diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 75e78bf..9f077c9 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -7175,6 +7175,9 @@ def err_opencl_return_value_with_address_space : Error<
   "return value cannot be qualified with address space">;
 def err_opencl_constant_no_init : Error<
   "variable in constant address space must be initialized">;
+def err_atomic_init_constant : Error <
+ "atomic variable can only be assigned to a compile time constant"
+ " in the declaration statement in the program scope">;
 } // end of sema category
 
 let CategoryName = "OpenMP Issue" in {
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 76e3612..b403e53 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -9489,6 +9489,20 @@ ExprResult Sema::CreateBuiltinBinOp(SourceLocation OpLoc,
       return ExprError();
   }
 
+  if (getLangOpts().OpenCL) {
+    // OpenCLC v2.0 s6.13.11.1 allows atomic variables to be initialized by
+    // the ATOMIC_VAR_INIT macro.
+    if (LHSExpr->getType()->isAtomicType() ||
+        RHSExpr->getType()->isAtomicType()) {
+      SourceRange SR(LHSExpr->getLocStart(), RHSExpr->getLocEnd());
+      if (BO_Assign == Opc)
+        Diag(OpLoc, diag::err_atomic_init_constant) << SR;
+      else
+        ResultTy = InvalidOperands(OpLoc, LHS, RHS);
+      return ExprError();
+    }
+  }
+
   switch (Opc) {
   case BO_Assign:
     ResultTy = CheckAssignmentOperands(LHS.get(), RHS, OpLoc, QualType());
@@ -9959,6 +9973,14 @@ ExprResult Sema::CreateBuiltinUnaryOp(SourceLocation OpLoc,
   ExprValueKind VK = VK_RValue;
   ExprObjectKind OK = OK_Ordinary;
   QualType resultType;
+  if (getLangOpts().OpenCL) {
+    // The only legal unary operation for atomics is '&'.
+    if (Opc != UO_AddrOf && InputExpr->getType()->isAtomicType()) {
+      return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr)
+                       << InputExpr->getType()
+                       << Input.get()->getSourceRange());
+    }
+  }
   switch (Opc) {
   case UO_PreInc:
   case UO_PreDec:
diff --git a/test/Parser/opencl-atomics-cl20.cl b/test/Parser/opencl-atomics-cl20.cl
index d5cecd1..4ba699b1 100644
--- a/test/Parser/opencl-atomics-cl20.cl
+++ b/test/Parser/opencl-atomics-cl20.cl
@@ -31,3 +31,16 @@ void atomic_types_test() {
 // expected-error@-16 {{use of undeclared identifier 'atomic_size_t'}}
 // expected-error@-16 {{use of undeclared identifier 'atomic_ptrdiff_t'}}
 #endif
+
+#ifdef CL20
+void foo(atomic_int * ptr) {}
+void atomic_ops_test() {
+  atomic_int i;
+  foo(&i);
+// OpenCL v2.0 s6.13.11.8, arithemtic operation are not permitted on atomic types.
+  i++; // expected-error {{invalid argument type 'atomic_int' (aka '_Atomic(int)') to unary expression}}
+  i = 1; // expected-error {{atomic variable can only be assigned to a compile time constant in the declaration statement in the program scope}}
+  i += 1; // expected-error {{invalid operands to binary expression ('atomic_int' (aka '_Atomic(int)') and 'int')}}
+  i = i + i; // expected-error {{invalid operands to binary expression ('atomic_int' (aka '_Atomic(int)') and 'atomic_int')}}
+}
+#endif