diff --git a/src/libcoreint/interpreter.c b/src/libcoreint/interpreter.c
index ad5c16b7c..a5a7c9ac6 100644
--- a/src/libcoreint/interpreter.c
+++ b/src/libcoreint/interpreter.c
@@ -361,35 +361,18 @@ run_int (void)
                                                          is_strict,
                                                          false);
 
-  switch ((ecma_completion_type_t) completion.type)
+  if (ecma_is_completion_value_exit (completion))
   {
-    case ECMA_COMPLETION_TYPE_NORMAL:
-    case ECMA_COMPLETION_TYPE_META:
-    {
-      JERRY_UNREACHABLE ();
-    }
-    case ECMA_COMPLETION_TYPE_EXIT:
-    {
-      ecma_deref_object (glob_obj_p);
-      ecma_deref_object (lex_env_p);
-      ecma_finalize ();
-      ecma_gc_run (ECMA_GC_GEN_COUNT - 1);
+    ecma_deref_object (glob_obj_p);
+    ecma_deref_object (lex_env_p);
+    ecma_finalize ();
+    ecma_gc_run (ECMA_GC_GEN_COUNT - 1);
 
-      return ecma_is_value_true (ecma_get_completion_value_value (completion));
-    }
-    case ECMA_COMPLETION_TYPE_BREAK:
-    case ECMA_COMPLETION_TYPE_CONTINUE:
-    case ECMA_COMPLETION_TYPE_RETURN:
-    {
-      /* SyntaxError should be treated as an early error */
-      JERRY_UNREACHABLE ();
-    }
-#ifdef CONFIG_ECMA_EXCEPTION_SUPPORT
-    case ECMA_COMPLETION_TYPE_THROW:
-    {
-      jerry_exit (ERR_UNHANDLED_EXCEPTION);
-    }
-#endif /* CONFIG_ECMA_EXCEPTION_SUPPORT */
+    return ecma_is_value_true (ecma_get_completion_value_value (completion));
+  }
+  else if (ecma_is_completion_value_throw (completion))
+  {
+    jerry_exit (ERR_UNHANDLED_EXCEPTION);
   }
 
   JERRY_UNREACHABLE ();
@@ -436,8 +419,8 @@ run_int_loop (int_data_t *int_data)
     }
     while (ecma_is_completion_value_normal (completion));
 
-    if (completion.type == ECMA_COMPLETION_TYPE_BREAK
-        || completion.type == ECMA_COMPLETION_TYPE_CONTINUE)
+    if (ecma_is_completion_value_break (completion)
+        || ecma_is_completion_value_continue (completion))
     {
       JERRY_UNIMPLEMENTED ("break and continue on labels are not supported.");
 
diff --git a/src/libcoreint/opcodes-native-call.c b/src/libcoreint/opcodes-native-call.c
index 817914328..92b28f8d5 100644
--- a/src/libcoreint/opcodes-native-call.c
+++ b/src/libcoreint/opcodes-native-call.c
@@ -45,7 +45,7 @@ opfunc_native_call (opcode_t opdata, /**< operation data */
 
   ecma_value_t arg_values[args_number + 1 /* length of array should not be zero */];
 
-  ecma_completion_value_t ret_value;
+  ecma_completion_value_t ret_value = 0;
 
   ecma_length_t args_read;
   ecma_completion_value_t get_arg_completion = fill_varg_list (int_data,
diff --git a/src/libcoreint/opcodes.c b/src/libcoreint/opcodes.c
index d4225673f..66c0d8d71 100644
--- a/src/libcoreint/opcodes.c
+++ b/src/libcoreint/opcodes.c
@@ -89,7 +89,7 @@ opfunc_assignment (opcode_t opdata, /**< operation data */
 
   int_data->pos++;
 
-  ecma_completion_value_t get_value_completion;
+  ecma_completion_value_t get_value_completion = 0;
 
   switch (type_value_right)
   {
diff --git a/src/libecmaobjects/ecma-globals.h b/src/libecmaobjects/ecma-globals.h
index 1236008c4..68ce93fb7 100644
--- a/src/libecmaobjects/ecma-globals.h
+++ b/src/libecmaobjects/ecma-globals.h
@@ -141,32 +141,43 @@ typedef uint16_t ecma_value_t;
  * Description of a block completion value
  *
  * See also: ECMA-262 v5, 8.9.
+ *
+ *                                               value (16)
+ * Bit-field structure: type (8) | padding (8) <
+ *                                               label_desc_cp (16)
  */
-typedef struct
-{
-  /** Type (ecma_completion_type_t) */
-  uint8_t type;
+typedef uint32_t ecma_completion_value_t;
 
