diff --git a/clang/include/clang/AST/ASTContext.h b/clang/include/clang/AST/ASTContext.h
--- a/clang/include/clang/AST/ASTContext.h
+++ b/clang/include/clang/AST/ASTContext.h
@@ -1155,6 +1155,10 @@
   /// attribute.
   QualType getObjCGCQualType(QualType T, Qualifiers::GC gcAttr) const;
 
+  /// Remove the existing address space on the type if it is a pointer size
+  /// address space and return the type with qualifiers intact.
+  QualType removePtrSizeAddrSpace(QualType T) const;
+
   /// Return the uniqued reference to the type for a \c restrict
   /// qualified type.
   ///
@@ -1209,6 +1213,15 @@
                            const FunctionProtoType::ExceptionSpecInfo &ESI,
                            bool AsWritten = false);
 
+  /// Get a function type and produce the equivalent function type where
+  /// pointer size address spaces in the return type and parameter tyeps are
+  /// replaced with the default address space.
+  QualType getFunctionTypeWithoutPtrSizes(QualType T);
+
+  /// Determine whether two function types are the same, ignoring pointer sizes
+  /// in the return type and parameter types.
+  bool hasSameFunctionTypeIgnoringPtrSizes(QualType T, QualType U);
+
   /// Return the uniqued reference to the type for a complex
   /// number with the specified element type.
   QualType getComplexType(QualType T) const;
diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -477,7 +477,10 @@
     return A == B ||
            // Otherwise in OpenCLC v2.0 s6.5.5: every address space except
            // for __constant can be used as __generic.
-           (A == LangAS::opencl_generic && B != LangAS::opencl_constant);
+           (A == LangAS::opencl_generic && B != LangAS::opencl_constant) ||
+           // Consider pointer size address spaces to be equivalent to default.
+           ((isPtrSizeAddressSpace(A) || A == LangAS::Default) &&
+            (isPtrSizeAddressSpace(B) || B == LangAS::Default));
   }
 
   /// Returns true if the address space in these qualifiers is equal to or
diff --git a/clang/include/clang/Basic/AddressSpaces.h b/clang/include/clang/Basic/AddressSpaces.h
--- a/clang/include/clang/Basic/AddressSpaces.h
+++ b/clang/include/clang/Basic/AddressSpaces.h
@@ -42,6 +42,11 @@
   cuda_constant,
   cuda_shared,
 
+  // Pointer size and extension address spaces.
+  ptr32_sptr,
+  ptr32_uptr,
+  ptr64,
+
   // This denotes the count of language-specific address spaces and also
   // the offset added to the target-specific address spaces, which are usually
   // specified by address space attributes __attribute__(address_space(n))).
@@ -68,6 +73,11 @@
                              (unsigned)LangAS::FirstTargetAddressSpace);
 }
 
+inline bool isPtrSizeAddressSpace(LangAS AS) {
+  return (AS == LangAS::ptr32_sptr || AS == LangAS::ptr32_uptr ||
+          AS == LangAS::ptr64);
+}
+
 } // namespace clang
 
 #endif // LLVM_CLANG_BASIC_ADDRESSSPACES_H
diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td
--- a/clang/include/clang/Basic/Attr.td
+++ b/clang/include/clang/Basic/Attr.td
@@ -2975,22 +2975,22 @@
 
 def Ptr32 : TypeAttr {
   let Spellings = [Keyword<"__ptr32">];
-  let Documentation = [Undocumented];
+  let Documentation = [Ptr32Docs];
 }
 
 def Ptr64 : TypeAttr {
   let Spellings = [Keyword<"__ptr64">];
-  let Documentation = [Undocumented];
+  let Documentation = [Ptr64Docs];
 }
 
 def SPtr : TypeAttr {
   let Spellings = [Keyword<"__sptr">];
-  let Documentation = [Undocumented];
+  let Documentation = [SPtrDocs];
 }
 
 def UPtr : TypeAttr {
   let Spellings = [Keyword<"__uptr">];
-  let Documentation = [Undocumented];
+  let Documentation = [UPtrDocs];
 }
 
