$ perl -Mstrict -Mwarnings -E '
my $passes = {
   t1 => { cpu => 73, xx => 3 },
   t2 => { cpu => q{-}, xx => 7 },
   t3 => { cpu => 17, xx => 0 },
   t4 => { cpu => 49, xx => 6 },
   t5 => { cpu => q{-}, xx => 4 },
   t6 => { cpu => 11, xx => 5 },
   };

say for
   map  { $_->[ 0 ] }
   sort {
           $a->[ 1 ] <=> $b->[ 1 ]
           ||
           ( $a->[ 1 ] ? 0 : $a->[ 2 ] <=> $b->[ 2 ] )
        }
   map  { [
           $_,
           $passes->{ $_ }->{ cpu } eq q{-},
           $passes->{ $_ }->{ cpu },
          ]
        }
   keys %$passes;'
t6
t3
t4
t1
t2
t5
$