Index: lib/Sema/SemaOverload.cpp
===================================================================
--- lib/Sema/SemaOverload.cpp
+++ lib/Sema/SemaOverload.cpp
@@ -7659,6 +7659,12 @@
     }
   }
 }
+/// Helper function for adjusting address spaces for the pointer or reference
+/// operands of builtin operators depending on the argument.
+static QualType AdjustAddressSpaceForBuiltinOperandType(Sema &S, QualType T,
+                                                        Expr *Arg) {
+  return S.Context.getAddrSpaceQualType(T, Arg->getType().getAddressSpace());
+}
 
 /// Helper function for AddBuiltinOperatorCandidates() that adds
 /// the volatile- and non-volatile-qualified assignment operators for the
@@ -7670,15 +7676,17 @@
   QualType ParamTypes[2];
 
   // T& operator=(T&, T)
-  ParamTypes[0] = S.Context.getLValueReferenceType(T);
+  ParamTypes[0] = S.Context.getLValueReferenceType(
+      AdjustAddressSpaceForBuiltinOperandType(S, T, Args[0]));
   ParamTypes[1] = T;
   S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
                         /*IsAssignmentOperator=*/true);
 
   if (!S.Context.getCanonicalType(T).isVolatileQualified()) {
     // volatile T& operator=(volatile T&, T)
-    ParamTypes[0]
-      = S.Context.getLValueReferenceType(S.Context.getVolatileType(T));
+    ParamTypes[0] = S.Context.getLValueReferenceType(
+        AdjustAddressSpaceForBuiltinOperandType(S, S.Context.getVolatileType(T),
+                                                Args[0]));
     ParamTypes[1] = T;
     S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
                           /*IsAssignmentOperator=*/true);
@@ -8573,8 +8581,9 @@
         ParamTypes[1] = ArithmeticTypes[Right];
 
         // Add this built-in operator as a candidate (VQ is empty).
-        ParamTypes[0] =
-          S.Context.getLValueReferenceType(ArithmeticTypes[Left]);
+        ParamTypes[0] = S.Context.getLValueReferenceType(
+            AdjustAddressSpaceForBuiltinOperandType(S, ArithmeticTypes[Left],
+                                                    Args[0]));
         S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
         if (VisibleTypeConversionsQuals.hasVolatile()) {
           // Add this built-in operator as a candidate (VQ is 'volatile').
Index: test/CodeGenOpenCLCXX/addrspace-operators.cl
===================================================================
--- test/CodeGenOpenCLCXX/addrspace-operators.cl
+++ test/CodeGenOpenCLCXX/addrspace-operators.cl
@@ -0,0 +1,46 @@
+//RUN: %clang_cc1 %s -triple spir -cl-std=c++ -emit-llvm -O0 -o - | FileCheck %s
+
+enum E {
+  a,
+  b,
+};
+
+class C {
+public:
+  void Assign(E e) { me = e; }
+  void OrAssign(E e) { mi |= e; }
+  E me;
+  int mi;
+};
+
+__global E globE;
+//CHECK-LABEL: define spir_func void @_Z3barv()
+void bar() {
+  C c;
+  //CHECK: addrspacecast %class.C* %c to %class.C addrspace(4)*
+  //CHECK: call void @_ZNU3AS41C6AssignE1E(%class.C addrspace(4)* %{{[0-9]+}}, i32 0)
+  c.Assign(a);
+  //CHECK: addrspacecast %class.C* %c to %class.C addrspace(4)*
+  //CHECK: call void @_ZNU3AS41C8OrAssignE1E(%class.C addrspace(4)* %{{[0-9]+}}, i32 0)
+  c.OrAssign(a);
+
+  E e;
+  // CHECK: store i32 1, i32* %e
+  e = b;
+  // CHECK: store i32 0, i32 addrspace(1)* @globE
+  globE = a;
+  // FIXME: Sema fails here because it thinks the types are incompatible.
+  //e = b;
+  //globE = a;
+}
+
+//CHECK: define linkonce_odr void @_ZNU3AS41C6AssignE1E(%class.C addrspace(4)* %this, i32 %e)
+//CHECK: [[E:%[0-9]+]] = load i32, i32* %e.addr
+//CHECK: %me = getelementptr inbounds %class.C, %class.C addrspace(4)* %this1, i32 0, i32 0
+//CHECK: store i32 [[E]], i32 addrspace(4)* %me
+
+//CHECK define linkonce_odr void @_ZNU3AS41C8OrAssignE1E(%class.C addrspace(4)* %this, i32 %e)
+//CHECK: [[E:%[0-9]+]] = load i32, i32* %e.addr
+//CHECK: %mi = getelementptr inbounds %class.C, %class.C addrspace(4)* %this1, i32 0, i32 1
+//CHECK: [[MI:%[0-9]+]] = load i32, i32 addrspace(4)* %mi
+//CHECK: %or = or i32 [[MI]], [[E]]