Benchmark: timing 5000 iterations of alt_1, alt_2, orig...
     alt_1:  3 wallclock secs ( 3.08 usr +  0.00 sys =  3.08 CPU) @ 1623.38/s (n=5000)
     alt_2:  2 wallclock secs ( 1.29 usr +  0.00 sys =  1.29 CPU) @ 3875.97/s (n=5000)
      orig:  1 wallclock secs ( 1.25 usr +  0.00 sys =  1.25 CPU) @ 4000.00/s (n=5000)
        Rate alt_1 alt_2  orig
alt_1 1623/s    --  -58%  -59%
alt_2 3876/s  139%    --   -3%
orig  4000/s  146%    3%    --