my ($x, $y) = (1,2);
if (<some complex condition depending on the environment>) {
    call_my_sub($x)
    } else {
    call_my_sub($y)
}

##</code><code>##

my ($x, $y) = (1,2);
if (<some complex condition depending on the environment>) {
    call_my_sub($x)
    } else {
    call_my_sub($y)
}

##</code><code>##

my ($x, $y) = (1,2);
if (<condition>) {
    call_my_sub($x)
    } else {
    call_my_sub($z)
}

##</code><code>##

my ($x, $y) = (1,2);
if (<some complex condition depending on the environment>) {
    call_my_sub($x)
    } else {
    call_my_sub($y)
}

##</code><code>##

if (<some complex condition depending on the environment>) {
    my $x = 1;
    call_my_sub($x)
} else {
    my $y = 2;
    call_my_sub($y)
}