While it is technically interesting to do such experiments, it is quite presumptuous imo to down value a portable and reasonably performing code. I never need t

While it is technically interesting to do such experiments, it is quite presumptuous imo to down value a portable and reasonably performing code. I never need to worry about libpng performance and it is likely the case for 99.9% of the cases. And when you really want to optimize it for a reason my experience is a well structured portable code is actually easier to begin with.