func g(a, b, c, d uint64) (uint64, uint64, uint64, uint64) {
	a = a + b
	d = rotr64(d^a, 32)
	c = c + d
	b = rotr64(b^c, 24)
	a = a + b
	d = rotr64(d^a, 16)
	c = c + d
	b = rotr64(b^c, 63)
	return a, b, c, d
}
func g(a, b, c, d uint64) (uint64, uint64, uint64, uint64) {
	a = a + b
	d = rotr64(d^a, 32)
	c = c + d
	b = rotr64(b^c, 24)
	a = a + b
	d = rotr64(d^a, 16)
	c = c + d
	b = rotr64(b^c, 63)
	return a, b, c, d
}
/*g is Blake2b's G function*/