Here's a confusing bit of code (below). I'm trying to figure out why it's faster to use split on a string than to pass an anonymous array to a function. (At least that's the case with ActivePerl Build 623.)

Is dereferencing that much of a slowdown?!?


use strict;

use Time::HiRes qw(time);

{

  my $mark = time();;

  sub mark_time() { $mark = time(); }

  sub get_time() {
    return time() - $mark;
  }

  sub show_time() {
    print "Time elapsed since last mark: ",
      sprintf('%1.4f', get_time() ),
      " seconds.\n";
  }

}

use constant COUNT => 1000000;

my $Regexp = qr/,/;

sub try_split
  {
    my ($arg) = @_;
    return split $Regexp, $arg;
  }

sub try_arrayref
  {
    my ($arg) = @_;
    return @$arg;
  }

print "split: ";

mark_time();

for (my $i=0; $i<COUNT; $i++)
  {
    my ($X, $Y) = try_split 'A,B';
  }

show_time();

print "array reference: ";

mark_time();

for (my $i=0; $i<COUNT; $i++)
  {
    my ($X, $Y) = try_arrayref  qw(A B) ;
  }

show_time();



In reply to Why is split faster than anonymous arrays? by rrwo

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