On Thu, Jan 11, 2018 at 03:46:51PM -0700, Jeff Law wrote:
> Note I'm expecting Uros to chime in. So please do not consider this
> ack'd until you hear from Uros.
>
> At a high level is there really that much value in having thunks in the
> object file? Why not put the full set of thunks into libgcc and just
> allow selection between inline sequences and external thunks
> (thunk-inline and thunk-external)? It's not a huge simplification, but
> if there isn't a compelling reason, let's drop the in-object-file thunks.
Not everything is linked against libgcc.a, something is linked against just
libgcc_s.so.1, other stuff against both, some libraries against none of that.
Probably it is undesirable to have the thunks at non-constant offsets from
the uses, that would need text relocations. Thunks emitted in the object
files, hidden and comdat merged between .o files like what we have say for
i686 PIC thunks seems like the best default to me and a way for the kernel
to override that.
Jakub
