  SDValue getMDNode(const MDNode *MD);
 
 
 
  /// Return a bitcast using the SDLoc of the value operand, and casting to the
 
  /// provided type. Use getNode to set a custom SDLoc.
 
  SDValue getBitcast(EVT VT, SDValue V);
 
 
 
  /// Return an AddrSpaceCastSDNode.
 
  SDValue getAddrSpaceCast(const SDLoc &dl, EVT VT, SDValue Ptr, unsigned SrcAS,
 
                           unsigned DestAS);
 
 
 
  /// Return a freeze using the SDLoc of the value operand.
 
  SDValue getFreeze(SDValue V);
 
 
 
  /// Return an AssertAlignSDNode.
 
  SDValue getAssertAlign(const SDLoc &DL, SDValue V, Align A);
 
 
 
  /// Swap N1 and N2 if Opcode is a commutative binary opcode
 
  /// and the canonical form expects the opposite order.
 
  void canonicalizeCommutativeBinop(unsigned Opcode, SDValue &N1,
 
                                    SDValue &N2) const;
 
 
 
  /// Return the specified value casted to
 
  /// the target's desired shift amount type.
 
  SDValue getShiftAmountOperand(EVT LHSTy, SDValue Op);
 
 
 
  /// Expand the specified \c ISD::VAARG node as the Legalize pass would.
 
  SDValue expandVAArg(SDNode *Node);
 
 
 
  /// Expand the specified \c ISD::VACOPY node as the Legalize pass would.
 
  SDValue expandVACopy(SDNode *Node);
 
 
 
  /// Returs an GlobalAddress of the function from the current module with
 
  /// name matching the given ExternalSymbol. Additionally can provide the
 
  /// matched function.
 
  /// Panics the function doesn't exists.
 
  SDValue getSymbolFunctionGlobalAddress(SDValue Op,
 
                                         Function **TargetFunction = nullptr);
 
 
 
  /// *Mutate* the specified node in-place to have the
 
  /// specified operands.  If the resultant node already exists in the DAG,
 
  /// this does not modify the specified node, instead it returns the node that
 
  /// already exists.  If the resultant node does not exist in the DAG, the
 
  /// input node is returned.  As a degenerate case, if you specify the same
 
  /// input operands as the node already has, the input node is returned.
 
  SDNode *UpdateNodeOperands(SDNode *N, SDValue Op);
 
  SDNode *UpdateNodeOperands(SDNode *N, SDValue Op1, SDValue Op2);
 
  SDNode *UpdateNodeOperands(SDNode *N, SDValue Op1, SDValue Op2,
 
                               SDValue Op3);
 
  SDNode *UpdateNodeOperands(SDNode *N, SDValue Op1, SDValue Op2,
 
                               SDValue Op3, SDValue Op4);
 
  SDNode *UpdateNodeOperands(SDNode *N, SDValue Op1, SDValue Op2,
 
                               SDValue Op3, SDValue Op4, SDValue Op5);
 
  SDNode *UpdateNodeOperands(SDNode *N, ArrayRef<SDValue> Ops);
 
 
 
  /// Creates a new TokenFactor containing \p Vals. If \p Vals contains 64k
 
  /// values or more, move values into new TokenFactors in 64k-1 blocks, until
 
  /// the final TokenFactor has less than 64k operands.
 
  SDValue getTokenFactor(const SDLoc &DL, SmallVectorImpl<SDValue> &Vals);
 
 
 
  /// *Mutate* the specified machine node's memory references to the provided
 
  /// list.
 
  void setNodeMemRefs(MachineSDNode *N,
 
                      ArrayRef<MachineMemOperand *> NewMemRefs);
 
 
 
  // Calculate divergence of node \p N based on its operands.
 
  bool calculateDivergence(SDNode *N);
 
 
 
  // Propagates the change in divergence to users
 
  void updateDivergence(SDNode * N);
 
 
 
  /// These are used for target selectors to *mutate* the
 
  /// specified node to have the specified return type, Target opcode, and
 
  /// operands.  Note that target opcodes are stored as
 
  /// ~TargetOpcode in the node opcode field.  The resultant node is returned.
 
  SDNode *SelectNodeTo(SDNode *N, unsigned MachineOpc, EVT VT);
 
  SDNode *SelectNodeTo(SDNode *N, unsigned MachineOpc, EVT VT, SDValue Op1);
 
  SDNode *SelectNodeTo(SDNode *N, unsigned MachineOpc, EVT VT,
 
                       SDValue Op1, SDValue Op2);
 
  SDNode *SelectNodeTo(SDNode *N, unsigned MachineOpc, EVT VT,
 
                       SDValue Op1, SDValue Op2, SDValue Op3);
 
  SDNode *SelectNodeTo(SDNode *N, unsigned MachineOpc, EVT VT,
 
                       ArrayRef<SDValue> Ops);
 
  SDNode *SelectNodeTo(SDNode *N, unsigned MachineOpc, EVT VT1, EVT VT2);
 
  SDNode *SelectNodeTo(SDNode *N, unsigned MachineOpc, EVT VT1,
 
                       EVT VT2, ArrayRef<SDValue> Ops);
 
  SDNode *SelectNodeTo(SDNode *N, unsigned MachineOpc, EVT VT1,
 
                       EVT VT2, EVT VT3, ArrayRef<SDValue> Ops);
 
  SDNode *SelectNodeTo(SDNode *N, unsigned MachineOpc, EVT VT1,
 
                       EVT VT2, SDValue Op1, SDValue Op2);
 
  SDNode *SelectNodeTo(SDNode *N, unsigned MachineOpc, SDVTList VTs,
 
                       ArrayRef<SDValue> Ops);
 
 
 
  /// This *mutates* the specified node to have the specified
 
  /// return type, opcode, and operands.
 
