//===-- LegalizeTypes.h - DAG Type Legalizer class definition ---*- 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 defines the DAGTypeLegalizer class.  This is a private interface
// shared between the code that implements the SelectionDAG::LegalizeTypes
// method.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_LIB_CODEGEN_SELECTIONDAG_LEGALIZETYPES_H
#define LLVM_LIB_CODEGEN_SELECTIONDAG_LEGALIZETYPES_H

#include "llvm/ADT/DenseMap.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/TargetLowering.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"

namespace llvm {

//===----------------------------------------------------------------------===//
/// This takes an arbitrary SelectionDAG as input and hacks on it until only
/// value types the target machine can handle are left. This involves promoting
/// small sizes to large sizes or splitting up large values into small values.
///
class LLVM_LIBRARY_VISIBILITY DAGTypeLegalizer {
  const TargetLowering &TLI;
  SelectionDAG &DAG;
public:
  /// This pass uses the NodeId on the SDNodes to hold information about the
  /// state of the node. The enum has all the values.
  enum NodeIdFlags {
    /// All operands have been processed, so this node is ready to be handled.
    ReadyToProcess = 0,

    /// This is a new node, not before seen, that was created in the process of
    /// legalizing some other node.
    NewNode = -1,

    /// This node's ID needs to be set to the number of its unprocessed
    /// operands.
    Unanalyzed = -2,

    /// This is a node that has already been processed.
    Processed = -3

    // 1+ - This is a node which has this many unprocessed operands.
  };
private:

  /// This is a bitvector that contains two bits for each simple value type,
  /// where the two bits correspond to the LegalizeAction enum from
  /// TargetLowering. This can be queried with "getTypeAction(VT)".
  TargetLowering::ValueTypeActionImpl ValueTypeActions;

  /// Return how we should legalize values of this type.
  TargetLowering::LegalizeTypeAction getTypeAction(EVT VT) const {
    return TLI.getTypeAction(*DAG.getContext(), VT);
  }

  /// Return true if this type is legal on this target.
  bool isTypeLegal(EVT VT) const {
    return TLI.getTypeAction(*DAG.getContext(), VT) == TargetLowering::TypeLegal;
  }

  /// Return true if this is a simple legal type.
  bool isSimpleLegalType(EVT VT) const {
    return VT.isSimple() && TLI.isTypeLegal(VT);
  }

  EVT getSetCCResultType(EVT VT) const {
    return TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
  }

  /// Pretend all of this node's results are legal.
  bool IgnoreNodeResults(SDNode *N) const {
    return N->getOpcode() == ISD::TargetConstant ||
           N->getOpcode() == ISD::Register;
  }

  // Bijection from SDValue to unique id. As each created node gets a
  // new id we do not need to worry about reuse expunging.  Should we
  // run out of ids, we can do a one time expensive compactifcation.
  typedef unsigned TableId;

  TableId NextValueId = 1;

  SmallDenseMap<SDValue, TableId, 8> ValueToIdMap;
  SmallDenseMap<TableId, SDValue, 8> IdToValueMap;

  /// For integer nodes that are below legal width, this map indicates what
  /// promoted value to use.
  SmallDenseMap<TableId, TableId, 8> PromotedIntegers;

  /// For integer nodes that need to be expanded this map indicates which
  /// operands are the expanded version of the input.
  SmallDenseMap<TableId, std::pair<TableId, TableId>, 8> ExpandedIntegers;

  /// For floating-point nodes converted to integers of the same size, this map
  /// indicates the converted value to use.
  SmallDenseMap<TableId, TableId, 8> SoftenedFloats;

  /// For floating-point nodes that have a smaller precision than the smallest
  /// supported precision, this map indicates what promoted value to use.
  SmallDenseMap<TableId, TableId, 8> PromotedFloats;

  /// For floating-point nodes that have a smaller precision than the smallest
  /// supported precision, this map indicates the converted value to use.
  SmallDenseMap<TableId, TableId, 8> SoftPromotedHalfs;

  /// For float nodes that need to be expanded this map indicates which operands
  /// are the expanded version of the input.
  SmallDenseMap<TableId, std::pair<TableId, TableId>, 8> ExpandedFloats;

  /// For nodes that are <1 x ty>, this map indicates the scalar value of type
  /// 'ty' to use.
  SmallDenseMap<TableId, TableId, 8> ScalarizedVectors;

  /// For nodes that need to be split this map indicates which operands are the
  /// expanded version of the input.
  SmallDenseMap<TableId, std::pair<TableId, TableId>, 8> SplitVectors;

  /// For vector nodes that need to be widened, indicates the widened value to
  /// use.
  SmallDenseMap<TableId, TableId, 8> WidenedVectors;

  /// For values that have been replaced with another, indicates the replacement
  /// value to use.
  SmallDenseMap<TableId, TableId, 8> ReplacedValues;

  /// This defines a worklist of nodes to process. In order to be pushed onto
  /// this worklist, all operands of a node must have already been processed.
  SmallVector<SDNode*, 128> Worklist;

  TableId getTableId(SDValue V) {
    assert(V.getNode() && "Getting TableId on SDValue()");

    auto I = ValueToIdMap.find(V);
    if (I != ValueToIdMap.end()) {
      // replace if there's been a shift.
      RemapId(I->second);
      assert(I->second && "All Ids should be nonzero");
      return I->second;
    }
    // Add if it's not there.
    ValueToIdMap.insert(std::make_pair(V, NextValueId));
    IdToValueMap.insert(std::make_pair(NextValueId, V));
    ++NextValueId;
    assert(NextValueId != 0 &&
           "Ran out of Ids. Increase id type size or add compactification");
    return NextValueId - 1;
  }

  const SDValue &getSDValue(TableId &Id) {
    RemapId(Id);
    assert(Id && "TableId should be non-zero");
    auto I = IdToValueMap.find(Id);
    assert(I != IdToValueMap.end() && "cannot find Id in map");
    return I->second;
  }

public:
  explicit DAGTypeLegalizer(SelectionDAG &dag)
    : TLI(dag.getTargetLoweringInfo()), DAG(dag),
    ValueTypeActions(TLI.getValueTypeActions()) {
    static_assert(MVT::LAST_VALUETYPE <= MVT::MAX_ALLOWED_VALUETYPE,
                  "Too many value types for ValueTypeActions to hold!");
  }

  /// This is the main entry point for the type legalizer.  This does a
  /// top-down traversal of the dag, legalizing types as it goes.  Returns
  /// "true" if it made any changes.
  bool run();

  void NoteDeletion(SDNode *Old, SDNode *New) {
    assert(Old != New && "node replaced with self");
    for (unsigned i = 0, e = Old->getNumValues(); i != e; ++i) {
      TableId NewId = getTableId(SDValue(New, i));
      TableId OldId = getTableId(SDValue(Old, i));

      if (OldId != NewId) {
        ReplacedValues[OldId] = NewId;

        // Delete Node from tables.  We cannot do this when OldId == NewId,
        // because NewId can still have table references to it in
        // ReplacedValues.
        IdToValueMap.erase(OldId);
        PromotedIntegers.erase(OldId);
        ExpandedIntegers.erase(OldId);
        SoftenedFloats.erase(OldId);
        PromotedFloats.erase(OldId);
        SoftPromotedHalfs.erase(OldId);
        ExpandedFloats.erase(OldId);
        ScalarizedVectors.erase(OldId);
        SplitVectors.erase(OldId);
        WidenedVectors.erase(OldId);
      }

