Messages in this thread | | | Date | Thu, 14 May 2015 10:08:01 -0700 | Subject | Re: [PATCH] x86/asm/entry/64: Use shorter MOVs from segmers registers | From | Linus Torvalds <> |
| |
On Thu, May 14, 2015 at 10:05 AM, Linus Torvalds <torvalds@linux-foundation.org> wrote: > > I don't object to the patch, but did we actually confirm that it > always overwrites all of %ecx?
Just to clarify: I don't object to the patch because the code doesn't actually end up *depending* on the high bits anyway, and does word-sized compares etc. And the instruction size and speed things I don't doubt. So it's just the commit message I wanted to check wrt that whole "always overwrites all of %ecx". Because older CPU's didn't necessarily (things like partial register writes are much less of an issue when you're in-order and stupid ;)
Linus
| |