  SDNode *MorphNodeTo(SDNode *N, unsigned Opc, SDVTList VTs,
 
                      ArrayRef<SDValue> Ops);
 
 
 
  /// Mutate the specified strict FP node to its non-strict equivalent,
 
  /// unlinking the node from its chain and dropping the metadata arguments.
 
  /// The node must be a strict FP node.
 
  SDNode *mutateStrictFPToFP(SDNode *Node);
 
 
 
  /// These are used for target selectors to create a new node
 
  /// with specified return type(s), MachineInstr opcode, and operands.
 
  ///
 
  /// Note that getMachineNode returns the resultant node.  If there is already
 
  /// a node of the specified opcode and operands, it returns that node instead
 
  /// of the current one.
 
  MachineSDNode *getMachineNode(unsigned Opcode, const SDLoc &dl, EVT VT);
 
  MachineSDNode *getMachineNode(unsigned Opcode, const SDLoc &dl, EVT VT,
 
                                SDValue Op1);
 
  MachineSDNode *getMachineNode(unsigned Opcode, const SDLoc &dl, EVT VT,
 
                                SDValue Op1, SDValue Op2);
 
  MachineSDNode *getMachineNode(unsigned Opcode, const SDLoc &dl, EVT VT,
 
                                SDValue Op1, SDValue Op2, SDValue Op3);
 
  MachineSDNode *getMachineNode(unsigned Opcode, const SDLoc &dl, EVT VT,
 
                                ArrayRef<SDValue> Ops);
 
  MachineSDNode *getMachineNode(unsigned Opcode, const SDLoc &dl, EVT VT1,
 
                                EVT VT2, SDValue Op1, SDValue Op2);
 
  MachineSDNode *getMachineNode(unsigned Opcode, const SDLoc &dl, EVT VT1,
 
                                EVT VT2, SDValue Op1, SDValue Op2, SDValue Op3);
 
  MachineSDNode *getMachineNode(unsigned Opcode, const SDLoc &dl, EVT VT1,
 
                                EVT VT2, ArrayRef<SDValue> Ops);
 
  MachineSDNode *getMachineNode(unsigned Opcode, const SDLoc &dl, EVT VT1,
 
                                EVT VT2, EVT VT3, SDValue Op1, SDValue Op2);
 
  MachineSDNode *getMachineNode(unsigned Opcode, const SDLoc &dl, EVT VT1,
 
                                EVT VT2, EVT VT3, SDValue Op1, SDValue Op2,
 
                                SDValue Op3);
 
  MachineSDNode *getMachineNode(unsigned Opcode, const SDLoc &dl, EVT VT1,
 
                                EVT VT2, EVT VT3, ArrayRef<SDValue> Ops);
 
  MachineSDNode *getMachineNode(unsigned Opcode, const SDLoc &dl,
 
                                ArrayRef<EVT> ResultTys, ArrayRef<SDValue> Ops);
 
  MachineSDNode *getMachineNode(unsigned Opcode, const SDLoc &dl, SDVTList VTs,
 
                                ArrayRef<SDValue> Ops);
 
 
 
  /// A convenience function for creating TargetInstrInfo::EXTRACT_SUBREG nodes.
 
  SDValue getTargetExtractSubreg(int SRIdx, const SDLoc &DL, EVT VT,
 
                                 SDValue Operand);
 
 
 
  /// A convenience function for creating TargetInstrInfo::INSERT_SUBREG nodes.
 
  SDValue getTargetInsertSubreg(int SRIdx, const SDLoc &DL, EVT VT,
 
                                SDValue Operand, SDValue Subreg);
 
 
 
  /// Get the specified node if it's already available, or else return NULL.
 
  SDNode *getNodeIfExists(unsigned Opcode, SDVTList VTList,
 
                          ArrayRef<SDValue> Ops, const SDNodeFlags Flags);
 
  SDNode *getNodeIfExists(unsigned Opcode, SDVTList VTList,
 
                          ArrayRef<SDValue> Ops);
 
 
 
  /// Check if a node exists without modifying its flags.
 
  bool doesNodeExist(unsigned Opcode, SDVTList VTList, ArrayRef<SDValue> Ops);
 
 
 
  /// Creates a SDDbgValue node.
 
  SDDbgValue *getDbgValue(DIVariable *Var, DIExpression *Expr, SDNode *N,
 
                          unsigned R, bool IsIndirect, const DebugLoc &DL,
 
                          unsigned O);
 
 
 
  /// Creates a constant SDDbgValue node.
 
  SDDbgValue *getConstantDbgValue(DIVariable *Var, DIExpression *Expr,
 
                                  const Value *C, const DebugLoc &DL,
 
                                  unsigned O);
 
 
 
  /// Creates a FrameIndex SDDbgValue node.
 
  SDDbgValue *getFrameIndexDbgValue(DIVariable *Var, DIExpression *Expr,
 
                                    unsigned FI, bool IsIndirect,
 
                                    const DebugLoc &DL, unsigned O);
 
 
 
  /// Creates a FrameIndex SDDbgValue node.
 
  SDDbgValue *getFrameIndexDbgValue(DIVariable *Var, DIExpression *Expr,
 
                                    unsigned FI,
 
                                    ArrayRef<SDNode *> Dependencies,
 
                                    bool IsIndirect, const DebugLoc &DL,
 
                                    unsigned O);
 
 
 
  /// Creates a VReg SDDbgValue node.
 
