On Sunday, 31 August 2025 04:40:00 Pacific Daylight Time Tiago Freire via Std-
Discussion wrote:
> Now imagine that a systems implementer comes along and sees 2 different AES
> libraries, one runs everywhere but is painfully slow, the other is
> blazingly fast but only runs on 1 or 2 systems. A system engineer couldn't
> care less if your code is portable, what they care about is that they have
> millions of requests per second that they have to respond to and has to
> figure out how many servers they have to buy. They don't have a to support
> a zoo of different systems, they only have to support one that they buy in
> bulk and the less they have to buy the better.
>
> Until of course the day they have to support a different system, and now
> their software doesn't run on it and it might take years to re-write the
> whole thing and that is if they even bother to sink that cost instead of
> giving up on the effort.
>
> How many times I have seen this?
>
> If I can take advantage of the hardware, and provide my users a better
> experience to convince them to keep using it, why shouldn't I be allowed to
> do it?

You're forgetting that the reason the faster implementation of AES can exist
is that it is using information about the hardware that is not cross-platform
in the first place. It's both the presence of specialised instructions (which
may do all of the AES or a portion of it) and details on how to use everything
else in the hardware.

You want to have your cake and eat it too: have fast and cross-platform basic
algorithms. You usually can't have both.

> What standard, other than THE C++ standard, should define this
> identification?

NO standard, because it isn't common at all.

-- 
Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org
  Principal Engineer - Intel Platform & System Engineering