Bug #76287 [NEW]: bcmod returns incorrect values

From: kacper dot rowinski at gmail dot com Operating system: Linux debian PHP version: 7.2.5 Package: BC math related Bug Type: Bug Bug description:bcmod returns incorrect values Description: ------------ Using bcmod on float return incorrect value Test script: --------------- <?php $leftOperand = '0.00000000099999'; $modulus = '-0.00056'; $scale =14; // incorrect : echo bcmod($leftOperand,$modulus, $scale); // this how it should work // mod(a, b) = a - b * floor(a/b) /* echo bcsub( $leftOperand, bcmul( $modulus, floor(bcdiv($leftOperand, $modulus, $scale)), $scale ), $scale ); */ Expected result: ---------------- -0.00055999900001 Actual result: -------------- 0.00000000099999 -- Edit bug report at https://bugs.php.net/bug.php?id=76287&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=76287&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=76287&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=76287&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=76287&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=76287&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=76287&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=76287&r=needscript Try newer version: https://bugs.php.net/fix.php?id=76287&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=76287&r=support Expected behavior: https://bugs.php.net/fix.php?id=76287&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=76287&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=76287&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=76287&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=76287&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=76287&r=dst IIS Stability: https://bugs.php.net/fix.php?id=76287&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=76287&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=76287&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=76287&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=76287&r=mysqlcfg