2 ms·

After the updates to the article, the takeaway seems to be "you can use AVX-512 dot product instructions to sum an array of bytes to int and get a 15% speedup o

After the updates to the article, the takeaway seems to be "you can use AVX-512 dot product instructions to sum an array of bytes to int and get a 15% speedup over more straightforward vector code". That's an interesting point, but it's now well-hidden among irrelevant things like the compressed representation that was only relevant to the article's original point. It might make sense to resubmit a completely rewritten and pared-down version of the article. The dot product trick is neat.

electricshampo1 6y ago
(Author here) The main focus of the article is to show a worked example of how to analyze the behavior of simple programs. The circuitous path taken in the article is similar to that which you might face when analyzing your own programs. The article is only incidentally about AVX512 and summing numbers. Thus any specific technique used or even the precise runtimes measured should not be given too much weight. Forgive me, but the journey is more important than the destination. The article is also meant to inspire others to learn and spend time deeply understanding (by looking at data that the hardware makes available) what actually happens to their code when it runs. It is too easy to lose sight of that in a professional setting, where business needs/requirements leave little time for deep analysis.