This is a bit odd. I ran the sames tests because i wanted to see how a map solution measured up.

#!/usr/bin/perl

use Benchmark qw(cmpthese);
use List::Util qw(reduce);


cmpthese (-5,
    {
        'initial' => sub {
            my @numbers = (2,3,4,5);
            my $total = 1;
            for(@numbers){
            $total = ($total * $_);
            }
        },
        'listutil' => sub {
            my @numbers = (2,3,4,5);
            reduce{ $a*=$b } @numbers;
        },
        'eval'    => sub {
            my @numbers = (2,3,4,5);
            eval join "*", @numbers;
        },
        '*='     => sub {
            my @numbers = (2,3,4,5);
            my $total=1;
            $total *= $_ for @numbers;
        },
        'map'     => sub {
            my @numbers = (2,3,4,5);
            my $total=1;
            map { $total *= $_ } @numbers;
        },        
        'reducing'     => sub {
            my @numbers = (2,3,4,5);
            $numbers[0] *= pop @numbers while ( @numbers > 1 );
        },
    });
[download]

And got the followin results on two runs.

C:\test>perl reduce.pl
             Rate     eval listutil  initial       *=      map reducin
+g
eval      19089/s       --     -86%     -90%     -91%     -93%     -93
+%
listutil 136513/s     615%       --     -27%     -39%     -47%     -51
+%
initial  187039/s     880%      37%       --     -16%     -27%     -33
+%
*=       223842/s    1073%      64%      20%       --     -13%     -20
+%
map      256001/s    1241%      88%      37%      14%       --      -8
+%
reducing 278189/s    1357%     104%      49%      24%       9%       -
+-

C:\test>perl reduce.pl
             Rate     eval listutil  initial       *= reducing      ma
+p
eval      19656/s       --     -87%     -92%     -92%     -93%     -94
+%
listutil 150598/s     666%       --     -35%     -39%     -47%     -51
+%
initial  232290/s    1082%      54%       --      -6%     -19%     -24
+%
*=       247322/s    1158%      64%       6%       --     -14%     -20
+%
reducing 286024/s    1355%      90%      23%      16%       --      -7
+%
map      307455/s    1464%     104%      32%      24%       7%       -
+-

C:\test>
[download]

It greatly surpised me how much slower the listutil function was on my machine. Are there different implementations of it for different platforms that would cause this? Or is the small number of array elements makeing everything else meaningless?

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