Don't assign to a global variable without localising it. You just clobbered your parent's data. 
sub do_stuff1 {
    local $_ = shift;
    chomp;
    say;
}

[download]
or even safer: 
sub do_stuff1 {
    ${ local *_ } = shift;
    chomp;
    say;
}

[download]

The latter handles the case where $_ is tied or otherwise magical. For example, $_ is magical if the parent does 

for (..., $tied, ...) {
   ...
   do_stuff1(...);
   ...
}

[download]
or 
for (..., substr($s, ...), ...) {
   ...
   do_stuff1(...);
   ...
}

[download]

You've ended up complicating things instead of simplifying them. It's best not to use $_ here.

In reply to Re: style guidance by ikegami
in thread style guidance by 7stud

Title:
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