sub test4 {

  my ( $iDays, $iCmp ) = @_;

  my $iRes = 0;
  for ( 1, 2, 4, 8, 16, 32, 64 ){ 
    if ( $iDays & $iCmp & $_ ){
      $iRes++;
    }
  }

  return $iRes;
}

sub test5 {

  my ( $iDays, $iCmp ) = @_;

  my $iRes = 0;
  $iRes++ if ( $iDays &  $iCmp &  1 );
  $iRes++ if ( $iDays &  $iCmp &  2 );
  $iRes++ if ( $iDays &  $iCmp &  4 );
  $iRes++ if ( $iDays &  $iCmp &  8 );
  $iRes++ if ( $iDays &  $iCmp & 16 );
  $iRes++ if ( $iDays &  $iCmp & 32 );
  $iRes++ if ( $iDays &  $iCmp & 64 );

  return $iRes;
}

cmpthese($count, {
  'Test4' => sub { test4( int ( rand(127) ), int( rand(127) ) ) },
  'Test5' => sub { test5( int ( rand(127) ), int( rand(127) ) ) }
});

__DATA__
          Rate Test4 Test5
Test4 162690/s    --  -46%
Test5 300000/s   84%    --