Index: lib/CodeGen/CGCXXABI.cpp
===================================================================
--- lib/CodeGen/CGCXXABI.cpp
+++ lib/CodeGen/CGCXXABI.cpp
@@ -30,6 +30,9 @@
 }
 
 bool CGCXXABI::canCopyArgument(const CXXRecordDecl *RD) const {
+  // See also Sema::ShouldDeleteSpecialMember. These two functions
+  // should be kept consistent.
+
   // If RD has a non-trivial move or copy constructor, we cannot copy the
   // argument.
   if (RD->hasNonTrivialCopyConstructor() || RD->hasNonTrivialMoveConstructor())
@@ -41,10 +44,7 @@
 
   // We can only copy the argument if there exists at least one trivial,
   // non-deleted copy or move constructor.
-  // FIXME: This assumes that all lazily declared copy and move constructors are
-  // not deleted.  This assumption might not be true in some corner cases.
-  bool CopyDeleted = false;
-  bool MoveDeleted = false;
+  bool CopyOrMoveDeleted = false;
   for (const CXXConstructorDecl *CD : RD->ctors()) {
     if (CD->isCopyConstructor() || CD->isMoveConstructor()) {
       assert(CD->isTrivial());
@@ -52,16 +52,25 @@
       // directly.
       if (!CD->isDeleted())
         return true;
-      if (CD->isCopyConstructor())
-        CopyDeleted = true;
-      else
-        MoveDeleted = true;
+      CopyOrMoveDeleted = true;
     }
   }
+  // If a move constructor or move assignment operator was declared, the
+  // default copy constructors are implicitly deleted, except in one case
+  // related to compatibility with MSVC pre-2015.
+  if (RD->hasUserDeclaredMoveConstructor())
+    return false;
+  if (RD->hasUserDeclaredMoveAssignment()) {
+    const LangOptions &opts = CGM.getLangOpts();
+    bool DeletesOnlyMatchingCopy =
+      opts.MSVCCompat && !opts.isCompatibleWithMSVC(LangOptions::MSVC2015);
+    if (!DeletesOnlyMatchingCopy)
+      return false;
+  }
 
   // If all trivial copy and move constructors are deleted, we cannot copy the
   // argument.
-  return !(CopyDeleted && MoveDeleted);
+  return !CopyOrMoveDeleted;
 }
 
 llvm::Constant *CGCXXABI::GetBogusMemberPointer(QualType T) {
Index: lib/CodeGen/ItaniumCXXABI.cpp
===================================================================
--- lib/CodeGen/ItaniumCXXABI.cpp
+++ lib/CodeGen/ItaniumCXXABI.cpp
@@ -63,11 +63,8 @@
   bool classifyReturnType(CGFunctionInfo &FI) const override;
 
   RecordArgABI getRecordArgABI(const CXXRecordDecl *RD) const override {
-    // Structures with either a non-trivial destructor or a non-trivial
-    // copy constructor are always indirect.
-    // FIXME: Use canCopyArgument() when it is fixed to handle lazily declared
-    // special members.
-    if (RD->hasNonTrivialDestructor() || RD->hasNonTrivialCopyConstructor())
+    // If C++ prohibits us from making a copy, pass by address.
+    if (!canCopyArgument(RD))
       return RAA_Indirect;
     return RAA_Default;
   }
@@ -988,10 +985,8 @@
   if (!RD)
     return false;
 
-  // Return indirectly if we have a non-trivial copy ctor or non-trivial dtor.
-  // FIXME: Use canCopyArgument() when it is fixed to handle lazily declared
-  // special members.
-  if (RD->hasNonTrivialDestructor() || RD->hasNonTrivialCopyConstructor()) {
+  // If C++ prohibits us from making a copy, return by address.
+  if (!canCopyArgument(RD)) {
     auto Align = CGM.getContext().getTypeAlignInChars(FI.getReturnType());
     FI.getReturnInfo() = ABIArgInfo::getIndirect(Align, /*ByVal=*/false);
     return true;
Index: test/CodeGenCXX/uncopyable-args.cpp
===================================================================
--- test/CodeGenCXX/uncopyable-args.cpp
+++ test/CodeGenCXX/uncopyable-args.cpp
@@ -52,12 +52,11 @@
 void bar() {
   foo({});
 }
-// FIXME: The copy ctor is implicitly deleted.
-// CHECK-DISABLED-LABEL: define void @_ZN9move_ctor3barEv()
-// CHECK-DISABLED: call void @_Z{{.*}}C1Ev(
-// CHECK-DISABLED-NOT: call
-// CHECK-DISABLED: call void @_ZN9move_ctor3fooENS_1AE(%"struct.move_ctor::A"* %{{.*}})
-// CHECK-DISABLED-LABEL: declare void @_ZN9move_ctor3fooENS_1AE(%"struct.move_ctor::A"*)
+// CHECK-LABEL: define void @_ZN9move_ctor3barEv()
+// CHECK: call void @_Z{{.*}}C1Ev(
+// CHECK-NOT: call
+// CHECK: call void @_ZN9move_ctor3fooENS_1AE(%"struct.move_ctor::A"* %{{.*}})
+// CHECK-LABEL: declare void @_ZN9move_ctor3fooENS_1AE(%"struct.move_ctor::A"*)
 
