Calc Log (u32 power)

1. Call Find MS Bit with power as argument. Save result as tmp

2. Set tmp1 to (1 << tmp)

3. Set tmp2 to 2 * tmp1
4. Set diff1 to power - tmp1
5. Set diff2 to tmp2 - power

6. If diff1 < diff2

   1. Return tmp
7. Otherwise
   1. Return tmp + 1