diff --git a/jerry-core/ecma/base/ecma-helpers-value.c b/jerry-core/ecma/base/ecma-helpers-value.c
index 23389ba00..a6626d8ed 100644
--- a/jerry-core/ecma/base/ecma-helpers-value.c
+++ b/jerry-core/ecma/base/ecma-helpers-value.c
@@ -66,7 +66,7 @@ JERRY_STATIC_ASSERT ((ECMA_SIMPLE_VALUE_FALSE | 0x1) == ECMA_SIMPLE_VALUE_TRUE
  *
  * @return type field
  */
-static inline ecma_type_t __attr_pure___ __attr_always_inline___
+static inline ecma_type_t __attr_const___ __attr_always_inline___
 ecma_get_value_type_field (ecma_value_t value) /**< ecma value */
 {
   return value & ECMA_VALUE_TYPE_MASK;
@@ -117,7 +117,7 @@ ecma_get_pointer_from_ecma_value (ecma_value_t value) /**< value */
  * @return true - if the value is a direct value,
  *         false - otherwise
  */
-inline bool __attr_pure___ __attr_always_inline___
+inline bool __attr_const___ __attr_always_inline___
 ecma_is_value_direct (ecma_value_t value) /**< ecma value */
 {
   return (ecma_get_value_type_field (value) == ECMA_TYPE_DIRECT);
@@ -129,7 +129,7 @@ ecma_is_value_direct (ecma_value_t value) /**< ecma value */
  * @return true - if the value is a simple value,
  *         false - otherwise
  */
-inline bool __attr_pure___ __attr_always_inline___
+inline bool __attr_const___ __attr_always_inline___
 ecma_is_value_simple (ecma_value_t value) /**< ecma value */
 {
   return (value & ECMA_DIRECT_TYPE_MASK) == ECMA_DIRECT_TYPE_SIMPLE_VALUE;
@@ -141,7 +141,7 @@ ecma_is_value_simple (ecma_value_t value) /**< ecma value */
  * @return true - if the value is equal to the given simple value,
  *         false - otherwise
  */
-static inline bool __attr_pure___ __attr_always_inline___
+static inline bool __attr_const___ __attr_always_inline___
 ecma_is_value_equal_to_simple_value (ecma_value_t value, /**< ecma value */
                                      ecma_simple_value_t simple_value) /**< simple value */
 {
@@ -154,7 +154,7 @@ ecma_is_value_equal_to_simple_value (ecma_value_t value, /**< ecma value */
  * @return true - if the value contains implementation-defined empty simple value,
  *         false - otherwise
  */
-inline bool __attr_pure___ __attr_always_inline___
+inline bool __attr_const___ __attr_always_inline___
 ecma_is_value_empty (ecma_value_t value) /**< ecma value */
 {
   return ecma_is_value_equal_to_simple_value (value, ECMA_SIMPLE_VALUE_EMPTY);
@@ -166,7 +166,7 @@ ecma_is_value_empty (ecma_value_t value) /**< ecma value */
  * @return true - if the value contains ecma-undefined simple value,
  *         false - otherwise
  */
-inline bool __attr_pure___ __attr_always_inline___
+inline bool __attr_const___ __attr_always_inline___
 ecma_is_value_undefined (ecma_value_t value) /**< ecma value */
 {
   return ecma_is_value_equal_to_simple_value (value, ECMA_SIMPLE_VALUE_UNDEFINED);
@@ -178,7 +178,7 @@ ecma_is_value_undefined (ecma_value_t value) /**< ecma value */
  * @return true - if the value contains ecma-null simple value,
  *         false - otherwise
  */
-inline bool __attr_pure___ __attr_always_inline___
+inline bool __attr_const___ __attr_always_inline___
 ecma_is_value_null (ecma_value_t value) /**< ecma value */
 {
   return ecma_is_value_equal_to_simple_value (value, ECMA_SIMPLE_VALUE_NULL);
@@ -190,7 +190,7 @@ 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
  */
-inline bool __attr_pure___ __attr_always_inline___
+inline bool __attr_const___ __attr_always_inline___
 ecma_is_value_boolean (ecma_value_t value) /**< ecma value */
 {
   return ecma_is_value_true (value | (1 << ECMA_DIRECT_SHIFT));
@@ -202,7 +202,7 @@ ecma_is_value_boolean (ecma_value_t value) /**< ecma value */
  * @return true - if the value contains ecma-true simple value,
  *         false - otherwise
  */
-inline bool __attr_pure___ __attr_always_inline___
+inline bool __attr_const___ __attr_always_inline___
 ecma_is_value_true (ecma_value_t value) /**< ecma value */
 {
   return ecma_is_value_equal_to_simple_value (value, ECMA_SIMPLE_VALUE_TRUE);
@@ -214,7 +214,7 @@ ecma_is_value_true (ecma_value_t value) /**< ecma value */
  * @return true - if the value contains ecma-false simple value,
  *         false - otherwise
  */
-inline bool __attr_pure___ __attr_always_inline___
+inline bool __attr_const___ __attr_always_inline___
 ecma_is_value_false (ecma_value_t value) /**< ecma value */
 {
   return ecma_is_value_equal_to_simple_value (value, ECMA_SIMPLE_VALUE_FALSE);
@@ -226,7 +226,7 @@ ecma_is_value_false (ecma_value_t value) /**< ecma value */
  * @return true - if the value contains ecma-not-found simple value,
  *         false - otherwise
  */
-inline bool __attr_pure___ __attr_always_inline___
+inline bool __attr_const___ __attr_always_inline___
 ecma_is_value_found (ecma_value_t value) /**< ecma value */
 {
   return value != ecma_make_simple_value (ECMA_SIMPLE_VALUE_NOT_FOUND);
@@ -238,7 +238,7 @@ ecma_is_value_found (ecma_value_t value) /**< ecma value */
  * @return true - if the value contains ecma-array-hole simple value,
  *         false - otherwise
  */
-inline bool __attr_pure___ __attr_always_inline___
+inline bool __attr_const___ __attr_always_inline___
 ecma_is_value_array_hole (ecma_value_t value) /**< ecma value */
 {
   return ecma_is_value_equal_to_simple_value (value, ECMA_SIMPLE_VALUE_ARRAY_HOLE);
