note 73934 added to function.mt-srand

Looks like mt_rand() gives same result for different seeds when the lowest bits are different only. Try this: #!/usr/bin/php -q <?php $min = -17; $max = $min + 48; // 48 is to fit the results in my console for ($testseed=$min; $testseed<$max; $testseed++) { mt_srand( $testseed ); $r = mt_rand(); printf("mt_srand( 0x%08x ): mt_rand() == 0x%08x == %d\n", $testseed, $r, $r); } ?> This is a snapshop of the results: ... mt_srand( 0xfffffffc ): mt_rand() == 0x0a223d97 == 170016151 mt_srand( 0xfffffffd ): mt_rand() == 0x0a223d97 == 170016151 mt_srand( 0xfffffffe ): mt_rand() == 0x350a9509 == 889885961 mt_srand( 0xffffffff ): mt_rand() == 0x350a9509 == 889885961 mt_srand( 0x00000000 ): mt_rand() == 0x71228443 == 1898087491 mt_srand( 0x00000001 ): mt_rand() == 0x71228443 == 1898087491 mt_srand( 0x00000002 ): mt_rand() == 0x4e0a2cdd == 1309289693 mt_srand( 0x00000003 ): mt_rand() == 0x4e0a2cdd == 1309289693 ... I found this occationally. I have no idea if it is a bug or not. In my real life I do not intend to use sequentional seeds. However, probably this may be important for somebody. ---- Server IP: 217.75.128.29 Probable Submitter: 82.103.91.3 ---- Manual Page -- http://www.php.net/manual/en/function.mt-srand.php Edit -- https://master.php.net/note/edit/73934 Del: integrated -- https://master.php.net/note/delete/73934/integrated Del: useless -- https://master.php.net/note/delete/73934/useless Del: bad code -- https://master.php.net/note/delete/73934/bad+code Del: spam -- https://master.php.net/note/delete/73934/spam Del: non-english -- https://master.php.net/note/delete/73934/non-english Del: in docs -- https://master.php.net/note/delete/73934/in+docs Del: other reasons-- https://master.php.net/note/delete/73934 Reject -- https://master.php.net/note/reject/73934 Search -- https://master.php.net/manage/user-notes.php