my @array1 = ( 1..6 );
my @array2 = ( 7..12 );
my_sub( \@array1, \@array2 );

sub my_sub {
    my ( $ref1, $ref2 ) = @_;  # get these as references...
    @arr1 = @$ref1;
    @arr2 = @$ref2; # either deference into new variables...
    print @arr1, @arr2;

    print @$ref1, @$ref2;  # or just use the reference directly
}