-  /** Just padding for the structure */
-  uint8_t padding;
+/**
+ * Type (ecma_completion_type_t)
+ */
+#define ECMA_COMPLETION_VALUE_TYPE_POS (0)
+#define ECMA_COMPLETION_VALUE_TYPE_WIDTH (8)
 
-  union
-  {
-    /**
-      * Value
-      *
-      * Used for normal, return, throw and exit completion types.
-      */
-    ecma_value_t value;
+/**
+ * Padding (1 byte)
+ */
+#define ECMA_COMPLETION_VALUE_PADDING_WIDTH (8)
 
-    /**
-      * Label
-      *
-      * Used for break and continue completion types.
-      */
-    uint16_t label_desc_cp;
-  } u;
-} ecma_completion_value_t;
+/**
+ * Value
+ *
+ * Used for normal, return, throw and exit completion types.
+ */
+#define ECMA_COMPLETION_VALUE_VALUE_POS (ECMA_COMPLETION_VALUE_TYPE_POS + \
+                                         ECMA_COMPLETION_VALUE_TYPE_WIDTH + \
+                                         ECMA_COMPLETION_VALUE_PADDING_WIDTH)
+#define ECMA_COMPLETION_VALUE_VALUE_WIDTH (ECMA_VALUE_SIZE)
+
+/**
+ * Label
+ *
+ * Used for break and continue completion types.
+ */
+#define ECMA_COMPLETION_VALUE_LABEL_DESC_CP_POS (ECMA_COMPLETION_VALUE_TYPE_POS + \
+                                                 ECMA_COMPLETION_VALUE_TYPE_WIDTH + \
+                                                 ECMA_COMPLETION_VALUE_PADDING_WIDTH)
+#define ECMA_COMPLETION_VALUE_LABEL_DESC_CP_WIDTH (ECMA_POINTER_FIELD_WIDTH)
 
