C++ High Performance

Performance evaluation

Continuing the naive implementation, let's measure its performance with a naive performance evaluation compared to std::transform() at a single CPU core.

We measure two scenarios:

1. Process 32 elements with an expensive function called heavy_f
2. Process 100,000,000 elements with an inexpensive function called light_f

The following code processes a low number of elements with the expensive heavy_f transform function:

// Low number of elements - heavy transform function 
auto heavy_f = [](float v) {  auto sum = v;  for (size_t i = 0; i < 100'000'000; ++i) { sum += (i*i*i*sum); }  return sum; 
}; 
auto measure_heavy() { 
  auto n = 32;
  auto src = std::vector<float>(n); auto dst = std::vector<float>(n); std::transform(src.begin(), ...