 def MSInheritance : InheritableAttr {
diff --git a/clang/include/clang/Basic/AttrDocs.td b/clang/include/clang/Basic/AttrDocs.td
--- a/clang/include/clang/Basic/AttrDocs.td
+++ b/clang/include/clang/Basic/AttrDocs.td
@@ -3139,6 +3139,44 @@
 by Clang.
   }];
 }
+
+def Ptr32Docs : Documentation {
+  let Category = DocCatType;
+  let Content = [{
+The ``__ptr32`` qualifier represents a native pointer on a 32-bit system. On a
+64-bit system, a pointer with ``__ptr32`` is extended to a 64-bit pointer. The
+``__sptr`` and ``__uptr`` qualifiers can be used to specify whether the pointer
+is sign extended or zero extended. This qualifier is enabled under
+``-fms-extensions``.
+  }];
+}
+
+def Ptr64Docs : Documentation {
+  let Category = DocCatType;
+  let Content = [{
+The ``__ptr64`` qualifier represents a native pointer on a 64-bit system. On a
+32-bit system, a ``__ptr64`` pointer is truncated to a 32-bit pointer. This
+qualifier is enabled under ``-fms-extensions``.
+  }];
+}
+
+def SPtrDocs : Documentation {
+  let Category = DocCatType;
+  let Content = [{
+The ``__sptr`` qualifier specifies that a 32-bit pointer should be sign
+extended when converted to a 64-bit pointer.
+  }];
+}
+
+def UPtrDocs : Documentation {
+  let Category = DocCatType;
+  let Content = [{
+The ``__uptr`` qualifier specifies that a 32-bit pointer should be zero
+extended when converted to a 64-bit pointer.
+  }];
+}
+
+
 def NullabilityDocs : DocumentationCategory<"Nullability Attributes"> {
   let Content = [{
 Whether a particular pointer may be "null" is an important concern when working with pointers in the C family of languages. The various nullability attributes indicate whether a particular pointer can be null or not, which makes APIs more expressive and can help static analysis tools identify bugs involving null pointers. Clang supports several kinds of nullability attributes: the ``nonnull`` and ``returns_nonnull`` attributes indicate which function or method parameters and result types can never be null, while nullability type qualifiers indicate which pointer types can be null (``_Nullable``) or cannot be null (``_Nonnull``).
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -825,15 +825,18 @@
     // The fake address space map must have a distinct entry for each
     // language-specific address space.
     static const unsigned FakeAddrSpaceMap[] = {
-      0, // Default
-      1, // opencl_global
-      3, // opencl_local
-      2, // opencl_constant
-      0, // opencl_private
-      4, // opencl_generic
-      5, // cuda_device
-      6, // cuda_constant
-      7  // cuda_shared
+        0, // Default
+        1, // opencl_global
+        3, // opencl_local
+        2, // opencl_constant
+        0, // opencl_private
+        4, // opencl_generic
+        5, // cuda_device
+        6, // cuda_constant
+        7, // cuda_shared
+        8, // ptr32_sptr
+        9, // ptr32_uptr
+        10 // ptr64
     };
     return &FakeAddrSpaceMap;
   } else {
@@ -2832,6 +2835,16 @@
   return getExtQualType(TypeNode, Quals);
 }
 
+QualType ASTContext::removePtrSizeAddrSpace(QualType T) const {
+  if (const PointerType *Ptr = T->getAs<PointerType>()) {
+    QualType Pointee = Ptr->getPointeeType();
+    if (isPtrSizeAddressSpace(Pointee.getAddressSpace())) {
+      return getPointerType(removeAddrSpaceQualType(Pointee));
+    }
+  }
+  return T;
+}
+
 const FunctionType *ASTContext::adjustFunctionType(const FunctionType *T,
                                                    FunctionType::ExtInfo Info) {
   if (T->getExtInfo() == Info)
@@ -2906,6 +2919,29 @@
                       getFunctionTypeWithExceptionSpec(U, EST_None)));
 }
 
