Re: CVS commit: src/crypto/external/bsd/openssl/lib/libcrypto/arch

[Joerg Sonnenberger <joerg%britannica.bec.de@localhost>]

On Mon, Jul 25, 2011 at 07:24:57PM +0100, David Laight wrote:
> On Mon, Jul 25, 2011 at 11:52:52AM +0200, Joerg Sonnenberger wrote:
> > Much better. One thing remains. It would be nice to replace
> >     .byte 0xf3,0xc3
> > with either a simple ret or a ret $0, depending on whether it has a
> > label on it or not. The reason for this mess seems to be a bug in
> > certain generation of AMD CPUs. So essentially,
> 
> IIRC it is something to do with branch prediction?
> But my memory keeps thinking of a constraint about the number
> of branches/labels in a cache line - and I'm sure the non-use of
> 1 byte return instructions was all related.

When I asked around, I get the following reference, which seems to
summarize the situation nicely:

http://mikedimmick.blogspot.com/2008/03/what-heck-does-ret-mean.html

Joerg