if( $vartocheck eq lc($firstchar) ) {
    ++$foo;
  }

##</code><code>##

#! /usr/bin/perl -w

use strict;
use Benchmark;

use vars qw/$vartocheck $firstchar/;

$vartocheck = 'x';
$firstchar  = 'y';

my $iters = shift || 10000;

timethese $iters, {
        'eq !=' => sub { return $vartocheck eq lc($firstchar) },
        're !=' => sub { return $vartocheck =~ /\Q$firstchar\E/i },
};

$firstchar  = 'x';

timethese $iters, {
        'eq ==' => sub { return $vartocheck ne lc($firstchar) },
        're ==' => sub { return $vartocheck !~ /\Q$firstchar\E/i },
};

__END__
% perl eqre 10000000
Benchmark: timing 10000000 iterations of eq !=, re !=...
     eq !=:  8 wallclock secs ( 8.00 usr +  0.02 sys =  8.02 CPU) @ 1246882.79/s (n=10000000)
     re !=: 14 wallclock secs (13.74 usr +  0.10 sys = 13.84 CPU) @ 722543.35/s (n=10000000)
Benchmark: timing 10000000 iterations of eq ==, re ==...
     eq ==:  8 wallclock secs ( 6.98 usr +  0.04 sys =  7.02 CPU) @ 1424501.42/s (n=10000000)
     re ==: 17 wallclock secs (16.76 usr + -0.01 sys = 16.75 CPU) @ 597014.93/s (n=10000000)

##</code><code>##

timethese $iters, {
        'eq !=' => sub { return $vartocheck eq lc($firstchar) },
        're !=' => sub { return $vartocheck =~ /^\Q$firstchar\E$/i },
};
__END__

% perl eqre 10000000
Benchmark: timing 10000000 iterations of eq !=, re !=...
     eq !=:  7 wallclock secs ( 7.42 usr +  0.00 sys =  7.42 CPU) @ 1347708.89/s (n=10000000)
     re !=: 26 wallclock secs (25.89 usr +  0.01 sys = 25.90 CPU) @ 386100.39/s (n=10000000)
Benchmark: timing 10000000 iterations of eq ==, re ==...
     eq ==:  8 wallclock secs ( 6.60 usr +  0.00 sys =  6.60 CPU) @ 1515151.52/s (n=10000000)
     re ==: 27 wallclock secs (27.77 usr +  0.00 sys = 27.77 CPU) @ 360100.83/s (n=10000000)