diff --git a/src/globals.h b/src/globals.h
index bd0e1d6ef..bcc9fa1e4 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -164,57 +164,4 @@ extern void __noreturn jerry_exit (jerry_status_t code);
 #define JERRY_MIN(v1, v2) ((v1 < v2) ? v1 : v2)
 #define JERRY_MAX(v1, v2) ((v1 < v2) ? v2 : v1)
 
-/**
- * Bit-fields
- */
-inline uint32_t jerry_extract_bit_field (uint32_t value, uint32_t lsb,
-                                         uint32_t width);
-inline uint32_t jerry_set_bit_field_value (uint32_t value, uint32_t bit_field_value,
-                                           uint32_t lsb, uint32_t width);
-
-/**
- * Extract a bit-field from the integer.
- *
- * @return bit-field's value
- */
-inline uint32_t
-jerry_extract_bit_field (uint32_t
-                         container, /**< container to extract bit-field from */
-                         uint32_t lsb, /**< least significant bit of the value
-                                     *   to be extracted */
-                         uint32_t width) /**< width of the bit-field to be extracted */
-{
-  JERRY_ASSERT (lsb < JERRY_BITSINBYTE * sizeof (uint32_t));
-  JERRY_ASSERT ((lsb + width) <= JERRY_BITSINBYTE * sizeof (uint32_t));
-
-  uint32_t shifted_value = container >> lsb;
-  uint32_t bit_field_mask = (1u << width) - 1;
-
-  return (shifted_value & bit_field_mask);
-} /* jerry_extract_bit_field */
-
-/**
- * Extract a bit-field from the integer.
- *
- * @return bit-field's value
- */
-inline uint32_t
-jerry_set_bit_field_value (uint32_t
-                           container, /**< container to insert bit-field to */
-                           uint32_t new_bit_field_value, /**< value of bit-field to insert */
-                           uint32_t lsb, /**< least significant bit of the value
-                                          *   to be extracted */
-                           uint32_t width) /**< width of the bit-field to be extracted */
-{
-  JERRY_ASSERT (lsb < JERRY_BITSINBYTE * sizeof (uint32_t));
-  JERRY_ASSERT ((lsb + width) <= JERRY_BITSINBYTE * sizeof (uint32_t));
-  JERRY_ASSERT (new_bit_field_value <= (1u << width));
-
-  uint32_t bit_field_mask = (1u << width) - 1;
-  uint32_t shifted_bit_field_mask = bit_field_mask << lsb;
-  uint32_t shifted_new_bit_field_value = new_bit_field_value << lsb;
-
-  return (container & ~shifted_bit_field_mask) | shifted_new_bit_field_value;
-} /* jerry_set_bit_field_value */
-
 #endif /* !JERRY_GLOBALS_H */
diff --git a/src/libecmaobjects/ecma-alloc.c b/src/libecmaobjects/ecma-alloc.c
index 35d4f9e4b..92b17d8ca 100644
--- a/src/libecmaobjects/ecma-alloc.c
+++ b/src/libecmaobjects/ecma-alloc.c
@@ -19,16 +19,17 @@
 #include "ecma-gc.h"
 #include "mem-poolman.h"
 
-JERRY_STATIC_ASSERT(sizeof (ecma_value_t) <= sizeof (uint16_t));
-JERRY_STATIC_ASSERT(sizeof (ecma_property_t) <= sizeof (uint64_t));
+JERRY_STATIC_ASSERT (sizeof (ecma_value_t) <= sizeof (uint16_t));
+JERRY_STATIC_ASSERT (sizeof (ecma_property_t) <= sizeof (uint64_t));
 
-FIXME(Pack ecma_object_t)
-JERRY_STATIC_ASSERT(sizeof (ecma_object_t) <= 2 * sizeof (uint64_t));
+JERRY_STATIC_ASSERT (sizeof (ecma_object_t) <= sizeof (uint64_t));
+JERRY_STATIC_ASSERT (ECMA_OBJECT_OBJ_TYPE_SIZE <= sizeof (uint64_t) * JERRY_BITSINBYTE);
+JERRY_STATIC_ASSERT (ECMA_OBJECT_LEX_ENV_TYPE_SIZE <= sizeof (uint64_t) * JERRY_BITSINBYTE);
 
-JERRY_STATIC_ASSERT(sizeof (ecma_collection_header_t) == sizeof (uint64_t));
-JERRY_STATIC_ASSERT(sizeof (ecma_collection_chunk_t) == sizeof (uint64_t));
-JERRY_STATIC_ASSERT(sizeof (ecma_string_t) == sizeof (uint64_t));
-JERRY_STATIC_ASSERT(sizeof (ecma_completion_value_t) == sizeof (uint32_t));
+JERRY_STATIC_ASSERT (sizeof (ecma_collection_header_t) == sizeof (uint64_t));
+JERRY_STATIC_ASSERT (sizeof (ecma_collection_chunk_t) == sizeof (uint64_t));
+JERRY_STATIC_ASSERT (sizeof (ecma_string_t) == sizeof (uint64_t));
+JERRY_STATIC_ASSERT (sizeof (ecma_completion_value_t) == sizeof (uint32_t));
 
 /** \addtogroup ecma ---TODO---
  * @{
diff --git a/src/libecmaobjects/ecma-gc.c b/src/libecmaobjects/ecma-gc.c
index 859e1e71e..9dacba0da 100644
--- a/src/libecmaobjects/ecma-gc.c
+++ b/src/libecmaobjects/ecma-gc.c
@@ -30,6 +30,7 @@
 #include "ecma-helpers.h"
 #include "globals.h"
 #include "jerry-libc.h"
+#include "jrt-bit-fields.h"
 
