+ PointerLikeTypeTraits<typename PointerUnion<PT1,PT2>::ValTy>
+ ::NumLowBitsAvailable
+ };
+ };
+
+
+ /// PointerUnion3 - This is a pointer union of three pointer types. See
+ /// documentation for PointerUnion for usage.
+ template <typename PT1, typename PT2, typename PT3>
+ class PointerUnion3 {
+ public:
+ typedef PointerUnion<PT1, PT2> InnerUnion;
+ typedef PointerUnion<InnerUnion, PT3> ValTy;
+ private:
+ ValTy Val;
+ public:
+ PointerUnion3() {}
+
+ PointerUnion3(PT1 V) {
+ Val = InnerUnion(V);
+ }
+ PointerUnion3(PT2 V) {
+ Val = InnerUnion(V);
+ }
+ PointerUnion3(PT3 V) {
+ Val = V;
+ }
+
+ /// isNull - Return true if the pointer help in the union is null,
+ /// regardless of which type it is.
+ bool isNull() const { return Val.isNull(); }
+ operator bool() const { return !isNull(); }
+
+ /// is<T>() return true if the Union currently holds the type matching T.
+ template<typename T>
+ int is() const {
+ // Is it PT1/PT2?
+ if (::llvm::getPointerUnionTypeNum<PT1, PT2>((T*)0) != -1)
+ return Val.get<InnerUnion>().is<T>();
+ // Must be PT3 or statically invalid.
+ assert(Val.is<T>());
+ return true;
+ }
+
+ /// get<T>() - Return the value of the specified pointer type. If the
+ /// specified pointer type is incorrect, assert.
+ template<typename T>
+ T get() const {
+ assert(is<T>() && "Invalid accessor called");
+ if (Val.is<T>())
+ return Val.get<T>();
+ return Val.get<InnerUnion>().get<T>();
+ }
+
+ /// dyn_cast<T>() - If the current value is of the specified pointer type,
+ /// return it, otherwise return null.
+ template<typename T>
+ T dyn_cast() const {
+ if (is<T>()) return get<T>();
+ return T();
+ }
+
+ /// Assignment operators - Allow assigning into this union from either
+ /// pointer type, setting the discriminator to remember what it came from.
+ const PointerUnion3 &operator=(const PT1 &RHS) {
+ Val = InnerUnion(RHS);
+ return *this;
+ }
+ const PointerUnion3 &operator=(const PT2 &RHS) {
+ Val = InnerUnion(RHS);
+ return *this;
+ }
+ const PointerUnion3 &operator=(const PT3 &RHS) {
+ Val = RHS;
+ return *this;
+ }
+
+ void *getOpaqueValue() const { return Val.getOpaqueValue(); }
+ static PointerUnion3 getFromOpaqueValue(void *VP) {
+ PointerUnion3 V;
+ V.Val = ValTy::getFromOpaqueValue(VP);
+ return V;
+ }
+ };
+
+ // Teach SmallPtrSet that PointerUnion3 is "basically a pointer", that has
+ // # low bits available = min(PT1bits,PT2bits,PT2bits)-2.
+ template<typename PT1, typename PT2, typename PT3>
+ class PointerLikeTypeTraits<PointerUnion3<PT1, PT2, PT3> > {
+ public:
+ static inline void *
+ getAsVoidPointer(const PointerUnion3<PT1, PT2, PT3> &P) {
+ return P.getOpaqueValue();
+ }
+ static inline PointerUnion3<PT1, PT2, PT3>
+ getFromVoidPointer(void *P) {
+ return PointerUnion3<PT1, PT2, PT3>::getFromOpaqueValue(P);
+ }
+
+ // The number of bits available are the min of the two pointer types.
+ enum {
+ NumLowBitsAvailable =
+ PointerLikeTypeTraits<typename PointerUnion3<PT1, PT2, PT3>::ValTy>
+ ::NumLowBitsAvailable