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			507 lines
		
	
	
		
			17 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			507 lines
		
	
	
		
			17 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
//===- llvm/ADT/PointerUnion.h - Discriminated Union of 2 Ptrs --*- C++ -*-===//
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//
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//                     The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines the PointerUnion class, which is a discriminated union of
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// pointer types.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_ADT_POINTERUNION_H
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#define LLVM_ADT_POINTERUNION_H
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#include "llvm/ADT/DenseMapInfo.h"
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#include "llvm/ADT/PointerIntPair.h"
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#include "llvm/Support/Compiler.h"
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namespace llvm {
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  template <typename T>
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  struct PointerUnionTypeSelectorReturn {
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    typedef T Return;
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  };
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  /// \brief Get a type based on whether two types are the same or not. For:
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  /// @code
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  /// typedef typename PointerUnionTypeSelector<T1, T2, EQ, NE>::Return Ret;
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  /// @endcode
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  /// Ret will be EQ type if T1 is same as T2 or NE type otherwise.
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  template <typename T1, typename T2, typename RET_EQ, typename RET_NE>
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  struct PointerUnionTypeSelector {
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    typedef typename PointerUnionTypeSelectorReturn<RET_NE>::Return Return;
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  };
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  template <typename T, typename RET_EQ, typename RET_NE>
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  struct PointerUnionTypeSelector<T, T, RET_EQ, RET_NE> {
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    typedef typename PointerUnionTypeSelectorReturn<RET_EQ>::Return Return;
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  };
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  template <typename T1, typename T2, typename RET_EQ, typename RET_NE>
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  struct PointerUnionTypeSelectorReturn<
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                            PointerUnionTypeSelector<T1, T2, RET_EQ, RET_NE> > {
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    typedef typename PointerUnionTypeSelector<T1, T2, RET_EQ, RET_NE>::Return
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        Return;
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  };
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  /// Provide PointerLikeTypeTraits for void* that is used by PointerUnion
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  /// for the two template arguments.
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  template <typename PT1, typename PT2>
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  class PointerUnionUIntTraits {
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  public:
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    static inline void *getAsVoidPointer(void *P) { return P; }
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    static inline void *getFromVoidPointer(void *P) { return P; }
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    enum {
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      PT1BitsAv = (int)(PointerLikeTypeTraits<PT1>::NumLowBitsAvailable),
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      PT2BitsAv = (int)(PointerLikeTypeTraits<PT2>::NumLowBitsAvailable),
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      NumLowBitsAvailable = PT1BitsAv < PT2BitsAv ? PT1BitsAv : PT2BitsAv
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    };
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  };
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  /// PointerUnion - This implements a discriminated union of two pointer types,
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  /// and keeps the discriminator bit-mangled into the low bits of the pointer.
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  /// This allows the implementation to be extremely efficient in space, but
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  /// permits a very natural and type-safe API.
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  ///
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  /// Common use patterns would be something like this:
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  ///    PointerUnion<int*, float*> P;
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  ///    P = (int*)0;
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  ///    printf("%d %d", P.is<int*>(), P.is<float*>());  // prints "1 0"
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  ///    X = P.get<int*>();     // ok.
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  ///    Y = P.get<float*>();   // runtime assertion failure.
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  ///    Z = P.get<double*>();  // compile time failure.
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  ///    P = (float*)0;
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  ///    Y = P.get<float*>();   // ok.
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  ///    X = P.get<int*>();     // runtime assertion failure.
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  template <typename PT1, typename PT2>
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  class PointerUnion {
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  public:
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    typedef PointerIntPair<void*, 1, bool, 
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                           PointerUnionUIntTraits<PT1,PT2> > ValTy;
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  private:
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    ValTy Val;
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    struct IsPT1 {
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      static const int Num = 0;
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    };
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    struct IsPT2 {
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      static const int Num = 1;
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    };
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    template <typename T>
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    struct UNION_DOESNT_CONTAIN_TYPE { };
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  public:
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    PointerUnion() {}
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    PointerUnion(PT1 V) : Val(
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      const_cast<void *>(PointerLikeTypeTraits<PT1>::getAsVoidPointer(V))) {
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    }
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    PointerUnion(PT2 V) : Val(
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      const_cast<void *>(PointerLikeTypeTraits<PT2>::getAsVoidPointer(V)), 1) {
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    }
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    /// isNull - Return true if the pointer held in the union is null,
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    /// regardless of which type it is.
