I wrote about the C-style for() in Re: Re: Believably slow... It is slower than the foreach() style for. Not significantly but slightly. I could only remove a few operations from your code, I noted each spot with an ALTER comment. I think your time is consumed by those print() statement - IO is always expensive.

## Print the given template sections to the supplied filehandle
sub printto
{
  my $self = shift;
  my $fh = shift;
  my $ret = 0;
  my($val,$sec,$v);

  # ALTER - foreach over C-style for
  foreach my $sec_k (@_)
  {
    $sec = $self->[_sec]{$sec_k};
    # ALTER - drop unnecessary defined()
    unless ( $sec )
    {
      # ALTER - remove indirect object syntax
      $fh->print( $self->_nosuchsec($sec_k) );
      next;
    }
    $ret++;
    foreach $v (@$sec)
    {
      if ($v->[_type] == type_text)
      {
        # ALTER - remove indirect object syntax
        $fh->print( $v->[_contents] );
      }
      else
      {
        $val = $self->[_assign]{$v->[_contents]};
        $fh->print(
          defined $val
            ? $val
            : $self->_nosuchvar($val,"\$".$val) );
      }
    }
  }
  return $ret;
}
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Thanks for the suggestions! Here's what I found...

I already changed the loops to use foreach; that seemed to be a little faster, and a lot more readable, so all benchmarks already have that in it. Here's what the numbers looked like before the other two changes:

Total Elapsed Time = 43.18577 Seconds
  User+System Time = 42.69577 Seconds
Exclusive Times
%Time ExclSec CumulS #Calls sec/call Csec/c  Name
 48.8   20.83 20.710 130000   0.0002 0.0002  FTS::printto

Changing if(!defined($sec)) to unless($sec) seemed to slow printto down just a hair. This could just be measurement error; for some reason apparently other parts of the code sped up with this change, which again points to measurement error...

Total Elapsed Time = 41.62356 Seconds
  User+System Time = 41.09356 Seconds
Exclusive Times
%Time ExclSec CumulS #Calls sec/call Csec/c  Name
 51.3   21.09 20.905 130000   0.0002 0.0002  FTS::printto

Changing print $fh to $fh->print seemed to slow things down significantly. The IO::Handle::print changes who the print calls get charged to, so the ExclSec for printto goes down, but it's made up for by all the calls to IO::Handle::print, and the CumulS and overall time go way up...

Total Elapsed Time = 51.91479 Seconds
  User+System Time = 51.32479 Seconds
Exclusive Times
%Time ExclSec CumulS #Calls sec/call Csec/c  Name
 41.5   21.31 18.510 281000   0.0000 0.0000  IO::Handle::print
 38.9   19.97 35.589 130000   0.0002 0.0003  FTS::printto

I have a hard time believing that you are really attempting to slice half a second off of your runtime. Results like this are easily attributed to system noise and frankly, I don't think that its worth spending this time on such miniscule results.

I'm a little surprised by this, actually; I expected using @_ directly to always be faster, since it would avoid copying values.

foreach my $section ( @_ ) { ... } doesn't copy value from @_ to $section. In the loop the variable $section is merely an alias to a currently selected element in @_ array. You can even modify @_ array by assigning a new value to $section. Example:

# adds 1 to all elements of array
foreach my $elem (@arr) {
    $elem ++;
}
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Ilya Martynov, ilya@iponweb.net
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