Benchmark: timing 10000 iterations of mapgen, xgen...
    mapgen:  5 wallclock secs ( 5.04 usr +  0.03 sys =  5.07 CPU) @ 1972.39/s (n=10000)
      xgen:  0 wallclock secs ( 0.03 usr +  0.00 sys =  0.03 CPU) @ 333333.33/s
(n=10000)
            (warning: too few iterations for a reliable count)
           Rate mapgen   xgen
mapgen   1972/s     --   -99%
xgen   333333/s 16800%     --