inline float dot()

in src/annoylib.h [214:233]

• 18 lines of code
• 4 McCabe index (conditional complexity)

inline float dot<float>(const float* x, const float *y, int f) {
  float result = 0;
  if (f > 7) {
    __m256 d = _mm256_setzero_ps();
    for (; f > 7; f -= 8) {
      d = _mm256_add_ps(d, _mm256_mul_ps(_mm256_loadu_ps(x), _mm256_loadu_ps(y)));
      x += 8;
      y += 8;
    }
    // Sum all floats in dot register.
    result += hsum256_ps_avx(d);
  }
  // Don't forget the remaining values.
  for (; f > 0; f--) {
    result += *x * *y;
    x++;
    y++;
  }
  return result;
}