SDPatternMatch.h

//==--------------- llvm/CodeGen/SDPatternMatch.h ---------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
/// \file
/// Contains matchers for matching SelectionDAG nodes and values.
///
//===----------------------------------------------------------------------===//

#ifndef LLVM_CODEGEN_SDPATTERNMATCH_H
#define LLVM_CODEGEN_SDPATTERNMATCH_H

#include "llvm/ADT/APInt.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/SelectionDAGNodes.h"
#include "llvm/CodeGen/TargetLowering.h"

namespace llvm {
namespace SDPatternMatch {

/// MatchContext can repurpose existing patterns to behave differently under
/// a certain context. For instance, `m_Opc(ISD::ADD)` matches plain ADD nodes
/// in normal circumstances, but matches VP_ADD nodes under a custom
/// VPMatchContext. This design is meant to facilitate code / pattern reusing.
class BasicMatchContext {
  const SelectionDAG *DAG;
  const TargetLowering *TLI;

public:
  explicit BasicMatchContext(const SelectionDAG *DAG)
      : DAG(DAG), TLI(DAG ? &DAG->getTargetLoweringInfo() : nullptr) {}

  explicit BasicMatchContext(const TargetLowering *TLI)
      : DAG(nullptr), TLI(TLI) {}

  // A valid MatchContext has to implement the following functions.

  const SelectionDAG *getDAG() const { return DAG; }

  const TargetLowering *getTLI() const { return TLI; }

  /// Return true if N effectively has opcode Opcode.
  bool match(SDValue N, unsigned Opcode) const {
    return N->getOpcode() == Opcode;
  }
};

template <typename Pattern, typename MatchContext>
[[nodiscard]] bool sd_context_match(SDValue N, const MatchContext &Ctx,
                                    Pattern &&P) {
  return P.match(Ctx, N);
}

template <typename Pattern, typename MatchContext>
[[nodiscard]] bool sd_context_match(SDNode *N, const MatchContext &Ctx,
                                    Pattern &&P) {
  return sd_context_match(SDValue(N, 0), Ctx, P);
}

template <typename Pattern>
[[nodiscard]] bool sd_match(SDNode *N, const SelectionDAG *DAG, Pattern &&P) {
  return sd_context_match(N, BasicMatchContext(DAG), P);
}

template <typename Pattern>
[[nodiscard]] bool sd_match(SDValue N, const SelectionDAG *DAG, Pattern &&P) {
  return sd_context_match(N, BasicMatchContext(DAG), P);
}

template <typename Pattern>
[[nodiscard]] bool sd_match(SDNode *N, Pattern &&P) {
  return sd_match(N, nullptr, P);
}

template <typename Pattern>
[[nodiscard]] bool sd_match(SDValue N, Pattern &&P) {
  return sd_match(N, nullptr, P);
}

// === Utilities ===
struct Value_match {
  SDValue MatchVal;

  Value_match() = default;

  explicit Value_match(SDValue Match) : MatchVal(Match) {}

  template <typename MatchContext> bool match(const MatchContext &, SDValue N) {
    if (MatchVal)
      return MatchVal == N;
    return N.getNode();
  }
};

/// Match any valid SDValue.
inline Value_match m_Value() { return Value_match(); }

inline Value_match m_Specific(SDValue N) {
  assert(N);
  return Value_match(N);
}

struct DeferredValue_match {
  SDValue &MatchVal;

  explicit DeferredValue_match(SDValue &Match) : MatchVal(Match) {}

  template <typename MatchContext> bool match(const MatchContext &, SDValue N) {
    return N == MatchVal;
  }
};

/// Similar to m_Specific, but the specific value to match is determined by
/// another sub-pattern in the same sd_match() expression. For instance,
/// We cannot match `(add V, V)` with `m_Add(m_Value(X), m_Specific(X))` since
/// `X` is not initialized at the time it got copied into `m_Specific`. Instead,
/// we should use `m_Add(m_Value(X), m_Deferred(X))`.
inline DeferredValue_match m_Deferred(SDValue &V) {
  return DeferredValue_match(V);
}

struct Opcode_match {
  unsigned Opcode;

  explicit Opcode_match(unsigned Opc) : Opcode(Opc) {}

  template <typename MatchContext>
  bool match(const MatchContext &Ctx, SDValue N) {
    return Ctx.match(N, Opcode);
  }
};

