$x /= $y;

##</code><code>##

2 2 5
5 7 13 29
71 839 1471 6857
2147483647

real    5m44.346s
user    5m43.718s
sys     0m0.030s

##</code><code>##

2 2 5
5 7 13 29
71 839 1471 6857
2147483647

real    0m0.064s
user    0m0.015s
sys     0m0.031s