Re: 80286 protected mode

Michael S <already5chosen@yahoo.com> writes:

On Mon, 14 Oct 2024 17:19:40 +0200
David Brown <david.brown@hesbynett.no> wrote:

[...]

My only point of contention is that the existence or lack of such
instructions does not make any difference to whether or not you can
write a good implementation of memcpy() or memmove() in portable
standard C.

>
You are moving a goalpost.

No, he isn't.

One does not need "good implementation" in a sense you have in mind.
All one needs is an implementation that pattern matching logic of
compiler unmistakably recognizes as memove/memcpy.  That is very easily
done in standard C. For memmove, I had shown how to do it in one of the
posts below.  For memcpy its very obvious, so no need to show.

You have misunderstood the meaning of "standard C", which means
code that does not rely on any implementation-specific behavior.
"All one needs is an implementation that ..." already invalidates
the requirement that the code not rely on implementation-specific
behavior.