  SDDbgValue *getVRegDbgValue(DIVariable *Var, DIExpression *Expr,
 
                              unsigned VReg, bool IsIndirect,
 
                              const DebugLoc &DL, unsigned O);
 
 
 
  /// Creates a SDDbgValue node from a list of locations.
 
  SDDbgValue *getDbgValueList(DIVariable *Var, DIExpression *Expr,
 
                              ArrayRef<SDDbgOperand> Locs,
 
                              ArrayRef<SDNode *> Dependencies, bool IsIndirect,
 
                              const DebugLoc &DL, unsigned O, bool IsVariadic);
 
 
 
  /// Creates a SDDbgLabel node.
 
  SDDbgLabel *getDbgLabel(DILabel *Label, const DebugLoc &DL, unsigned O);
 
 
 
  /// Transfer debug values from one node to another, while optionally
 
  /// generating fragment expressions for split-up values. If \p InvalidateDbg
 
  /// is set, debug values are invalidated after they are transferred.
 
  void transferDbgValues(SDValue From, SDValue To, unsigned OffsetInBits = 0,
 
                         unsigned SizeInBits = 0, bool InvalidateDbg = true);
 
 
 
  /// Remove the specified node from the system. If any of its
 
  /// operands then becomes dead, remove them as well. Inform UpdateListener
 
  /// for each node deleted.
 
  void RemoveDeadNode(SDNode *N);
 
 
 
  /// This method deletes the unreachable nodes in the
 
  /// given list, and any nodes that become unreachable as a result.
 
  void RemoveDeadNodes(SmallVectorImpl<SDNode *> &DeadNodes);
 
 
 
  /// Modify anything using 'From' to use 'To' instead.
 
  /// This can cause recursive merging of nodes in the DAG.  Use the first
 
  /// version if 'From' is known to have a single result, use the second
 
  /// if you have two nodes with identical results (or if 'To' has a superset
 
  /// of the results of 'From'), use the third otherwise.
 
  ///
 
  /// These methods all take an optional UpdateListener, which (if not null) is
 
  /// informed about nodes that are deleted and modified due to recursive
 
  /// changes in the dag.
 
  ///
 
  /// These functions only replace all existing uses. It's possible that as
 
  /// these replacements are being performed, CSE may cause the From node
 
  /// to be given new uses. These new uses of From are left in place, and
 
  /// not automatically transferred to To.
 
  ///
 
  void ReplaceAllUsesWith(SDValue From, SDValue To);
 
  void ReplaceAllUsesWith(SDNode *From, SDNode *To);
 
  void ReplaceAllUsesWith(SDNode *From, const SDValue *To);
 
 
 
  /// Replace any uses of From with To, leaving
 
  /// uses of other values produced by From.getNode() alone.
 
  void ReplaceAllUsesOfValueWith(SDValue From, SDValue To);
 
 
 
  /// Like ReplaceAllUsesOfValueWith, but for multiple values at once.
 
  /// This correctly handles the case where
 
  /// there is an overlap between the From values and the To values.
 
  void ReplaceAllUsesOfValuesWith(const SDValue *From, const SDValue *To,
 
                                  unsigned Num);
 
 
 
  /// If an existing load has uses of its chain, create a token factor node with
 
  /// that chain and the new memory node's chain and update users of the old
 
  /// chain to the token factor. This ensures that the new memory node will have
 
  /// the same relative memory dependency position as the old load. Returns the
 
  /// new merged load chain.
 
  SDValue makeEquivalentMemoryOrdering(SDValue OldChain, SDValue NewMemOpChain);
 
 
 
  /// If an existing load has uses of its chain, create a token factor node with
 
  /// that chain and the new memory node's chain and update users of the old
 
  /// chain to the token factor. This ensures that the new memory node will have
 
  /// the same relative memory dependency position as the old load. Returns the
 
  /// new merged load chain.
 
  SDValue makeEquivalentMemoryOrdering(LoadSDNode *OldLoad, SDValue NewMemOp);
 
 
 
  /// Topological-sort the AllNodes list and a
 
  /// assign a unique node id for each node in the DAG based on their
 
  /// topological order. Returns the number of nodes.
 
  unsigned AssignTopologicalOrder();
 
 
 
  /// Move node N in the AllNodes list to be immediately
 
  /// before the given iterator Position. This may be used to update the
 
  /// topological ordering when the list of nodes is modified.
 
  void RepositionNode(allnodes_iterator Position, SDNode *N) {
 
    AllNodes.insert(Position, AllNodes.remove(N));
 
  }
 
 
 
  /// Returns an APFloat semantics tag appropriate for the given type. If VT is
 
  /// a vector type, the element semantics are returned.
 
  static const fltSemantics &EVTToAPFloatSemantics(EVT VT) {
 
    switch (VT.getScalarType().getSimpleVT().SimpleTy) {
 
    default: llvm_unreachable("Unknown FP format");
 
    case MVT::f16:     return APFloat::IEEEhalf();
 
    case MVT::bf16:    return APFloat::BFloat();
 
    case MVT::f32:     return APFloat::IEEEsingle();
 
    case MVT::f64:     return APFloat::IEEEdouble();
 
    case MVT::f80:     return APFloat::x87DoubleExtended();
 
    case MVT::f128:    return APFloat::IEEEquad();
 
    case MVT::ppcf128: return APFloat::PPCDoubleDouble();
 
    }
 
  }
 
 
 
  /// Add a dbg_value SDNode. If SD is non-null that means the
 
  /// value is produced by SD.
 
  void AddDbgValue(SDDbgValue *DB, bool isParameter);
 
 
 
  /// Add a dbg_label SDNode.
 
  void AddDbgLabel(SDDbgLabel *DB);
 
 
 
  /// Get the debug values which reference the given SDNode.
 
