Bug #72640 [Nab->Opn]: Regexp with possessive/atomic grouping 25x slower compared to 5.6.x

Edit report at https://bugs.php.net/bug.php?id=72640&edit=1 ID: 72640 Updated by: leigh@php.net Reported by: arjen at parse dot nl Summary: Regexp with possessive/atomic grouping 25x slower compared to 5.6.x -Status: Not a bug +Status: Open Type: Bug -Package: PCRE related +Package: Performance problem Operating System: Linux PHP Version: 7.0.9 Block user comment: N Private report: N New Comment: Not PCRE related. Running it without the concat of 'x' results in normal performance: https://3v4l.org/QbJP1/perf#tabs <?php preg_replace('~(?>[\pZ\pC]+)$~u', '', str_repeat("\u{2029}", 20000)); Previous Comments: ------------------------------------------------------------------------ [2016-07-21 14:58:29] bwoebi@php.net I recommend using (*SKIP) though - this is the fastest you'll get. preg_replace('~[\pZ\pC]+(*SKIP)$~u', '', str_repeat("\u{2029}", 20000) . 'x'); ------------------------------------------------------------------------ [2016-07-21 14:54:14] arjen at parse dot nl \u{2029} is a PHP7 feature, so test in 5.6 is not the same.. :-/ See https://3v4l.org/7Wfc5/perf#tabs PHP7 is faster. Regexp still slow, but no regression. Please close :X ------------------------------------------------------------------------ [2016-07-21 14:22:27] cmb@php.net > Please take a look at the user time, not at system time. Ah, you're right! ------------------------------------------------------------------------ [2016-07-21 14:02:59] arjen at parse dot nl Please take a look at the user time, not at system time. Or confirm by running it at CLI: time php -r 'preg_replace("~(?>[\pZ\pC]+)$~u", "", str_repeat("\u{2029}", 20000) . "x");' real 0m0.975s user 0m0.973s sys 0m0.000s ------------------------------------------------------------------------ [2016-07-21 13:57:59] cmb@php.net Having a closer look at the performance result shows that PHP 7.0.1 - 7.0.5 appear to be really slow, but that current versions are not affected, so I'm closing this ticket. ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at https://bugs.php.net/bug.php?id=72640 -- Edit this bug report at https://bugs.php.net/bug.php?id=72640&edit=1