YourWishes/jerryscript
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Implementing Math.exp built-in.

Browse Source
This commit is contained in:
Ruben Ayrapetyan
2014-09-24 16:01:42 +04:00
parent 0738ec6a54
commit 85a3a9a690
2 changed files with 113 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/libecmabuiltins/ecma-builtin-math-object.c
+83 -2
View File
@@ -42,7 +42,7 @@
#if defined (CONFIG_ECMA_NUMBER_FLOAT32)
const ecma_number_t ecma_builtin_math_object_relative_eps = 1.0e-10f;
#elif defined (CONFIG_ECMA_NUMBER_FLOAT64)
const ecma_number_t ecma_builtin_math_object_relative_eps = 1.0e-16f;
const ecma_number_t ecma_builtin_math_object_relative_eps = 1.0e-16;
#else /* !CONFIG_ECMA_NUMBER_FLOAT32 && !CONFIG_ECMA_NUMBER_FLOAT64 */
# error "!CONFIG_ECMA_NUMBER_FLOAT32 && !CONFIG_ECMA_NUMBER_FLOAT64"
#endif /* !CONFIG_ECMA_NUMBER_FLOAT32 && !CONFIG_ECMA_NUMBER_FLOAT64 */
@@ -300,7 +300,88 @@ ecma_builtin_math_object_cos (ecma_value_t arg) /**< routine's argument */
static ecma_completion_value_t
ecma_builtin_math_object_exp (ecma_value_t arg) /**< routine's argument */
{
JERRY_UNIMPLEMENTED_REF_UNUSED_VARS (arg);
ecma_completion_value_t ret_value;
ECMA_TRY_CATCH (arg_num_value,
ecma_op_to_number (arg),
ret_value);
ecma_number_t *num_p = ecma_alloc_number ();
const ecma_number_t arg_num = *(ecma_number_t*) ECMA_GET_POINTER (arg_num_value.u.value.value);
if (ecma_number_is_nan (arg_num))
{
*num_p = arg_num;
}
else if (ecma_number_is_zero (arg_num))
{
*num_p = ECMA_NUMBER_ONE;
}
else if (ecma_number_is_infinity (arg_num))
{
if (ecma_number_is_negative (arg_num))
{
*num_p = ECMA_NUMBER_ZERO;
}
else
{
*num_p = arg_num;
}
}
else
{
bool invert = false;
ecma_number_t pow_e;
if (ecma_number_is_negative (arg_num))
{
invert = true;
pow_e = ecma_number_negate (arg_num);
}
else
{
pow_e = arg_num;
}
/* Taylor series of e^x is 1 + x/1! + x^2/2! + x^3/3! + ... + x^n/n! + ... */
ecma_number_t sum = ECMA_NUMBER_ONE;
ecma_number_t next_addendum = ecma_op_number_divide (pow_e, ECMA_NUMBER_ONE);
ecma_number_t next_factorial_factor = ECMA_NUMBER_ONE;
ecma_number_t diff = ecma_number_make_infinity (false);
while (ecma_op_number_divide (diff, sum) > ecma_builtin_math_object_relative_eps)
{
ecma_number_t next_sum = ecma_op_number_add (sum, next_addendum);
next_factorial_factor = ecma_op_number_add (next_factorial_factor, ECMA_NUMBER_ONE);
next_addendum = ecma_op_number_multiply (next_addendum, pow_e);
next_addendum = ecma_op_number_divide (next_addendum, next_factorial_factor);
diff = ecma_op_number_substract (sum, next_sum);
if (diff < 0)
{
diff = ecma_number_negate (diff);
}
sum = next_sum;
}
if (invert)
{
sum = ecma_op_number_divide (ECMA_NUMBER_ONE, sum);
}
*num_p = sum;
}
ret_value = ecma_make_normal_completion_value (ecma_make_number_value (num_p));
ECMA_FINALIZE (arg_num_value);
return ret_value;
} /* ecma_builtin_math_object_exp */
/**