@@ -250,7 +250,7 @@ ecma_is_value_array_hole (ecma_value_t value) /**< ecma value */
  * @return true - if the value contains an integer ecma-number value,
  *         false - otherwise
  */
-inline bool __attr_pure___ __attr_always_inline___
+inline bool __attr_const___ __attr_always_inline___
 ecma_is_value_integer_number (ecma_value_t value) /**< ecma value */
 {
   return (value & ECMA_DIRECT_TYPE_MASK) == ECMA_DIRECT_TYPE_INTEGER_VALUE;
@@ -262,7 +262,7 @@ ecma_is_value_integer_number (ecma_value_t value) /**< ecma value */
  * @return true - if both values contain integer ecma-number values,
  *         false - otherwise
  */
-inline bool __attr_pure___ __attr_always_inline___
+inline bool __attr_const___ __attr_always_inline___
 ecma_are_values_integer_numbers (ecma_value_t first_value, /**< first ecma value */
                                  ecma_value_t second_value) /**< second ecma value */
 {
@@ -278,7 +278,7 @@ ecma_are_values_integer_numbers (ecma_value_t first_value, /**< first ecma value
  * @return true - if the value contains a floating-point ecma-number value,
  *         false - otherwise
  */
-inline bool __attr_pure___ __attr_always_inline___
+inline bool __attr_const___ __attr_always_inline___
 ecma_is_value_float_number (ecma_value_t value) /**< ecma value */
 {
   return (ecma_get_value_type_field (value) == ECMA_TYPE_FLOAT);
@@ -290,7 +290,7 @@ ecma_is_value_float_number (ecma_value_t value) /**< ecma value */
  * @return true - if the value contains ecma-number value,
  *         false - otherwise
  */
-inline bool __attr_pure___ __attr_always_inline___
+inline bool __attr_const___ __attr_always_inline___
 ecma_is_value_number (ecma_value_t value) /**< ecma value */
 {
   return (ecma_is_value_integer_number (value)
@@ -303,7 +303,7 @@ ecma_is_value_number (ecma_value_t value) /**< ecma value */
  * @return true - if the value contains ecma-string value,
  *         false - otherwise
  */
-inline bool __attr_pure___ __attr_always_inline___
+inline bool __attr_const___ __attr_always_inline___
 ecma_is_value_string (ecma_value_t value) /**< ecma value */
 {
   return (ecma_get_value_type_field (value) == ECMA_TYPE_STRING);
@@ -315,7 +315,7 @@ ecma_is_value_string (ecma_value_t value) /**< ecma value */
  * @return true - if the value contains object value,
  *         false - otherwise
  */
-inline bool __attr_pure___ __attr_always_inline___
+inline bool __attr_const___ __attr_always_inline___
 ecma_is_value_object (ecma_value_t value) /**< ecma value */
 {
   return (ecma_get_value_type_field (value) == ECMA_TYPE_OBJECT);
@@ -378,7 +378,7 @@ ecma_make_integer_value (ecma_integer_value_t integer_value) /**< integer number
  *
  * @return ecma-value
  */
-static ecma_value_t __attr_const___
+static ecma_value_t
 ecma_create_float_number (ecma_number_t ecma_number) /**< value of the float number */
 {
   ecma_number_t *ecma_num_p = ecma_alloc_number ();
@@ -485,7 +485,7 @@ ecma_make_uint32_value (uint32_t uint32_number) /**< uint32 number to be encoded
 /**
  * String value constructor
  */
-ecma_value_t __attr_const___
+ecma_value_t __attr_pure___
 ecma_make_string_value (const ecma_string_t *ecma_string_p) /**< string to reference in value */
 {
   JERRY_ASSERT (ecma_string_p != NULL);
@@ -496,7 +496,7 @@ ecma_make_string_value (const ecma_string_t *ecma_string_p) /**< string to refer
 /**
  * Object value constructor
  */
-ecma_value_t __attr_const___
+ecma_value_t __attr_pure___
 ecma_make_object_value (const ecma_object_t *object_p) /**< object to reference in value */
 {
   JERRY_ASSERT (object_p != NULL);
@@ -519,7 +519,7 @@ ecma_make_error_value (ecma_value_t value) /**< original ecma value */
 /**
  * Error value constructor
  */
-ecma_value_t __attr_const___
+ecma_value_t __attr_pure___
 ecma_make_error_obj_value (const ecma_object_t *object_p) /**< object to reference in value */
 {
   return ecma_make_error_value (ecma_make_object_value (object_p));
@@ -530,7 +530,7 @@ ecma_make_error_obj_value (const ecma_object_t *object_p) /**< object to referen
  *
  * @return floating point value
  */
-inline ecma_integer_value_t __attr_pure___ __attr_always_inline___
+inline ecma_integer_value_t __attr_const___ __attr_always_inline___
 ecma_get_integer_from_value (ecma_value_t value) /**< ecma value */
 {
   JERRY_ASSERT (ecma_is_value_integer_number (value));
@@ -593,7 +593,7 @@ ecma_get_object_from_value (ecma_value_t value) /**< ecma value */
  *
  * @return ecma value
  */
-inline ecma_value_t __attr_pure___ __attr_always_inline___
+inline ecma_value_t __attr_const___ __attr_always_inline___
 ecma_invert_boolean_value (ecma_value_t value) /**< ecma value */
 {
   JERRY_ASSERT (ecma_is_value_boolean (value));
@@ -606,7 +606,7 @@ ecma_invert_boolean_value (ecma_value_t value) /**< ecma value */
  *
  * @return ecma value
  */
-ecma_value_t __attr_pure___
+ecma_value_t __attr_const___
 ecma_get_value_from_error_value (ecma_value_t value) /**< ecma value */
 {
   JERRY_ASSERT (ECMA_IS_VALUE_ERROR (value));
diff --git a/jerry-core/ecma/base/ecma-helpers.h b/jerry-core/ecma/base/ecma-helpers.h
index a0b56e2d3..1731a5942 100644
--- a/jerry-core/ecma/base/ecma-helpers.h
+++ b/jerry-core/ecma/base/ecma-helpers.h
@@ -111,23 +111,23 @@
   }
 