      ValueToIdMap.erase(SDValue(Old, i));
    }
  }

  SelectionDAG &getDAG() const { return DAG; }

private:
  SDNode *AnalyzeNewNode(SDNode *N);
  void AnalyzeNewValue(SDValue &Val);
  void PerformExpensiveChecks();
  void RemapId(TableId &Id);
  void RemapValue(SDValue &V);

  // Common routines.
  SDValue BitConvertToInteger(SDValue Op);
  SDValue BitConvertVectorToIntegerVector(SDValue Op);
  SDValue CreateStackStoreLoad(SDValue Op, EVT DestVT);
  bool CustomLowerNode(SDNode *N, EVT VT, bool LegalizeResult);
  bool CustomWidenLowerNode(SDNode *N, EVT VT);

  /// Replace each result of the given MERGE_VALUES node with the corresponding
  /// input operand, except for the result 'ResNo', for which the corresponding
  /// input operand is returned.
  SDValue DisintegrateMERGE_VALUES(SDNode *N, unsigned ResNo);

  SDValue JoinIntegers(SDValue Lo, SDValue Hi);

  std::pair<SDValue, SDValue> ExpandAtomic(SDNode *Node);

  SDValue PromoteTargetBoolean(SDValue Bool, EVT ValVT);

  void ReplaceValueWith(SDValue From, SDValue To);
  void SplitInteger(SDValue Op, SDValue &Lo, SDValue &Hi);
  void SplitInteger(SDValue Op, EVT LoVT, EVT HiVT,
                    SDValue &Lo, SDValue &Hi);

  //===--------------------------------------------------------------------===//
  // Integer Promotion Support: LegalizeIntegerTypes.cpp
  //===--------------------------------------------------------------------===//

  /// Given a processed operand Op which was promoted to a larger integer type,
  /// this returns the promoted value. The low bits of the promoted value
  /// corresponding to the original type are exactly equal to Op.
  /// The extra bits contain rubbish, so the promoted value may need to be zero-
  /// or sign-extended from the original type before it is usable (the helpers
  /// SExtPromotedInteger and ZExtPromotedInteger can do this for you).
  /// For example, if Op is an i16 and was promoted to an i32, then this method
  /// returns an i32, the lower 16 bits of which coincide with Op, and the upper
  /// 16 bits of which contain rubbish.
  SDValue GetPromotedInteger(SDValue Op) {
    TableId &PromotedId = PromotedIntegers[getTableId(Op)];
    SDValue PromotedOp = getSDValue(PromotedId);
    assert(PromotedOp.getNode() && "Operand wasn't promoted?");
    return PromotedOp;
  }
  void SetPromotedInteger(SDValue Op, SDValue Result);

  /// Get a promoted operand and sign extend it to the final size.
  SDValue SExtPromotedInteger(SDValue Op) {
    EVT OldVT = Op.getValueType();
    SDLoc dl(Op);
    Op = GetPromotedInteger(Op);
    return DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, Op.getValueType(), Op,
                       DAG.getValueType(OldVT));
  }

  /// Get a promoted operand and zero extend it to the final size.
  SDValue ZExtPromotedInteger(SDValue Op) {
    EVT OldVT = Op.getValueType();
    SDLoc dl(Op);
    Op = GetPromotedInteger(Op);
    return DAG.getZeroExtendInReg(Op, dl, OldVT);
  }

  // Get a promoted operand and sign or zero extend it to the final size
  // (depending on TargetLoweringInfo::isSExtCheaperThanZExt). For a given
  // subtarget and type, the choice of sign or zero-extension will be
  // consistent.
  SDValue SExtOrZExtPromotedInteger(SDValue Op) {
    EVT OldVT = Op.getValueType();
    SDLoc DL(Op);
    Op = GetPromotedInteger(Op);
    if (TLI.isSExtCheaperThanZExt(OldVT, Op.getValueType()))
      return DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, Op.getValueType(), Op,
                         DAG.getValueType(OldVT));
    return DAG.getZeroExtendInReg(Op, DL, OldVT);
  }

  // Integer Result Promotion.
  void PromoteIntegerResult(SDNode *N, unsigned ResNo);
  SDValue PromoteIntRes_MERGE_VALUES(SDNode *N, unsigned ResNo);
  SDValue PromoteIntRes_AssertSext(SDNode *N);
  SDValue PromoteIntRes_AssertZext(SDNode *N);
  SDValue PromoteIntRes_Atomic0(AtomicSDNode *N);
  SDValue PromoteIntRes_Atomic1(AtomicSDNode *N);
  SDValue PromoteIntRes_AtomicCmpSwap(AtomicSDNode *N, unsigned ResNo);
  SDValue PromoteIntRes_EXTRACT_SUBVECTOR(SDNode *N);
  SDValue PromoteIntRes_VECTOR_REVERSE(SDNode *N);
  SDValue PromoteIntRes_VECTOR_SHUFFLE(SDNode *N);
  SDValue PromoteIntRes_VECTOR_SPLICE(SDNode *N);
  SDValue PromoteIntRes_BUILD_VECTOR(SDNode *N);
  SDValue PromoteIntRes_SCALAR_TO_VECTOR(SDNode *N);
  SDValue PromoteIntRes_SPLAT_VECTOR(SDNode *N);
  SDValue PromoteIntRes_STEP_VECTOR(SDNode *N);
  SDValue PromoteIntRes_EXTEND_VECTOR_INREG(SDNode *N);
  SDValue PromoteIntRes_INSERT_VECTOR_ELT(SDNode *N);
  SDValue PromoteIntRes_CONCAT_VECTORS(SDNode *N);
  SDValue PromoteIntRes_BITCAST(SDNode *N);
  SDValue PromoteIntRes_BSWAP(SDNode *N);
  SDValue PromoteIntRes_BITREVERSE(SDNode *N);
  SDValue PromoteIntRes_BUILD_PAIR(SDNode *N);
  SDValue PromoteIntRes_Constant(SDNode *N);
  SDValue PromoteIntRes_CTLZ(SDNode *N);
  SDValue PromoteIntRes_CTPOP_PARITY(SDNode *N);
  SDValue PromoteIntRes_CTTZ(SDNode *N);
  SDValue PromoteIntRes_EXTRACT_VECTOR_ELT(SDNode *N);
  SDValue PromoteIntRes_FP_TO_XINT(SDNode *N);
  SDValue PromoteIntRes_FP_TO_XINT_SAT(SDNode *N);
  SDValue PromoteIntRes_FP_TO_FP16(SDNode *N);
  SDValue PromoteIntRes_FREEZE(SDNode *N);
  SDValue PromoteIntRes_INT_EXTEND(SDNode *N);
  SDValue PromoteIntRes_LOAD(LoadSDNode *N);
  SDValue PromoteIntRes_MLOAD(MaskedLoadSDNode *N);
  SDValue PromoteIntRes_MGATHER(MaskedGatherSDNode *N);
  SDValue PromoteIntRes_Overflow(SDNode *N);
  SDValue PromoteIntRes_SADDSUBO(SDNode *N, unsigned ResNo);
  SDValue PromoteIntRes_SELECT(SDNode *N);
  SDValue PromoteIntRes_VSELECT(SDNode *N);
  SDValue PromoteIntRes_SELECT_CC(SDNode *N);
  SDValue PromoteIntRes_SETCC(SDNode *N);
  SDValue PromoteIntRes_SHL(SDNode *N);
  SDValue PromoteIntRes_SimpleIntBinOp(SDNode *N);
  SDValue PromoteIntRes_ZExtIntBinOp(SDNode *N);
  SDValue PromoteIntRes_SExtIntBinOp(SDNode *N);
  SDValue PromoteIntRes_UMINUMAX(SDNode *N);
  SDValue PromoteIntRes_SIGN_EXTEND_INREG(SDNode *N);
  SDValue PromoteIntRes_SRA(SDNode *N);
  SDValue PromoteIntRes_SRL(SDNode *N);
  SDValue PromoteIntRes_TRUNCATE(SDNode *N);
  SDValue PromoteIntRes_UADDSUBO(SDNode *N, unsigned ResNo);
  SDValue PromoteIntRes_ADDSUBCARRY(SDNode *N, unsigned ResNo);
  SDValue PromoteIntRes_SADDSUBO_CARRY(SDNode *N, unsigned ResNo);
  SDValue PromoteIntRes_UNDEF(SDNode *N);
  SDValue PromoteIntRes_VAARG(SDNode *N);
  SDValue PromoteIntRes_VSCALE(SDNode *N);
  SDValue PromoteIntRes_XMULO(SDNode *N, unsigned ResNo);
  SDValue PromoteIntRes_ADDSUBSHLSAT(SDNode *N);
  SDValue PromoteIntRes_MULFIX(SDNode *N);
  SDValue PromoteIntRes_DIVFIX(SDNode *N);
  SDValue PromoteIntRes_FLT_ROUNDS(SDNode *N);
  SDValue PromoteIntRes_VECREDUCE(SDNode *N);
  SDValue PromoteIntRes_ABS(SDNode *N);
  SDValue PromoteIntRes_Rotate(SDNode *N);
  SDValue PromoteIntRes_FunnelShift(SDNode *N);

