3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $bits64 = 64; $N64 = 0xfffffffffffffffe; $result = -( bcpow(2, $bits64) - $N64 ); echo $result,"\n"; echo bcpow(2,$bits64) , "\n",$N64;
Output for 7.0.2 - 7.2.0
-0 18446744073709551616 1.844674407371E+19
Output for 4.3.0 - 7.0.1
0 18446744073709551616 1.844674407371E+19