/*
* Rounds a number to a certain number of decimal places in a certain rounding
* mode. For the specifics of the algorithm, see http://wiki.php.net/rfc/rounding
*/
PHPAPI double _php_math_round(double value, int places, int mode) {
double f1, f2;
double tmp_value;
int precision_places;
if (!php_math_is_finite(value)) {
return value;
}
precision_places = 14 - php_intlog10abs(value);
f1 = php_intpow10(abs(places));
/* If the decimal precision guaranteed by FP arithmetic is higher than
the requested places BUT is small enough to make sure a non-zero value
is returned, pre-round the result to the precision */
if (precision_places > places && precision_places - places < 15) {
f2 = php_intpow10(abs(precision_places));
if (precision_places >= 0) {
tmp_value = value * f2;
} else {
tmp_value = value / f2;
}
/* preround the result (tmp_value will always be something * 1e14,
thus never larger than 1e15 here) */
tmp_value = php_round_helper(tmp_value, mode);
/* now correctly move the decimal point */
f2 = php_intpow10(abs(places - precision_places));
/* because places < precision_places */
tmp_value = tmp_value / f2;
} else {
/* adjust the value */
if (places >= 0) {
tmp_value = value * f1;
} else {
tmp_value = value / f1;
}
/* This value is beyond our precision, so rounding it is pointless */
if (fabs(tmp_value) >= 1e15) {
return value;
}
}
/* round the temp value */
tmp_value = php_round_helper(tmp_value, mode);
/* see if it makes sense to use simple division to round the value */
if (abs(places) < 23) {
if (places > 0) {
tmp_value = tmp_value / f1;
} else {
tmp_value = tmp_value * f1;
}
} else {
/* Simple division can't be used since that will cause wrong results.
Instead, the number is converted to a string and back again using
strtod(). strtod() will return the nearest possible FP value for
that string. */
/* 40 Bytes should be more than enough for this format string. The
float won't be larger than 1e15 anyway. But just in case, use
snprintf() and make sure the buffer is zero-terminated */
char buf[40];
snprintf(buf, 39, "%15fe%d", tmp_value, -places);
buf[39] = '\0';
tmp_value = zend_strtod(buf, NULL);
/* couldn't convert to string and back */
if (!zend_finite(tmp_value) || zend_isnan(tmp_value)) {
tmp_value = value;
}
}
return tmp_value;
}
/* php_spintf_appenddouble() {{{ */
inline static void
php_sprintf_appenddouble(char **buffer, int *pos,
int *size, double number,
int width, char padding,
int alignment, int precision,
int adjust, char fmt,
int always_sign
TSRMLS_DC)
{
char num_buf[NUM_BUF_SIZE];
char *s = NULL;
int s_len = 0, is_negative = 0;
#ifdef HAVE_LOCALE_H
struct lconv *lconv;
#endif
PRINTF_DEBUG(("sprintf: appenddouble(%x, %x, %x, %f, %d, '%c', %d, %c)\n",
*buffer, pos, size, number, width, padding, alignment, fmt));
if ((adjust & ADJ_PRECISION) == 0) {
precision = FLOAT_PRECISION;
} else if (precision > MAX_FLOAT_PRECISION) {
php_error_docref(NULL TSRMLS_CC, E_NOTICE, "Requested precision of %d digits was truncated to PHP maximum of %d digits", precision, MAX_FLOAT_PRECISION);
precision = MAX_FLOAT_PRECISION;
}
if (zend_isnan(number)) {
is_negative = (number<0);
php_sprintf_appendstring(buffer, pos, size, "NaN", 3, 0, padding,
alignment, 3, is_negative, 0, always_sign);
return;
}
if (zend_isinf(number)) {
is_negative = (number<0);
php_sprintf_appendstring(buffer, pos, size, "INF", 3, 0, padding,
alignment, 3, is_negative, 0, always_sign);
return;
}
switch (fmt) {
case 'e':
case 'E':
case 'f':
case 'F':
#ifdef HAVE_LOCALE_H
lconv = localeconv();
#endif
s = php_conv_fp((fmt == 'f')?'F':fmt, number, 0, precision,
(fmt == 'f')?LCONV_DECIMAL_POINT:'.',
&is_negative, &num_buf[1], &s_len);
if (is_negative) {
num_buf[0] = '-';
s = num_buf;
s_len++;
} else if (always_sign) {
num_buf[0] = '+';
s = num_buf;
s_len++;
}
break;
case 'g':
case 'G':
if (precision == 0)
precision = 1;
/*
* * We use &num_buf[ 1 ], so that we have room for the sign
*/
#ifdef HAVE_LOCALE_H
lconv = localeconv();
#endif
s = php_gcvt(number, precision, LCONV_DECIMAL_POINT, (fmt == 'G')?'E':'e', &num_buf[1]);
is_negative = 0;
if (*s == '-') {
is_negative = 1;
s = &num_buf[1];
} else if (always_sign) {
num_buf[0] = '+';
s = num_buf;
}
s_len = strlen(s);
break;
}
php_sprintf_appendstring(buffer, pos, size, s, width, 0, padding,
alignment, s_len, is_negative, 0, always_sign);
}
static inline int php_bencode_is_valid_double(double d) /* {{{ */
{
return !zend_isinf(d) && !zend_isnan(d);
}
