Re: [PATCH v2] x86: bring back rep movsq for user access on CPUs without ERMS

[Linus Torvalds]

On Tue, 12 Sept 2023 at 12:41, David Laight <David.Laight@xxxxxxxxxx> wrote:
>
> What I found seemed to imply that 'rep movsq' used the same internal
> logic as 'rep movsb' (pretty easy to do in hardware)

Christ.

I told you. It's pretty easy in hardware  AS LONG AS IT'S ALIGNED.

And if it's unaligned, "rep movsq" is FUNDAMENTALLY HARDER.

Really.

                    Linus