What perl version? Have you tried 5.6,5.8,5.10,5.12,5.14,5.16,5.18? :)

I don't understand what you're after (i'm tired) but maybe you can find some winsdom at the following

Pre vs Post Incrementing variables
Prefix and postfix increment/decrement operator query
Pre-increment *and* Post-increment
Auto Increment "magic" Inquiry
Re^3: $1 not "freezing" in an addition
Quantum Weirdness and the Increment Operator

The Universe of Discourse: Undefined behavior in Perl and other languages
Order of operations, mutators, aliasing and whammies
order of operations with conditionals at the end
Perl::Critic::Policy::ValuesAndExpressions::UndefinedBehaviourMaybeQuoteit / $1 not quoted (value not frozen) undefined behaviour