Index: clang/lib/CodeGen/CGClass.cpp
===================================================================
--- clang/lib/CodeGen/CGClass.cpp
+++ clang/lib/CodeGen/CGClass.cpp
@@ -914,6 +914,8 @@
     }
 
     void addMemcpyableField(FieldDecl *F) {
+      if (F->isZeroSize(CGF.getContext()))
+        return;
       if (!FirstField)
         addInitialField(F);
       else
Index: clang/test/CodeGenCXX/no-unique-address-2.cpp
===================================================================
--- /dev/null
+++ clang/test/CodeGenCXX/no-unique-address-2.cpp
@@ -0,0 +1,26 @@
+// RUN: %clang_cc1 -std=c++2a %s -emit-llvm -o - -triple x86_64-linux-gnu | FileCheck %s
+
+struct TriviallyCopyable {};
+
+struct NonTriviallyCopyable {
+  NonTriviallyCopyable() = default;
+  NonTriviallyCopyable(const NonTriviallyCopyable&) = default;
+  NonTriviallyCopyable(NonTriviallyCopyable &&) {}
+};
+
+struct Foo {
+  int i;
+  [[no_unique_address]] TriviallyCopyable m;
+  [[no_unique_address]] NonTriviallyCopyable n;
+};
+
+void call()
+{
+  Foo foo;
+  Foo foo2(static_cast<Foo&&>(foo));
+}
+
+// The memcpy call should copy exact 4 bytes for member 'int i'
+// CHECK: define {{.*}} void @_ZN3FooC2EOS_
+// CHECK:  call void @llvm.memcpy.p0i8.p0i8.i64(i8* {{.+}}, i8* {{.+}}, i64 4, i1 false)
+// CHECK:  call void @_ZN20NonTriviallyCopyableC2EOS_