+QualType ASTContext::getFunctionTypeWithoutPtrSizes(QualType T) {
+  if (const auto *Proto = T->getAs<FunctionProtoType>()) {
+    QualType RetTy = removePtrSizeAddrSpace(Proto->getReturnType());
+    SmallVector<QualType, 16> Args(Proto->param_types());
+    for (unsigned i = 0, n = Args.size(); i != n; ++i)
+      Args[i] = removePtrSizeAddrSpace(Args[i]);
+    return getFunctionType(RetTy, Args, Proto->getExtProtoInfo());
+  }
+
+  if (const FunctionNoProtoType *Proto = T->getAs<FunctionNoProtoType>()) {
+    QualType RetTy = removePtrSizeAddrSpace(Proto->getReturnType());
+    return getFunctionNoProtoType(RetTy, Proto->getExtInfo());
+  }
+
+  return T;
+}
+
+bool ASTContext::hasSameFunctionTypeIgnoringPtrSizes(QualType T, QualType U) {
+  return hasSameType(T, U) ||
+         hasSameType(getFunctionTypeWithoutPtrSizes(T),
+                     getFunctionTypeWithoutPtrSizes(U));
+}
+
 void ASTContext::adjustExceptionSpec(
     FunctionDecl *FD, const FunctionProtoType::ExceptionSpecInfo &ESI,
     bool AsWritten) {
diff --git a/clang/lib/AST/ItaniumMangle.cpp b/clang/lib/AST/ItaniumMangle.cpp
--- a/clang/lib/AST/ItaniumMangle.cpp
+++ b/clang/lib/AST/ItaniumMangle.cpp
@@ -2301,6 +2301,16 @@
       case LangAS::cuda_device:     ASString = "CUdevice";   break;
       case LangAS::cuda_constant:   ASString = "CUconstant"; break;
       case LangAS::cuda_shared:     ASString = "CUshared";   break;
+      //  <ptrsize-addrspace> ::= [ "ptr32_sptr" | "ptr32_uptr" | "ptr64" ]
+      case LangAS::ptr32_sptr:
+        ASString = "ptr32_sptr";
+        break;
+      case LangAS::ptr32_uptr:
+        ASString = "ptr32_uptr";
+        break;
+      case LangAS::ptr64:
+        ASString = "ptr64";
+        break;
       }
     }
     if (!ASString.empty())
diff --git a/clang/lib/AST/MicrosoftMangle.cpp b/clang/lib/AST/MicrosoftMangle.cpp
--- a/clang/lib/AST/MicrosoftMangle.cpp
+++ b/clang/lib/AST/MicrosoftMangle.cpp
@@ -279,8 +279,6 @@
 
   ASTContext &getASTContext() const { return Context.getASTContext(); }
 
-  // FIXME: If we add support for __ptr32/64 qualifiers, then we should push
-  // this check into mangleQualifiers().
   const bool PointersAre64Bit;
 
 public:
@@ -335,6 +333,13 @@
     return ND == Structor || getStructor(ND) == Structor;
   }
 
+  bool is64BitPointer(Qualifiers Quals) const {
+    LangAS AddrSpace = Quals.getAddressSpace();
+    return AddrSpace == LangAS::ptr64 ||
+           (PointersAre64Bit && !(AddrSpace == LangAS::ptr32_sptr ||
+                                  AddrSpace == LangAS::ptr32_uptr));
+  }
+
   void mangleUnqualifiedName(const NamedDecl *ND) {
     mangleUnqualifiedName(ND, ND->getDeclName());
   }
@@ -1703,8 +1708,10 @@
 
 void MicrosoftCXXNameMangler::manglePointerExtQualifiers(Qualifiers Quals,
                                                          QualType PointeeType) {
-  if (PointersAre64Bit &&
-      (PointeeType.isNull() || !PointeeType->isFunctionType()))
+  // Check if this is a default 64-bit pointer or has __ptr64 qualifier.
+  bool is64Bit = PointeeType.isNull() ? PointersAre64Bit :
+      is64BitPointer(PointeeType.getQualifiers());
+  if (is64Bit && (PointeeType.isNull() || !PointeeType->isFunctionType()))
     Out << 'E';
 
   if (Quals.hasRestrict())
@@ -1864,6 +1871,10 @@
     case LangAS::cuda_shared:
       Extra.mangleSourceName("_ASCUshared");
       break;
+    case LangAS::ptr32_sptr:
+    case LangAS::ptr32_uptr:
+    case LangAS::ptr64:
+      llvm_unreachable("don't mangle ptr address spaces with _AS");
     }
   }
 
