Optimize conditional jumps.

The ecma_op_to_boolean return value is changed to bool for faster
evaluation, and no need to swap operandos of relational compare.

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

Author: zherczeg

jerry-core/ecma/base/ecma-globals.h

@@ -73,12 +73,12 @@ typedef enum
    *   - immutable binding values
    *   - special register or stack values for vm
    */
-  ECMA_SIMPLE_VALUE_EMPTY,
-  ECMA_SIMPLE_VALUE_UNDEFINED, /**< undefined value */
-  ECMA_SIMPLE_VALUE_NULL, /**< null value */
+  ECMA_SIMPLE_VALUE_EMPTY, /**< uninitialized value */
+  ECMA_SIMPLE_VALUE_ARRAY_HOLE, /**< array hole, used for initialization of an array literal */
   ECMA_SIMPLE_VALUE_FALSE, /**< boolean false */
   ECMA_SIMPLE_VALUE_TRUE, /**< boolean true */
-  ECMA_SIMPLE_VALUE_ARRAY_HOLE, /**< array hole, used for initialization of an array literal */
+  ECMA_SIMPLE_VALUE_UNDEFINED, /**< undefined value */
+  ECMA_SIMPLE_VALUE_NULL, /**< null value */
   ECMA_SIMPLE_VALUE_REGISTER_REF, /**< register reference, a special "base" value for vm */
   ECMA_SIMPLE_VALUE__COUNT /** count of simple ecma values */
 } ecma_simple_value_t;

jerry-core/ecma/base/ecma-helpers-value.c

@@ -59,6 +59,10 @@ JERRY_STATIC_ASSERT (sizeof (uintptr_t) > sizeof (ecma_value_t),
 
 #endif /* ECMA_VALUE_CAN_STORE_UINTPTR_VALUE_DIRECTLY */
 
+JERRY_STATIC_ASSERT ((ECMA_SIMPLE_VALUE_FALSE | 0x1) == ECMA_SIMPLE_VALUE_TRUE
+                     && ECMA_SIMPLE_VALUE_FALSE != ECMA_SIMPLE_VALUE_TRUE,
+                     only_the_lowest_bit_must_be_different_for_simple_value_true_and_false);
+
 /**
  * Get type field of ecma value
  *
@@ -109,6 +113,18 @@ ecma_get_pointer_from_ecma_value (ecma_value_t value) /**< value */
 #endif /* ECMA_VALUE_CAN_STORE_UINTPTR_VALUE_DIRECTLY */
 } /* ecma_get_pointer_from_ecma_value */
 
+/**
+ * Check if the value is simple ecma-value.
+ *
+ * @return true - if the value is a simple value,
+ *         false - otherwise.
+ */
+inline bool __attr_pure___ __attr_always_inline___
+ecma_is_value_simple (ecma_value_t value) /**< ecma value */
+{
+  return (value & ECMA_DIRECT_TYPE_MASK) == ECMA_DIRECT_TYPE_SIMPLE_VALUE;
+} /* ecma_is_value_simple */
+
 /**
  * Check whether the value is a given simple value.
  *
@@ -167,7 +183,7 @@ ecma_is_value_null (ecma_value_t value) /**< ecma value */
 inline bool __attr_pure___ __attr_always_inline___
 ecma_is_value_boolean (ecma_value_t value) /**< ecma value */
 {
-  return ecma_is_value_true (value) || ecma_is_value_false (value);
+  return ecma_is_value_true (value | (1 << ECMA_DIRECT_SHIFT));
 } /* ecma_is_value_boolean */
 
 /**
@@ -500,6 +516,14 @@ ecma_get_integer_from_value (ecma_value_t value) /**< ecma value */
   return ((ecma_integer_value_t) value) >> ECMA_DIRECT_SHIFT;
 } /* ecma_get_integer_from_value */
 
