B::Deparse is occasionally wrong, it has to guess which code was optimized to what it finally sees.
But the op-tree is more reliable
D:\tmp\pm>perl -Mstrict -Mwarnings -MO=Concise
my ($u, $v) = split /,/, 'U,V';
__END__
9 <@> leave[1 ref] vKP/REFC ->(end)
1 <0> enter v ->2
2 <;> nextstate(main 1 -:1) v:*,&,{,x*,x&,x$,$ ->3
8 <2> aassign[t4] vKS ->9
- <1> ex-list lK ->7
3 <0> pushmark s ->4
6 </> split(/","/)[t3] lK/IMPLIM ->7
4 <$> const[PV "U,V"] s ->5
5 <$> const[IV 3] s ->6
- <1> ex-list lKPRM* ->8
7 <0> padrange[$u:1,2; $v:1,2] RM/LVINTRO,range=2 ->8
- <0> padsv[$u:1,2] sRM*/LVINTRO ->-
- <0> padsv[$v:1,2] sRM*/LVINTRO ->-
- syntax OK
D:\tmp\pm>perl -Mstrict -Mwarnings -MO=Concise
(my $u, my $v) = split /,/, 'U,V';
__END__
9 <@> leave[1 ref] vKP/REFC ->(end)
1 <0> enter v ->2
2 <;> nextstate(main 1 -:1) v:*,&,{,x*,x&,x$,$ ->3
8 <2> aassign[t4] vKS ->9
- <1> ex-list lK ->7
3 <0> pushmark s ->4
6 </> split(/","/)[t3] lK/IMPLIM ->7
4 <$> const[PV "U,V"] s ->5
5 <$> const[IV 3] s ->6
- <1> ex-list lKPRM* ->8
7 <0> padrange[$u:1,2; $v:1,2] RM/LVINTRO,range=2 ->8
- <0> padsv[$u:1,2] sRM*/LVINTRO ->-
- <0> padsv[$v:1,2] sRM*/LVINTRO ->-
- syntax OK
D:\tmp\pm>
Now, spot the difference! ;-)