 /**
  * Global lists of objects sorted by generation identifier.
@@ -47,7 +48,9 @@ ecma_gc_get_object_refs (ecma_object_t *object_p) /**< object */
 {
   JERRY_ASSERT (object_p != NULL);
 
-  return object_p->gc_info.refs;
+  return (uint32_t) jrt_extract_bit_field (object_p->container,
+                                           ECMA_OBJECT_GC_REFS_POS,
+                                           ECMA_OBJECT_GC_REFS_WIDTH);
 } /* ecma_gc_get_object_refs */
 
 /**
@@ -59,9 +62,10 @@ ecma_gc_set_object_refs (ecma_object_t *object_p, /**< object */
 {
   JERRY_ASSERT (object_p != NULL);
 
-  object_p->gc_info.refs = refs & ((1u << CONFIG_ECMA_REFERENCE_COUNTER_WIDTH) - 1);
-
-  JERRY_ASSERT (object_p->gc_info.refs == refs);
+  object_p->container = jrt_set_bit_field_value (object_p->container,
+                                                 refs,
+                                                 ECMA_OBJECT_GC_REFS_POS,
+                                                 ECMA_OBJECT_GC_REFS_WIDTH);
 } /* ecma_gc_set_object_refs */
 
 /**
@@ -72,7 +76,13 @@ ecma_gc_get_object_generation (ecma_object_t *object_p) /**< object */
 {
   JERRY_ASSERT (object_p != NULL);
 
-  return object_p->gc_info.generation;
+  ecma_gc_gen_t ret = (ecma_gc_gen_t) jrt_extract_bit_field (object_p->container,
+                                                             ECMA_OBJECT_GC_GENERATION_POS,
+                                                             ECMA_OBJECT_GC_GENERATION_WIDTH);
+
+  JERRY_ASSERT (ret < ECMA_GC_GEN_COUNT);
+
+  return ret;
 } /* ecma_gc_get_object_generation */
 
 /**
@@ -85,7 +95,10 @@ ecma_gc_set_object_generation (ecma_object_t *object_p, /**< object */
   JERRY_ASSERT (object_p != NULL);
   JERRY_ASSERT (generation < ECMA_GC_GEN_COUNT);
 
-  object_p->gc_info.generation = generation;
+  object_p->container = jrt_set_bit_field_value (object_p->container,
+                                                 generation,
+                                                 ECMA_OBJECT_GC_GENERATION_POS,
+                                                 ECMA_OBJECT_GC_GENERATION_WIDTH);
 } /* ecma_gc_set_object_generation */
 
 /**
@@ -96,7 +109,12 @@ ecma_gc_get_object_next (ecma_object_t *object_p) /**< object */
 {
   JERRY_ASSERT (object_p != NULL);
 
-  return ECMA_GET_POINTER (object_p->gc_info.next_cp);
+  JERRY_ASSERT (sizeof (uintptr_t) * JERRY_BITSINBYTE >= ECMA_OBJECT_PROPERTIES_CP_WIDTH);
+  uintptr_t next_cp = (uintptr_t) jrt_extract_bit_field (object_p->container,
+                                                         ECMA_OBJECT_GC_NEXT_CP_POS,
+                                                         ECMA_OBJECT_GC_NEXT_CP_WIDTH);
+
+  return ECMA_GET_POINTER (next_cp);
 } /* ecma_gc_get_object_next */
 
 /**
@@ -108,7 +126,14 @@ ecma_gc_set_object_next (ecma_object_t *object_p, /**< object */
 {
   JERRY_ASSERT (object_p != NULL);
 
-  ECMA_SET_POINTER (object_p->gc_info.next_cp, next_object_p);
+  uintptr_t next_cp;
+  ECMA_SET_POINTER (next_cp, next_object_p);
+
+  JERRY_ASSERT (sizeof (uintptr_t) * JERRY_BITSINBYTE >= ECMA_OBJECT_PROPERTIES_CP_WIDTH);
+  object_p->container = jrt_set_bit_field_value (object_p->container,
+                                                 next_cp,
+                                                 ECMA_OBJECT_GC_NEXT_CP_POS,
+                                                 ECMA_OBJECT_GC_NEXT_CP_WIDTH);
 } /* ecma_gc_set_object_next */
 
 /**
@@ -119,7 +144,9 @@ ecma_gc_is_object_visited (ecma_object_t *object_p) /**< object */
 {
   JERRY_ASSERT (object_p != NULL);
 
-  return object_p->gc_info.visited;
+  return jrt_extract_bit_field (object_p->container,
+                                ECMA_OBJECT_GC_VISITED_POS,
+                                ECMA_OBJECT_GC_VISITED_WIDTH);
 } /* ecma_gc_is_object_visited */
 
 /**
@@ -131,7 +158,10 @@ ecma_gc_set_object_visited (ecma_object_t *object_p, /**< object */
 {
   JERRY_ASSERT (object_p != NULL);
 
-  object_p->gc_info.visited = is_visited;
+  object_p->container = jrt_set_bit_field_value (object_p->container,
+                                                 is_visited,
+                                                 ECMA_OBJECT_GC_VISITED_POS,
+                                                 ECMA_OBJECT_GC_VISITED_WIDTH);
 } /* ecma_gc_set_object_visited */
 
