use Benchmark 'cmpthese';

my $x = 1;
$x = 1.1; # $x promoted to PVNV
our @a = map $x, 1..1e6;

my $y = 1.1;
our @b = map $y, 1..1e6;

cmpthese( -2, {
    1 => '{my @c = @a}',
    2 => '{my @c = @b}',

__END__
    Rate    1    2
1 26.7/s   -- -35%
2 40.9/s  53%   --