Index: clang/include/clang/Basic/TargetInfo.h
===================================================================
--- clang/include/clang/Basic/TargetInfo.h
+++ clang/include/clang/Basic/TargetInfo.h
@@ -1092,6 +1092,13 @@
   /// either; the entire thing is pretty badly mangled.
   virtual bool hasProtectedVisibility() const { return true; }
 
+  /// Does this target aim for semantic compatibility with
+  /// Microsoft C++ code using dllimport/export attributes?
+  virtual bool shouldDLLImportComdatSymbols() const {
+    return getTriple().isWindowsMSVCEnvironment() ||
+           getTriple().isWindowsItaniumEnvironment() || getTriple().isPS4CPU();
+  }
+
   /// An optional hook that targets can implement to perform semantic
   /// checking on attribute((section("foo"))) specifiers.
   ///
Index: clang/lib/Sema/SemaDecl.cpp
===================================================================
--- clang/lib/Sema/SemaDecl.cpp
+++ clang/lib/Sema/SemaDecl.cpp
@@ -6510,9 +6510,7 @@
   // special MSVC extension: in the last case, the declaration is treated as if
   // it were marked dllexport.
   bool IsInline = false, IsStaticDataMember = false, IsQualifiedFriend = false;
-  bool IsMicrosoft =
-      S.Context.getTargetInfo().getCXXABI().isMicrosoft() ||
-      S.Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment();
+  bool IsMicrosoft = S.Context.getTargetInfo().shouldDLLImportComdatSymbols();
   if (const auto *VD = dyn_cast<VarDecl>(NewDecl)) {
     // Ignore static data because out-of-line definitions are diagnosed
     // separately.
Index: clang/lib/Sema/SemaDeclAttr.cpp
===================================================================
--- clang/lib/Sema/SemaDeclAttr.cpp
+++ clang/lib/Sema/SemaDeclAttr.cpp
@@ -6775,16 +6775,14 @@
 
 static void handleDLLAttr(Sema &S, Decl *D, const ParsedAttr &A) {
   if (isa<ClassTemplatePartialSpecializationDecl>(D) &&
-      (S.Context.getTargetInfo().getCXXABI().isMicrosoft() ||
-       S.Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment())) {
+      (S.Context.getTargetInfo().shouldDLLImportComdatSymbols())) {
     S.Diag(A.getRange().getBegin(), diag::warn_attribute_ignored) << A;
     return;
   }
 
   if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
     if (FD->isInlined() && A.getKind() == ParsedAttr::AT_DLLImport &&
-        !(S.Context.getTargetInfo().getCXXABI().isMicrosoft() ||
-          S.Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment())) {
+        !(S.Context.getTargetInfo().shouldDLLImportComdatSymbols())) {
       // MinGW doesn't allow dllimport on inline functions.
       S.Diag(A.getRange().getBegin(), diag::warn_attribute_ignored_on_inline)
           << A;
@@ -6793,8 +6791,7 @@
   }
 
   if (const auto *MD = dyn_cast<CXXMethodDecl>(D)) {
-    if ((S.Context.getTargetInfo().getCXXABI().isMicrosoft() ||
-         S.Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment()) &&
+    if ((S.Context.getTargetInfo().shouldDLLImportComdatSymbols()) &&
         MD->getParent()->isLambda()) {
       S.Diag(A.getRange().getBegin(), diag::err_attribute_dll_lambda) << A;
       return;
Index: clang/lib/Sema/SemaDeclCXX.cpp
===================================================================
--- clang/lib/Sema/SemaDeclCXX.cpp
+++ clang/lib/Sema/SemaDeclCXX.cpp
@@ -6082,8 +6082,7 @@
   Attr *ClassAttr = getDLLAttr(Class);
 
   // MSVC inherits DLL attributes to partial class template specializations.
-  if ((Context.getTargetInfo().getCXXABI().isMicrosoft() || 
-       Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment()) && !ClassAttr) {
+  if (Context.getTargetInfo().shouldDLLImportComdatSymbols() && !ClassAttr) {
     if (auto *Spec = dyn_cast<ClassTemplatePartialSpecializationDecl>(Class)) {
       if (Attr *TemplateAttr =
               getDLLAttr(Spec->getSpecializedTemplate()->getTemplatedDecl())) {
@@ -6103,8 +6102,7 @@
     return;
   }
 
