### Re: A mod2 Machine.

by zork42 (Monk)
 on Jul 13, 2013 at 09:22 UTC ( #1044135=note: print w/replies, xml ) Need Help??

in reply to A mod2 Machine.

using floats to compute modulo does not seem reasonable to me.
I only included this:
```my \$n = 534587;
print "even\n" if(\$n % 2 == 0);    # modulo operator of possibly a flo
+at or possibly an integer (*)
because
1. it is equivalent to the OP's "Most obvious (easiest) solution" (infact code-ninja used this exact example here: Re^2: A mod2 Machine.)
2. it might actually be doing a (possibly comparatively slow) float operation because use integer was not used.
It probably had to go: float 534587 --> integer 534587 --> integer modulo operation on integer 534587

Whereas doing a proper integer bit test should be faster:
```use integer;
my \$n = 534587;
print "even\n" if(\$n & 1 == 0);    # checking LSB with Bitwise And on
+an integer

Replies are listed 'Best First'.
Re^2: A mod2 Machine.
by code-ninja (Scribe) on Jul 13, 2013 at 12:34 UTC
should be faster

Why art thou speculating? use Benchmark;

I benchmarked the bitwise operation with my method and even then my method wins... for 1e6 iterations.

```             Rate machine bitwise
machine  819199/s      --    -43%
bitwise 1448690/s     77%      --

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