[Salik Syed]

It won't work on signed integers, because in order to have fast add and subtract between positive integers most procecssors use a twos complement system.
Basically there is a sign bit, and if the bit is enabled then you reverse the 1 for a 0, so if a number is negative it is instead represented by it's not'd equivalent

So -2 would be
11111110 (for an 8 bit signed char)
The most significant bit is the sign bit.

Now lets try adding -2 to 3:
00000011
11111110
---------
00000001

Tada ..
The extra bit overflows and is discarded... so we can use the same logic adding positive and negative numbers together ... yay!


When you try to bit shift a signed int this is what may happen:
11111100 (-3)
becomes 01111110 (126)

You can still bit shift but the sign bit needs to be replaced... you can do this by XORing the result with 10000000



I actually don't think dividing by two using the bit shift operator really matters, most optimizing compilers should realize that an unsigned int is being divided by two and just swap that in at the assembly level. Secondly most first applications I have seen don't even come close to being computationally intensive enough to warrant such an optimization.
(I don't know if this is actually what happens when using MC18 or whatever it's called)

BTW: for printf I think you can just use %f to print floats