 /**
@@ -142,7 +172,9 @@ ecma_gc_is_object_may_ref_younger_objects (ecma_object_t *object_p) /**< object
 {
   JERRY_ASSERT (object_p != NULL);
 
-  return object_p->gc_info.may_ref_younger_objects;
+  return jrt_extract_bit_field (object_p->container,
+                                ECMA_OBJECT_GC_REFS_POS,
+                                ECMA_OBJECT_GC_REFS_WIDTH);
 } /* ecma_gc_is_object_may_ref_younger_objects */
 
 /**
@@ -154,7 +186,10 @@ ecma_gc_set_object_may_ref_younger_objects (ecma_object_t *object_p, /**< object
 {
   JERRY_ASSERT (object_p != NULL);
 
-  object_p->gc_info.may_ref_younger_objects = is_may_ref_younger_objects;
+  object_p->container = jrt_set_bit_field_value (object_p->container,
+                                                 is_may_ref_younger_objects,
+                                                 ECMA_OBJECT_GC_MAY_REF_YOUNGER_OBJECTS_POS,
+                                                 ECMA_OBJECT_GC_MAY_REF_YOUNGER_OBJECTS_WIDTH);
 } /* ecma_gc_set_object_may_ref_younger_objects */
 
 /**
@@ -362,9 +397,9 @@ ecma_gc_mark (ecma_object_t *object_p, /**< start object */
           }
 
           case ECMA_INTERNAL_PROPERTY_PROTOTYPE: /* the property's value is located in ecma_object_t
-                                                    (see above in the routine) */
+                                                      (see above in the routine) */
           case ECMA_INTERNAL_PROPERTY_EXTENSIBLE: /* the property's value is located in ecma_object_t
-                                                     (see above in the routine) */
+                                                       (see above in the routine) */
           {
             JERRY_UNREACHABLE();
           }
diff --git a/src/libecmaobjects/ecma-globals.h b/src/libecmaobjects/ecma-globals.h
index 418b44ffd..cd0414e24 100644
--- a/src/libecmaobjects/ecma-globals.h
+++ b/src/libecmaobjects/ecma-globals.h
@@ -282,39 +282,6 @@ typedef struct ecma_property_t
   } u;
 } ecma_property_t;
 
-/**
- * Description of GC's information layout
- */
-typedef struct
-{
-  /**
-   * Reference counter of the object.
-   *
-   *  Number of references to the object from stack variables.
-   */
-  unsigned int refs : CONFIG_ECMA_REFERENCE_COUNTER_WIDTH;
-
-  /**
-   * Identifier of GC generation.
-   */
-  unsigned int generation : 2;
-
-  /**
-   * Compressed pointer to next object in the global list of objects with same generation.
-   */
-  unsigned int next_cp : ECMA_POINTER_FIELD_WIDTH;
-
-  /**
-   * Marker that is set if the object was visited during graph traverse.
-   */
-  unsigned int visited : 1;
-
-  /**
-   * Flag indicating that the object may reference objects of younger generations in its properties.
-   */
-  unsigned int may_ref_younger_objects : 1;
-} __packed ecma_gc_info_t;
-
 /**
  * Types of lexical environments
  */
@@ -363,57 +330,116 @@ typedef enum
  * Description of ECMA-object or lexical environment
  * (depending on is_lexical_environment).
  */
-typedef struct ecma_object_t
+typedef struct
 {
-  /** Compressed pointer to property list */
-  unsigned int properties_cp : ECMA_POINTER_FIELD_WIDTH;
+/* Common part for objects and lexical environments */
 
-  /** Flag indicating whether it is a general object (false)
-       or a lexical environment (true) */
-  unsigned int is_lexical_environment : 1;
+/**
+ * Compressed pointer to property list
+ */
+#define ECMA_OBJECT_PROPERTIES_CP_POS   (0)
+#define ECMA_OBJECT_PROPERTIES_CP_WIDTH (ECMA_POINTER_FIELD_WIDTH)
 
-  /**
-   * Attributes of either general object or lexical environment
-   * (depending on is_lexical_environment)
-   */
-  union
-  {
-    /**
-     * A general object's attributes (if !is_lexical_environment)
-     */
-    struct
-    {
-      /** Attribute 'Extensible' */
-      unsigned int extensible : 1;
+/**
+ * Flag indicating whether it is a general object (false)
+ * or a lexical environment (true)
+ */
+#define ECMA_OBJECT_IS_LEXICAL_ENVIRONMENT_POS (ECMA_OBJECT_PROPERTIES_CP_POS + \
+                                                ECMA_OBJECT_PROPERTIES_CP_WIDTH)
+#define ECMA_OBJECT_IS_LEXICAL_ENVIRONMENT_WIDTH (1)
 
-      /** Implementation internal object type (ecma_object_type_t) */
-      unsigned int type : 3;
+/**
+ * Reference counter of the object, i.e. number of references
+ * to the object from stack variables.
+ */
+#define ECMA_OBJECT_GC_REFS_POS (ECMA_OBJECT_IS_LEXICAL_ENVIRONMENT_POS + \
+                                 ECMA_OBJECT_IS_LEXICAL_ENVIRONMENT_WIDTH)
+#define ECMA_OBJECT_GC_REFS_WIDTH (CONFIG_ECMA_REFERENCE_COUNTER_WIDTH)
 