-  if ((Context.getTargetInfo().getCXXABI().isMicrosoft() || 
-       Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment()) &&
+  if (Context.getTargetInfo().shouldDLLImportComdatSymbols() &&
       !ClassAttr->isInherited()) {
     // Diagnose dll attributes on members of class with dll attribute.
     for (Decl *Member : Class->decls()) {
@@ -6169,8 +6167,7 @@
       if (MD->isInlined()) {
         // MinGW does not import or export inline methods. But do it for
         // template instantiations.
-        if (!Context.getTargetInfo().getCXXABI().isMicrosoft() &&
-            !Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment() &&
+        if (!Context.getTargetInfo().shouldDLLImportComdatSymbols() &&
             TSK != TSK_ExplicitInstantiationDeclaration &&
             TSK != TSK_ExplicitInstantiationDefinition)
           continue;
Index: clang/lib/Sema/SemaTemplate.cpp
===================================================================
--- clang/lib/Sema/SemaTemplate.cpp
+++ clang/lib/Sema/SemaTemplate.cpp
@@ -9759,8 +9759,8 @@
       Def->setTemplateSpecializationKind(TSK);
 
       if (!getDLLAttr(Def) && getDLLAttr(Specialization) &&
-          (Context.getTargetInfo().getCXXABI().isMicrosoft() ||
-           Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment())) {
+          (Context.getTargetInfo().shouldDLLImportComdatSymbols() &&
+           !Context.getTargetInfo().getTriple().isPS4CPU())) {
         // In the MS ABI, an explicit instantiation definition can add a dll
         // attribute to a template with a previous instantiation declaration.
         // MinGW doesn't allow this.
@@ -9777,8 +9777,8 @@
     bool NewlyDLLExported =
         !PreviouslyDLLExported && Specialization->hasAttr<DLLExportAttr>();
     if (Old_TSK == TSK_ImplicitInstantiation && NewlyDLLExported &&
-        (Context.getTargetInfo().getCXXABI().isMicrosoft() ||
-         Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment())) {
+        (Context.getTargetInfo().shouldDLLImportComdatSymbols() &&
+         !Context.getTargetInfo().getTriple().isPS4CPU())) {
       // In the MS ABI, an explicit instantiation definition can add a dll
       // attribute to a template with a previous implicit instantiation.
       // MinGW doesn't allow this. We limit clang to only adding dllexport, to
Index: clang/test/CodeGenCXX/dllexport-vtable-thunks.cpp
===================================================================
--- clang/test/CodeGenCXX/dllexport-vtable-thunks.cpp
+++ clang/test/CodeGenCXX/dllexport-vtable-thunks.cpp
@@ -1,5 +1,6 @@
-// RUN: %clang_cc1 -triple x86_64-windows-gnu -fdeclspec -emit-llvm -o - %s | FileCheck %s
-// RUN: %clang_cc1 -triple x86_64-windows-itanium -fdeclspec -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple x86_64-windows-gnu     -fdeclspec -emit-llvm -o - %s | FileCheck %s -DDSO_ATTRS="dso_local dllexport"
+// RUN: %clang_cc1 -triple x86_64-windows-itanium -fdeclspec -emit-llvm -o - %s | FileCheck %s -DDSO_ATTRS="dso_local dllexport"
+// RUN: %clang_cc1 -triple x86_64-scei-ps4        -fdeclspec -emit-llvm -o - %s | FileCheck %s -DDSO_ATTRS=dllexport
 
 struct __declspec(dllexport) A {
   virtual void m();
@@ -11,7 +12,7 @@
   virtual void m();
 };
 void C::m() {}
-// CHECK: define dso_local dllexport void @_ZThn8_N1C1mEv
+// CHECK: define [[DSO_ATTRS]] void @_ZThn8_N1C1mEv
 