inline Opcode_match m_Opc(unsigned Opcode) { return Opcode_match(Opcode); }

template <unsigned NumUses, typename Pattern> struct NUses_match {
  Pattern P;

  explicit NUses_match(const Pattern &P) : P(P) {}

  template <typename MatchContext>
  bool match(const MatchContext &Ctx, SDValue N) {
    // SDNode::hasNUsesOfValue is pretty expensive when the SDNode produces
    // multiple results, hence we check the subsequent pattern here before
    // checking the number of value users.
    return P.match(Ctx, N) && N->hasNUsesOfValue(NumUses, N.getResNo());
  }
};

template <typename Pattern>
inline NUses_match<1, Pattern> m_OneUse(const Pattern &P) {
  return NUses_match<1, Pattern>(P);
}
template <unsigned N, typename Pattern>
inline NUses_match<N, Pattern> m_NUses(const Pattern &P) {
  return NUses_match<N, Pattern>(P);
}

inline NUses_match<1, Value_match> m_OneUse() {
  return NUses_match<1, Value_match>(m_Value());
}
template <unsigned N> inline NUses_match<N, Value_match> m_NUses() {
  return NUses_match<N, Value_match>(m_Value());
}

struct Value_bind {
  SDValue &BindVal;

  explicit Value_bind(SDValue &N) : BindVal(N) {}

  template <typename MatchContext> bool match(const MatchContext &, SDValue N) {
    BindVal = N;
    return true;
  }
};

inline Value_bind m_Value(SDValue &N) { return Value_bind(N); }

template <typename Pattern, typename PredFuncT> struct TLI_pred_match {
  Pattern P;
  PredFuncT PredFunc;

  TLI_pred_match(const PredFuncT &Pred, const Pattern &P)
      : P(P), PredFunc(Pred) {}

  template <typename MatchContext>
  bool match(const MatchContext &Ctx, SDValue N) {
    assert(Ctx.getTLI() && "TargetLowering is required for this pattern.");
    return PredFunc(*Ctx.getTLI(), N) && P.match(Ctx, N);
  }
};

// Explicit deduction guide.
template <typename PredFuncT, typename Pattern>
TLI_pred_match(const PredFuncT &Pred, const Pattern &P)
    -> TLI_pred_match<Pattern, PredFuncT>;

/// Match legal SDNodes based on the information provided by TargetLowering.
template <typename Pattern> inline auto m_LegalOp(const Pattern &P) {
  return TLI_pred_match{[](const TargetLowering &TLI, SDValue N) {
                          return TLI.isOperationLegal(N->getOpcode(),
                                                      N.getValueType());
                        },
                        P};
}

/// Switch to a different MatchContext for subsequent patterns.
template <typename NewMatchContext, typename Pattern> struct SwitchContext {
  const NewMatchContext &Ctx;
  Pattern P;

  template <typename OrigMatchContext>
  bool match(const OrigMatchContext &, SDValue N) {
    return P.match(Ctx, N);
  }
};

template <typename MatchContext, typename Pattern>
inline SwitchContext<MatchContext, Pattern> m_Context(const MatchContext &Ctx,
                                                      Pattern &&P) {
  return SwitchContext<MatchContext, Pattern>{Ctx, std::move(P)};
}

// === Value type ===
struct ValueType_bind {
  EVT &BindVT;

  explicit ValueType_bind(EVT &Bind) : BindVT(Bind) {}

  template <typename MatchContext> bool match(const MatchContext &, SDValue N) {
    BindVT = N.getValueType();
    return true;
  }
};

/// Retreive the ValueType of the current SDValue.
inline ValueType_bind m_VT(EVT &VT) { return ValueType_bind(VT); }

template <typename Pattern, typename PredFuncT> struct ValueType_match {
  PredFuncT PredFunc;
  Pattern P;

  ValueType_match(const PredFuncT &Pred, const Pattern &P)
      : PredFunc(Pred), P(P) {}

  template <typename MatchContext>
  bool match(const MatchContext &Ctx, SDValue N) {
    return PredFunc(N.getValueType()) && P.match(Ctx, N);
  }
};

// Explicit deduction guide.
template <typename PredFuncT, typename Pattern>
ValueType_match(const PredFuncT &Pred, const Pattern &P)
    -> ValueType_match<Pattern, PredFuncT>;