 /* ecma-helpers-value.c */
-bool ecma_is_value_direct (ecma_value_t value) __attr_pure___;
-bool ecma_is_value_simple (ecma_value_t value) __attr_pure___;
-bool ecma_is_value_empty (ecma_value_t value) __attr_pure___;
-bool ecma_is_value_undefined (ecma_value_t value) __attr_pure___;
-bool ecma_is_value_null (ecma_value_t value) __attr_pure___;
-bool ecma_is_value_boolean (ecma_value_t value) __attr_pure___;
-bool ecma_is_value_true (ecma_value_t value) __attr_pure___;
-bool ecma_is_value_false (ecma_value_t value) __attr_pure___;
-bool ecma_is_value_found (ecma_value_t value) __attr_pure___;
-bool ecma_is_value_array_hole (ecma_value_t value) __attr_pure___;
+bool ecma_is_value_direct (ecma_value_t value) __attr_const___;
+bool ecma_is_value_simple (ecma_value_t value) __attr_const___;
+bool ecma_is_value_empty (ecma_value_t value) __attr_const___;
+bool ecma_is_value_undefined (ecma_value_t value) __attr_const___;
+bool ecma_is_value_null (ecma_value_t value) __attr_const___;
+bool ecma_is_value_boolean (ecma_value_t value) __attr_const___;
+bool ecma_is_value_true (ecma_value_t value) __attr_const___;
+bool ecma_is_value_false (ecma_value_t value) __attr_const___;
+bool ecma_is_value_found (ecma_value_t value) __attr_const___;
+bool ecma_is_value_array_hole (ecma_value_t value) __attr_const___;
 