 struct Base {
   virtual void m();
@@ -20,4 +21,4 @@
   virtual void m();
 };
 void Derived::m() {}
-// CHECK: define dso_local dllexport void @_ZTv0_n24_N7Derived1mEv
+// CHECK: define [[DSO_ATTRS]] void @_ZTv0_n24_N7Derived1mEv
Index: clang/test/CodeGenCXX/windows-implicit-dllexport-template-specialization.cpp
===================================================================
--- clang/test/CodeGenCXX/windows-implicit-dllexport-template-specialization.cpp
+++ clang/test/CodeGenCXX/windows-implicit-dllexport-template-specialization.cpp
@@ -1,5 +1,6 @@
-// RUN: %clang_cc1 -std=c++11 -triple i686-windows -fdeclspec -emit-llvm %s -o - | FileCheck %s -check-prefix CHECK-MS
+// RUN: %clang_cc1 -std=c++11 -triple i686-windows         -fdeclspec -emit-llvm %s -o - | FileCheck %s -check-prefix CHECK-MS
 // RUN: %clang_cc1 -std=c++11 -triple i686-windows-itanium -fdeclspec -emit-llvm %s -o - | FileCheck %s -check-prefix CHECK-IA
+// RUN: %clang_cc1 -std=c++11 -triple x86_64-scei-ps4      -fdeclspec -emit-llvm %s -o - | FileCheck %s -check-prefix CHECK-PS4
 
 template <typename>
 struct s {};
@@ -16,3 +17,5 @@
 // CHECK-IA: dllexport {{.*}} @_ZN1tIcEaSERKS0_
 // CHECK-IA: dllexport {{.*}} @_ZN1sIcEaSERKS0_
 
+// CHECK-PS4-NOT: @_ZN1tIcEaSERKS0_
+// CHECK-PS4-NOT: @_ZN1sIcEaSERKS0_
Index: clang/test/CodeGenCXX/windows-itanium-dllexport.cpp
===================================================================
--- clang/test/CodeGenCXX/windows-itanium-dllexport.cpp
+++ clang/test/CodeGenCXX/windows-itanium-dllexport.cpp
@@ -1,4 +1,5 @@
-// RUN: %clang_cc1 -emit-llvm -triple i686-windows-itanium -fdeclspec %s -o - | FileCheck %s
+// RUN: %clang_cc1 -emit-llvm -triple i686-windows-itanium -fdeclspec %s -o - | FileCheck %s --check-prefixes=CHECK,WI
+// RUN: %clang_cc1 -emit-llvm -triple x86_64-scei-ps4 -fdeclspec %s -o - | FileCheck %s --check-prefixes=CHECK,PS4
 
 #define JOIN2(x, y) x##y
 #define JOIN(x, y) JOIN2(x, y)
@@ -25,14 +26,18 @@
 extern template class c<char>;
 template class __declspec(dllexport) c<char>;
 
-// CHECK: define {{.*}} dllexport {{.*}} @_ZN1cIcEaSERKS0_
-// CHECK: define {{.*}} dllexport {{.*}} @_ZN1cIcE1fEv
+// WI: define {{.*}} dllexport {{.*}} @_ZN1cIcEaSERKS0_
+// WI: define {{.*}} dllexport {{.*}} @_ZN1cIcE1fEv
+// PS4-NOT: @_ZN1cIcEaSERKS0_
+// PS4: define weak_odr void @_ZN1cIcE1fEv
 
 c<double> g;
 template class __declspec(dllexport) c<double>;
 
-// CHECK: define {{.*}} dllexport {{.*}} @_ZN1cIdEaSERKS0_
-// CHECK: define {{.*}} dllexport {{.*}} @_ZN1cIdE1fEv
+// WI: define {{.*}} dllexport {{.*}} @_ZN1cIdEaSERKS0_
+// WI: define {{.*}} dllexport {{.*}} @_ZN1cIdE1fEv
+// PS4-NOT: @_ZN1cIdEaSERKS0_
+// PS4: define weak_odr void @_ZN1cIdE1fEv
 
 template <class T>
 struct outer {
@@ -51,5 +56,6 @@
 USEMEMFUNC(outer<char>, f)
 USEMEMFUNC(outer<char>::inner, f)
 
