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