 /**
  * Label
diff --git a/src/libecmaobjects/ecma-helpers-value.c b/src/libecmaobjects/ecma-helpers-value.c
index ef4c91d1d..fb9fb822f 100644
--- a/src/libecmaobjects/ecma-helpers-value.c
+++ b/src/libecmaobjects/ecma-helpers-value.c
@@ -34,7 +34,7 @@ JERRY_STATIC_ASSERT (sizeof (ecma_value_t) * JERRY_BITSINBYTE == ECMA_VALUE_SIZE
  *
  * @return type field
  */
-static ecma_type_t
+static ecma_type_t __attribute_const__
 ecma_get_value_type_field (ecma_value_t value) /**< ecma-value */
 {
   return jrt_extract_bit_field (value,
@@ -47,7 +47,7 @@ ecma_get_value_type_field (ecma_value_t value) /**< ecma-value */
  *
  * @return value field
  */
-static uintptr_t
+static uintptr_t __attribute_const__
 ecma_get_value_value_field (ecma_value_t value) /**< ecma-value */
 {
   return (uintptr_t) jrt_extract_bit_field (value,
@@ -60,7 +60,7 @@ ecma_get_value_value_field (ecma_value_t value) /**< ecma-value */
  *
  * @return ecma-value with updated field
  */
-static ecma_value_t
+static ecma_value_t __attribute_const__
 ecma_set_value_type_field (ecma_value_t value, /**< ecma-value to set field in */
                            ecma_type_t type_field) /**< new field value */
 {
@@ -75,7 +75,7 @@ ecma_set_value_type_field (ecma_value_t value, /**< ecma-value to set field in *
  *
  * @return ecma-value with updated field
  */
-static ecma_value_t
+static ecma_value_t __attribute_const__
 ecma_set_value_value_field (ecma_value_t value, /**< ecma-value to set field in */
                             uintptr_t value_field) /**< new field value */
 {
@@ -91,7 +91,7 @@ ecma_set_value_value_field (ecma_value_t value, /**< ecma-value to set field in
  * @return true - if the value contains implementation-defined empty simple value,
  *         false - otherwise.
  */
-bool
+bool __attribute_const__
 ecma_is_value_empty (ecma_value_t value) /**< ecma-value */
 {
   return (ecma_get_value_type_field (value) == ECMA_TYPE_SIMPLE
@@ -104,7 +104,7 @@ ecma_is_value_empty (ecma_value_t value) /**< ecma-value */
  * @return true - if the value contains ecma-undefined simple value,
  *         false - otherwise.
  */
-bool
+bool __attribute_const__
 ecma_is_value_undefined (ecma_value_t value) /**< ecma-value */
 {
   return (ecma_get_value_type_field (value) == ECMA_TYPE_SIMPLE
@@ -117,7 +117,7 @@ ecma_is_value_undefined (ecma_value_t value) /**< ecma-value */
  * @return true - if the value contains ecma-null simple value,
  *         false - otherwise.
  */
-bool
+bool __attribute_const__
 ecma_is_value_null (ecma_value_t value) /**< ecma-value */
 {
   return (ecma_get_value_type_field (value) == ECMA_TYPE_SIMPLE
@@ -130,7 +130,7 @@ ecma_is_value_null (ecma_value_t value) /**< ecma-value */
  * @return true - if the value contains ecma-true or ecma-false simple values,
  *         false - otherwise.
  */
-bool
+bool __attribute_const__
 ecma_is_value_boolean (ecma_value_t value) /**< ecma-value */
 {
   return (ecma_get_value_type_field (value) == ECMA_TYPE_SIMPLE
@@ -147,7 +147,7 @@ ecma_is_value_boolean (ecma_value_t value) /**< ecma-value */
  * @return true - if the value contains ecma-true simple value,
  *         false - otherwise.
  */
-bool
+bool __attribute_const__
 ecma_is_value_true (ecma_value_t value) /**< ecma-value */
 {
   return (ecma_get_value_type_field (value) == ECMA_TYPE_SIMPLE
@@ -160,7 +160,7 @@ ecma_is_value_true (ecma_value_t value) /**< ecma-value */
  * @return true - if the value contains ecma-number value,
  *         false - otherwise.
  */
-bool
+bool __attribute_const__
 ecma_is_value_number (ecma_value_t value) /**< ecma-value */
 {
   return (ecma_get_value_type_field (value) == ECMA_TYPE_NUMBER);
@@ -172,7 +172,7 @@ ecma_is_value_number (ecma_value_t value) /**< ecma-value */
  * @return true - if the value contains ecma-string value,
  *         false - otherwise.
  */
-bool
+bool __attribute_const__
 ecma_is_value_string (ecma_value_t value) /**< ecma-value */
 {
   return (ecma_get_value_type_field (value) == ECMA_TYPE_STRING);
@@ -184,7 +184,7 @@ ecma_is_value_string (ecma_value_t value) /**< ecma-value */
  * @return true - if the value contains object value,
  *         false - otherwise.
  */
-bool
+bool __attribute_const__
 ecma_is_value_object (ecma_value_t value) /**< ecma-value */
 {
   return (ecma_get_value_type_field (value) == ECMA_TYPE_OBJECT);
@@ -208,7 +208,7 @@ ecma_check_value_type_is_spec_defined (ecma_value_t value) /**< ecma-value */
 /**
  * Simple value constructor
  */
-ecma_value_t
+ecma_value_t __attribute_const__
 ecma_make_simple_value (ecma_simple_value_t value) /**< simple value */
 {
   ecma_value_t ret_value = 0;
@@ -222,7 +222,7 @@ ecma_make_simple_value (ecma_simple_value_t value) /**< simple value */
 /**
  * Number value constructor
  */
-ecma_value_t
+ecma_value_t __attribute_const__
 ecma_make_number_value (ecma_number_t* num_p) /**< number to reference in value */
 {
   JERRY_ASSERT(num_p != NULL);
@@ -241,7 +241,7 @@ ecma_make_number_value (ecma_number_t* num_p) /**< number to reference in value
 /**
  * String value constructor
  */
-ecma_value_t
+ecma_value_t __attribute_const__
 ecma_make_string_value (ecma_string_t* ecma_string_p) /**< string to reference in value */
 {
   JERRY_ASSERT(ecma_string_p != NULL);
@@ -260,7 +260,7 @@ ecma_make_string_value (ecma_string_t* ecma_string_p) /**< string to reference i
 /**
  * object value constructor
  */
-ecma_value_t
+ecma_value_t __attribute_const__
 ecma_make_object_value (ecma_object_t* object_p) /**< object to reference in value */
 {
   JERRY_ASSERT(object_p != NULL);
@@ -431,12 +431,103 @@ ecma_free_value (ecma_value_t value, /**< value description */
   }
 } /* ecma_free_value */
 