-      /** Compressed pointer to prototype object (ecma_object_t) */
-      unsigned int prototype_object_cp : ECMA_POINTER_FIELD_WIDTH;
-    } __packed object;
+/**
+ * Identifier of GC generation.
+ */
+#define ECMA_OBJECT_GC_GENERATION_POS (ECMA_OBJECT_GC_REFS_POS + \
+                                       ECMA_OBJECT_GC_REFS_WIDTH)
+#define ECMA_OBJECT_GC_GENERATION_WIDTH (2)
 
-    /**
-     * A lexical environment's attribute (if is_lexical_environment)
-     */
-    struct
-    {
-      /**
-       * Type of lexical environment (ecma_lexical_environment_type_t).
-       */
-      unsigned int type : 1;
+/**
+ * Compressed pointer to next object in the global list of objects with same generation.
+ */
+#define ECMA_OBJECT_GC_NEXT_CP_POS (ECMA_OBJECT_GC_GENERATION_POS + \
+                                    ECMA_OBJECT_GC_GENERATION_WIDTH)
+#define ECMA_OBJECT_GC_NEXT_CP_WIDTH (ECMA_POINTER_FIELD_WIDTH)
 
-      /** Compressed pointer to outer lexical environment */
-      unsigned int outer_reference_cp : ECMA_POINTER_FIELD_WIDTH;
-    } __packed lexical_environment;
+/**
+ * Marker that is set if the object was visited during graph traverse.
+ */
+#define ECMA_OBJECT_GC_VISITED_POS (ECMA_OBJECT_GC_NEXT_CP_POS + \
+                                    ECMA_OBJECT_GC_NEXT_CP_WIDTH)
+#define ECMA_OBJECT_GC_VISITED_WIDTH (1)
 
-  } __packed u;
+/**
+ * Flag indicating that the object may reference objects of younger generations in its properties.
+ */
+#define ECMA_OBJECT_GC_MAY_REF_YOUNGER_OBJECTS_POS (ECMA_OBJECT_GC_VISITED_POS + \
+                                                    ECMA_OBJECT_GC_VISITED_WIDTH)
+#define ECMA_OBJECT_GC_MAY_REF_YOUNGER_OBJECTS_WIDTH (1)
 
-  /** GC's information */
-  ecma_gc_info_t gc_info;
 
-  FIXME(Remove aligned attribute after packing the struct)
-} __packed __attribute__ ((aligned (16))) ecma_object_t;
+/* Objects' only part */
+
+/**
+ * Attribute 'Extensible'
+ */
+#define ECMA_OBJECT_OBJ_EXTENSIBLE_POS (ECMA_OBJECT_GC_MAY_REF_YOUNGER_OBJECTS_POS + \
+                                        ECMA_OBJECT_GC_MAY_REF_YOUNGER_OBJECTS_WIDTH)
+#define ECMA_OBJECT_OBJ_EXTENSIBLE_WIDTH (1)
+
+/**
+ * Implementation internal object type (ecma_object_type_t)
+ */
+#define ECMA_OBJECT_OBJ_TYPE_POS (ECMA_OBJECT_OBJ_EXTENSIBLE_POS + \
+                                  ECMA_OBJECT_OBJ_EXTENSIBLE_WIDTH)
+#define ECMA_OBJECT_OBJ_TYPE_WIDTH (3)
+
+/**
+ * Compressed pointer to prototype object (ecma_object_t)
+ */
+#define ECMA_OBJECT_OBJ_PROTOTYPE_OBJECT_CP_POS (ECMA_OBJECT_OBJ_TYPE_POS + \
+                                                 ECMA_OBJECT_OBJ_TYPE_WIDTH)
+#define ECMA_OBJECT_OBJ_PROTOTYPE_OBJECT_CP_WIDTH (ECMA_POINTER_FIELD_WIDTH)
+
+/**
+ * Size of structure for objects
+ */
+#define ECMA_OBJECT_OBJ_TYPE_SIZE (ECMA_OBJECT_OBJ_PROTOTYPE_OBJECT_CP_POS + \
+                                   ECMA_OBJECT_OBJ_PROTOTYPE_OBJECT_CP_WIDTH)
+
+
+/* Lexical environments' only part */
+
+/**
+ * Type of lexical environment (ecma_lexical_environment_type_t).
+ */
+#define ECMA_OBJECT_LEX_ENV_TYPE_POS (ECMA_OBJECT_GC_MAY_REF_YOUNGER_OBJECTS_POS + \
+                                      ECMA_OBJECT_GC_MAY_REF_YOUNGER_OBJECTS_WIDTH)
+#define ECMA_OBJECT_LEX_ENV_TYPE_WIDTH (1)
+
+/**
+ * Compressed pointer to outer lexical environment
+ */
+#define ECMA_OBJECT_LEX_ENV_OUTER_REFERENCE_CP_POS (ECMA_OBJECT_LEX_ENV_TYPE_POS + \
+                                                    ECMA_OBJECT_LEX_ENV_TYPE_WIDTH)
+#define ECMA_OBJECT_LEX_ENV_OUTER_REFERENCE_CP_WIDTH (ECMA_POINTER_FIELD_WIDTH)
+
+/**
+ * Size of structure for lexical environments
+ */
+#define ECMA_OBJECT_LEX_ENV_TYPE_SIZE (ECMA_OBJECT_LEX_ENV_OUTER_REFERENCE_CP_POS + \
+                                       ECMA_OBJECT_LEX_ENV_OUTER_REFERENCE_CP_WIDTH)
+
+  uint64_t container; /**< container for fields described above */
+} ecma_object_t;
+
 