+inline ecma_number_t __attr_pure___ __attr_always_inline___
+ecma_get_float_from_value (ecma_value_t value) /**< ecma value */
+{
+  JERRY_ASSERT (ecma_get_value_type_field (value) == ECMA_TYPE_FLOAT);
+
+  return *(ecma_number_t *) ecma_get_pointer_from_ecma_value (value);
+} /* ecma_get_float_from_value */
+
 /**
  * Get floating point value from an ecma value
  *
@@ -513,9 +537,7 @@ ecma_get_number_from_value (ecma_value_t value) /**< ecma value */
     return (ecma_number_t) ecma_get_integer_from_value (value);
   }
 
-  JERRY_ASSERT (ecma_get_value_type_field (value) == ECMA_TYPE_FLOAT);
-
-  return *(ecma_number_t *) ecma_get_pointer_from_ecma_value (value);
+  return ecma_get_float_from_value (value);
 } /* ecma_get_number_from_value */
 
 /**
@@ -563,6 +585,19 @@ ecma_get_object_from_value (ecma_value_t value) /**< ecma value */
   return (ecma_object_t *) ecma_get_pointer_from_ecma_value (value);
 } /* ecma_get_object_from_value */
 
+/**
+ * Invert a boolean value
+ *
+ * @return ecma value
+ */
+inline ecma_value_t __attr_pure___ __attr_always_inline___
+ecma_invert_boolean_value (ecma_value_t value) /**< ecma value */
+{
+  JERRY_ASSERT (ecma_is_value_boolean (value));
+
+  return (value ^ (1 << ECMA_DIRECT_SHIFT));
+} /* ecma_invert_boolean_value */
+
 /**
  * Get the value from an error ecma value
  *

jerry-core/ecma/base/ecma-helpers.h

@@ -114,26 +114,27 @@
   }
 
 /* ecma-helpers-value.c */
-extern bool ecma_is_value_empty (ecma_value_t);
-extern bool ecma_is_value_undefined (ecma_value_t);
-extern bool ecma_is_value_null (ecma_value_t);
-extern bool ecma_is_value_boolean (ecma_value_t);
-extern bool ecma_is_value_true (ecma_value_t);
-extern bool ecma_is_value_false (ecma_value_t);
-extern bool ecma_is_value_array_hole (ecma_value_t);
-
-extern bool ecma_is_value_integer_number (ecma_value_t);
-extern bool ecma_are_values_integer_numbers (ecma_value_t, ecma_value_t);
-extern bool ecma_is_value_float_number (ecma_value_t);
-extern bool ecma_is_value_number (ecma_value_t);
-extern bool ecma_is_value_string (ecma_value_t);
-extern bool ecma_is_value_object (ecma_value_t);
-extern bool ecma_is_value_error (ecma_value_t);
+extern bool ecma_is_value_simple (ecma_value_t) __attr_pure___;
+extern bool ecma_is_value_empty (ecma_value_t) __attr_pure___;
+extern bool ecma_is_value_undefined (ecma_value_t) __attr_pure___;
+extern bool ecma_is_value_null (ecma_value_t) __attr_pure___;
+extern bool ecma_is_value_boolean (ecma_value_t) __attr_pure___;
+extern bool ecma_is_value_true (ecma_value_t) __attr_pure___;
+extern bool ecma_is_value_false (ecma_value_t) __attr_pure___;
+extern bool ecma_is_value_array_hole (ecma_value_t) __attr_pure___;
+
+extern bool ecma_is_value_integer_number (ecma_value_t) __attr_pure___;
+extern bool ecma_are_values_integer_numbers (ecma_value_t, ecma_value_t) __attr_pure___;
+extern bool ecma_is_value_float_number (ecma_value_t) __attr_pure___;
+extern bool ecma_is_value_number (ecma_value_t) __attr_pure___;
+extern bool ecma_is_value_string (ecma_value_t) __attr_pure___;
+extern bool ecma_is_value_object (ecma_value_t) __attr_pure___;
+extern bool ecma_is_value_error (ecma_value_t) __attr_pure___;
 
 extern void ecma_check_value_type_is_spec_defined (ecma_value_t);
 