@@ -2597,10 +2608,13 @@
   manglePointerCVQualifiers(Quals);
   manglePointerExtQualifiers(Quals, PointeeType);
 
-  if (PointeeType.getQualifiers().hasAddressSpace())
-    mangleAddressSpaceType(PointeeType, PointeeType.getQualifiers(), Range);
-  else
+  // For pointer size address spaces, go down the same type mangling path as
+  // non address space types.
+  LangAS AddrSpace = PointeeType.getQualifiers().getAddressSpace();
+  if (isPtrSizeAddressSpace(AddrSpace) || AddrSpace == LangAS::Default)
     mangleType(PointeeType, Range);
+  else
+    mangleAddressSpaceType(PointeeType, PointeeType.getQualifiers(), Range);
 }
 
 void MicrosoftCXXNameMangler::mangleType(const ObjCObjectPointerType *T,
diff --git a/clang/lib/AST/TypePrinter.cpp b/clang/lib/AST/TypePrinter.cpp
--- a/clang/lib/AST/TypePrinter.cpp
+++ b/clang/lib/AST/TypePrinter.cpp
@@ -1792,6 +1792,12 @@
     return "__constant__";
   case LangAS::cuda_shared:
     return "__shared__";
+  case LangAS::ptr32_sptr:
+    return "__sptr __ptr32";
+  case LangAS::ptr32_uptr:
+    return "__uptr __ptr32";
+  case LangAS::ptr64:
+    return "__ptr64";
   default:
     return std::to_string(toTargetAddressSpace(AS));
   }
diff --git a/clang/lib/Basic/Targets/AMDGPU.cpp b/clang/lib/Basic/Targets/AMDGPU.cpp
--- a/clang/lib/Basic/Targets/AMDGPU.cpp
+++ b/clang/lib/Basic/Targets/AMDGPU.cpp
@@ -47,7 +47,10 @@
     Generic,  // opencl_generic
     Global,   // cuda_device
     Constant, // cuda_constant
-    Local     // cuda_shared
+    Local,    // cuda_shared
+    Generic,  // ptr32_sptr
+    Generic,  // ptr32_uptr
+    Generic   // ptr64
 };
 
 const LangASMap AMDGPUTargetInfo::AMDGPUDefIsPrivMap = {
@@ -59,7 +62,11 @@
     Generic,  // opencl_generic
     Global,   // cuda_device
     Constant, // cuda_constant
-    Local     // cuda_shared
+    Local,    // cuda_shared
+    Generic,  // ptr32_sptr
+    Generic,  // ptr32_uptr
+    Generic   // ptr64
+
 };
 } // namespace targets
 } // namespace clang
diff --git a/clang/lib/Basic/Targets/NVPTX.h b/clang/lib/Basic/Targets/NVPTX.h
--- a/clang/lib/Basic/Targets/NVPTX.h
+++ b/clang/lib/Basic/Targets/NVPTX.h
@@ -33,6 +33,9 @@
     1, // cuda_device
     4, // cuda_constant
     3, // cuda_shared
+    0, // ptr32_sptr
+    0, // ptr32_uptr
+    0  // ptr64
 };
 
