3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $bits = 64; $N = 0xfffffffffffffffe; var_dump($N); $result = -( pow(2, $bits) - $N ); echo $result;
Output for 7.0.2 - 7.1.0
float(1.844674407371E+19) -0
Output for 4.3.0 - 7.0.1
float(1.844674407371E+19) 0