-bool ecma_is_value_integer_number (ecma_value_t value) __attr_pure___;
-bool ecma_are_values_integer_numbers (ecma_value_t first_value, ecma_value_t second_value) __attr_pure___;
-bool ecma_is_value_float_number (ecma_value_t value) __attr_pure___;
-bool ecma_is_value_number (ecma_value_t value) __attr_pure___;
-bool ecma_is_value_string (ecma_value_t value) __attr_pure___;
-bool ecma_is_value_object (ecma_value_t value) __attr_pure___;
+bool ecma_is_value_integer_number (ecma_value_t value) __attr_const___;
+bool ecma_are_values_integer_numbers (ecma_value_t first_value, ecma_value_t second_value) __attr_const___;
+bool ecma_is_value_float_number (ecma_value_t value) __attr_const___;
+bool ecma_is_value_number (ecma_value_t value) __attr_const___;
+bool ecma_is_value_string (ecma_value_t value) __attr_const___;
+bool ecma_is_value_object (ecma_value_t value) __attr_const___;
 
 void ecma_check_value_type_is_spec_defined (ecma_value_t value);
 
@@ -138,17 +138,17 @@ ecma_value_t ecma_make_nan_value (void);
 ecma_value_t ecma_make_number_value (ecma_number_t ecma_number);
 ecma_value_t ecma_make_int32_value (int32_t int32_number);
 ecma_value_t ecma_make_uint32_value (uint32_t uint32_number);
-ecma_value_t ecma_make_string_value (const ecma_string_t *ecma_string_p);
-ecma_value_t ecma_make_object_value (const ecma_object_t *object_p);
-ecma_value_t ecma_make_error_value (ecma_value_t value);
-ecma_value_t ecma_make_error_obj_value (const ecma_object_t *object_p);
-ecma_integer_value_t ecma_get_integer_from_value (ecma_value_t value) __attr_pure___;
+ecma_value_t ecma_make_string_value (const ecma_string_t *ecma_string_p) __attr_pure___;
+ecma_value_t ecma_make_object_value (const ecma_object_t *object_p) __attr_pure___;
+ecma_value_t ecma_make_error_value (ecma_value_t value) __attr_const___;
+ecma_value_t ecma_make_error_obj_value (const ecma_object_t *object_p) __attr_pure___;
+ecma_integer_value_t ecma_get_integer_from_value (ecma_value_t value) __attr_const___;
 ecma_number_t ecma_get_float_from_value (ecma_value_t value) __attr_pure___;
 ecma_number_t ecma_get_number_from_value (ecma_value_t value) __attr_pure___;
 ecma_string_t *ecma_get_string_from_value (ecma_value_t value) __attr_pure___;
 ecma_object_t *ecma_get_object_from_value (ecma_value_t value) __attr_pure___;
-ecma_value_t ecma_get_value_from_error_value (ecma_value_t value) __attr_pure___;
-ecma_value_t ecma_invert_boolean_value (ecma_value_t value) __attr_pure___;
+ecma_value_t ecma_get_value_from_error_value (ecma_value_t value) __attr_const___;
+ecma_value_t ecma_invert_boolean_value (ecma_value_t value) __attr_const___;
 ecma_value_t ecma_copy_value (ecma_value_t value);
 ecma_value_t ecma_fast_copy_value (ecma_value_t value);
 ecma_value_t ecma_copy_value_if_not_object (ecma_value_t value);
diff --git a/jerry-core/jmem/jmem-allocator.c b/jerry-core/jmem/jmem-allocator.c
index f79d649d9..a99dc19c5 100644
--- a/jerry-core/jmem/jmem-allocator.c
+++ b/jerry-core/jmem/jmem-allocator.c
@@ -56,7 +56,7 @@ jmem_finalize (void)
  *
  * @return packed pointer
  */
-inline jmem_cpointer_t __attr_always_inline___
+inline jmem_cpointer_t __attr_pure___ __attr_always_inline___
 jmem_compress_pointer (const void *pointer_p) /**< pointer to compress */
 {
   JERRY_ASSERT (pointer_p != NULL);
@@ -90,7 +90,7 @@ jmem_compress_pointer (const void *pointer_p) /**< pointer to compress */
  *
  * @return unpacked pointer
  */
-inline void * __attr_always_inline___
+inline void * __attr_pure___ __attr_always_inline___
 jmem_decompress_pointer (uintptr_t compressed_pointer) /**< pointer to decompress */
 {
   JERRY_ASSERT (compressed_pointer != JMEM_CP_NULL);
diff --git a/jerry-core/jmem/jmem.h b/jerry-core/jmem/jmem.h
index edab5acc4..5168adf2b 100644
--- a/jerry-core/jmem/jmem.h
+++ b/jerry-core/jmem/jmem.h
@@ -16,6 +16,8 @@
 #ifndef JMEM_H
 #define JMEM_H
 