 /**
  * Description of ECMA property descriptor
diff --git a/src/libecmaobjects/ecma-helpers.c b/src/libecmaobjects/ecma-helpers.c
index a19311cfb..611893742 100644
--- a/src/libecmaobjects/ecma-helpers.c
+++ b/src/libecmaobjects/ecma-helpers.c
@@ -24,6 +24,7 @@
 #include "ecma-gc.h"
 #include "ecma-globals.h"
 #include "ecma-helpers.h"
+#include "jrt-bit-fields.h"
 
 /**
  * Create an object with specified prototype object
@@ -42,12 +43,30 @@ ecma_create_object (ecma_object_t *prototype_object_p, /**< pointer to prototybe
   ecma_object_t *object_p = ecma_alloc_object ();
   ecma_init_gc_info (object_p);
 
-  object_p->properties_cp = ECMA_NULL_POINTER;
-  object_p->is_lexical_environment = false;
+  object_p->container = jrt_set_bit_field_value (object_p->container,
+                                                 ECMA_NULL_POINTER,
+                                                 ECMA_OBJECT_PROPERTIES_CP_POS,
+                                                 ECMA_OBJECT_PROPERTIES_CP_WIDTH);
+  object_p->container = jrt_set_bit_field_value (object_p->container,
+                                                 false,
+                                                 ECMA_OBJECT_IS_LEXICAL_ENVIRONMENT_POS,
+                                                 ECMA_OBJECT_IS_LEXICAL_ENVIRONMENT_WIDTH);
+  object_p->container = jrt_set_bit_field_value (object_p->container,
+                                                 is_extensible,
+                                                 ECMA_OBJECT_OBJ_EXTENSIBLE_POS,
+                                                 ECMA_OBJECT_OBJ_EXTENSIBLE_WIDTH);
+  object_p->container = jrt_set_bit_field_value (object_p->container,
+                                                 type,
+                                                 ECMA_OBJECT_OBJ_TYPE_POS,
+                                                 ECMA_OBJECT_OBJ_TYPE_WIDTH);
 
-  object_p->u.object.extensible = is_extensible;
-  ECMA_SET_POINTER(object_p->u.object.prototype_object_cp, prototype_object_p);
-  object_p->u.object.type = type;
+  uint64_t prototype_object_cp;
+  ECMA_SET_POINTER (prototype_object_cp, prototype_object_p);
+
+  object_p->container = jrt_set_bit_field_value (object_p->container,
+                                                 prototype_object_cp,
+                                                 ECMA_OBJECT_OBJ_PROTOTYPE_OBJECT_CP_POS,
+                                                 ECMA_OBJECT_OBJ_PROTOTYPE_OBJECT_CP_WIDTH);
 
   return object_p;
 } /* ecma_create_object */
@@ -68,12 +87,26 @@ ecma_create_decl_lex_env (ecma_object_t *outer_lexical_environment_p) /**< outer
   ecma_object_t *new_lexical_environment_p = ecma_alloc_object ();
   ecma_init_gc_info (new_lexical_environment_p);
 
-  new_lexical_environment_p->is_lexical_environment = true;
-  new_lexical_environment_p->u.lexical_environment.type = ECMA_LEXICAL_ENVIRONMENT_DECLARATIVE;
+  new_lexical_environment_p->container = jrt_set_bit_field_value (new_lexical_environment_p->container,
+                                                                  ECMA_NULL_POINTER,
+                                                                  ECMA_OBJECT_PROPERTIES_CP_POS,
+                                                                  ECMA_OBJECT_PROPERTIES_CP_WIDTH);
+  new_lexical_environment_p->container = jrt_set_bit_field_value (new_lexical_environment_p->container,
+                                                                  true,
+                                                                  ECMA_OBJECT_IS_LEXICAL_ENVIRONMENT_POS,
+                                                                  ECMA_OBJECT_IS_LEXICAL_ENVIRONMENT_WIDTH);
 
-  new_lexical_environment_p->properties_cp = ECMA_NULL_POINTER;
+  new_lexical_environment_p->container = jrt_set_bit_field_value (new_lexical_environment_p->container,
+                                                                  ECMA_LEXICAL_ENVIRONMENT_DECLARATIVE,
+                                                                  ECMA_OBJECT_LEX_ENV_TYPE_POS,
+                                                                  ECMA_OBJECT_LEX_ENV_TYPE_WIDTH);
 
-  ECMA_SET_POINTER(new_lexical_environment_p->u.lexical_environment.outer_reference_cp, outer_lexical_environment_p);
+  uint64_t outer_reference_cp;
+  ECMA_SET_POINTER (outer_reference_cp, outer_lexical_environment_p);
+  new_lexical_environment_p->container = jrt_set_bit_field_value (new_lexical_environment_p->container,
+                                                                  outer_reference_cp,
+                                                                  ECMA_OBJECT_LEX_ENV_OUTER_REFERENCE_CP_POS,
+                                                                  ECMA_OBJECT_LEX_ENV_OUTER_REFERENCE_CP_WIDTH);
 
   return new_lexical_environment_p;
 } /* ecma_create_decl_lex_env */
@@ -99,12 +132,26 @@ ecma_create_object_lex_env (ecma_object_t *outer_lexical_environment_p, /**< out
   ecma_object_t *new_lexical_environment_p = ecma_alloc_object ();
   ecma_init_gc_info (new_lexical_environment_p);
 
