That prints two different addresses. But since it's a sub that does refer to a lexical variable, it neither proves, nor disproves your claim about optimization.

But note this:

$ perl5.10.1 -we 'sub f { our $t; sub { $t } }; $x = f(); $y = f(); wa
+rn "$x $y";'
CODE(0x95ca930) CODE(0x95ca930) at -e line 1.
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Same address. But not so in 5.8.9

$ perl5.8.9 -we 'sub f { our $t; sub { $t } }; $x = f(); $y = f(); war
+n "$x $y";'
CODE(0x867218c) CODE(0x8672258) at -e line 1.
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