alias float T;
T val = 1;

int plot(T a, T b, T c, T d, T e, T f, T g, T h) {
  assert(a == val);
  return 0;
}

int main() {
  return plot(
      val,
      val,
      val,
      val,
      val,
      val,
      val,
      val,
  );
}

--

The values h-b are correctly loaded from XMM0-XMM6.
The calling function put a correctly into XMM7 but the plot
function loads it from the calling stack (misinterpreted as push parameter).