 /// The DWARF address class. Taken from
diff --git a/clang/lib/Basic/Targets/SPIR.h b/clang/lib/Basic/Targets/SPIR.h
--- a/clang/lib/Basic/Targets/SPIR.h
+++ b/clang/lib/Basic/Targets/SPIR.h
@@ -30,7 +30,10 @@
     4, // opencl_generic
     0, // cuda_device
     0, // cuda_constant
-    0  // cuda_shared
+    0, // cuda_shared
+    0, // ptr32_sptr
+    0, // ptr32_uptr
+    0  // ptr64
 };
 
 class LLVM_LIBRARY_VISIBILITY SPIRTargetInfo : public TargetInfo {
diff --git a/clang/lib/Basic/Targets/TCE.h b/clang/lib/Basic/Targets/TCE.h
--- a/clang/lib/Basic/Targets/TCE.h
+++ b/clang/lib/Basic/Targets/TCE.h
@@ -39,7 +39,10 @@
     0, // opencl_generic
     0, // cuda_device
     0, // cuda_constant
-    0  // cuda_shared
+    0, // cuda_shared
+    0, // ptr32_sptr
+    0, // ptr32_uptr
+    0, // ptr64
 };
 
 class LLVM_LIBRARY_VISIBILITY TCETargetInfo : public TargetInfo {
diff --git a/clang/lib/Basic/Targets/X86.h b/clang/lib/Basic/Targets/X86.h
--- a/clang/lib/Basic/Targets/X86.h
+++ b/clang/lib/Basic/Targets/X86.h
@@ -22,6 +22,21 @@
 namespace clang {
 namespace targets {
 
+static const unsigned X86AddrSpaceMap[] = {
+    0,   // Default
+    0,   // opencl_global
+    0,   // opencl_local
+    0,   // opencl_constant
+    0,   // opencl_private
+    0,   // opencl_generic
+    0,   // cuda_device
+    0,   // cuda_constant
+    0,   // cuda_shared
+    270, // ptr32_sptr
+    271, // ptr32_uptr
+    272  // ptr64
+};
+
 // X86 target abstract base class; x86-32 and x86-64 are very close, so
 // most of the implementation can be shared.
 class LLVM_LIBRARY_VISIBILITY X86TargetInfo : public TargetInfo {
@@ -45,6 +60,7 @@
     AMD3DNowAthlon
   } MMX3DNowLevel = NoMMX3DNow;
   enum XOPEnum { NoXOP, SSE4A, FMA4, XOP } XOPLevel = NoXOP;
+  enum AddrSpace { ptr32_sptr = 270, ptr32_uptr = 271, ptr64 = 272 };
 
   bool HasAES = false;
   bool HasVAES = false;
@@ -130,6 +146,7 @@
   X86TargetInfo(const llvm::Triple &Triple, const TargetOptions &)
       : TargetInfo(Triple) {
     LongDoubleFormat = &llvm::APFloat::x87DoubleExtended();
+    AddrSpaceMap = &X86AddrSpaceMap;
   }
 
   const char *getLongDoubleMangling() const override {
@@ -328,6 +345,18 @@
   void setSupportedOpenCLOpts() override {
     getSupportedOpenCLOpts().supportAll();
   }
+
+  uint64_t getPointerWidthV(unsigned AddrSpace) const override {
+    if (AddrSpace == ptr32_sptr || AddrSpace == ptr32_uptr)
+      return 32;
+    if (AddrSpace == ptr64)
+      return 64;
+    return PointerWidth;
+  }
+
+  uint64_t getPointerAlignV(unsigned AddrSpace) const override {
+    return getPointerWidthV(AddrSpace);
+  }
 };
 
 // X86-32 generic target
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -3656,6 +3656,11 @@
     return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld);
   }
 
+  // Check if the function types are compatible when pointer size address
+  // spaces are ignored.
+  if (Context.hasSameFunctionTypeIgnoringPtrSizes(OldQType, NewQType))
+    return false;
+
   // GNU C permits a K&R definition to follow a prototype declaration
   // if the declared types of the parameters in the K&R definition
   // match the types in the prototype declaration, even when the
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -2933,8 +2933,12 @@
                                               N = NewType->param_type_begin(),
                                               E = OldType->param_type_end();
        O && (O != E); ++O, ++N) {
-    if (!Context.hasSameType(O->getUnqualifiedType(),
-                             N->getUnqualifiedType())) {
+    // Ignore address spaces in pointee type. This is to disallow overloading
+    // on __ptr32/__ptr64 address spaces.
+    QualType Old = Context.removePtrSizeAddrSpace(O->getUnqualifiedType());
+    QualType New = Context.removePtrSizeAddrSpace(N->getUnqualifiedType());
+
+    if (!Context.hasSameType(Old, New)) {
       if (ArgPos)
         *ArgPos = O - OldType->param_type_begin();
       return false;
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -6497,35 +6497,36 @@
     break;
   }
 
