use Benchmark;

package Bar;

sub new {};

package main;

my $obj;
my $class = "Bar";  # "our" *is* slower, though.

timethese -1, {
    bareword => sub { $x = Bar->new()    },
    var      => sub { $x = $class->new() },
};

#########################################

Benchmark: running bareword, var for at least 1 CPU seconds...
  bareword:  1 wallclock secs ( 1.06 usr +  0.00 sys =  1.06 CPU) @ 590160.38/s (n=625570)
       var:  1 wallclock secs ( 1.06 usr +  0.00 sys =  1.06 CPU) @ 590160.38/s (n=625570)