@list has 17576 elements!
            Rate   grep_re splice_re splice_eq   grep_eq
grep_re   24.6/s        --      -36%      -46%      -53%
splice_re 38.6/s       57%        --      -16%      -27%
splice_eq 45.9/s       87%       19%        --      -13%
grep_eq   52.8/s      115%       37%       15%        --

#!/usr/bin/perl
use strict;
use warnings;
use Benchmark qw( cmpthese );


my @list = ( ( 'AAA' .. 'ZZZ' ) x 1 );
my $pattern = 'WVX';

print "\@list has " . @list . " elements!\n";


cmpthese( -2, {
        'grep_eq'   => \&grepped_eq,
        'splice_eq' => \&spliced_eq,
        'grep_re'   => \&grepped_re,
        'splice_re' => \&spliced_re,
} );


sub grepped_eq {
        my @aa = @list;
        @aa = grep { $_ eq $pattern } @aa;
}

sub spliced_eq { 
        my @aa = @list;
        for my $i ( reverse 0 .. $#aa ) {
                splice @aa, $i, 1 if $aa[$i] eq $pattern;
        }
}

sub grepped_re {
        my @aa = @list;
        @aa = grep { m/\Q$pattern\E/ } @aa;
}

sub spliced_re {
        my @aa = @list;
        for my $i ( reverse 0 .. $#aa ) {
                splice @aa, $i, 1 if $aa[$i] =~ m/\Q$pattern\E/;
        }
}

__END__