Bug #70363 [NEW]: why mb_* so slow?

From: jhdxr Operating system: irrelevent PHP version: 7.0.0RC1 Package: mbstring related Bug Type: Bug Bug description:why mb_* so slow? Description: ------------ It seems mb_* is much slower than the original string related method, there are lots of data in the user contribution section of the manual (<http://php.net/mb_strlen>, <http://php.net/manual/en/function.mb-strtolower.php>). and today I read a post talk about this topic (<https://v2ex.com/t/216212>), and the author use an regular expression instead of mb_*, which is, and to my surprise, much faster. Here is his code: <https://3v4l.org/d8IAo>. So i'm wondering why mb_* is so slow. Are the users use them in a wrong manner, or our implements has some problem? -- Edit bug report at https://bugs.php.net/bug.php?id=70363&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=70363&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=70363&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=70363&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=70363&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=70363&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=70363&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=70363&r=needscript Try newer version: https://bugs.php.net/fix.php?id=70363&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=70363&r=support Expected behavior: https://bugs.php.net/fix.php?id=70363&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=70363&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=70363&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=70363&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=70363&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=70363&r=dst IIS Stability: https://bugs.php.net/fix.php?id=70363&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=70363&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=70363&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=70363&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=70363&r=mysqlcfg