use strict;
use warnings 'all';

my ($first, $second) = qw /first second/;
open my $f1h => $first  or die "open $first: $!\n";
open my $f2h => $second or die "open $second: $!\n";

my %first  = reverse map  {/(\d+)\s+\w+\s+\d+\s+\d+:\d+\s+(.*)/}
                     grep {/\.o$/} <$f1h>;
my %second = reverse map  {/(\d+)\s+\w+\s+\d+\s+\d+:\d+\s+(.*)/}
                     grep {/\.o$/} <$f2h>;

my ($file, $size);
print "$file: $size <-> $second{$file}\n" while +($file, $size) = each %first;