  ArrayRef<SDDbgValue*> GetDbgValues(const SDNode* SD) const {
 
    return DbgInfo->getSDDbgValues(SD);
 
  }
 
 
 
public:
 
  /// Return true if there are any SDDbgValue nodes associated
 
  /// with this SelectionDAG.
 
  bool hasDebugValues() const { return !DbgInfo->empty(); }
 
 
 
  SDDbgInfo::DbgIterator DbgBegin() const { return DbgInfo->DbgBegin(); }
 
  SDDbgInfo::DbgIterator DbgEnd() const  { return DbgInfo->DbgEnd(); }
 
 
 
  SDDbgInfo::DbgIterator ByvalParmDbgBegin() const {
 
    return DbgInfo->ByvalParmDbgBegin();
 
  }
 
  SDDbgInfo::DbgIterator ByvalParmDbgEnd() const {
 
    return DbgInfo->ByvalParmDbgEnd();
 
  }
 
 
 
  SDDbgInfo::DbgLabelIterator DbgLabelBegin() const {
 
    return DbgInfo->DbgLabelBegin();
 
  }
 
  SDDbgInfo::DbgLabelIterator DbgLabelEnd() const {
 
    return DbgInfo->DbgLabelEnd();
 
  }
 
 
 
  /// To be invoked on an SDNode that is slated to be erased. This
 
  /// function mirrors \c llvm::salvageDebugInfo.
 
  void salvageDebugInfo(SDNode &N);
 
 
 
  void dump() const;
 
 
 
  /// In most cases this function returns the ABI alignment for a given type,
 
  /// except for illegal vector types where the alignment exceeds that of the
 
  /// stack. In such cases we attempt to break the vector down to a legal type
 
  /// and return the ABI alignment for that instead.
 
  Align getReducedAlign(EVT VT, bool UseABI);
 
 
 
  /// Create a stack temporary based on the size in bytes and the alignment
 
  SDValue CreateStackTemporary(TypeSize Bytes, Align Alignment);
 
 
 
  /// Create a stack temporary, suitable for holding the specified value type.
 
  /// If minAlign is specified, the slot size will have at least that alignment.
 
  SDValue CreateStackTemporary(EVT VT, unsigned minAlign = 1);
 
 
 
  /// Create a stack temporary suitable for holding either of the specified
 
  /// value types.
 
  SDValue CreateStackTemporary(EVT VT1, EVT VT2);
 
 
 
  SDValue FoldSymbolOffset(unsigned Opcode, EVT VT,
 
                           const GlobalAddressSDNode *GA,
 
                           const SDNode *N2);
 
 
 
  SDValue FoldConstantArithmetic(unsigned Opcode, const SDLoc &DL, EVT VT,
 
                                 ArrayRef<SDValue> Ops);
 
 
 
  /// Fold floating-point operations with 2 operands when both operands are
 
  /// constants and/or undefined.
 
  SDValue foldConstantFPMath(unsigned Opcode, const SDLoc &DL, EVT VT,
 
                             SDValue N1, SDValue N2);
 
 
 
  /// Constant fold a setcc to true or false.
 
  SDValue FoldSetCC(EVT VT, SDValue N1, SDValue N2, ISD::CondCode Cond,
 
                    const SDLoc &dl);
 
 
 
  /// Return true if the sign bit of Op is known to be zero.
 
  /// We use this predicate to simplify operations downstream.
 
  bool SignBitIsZero(SDValue Op, unsigned Depth = 0) const;
 
 
 
  /// Return true if 'Op & Mask' is known to be zero.  We
 
  /// use this predicate to simplify operations downstream.  Op and Mask are
 
  /// known to be the same type.
 
  bool MaskedValueIsZero(SDValue Op, const APInt &Mask,
 
                         unsigned Depth = 0) const;
 
 
 
  /// Return true if 'Op & Mask' is known to be zero in DemandedElts.  We
 
  /// use this predicate to simplify operations downstream.  Op and Mask are
 
  /// known to be the same type.
 
  bool MaskedValueIsZero(SDValue Op, const APInt &Mask,
 
                         const APInt &DemandedElts, unsigned Depth = 0) const;
 
 
 
  /// Return true if 'Op' is known to be zero in DemandedElts.  We
 
  /// use this predicate to simplify operations downstream.
 
  bool MaskedVectorIsZero(SDValue Op, const APInt &DemandedElts,
 
                          unsigned Depth = 0) const;
 
 
 
  /// Return true if '(Op & Mask) == Mask'.
 
  /// Op and Mask are known to be the same type.
 
  bool MaskedValueIsAllOnes(SDValue Op, const APInt &Mask,
 
                            unsigned Depth = 0) const;
 
 
 
  /// For each demanded element of a vector, see if it is known to be zero.
 
  APInt computeVectorKnownZeroElements(SDValue Op, const APInt &DemandedElts,
 
                                       unsigned Depth = 0) const;
 
 
 
  /// Determine which bits of Op are known to be either zero or one and return
 
  /// them in Known. For vectors, the known bits are those that are shared by
 
  /// every vector element.
 
  /// Targets can implement the computeKnownBitsForTargetNode method in the
 
  /// TargetLowering class to allow target nodes to be understood.
 