+#include "jrt.h"
+
 /** \addtogroup mem Memory allocation
  * @{
  *
@@ -143,8 +145,8 @@ void jmem_stats_reset_peak (void);
 void jmem_stats_print (void);
 #endif /* JMEM_STATS */
 
-jmem_cpointer_t jmem_compress_pointer (const void *pointer_p);
-void *jmem_decompress_pointer (uintptr_t compressed_pointer);
+jmem_cpointer_t jmem_compress_pointer (const void *pointer_p) __attr_pure___;
+void *jmem_decompress_pointer (uintptr_t compressed_pointer) __attr_pure___;
 
 /**
  * A free memory callback routine type.
diff --git a/jerry-core/jrt/jrt.h b/jerry-core/jrt/jrt.h
index 1f781637c..d5181aa0c 100644
--- a/jerry-core/jrt/jrt.h
+++ b/jerry-core/jrt/jrt.h
@@ -31,13 +31,13 @@
 #define __attr_return_value_should_be_checked___ __attribute__((warn_unused_result))
 #define __attr_hot___ __attribute__((hot))
 #ifndef __attr_always_inline___
-# define __attr_always_inline___ __attribute__((always_inline))
+#define __attr_always_inline___ __attribute__((always_inline))
 #endif /* !__attr_always_inline___ */
 #ifndef __attr_const___
-# define __attr_const___ __attribute__((const))
+#define __attr_const___ __attribute__((const))
 #endif /* !__attr_const___ */
 #ifndef __attr_pure___
-# define __attr_pure___ __attribute__((pure))
+#define __attr_pure___ __attribute__((pure))
 #endif /* !__attr_pure___ */
 
 /*
diff --git a/jerry-core/parser/regexp/re-bytecode.h b/jerry-core/parser/regexp/re-bytecode.h
index 43f54e738..c1661515b 100644
--- a/jerry-core/parser/regexp/re-bytecode.h
+++ b/jerry-core/parser/regexp/re-bytecode.h
@@ -103,7 +103,7 @@ typedef struct
 re_opcode_t re_get_opcode (uint8_t **bc_p);
 ecma_char_t re_get_char (uint8_t **bc_p);
 uint32_t re_get_value (uint8_t **bc_p);
-uint32_t re_get_bytecode_length (re_bytecode_ctx_t *bc_ctx_p);
+uint32_t re_get_bytecode_length (re_bytecode_ctx_t *bc_ctx_p) __attr_pure___;
 
 void re_append_opcode (re_bytecode_ctx_t *bc_ctx_p, re_opcode_t opcode);
 void re_append_u32 (re_bytecode_ctx_t *bc_ctx_p, uint32_t value);