/// Match a specific ValueType.
template <typename Pattern>
inline auto m_SpecificVT(EVT RefVT, const Pattern &P) {
  return ValueType_match{[=](EVT VT) { return VT == RefVT; }, P};
}
inline auto m_SpecificVT(EVT RefVT) {
  return ValueType_match{[=](EVT VT) { return VT == RefVT; }, m_Value()};
}

inline auto m_Glue() { return m_SpecificVT(MVT::Glue); }
inline auto m_OtherVT() { return m_SpecificVT(MVT::Other); }

/// Match any integer ValueTypes.
template <typename Pattern> inline auto m_IntegerVT(const Pattern &P) {
  return ValueType_match{[](EVT VT) { return VT.isInteger(); }, P};
}
inline auto m_IntegerVT() {
  return ValueType_match{[](EVT VT) { return VT.isInteger(); }, m_Value()};
}

/// Match any floating point ValueTypes.
template <typename Pattern> inline auto m_FloatingPointVT(const Pattern &P) {
  return ValueType_match{[](EVT VT) { return VT.isFloatingPoint(); }, P};
}
inline auto m_FloatingPointVT() {
  return ValueType_match{[](EVT VT) { return VT.isFloatingPoint(); },
                         m_Value()};
}

/// Match any vector ValueTypes.
template <typename Pattern> inline auto m_VectorVT(const Pattern &P) {
  return ValueType_match{[](EVT VT) { return VT.isVector(); }, P};
}
inline auto m_VectorVT() {
  return ValueType_match{[](EVT VT) { return VT.isVector(); }, m_Value()};
}

/// Match fixed-length vector ValueTypes.
template <typename Pattern> inline auto m_FixedVectorVT(const Pattern &P) {
  return ValueType_match{[](EVT VT) { return VT.isFixedLengthVector(); }, P};
}
inline auto m_FixedVectorVT() {
  return ValueType_match{[](EVT VT) { return VT.isFixedLengthVector(); },
                         m_Value()};
}

/// Match scalable vector ValueTypes.
template <typename Pattern> inline auto m_ScalableVectorVT(const Pattern &P) {
  return ValueType_match{[](EVT VT) { return VT.isScalableVector(); }, P};
}
inline auto m_ScalableVectorVT() {
  return ValueType_match{[](EVT VT) { return VT.isScalableVector(); },
                         m_Value()};
}

/// Match legal ValueTypes based on the information provided by TargetLowering.
template <typename Pattern> inline auto m_LegalType(const Pattern &P) {
  return TLI_pred_match{[](const TargetLowering &TLI, SDValue N) {
                          return TLI.isTypeLegal(N.getValueType());
                        },
                        P};
}

// === Patterns combinators ===
template <typename... Preds> struct And {
  template <typename MatchContext> bool match(const MatchContext &, SDValue N) {
    return true;
  }
};

template <typename Pred, typename... Preds>
struct And<Pred, Preds...> : And<Preds...> {
  Pred P;
  And(Pred &&p, Preds &&...preds)
      : And<Preds...>(std::forward<Preds>(preds)...), P(std::forward<Pred>(p)) {
  }

  template <typename MatchContext>
  bool match(const MatchContext &Ctx, SDValue N) {
    return P.match(Ctx, N) && And<Preds...>::match(Ctx, N);
  }
};

template <typename... Preds> struct Or {
  template <typename MatchContext> bool match(const MatchContext &, SDValue N) {
    return false;
  }
};

template <typename Pred, typename... Preds>
struct Or<Pred, Preds...> : Or<Preds...> {
  Pred P;
  Or(Pred &&p, Preds &&...preds)
      : Or<Preds...>(std::forward<Preds>(preds)...), P(std::forward<Pred>(p)) {}

  template <typename MatchContext>
  bool match(const MatchContext &Ctx, SDValue N) {
    return P.match(Ctx, N) || Or<Preds...>::match(Ctx, N);
  }
};

template <typename... Preds> And<Preds...> m_AllOf(Preds &&...preds) {
  return And<Preds...>(std::forward<Preds>(preds)...);
}

template <typename... Preds> Or<Preds...> m_AnyOf(Preds &&...preds) {
  return Or<Preds...>(std::forward<Preds>(preds)...);
}

// === Generic node matching ===
template <unsigned OpIdx, typename... OpndPreds> struct Operands_match {
  template <typename MatchContext>
  bool match(const MatchContext &Ctx, SDValue N) {
    // Returns false if there are more operands than predicates;
    return N->getNumOperands() == OpIdx;
  }
};

template <unsigned OpIdx, typename OpndPred, typename... OpndPreds>
struct Operands_match<OpIdx, OpndPred, OpndPreds...>
    : Operands_match<OpIdx + 1, OpndPreds...> {
  OpndPred P;

