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by boroadlkjq 4501 days ago
Are there other weird number hacks like this one?
1 comments

Look at the hashCode() implementations in http://grepcode.com/file/repository.grepcode.com/java/root/j...

For example:

public static int hashCode(double a[])

{

if (a == null) return 0;

        int result = 1;
        for (double element : a) {
            long bits = Double.doubleToLongBits(element);
            result = 31 * result + (int)(bits ^ (bits >>> 32));
        }
        return result;
    }
Why is this weird? It's the textbook method for doing hashes.
It is textbook, but the poster asked for seemingly random numbers in code. Based on all the places the invsqrt method has popped up, it also was a textbook method for doing it quickly.