+  llvm::SmallSet<attr::Kind, 2> Attrs;
   attr::Kind NewAttrKind = A->getKind();
   QualType Desugared = Type;
   const AttributedType *AT = dyn_cast<AttributedType>(Type);
   while (AT) {
-    attr::Kind CurAttrKind = AT->getAttrKind();
-
-    // You cannot specify duplicate type attributes, so if the attribute has
-    // already been applied, flag it.
-    if (NewAttrKind == CurAttrKind) {
-      S.Diag(PAttr.getLoc(), diag::warn_duplicate_attribute_exact) << PAttr;
-      return true;
-    }
+    Attrs.insert(AT->getAttrKind());
+    Desugared = AT->getModifiedType();
+    AT = dyn_cast<AttributedType>(Desugared);
+  }
 
-    // You cannot have both __sptr and __uptr on the same type, nor can you
-    // have __ptr32 and __ptr64.
-    if ((CurAttrKind == attr::Ptr32 && NewAttrKind == attr::Ptr64) ||
-        (CurAttrKind == attr::Ptr64 && NewAttrKind == attr::Ptr32)) {
-      S.Diag(PAttr.getLoc(), diag::err_attributes_are_not_compatible)
-        << "'__ptr32'" << "'__ptr64'";
-      return true;
-    } else if ((CurAttrKind == attr::SPtr && NewAttrKind == attr::UPtr) ||
-               (CurAttrKind == attr::UPtr && NewAttrKind == attr::SPtr)) {
-      S.Diag(PAttr.getLoc(), diag::err_attributes_are_not_compatible)
-        << "'__sptr'" << "'__uptr'";
-      return true;
-    }
+  // You cannot specify duplicate type attributes, so if the attribute has
+  // already been applied, flag it.
+  if (Attrs.count(NewAttrKind)) {
+    S.Diag(PAttr.getLoc(), diag::warn_duplicate_attribute_exact) << PAttr;
+    return true;
+  }
+  Attrs.insert(NewAttrKind);
 
-    Desugared = AT->getEquivalentType();
-    AT = dyn_cast<AttributedType>(Desugared);
+  // You cannot have both __sptr and __uptr on the same type, nor can you
+  // have __ptr32 and __ptr64.
+  if (Attrs.count(attr::Ptr32) && Attrs.count(attr::Ptr64)) {
+    S.Diag(PAttr.getLoc(), diag::err_attributes_are_not_compatible)
+        << "'__ptr32'"
+        << "'__ptr64'";
+    return true;
+  } else if (Attrs.count(attr::SPtr) && Attrs.count(attr::UPtr)) {
+    S.Diag(PAttr.getLoc(), diag::err_attributes_are_not_compatible)
+        << "'__sptr'"
+        << "'__uptr'";
+    return true;
   }
 
   // Pointer type qualifiers can only operate on pointer types, but not
@@ -6543,7 +6544,26 @@
     return true;
   }
 
-  Type = State.getAttributedType(A, Type, Type);
+  // Add address space to type based on its attributes.
+  LangAS ASIdx = LangAS::Default;
+  uint64_t PtrWidth = S.Context.getTargetInfo().getPointerWidth(0);
+  if (PtrWidth == 32) {
+    if (Attrs.count(attr::Ptr64))
+      ASIdx = LangAS::ptr64;
+    else if (Attrs.count(attr::UPtr))
+      ASIdx = LangAS::ptr32_uptr;
+  } else if (PtrWidth == 64 && Attrs.count(attr::Ptr32)) {
+    if (Attrs.count(attr::UPtr))
+      ASIdx = LangAS::ptr32_uptr;
+    else
+      ASIdx = LangAS::ptr32_sptr;
+  }
+
+  QualType Pointee = Type->getPointeeType();
+  if (ASIdx != LangAS::Default)
+    Pointee = S.Context.getAddrSpaceQualType(
+        S.Context.removeAddrSpaceQualType(Pointee), ASIdx);
+  Type = State.getAttributedType(A, Type, S.Context.getPointerType(Pointee));
   return false;
 }
 
