strange -O2 bugs

[Lykos42]

Hi,
since two days, I'm working on a problem with my bots. Three days ago, my bot scored quite good and was on rank 3 once. But then I submitted a new version and since then, he only does silly things. But he never did those things on my computer. I didn't really understand what was going on because every time when I gave him one of the positions, where he made a stupid move at the tournament, he proposed a better move at home. Now I tried to compile everything with -O2 and then he suddenly made those mistakes at home, too! I thought I was seeing ghosts, but it really is like that: If I compile without -O2, it works, if I use -O2, he makes those mistakes. Does anyone have a clue why this happens?

[a1k0n]

I highly recommend using valgrind if you can.