-  new_lexical_environment_p->is_lexical_environment = true;
-  new_lexical_environment_p->u.lexical_environment.type = ECMA_LEXICAL_ENVIRONMENT_OBJECTBOUND;
+  new_lexical_environment_p->container = jrt_set_bit_field_value (new_lexical_environment_p->container,
+                                                                  ECMA_NULL_POINTER,
+                                                                  ECMA_OBJECT_PROPERTIES_CP_POS,
+                                                                  ECMA_OBJECT_PROPERTIES_CP_WIDTH);
+  new_lexical_environment_p->container = jrt_set_bit_field_value (new_lexical_environment_p->container,
+                                                                  true,
+                                                                  ECMA_OBJECT_IS_LEXICAL_ENVIRONMENT_POS,
+                                                                  ECMA_OBJECT_IS_LEXICAL_ENVIRONMENT_WIDTH);
 
-  new_lexical_environment_p->properties_cp = ECMA_NULL_POINTER;
+  new_lexical_environment_p->container = jrt_set_bit_field_value (new_lexical_environment_p->container,
+                                                                  ECMA_LEXICAL_ENVIRONMENT_OBJECTBOUND,
+                                                                  ECMA_OBJECT_LEX_ENV_TYPE_POS,
+                                                                  ECMA_OBJECT_LEX_ENV_TYPE_WIDTH);
 
-  ECMA_SET_POINTER(new_lexical_environment_p->u.lexical_environment.outer_reference_cp, outer_lexical_environment_p);
+  uint64_t outer_reference_cp;
+  ECMA_SET_POINTER (outer_reference_cp, outer_lexical_environment_p);
+  new_lexical_environment_p->container = jrt_set_bit_field_value (new_lexical_environment_p->container,
+                                                                  outer_reference_cp,
+                                                                  ECMA_OBJECT_LEX_ENV_OUTER_REFERENCE_CP_POS,
+                                                                  ECMA_OBJECT_LEX_ENV_OUTER_REFERENCE_CP_WIDTH);
 
   ecma_property_t *provide_this_prop_p = ecma_create_internal_property (new_lexical_environment_p,
                                                                         ECMA_INTERNAL_PROPERTY_PROVIDE_THIS);
@@ -127,7 +174,9 @@ ecma_is_lexical_environment (ecma_object_t *object_p) /**< object or lexical env
 {
   JERRY_ASSERT (object_p != NULL);
 
-  return object_p->is_lexical_environment;
+  return jrt_extract_bit_field (object_p->container,
+                                ECMA_OBJECT_IS_LEXICAL_ENVIRONMENT_POS,
+                                ECMA_OBJECT_IS_LEXICAL_ENVIRONMENT_WIDTH);
 } /* ecma_is_lexical_environment */
 
 /**
@@ -139,7 +188,9 @@ ecma_get_object_extensible (ecma_object_t *object_p) /**< object */
   JERRY_ASSERT (object_p != NULL);
   JERRY_ASSERT (!ecma_is_lexical_environment (object_p));
 
-  return object_p->u.object.extensible;
+  return jrt_extract_bit_field (object_p->container,
+                                ECMA_OBJECT_OBJ_EXTENSIBLE_POS,
+                                ECMA_OBJECT_OBJ_EXTENSIBLE_WIDTH);
 } /* ecma_get_object_extensible */
 
 /**
@@ -152,7 +203,10 @@ ecma_set_object_extensible (ecma_object_t *object_p, /**< object */
   JERRY_ASSERT (object_p != NULL);
   JERRY_ASSERT (!ecma_is_lexical_environment (object_p));
 
-  object_p->u.object.extensible = is_extensible;
+  object_p->container = jrt_set_bit_field_value (object_p->container,
+                                                 is_extensible,
+                                                 ECMA_OBJECT_OBJ_EXTENSIBLE_POS,
+                                                 ECMA_OBJECT_OBJ_EXTENSIBLE_WIDTH);
 } /* ecma_set_object_extensible */
 
 /**
@@ -164,7 +218,9 @@ ecma_get_object_type (ecma_object_t *object_p) /**< object */
   JERRY_ASSERT (object_p != NULL);
   JERRY_ASSERT (!ecma_is_lexical_environment (object_p));
 
-  return object_p->u.object.type;
+  return jrt_extract_bit_field (object_p->container,
+                                ECMA_OBJECT_OBJ_TYPE_POS,
+                                ECMA_OBJECT_OBJ_TYPE_WIDTH);
 } /* ecma_get_object_type */
 
 /**
@@ -177,7 +233,10 @@ ecma_set_object_type (ecma_object_t *object_p, /**< object */
   JERRY_ASSERT (object_p != NULL);
   JERRY_ASSERT (!ecma_is_lexical_environment (object_p));
 
-  object_p->u.object.type = type;
+  object_p->container = jrt_set_bit_field_value (object_p->container,
+                                                 type,
+                                                 ECMA_OBJECT_OBJ_TYPE_POS,
+                                                 ECMA_OBJECT_OBJ_TYPE_WIDTH);
 } /* ecma_set_object_type */
 
 /**
@@ -189,7 +248,11 @@ ecma_get_object_prototype (ecma_object_t *object_p) /**< object */
   JERRY_ASSERT (object_p != NULL);
   JERRY_ASSERT (!ecma_is_lexical_environment (object_p));
 