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    bool isNull() const {
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      // Convert from the void* to one of the pointer types, to make sure that
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      // we recursively strip off low bits if we have a nested PointerUnion.
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      return !PointerLikeTypeTraits<PT1>::getFromVoidPointer(Val.getPointer());
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    }
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    LLVM_EXPLICIT operator bool() const { return !isNull(); }
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    /// is<T>() return true if the Union currently holds the type matching T.
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    template<typename T>
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    int is() const {
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      typedef typename
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        ::llvm::PointerUnionTypeSelector<PT1, T, IsPT1,
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          ::llvm::PointerUnionTypeSelector<PT2, T, IsPT2,
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                                    UNION_DOESNT_CONTAIN_TYPE<T> > >::Return Ty;
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      int TyNo = Ty::Num;
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      return static_cast<int>(Val.getInt()) == TyNo;
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    }
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    /// get<T>() - Return the value of the specified pointer type. If the
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    /// specified pointer type is incorrect, assert.
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    template<typename T>
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    T get() const {
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      assert(is<T>() && "Invalid accessor called");
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      return PointerLikeTypeTraits<T>::getFromVoidPointer(Val.getPointer());
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    }
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    /// dyn_cast<T>() - If the current value is of the specified pointer type,
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    /// return it, otherwise return null.
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    template<typename T>
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    T dyn_cast() const {
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      if (is<T>()) return get<T>();
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      return T();
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    }
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    /// \brief If the union is set to the first pointer type get an address
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    /// pointing to it.
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    PT1 const *getAddrOfPtr1() const {
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      return const_cast<PointerUnion *>(this)->getAddrOfPtr1();
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    }
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    /// \brief If the union is set to the first pointer type get an address
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    /// pointing to it.
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    PT1 *getAddrOfPtr1() {
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      assert(is<PT1>() && "Val is not the first pointer");
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      assert(get<PT1>() == Val.getPointer() &&
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         "Can't get the address because PointerLikeTypeTraits changes the ptr");
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      return (PT1 *)Val.getAddrOfPointer();
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    }
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    /// \brief Assignment from nullptr which just clears the union.
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    const PointerUnion &operator=(std::nullptr_t) {
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      Val.initWithPointer(nullptr);
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      return *this;
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    }
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    /// Assignment operators - Allow assigning into this union from either
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    /// pointer type, setting the discriminator to remember what it came from.
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    const PointerUnion &operator=(const PT1 &RHS) {
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      Val.initWithPointer(
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         const_cast<void *>(PointerLikeTypeTraits<PT1>::getAsVoidPointer(RHS)));
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      return *this;
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    }
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    const PointerUnion &operator=(const PT2 &RHS) {
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      Val.setPointerAndInt(
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        const_cast<void *>(PointerLikeTypeTraits<PT2>::getAsVoidPointer(RHS)),
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        1);
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      return *this;
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    }
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    void *getOpaqueValue() const { return Val.getOpaqueValue(); }
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    static inline PointerUnion getFromOpaqueValue(void *VP) {
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      PointerUnion V;
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      V.Val = ValTy::getFromOpaqueValue(VP);
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      return V;
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    }
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  };
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  template<typename PT1, typename PT2>
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  static bool operator==(PointerUnion<PT1, PT2> lhs,
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                         PointerUnion<PT1, PT2> rhs) {
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    return lhs.getOpaqueValue() == rhs.getOpaqueValue();
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  }
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  template<typename PT1, typename PT2>
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  static bool operator!=(PointerUnion<PT1, PT2> lhs,
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                         PointerUnion<PT1, PT2> rhs) {
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    return lhs.getOpaqueValue() != rhs.getOpaqueValue();
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  }
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  // Teach SmallPtrSet that PointerUnion is "basically a pointer", that has
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  // # low bits available = min(PT1bits,PT2bits)-1.
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  template<typename PT1, typename PT2>
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  class PointerLikeTypeTraits<PointerUnion<PT1, PT2> > {
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  public:
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    static inline void *
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    getAsVoidPointer(const PointerUnion<PT1, PT2> &P) {
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      return P.getOpaqueValue();
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    }
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    static inline PointerUnion<PT1, PT2>
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    getFromVoidPointer(void *P) {
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      return PointerUnion<PT1, PT2>::getFromOpaqueValue(P);
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    }
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    // The number of bits available are the min of the two pointer types.
