I don’t really know what it changes. I wonder why the define was made in the first place. The code should be able to determine whether it’s running on a SSE2 CPU or not. I discovered it while comparing my 4xSSE2 hash function to the original one in 0.3.6 so it really means, that no 64bit build since 0.3.6 was able to generate any coins. Maybe satoshi can tell us why he put the define in the makefile.
Re: bitcoin generation broken in 0.3.8?
Figures: tcatm