+/**
+ * Get type field of completion value
+ *
+ * @return type field
+ */
+static ecma_completion_type_t __attribute_const__
+ecma_get_completion_value_type_field (ecma_completion_value_t completion_value) /**< completion value */
+{
+  return jrt_extract_bit_field (completion_value,
+                                ECMA_COMPLETION_VALUE_TYPE_POS,
+                                ECMA_COMPLETION_VALUE_TYPE_WIDTH);
+} /* ecma_get_completion_value_type_field */
+
+/**
+ * Get value field of completion value
+ *
+ * @return value field
+ */
+static ecma_value_t __attribute_const__
+ecma_get_completion_value_value_field (ecma_completion_value_t completion_value) /**< completion value */
+{
+  return (ecma_value_t) jrt_extract_bit_field (completion_value,
+                                               ECMA_COMPLETION_VALUE_VALUE_POS,
+                                               ECMA_COMPLETION_VALUE_VALUE_WIDTH);
+} /* ecma_get_completion_value_value_field */
+
+/**
+ * Get pointer to label descriptor from completion value
+ *
+ * @return pointer to label descriptor
+ */
+static ecma_label_descriptor_t* __attribute_const__
+ecma_get_completion_value_label_descriptor (ecma_completion_value_t completion_value) /**< completion value */
+{
+  return ECMA_GET_NON_NULL_POINTER ((uintptr_t) jrt_extract_bit_field (completion_value,
+                                                                       ECMA_COMPLETION_VALUE_LABEL_DESC_CP_POS,
+                                                                       ECMA_COMPLETION_VALUE_LABEL_DESC_CP_WIDTH));
+} /* ecma_get_completion_value_label_descriptor */
+
+/**
+ * Set type field of completion value
+ *
+ * @return completion value with updated field
+ */
+static ecma_completion_value_t __attribute_const__
+ecma_set_completion_value_type_field (ecma_completion_value_t completion_value, /**< completion value
+                                                                                 * to set field in */
+                                      ecma_completion_type_t type_field) /**< new field value */
+{
+  return (ecma_completion_value_t) jrt_set_bit_field_value (completion_value,
+                                                            type_field,
+                                                            ECMA_COMPLETION_VALUE_TYPE_POS,
+                                                            ECMA_COMPLETION_VALUE_TYPE_WIDTH);
+} /* ecma_set_completion_value_type_field */
+
+/**
+ * Set value field of completion value
+ *
+ * @return completion value with updated field
+ */
+static ecma_completion_value_t __attribute_const__
+ecma_set_completion_value_value_field (ecma_completion_value_t completion_value, /**< completion value
+                                                                                  * to set field in */
+                                       ecma_value_t value_field) /**< new field value */
+{
+  return (ecma_completion_value_t) jrt_set_bit_field_value (completion_value,
+                                                            value_field,
+                                                            ECMA_COMPLETION_VALUE_VALUE_POS,
+                                                            ECMA_COMPLETION_VALUE_VALUE_WIDTH);
+} /* ecma_set_completion_value_value_field */
+
+/**
+ * Set label descriptor of completion value
+ *
+ * @return completion value with updated field
+ */
+static ecma_completion_value_t __attribute_const__
+ecma_set_completion_value_label_descriptor (ecma_completion_value_t completion_value, /**< completion value
+                                                                                       * to set field in */
+                                            ecma_label_descriptor_t* label_desc_p) /**< pointer to the
+                                                                                    *   label descriptor */
+{
+  uintptr_t label_desc_cp;
+  ECMA_SET_NON_NULL_POINTER (label_desc_cp, label_desc_p);
+
+  return (ecma_completion_value_t) jrt_set_bit_field_value (completion_value,
+                                                            label_desc_cp,
+                                                            ECMA_COMPLETION_VALUE_LABEL_DESC_CP_POS,
+                                                            ECMA_COMPLETION_VALUE_LABEL_DESC_CP_WIDTH);
+} /* ecma_set_completion_value_label_descriptor */
+
 /**
  * Normal, throw, return, exit and meta completion values constructor
  *
  * @return completion value
  */
-ecma_completion_value_t
+ecma_completion_value_t __attribute_const__
 ecma_make_completion_value (ecma_completion_type_t type, /**< type */
                             ecma_value_t value) /**< value */
 {
@@ -451,19 +542,14 @@ ecma_make_completion_value (ecma_completion_type_t type, /**< type */
 
   JERRY_ASSERT (is_type_ok);
 
-  union
-  {
-    ecma_completion_value_t value;
-    uint32_t uint32;
-  } u_cv;
+  ecma_completion_value_t completion_value = 0;
 
