Redundant mods ?

[mogando668]

From the file Math-Prime-Util/blob/master/congruent_numbers.c- quote :

 /* The ACK conjecture (Alter, Curtz, and Kubota 1972):
   *     n = {5,6,7} mod 8   =>  n is a congruent number
   * also follows from the weak BSD conjecture.
   */
  if (n % 8 == 5 || n % 8 == 6 || n % 8 == 7)  return 1;

Wouldn't it be the same with

    if ((n & 7) >= 5) {
        return 1
    }

or if you prefer to do away with the >= altogether, then a very weird way to express that would be

    if ((n & 4) * (n & 3)) {
        return 1
    }

[danaj]

It isn't really a high performance part of the code, so the original is very basic. But it's probably better simplified. I chose:

if ((n % 8) >= 5) return 1;

which since n is unsigned should be identical to ((n & 7) >= 5).

Thank you!