  // Integer Operand Promotion.
  bool PromoteIntegerOperand(SDNode *N, unsigned OpNo);
  SDValue PromoteIntOp_ANY_EXTEND(SDNode *N);
  SDValue PromoteIntOp_ATOMIC_STORE(AtomicSDNode *N);
  SDValue PromoteIntOp_BITCAST(SDNode *N);
  SDValue PromoteIntOp_BUILD_PAIR(SDNode *N);
  SDValue PromoteIntOp_BR_CC(SDNode *N, unsigned OpNo);
  SDValue PromoteIntOp_BRCOND(SDNode *N, unsigned OpNo);
  SDValue PromoteIntOp_BUILD_VECTOR(SDNode *N);
  SDValue PromoteIntOp_INSERT_VECTOR_ELT(SDNode *N, unsigned OpNo);
  SDValue PromoteIntOp_EXTRACT_VECTOR_ELT(SDNode *N);
  SDValue PromoteIntOp_EXTRACT_SUBVECTOR(SDNode *N);
  SDValue PromoteIntOp_CONCAT_VECTORS(SDNode *N);
  SDValue PromoteIntOp_SCALAR_TO_VECTOR(SDNode *N);
  SDValue PromoteIntOp_SPLAT_VECTOR(SDNode *N);
  SDValue PromoteIntOp_SELECT(SDNode *N, unsigned OpNo);
  SDValue PromoteIntOp_SELECT_CC(SDNode *N, unsigned OpNo);
  SDValue PromoteIntOp_SETCC(SDNode *N, unsigned OpNo);
  SDValue PromoteIntOp_Shift(SDNode *N);
  SDValue PromoteIntOp_SIGN_EXTEND(SDNode *N);
  SDValue PromoteIntOp_SINT_TO_FP(SDNode *N);
  SDValue PromoteIntOp_STRICT_SINT_TO_FP(SDNode *N);
  SDValue PromoteIntOp_STORE(StoreSDNode *N, unsigned OpNo);
  SDValue PromoteIntOp_TRUNCATE(SDNode *N);
  SDValue PromoteIntOp_UINT_TO_FP(SDNode *N);
  SDValue PromoteIntOp_STRICT_UINT_TO_FP(SDNode *N);
  SDValue PromoteIntOp_ZERO_EXTEND(SDNode *N);
  SDValue PromoteIntOp_MSTORE(MaskedStoreSDNode *N, unsigned OpNo);
  SDValue PromoteIntOp_MLOAD(MaskedLoadSDNode *N, unsigned OpNo);
  SDValue PromoteIntOp_MSCATTER(MaskedScatterSDNode *N, unsigned OpNo);
  SDValue PromoteIntOp_MGATHER(MaskedGatherSDNode *N, unsigned OpNo);
  SDValue PromoteIntOp_ADDSUBCARRY(SDNode *N, unsigned OpNo);
  SDValue PromoteIntOp_FRAMERETURNADDR(SDNode *N);
  SDValue PromoteIntOp_PREFETCH(SDNode *N, unsigned OpNo);
  SDValue PromoteIntOp_FIX(SDNode *N);
  SDValue PromoteIntOp_FPOWI(SDNode *N);
  SDValue PromoteIntOp_VECREDUCE(SDNode *N);
  SDValue PromoteIntOp_SET_ROUNDING(SDNode *N);

  void PromoteSetCCOperands(SDValue &LHS,SDValue &RHS, ISD::CondCode Code);

  //===--------------------------------------------------------------------===//
  // Integer Expansion Support: LegalizeIntegerTypes.cpp
  //===--------------------------------------------------------------------===//

  /// Given a processed operand Op which was expanded into two integers of half
  /// the size, this returns the two halves. The low bits of Op are exactly
  /// equal to the bits of Lo; the high bits exactly equal Hi.
  /// For example, if Op is an i64 which was expanded into two i32's, then this
  /// method returns the two i32's, with Lo being equal to the lower 32 bits of
  /// Op, and Hi being equal to the upper 32 bits.
  void GetExpandedInteger(SDValue Op, SDValue &Lo, SDValue &Hi);
  void SetExpandedInteger(SDValue Op, SDValue Lo, SDValue Hi);