-  u_cv.uint32 = ((uint32_t) type | (uint32_t) (value << 16u));
+  completion_value = ecma_set_completion_value_type_field (completion_value,
+                                                           type);
+  completion_value = ecma_set_completion_value_value_field (completion_value,
+                                                            value);
 
-  JERRY_ASSERT (u_cv.value.type == type &&
-                u_cv.value.padding == 0u &&
-                u_cv.value.u.value == value);
-
-  return u_cv.value;
+  return completion_value;
 } /* ecma_make_completion_value */
 
 /**
@@ -471,7 +557,7 @@ ecma_make_completion_value (ecma_completion_type_t type, /**< type */
  *
  * @return completion value
  */
-ecma_completion_value_t
+ecma_completion_value_t __attribute_const__
 ecma_make_label_completion_value (ecma_completion_type_t type, /**< type */
                                   uint8_t depth_level, /**< depth level (in try constructions,
                                                             with blocks, etc.) */
@@ -480,8 +566,6 @@ ecma_make_label_completion_value (ecma_completion_type_t type, /**< type */
   JERRY_ASSERT (type == ECMA_COMPLETION_TYPE_BREAK
                 || type == ECMA_COMPLETION_TYPE_CONTINUE);
 
-  ecma_completion_value_t ret_value;
-
   ecma_label_descriptor_t *label_desc_p = ecma_alloc_label_descriptor ();
   *label_desc_p = (ecma_label_descriptor_t)
   {
@@ -489,10 +573,14 @@ ecma_make_label_completion_value (ecma_completion_type_t type, /**< type */
     .depth = depth_level
   };
 
-  ret_value.type = type;
-  ECMA_SET_POINTER (ret_value.u.label_desc_cp, label_desc_p);
+  ecma_completion_value_t completion_value = 0;
 
-  return ret_value;
+  completion_value = ecma_set_completion_value_type_field (completion_value,
+                                                           type);
+  completion_value = ecma_set_completion_value_label_descriptor (completion_value,
+                                                                 label_desc_p);
+
+  return completion_value;
 } /* ecma_make_label_completion_value */
 
 /**
@@ -500,7 +588,7 @@ ecma_make_label_completion_value (ecma_completion_type_t type, /**< type */
  *
  * @return completion value
  */
-ecma_completion_value_t
+ecma_completion_value_t __attribute_const__
 ecma_make_simple_completion_value (ecma_simple_value_t simple_value) /**< simple ecma-value */
 {
   JERRY_ASSERT(simple_value == ECMA_SIMPLE_VALUE_UNDEFINED
@@ -517,7 +605,7 @@ ecma_make_simple_completion_value (ecma_simple_value_t simple_value) /**< simple
  *
  * @return completion value
  */
-ecma_completion_value_t
+ecma_completion_value_t __attribute_const__
 ecma_make_normal_completion_value (ecma_value_t value) /**< value */
 {
   return ecma_make_completion_value (ECMA_COMPLETION_TYPE_NORMAL, value);
@@ -528,7 +616,7 @@ ecma_make_normal_completion_value (ecma_value_t value) /**< value */
  *
  * @return completion value
  */
-ecma_completion_value_t
+ecma_completion_value_t __attribute_const__
 ecma_make_throw_completion_value (ecma_value_t value) /**< value */
 {
 #ifdef CONFIG_ECMA_EXCEPTION_SUPPORT
@@ -545,7 +633,7 @@ ecma_make_throw_completion_value (ecma_value_t value) /**< value */
  *
  * @return 'throw' completion value
  */
-ecma_completion_value_t
+ecma_completion_value_t __attribute_const__
 ecma_make_throw_obj_completion_value (ecma_object_t *exception_p) /**< an object */
 {
   JERRY_ASSERT(exception_p != NULL
@@ -561,7 +649,7 @@ ecma_make_throw_obj_completion_value (ecma_object_t *exception_p) /**< an object
  *
  * @return (normal, empty, reserved) completion value.
  */
-ecma_completion_value_t
+ecma_completion_value_t __attribute_const__
 ecma_make_empty_completion_value (void)
 {
   return ecma_make_completion_value (ECMA_COMPLETION_TYPE_NORMAL,
@@ -573,7 +661,7 @@ ecma_make_empty_completion_value (void)
  *
  * @return completion value
  */
-ecma_completion_value_t
+ecma_completion_value_t __attribute_const__
 ecma_make_return_completion_value (ecma_value_t value) /**< value */
 {
   return ecma_make_completion_value (ECMA_COMPLETION_TYPE_RETURN, value);
@@ -584,7 +672,7 @@ ecma_make_return_completion_value (ecma_value_t value) /**< value */
  *
  * @return completion value
  */
-ecma_completion_value_t
+ecma_completion_value_t __attribute_const__
 ecma_make_exit_completion_value (bool is_successful) /**< does completion value indicate
                                                           successfulness completion
                                                           of script execution (true) or not (false) */
@@ -599,7 +687,7 @@ ecma_make_exit_completion_value (bool is_successful) /**< does completion value
  *
  * @return completion value
  */
-ecma_completion_value_t
+ecma_completion_value_t __attribute_const__
 ecma_make_meta_completion_value (void)
 {
   return ecma_make_completion_value (ECMA_COMPLETION_TYPE_META,
@@ -614,7 +702,7 @@ ecma_make_meta_completion_value (void)
 ecma_value_t __attribute_const__
 ecma_get_completion_value_value (ecma_completion_value_t completion_value) /**< completion value */
 {
-  const ecma_completion_type_t type = completion_value.type;
+  const ecma_completion_type_t type = ecma_get_completion_value_type_field (completion_value);
 
