Welcome to the world of open-source, GCC can be used for the AVR, which means that you have a free C compiler that includes single floating-point and standard number representations etc. No more f$%&ing around with doing complex ineger math - I'd swear my head nearly exploded once or twice doing a particularly complicated two-variable function in integer math. In GCC it will all be, well, a distant memory.

Actually I'm not going to use an AVR straight off, I'm going to get an Allegro 3936 BLDC motor controller. But I am going to use AVRs whenever I can in the future...