diff --git a/llvm/include/llvm/ADT/PointerUnion.h b/llvm/include/llvm/ADT/PointerUnion.h
--- a/llvm/include/llvm/ADT/PointerUnion.h
+++ b/llvm/include/llvm/ADT/PointerUnion.h
@@ -18,6 +18,7 @@
 #include "llvm/ADT/DenseMapInfo.h"
 #include "llvm/ADT/PointerIntPair.h"
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/Support/Casting.h"
 #include "llvm/Support/PointerLikeTypeTraits.h"
 #include <algorithm>
 #include <cassert>
@@ -205,6 +206,28 @@
   return lhs.getOpaqueValue() < rhs.getOpaqueValue();
 }
 
+// Specialization of CastInfo for PointerUnion
+template <typename To, typename... PTs>
+struct CastInfo<To, PointerUnion<PTs...>>
+    : NullableValueCastFailed<To>,
+      DefaultDoCastIfPossible<To, PointerUnion<PTs...>,
+                              CastInfo<To, PointerUnion<PTs...>>> {
+  using From = PointerUnion<PTs...>;
+
+  static inline bool isPossible(From &f) { return f.template is<To>(); }
+
+  static To doCast(From &f) {
+    assert(f.template is<To>() &&
+           "cast to incompatible pointer type from PointerUnion !");
+    return f.template get<To>();
+  }
+};
+
+template <typename To, typename... PTs>
+struct CastInfo<To, const PointerUnion<PTs...>>
+    : ConstStrippingForwardingCast<To, const PointerUnion<PTs...>,
+                                   CastInfo<To, PointerUnion<PTs...>>> {};
+
 // Teach SmallPtrSet that PointerUnion is "basically a pointer", that has
 // # low bits available = min(PT1bits,PT2bits)-1.
 template <typename ...PTs>
diff --git a/llvm/unittests/ADT/PointerUnionTest.cpp b/llvm/unittests/ADT/PointerUnionTest.cpp
--- a/llvm/unittests/ADT/PointerUnionTest.cpp
+++ b/llvm/unittests/ADT/PointerUnionTest.cpp
@@ -156,4 +156,120 @@
   EXPECT_TRUE((void *)n.getAddrOfPtr1() == (void *)&n);
 }
 
+TEST_F(PointerUnionTest, NewCastInfra) {
+  // test isa<>
+  EXPECT_TRUE(isa<float *>(a));
+  EXPECT_TRUE(isa<int *>(b));
+  EXPECT_TRUE(isa<int *>(c));
+  EXPECT_TRUE(isa<int *>(n));
+  EXPECT_TRUE(isa<int *>(i3));
+  EXPECT_TRUE(isa<float *>(f3));
+  EXPECT_TRUE(isa<long long *>(l3));
+  EXPECT_TRUE(isa<int *>(i4));
+  EXPECT_TRUE(isa<float *>(f4));
+  EXPECT_TRUE(isa<long long *>(l4));
+  EXPECT_TRUE(isa<double *>(d4));
+  EXPECT_TRUE(isa<int *>(i4null));
+  EXPECT_TRUE(isa<float *>(f4null));
+  EXPECT_TRUE(isa<long long *>(l4null));
+  EXPECT_TRUE(isa<double *>(d4null));
+  EXPECT_FALSE(isa<int *>(a));
+  EXPECT_FALSE(isa<float *>(b));
+  EXPECT_FALSE(isa<float *>(c));
+  EXPECT_FALSE(isa<float *>(n));
+  EXPECT_FALSE(isa<float *>(i3));
+  EXPECT_FALSE(isa<long long *>(i3));
+  EXPECT_FALSE(isa<int *>(f3));
+  EXPECT_FALSE(isa<long long *>(f3));
+  EXPECT_FALSE(isa<int *>(l3));
+  EXPECT_FALSE(isa<float *>(l3));
+  EXPECT_FALSE(isa<float *>(i4));
+  EXPECT_FALSE(isa<long long *>(i4));
+  EXPECT_FALSE(isa<double *>(i4));
+  EXPECT_FALSE(isa<int *>(f4));
+  EXPECT_FALSE(isa<long long *>(f4));
+  EXPECT_FALSE(isa<double *>(f4));
+  EXPECT_FALSE(isa<int *>(l4));
+  EXPECT_FALSE(isa<float *>(l4));
+  EXPECT_FALSE(isa<double *>(l4));
+  EXPECT_FALSE(isa<int *>(d4));
+  EXPECT_FALSE(isa<float *>(d4));
+  EXPECT_FALSE(isa<long long *>(d4));
+  EXPECT_FALSE(isa<float *>(i4null));
