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Improve toFixed function

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Fixes #1367.
From now numbers are represented as binary floating-point which guarantees the expected operation of toFixed function.

JerryScript-DCO-1.0-Signed-off-by: Robert Fancsik frobert@inf.u-szeged.hu
This commit is contained in:
Robert Fancsik
2017-07-14 19:38:13 +02:00
committed by yichoi
parent 148f91c90d
commit ad608e30dc
4 changed files with 199 additions and 22 deletions
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jerry-core/ecma/builtin-objects/ecma-builtin-number-prototype.c
+56 -17
View File
@@ -125,6 +125,41 @@ ecma_builtin_number_prototype_helper_to_string (lit_utf8_byte_t *digits_p, /**<
return (lit_utf8_size_t) (p - to_digits_p);
} /* ecma_builtin_number_prototype_helper_to_string */
static inline lit_utf8_size_t __attr_always_inline___
ecma_builtin_binary_floating_number_to_string (lit_utf8_byte_t *digits_p, /**< number as string
* in binary-floating point number */
lit_utf8_size_t num_digits, /**< length of the string representation */
int32_t exponent, /**< decimal exponent */
lit_utf8_byte_t *to_digits_p, /**< [out] buffer to write */
lit_utf8_size_t to_num_digits) /**< requested number of digits */
{
lit_utf8_byte_t *p = to_digits_p;
/* Add significant digits of the decimal part. */
while (exponent > 0)
{
*p++ = *digits_p++;
exponent--;
to_num_digits--;
}
if (to_num_digits > 0)
{
*p++ = '.';
}
if (to_num_digits > 0)
{
/* Add significant digits of the fraction part. */
while (to_num_digits > 0)
{
*p++ = num_digits == 1 ? '0' : *digits_p++;
to_num_digits--;
}
}
return (lit_utf8_size_t) (p - to_digits_p);
} /* ecma_builtin_binary_floating_number_to_string */
/**
* Helper for rounding numbers
*
@@ -135,14 +170,15 @@ ecma_builtin_number_prototype_helper_round (lit_utf8_byte_t *digits_p, /**< [in,
* form */
lit_utf8_size_t num_digits, /**< length of the string representation */
int32_t round_num, /**< number of digits to keep */
int32_t *exponent_p) /**< [in, out] decimal exponent */
int32_t *exponent_p, /**< [in, out] decimal exponent */
bool zero) /**< true if digits_p represents zero */
{
if (round_num < 1)
{
return 0;
}
if ((lit_utf8_size_t) round_num >= num_digits)
if ((lit_utf8_size_t) round_num >= num_digits || zero)
{
return num_digits;
}
@@ -509,7 +545,7 @@ ecma_builtin_number_prototype_object_to_fixed (ecma_value_t this_arg, /**< this
bool is_negative = false;
if (ecma_number_is_negative (this_num))
{
is_negative = true;
is_negative = ecma_number_is_zero (this_num) ? false : true;
this_num *= -1;
}
@@ -537,15 +573,19 @@ ecma_builtin_number_prototype_object_to_fixed (ecma_value_t this_arg, /**< this
lit_utf8_byte_t digits[ECMA_MAX_CHARS_IN_STRINGIFIED_NUMBER];
lit_utf8_size_t num_digits;
int32_t exponent;
int32_t frac_digits = ecma_number_to_int32 (arg_num);
if (!ecma_number_is_zero (this_num))
{
num_digits = ecma_number_to_decimal (this_num, digits, &exponent);
num_digits = ecma_number_to_binary_floating_point_number (this_num, digits, &exponent);
}
else
{
digits[0] = '0';
num_digits = 1;
for (int32_t i = 0; i <= frac_digits; i++)
{
digits[i] = '0';
}
num_digits = (lit_utf8_size_t) frac_digits + 1;
exponent = 1;
}
@@ -558,12 +598,11 @@ ecma_builtin_number_prototype_object_to_fixed (ecma_value_t this_arg, /**< this
else
{
/* 1. */
int32_t frac_digits = ecma_number_to_int32 (arg_num);
num_digits = ecma_builtin_number_prototype_helper_round (digits,
num_digits,
num_digits + 1,
exponent + frac_digits,
&exponent);
&exponent,
ecma_number_is_zero (this_num) ? true : false);
/* Buffer that is used to construct the string. */
int buffer_size = (exponent > 0) ? exponent + frac_digits + 2 : frac_digits + 3;
@@ -585,11 +624,11 @@ ecma_builtin_number_prototype_object_to_fixed (ecma_value_t this_arg, /**< this
lit_utf8_size_t to_num_digits = ((exponent > 0) ? (lit_utf8_size_t) (exponent + frac_digits)
: (lit_utf8_size_t) (frac_digits + 1));
p += ecma_builtin_number_prototype_helper_to_string (digits,
num_digits,
exponent,
p,
to_num_digits);
p += ecma_builtin_binary_floating_number_to_string (digits,
num_digits,
exponent,
p,
to_num_digits);
JERRY_ASSERT (p - buff < buffer_size);
/* String terminator. */
@@ -698,7 +737,7 @@ ecma_builtin_number_prototype_object_to_exponential (ecma_value_t this_arg, /**<
frac_digits = ecma_number_to_int32 (arg_num);
}
num_digits = ecma_builtin_number_prototype_helper_round (digits, num_digits, frac_digits + 1, &exponent);
num_digits = ecma_builtin_number_prototype_helper_round (digits, num_digits, frac_digits + 1, &exponent, false);
/* frac_digits + 2 characters for number, 5 characters for exponent, 1 for \0. */
int buffer_size = frac_digits + 2 + 5 + 1;
@@ -842,7 +881,7 @@ ecma_builtin_number_prototype_object_to_precision (ecma_value_t this_arg, /**< t
int32_t precision = ecma_number_to_int32 (arg_num);
num_digits = ecma_builtin_number_prototype_helper_round (digits, num_digits, precision, &exponent);
num_digits = ecma_builtin_number_prototype_helper_round (digits, num_digits, precision, &exponent, false);
int buffer_size;
if (exponent < -5 || exponent > precision)