$ perl -MO=Concise,-exec -e'while (foo()) { bar() }'
3  <{> enterloop(next->8 last->d redo->4) v

$ perl -MO=Concise,-exec -e'bar() while foo()'

$ perl -MO=Concise,-exec -e'do { bar() } while foo()'

$ perl -MO=Concise,-exec -e'for (foo()) { bar() }'
8  <{> enteriter(next->d last->g redo->9) lK

$ perl -MO=Concise,-exec -e'bar() for foo()'
9  <{> enteriter(next->d last->g redo->a) lK