or download this
$ ./dave_the_m.pl
Benchmark: timing 1000000 iterations of for, map...
for: 2 wallclock secs ( 2.03 usr + 0.00 sys = 2.03 CPU) @ 49
+2610.84/s
(n=1000000)
map: 1 wallclock secs ( 1.12 usr + 0.00 sys = 1.12 CPU) @ 89
+2857.14/s
(n=1000000)