  KnownBits computeKnownBits(SDValue Op, unsigned Depth = 0) const;
 
 
 
  /// Determine which bits of Op are known to be either zero or one and return
 
  /// them in Known. The DemandedElts argument allows us to only collect the
 
  /// known bits that are shared by the requested vector elements.
 
  /// Targets can implement the computeKnownBitsForTargetNode method in the
 
  /// TargetLowering class to allow target nodes to be understood.
 
  KnownBits computeKnownBits(SDValue Op, const APInt &DemandedElts,
 
                             unsigned Depth = 0) const;
 
 
 
  /// Used to represent the possible overflow behavior of an operation.
 
  /// Never: the operation cannot overflow.
 
  /// Always: the operation will always overflow.
 
  /// Sometime: the operation may or may not overflow.
 
  enum OverflowKind {
 
    OFK_Never,
 
    OFK_Sometime,
 
    OFK_Always,
 
  };
 
 
 
  /// Determine if the result of the addition of 2 node can overflow.
 
  OverflowKind computeOverflowKind(SDValue N0, SDValue N1) const;
 
 
 
  /// Test if the given value is known to have exactly one bit set. This differs
 
  /// from computeKnownBits in that it doesn't necessarily determine which bit
 
  /// is set.
 
  bool isKnownToBeAPowerOfTwo(SDValue Val) const;
 
 
 
  /// Return the number of times the sign bit of the register is replicated into
 
  /// the other bits. We know that at least 1 bit is always equal to the sign
 
  /// bit (itself), but other cases can give us information. For example,
 
  /// immediately after an "SRA X, 2", we know that the top 3 bits are all equal
 
  /// to each other, so we return 3. Targets can implement the
 
  /// ComputeNumSignBitsForTarget method in the TargetLowering class to allow
 
  /// target nodes to be understood.
 
  unsigned ComputeNumSignBits(SDValue Op, unsigned Depth = 0) const;
 
 
 
  /// Return the number of times the sign bit of the register is replicated into
 
  /// the other bits. We know that at least 1 bit is always equal to the sign
 
  /// bit (itself), but other cases can give us information. For example,
 
  /// immediately after an "SRA X, 2", we know that the top 3 bits are all equal
 
  /// to each other, so we return 3. The DemandedElts argument allows
 
  /// us to only collect the minimum sign bits of the requested vector elements.
 
  /// Targets can implement the ComputeNumSignBitsForTarget method in the
 
  /// TargetLowering class to allow target nodes to be understood.
 
  unsigned ComputeNumSignBits(SDValue Op, const APInt &DemandedElts,
 
                              unsigned Depth = 0) const;
 
 
 
  /// Get the upper bound on bit size for this Value \p Op as a signed integer.
 
  /// i.e.  x == sext(trunc(x to MaxSignedBits) to bitwidth(x)).
 
  /// Similar to the APInt::getSignificantBits function.
 
  /// Helper wrapper to ComputeNumSignBits.
 
  unsigned ComputeMaxSignificantBits(SDValue Op, unsigned Depth = 0) const;
 
 
 
  /// Get the upper bound on bit size for this Value \p Op as a signed integer.
 
  /// i.e.  x == sext(trunc(x to MaxSignedBits) to bitwidth(x)).
 
  /// Similar to the APInt::getSignificantBits function.
 
  /// Helper wrapper to ComputeNumSignBits.
 
  unsigned ComputeMaxSignificantBits(SDValue Op, const APInt &DemandedElts,
 
                                     unsigned Depth = 0) const;
 
 
 
  /// Return true if this function can prove that \p Op is never poison
 
  /// and, if \p PoisonOnly is false, does not have undef bits.
 
  bool isGuaranteedNotToBeUndefOrPoison(SDValue Op, bool PoisonOnly = false,
 
                                        unsigned Depth = 0) const;
 
 
 
  /// Return true if this function can prove that \p Op is never poison
 
  /// and, if \p PoisonOnly is false, does not have undef bits. The DemandedElts
 
  /// argument limits the check to the requested vector elements.
 
  bool isGuaranteedNotToBeUndefOrPoison(SDValue Op, const APInt &DemandedElts,
 
                                        bool PoisonOnly = false,
 
                                        unsigned Depth = 0) const;
 
 
 
  /// Return true if this function can prove that \p Op is never poison.
 
  bool isGuaranteedNotToBePoison(SDValue Op, unsigned Depth = 0) const {
 
    return isGuaranteedNotToBeUndefOrPoison(Op, /*PoisonOnly*/ true, Depth);
 
  }
 
 
 
  /// Return true if this function can prove that \p Op is never poison. The
 
  /// DemandedElts argument limits the check to the requested vector elements.
 
  bool isGuaranteedNotToBePoison(SDValue Op, const APInt &DemandedElts,
 
                                 unsigned Depth = 0) const {
 
    return isGuaranteedNotToBeUndefOrPoison(Op, DemandedElts,
 
                                            /*PoisonOnly*/ true, Depth);
 
  }
 
 
 
  /// Return true if Op can create undef or poison from non-undef & non-poison
 
  /// operands. The DemandedElts argument limits the check to the requested
 
  /// vector elements.
 
