#32434 [NEW]: Bad result for float multiplication

From: vblavet@php.net Operating system: Windows XP PHP version: 4.3.10 PHP Bug Type: Variables related Bug description: Bad result for float multiplication Description: ------------ When multiplying two float, the truncated result is not correct. Reproduce code: --------------- <?php $v1 = (float)0x5a05df1b; $v2 = (float)0x2d02ef8d; echo 'v1='.sprintf("0x%X (%d)", $v1, $v1).'<br>'; echo 'v2='.sprintf("0x%X (%d)", $v2, $v2).'<br>'; (float)$v3=(float)$v1*(float)$v2; echo 'v1*v2='.sprintf("0x%X (%d)", (float)$v3, (float)$v3).'<br>'; // Actual result is : // v1=0x5A05DF1B (1510334235) // v2=0x2D02EF8D (755167117) // v1*v2=0x8DBC1700 (-1917053184) // // Result should be : 0xFD410808DBC16DF // Truncated should be : 0x8DBC16DF ?> Expected result: ---------------- Result should be : 0xFD410808DBC16DF, because variable is a float, result should be truncated like that : 0x8DBC16DF Actual result: -------------- v1*v2=0x8DBC1700 (-1917053184) -- Edit bug report at http://bugs.php.net/?id=32434&edit=1 -- Try a CVS snapshot (php4): http://bugs.php.net/fix.php?id=32434&r=trysnapshot4 Try a CVS snapshot (php5.0): http://bugs.php.net/fix.php?id=32434&r=trysnapshot50 Try a CVS snapshot (php5.1): http://bugs.php.net/fix.php?id=32434&r=trysnapshot51 Fixed in CVS: http://bugs.php.net/fix.php?id=32434&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=32434&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=32434&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=32434&r=needscript Try newer version: http://bugs.php.net/fix.php?id=32434&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=32434&r=support Expected behavior: http://bugs.php.net/fix.php?id=32434&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=32434&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=32434&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=32434&r=globals PHP 3 support discontinued: http://bugs.php.net/fix.php?id=32434&r=php3 Daylight Savings: http://bugs.php.net/fix.php?id=32434&r=dst IIS Stability: http://bugs.php.net/fix.php?id=32434&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=32434&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=32434&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=32434&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=32434&r=mysqlcfg