Try this:

#!/usr/bin/perl
foo();
bar();
for (1..3) {
    my $x;
    sub foo { print ++$x, "f\n" }
    sub bar { print ++$x, "b\n" }
    print ++$x, "m\n";
}
foo();
bar();
resulting in 
1f
2b
3m
1m
1m
4f
5b

foo and bar hold the first incarnation of x in the loop. The second and third incarnation of my $x is initialised with 0 so you get the 1m 1m lines in the midd.