C:\test\C>bufswap 536870855 268435399
size:536870855 offset;268435399
[   0    1    2    3    4    5    6    7    8    9 ...268435389 268435390 268435391 268435392 2684353 ...
[268435399 268435400 268435401 268435402 268435403 268435404 268435405 268435406 268435407 268435408 ...
iterative: swaps:536870855 took 23.625009728 secs.

[   0    1    2    3    4    5    6    7    8    9 ...268435389 268435390 268435391 268435392 2684353 ...
[268435399 268435400 268435401 268435402 268435403 268435404 268435405 268435406 268435407 268435408 ...
recursive: swaps:536870854 took 3.580721198 secs.