D:\tmp\pm>perl -MO=Concise,TST::foo -e"package TST; our $xxx=666; sub foo { print $xxx}"
TST::foo:
5  <1> leavesub[1 ref] K/REFC,1 ->(end)
-     <@> lineseq KP ->5
1        <;> nextstate(TST 3 -e:1) v ->2
4        <@> print sK ->5
2           <0> pushmark s ->3
-           <1> ex-rv2sv sK/1 ->4
3              <#> gvsv[*TST::xxx] s ->4
-e syntax OK