diff --git a/src/libjsparser/lexer.c b/src/libjsparser/lexer.c
index 0e4da1cb3..b2e338e2f 100644
--- a/src/libjsparser/lexer.c
+++ b/src/libjsparser/lexer.c
@@ -14,19 +14,23 @@
  */
 
 #include "mem-allocator.h"
-#include "globals.h"
 #include "jerry-libc.h"
 #include "lexer.h"
 #include "parser.h"
 
 static token saved_token;
-static token empty_token = { .type = TOK_EMPTY, .data.uid = 0 };
+static token empty_token =
+{
+  .type =
+  TOK_EMPTY,
+  .data.uid = 0
+};
 static bool allow_dump_lines = false;
 static size_t buffer_size = 0;
 
 typedef struct
 {
-  int num;
+  ecma_number_t num;
   token tok;
 }
 num_and_token;
@@ -35,12 +39,8 @@ num_and_token;
 
 static uint8_t seen_names_count = 0;
 
-static num_and_token seen_nums[MAX_NUMS] =
-{
-  [0] = { .num = 0, .tok = { .type = TOK_INT, .data.uid = 0 } },
-  [1] = { .num = 1, .tok = { .type = TOK_INT, .data.uid = 1 } }
-};
-static uint8_t seen_nums_count = 2;
+static num_and_token seen_nums[MAX_NUMS];
+static uint8_t seen_nums_count = 0;
 
 static bool
 is_empty (token tok)
@@ -574,12 +574,13 @@ add_token_to_seen_names (token_type tt, const char *string)
 }
 
 static token
-convert_seen_num_to_token (int num)
+convert_seen_num_to_token (ecma_number_t num)
 {
   size_t i;
 
   for (i = 0; i < seen_nums_count; i++)
   {
+    // token must be exactly the same as seen
     if (seen_nums[i].num == num)
     {
       return seen_nums[i].tok;
@@ -636,7 +637,7 @@ lexer_get_string_by_id (uint8_t id)
 }
 
 uint8_t
-lexer_get_nums (int32_t *nums)
+lexer_get_nums (ecma_number_t *nums)
 {
   int i;
 
@@ -868,7 +869,16 @@ parse_number (void)
 
     token_start = NULL;
 
-    known_token = convert_seen_num_to_token (res);
+    if (res <= 255)
+    {
+      return (token)
+      {
+        .type = TOK_SMALL_INT,
+        .data.uid = (uint8_t) res
+      };
+    }
+
+    known_token = convert_seen_num_to_token ((ecma_number_t) res);
     if (!is_empty (known_token))
     {
       return known_token;
@@ -876,12 +886,16 @@ parse_number (void)
 
     known_token = (token)
     {
-      .type = TOK_INT, .data.uid = seen_nums_count
+      .type = TOK_NUMBER,
+      .data.uid = seen_nums_count
     };
-    add_num_to_seen_tokens ((num_and_token)
-    {
-      .num = res, .tok = known_token
-    });
+    add_num_to_seen_tokens (
+      (num_and_token)
+      {
+        .num = (ecma_number_t) res,
+        .tok = known_token
+      }
+    );
     return known_token;
   }
 
@@ -948,10 +962,28 @@ parse_number (void)
 
   if (is_fp || is_exp)
   {
-    float res = __strtof (token_start, NULL);
+    ecma_number_t res = __strtof (token_start, NULL);
     token_start = NULL;
-    JERRY_UNIMPLEMENTED_REF_UNUSED_VARS (res);
-    return empty_token;
+
+    known_token = convert_seen_num_to_token (res);
+    if (!is_empty (known_token))
+    {
+      return known_token;
+    }
+
+    known_token = (token)
+    {
+      .type = TOK_NUMBER,
+      .data.uid = seen_nums_count
+    };
+    add_num_to_seen_tokens (
+      (num_and_token)
+      {
+        .num = res,
+        .tok = known_token
+      }
+    );
+    return known_token;
   }
 
   tok_length = (size_t) (buffer - token_start);;
@@ -962,7 +994,16 @@ parse_number (void)
 
   token_start = NULL;
 
