FMA not used

Hi,

I have been surprised to spot the following behavior of Intel compiler (17.0.2 20170213 on Linux), using -xCORE-AVX2. The following code generates FMA instructions

double norm(double* x, int n) {
  ans = 0.0;
  for (int i = 0; i < n; ++i) {
    ans += x[i] * x[i];
  }
  return ans;
}

but the following code does not

float norm(float* x, int n) {
  ans = 0.0f;
  for (int i = 0; i < n; ++i) {
    ans += x[i] * x[i];
  }
  return ans;
}

Is there a reason for this, or is it a missed optimization form the compiler?

Best regards,

Francois