  // Integer Result Expansion.
  void ExpandIntegerResult(SDNode *N, unsigned ResNo);
  void ExpandIntRes_ANY_EXTEND        (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_AssertSext        (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_AssertZext        (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_Constant          (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_ABS               (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_CTLZ              (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_CTPOP             (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_CTTZ              (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_LOAD          (LoadSDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_READCYCLECOUNTER  (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_SIGN_EXTEND       (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_SIGN_EXTEND_INREG (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_TRUNCATE          (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_ZERO_EXTEND       (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_FLT_ROUNDS        (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_FP_TO_SINT        (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_FP_TO_UINT        (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_FP_TO_XINT_SAT    (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_LLROUND_LLRINT    (SDNode *N, SDValue &Lo, SDValue &Hi);

  void ExpandIntRes_Logical           (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_ADDSUB            (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_ADDSUBC           (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_ADDSUBE           (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_ADDSUBCARRY       (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_SADDSUBO_CARRY    (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_BITREVERSE        (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_BSWAP             (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_PARITY            (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_MUL               (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_SDIV              (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_SREM              (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_UDIV              (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_UREM              (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_Shift             (SDNode *N, SDValue &Lo, SDValue &Hi);

  void ExpandIntRes_MINMAX            (SDNode *N, SDValue &Lo, SDValue &Hi);

  void ExpandIntRes_SADDSUBO          (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_UADDSUBO          (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_XMULO             (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_ADDSUBSAT         (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_SHLSAT            (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_MULFIX            (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_DIVFIX            (SDNode *N, SDValue &Lo, SDValue &Hi);

  void ExpandIntRes_ATOMIC_LOAD       (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_VECREDUCE         (SDNode *N, SDValue &Lo, SDValue &Hi);

  void ExpandIntRes_Rotate            (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandIntRes_FunnelShift       (SDNode *N, SDValue &Lo, SDValue &Hi);

  void ExpandShiftByConstant(SDNode *N, const APInt &Amt,
                             SDValue &Lo, SDValue &Hi);
  bool ExpandShiftWithKnownAmountBit(SDNode *N, SDValue &Lo, SDValue &Hi);
  bool ExpandShiftWithUnknownAmountBit(SDNode *N, SDValue &Lo, SDValue &Hi);

  // Integer Operand Expansion.
  bool ExpandIntegerOperand(SDNode *N, unsigned OpNo);
  SDValue ExpandIntOp_BR_CC(SDNode *N);
  SDValue ExpandIntOp_SELECT_CC(SDNode *N);
  SDValue ExpandIntOp_SETCC(SDNode *N);
  SDValue ExpandIntOp_SETCCCARRY(SDNode *N);
  SDValue ExpandIntOp_Shift(SDNode *N);
  SDValue ExpandIntOp_SINT_TO_FP(SDNode *N);
  SDValue ExpandIntOp_STORE(StoreSDNode *N, unsigned OpNo);
  SDValue ExpandIntOp_TRUNCATE(SDNode *N);
  SDValue ExpandIntOp_UINT_TO_FP(SDNode *N);
  SDValue ExpandIntOp_RETURNADDR(SDNode *N);
  SDValue ExpandIntOp_ATOMIC_STORE(SDNode *N);
  SDValue ExpandIntOp_SPLAT_VECTOR(SDNode *N);

  void IntegerExpandSetCCOperands(SDValue &NewLHS, SDValue &NewRHS,
                                  ISD::CondCode &CCCode, const SDLoc &dl);

  //===--------------------------------------------------------------------===//
  // Float to Integer Conversion Support: LegalizeFloatTypes.cpp
  //===--------------------------------------------------------------------===//

  /// GetSoftenedFloat - Given a processed operand Op which was converted to an
  /// integer of the same size, this returns the integer.  The integer contains
  /// exactly the same bits as Op - only the type changed.  For example, if Op
  /// is an f32 which was softened to an i32, then this method returns an i32,
  /// the bits of which coincide with those of Op
  SDValue GetSoftenedFloat(SDValue Op) {
    TableId Id = getTableId(Op);
    auto Iter = SoftenedFloats.find(Id);
    if (Iter == SoftenedFloats.end()) {
      assert(isSimpleLegalType(Op.getValueType()) &&
             "Operand wasn't converted to integer?");
      return Op;
    }
    SDValue SoftenedOp = getSDValue(Iter->second);
    assert(SoftenedOp.getNode() && "Unconverted op in SoftenedFloats?");
    return SoftenedOp;
  }
  void SetSoftenedFloat(SDValue Op, SDValue Result);

  // Convert Float Results to Integer.
  void SoftenFloatResult(SDNode *N, unsigned ResNo);
  SDValue SoftenFloatRes_Unary(SDNode *N, RTLIB::Libcall LC);
  SDValue SoftenFloatRes_Binary(SDNode *N, RTLIB::Libcall LC);
  SDValue SoftenFloatRes_MERGE_VALUES(SDNode *N, unsigned ResNo);
  SDValue SoftenFloatRes_BITCAST(SDNode *N);
  SDValue SoftenFloatRes_BUILD_PAIR(SDNode *N);
  SDValue SoftenFloatRes_ConstantFP(SDNode *N);
  SDValue SoftenFloatRes_EXTRACT_VECTOR_ELT(SDNode *N, unsigned ResNo);
  SDValue SoftenFloatRes_FABS(SDNode *N);
  SDValue SoftenFloatRes_FMINNUM(SDNode *N);
  SDValue SoftenFloatRes_FMAXNUM(SDNode *N);
  SDValue SoftenFloatRes_FADD(SDNode *N);
  SDValue SoftenFloatRes_FCBRT(SDNode *N);
  SDValue SoftenFloatRes_FCEIL(SDNode *N);
  SDValue SoftenFloatRes_FCOPYSIGN(SDNode *N);
  SDValue SoftenFloatRes_FCOS(SDNode *N);
  SDValue SoftenFloatRes_FDIV(SDNode *N);
  SDValue SoftenFloatRes_FEXP(SDNode *N);
  SDValue SoftenFloatRes_FEXP2(SDNode *N);
  SDValue SoftenFloatRes_FFLOOR(SDNode *N);
  SDValue SoftenFloatRes_FLOG(SDNode *N);
  SDValue SoftenFloatRes_FLOG2(SDNode *N);
  SDValue SoftenFloatRes_FLOG10(SDNode *N);
  SDValue SoftenFloatRes_FMA(SDNode *N);
  SDValue SoftenFloatRes_FMUL(SDNode *N);
  SDValue SoftenFloatRes_FNEARBYINT(SDNode *N);
  SDValue SoftenFloatRes_FNEG(SDNode *N);
  SDValue SoftenFloatRes_FP_EXTEND(SDNode *N);
  SDValue SoftenFloatRes_FP16_TO_FP(SDNode *N);
  SDValue SoftenFloatRes_FP_ROUND(SDNode *N);
  SDValue SoftenFloatRes_FPOW(SDNode *N);
  SDValue SoftenFloatRes_FPOWI(SDNode *N);
  SDValue SoftenFloatRes_FREEZE(SDNode *N);
  SDValue SoftenFloatRes_FREM(SDNode *N);
  SDValue SoftenFloatRes_FRINT(SDNode *N);
  SDValue SoftenFloatRes_FROUND(SDNode *N);
  SDValue SoftenFloatRes_FROUNDEVEN(SDNode *N);
  SDValue SoftenFloatRes_FSIN(SDNode *N);
  SDValue SoftenFloatRes_FSQRT(SDNode *N);
  SDValue SoftenFloatRes_FSUB(SDNode *N);
  SDValue SoftenFloatRes_FTRUNC(SDNode *N);
  SDValue SoftenFloatRes_LOAD(SDNode *N);
  SDValue SoftenFloatRes_SELECT(SDNode *N);
  SDValue SoftenFloatRes_SELECT_CC(SDNode *N);
  SDValue SoftenFloatRes_UNDEF(SDNode *N);
  SDValue SoftenFloatRes_VAARG(SDNode *N);
  SDValue SoftenFloatRes_XINT_TO_FP(SDNode *N);
  SDValue SoftenFloatRes_VECREDUCE(SDNode *N);
  SDValue SoftenFloatRes_VECREDUCE_SEQ(SDNode *N);

