diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -1587,12 +1587,14 @@
   // All parameters are already in place except VTT, which goes after 'this'.
   // These are Clang types, so we don't need to worry about sret yet.
 
-  // Check if we need to add a VTT parameter (which has type void **).
+  // Check if we need to add a VTT parameter (which has type global void **).
   if ((isa<CXXConstructorDecl>(GD.getDecl()) ? GD.getCtorType() == Ctor_Base
                                              : GD.getDtorType() == Dtor_Base) &&
       cast<CXXMethodDecl>(GD.getDecl())->getParent()->getNumVBases() != 0) {
+    LangAS AS = CGM.GetGlobalVarAddressSpace(nullptr);
+    QualType Q = Context.getAddrSpaceQualType(Context.VoidPtrTy, AS);
     ArgTys.insert(ArgTys.begin() + 1,
-                  Context.getPointerType(Context.VoidPtrTy));
+                  Context.getPointerType(CanQualType::CreateUnsafe(Q)));
     return AddedStructorArgCounts::prefix(1);
   }
   return AddedStructorArgCounts{};
@@ -1625,7 +1627,9 @@
     ASTContext &Context = getContext();
 
     // FIXME: avoid the fake decl
-    QualType T = Context.getPointerType(Context.VoidPtrTy);
+    LangAS AS = CGM.GetGlobalVarAddressSpace(nullptr);
+    QualType Q = Context.getAddrSpaceQualType(Context.VoidPtrTy, AS);
+    QualType T = Context.getPointerType(Q);
     auto *VTTDecl = ImplicitParamDecl::Create(
         Context, /*DC=*/nullptr, MD->getLocation(), &Context.Idents.get("vtt"),
         T, ImplicitParamDecl::CXXVTT);
@@ -1667,10 +1671,14 @@
   if (!NeedsVTTParameter(GlobalDecl(D, Type)))
     return AddedStructorArgs{};
 
-  // Insert the implicit 'vtt' argument as the second argument.
+  // Insert the implicit 'vtt' argument as the second argument. Make sure to
+  // correctly reflect its address space, which can differ from generic on
+  // some targets.
   llvm::Value *VTT =
       CGF.GetVTTParameter(GlobalDecl(D, Type), ForVirtualBase, Delegating);
-  QualType VTTTy = getContext().getPointerType(getContext().VoidPtrTy);
+  LangAS AS = CGM.GetGlobalVarAddressSpace(nullptr);
+  QualType Q = getContext().getAddrSpaceQualType(getContext().VoidPtrTy, AS);
+  QualType VTTTy = getContext().getPointerType(Q);
   return AddedStructorArgs::prefix({{VTT, VTTTy}});
 }
 
