Benchmark: running tp_for, tp_map for at least 2 CPU seconds...
    tp_for:  2 wallclock secs ( 1.81 usr +  0.24 sys =  2.05 CPU) @ 11155.46/s (n=22891)
    tp_map:  3 wallclock secs ( 1.96 usr +  0.23 sys =  2.19 CPU) @ 10615.60/s (n=23280)
          Rate tp_map tp_for
tp_map 10616/s     --    -5%
tp_for 11155/s     5%     --

This is perl, v5.8.0 built for MSWin32-x86-multi-thread