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    enum {
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      NumLowBitsAvailable = 
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        PointerLikeTypeTraits<typename PointerUnion<PT1,PT2>::ValTy>
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          ::NumLowBitsAvailable
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    };
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  };
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  /// PointerUnion3 - This is a pointer union of three pointer types.  See
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  /// documentation for PointerUnion for usage.
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  template <typename PT1, typename PT2, typename PT3>
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  class PointerUnion3 {
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  public:
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    typedef PointerUnion<PT1, PT2> InnerUnion;
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    typedef PointerUnion<InnerUnion, PT3> ValTy;
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  private:
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    ValTy Val;
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    struct IsInnerUnion {
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      ValTy Val;
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      IsInnerUnion(ValTy val) : Val(val) { }
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      template<typename T>
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      int is() const {
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        return Val.template is<InnerUnion>() && 
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               Val.template get<InnerUnion>().template is<T>();
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      }
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      template<typename T>
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      T get() const {
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        return Val.template get<InnerUnion>().template get<T>();
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      }
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    };
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    struct IsPT3 {
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      ValTy Val;
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      IsPT3(ValTy val) : Val(val) { }
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      template<typename T>
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      int is() const {
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        return Val.template is<T>();
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      }
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      template<typename T>
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      T get() const {
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        return Val.template get<T>();
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      }
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    };
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  public:
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    PointerUnion3() {}
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    PointerUnion3(PT1 V) {
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      Val = InnerUnion(V);
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    }
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    PointerUnion3(PT2 V) {
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      Val = InnerUnion(V);
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    }
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    PointerUnion3(PT3 V) {
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      Val = V;
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    }
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    /// isNull - Return true if the pointer held in the union is null,
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    /// regardless of which type it is.
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    bool isNull() const { return Val.isNull(); }
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    LLVM_EXPLICIT operator bool() const { return !isNull(); }
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    /// is<T>() return true if the Union currently holds the type matching T.
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    template<typename T>
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    int is() const {
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      // If T is PT1/PT2 choose IsInnerUnion otherwise choose IsPT3.
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      typedef typename
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        ::llvm::PointerUnionTypeSelector<PT1, T, IsInnerUnion,
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          ::llvm::PointerUnionTypeSelector<PT2, T, IsInnerUnion, IsPT3 >
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                                                                   >::Return Ty;
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      return Ty(Val).template is<T>();
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    }
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    /// get<T>() - Return the value of the specified pointer type. If the
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    /// specified pointer type is incorrect, assert.
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    template<typename T>
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    T get() const {
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      assert(is<T>() && "Invalid accessor called");
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      // If T is PT1/PT2 choose IsInnerUnion otherwise choose IsPT3.
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      typedef typename
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        ::llvm::PointerUnionTypeSelector<PT1, T, IsInnerUnion,
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          ::llvm::PointerUnionTypeSelector<PT2, T, IsInnerUnion, IsPT3 >
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                                                                   >::Return Ty;
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      return Ty(Val).template get<T>();
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    }
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    /// dyn_cast<T>() - If the current value is of the specified pointer type,
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    /// return it, otherwise return null.
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    template<typename T>
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    T dyn_cast() const {
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      if (is<T>()) return get<T>();
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      return T();
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    }
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    /// \brief Assignment from nullptr which just clears the union.
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    const PointerUnion3 &operator=(std::nullptr_t) {
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      Val = nullptr;
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      return *this;
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    }
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    /// Assignment operators - Allow assigning into this union from either
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    /// pointer type, setting the discriminator to remember what it came from.
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    const PointerUnion3 &operator=(const PT1 &RHS) {
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      Val = InnerUnion(RHS);
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      return *this;
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    }
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    const PointerUnion3 &operator=(const PT2 &RHS) {
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      Val = InnerUnion(RHS);
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      return *this;
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    }
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    const PointerUnion3 &operator=(const PT3 &RHS) {
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      Val = RHS;
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      return *this;
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    }
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    void *getOpaqueValue() const { return Val.getOpaqueValue(); }
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    static inline PointerUnion3 getFromOpaqueValue(void *VP) {
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      PointerUnion3 V;
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      V.Val = ValTy::getFromOpaqueValue(VP);
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      return V;
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    }
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  };
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  // Teach SmallPtrSet that PointerUnion3 is "basically a pointer", that has
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  // # low bits available = min(PT1bits,PT2bits,PT2bits)-2.