-// CHECK: declare dllimport {{.*}} @_ZN5outerIcE1fEv
-// CHECK: define {{.*}} @_ZN5outerIcE5inner1fEv
+// CHECK-DAG: declare dllimport {{.*}} @_ZN5outerIcE1fEv
+// WI-DAG: define {{.*}} @_ZN5outerIcE5inner1fEv
+// PS4-DAG: declare {{.*}} @_ZN5outerIcE5inner1fEv
Index: clang/test/Sema/dllimport.c
===================================================================
--- clang/test/Sema/dllimport.c
+++ clang/test/Sema/dllimport.c
@@ -5,6 +5,8 @@
 // RUN: %clang_cc1 -triple aarch64-win32          -fsyntax-only -fms-extensions -verify -std=c99 -DMS %s
 // RUN: %clang_cc1 -triple i686-windows-itanium   -fsyntax-only -fms-extensions -verify -std=c99 -DWI %s
 // RUN: %clang_cc1 -triple x86_64-windows-itanium -fsyntax-only -fms-extensions -verify -std=c11 -DWI %s
+// RUN: %clang_cc1 -triple x86_64-scei-ps4        -fsyntax-only -fms-extensions -verify -std=c11 -DWI %s
+// RUN: %clang_cc1 -triple x86_64-scei-ps4        -fsyntax-only -fms-extensions -verify -std=c99 -DWI %s
 
 // Invalid usage.
 __declspec(dllimport) typedef int typedef1;
Index: clang/test/SemaCXX/dllexport.cpp
===================================================================
--- clang/test/SemaCXX/dllexport.cpp
+++ clang/test/SemaCXX/dllexport.cpp
@@ -4,6 +4,7 @@
 // RUN: %clang_cc1 -triple x86_64-mingw32         -fsyntax-only -fms-extensions -verify -std=c++11 -Wunsupported-dll-base-class-template %s
 // RUN: %clang_cc1 -triple i686-windows-itanium   -fsyntax-only -fms-extensions -verify -std=c++11 -Wunsupported-dll-base-class-template -DWI %s
 // RUN: %clang_cc1 -triple x86_64-windows-itanium -fsyntax-only -fms-extensions -verify -std=c++1y -Wunsupported-dll-base-class-template -DWI %s
+// RUN: %clang_cc1 -triple x86_64-scei-ps4        -fsyntax-only -fdeclspec      -verify -std=c++1y -Wunsupported-dll-base-class-template -DWI %s
 
 // Helper structs to make templates more expressive.
 struct ImplicitInst_Exported {};
Index: clang/test/SemaCXX/dllimport.cpp
===================================================================
--- clang/test/SemaCXX/dllimport.cpp
+++ clang/test/SemaCXX/dllimport.cpp
@@ -5,6 +5,8 @@
 // RUN: %clang_cc1 -triple x86_64-mingw32         -fsyntax-only -fms-extensions -verify -std=c++17 -Wunsupported-dll-base-class-template -DGNU %s
 // RUN: %clang_cc1 -triple i686-windows-itanium   -fsyntax-only -fms-extensions -verify -std=c++11 -Wunsupported-dll-base-class-template -DWI %s
 // RUN: %clang_cc1 -triple x86_64-windows-itanium -fsyntax-only -fms-extensions -verify -std=c++17 -Wunsupported-dll-base-class-template -DWI %s
+// RUN: %clang_cc1 -triple x86_64-scei-ps4        -fsyntax-only -fdeclspec      -verify -std=c++11 -Wunsupported-dll-base-class-template -DWI %s
+// RUN: %clang_cc1 -triple x86_64-scei-ps4        -fsyntax-only -fdeclspec      -verify -std=c++17 -Wunsupported-dll-base-class-template -DWI %s
 
 // Helper structs to make templates more expressive.
 struct ImplicitInst_Imported {};