Sorry, I haven't found any time spending on this topic the last days...

Your benchmarks are not exactly what I thought about, what I have in my mind is: 
#!/usr/bin/perl --
use Benchmark qw/ cmpthese /;
print "$]\n";
my $what1 = 'WWWA';
my $what2 = $what1;
cmpthese(
    -3,
    {
        circumcised => sub {
            $what1 =~ /EB.*Z/; # fail one
            $what1 .='DBBBABC';
            substr $what1, 0, 8, '';
            $what1 =~ /EB.*Z/; # fail another
            return;
        },
        uncut => sub {
            $what2 =~ /EB.*Z/; # fail one
            $what2 .='DBBBABC';
            $what2 =~ /EB.*Z/; # fail another
            return;
        },
    },
);

print "\n\n";
__END__

5.010001
                 Rate       uncut circumcised
uncut          2735/s          --       -100%
circumcised 3398892/s     124179%          --

[download]

In reply to Re^8: Find Prefix if regex didn't match by demoralizer
in thread Find Prefix if regex didn't match by demoralizer

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