  // Convert Float Operand to Integer.
  bool SoftenFloatOperand(SDNode *N, unsigned OpNo);
  SDValue SoftenFloatOp_Unary(SDNode *N, RTLIB::Libcall LC);
  SDValue SoftenFloatOp_BITCAST(SDNode *N);
  SDValue SoftenFloatOp_BR_CC(SDNode *N);
  SDValue SoftenFloatOp_FP_ROUND(SDNode *N);
  SDValue SoftenFloatOp_FP_TO_XINT(SDNode *N);
  SDValue SoftenFloatOp_FP_TO_XINT_SAT(SDNode *N);
  SDValue SoftenFloatOp_LROUND(SDNode *N);
  SDValue SoftenFloatOp_LLROUND(SDNode *N);
  SDValue SoftenFloatOp_LRINT(SDNode *N);
  SDValue SoftenFloatOp_LLRINT(SDNode *N);
  SDValue SoftenFloatOp_SELECT_CC(SDNode *N);
  SDValue SoftenFloatOp_SETCC(SDNode *N);
  SDValue SoftenFloatOp_STORE(SDNode *N, unsigned OpNo);
  SDValue SoftenFloatOp_FCOPYSIGN(SDNode *N);

  //===--------------------------------------------------------------------===//
  // Float Expansion Support: LegalizeFloatTypes.cpp
  //===--------------------------------------------------------------------===//

  /// Given a processed operand Op which was expanded into two floating-point
  /// values of half the size, this returns the two halves.
  /// The low bits of Op are exactly equal to the bits of Lo; the high bits
  /// exactly equal Hi.  For example, if Op is a ppcf128 which was expanded
  /// into two f64's, then this method returns the two f64's, with Lo being
  /// equal to the lower 64 bits of Op, and Hi to the upper 64 bits.
  void GetExpandedFloat(SDValue Op, SDValue &Lo, SDValue &Hi);
  void SetExpandedFloat(SDValue Op, SDValue Lo, SDValue Hi);

  // Float Result Expansion.
  void ExpandFloatResult(SDNode *N, unsigned ResNo);
  void ExpandFloatRes_ConstantFP(SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_Unary(SDNode *N, RTLIB::Libcall LC,
                            SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_Binary(SDNode *N, RTLIB::Libcall LC,
                             SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FABS      (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FMINNUM   (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FMAXNUM   (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FADD      (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FCBRT     (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FCEIL     (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FCOPYSIGN (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FCOS      (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FDIV      (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FEXP      (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FEXP2     (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FFLOOR    (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FLOG      (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FLOG2     (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FLOG10    (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FMA       (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FMUL      (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FNEARBYINT(SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FNEG      (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FP_EXTEND (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FPOW      (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FPOWI     (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FREEZE    (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FREM      (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FRINT     (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FROUND    (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FROUNDEVEN(SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FSIN      (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FSQRT     (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FSUB      (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_FTRUNC    (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_LOAD      (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandFloatRes_XINT_TO_FP(SDNode *N, SDValue &Lo, SDValue &Hi);

  // Float Operand Expansion.
  bool ExpandFloatOperand(SDNode *N, unsigned OpNo);
  SDValue ExpandFloatOp_BR_CC(SDNode *N);
  SDValue ExpandFloatOp_FCOPYSIGN(SDNode *N);
  SDValue ExpandFloatOp_FP_ROUND(SDNode *N);
  SDValue ExpandFloatOp_FP_TO_XINT(SDNode *N);
  SDValue ExpandFloatOp_LROUND(SDNode *N);
  SDValue ExpandFloatOp_LLROUND(SDNode *N);
  SDValue ExpandFloatOp_LRINT(SDNode *N);
  SDValue ExpandFloatOp_LLRINT(SDNode *N);
  SDValue ExpandFloatOp_SELECT_CC(SDNode *N);
  SDValue ExpandFloatOp_SETCC(SDNode *N);
  SDValue ExpandFloatOp_STORE(SDNode *N, unsigned OpNo);

  void FloatExpandSetCCOperands(SDValue &NewLHS, SDValue &NewRHS,
                                ISD::CondCode &CCCode, const SDLoc &dl,
                                SDValue &Chain, bool IsSignaling = false);

  //===--------------------------------------------------------------------===//
  // Float promotion support: LegalizeFloatTypes.cpp
  //===--------------------------------------------------------------------===//

  SDValue GetPromotedFloat(SDValue Op) {
    TableId &PromotedId = PromotedFloats[getTableId(Op)];
    SDValue PromotedOp = getSDValue(PromotedId);
    assert(PromotedOp.getNode() && "Operand wasn't promoted?");
    return PromotedOp;
  }
  void SetPromotedFloat(SDValue Op, SDValue Result);

  void PromoteFloatResult(SDNode *N, unsigned ResNo);
  SDValue PromoteFloatRes_BITCAST(SDNode *N);
  SDValue PromoteFloatRes_BinOp(SDNode *N);
  SDValue PromoteFloatRes_ConstantFP(SDNode *N);
  SDValue PromoteFloatRes_EXTRACT_VECTOR_ELT(SDNode *N);
  SDValue PromoteFloatRes_FCOPYSIGN(SDNode *N);
  SDValue PromoteFloatRes_FMAD(SDNode *N);
  SDValue PromoteFloatRes_FPOWI(SDNode *N);
  SDValue PromoteFloatRes_FP_ROUND(SDNode *N);
  SDValue PromoteFloatRes_LOAD(SDNode *N);
  SDValue PromoteFloatRes_SELECT(SDNode *N);
  SDValue PromoteFloatRes_SELECT_CC(SDNode *N);
  SDValue PromoteFloatRes_UnaryOp(SDNode *N);
  SDValue PromoteFloatRes_UNDEF(SDNode *N);
  SDValue BitcastToInt_ATOMIC_SWAP(SDNode *N);
  SDValue PromoteFloatRes_XINT_TO_FP(SDNode *N);
  SDValue PromoteFloatRes_VECREDUCE(SDNode *N);
  SDValue PromoteFloatRes_VECREDUCE_SEQ(SDNode *N);

  bool PromoteFloatOperand(SDNode *N, unsigned OpNo);
  SDValue PromoteFloatOp_BITCAST(SDNode *N, unsigned OpNo);
  SDValue PromoteFloatOp_FCOPYSIGN(SDNode *N, unsigned OpNo);
  SDValue PromoteFloatOp_FP_EXTEND(SDNode *N, unsigned OpNo);
  SDValue PromoteFloatOp_FP_TO_XINT(SDNode *N, unsigned OpNo);
  SDValue PromoteFloatOp_FP_TO_XINT_SAT(SDNode *N, unsigned OpNo);
  SDValue PromoteFloatOp_STORE(SDNode *N, unsigned OpNo);
  SDValue PromoteFloatOp_SELECT_CC(SDNode *N, unsigned OpNo);
  SDValue PromoteFloatOp_SETCC(SDNode *N, unsigned OpNo);

