What's the different of phalcon compile architecture?

Hello everyone!

due to some phalcon internal error, I found this post on stackoverflow :

http://stackoverflow.com/questions/22848271/phalcon-installation-on-ubuntu-13-10-php-5-5-invalid-opcode

and I found out there are different compile architecture that I can choose, but I really don't know what is exactly different between the 32bit/64bit/safe ? special the safe architecture !

Any Comment & explanation are welcome! Thanks!

32/64bit is dependant on the processor you have - most (all?) new processors are 64 bit. When you build phalcon, it's supposed to detect which type of processor you have, and compile accordingly.

I'm not sure what safe mode is - my guess is it compiles in such a way that it will run on 32bit processors, but will use 64 bit process commands if possible.