-  known_token = convert_seen_num_to_token (res);
+  if (res <= 255)
+  {
+    return (token)
+    {
+      .type = TOK_SMALL_INT,
+      .data.uid = (uint8_t) res
+    };
+  }
+
+  known_token = convert_seen_num_to_token ((ecma_number_t) res);
   if (!is_empty (known_token))
   {
     return known_token;
@@ -970,12 +1011,16 @@ parse_number (void)
 
   known_token = (token)
   {
-    .type = TOK_INT, .data.uid = seen_nums_count
+    .type = TOK_NUMBER,
+    .data.uid = seen_nums_count
   };
-  add_num_to_seen_tokens ((num_and_token)
-  {
-    .num = res, .tok = known_token
-  });
+  add_num_to_seen_tokens (
+    (num_and_token)
+    {
+      .num = (ecma_number_t) res,
+      .tok = known_token
+    }
+  );
   return known_token;
 }
 
diff --git a/src/libjsparser/lexer.h b/src/libjsparser/lexer.h
index 9b7f3b62d..0d9627e26 100644
--- a/src/libjsparser/lexer.h
+++ b/src/libjsparser/lexer.h
@@ -17,7 +17,7 @@
 #define LEXER_H
 
 #include "globals.h"
-
+#include "ecma-globals.h"
 
 /* Keywords.  */
 typedef uint8_t keyword;
@@ -65,8 +65,8 @@ typedef uint8_t token_type;
 #define TOK_EOF 0 // End of file
 #define TOK_NAME 1 // Identifier
 #define TOK_KEYWORD 2 // Keyword
-#define TOK_INT 3
-#define TOK_FLOAT 4
+#define TOK_SMALL_INT 3
+#define TOK_NUMBER 4
 
 #define TOK_NULL 5
 #define TOK_BOOL 6
@@ -144,7 +144,8 @@ typedef struct
     uint8_t uid;
   }
   data;
-} __packed
+}
+__packed
 token;
 
 void lexer_init (const char *, size_t, bool);
@@ -156,7 +157,7 @@ void lexer_dump_buffer_state (void);
 uint8_t lexer_get_strings (const char **);
 uint8_t lexer_get_reserved_ids_count (void);
 const char *lexer_get_string_by_id (uint8_t);
-uint8_t lexer_get_nums (int32_t *);
+uint8_t lexer_get_nums (ecma_number_t *);
 void lexer_adjust_num_ids (void);
 
 #endif
diff --git a/src/libjsparser/parser.c b/src/libjsparser/parser.c
index 9428f4c2e..7e72fc012 100644
--- a/src/libjsparser/parser.c
+++ b/src/libjsparser/parser.c
@@ -38,7 +38,8 @@ typedef struct
   uint8_t size;
   uint8_t head;
   opcode_counter_t *oc_stack;
-} __packed
+}
+__packed
 rewritable_opcode;
 
 #define NESTING_ITERATIONAL 1
@@ -160,7 +161,7 @@ is_keyword (keyword kw)
 }
 
 static void
-current_token_must_be(token_type tt)
+current_token_must_be (token_type tt)
 {
   if (tok.type != tt)
   {
@@ -296,10 +297,10 @@ integer_zero (void)
 }
 
 static T_IDX
-integer_one (void)
+boolean_true (void)
 {
   T_IDX lhs = next_temp_name ();
-  DUMP_OPCODE_3 (assignment, lhs, OPCODE_ARG_TYPE_SMALLINT, 1);
+  DUMP_OPCODE_3 (assignment, lhs, OPCODE_ARG_TYPE_SIMPLE, ECMA_SIMPLE_VALUE_TRUE);
   return lhs;
 }
 
@@ -416,13 +417,20 @@ dump_intrinsic (T_IDX obj, T_IDX args[3])
 static T_IDX
 parse_property_name (void)
 {
+  T_IDX lhs;
+
   switch (tok.type)
   {
     case TOK_NAME:
     case TOK_STRING:
-    case TOK_INT:
+    case TOK_NUMBER:
       return tok.data.uid;
 
+    case TOK_SMALL_INT:
+      lhs = next_temp_name ();
+      DUMP_OPCODE_3 (assignment, lhs, OPCODE_ARG_TYPE_SMALLINT, tok.data.uid);
+      return lhs;
+
     default:
       JERRY_UNREACHABLE ();
   }
@@ -845,7 +853,7 @@ parse_function_expression (void)
   T_IDX name, lhs;
   opcode_counter_t jmp_oc;
 
-  assert_keyword  (KW_FUNCTION);
+  assert_keyword (KW_FUNCTION);
 
   skip_newlines ();
   if (tok.type == TOK_NAME)
@@ -915,11 +923,16 @@ parse_literal (void)
                      tok.data.uid ? ECMA_SIMPLE_VALUE_TRUE : ECMA_SIMPLE_VALUE_FALSE);
       return lhs;
 
-    case TOK_INT:
+    case TOK_NUMBER:
       lhs = next_temp_name ();
       DUMP_OPCODE_3 (assignment, lhs, OPCODE_ARG_TYPE_NUMBER, tok.data.uid);
       return lhs;
 