-extern ecma_value_t ecma_make_simple_value (const ecma_simple_value_t value);
-extern ecma_value_t ecma_make_integer_value (ecma_integer_value_t);
+extern ecma_value_t ecma_make_simple_value (const ecma_simple_value_t value) __attr_const___;
+extern ecma_value_t ecma_make_integer_value (ecma_integer_value_t) __attr_const___;
 extern ecma_value_t ecma_make_nan_value (void);
 extern ecma_value_t ecma_make_number_value (ecma_number_t);
 extern ecma_value_t ecma_make_int32_value (int32_t);
@@ -142,12 +143,14 @@ extern ecma_value_t ecma_make_string_value (const ecma_string_t *);
 extern ecma_value_t ecma_make_object_value (const ecma_object_t *);
 extern ecma_value_t ecma_make_error_value (ecma_value_t);
 extern ecma_value_t ecma_make_error_obj_value (const ecma_object_t *);
-extern ecma_integer_value_t ecma_get_integer_from_value (ecma_value_t);
+extern ecma_integer_value_t ecma_get_integer_from_value (ecma_value_t) __attr_pure___;
+extern ecma_number_t ecma_get_float_from_value (ecma_value_t value) __attr_pure___;
 extern ecma_number_t ecma_get_number_from_value (ecma_value_t) __attr_pure___;
 extern uint32_t ecma_get_uint32_from_value (ecma_value_t) __attr_pure___;
 extern ecma_string_t *ecma_get_string_from_value (ecma_value_t) __attr_pure___;
 extern ecma_object_t *ecma_get_object_from_value (ecma_value_t) __attr_pure___;
 extern ecma_value_t ecma_get_value_from_error_value (ecma_value_t) __attr_pure___;
+extern ecma_value_t ecma_invert_boolean_value (ecma_value_t) __attr_pure___;
 extern ecma_value_t ecma_copy_value (ecma_value_t);
 extern ecma_value_t ecma_fast_copy_value (ecma_value_t);
 extern ecma_value_t ecma_copy_value_if_not_object (ecma_value_t);

jerry-core/ecma/builtin-objects/ecma-builtin-array-prototype.c

@@ -2027,8 +2027,8 @@ ecma_builtin_array_prototype_object_every (ecma_value_t this_arg, /**< this argu
         /* 7.c.ii */
         ECMA_TRY_CATCH (call_value, ecma_op_function_call (func_object_p, arg2, call_args, 3), ret_value);
 
-        /* 7.c.iii, ecma_op_to_boolean always returns a simple value, so no need to free. */
-        if (ecma_is_value_false (ecma_op_to_boolean (call_value)))
+        /* 7.c.iii */
+        if (!ecma_op_to_boolean (call_value))
         {
           ret_value = ecma_make_simple_value (ECMA_SIMPLE_VALUE_FALSE);
         }
@@ -2125,8 +2125,8 @@ ecma_builtin_array_prototype_object_some (ecma_value_t this_arg, /**< this argum
         /* 7.c.ii */
         ECMA_TRY_CATCH (call_value, ecma_op_function_call (func_object_p, arg2, call_args, 3), ret_value);
 
-        /* 7.c.iii, ecma_op_to_boolean always returns a simple value, so no need to free. */
-        if (ecma_is_value_true (ecma_op_to_boolean (call_value)))
+        /* 7.c.iii */
+        if (ecma_op_to_boolean (call_value))
         {
           ret_value = ecma_make_simple_value (ECMA_SIMPLE_VALUE_TRUE);
         }
@@ -2430,8 +2430,8 @@ ecma_builtin_array_prototype_object_filter (ecma_value_t this_arg, /**< this arg
         /* 9.c.ii */
         ECMA_TRY_CATCH (call_value, ecma_op_function_call (func_object_p, arg2, call_args, 3), ret_value);
 