diff --git a/clang/test/CodeGen/ms-mixed-ptr-sizes.c b/clang/test/CodeGen/ms-mixed-ptr-sizes.c
new file mode 100644
--- /dev/null
+++ b/clang/test/CodeGen/ms-mixed-ptr-sizes.c
@@ -0,0 +1,51 @@
+// RUN: %clang_cc1 -triple x86_64-windows-msvc -fms-extensions -emit-llvm -O2 \
+// RUN:   < %s | FileCheck %s --check-prefixes=X64,CHECK
+// RUN: %clang_cc1 -triple i386-pc-win32 -fms-extensions -emit-llvm -O2 \
+// RUN:   < %s | FileCheck %s --check-prefixes=X86,CHECK
+
+struct Foo {
+  int * __ptr32 p32;
+  int * __ptr64 p64;
+};
+void use_foo(struct Foo *f);
+void test_sign_ext(struct Foo *f, int * __ptr32 __sptr i) {
+// X64-LABEL: define dso_local void @test_sign_ext({{.*}}i32 addrspace(270)* %i)
+// X86-LABEL: define dso_local void @test_sign_ext(%struct.Foo* %f, i32* %i)
+// X64: %{{.+}} = addrspacecast i32 addrspace(270)* %i to i32*
+// X86: %{{.+}} = addrspacecast i32* %i to i32 addrspace(272)*
+  f->p64 = i;
+  use_foo(f);
+}
+void test_zero_ext(struct Foo *f, int * __ptr32 __uptr i) {
+// X64-LABEL: define dso_local void @test_zero_ext({{.*}}i32 addrspace(271)* %i)
+// X86-LABEL: define dso_local void @test_zero_ext({{.*}}i32 addrspace(271)* %i)
+// X64: %{{.+}} = addrspacecast i32 addrspace(271)* %i to i32*
+// X86: %{{.+}} = addrspacecast i32 addrspace(271)* %i to i32 addrspace(272)*
+  f->p64 = i;
+  use_foo(f);
+}
+void test_trunc(struct Foo *f, int * __ptr64 i) {
+// X64-LABEL: define dso_local void @test_trunc(%struct.Foo* %f, i32* %i)
+// X86-LABEL: define dso_local void @test_trunc({{.*}}i32 addrspace(272)* %i)
+// X64: %{{.+}} = addrspacecast i32* %i to i32 addrspace(270)*
+// X86: %{{.+}} = addrspacecast i32 addrspace(272)* %i to i32*
+  f->p32 = i;
+  use_foo(f);
+}
+void test_noop(struct Foo *f, int * __ptr32 i) {
+// X64-LABEL: define dso_local void @test_noop({{.*}}i32 addrspace(270)* %i)
+// X86-LABEL: define dso_local void @test_noop({{.*}}i32* %i)
+// X64-NOT: addrspacecast
+// X86-NOT: addrspacecast
+  f->p32 = i;
+  use_foo(f);
+}
+
+void test_other(struct Foo *f, __attribute__((address_space(10))) int *i) {
+// X64-LABEL: define dso_local void @test_other({{.*}}i32 addrspace(10)* %i)
+// X86-LABEL: define dso_local void @test_other({{.*}}i32 addrspace(10)* %i)
+// X64: %{{.+}} = addrspacecast i32 addrspace(10)* %i to i32 addrspace(270)*
+// X86: %{{.+}} = addrspacecast i32 addrspace(10)* %i to i32*
+  f->p32 = (int * __ptr32)i;
+  use_foo(f);
+}
diff --git a/clang/test/CodeGenCXX/mangle-ptr-size-address-space.cpp b/clang/test/CodeGenCXX/mangle-ptr-size-address-space.cpp
new file mode 100644
--- /dev/null
+++ b/clang/test/CodeGenCXX/mangle-ptr-size-address-space.cpp
@@ -0,0 +1,18 @@
+// RUN: %clang_cc1 -fms-extensions -emit-llvm -triple %itanium_abi_triple -o - %s | FileCheck %s --check-prefixes=CHECK
+// RUN: %clang_cc1 -fms-extensions -emit-llvm -triple x86_64-windows-msvc -o - %s | FileCheck %s --check-prefixes=WIN
+
+// CHECK-LABEL: define {{.*}}void @_Z2f0PU10ptr32_sptri
+// WIN-LABEL: define {{.*}}void @"?f0@@YAXPAH@Z"
+void f0(int * __ptr32 p) {}
+
+// CHECK-LABEL: define {{.*}}i8 addrspace(271)* @_Z2f1PU10ptr32_sptri
+// WIN-LABEL: define {{.*}}i8 addrspace(271)* @"?f1@@YAPAXPAH@Z"
+void * __ptr32 __uptr f1(int * __ptr32 p) { return 0; }
+
+// CHECK-LABEL: define {{.*}}void @_Z2f2Pi
+// WIN-LABEL: define {{.*}}void @"?f2@@YAXPEAH@Z"
+void f2(int * __ptr64 p) {}
+
+  // CHECK-LABEL: define {{.*}}i8* @_Z2f3Pi
+// WIN-LABEL: define {{.*}}i8* @"?f3@@YAPEAXPEAH@Z"
+void * __ptr64 f3(int * __ptr64 p) { return 0; }
diff --git a/clang/test/Sema/MicrosoftExtensions.c b/clang/test/Sema/MicrosoftExtensions.c
--- a/clang/test/Sema/MicrosoftExtensions.c
+++ b/clang/test/Sema/MicrosoftExtensions.c
@@ -150,6 +150,20 @@
 void ptr_func2(int * __sptr __ptr32 i) {}  // expected-note {{previous definition is here}}
 void ptr_func2(int * __uptr __ptr32 i) {} // expected-error {{redefinition of 'ptr_func2'}}
 