  ///
 
  /// \p ConsiderFlags controls whether poison producing flags on the
 
  /// instruction are considered.  This can be used to see if the instruction
 
  /// could still introduce undef or poison even without poison generating flags
 
  /// which might be on the instruction.  (i.e. could the result of
 
  /// Op->dropPoisonGeneratingFlags() still create poison or undef)
 
  bool canCreateUndefOrPoison(SDValue Op, const APInt &DemandedElts,
 
                              bool PoisonOnly = false,
 
                              bool ConsiderFlags = true,
 
                              unsigned Depth = 0) const;
 
 
 
  /// Return true if Op can create undef or poison from non-undef & non-poison
 
  /// operands.
 
  ///
 
  /// \p ConsiderFlags controls whether poison producing flags on the
 
  /// instruction are considered.  This can be used to see if the instruction
 
  /// could still introduce undef or poison even without poison generating flags
 
  /// which might be on the instruction.  (i.e. could the result of
 
  /// Op->dropPoisonGeneratingFlags() still create poison or undef)
 
  bool canCreateUndefOrPoison(SDValue Op, bool PoisonOnly = false,
 
                              bool ConsiderFlags = true,
 
                              unsigned Depth = 0) const;
 
 
 
  /// Return true if the specified operand is an ISD::ADD with a ConstantSDNode
 
  /// on the right-hand side, or if it is an ISD::OR with a ConstantSDNode that
 
  /// is guaranteed to have the same semantics as an ADD. This handles the
 
  /// equivalence:
 
  ///     X|Cst == X+Cst iff X&Cst = 0.
 
  bool isBaseWithConstantOffset(SDValue Op) const;
 
 
 
  /// Test whether the given SDValue (or all elements of it, if it is a
 
  /// vector) is known to never be NaN. If \p SNaN is true, returns if \p Op is
 
  /// known to never be a signaling NaN (it may still be a qNaN).
 
  bool isKnownNeverNaN(SDValue Op, bool SNaN = false, unsigned Depth = 0) const;
 
 
 
  /// \returns true if \p Op is known to never be a signaling NaN.
 
  bool isKnownNeverSNaN(SDValue Op, unsigned Depth = 0) const {
 
    return isKnownNeverNaN(Op, true, Depth);
 
  }
 
 
 
  /// Test whether the given floating point SDValue is known to never be
 
  /// positive or negative zero.
 
  bool isKnownNeverZeroFloat(SDValue Op) const;
 
 
 
  /// Test whether the given SDValue is known to contain non-zero value(s).
 
  bool isKnownNeverZero(SDValue Op) const;
 
 
 
  /// Test whether two SDValues are known to compare equal. This
 
  /// is true if they are the same value, or if one is negative zero and the
 
  /// other positive zero.
 
  bool isEqualTo(SDValue A, SDValue B) const;
 
 
 
  /// Return true if A and B have no common bits set. As an example, this can
 
  /// allow an 'add' to be transformed into an 'or'.
 
  bool haveNoCommonBitsSet(SDValue A, SDValue B) const;
 
 
 
  /// Test whether \p V has a splatted value for all the demanded elements.
 
  ///
 
  /// On success \p UndefElts will indicate the elements that have UNDEF
 
  /// values instead of the splat value, this is only guaranteed to be correct
 
  /// for \p DemandedElts.
 
  ///
 
  /// NOTE: The function will return true for a demanded splat of UNDEF values.
 
  bool isSplatValue(SDValue V, const APInt &DemandedElts, APInt &UndefElts,
 
                    unsigned Depth = 0) const;
 
 
 
  /// Test whether \p V has a splatted value.
 
  bool isSplatValue(SDValue V, bool AllowUndefs = false) const;
 
 
 
  /// If V is a splatted value, return the source vector and its splat index.
 
  SDValue getSplatSourceVector(SDValue V, int &SplatIndex);
 
 
 
  /// If V is a splat vector, return its scalar source operand by extracting
 
  /// that element from the source vector. If LegalTypes is true, this method
 
  /// may only return a legally-typed splat value. If it cannot legalize the
 
  /// splatted value it will return SDValue().
 
  SDValue getSplatValue(SDValue V, bool LegalTypes = false);
 
 
 
  /// If a SHL/SRA/SRL node \p V has a constant or splat constant shift amount
 
  /// that is less than the element bit-width of the shift node, return it.
 
  const APInt *getValidShiftAmountConstant(SDValue V,
 
                                           const APInt &DemandedElts) const;
 
 
 
  /// If a SHL/SRA/SRL node \p V has constant shift amounts that are all less
 
  /// than the element bit-width of the shift node, return the minimum value.
 
  const APInt *
 
  getValidMinimumShiftAmountConstant(SDValue V,
 
                                     const APInt &DemandedElts) const;
 
 
 
  /// If a SHL/SRA/SRL node \p V has constant shift amounts that are all less
 
  /// than the element bit-width of the shift node, return the maximum value.
 
  const APInt *
 
  getValidMaximumShiftAmountConstant(SDValue V,
 
                                     const APInt &DemandedElts) const;
 
 
 
  /// Match a binop + shuffle pyramid that represents a horizontal reduction
 
  /// over the elements of a vector starting from the EXTRACT_VECTOR_ELT node /p
 
  /// Extract. The reduction must use one of the opcodes listed in /p
 
  /// CandidateBinOps and on success /p BinOp will contain the matching opcode.
 
  /// Returns the vector that is being reduced on, or SDValue() if a reduction
 
  /// was not matched. If \p AllowPartials is set then in the case of a
 
  /// reduction pattern that only matches the first few stages, the extracted
 
  /// subvector of the start of the reduction is returned.
 
