$ perl -MO=Concise,-exec -e'if (!f()) { g() }'
1  <0> enter v
2  <;> nextstate(main 1 -e:1) v:{
3  <0> pushmark s
4  <#> gv[*f] s/EARLYCV
5  <1> entersub[t2] sKS/TARG
6  <|> or(other->7) vK/1
7      <0> pushmark s
8      <#> gv[*g] s/EARLYCV
9      <1> entersub[t4] vKS/TARG
a  <@> leave[1 ref] vKP/REFC
-e syntax OK