+// Check for warning when return types have the type attribute.
+void *__ptr32 ptr_func3() { return 0; } // expected-note {{previous definition is here}}
+void *__ptr64 ptr_func3() { return 0; } // expected-error {{redefinition of 'ptr_func3'}}
+
+// Test that __ptr32/__ptr64 can be passed as arguments with other address
+// spaces.
+void ptr_func4(int *i);
+void ptr_func5(int *__ptr32 i);
+void test_ptr_arguments() {
+  int *__ptr64 i64;
+  ptr_func4(i64);
+  ptr_func5(i64);
+}
+
 int * __sptr __ptr32 __sptr wrong4; // expected-warning {{attribute '__sptr' is already applied}}
 
 __ptr32 int *wrong5; // expected-error {{'__ptr32' attribute only applies to pointer arguments}}
diff --git a/clang/test/SemaTemplate/address_space-dependent.cpp b/clang/test/SemaTemplate/address_space-dependent.cpp
--- a/clang/test/SemaTemplate/address_space-dependent.cpp
+++ b/clang/test/SemaTemplate/address_space-dependent.cpp
@@ -43,7 +43,7 @@
 
 template <long int I>
 void tooBig() {
-  __attribute__((address_space(I))) int *bounds; // expected-error {{address space is larger than the maximum supported (8388598)}}
+  __attribute__((address_space(I))) int *bounds; // expected-error {{address space is larger than the maximum supported (8388595)}}
 }
 
 template <long int I>
@@ -101,7 +101,7 @@
   car<1, 2, 3>(); // expected-note {{in instantiation of function template specialization 'car<1, 2, 3>' requested here}}
   HasASTemplateFields<1> HASTF;
   neg<-1>(); // expected-note {{in instantiation of function template specialization 'neg<-1>' requested here}}
-  correct<0x7FFFF6>();
+  correct<0x7FFFF3>();
   tooBig<8388650>(); // expected-note {{in instantiation of function template specialization 'tooBig<8388650>' requested here}}
 
   __attribute__((address_space(1))) char *x;