  Operands_match(OpndPred &&p, OpndPreds &&...preds)
      : Operands_match<OpIdx + 1, OpndPreds...>(
            std::forward<OpndPreds>(preds)...),
        P(std::forward<OpndPred>(p)) {}

  template <typename MatchContext>
  bool match(const MatchContext &Ctx, SDValue N) {
    if (OpIdx < N->getNumOperands())
      return P.match(Ctx, N->getOperand(OpIdx)) &&
             Operands_match<OpIdx + 1, OpndPreds...>::match(Ctx, N);

    // This is the case where there are more predicates than operands.
    return false;
  }
};

template <typename... OpndPreds>
auto m_Node(unsigned Opcode, OpndPreds &&...preds) {
  return m_AllOf(m_Opc(Opcode), Operands_match<0, OpndPreds...>(
                                    std::forward<OpndPreds>(preds)...));
}

/// Provide number of operands that are not chain or glue, as well as the first
/// index of such operand.
template <bool ExcludeChain> struct EffectiveOperands {
  unsigned Size = 0;
  unsigned FirstIndex = 0;

  explicit EffectiveOperands(SDValue N) {
    const unsigned TotalNumOps = N->getNumOperands();
    FirstIndex = TotalNumOps;
    for (unsigned I = 0; I < TotalNumOps; ++I) {
      // Count the number of non-chain and non-glue nodes (we ignore chain
      // and glue by default) and retreive the operand index offset.
      EVT VT = N->getOperand(I).getValueType();
      if (VT != MVT::Glue && VT != MVT::Other) {
        ++Size;
        if (FirstIndex == TotalNumOps)
          FirstIndex = I;
      }
    }
  }
};

template <> struct EffectiveOperands<false> {
  unsigned Size = 0;
  unsigned FirstIndex = 0;

  explicit EffectiveOperands(SDValue N) : Size(N->getNumOperands()) {}
};

// === Binary operations ===
template <typename LHS_P, typename RHS_P, bool Commutable = false,
          bool ExcludeChain = false>
struct BinaryOpc_match {
  unsigned Opcode;
  LHS_P LHS;
  RHS_P RHS;

  BinaryOpc_match(unsigned Opc, const LHS_P &L, const RHS_P &R)
      : Opcode(Opc), LHS(L), RHS(R) {}

  template <typename MatchContext>
  bool match(const MatchContext &Ctx, SDValue N) {
    if (sd_context_match(N, Ctx, m_Opc(Opcode))) {
      EffectiveOperands<ExcludeChain> EO(N);
      assert(EO.Size == 2);
      return (LHS.match(Ctx, N->getOperand(EO.FirstIndex)) &&
              RHS.match(Ctx, N->getOperand(EO.FirstIndex + 1))) ||
             (Commutable && LHS.match(Ctx, N->getOperand(EO.FirstIndex + 1)) &&
              RHS.match(Ctx, N->getOperand(EO.FirstIndex)));
    }

    return false;
  }
};

template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, false> m_BinOp(unsigned Opc, const LHS &L,
                                                const RHS &R) {
  return BinaryOpc_match<LHS, RHS, false>(Opc, L, R);
}
template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, true> m_c_BinOp(unsigned Opc, const LHS &L,
                                                 const RHS &R) {
  return BinaryOpc_match<LHS, RHS, true>(Opc, L, R);
}

template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, false, true>
m_ChainedBinOp(unsigned Opc, const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, false, true>(Opc, L, R);
}
template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, true, true>
m_c_ChainedBinOp(unsigned Opc, const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, true, true>(Opc, L, R);
}