   const bool is_type_ok = (type == ECMA_COMPLETION_TYPE_NORMAL
 #ifdef CONFIG_ECMA_EXCEPTION_SUPPORT
@@ -625,7 +713,7 @@ ecma_get_completion_value_value (ecma_completion_value_t completion_value) /**<
 
   JERRY_ASSERT (is_type_ok);
 
-  return completion_value.u.value;
+  return ecma_get_completion_value_value_field (completion_value);
 } /* ecma_get_completion_value_value */
 
 /**
@@ -669,17 +757,19 @@ ecma_get_object_from_completion_value (ecma_completion_value_t completion_value)
 ecma_completion_value_t
 ecma_copy_completion_value (ecma_completion_value_t value) /**< completion value */
 {
-  const bool is_type_ok = (value.type == ECMA_COMPLETION_TYPE_NORMAL
+  const ecma_completion_type_t type = ecma_get_completion_value_type_field (value);
+  const bool is_type_ok = (type == ECMA_COMPLETION_TYPE_NORMAL
 #ifdef CONFIG_ECMA_EXCEPTION_SUPPORT
-                           || value.type == ECMA_COMPLETION_TYPE_THROW
+                           || type == ECMA_COMPLETION_TYPE_THROW
 #endif /* CONFIG_ECMA_EXCEPTION_SUPPORT */
-                           || value.type == ECMA_COMPLETION_TYPE_RETURN
-                           || value.type == ECMA_COMPLETION_TYPE_EXIT);
+                           || type == ECMA_COMPLETION_TYPE_RETURN
+                           || type == ECMA_COMPLETION_TYPE_EXIT);
 
   JERRY_ASSERT (is_type_ok);
 
-  return ecma_make_completion_value (value.type,
-                                     ecma_copy_value (value.u.value, true));
+  return ecma_make_completion_value (type,
+                                     ecma_copy_value (ecma_get_completion_value_value_field (value),
+                                                      true));
 } /* ecma_copy_completion_value */
 
 /**
@@ -688,7 +778,7 @@ ecma_copy_completion_value (ecma_completion_value_t value) /**< completion value
 void
 ecma_free_completion_value (ecma_completion_value_t completion_value) /**< completion value */
 {
-  switch ((ecma_completion_type_t)completion_value.type)
+  switch (ecma_get_completion_value_type_field (completion_value))
   {
     case ECMA_COMPLETION_TYPE_NORMAL:
 #ifdef CONFIG_ECMA_EXCEPTION_SUPPORT
@@ -696,7 +786,7 @@ ecma_free_completion_value (ecma_completion_value_t completion_value) /**< compl
 #endif /* CONFIG_ECMA_EXCEPTION_SUPPORT */
     case ECMA_COMPLETION_TYPE_RETURN:
     {
-      ecma_free_value (completion_value.u.value, true);
+      ecma_free_value (ecma_get_completion_value_value_field (completion_value), true);
       break;
     }
     case ECMA_COMPLETION_TYPE_EXIT:
@@ -707,7 +797,7 @@ ecma_free_completion_value (ecma_completion_value_t completion_value) /**< compl
     case ECMA_COMPLETION_TYPE_CONTINUE:
     case ECMA_COMPLETION_TYPE_BREAK:
     {
-      ecma_dealloc_label_descriptor (ECMA_GET_NON_NULL_POINTER (completion_value.u.label_desc_cp));
+      ecma_dealloc_label_descriptor (ecma_get_completion_value_label_descriptor (completion_value));
       break;
     }
     case ECMA_COMPLETION_TYPE_META:
@@ -723,10 +813,10 @@ ecma_free_completion_value (ecma_completion_value_t completion_value) /**< compl
  * @return true - if the completion type is normal,
  *         false - otherwise.
  */
-bool
+bool __attribute_const__
 ecma_is_completion_value_normal (ecma_completion_value_t value) /**< completion value */
 {
-  return (value.type == ECMA_COMPLETION_TYPE_NORMAL);
+  return (ecma_get_completion_value_type_field (value) == ECMA_COMPLETION_TYPE_NORMAL);
 } /* ecma_is_completion_value_normal */
 