-        /* 9.c.iii, ecma_op_to_boolean always returns a simple value, so no need to free. */
-        if (ecma_is_value_true (ecma_op_to_boolean (call_value)))
+        /* 9.c.iii */
+        if (ecma_op_to_boolean (call_value))
         {
           ecma_string_t *to_index_string_p = ecma_new_ecma_string_from_uint32 (new_array_index);
 

jerry-core/ecma/builtin-objects/ecma-builtin-boolean.c

@@ -66,7 +66,8 @@ ecma_builtin_boolean_dispatch_call (const ecma_value_t *arguments_list_p, /**< a
     arg_value = arguments_list_p[0];
   }
 
-  return ecma_op_to_boolean (arg_value);
+  return ecma_make_simple_value (ecma_op_to_boolean (arg_value) ? ECMA_SIMPLE_VALUE_TRUE
+                                                                : ECMA_SIMPLE_VALUE_FALSE);
 } /* ecma_builtin_boolean_dispatch_call */
 
 /**

jerry-core/ecma/operations/ecma-boolean-object.c

@@ -41,12 +41,7 @@
 ecma_value_t
 ecma_op_create_boolean_object (ecma_value_t arg) /**< argument passed to the Boolean constructor */
 {
-  ecma_value_t conv_to_boolean_completion = ecma_op_to_boolean (arg);
-
-  if (ecma_is_value_error (conv_to_boolean_completion))
-  {
-    return conv_to_boolean_completion;
-  }
+  bool boolean_value = ecma_op_to_boolean (arg);
 
 #ifndef CONFIG_ECMA_COMPACT_PROFILE_DISABLE_BOOLEAN_BUILTIN
   ecma_object_t *prototype_obj_p = ecma_builtin_get (ECMA_BUILTIN_ID_BOOLEAN_PROTOTYPE);
@@ -64,7 +59,11 @@ ecma_op_create_boolean_object (ecma_value_t arg) /**< argument passed to the Boo
 
   ecma_property_t *prim_value_prop_p = ecma_create_internal_property (obj_p,
                                                                       ECMA_INTERNAL_PROPERTY_ECMA_VALUE);
-  ecma_set_internal_property_value (prim_value_prop_p, conv_to_boolean_completion);
+
+  ecma_value_t prim_value = ecma_make_simple_value (boolean_value ? ECMA_SIMPLE_VALUE_TRUE
+                                                                  : ECMA_SIMPLE_VALUE_FALSE);
+
+  ecma_set_internal_property_value (prim_value_prop_p, prim_value);
 
   return ecma_make_object_value (obj_p);
 } /* ecma_op_create_boolean_object */

jerry-core/ecma/operations/ecma-comparison.c

@@ -334,15 +334,12 @@ ecma_op_abstract_relational_compare (ecma_value_t x, /**< first operand */
 {
   ecma_value_t ret_value = ecma_make_simple_value (ECMA_SIMPLE_VALUE_EMPTY);
 
-  ecma_value_t first_converted_value = left_first ? x : y;
-  ecma_value_t second_converted_value = left_first ? y : x;
-
   // 1., 2.
   ECMA_TRY_CATCH (prim_first_converted_value,
-                  ecma_op_to_primitive (first_converted_value, ECMA_PREFERRED_TYPE_NUMBER),
+                  ecma_op_to_primitive (x, ECMA_PREFERRED_TYPE_NUMBER),
                   ret_value);
   ECMA_TRY_CATCH (prim_second_converted_value,
-                  ecma_op_to_primitive (second_converted_value, ECMA_PREFERRED_TYPE_NUMBER),
+                  ecma_op_to_primitive (y, ECMA_PREFERRED_TYPE_NUMBER),
                   ret_value);
 
   const ecma_value_t px = left_first ? prim_first_converted_value : prim_second_converted_value;