// Common binary operations
template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, true> m_Add(const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, true>(ISD::ADD, L, R);
}

template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, false> m_Sub(const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, false>(ISD::SUB, L, R);
}

template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, true> m_Mul(const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, true>(ISD::MUL, L, R);
}

template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, true> m_And(const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, true>(ISD::AND, L, R);
}

template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, true> m_Or(const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, true>(ISD::OR, L, R);
}

template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, true> m_Xor(const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, true>(ISD::XOR, L, R);
}

template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, true> m_SMin(const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, true>(ISD::SMIN, L, R);
}

template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, true> m_SMax(const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, true>(ISD::SMAX, L, R);
}

template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, true> m_UMin(const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, true>(ISD::UMIN, L, R);
}

template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, true> m_UMax(const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, true>(ISD::UMAX, L, R);
}

template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, false> m_UDiv(const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, false>(ISD::UDIV, L, R);
}
template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, false> m_SDiv(const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, false>(ISD::SDIV, L, R);
}

template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, false> m_URem(const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, false>(ISD::UREM, L, R);
}
template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, false> m_SRem(const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, false>(ISD::SREM, L, R);
}

template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, false> m_Shl(const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, false>(ISD::SHL, L, R);
}

template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, false> m_Sra(const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, false>(ISD::SRA, L, R);
}
template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, false> m_Srl(const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, false>(ISD::SRL, L, R);
}

template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, true> m_FAdd(const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, true>(ISD::FADD, L, R);
}

template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, false> m_FSub(const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, false>(ISD::FSUB, L, R);
}

template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, true> m_FMul(const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, true>(ISD::FMUL, L, R);
}

template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, false> m_FDiv(const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, false>(ISD::FDIV, L, R);
}

template <typename LHS, typename RHS>
inline BinaryOpc_match<LHS, RHS, false> m_FRem(const LHS &L, const RHS &R) {
  return BinaryOpc_match<LHS, RHS, false>(ISD::FREM, L, R);
}

// === Unary operations ===
template <typename Opnd_P, bool ExcludeChain = false> struct UnaryOpc_match {
  unsigned Opcode;
  Opnd_P Opnd;

  UnaryOpc_match(unsigned Opc, const Opnd_P &Op) : Opcode(Opc), Opnd(Op) {}

  template <typename MatchContext>
  bool match(const MatchContext &Ctx, SDValue N) {
    if (sd_context_match(N, Ctx, m_Opc(Opcode))) {
      EffectiveOperands<ExcludeChain> EO(N);
      assert(EO.Size == 1);
      return Opnd.match(Ctx, N->getOperand(EO.FirstIndex));
    }

    return false;
  }
};

template <typename Opnd>
inline UnaryOpc_match<Opnd> m_UnaryOp(unsigned Opc, const Opnd &Op) {
  return UnaryOpc_match<Opnd>(Opc, Op);
}
template <typename Opnd>
inline UnaryOpc_match<Opnd, true> m_ChainedUnaryOp(unsigned Opc,
                                                   const Opnd &Op) {
  return UnaryOpc_match<Opnd, true>(Opc, Op);
}

template <typename Opnd> inline UnaryOpc_match<Opnd> m_ZExt(const Opnd &Op) {
  return UnaryOpc_match<Opnd>(ISD::ZERO_EXTEND, Op);
}

template <typename Opnd> inline UnaryOpc_match<Opnd> m_SExt(const Opnd &Op) {
  return UnaryOpc_match<Opnd>(ISD::SIGN_EXTEND, Op);
}

template <typename Opnd> inline UnaryOpc_match<Opnd> m_AnyExt(const Opnd &Op) {
  return UnaryOpc_match<Opnd>(ISD::ANY_EXTEND, Op);
}

template <typename Opnd> inline UnaryOpc_match<Opnd> m_Trunc(const Opnd &Op) {
  return UnaryOpc_match<Opnd>(ISD::TRUNCATE, Op);
}

// === Constants ===
struct ConstantInt_match {
  APInt *BindVal;

  explicit ConstantInt_match(APInt *V) : BindVal(V) {}

  template <typename MatchContext> bool match(const MatchContext &, SDValue N) {
    // The logics here are similar to that in
    // SelectionDAG::isConstantIntBuildVectorOrConstantInt, but the latter also
    // treats GlobalAddressSDNode as a constant, which is difficult to turn into
    // APInt.
    if (auto *C = dyn_cast_or_null<ConstantSDNode>(N.getNode())) {
      if (BindVal)
        *BindVal = C->getAPIntValue();
      return true;
    }

    APInt Discard;
    return ISD::isConstantSplatVector(N.getNode(),
                                      BindVal ? *BindVal : Discard);
  }
};
/// Match any interger constants or splat of an integer constant.
inline ConstantInt_match m_ConstInt() { return ConstantInt_match(nullptr); }
/// Match any interger constants or splat of an integer constant; return the
/// specific constant or constant splat value.
inline ConstantInt_match m_ConstInt(APInt &V) { return ConstantInt_match(&V); }

struct SpecificInt_match {
  APInt IntVal;

  explicit SpecificInt_match(APInt APV) : IntVal(std::move(APV)) {}

  template <typename MatchContext>
  bool match(const MatchContext &Ctx, SDValue N) {
    APInt ConstInt;
    if (sd_context_match(N, Ctx, m_ConstInt(ConstInt)))
      return APInt::isSameValue(IntVal, ConstInt);
    return false;
  }
};