diff --git a/clang/test/CodeGenCXX/vtt-address-space.cpp b/clang/test/CodeGenCXX/vtt-address-space.cpp
new file mode 100644
--- /dev/null
+++ b/clang/test/CodeGenCXX/vtt-address-space.cpp
@@ -0,0 +1,30 @@
+// RUN: %clang_cc1 %s -triple=amdgcn-amd-amdhsa -std=c++11 -emit-llvm -o - | FileCheck %s
+// This is temporarily disabled as it requires fixing typeinfo & vptr handling
+// as well; it will be enabled once those fixes are in.
+// XFAIL: *
+
+// This is the sample from the C++ Itanium ABI, p2.6.2.
+namespace Test {
+  class A1 { int i; };
+  class A2 { int i; virtual void f(); };
+  class V1 : public A1, public A2 { int i; };
+  class B1 { int i; };
+  class B2 { int i; };
+  class V2 : public B1, public B2, public virtual V1 { int i; };
+  class V3 { virtual void g(); };
+  class C1 : public virtual V1 { int i; };
+  class C2 : public virtual V3, virtual V2 { int i; };
+  class X1 { int i; };
+  class C3 : public X1 { int i; };
+  class D : public C1, public C2, public C3 { int i;  };
+
+  D d;
+}
+
+// CHECK: @_ZTTN4Test1DE = linkonce_odr unnamed_addr addrspace(1) constant [13 x ptr] [ptr addrspacecast (ptr addrspace(1) getelementptr inbounds ({ [5 x ptr], [7 x ptr], [4 x ptr], [3 x ptr] }, ptr addrspace(1) @_ZTVN4Test1DE, i32 0, inrange i32 0, i32 5) to ptr), ptr addrspacecast (ptr addrspace(1) getelementptr inbounds ({ [3 x ptr], [4 x ptr] }, ptr addrspace(1) @_ZTCN4Test1DE0_NS_2C1E, i32 0, inrange i32 0, i32 3) to ptr), ptr addrspacecast (ptr addrspace(1) getelementptr inbounds ({ [3 x ptr], [4 x ptr] }, ptr addrspace(1) @_ZTCN4Test1DE0_NS_2C1E, i32 0, inrange i32 1, i32 3) to ptr), ptr addrspacecast (ptr addrspace(1) getelementptr inbounds ({ [7 x ptr], [3 x ptr], [4 x ptr] }, ptr addrspace(1) @_ZTCN4Test1DE16_NS_2C2E, i32 0, inrange i32 0, i32 6) to ptr), ptr addrspacecast (ptr addrspace(1) getelementptr inbounds ({ [7 x ptr], [3 x ptr], [4 x ptr] }, ptr addrspace(1) @_ZTCN4Test1DE16_NS_2C2E, i32 0, inrange i32 0, i32 6) to ptr), ptr addrspacecast (ptr addrspace(1) getelementptr inbounds ({ [7 x ptr], [3 x ptr], [4 x ptr] }, ptr addrspace(1) @_ZTCN4Test1DE16_NS_2C2E, i32 0, inrange i32 1, i32 3) to ptr), ptr addrspacecast (ptr addrspace(1) getelementptr inbounds ({ [7 x ptr], [3 x ptr], [4 x ptr] }, ptr addrspace(1) @_ZTCN4Test1DE16_NS_2C2E, i32 0, inrange i32 2, i32 3) to ptr), ptr addrspacecast (ptr addrspace(1) getelementptr inbounds ({ [5 x ptr], [7 x ptr], [4 x ptr], [3 x ptr] }, ptr addrspace(1) @_ZTVN4Test1DE, i32 0, inrange i32 2, i32 3) to ptr), ptr addrspacecast (ptr addrspace(1) getelementptr inbounds ({ [5 x ptr], [7 x ptr], [4 x ptr], [3 x ptr] }, ptr addrspace(1) @_ZTVN4Test1DE, i32 0, inrange i32 1, i32 6) to ptr), ptr addrspacecast (ptr addrspace(1) getelementptr inbounds ({ [5 x ptr], [7 x ptr], [4 x ptr], [3 x ptr] }, ptr addrspace(1) @_ZTVN4Test1DE, i32 0, inrange i32 1, i32 6) to ptr), ptr addrspacecast (ptr addrspace(1) getelementptr inbounds ({ [5 x ptr], [7 x ptr], [4 x ptr], [3 x ptr] }, ptr addrspace(1) @_ZTVN4Test1DE, i32 0, inrange i32 3, i32 3) to ptr), ptr addrspacecast (ptr addrspace(1) getelementptr inbounds ({ [3 x ptr], [4 x ptr] }, ptr addrspace(1) @_ZTCN4Test1DE64_NS_2V2E, i32 0, inrange i32 0, i32 3) to ptr), ptr addrspacecast (ptr addrspace(1) getelementptr inbounds ({ [3 x ptr], [4 x ptr] }, ptr addrspace(1) @_ZTCN4Test1DE64_NS_2V2E, i32 0, inrange i32 1, i32 3) to ptr)], comdat, align 8
+// CHECK: call void @_ZN4Test2V2C2Ev(ptr noundef nonnull align 8 dereferenceable(20) %2, ptr addrspace(1) noundef getelementptr inbounds ([13 x ptr], ptr addrspace(1) @_ZTTN4Test1DE, i64 0, i64 11))
+// CHECK: call void @_ZN4Test2C1C2Ev(ptr noundef nonnull align 8 dereferenceable(12) %this1, ptr addrspace(1) noundef getelementptr inbounds ([13 x ptr], ptr addrspace(1) @_ZTTN4Test1DE, i64 0, i64 1))
+// CHECK: call void @_ZN4Test2C2C2Ev(ptr noundef nonnull align 8 dereferenceable(12) %3, ptr addrspace(1) noundef getelementptr inbounds ([13 x ptr], ptr addrspace(1) @_ZTTN4Test1DE, i64 0, i64 3))
+// CHECK-NEXT: define linkonce_odr void @_ZN4Test2V2C2Ev(ptr noundef nonnull align 8 dereferenceable(20) %this, ptr addrspace(1) noundef %vtt)
+// CHECK-NEXT: define linkonce_odr void @_ZN4Test2C1C2Ev(ptr noundef nonnull align 8 dereferenceable(12) %this, ptr addrspace(1) noundef %vtt)
+// CHECK-NEXT: define linkonce_odr void @_ZN4Test2C2C2Ev(ptr noundef nonnull align 8 dereferenceable(12) %this, ptr addrspace(1) noundef %vtt)