Optimize LCache operation.

The cache stores only real properties now, because storing NULLs has
little benefit according to tests. Since only real properties are
stored now, there is no need to create real references to objects
and property names, which reduces the keeping of dead objects after
garbage collection.

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

jerry-core/vm/vm.c

@@ -24,6 +24,7 @@
 #include "ecma-function-object.h"
 #include "ecma-gc.h"
 #include "ecma-helpers.h"
+#include "ecma-lcache.h"
 #include "ecma-lex-env.h"
 #include "ecma-objects.h"
 #include "ecma-objects-general.h"
@@ -65,31 +66,40 @@ static ecma_compiled_code_t *__program = NULL;
  */
 static ecma_value_t
 vm_op_get_value (ecma_value_t object, /**< base object */
-                 ecma_value_t property, /**< property name */
-                 bool is_strict) /**< strict mode */
+                 ecma_value_t property) /**< property name */
 {
   if (unlikely (ecma_is_value_undefined (object) || ecma_is_value_null (object)))
   {
     return ecma_raise_type_error (ECMA_ERR_MSG (""));
   }
 
-  ecma_value_t completion_value = ecma_make_simple_value (ECMA_SIMPLE_VALUE_EMPTY);
+  ecma_value_t prop_to_string_result = ecma_op_to_string (property);
 
-  ECMA_TRY_CATCH (property_val,
-                  ecma_op_to_string (property),
-                  completion_value);
+  if (ecma_is_value_error (prop_to_string_result))
+  {
+    return prop_to_string_result;
+  }
 
-  ecma_string_t *property_p = ecma_get_string_from_value (property_val);
+  ecma_string_t *property_name_p = ecma_get_string_from_value (prop_to_string_result);
 
-  ecma_reference_t reference = ecma_make_reference (object, property_p, is_strict);
+  if (ecma_is_value_object (object))
+  {
+    ecma_object_t *object_p = ecma_get_object_from_value (object);
 
-  completion_value = ecma_op_get_value_object_base (reference);
+    ecma_property_t *property_p = ecma_lcache_lookup (object_p, property_name_p);
 
-  ecma_free_reference (reference);
+    if (property_p != NULL &&
+        ECMA_PROPERTY_GET_TYPE (property_p) == ECMA_PROPERTY_TYPE_NAMEDDATA)
+    {
+      ecma_deref_ecma_string (property_name_p);
+      return ecma_fast_copy_value (ecma_get_named_data_property_value (property_p));
+    }
+  }
 
-  ECMA_FINALIZE (property_val);
+  ecma_value_t get_value_result = ecma_op_get_value_object_base (object, property_name_p);
 
-  return completion_value;
+  ecma_deref_ecma_string (property_name_p);
+  return get_value_result;
 } /* vm_op_get_value */
 
 /**
@@ -1145,8 +1155,7 @@ vm_loop (vm_frame_ctx_t *frame_ctx_p) /**< frame context */
         case VM_OC_PROP_POST_DECR:
         {
           last_completion_value = vm_op_get_value (left_value,
-                                                   right_value,
-                                                   is_strict);
+                                                   right_value);
 
           if (ecma_is_value_error (last_completion_value))
           {