-  return (ecma_object_t*) ECMA_GET_POINTER (object_p->u.object.prototype_object_cp);
+  JERRY_ASSERT (sizeof (uintptr_t) * JERRY_BITSINBYTE >= ECMA_OBJECT_PROPERTIES_CP_WIDTH);
+  uintptr_t prototype_object_cp = (uintptr_t) jrt_extract_bit_field (object_p->container,
+                                                                     ECMA_OBJECT_OBJ_PROTOTYPE_OBJECT_CP_POS,
+                                                                     ECMA_OBJECT_OBJ_PROTOTYPE_OBJECT_CP_WIDTH);
+  return ECMA_GET_POINTER (prototype_object_cp);
 } /* ecma_get_object_prototype */
 
 /**
@@ -201,7 +264,9 @@ ecma_get_lex_env_type (ecma_object_t *object_p) /**< lexical environment */
   JERRY_ASSERT (object_p != NULL);
   JERRY_ASSERT (ecma_is_lexical_environment (object_p));
 
-  return (ecma_lexical_environment_type_t) object_p->u.lexical_environment.type;
+  return jrt_extract_bit_field (object_p->container,
+                                ECMA_OBJECT_LEX_ENV_TYPE_POS,
+                                ECMA_OBJECT_LEX_ENV_TYPE_WIDTH);
 } /* ecma_get_lex_env_type */
 
 /**
@@ -213,7 +278,11 @@ ecma_get_lex_env_outer_reference (ecma_object_t *object_p) /**< lexical environm
   JERRY_ASSERT (object_p != NULL);
   JERRY_ASSERT (ecma_is_lexical_environment (object_p));
 
-  return (ecma_object_t*) ECMA_GET_POINTER (object_p->u.lexical_environment.outer_reference_cp);
+  JERRY_ASSERT (sizeof (uintptr_t) * JERRY_BITSINBYTE >= ECMA_OBJECT_PROPERTIES_CP_WIDTH);
+  uintptr_t outer_reference_cp = (uintptr_t) jrt_extract_bit_field (object_p->container,
+                                                                    ECMA_OBJECT_LEX_ENV_OUTER_REFERENCE_CP_POS,
+                                                                    ECMA_OBJECT_LEX_ENV_OUTER_REFERENCE_CP_WIDTH);
+  return ECMA_GET_POINTER (outer_reference_cp);
 } /* ecma_get_lex_env_outer_reference */
 
 /**
@@ -224,9 +293,31 @@ ecma_get_property_list (ecma_object_t *object_p) /**< object or lexical environm
 {
   JERRY_ASSERT (object_p != NULL);
 
-  return (ecma_property_t*) ECMA_GET_POINTER (object_p->properties_cp);
+  JERRY_ASSERT (sizeof (uintptr_t) * JERRY_BITSINBYTE >= ECMA_OBJECT_PROPERTIES_CP_WIDTH);
+  uintptr_t properties_cp = (uintptr_t) jrt_extract_bit_field (object_p->container,
+                                                               ECMA_OBJECT_PROPERTIES_CP_POS,
+                                                               ECMA_OBJECT_PROPERTIES_CP_WIDTH);
+  return ECMA_GET_POINTER (properties_cp);
 } /* ecma_get_property_list */
 
+/**
+ * Set object's/lexical environment's property list.
+ */
+static void
+ecma_set_property_list (ecma_object_t *object_p, /**< object or lexical environment */
+                        ecma_property_t *property_list_p) /**< properties' list */
+{
+  JERRY_ASSERT (object_p != NULL);
+
+  uint64_t properties_cp;
+  ECMA_SET_POINTER (properties_cp, property_list_p);
+
+  object_p->container = jrt_set_bit_field_value (object_p->container,
+                                                 properties_cp,
+                                                 ECMA_OBJECT_PROPERTIES_CP_POS,
+                                                 ECMA_OBJECT_PROPERTIES_CP_WIDTH);
+} /* ecma_set_property_list */
+
 /**
  * Create internal property in an object and link it into
  * the object's properties' linked-list (at start of the list).
@@ -241,9 +332,9 @@ ecma_create_internal_property (ecma_object_t *object_p, /**< the object */
 
   new_property_p->type = ECMA_PROPERTY_INTERNAL;
 
-  ecma_property_t *list_head_p = ECMA_GET_POINTER(object_p->properties_cp);
+  ecma_property_t *list_head_p = ecma_get_property_list (object_p);
   ECMA_SET_POINTER(new_property_p->next_property_p, list_head_p);
-  ECMA_SET_NON_NULL_POINTER(object_p->properties_cp, new_property_p);
+  ecma_set_property_list (object_p, new_property_p);
 
   new_property_p->u.internal_property.type = property_id;
   new_property_p->u.internal_property.value = ECMA_NULL_POINTER;
@@ -329,10 +420,10 @@ ecma_create_named_data_property (ecma_object_t *obj_p, /**< object */
 
   prop_p->u.named_data_property.value = ecma_make_simple_value (ECMA_SIMPLE_VALUE_UNDEFINED);
 
-  ecma_property_t *list_head_p = ECMA_GET_POINTER(obj_p->properties_cp);
+  ecma_property_t *list_head_p = ecma_get_property_list (obj_p);
 
   ECMA_SET_POINTER(prop_p->next_property_p, list_head_p);
-  ECMA_SET_NON_NULL_POINTER(obj_p->properties_cp, prop_p);
+  ecma_set_property_list (obj_p, prop_p);
 
   return prop_p;
 } /* ecma_create_named_data_property */
@@ -368,9 +459,9 @@ ecma_create_named_accessor_property (ecma_object_t *obj_p, /**< object */
   prop_p->u.named_accessor_property.enumerable = enumerable;
   prop_p->u.named_accessor_property.configurable = configurable;
 
