Restrict

void Add2Elems(int * __restrict a, int * __restrict b, int x) {
  for (int i = 0; i < 50; ++i) {
    a[i] += x;
    b[i] += x;
  }
}

void Add2Elems(int *a, int *b, int x) {
  for (int i = 0; i < 50; ++i) {
    a[i] += x;
    b[i] += x;
  }
}