 /**
@@ -735,11 +825,11 @@ ecma_is_completion_value_normal (ecma_completion_value_t value) /**< completion
  * @return true - if the completion type is throw,
  *         false - otherwise.
  */
-bool
+bool __attribute_const__
 ecma_is_completion_value_throw (ecma_completion_value_t value) /**< completion value */
 {
 #ifdef CONFIG_ECMA_EXCEPTION_SUPPORT
-  return (value.type == ECMA_COMPLETION_TYPE_THROW);
+  return (ecma_get_completion_value_type_field (value) == ECMA_COMPLETION_TYPE_THROW);
 #else /* CONFIG_ECMA_EXCEPTION_SUPPORT */
   (void) value;
 
@@ -753,10 +843,10 @@ ecma_is_completion_value_throw (ecma_completion_value_t value) /**< completion v
  * @return true - if the completion type is return,
  *         false - otherwise.
  */
-bool
+bool __attribute_const__
 ecma_is_completion_value_return (ecma_completion_value_t value) /**< completion value */
 {
-  return (value.type == ECMA_COMPLETION_TYPE_RETURN);
+  return (ecma_get_completion_value_type_field (value) == ECMA_COMPLETION_TYPE_RETURN);
 } /* ecma_is_completion_value_return */
 
 /**
@@ -765,12 +855,12 @@ ecma_is_completion_value_return (ecma_completion_value_t value) /**< completion
  * @return true - if the completion type is exit,
  *         false - otherwise.
  */
-bool
+bool __attribute_const__
 ecma_is_completion_value_exit (ecma_completion_value_t value) /**< completion value */
 {
-  if (value.type == ECMA_COMPLETION_TYPE_EXIT)
+  if (ecma_get_completion_value_type_field (value) == ECMA_COMPLETION_TYPE_EXIT)
   {
-    JERRY_ASSERT (ecma_is_value_boolean (value.u.value));
+    JERRY_ASSERT (ecma_is_value_boolean (ecma_get_completion_value_value_field (value)));
 
     return true;
   }
@@ -786,12 +876,12 @@ ecma_is_completion_value_exit (ecma_completion_value_t value) /**< completion va
  * @return true - if the completion type is meta,
  *         false - otherwise.
  */
-bool
+bool __attribute_const__
 ecma_is_completion_value_meta (ecma_completion_value_t value) /**< completion value */
 {
-  if (value.type == ECMA_COMPLETION_TYPE_META)
+  if (ecma_get_completion_value_type_field (value) == ECMA_COMPLETION_TYPE_META)
   {
-    JERRY_ASSERT (ecma_is_value_empty (value.u.value));
+    JERRY_ASSERT (ecma_is_value_empty (ecma_get_completion_value_value_field (value)));
 
     return true;
   }
@@ -801,6 +891,30 @@ ecma_is_completion_value_meta (ecma_completion_value_t value) /**< completion va
   }
 } /* ecma_is_completion_value_meta */
 
+/**
+ * Check if the completion value is break value.
+ *
+ * @return true - if the completion type is break,
+ *         false - otherwise.
+ */
+bool __attribute_const__
+ecma_is_completion_value_break (ecma_completion_value_t value) /**< completion value */
+{
+  return (ecma_get_completion_value_type_field (value) == ECMA_COMPLETION_TYPE_BREAK);
+} /* ecma_is_completion_value_break */
+
+/**
+ * Check if the completion value is continue value.
+ *
+ * @return true - if the completion type is continue,
+ *         false - otherwise.
+ */
+bool __attribute_const__
+ecma_is_completion_value_continue (ecma_completion_value_t value) /**< completion value */
+{
+  return (ecma_get_completion_value_type_field (value) == ECMA_COMPLETION_TYPE_CONTINUE);
+} /* ecma_is_completion_value_continue */
+
 /**
  * Check if the completion value is specified normal simple value.
  *
@@ -808,13 +922,12 @@ ecma_is_completion_value_meta (ecma_completion_value_t value) /**< completion va
  *                value contains specified simple ecma-value,
  *         false - otherwise.
  */
-bool
+bool __attribute_const__
 ecma_is_completion_value_normal_simple_value (ecma_completion_value_t value, /**< completion value */
                                               ecma_simple_value_t simple_value) /**< simple value to check
                                                                                      for equality with */
 {
-  return (ecma_is_completion_value_normal (value)
-          && value.u.value == ecma_make_simple_value (simple_value));
+  return (value == ecma_make_simple_completion_value (simple_value));
 } /* ecma_is_completion_value_normal_simple_value */
 