  //===--------------------------------------------------------------------===//
  // Half soft promotion support: LegalizeFloatTypes.cpp
  //===--------------------------------------------------------------------===//

  SDValue GetSoftPromotedHalf(SDValue Op) {
    TableId &PromotedId = SoftPromotedHalfs[getTableId(Op)];
    SDValue PromotedOp = getSDValue(PromotedId);
    assert(PromotedOp.getNode() && "Operand wasn't promoted?");
    return PromotedOp;
  }
  void SetSoftPromotedHalf(SDValue Op, SDValue Result);

  void SoftPromoteHalfResult(SDNode *N, unsigned ResNo);
  SDValue SoftPromoteHalfRes_BinOp(SDNode *N);
  SDValue SoftPromoteHalfRes_BITCAST(SDNode *N);
  SDValue SoftPromoteHalfRes_ConstantFP(SDNode *N);
  SDValue SoftPromoteHalfRes_EXTRACT_VECTOR_ELT(SDNode *N);
  SDValue SoftPromoteHalfRes_FCOPYSIGN(SDNode *N);
  SDValue SoftPromoteHalfRes_FMAD(SDNode *N);
  SDValue SoftPromoteHalfRes_FPOWI(SDNode *N);
  SDValue SoftPromoteHalfRes_FP_ROUND(SDNode *N);
  SDValue SoftPromoteHalfRes_LOAD(SDNode *N);
  SDValue SoftPromoteHalfRes_SELECT(SDNode *N);
  SDValue SoftPromoteHalfRes_SELECT_CC(SDNode *N);
  SDValue SoftPromoteHalfRes_UnaryOp(SDNode *N);
  SDValue SoftPromoteHalfRes_XINT_TO_FP(SDNode *N);
  SDValue SoftPromoteHalfRes_UNDEF(SDNode *N);
  SDValue SoftPromoteHalfRes_VECREDUCE(SDNode *N);
  SDValue SoftPromoteHalfRes_VECREDUCE_SEQ(SDNode *N);

  bool SoftPromoteHalfOperand(SDNode *N, unsigned OpNo);
  SDValue SoftPromoteHalfOp_BITCAST(SDNode *N);
  SDValue SoftPromoteHalfOp_FCOPYSIGN(SDNode *N, unsigned OpNo);
  SDValue SoftPromoteHalfOp_FP_EXTEND(SDNode *N);
  SDValue SoftPromoteHalfOp_FP_TO_XINT(SDNode *N);
  SDValue SoftPromoteHalfOp_FP_TO_XINT_SAT(SDNode *N);
  SDValue SoftPromoteHalfOp_SETCC(SDNode *N);
  SDValue SoftPromoteHalfOp_SELECT_CC(SDNode *N, unsigned OpNo);
  SDValue SoftPromoteHalfOp_STORE(SDNode *N, unsigned OpNo);

  //===--------------------------------------------------------------------===//
  // Scalarization Support: LegalizeVectorTypes.cpp
  //===--------------------------------------------------------------------===//

  /// Given a processed one-element vector Op which was scalarized to its
  /// element type, this returns the element. For example, if Op is a v1i32,
  /// Op = < i32 val >, this method returns val, an i32.
  SDValue GetScalarizedVector(SDValue Op) {
    TableId &ScalarizedId = ScalarizedVectors[getTableId(Op)];
    SDValue ScalarizedOp = getSDValue(ScalarizedId);
    assert(ScalarizedOp.getNode() && "Operand wasn't scalarized?");
    return ScalarizedOp;
  }
  void SetScalarizedVector(SDValue Op, SDValue Result);

  // Vector Result Scalarization: <1 x ty> -> ty.
  void ScalarizeVectorResult(SDNode *N, unsigned ResNo);
  SDValue ScalarizeVecRes_MERGE_VALUES(SDNode *N, unsigned ResNo);
  SDValue ScalarizeVecRes_BinOp(SDNode *N);
  SDValue ScalarizeVecRes_TernaryOp(SDNode *N);
  SDValue ScalarizeVecRes_UnaryOp(SDNode *N);
  SDValue ScalarizeVecRes_StrictFPOp(SDNode *N);
  SDValue ScalarizeVecRes_OverflowOp(SDNode *N, unsigned ResNo);
  SDValue ScalarizeVecRes_InregOp(SDNode *N);
  SDValue ScalarizeVecRes_VecInregOp(SDNode *N);

  SDValue ScalarizeVecRes_BITCAST(SDNode *N);
  SDValue ScalarizeVecRes_BUILD_VECTOR(SDNode *N);
  SDValue ScalarizeVecRes_EXTRACT_SUBVECTOR(SDNode *N);
  SDValue ScalarizeVecRes_FP_ROUND(SDNode *N);
  SDValue ScalarizeVecRes_FPOWI(SDNode *N);
  SDValue ScalarizeVecRes_INSERT_VECTOR_ELT(SDNode *N);
  SDValue ScalarizeVecRes_LOAD(LoadSDNode *N);
  SDValue ScalarizeVecRes_SCALAR_TO_VECTOR(SDNode *N);
  SDValue ScalarizeVecRes_VSELECT(SDNode *N);
  SDValue ScalarizeVecRes_SELECT(SDNode *N);
  SDValue ScalarizeVecRes_SELECT_CC(SDNode *N);
  SDValue ScalarizeVecRes_SETCC(SDNode *N);
  SDValue ScalarizeVecRes_UNDEF(SDNode *N);
  SDValue ScalarizeVecRes_VECTOR_SHUFFLE(SDNode *N);
  SDValue ScalarizeVecRes_FP_TO_XINT_SAT(SDNode *N);

  SDValue ScalarizeVecRes_FIX(SDNode *N);

  // Vector Operand Scalarization: <1 x ty> -> ty.
  bool ScalarizeVectorOperand(SDNode *N, unsigned OpNo);
  SDValue ScalarizeVecOp_BITCAST(SDNode *N);
  SDValue ScalarizeVecOp_UnaryOp(SDNode *N);
  SDValue ScalarizeVecOp_UnaryOp_StrictFP(SDNode *N);
  SDValue ScalarizeVecOp_CONCAT_VECTORS(SDNode *N);
  SDValue ScalarizeVecOp_EXTRACT_VECTOR_ELT(SDNode *N);
  SDValue ScalarizeVecOp_VSELECT(SDNode *N);
  SDValue ScalarizeVecOp_VSETCC(SDNode *N);
  SDValue ScalarizeVecOp_STORE(StoreSDNode *N, unsigned OpNo);
  SDValue ScalarizeVecOp_FP_ROUND(SDNode *N, unsigned OpNo);
  SDValue ScalarizeVecOp_STRICT_FP_ROUND(SDNode *N, unsigned OpNo);
  SDValue ScalarizeVecOp_FP_EXTEND(SDNode *N);
  SDValue ScalarizeVecOp_STRICT_FP_EXTEND(SDNode *N);
  SDValue ScalarizeVecOp_VECREDUCE(SDNode *N);
  SDValue ScalarizeVecOp_VECREDUCE_SEQ(SDNode *N);

