On Tue, Feb 06, 2018 at 01:30:28PM +0100, David Hildenbrand wrote: > On 06.02.2018 12:21, Christian Borntraeger wrote: > > Some old patches refreshed. > > > > Certainly the right thing to do. Especially also interesting due to > retpotline (if we get something like that on s390x). If I remember > correctly, x86 highly benefits by replacing magic function pointer by > switch statements. If you look at the generated code for the first patch: gcc now generates its own jump table which then jumps (indirectly) to a brasl... So it's two instead of one branch. I'm not saying that this patch is not good, but there seem be a wrong assumptions about the benefit here.