+    case TOK_SMALL_INT:
+      lhs = next_temp_name ();
+      DUMP_OPCODE_3 (assignment, lhs, OPCODE_ARG_TYPE_SMALLINT, tok.data.uid);
+      return lhs;
+
     case TOK_STRING:
       lhs = next_temp_name ();
       DUMP_OPCODE_3 (assignment, lhs, OPCODE_ARG_TYPE_STRING, tok.data.uid);
@@ -949,34 +962,38 @@ parse_primary_expression (void)
     DUMP_OPCODE_1 (this, lhs);
     return lhs;
   }
-  else if (tok.type == TOK_NAME)
+
+  switch (tok.type)
   {
-    return tok.data.uid;
+    case TOK_NAME:
+      return tok.data.uid;
+
+    case TOK_NULL:
+    case TOK_BOOL:
+    case TOK_SMALL_INT:
+    case TOK_NUMBER:
+    case TOK_STRING:
+      return parse_literal ();
+
+    case TOK_OPEN_SQUARE:
+      return parse_array_literal ();
+
+    case TOK_OPEN_BRACE:
+      return parse_object_literal ();
+
+    case TOK_OPEN_PAREN:
+      skip_newlines ();
+      if (tok.type != TOK_CLOSE_PAREN)
+      {
+        lhs = parse_expression ();
+        token_after_newlines_must_be (TOK_CLOSE_PAREN);
+        return lhs;
+      }
+      // FALLTHRU
+
+    default:
+      JERRY_UNREACHABLE ();
   }
-  else if (tok.type == TOK_NULL || tok.type == TOK_BOOL
-           || tok.type == TOK_INT || tok.type == TOK_STRING)
-  {
-    return parse_literal ();
-  }
-  else if (tok.type == TOK_OPEN_SQUARE)
-  {
-    return parse_array_literal ();
-  }
-  else if (tok.type == TOK_OPEN_BRACE)
-  {
-    return parse_object_literal ();
-  }
-  else if (tok.type == TOK_OPEN_PAREN)
-  {
-    skip_newlines ();
-    if (tok.type != TOK_CLOSE_PAREN)
-    {
-      lhs = parse_expression ();
-      token_after_newlines_must_be (TOK_CLOSE_PAREN);
-      return lhs;
-    }
-  }
-  JERRY_UNREACHABLE ();
 }
 
 /* member_expression
@@ -1677,7 +1694,7 @@ parse_for_or_for_in_statement (void)
   T_IDX stop;
   opcode_counter_t cond_oc, body_oc, step_oc, end_oc;
 
-  assert_keyword  (KW_FOR);
+  assert_keyword (KW_FOR);
   token_after_newlines_must_be (TOK_OPEN_PAREN);
 
   skip_newlines ();
@@ -1771,7 +1788,7 @@ plain_for:
   }
   else
   {
-    stop = integer_one ();
+    stop = boolean_true ();
   }
 
   end_oc = opcode_counter;
@@ -2239,5 +2256,5 @@ parser_fatal (jerry_status_t code)
   __printf ("FATAL: %d\n", code);
   lexer_dump_buffer_state ();
 
-  jerry_exit( code);
+  jerry_exit (code);
 }
diff --git a/src/liboptimizer/deserializer.c b/src/liboptimizer/deserializer.c
index f2f7c88fe..4ec0a3824 100644
--- a/src/liboptimizer/deserializer.c
+++ b/src/liboptimizer/deserializer.c
@@ -16,7 +16,7 @@
 #include "deserializer.h"
 #include "bytecode-data.h"
 
-int *num_data = NULL;
+ecma_number_t *num_data = NULL;
 uint8_t num_size = 0;
 
 const ecma_char_t *
@@ -42,7 +42,7 @@ deserialize_string_by_id (uint8_t id)
   return ((const ecma_char_t *) bytecode_data + offset);
 }
 