  //===--------------------------------------------------------------------===//
  // Vector Splitting Support: LegalizeVectorTypes.cpp
  //===--------------------------------------------------------------------===//

  /// Given a processed vector Op which was split into vectors of half the size,
  /// this method returns the halves. The first elements of Op coincide with the
  /// elements of Lo; the remaining elements of Op coincide with the elements of
  /// Hi: Op is what you would get by concatenating Lo and Hi.
  /// For example, if Op is a v8i32 that was split into two v4i32's, then this
  /// method returns the two v4i32's, with Lo corresponding to the first 4
  /// elements of Op, and Hi to the last 4 elements.
  void GetSplitVector(SDValue Op, SDValue &Lo, SDValue &Hi);
  void SetSplitVector(SDValue Op, SDValue Lo, SDValue Hi);

  // Helper function for incrementing the pointer when splitting
  // memory operations
  void IncrementPointer(MemSDNode *N, EVT MemVT, MachinePointerInfo &MPI,
                        SDValue &Ptr, uint64_t *ScaledOffset = nullptr);

  // Vector Result Splitting: <128 x ty> -> 2 x <64 x ty>.
  void SplitVectorResult(SDNode *N, unsigned ResNo);
  void SplitVecRes_BinOp(SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_TernaryOp(SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_UnaryOp(SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_ExtendOp(SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_InregOp(SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_ExtVecInRegOp(SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_StrictFPOp(SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_OverflowOp(SDNode *N, unsigned ResNo,
                              SDValue &Lo, SDValue &Hi);

  void SplitVecRes_FIX(SDNode *N, SDValue &Lo, SDValue &Hi);

  void SplitVecRes_BITCAST(SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_BUILD_VECTOR(SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_CONCAT_VECTORS(SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_EXTRACT_SUBVECTOR(SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_INSERT_SUBVECTOR(SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_FPOWI(SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_FCOPYSIGN(SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_INSERT_VECTOR_ELT(SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_LOAD(LoadSDNode *LD, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_MLOAD(MaskedLoadSDNode *MLD, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_MGATHER(MaskedGatherSDNode *MGT, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_ScalarOp(SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_STEP_VECTOR(SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_SETCC(SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_VECTOR_REVERSE(SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_VECTOR_SHUFFLE(ShuffleVectorSDNode *N, SDValue &Lo,
                                  SDValue &Hi);
  void SplitVecRes_VECTOR_SPLICE(SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_VAARG(SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitVecRes_FP_TO_XINT_SAT(SDNode *N, SDValue &Lo, SDValue &Hi);

  // Vector Operand Splitting: <128 x ty> -> 2 x <64 x ty>.
  bool SplitVectorOperand(SDNode *N, unsigned OpNo);
  SDValue SplitVecOp_VSELECT(SDNode *N, unsigned OpNo);
  SDValue SplitVecOp_VECREDUCE(SDNode *N, unsigned OpNo);
  SDValue SplitVecOp_VECREDUCE_SEQ(SDNode *N);
  SDValue SplitVecOp_UnaryOp(SDNode *N);
  SDValue SplitVecOp_TruncateHelper(SDNode *N);

  SDValue SplitVecOp_BITCAST(SDNode *N);
  SDValue SplitVecOp_INSERT_SUBVECTOR(SDNode *N, unsigned OpNo);
  SDValue SplitVecOp_EXTRACT_SUBVECTOR(SDNode *N);
  SDValue SplitVecOp_EXTRACT_VECTOR_ELT(SDNode *N);
  SDValue SplitVecOp_ExtVecInRegOp(SDNode *N);
  SDValue SplitVecOp_STORE(StoreSDNode *N, unsigned OpNo);
  SDValue SplitVecOp_MSTORE(MaskedStoreSDNode *N, unsigned OpNo);
  SDValue SplitVecOp_MSCATTER(MaskedScatterSDNode *N, unsigned OpNo);
  SDValue SplitVecOp_MGATHER(MaskedGatherSDNode *MGT, unsigned OpNo);
  SDValue SplitVecOp_CONCAT_VECTORS(SDNode *N);
  SDValue SplitVecOp_VSETCC(SDNode *N);
  SDValue SplitVecOp_FP_ROUND(SDNode *N);
  SDValue SplitVecOp_FCOPYSIGN(SDNode *N);
  SDValue SplitVecOp_FP_TO_XINT_SAT(SDNode *N);

  //===--------------------------------------------------------------------===//
  // Vector Widening Support: LegalizeVectorTypes.cpp
  //===--------------------------------------------------------------------===//

  /// Given a processed vector Op which was widened into a larger vector, this
  /// method returns the larger vector. The elements of the returned vector
  /// consist of the elements of Op followed by elements containing rubbish.
  /// For example, if Op is a v2i32 that was widened to a v4i32, then this
  /// method returns a v4i32 for which the first two elements are the same as
  /// those of Op, while the last two elements contain rubbish.
  SDValue GetWidenedVector(SDValue Op) {
    TableId &WidenedId = WidenedVectors[getTableId(Op)];
    SDValue WidenedOp = getSDValue(WidenedId);
    assert(WidenedOp.getNode() && "Operand wasn't widened?");
    return WidenedOp;
  }
  void SetWidenedVector(SDValue Op, SDValue Result);

  // Widen Vector Result Promotion.
  void WidenVectorResult(SDNode *N, unsigned ResNo);
  SDValue WidenVecRes_MERGE_VALUES(SDNode* N, unsigned ResNo);
  SDValue WidenVecRes_BITCAST(SDNode* N);
  SDValue WidenVecRes_BUILD_VECTOR(SDNode* N);
  SDValue WidenVecRes_CONCAT_VECTORS(SDNode* N);
  SDValue WidenVecRes_EXTEND_VECTOR_INREG(SDNode* N);
  SDValue WidenVecRes_EXTRACT_SUBVECTOR(SDNode* N);
  SDValue WidenVecRes_INSERT_VECTOR_ELT(SDNode* N);
  SDValue WidenVecRes_LOAD(SDNode* N);
  SDValue WidenVecRes_MLOAD(MaskedLoadSDNode* N);
  SDValue WidenVecRes_MGATHER(MaskedGatherSDNode* N);
  SDValue WidenVecRes_ScalarOp(SDNode* N);
  SDValue WidenVecRes_SELECT(SDNode* N);
  SDValue WidenVSELECTMask(SDNode *N);
  SDValue WidenVecRes_SELECT_CC(SDNode* N);
  SDValue WidenVecRes_SETCC(SDNode* N);
  SDValue WidenVecRes_STRICT_FSETCC(SDNode* N);
  SDValue WidenVecRes_UNDEF(SDNode *N);
  SDValue WidenVecRes_VECTOR_SHUFFLE(ShuffleVectorSDNode *N);

  SDValue WidenVecRes_Ternary(SDNode *N);
  SDValue WidenVecRes_Binary(SDNode *N);
  SDValue WidenVecRes_BinaryCanTrap(SDNode *N);
  SDValue WidenVecRes_BinaryWithExtraScalarOp(SDNode *N);
  SDValue WidenVecRes_StrictFP(SDNode *N);
  SDValue WidenVecRes_OverflowOp(SDNode *N, unsigned ResNo);
  SDValue WidenVecRes_Convert(SDNode *N);
  SDValue WidenVecRes_Convert_StrictFP(SDNode *N);
  SDValue WidenVecRes_FP_TO_XINT_SAT(SDNode *N);
  SDValue WidenVecRes_FCOPYSIGN(SDNode *N);
  SDValue WidenVecRes_POWI(SDNode *N);
  SDValue WidenVecRes_Unary(SDNode *N);
  SDValue WidenVecRes_InregOp(SDNode *N);

