Bug #70447 [NEW]: Wrong float rounding using round function

From: m dot mochetti at design-it dot de Operating system: Linux (ubuntu) PHP version: 5.5.29 Package: *General Issues Bug Type: Bug Bug description:Wrong float rounding using round function Description: ------------ I'm having a serious issue regarding prices not being properly rounded in a sales platform the company I work for is currently developing. Please take a look at the Test script attached, it showcases the issue. Test script: --------------- <?php $float = 87.755; $units = (int)floor($float); $cents = (float)($float - $units); echo "UNITS = ".$units; // UNITS = 87 echo "<br>"; echo "CENTS = ".$cents; // CENTS = 0.755 echo "<br>"; echo "ROUNDED CENTS = ".round($cents, 2); // ROUNDED CENTS = 0.75 --> WRONG!! echo "<br>"; echo "ROUNDED CENTS (without using variable): ".round(0.755, 2); // ROUNDED CENTS (without var) : 0.76 --> CORRECT!! ?> Expected result: ---------------- round(0.755, 2) should return the same result as round($var, 2) // being $var a calculated value that ended up to be 0.755 Actual result: -------------- round(0.755,2) = 0.76 round($var, 2) = 0.75 -- Edit bug report at https://bugs.php.net/bug.php?id=70447&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=70447&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=70447&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=70447&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=70447&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=70447&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=70447&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=70447&r=needscript Try newer version: https://bugs.php.net/fix.php?id=70447&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=70447&r=support Expected behavior: https://bugs.php.net/fix.php?id=70447&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=70447&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=70447&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=70447&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=70447&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=70447&r=dst IIS Stability: https://bugs.php.net/fix.php?id=70447&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=70447&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=70447&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=70447&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=70447&r=mysqlcfg