 /**
@@ -824,7 +937,7 @@ ecma_is_completion_value_normal_simple_value (ecma_completion_value_t value, /**
  *                value contains ecma-true simple value,
  *         false - otherwise.
  */
-bool
+bool __attribute_const__
 ecma_is_completion_value_normal_true (ecma_completion_value_t value) /**< completion value */
 {
   return ecma_is_completion_value_normal_simple_value (value, ECMA_SIMPLE_VALUE_TRUE);
@@ -837,7 +950,7 @@ ecma_is_completion_value_normal_true (ecma_completion_value_t value) /**< comple
  *                value contains ecma-false simple value,
  *         false - otherwise.
  */
-bool
+bool __attribute_const__
 ecma_is_completion_value_normal_false (ecma_completion_value_t value) /**< completion value */
 {
   return ecma_is_completion_value_normal_simple_value (value, ECMA_SIMPLE_VALUE_FALSE);
@@ -850,11 +963,11 @@ ecma_is_completion_value_normal_false (ecma_completion_value_t value) /**< compl
  *                value contains empty simple value,
  *         false - otherwise.
  */
-bool
+bool __attribute_const__
 ecma_is_completion_value_empty (ecma_completion_value_t value) /**< completion value */
 {
   return (ecma_is_completion_value_normal (value)
-          && ecma_is_value_empty (value.u.value));
+          && ecma_is_value_empty (ecma_get_completion_value_value_field (value)));
 } /* ecma_is_completion_value_empty */
 
 /**
diff --git a/src/libecmaobjects/ecma-helpers.h b/src/libecmaobjects/ecma-helpers.h
index d16dadcd3..c0876f90f 100644
--- a/src/libecmaobjects/ecma-helpers.h
+++ b/src/libecmaobjects/ecma-helpers.h
@@ -111,6 +111,8 @@ extern bool ecma_is_completion_value_throw (ecma_completion_value_t value);
 extern bool ecma_is_completion_value_return (ecma_completion_value_t value);
 extern bool ecma_is_completion_value_exit (ecma_completion_value_t value);
 extern bool ecma_is_completion_value_meta (ecma_completion_value_t value);
+extern bool ecma_is_completion_value_break (ecma_completion_value_t value);
+extern bool ecma_is_completion_value_continue (ecma_completion_value_t value);
 extern bool ecma_is_completion_value_normal_simple_value (ecma_completion_value_t value,
                                                           ecma_simple_value_t simple_value);
 extern bool ecma_is_completion_value_normal_true (ecma_completion_value_t value);
diff --git a/src/libecmaoperations/ecma-comparison.c b/src/libecmaoperations/ecma-comparison.c
index c0e03a540..c360796c9 100644
--- a/src/libecmaoperations/ecma-comparison.c
+++ b/src/libecmaoperations/ecma-comparison.c
@@ -322,7 +322,7 @@ ecma_op_abstract_relational_compare (ecma_value_t x, /**< first operand */
                                      ecma_value_t y, /**< second operand */
                                      bool left_first) /**< 'LeftFirst' flag */
 {
-  ecma_completion_value_t ret_value, px, py;
+  ecma_completion_value_t ret_value;
 
   ecma_value_t first_converted_value = left_first ? x : y;
   ecma_value_t second_converted_value = left_first ? y : x;
@@ -335,6 +335,8 @@ ecma_op_abstract_relational_compare (ecma_value_t x, /**< first operand */
                  ecma_op_to_primitive (second_converted_value, ECMA_PREFERRED_TYPE_NUMBER),
                  ret_value);
 
+  ecma_completion_value_t px, py;
+
   px = left_first ? prim_first_converted_value : prim_second_converted_value;
   py = left_first ? prim_second_converted_value : prim_first_converted_value;