This benchmark would be far better if you had named the subroutines correctly. :-) Youll notice that you have the names for the two subs reversed.

Also, I personally wouldn't do a benchmark with an empty block. Put something in it just in case Perl gets smart enough to optimize both of those subroutines down to sub{} and then maybe even just tosses any calls to them becuase they dont really do anything....

use Benchmark 'cmpthese';

#16777216

my @num=0..1000;
my ($x,$y,$z);


my $subhash={
    'rangefor' => sub {
            for my $num (0 .. 1000) { $x++ }
            return();
     },
     'c-style' => sub {
            for( my $num = 0; $num < 1000; $num++) { $y++ }
            return();
     },
     'foreach' => sub {
            foreach my $num (@num) { $z++ }
            return();
     },
};

cmpthese(-3,$subhash) for 1..3;

__END__
Benchmark: running c-style, foreach, rangefor, each for at least 3 CPU
+ secs...
   c-style:  3 wall secs ( 3.25 usr + 0 sys =  3.25 CPU) @3039.64/s (n
+=9891)
   foreach:  3 wall secs ( 3.30 usr + 0 sys =  3.30 CPU) @3930.39/s (n
+=12986)
  rangefor:  3 wall secs ( 3.22 usr + 0 sys =  3.22 CPU) @4133.68/s (n
+=13327)
           Rate  c-style  foreach rangefor
c-style  3040/s       --     -23%     -26%
foreach  3930/s      29%       --      -5%
rangefor 4134/s      36%       5%       --
Benchmark: running c-style, foreach, rangefor, each for at least 3 CPU
+ secs...
   c-style:  3 wall secs ( 3.16 usr + 0 sys =  3.16 CPU) @3046.59/s (n
+=9612)
   foreach:  3 wall secs ( 3.20 usr + 0 sys =  3.20 CPU) @3921.37/s (n
+=12568)
  rangefor:  4 wall secs ( 3.18 usr + 0 sys =  3.18 CPU) @4080.31/s (n
+=12955)
           Rate  c-style  foreach rangefor
c-style  3047/s       --     -22%     -25%
foreach  3921/s      29%       --      -4%
rangefor 4080/s      34%       4%       --
Benchmark: running c-style, foreach, rangefor, each for at least 3 CPU
+ secs...
   c-style:  3 wall secs ( 3.14 usr + 0 sys =  3.14 CPU) @3037.84/s (n
+=9554)
   foreach:  3 wall secs ( 3.30 usr + 0 sys =  3.30 CPU) @3941.12/s (n
+=12986)
  rangefor:  3 wall secs ( 3.10 usr + 0 sys =  3.10 CPU) @4079.25/s (n
+=12662)
           Rate  c-style  foreach rangefor
c-style  3038/s       --     -23%     -26%
foreach  3941/s      30%       --      -3%
rangefor 4079/s      34%       4%       --
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