  SDValue matchBinOpReduction(SDNode *Extract, ISD::NodeType &BinOp,
 
                              ArrayRef<ISD::NodeType> CandidateBinOps,
 
                              bool AllowPartials = false);
 
 
 
  /// Utility function used by legalize and lowering to
 
  /// "unroll" a vector operation by splitting out the scalars and operating
 
  /// on each element individually.  If the ResNE is 0, fully unroll the vector
 
  /// op. If ResNE is less than the width of the vector op, unroll up to ResNE.
 
  /// If the  ResNE is greater than the width of the vector op, unroll the
 
  /// vector op and fill the end of the resulting vector with UNDEFS.
 
  SDValue UnrollVectorOp(SDNode *N, unsigned ResNE = 0);
 
 
 
  /// Like UnrollVectorOp(), but for the [US](ADD|SUB|MUL)O family of opcodes.
 
  /// This is a separate function because those opcodes have two results.
 
  std::pair<SDValue, SDValue> UnrollVectorOverflowOp(SDNode *N,
 
                                                     unsigned ResNE = 0);
 
 
 
  /// Return true if loads are next to each other and can be
 
  /// merged. Check that both are nonvolatile and if LD is loading
 
  /// 'Bytes' bytes from a location that is 'Dist' units away from the
 
  /// location that the 'Base' load is loading from.
 
  bool areNonVolatileConsecutiveLoads(LoadSDNode *LD, LoadSDNode *Base,
 
                                      unsigned Bytes, int Dist) const;
 
 
 
  /// Infer alignment of a load / store address. Return std::nullopt if it
 
  /// cannot be inferred.
 
  MaybeAlign InferPtrAlign(SDValue Ptr) const;
 
 
 
  /// Compute the VTs needed for the low/hi parts of a type
 
  /// which is split (or expanded) into two not necessarily identical pieces.
 
  std::pair<EVT, EVT> GetSplitDestVTs(const EVT &VT) const;
 
 
 
  /// Compute the VTs needed for the low/hi parts of a type, dependent on an
 
  /// enveloping VT that has been split into two identical pieces. Sets the
 
  /// HisIsEmpty flag when hi type has zero storage size.
 
  std::pair<EVT, EVT> GetDependentSplitDestVTs(const EVT &VT, const EVT &EnvVT,
 
                                               bool *HiIsEmpty) const;
 
 
 
  /// Split the vector with EXTRACT_SUBVECTOR using the provides
 
  /// VTs and return the low/high part.
 
  std::pair<SDValue, SDValue> SplitVector(const SDValue &N, const SDLoc &DL,
 
                                          const EVT &LoVT, const EVT &HiVT);
 
 
 
  /// Split the vector with EXTRACT_SUBVECTOR and return the low/high part.
 
  std::pair<SDValue, SDValue> SplitVector(const SDValue &N, const SDLoc &DL) {
 
    EVT LoVT, HiVT;
 
    std::tie(LoVT, HiVT) = GetSplitDestVTs(N.getValueType());
 
    return SplitVector(N, DL, LoVT, HiVT);
 
  }
 
 
 
  /// Split the explicit vector length parameter of a VP operation.
 
  std::pair<SDValue, SDValue> SplitEVL(SDValue N, EVT VecVT, const SDLoc &DL);
 
 
 
  /// Split the node's operand with EXTRACT_SUBVECTOR and
 
  /// return the low/high part.
 
  std::pair<SDValue, SDValue> SplitVectorOperand(const SDNode *N, unsigned OpNo)
 
  {
 
    return SplitVector(N->getOperand(OpNo), SDLoc(N));
 
  }
 
 
 
  /// Widen the vector up to the next power of two using INSERT_SUBVECTOR.
 
  SDValue WidenVector(const SDValue &N, const SDLoc &DL);
 
 
 
  /// Append the extracted elements from Start to Count out of the vector Op in
 
  /// Args. If Count is 0, all of the elements will be extracted. The extracted
 
  /// elements will have type EVT if it is provided, and otherwise their type
 
  /// will be Op's element type.
 
  void ExtractVectorElements(SDValue Op, SmallVectorImpl<SDValue> &Args,
 
                             unsigned Start = 0, unsigned Count = 0,
 
                             EVT EltVT = EVT());
 
 
 
  /// Compute the default alignment value for the given type.
 
  Align getEVTAlign(EVT MemoryVT) const;
 
 
 
  /// Test whether the given value is a constant int or similar node.
 
  SDNode *isConstantIntBuildVectorOrConstantInt(SDValue N) const;
 
 
 
  /// Test whether the given value is a constant FP or similar node.
 
  SDNode *isConstantFPBuildVectorOrConstantFP(SDValue N) const ;
 
 
 
  /// \returns true if \p N is any kind of constant or build_vector of
 
  /// constants, int or float. If a vector, it may not necessarily be a splat.
 
  inline bool isConstantValueOfAnyType(SDValue N) const {
 
    return isConstantIntBuildVectorOrConstantInt(N) ||
 
           isConstantFPBuildVectorOrConstantFP(N);
 
  }
 
 
 
  /// Set CallSiteInfo to be associated with Node.
 
  void addCallSiteInfo(const SDNode *Node, CallSiteInfoImpl &&CallInfo) {
 
    SDEI[Node].CSInfo = std::move(CallInfo);
 
  }
 
  /// Return CallSiteInfo associated with Node, or a default if none exists.
 
  CallSiteInfo getCallSiteInfo(const SDNode *Node) {
 
    auto I = SDEI.find(Node);
 
    return I != SDEI.end() ? std::move(I->second).CSInfo : CallSiteInfo();
 
  }
 
  /// Set HeapAllocSite to be associated with Node.
 
  void addHeapAllocSite(const SDNode *Node, MDNode *MD) {
 
    SDEI[Node].HeapAllocSite = MD;
 
  }
 
  /// Return HeapAllocSite associated with Node, or nullptr if none exists.
 
