Hah, another old benchmark i had laying around 
#!/usr/bin/perl --
use strict;
use warnings;
use Benchmark 'cmpthese';

my @small = 1;
cmpthese( 500_000, {
    '__' => sub {
        for my $line ( @small ){
            next if $line !~ /\s+(-?\d+\.\d+)\s+(-?\d+\.\d+)/;
        }
        return;
    },
    '/_'.$].'_/' => eval '
        sub {
            for my $line ( @small ){
                next if $line !~ /'.
                qr{\s+(-?\d+\.\d+)\s+(-?\d+\.\d+)} # 5.12.2 (?-xism:
                                                   # 5.14.1 (?^:
                .'/;
            }
            return;
        }
    ',
    'qr' => sub {
        my $re = qr{\s+(-?\d+\.\d+)\s+(-?\d+\.\d+)};
        for my $line ( @small ){
            next if $line !~ $re;
        }
        return;
    },
    '/qr/' => sub {
        my $re = qr{\s+(-?\d+\.\d+)\s+(-?\d+\.\d+)};
        for my $line ( @small ){
            next if $line !~ /$re/;
        }
        return;
    },
## 2014-02-21-11:33:11
    'qr,//o' => do {
        our $gre = qr{\s+(-?\d+\.\d+)\s+(-?\d+\.\d+)};
        sub {
            for my $line ( @small ){
                next if $line !~ /$gre/;
            }
            return;
        };
    },
});

__END__
                 Rate        /qr/          qr     qr,//o         __ /_
+5.016001_/
/qr/         198807/s          --         -0%       -48%       -71%   
+      -75%
qr           198807/s          0%          --       -48%       -71%   
+      -75%
qr,//o       385505/s         94%         94%         --       -43%   
+      -52%
__           680272/s        242%        242%        76%         --   
+      -15%
/_5.016001_/ 800000/s        302%        302%       108%        18%   
+        --

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In reply to Re^3: qr//i versus m//i ( benchmark.qr.versus.inline.pl eval ) by Anonymous Monk
in thread qr//i versus m//i by hazylife

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