Benchmark: running tp_for, tp_map for at least 2 CPU seconds...
    tp_for:  2 wallclock secs ( 2.02 usr +  0.28 sys =  2.30 CPU) @ 35695.65/s (n=82100)
    tp_map:  2 wallclock secs ( 1.80 usr +  0.30 sys =  2.10 CPU) @ 39710.48/s (n=83392)
          Rate tp_for tp_map
tp_for 35696/s     --   -10%
tp_map 39710/s    11%     --

This is perl, v5.8.4 built for i486-linux