  MDNode *getHeapAllocSite(const SDNode *Node) const {
 
    auto I = SDEI.find(Node);
 
    return I != SDEI.end() ? I->second.HeapAllocSite : nullptr;
 
  }
 
  /// Set PCSections to be associated with Node.
 
  void addPCSections(const SDNode *Node, MDNode *MD) {
 
    SDEI[Node].PCSections = MD;
 
  }
 
  /// Return PCSections associated with Node, or nullptr if none exists.
 
  MDNode *getPCSections(const SDNode *Node) const {
 
    auto It = SDEI.find(Node);
 
    return It != SDEI.end() ? It->second.PCSections : nullptr;
 
  }
 
  /// Set NoMergeSiteInfo to be associated with Node if NoMerge is true.
 
  void addNoMergeSiteInfo(const SDNode *Node, bool NoMerge) {
 
    if (NoMerge)
 
      SDEI[Node].NoMerge = NoMerge;
 
  }
 
  /// Return NoMerge info associated with Node.
 
  bool getNoMergeSiteInfo(const SDNode *Node) const {
 
    auto I = SDEI.find(Node);
 
    return I != SDEI.end() ? I->second.NoMerge : false;
 
  }
 
 
 
  /// Copy extra info associated with one node to another.
 
  void copyExtraInfo(SDNode *From, SDNode *To);
 
 
 
  /// Return the current function's default denormal handling kind for the given
 
  /// floating point type.
 
  DenormalMode getDenormalMode(EVT VT) const {
 
    return MF->getDenormalMode(EVTToAPFloatSemantics(VT));
 
  }
 
 
 
  bool shouldOptForSize() const;
 
 
 
  /// Get the (commutative) neutral element for the given opcode, if it exists.
 
  SDValue getNeutralElement(unsigned Opcode, const SDLoc &DL, EVT VT,
 
                            SDNodeFlags Flags);
 
 
 
  /// Some opcodes may create immediate undefined behavior when used with some
 
  /// values (integer division-by-zero for example). Therefore, these operations
 
  /// are not generally safe to move around or change.
 
  bool isSafeToSpeculativelyExecute(unsigned Opcode) const {
 
    switch (Opcode) {
 
    case ISD::SDIV:
 
    case ISD::SREM:
 
    case ISD::SDIVREM:
 
    case ISD::UDIV:
 
    case ISD::UREM:
 
    case ISD::UDIVREM:
 
      return false;
 
    default:
 
      return true;
 
    }
 
  }
 
 
 
private:
 
  void InsertNode(SDNode *N);
 
  bool RemoveNodeFromCSEMaps(SDNode *N);
 
  void AddModifiedNodeToCSEMaps(SDNode *N);
 
  SDNode *FindModifiedNodeSlot(SDNode *N, SDValue Op, void *&InsertPos);
 
  SDNode *FindModifiedNodeSlot(SDNode *N, SDValue Op1, SDValue Op2,
 
                               void *&InsertPos);
 
  SDNode *FindModifiedNodeSlot(SDNode *N, ArrayRef<SDValue> Ops,
 
                               void *&InsertPos);
 
  SDNode *UpdateSDLocOnMergeSDNode(SDNode *N, const SDLoc &loc);
 
 
 
  void DeleteNodeNotInCSEMaps(SDNode *N);
 
  void DeallocateNode(SDNode *N);
 
 
 
  void allnodes_clear();
 
 
 
  /// Look up the node specified by ID in CSEMap.  If it exists, return it.  If
 
  /// not, return the insertion token that will make insertion faster.  This
 
  /// overload is for nodes other than Constant or ConstantFP, use the other one
 
  /// for those.
 
  SDNode *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos);
 
 
 
  /// Look up the node specified by ID in CSEMap.  If it exists, return it.  If
 
  /// not, return the insertion token that will make insertion faster.  Performs
 
  /// additional processing for constant nodes.
 
  SDNode *FindNodeOrInsertPos(const FoldingSetNodeID &ID, const SDLoc &DL,
 
                              void *&InsertPos);
 
 
 
  /// Maps to auto-CSE operations.
 
  std::vector<CondCodeSDNode*> CondCodeNodes;
 
 
 
  std::vector<SDNode*> ValueTypeNodes;
 
  std::map<EVT, SDNode*, EVT::compareRawBits> ExtendedValueTypeNodes;
 
  StringMap<SDNode*> ExternalSymbols;
 
 
 
  std::map<std::pair<std::string, unsigned>, SDNode *> TargetExternalSymbols;
 
  DenseMap<MCSymbol *, SDNode *> MCSymbols;
 
 
 
  FlagInserter *Inserter = nullptr;
 
};
 
 
 
template <> struct GraphTraits<SelectionDAG*> : public GraphTraits<SDNode*> {
 
  using nodes_iterator = pointer_iterator<SelectionDAG::allnodes_iterator>;
 
 
 
  static nodes_iterator nodes_begin(SelectionDAG *G) {
 
    return nodes_iterator(G->allnodes_begin());
 
  }
 
 
 
  static nodes_iterator nodes_end(SelectionDAG *G) {
 
    return nodes_iterator(G->allnodes_end());
 
  }
 
};
 
 
 
} // end namespace llvm
 
 
 
#endif // LLVM_CODEGEN_SELECTIONDAG_H