 // WIN64-LABEL: declare void @"\01?foo@move_ctor@@YAXUA@1@@Z"(%"struct.move_ctor::A"*)
 }
@@ -73,12 +72,11 @@
 void bar() {
   foo({});
 }
-// FIXME: The copy ctor is deleted.
-// CHECK-DISABLED-LABEL: define void @_ZN11all_deleted3barEv()
-// CHECK-DISABLED: call void @_Z{{.*}}C1Ev(
-// CHECK-DISABLED-NOT: call
-// CHECK-DISABLED: call void @_ZN11all_deleted3fooENS_1AE(%"struct.all_deleted::A"* %{{.*}})
-// CHECK-DISABLED-LABEL: declare void @_ZN11all_deleted3fooENS_1AE(%"struct.all_deleted::A"*)
+// CHECK-LABEL: define void @_ZN11all_deleted3barEv()
+// CHECK: call void @_Z{{.*}}C1Ev(
+// CHECK-NOT: call
+// CHECK: call void @_ZN11all_deleted3fooENS_1AE(%"struct.all_deleted::A"* %{{.*}})
+// CHECK-LABEL: declare void @_ZN11all_deleted3fooENS_1AE(%"struct.all_deleted::A"*)
 
 // WIN64-LABEL: declare void @"\01?foo@all_deleted@@YAXUA@1@@Z"(%"struct.all_deleted::A"*)
 }
@@ -93,12 +91,11 @@
 void bar() {
   foo({});
 }
-// FIXME: The copy and move ctors are implicitly deleted.
-// CHECK-DISABLED-LABEL: define void @_ZN18implicitly_deleted3barEv()
-// CHECK-DISABLED: call void @_Z{{.*}}C1Ev(
-// CHECK-DISABLED-NOT: call
-// CHECK-DISABLED: call void @_ZN18implicitly_deleted3fooENS_1AE(%"struct.implicitly_deleted::A"* %{{.*}})
-// CHECK-DISABLED-LABEL: declare void @_ZN18implicitly_deleted3fooENS_1AE(%"struct.implicitly_deleted::A"*)
+// CHECK-LABEL: define void @_ZN18implicitly_deleted3barEv()
+// CHECK: call void @_Z{{.*}}C1Ev(
+// CHECK-NOT: call
+// CHECK: call void @_ZN18implicitly_deleted3fooENS_1AE(%"struct.implicitly_deleted::A"* %{{.*}})
+// CHECK-LABEL: declare void @_ZN18implicitly_deleted3fooENS_1AE(%"struct.implicitly_deleted::A"*)
 
 // WIN64-LABEL: declare void @"\01?foo@implicitly_deleted@@YAXUA@1@@Z"(%"struct.implicitly_deleted::A"*)
 }
@@ -113,12 +110,11 @@
 void bar() {
   foo({});
 }
-// FIXME: The copy constructor is implicitly deleted.
-// CHECK-DISABLED-LABEL: define void @_ZN11one_deleted3barEv()
-// CHECK-DISABLED: call void @_Z{{.*}}C1Ev(
-// CHECK-DISABLED-NOT: call
-// CHECK-DISABLED: call void @_ZN11one_deleted3fooENS_1AE(%"struct.one_deleted::A"* %{{.*}})
-// CHECK-DISABLED-LABEL: declare void @_ZN11one_deleted3fooENS_1AE(%"struct.one_deleted::A"*)
+// CHECK-LABEL: define void @_ZN11one_deleted3barEv()
+// CHECK: call void @_Z{{.*}}C1Ev(
+// CHECK-NOT: call
+// CHECK: call void @_ZN11one_deleted3fooENS_1AE(%"struct.one_deleted::A"* %{{.*}})
+// CHECK-LABEL: declare void @_ZN11one_deleted3fooENS_1AE(%"struct.one_deleted::A"*)
 
 // WIN64-LABEL: declare void @"\01?foo@one_deleted@@YAXUA@1@@Z"(%"struct.one_deleted::A"*)
 }
@@ -195,12 +191,10 @@
 void bar() {
   foo({});
 }
-// FIXME: This class has a non-trivial copy ctor and a trivial copy ctor.  It's
-// not clear whether we should pass by address or in registers.
-// CHECK-DISABLED-LABEL: define void @_ZN14two_copy_ctors3barEv()
-// CHECK-DISABLED: call void @_Z{{.*}}C1Ev(
-// CHECK-DISABLED: call void @_ZN14two_copy_ctors3fooENS_1BE(%"struct.two_copy_ctors::B"* %{{.*}})
-// CHECK-DISABLED-LABEL: declare void @_ZN14two_copy_ctors3fooENS_1BE(%"struct.two_copy_ctors::B"*)
+// CHECK-LABEL: define void @_ZN14two_copy_ctors3barEv()
+// CHECK: call void @_Z{{.*}}C1Ev(
+// CHECK: call void @_ZN14two_copy_ctors3fooENS_1BE(%"struct.two_copy_ctors::B"* %{{.*}})
+// CHECK-LABEL: declare void @_ZN14two_copy_ctors3fooENS_1BE(%"struct.two_copy_ctors::B"*)
 
 // WIN64-LABEL: declare void @"\01?foo@two_copy_ctors@@YAXUB@1@@Z"(%"struct.two_copy_ctors::B"*)
 }