/// Match a specific integer constant or constant splat value.
inline SpecificInt_match m_SpecificInt(APInt V) {
  return SpecificInt_match(std::move(V));
}
inline SpecificInt_match m_SpecificInt(uint64_t V) {
  return SpecificInt_match(APInt(64, V));
}

inline SpecificInt_match m_Zero() { return m_SpecificInt(0U); }
inline SpecificInt_match m_One() { return m_SpecificInt(1U); }
inline SpecificInt_match m_AllOnes() { return m_SpecificInt(~0U); }

/// Match true boolean value based on the information provided by
/// TargetLowering.
inline auto m_True() {
  return TLI_pred_match{
      [](const TargetLowering &TLI, SDValue N) {
        APInt ConstVal;
        if (sd_match(N, m_ConstInt(ConstVal)))
          switch (TLI.getBooleanContents(N.getValueType())) {
          case TargetLowering::ZeroOrOneBooleanContent:
            return ConstVal.isOne();
          case TargetLowering::ZeroOrNegativeOneBooleanContent:
            return ConstVal.isAllOnes();
          case TargetLowering::UndefinedBooleanContent:
            return (ConstVal & 0x01) == 1;
          }

        return false;
      },
      m_Value()};
}
/// Match false boolean value based on the information provided by
/// TargetLowering.
inline auto m_False() {
  return TLI_pred_match{
      [](const TargetLowering &TLI, SDValue N) {
        APInt ConstVal;
        if (sd_match(N, m_ConstInt(ConstVal)))
          switch (TLI.getBooleanContents(N.getValueType())) {
          case TargetLowering::ZeroOrOneBooleanContent:
          case TargetLowering::ZeroOrNegativeOneBooleanContent:
            return ConstVal.isZero();
          case TargetLowering::UndefinedBooleanContent:
            return (ConstVal & 0x01) == 0;
          }

        return false;
      },
      m_Value()};
}

/// Match a negate as a sub(0, v)
template <typename ValTy>
inline BinaryOpc_match<SpecificInt_match, ValTy> m_Neg(const ValTy &V) {
  return m_Sub(m_Zero(), V);
}

/// Match a Not as a xor(v, -1) or xor(-1, v)
template <typename ValTy>
inline BinaryOpc_match<ValTy, SpecificInt_match, true> m_Not(const ValTy &V) {
  return m_Xor(V, m_AllOnes());
}

/// Match a zext or identity
/// Allows to peek through optional extensions
template <typename Opnd>
inline Or<UnaryOpc_match<Opnd>, Opnd> m_ZExtOrSelf(Opnd &&Op) {
  return Or<UnaryOpc_match<Opnd>, Opnd>(m_ZExt(std::forward<Opnd>(Op)),
                                        std::forward<Opnd>(Op));
}

/// Match a sext or identity
/// Allows to peek through optional extensions
template <typename Opnd>
inline Or<UnaryOpc_match<Opnd>, Opnd> m_SExtOrSelf(Opnd &&Op) {
  return Or<UnaryOpc_match<Opnd>, Opnd>(m_SExt(std::forward<Opnd>(Op)),
                                        std::forward<Opnd>(Op));
}

/// Match a aext or identity
/// Allows to peek through optional extensions
template <typename Opnd>
inline Or<UnaryOpc_match<Opnd>, Opnd> m_AExtOrSelf(Opnd &&Op) {
  return Or<UnaryOpc_match<Opnd>, Opnd>(m_AnyExt(std::forward<Opnd>(Op)),
                                        std::forward<Opnd>(Op));
}

/// Match a trunc or identity
/// Allows to peek through optional truncations
template <typename Opnd>
inline Or<UnaryOpc_match<Opnd>, Opnd> m_TruncOrSelf(Opnd &&Op) {
  return Or<UnaryOpc_match<Opnd>, Opnd>(m_Trunc(std::forward<Opnd>(Op)),
                                        std::forward<Opnd>(Op));
}

} // namespace SDPatternMatch
} // namespace llvm
#endif