-  ecma_property_t *list_head_p = ECMA_GET_POINTER(obj_p->properties_cp);
+  ecma_property_t *list_head_p = ecma_get_property_list (obj_p);
   ECMA_SET_POINTER(prop_p->next_property_p, list_head_p);
-  ECMA_SET_NON_NULL_POINTER(obj_p->properties_cp, prop_p);
+  ecma_set_property_list (obj_p, prop_p);
 
   return prop_p;
 } /* ecma_create_named_accessor_property */
@@ -577,7 +668,7 @@ void
 ecma_delete_property (ecma_object_t *obj_p, /**< object */
                       ecma_property_t *prop_p) /**< property */
 {
-  for (ecma_property_t *cur_prop_p = ECMA_GET_POINTER(obj_p->properties_cp), *prev_prop_p = NULL, *next_prop_p;
+  for (ecma_property_t *cur_prop_p = ecma_get_property_list (obj_p), *prev_prop_p = NULL, *next_prop_p;
        cur_prop_p != NULL;
        prev_prop_p = cur_prop_p, cur_prop_p = next_prop_p)
   {
@@ -589,7 +680,7 @@ ecma_delete_property (ecma_object_t *obj_p, /**< object */
 
       if (prev_prop_p == NULL)
       {
-        ECMA_SET_POINTER(obj_p->properties_cp, next_prop_p);
+        ecma_set_property_list (obj_p, next_prop_p);
       }
       else
       {
diff --git a/src/libecmaoperations/ecma-lex-env.c b/src/libecmaoperations/ecma-lex-env.c
index a2abc89e1..2452249ad 100644
--- a/src/libecmaoperations/ecma-lex-env.c
+++ b/src/libecmaoperations/ecma-lex-env.c
@@ -517,7 +517,7 @@ ecma_is_lexical_environment_global (ecma_object_t *lex_env_p) /**< lexical envir
   JERRY_ASSERT(lex_env_p != NULL
                && ecma_is_lexical_environment (lex_env_p));
 
-  ecma_lexical_environment_type_t type = lex_env_p->u.lexical_environment.type;
+  ecma_lexical_environment_type_t type = ecma_get_lex_env_type (lex_env_p);
 
   bool ret_value = false;
 
diff --git a/src/libruntime/jrt-bit-fields.c b/src/libruntime/jrt-bit-fields.c
new file mode 100644
index 000000000..0f0870db8
--- /dev/null
+++ b/src/libruntime/jrt-bit-fields.c
@@ -0,0 +1,60 @@
+/* Copyright 2014 Samsung Electronics Co., Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "globals.h"
+#include "jrt-bit-fields.h"
+
+/**
+ * Extract a bit-field from the integer.
+ *
+ * @return bit-field's value
+ */
+extern uint64_t
+jrt_extract_bit_field (uint64_t container, /**< container to extract bit-field from */
+                       uint32_t lsb, /**< least significant bit of the value
+                                      *   to be extracted */
+                       uint32_t width) /**< width of the bit-field to be extracted */
+{
+  JERRY_ASSERT (lsb < JERRY_BITSINBYTE * sizeof (uint64_t));
+  JERRY_ASSERT ((lsb + width) <= JERRY_BITSINBYTE * sizeof (uint64_t));
+
+  uint64_t shifted_value = container >> lsb;
+  uint64_t bit_field_mask = (1ull << width) - 1;
+
+  return (shifted_value & bit_field_mask);
+} /* jrt_extract_bit_field */
+
+/**
+ * Extract a bit-field from the integer.
+ *
+ * @return bit-field's value
+ */
+extern uint64_t
+jrt_set_bit_field_value (uint64_t container, /**< container to insert bit-field to */
+                         uint64_t new_bit_field_value, /**< value of bit-field to insert */
+                         uint32_t lsb, /**< least significant bit of the value
+                                        *   to be extracted */
+                         uint32_t width) /**< width of the bit-field to be extracted */
+{
+  JERRY_ASSERT (lsb < JERRY_BITSINBYTE * sizeof (uint64_t));
+  JERRY_ASSERT ((lsb + width) <= JERRY_BITSINBYTE * sizeof (uint64_t));
+  JERRY_ASSERT (new_bit_field_value <= (1ull << width));
+
+  uint64_t bit_field_mask = (1ull << width) - 1;
+  uint64_t shifted_bit_field_mask = bit_field_mask << lsb;
+  uint64_t shifted_new_bit_field_value = new_bit_field_value << lsb;
+
+  return (container & ~shifted_bit_field_mask) | shifted_new_bit_field_value;
+} /* jrt_set_bit_field_value */
diff --git a/src/libruntime/jrt-bit-fields.h b/src/libruntime/jrt-bit-fields.h
new file mode 100644
index 000000000..34112409b
--- /dev/null
+++ b/src/libruntime/jrt-bit-fields.h
@@ -0,0 +1,24 @@
+/* Copyright 2014 Samsung Electronics Co., Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef JERRY_BIT_FIELDS_H
+#define JERRY_BIT_FIELDS_H
+
+extern uint64_t jrt_extract_bit_field (uint64_t value, uint32_t lsb,
+                                       uint32_t width);
+extern uint64_t jrt_set_bit_field_value (uint64_t value, uint64_t bit_field_value,
+                                         uint32_t lsb, uint32_t width);
+
+#endif /* !JERRY_BIT_FIELDS_H */