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  template<typename PT1, typename PT2, typename PT3>
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  class PointerLikeTypeTraits<PointerUnion3<PT1, PT2, PT3> > {
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  public:
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    static inline void *
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    getAsVoidPointer(const PointerUnion3<PT1, PT2, PT3> &P) {
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      return P.getOpaqueValue();
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    }
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    static inline PointerUnion3<PT1, PT2, PT3>
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    getFromVoidPointer(void *P) {
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      return PointerUnion3<PT1, PT2, PT3>::getFromOpaqueValue(P);
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    }
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    // The number of bits available are the min of the two pointer types.
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    enum {
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      NumLowBitsAvailable = 
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        PointerLikeTypeTraits<typename PointerUnion3<PT1, PT2, PT3>::ValTy>
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          ::NumLowBitsAvailable
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    };
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  };
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  /// PointerUnion4 - This is a pointer union of four pointer types.  See
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  /// documentation for PointerUnion for usage.
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  template <typename PT1, typename PT2, typename PT3, typename PT4>
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  class PointerUnion4 {
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  public:
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    typedef PointerUnion<PT1, PT2> InnerUnion1;
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    typedef PointerUnion<PT3, PT4> InnerUnion2;
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    typedef PointerUnion<InnerUnion1, InnerUnion2> ValTy;
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  private:
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    ValTy Val;
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  public:
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    PointerUnion4() {}
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    PointerUnion4(PT1 V) {
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      Val = InnerUnion1(V);
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    }
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    PointerUnion4(PT2 V) {
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      Val = InnerUnion1(V);
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    }
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    PointerUnion4(PT3 V) {
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      Val = InnerUnion2(V);
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    }
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    PointerUnion4(PT4 V) {
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      Val = InnerUnion2(V);
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    }
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    /// isNull - Return true if the pointer held in the union is null,
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    /// regardless of which type it is.
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    bool isNull() const { return Val.isNull(); }
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    LLVM_EXPLICIT operator bool() const { return !isNull(); }
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    /// is<T>() return true if the Union currently holds the type matching T.
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    template<typename T>
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    int is() const {
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      // If T is PT1/PT2 choose InnerUnion1 otherwise choose InnerUnion2.
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      typedef typename
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        ::llvm::PointerUnionTypeSelector<PT1, T, InnerUnion1,
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          ::llvm::PointerUnionTypeSelector<PT2, T, InnerUnion1, InnerUnion2 >
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                                                                   >::Return Ty;
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      return Val.template is<Ty>() && 
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             Val.template get<Ty>().template is<T>();
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    }
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    /// get<T>() - Return the value of the specified pointer type. If the
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    /// specified pointer type is incorrect, assert.
 | 
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    template<typename T>
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						|
    T get() const {
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      assert(is<T>() && "Invalid accessor called");
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      // If T is PT1/PT2 choose InnerUnion1 otherwise choose InnerUnion2.
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						|
      typedef typename
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        ::llvm::PointerUnionTypeSelector<PT1, T, InnerUnion1,
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          ::llvm::PointerUnionTypeSelector<PT2, T, InnerUnion1, InnerUnion2 >
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                                                                   >::Return Ty;
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      return Val.template get<Ty>().template get<T>();
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    }
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    /// dyn_cast<T>() - If the current value is of the specified pointer type,
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    /// return it, otherwise return null.
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						|
    template<typename T>
 | 
						|
    T dyn_cast() const {
 | 
						|
      if (is<T>()) return get<T>();
 | 
						|
      return T();
 | 
						|
    }
 | 
						|
 | 
						|
    /// \brief Assignment from nullptr which just clears the union.
 | 
						|
    const PointerUnion4 &operator=(std::nullptr_t) {
 | 
						|
      Val = nullptr;
 | 
						|
      return *this;
 | 
						|
    }
 | 
						|
    
 | 
						|
    /// Assignment operators - Allow assigning into this union from either
 | 
						|
    /// pointer type, setting the discriminator to remember what it came from.