  // Widen Vector Operand.
  bool WidenVectorOperand(SDNode *N, unsigned OpNo);
  SDValue WidenVecOp_BITCAST(SDNode *N);
  SDValue WidenVecOp_CONCAT_VECTORS(SDNode *N);
  SDValue WidenVecOp_EXTEND(SDNode *N);
  SDValue WidenVecOp_EXTRACT_VECTOR_ELT(SDNode *N);
  SDValue WidenVecOp_EXTRACT_SUBVECTOR(SDNode *N);
  SDValue WidenVecOp_STORE(SDNode* N);
  SDValue WidenVecOp_MSTORE(SDNode* N, unsigned OpNo);
  SDValue WidenVecOp_MGATHER(SDNode* N, unsigned OpNo);
  SDValue WidenVecOp_MSCATTER(SDNode* N, unsigned OpNo);
  SDValue WidenVecOp_SETCC(SDNode* N);
  SDValue WidenVecOp_STRICT_FSETCC(SDNode* N);
  SDValue WidenVecOp_VSELECT(SDNode *N);

  SDValue WidenVecOp_Convert(SDNode *N);
  SDValue WidenVecOp_FP_TO_XINT_SAT(SDNode *N);
  SDValue WidenVecOp_FCOPYSIGN(SDNode *N);
  SDValue WidenVecOp_VECREDUCE(SDNode *N);
  SDValue WidenVecOp_VECREDUCE_SEQ(SDNode *N);

  /// Helper function to generate a set of operations to perform
  /// a vector operation for a wider type.
  ///
  SDValue UnrollVectorOp_StrictFP(SDNode *N, unsigned ResNE);

  //===--------------------------------------------------------------------===//
  // Vector Widening Utilities Support: LegalizeVectorTypes.cpp
  //===--------------------------------------------------------------------===//

  /// Helper function to generate a set of loads to load a vector with a
  /// resulting wider type. It takes:
  ///   LdChain: list of chains for the load to be generated.
  ///   Ld:      load to widen
  SDValue GenWidenVectorLoads(SmallVectorImpl<SDValue> &LdChain,
                              LoadSDNode *LD);

  /// Helper function to generate a set of extension loads to load a vector with
  /// a resulting wider type. It takes:
  ///   LdChain: list of chains for the load to be generated.
  ///   Ld:      load to widen
  ///   ExtType: extension element type
  SDValue GenWidenVectorExtLoads(SmallVectorImpl<SDValue> &LdChain,
                                 LoadSDNode *LD, ISD::LoadExtType ExtType);

  /// Helper function to generate a set of stores to store a widen vector into
  /// non-widen memory.
  ///   StChain: list of chains for the stores we have generated
  ///   ST:      store of a widen value
  void GenWidenVectorStores(SmallVectorImpl<SDValue> &StChain, StoreSDNode *ST);

  /// Modifies a vector input (widen or narrows) to a vector of NVT.  The
  /// input vector must have the same element type as NVT.
  /// When FillWithZeroes is "on" the vector will be widened with zeroes.
  /// By default, the vector will be widened with undefined values.
  SDValue ModifyToType(SDValue InOp, EVT NVT, bool FillWithZeroes = false);

  /// Return a mask of vector type MaskVT to replace InMask. Also adjust
  /// MaskVT to ToMaskVT if needed with vector extension or truncation.
  SDValue convertMask(SDValue InMask, EVT MaskVT, EVT ToMaskVT);

  //===--------------------------------------------------------------------===//
  // Generic Splitting: LegalizeTypesGeneric.cpp
  //===--------------------------------------------------------------------===//

  // Legalization methods which only use that the illegal type is split into two
  // not necessarily identical types.  As such they can be used for splitting
  // vectors and expanding integers and floats.

  void GetSplitOp(SDValue Op, SDValue &Lo, SDValue &Hi) {
    if (Op.getValueType().isVector())
      GetSplitVector(Op, Lo, Hi);
    else if (Op.getValueType().isInteger())
      GetExpandedInteger(Op, Lo, Hi);
    else
      GetExpandedFloat(Op, Lo, Hi);
  }

  /// Use ISD::EXTRACT_ELEMENT nodes to extract the low and high parts of the
  /// given value.
  void GetPairElements(SDValue Pair, SDValue &Lo, SDValue &Hi);

  // Generic Result Splitting.
  void SplitRes_MERGE_VALUES(SDNode *N, unsigned ResNo,
                             SDValue &Lo, SDValue &Hi);
  void SplitRes_SELECT      (SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitRes_SELECT_CC   (SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitRes_UNDEF       (SDNode *N, SDValue &Lo, SDValue &Hi);
  void SplitRes_FREEZE      (SDNode *N, SDValue &Lo, SDValue &Hi);

  //===--------------------------------------------------------------------===//
  // Generic Expansion: LegalizeTypesGeneric.cpp
  //===--------------------------------------------------------------------===//

  // Legalization methods which only use that the illegal type is split into two
  // identical types of half the size, and that the Lo/Hi part is stored first
  // in memory on little/big-endian machines, followed by the Hi/Lo part.  As
  // such they can be used for expanding integers and floats.

  void GetExpandedOp(SDValue Op, SDValue &Lo, SDValue &Hi) {
    if (Op.getValueType().isInteger())
      GetExpandedInteger(Op, Lo, Hi);
    else
      GetExpandedFloat(Op, Lo, Hi);
  }


  /// This function will split the integer \p Op into \p NumElements
  /// operations of type \p EltVT and store them in \p Ops.
  void IntegerToVector(SDValue Op, unsigned NumElements,
                       SmallVectorImpl<SDValue> &Ops, EVT EltVT);

  // Generic Result Expansion.
  void ExpandRes_MERGE_VALUES      (SDNode *N, unsigned ResNo,
                                    SDValue &Lo, SDValue &Hi);
  void ExpandRes_BITCAST           (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandRes_BUILD_PAIR        (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandRes_EXTRACT_ELEMENT   (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandRes_EXTRACT_VECTOR_ELT(SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandRes_NormalLoad        (SDNode *N, SDValue &Lo, SDValue &Hi);
  void ExpandRes_VAARG             (SDNode *N, SDValue &Lo, SDValue &Hi);

  // Generic Operand Expansion.
  SDValue ExpandOp_BITCAST          (SDNode *N);
  SDValue ExpandOp_BUILD_VECTOR     (SDNode *N);
  SDValue ExpandOp_EXTRACT_ELEMENT  (SDNode *N);
  SDValue ExpandOp_INSERT_VECTOR_ELT(SDNode *N);
  SDValue ExpandOp_SCALAR_TO_VECTOR (SDNode *N);
  SDValue ExpandOp_NormalStore      (SDNode *N, unsigned OpNo);
};

} // end namespace llvm.

#endif