fastest method for minimum of two numbers
- by user85030
I was going through mit's opencourseware related to performance engineering.
The quickest method (requiring least number of clock cycles) for finding the minimum of two numbers(say x and y) is stated as:
min= y^((x^y) & -(x<y))
The output of the expression x < y can be 0 or 1 (assuming C is being used) which then changes to -0 or -1. I understand that xor can be used to swap two numbers.
Questions:
1. How is -0 different from 0 and -1 in terms of binary?
2. How is that result used with the and operator to get the minimum?
Thanks in advance.