+  EXPECT_FALSE(isa<long long *>(i4null));
+  EXPECT_FALSE(isa<double *>(i4null));
+  EXPECT_FALSE(isa<int *>(f4null));
+  EXPECT_FALSE(isa<long long *>(f4null));
+  EXPECT_FALSE(isa<double *>(f4null));
+  EXPECT_FALSE(isa<int *>(l4null));
+  EXPECT_FALSE(isa<float *>(l4null));
+  EXPECT_FALSE(isa<double *>(l4null));
+  EXPECT_FALSE(isa<int *>(d4null));
+  EXPECT_FALSE(isa<float *>(d4null));
+  EXPECT_FALSE(isa<long long *>(d4null));
+
+  // test cast<>
+  EXPECT_EQ(cast<float *>(a), &f);
+  EXPECT_EQ(cast<int *>(b), &i);
+  EXPECT_EQ(cast<int *>(c), &i);
+  EXPECT_EQ(cast<int *>(i3), &i);
+  EXPECT_EQ(cast<float *>(f3), &f);
+  EXPECT_EQ(cast<long long *>(l3), &l);
+  EXPECT_EQ(cast<int *>(i4), &i);
+  EXPECT_EQ(cast<float *>(f4), &f);
+  EXPECT_EQ(cast<long long *>(l4), &l);
+  EXPECT_EQ(cast<double *>(d4), &d);
+
+  // test dyn_cast
+  EXPECT_EQ(dyn_cast<int *>(a), nullptr);
+  EXPECT_EQ(dyn_cast<float *>(a), &f);
+  EXPECT_EQ(dyn_cast<int *>(b), &i);
+  EXPECT_EQ(dyn_cast<float *>(b), nullptr);
+  EXPECT_EQ(dyn_cast<int *>(c), &i);
+  EXPECT_EQ(dyn_cast<float *>(c), nullptr);
+  EXPECT_EQ(dyn_cast<int *>(n), nullptr);
+  EXPECT_EQ(dyn_cast<float *>(n), nullptr);
+  EXPECT_EQ(dyn_cast<int *>(i3), &i);
+  EXPECT_EQ(dyn_cast<float *>(i3), nullptr);
+  EXPECT_EQ(dyn_cast<long long *>(i3), nullptr);
+  EXPECT_EQ(dyn_cast<int *>(f3), nullptr);
+  EXPECT_EQ(dyn_cast<float *>(f3), &f);
+  EXPECT_EQ(dyn_cast<long long *>(f3), nullptr);
+  EXPECT_EQ(dyn_cast<int *>(l3), nullptr);
+  EXPECT_EQ(dyn_cast<float *>(l3), nullptr);
+  EXPECT_EQ(dyn_cast<long long *>(l3), &l);
+  EXPECT_EQ(dyn_cast<int *>(i4), &i);
+  EXPECT_EQ(dyn_cast<float *>(i4), nullptr);
+  EXPECT_EQ(dyn_cast<long long *>(i4), nullptr);
+  EXPECT_EQ(dyn_cast<double *>(i4), nullptr);
+  EXPECT_EQ(dyn_cast<int *>(f4), nullptr);
+  EXPECT_EQ(dyn_cast<float *>(f4), &f);
+  EXPECT_EQ(dyn_cast<long long *>(f4), nullptr);
+  EXPECT_EQ(dyn_cast<double *>(f4), nullptr);
+  EXPECT_EQ(dyn_cast<int *>(l4), nullptr);
+  EXPECT_EQ(dyn_cast<float *>(l4), nullptr);
+  EXPECT_EQ(dyn_cast<long long *>(l4), &l);
+  EXPECT_EQ(dyn_cast<double *>(l4), nullptr);
+  EXPECT_EQ(dyn_cast<int *>(d4), nullptr);
+  EXPECT_EQ(dyn_cast<float *>(d4), nullptr);
+  EXPECT_EQ(dyn_cast<long long *>(d4), nullptr);
+  EXPECT_EQ(dyn_cast<double *>(d4), &d);
+  EXPECT_EQ(dyn_cast<int *>(i4null), nullptr);
+  EXPECT_EQ(dyn_cast<float *>(i4null), nullptr);
+  EXPECT_EQ(dyn_cast<long long *>(i4null), nullptr);
+  EXPECT_EQ(dyn_cast<double *>(i4null), nullptr);
+  EXPECT_EQ(dyn_cast<int *>(f4null), nullptr);
+  EXPECT_EQ(dyn_cast<float *>(f4null), nullptr);
+  EXPECT_EQ(dyn_cast<long long *>(f4null), nullptr);
+  EXPECT_EQ(dyn_cast<double *>(f4null), nullptr);
+  EXPECT_EQ(dyn_cast<int *>(l4null), nullptr);
+  EXPECT_EQ(dyn_cast<float *>(l4null), nullptr);
+  EXPECT_EQ(dyn_cast<long long *>(l4null), nullptr);
+  EXPECT_EQ(dyn_cast<double *>(l4null), nullptr);
+  EXPECT_EQ(dyn_cast<int *>(d4null), nullptr);
+  EXPECT_EQ(dyn_cast<float *>(d4null), nullptr);
+  EXPECT_EQ(dyn_cast<long long *>(d4null), nullptr);
+  EXPECT_EQ(dyn_cast<double *>(d4null), nullptr);
+}
+
 } // end anonymous namespace