-int 
+ecma_number_t 
 deserialize_num_by_id (uint8_t id)
 {
   uint16_t str_size, str_offset;
@@ -65,7 +65,7 @@ deserialize_num_by_id (uint8_t id)
         data++;
   
       num_size = *(++data);
-      num_data = (int *) ++data;
+      num_data = (ecma_number_t *) ++data;
     }
 
   if (id >= num_size)
diff --git a/src/liboptimizer/deserializer.h b/src/liboptimizer/deserializer.h
index d3253f43c..45f067930 100644
--- a/src/liboptimizer/deserializer.h
+++ b/src/liboptimizer/deserializer.h
@@ -20,7 +20,7 @@
 #include "ecma-globals.h"
 
 const ecma_char_t *deserialize_string_by_id (uint8_t);
-int deserialize_num_by_id (uint8_t);
+ecma_number_t deserialize_num_by_id (uint8_t);
 const void *deserialize_bytecode (void);
 uint8_t deserialize_min_temp (void);
 
diff --git a/src/liboptimizer/pretty-printer.c b/src/liboptimizer/pretty-printer.c
index 2535a2815..865d5254f 100644
--- a/src/liboptimizer/pretty-printer.c
+++ b/src/liboptimizer/pretty-printer.c
@@ -52,14 +52,14 @@ pp_strings (const char *strings[], uint8_t size)
 }
 
 void 
-pp_nums (const int32_t nums[], uint8_t size, uint8_t strings_num)
+pp_nums (const ecma_number_t nums[], uint8_t size, uint8_t strings_num)
 {
   uint8_t i;
 
   __printf ("NUMS %d:\n", size);
   for (i = 0; i < size; i++)
     {
-      __printf ("%3d %7d\n", i + strings_num, nums[i]);
+      __printf ("%3d %7d\n", i + strings_num, (int) nums[i]);
     }
   __printf ("\n");
 }
diff --git a/src/liboptimizer/pretty-printer.h b/src/liboptimizer/pretty-printer.h
index 608b482d5..bb22b550c 100644
--- a/src/liboptimizer/pretty-printer.h
+++ b/src/liboptimizer/pretty-printer.h
@@ -20,6 +20,6 @@
 
 void pp_opcode (opcode_counter_t, OPCODE, bool);
 void pp_strings (const char **, uint8_t);
-void pp_nums (const int32_t *, uint8_t, uint8_t);
+void pp_nums (const ecma_number_t *, uint8_t, uint8_t);
 
 #endif // PRETTY_PRINTER
diff --git a/src/liboptimizer/serializer.c b/src/liboptimizer/serializer.c
index 731238808..55debc942 100644
--- a/src/liboptimizer/serializer.c
+++ b/src/liboptimizer/serializer.c
@@ -72,14 +72,14 @@ serializer_dump_strings (const char *strings[], uint8_t size)
 }
 
 void 
-serializer_dump_nums (const int32_t nums[], uint8_t size, uint16_t offset, uint8_t strings_num)
+serializer_dump_nums (const ecma_number_t nums[], uint8_t size, uint16_t offset, uint8_t strings_num)
 {
-  uint8_t i, *data;
+  uint8_t i, *data, type_size = sizeof (ecma_number_t);
 
   if (print_opcodes)
     pp_nums (nums, size, strings_num);
 
-  data = mem_heap_alloc_block ((size_t) (offset + size * 4 + 1), MEM_HEAP_ALLOC_LONG_TERM);
+  data = mem_heap_alloc_block ((size_t) (offset + size * type_size + 1), MEM_HEAP_ALLOC_LONG_TERM);
   if (!data)
     parser_fatal (ERR_MEMORY);
   
@@ -91,8 +91,8 @@ serializer_dump_nums (const int32_t nums[], uint8_t size, uint16_t offset, uint8
   data++;
   for (i = 0; i < size; i++)
     {
-      __memcpy (data, nums + i, 4);
-      data += 4;
+      __memcpy (data, nums + i, type_size);
+      data += type_size;
     }
 
 #ifndef JERRY_NDEBUG
diff --git a/src/liboptimizer/serializer.h b/src/liboptimizer/serializer.h
index efb4f938b..38a8eb7a6 100644
--- a/src/liboptimizer/serializer.h
+++ b/src/liboptimizer/serializer.h
@@ -24,7 +24,7 @@ void serializer_init (bool show_opcodes);
 
 uint16_t serializer_dump_strings (const char **, uint8_t);
 
-void serializer_dump_nums (const int32_t *, uint8_t, uint16_t, uint8_t);
+void serializer_dump_nums (const ecma_number_t *, uint8_t, uint16_t, uint8_t);
 
 void serializer_dump_opcode (OPCODE);
 
diff --git a/src/main.c b/src/main.c
index 07ce24a54..569cf83cf 100644
--- a/src/main.c
+++ b/src/main.c
@@ -36,7 +36,7 @@ static const OPCODE *
 parser_run (const char *script_source, size_t script_source_size, bool is_show_opcodes)
 {
   const char *strings[MAX_STRINGS];
-  int32_t nums[MAX_NUMS];
+  ecma_number_t nums[MAX_NUMS];
   uint8_t strings_num, nums_count;
   uint16_t offset;
   const OPCODE *opcodes;