Bug #67124 [Com]: Typecast (bool) $array slowdown according to array length

Edit report at https://bugs.php.net/bug.php?id=67124&edit=1 ID: 67124 Comment by: vovan-ve at yandex dot ru Reported by: vovan-ve at yandex dot ru Summary: Typecast (bool) $array slowdown according to array length Status: Open Type: Bug Package: Performance problem Operating System: Linux PHP Version: Irrelevant Block user comment: N Private report: N New Comment: Yes, "workaround" to pass thru the bugs maze. Welcome to PHP. Did you expect something else?.. Previous Comments: ------------------------------------------------------------------------ [2014-04-26 09:43:59] hanskrentel at yahoo dot de The workaround is to first count with arrays as the count is cached. (bool) count($array); ------------------------------------------------------------------------ [2014-04-24 04:47:35] vovan-ve at yandex dot ru Looks like array is copied while casting: # memory_limit=1G echo "Create array..."; $array = array_fill(0, 10 * 1000 * 1000, null); echo " ok\nCasting..."; $start = microtime(true); (bool) $array; printf(" %.3F sec.\n", microtime(true) - $start); Output: Create array... ok Casting...Fatal error: Allowed memory size of 1073741824 bytes exhausted (tried to allocate 35 bytes) in ... ------------------------------------------------------------------------ [2014-04-24 03:55:47] vovan-ve at yandex dot ru More clear test cases: $tests = array( 'empty' => array(), 'x10' => range(1, 10), 'x100' => range(1, 100), 'x1000' => range(1, 1000), ); Result: empty 0.15 sec. total x10 0.65 sec. total x100 5.14 sec. total x1000 49.91 sec. total ------------------------------------------------------------------------ [2014-04-24 03:09:36] vovan-ve at yandex dot ru Description: ------------ Casting non-empty array to boolean using (bool) takes a time with respect to array length. There are no reasons for this. This is abnormal. Any other checks like if ($array), ($array) ?:, [] === $array and so on are not affected. At least whole PHP 5 is affected by this issue. Test script: --------------- $tests = array( '$empty' => array(), '$full' => range(1, 1000), ); $count = 1 * 1000 * 1000; foreach ($tests as $name => $array) { printf("%-10s", $name); $start = microtime(true); $i = $count; while ($i-- > 0) { (bool) $array; } $total = microtime(true) - $start; printf("%6.2F sec. total\n", $total, $total / $count); } Actual result: -------------- $empty 0.15 sec. total $full 52.03 sec. total ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=67124&edit=1