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
