php-src/ext/standard/float_to_double.c
Keyur Govande f2eadb93b9 Fix for bugs #68114 (Build fails on OS X due to undefined symbols)
and #68657 (Reading 4 byte floats with Mysqli and libmysqlclient
has rounding errors).

The patch removes support for Decimal floating point numbers and
now defaults to using similar logic as what libmysqlclient does:
convert a 4 byte floating point number into a string, and then the
string into a double. The quirks of MySQL are maintained as seen in
Field_Float::val_str()
2015-01-07 22:45:23 +00:00

55 lines
2 KiB
C

/*
+----------------------------------------------------------------------+
| PHP Version 5 |
+----------------------------------------------------------------------+
| Copyright (c) 2006-2014 The PHP Group |
+----------------------------------------------------------------------+
| This source file is subject to version 3.01 of the PHP license, |
| that is bundled with this package in the file LICENSE, and is |
| available through the world-wide-web at the following url: |
| http://www.php.net/license/3_01.txt |
| If you did not receive a copy of the PHP license and are unable to |
| obtain it through the world-wide-web, please send a note to |
| license@php.net so we can mail you a copy immediately. |
+----------------------------------------------------------------------+
| Authors: Keyur Govande <kgovande@gmail.com> |
+----------------------------------------------------------------------+
*/
#include <float.h>
#include "float_to_double.h"
#include "main/snprintf.h"
#define MAX_BUF_LEN 255
#ifndef FLT_DIG
# define FLT_DIG 6
#endif
/*
* Convert from a 4-byte float to a 8-byte decimal by first converting
* the float to a string, and then the string to a double.
* The decimals argument specifies the precision of the output. If decimals
* is less than zero, then a gcvt(3) like logic is used with the significant
* digits set to FLT_DIG i.e. 6.
*/
double float_to_double(float fp4, int decimals) {
char num_buf[MAX_BUF_LEN]; /* Over allocated */
if (decimals < 0) {
php_gcvt(fp4, FLT_DIG, '.', 'e', num_buf);
} else {
php_sprintf(num_buf, "%.*f", decimals, fp4);
}
return zend_strtod(num_buf, NULL);
}
/*
* Local variables:
* tab-width: 4
* c-basic-offset: 4
* End:
* vim600: noet sw=4 ts=4 fdm=marker
* vim<600: noet sw=4 ts=4
*/