[PATCH 2/2] Improve 64bit memcpy/memmove for Corei7 with avx2 instruction

[Ondřej Bílka]

On Fri, Jun 07, 2013 at 01:18:19PM +0100, Nix wrote:
> On 7 Jun 2013, Ondřej Bílka said:
> 
> > On Thu, Jun 06, 2013 at 08:11:15PM +0800, Ling Ma wrote:
> > I got some afterthoughts how improve memcpy/memset.
> >
> > First is to copy in backward direction.
> 
> Don't we already do this in some situations? That's why there's a new
> symbol version of memcpy() et al on glibc 2.14+, because overlapping
> memcpy() no longer works and lots and lots of programs were relying on
> this (even though it was never ever guaranteed) and were breaking.
> 
A version I wrote actually has check for overlap and can be aliased to
memmove.