Fix C++ compat.
Make 'show' consist of size_t instead of uint32; makes many outer loops run half as many times. Various cleanups.
Getting rid of the third conditional boosts speed a little. Also fixing alignment issues because bsnes is an idiot.
Hoist these comparisons from the inner loop - 5% speedup.
Apparently I've been testing the speed of wrong code path all this time. Time to restart optimizating.
3208MB/s this way...
3754MB/s on comparing to previous.
4041MB/s compare to constant.