-/* Get negative value: out = -in */
-/* Assumes in[i] < 2^57 */
-static void felem_neg(felem out, const felem in)
-{
- static const limb two58p2 = (((limb) 1) << 58) + (((limb) 1) << 2);
- static const limb two58m2 = (((limb) 1) << 58) - (((limb) 1) << 2);
- static const limb two58m42m2 = (((limb) 1) << 58) -
- (((limb) 1) << 42) - (((limb) 1) << 2);
-
- /* Set to 0 mod 2^224-2^96+1 to ensure out > in */
- out[0] = two58p2 - in[0];
- out[1] = two58m42m2 - in[1];
- out[2] = two58m2 - in[2];
- out[3] = two58m2 - in[3];
-}
-