 | 
						|
    const PointerUnion4 &operator=(const PT1 &RHS) {
 | 
						|
      Val = InnerUnion1(RHS);
 | 
						|
      return *this;
 | 
						|
    }
 | 
						|
    const PointerUnion4 &operator=(const PT2 &RHS) {
 | 
						|
      Val = InnerUnion1(RHS);
 | 
						|
      return *this;
 | 
						|
    }
 | 
						|
    const PointerUnion4 &operator=(const PT3 &RHS) {
 | 
						|
      Val = InnerUnion2(RHS);
 | 
						|
      return *this;
 | 
						|
    }
 | 
						|
    const PointerUnion4 &operator=(const PT4 &RHS) {
 | 
						|
      Val = InnerUnion2(RHS);
 | 
						|
      return *this;
 | 
						|
    }
 | 
						|
    
 | 
						|
    void *getOpaqueValue() const { return Val.getOpaqueValue(); }
 | 
						|
    static inline PointerUnion4 getFromOpaqueValue(void *VP) {
 | 
						|
      PointerUnion4 V;
 | 
						|
      V.Val = ValTy::getFromOpaqueValue(VP);
 | 
						|
      return V;
 | 
						|
    }
 | 
						|
  };
 | 
						|
  
 | 
						|
  // Teach SmallPtrSet that PointerUnion4 is "basically a pointer", that has
 | 
						|
  // # low bits available = min(PT1bits,PT2bits,PT2bits)-2.
 | 
						|
  template<typename PT1, typename PT2, typename PT3, typename PT4>
 | 
						|
  class PointerLikeTypeTraits<PointerUnion4<PT1, PT2, PT3, PT4> > {
 | 
						|
  public:
 | 
						|
    static inline void *
 | 
						|
    getAsVoidPointer(const PointerUnion4<PT1, PT2, PT3, PT4> &P) {
 | 
						|
      return P.getOpaqueValue();
 | 
						|
    }
 | 
						|
    static inline PointerUnion4<PT1, PT2, PT3, PT4>
 | 
						|
    getFromVoidPointer(void *P) {
 | 
						|
      return PointerUnion4<PT1, PT2, PT3, PT4>::getFromOpaqueValue(P);
 | 
						|
    }
 | 
						|
    
 | 
						|
    // The number of bits available are the min of the two pointer types.
 | 
						|
    enum {
 | 
						|
      NumLowBitsAvailable = 
 | 
						|
        PointerLikeTypeTraits<typename PointerUnion4<PT1, PT2, PT3, PT4>::ValTy>
 | 
						|
          ::NumLowBitsAvailable
 | 
						|
    };
 | 
						|
  };
 | 
						|
 | 
						|
  // Teach DenseMap how to use PointerUnions as keys.
 | 
						|
  template<typename T, typename U>
 | 
						|
  struct DenseMapInfo<PointerUnion<T, U> > {
 | 
						|
    typedef PointerUnion<T, U> Pair;
 | 
						|
    typedef DenseMapInfo<T> FirstInfo;
 | 
						|
    typedef DenseMapInfo<U> SecondInfo;
 | 
						|
 | 
						|
    static inline Pair getEmptyKey() {
 | 
						|
      return Pair(FirstInfo::getEmptyKey());
 | 
						|
    }
 | 
						|
    static inline Pair getTombstoneKey() {
 | 
						|
      return Pair(FirstInfo::getTombstoneKey());
 | 
						|
    }
 | 
						|
    static unsigned getHashValue(const Pair &PairVal) {
 | 
						|
      intptr_t key = (intptr_t)PairVal.getOpaqueValue();
 | 
						|
      return DenseMapInfo<intptr_t>::getHashValue(key);
 | 
						|
    }
 | 
						|
    static bool isEqual(const Pair &LHS, const Pair &RHS) {
 | 
						|
      return LHS.template is<T>() == RHS.template is<T>() &&
 | 
						|
             (LHS.template is<T>() ?
 | 
						|
              FirstInfo::isEqual(LHS.template get<T>(),
 | 
						|
                                 RHS.template get<T>()) :
 | 
						|
              SecondInfo::isEqual(LHS.template get<U>(),
 | 
						|
                                  RHS.template get<U>()));
 | 
						|
    }
 | 
						|
  };
 | 
						|
}
 | 
						|
 | 
						|
#endif
 |