>perl -MO=Concise -e"my $data = 1; if ($data) { print 'moo' }"
c  <@> leave[1 ref] vKP/REFC ->(end)
1     <0> enter ->2
2     <;> nextstate(main 1 -e:1) v ->3
5     <2> sassign vKS/2 ->6
3        <$> const[IV 1] s ->4
4        <0> padsv[$data:1,4] sRM*/LVINTRO ->5
6     <;> nextstate(main 4 -e:1) v ->7
-     <1> null vK/1 ->c
8        <|> and(other->9) vK/1 ->c      <-- "if" not optimized away.
7           <0> padsv[$data:1,4] s ->8   <-- Lex not optimized away.
-           <@> scope vK ->-
-              <0> ex-nextstate v ->9
b              <@> print vK ->c
9                 <0> pushmark s ->a
a                 <$> const[PV "moo"] s ->b
-e syntax OK

>perl -MO=Concise -e"if (1) { print 'moo' }"
6  <@> leave[1 ref] vKP/REFC ->(end)
1     <0> enter ->2
2     <;> nextstate(main 3 -e:1) v ->3
-     <@> scope vK ->6                  <-- "if" optimized away.
-        <0> ex-nextstate v ->3
5        <@> print vK ->6
3           <0> pushmark s ->4
4           <$> const[PV "moo"] s ->5
-e syntax OK