in reply to
Re^2: Benchmark, -s versus schwartzian (vs hash)
in thread Benchmark, -s versus schwartzian
B::Deparse has the option -x$LEVEL, which at level 7 reveals the internal representation of the code quite closely. Then there's the various other modules like B::Terse which will show you exactly what opcodes you get. That should be enough to examine whether any particular construct gets optimized; of course it won't provide a full overview of all the possible optimizations.
Makeshifts last the longest.